JPS63105709A - Cushion body for seat excellent in air permeability - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a seat cushion body with excellent air permeability suitable for vehicle seats, furniture, bedding, and the like.

[Conventional technology]

General-purpose urethane foams, which are used in various applications such as automobile front seats, back seats, furniture, and bedding, are made by using polyether polyol alone or unsaturated monomer polymerized polyol (general name, polymer polyol, hereinafter referred to as this name). The main raw material is polyisocyanate and foaming agent, catalyst, and foam stabilizer are added to this and foam molded into a predetermined shape and thickness.It has a relatively low foam density. A lightweight cushion body is obtained. This type of general-purpose urethane foam is also advantageous in terms of cost.

[Problem that the invention seeks to solve]

Conventional general-purpose urethane foam is lightweight, but has low rebound resilience, so its thickness has been reduced to 10011! It is used with a relatively thick thickness of R or more. In other words, when this type of urethane foam is made thinner, it gives rise to a so-called bottoming out feeling, resulting in poor ride comfort.

However, in recent automobiles, in order to obtain a large interior space, there is a trend that not only good cushioning properties but also thinness are desired.

High modulus urethane foams have also been developed to solve the above problems. However, this foam has a much higher foam density than general-purpose urethane foam, so even though it can be made thinner, it is heavier, which is another problem. In addition, conventional high-elastic foams have disadvantages such as poor air permeability and poor seating feel due to the cell membrane remaining in the foam skeleton.

[Means for solving problems]

The cushion body of the present invention uses a polyol in which finely divided silica is dispersed alone or in combination with a polymer polyol, and polyisocyanate as the main raw materials, and a blowing agent, a catalyst, and a foam stabilizer are added thereto. This is a seat cushion body characterized by being foam-molded to the shape and thickness of .

The bipedal fine-grain silica-dispersed polyol is prepared by removing the dispersion medium from a mixture of silica sol and high molecular weight polyol contained in a dispersion medium such as water or an organic solvent. The average particle diameter of silica is usually 1 μm or less, preferably 1 to 100 μm.

The dispersion medium used in silica sol is, for example, water.

In addition, there are also silica sols using hydrophilic organic solvents such as monovalent or polyhydric alcohols as dispersion media. As the polymer polyol, for example, polymer polyether polyol, polyester polyol, etc. are used. Since the boiling point of the polyol is sufficiently higher than that of the organic solvent which is the dispersion medium of the silica sol, the organic solvent can be removed from a mixture of the two by distillation. When the dispersion medium of the silica sol is water, a finely divided silica-dispersed polyol with high dispersion stability can be obtained by distillation at a low temperature and, if necessary, dehydration under reduced pressure. The finely divided silica-dispersed polyol thus obtained is used alone or in combination with a polymer polyol.

On the other hand, as the polyisocyanate, aromatic polyisocyanate, mainly tolylene diisocyanate, is used.

Components used in addition to the above-mentioned main raw materials include a catalyst 2 blowing agent, a foam stabilizer, etc. As the catalyst, an organic metal catalyst and a tertiary amine catalyst are used alone or in combination. As the blowing agent, trichlorofluoromethane, dichlorodifluoromethane, methylene chloride, water, etc. are used. As the foam stabilizer, an alkylene polyether modified silicone surfactant is used.

[Effect]

In the cushion body according to the present invention, due to the foam-breaking effect of the fine-grained silica dispersed in the polyol, the generation of cell membranes remaining in the foam skeleton is suppressed, and the foam skeleton is enriched to the extent that the cell membranes are broken. , it has excellent rebound resilience. Furthermore, since the occurrence rate of closed cells is low, the air permeability is extremely excellent, and the density is lower than that of conventional high elastic foams. Furthermore, since the occurrence of closed cells is suppressed, the resistance to inflow and outflow of air inside the cushion body when a seating load is applied to the cushion body is reduced. This improves the damping performance when sitting, resulting in even better seating comfort.

[Example 1] A mold foam was prepared by using a polyol in which particulate silica was dispersed and a polymer polyol together with the following formulation (parts by weight).

The composition is as follows: 8 parts of finely divided silica-dispersed polyol, 20 parts of polymer polyol, 2.8 parts of water as a blowing agent, 4.0 parts of trichlorofluoromethane, and 1.0 parts of foam stabilizer. .

part, triethylenediamine dilute solution (33%
) and 0.1 part of dibutyltin dilaurate,
Tolylene diisocyphate (T-
80) INDEXI 00.

With the above composition, length 500 zm x width 500 mz x thickness 7
A test piece of urethane foam No. 51121 was foam-molded. The physical properties of the obtained test piece are shown in Table 1 below.

[Example 2] In the same manner as in Example 1, a cushion body having the same size and shape as an actually used automobile rear seat was produced using a finely divided silica-dispersed polyol according to the following formulation.

The seat surface of the cushion body is thin and has a thickness of 75I.
Various physical properties were evaluated using IIz. An example of the cushion body 1 is shown in the drawing.

The formulation was: 75 parts of finely divided silica-dispersed polyol, 25 parts of polymer polyol, 2.5 parts of water and 4.0 parts of trichlorofluoromethane as blowing agents, 1.0 part of 'M1 foaming agent, and a dilute solution of triethylenediamine (as a catalyst). 33%) to 0
．． 28 parts, dibutyltin dilaurate 0.1 part, and tolylene diisocyanate (T-80) INDEXloo.

[Comparative Example 1] A general-purpose molded urethane foam was produced in the same size as in Example 1 using the formulation shown below.

70 parts of polyether polyol, 3 parts of polymer polyol
0 parts 1 4.0 parts of water as a blowing agent, 5.0 parts of trichlorofluoromethane, 1.0 part of a foam stabilizer, 0.2 parts of diluted triethylenediamine solution (33%) as a catalyst and 0 parts of dibutyltin dilaurate .06 parts tolylene diisocyanate (T-80) NDEXloo.

[Comparative Example 2] A highly elastic molded foam developed for the purpose of improving riding comfort was produced in the same size as in Example 1 using the formulation shown below.

50 parts of polyether polyol, 5 parts of polymer polyol
0 parts 1 2.6 parts of water as a foaming agent, 1.0 parts of a foam stabilizer.

Triethylenediamine dilute solution (3396) as catalyst
and 0.4 parts of tetramethylhexamethylenediamine.
3 parts, diphenylmethane diisocyanate/toluene diisocyanate (-20/80) I N D E
X105° [Comparative Example 2'] The formulation was exactly the same as in Comparative Example 2 above, but the product was foam-molded into the same product shape as an actual automobile rear seat as illustrated in the drawing. Therefore, the foaming state and thickness vary slightly in each part of the sheet. The seating surface of the cushion body was made thin, and various physical properties were evaluated at 75M+21. Table 2 below shows data compared with Example 2.

Table 1 In Table 1 above, the impact resilience, tear strength, tensile strength, and elongation rate 1 air permeability are all values for a portion of the core of the cushion body. Note that the air permeability is a value measured using a Frazier air permeability tester used to measure the air permeability of woven fabrics.

As can be seen from Table 1, the general-purpose foam of Comparative Example 1 has low rebound resilience and is a shock body with poor ride comfort. Comparative Example 2 has a high foam density and high impact resilience, and is rated good in terms of ride comfort, but its breathability is extremely poor, resulting in poor seating feel. Moreover, it is heavy.

On the other hand, Example 1 has extremely good breathability and is a cushion body with considerably high rebound resilience, so it has a thickness of 100 mm or less, which provides good riding comfort even though it is thinner than conventional products. . And the foam density is Comparative Example 1
It is not much different from the general-purpose form and is lightweight. For this reason,
It has excellent cushioning properties, is lightweight, and has good breathability, so it feels very comfortable when sitting on it.

Table 2 below shows the results of a bottom thrust test conducted to examine the seating feel from another perspective. In this case, the automotive rear seat cushions of Example 2 and Comparative Example 2' were compared. The bottom thrust test measures the impact level when a person weighing BOKg sits on the seat from a height of 120mm above the seat surface. In both Example 2 and Comparative Example 2', the cushion body had a thin seat form, and the evaluation was conducted at a thickness of 75M.

Table 2 (bottom thrust test) In the urethane foam of Example 2, a smaller value of acceleration against seating load was obtained compared to the high elasticity foam of Comparative Example 2', and it was judged that the feel when sitting was superior. .

The urethane foam mixed with finely divided silica, as in the case of the cushion body of the present invention, suppresses the incidence of closed cells that occur when the foam becomes thinner. This is most noticeable in the area where the foam thickness is 40 to 100 mx. By the way, the conventional foam thickness is 100
It was more than M. We investigated the relationship between the thickness of the foam of the cushion body and its breathability using a large number of samples.
For a foam thickness of 40 m to 100 m, which is applied as a thin sheet, if the above cushion body is made so that the air permeability satisfies the following formula, it will not only have good air permeability but also good impact resilience and light weight, etc. It was found that a cushion body with excellent properties could be obtained.

A≧0.9t-20 A: Foam breathability (cc/cIj/see).

t: Foam thickness rtm) [Effects of the Invention] The cushion body of the present invention has extremely good air permeability because it can suppress the occurrence of closed cells due to the foam-breaking effect of the particulate silica mixed in the polyol. It also reduces the damping characteristics (value) when sitting, improving cushioning properties. In addition, the foam has a richer skeleton due to the cell membrane being ruptured, and not only does it have excellent impact resilience, but it also has a lower density than conventional high elasticity foams. For the above reasons, we provide a cushion body that is light, has excellent cushioning properties, can be made thin, and has extremely good breathability, making it an excellent overall choice for vehicle seats, furniture, and bedding. can.

[Brief explanation of the drawing]

The drawing is a perspective view of a portion of a cushion body showing an embodiment of the present invention. 1...Cushion body.

Claims (1)

[Claims] The main raw materials are a polyol in which finely divided silica is dispersed, either alone or in combination with an unsaturated monomer polymerized polyol, and polyisocyanate, and a blowing agent, a catalyst, and a foam stabilizer are added to this to create a desired shape. Seat cushion body with excellent breathability, characterized by thick foam molding.