JPH05311559A - Novel high performance cushion structure and its production - Google Patents

Abstract

PURPOSE:To provide a cushion material high in cushion property, durability, stability and air permeability, minimized in stuffiness and the processing irregularity, facilitating the diversifying of the processing and capable of being readily produced in a short process. CONSTITUTION:The cushion structure is characterized in that elastic conjugate fibers comprising a thermoplastic elastomer having a melting point >=40 deg.C lower than the melting point of a polyester polymer constituting the short fibers of the short fiber aggregate and a non-elastic polyester, the thermoplastic elastomer being exposed to the surface of the elastic conjugate fibers, are scattered and mixed in the short fiber aggregate, in that (A) amebic omnidirectional flexible thermally fixed points formed by melt-fusing the elastic conjugate fibers to each other in the mutually crossed state and (B) semi-omnidirectional flexible thermal fixed points formed by thermally fusing the elastic conjugate fibers and the non-elastic polyester short fibers in the crossed state are scattered in the short fiber aggregate, and further in that spindle-like knots exist in an amount of 2X10<4> knots per g of the cushion structure in the conjugate fiber group along its longitudinal direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel cushion structure having high resilience and high durability, in which a non-elastic polyester crimped short fiber is used as a matrix, and heat-fixing points due to elastic composite fibers are scattered therein, and a method for producing the same. It is about.

[0002]

2. Description of the Related Art In the field of cushion structures used for furniture, beds, etc., urethane foam, non-elastic polyester crimped short fiber wadding, polyester cotton crimped short fiber-bonded resin cotton or hard cotton are used. Has been done.

[0003]

However, the foamed urethane foam has the problems that it is difficult to handle the chemicals used during its manufacture and that it discharges CFCs. Further, the obtained urethane foam has a unique compression characteristic that it is hard in the initial stage of compression and then suddenly sinks. Therefore, not only the cushioning property is poor, but also the bottoming feeling is large. Moreover, since the foam has poor air permeability, it tends to get damp and is often not preferred as a cushion structure. Further, since urethane foam is soft and foamed, it has a drawback that it has a poor resilience against compression. To increase the resilience,
It is sufficient to increase the density of the urethane foam, but in this case, there is a fatal defect that the weight is increased and the air permeability is further deteriorated. Next, in the non-elastic polyester short fiber wadding, since the aggregate structure is not fixed, the shape easily collapses during use, the constituent short fibers move, or the short fibers are crimped. Then, there is a drawback that the bulkiness and the repulsion property are greatly reduced.

On the other hand, a non-elastic polyester crimped short fiber aggregate is treated with a resin (for example, an acrylate polymer),
A resin fiber or a solid cotton fixed with a binder fiber (Japanese Patent Laid-Open No. 58-31150) composed of a polymer having a melting point lower than that of the polymer forming the matrix short fiber has a weak fixing force and has a polymer film. Has a low elongation and a low recovery property against stretching, so the durability of the fixing point is low, and if the fixing point is deformed during use, it will be destroyed or recovery from deformation will be poor, resulting in morphological stability. And the repulsion property is greatly reduced. Moreover, since the fixing point is a polymer having a small elongation and is hard and has no mobility, only a cushioning property is obtained. As one means for enhancing the cushioning property, Japanese Patent Application Laid-Open No. 62-102712 proposes a cushion structure in which the intersections of polyester crimped short fibers are fixed with a urethane foam binder. However, here, since the solution type crosslinkable urethane is impregnated, processing unevenness is likely to occur, and therefore the handling of the treatment liquid is complicated, the adhesiveness between the urethane and polyester fibers is low, and the binder is crosslinked. Therefore, the elongation is low and it is easy to be broken by deformation, and when the resin part is foamed, the deformation is likely to be partially concentrated, so it is more easily broken when the urethane foam at the fiber crossing part is largely deformed, There are problems such as low durability.

[0005]

The present invention remarkably stabilizes the adhered state particularly at the intersections of short fibers, whereby the cushioning property, compression repulsion property, compression durability and compression recovery property are greatly improved. The present invention seeks to provide a new, high performance cushioning structure.

Further, according to the present invention, processing spots do not occur.
It is intended to provide the above cushion structure by a simpler method.

The novel cushion structure according to the present invention is
A non-elastic polyester crimped short fiber aggregate is used as a matrix, and the density is 0.005 to 0.10 g / cm ³ and the thickness is 5
In the cushion structure having a size of at least mm, the short fiber aggregate is composed of a thermoplastic elastomer having a melting point of 40 ° C. or more lower than the melting point of the polyester polymer constituting the short fibers, and an inelastic polyester, and the former is at least the fiber. The elastic composite fibers exposed on the surface (conjugate / staple fiber) are dispersed / mixed, and at this time, (A) the elastic composite fibers are formed by heat fusion in a state where the elastic composite fibers intersect with each other in the cushion structure. Amoeba-like omnidirectional flexible heat-fixing point, and (B) quasi-omnidirectional flexible heat-bonding formed by heat fusion in a state where the elastic composite fiber and the non-elastic polyester short fiber cross each other. Points are scattered and between the adjacent flexible heat fixing points ((A)-
Between (A), between (A) and (B), and between (B) and (B)
In the elastic composite fiber group present in (between), the composite fiber is characterized by having 2 × 10 ⁴ or more spindle-shaped nodes along the longitudinal direction per 1 g of the cushion structure. is there.

Further, the above-mentioned method for producing a new cushion structure according to the present invention has a melting point of 40 ° C. or more lower than the melting points of the non-elastic polyester crimped short fibers and the polyester polymer constituting the non-elastic polyester crimped short fibers. Elastic composite fiber comprising a thermoplastic elastomer and non-elastic polyester, the former being mixed with elastic composite fiber occupying at least ½ of the fiber surface to form a web having a bulkiness of at least 30 cm ³ / g. A temperature lower than the melting point of the polyester polymer and 25 to 80 ° C. higher than the melting point of the elastomer after forming a three-dimensional fiber crossing point between them and between the non-elastic polyester crimped short fiber and the elastic composite fiber. Heat treatment in
More preferably, the thermoplastic elastomer constituting the elastic composite fiber has a melt viscosity of 4 × 10 ³ poise or less, and at least some of the fiber intersections are heat-sealed. Is.

[0009]

The present invention will be specifically described in more detail. Figure 1
In FIG. 6 (traced in FIG. 6), 1 is a non-elastic polyester crimped short fiber that serves as a matrix of a cushion structure, and 2 is a thermoplastic elastomer having a melting point of 40 ° C. or more lower than the melting point of the polyester polymer that constitutes the short fiber. And the non-elastic polyester, and the former is an elastic composite fiber exposed at least on the fiber surface and is dispersed and mixed in the matrix. Through this figure, the characteristic feature is that in the cushion structure, as shown in (A), an amoeber-like structure formed by heat-sealing thermoplastic elastomers with elastic composite fibers 2 crossing each other. The omnidirectional flexible heat-fixing point, and the elastic composite fiber 2 and the non-elastic polyester-based short fiber 1 as shown in (B) were formed by heat-sealing the elastomer component in a state of intersecting each other. The quasi-omnidirectional flexible heat fixation points are scattered (that is, there are no fixation points between matrix short fibers), and moreover, between adjacent flexible heat fixation points ((A)-(A )while,
In the elastic composite fiber group existing between (A) and (B) and between (B) and (B), the elastic fiber has a large number of spindle-shaped nodes 3 along the longitudinal direction. To exist.

As used herein, the term "omnidirectional flexible thermal fixation point" means that when a load is applied to the cushion structure, and therefore, a load is also applied to the fixation point, this fixation point is the load. It means a flexible heat fixing point that is freely deformable along a direction and is recoverable. The heat-fixing points are classified into two, one is an amoeber-like one that is generated by heat-sealing thermoplastic elastomers in a state where elastic composite fibers are crossed with each other as shown in (A) above. The other is, as shown in (B), the thermoplastic elastomer component in the elastic composite fiber 2 and the inelastic polyester crimped short fiber 1 are 45 ° to 90 °.
It is a heat-fixing point that occurs when crossed at a crossing angle θ of °.

The features of the spindle-shaped nodes that contribute to the formation of amoebar-like omnidirectional flexible heat-fixing points and quasi-omnidirectional flexible heat-fixing points will be described.

The amoeber-like omnidirectional flexible heat fixing point and the quasi-omnidirectional flexible heat fixing point are the melting viscosity and its surface tension, due to the melting of the thermoplastic elastomer exposed on the surface of the composite fiber by heating. Movement in the fiber axis direction occurs due to the affinity with the non-elastic polyester. Then, a portion not involved in this fusion remains as a spindle-shaped node. Therefore, the larger the number of spindle-shaped nodes, the higher the probability that the ideal amoeber-like omnidirectional heat-fixing point or quasi-omnidirectional heat-fixing point will be formed. Therefore, as a result of the examination, at least 2 × 10 ⁴ pieces / g (structure 1
2 × 10 ⁴ pieces per g) are required to have spindle-shaped nodes, and more preferably 5 × 10 ⁴ pieces / g (structure 1 g)
(5 × 10 ⁴ pieces per one).

Of course, the shape of this fusiform node is also important,
The shape of the spindle-shaped node here is the most diameter r of the spindle with respect to the diameter r ₁ of the fiber at the root of the spindle that suspends the spindle.
The ratio I = r ₂ / r and at ² large refers to more than 1.5. It is more preferable to grow to I = 2.0 or more.

For the formation of these spindles, the melt viscosity of the thermoplastic elastomer at the time of processing is greatly related, and it is preferable to select the polymer composition and the processing temperature so as to be 4 × 10 ³ poise or less at the time of processing. This melt viscosity is 4
At a density of × 10 ³ poise or more, the frequency of occurrence of spindle-shaped nodules grown to I = 1.5 or more becomes small, resulting in an amoebar-shaped omnidirectional flexible heat fixing point or quasi-omnidirectional flexible heat. It is difficult to form the fixing points, the physical properties of the flexible heat fixing points are low, and the cushioning material has low resilience and durability.

By the way, the elastic composite fibers 2 dispersed / mixed in the matrix are stochastically formed so as to cross each other or the non-elastic polyester crimped short fibers 1 and heat-bonded in this state. At this time, it was found that a spindle-shaped node indicated by 3 is intermittently generated along the longitudinal direction of the elastic composite fiber 2. A thermoplastic elastomer, which is a component of the elastic composite fiber 2, moves in the node portion 3 in the axial direction of the fiber due to the melt viscosity, the surface tension, and the affinity of the composite fiber component for the other component of the thermoplastic elastomer. Which occurs, said (A),
When the flexible heat-fixing point of (B) is formed, the thermoplastic elastomer in a fluidized state moves to those fiber intersections.
The aggregates form amoeber-like or quasi-amoeber-like fixing points. That is, as shown in (A), the heat-fixing points generated by heat-sealing the elastic composite fibers eventually become heat-bonding between the spindle-shaped node portions 3, so that an amoeber-like shape is exhibited, while In the formation of the heat-fixing point of (B), the spindle-shaped knot portion 3 fixes the non-elastic crimped short fibers 1 by itself. Therefore, in comparison with the amoeber shape of (A), the semi-amoeber shape is used. Can be said. Therefore, the formation behavior of the spindle-shaped nodes has a great influence on the formation of the amoebar-shaped and quasi-omnidirectional flexible heat-fixing points, and also has a significant influence on the cushion performance of the cushion structure.

The occurrence of many spindle-shaped nodes 3 is caused by the local movement / aggregation of the thermoplastic elastomer, and the probability of formation of the flexible heat-fixing points (A) and (B) in the cushion structure is therefore high. Means to increase that much. Of course, the spindle-shaped nodal portion 3 that was not involved in the fusion remains, and as a result, the heat fixing point (A)-
Between (A), (A)-(B) and (B)-(B),
They are connected by elastic composite fibers with some spindle-shaped nodes left. That is, the larger this number is, the more the formation of the heat fixing points of (A) and (B) is increased, and the cushion performance is improved.

In forming the flexible heat fixing point as described above, the density of the cushion structure itself is also involved. When the density is higher than 0.10 g / cm ³ , the fiber density becomes excessively high, and the thermoplastic elastomers are likely to be densely fused to each other. Of course, the composite fibers become too close to each other and fuse together, making it difficult to form spindle-shaped nodes. Therefore, in such a structure, the elasticity in the thickness direction is remarkably reduced, the air permeability is extremely reduced, and the composition is apt to become damp, so that it cannot be used as a cushion structure any longer.

On the other hand, when the density is less than 0.005 g / cm ³ , such structure has poor resilience.
The number of non-elastic polyester crimped short fibers forming the matrix is reduced. As a result, when a load is applied to the structure, too much strain or stress is applied to each fiber,
Since the structure itself is easily deformed and the durability is lost, it cannot be used as a cushion structure.

In this respect, in Japanese Patent Laid-Open No. 58-197312 and Japanese Patent Laid-Open No. 52-85575, most of the elastic composite fibers are fused to each other in a parallel state when viewed substantially from the sectional direction. Is recommended. However, such a situation should be absolutely avoided in the present invention.

When the cushion structure of the present invention is compared with the conventional cushion structure, there are the following notable differences between them.

In the conventional product, for example, only the crossing points of the non-elastic crimped short fibers constituting the matrix are fixed with a non-fiber resin or a solution-type cross-linkable urethane, and there are spindle-shaped nodes. There are few things. On the other hand, in the cushion structure of the present invention, in order to generate a large number of fusiform knots only in the composite fiber, a fixed point is not formed at the intersection of the crimped short fibers constituting the matrix. Rather, the fixing points are formed by heat fusion of the thermoplastic elastomer in the elastic composite fibers only at the intersections of the elastic composite fibers and the intersections of the elastic composite fibers and the crimped short fibers constituting the matrix. further,
In a cushion structure using a composite fiber having a low melting point non-elastic polymer as a fusion component as a binder, the elastic composite fiber is less likely to have spindle-shaped nodes, and the heat fixing point is close to a point adhesive shape. It does not take the shape of an amoeber. Moreover, the fixing points are inflexible, the binder fibers themselves existing between the fixing points do not have spindle-shaped nodes, and the recovery from deformation is poor. In the present invention, it exhibits omnidirectional flexibility, and these flexible fixing points are connected by elastic composite fibers having a high degree of deformation recovery.

From the above, in the cushion structure of the present invention, heat fixing points (A) and (B) exhibiting omnidirectional flexibility formed by the spindle-shaped nodes of the composite fiber, and further, Since the elastic composite fibers connecting these heat fixing points are present and form a three-dimensional elastic structure, a cushion structure excellent in compression rebound and compression recovery can be realized.

Here, the features of the omnidirectional flexible heat fixing point (A) of the present invention will be mentioned.

Since the points are generated by the movement / aggregation of the thermoplastic elastomer in the composite fiber, the intersection points of the fibers are widely covered and the surface thereof is smooth. In addition, a curved surface like a hyperbola is present at the outer circumference of the intersection of the fibers. Therefore, (i) there is no stress concentration. (Ii) Since the strength and the elongation are remarkably improved, they are not broken even by repeated compression. (Iii) Hard to be deformed by compression (strong repulsion against deformation). (Iv) Once deformed, it is easy to deform in any direction (omnidirectionally). (V) Further, it is easy to recover smoothly from deformation from any direction. (Iv) Since the adjacent heat-fixing points are connected to each other by the elastic composite fiber, it is easy to return to the original position even if the heat-fixing points are displaced.

On the other hand, quasi-omnidirectional flexible heat fixing point (B)
However, it is easily understood that the degree thereof is inferior to that of the heat fixation point of (A) but shows the same tendency.

Next, the requirements associated with the cushion structure of the present invention will be described.

First, the amoebar-like omnidirectional flexible heat-fixing point preferably has a W / D in the range of 2.0 to 4.0. Here, W is the width of the heat fixing point and is the average value of W ₁ and W ₂ as shown in FIG. D is the average diameter of the elastic composite fibers involved in heat fixation, and each diameter is the diameter (d ₁ , of the portion adjacent to the root of the fixation point as shown in FIG. 2).
d ₂ , d ₃ and d ₄ ). In addition, many spindle-shaped knots 3 are present in the elastic composite fiber located between these heat fixing points. Further, the elastic composite fibers located between these heat-fixing points may exist in the form 4 which is curved in a loop shape, or sometimes in the form which develops a coil-like elastic crimp, as shown in FIG.

In the present invention, the omnidirectional or quasi-omnidirectional flexible heat fixing point (hereinafter, both may be simply referred to as "heat fixing point") is a load (compressive force) on the cushion structure. ) Is applied, it freely deforms in response to the stress and strain, and by dispersing these stress and strain, it has the function of reducing the stress and strain applied to the crimped short fibers constituting the matrix. Therefore, the physical properties of the heat fixing point cannot be overlooked. As for these physical properties,
The breaking strength, the breaking elongation, and the 10% elongation elastic recovery rate defined later are included. Breaking strength is 0.3g / de
It is preferably in the range of to 5.0 g / de. When the breaking strength is less than 0.3 g / de, when the cushion structure is subjected to a large deformation of compression (for example, 75% of the initial thickness), the heat fixing point is easily broken, resulting in durability and shape stability. May decrease.

On the other hand, when the strength of the heat fixing point exceeds 5 g / de, the fusion processing is performed at a considerably high temperature, and as a result, the physical properties of the crimped short fibers themselves constituting the matrix deteriorate.

The breaking elongation is preferably in the range of 15 to 200%. If the elongation at break is less than 15%,
When a large deformation due to compression is applied to the cushion structure,
In addition to further displacement and displacement occurring at these heat fixing points, the crossing angle θ also changes beyond the deformation limit, and eventually the fixing points are easily broken.

On the other hand, when the elongation exceeds 100%, the thermal fixation point is likely to be displaced when the same displacement is applied, and the durability may be deteriorated.

Further, the 10% elongation elastic recovery rate is preferably 80% or more, and particularly preferably in the range of 80 to 95%. When the 10% elongation elastic modulus is less than 80%, when stress or displacement occurs at the heat fixing point, the recovery property against deformation is lowered, and durability against repeated compression and dimensional stability may be deteriorated.

In the present invention, the non-elastic polyester crimped short fibers constituting the matrix are ordinary polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polytetramethylene terephthalate, poly-1,4-dimethylcyclohexane terephthalate, poly It is a short fiber made of pivalolactone or a copolymerized ester thereof, a cotton blend of these fibers, or a composite fiber made of two or more of the above polymer components. The cross-sectional shape of the single fiber may be circular, flat, atypical or hollow. The monofilament has a thickness of 2 to 500 denier, especially 6 to 300.
It is preferably in the range of denier. When the thickness of the single fiber is small, the density of the cushion structure is increased and the elasticity of the structure itself is often lowered. If the monofilament is too thick, the handleability, particularly the web forming property, deteriorates. Also, the number of constituents is too small, and the number of intersections formed with the elastic composite fiber is small,
The elasticity of the cushion structure may be less likely to be exhibited, and at the same time, the durability may be reduced. Further, the texture becomes too hard.

On the other hand, the elastic composite fiber used for forming the heat fixing point which plays an important role in the present invention is formed of a thermoplastic elastomer and a non-elastic polyester. In that case, it is preferable that the former occupy at least ½ of the fiber surface. In terms of weight ratio, it is suitable that the former and the latter are in a composite ratio of 30/70 to 70/30. The form of the elastic composite fiber may be either a side-by-side type or a sheath-core type, but the latter is preferable. In this sheath-core type, the inelastic polyester is of course the core, but the core may be concentric or eccentric. In particular, the eccentric type is more preferable because the coil-shaped elastic crimp is developed.

As the thermoplastic elastomer, a polyurethane elastomer or a polyester elastomer is preferable.

On the other hand, as the polyurethane elastomer, a low melting point polyol having a molecular weight of about 500 to 6000, such as dihydroxypolyether, dihydroxypolyester, dihydroxypolycarbonate, dihydroxypolyesteramide, etc., and an organic diisocyanate having a molecular weight of 500 or less, such as p and p. ′ -Diphenylmethane diisocyanate, tolylene diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, xylylene diisocyanate, 2,6-diisocyanate methylcaproate, hexamethylene diisocyanate and the like, and a chain extender having a molecular weight of 500 or less, such as glycol or amino alcohol. Alternatively, it is a polymer obtained by reaction with triol. Among these polymers, particularly preferred are polyurethanes using polytetramethylene glycol as the polyol, or poly-ε-caprolactone or polybutylene adipate. In this case, p, p'-diphenylmethane diisocyanate is preferable as the organic diisocyanate. As the chain extender, p, p'-bishydroxyethoxybenzene and 1,4-butanediol are suitable. Of course, in the polymer, various stabilizers, UV absorbers, thickening and thickening branching agents with fine particles of metals and oxides, thinning agents with organic plasticizers, matting agents, coloring agents, various other improving agents, etc. The additive is often required, and it is necessary to design the melt viscosity to be 4 × 10 ³ poise or less.

The polyester elastomer is a polyether ester block copolymer obtained by copolymerizing thermoplastic polyester as a hard segment and poly (alkylene oxide) glycol as a soft segment, and more specifically, terephthalic acid and isophthalic acid. , Phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, aromatic dicarboxylic acid such as sodium 3-sulfoisophthalate ,
Selected from alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, succinic acid, oxalic acid, adipic acid, sebacic acid, dodecanedioic acid, dimeric acids and other aliphatic dicarboxylic acids, or ester-forming derivatives thereof At least one dicarboxylic acid, 1,4-butanediol, ethylene glycol, trimethylene glycol,
Aliphatic diols such as tetramethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol and decamethylene glycol, and fats such as 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol and tricyclodecanedimethanol. At least one of diol components selected from cyclic diols or their ester-forming derivatives
Species, and polyethylene glycol, poly (1,2- and 1,3-) having an average molecular weight of about 400 to 5,000.
Ternary composed of at least one of poly (alkylene oxide) glycols such as propylene oxide) glycol, poly (tetramethylene oxide) glycol, copolymer of ethylene oxide and propylene oxide, copolymer of ethylene oxide and tetrahydrofuran It is a copolymer.

However, in terms of adhesiveness with non-elastic polyester crimped short fibers, temperature characteristics, and strength, polybutylene terephthalate is used as a hard segment,
A block copolymerized polyether polyester having polyoxybutylene glycol as a soft segment is preferable. In this case, the polyester portion constituting the hard segment is polybutylene terephthalate whose main acid component is terephthalic acid and whose main diol component is butylene glycol component. Of course, a part of this acid component (usually 3
0 mol% or less) may be substituted with another dicarboxylic acid component or an oxycarboxylic acid component, and similarly, a part (usually 30 mol% or less) of the glycol component may be substituted with a dioxy component other than the butylene glycol component. May be.

The polyether moiety constituting the soft segment may be a polyether substituted with a dioxy component other than butylene glycol. In the polymer, various stabilizers, UV absorbers, thickening and thickening branching agents with fine particles of metals and oxides, thinning agents with organic plasticizers, matting agents, coloring agents, and various other improvements Agents and the like may be blended as necessary. Usually, thermoplastic elastomers have a lower viscosity above the melting point than other general low-melting polymers, and are easily decomposed, so a thickener and stabilizers are often added to prevent fiber decomposition from stabilizing the spinning process. ..
And these thermoplastic elastomers are 4 × 10 when processed.
^It must be set to ³ poise or less.

The degree of polymerization of the polyester elastomer is preferably 0.8 to 1.7, and more preferably 0.9 to 1.5 in terms of intrinsic viscosity. If this intrinsic viscosity is too low, the heat-fixing points formed with the non-elastic polyester crimped short fibers constituting the matrix will be easily broken. On the other hand, if this viscosity is too high, the melt viscosity is less likely to decrease during heat fusion, and spindle-shaped nodes are less likely to be formed.

As a basic characteristic of the thermoplastic elastomer, a breaking elongation defined later is preferably 500% or more,
More preferably, it is 800% or more. If this elongation is too low, when the cushion structure is compressed and its deformation reaches the heat fixing point, the bond at this portion is easily broken.

On the other hand, the elongation stress of 300% of the thermoplastic elastomer is preferably 0.8 kg / mm ² or less, more preferably 0.6 kg / mm ² or less. If this stress is too large, it becomes difficult for the heat fixing point to disperse the force applied to the cushion structure, and when the cushion structure is compressed, the heat fixing point may destroy the heat fixing point, or Even if it is not broken, even the non-elastic polyester crimped short fibers constituting the matrix may be distorted or crimped.

The 300% elongation recovery of the thermoplastic elastomer is preferably 60% or more, more preferably 7%.
It is 0% or more. If the extension recovery rate is low, the cushion structure may be compressed and the heat fixing point may be deformed, but it may be difficult to return to the original state.

These thermoplastic elastomers have a lower melting point than the polymer constituting the non-elastic polyester crimped short fibers, produce a large number of spindle-shaped knots that have grown, and fuse to form heat-fixing points. It is necessary that the crimp of the crimped short fibers is not thermally sagged during the treatment. From this point of view, the melting point is preferably 40 ° C. or more, particularly 60 ° C. or more lower than the melting point of the polymer constituting the short fiber. The melting point of such a thermoplastic elastomer can be a temperature in the range of, for example, 130 to 190 ° C.

If this difference in melting point is less than 40 ° C., the heat treatment temperature at the time of fusion processing as described below becomes too high, causing crimping of the inelastic polyester crimped short fibers,
Moreover, the mechanical properties of the crimped short fibers are deteriorated. When the melting point of the thermoplastic elastomer is not clearly observed, the melting point is replaced with the softening point.

On the other hand, as the non-elastic polyester used as the counterpart component of the above-mentioned thermoplastic elastomer,
As described above, the polyester polymer constituting the crimped short fibers forming the matrix is adopted, and among them, polybutylene terephthalate is more preferably adopted.

The above-mentioned composite fiber is 10 to 70%, preferably 20 to 60% based on the weight of the cushion structure.
It is dispersed and mixed in the range of%. If the dispersion / mixing rate is too low, the number of heat fixing points may be reduced, the cushion structure may be easily deformed, and the elasticity, repulsion and durability may be low.

On the other hand, if the dispersion / mixing rate is too high, the number of non-elastic polyester crimped short fibers that impart repulsion becomes too small, and the repulsion as a structure becomes insufficient.

Since the cushion structure is a material which is compressed in the thickness direction and repels, it has a thickness of at least 5 mm or more, preferably 10 mm or more, more preferably 20 mm or more in order to exert its performance. Preferably. Thus, the thickness is usually about 5 to 30 cm, but in some cases, it may reach about 1 to 2 m.

In producing the cushion structure of the present invention, a non-elastic polyester crimped short fiber and a thermoplastic elastomer having a melting point lower than 40 ° C. lower than the melting point of the polyester polymer constituting the non-elastic polyester crimped short fiber are used. An elastic composite fiber composed of an elastic polyester, the former of which occupies at least 1/2 of the fiber surface, is mixed to form a web having a bulkiness of at least 30 cm ³ / g. After forming a three-dimensional fiber crossing point between the elastic polyester crimped short fiber and the composite fiber, it is 2 from the melting point of the elastomer.
Heat treatment is performed at a temperature higher by 5 to 80 ° C. to heat-bond at least a part of the fiber entanglement points.

More specifically, a crimp is applied, and 50 cm ³
/ G, preferably 80 cm ³ / g of non-elastic polyester short fiber mass (or web) having bulkiness, and preferably elastic composite fiber mass expressing crimp, both of which are uniformly mixed through a card. To get Due to such blended cotton, innumerable fiber cross points are formed in the web between the elastic composite fibers and between the composite fibers and the non-elastic polyester crimped short fibers. Next, such a web is placed in a mold so as to have a predetermined density, and is lower than the melting point of the polyester polymer and 10 to 8 from the melting point (or flow starting point) of the thermoplastic elastomer in the elastic composite fiber.
By performing the fusion treatment under the condition that the melt viscosity is 4 × 10 ³ poise or less at a high temperature of 0 ° C., many spindle-shaped knots are formed in the elastic composite fibers, and the elastomer component is melted at the fiber intersection points. To form the amoebic omnidirectional flexible heat-fixing points of (A) and the quasi-omnidirectional flexible heat-fixing points of (B). In particular, the thermoplastic elastomer is more likely to have a lower melt viscosity than other low-melting-point polymers at a temperature higher than the melting point, and in particular, it is easy to form the heat fixing point or the spindle-shaped knot portion.

Here, the three-dimensional fiber crossing points are literally crossing points existing at an angle of less than 90 ° with respect to a plane parallel to the thickness direction of the web. Of course, in this web, a large number of fiber crossing points are simultaneously formed on a plane parallel to the horizontal plane of the web. However, they are rather characteristic of aggregates (eg nonwovens) such as artificial leather, which have a much higher density than the cushion structure.
In this respect, the method of the present invention is characterized in that a three-dimensional fiber crossing point is formed by setting the web density to 30 cm ³ / g or more in addition to the above planar fiber crossing point. Most of the three-dimensional fiber crossing points are maintained even when a cushion structure of 0.1 g / cm ³ or less is formed after the heat fusion treatment.

The non-elastic polyester crimped short fibers and elastic composite fibers can be obtained by a known spinning method. At that time, the polymer to be used, the thickness of the single fiber, the mixing ratio of the both, and the like are as described above. However, both fibers are preferably stretched 1.5 times or more after spinning. A cushion structure made of stretched fibers is superior in resilience to a cushion structure made of unstretched fibers and is less tired. The reason for this is that the amorphous part is relaxed in the process of being stretched into short fibers and in a relaxed state, and the amorphous parts become randomized, resulting in a fiber structure with more elasticity, which is maintained even after melting and solidification. It is presumed that it is easy. Further, the elastic composite fiber preferably has a low heat shrinkage. If the heat shrinkage is high, the thermoplastic elastomer is significantly shrunk by the time of heat fusion until it is melted, and the number of fibers which are converted into heat fixation points among the fiber crossing points is reduced. In order to reduce the heat shrinkage of the elastic composite fiber, 40 to 1 after stretching is used.
The heat treatment may be performed at a temperature of 20 ° C. for 20 seconds or more.

As the crimp applied to the short fibers, the indentation crimp is sufficient. In that case, the number of crimps is 5 to 15 / inch
(Measured according to JIS L1045) is preferable, and 8 to 1
2 pieces / inch (same) is more preferable. However, it is also useful to impart anisotropy to the fiber structure by imparting anisotropy to the fiber structure by means such as anisotropic cooling at the time of spinning each fiber, and then subjecting it to indentation crimping.

[0055]

[Effect] The cushion structure of the present invention does not have an initial hardness in compression as compared with urethane foam and has a very large repulsion property, and since it increases substantially in proportion to the compression amount, the feeling of bottom strike is extremely small. .. Moreover, since the structure itself has a low density, it is highly breathable and there is no risk of stuffiness.

Regarding the durability against repeated compression, the heat-fixing point is not easily broken, and even if it is deformed, it is easy to return to its original shape after unloading, and its compression durability is very excellent.

On the other hand, in the production of this structure, a uniform cushion structure can be obtained by a simple and short process of dry heat treating a web of short fibers, and the hardness of the structure may be partially changed. The hardness in the thickness direction can be easily changed by changing the mixing ratio of fibers, the structure of fibers, or the density.

Therefore, the cushion structure of the present invention is characterized by being excellent in cushioning property, repulsion property, durability and recovery property, and having high air permeability, so that it does not easily get damp. Further, in manufacturing, unevenness in processing is unlikely to occur, diversification in processing can be easily achieved, and manufacturing can be performed in a short process.
Therefore, the range of use of this structure is suitable for various cushion materials, such as cushion materials for furniture, beds, bedding, and various seats.

In the present invention, various parameters are based on the following measuring methods.

[0060]

The present invention will be further described with reference to examples.

The following measurements were carried out in the examples.

Measurement of Breaking Strength and Breaking Elongation at Thermal Fixing Point In a cushion structure, two fibers are 45 ° to 90 °.
Sampling is performed by intersecting at a crossing angle of °, and a portion where the crossing points are fixed includes two different fibers.
Next, the two different fibers fixed and connected to each other with the heat fixing point at the center are attached to the grip portion of the tensile tester at intervals of 2 mm in sample length, and pulled at a speed of 2 mm / min.
The elongation when the initial load of 0.3 g is read as looseness, and the sample is further pulled to measure the maximum load (g) until the fixing point of the sample breaks and the elongation at that time. The breaking strength and the breaking elongation of each were calculated. The number of tests for calculating the breaking strength is represented by an average value of the number of samples n = 20 with 10 randomly sampled fixation points (A) and 10 fixation points (B).
(Number of (A) :( B) is 1: 1)

Breaking strength (g / de) = [load (g) at break] / [average denier of two short fibers in sample] Breaking elongation (%) = [(E ₂ −E ₁ ) / (L + E ₁ )] ×
100 E ₁ ; Looseness (mm) E ₂ ; Elongation at maximum stress (mm) L; Grip spacing (mm)

Measurement of 10% elongation elastic recovery rate of heat-fixing point Sampling and sample mounting were carried out in the same manner as in the measurement of breaking strength and breaking elongation of heat-fixing point, and initial load was 0.3.
Set the test length of L _{0 to} the point multiplied by g and start the tension at 2 mm / min. After pulling to 10% elongation to the test length,
Immediately remove the weight at the same speed, leave the weight for 2 minutes, and then pull again at the same speed. The 10% elongation elastic recovery rate was calculated from the difference l (mm) between the initial test length of 0.3 g and the test length when the tensile load of 0.3 g was applied again by the following formula. The number of tests and sampling are the same as in the case of measuring the breaking strength.

10% elongation elastic recovery rate = (1-l / l ₀ ).
× 100 (%) l ₀ ; 10% elongation length (mm) = L ₀ × 0.1 l; residual elongation (mm) (trial length when the initial load of 0.3 g is applied-2 times 0) (Trial length when a load of 3 g is applied)

Measurement of Cushion Material Thickness and Density The basis weight (g /
m ² ), and the thickness under a load of 0.5 g / cm ² (c
m) was measured and the density (g / cm ³ ) was calculated.

Measurement of Intrinsic Viscosity of Polyester Elastic Body The intrinsic viscosity of the polyester elastic body was measured at 35 ° C. by using an equal weight mixed solvent of phenol and tetrachloroethane.

Measurement of bulkiness of web Short fibers were webbed and superposed to give a basis weight of 1000 g /
A load of 10 g / cm ² was applied to the sample cut out as m ² for 1 minute, and 1 minute after the release, the thickness was measured under a load of 0.5 g / cm ² to calculate the bulkiness (cm ³ / g).

Measurement of Physical Properties of Thermoplastic Polymer (1) Preparation of Film for Measurement Melting the polymer in a nitrogen atmosphere at 300 ° C. and defoaming 1
Rolled at a speed of 20 m / min between a pair of metal rollers having a clearance of 0.5 mm at 00 ° C. and rolled to a thickness of about 0.
A 5 mm film was obtained. 5mm vertically from the film
A sample having a width of 50 mm and a length of 50 mm was punched out to obtain a film for measuring physical properties of a thermoplastic polymer.

(2) Measurement of elongation at break The elongation at break was measured at a test length of 50 mm and a tensile speed of 50 mm / min.

(3) Measurement of 300% elongation stress The film for physical property measurement has a trial length of 50 mm and a tensile speed of 50 mm / min, and is 300% stretched. The stress at that time is expressed by the initial cross-sectional area (thickness × width) of the sample. The calculated value was 300%, and the elongation stress (kg / mm ² ) was calculated.

(4) Measurement of 300% elongation recovery rate The sample length of the film for measuring physical properties was set to 50 mm, the pulling speed was set to 50 mm / min, and the film was pulled to 300% and then returned to the original zero point at a speed of 50 mm / min and left for 2 minutes. After that, it was pulled again at a pulling speed of 50 mm / min. Determine the loosening length (mm) of the sample from the rise of the initial stress and the rise after leaving (2g stress), and the ratio (%) to the extension amount 150mm is calculated by (1-loosening length / 150) × 100 (%) It was calculated to be 300% elongation recovery rate.

(5) Melting point Using a thermal differential analyzer 990 type manufactured by Du Pont Co., measurement was performed at a temperature rising rate of 20 ° C./min to obtain a melting peak temperature.

(6) Softening point Using a trace melting point measuring device (manufactured by Yanagimoto Seisakusho), about 3 g of polymer was sandwiched between two cover glasses and lightly held down with tweezers at a heating rate of about 10 ° C./min. The temperature is raised and the thermal change of the polymer is observed. At that time, the temperature at which the polymer softens and begins to flow is defined as the softening point.

(7) Melt Viscosity (MV) At a processing temperature, a thermoplastic elastomer was subjected to a shear rate of 1
Apparent melt viscosity in the range of ^{0 to} 10000 sec ^-1 (M
V) measuring the melt viscosity shear rate 1000 sec ^-1 (M
V) was calculated.

Number of spindle-shaped knots in the cushion structure
(Pieces / g) The cushion structure is thinly sliced and cut with a sharp blade, the weight is weighed (about 0.01 g), and the number N of spindle-shaped nodes is counted under a microscope (n = 5).

On the other hand, the spindle structure was randomly photographed (× 350 times) with an electron microscope (n = 10).
0), the diameter r of the root of the spindle of the fiber that pierces the fusiform node
Ratio of ₁ to diameter r ₂ of the thickest part of the spindle I = r ₂ / r
The ratio R of ₁ = 1.5 or more and I = r ₂ / r ₁ = 1.5 or less was calculated, and N × R / m (pieces / g) was calculated.

The cushioning material has good compression resilience and compression durability.
Measuring density adjusted to flat plate shape 0.035g / cm ³ , thickness 5cm
The cushion structure (1) was compressed by 1 cm with a cylindrical rod having a flat lower surface with a cross-sectional area of 20 cm ² , and the stress (initial stress) was measured, and this was designated as compression rebound. 800g / cm after measurement
The operation of compressing under a load of ² for 10 seconds, removing the weight, and leaving for 5 seconds was repeated 360 times, and after 24 hours, the compressive stress was measured again. The ratio% of the stress after repeated compression to the initial stress was defined as the compression durability of the cushion material.

Measurement of compression recovery of cushion structure Density adjusted to flat plate shape 0.035 g / cm ³ , thickness 5 cm
10 the cushion structure to a load of 500 g / cm ² a cylindrical rod having a flat lower surface of the cross-sectional area 20 cm ²
After compressing at a speed of 0 mm / min, the load was immediately removed at a speed of 100 mm / min, and the compression recovery (Rc) was calculated from the area obtained from the compression length-stress curve (FIG. 3) drawn by this measurement. .. Compression recovery (RC)% = [(Area surrounded by ODAB)
/ (Area surrounded by OCAB)] × 100

[0080]

Example 1 Dimethyl terephthalate and isodimethyl terephthalate
Mix butylene with 80/20 (mol%) butylene
The resulting polybutylene-based terephthalate was reacted with glycol.
Addition of polybutyrate to phthalate 38% (wt%) low polymer
Glycol (molecular weight 2000) 62% (wt%)
Heat block copolymerization reaction, polyether polyester
A block copolymer elastomer is obtained, and then a predetermined additive
In addition to this, an appropriate amount of an organic plastic type viscosity reducing agent was further mixed. This heat
The intrinsic viscosity of the plastic elastomer is 1.0, the melting point is 155 ° C,
Elongation at break in film is 1420%, 300% elongation stress
Is 0.3 kg / mm ², 300% growth recovery rate was 73%
It was

This thermoplastic elastomer was spun into a sheath and polybutylene terephthalate was spun into a core by a conventional method so that the weight ratio of core / sheath was 50/50. The conjugate fiber is an eccentric sheath / core type conjugate fiber. The fiber was stretched 2.0 times, indented and crimped, and then cut into 64 mm. After drying, an oil agent was applied. The thickness of the single fiber of the elastic composite fiber obtained here was 6 denier.

40% (by weight) of this elastic composite fiber and hollow section polyethylene terephthalate short fiber having a diameter of 14 denier, a fiber length of 64 mm, and a crimping number of 9 / inch obtained by a conventional method ( A web having a bulk of 112 cm ³ / g and polyethylene terephthalate having a melting point of 259 ° C. and 60% (weight) was mixed with a card to obtain a web having a bulkiness of 69 cm ³ / g. Put these webs on top of each other and put them in a flat mold so that the thickness is 5 cm and the density is 0.035 g / cm ³ .
A heat treatment was performed at 200 ° C. for 5 minutes to obtain a flat cushion material (the thermoplastic elastomer accounts for (20% by weight) in the cushion structure).

When the cushion structure was observed in detail with an electron microscope, it had the structure shown in FIGS. 6 to 7, and a great number of spindle-shaped knots were generated in the elastic composite fibers, so that the elastic composite fibers were That the crossing points are fused and integrated by the thermoplastic elastomer to form the amoebar-like heat fixing points in a scattered state (FIGS. 1 and 2), and the non-elastic polyester crimped short fibers and the elastic composite fibers are further formed. It was observed that the intersection points of (1) and (2) were also fused and integrated by the thermoplastic elastomer to form the heat-fixed portions (FIGS. 1 and 2) in a scattered state. Further, the number of spindle-shaped nodes in the cushion structure was 1.6 × 10 ⁶ pieces / g. By the way, I was 2.2. W / D (n =
20) was 3.40. Also, (A) and (B)
The rupture strength at the heat-fixing point including was 0.8 g / de, the rupture elongation was 73%, and the 10% elongation elastic modulus was 97%. The density of the cushion structure was as low as 0.035 g / cm ^3, and a considerable number of portions in which the elastic composite fibers were three-dimensionally and tightly fused to each other were found. The melt viscosity of this thermoplastic elastomer at 200 ° C. was 680 pois.
It was e.

Therefore, the breathability of the cushion structure was very excellent. Further, this cushion structure did not have an initial hardness against compression as seen in urethane foam, and had excellent cushioning properties. Furthermore, the compression resilience and compression durability are as high as 8.5 kg and 89%, respectively, and the compression recovery is improved up to 82%.
It was an extremely ideal cushion structure.

[0085]

Comparative Example 1 In the same manner as in Example 1, a block-copolymerized polyether polyester elastomer containing the specified additives was obtained.

This thermoplastic elastomer has an intrinsic viscosity of 1.0, a melting point of 155 ° C. and a breaking elongation in a film of 150.
0%, 300% elongation stress is 0.25kg / mm ² , 300%
The extension recovery rate was 76%.

Using this polymer, a composite fiber was obtained in the same manner as in Example 1. The monofilament had a thickness of 6 denier and a cut length of 64 mm. Then, a cushion structure was obtained in the same manner as in Example 1.

Observation of this cushion structure with an electron microscope revealed that spindle-shaped nodules were few, and I =
R = 30% at 1.40, and spindle-shaped nodal portion is 1.0 x 1
The number was 0 ³ pieces / g, which was slightly small.

However, the intersecting points of the elastic composite fibers are fused and integrated by the thermoplastic elastomer to form the amoebar-like heat fixing points in a scattered state, and further, the non-elastic polyester crimped short fibers and the elastic composite fibers are combined. Similarly, it was observed that the intersections were fused and integrated with the thermoplastic elastomer and the heat-fixed portions were scattered. However, the heat-fixed part of (A) is W /
D = 3.2, the rupture elongation at the heat fixing point including (A) and (B) was 62%, and the 10% elongation elastic modulus was 92%, which was slightly low.

On the other hand, the thermoplastic elastomer of 200
The melt viscosity at 4.5 ° C. was slightly high at 4.5 × 10 ³ poise, the compression resilience was 4 kg, and the compression durability was 60%, which was rather low. The compression recovery property was 72%, which was rather low.

[0091]

Comparative Examples 2 and 3 In the same manner as in Example 1, block copolymerized polyether polyester elastomers containing predetermined additives were obtained. As a thickener, 0.1 is added to this polymer.
A small amount of mm metal oxide was added to increase the viscosity.

Using this polymer, a cushion structure was obtained in the same manner as in Example 1. When this cushion structure was observed with an electron microscope, the occurrence of spindle-shaped nodes was small (I =
1.3), R is also extremely small and the spindle-shaped nodal portion is 7.1 × 10.
The number of particles / g, and the melt viscosity of this polymer is 8.1 × 10.
It was ³ poise.

On the other hand, the intersecting portions of the elastic fibers were fused and integrated by the thermoplastic elastomer, and amoebar-like heat-fixed portions were scattered, but W / D = 2.5. Of course, the cross points of the elastic fibers and the non-elastic polyester crimped short fibers were also heat-fixed and integrated. But (A)
The fracture elongation of the heat-fixed portion of (B) was 48%, 10%, and the elongation elastic modulus was 70%.

The obtained cushion structure had a compression repulsive force of 3.1 kg and a compression durability of 62%. Both had poor cushioning performance. As Comparative Example 3, a cushion structure was obtained in the same manner except that the heat treatment temperature was 222 ° C. However, this cushion structure was yellowed, had no elasticity, and had a low compression durability of 30%.

[0095]

Example 2 A block copolymerized polyether polyester elastomer was obtained in the same manner as in Example 1. Using this polymer, a composite fiber of 6 denier and a cut length of 64 mm were obtained in the same manner as in Example 1. Then, the working temperature is set to 22 in Example 1.
A cushion structure was obtained in the same manner as in Example 1 except that the cushion structure was molded in 0 ° C nitrogen substitution.

When this cushion structure is observed with an electron microscope, many fusiform knots are generated in the composite fiber, and the intersections of the elastic composite fibers are fused and integrated by the thermoplastic elastomer to form an amoeber-like heat bond. The dots existed in a scattered state, and further, the intersections of the non-elastic polyester crimped short fibers and the elastic composite fibers were similarly fused and integrated by the thermoplastic elastomer, and the heat-fixed portions were scattered. The W / D of the heat-fixing portion of (A) is 3.30, the breaking strength at the heat-fixing point including (A) and (B) is 1.2 g / de, and the breaking elongation is 65.
%Met. The 70% elongation elastic modulus was 96%.

On the other hand, the spindle-shaped nodes in this structure are 1.2 ×
It was 10 ⁵ pieces / g. The melt viscosity of this thermoplastic elastomer at 220 ° C. was 2 × 10 ³ poise.

This cushion structure was excellent in breathability and elasticity, and had good compression resilience of 6.5 kg, high compression durability of 78%, and high compression recovery of 77%, which was an excellent cushion material.

[0099]

[Comparative Example 4] As Comparative Example 4, processing was performed in the same manner as in Example 2 except that the processing temperature was 170 ° C. When the cushion structure was observed with an electron microscope, no spindle-shaped nodules were observed. However, the one that seems to be a spindle was slightly seen at I = 1.2. However, the unevenness was great. The melt viscosity at this processing temperature was 1.4 × 10 ⁴ poise. Amoeba-like heat fixing points were scattered, but W / D = 2.2
Was low. The rupture elongation at the heat fixing points of (A) and (B) was 20%, and the 10% extension elastic modulus was 65%.

The cushion structure thus obtained had a compression impact resilience of 2.5 kg, a compression durability of 52%, a compression recovery of 55%, and a slightly inferior cushion performance.

[0101]

Example 3 70/3 of terephthalic acid and isophthalic acid
Polybutylene-based terephthalate 50 obtained by polymerizing an acid component mixed with 0 (mol%) and butylene glycol
% (Wt%) to polybutylene glycol (molecular weight 2
000) 50 (wt%) and reacted by heating to obtain a block copolymerized polyether polyester elastomer. At this time, the prescribed additive was not used. This thermoplastic elastomer has an intrinsic viscosity of 1.5, a melting point of 150 ° C., a breaking elongation in a film of 1850%, and a 300% elongation stress of 0.2 kg /
mm ² , 300% elongation recovery was 78%.

A cushion structure was obtained in the same manner as in Example 1 except that the heat treatment temperature was changed to 200 ° C.

When this cushion structure was observed, the amoeber-shaped heat fixing points between the elastic composite fibers and the intersections of the elastic composite fibers and the non-elastic polyester were also fused and integrated.
The heat fixation point of (A) was W / D = 3.2. Many fusiform nodules were also observed.

The number of spindle-shaped knots was 1.9 × 10 ⁴ pieces / g. At this time, the melt viscosity at 190 ° C. is 2.8 ×
It was 10 ³ . The strength and elongation of the heat fixing point including (A) and (B) are 0.9 g / de and 64, respectively.
%, 10% elongation elastic modulus was 96%.

The compression rebound of this cushion structure is 5.
5 kg, the compression durability was 70%, which was high, and the compression recovery property was 75%, which was good.

Regarding the above Examples and Comparative Examples, the relationship between the melt viscosity of the thermoplastic elastomer and the spindle-shaped nodes and the relationship between the spindle-shaped nodes and the compression repulsive force of the cushion structure are summarized and shown. 4 and 5 respectively.

[0107]

[Reference example] 60/40 terephthalic acid and isophthalic acid
A copolymerized polyester was obtained from the acid component mixed in (mol%) and the diol component mixed in ethylene glycol and diethylene glycol at 85/15 (mol%). The intrinsic viscosity of this polymer was 0.5. The melting point is not clear, but since it softened and began to flow from around 100 ° C,
The softening point was set at 110 ° C. Although the strength of this film was about the same as in Example 1, the elongation at break was 5% and it was a hard polymer.

A cushion structure was obtained in the same manner as in Example 1 except that this polymer was used as the sheath component of the composite fiber and the heat treatment temperature was 180 ° C., which is higher than the temperature usually used. When the bonding morphology of the obtained cushion structure was observed with an electron microscope, it was not found that it had an amoeber-like heat-fixing point in the present invention, and a spindle-shaped knot was not recognized. By the way, (A)
The W / D of the heat fixing point of was 1.7. Further, the breaking strength at the heat fixing point including (A) and (B) is 0.3 g / de,
The breaking elongation was 4%. Therefore, the 10% elongation elastic modulus at the heat fixing point could not be measured. The melt viscosity at this temperature was 1.7 × 10 ⁴ poise.

The cushioning property of this cushion structure was poor, and the compression resilience at the first time was as high as 6 kg, but the compression resilience was significantly reduced at the second and subsequent compressions. Actually, when examining the compression durability and compression recovery, it was found that each was 25%.
And 50%, which was a cushion structure having extremely poor durability.

[Brief description of drawings]

1 is a cross-sectional view of a cushion structure of the present invention, taken from an electron micrograph (50 ×) of FIG.

FIG. 2 is a front view of amoeber-like flexible thermal fixation points scattered as peculiar fixation points in the cushion structure of the present invention, taken from the electron micrograph (350 times) of FIG.

FIG. 3 is a graph used to calculate compression recovery of a cushion structure.

FIG. 4 is a graph showing the relationship between the melt viscosity of a thermoplastic elastomer, which is a constituent of elastic composite fibers, and the number of spindle-shaped knots to be generated.

FIG. 5 is a graph showing the relationship between the spindle-shaped knot portion and the compression repulsive force of the cushion structure.

FIG. 6 is an electron micrograph (× 50) showing the structure of the cushion structure of the present invention.

FIG. 7 is an electron micrograph (350 times) of amoebar-like flexible heat-fixing points and quasi-flexible heat-fixing points scattered in the cushion structure of the present invention.

[Explanation of symbols]

1 non-elastic polyester crimped short fiber 2 elastic composite fiber 3 spindle-shaped nodal section 4 loop A amoeber-like flexible heat-fixing point B quasi-flexible heat-fixing point θ crossing angle between elastic composite fibers

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location B68G 5/00 6908-3K D01G 25/00 A 7152-3B D04H 1/42 T 7199-3B 1 / 50 7199-3B D05B 13/02 7152-3B // B29L 31:44 4F

Claims (3)

[Claims] 1. A non-elastic polyester crimped short fiber aggregate is used as a matrix and has a density of 0.005 to 0.10 g /
In a cushion structure having a cm ³ thickness of 5 mm or more, a thermoplastic elastomer having a melting point of 40 ° C. or more lower than the melting point of the polyester polymer forming the short fibers in the short fiber aggregate, and a non-elastic polyester. In the former case, at least the elastic composite fibers exposed on the surface of the fibers are dispersed and mixed, and at this time, (A) the elastic composite fibers are formed by heat fusion in a state where the elastic composite fibers cross each other in the cushion structure. Amoeba-like omnidirectional flexible heat fixing point, and (B) quasi-omnidirectional flexible heat formed by heat fusion in a state where the elastic composite fiber and the inelastic polyester short fiber intersect. Adhering points are scattered, and between adjacent flexible thermal fixing points (between (A)-(A), (A)-
In the composite fiber group existing between (B) and (B)-(B)), the composite fiber has spindle-shaped nodes along the longitudinal direction of 2 × 10 ⁴ per 1 g of the cushion structure. A cushion structure characterized by the presence of at least one. 2. A non-elastic polyester crimped short fiber, a thermoplastic elastomer having a melting point of 40 ° C. or more lower than the melting point of the polyester polymer constituting the non-elastic polyester crimped short fiber, and a non-elastic polyester, wherein the former is a fiber. Elastic composite fibers occupying at least ½ of the surface are mixed to form a web having a bulkiness of at least 30 cm ³ / g, thereby forming a web between the composite fibers and between the non-elastic polyester crimped short fibers and the composite fibers. At least a part of these fiber entanglement points by heat-treating at a temperature lower than the melting point of the polyester polymer and higher than the melting point of the elastomer by 25 to 80 ° C. A method for manufacturing a novel high-performance cushion structure, characterized in that the fiber entanglement points are heat-sealed. 3. The melt viscosity of the thermoplastic elastomer is 4 ×
The method for manufacturing a cushion structure according to claim 6, wherein the heat treatment is performed while holding the heat treatment at 10 ³ poise or less.