JP2010017962A - Foam molded article and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet pad which prevents an excess infiltration of a resin into a material to be coated in a foam molded article such as a sheet pad having an incorporated coating material without increasing an amount of a urethane, keeps hardness property excellent, develops no defect such as void, and further prevents rubbing sound. <P>SOLUTION: A sheet pad 1 comprises a bad body 2 made of a foamed resin and a reinforcing cloth 3 incorporating the back surface of the pad body 2, and a film 4 is formed in the side of the pad body 2 of the reinforcing cloth 3. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a foam molded article suitable as a seat pad installed in a vehicle or the like, and more particularly to a foam molded article in which a substrate such as a reinforcing cloth is integrated on the back surface of a foam main body. Moreover, this invention relates to the manufacturing method of this foaming molded product.

  As vehicle seat pads, those made of polyurethane foam are widely used.

  Since the back surface of the seat pad rubs against the support member due to the swing of the vehicle or the movement of the body such as an occupant, the pad body alone is easily damaged. Therefore, a reinforcing cloth made of a nonwoven fabric called a supporter material may be provided on the back surface of the seat pad.

  Since this reinforcing cloth protects the pad body from damage, it is formed integrally with the pad body so as not to be displaced or peeled from the pad body. That is, in the foam molding process for manufacturing the seat pad, a method is adopted in which resin is injected and foamed into the mold with the reinforcing cloth set in advance on the inner surface of the mold, and the pad body is molded and the reinforcing cloth is integrated at the same time. (Patent Document 1).

In Patent Document 1, the peripheral edge of the nonwoven fabric is sandwiched between an upper mold and a lower mold, thereby preventing liquid leakage from the cavity.
JP-A-2-145308

  As described above, when the reinforcing cloth made of nonwoven fabric is set on the cavity surface and urethane foam molding is performed, the urethane penetrates into the reinforcing cloth. When this amount of penetration is large, the amount of resin foamed in the cavity is relatively small, and as a result, there is a risk that the density and hardness of the foam will be insufficient. In order to prevent this, it is necessary to increase the amount of urethane.

  In addition, due to the setting of the reinforcing cloth (supporter material) and the variation in the fabric weight (fiber density), the way the gas escapes from the mold is non-uniform, so the molding of the foam inside the mold is non-uniform, Hardness stability may be impaired. Furthermore, the foam filled to some extent may move vigorously due to the generated gas, and defects such as voids (product chipping) may occur.

  When a seat pad having a supporter material impregnated with resin is mounted on the frame of a vehicle seat, a “sliding noise” is generated due to sliding of the seat frame bracket and the resin impregnated supporter material. May be uncomfortable for the user.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described conventional problems and prevent excessive penetration of resin into a substrate in a foam-molded product such as a sheet pad integrated with a substrate.

  An object of the present invention is to provide a seat pad that is excellent in hardness characteristics, free from defects such as voids, and prevents sliding noise without increasing the amount of urethane.

  The foam molded article according to claim 1 is a foam molded article having a foam main body made of a resin foam and a substrate integrated on at least a part of the outer surface of the foam main body. At least a part of the foam main body side is a hard-penetrating part in which the resin permeability for foam-molding the resin foam is lower than other parts.

  According to a second aspect of the present invention, the foam molded product according to the first aspect is characterized in that the hardly permeable portion is formed by providing a film on the foam body side of the substrate.

  According to a third aspect of the present invention, there is provided the foam molded article according to the first aspect, wherein the hardly permeable portion is formed by attaching a resin material to the foam main body side of the substrate.

  According to a fourth aspect of the present invention, there is provided a foam molded product according to any one of the first to third aspects, wherein the covering material is a non-woven fabric.

  According to a fifth aspect of the present invention, the foam molded product according to any one of the first to fourth aspects is characterized in that the foam body is made of polyurethane foam.

  A foamed molded product according to a sixth aspect is the vehicle member according to any one of the first to fifth aspects.

  A foamed molded article according to a seventh aspect is the seat pad according to the sixth aspect.

  The method for producing a foam molded article according to claim 8 is a method for producing a foam molded article according to any one of claims 1 to 7, wherein the substrate having the hardly penetrating portion is formed by the method. Forming the foam body in which the substrate is integrated by foaming the foamed resin stock solution in the mold so that the hard-to-penetrate part is on the cavity side And the step of performing.

  The method for producing a foam molded article according to claim 9 is the method according to claim 8, wherein the mold has an upper mold and a lower mold, the workpiece is held by the upper mold, and the workpiece is provided. The foam is molded by holding the peripheral edge of the upper mold and the lower mold together.

  The foam-molded article provided by the present invention has a foam body and a covering material made of a nonwoven fabric or the like integrated by integral foaming on at least a part of its outer surface. At least a part on the foam main body side of the covering material is a hardly permeable part, and the resin for molding the foam main body does not penetrate at all or so much in the hardly permeable part. Therefore, when foam-molding this foam-molded product with resin, the resin is prevented from excessively penetrating into the substrate, and an excessive amount of raw material resin is used for the foam-molded product having a predetermined density and hardness characteristics. Can be foam-molded without any problems.

  According to the present invention, effects such as a reduction in product quality, a reduction in man-hours (burr cutting, mold maintenance), and a decrease in the number of defective products generated due to a vent failure can be obtained.

  In order to form a hard-penetrating part in the covering material, it is convenient and preferable to provide a film on the foam body side of the covering material, but the resin material is attached to the foam body side of the covering material. It may be.

  As the covering material, materials having resin permeability such as nonwoven fabric, wool, cotton, net, paper, etc. are used, and nonwoven fabric is particularly preferable.

  As the above resin foam, polyurethane foam is suitable, but other resin foam may be used.

  The present invention is suitable for application to a vehicle seat pad. When molding this seat pad, it is preferable to hold the workpiece on the upper mold and to hold the peripheral edge of the workpiece between the mating surfaces of the upper mold and the lower mold. If it does in this way, since the gas in a cavity will be discharged | emitted from a mating surface, it will also become possible to abbreviate | omit the vent part of a metal mold | die. If the vent portion is omitted, the generation of burrs caused by the resin entering the vent portion is eliminated. Also, deburring work from the product is not necessary.

  When the periphery of the substrate is sandwiched between the mating surfaces of the upper mold and the lower mold and the gas is discharged from the mating surface, excessive penetration of resin such as urethane into the substrate is prevented. The gas escape from the mating surfaces is uniform, the foam body is uniformly molded, and the hardness stability is also good. Moreover, since the gas escape is good, the foam filled to some extent is prevented from moving by the gas, and the occurrence of defects such as voids (product chipping) is prevented.

  Furthermore, since the resin such as urethane is prevented from penetrating excessively into the covering material, the covering material is prevented from becoming excessively hard. As a result, no sliding noise is generated even when the workpiece and the seat frame slide, and the comfort level of the occupant is improved.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a vehicle seat pad 1 according to an embodiment.

  The vehicle seat pad 1 is composed of a pad main body 2 made of urethane foam or the like, and a reinforcing cloth (supporter material) 3 as a covering material integrated on the back surface of the pad main body 2. The reinforcing cloth 3 is made of a nonwoven fabric. A film 4 is provided on the pad body 2 side of the reinforcing cloth 3. The film 4 is provided other than the peripheral edge of the reinforcing cloth 3. The film 4 is preferably bonded to the reinforcing cloth 3 with an adhesive. A water-based adhesive or the like can be used as the adhesive, but is not limited to this. The reinforcing cloth 3 with the film 4 is integrated with the pad main body 2 by foam molding of the pad main body 2 as described later. By providing the film 4, urethane or the like is prevented from excessively penetrating into the reinforcing cloth 3.

  The back surface of the vehicle seat pad 1 is fixed to a metal seat frame (not shown). At this time, since the reinforcing cloth 3 is interposed between the pad main body 2 and the metal seat frame, the pad main body 2 is prevented from being damaged and the pad main body 2 and the metal frame are directly rubbed with each other. Generation of abnormal noise (sliding noise) is prevented. Further, as will be described in detail later, since the amount of urethane impregnated into the reinforcing cloth 3 is not excessive, no sliding sound between the reinforcing cloth 3 and the frame is generated.

  Next, a method for manufacturing the vehicle seat pad 1 will be described.

  FIG. 2 is a cross-sectional view for explaining an example of a method for manufacturing the vehicle pad 1. In FIG. 2, the mold 10 is composed of a lower mold 10a and an upper mold 10b. In the figure, reference numeral 11 denotes a cavity.

  The reinforcing cloth 3 is held on the inner surface of the upper mold 10b so that the film 4 side is the cavity side. The reinforcing cloth 3 is attached to the upper mold 10b using a double-sided tape, a magnet tape, or the like. Next, a raw material for flexible foam such as a urethane stock solution is supplied into the cavity 11 and the mold is closed.

  The reinforcing cloth 3 has a larger area than the cavity surface of the upper mold 10b, and is configured such that when the mold is closed, the peripheral edge of the reinforcing cloth 3 is sandwiched between the upper mold 10b and the lower mold 10a over the entire circumference. . Therefore, the gas generated in the cavity 11 at the time of foaming is discharged from the mating surface of the upper mold 11b and the lower mold 11a. After foam molding, the sheet pad 1 in which the reinforcing cloth 3 and the pad main body 2 are integrated is obtained by removing the mold.

  At the time of foam molding, the reinforcing cloth 3 is provided with the film 4, so that foam material such as urethane is not impregnated in the reinforcing cloth 3 in the area where the film 4 is attached, and the hardness and rigidity are increased or not substantially increased. do not do.

  In this way, the reinforcing cloth 3 does not have so high hardness and rigidity even after foam molding, so no sliding noise is generated. In addition, since a resin such as urethane does not excessively penetrate into the reinforcing cloth 3, a sheet pad having a predetermined density and hardness can be formed without using an excessive amount of resin such as urethane.

  Further, by preventing excessive penetration of a resin such as urethane into the reinforcing cloth 3, the escape of gas from the mating surfaces becomes uniform, the sheet pad body 2 is uniformly molded, and the stability of hardness is good. Become. Further, since the gas escape is good, the foamed material such as urethane filled to some extent is prevented from moving by the gas, and the occurrence of defects such as voids (product chipping) is prevented.

  Next, suitable materials for the pad main body 2, the reinforcing cloth 3, and the film will be described in detail.

<Pad body 2>
The pad body 2 is preferably made of polyurethane foam. The polyurethane foam stock solution is a polyurethane foam blend mainly composed of polyol and isocyanate. From the viewpoint of adjusting (increasing) the hardness of the polyurethane foam molded article, a crosslinking agent can also be blended in the polyurethane foam blend.

  In the polyurethane foam formulation, a foaming agent, a catalyst, a foam stabilizer and the like can be blended as necessary in the same manner as in a normal polyurethane foam formulation. Water is suitable as the foaming agent, but low boiling point compounds such as methylene chloride and monofluorotrichloromethane can also be used. As the catalyst, for example, amine-based and tin-based catalysts are preferably used. Examples of the foam stabilizer include organopolysiloxanes, alkyl carboxylates, and alkylbenzene sulfonates.

<Reinforcing cloth>
As the nonwoven fabric constituting the reinforcing fabric, at least one nonwoven fabric of polypropylene, polyethylene, polyethylene terephthalate, acrylic, wool, rayon and polyester is suitable. The basis weight of the nonwoven fabric is preferably about 10 to 300 g / m ^2, particularly about 50 to 150 g / m ² .

  In addition, instead of the reinforcing cloth 3 made of a non-woven fabric, one having an air conduit effect such as wool, hemp, net, or paper may be used.

<Film>
As the film, a synthetic resin film such as PP, PE or cellophane is suitable. The thickness of the film is preferably about 5 to 200 μm, particularly about 10 to 50 μm, but is not limited thereto.

  It is preferable that the film 4 has an area of about 60 to 99%, particularly about 78 to 98% with respect to the area of the portion of the reinforcing cloth 3 disposed in the cavity 11. The peripheral edge of the film 4 is preferably separated from the mating surface of the upper mold 10b and the lower mold 10a by 5 to 50 mm, particularly about 5 to 15 mm. Thereby, the reinforcing cloth 3 between the mating surface and the outer edge of the film is integrated with the pad body 2 over the entire circumference.

  Note that one or a plurality of small holes may be provided near the central portion other than the peripheral portion of the film 4 so that urethane or the like partially penetrates the reinforcing cloth 3 through the small holes. In this way, the reinforcing cloth 3 is coupled to the pad body 2 in the vicinity of the small hole.

  Instead of forming the hardly permeable portion with a film, liquid resin may be sprayed on the reinforcing cloth to clog the reinforcing cloth so that urethane or the like does not easily penetrate. As such a resin, urethane elastomer or the like can be used.

  The present invention can also be applied to foam molded articles other than seat pads, for example, vehicle interior materials other than seat pads.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples.

Example 1
As the mold, the mold 20 having the upper mold 21 and the lower mold 22 shown in FIG. 3 and the square cavity 23 of 400 × 400 × 100 mm was used. A nonwoven fabric 30 with a film 31 was attached to the upper mold 21, and urethane foam molding was performed. The mold 20 is not provided with a gas venting path such as a vent hole.

As shown in FIG. 4, the nonwoven fabric 30 is 460 × 460 mm, and the film 31 is 380 × 380 mm. It was attached to the upper mold 21 so that the film 31 side was the cavity 23 side. The nonwoven fabric has an air permeability of 149 mL / cm ² · s. The film 31 is a cellophane film having a thickness of 150 μm, and the air permeability is 0.94 mL / cm ² · s. The film 31 was attached to the nonwoven fabric 30 with an adhesive. 880 g of urethane stock solution was supplied, the mold was closed, foam-molded, cured, and demolded.

  As a raw material for flexible urethane foam, a mixture of 650 parts by mass of a polyol, a crosslinking agent, a catalyst, a foam stabilizer, and water and 230 parts by mass of isocyanate was used.

  In foam molding, the liquid temperature of this raw material was set to 30 ° C., and the mold temperature was maintained at 60 ° C.

  Table 1 shows the measurement results of the maximum internal pressure during foam molding, the internal pressure during demolding, the initial pressure, and the 25% hardness of the molded urethane foam.

Example 2
Foam molding was performed in the same manner as in Example 1 except that cellophane having a thickness of 150 μm was used as the film. Similar measurement results are shown in Table 1.

Comparative Example 1
Foam molding was performed in the same manner as in Example 1 except that only the nonwoven fabric was used, the size of the nonwoven fabric was 380 × 380, and the upper mold 21 and the lower mold 22 were not sandwiched. Similar measurement results are shown in Table 1.

Comparative Example 2
As shown in FIGS. 5 (a) and 5 (b), foam molding was performed in the same manner as in Example 1 except that the film 32 was applied to the entire surface of the nonwoven fabric 30. Similar measurement results are shown in Table 1.

Comparative Example 3
In Comparative Example 2, foam molding was performed in the same manner except that the nonwoven fabric 30 was on the cavity side and the film 32 was on the upper mold 21 side as shown in FIG. Similar measurement results are shown in Table 1.

Comparative Example 4
As shown in FIG. 7, foam molding was performed in the same manner as in Example 1 except that the film 33 was provided only on the peripheral edge of the nonwoven fabric 30 (the portion sandwiched between the upper die 21 and the lower die 22). Similar measurement results are shown in Table 1.

Comparative Example 5
Foam molding was performed in the same manner as in Example 1 except that only the nonwoven fabric 30 was used, the size of the nonwoven fabric was 460 × 460, and the periphery of the nonwoven fabric was sandwiched between the upper mold 21 and the lower mold 22. . Similar measurement results are shown in Table 1.

Comparative Example 6
Foam molding was performed in the same manner as in Example 1 except that a waterproof spray (Scotch Guard manufactured by Este Co., Ltd.) was sprayed over the entire surface of the nonwoven fabric 30 and the air permeability of the nonwoven fabric was set to 139 mL / cm ² · s. Similar measurement results are shown in Table 1.

  As shown in Table 1, according to Examples 1 and 2, foams having a maximum internal pressure higher than those of Comparative Examples 2 to 6, no voids, and having a 25% hardness close to that of Comparative Example 1 are obtained.

It is typical sectional drawing of the vehicle seat pad which concerns on embodiment. It is sectional drawing explaining an example of the manufacturing method of the vehicle seat pad of FIG. It is sectional drawing of the metal mold | die of an Example. (A) A figure is a top view of a film and a nonwoven fabric, (b) A figure is BB sectional drawing of (a) figure. (A) A figure is a top view of a film and a nonwoven fabric, (b) A figure is BB sectional drawing of (a) figure. It is sectional drawing of a film and a nonwoven fabric. (A) A figure is a top view of a film and a nonwoven fabric, (b) A figure is BB sectional drawing of (a) figure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle seat pad 2 Pad main body 3 Reinforcement cloth 4 Film 30 Non-woven fabric 31, 32, 33 Film

Claims (9)

In a foam molded article having a foam body made of a resin foam and a substrate integrated on at least a part of the outer surface of the foam body,
Foam characterized in that at least a part of the substrate on the side of the foam body is a hard-to-penetrate part in which the resin permeability for foam-molding the resin foam is lower than other parts. Molding.   2. The foam molded product according to claim 1, wherein the hardly permeable portion is formed by providing a film on the foam body side of the substrate.   2. The foam molded article according to claim 1, wherein the hardly permeable portion is formed by attaching a resin material to the foam body side of the substrate.   The foamed molded article according to any one of claims 1 to 3, wherein the covering material is made of a nonwoven fabric.   5. The foam molded product according to claim 1, wherein the foam body is made of polyurethane foam.   The foam molded product according to any one of claims 1 to 5, wherein the foam molded product is a member for a vehicle.   The foam molded product according to claim 6, wherein the foam molded product is a seat pad. A method for producing a foamed molded article according to any one of claims 1 to 7,
A step of disposing the substrate having the hardly permeable portion in a mold such that the hardly permeable portion is on the cavity side;
Forming the foam body in which the substrate is integrated by foaming a foamed resin stock solution in the mold.   9. The mold according to claim 8, wherein the mold includes an upper mold and a lower mold, the holding material is held by the upper mold, and a peripheral portion of the covering material is aligned with the upper mold and the lower mold. A method for producing a foam-molded article, wherein the foam-molding is performed by sandwiching the surfaces.

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