JP2957290B2 - Cushioning material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material, and more particularly to a cushioning material having excellent elastic properties (compression and expansion properties) and shape retention.

[0002]

2. Description of the Related Art In the field of cushioning materials such as furniture and beds, foamed urethane foam, polyester fiber-filled cotton, resin cotton or polyester cotton having polyester fibers adhered thereto are currently used.

[0003] However, the urethane foam has problems that it is difficult to handle chemicals and the like used during production and that fluorocarbon is discharged. In addition, the compression characteristics of the obtained urethane foam are poor in cushioning properties due to its unique characteristics of being hard in the initial stage of compression and then sinking suddenly. Often not preferred as a material. Further, since the polymer is soft and foamed, there is a drawback that the density must be increased in order to exhibit repulsion against compression. In addition, since the fibers and structure are not fixed in the polyester fiber-filled cotton, there is a drawback that the shape and shape are lost during use, the fibers are moved or the crimp is reduced, and the bulk and rebound are greatly reduced. .

On the other hand, resin cotton or solid cotton obtained by bonding polyester fiber with a resin or a low-melting polymer (see, for example,
JP-A-31150), only adhesives with poor cushioning properties are obtained because adhesives are weak, adhesives are low in durability, the adhesives are broken during use, and the form and rebound are greatly reduced. There are drawbacks such as not being able to. In order to enhance cushioning properties, a cushioning material in which entangled portions of polyester fibers are bonded with a urethane foam binder as in Japanese Patent Application Laid-Open No. 62-102712 has been proposed. There are problems that spots are easily formed and handling is troublesome, adhesiveness between urethane and fiber is low, it is easily broken when the entangled part is greatly deformed due to low elongation of the binder, and durability is low. is there.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cushioning material which exhibits excellent cushioning properties, has excellent durability and stability, and has high air permeability in view of the above-mentioned problems of the prior art. is there.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, the intrinsic viscosity and the melt viscosity under specific conditions are within a specific range. It has been found that when a polyester-based thermoadhesive conjugate fiber containing a specific polyetherester block copolymer as a thermoadhesive component is applied to a cushion material, a cushion material excellent in the above characteristics can be obtained. The present inventors have further studied based on such knowledge, and as a result, have completed the present invention.

[0007] That is, the object of the present invention is that the melting point is 200
A conjugate fiber comprising a polyester component having a melting point of 180 ° C. or higher and a polyether ester block copolymer having a melting point of 180 ° C. or lower, wherein the polyether ester block copolymer has (A) terephthalic acid relative to all acid components. 50 to 8
An acid component containing 0 mol%, (B) a glycol component mainly containing 1,4-butanediol, and (C) an average molecular weight of 40
A poly (alkylene oxide) glycol component of 0 to 4000, the copolymerization amount of the component (C) in the polyetherester block copolymer is 30 to 50% by weight, and the melt viscosity MV (Poise ) And the intrinsic viscosity IV after holding in air at 180 ° C. for 3 minutes satisfies the following formulas (I) and (II) simultaneously: (I) 4000-2500 × IV <MV <10000-2500 × IV (II) 0 .6 <IV <1.5 [However, MV is a shear rate of 1000 sec at 180 ° C.]
The melt viscosity at c ⁻¹ , IV indicates the intrinsic viscosity in a 35 ° C. orthochlorophenol solution. And a fiber assembly containing at least 20% by weight of a polyester-based heat-adhesive conjugate fiber in which the polyetherester block copolymer component occupies 40% or more in fiber cross-sectional area ratio, by 20% or more from the melting point of the block copolymer. Achieved by a cushion material which is fused and integrated at a temperature higher by ℃ 80 ° C.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the polyester used as one of the heat-adhesive conjugate fibers has a melting point of 200 ° C.
There is no particular limitation as long as it has the above-mentioned properties and has a fiber-forming property. Among them, polyethylene terephthalate, polybutylene terephthalate, or a copolymerized polyester obtained by copolymerizing a small amount of the third component with these is preferred.

[0009] The preferably used copolymer components include:
For example, dicarboxylic acid components such as isophthalic acid, adipic acid, sebacic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, propylene glycol, diethylene glycol, neopentyl glycol, polyethylene glycol, and p-xylylene glycol Diol components such as 1,4-cyclohexanedimethanol and 5-sodium sulforesorcin; polyfunctional carboxylic acid components such as trimellitic acid and pyromellitic acid;
And difunctional monocarboxylic acids such as -oxybenzoic acid and p-oxyethoxybenzoic acid.

In the present invention, the polyetherester block copolymer, which is another component of the heat-adhesive conjugate fiber, is used in a copolymerization ratio of the copolymer to the total acid component (mol% based on the total acid component). The one containing 50 to 80 mol% of terephthalic acid is used. Acid components other than terephthalic acid include isophthalic acid, phthalic acid, adipic acid, sebacic acid, azelaic acid, dodecane diacid, 2,6-naphthalenedicarboxylic acid, 5-sodium sulfoisophthalic acid, and 1,4-cyclohexanedicarboxylic acid And the like are preferably used.

The polyetherester block copolymer used in the present invention contains 1,4-butanediol as a main glycol component. The term "main" used herein means that 80 mol% or more of all glycol components is 1,4-butanediol, and other glycol components may be copolymerized within a range of 20 mol% or less. Say. Preferred examples of the copolymerized glycol component include ethylene glycol, trimethylene glycol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol. be able to.

Further, the polyetherester block copolymer used in the present invention has an average molecular weight of 400.
4,000 poly (alkylene oxide) glycol components in an amount of 30 to 50% by weight. Average molecular weight of 4
When it is less than 00, the blockability of the obtained block copolymer is reduced and the elastic recovery performance becomes insufficient. On the other hand, when it exceeds 4000, the copolymerizability of the poly (alkylene oxide) glycol component becomes insufficient. As a result, the phase separation of the produced polymer becomes severe and the elastic recovery performance becomes insufficient, which is not preferable. If the copolymerization amount is less than 30% by weight, even if the conjugate fiber is subjected to heat bonding treatment and molded into a cushion material or the like, a material having good elastic properties aimed at by the present invention cannot be obtained. If the amount exceeds 50% by weight, the mechanical properties and durability of the block copolymer, such as heat resistance and light resistance, are undesirably reduced.

The poly (alkylene oxide) glycol preferably used includes polyethylene glycol,
Examples thereof include poly (propylene oxide) glycol and poly (tetramethylene oxide) glycol, and a homopolymer of poly (tetramethylene oxide) glycol is particularly preferable. Further, a random copolymer or a block copolymer in which two or more of the repeating monomers constituting the homopolymer are copolymerized in a random or block manner may be used, or the homopolymer or the copolymer may be used. A mixed polymer in which two or more of the above are mixed may be used.

[0014] The polyetherester block copolymer used in the heat-adhesive conjugate fiber of the present invention must satisfy the above-mentioned compositional conditions. It has been found that it is important to further control the melting point, melt viscosity, and intrinsic viscosity of the copolymer within appropriate ranges in order to ensure process stability, quality such as elastic properties and thermal adhesiveness.

That is, the polyetherester block copolymer according to the present invention has a melting point of 180 ° C. or less. When the melting point exceeds 180 ° C., the heat treatment temperature for producing the cushioning material from the conjugate fiber of the present invention must be 180 ° C. or more, and the thermal decomposition of the block copolymer occurs during this heat treatment. The mechanical properties of the obtained cushion material will be reduced.

The block copolymer used in the present invention has a melt viscosity MV at 180 ° C. (shear rate 1000
(measured in sec ^-1 ) and intrinsic viscosity IV after keeping in air at 180 ° C. for 3 minutes must satisfy the following formulas (I) and (II). (I) 4000-2500 × IV <MV <10000-2500 × IV (II) 0.6 <IV <1.5 When IV is 0.6 or less, the mechanical performance of the cushion material finally obtained is inferior, On the other hand, if it is 1.5 or more, not only does the fluidity of the block copolymer decrease and the adhesion at the time of heat treatment becomes insufficient, but also the block copolymer thermally decomposes because the heat treatment temperature needs to be set high. The elastic properties are also reduced.

Further, at 180 ° C. and at a shear rate of 1000 sec ^-1
When the melt viscosity MV is 4000 to 2500 × IV or less, the spinning condition such as breaking during spinning during production of a conjugate fiber deteriorates, and when producing a cushion material,
Even after heat treatment, flow occurs in the adhesive part and the adhesive strength decreases,
Insufficient elastic and mechanical properties. On the other hand, 100
If it exceeds 00-2500 × IV, the fluidity during the heat treatment is too low, so that the adhesion at the fiber entanglement point does not occur sufficiently, resulting in insufficient elasticity and mechanical properties. Not preferred.

In the present invention, the terminal carboxyl group concentration (CV) of the block copolymer is further reduced to 30 equivalent / 10
^The weight is preferably ⁶ g or more. By doing so, the adhesive force between the fibers is improved, and the elastic properties of the cushioning material are further improved.

The polyetherester block copolymer described in detail above can be produced according to a conventionally well-known conventional production method of a copolyester. Specifically, a terephthalic acid component, a dicarboxylic acid component other than terephthalic acid, a glycol component mainly comprising 1,4-butanediol, and a poly (alkylene oxide) glycol are placed in a reactor, and are charged in the presence or absence of a catalyst. This is a method in which a transesterification reaction or an esterification reaction is carried out in the presence, and then a polycondensation reaction is carried out under a high vacuum in the presence of a catalyst to raise the degree of polymerization to a desired degree.

In the present invention, the melting point Tm of the block copolymer, the melt viscosity MV at 180.degree.
In order to set the intrinsic viscosity IV and the terminal carboxyl group concentration after the retention in the above-mentioned ranges, the above-mentioned polymerization reaction conditions are appropriately set, and the physical properties in consideration of the rate of change in the physical properties of the block copolymer by the spinning method. Need to be

For example, the intrinsic viscosity depends on the polymerization time, the polymerization temperature, the stirring speed, the type of catalyst, the amount of catalyst added, and the like.
As the polymerization time is increased, the polymerization temperature is increased, the stirring speed is increased, and the amount of the catalyst added is increased, the intrinsic viscosity can be increased, and the intrinsic viscosity after holding at 180 ° C. in air for 3 minutes also increases.

The melt viscosity MV is determined by the intrinsic viscosity of the block copolymer, the type of components constituting the block copolymer, the molecular weight and copolymerization amount of poly (alkylene oxide) glycol, the addition of other stabilizers, antioxidants and the like. It depends on the type and amount of the agent, or the melting point Tm of the block copolymer, and the like. As the intrinsic viscosity increases, the amount of the poly (alkylene oxide) glycol copolymerized decreases, and the amount of the additive increases. In general, the higher the melting point, the higher the MV can be.

The melting point of the block copolymer depends on the composition and copolymerization ratio of the polyester segment constituting the block copolymer and the average molecular weight of the poly (alkylene oxide) glycol. To reduce dicarboxylic acid components other than terephthalic acid or poly (alkylene oxide)
The higher the average molecular weight of the glycol, the higher the melting point.

Further, the terminal carboxyl group concentration CV depends on the polymerization time, polymerization temperature, type and amount of catalyst added, intrinsic viscosity of the block copolymer, and the like. In general, the longer the polymerization time and the higher the polymerization temperature, the higher the CV can be.

Therefore, the above polymerization conditions and composition are
What is necessary is just to change and combine them appropriately.

The above-mentioned polyetherester block copolymer according to the present invention may contain matting agents, pigments (eg, carbon black), antioxidants (eg, hindered phenolic compounds, Compounds), UV absorbers (eg, benzophenone-based compounds, benzotriazole-based compounds, sacylate-based compounds, etc.), cross-linking agents (eg, isocyanate compounds)
Even if it contains etc., it can not do anything.

The polyester-based heat-adhesive conjugate fiber of the present invention is obtained by spinning the above-mentioned polyester component having a melting point of 200 ° C. or more and a polyetherester block copolymer component having a melting point of 180 ° C. or less. In this case, it is necessary that the composite ratio is such that the block copolymer component accounts for 40% or more of the total peripheral length of the cross section of the composite fiber, that is, the fiber cross section peripheral ratio is 40% or more. Alternatively, a composite fiber such as an eccentric core-sheath type in which the fiber is eccentric can be exemplified. Among them, the eccentric core-sheath type conjugate fiber is preferable because the crimp can be easily developed by heat treatment or the like, and thus the carding process permeability is improved.

Further, the heat-adhesive conjugate fiber used in the present invention is preferably a fiber drawn 1.5 times or more. The cushioning material containing the stretched heat-adhesive conjugate fiber as a constituent fiber is superior in elasticity to the cushioning material containing a non-stretched heat-adhesive conjugate fiber as a constituent fiber, and does not easily settle. Although the reason for this is not clear, in the process of the stretched fiber being heat-treated in a relaxed state,
It is presumed that the amorphous portion of the block copolymer component is relaxed, resulting in a polymer structure having more excellent elastic properties, and the structure is maintained even after molding into a cushion material or the like.

The conjugate fiber used in the present invention preferably has a low shrinkage, and is preferably heat set. That is, when the shrinkage is high, the shrinkage is remarkable during the heat bonding process, so that not only the resilience of the cushion material obtained by reducing the heat bonding efficiency between the fibers but also the hand becomes extremely hard.

In order to produce the cushioning material of the present invention, an aggregate of the above-described composite fiber alone or an aggregate of a mixture with other fibers is used. Among these, polyethylene terephthalate, When a fiber made of polyester such as polybutylene terephthalate is used, not only the conjugate fibers of the present invention but also the thermal adhesion between the mixed fiber and the conjugate fiber is good, and both the mechanical properties and the elastic properties are excellent. Cushion material can be obtained. here,
In the case of a mixed aggregate, the mixing ratio is required to include at least 20% by weight of the above-described conjugate fiber.

The cushioning material of the present invention can be obtained by heat-treating the above-mentioned aggregate and thermally bonding at least a part of the fiber entanglement points.
20 to 80 ° C. higher than the melting point of the block copolymer disposed on the heat-adhesive conjugate fiber, and the melting point of the component of the purchased fiber when the polyester component and other fibers constituting the conjugate fiber are mixed. Processing may be performed at a lower temperature.
If the processing temperature is too low, it becomes impossible for the molten polymer to flow into the entangled portion and bond properly. descend. On the other hand, if the processing temperature is too high, the block copolymer is deteriorated by heat, resulting in poor elasticity and remarkable discoloration.

[0032]

The cushioning material of the present invention is thermally and thermally bonded at the entanglement point of the constituent fibers, and the thermal bonding point is formed from a polyetherester block copolymer having a specific performance. It has the characteristic that the strength and elastic properties (deformation recovery properties) of the body are extremely excellent.

Furthermore, as compared with the foamed urethane foam which has been widely used in the past, there is no initial hardness in compression, the resilience is large and the proportion increases in proportion to the amount of compression, so that the feeling of bottom contact is extremely small, and the density is low and the ventilation is low. It has excellent properties such as good heat resistance and no fear of stuffiness. In addition, since the adhesiveness at the fiber entanglement point is also good, the adhesive portion at the time of deformation is hardly broken, and it has the property that it is easily deformed but the recovery is good, and the durability against repeated compression is the durability of urethane. It is sex.

In producing these fiber aggregates, a uniform product can be easily obtained by a simple and short process in which a web is formed and then heat-treated. Moreover, by changing the mixing ratio of the constituent fibers, the structure, or the density of the fiber aggregate, the hardness can be arbitrarily changed in both the thickness direction and the planar direction.

Therefore, the cushioning material of the present invention is a cushioning material which is excellent in cushioning property, durability and stability, has high air permeability and is hardly stuffy, does not easily produce unevenness in processing, and is easy to diversify in processing. The range of use is suitable for various cushion materials, for example, furniture, beds, bedding, seat cushions, and the like.

[0036]

The present invention will be described below in detail with reference to examples. In the examples, all “parts” indicate parts by weight. The evaluation in the examples was measured by the following method.

1. Intrinsic viscosity (IV) It was measured in an orthochlorophenol solvent at 35 ° C.

[0038] 2. Melting point (Tm) Using a thermal differential analyzer type 990, manufactured by Du Pont,
The measurement was carried out at a heating rate of 20 ° C./min to determine the melting peak temperature.

[0039] 3. Melt Viscosity (MV) The apparent melt viscosity (MV) was measured at a temperature of 180 ° C. and a shear rate of 10 to 10000 sec ⁻¹ , and a shear rate of 10
The melt viscosity (MV) of 00 sec ^-1 was calculated.

[0040] 4. Terminal Carboxyl Group Concentration (CV) 0.1 g of the polymer is dissolved in 10 ml of benzyl alcohol, 10 ml of chloroform is added, and the mixture is titrated with sodium hydroxide-benzyl alcohol. Use phenol red as an indicator.

[0041] 5. Measurement of the compression elasticity and compression durability of the cushioning material A density of 0.035 g / cm ³ and a thickness of 5 molded into a flat plate
cm cushion material was compressed 1 cm with a cylindrical rod having a flat lower surface with a cross-sectional area of 20 cm ² and its stress (initial stress) was measured. After the measurement, 1 with a load of 800 g / cm ²
Compressed for 0 seconds, then de-weighted and left for 5 seconds to repeat 3
Compression and standing were repeated 60 times, and the compression stress was measured again after 24 hours. The ratio of the stress after repeated compression to the initial stress was defined as the compression durability of the cushioning material.

[Examples 1 to 6, Comparative Examples 1 to 8] 117.1 parts of dimethyl terephthalate, polytetramethylene glycol described in (Table 1), an additive, a catalyst, and 1,4-butanediol (of an acid component) (1.4 mol times) was charged into a reactor, and a transesterification reaction was performed at an internal temperature of 190 ° C. After about 80% of the theoretical amount of methanol was distilled off, the polycondensation reaction was started by raising the temperature and reducing the pressure. The polycondensation reaction was performed while gradually reducing the pressure, and after reaching a vacuum of 1 mmHg or less, the reaction was performed at the internal temperature and time described in (Table 1).

The resulting polyetherester block copolymer was pelletized.

Using the polyetherester block copolymer as a sheath and polyethylene terephthalate as a core, spinning was carried out by a conventional method so that the weight ratio of the core / sheath was 50/50. The composite fiber is an eccentric core-sheath type composite fiber.
This fiber is stretched 2.0 times, cut into 64 mm, and then 95
Heat treatment was carried out with warm water at ℃ to reduce the shrinkage and develop crimp, and after drying, an oil agent was applied. The single fiber fineness of the conjugate short fiber obtained here is 6 denier.

40% of the composite staple fiber containing the polyetherester block copolymer and 60% of a hollow polyethylene terephthalate staple fiber having a fiber denier of 6 denier and a fiber length of 64 mm obtained by a conventional method are mixed with a card. A web (web bulk 120 cm ³ / g) was obtained. This web was layered, thickness 5cm, density 0.035g / cm
^The mixture was placed in a flat mold so as to obtain a heat treatment at 200 ° C. for 10 minutes to obtain a flat cushion material. The properties of the obtained cushion material are shown in (Table 2).

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

[0049]

[Table 4]

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-220316 (JP, A) JP-B 60-1404 (JP, B2) JP-B 53-19638 (JP, B2) (58) Field (Int.Cl. ⁶ , DB name) D04H 1/54 B68G 5/00 D01F 8/14

Claims (3)

(57) [Claims] 1. A composite fiber comprising a polyester component having a melting point of 200 ° C. or higher and a polyetherester block copolymer component having a melting point of 180 ° C. or lower, wherein the polyetherester block copolymer is (A) An acid component containing 50 to 80 mol% of terephthalic acid based on the total acid component;
(B) a glycol component mainly composed of 1,4-butanediol; and (C) a poly (alkylene oxide) glycol component having an average molecular weight of 400 to 4,000, and the above-mentioned (C) in the polyetherester block copolymer. The copolymerization amount of the components is 30 to 50% by weight, and the melt viscosity MV (Poise) at 180 ° C. and the intrinsic viscosity IV after holding in air at 180 ° C. for 3 minutes simultaneously satisfy the following formulas (I) and (II). (I) 4000-2500 × IV <MV <10000-2500 × IV (II) 0.6 <IV <1.5 [However, MV is a shear rate at 180 ° C. of 1000 sec.
The melt viscosity at c ⁻¹ , IV indicates the intrinsic viscosity in a 35 ° C. orthochlorophenol solution. And a fiber assembly containing at least 20% by weight of a polyester-based heat-adhesive conjugate fiber in which the polyetherester block copolymer component occupies 40% or more in fiber cross-sectional area ratio, by 20% or more based on the melting point of the block copolymer. Cushion material that is fused and integrated at a high temperature of up to 80 ° C. 2. The cushion material according to claim 1, wherein the polyetherester block copolymer has a terminal carboxyl group concentration of 30 equivalents / 10 ⁶ g or more. 3. The cushion material according to claim 1, wherein the conjugate fiber is a core-sheath type conjugate fiber.