JPH06143475A - Foamed molded object and production thereof - Google Patents

Abstract

PURPOSE:To prevent the deformation of a foamed molded object due to CO2 generated from a foamable resin material. CONSTITUTION:A foamed molded object W has a skin material 1 composed of a laminate of a PCV sheet 3 and PP foam 4 and the foamable resin material 2 laminated to the inside of the skin material 1 and consisting of a primary foam layer 5 and a secondary foam layer 6. A large number of gas vent holes 7 are bored in the foamable resin material and CO2 is discharged to the outside through the gas vent holes 7 to prevent the expansion of the skin material 1 and the release of the primary and secondary foam layers 5,6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foamed molded product obtained by laminating a foamable resin material on the back surface of a skin material, and a manufacturing method thereof.

[0002]

2. Description of the Related Art For example, a foam molding used for an instrument panel or a door trim of an automobile is a skin sheet made of vinyl chloride or the like, or a skin material obtained by laminating a foam sheet on the back surface of the skin sheet. After being set in the cavity of the molding die, the cavity is manufactured by foaming and filling a foaming resin material such as a hard urethane resin.

By the way, the foamable resin material is
CO due to chemical reaction when foaming ₂Gas is generated
This CO₂The gas is trapped inside the foamable resin material.
The foamed molded product is molded in the closed state. Inside
CO₂The foamed molded product in which gas is trapped is in a high temperature state for a long time.
When exposed to CO₂Gas causes volume expansion to cause epidermis
A part of the material is pushed up from the foamable resin material,
There is a problem that the surface bulges. In addition, foamable resin material
Composed of a primary foam layer and a secondary foam layer in which the
If CO₂Depending on the gas pressure, the primary foam layer and the secondary
There is a problem that the next foam layer is peeled off.

In order to avoid such an inconvenience, it has been proposed that CO ₂ gas generated during foaming of the expandable resin material is released to the outside from the mating surface of the female mold and the male mold of the molding die (special feature). (See Kaihei 3-2150012).

[0005]

When the method described in the above publication is used, CO ₂ gas generated on the cavity surface of the molding die is discharged to the outside, but the shape of the molding die is complicated. However, it is difficult to discharge CO ₂ gas trapped inside the foamable resin material without reaching the cavity surface of the molding die.

That is, since the resin liquid of the foamable resin material is injected into the cavity of the molding die over a predetermined time, the reaction of the resin liquid injected first and the resin liquid injected later are performed. Since there is a time lag between the reaction and the reaction, the CO ₂ gas generated from the resin liquid injected first is held by the resin liquid injected later, so that the CO ₂ gas does not reach the cavity surface It is trapped between layers of resin material.

Further, even after the molding is completed, the foamable resin material reacts with the moisture in the air to generate CO ₂ gas.
₂ gas cannot be discharged by the conventional method, which causes defective products.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to reliably discharge the gas generated inside the foamable resin material of the foam molded article.

[0009]

In order to achieve the above-mentioned object, the present invention provides a foamed molded article obtained by integrally laminating a foamable resin material on the back surface of a skin material, wherein the foamable resin material is
The first feature is to have a large number of gas vent holes, one end of which opens to the atmosphere and the other end of which reaches the vicinity of the skin material.

In addition to the above-mentioned first feature, the present invention also provides:
The foamable resin material includes a primary foam layer laminated on the back surface of the skin material and a secondary foam layer laminated on the back surface of the primary foam layer, and the bonding of the primary foam layer and the secondary foam layer. A second feature is that the gas vent hole penetrates the surface.

Further, in the method for producing a foamed molded product of the present invention, the foamable resin material is foam-filled in the cavity of the molding die in which the skin material is installed, so that the foamable resin material is integrally laminated on the back surface of the skin material. And a step of forming a large number of gas vent holes in the foamable resin material of the foamed molded article, the one end opening to the atmosphere and the other end reaching the vicinity of the skin material. The third feature is the provision.

In the method for producing a foamed molded article of the present invention, the step of laminating the first foamed layer on the back surface of the skin material by foam-filling the cavity of the molding die in which the skin material is installed with the foamable resin material. And a second foam layer is laminated on the back surface of the first foam layer by foam-filling a cavity of a molding die in which a semi-finished product composed of the skin material and the first foam layer is installed with a foamable resin material. A step of molding a foamed molded article, and a foamable resin material of this foamed molded article, which penetrates the bonding surface of the primary foamed layer and the secondary foamed layer and has one end open to the atmosphere and the other end near the skin material. And a step of forming a large number of gas vent holes reaching the above.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

1 to 7 show an embodiment of the present invention. FIG. 1 is a sectional view of an instrument panel of an automobile,
2 is an enlarged view of part 2 of FIG. 1, FIG. 3 is a cross-sectional view of a molding die for a primary foam layer of a foamable resin material, FIG. 4 is a cross-sectional view of a molding die for a secondary foam layer of a foamable resin material, FIG. 5 is an explanatory diagram of a method for processing a gas vent hole, FIG. 6 is a diagram showing a test piece for examining the CO ₂ gas discharge amount, and FIG. 7 is a graph showing the CO ₂ gas discharge amount.

As shown in FIGS. 1 and 2, an automobile instrument panel W as a foam molded article has an outer skin material 1 and a foaming resin material 2 integrally laminated on the back surface of the outer skin material 1. Composed of and. Outer skin 1 is PVC on the outside
The sheet 3 and the inner PP foam 4 are laminated,
It is formed into a product shape by a molding die (not shown). The foamable resin material 2 is made of a hard urethane resin, and includes a primary foam layer 5 laminated on the back surface of the skin material 1 and a secondary foam layer 6 laminated on the back surface of the primary foam layer 5. As is clear from FIG. 2, the foamable resin material 2 is provided with a large number of gas vent holes 7 that penetrate the secondary foam layer 6 and reach the middle portion in the thickness direction of the primary foam layer 5.

As shown in FIG. 3, a molding die 8 for molding the primary foam layer 5 of the expandable resin material 2 is formed by stacking a female die 9 supporting the skin material 1 and an upper portion of the female die 9. A male mold 11 that defines a cavity 10 between the skin material 1 and the back surface thereof.
With. The cavity 10 is formed on the upper surface of the male mold 11.
A resin liquid supply means 12 for injecting the resin liquid of the foamable resin material 2 is provided therein. A pair of levers 14, 14 are pivotally supported on the side surface of the male die 11 via pins 13, 13, and the upper ends of the levers 14, 14 are a pair of cylinders 15, provided on the upper surface of the male die 11. 15 and the locking projections 9 ₁ , 9 ₁ ; 1 formed at the joint between the female mold 9 and the male mold 11 at the lower ends of the levers 14, 14 respectively.
1 _1, 11 locking portion 1 having a notch engageable with ₁
4 ₁ and 14 ₁ are formed.

FIG. 4 shows a molding die 16 for molding the secondary foam layer 6 of the foamable resin material 2. This mold 1
6 is a molding die 8 of FIG. 3 for molding the primary foam layer 5.
Since it has substantially the same structure as the above, the duplicated description will be omitted by giving the same reference numerals to corresponding members. The difference between the molding die 8 of FIG. 3 and the molding die 16 of FIG. 4 is that the shape of the cavity 10 and the shape of the male mold 11 are slightly different.

In order to mold the instrument panel W, as shown in FIG. 3, the female mold 9 of the molding die 8 in which the skin material 1 molded in the shape of the instrument panel W is set in advance is used as a male mold. Cylinder 1 after stacking molds 11
Locking protrusions 9 ₁ , 9 ₁ ; 11 ₁ , 11 ₁ formed by connecting the locking parts 14 ₁ , 14 ₁ of the levers 14, 14 to the joint part of the female mold 9 and the male mold 11 by extending and driving the levers 5, 15. And clamp the mold. Subsequently, the resin liquid is injected into the cavity 10 from the resin liquid supply means 12 to be foam-filled, and the first foam layer 5 of the foamable resin material 1 is integrally formed on the back surface of the skin material 1.

Next, as shown in FIG. 4, the skin material 1 and the first
After the male mold 11 is superposed on the female mold 9 of the molding die 16 in which the semi-finished product in which the foam layer 5 is integrated is set, and the mold is clamped,
The resin liquid is injected into the cavity 10 from the resin liquid supply means 12 to foam and fill the cavity 10, and the second foam layer is formed on the back surface of the first foam layer 5.

When the instrument panel W in which the skin material 1 and the expandable resin material 2 are integrated as described above is molded, as shown in FIG. 5, a drilling tool having a plurality of cones 17 is formed. 18, a plurality of gas vent holes 7 are formed in the expandable resin material 2 from the second foam layer 6 to the first foam layer 5, and an instrument panel W having the gas vent holes 7 shown in FIG. obtain. The gas vent hole 7 completely penetrates the secondary foam layer 6 and further penetrates the primary foam layer 5 partway to reach the vicinity of the back surface of the skin material 1. The depth of the gas vent hole 7 is regulated by the stopper surface 17 ₁ formed at the base end of the cone 17. The drilling tool 18 may be a tool that is mounted on a head of a processing machine to automatically perform drilling work, or may be a manual tool.

By forming a large number of gas vent holes 7 in the foamable resin material 2 of the instrument panel W, CO ₂ gas generated during foaming of the resin liquid is confined inside the foamable resin material 2. However, the CO ₂ gas can be completely discharged to the outside. Further, the CO ₂ gas generated by the reaction with the moisture in the air after the foamable resin material 2 is cured can be similarly discharged from the gas vent hole 7. Therefore, even if the temperature of the instrument panel W rises due to direct sunlight in the summer, for example, CO ₂
It is possible to reliably avoid the inconvenience that the skin material 1 swells due to the pressure of the gas and the first layer 5 and the second layer 6 of the foamable resin material 2 are separated.

FIG. 5 shows a test piece for experimenting the effect of the gas vent hole 7, in which a block made of the same hard urethane resin as the foaming resin material 2 is provided with nine gas vent holes. Is.

As is apparent from the graph of FIG. 6, the CO ₂ gas content immediately after molding is 0.2549%, but the CO ₂ gas content of the gas having vent holes is 8%.
0.0417% after 24 hours in an atmosphere of 0 ° C, 10
After 0 hours, it has decreased to 0.0116%. On the other hand, those without a vent hole have a CO ₂ gas content of 8
0.1396% after 10 hours at 0 ° C, 10%
It is 0.0142% after a lapse of 0 hours, and it is understood that the one having the gas vent hole is excellent in the CO ₂ gas discharge characteristic.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-mentioned embodiments, and various design changes can be made.

For example, the application of the present invention is not limited to the instrument panel W, but can be applied to other appropriate foam molded articles such as door trims.

[0026]

As described above, according to the first or third feature of the present invention, CO ₂ gas generated from the foamable resin material integrally laminated on the back surface of the skin material is passed through the gas vent hole. Since it can be discharged to the outside, it is possible to avoid inconveniences such as the swelling of the skin material of the foamed molded product under the pressure of CO ₂ gas at high temperature.

According to the second or fourth aspect of the present invention, in addition to the effect of the first or third aspect of the present invention described above, the primary foamed layer of the foamable resin material under the pressure of CO ₂ gas. It is possible to reliably prevent the second foam layer from peeling off.

[Brief description of drawings]

FIG. 1 is a sectional view of an automobile instrument panel.

FIG. 2 is an enlarged view of part 2 of FIG.

FIG. 3 is a sectional view of a molding die for a primary foam layer of a foamable resin material.

FIG. 4 is a sectional view of a molding die for a secondary foam layer of a foamable resin material.

FIG. 5 is an explanatory diagram of a method for processing a gas vent hole.

FIG. 6 is a diagram showing a test piece for investigating the emission amount of CO ₂ gas.

FIG. 7 is a graph showing CO ₂ gas emissions.

[Explanation of symbols]

 1 Skin Material 2 Foaming Resin Material 5 Primary Foaming Layer 6 Secondary Foaming Layer 7 Gas Venting Hole 8 Molding Die 10 Cavity 16 Molding Die W Instrument Panel (Foaming Molding)

Claims (4)

[Claims] 1. A foamed molded product obtained by integrally laminating a foamable resin material (2) on the back surface of a skin material (1), wherein the foamable resin material (2) has one end open to the atmosphere and the other end. Having a plurality of gas vent holes (7) reaching near the skin material (1). 2. A primary foam layer (5) in which the foamable resin material (2) is laminated on the back surface of the skin material (1), and a secondary foam layer (5) laminated on the back surface of the primary foam layer (5). A foam layer (6), and these primary foam layer (5) and secondary foam layer (6)
The foam molded article according to claim 1, wherein the gas vent hole (7) penetrates through the joint surface of the foam molded article. 3. A molding die (8, 8) provided with a skin material (1).
By foam-filling the foamable resin material (2) into the cavity (10) of 16), a foam molding (W) in which the foamable resin material (2) is integrally laminated on the back surface of the skin material (1) is obtained. In the step of molding and in the foamable resin material (2) of the foamed molded body (W), one end is open to the atmosphere and the other end is the skin material (1).
And a step of forming a large number of gas vent holes (7) that reach the vicinity of the foam molded article. 4. A molding die (8) provided with a skin material (1).
Laminating the first foam layer (5) on the back surface of the skin material (1) by foam-filling the foamable resin material (2) in the cavity (10), and the skin material (1) and the first skin layer (1). Molding die (16) with semi-finished product consisting of foam layer (5)
The foaming resin material (2) is foam-filled into the cavity (10) of the first foam layer (5) to form the second foam layer on the back surface of the first foam layer (5).
The step of laminating the foam layer (6) to form the foam molded body (W), and the foamable resin material (2) of the foam molded body (W),
A large number of gas vent holes (7) which penetrate the joining surfaces of the primary foam layer (5) and the secondary foam layer (6) and open at one end to the atmosphere and reach the vicinity of the skin material (1) at the other end. A method for manufacturing a foam-molded article, comprising the step of boring.