JP3233227B2 - Cushion material and its manufacturing method - 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 which is excellent in heat resistance and heat resistance, is light, hardly stuffy, has excellent elasticity, is recyclable, and is 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 used for all kinds of cushioning materials because it is excellent in heat resistance and resistance, elasticity, body shape retention, lightness and vibration absorption, and is easy to process and inexpensive. However, in recent years, soft urethane foam for cushions is difficult to recycle, it is difficult to generate poisonous gas during incineration, it is difficult to fill, and there is a problem of pollution, safety such as generation of halogen gas at the time of fire, and severe stuffiness. The problem of comfort has been said. On the other hand, cushion materials using polyester fibers as a base material are also known. Those using rubber or urethane as the adhesive component are difficult to recycle and have a problem of toxic gas during incineration.
Also, cushion materials using a polyester non-elastomeric low melting point polyester as an adhesive component are known. Since this cushion material uses a low-melting polyester, the heat resistance and the set resistance are remarkably inferior. Therefore, a proposal for improving the crystallinity of the low melting point polyester has also been made in Japanese Patent Application Laid-Open No.
As described in Japanese Patent Application Laid-Open No. H10-264, if it is non-elastomeric and undergoes deformation under heating, it is plastically deformed and does not recover, so that its heat resistance and heat resistance are inferior. The present inventors have made a proposal to use a polyester elastomer for an adhesion point and utilize the recoverability of the elastomer. However, there is a problem that the expected resilience is not sufficiently exhibited only by using the polyester elastomer for the adhesion point.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and has a heat-resistant, anti-shattering and elasticity which can replace polyurethane, and is light, hardly stuffy and recyclable, and is particularly suitable for vehicles. The material and its manufacturing method are not provided.

[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 to form an integral structure. It is a cushion material, and the bonding points formed by heat fusion make polytetramethylene glycol a soft segment.
Cushioning material and polytetramethylene comprising a crystallization-treated polyester elastomer having the same
A web obtained by mixing and opening the heat-bonding fiber (A) made of polyester and the polyester three-dimensional crimped yarn (B) having polyester as a heat-bonding component and having a polyester elastomer having lenglycol as a soft segment , and laminating the web. Compression molding, thermoforming at a temperature higher than the melting point of the polyester elastomer, cooling once, then applying compressive strain, and re-heat-treating at a temperature of at least 10 ° C or higher and lower than the melting point. It is.

The thermal adhesive component constituting the cushioning material of the present invention comprises polytetramethylene glycol as a soft segment.
Is a polyester elastomer having It is indispensable to recover the contact deformed by the rubber elasticity of the polyester elastomer and to develop the set resistance. The polyester elastomer referred to in the present invention includes, as hard segments, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polycyclohexylene dimethyl phthalate (PCHDT), and the like. Means polytetramethylene glycol (PTM
G). A particularly preferred combination is PBT-P
T M G, etc. PEN-PTMG can be exemplified.

The bonding points formed by the thermal bonding component of the cushioning material of the present invention need to be crystallized.
By melting the hard cotton molding above the melting point to form an adhesion point, after cooling, applying compression strain, and then re-heat-treating at least 10 ° C or higher and lower than the melting point, the heat resistance of the cushioning material is reduced. Significantly improved. Although the reason for this is not clear, the molecular chain of the elastomer is elongated by the application of compressive strain, the molecular chain of the hard segment is also oriented and easily crystallized, and then the soft segment is crystallized by heat treatment. It is speculated that the heat resistance and durability of the hard segment acting as a cross-linking point may be improved, plastic deformation may be suppressed, and the resilience may be improved.
When heat treatment is performed after compression at room temperature, the recoverability is significantly improved even in a short time treatment. Therefore, it is presumed that orientation is performed at room temperature, and heat treatment promotes crystallization. On the other hand, when the crystallization treatment is not performed, that is, when the crystallization treatment is simply performed after the heat fusion treatment, the heat resistance and the settling resistance are 3 times smaller than those of the oriented crystallization treatment.
0% or worse.

[0007] When the cushion material of the present invention is formed, the compression strain before the second-stage crystallization treatment is preferably at least 10% or more, more preferably 20% or more. Can be done. Unless the reheat treatment temperature is lower than the melting point by 10 ° C. or more, improvement in heat resistance and anti-settling property is not sufficient. The processing temperature is preferably 70 ° C. or higher and 20 ° C. lower than the melting point (Tm) obtained by differential thermal analysis (DSC). still,
The melting point of a preferable elastomer is 150 ° C. or more and 220 ° C. or less.

[0008] The thermal bonding fiber constituting the cushioning material of the present invention is a composite fiber comprising only a thermal bonding component or a core comprising polyester. It is not preferable because the efficiency of decomposition and monomer recovery during recycling containing other components is reduced. Preferably, at least 99% is composed of polyester. As the core material, known polyesters such as PET, PBT, PEN, PCHDT, various polyesters, and copolymerized polyesters thereof are used.

The matrix constituting the cushioning material of the present invention is a polyester fiber having a three-dimensional crimp. Known materials can be used for the polyester. If 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 components other than polyester, because the recovery efficiency in recycling is reduced. The base material of the cushion of the present invention is formed of a three-dimensional crimped yarn in order to make it bulky and light and to provide resilience. Mechanically wound crimped yarn has low bulk and poor rebound resilience. The preferred degree of crimp (Ci) of the three-dimensional crimp is 15% or more, more preferably 20%.
As described above, the preferred number of crimps is 10 pieces / inch or more, more preferably 15 pieces / inch or more, whereby a bulky material having excellent rebound resilience can be obtained.

The cross-section of the three-dimensionally crimped yarn is preferably a hollow fiber, and more preferably, a modified hollow fiber can improve the bending stiffness, so that the elasticity and the set resistance are improved.
In addition, the bulkiness is improved. It is preferable that the initial tensile resistance (IS) of the three-dimensionally wound yarn is high because the heat resistance and the rebound resilience are improved. More preferable IS in the cushion material is 35 g / denier or more and specific gravity is 1.395 or more. By setting such a high IS and a high degree of crystallinity, plastic deformation of crimping is reduced, and heat resistance and set resistance are improved. The denier of the three-dimensionally wound 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 thermal bonding fiber (A) and the matrix fiber (B) constituting the cushion material of the present invention is 5/9.
5-80 / 20 is preferred. When A is 5% or less, the shape retention is poor, which is not preferable. If B is less than 20%, the bulkiness is inferior, which is not preferable. In order to provide a soft feel in combination with the base material, the weight composition ratio of A is 5 to 50%, particularly 1
0-30%, to give a hard texture,
The composition ratio of A is preferably 20 to 80%, particularly preferably 30 to 50%.

The apparent density of the cushioning material of the present invention is not particularly limited, but if lightness (bulkness) is desired, 0.05 g
/ Cm ³ or less, and preferably 0.02 g / cm ³ or less when softness and bulkiness are desired. In the case of imparting such bulkiness, according to the method of the present invention, the first-stage fusion process during thermoforming is performed by compressing to a desired volume of 1/2 to 2/3, then cooling, and then performing a desired process. 100% to 1 of bulk
It is preferable to perform crystallization heat treatment after compression to 20%.

The following is an example of a method for producing the cushion of the present invention. The polyester elastomer is prepared by a known method, for example, by charging a small amount of dimethyl terephthalate and tetramethylene glycol and polytetramethylene glycol together with a catalyst and an antioxidant, subjecting them to transesterification and polycondensation.
-A PTMG block copolymer elastomer is obtained. Next, for example, sea core fiber is spun at 265 ° C. by a known composite spinning machine using PBT obtained by a conventional method as a core component. Melting point of polyester elastomer is 18
If the temperature is 0 ° C. or lower, the filaments will be fused together unless they are cooled and completed before the bundle is condensed. The undrawn yarn thus obtained is drawn at a temperature at which the polyelastomer does not fuse, and after imparting mechanical crimp,
It cuts and obtains the heat bonding fiber (A).

The base fiber is spun into an undrawn yarn by imparting latent crimpability to PET obtained by a known method, for example, a PET obtained by a conventional method by an asymmetric cooling method or a side-by-side method. At this time, a hollow nozzle or a modified hollow nozzle is preferably used. Then, it is drawn and cut by expressing a three-dimensional crimp, or after the cutting, a three-dimensional crimp is developed to obtain a base material fiber (B). Preferred stretching conditions are as follows: First stage: 60 ° C. to 90 ° C. hot bath;
DR) 0.75 times the MDR at the second stage at 130 to 180 ° C. and the third stage at 0.9 to 0.95 times the MDR at 210 ° C. to 230 ° C. . More preferably, in the fourth stage, the constant-length lower thread temperature is adjusted to the glass transition point (Tg).
After lowering to crimp expression treatment or cutting. In the crimp onset process, the crimp onset process is performed at about 160 ° C under a constraint close to a free state, and then heat-fixed at around 200 ° C under a condition close to the confinement, the heat resistance of the crimp is significantly improved. It is more preferable. The heat-bonded fiber (A) and the matrix fiber (B) thus obtained are preliminarily mixed with an opener at a mixing ratio of, for example, 30/70, then opened with a card, laminated, and laminated to obtain a web having a desired basis weight. Get. A known method such as air laying or air opening can be used for the opening.

Next, the material is continuously or cut as needed, 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. Preferred thermoforming temperature is 10 ° C or more and 30 ° C from the melting point
If it is set as follows, it will flow well and form a strong adhesion point (ball shape). If the temperature is higher than 30 ° C., the polyester elastomer is decomposed, and the recovery of the adhesion point is inferior. Then, after compression to a desired bulk of 100% to 120% without heating, re-heat treatment is performed at least at a temperature lower than the melting point by at least 10 ° C. to crystallize. By this treatment, the heat resistance and heat resistance of the cushion material are dramatically improved. The preferred processing temperature is 70
20 ° C lower than the melting point by 20 ° C or more, processing time is 5 minutes to 30 minutes
Within minutes is preferred. The larger the compressive strain applied before the treatment, the better, but it is better to determine the balance between the heat formation and the crystallization treatment within a range that gives the desired bulk.

The cushion material thus obtained is excellent in heat resistance and resistance to settling, light, resistant to stuffiness, has elasticity, and is excellent in vibration absorption, so that it is particularly suitable as a cushion material for vehicles. . Of course, it is also useful for furniture, beds, mattresses, etc. In addition, it is extremely useful as an interior material that utilizes 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 and polycondensed with a small amount of a catalyst and an antioxidant to produce a polyester elastomer. The resulting polyester elastomer was pelletized and vacuum-dried at 40 ° C. for 48 hours and used as a heat bonding component. Table 1 shows the processing method and melting point of the obtained polyester elastomer.

[0019]

[Table 1]

For comparison, dimethyl terephthalate (D
MT), dimethyl isophthalate (DMI), diethylene glycol (DEG), and a small amount of a catalyst.

Preparation of Thermal Bonding Fiber The sheath component is melted at 220 ° C. and discharged at a rate of 3 g / min.
The core component is a PBT with an intrinsic viscosity of 1.68 or an intrinsic viscosity (I
V) 0.63 PET was melted at 260 ° C. or 280 ° C., fed together at a discharge rate of 3 g / min, and spun from a 4-hole composite spinning nozzle at a spinning temperature of 265 ° C. or 285 ° C. Each of the filaments is oiled by one guide oiling device, then bundled and spun for fusion.
It was taken off at 0 m / min to obtain an undrawn yarn. Under the same conditions, an unstretched yarn containing only the 100% heat-adhesive component was melted at 220 ° C. under the same conditions except that only the heat-adhesive 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 obtained undrawn yarn was drawn in a warm bath at 60 ° C. at 0.8 times the cutting ratio (MDR). Next, the drawn yarn is combined into 2 deniers, mechanically crimped with a crimper, and the cut staples are
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 0.63 IV is spun at 285 ° C. from a C-type or Y-U type nozzle at a discharge rate of 6 g / min per hole, and rapidly cooled from 30 mm immediately below the nozzle to an air stream of 2 m / sec. 1080m /
The undrawn yarn taken in one minute is 0.7 times the MDR at 80 ° C in the first stage, 0.85 times the MDR at 160 ° C in the second stage, 0.95 times the MDR at 220 ° C in the third stage, At the fourth stage, the yarn temperature was lowered to room temperature and wound. 64 m of drawn yarn obtained
The properties of the mother material obtained by cutting into pieces at 160 ° C., developing crimp at 160 ° C. after opening, then slightly compressing and re-heat-treating at 200 ° C. are shown in Table 3.

[0024]

[Table 3]

Preparation of Cushion Material The obtained heat-bonded fibers were mixed with a base material in a 30/70 weight ratio with an opener, and the pre-spread cotton blend was spread with a card and laminated to 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 of 10 ° C. or more higher than the thermal bonding component for 5 minutes, cooled to a thickness of 5 cm, and then compressed to a thickness of 5 cm, and crystallized at 130 ° C. for 15 minutes. After processing and cooling, a cushion material was obtained. For comparison, a cushion material which was compressed in one step to a thickness of 5 cm and was thermoformed only was also prepared. The obtained cushioning material is apparent bulk after one day,
The heat resistance at 70 ° C. and the 50% compression rebound and rebound resilience were evaluated. Table 4 shows the results.

The cushioning material was evaluated by the following method. 70 ° C heat and heat resistance Cushion material cut to 15cm x 15cm, 50%
Compressed and left in a dry heat at 70 ° C. for 22 hours, then cooled to remove the strain, left standing for 1 day, and compressed the recovered thickness (li) before processing.
It was determined by the ratio (li / lo) to the thickness (lo) × 100%. Average value of n = 3 50% compression repulsion The cushioning material was cut into 20 cm × 20 cm, and the resilience 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 the average value of n = 3. Rebound resilience According to JIS K 6382, rebound resilience test method.

[0027]

[Table 4]

[0028]

The cushioning material of the present invention thus obtained is excellent in heat resistance and settling resistance, lightly resistant to stuffiness, elastic, and excellent in vibration absorption. Since it can be replaced, it is useful for solving environmental problems. Of course, it is also useful for applications such as furniture, beds, mattresses, and thermal insulation.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B68G 1/00 B68G 7/02 D04H 1/54

Claims (2)

(57) [Claims] 1. A matrix fiber and a heat bonding fiber are mixed and dispersed,
The adhesive component of the heat-bonded fiber is melted by thermoforming to form a bonding point of the fiber, and the cushioning material is integrally structured. The bonding point formed by the heat fusion is a polytetramethylene group.
A cushioning material comprising a crystallized polyester elastomer having recall as a soft segment . 2. Polytetramethylene glycol is softened
Thermal bonding fiber (A) made of polyester using polyester elastomer having segments as a thermal bonding component
And polyester three-dimensional crimped yarn (B) are mixed and opened, and the laminated web is compressed, thermoformed at a temperature higher than the melting point of the polyester elastomer, cooled once, and then subjected to compression strain. A method for producing a cushioning material, comprising re-heating at a temperature of 10 ° C. or higher and lower than a melting point.