JPH05247819A - Cushioning material - Google Patents

Abstract

PURPOSE:To obtain a cushioning material suitable for vehicle seats, capable of being recycled, having especially excellent heat-resistant and shape retention resistances. CONSTITUTION:This cushioning material is obtained by blending parent material fibers with thermally bondable fibers, partially fusing the blend between the fibers to form points of contact and an integrated structure, wherein the parent material fibers have >=30g/d initial tensile resistance, specific correlation between the initial tensile resistance and elastic limit elongation and solid crimping, and the thermally bondable fibers have a combination of sheath core type fibers comprising a polyester ether elastomer having 160-220 deg.C melting point, a specific betadispersion peak temperature of Tandelta and a specific alpha dispersion build up temperature as a bonding component. The cushioning material is suitably useful as a cushioning material, has extremely excellent heat resistance and shape retention resistance, improved air passability, water permeability, low-frequency wave absorption characteristics and is a comfortable cushioning material. The material can be recycled and is especially admirable as a cushioning material substitutable for polyurethane material in problems of environmental pollution.

Description

Detailed Description of the Invention

[0001]

[Industrial application] The present invention relates to a cushioning material that is recyclable and has excellent heat and fatigue resistance and is suitable for vehicle seats.

[0002]

2. Description of the Related Art A cushion material having a polyester three-dimensional crimped yarn, which is a non-elastomer polyester fiber as a heat-bonding component, as a base material is known. This cushion material is recyclable (monomers can be recovered by decomposing methanol, etc.), but since the adhesive component is amorphous, it is easily plastically deformed by compression under heating (70 ° C),
In addition, since the base material fiber is polyester terephthalate, the glass transition temperature (abbreviated as Tg) is 70 ° C or less, and plastic deformation is large, and the heat and fatigue resistance at 70 ° C required for vehicles is poor and it is practically used. I won't. A cushion material is also known in which polyester three-dimensional crimped yarn is used as a base material fiber in which an adhesive component is impregnated with a rubber emulsion or polyurethane.
Those using a thick denier polyester fiber impregnated with a rubber adhesive are difficult to recycle, and the heat resistance to heat settling is poor because the crimp fastness of the base material is poor. A product impregnated with polyurethane as an adhesive has a considerably improved heat and settling resistance, but is difficult to recycle.

The inventors of the present invention have previously proposed a cushioning material using a polyester fiber containing a commonly known polyester elastomer as an adhesive component and a matrix fiber having improved retention of initial tensile resistance. It was found that the improvement of only the retention rate of the initial tensile resistance of No. 1 cannot maintain sufficient heat and settling resistance imparted for vehicles.

[0004]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art and provides a cushioning material which is excellent in heat resistance and durability at 70 ° C. and is composed only of recyclable polyester fibers. To do.

[0005]

[Means for Solving the Problems] Means for solving the above-mentioned problems, that is, the present invention, a base material fiber and a heat-bonding fiber are mixed and dispersed, and an adhesive component of the heat-bonding fiber is melted by thermoforming to form a fiber. Is a cushion material which is formed into an integral structure by forming the contact points of the matrix material, and the matrix fiber constituting the cushion material is made of polyester and has an initial tensile resistance (IS) of 30 g / d or more and an elastic limit elongation (Δε). ) Is IS ≧ (Δε
+0.6) ^−2.8 × 10 ³ +8 is satisfied, and three-dimensional crimp is provided, the heat-bonding fiber is a sheath-core type bicomponent fiber, and the sheath component has a melting point (Tm ₁ ). 160 ℃ ~ 2
20 ° C, Tan δ β dispersion peak temperature (Tβ) is -40
Below ℃, Tanδ α dispersion rising temperature (Tαcr) is 5
A cushion material comprising a polyester ether elastomer having a temperature of 0 ° C. or higher, and a core component made of a non-elastomeric polyester having a melting point (Tm ₂ ) higher than Tm ₁ by 20 ° C. or more.

Since the cushion material of the present invention is made of polyester fiber, it can be recovered by decomposing it into a monomer by a known method such as methanol decomposition. It is at least 95% or more, preferably 99% or more polyester, and other compositions are limited except those used as additives.
The halogen-based composition and the nitrogen-based composition in the additive generate noxious gas upon combustion such as a fire, and therefore are preferably not contained. Preferred compositions include PET, PEN, PCHDT,
PBT etc. can be illustrated. The cushioning material of the present invention is a cushioning material in which the base material fibers and the heat-bonding fibers are mixed and dispersed, and the heat-bonding components are melted by thermoforming to form a contact, thereby forming an integral structure. With such a structure, bulkiness, ventilation, water permeability, and cushioning properties can be imparted.

The matrix fiber in the cushion material of the present invention has an initial tensile resistance (Is) of 30 g / d or more. 30 g /
If it is less than d, the elasticity is insufficient, and the plastic deformation of the crimp is increased, and the settling resistance for repeated compression under heating at 70 ° C. is deteriorated, which is not preferable. In addition, the matrix fiber in the cushion material of the present invention has a relationship between the elastic limit elongation (Δε) and Is of I.
It is necessary to satisfy s ≧ (Δε + 0.6) ^−2.8 × 10 ³ +8. Those that do not satisfy this relationship are inferior in heat and settling resistance.

The reason for this has not been clarified, but it is speculated that Δε is an alternative measure for toughness and Is is an alternative measure for hard, so that the heat and settling resistance of the crimp is not achieved until it has the characteristics of being hard and tough. It is thought that it will be improved. The preferable relationship between Is and Δε in the cushion of the present invention is Is ≧ (Δε + 0.6) ^−2.8.
× 10 ³ +10, more preferably Is ≧ (Δε +
0.6) ^−2.8 × 10 ³ +12. The base material in the cushion of the present invention is a three-dimensional crimp. If it is not a three-dimensional crimp, the bulkiness is inferior. However, the three-dimensional crimp has a larger torsional deformation than the mechanical crimp, and the crimp is weaker, so that the above-mentioned requirements are particularly required.

The adhesive component of the cushioning material of the present invention has a melting point of 160 ° C. or more and 220 ° C. or less, a tan δ beta dispersion peak temperature (Tβ) of -40 ° C. or less, and a tan δ α dispersion rising temperature (Tαcr) of 50 ° C. The above polyester ether elastomer. The polyester ether elastomer is a polyester showing rubber elasticity in which a hard segment and a soft segment are block-copolymerized. The hard segment is polyethylene terephthalate (PET), polybutylene terephthalate (PBT),
Examples thereof include polyethylene naphthalate (PEN) polycyclohexylene dimethyl terephthalate (PCHDT). As the soft segment, polytetramethylene glycol (PTMG), polyhexamethylene glycol (PHMG), polypropylene glycol (PPG),
Examples thereof include polycaprolactam (PCL). Particularly preferred combinations are PBT and PTMG, PEN and P
Examples include TMG, PBT, and PCL. When the soft segment is PTMG, the preferable molecular weight (Mw) is 10
Although it is from 00 to 3000, there is an optimum combination that is considered to be related to the crystallinity due to the composition of the hard segment.
In such a combination, Tβ is −40 ° C. or lower and Tαcr is 50 ° C. or higher even when the melting point is in the range of 160 ° C. to 220 ° C. If the melting point is 160 ° C. or lower, the heat resistance is poor, and if it is 220 ° C. or higher, the high temperature treatment during thermoforming (at least the melting point + 10 ° C.) causes decomposition and deterioration of the soft segment and deterioration of the base material. .. Base material is PE
In the case of T, the melting point is preferably 160 to 200 ° C, more preferably 170 to 190 ° C. When Tβ is -40 ° C or higher, the rubber elastic property is deteriorated, and when Tαcr is 50 ° C or lower, it is 7
Since the plastic deformation becomes large when the deformation strain is applied at 0 ° C, both the heat resistance and the sag resistance are inferior. The preferred Tβ of the adhesive component of the cushion material of the present invention is −45 ° C. or lower, more preferably −50 ° C.
It is below, Tαcr is preferably 55 ° C or higher, 60 ° C
The above is more preferable. The cushion material having excellent heat and fatigue resistance cannot be obtained until the above requirements of the cushion material of the present invention are satisfied.

The core component of the heat-bonding fiber in the cushioning material of the present invention is polyester. Examples of preferable polyester composition include PET, PEN, PCHDT and the like. When hardness is desired, PET, PEN, etc. are preferable, and when softness is desired, PBAT, PCHD
T and the like are preferable.

The base material content of the cushion of the present invention is 30 to 9
5% by weight is preferred. If it is less than 30%, the bulkiness cannot be maintained. If it exceeds 95%, the number of adhesion points decreases, and the elastic recovery becomes constant. Particularly preferred content of both groups 50-80
% By weight. It is speculated that by forming the contact point with an elastomer with such a content, the force is uniformly dispersed in the structure and the damage to each fiber in the structure is reduced.

The denier of the base material fiber of the cushion of the present invention is not particularly limited, but is preferably 8 denier or more and 20 denier or less when it is desired to impart hardness, and is preferably 4 denier or more and 8 denier or less when imparting softness. The cross section is preferably hollow or modified hollow.

The preferred range of the denier of the heat-bonded fibers in the cushioning material of the present invention varies depending on the denier of the base material. For example, the base material of 13 denier has 4d to 8d (processed with a balance of the effect of increasing the number of contact points and uniform mixed fiber property). The above is optimized.) Is preferable. For a 6 denier base material, 2 to 4 denier is preferred.

The cushion material of the present invention can be obtained only when it is molded from the heat-bonding fiber having the specified characteristics and the base material.

An example of the composition of the heat-bonding fiber necessary for forming the cushion material of the present invention will be shown. Tan having a melting point of 160 ° C. or more and 220 ° C. or less, which is the characteristic specified by the cushion material of the present invention
The peak temperature (Tβ) of β dispersion of δ is −40 ° C. or lower, Ta
Polyester ether elastomer having a rising temperature of α dispersion of nδ (Tαcr) of 50 ° C. or higher is melted at 180 ° C. to 270 ° C. in a composite fiber as a sheath component, while the core component is melted at 250 ° C. to 295 ° C. In the composite, the yarn which is set to the same temperature and is subjected to the composite spinning and discharged is obtained as a drawn undrawn yarn at a spinning speed of 500 m / min or more. When the melting point of the sheath component is 180 ° C. or less, the distance between the nozzle surface and the yarn collecting point is preferably 6 m or more so that fusion does not occur.

Stretching is carried out at a temperature at which fusion does not occur and at a temperature higher than the glass transition temperature of the core component (for example, in a warm bath at 60 ° C. when the core is PBT, in a warm bath at 70 ° C. when the core is PET). Accordingly, relaxation heat treatment or the like is performed at a temperature that is not higher than the drawing temperature and does not cause fusion, and then the filament is once wound or continuously crimped and cut to obtain a staple. It is preferable because the shrinkage rate due to the heat treatment is reduced, the Is retention is also improved, the passability in the processing step is improved, and the delamination due to the shrinkage during thermoforming can be suppressed.

An example of a method for producing the matrix fiber necessary for forming the cushion material of the present invention will be shown. The asymmetric cooling method or the composite spinning method is used to give the three-dimensional crimp. In the asymmetric cooling method, if the cross-section anisotropy is not imparted to a high degree, it is difficult to develop the required three-dimensional crimp by eliminating the cross-section anisotropy because heat resistance and durability are imparted by high temperature high tension drawing. In the case of composite spinning, if the latent crimping ability is to be imparted only by the difference in the limit year, in the case of PET, it is 0.05 or more, preferably 0.08 or more. When it is 0.15 or more, spinning is difficult due to bending of holes, which is not preferable. The nozzles used are preferably both C-shaped and C-shaped with a projection. The spinning temperature is preferably from the melting point + 20 ° C to + 30 ° C.

The unstretched yarn thus obtained is once wound or shaken off and then used for stretching. As an example of PET, many stretchings are performed. The first stage has a glass transition point (Tg) or more and 100 ° C. or less and a breaking draw ratio (MDR) of 0.7 to 0.
Stretch 75 times. The third stage is MDR 0.8-0.85
The film is stretched at 120 to 180 ° C. The third stage is stretched at 210 to 230 ° C. with 0.9 to 0.95 times MDR. Four
At the stage, the temperature of the fiber is lowered to 60 ° C. or lower with the draw ratio being 0% to 1% lower than the draw ratio of the third stage to complete the structure. In the conventionally known method, since the fourth stage was not stretched, the tension strain was released after the third stage, resulting in a reduction in the crimping force and a reduction in Is. In addition, in the fourth stage, the yarn tensioned at a high temperature is cooled in a tension state of Tg or less, so that the drawing tension is remarkably high, and the undrawn yarn, which has a lot of yarn unevenness, breaks the drawn yarn. Need to be suppressed as much as possible. The drawn yarn thus obtained is cut into a desired length and subjected to crimping treatment by heat treatment, but after the crimping treatment treatment, it is cut into staples. The crimping process is preferably performed in two stages. The first stage is 140-16 under tension close to free.
Initiate crimping at 0 ° C. At this time, a remarkable crimping force is exhibited despite the high temperature drawing. Then, the second stage is heat-set at 200 to 220 ° C. in a state close to the restrained state. The crimped base material fibers thus obtained have remarkably excellent heat resistance and durability.

An example of a method for producing the cushioning material of the present invention using the thus obtained heat-bonding fiber and base material fiber will be described. The heat-bonded fibers and the base material fibers are pre-opened with a Hopper. A heat-bonding fiber is laminated on the base material fiber in a desired mixing ratio in a sheet shape and supplied to the opener. By this method, a pre-opening raw cotton with a good mixed state is prepared and supplied to a card to prepare an opening web. The open web can also be made using air lay. Since a more uniform web can be obtained as compared with the case of air lay, delamination can be reduced. The spread webs are laminated to give a desired basis weight. At this time, a method of temporarily adhering the open web with a far infrared heater or the like can be used. The laminated web is multi-staged when thermoformed.

The first step is the melting point of the adhesive component of the heat-adhesive fiber to +
At a temperature of 10 ° C., it is compressed to 1/2 of a predetermined apparent bulk and temporarily molded. As a result, the heat-adhesive fibers can be temporarily fixed to prevent delamination and prevent localization of the contacts. The second stage is compressed to a predetermined apparent bulk and thermoformed at a temperature 10 ° C to 30 ° C higher than the melting point. More preferably at this time, a predetermined apparent bulk of 80
% To 90%, and re-compression molding to a predetermined apparent bulk in the third step improves the heat-resistant settling resistance compared to the two-step molding.

[0021]

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

The characteristics specified in the present invention are measured by the following method. Melting point A melting peak temperature was determined by measuring at a temperature rising rate of 20 ° C./min using a Shimadzu TA50, DSC50 type differential thermal analyzer.

Tβ, Tαcr Piperon DDVII type manufactured by Orientec Co. is used, and 1
Measured at 10 Hz and a heating rate of 1 ° C./min (imaginary modulus M ″
Ratio of the elastic modulus to the real part M'M "/ M '= Tanδ)
The β dispersion peak temperature (Tβ) of Tan δ and the rising temperature of α dispersion (Tαcr) corresponding to the dislocation temperature from the rubber elastic region to the melting region rise with the middle point between the lowest point and the highest point of the rubber elastic region as the baseline. The temperature at the intersection with the same baseline later was calculated.

Initial Tensile Resistance (Is) The heat-bonded fiber portion in the cushion material is carefully cut to take out the matrix fiber. The initial load is determined by calculating the denier by calculating the cross-sectional area from the specific gravity of the matrix fiber and the cross-sectional photograph. SS
The curve is measured by the method of JIS-L-1063.

Elastic Limit Elongation Elongation from the SS curve measured by the initial tensile resistance to the point where the tangent line of the maximum slope drawn for Is measurement deviates from the SS curve is taken as the elastic limit elongation. Like Is, n = 5
The average value of 0 is calculated.

Examples and Comparative Examples Preparation of Heat-Adhesive Fibers Dimethyl terephthalate or dimethyl naphthalate and tetramethylene glycol and polytetramethylene glycol were charged together with a small amount of a catalyst and an antioxidant, and transesterification was carried out by a known method. While polycondensing,
A polyester ether copolymer elastomer was produced.
The polyester ether copolymer elastomer thus produced was pelletized and vacuum dried at 40 ° C. for 48 hours, and used as a sheath component. The polyester ether copolymer elastomer produced as the sheath component is 220 ° C to 24 ° C.
PBT having an intrinsic viscosity of 1.400 as a core component is melted at 260 ° C. until melted at 0 ° C. and discharged at 3 g / min.
The sheath core fibers were spun out at a spinning temperature of 260 ° C., and the sheath core fiber was spun at a spinning temperature of 260 ° C. to obtain a sheath core undrawn yarn at a take-up speed of 700 m / min.

PET was used as a core component and melted at 285 ° C., and a sheath core undrawn yarn was obtained by the same method at a spinning temperature of 285 ° C. The obtained undrawn yarn is drawn in a hot bath at 60 ° C at a cutting ratio of 0.8 times, and subsequently heat-treated at a constant temperature in an oven at 70 ° C, wound into 20,000 denier yarn, and mechanically crimped after applying a finishing oil agent. Tables 1 and 2 show the characteristics of the staples obtained by applying the test pieces and cutting them to 64 mm.

[0028]

[Table 1]

[0029]

[Table 2]

Fabrication of base material fiber PET of 0.63 of extreme clay was produced from Y / U type orifice and C type orifice at a spinning temperature of 285 ° C. and 6 g per single hole.
Spinning at a discharge rate of 1 minute / minute, 2m from 30mm directly under the nozzle
The unstretched yarn was drawn at 1080 m / min while being rapidly cooled at a wind speed of 3 m / sec to 3 m / sec while imparting cross-section anisotropy, and stretched under the following conditions. (A) 0.7 times the MDR at the first step 80 ° C 0.85 times the MDR at the second step 160 ° C 0.95 times the MDR at the third step 220 ° C The thread temperature at the fourth step fixed length To room temperature and wind. (B) Wrapped by omitting the 4th step of the condition of (a). (C) The 2nd step of the condition of (a) was stretched at 160 ° C. to 0.95 times the MDR, and the 3rd step, Wound with the fourth step omitted (d) First step drawn at 80 ° C. at 0.90 times MDR and wound up The drawn yarn thus obtained was cut into 64 mm and The crimping heat treatment was performed under the same conditions to obtain a staple having a three-dimensional crimp.

(A) After cutting the cut fibers with air, 16
After processing at 0 ° C for 5 minutes to cause crimping, apparent bulk 0.0
5 g at 200 ° C in a compressed state of 5 g / cm ²
Heat treated again for minutes. (B) The cut fibers are heat-treated at 160 ° C. for 5 minutes without air-spreading to cause crimping. Table 3 shows the properties of the obtained staples.

[0032]

[Table 3]

Molding of Cushion Material The obtained heat-bonded fiber is used as the base material fiber in 20/80 to 50/5.
The mixed web was mixed with an opener at a weight ratio of 0 and pre-opened with a card, and a mixed web opened with a card was laminated to a weight of 1500 g / m ² , compressed to a thickness of 10 cm, and heated with hot air at a temperature 5 ° C. higher than the melting point of the heat-adhesive component. It is treated for 5 minutes, cooled to room temperature once, and then compressed to a thickness of 5 cm.
Cushion material was obtained by thermoforming at a high temperature of 30 ° C to 30 ° C and forced cooling in a compressed state. The cushion material thus obtained was allowed to stand for 1 day, and then the apparent bulk temperature at 70 ° C., heat resistance and settling resistance, and fiber characteristics of the base material in the hard cotton were measured. The results are shown in Tables 4-6.

[0034]

[Table 4]

[0035]

[Table 5]

[0036]

[Table 6]

The evaluation of hard cotton was carried out by the following method. 70 ℃ recovery rate Hard cotton is cut into 15 cm x 15 cm and compressed by 50% to 7
After being left in the dry heat at 0 ° C for 22 hours and cooled to remove the compression strain, the ratio of the thickness (li) after left for 1 day and the thickness (lo) before the treatment (l
i / lo) × 100 (%). in = 3 The average value is shown.

Repeated compression recovery rate Hard cotton is cut into 15 cm × 15 cm and 25 ° C. 65% RH
The compression recovery was repeated at 1HZ continuously up to 50% thickness in the room, and the thickness of the sample after 20,000 times was left for 1 day (lj) and the ratio before the treatment (lo) (lj / lo) ×
It is shown as 100 (%). It is calculated as an average value of n = 3. A servo pulsar manufactured by Shimadzu Corporation was used.

50% compression repulsion Hard cotton is cut into 20 cm × 20 cm and φ is used with Tensilon
The repulsive force when compressed to 50% with a 150 compression plate was measured and the value is shown in Kg. It was determined as an average value of n = 3.

Rebound resilience According to JIS K6382, rebound resilience test method.

[0041]

The cushion material thus obtained has appropriate repulsive force and impact resilience necessary for vehicles and is particularly excellent in heat and settling resistance, and is optimal as a cushion material for vehicles. In addition, since it is made of polyester, it is recyclable, bulky, has good breathability and permeability, has good elasticity, and has good low-frequency absorption, making it an optimal cushioning material. Of course, it is also useful for furniture, beds, and futons because it has excellent durability. Further, the cushioning material of the present invention is suitable for vehicles, and by using polyester fiber for the side material, the problem of environmental pollution can be reduced. The cushion material of the present invention can be cut and laminated into a desired shape and integrally thermoformed together with the side material, and has good workability.

Claims (2)

[Claims] 1. A base material fiber and a heat bonding fiber are mixed and dispersed,
This is a cushion material integrally formed by melting the adhesive component of the heat-bonded fiber by thermoforming to form a contact point of the fiber, and the matrix fiber constituting the cushion material is made of polyester and has an initial tensile resistance (IS). Is 30 g / d or more and the relationship with the elastic limit elongation (Δε) is IS ≧ (Δε + 0.6)
Satisfying ^-2.8 × 10 ³ +8 and having a three-dimensional crimp, the heat-bonding fiber is a sheath-core type two-component fiber, and the sheath component has a melting point (Tm ₁ ) of 160 ° C. to 220 ° C. ℃, T
The β dispersion peak temperature (Tβ) of an δ is −40 ° C. or lower, T
an an δ α dispersion rising temperature (Tαcr) is made of a polyester ether elastomer having a temperature of 50 ° C. or higher, and the core component is made of a non-elastomeric polyester having a melting point (Tm ₂ ) higher than Tm ₁ by 20 ° C. or more. Cushion material. 2. The content of matrix fiber in the cushion material is 5
The cushioning material according to claim 1, which is 0 to 95% by weight.