JP2002306274A - Seat cushion pad and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seat cushion pad subtly adjusting static characteristics and dynamic characteristics, especially a vibration characteristic, by a simple method without preparing various types of materials and to provide its manufacturing method. SOLUTION: This seat cushion pad 21 is so formed that its seating part comprises, at least, a molded polyurethane foam layer 22, a porous sheet layer 25, and a soft polyurethane layer 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle seat cushion pad in which the static and dynamic characteristics of a seat portion are adjusted, and more particularly to a vehicle seat cushion pad.

[0002]

2. Description of the Related Art A technique for producing a seat cushion pad by foaming and curing a reactive composition for forming a polyurethane foam in a mold having a predetermined shape is well known, and is generally used as a seat cushion material for railway vehicles, automobiles and the like. Is used regularly.

[0003] Such seat cushion pads include:
It is required to satisfy various shapes and characteristics according to the type of the vehicle to which this is mounted, the size of the vehicle, the purpose, and the like. In particular, it is required that static characteristics such as hardness, load / deflection characteristics, and rebound resilience, and dynamic characteristics such as vibration absorption characteristics are within predetermined ranges. Further, these characteristics may be balanced. Required. Conventionally, such a request has been handled by the following method.

(1) A method for improving the selection and formulation of raw material compounds of a polyurethane foam-forming composition used for a seat cushion pad. (2) A method of injecting a reactive composition for forming two types of polyurethane foams having different properties into a mold at a predetermined position, foaming and curing the same, and molding a seat cushion pad having a portion having different properties. (3) A method in which foams having different characteristics are bonded to a seat portion of the seat cushion pad with an adhesive after the seat cushion pad is molded. (4) A flexible polyurethane foam sheet (slab foam sheet) is disposed in a mold, a reactive composition for forming a polyurethane foam is injected, foamed and cured, and a seat cushion having a flexible polyurethane foam sheet layer on a seat surface portion. How to make a pad.

[0005]

However, in the method (1), the required characteristics can be generally achieved, but fine adjustments cannot be made. However, it is not possible to respond to slightly different requests depending on the type of vehicle.

[0006] In the method (2), the characteristic corresponding to the feeling of sitting cannot be finely adjusted as required.

According to the method (3), the characteristics can be adjusted more than the above two methods. In particular, in order to simultaneously adjust the dynamic characteristics and the static characteristics, it is necessary to use a seat cushion pad to be molded. It is necessary to prepare many types of both polyurethane foams to be bonded, which is complicated. Moreover, it is difficult to finely adjust the dynamic characteristics and the static characteristics at the same time.

According to the method (4), the reactive composition penetrates into the cells of the foam and hardens at the contact portion between the reactive composition and the slab foam sheet. Does not feel so good.

An object of the present invention is to provide a seat cushion pad in which static characteristics and dynamic characteristics, particularly vibration absorption characteristics, are finely adjusted by a simple method without preparing various kinds of materials, and a method of manufacturing the same. is there.

[0010]

A seat cushion pad according to the present invention is characterized in that a flexible polyurethane foam sheet is laminated on a seat surface of a molded polyurethane foam pad using a thin layer material as an intermediate layer.

[0011] In the above structure, by providing the thin layer material layer between the seating surface of the polyurethane foam pad and the flexible polyurethane foam sheet, the static characteristics and the dynamic characteristics, particularly the vibration absorption characteristics, are finely adjusted. A cushion pad can be obtained.

Due to the rigidity of the thin layer material, dynamic characteristics such as vibration transmission characteristics can be adjusted while increasing the degree of freedom in adjusting the soft feeling of the seat surface. This is because, when the elasticity of the thin-layer material is high, the elasticity of the foam is suppressed by the bending deformation caused by the compression of the seat portion of the seat cushion pad when a person is seated. Is a non-porous or less porous elastomer film, all of which are considered to be able to obtain dynamic characteristics such as reduced vibration transmissibility due to the effect such as the orifice effect of the air spring due to reduced air permeability. Can be

The thin layer material may be formed of a flexible material, and has a thickness of 5 μm to 5 mm.
It is. For a film, the thickness is about 5 μm to 500 μm, but for a material such as a nonwoven fabric, a relatively thick material of 5 mm or less can be used.

It is preferable that the thin layer material is a porous polymer material. By using a porous polymer material, it is not necessary to apply an adhesive to the seat itself, just apply an adhesive to the adhesive surface between the seat cushion pad seat surface and the flexible polyurethane foam sheet. The seat surface of the seat cushion pad and the flexible polyurethane foam sheet are adhered to each other through the void portion, or in the case of a fibrous material such as a non-woven fabric, the flexible polyurethane foam sheet becomes a thin layer material by an anchor effect between the fiber and the adhesive. As a result of the formation of a laminate that is strongly adhered and has a thin material layer in each case, the manufacturing process is simplified.

The porous polymer material is a polymer sheet (film) having a large number of holes, a fiber product such as a nonwoven fabric or felt, a cold gauze, a mesh material, or a thin film formed in a lattice shape. A material having a relatively large hole or a material having good air permeability, which is compressed by being overlapped on a sheet.

When a porous polymer material is used as the thin layer material, since the effect of suppressing the air permeability of the thin layer material is small, a film formed from a resin material which is flexible and has a high elastic modulus, The use of sheets is preferred.

Preferably, the thin layer material is a non-porous or porous polyurethane film. Preferably, the porous polymer material is a cold gauze. It is also preferable that the porous polymer material is a spun bond. It is also preferable that the porous polymer material is a warif. Further, the porous polymer material is preferably a polypropylene net.

Both are relatively low-cost, and by laminating between the seat surface of the polyurethane foam pad and the flexible polyurethane foam sheet, the effect of finely adjusting the static characteristics and the dynamic characteristics, especially the vibration absorption characteristics, is obtained. Is obtained.

The thin layer material used for the seat cushion pad of the present invention is also preferably a thermoplastic elastomer film.

The thermoplastic elastomer film has a low rigidity (initial tensile modulus) but a low air permeability of the polyurethane foam by making the film non-porous or moderately porous. This makes it possible to adjust the vibration absorption characteristics.

The method for producing a seat cushion pad according to the present invention comprises a molding step of producing a molded polyurethane foam pad by injecting a reactive composition for forming a polyurethane foam into a mold; A thin layer material bonding step of bonding the thin layer material to the seat surface or the flexible polyurethane foam sheet; and a foam bonding step of bonding the flexible polyurethane foam to the seat surface of the polyurethane foam pad using the thin layer material as an intermediate layer. It is characterized by obtaining a seat cushion pad in which a flexible polyurethane foam sheet is laminated on a face portion with a thin layer material as an intermediate layer.

According to this manufacturing method, a seat cushion pad in which static characteristics and dynamic characteristics, particularly vibration absorption characteristics are finely adjusted can be manufactured by a simple method without preparing various kinds of materials.

Further, another manufacturing method of the seat cushion pad of the present invention is a film bonding step of bonding a flexible polyurethane foam using a thin layer material as an intermediate layer to form a film laminated foam, and a method for forming a seat surface portion in a mold. Disposing a film laminated foam, injecting a reactive composition for forming a polyurethane foam, and having a molding step of producing a molded polyurethane foam pad, a flexible polyurethane foam sheet is formed on a seat portion by a thin layer material. A seat cushion pad laminated as an intermediate layer is obtained.

According to this manufacturing method, a seat cushion pad having the same effect as the method according to the ninth aspect can be obtained.

In the above manufacturing method, the thin layer material is preferably a porous polymer material, and is preferably a thermoplastic elastomer film.

[0026]

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the shape of a seat cushion pad formed of a polyurethane foam and molded. In this example, the seat cushion pad 1 includes a raised side portion 3 and a seat surface portion 5, and grooves 11 and 9 are formed near the center of the seat surface portion 5 and between the seat surface portion 5 and the side portion 3, respectively. Is formed. Groove 11,
9 need not be provided. The lamination of the flexible polyurethane foam sheet for adjusting the physical properties to improve the sitting comfort is performed on the rear portion (back side) of the seat surface portion 5 or on the entire seat surface portion 5.

FIG. 2 is a longitudinal sectional side view taken along the line AA in FIG. 1, and a thin layer material 25 is interposed on the polyurethane foam layer 22 of the seat cushion pad constituting the seat rear part 5A of the seat part 5. 2 illustrates a structure in which a flexible polyurethane foam sheet layer 23 is formed. The thin layer material 25 needs to have an area that covers at least the contact area between the buttocks of the person and the seat cushion pad when the person is seated, and is preferably at least about 25 cm × 25 cm.

The porous polymer material suitable as the thin layer material used in the present invention is preferably formed of a resin having a relatively high tensile elastic modulus. As the layer material, specifically, polyethylene, polypropylene, aromatic polyester such as polyethylene terephthalate, polyamide resin,
Examples thereof include materials using a polyaramid resin, a polyimide resin, a high-hardness polyurethane resin, and the like. In addition, the hole shape,
Depending on the arrangement, the tensile elastic modulus of the porous polymer material may have anisotropy depending on the direction of elongation. For example, in the case of a mesh-like material, the elastic modulus in the fiber direction is larger than the elastic modulus in the fiber direction and the 45-degree direction.

As a thin layer material using such a material,
A porous film, a punching film, a mesh made of nylon filaments or polyolefin filaments, etc. It is exemplified as a suitable material.

As the thermoplastic elastomer constituting the thermoplastic elastomer film, a known thermoplastic elastomer (TPE) can be used without any particular limitation, and polyester-based TPE, polyamide-based TPE, polyolefin-based TPE, ethylene / vinyl acetate copolymer, etc. Coalescence (EVA),
Styrene / butadiene block copolymer (SBS), polyurethane TPE and the like are exemplified. Among these, the use of a polyurethane elastomer film is preferred.

As the thin layer material, it is also preferable to use a material in which an adhesive (including an adhesive) has been applied to both surfaces in advance, such as a double-sided adhesive tape # 501 (manufactured by Nitto Denko). It is preferable to use such a material in which the adhesive is applied to both surfaces in advance, when the adhesive needs to be applied to the thin layer material, such an application step can be omitted.

As the molded seat cushion pad, one conventionally used as a vehicle seat cushion pad can be appropriately used. The polyurethane foam constituting the molded seat cushion pad has a density of 30 to 70 kg / m ³ , a hardness (measured according to JIS K6400) of 15 to 30 kgf / 314 cm ² , and a rebound resilience of 40 to 80%. Use

An example of the method for manufacturing the seat cushion pad of the present invention will be described. (1) Molding Step A reactive composition for forming a polyurethane foam, a so-called foaming stock solution, is injected into a heated mold using a casting machine equipped with a mixing head, and foamed and cured to form a seat cushion. Form the pad. The seat cushion pad may be lined with a known backing material such as a nonwoven fabric or a cold gauze. It is also a preferred embodiment to integrate a metal wire and a surface fastener for fixing the surface material.

(2) Preparation of Flexible Polyurethane Foam Sheet The flexible polyurethane foam sheet is prepared by cutting a flexible polyurethane slab foam into a slab sheet having a thickness of about 5 to 30 mm, preferably 8 to 20 mm.
The slab sheet is cut to the size of the seat to be bonded.
As the slab sheet, those having characteristics such as various densities, hardness, and rebound resilience are usually manufactured and marketed, and may be appropriately selected and used according to the purpose. The flexible polyurethane foam sheet has a density of 15 to 50 kg / m ³ and a hardness of 4
２０20 kgf / 314 cm ² , rebound resilience 35-55
%%

(3) Adhesive application step An adhesive is applied to the bonding surface. Generally, the adhesive is applied to both the surface of the molded pad and the bonding surface of the flexible polyurethane foam sheet (slab sheet), and then dried.

(4) Thin-Layer Material Bonding Step The thin-layer material is bonded to the seat surface of the seat cushion pad to which the adhesive has been applied or to the bonding surface of the flexible polyurethane foam sheet. An adhesive may or may not be applied to the thin layer material.

(5) Foam Bonding Step The slab sheet is bonded to the seat surface of the seat cushion pad to which the adhesive has been applied. Through the above steps, a seat cushion pad having the target thin material layer can be obtained.

As the adhesive used for bonding, known adhesives used for bonding flexible polyurethane foam can be used without limitation, but generally, polychloroprene rubber dissolved in an organic solvent such as toluene is used. A rubber-based adhesive such as is used.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments and the like specifically showing the configuration and effects of the present invention will be described below. (Example) Total density 60 kg / m ³ , hardness 20 kgf / 3
14 cm ² , a rebound resilience of 70%, a density of 29 kg / m ³ and a hardness of 11 kgf / 314c at the center of a molded seat cushion pad having the shape shown in FIG.
m ² , a rebound resilience of 47%, a slab sheet having a thickness of 12 mm, a basis weight of 35 g / m ² , and a tensile modulus of 3 in the fiber direction.
77 N / cm (70 μm), 16 N / cm in 45 degree direction
(70 μm) through a polyester wari (Nisseki) and laminated. As the adhesive, a polychloroprene-based adhesive (manufactured by Konishi) was used and brush-coated.

(Comparative Example) The same slab sheet and seat cushion pad as in the example were used, and the slab sheet was bonded and laminated at the same seat surface center position as the slab sheet bonding position in the example without using a warp. Then, a seat cushion pad was obtained.

(Evaluation Method) a) Initial Deflection Characteristics A disk having a diameter of 200 mm was pressed against the seat of the seat cushion pad at a constant speed, and the strain-load was measured. An autograph (manufactured by Shimadzu Corporation) was used for the measurement, and compression was performed at a crosshead speed of 50 mm / min. The evaluation result is
FIG. 3 is a graph showing the relationship between the load and the amount of deflection. Table 1 shows the amount of deflection when the load was 196N.

B) Rebound resilience Measured on the seat surface of the seat cushion pad in accordance with JIS K6400.

C) Vibration characteristics According to JASO B-407, a load of 490 N was applied using a butt type JM-50 pressure plate, and the amplitude was ± 2.5 m.
m. The measured frequency range is 1-10H
z. The outline of the measurement method is as follows. A seat cushion pad is fixed on a shaking table, and a load is applied by placing a buttocks-shaped JM-50 press plate at a predetermined position on a seating surface of the shaking table. While vibrating and changing the frequency, the acceleration or the absolute displacement of the pressure plate is measured by an accelerometer or a displacement meter, respectively. From this result, the transmissivity is determined. In general, the evaluation result is displayed as a graph with the horizontal axis representing the frequency and the vertical axis representing the transmissivity. The transmissivity is the ratio of the acceleration of the pressure plate to the acceleration of the shaking table when measuring the acceleration, and the ratio of the absolute displacement of the pressure plate to the amplitude of the vibration table when measuring the absolute displacement. is there.

(Evaluation Results) The initial deflection characteristics are shown in FIG. In FIG. 3, the points to be noted are the steps (i) and (ii) in the low-deflection region, and the point E where the sea cushion pad bottoms out is almost the same, but the step (ii).
Are greatly different. Due to this difference, the laminated seat cushion pad of the present invention has improved stability when compared with the seat cushion pad of the comparative example.
That is, by softening the seat surface of the seat cushion pad at the time of sitting, it is possible to improve the fit and to firmly support the inside of the pad.

FIG. 2 is a sectional view B when a person is seated.
The surface pressure measured along -B 'is shown in FIG. The total load is 490 N (50 kg weight).

From these results, it can be seen that the seat cushion pad of the present invention improves the fit by softening the seat surface of the seat cushion pad when seated, and at the same time, firmly supports the inside of the pad. Understand.

Table 1 summarizes the results of the measurement of the vibration characteristics. From the results shown in Table 1, the laminated seat cushion pad of the present invention has a smaller static amount under a load of 196 N as a static characteristic as compared with the seat cushion pad of the comparative example, and has a firm and dynamic characteristic. It can be seen that the resonance magnification is low in the characteristics.

[0048]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of the shape of a molded seat cushion pad.

FIG. 2 is a longitudinal sectional side view showing a structure in which a flexible polyurethane foam is bonded to a seat portion of a molded seat cushion pad via a porous sheet layer on a seat portion.

FIG. 3 is a graph showing a result of measuring a load-deflection relationship.

FIG. 4 is a graph showing surface pressure measured along a cross-sectional view BB ′ of FIG. 2 when a person is seated.

[Explanation of symbols]

 Reference Signs List 21 seat cushion pad 22 molded polyurethane foam layer 23 soft polyurethane layer 25 porous sheet layer

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) B32B 5/18 B32B 5/18 27/40 27/40 // B29K 75:00 B29K 75:00 105: 04 105: 04 B29L 31:58 B29L 31:58 F-term (reference) 3B084 CA07 CB01 3B096 AB09 AB10 AD04 AD07 4F100 AK01B AK07B AK14G AK41B AK51A AK51B AK51C AL09B AN02G AT00B BA03 BA07 CB01G02 AJB DJB14A14 EA01 EA04 EK17 EW02 EW50

Claims (12)

[Claims] 1. A seat cushion pad in which a flexible polyurethane foam sheet is laminated on a seat surface of a molded polyurethane foam pad with a thin layer material as an intermediate layer. 2. The seat cushion pad according to claim 1, wherein the thin layer material is a porous polymer material. 3. The seat cushion pad according to claim 1, wherein the thin layer material is a thermoplastic elastomer film. 4. The thermoplastic elastomer film according to claim 1,
The seat cushion pad according to claim 3, which is a thermoplastic polyurethane film. 5. The seat cushion pad according to claim 3, wherein the porous polymer material is a cold gauze. 6. The seat cushion pad according to claim 3, wherein the porous polymer material is a spun bond. 7. The seat cushion pad according to claim 3, wherein the porous polymer material is warif. 8. The seat cushion pad according to claim 3, wherein the porous polymer material is a polypropylene net. 9. A molding step for producing a molded polyurethane foam pad by injecting a reactive composition for forming a polyurethane foam into a mold, and forming a thin polyurethane foam pad on a seat surface portion or a flexible polyurethane foam sheet of the polyurethane foam pad. A flexible polyurethane foam sheet on the seat surface, comprising a thin layer material bonding step of bonding a layer material, and a foam bonding step of bonding a flexible polyurethane foam with the thin layer material as an intermediate layer on the seat surface of the polyurethane foam pad. A method for manufacturing a seat cushion pad laminated with an intermediate layer. 10. A film bonding step of bonding a flexible polyurethane foam to a film laminated foam by using a thin layer material as an intermediate layer to form a film laminated foam, and disposing the film laminated foam at a position where a seat surface is formed in a mold to form a polyurethane foam. A method for producing a seat cushion pad in which a flexible polyurethane foam sheet is laminated on a seat portion with a thin layer material as an intermediate layer, comprising a molding step of producing a molded polyurethane foam pad by injecting a reactive composition to be molded. 11. The method according to claim 9, wherein the thin layer material is a porous polymer material. 12. The method according to claim 9, wherein the thin layer material is a thermoplastic elastomer film.