JPS5919708B2 - Manufacturing method of cushion material for seats - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a seat cushion material.

More specifically, the present invention relates to a method of manufacturing seat cushioning material with low compression set using rigid fibers such as palm and palm fibers.

Traditionally, cushioning materials for seats in automobiles, vehicles, etc.
Animal and vegetable fibers or sponges are used, but the work is complicated because the periphery is clipped to the spring frame line or supporter, and one periphery is uneven and lacks softness. was there.

In order to improve the various drawbacks of cushioning materials, a glue is used in a highly rigid fiber layered material such as palm or palm, and the cushion is made into an appropriate shape to create a cushion that is relatively flexible and has a firm feel. It has a highly elastic main body, and a hard and strong elastic body that is attached to the edge of the seat frame line etc. by pushing it out by hand and bending inward so as to hold the attached member. A seat cushion material has been proposed in which a curved groove portion and an elastic sleeve piece are connected (Japanese Patent Publication No. 4907/1983).

However, since such cushioning materials have a relatively high bulk density, the only way to reduce the weight of automobiles and the like is to reduce the thickness of the cushioning materials.

However, when the thickness of the cushioning material is made thinner, the compression set is large, resulting in the so-called "depression phenomenon", and the overall strength is weakened due to insufficient adhesive strength, and the appearance of the cushioning material itself is also affected. The drawback was that it got worse.

The present invention has been made in order to eliminate the various drawbacks of the conventional methods as described above, and after applying an adhesive to a layered body made by loosening and intersecting rigid fibers, it is dried to perform primary adhesion of the fiber layers. After modification, a foaming solution of polyurethane is applied to the thus obtained primary adhesive layered body to form a main body corresponding to the main body of the seat, etc., followed by a seat frame, a supporter, a frame, etc. of the seat etc. The foaming solution is foamed in a steam atmosphere while strongly compressing the folded part and the sleeve part corresponding to the member to be attached to form a thin layer, and the polyurethane foam is applied to the intersecting part of each fiber. This is a method for producing a seat cushion material, which is characterized by forming grains and then drying them.

The rigid fibers used in the present invention are, for example, coconut fibers, palm fibers, etc., and usually have a bulk density of 30 to 100%.
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Adhesives used for primary adhesion and modification include natural rubber, styrene-butadiene rubber, nitrile rubber, etc., containing necessary chemicals such as vulcanizing agents and vulcanization accelerators.
There are synthetic resin emulsions such as latex such as acrylic rubber and urethane rubber, acrylic adhesives, polyvinyl acetate adhesives, cellulose adhesives, etc., and these adhesives have 30 to 200 f/100 R-fibers, Preferably, 70 to 100 f/100 goo fibers are used.

To apply this adhesive, for example, rigid fibers supplied from a supply port such as a hopper are loosened, and then fed to a substantially uniform thickness onto a conveying device such as a belt conveyor or net conveyor, and then transferred. After spraying the adhesive liquid, dry it to remove moisture, solvent, etc.

If adhesion and modification are insufficient by spraying from one side, the fiber layer may be immersed in an adhesive liquid bath, or the fiber layer may be turned over and adhesive liquid may be sprayed from the other side and then dried. .

Through this drying, each intersecting part of the fibers is bonded by the adhesive, and the fiber layer is temporarily bonded.At the same time, the adhesive liquid is absorbed into the fiber or adheres to the surface, increasing the fiber strength.

A raw fabric is obtained by cutting the fiber layer that has been primarily bonded in this manner into a predetermined size.

After the thickness of the fabric thus obtained is controlled by passing it between rolls or by using a press or the like, a foaming solution of polyurethane foam is applied by a spraying method, dipping method, etc.

The amount of adhesion is usually 50 to 300 S'/100 g of the original fabric, preferably 70 to 200 f/100 P of the original fabric.

Although various polyurethanes can be used in the method of the present invention, reaction products of urethane prepolymers and diisocyanates are particularly preferred.

As a urethane prepolymer, the base polyether has a molecular weight of 700 to 3,000 per OH group in terms of compression set, expansion ratio, and foam feel.
Also, it is preferable that the ethylene oxide content in the alkylene oxide is 40 parts or more.

and tolylene diisocyanate, which is reacted with the base polyether to form a urethane prepolymer; 4.
4'-diphenylmethane diisocyanate, dianiline diisocyanate, hexamethylene diisocyanate,
Among them, metaxylylene diisocyanate and the like are most preferred, and tolylene diisocyanate is the most preferred.

There are various types of free diisocyanate to be reacted with the prepolymer, and the same incyanate as mentioned above is used, but in order to prevent feeling and phase separation with water, NC0% is 7 to 23%. 4,4'-diphenylmethane diisocyanate (C-MDI) is preferred from the viewpoint of workability.

As a catalyst, a normal polyurethane catalyst is sufficient, but in order to increase the expansion ratio, N-methylmorpholine,
N-ethylmorpholine, triethylamine, N,N'-
Amine catalysts such as dimethylpiperazine and triethylenediamine are preferred, and morpholines are particularly preferred.

As silicone, 5RX-274C (manufactured by Toray Silicone Co., Ltd.), L-5305 (manufactured by Unitika Co., Ltd.), ])-2
53 (manufactured by Dai-ichi Kogyo Co., Ltd.).

Water (steam) is preferred as the blowing agent.

The raw fabric coated with the polyurethane foaming solution in this way is placed in a predetermined mold, heated under pressure in a steam atmosphere to foam the polyurethane, and then dried to form the intersecting parts of each fiber. A seat cushioning material is obtained by forming polyurethane foam grains on the polyurethane foam.

In this case, the polyurethane foaming temperature is 20-100°C, preferably 70-100°C, and the heating time is 3-20 minutes, preferably 3-7 minutes.

Furthermore, the drying temperature and time are sufficient as long as the moisture used in the atmosphere is completely evaporated.

As a molding device, there is a molding device 1 as shown in FIG. 1, for example.

That is, the upper plate 3 having the shaft molds 2, 2, the base 5 having the bottom plate 4, and the arm 6.6 are rotatably attached to the arm 6.6 with a bin 7, and the bin 8 is attached to the base 5 of the bottom plate 4. , 8 to face the shaft molds 2, 2, respectively,
The rings io, io are tightened and locked with clips 11, 11, and the top plate 3 and side plates 9°9 are opened.
Place the above-mentioned single layer or multiple layered body on the bottom plate 4, close the plates 3 and 9, lock with the clips 11 and 11, strongly tighten the edge portion of the layered body to compress it, and bend it inward. Shape into shape.

In this way, as shown in FIG. 2, the main body portion 12, which is relatively flexible and elastic, is bent inward from the front and back edges of the main body portion 12 through a symmetrical and elastic bending zone, and is gradually compressed. A cushioning material 16 is obtained in which the elastic fastening sleeve pieces 14, 14 are densified into a thin layer and have hardness and elasticity, and the bending grooves 15, 15 are formed inside the elastic fastening sleeve pieces 14, 14.

To attach the cushioning material 16 to the spring assembly 17 of the automobile seat cushion, the elastic fastening sleeve 14 is
, 14 against its elasticity and spread over the frame line 18,
Alternatively, it can be easily done by inserting the spring frame line 18 into the locking grooves 15, 15 while similarly pushing out the elastic fastening sleeve pieces 14° 14 from the side surface of the cushioning material 16 where there is no elastic fastening piece, and returning the spring frame line 18 elastically. A seat cover (not shown) can be placed thereon.

As described above, the seat cushioning material according to the present invention is manufactured by first applying an adhesive to a layered body made by relaxing and intersecting rigid fibers, and then drying the material.
Not only does the primary adhesion provide shapeability and facilitate the application of the polyurethane foaming solution, but the fiber itself is modified by the adhesive solution impregnated inside the fiber or coated on the surface, and the fiber itself is modified. Elastic recovery power, ease of breakage, etc. are improved.

In addition, a foaming solution of polyurethane is applied to the primary bonded original fabric to form a main body portion corresponding to the main body of the seat, etc., followed by a seat frame line of the seat etc.

The foaming solution is foamed in a steam atmosphere while strongly compressing the folded part and sleeve piece part corresponding to the attached member such as the supporter and frame to form a thin, dense layer, thereby intersecting each fiber. Since it is made by forming polyurethane foam grains in the parts, it not only reduces the apparent density, but also improves compression set and rebound resilience.
Moreover, it has the advantage of improved appearance and texture.

This is because the rigid fibers such as coconut fibers and palm fibers and the polyurethane foam attached to them are crushed by the compression applied to the cushioning material, but when the compression is released, the fibers, which have poor recovery properties, recover. This is thought to be due to the rapid recovery due to the good quality of polyurethane foam.

Next, the method of the present invention will be explained in more detail with reference to Examples.

Example 1 An adhesive consisting of an acrylic emulsion (solid content 50 weight 0; did.

The total amount of adhesive applied at this time was 501 (solid content)/
It was 100S'-fiber.

This is passed between rolls to control the thickness, and the bulk density is 50.
Kg/? ? An original fabric of Z' was obtained.

Next, the molecular weight 3,000, the number of functional groups 2,
Methylene chloride obtained by reacting a polyether having an ethylene oxide content of 16 units with tolylene diisocyanate having a free NCO group content of 8 units (based on DI)
64 parts by weight of urethane prepolymer containing % by weight, C
- A polyurethane foaming stock solution consisting of 16 parts by weight of MDI, 16 parts by weight of N-methylmorpholine, and 4 parts by weight of silicone was sprayed in an amount of 95 parts by weight (in terms of solid content) per 100 parts by weight of the raw material, and then molded as shown in FIG. The polyurethane was foamed by heating at 80° C. for 4 minutes in a steam atmosphere using a mold, and then dried at 100° C. for 15 minutes to obtain a seat cushioning material as shown in FIG.

When the cushion material thus obtained was tested, the 50% compression set was 25.9 inches and the 1-repulsion elasticity was 50%.

Example 2 In the method of Example 1, N-
The amount of methylmorpholine was changed to 8 parts by weight, and 10 parts by weight of the original fabric was added.
When the same method was carried out except that the amount of foaming stock solution used was changed to 105 parts by weight, the 50 compression set was 20.7% and the rebound resilience was 45 inches.

Example 3 Using the same raw fabric as in Example 1, a polyurethane foam stock solution consisting of 64 parts by weight of the same urethane prepolymer, 116 parts by weight of C-MD and 4 parts by weight of silicone was sprayed, and further 16 parts by weight of KN-methylmorpholine was added. After spraying a mixture consisting of parts by weight and 64 parts by weight of water, Example 1
Pressure was applied in the same manner as above, foaming was performed at 80°C for 4 minutes, and then drying was performed at 100°C for 15 minutes.

Note that the amount of adhesion at this time was 90 parts by weight (in terms of solid content) per 100 parts by weight of the original fabric.

The cushioning material thus obtained had a 50 coefficient compression set of 26.0% and a rebound resilience of 50 coefficient.

Comparative Example An adhesive consisting of an acrylic emulsion (solid content: 50% by weight) was sprayed onto a layered body made of softened and interlaced palm fibers, the mixture was inverted once, and the adhesive was further sprayed and dried.

The total amount of adhesive applied at this time was 105 parts by weight per 100 parts by weight of the fibers.

This was passed between rolls to control the thickness to obtain a raw fabric.

This original fabric was molded in the same manner as in Example 1, and heated and pressed at 100° C. for 15 minutes.

The cushion material thus obtained had a 50% compression set of 46.6% and an impact resilience of 45%.

[Brief explanation of the drawing]

FIG. 1 is a route map showing an example of a mold used in the method of the present invention, FIG. 2 is a sectional view showing an example of a seat cushion material obtained by the method of the present invention, and FIG. It is a perspective view showing a state. 1... Molding mold, 12... Body part, 1
4...Elastic fastening sleeve piece, 15...Bending groove, 16...Cushion material.

Claims (1)

[Scope of Claims] 1. An adhesive is applied to a layered body made by loosening and intersecting rigid fibers, and then drying to perform primary adhesion and modification of the fiber layer. Apply polyurethane foaming solution to the body. The main body part corresponding to the main body of the seat, etc., followed by the bent part and sleeve part corresponding to the seat frame line, supporter, frame, etc. of the seat etc. are strongly compressed and densified into a thin layer. A method for manufacturing a seat cushion material, which comprises foaming the foaming stock solution in a steam atmosphere while pressurizing the foam to form polyurethane foam grains at the intersecting portions of each fiber, and then drying.