JPH05261184A - Cushion material and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve thermal/fatigue and resiliency by taking crystallized polyester elastomer as an adhesive point formed by heat fusion at the time of mixing and dispersing base material fiber and heat adhesive fiber and melting adhesive components of the heat adhesive fiber by thermomolding to form an adhesive point of the fiber. CONSTITUTION:The composition ratio A/B of heat adhesive fiber A to base material fiber B for forming a cushion maternal is preferably 5/95-80/20. If A is 5% or less, the form retaining ability is deteriorated, and if B is 20% or less, bulkiness is deteriorated. In order to apply soft feeling by combination with the base material, the weight composition ratio of A is 5-20%, and in order to impart hard feeling, the composition ratio of A is 20-80%. Further, it is necessary to crystallize an adhesive point formed by the heat adhesive component of the cushion material. Steel wool mold is molten above the melting point to form an adhesive point, and once cooled, and compressive strain is applied thereto, and then re-heat treatment is performed at a temperature lower than the melting point by 10 deg.C or more to improve the thermal/fatigue resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushioning material which is excellent in heat and settling resistance, light in weight, resistant to stuffiness, excellent in elasticity and recyclable, and particularly suitable for vehicles, and a method for producing the same.

[0002]

2. Description of the Related Art Polyurethane is known as a cushion material for vehicles. Polyurethane is excellent in heat sink resistance, elasticity, shape retention, lightness, and vibration absorption, and is easy and inexpensive to process, so it is used for all cushioning applications. However, in recent years, soft foamed urethane for cushions is difficult to recycle, toxic gas is generated when incinerated, it is difficult to populate it, and pollution such as halogen gas is generated at the time of fire, safety issues, and significant stuffiness etc. The issue of comfort is said. On the other hand, a cushion material using polyester fiber as a base material is also known. Those that use rubber or urethane as an adhesive component are difficult to recycle and have the problem of toxic gas when incinerated.
Also, a cushion material using a low melting point polyester which is a polyester non-elastomer as an adhesive component is known. Since this cushion material uses a low-melting point polyester, it is extremely inferior in heat and settling resistance. Therefore, a proposal for improving the crystallinity of the low melting point polyester is also disclosed in JP-A-57-101018.
As disclosed in Japanese Patent Laid-Open Publication No. 2003-187, since it is a non-elastomer, it is plastically deformed and does not recover when it is deformed under heating, and therefore the heat and fatigue resistance are inferior. The present inventors have proposed to use the recoverability of the elastomer by using a polyester elastomer at the adhesion point. However, there is a problem in that the expected recovery force is not sufficiently expressed by simply using the polyester elastomer for the adhesion points.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems and has a heat-resistant settling-resistant elasticity which replaces polyurethane, and is lightweight, resistant to stuffiness, and recyclable, and particularly suitable for vehicles. The purpose is to provide wood and its manufacturing method.

[0004]

According to the present invention, a matrix 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 bonding point of the fiber, thereby forming an integrated structure. A cushion material, wherein the adhesive points formed by heat fusion are made of a crystallization-treated polyester elastomer, and a cushion material and a thermal adhesive fiber (A) made of polyester having a polyester elastomer as a thermal adhesive component and a polyester solid The crimped yarn (B) is mixed and opened using the base material, the laminated web is compressed, thermoformed at a temperature higher than the melting point of the polyester elastomer, and once cooled,
Then, a compressive strain is applied, and then a reheat treatment is performed at a temperature of at least 10 ° C. and lower than the melting point, which is a method for producing a cushion material.

The heat-adhesive component constituting the cushioning material of the present invention is a polyester elastomer. It is indispensable for recovering the contact deformed by the rubber elasticity of polyester elastomer and developing the set resistance. Examples of the polyester elastomer referred to in the present invention include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycyclohexylene dimethyl phthalate (PCHDT), and the like as the hard segment. Is polytetramethylene glycol (PTMG),
Polyhexamethylene glycol (PHMG), polypropylene glycol (PPG), polycaprolactam (P
CL) etc. can be illustrated. A particularly preferred combination is PBT-PTHG, PEN-PTMG, PBT-P.
CL etc. can be illustrated.

The bonding points formed by the heat bonding component of the cushion material of the present invention must be crystallized.
Cushion molding is melted above the melting point to form an adhesive point, and after cooling for a while, compressive strain is applied and then reheat treatment is performed at a temperature of at least 10 ° C and lower than the melting point, so that the cushioning material has a high heat and fatigue resistance. Remarkably improved. The reason for this is not clear, but the molecular chain of the elastomer is elongated by applying compressive strain, the molecular chain of the hard segment is also oriented and easily crystallized, and then by heat treatment to crystallize the soft segment. It is presumed that the heat resistance and durability of the hard segment acting as a cross-linking point may be improved, the plastic deformation is suppressed, and the recovery force is improved.
Since heat recovery after compression at room temperature significantly improves recovery even after a short time treatment, it is presumed that crystallization is promoted by orienting at room temperature and heat treatment. On the other hand, in the case where the crystallization treatment is not performed, that is, in the case of simply cooling after the heat fusion treatment, the heat-resistant settling resistance is 3% higher than that of the orientation crystallization treatment.
0% or more inferior.

When the cushioning material of the present invention is molded, the compressive strain before the second crystallization treatment is preferably at least 10% or more, more preferably 20% or more. Can be made If the reheat treatment temperature is not lower than the melting point by 10 ° C. or more, the improvement in heat resistance and sag resistance is not sufficient. The preferable treatment temperature is 70 ° C. or higher, and the temperature is 20 ° C. lower than the melting point (Tm) obtained by differential thermal analysis (DSC). still,
A preferable melting point of the elastomer is 150 ° C. or higher and 220 ° C. or lower.

The heat-bonding fibers constituting the cushioning material of the present invention are composed of only heat-bonding components, or the core material is a composite fiber made of polyester. It is not preferable because the efficiency of decomposition and monomer recovery at the time of recycling containing other components decreases. Preferably at least 99% is composed of polyester. As the core material, known polyesters such as PET, PBT, PEN, PCHDT, various polyesters and copolyesters thereof are used.

The base material constituting the cushion material of the present invention is a polyester fiber having a three-dimensional crimp. Known materials can be used for the polyester. When heat resistance is required,
It is preferable to use PET, PEN, PCHDT or the like. It is not preferable to contain a large amount of other components other than polyester, because the recovery efficiency in recycling is lowered. The base material of the cushion of the present invention is composed of three-dimensional crimped yarns in order to make it bulky and light, and to impart repulsive elasticity. Mechanically crimped yarn has low bulk and poor resilience. The preferred crimping degree (Ci) of three-dimensional crimping is 15% or more, more preferably 20%.
As described above, the preferred number of crimps is 10 or more, and more preferably 15 or more, whereby a product having bulkiness and excellent resilience can be obtained.

The cross-section of the three-dimensional crimped yarn is preferably a hollow fiber, and more preferably a deformed hollow fiber can improve the bending rigidity and thus impart elasticity and settling resistance.
In addition, bulkiness is also improved. The higher the initial tensile resistance (IS) of the three-dimensional crimped yarn, the better the heat-resistant settling resistance and the rebound resilience. The more preferred IS in the cushion material is 35 g / denier or more and the specific gravity is 1.395 or more. With such a high IS and crystallinity, the plastic deformation of the crimp is reduced, and the heat and fatigue resistance are improved. The denier of the three-dimensional crimped yarn is preferably 4 to 8 denier when softness is desired and 8 to 20 denier when hardness is desired.

The composition ratio (A / B) of the heat-bonding fiber (A) and the base material fiber (B) constituting the cushioning material of the present invention is 5/9.
5-80 / 20 is preferable. When A is 5% or less, the shape retention is inferior, which is not preferable. When B is 20% or less, the bulkiness is inferior, which is not preferable. In order to give a soft texture in combination with the base material, the weight composition ratio of A is 5 to 50%, especially 1
It is 0 to 30%, and in order to give a hard texture,
The composition ratio of A is preferably 20 to 80%, particularly 30 to 50%.

The apparent density of the cushion material of the present invention is not particularly limited, but when lightness (bulkness) is desired, it is 0.05 g.
/ Cm ³ or less is preferable, and when it is desired to be soft and bulky, it is preferably 0.02 g / cm ³ or less. In the case of imparting such a bulkiness, in the method of the present invention, the first-stage fusion treatment at the time of thermoforming is performed by compressing to a desired bulk of 1/2 to 2/3, and then, after cooling, the desired bulkiness is obtained. 100% to 1 of bulk
It is preferable to perform crystallization heat treatment after compressing to 20%.

An example of the method for producing the cushion of the present invention will be described below. The polyester elastomer may be prepared by a known method, for example, by adding dimethyl terephthalate, tetramethylene glycol and polytetramethylene glycol together with a small amount of a catalyst and an antioxidant, transesterifying them, and then polycondensing them to obtain PBT.
A PTMG block copolymer elastomer is obtained. Then, for example, using PBT obtained by a conventional method as the core component, the sheath core fiber is spun at 265 ° C. by a known composite spinning machine. The melting point of polyester elastomer is 18
If the temperature is 0 ° C. or lower, the filaments will be fused unless they are cooled and wound before they are bundled. The unstretched yarn thus obtained is stretched at a temperature at which the polyelastomer does not fuse, and after mechanical crimping,
It cut | disconnects and a heat-bonding fiber (A) is obtained.

The matrix fiber is prepared by a known method, for example, PET obtained by a conventional method is imparted with a latent crimping ability by an asymmetric cooling method or a side-by-side method to spin an undrawn yarn. At this time, a hollow nozzle or a modified hollow nozzle is preferably used. Next, the base material fiber (B) is obtained by drawing and developing a three-dimensional crimp and cutting it, or expressing the three-dimensional crimp after cutting. The preferred stretching conditions are a first stage 60 ° C. to 90 ° C. hot bath and a cutting ratio (M
(DR) 0.7 times, the second step is 0.85 times MDR at 130 to 180 ° C, and the third step is 0.9 to 0.95 times MDR at 210 ° C to 230 ° C. .. More preferably, the constant length bobbin temperature is set to the glass transition point (Tg) in the fourth step.
After lowering it to the crimp expression processing or cutting. When the crimping expression treatment is performed at 160 ° C under a contracted condition close to the free state, and then heat-set at 200 ° C before and after the contracted condition, the heat shrinkage resistance of the crimp is remarkably improved. Therefore, it is more preferable. The heat-bonded fiber (A) thus obtained and the base material fiber (B) are mixed by an opener at a mixing ratio of, for example, 30/70, pre-opened, then opened by a card and laminated to obtain a web having a desired fabric weight. To get A known method such as air ray or air opening can be used for the opening.

Then, continuously or if necessary, cut, compressed to 1/2 to 2/3 of the desired bulk, thermoformed at a temperature not lower than the melting point of the polyester elastomer, and cooled for a while. The preferred thermoforming temperature is 10 ° C or higher and 30 ° C or higher than the melting point.
When it is set to the following, it flows well and forms a strong bonding point (ball-shaped). If the temperature is higher than 30 ° C., the polyester elastomer is decomposed and the recovery of the adhesive point is poor, which is not preferable. Next, after compression to a desired bulk of 100% to 120% without heating, reheat treatment is performed at a temperature at least 10 ° C. lower than the melting point to crystallize. By this treatment, the heat and fatigue resistance of the cushion material is dramatically improved. The preferred processing temperature is 70
℃ or more and 20 ℃ lower than melting point, treatment time is 5 minutes to 30
Within minutes is preferable. The larger the compressive strain applied before the treatment is, the more preferable, but it is preferable to determine the balance between the heat formation and the crystallization treatment in a range so as to obtain a desired bulk.

The cushion material thus obtained is particularly suitable as a cushion material for vehicles because it has excellent heat and fatigue resistance, is light, does not easily get stuffy, has elasticity, and has excellent vibration absorption. .. Of course, it is also useful for applications such as furniture, beds, and mattresses. In addition, it is also extremely useful as an interior material that makes use of the characteristics of vibration absorption.

[0017]

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

Examples and Comparative Examples Preparation of Thermal Adhesive Component Dimethyl terephthalate (DMT) or dimethyl naphthalate (DMN) and 1.4 butanediol (1.4B).
D) and polytetramethylene glycol (PTMG) were charged together with a small amount of a catalyst and an antioxidant and polycondensed to produce a polyester elastomer. The produced polyester elastomer was pelletized and vacuum dried at 40 ° C. for 48 hours, which was used as a heat-adhesive component. Table 1 shows the treatment method and melting point of the obtained polyester elastomer.

[0019]

[Table 1]

For comparison, dimethyl terephthalate (D
Table 1 also shows the processing method and melting point of the low-melting point non-elastomeric polyester obtained by charging polycondensation with MT), dimethyl isophthalate (DMI), diethylene glycol (DEG) and a small amount of a catalyst.

Preparation of heat-bonded fiber The sheath component is melted at 220 ° C. and discharged at 3 g / min.
The core component is PBT having an intrinsic viscosity of 1.68 or an intrinsic viscosity (I
V) PET of 0.63 was melted at 260 ° C. or 280 ° C., co-fed at a discharge rate of 3 g / min, and spun at a spinning temperature of 265 ° C. or 285 ° C. from a 4-hole composite spinning nozzle. For each filament, one guide oiling device is used for oiling, then focusing and spinning for fusion.
It was taken out at 0 m / min to obtain an undrawn yarn. Only the heat-bonding component of R-3 was melted at 220 ° C. and spun at a discharge rate of 6 g / min from a 4-hole round nozzle at 220 ° C. Obtained. The undrawn yarn thus obtained was drawn in a 60 ° C. hot bath at a cutting ratio (MDR) of 0.8 times. Then, the drawn yarn is combined into 2 denier, mechanical crimp is applied with a crimper, and the cut staple is cut into 4 pieces.
Table 2 shows the properties of the heat-bonded fibers obtained by free treatment with hot air at 0 ° C.

[0022]

[Table 2]

Preparation of base material PET of IV0.63 was spun at 285 ° C. from a C-type nozzle and a Y-U type nozzle at a discharge rate of 6 g / min per single hole, and rapidly cooled from 30 mm directly below the nozzle with an air stream of 2 m / sec. Then 1080m /
The unstretched yarn collected in minutes is 0.7 times the MDR at 1st stage 80 ° C, 0.85 times the MDR at 2nd stage 160 ° C, 0.95 times the MDR at 3rd stage 220 ° C, The yarn temperature was lowered to room temperature with the fourth length fixed length and the yarn was wound. 64 m of the obtained drawn yarn
Table 3 shows the characteristics of the mother obtained by cutting into m, developing crimps at 160 ° C. after opening, then slightly heat-treating at 200 ° C.

[0024]

[Table 3]

Preparation of cushioning material The obtained heat-bonded fibers were mixed with the base material in a weight ratio of 30/70 by an opener, pre-opened mixed cotton was opened with a card, and laminated with a basis weight of 1500 g / m ² . The mixed fiber web is compressed to a thickness of 10 cm, thermoformed with hot air at a temperature 10 ° C or more higher than the heat-adhesive component for 5 minutes, cooled for a while and then compressed to a thickness of 5 cm, and crystallized at 130 ° C for 15 minutes. It processed and cooled and the cushion material was obtained. For comparison, a cushion material which was compressed by one step to a thickness of 5 cm and only thermoformed was prepared. The obtained cushion material has an apparent bulk after standing for 1 day,
The 70 ° C heat-resistant settling resistance, 50% compression repulsion force and impact resilience were evaluated. The results are shown in Table 4.

The cushion material was evaluated by the following method. 70 ℃ heat and fatigue resistance Cushion material is cut into 15cm × 15cm, 50%
Compressed to 70 ° C. dry heat stroke 22 hours left to after cooling remove strain, 1 day left after compressing pretreating the recovered thickness (li)
The thickness (lo) and the ratio (li / lo) × 100%. The average value of n = 3 50% compression repulsion force The cushioning material was cut into 20 cm × 20 cm, and the repulsion force when compressed to 50% with a φ150 mm compression plate was measured using Tensilon, and the value is shown in kg. It was determined as an average value of n = 3. Impact resilience According to JISK-6382, Impact resilience test method.

[0027]

[Table 4]

[0028]

The thus obtained cushioning material of the present invention is excellent in heat and fatigue resistance, lightly stuffy, has elasticity, and is excellent in vibration absorption. Since it can be substituted, it is useful for solving environmental problems. Of course, it is also useful for applications such as furniture, beds, duvets, and heat insulating materials.

Claims (2)

[Claims] 1. A base material fiber and a heat bonding fiber are mixed and dispersed,
It is a cushion material that has an integrally structured structure in which the adhesive components of the heat-bonded fibers are melted by thermoforming to form the bond points of the fibers, and the bond points formed by heat fusion are made of a crystallization-treated polyester elastomer. Cushion material to be used. 2. A heat-bonding fiber (A) made of polyester having a polyester elastomer as a heat-bonding component and a polyester three-dimensional crimped yarn (B) are mixed and opened, and the laminated web is compressed to obtain a polyester elastomer. A process for producing a cushioning material, which comprises thermoforming at a temperature higher than the melting point, once cooling, then applying compressive strain, and then performing reheat treatment at a temperature of at least 10 ° C. and lower than the melting point.