JP2003089960A - Flame retardant net-shaped cushion material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flame retardant net-shaped cushion material without containing any flame retardant, having a light weight and showing less permanent set in fatigue. SOLUTION: This flame retardant net-shaped cushion material consists of a three dimensional net-shaped structural material having 0.005-0.200 g/cm<3> apparent density and is obtained by winding multiple continuous thready materials having >=300 denier fineness and containing a thermoplastic polyester elastomer and thermoplastic polyurethane elastomer as the thermoplastic elastomer in a loop state and also meltadhering each of the loops each other at their contact parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to furniture, vehicle seats,
The present invention relates to a flame-retardant reticulated cushioning body made of a thermoplastic elastomer that is easily recycled and is used for seats for ships, seats for airplanes, and the like.

[0002]

2. Description of the Related Art At present, most seat cushions are made of thermosetting urethane foam, which makes recycling difficult. Therefore, there is a demand for a recyclable cushion body.

Hitherto, as a recyclable cushion body, a main fiber and a binder fiber are mixed and opened.
There is known a fiber cushion body obtained by heating the binder fibers to a temperature higher than the melting temperature to bond the mutual contact points. However, such a fiber cushion body is inferior in terms of cushioning property, and when it is used for a long period of time, it causes a settling, so that it has not been widely accepted in the market.

As a recyclable cushion body, a reticulated cushion body using a thermoplastic polyester elastomer is also provided on the market. This net-like cushion body has improved fatigue as compared with the fiber cushion body. However, in a vehicle seat application where flame retardancy is required, a flame-retardant agent must be added to produce a reticulated cushioning body, which causes a problem of environmental pollution due to thermal decomposition of the flame-retardant agent during recycling. Further, the thermoplastic polyester elastomer is inferior in moldability, and there is room for improvement in the performance of the reticulated cushion body using the same.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a flame-retardant reticulated cushioning body which can be easily recycled because it can impart flame retardancy without adding a flame retardant, and is lightweight and less susceptible to settling. Especially.

[0006]

The flame-retardant reticulated cushion body of the present invention comprises a plurality of continuous linear bodies having a fineness of 300 denier or more containing a thermoplastic polyester elastomer and a thermoplastic polyurethane elastomer as a resin component and bent in a loop shape. The apparent density is 0.005 to 0.200 g, in which the loops are twisted and each loop is fused at the contact portion.
It is characterized in that it is composed of a three-dimensional net-like structure of / cm ³ .

In the present invention, as the resin component of the continuous linear body, it is preferable to use a mixture of 20 to 50% of thermoplastic polyester elastomer and 80 to 50% of thermoplastic polyurethane elastomer.

In the present invention, as the thermoplastic polyurethane elastomer, it is preferable to use one obtained by reacting a polyol component, an isocyanate component and a chain extender, and particularly as the chain extender, the following general formula (1) is used.

[Chemical 2]

(Where R ₁ and R ₂ are-(CH ₂ ).
_{n -, - O- (CH 2} ) m -, - CO- (CH 2) m - and -COO- (CH _{2) m} - is selected from the group consisting of, n
Is 1 to 4 and m is 1 to 3. It is preferable to use the one represented by (4).

Specific examples of the thermoplastic polyurethane elastomer include polytetramethylene glycol as a polyol component, 4,4-diphenylmethane diisocyanate as an isocyanate component, and 1,4-bis (β-hydroxyethoxy) benzene as a chain extender.
1,4-bis (β-hydroxyethyl) terephthalate, 1,4-bis (β-hydroxyethyl) benzene,
Examples thereof include those obtained by reacting 1,4-bis (γ-hydroxypropyl) benzene or 1,4-bis (3-hydroxy-1-oxypropyl) benzene.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A net-like cushion body according to the present invention has a structure in which a plurality of continuous linear bodies made of resin and having a fineness of 300 denier or more are meandered in a loop shape, and the loops are fused to each other at their contact portions. And has a three-dimensional network structure, and is characterized in that a thermoplastic polyester elastomer and a thermoplastic polyurethane elastomer are used as the thermoplastic elastomer forming the continuous linear body. Since the thermoplastic polyurethane elastomer exhibits flame retardancy, it is not necessary to add a flame retardant to the reticulated cushion body of the present invention.

Examples of the thermoplastic polyester elastomer include a polyester ether block copolymer having a thermoplastic polyester as a hard segment and a polyalkylene glycol as a soft segment, or a polyester ester block copolymer having an aliphatic polyester as a soft segment. Is mentioned.

As the thermoplastic polyurethane elastomer, those obtained by reacting a polyol component, an isocyanate component and a chain extender can be preferably used. For example, a thermoplastic polyurethane elastomer synthesized by a method (prepolymer method) of adding a chain extender to an intermediate (prepolymer) having a terminal NCO structure in which a polyol and an isocyanate are preliminarily reacted can be mentioned. An appropriate amount (10-1000 ppm) of catalyst may be added to control this reaction. Examples of the catalyst include amine catalysts such as tertiary amine, triethylenediamine, ethylmorpholine and tin catalysts such as tin octylate and dibutyltin laurate.

Polytetramethylene glycol (PTMG) is a typical polyol component, and 4,4-diphenylmethane diisocyanate (MDI) is a typical isocyanate component.

As the chain extender, those represented by the above general formula (1) can be preferably used. The chain extender represented by the general formula (1) has a benzene ring at the center, and a substituent having a terminal hydroxyl group is introduced at the 1,4-position (para position) of the benzene ring to form a benzene ring and a hydroxyl group. The linking groups R ₁ and R ₂ between are — (CH ₂ ) _n —, —O— (CH ₂ ) _m —, and —C.
O- (CH _{2) m} - and -COO- (CH _{2) m} - is one selected from the group consisting of. When the linking group is a linear carbon chain, the number m of methylene groups is 1 to 4, and when the linking group is a carbon chain containing an oxygen atom, the number m of methylene groups is 1 to 1.
It is preferably 3.

Specific examples of suitable chain extenders include 1,4
-Bis (β-hydroxyethoxy) benzene (BHE
B), 1,4-bis (β-hydroxyethyl) terephthalate (BHET), 1,4-bis (β-hydroxyethyl) benzene, 1,4-bis (γ-hydroxypropyl) benzene, 1,4-bis (3-hydroxy-1-oxypropyl) benzene and the like can be mentioned.

A reticulated cushion body produced by using a chain extender other than the one represented by the general formula (1), for example, an aliphatic diol, or a thermoplastic polyurethane elastomer containing a diol having bisphenol at the center, Since sufficient hardness cannot be obtained, it is difficult to reduce the weight, and the settling resistance tends to be insufficient.

In the present invention, the thermoplastic elastomer forming the continuous linear body is preferably a mixture of 20 to 50% by weight of a thermoplastic polyester elastomer and 80 to 50% by weight of a thermoplastic polyurethane elastomer. Blending ratio of thermoplastic polyester elastomer is 20
If it is less than wt% (the blending ratio of the thermoplastic polyurethane elastomer is more than 80 wt%), sufficient hardness cannot be obtained, and it is difficult to reduce the weight of the reticulated cushion body. If the blending ratio of the thermoplastic polyester elastomer exceeds 50% by weight (the blending ratio of the thermoplastic polyurethane elastomer is less than 50% by weight), the settling resistance and flame retardancy of the reticulated cushion will be insufficient.

The flame-retardant reticulated cushion body according to the present invention is
It can be manufactured by the following method. The thermoplastic elastomer is supplied to the extruder and melted, adjusted to, for example, a temperature 30 ° C. to 50 ° C. higher than the melting point of the resin, and discharged downward from a plurality of nozzles provided in the die. The thermoplastic elastomer falls freely as a continuous linear body without interruption. Below the die, for example, a pair of take-up conveyors made of a flexible metal net made of metal such as stainless steel stretched over rollers are provided, and a cooling liquid such as water is also provided. The upper part of the take-up conveyor is exposed on the surface of the cooling liquid, and the lower part is immersed in the cooling liquid. When the molten thermoplastic elastomer falls into the cooling liquid between the take-up conveyors as a continuous linear body of the number corresponding to the number of nozzles, it forms a random loop while winding, and the loops come into contact with each other and the contact portion becomes As a result of fusing, a three-dimensional network structure is obtained. Then, the network structure is hardened in the cooling liquid, and the fusion-bonded portion of each loop is fixed. The obtained reticulated structure is annealed if necessary and cut into a predetermined size to obtain a reticulated cushion body.

Incidentally, in the case of manufacturing a mesh cushion body having a complicated shape such as a seat of an automobile, it is disclosed in Japanese Patent Laid-Open No. 2000-
The method described in 248455 can be used.
This method is provided with first and second guide means for forming shaping guide surfaces in the thickness direction and the width direction, respectively, according to the contour of the cross-sectional shape of the net-like cushion body to be molded. From the above, a net-like structure is obtained in the same manner as described above while being brought inward. The above-mentioned guide portion has two pairs of rollers having an uneven shape corresponding to the shape of the mesh cushion body to be molded in the thickness direction (or width direction), and a pair of flexible rollers stretched between the pair of upper and lower rollers. It consists of a flexible endless belt. Each of these rollers has a curved outer peripheral surface corresponding to the contour of the cross-sectional shape of the mesh cushion body to be molded. By the endless belt running endlessly between the upper and lower rollers, each belt has an outer peripheral surface. The shaped guide surface is formed by deforming into a shape corresponding to the surface.

The net-like cushion body according to the present invention absorbs stress while the whole net-like structure deforms three-dimensionally even if it is deformed by a large stress during use, and when the stress is released, the thermoplastic elastomer is released. Due to the rubber elasticity of, the network structure can be restored to its original shape.

In the present invention, the fineness of the continuous linear body is 30.
The definition of 0 denier or more is because when the fineness is less than 300 denier, the strength of the reticulated cushion body is reduced and the repulsion force is reduced. However, the fineness of the continuous linear body is 100.
If it exceeds 000 denier, the number of continuous linear members per unit volume decreases, and the compression characteristics deteriorate, which is not preferable. Therefore, in order to obtain a preferable repulsive force as the mesh cushion body, the fineness of the continuous linear body is 300 denier or more, preferably 400 denier or more, 10000.
It is set to 0 denier or less, and more preferably 500 to 50,000 denier.

In the present invention, the apparent density of the reticulated cushion is defined as 0.005 to 0.200 g / cm ³ for the following reason. That is, when the apparent density is less than 0.005 g / cm ³ , the repulsive force is lost, so that the mesh cushion is not suitable. On the other hand, if the apparent density exceeds 0.20 g / cm ³ , the resilience becomes too strong and the sitting comfort becomes poor, so that it is also unsuitable as a mesh cushion body. A more preferable apparent density is 0.
It is not less than 01 g / cm ^{3 and not} more than 0.05 g / cm ³ .

[0024]

EXAMPLES In each of the following examples, a mesh cushion body was manufactured as follows. Commercially available or synthetic
Pellets of thermoplastic polyester elastomer and thermoplastic polyurethane elastomer were prepared. For example,
Pellets of the synthesized thermoplastic polyurethane elastomer were prepared as follows. That is, by a prepolymer method, a chain extender is added to a prepolymer having a terminal NCO structure in which a polyol and an isocyanate are preliminarily reacted to synthesize a thermoplastic polyurethane elastomer, and after aging to complete the reaction, a pelletizer is used. Used to obtain pellets.

On the other hand, the following equipment was used as a manufacturing apparatus. Width 10 cm, length 60 cm at the tip of the extruder
A die in which nozzles having a hole diameter of 0.7 mm were arranged at a nozzle pitch of 7 mm was attached to the nozzle effective surface of the above. A water tank was provided below the die to contain cooling water set at 25 ° C. so that the water surface was 25 cm below the die surface. A pair of endless nets made of stainless steel having a width of 80 cm were stretched over two pairs of rollers, which are paired up and down, and were arranged in parallel at intervals of 8 cm in a water tank and used as a take-up conveyor. The upper part of the take-up conveyor is exposed above the water surface,
The lower part is immersed in water.

Pellets of the thermoplastic polyester elastomer and the thermoplastic polyurethane elastomer are premixed at a predetermined mixing ratio and supplied to an extruder, heated to a temperature equal to or higher than the melting temperature of the resin to be melted, and then a net-like shape to be obtained. Depending on the apparent density of the cushion body, the single hole discharge rate is 0.5-
It was adjusted to 1.5 g / min and discharged from the nozzle. A large number of continuous linear bodies discharged from the nozzle are taken by a take-up conveyor, and while the contact portions of the loops of the continuous linear bodies are being fused, the continuous linear bodies are drawn into water at a speed of 1 m / min and cured to form a continuous block. A net-like structure was obtained. This reticulated structure was cut into a predetermined size and annealed to improve distortion, thereby producing a reticulated cushion.

Regarding the obtained mesh cushion, JIS
The following tests were carried out according to K6400 to evaluate the physical properties.

Apparent density: A test piece of 100 × 100 × 100 mm was cut out from a block-shaped mesh cushion body. The volume and weight were measured to obtain the apparent density. The table below shows the average value of n number 4. In the following examples, the net-like cushion having an apparent density of 50 kg / m ³ (0.05 g / cm ³ ) was adjusted by adjusting the single hole discharge rate and the take-up speed so that the data can be easily compared. Manufactured body.

Hardness (25% compression hardness): A 400 × 400 × 50 mm test piece was cut out from a block-shaped mesh cushion body. According to the method of JIS K6400, the load (reaction force) when the test piece was compressed to 25% with a disc having a diameter of 20 cmφ was measured.

50% compression residual strain: A test piece having a size of 100 × 100 × 100 mm was cut out from a block-shaped mesh cushion body. According to the method of JIS K6400, the residual strain after compressing the sample to 50% was measured. The table below shows the average value of n number 4.

Flammability: A test piece of 100 × 360 × 13 mm was cut out from a block-shaped mesh cushion body. Flammability was measured by the method of JIS K6400. In the table below, the average values of n number 5 are displayed.

In each of the examples, the evaluation was performed on the basis of the physical properties required for the seat cushion body. Here, the compression residual strain is 15% or less from the viewpoint of fatigue resistance,
From the viewpoint of weight reduction, the hardness is 180 N / 314 cm ² or more,
From the viewpoint of flame retardancy, those showing self-extinguishing property are judged to be reticulated cushions having particularly good physical properties.

Example 1 In this example, the kind of the thermoplastic polyester elastomer was changed and the influence on the physical properties of the mesh cushion was examined.

As the thermoplastic polyester elastomer, any one of the following five kinds of Toyobo's perprenes (TPEE1 to 5) corresponding to the required hardness of the mesh cushion was used. The hardness of these thermoplastic polyester elastomers is adjusted by the ratio of the soft segment (PTMG) and the hard segment (PBT). These Shore D hardnesses (catalog values) are also shown. That is, the smaller the product number, the smaller the proportion of hard segments and the larger the proportion of soft segments.

[0035] TPEE1: Perprene P-70B Shore D hardness 46 TPEE2: Perprene P-90B Shore D hardness 52 TPEE3: Perprene P-150B Shore D hardness 57 TPEE4: Perprene P-280B Shore D hardness 68 TPEE5: Perprene E-450B Shore D hardness 78.

The thermoplastic polyurethane elastomer is a commercially available polytetramethylene glycol (PTMG # 1000, polyol component constituting the soft segment).
2.5 kg of average molecular weight 1000 g / mol), 1.75 kg of commercially available 4,4-diphenylmethane diisocyanate (MDI) as an isocyanate component, and commercially available 1,4-bis (β-hydroxyethoxy) benzene (BHEB) 0 as a chain extender. It was synthesized by the prepolymer method using 0.75 kg. This thermoplastic polyurethane elastomer is designated as TPUE1. Note that the blending ratio of each component may require fine adjustment depending on the chemical equivalent. Moreover, you may add a deterioration inhibitor as needed.

According to the above-mentioned manufacturing method, 30% by weight of the pellets of the thermoplastic polyester elastomer and 70% by weight of the pellets of the thermoplastic polyurethane elastomer are premixed and supplied to the extruder and melted at 230 to 245 ° C. to form a reticulated cushion body. Obtained. As described above, the single-hole discharge amount and the take-up speed were adjusted so that the apparent density of the reticulated cushion body was 50 kg / cm ³ . The reticulated cushion body thus obtained was annealed at 100 ° C. for 24 hours. Table 1 shows the results of moldability, apparent density, hardness, 50% compression residual strain, and flammability.

[0038]

[Table 1]

From Table 1, it is understood that by selecting the type of the thermoplastic polyester elastomer, the hardness and the sag resistance (50% compressive residual strain) of the mesh cushion can be controlled. It can be seen that when Perprene E-450B is used as the thermoplastic polyester elastomer, a reticulated cushion body having good hardness is obtained, and it is effective for weight reduction. On the other hand, when a net-like cushion body having a high settling resistance (small 50% compression residual strain) is desired, it is understood that a low product number of perprene may be used.

Example 2 In this example, the blending ratio of the thermoplastic polyester elastomer and the thermoplastic polyurethane elastomer was changed to examine the influence on the physical properties of the mesh cushion body.

A reticulated cushion body was manufactured in the same manner as in Example 1, except that TPEE5 (Perprene E-450B manufactured by Toyobo Co., Ltd.) was used as the thermoplastic polyester elastomer and TPUE1 was used as the thermoplastic polyurethane elastomer, and the compounding ratio of the both was variously changed. . Table 2 shows the results of moldability, apparent density, hardness, 50% compression residual strain, and flammability.

[0042]

[Table 2]

From Table 2, the compression residual strain is as small as 15% or less.
Drilling, hardness 180N / 314cm ²Higher than above, good
In order to obtain a net-like cushion body with excellent flame retardancy,
20 to 50% by weight of polyester elastomer
It is understood that it is preferable to set in the range of.

Example 3 In this example, the chain extender used in the thermoplastic polyurethane elastomer was changed, and the effect on the physical properties of the reticulated cushion was investigated.

As in Example 1, PTMG # 1000 was used as the polyol component and MD was used as the isocyanate component.
I, any one of CE1 to CE10 shown in the following chemical formula is used as a chain extender, and a thermoplastic polyurethane elastomer TP
UE1-10 were synthesized. As mentioned above, an appropriate amount (10 to 1000 ppm) of catalyst may be added during this reaction. CE1 is 1,4-bis (β-hydroxyethoxy) benzene (BHEB) described above, and TPUE
1 is the thermoplastic polyurethane elastomer of the above-mentioned sample number 1-5.

[0046]

[Chemical 3]

30% by weight of TPEE5 (Toyobo's Perprene E-450B) as a thermoplastic polyester elastomer, TPU as a thermoplastic polyurethane elastomer
A reticulated cushion body was manufactured in the same manner as in Example 1 using 70% by weight of any of E1 to E10. Table 3 and Table 4
Shows the results of moldability, apparent density, hardness, 50% compression residual strain, and flammability.

[0048]

[Table 3]

[0049]

[Table 4]

From Table 3 and Table 4, BH was used as a chain extender.
It can be seen that the reticulated cushion body manufactured using the thermoplastic polyester elastomers TPUE1 to 5 containing EB (CE1) and a diol (CE2 to 5) having a structure similar to EB (CE1) has good physical properties. These chain extenders are represented by the above-mentioned general formula (1).
On the other hand, the reticulated cushion body manufactured using the thermoplastic polyurethane elastomers TPUE6 to 10 containing an aliphatic diol or a diol having a bisphenol in the center (CE6 to 10) does not have sufficient hardness and has a compressive residual strain. Is also big.

Example 4 In this example, various thermoplastic polyurethane elastomers having different soft segments were used, and the influence on the physical properties of the mesh cushion was examined. Table 5 shows the thermoplastic polyurethane elastomers TPUE11 to 15 used.

30% by weight of TPEE5 (Toyobo's Perprene E-450B) as a thermoplastic polyester elastomer, TPU as a thermoplastic polyurethane elastomer
A reticulated cushion body was manufactured in the same manner as in Example 1 using 70% by weight of any of E11 to E15. Table 6 shows the results of moldability, apparent density, hardness, 50% compression residual strain, and flammability. For comparison, Table 6 shows the thermoplastic polyurethane elastomer TPU of the sample Nos. 1-5 described above.
The results of the mesh cushion body using E1 are also shown.

[0053]

[Table 5]

[0054]

[Table 6]

From Table 6, the reticulated cushion body manufactured using the thermoplastic polyurethane elastomer TPUE1 in which the soft segment is the polyether type PTMG has good physical properties, but the thermoplastic cushion containing other types of soft segment is used. Polyurethane elastomer TP
The net-like cushion body manufactured by using the UEs 11 to 15 does not have sufficient hardness and has a large compressive residual strain.

[0056]

As described in detail above, according to the present invention, a flame-retardant reticulated cushion body which is easy to recycle because it can impart flame retardancy without adding a flame retardant, is lightweight, and has little settling. Can be provided.

Continued front page    F-term (reference) 3B096 AD00 BA01                 4L047 AA21 AA25 AA28 AB03 AB07                       BA08 CA19 CB01 CB05 CB10                       CC09

Claims (4)

[Claims] 1. A plurality of continuous linear bodies containing a thermoplastic polyester elastomer and a thermoplastic polyurethane elastomer as a thermoplastic elastomer and having a fineness of 300 denier or more are bent in a loop shape, and the respective loops are fused to each other at a contact portion. The apparent density was 0.005
A flame-retardant reticulated cushion body characterized by comprising a three-dimensional reticulated structure of 0.200 g / cm ³ . 2. The thermoplastic elastomer constituting the continuous linear body is a mixture of 20 to 50% thermoplastic polyester elastomer and 80 to 50% thermoplastic polyurethane elastomer. Flame-retardant mesh cushion body. 3. The thermoplastic polyurethane elastomer is obtained by reacting a polyol component, an isocyanate component and a chain extender, and the chain extender has the following general formula (1): (Here, R ₁ and R ₂ are-(CH ₂ ) _n- , -O- (C
_{H 2) m -, - CO-} (CH 2) m - and -COO- (C
H ₂ ) _m- , wherein n is 1 to 4 and m is 1
~ 3. ) The flame-retardant reticulated cushion body according to claim 1 or 2, wherein 4. The thermoplastic polyurethane elastomer comprises polytetramethylene glycol as a polyol component, 4,4-diphenylmethane diisocyanate as an isocyanate component, and 1,4-bis (β-hydroxyethoxy) benzene as a chain extender, 4-bis (β-hydroxyethyl) terephthalate, 1,4-bis (β-hydroxyethyl) benzene, 1,4-bis (γ-hydroxypropyl) benzene or 1,4-bis (3-hydroxy-1-oxy) 4. Propyl) benzene reacted with the propyl group.
A flame-retardant reticulated cushion body according to any one of 1.