JP6809757B2 - Foam, resin panel - Google Patents

Description

The present invention relates to foam and resin panels.

Conventionally, resin panels in which a foam as an interior material is covered with a skin material sheet have been used for various purposes such as for automobiles, building materials, and sports / leisure. Further, it is known that a reinforcing material (reinforce) is interposed between two foamed portions constituting the interior material in order to locally reinforce the resin panel (for example, Reference 1).

JP-A-2015-164763

The reinforcing material is generally made of metal, but the metal reinforcing material may not be used at a desired position depending on the shape of the resin panel and the usage environment.
From this point of view, an object of the present disclosure is to make it possible to reinforce a desired position of the resin panel without being restricted by the shape of the resin panel and the usage environment.

The first aspect of the present disclosure is a plate-shaped foam.
It is provided with a first foaming region having a first foaming ratio and a second foaming region having a second foaming ratio lower than the first foaming ratio.
The second foam region is formed at least partially along the periphery of the foam, or is formed so as to cross from one part of the periphery of the foam to another.
The first foamed portion having the first foamed region and the second foamed portion having the second foamed region are connected to each other.
The first foamed portion and the second foamed portion have irregularities along the sides facing each other.
The unevenness of the first foamed portion and the second foamed portion is unevenness in a direction facing each other, and is characterized in that the unevenness is connected by fitting these unevennesses.
The second aspect of the present disclosure is a plate-shaped foam.
It is provided with a first foaming region having a first foaming ratio and a second foaming region having a second foaming ratio lower than the first foaming ratio.
The second foam region is formed at least partially along the periphery of the foam, or is formed so as to cross from one part of the periphery of the foam to another.
The first foamed portion having the first foamed region and the second foamed portion having the second foamed region are connected to each other.
The unevenness of the first foamed portion and the second foamed portion is formed as a stepped portion in the thickness direction.
A protrusion is formed on at least one of the first foamed portion and the second foamed portion, and the first foamed portion and the second foamed portion are connected by engaging the protrusions. To do.

In the foam, the cross-sectional thickness of the second foam region does not have to be uniform.

In the foam, a hinge may be formed in at least a part of the second foam region.

In the foam, the first foam portion having the first foam region and the second foam portion having the second foam region may be connected.

In the foam, in the connecting region where the first foam portion and the second foam portion are connected, both the first foam portion and the second foam portion are the front of the foam. It may have a portion that penetrates between the front surface and the back surface.

A second aspect of the present disclosure is a resin panel in which the above-mentioned foam is covered with a skin material sheet.

The desired position of the resin panel can be reinforced without being restricted by the shape of the resin panel and the usage environment.

A perspective view of the resin panel of the embodiment and an enlarged fracture view of a part thereof. The perspective view of the interior material which is contained in the resin panel of an embodiment. The figure explaining the method of forming the interior material of an embodiment by a plurality of foam parts. The figure explaining the process of molding the skin material of the resin panel of an embodiment. The figure explaining the process of molding the skin material of the resin panel of an embodiment. The plan view which shows the use example of the resin panel of an embodiment. The figure which shows the interior material which concerns on the modification of embodiment. The figure which shows the interior material which concerns on the modification of embodiment. The figure which shows the interior material which concerns on the modification of embodiment. The figure which shows the interior material which concerns on the modification of embodiment. The figure which shows the interior material which concerns on the modification of embodiment. The figure which shows the interior material which concerns on the modification of embodiment. The figure which illustrates the connection method of two foam parts. The figure which illustrates the connection method of two foam parts. The figure which illustrates the connection method of two foam parts. The figure which illustrates the connection method of two foam parts. The figure which illustrates the connection method of two foam parts. The figure which illustrates the connection method of two foam parts. The plan view of the interior material which concerns on Example. Top view of the interior material according to the comparative example.

Hereinafter, the resin panel 1 and the interior material 2 for the resin panel 1 according to the embodiment of the present invention will be described. The interior material 2 for the resin panel 1 is an example of the foam of the present invention, and is the core material of the resin panel 1.

(1) Resin panel 1 and interior material 2 for resin panel 1
First, the configurations of the resin panel 1 and the interior material 2 of the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a perspective view of the resin panel 1 of the present embodiment and an enlarged fracture view of a part thereof. FIG. 2 is a perspective view of the interior material 2 of the present embodiment.

As shown in FIG. 1, the outer shape of the resin panel 1 according to the embodiment includes a front surface 1a, a back surface 1b, and a long side side wall surface 1c interposed between the front surface 1a and the back surface 1b. It has a substantially rectangular parallelepiped shape composed of a side wall surface 1d on the short side. The front surface 1a, the back surface 1b, the long side side wall surface 1c, and the short side side wall surface 1d are composed of a skin material sheet S made of a thermoplastic resin, and an interior material 2 is incorporated therein. There is. That is, the resin panel 1 has a structure in which the interior material 2 is covered with the skin material sheet S of the thermoplastic resin.

In the resin panel 1 of the embodiment, the skin material sheet S to be the skin material sheet is not limited to the resin material, but is preferably formed of a non-foamed resin in order to secure the rigidity of the resin panel 1. For example, in consideration of moldability, the skin material sheet S may be made by mixing polystyrene (PS) and styrene ethylenebutylene styrene block copolymer resin (SEBS) with polypropylene (PP) as a main material.

As shown in FIG. 2, the interior material 2 is a composite structure in which foam portions 21 to 23 are connected and integrated. The shapes of the foamed portions 21 to 23 may be appropriately determined according to the appearance and usage environment required for the resin panel 1, and are not particularly limited.

In the resin panel 1 of the embodiment, the foamed portions 21 to 23 are molded using, for example, a thermoplastic resin. The resin material is not limited, and includes, for example, any of polyolefins such as polypropylene and polyethylene, acrylic derivatives such as polyamide, polystyrene and polyvinyl chloride, or a mixture of two or more kinds.

Examples of the foaming agent that can be used in the foaming portions 21 to 23 in the resin panel 1 of the embodiment include known physical foaming agents, chemical foaming agents, and mixtures thereof. For example, as the physical foaming agent, an inorganic physical foaming agent such as air, carbon dioxide gas, nitrogen gas, and an organic physical foaming agent such as butane, pentane, hexane, dichloromethane, and dichloroethane can be applied. Examples of the chemical foaming agent include azodicarboxylic amide (ADCA), N, N'-dinitrosopentamethylenetetramine, 4,4'-oxybis (benzenesulfonylhydrazide), and diphenylsulfone-3,3'-disulfonyl. Organic foaming agents such as hydrazide, p-toluenesulfonyl semicarbazide, trihydrazinotriazine or azobisisobutyronitrile, citric acid, oxalic acid, fumaric acid, phthalic acid, malic acid, tartaric acid, cyclohexane-1,2-dicarboxylic acid , A mixture of polycarboxylic acids such as citric acid, ethylenediamine tetraacetic acid, triethylenetetramine hexaacetic acid, and nitriloic acid, and inorganic carbonate compounds such as sodium hydrogen carbonate, sodium hydrogen carbonate aluminum, potassium hydrogen carbonate, ammonium hydrogen carbonate, and ammonium carbonate. , Sodium dihydrogen citrate, potassium oxalate and other polycarboxylic acid salts are mentioned as inorganic foaming agents.

If a foam having a low expansion ratio is used as the interior material of the resin panel 1, it is not preferable in that the required rigidity can be secured but the overall weight increases. Therefore, in the interior material 2 of the present embodiment, a foamed portion having a low foaming ratio is applied to a portion requiring reinforcement (for example, a portion having the lowest rigidity), and foaming having a high foaming ratio is applied to a portion not requiring much reinforcement. By applying the part, it is characterized in that the rigidity is locally increased while suppressing the overall weight.

In the example shown in FIG. 2, it is assumed that reinforcement is required in the vicinity of the short side side wall surface 1d of the resin panel 1. Therefore, the foaming ratios of the foamed portion 21 and the foamed portion 23 corresponding to the vicinity of the short side side wall surface 1d are relatively low, and the foaming ratio of the foamed portion 22 between the foamed portion 21 and the foamed portion 23 is relatively set. It is high.
In this embodiment, the foamed portion 22 is an example of the first foamed region of the interior material 2. The foamed portions 21 and 23 are an example of the second foamed region of the interior material 2, and are partially formed along the peripheral edge of the interior material 2.

As illustrated in FIG. 2, when the interior material 2 is composed of two or more foamed portions having different foaming ratios, the foaming ratio of each foamed portion is not particularly limited, but for example, a relatively high foaming ratio is used. Is 30 to 40 times, and the relatively low foaming ratio is 10 to 20 times. The foaming ratio is a value obtained by dividing the density of the mixed resin before foaming by the apparent density of the foamed resin after foaming.

The skin material sheet S and the foamed portions 21 to 23 may be molded using a resin material mixed with a glass filler for the purpose of increasing rigidity and strength.
Examples of the glass filler include glass fiber, glass fiber cloth such as glass cloth and glass non-woven fabric, glass beads, glass flakes, glass powder, and milled glass. Examples of the type of glass include E glass, C glass, A glass, S glass, D glass, NE glass, T glass, quartz, low dielectric constant glass, high dielectric constant glass and the like.
In addition to the glass filler, talc, calcium carbonate, wollastonite, an inorganic filler such as a magnesium-based material, carbon fiber, or the like may be mixed to increase the rigidity.

(2) Assembling Method of Interior Material 2 A method of assembling the interior material 2 will be described with reference to FIG. FIG. 3 is a diagram illustrating a method of forming the interior material 2 of the embodiment by a plurality of foamed portions, and shows a method of connecting the foamed portion 21 and the foamed portion 22 as an example.
In order to assemble the interior material 2 of the present embodiment, first, the foamed portions 21 and 23 having a low foaming ratio and the foamed portions 22 having a high foaming ratio are separately molded. In the example shown in FIG. 3A, the end portion serving as the boundary between the foamed portion 21 and the foamed portion 22 is a U-shaped groove and a U-shaped protrusion. After molding the foamed portions 21 to 23, as shown in FIG. 3B, foaming is performed by engaging the U-shaped groove and the U-shaped protrusion at the ends of the foamed portion 21 and the foamed portion 22. The portion 21 and the foamed portion 22 are connected. Although not shown, the foamed portion 22 and the foamed portion 23 are also connected to each other by engaging the U-shaped groove and the U-shaped protrusion at the end of each foamed portion. In FIG. 3B, the connecting region H indicates a region in which a foamed portion having a low foaming ratio and a foamed portion having a high foaming ratio are mixed.
The foamed portions 21 to 23 are molded by, for example, a bead method in-mold foam molding method. For an example of molding by the bead method in-mold foam molding method, refer to, for example, Japanese Patent Application Laid-Open No. 2014-128938.

(3) Method for Molding Resin Panel 1 Next, a method for molding the resin panel 1 of the embodiment using a mold will be described with reference to FIGS. 4 and 5. 4 and 5 are diagrams for explaining a process of molding the skin material sheet S of the resin panel 1 of the present embodiment, respectively.

Referring to FIG. 4, the mold clamping device 70 is located between the open position and the closed position in a direction substantially orthogonal to the molten resin sheets P and P extruded vertically downward from the extruder (not shown). It has a pair of split molds 71A and 71B that can be moved. The pair of split dies 71A and 71B are arranged so that the corresponding forming surfaces 72A and 72B face each other. The forming surface 72A has a shape corresponding to the front surface and the back surface of the interior material 2.

In each of the pair of split dies 71A and 71B, pinch-off portions 74A and 74B are formed in the vicinity of the upper and lower ends of the forming surfaces 72A and 72B corresponding to each. The pinch-off portions 74A and 74B are formed in an annular shape around the forming surfaces 72A and 72B, respectively, and project toward the opposing split dies 71B and 71A. As a result, when the pair of split dies 71A and 71B are molded, the tips of the pinch-off portions 74A and 74B come into contact with each other, and a parting line is formed on the peripheral edges of the molten resin sheets P and P. ing.

The pair of split dies 71A and 71B are provided with sliding portions 75A and 75B so as to be able to project from the forming surfaces 72A and 72B around the forming surfaces 72A and 72B. The sliding portions 75A and 75B are brought into contact with the molten resin sheets P and P in a state of protruding from the forming surfaces 72A and 72B, whereby the molten resin sheets P and P and the pair of split dies 71A and 71B are formed. It is provided to form a closed space between the forming surfaces 72A and 72B.

A vacuum chamber (not shown) is built in the pair of split dies 71A and 71B. The vacuum chamber is connected to a vacuum pump and a vacuum tank (neither shown). A communication path (not shown) for vacuum suction is provided between the vacuum chamber and the forming surfaces 72A and 72B.

The pair of split molds 71A and 71B are driven by a mold driving device (not shown) so as to be movable between an open position and a closed position. In the open position, two continuous molten resin sheets P and P can be arranged between the pair of split dies 71A and 71B at intervals from each other. The two molten resin sheets P and P become the skin material sheet S in the resin panel 1 after molding. In the closed position, the pinch-off portions 74A and 74B of the pair of split dies 71A and 71B come into contact with each other.

Next, the molding method of the resin panel 1 will be described.
First, as shown in FIG. 4, the molten resin sheets P and P are extruded vertically downward from the extruder and supplied between the forming surfaces 72A and 72B of the pair of split dies 71A and 71B. At this point, the pair of split dies 71A and 71B are in the open position.

Next, the sliding portions 75A and 75B around the forming surfaces 72A and 72B are projected, and the end surfaces thereof are brought into contact with the molten resin sheets P and P. As a result, a closed space is formed between the molten resin sheets P and P and the forming surfaces 72A and 72B of the pair of split dies 71A and 71B. Then, the air in the closed space is sucked by the communication passage provided between the vacuum chamber and the forming surfaces 72A and 72B. By this suction, the two molten resin sheets P and P are pressed against the forming surfaces 72A and 72B of the pair of split dies 71A and 71B, respectively, and along the forming surfaces 72A and 72B as shown in FIG. It is shaped (formed) into a shape, that is, a substantially outer shape of the resin panel 1.

Next, the interior material 2 assembled as described above is positioned between the pair of split dies 71A and 71B using a manipulator (not shown), and as shown in FIG. 5, one of them is positioned from the side. It is inserted by pressing it against the split die (split die 71B in FIG. 5). As a result, the interior material 2 is welded to one of the molten resin sheets P.

After that, the pair of split dies 71A and 71B are moved from the open position to the closed position and molded. As a result, the interior material 2 that has been welded to one molten resin sheet P (right side in the drawing) is also welded to the other molten resin sheet P (left side in the drawing). Further, in the pinch-off portions 74A and 74B of the pair of split dies 71A and 71B, the peripheral edges of the pair of molten resin sheets P and P are welded to form a parting line PL.

Finally, the pair of split dies 71A and 71B are moved to the open positions again, the molded resin panel 1 is separated from the forming surfaces 72A and 72B, and the burrs formed around the parting line PL are removed by a cutter or the like. Cut and remove. With the above, the resin panel 1 having a structure in which the interior material 2 is covered with the skin material sheet S is completed.
In the above-mentioned molding method of the resin panel 1, the case where the molten resin sheet P is pressed against the forming surfaces 72A and 72B of the pair of split dies 71A and 71B by suction has been described, but this is not the case. The molten resin sheet P may be pressed against the forming surfaces 72A and 72B of the pair of split dies 71A and 71B by blowing a fluid such as air on the molten resin sheet P (blow molding).

As described above, according to the resin panel 1 of the present embodiment, since the interior material 2 is formed by combining the foamed portion having a low foaming ratio and the foamed portion having a high foaming ratio, the foamed portion having a low foaming ratio locally causes the foamed portion. It is possible to suppress the overall weight while ensuring sufficient rigidity.

FIG. 6 shows an example of using the resin panel 1 of the present embodiment. In FIG. 6, the skin material sheet S is removed from the resin panel 1 (that is, the interior material 2) so that the connected state of the plurality of foamed portions can be seen. In FIG. 6, the resin panel 1 is mounted on the table ST and used, but an example of use is assumed when the area of the resin panel 1 in contact with the table ST is small. In such a usage example, even if a reinforcing material (reinforce) is incorporated along the short side side wall surface 2d of the interior material, the resin panel cannot be effectively reinforced. The reason is that if the edge of the reinforcing material is too close to the skin material sheet S, the skin material sheet S may be damaged. Therefore, both ends of the reinforcing material may be arranged up to the long side side wall surface 2c of the interior material. Because it cannot be done.
On the other hand, in the interior material 2 of the resin panel 1 of the present embodiment, the foamed portions 21 and 23 having a relatively high rigidity and a low foaming ratio are formed over the entire area of the side wall surface 2d on the short side. Even when the area of the resin panel 1 in contact with the ST is small, the resin panel 1 can be locally reinforced.

(4) Deformation Example of Resin Panel Next, the resin panel according to the modification will be described with reference to FIGS. 7 to 12. 7 to 12 are diagrams showing interior materials incorporated in the resin panel according to the modified example of the embodiment, respectively. In each figure, the state in which the skin material sheet is removed from the resin panel (that is, the interior material) is shown so that the engaged state of the plurality of foamed portions can be seen.

(4-1) First Deformation Example FIG. 7A is a plan view of the interior material 2A according to the first modification and the table ST on which the interior material 2A is placed. 7 (b) and 7 (c) show examples of the AA cross sections of FIG. 7 (a), respectively.
As shown in FIG. 7A, in the interior material 2A according to the first modification, similarly to the interior material 2, the foamed portions 21A and 23A having a low foaming ratio and the foamed portions 22A having a high foaming ratio are connected. Is formed. As illustrated in FIGS. 7 (b) and 7 (c), the interior material 2A according to the first modification has a uniform cross-sectional shape because the cross-section of the interior material 2A is not uniform. Reinforcing material cannot be used. In particular, in the case of FIG. 7C, it is even more difficult to use a reinforcing material because the end portion of the interior material 2A is thin.
However, since the interior material 2A according to the first modification includes foamed portions 21A and 23A having a relatively high foaming ratio and a low foaming ratio, the rigidity of the interior material 2A should be locally increased without using a reinforcing material. Can be done.
Further, when a resin panel having a structure having a recess in the center as shown in FIG. 7B is used for the rear parcel shelf of the vehicle, the seat is seated in the recess to protect the occupants in the event of a rear collision of the vehicle. It is required to give in (that is, to have a shock absorbing effect). Here, if a general-purpose reinforcing material (reinforce) is used instead of the foamed portions 21A and 23A, the reinforcing material may not be properly broken at the time of collision, which may cause an unfavorable situation for occupant protection. On the other hand, in this modified example, since it is easy to buckle in the central recess, there is an advantage that it is easy to exert a shock absorbing effect while ensuring local rigidity.

(4-2) Second Deformation Example FIG. 8 is a plan view of the interior material 2B according to the second modification and the table ST on which the interior material 2B is placed.
As shown in FIG. 8, the interior material 2B according to the second modification is placed on the base ST at the left and right ends, and the foamed portion 21B having a low foaming ratio and the foamed portion 22B having a high foaming ratio are connected. Is formed. The foamed portion 21B of the interior material 2B has an overall curved shape over the left and right ends on the lower side in the drawing. In the case of such a curved shape, it is not possible to use a general-purpose reinforcing material having a uniform cross-sectional shape even if the thickness is uniform. However, in the interior material 2B according to the second modification, since the foaming ratio of the foamed portion 21B is lowered, the rigidity of the curved shape portion can be locally increased without using a reinforcing material.

(4-3) Third Deformation Example FIG. 9 is a plan view of the interior material 2C according to the third modification and the table ST on which the interior material 2C is placed.
As shown in FIG. 9, the interior material 2B according to the third modification is placed on the base ST at the left and right ends, and the foamed portion 21C having a low foaming ratio and the foamed portion 22C having a high foaming ratio are connected. Is formed. Since the handle 21Ch is attached to the foamed portion 21C of the interior material 2C, the cross-sectional shape of the foamed portion 21C is not uniform, so that a general-purpose reinforcing material having a uniform cross-sectional shape can be used. Can not. However, in the interior material 2C according to the third modification, since the foaming ratio of the foamed portion 21C is lowered, the rigidity of the interior material 2C can be locally increased even when the handle 21Ch is provided.

(4-4) Fourth Deformation Example FIG. 10 is a plan view of the interior material 2D according to the fourth modification and the table ST on which the interior material 2D is placed.
In the interior material 2 of the above-described embodiment and the interior materials 2A to 2C according to the first to third modifications, a case where a foamed portion having a high rigidity and a low foaming ratio is arranged along the peripheral edge of the interior material will be described. However, it is not limited to that case. In the fourth modification, the foamed portion having a low foaming ratio is formed so as to cross from a part of the peripheral edge of the interior material to another portion.
The interior material 2D according to the fourth modification shown in FIG. 10 is placed on the table ST over the entire peripheral edge. The interior material 2D is formed by connecting the foamed portions 21D and 23D having a high foaming ratio and the foamed portions 22D having a low foaming ratio. The foamed portion 22D having a high rigidity and a low foaming ratio is formed between a pair of long side side wall surfaces 2c facing each other in the central portion of the interior material 2D.

(4-5) Fifth Deformation Example FIG. 11A is a plan view of the interior material 2E according to the fifth modification and the table ST on which the interior material 2E is placed. FIG. 11B is an enlarged cross-sectional view taken along the line BB of FIG. 11A.
In the interior material 2 of the above-described embodiment and the interior materials 2A to 2D according to the first to fourth modifications, the case where a foamed portion having a low foaming ratio is applied instead of the reinforcing material has been described. Reinforcing material can also be used in addition to the foamed portion of the magnification. The interior material 2E according to the fifth modification is different in that the reinforcing material 3 is arranged between the pair of short side side wall surfaces 2d facing each other with respect to the interior material 2D according to the fourth modification.
As shown in FIG. 11B, the reinforcing material 3 is a reinforcement having an H-shaped cross section. With the arrangement of the reinforcing material 3, the interior material 2E is formed by connecting the foamed portions 21E, 22E, 23E, 24E having a high foaming ratio and the foamed portions 25E, 26E having a low foaming ratio. The foamed portion 25E is fitted from one side of the reinforcing material 3, and the foamed portion 26E is fitted from the other side of the reinforcing material 3.

(4-6) Sixth Deformation Example FIG. 12 is a perspective view of the interior material 2F according to the sixth deformation example.
The interior material 2F shown in FIG. 12 is formed by connecting the foamed portions 21F and 23F having a low foaming ratio and the foamed portions 22F having a high foaming ratio. A hinge HG is formed on the interior material 2F so as to cross between the pair of long side side wall surfaces 2c. As shown in FIG. 12, when the hinge HG is formed in at least a part of the foamed portions 21F and 23F, if a reinforcing material is to be incorporated at the position where the foamed portions 21F and 23F are provided, the hinge function is activated. In order to secure the reinforcing material, the end portion in the extending direction must be separated from the hinge HG, and it is difficult to reinforce the vicinity of the hinge HG. On the other hand, in the interior material 2F of this modified example, since the foamed portions 21F and 23F having relatively high rigidity and low foaming ratio are applied in the vicinity of the hinge HG, it is possible to reinforce the vicinity of the hinge HG. ..

(5) Modification Example of Connection Method of Two Adjacent Foaming Parts In the above-described embodiment, foaming is performed by engaging a U-shaped groove and a U-shaped protrusion at the ends of the foaming portion 21 and the foaming portion 22. Although the connection method for connecting the foamed portion 21 and the foamed portion 22 has been illustrated, the method for connecting the foamed portions is not limited to this.
Hereinafter, a modified example of the method of connecting two adjacent foam portions in the interior material will be described with reference to FIGS. 13 to 18. 13, 14, 16 to 18 are perspective views illustrating a method of connecting the first foamed portion J1 and the second foamed portion J2, respectively. (A) of FIGS. 13, 14, 16 to 18 shows the state before connection, and (b) of FIGS. 13, 14, 16 to 18 shows the state after connection. In FIGS. 13, 14, 16 to 18 (b), the connecting region H between the foamed portions is shown. FIG. 15A is a plan view of the modified example shown in FIG. 15 (b) and 15 (c) are enlarged cross-sectional views of CC and DD of FIG. 15 (a), respectively.

(5-1) First Deformation Example In the first modification shown in FIG. 13, the connection method is to engage the trapezoidal groove and the trapezoidal protrusion to make the first foam portion J1 and the second foam portion J1 and the second. This is a method of connecting the foamed portions J2. In this connection method, the trapezoidal groove of the first foamed portion J1 and the second foamed portion J2 and the trapezoidal protrusion are engaged in the vertical direction to connect the two. The connecting method of the present modification is effective in that the relative movement of the first foamed portion J1 and the second foamed portion J2 in the lateral direction is restricted once they are engaged.

(5-2) Second Modified Example In the connecting method according to the second modified example shown in FIG. 14, holes J1h and protrusions J1p are alternately formed in the first foamed portion J1, and the second foamed portion is formed. Holes J2h and protrusions J2p are alternately formed in J2. The hole J1h of the first foamed portion J1 and the protrusion J2p of the second foamed portion J2 are engaged, and the protrusion J1p of the first foamed portion J1 and the hole J2h of the second foamed portion J2 are engaged in the vertical direction. As a result, the first foamed portion J1 and the second foamed portion J2 are connected. The plate thickness in the connecting region H of the first foamed portion J1 and the second foamed portion J2 is set so as to obtain a desired plate thickness in the connecting region H. The number of holes and protrusions in each foamed portion can be arbitrarily selected.

As shown in FIGS. 15 (b) and 15 (c), in the connecting method according to the present modification, both the first foamed portion J1 and the second foamed portion J2 are made of the interior material in the connecting region H. It has a portion (penetrating portion) that penetrates between the front surface and the back surface at the shortest distance. When the skin material is molded on the interior material, the penetrating portion is welded to the molten resin sheet serving as the skin material on both the front surface and the back surface of the interior material, so that the first in the connecting region H. There is an effect that the connecting force between the foamed portion J1 and the second foamed portion J2 is increased.
In addition, also in the connection method (FIG. 3) of the above-described embodiment and the connection method (FIG. 13) according to the first modification, both the first foam portion J1 and the second foam portion J2 in the connection region H Since it has a portion that penetrates between the front surface and the back surface of the interior material at the shortest distance, it also has the effect of having a high connecting force.

(5-3) Third Modified Example In the connecting method according to the third modified example shown in FIG. 16, a protrusion J1p is formed in the first foamed portion J1, and a hole J2h is formed in the second foamed portion J2. It is formed. By engaging the protrusion J1p of the first foamed portion J1 and the hole J2h of the second foamed portion J2, the first foamed portion J1 and the second foamed portion J2 are connected. The plate thickness in the connecting region H of the first foamed portion J1 and the second foamed portion J2 is set so as to obtain a desired plate thickness in the connecting region H. The number of protrusions J1p of the first foaming portion J1 and the number of holes J2h of the second foaming portion J2 can be arbitrarily selected.

(5-4) Fourth Modified Example In the connecting method according to the fourth modified example shown in FIG. 17, a U-shaped groove and a U-shape are formed at the ends of the first foamed portion J1 and the second foamed portion J2. The point where the shaped protrusions are formed is the same as the example shown in FIG. 3, but the U-shaped groove and the pattern of the U-shaped protrusions are complementary on the front side and the back side. Is different from the example shown in FIG. In this modified example as well, as in FIG. 3, the U-shaped groove of the first foamed portion J1 and the first foamed portion J1 and the U-shaped protrusion are engaged with each other to provide a connecting region H.

(5-5) Fifth Deformation Example In the connection method according to the fifth modification shown in FIG. 18, the holes are compared with the second modification (FIG. 14) and the third modification (FIG. 16). The difference is that there are no protrusions. In this modification, since the first foamed portion J1 and the second foamed portion J2 easily move relative to each other, it is preferable to bond the first foamed portion J1 and the second foamed portion J2 with an adhesive.

Although the embodiment of the present invention and its modification have been described in detail above, the resin panel and foam of the present invention are not limited to the above embodiment and its modification, and are not deviated from the gist of the present invention. Of course, various improvements and changes may be made.
For example, in the above-described embodiment and its modification, the interior material as a foam is formed by connecting the two foamed portions, but the present invention is not limited to this. In one foam molding step, foam regions having different foam ratios may be formed at the same time.

Hereinafter, the present invention will be further described with reference to Examples. However, the present invention is not limited to the embodiments shown in the examples.

(1) Production of Resin Panels According to Examples and Comparative Examples FIG. 19 shows the shape (substantially rectangular parallelepiped) and configuration of the interior material contained in the resin panel according to the examples.
As shown in FIG. 19, the foamed portions J1 to J3 were separately foam-molded and then connected to prepare the interior material according to the embodiment. The foamed portion J2 has a hinge set as shown in FIG. A U-shaped groove and a U-shaped protrusion are set in the connecting portion of the foamed portions J1 and J2 and the connecting portion of the foamed portions J2 and J3.
FIG. 20 shows the shape and configuration of the interior material contained in the resin panel according to the comparative example.
As shown in FIG. 20, the overall shape and size of the interior material of the comparative example are the same as those of the interior material of the example, but are different from the example in that they are molded with a single foam material.

As the interior material according to Examples and Comparative Examples, polystyrene (PS) and polyethylene (PE) were foam-molded (Pioceran (registered trademark) of Sekisui Plastics Co., Ltd.).
In the interior material according to the embodiment, the foaming ratio of the foamed portions J1 and J3 was set to 15 times, and the foaming ratio of the foamed portion J2 was set to 30 times.
In the interior material of Comparative Example 1, the foaming ratio was set to 30 times.
In the interior material of Comparative Example 2, the foaming ratio was set to 20 times.
In the interior material of Comparative Example 3, the foaming ratio was set to 15 times.
In the interior material of Comparative Example 4, the foaming ratio was set to 30 times.
The plate thickness of the interior materials of Examples and Comparative Examples 1 to 4 was 19 mm.

In the interior material of Comparative Example 4, an aluminum cross-section I-shaped reinforce (second moment of area: 3400 mm ⁴ ) was fitted to the foam material at four positions shown by broken lines in FIG. 20 as a reinforcing material.

Next, as described with reference to FIGS. 4 and 5, a pair of molten resin sheets to be the skin material sheets are hung between the pair of split dies and molded along the molding surface to produce an interior material. Was welded to the molten resin sheet. Then, the split mold was molded to form a parting line on the periphery of the pair of molten resin sheets. Further, the pair of split dies were moved to the open position, separated from the forming surface of the molded resin panel split die, and the burrs were removed with a cutter to prepare a resin panel.
Here, as the molten resin to be the skin material sheet, a kneaded product of polypropylene (PP) and linear polyethylene (LLDPE) was used, and the sheet thickness was 1.0 mm.
The thickness of the resin panel according to the examples and the comparative examples was 21 mm.

(2) Evaluation of Samples Related to Examples and Comparative Examples The rigidity of the resin panels according to Examples and Comparative Examples 1 to 4 was evaluated.
Specifically, first, as shown in FIGS. 19 and 20, the resin panels according to the examples and the comparative examples are based on a pair of long side end portions of a substantially rectangular parallelepiped resin panel 1. It was placed. Here, the span L between the pedestals was set to 500 mm or 600 mm.
Next, loads of 20 kg, 40 kg, 60 kg, and 80 kg were applied to a range of 60 mm in diameter centered on points A and B in FIGS. 19 and 20, and the displacement was measured. Point A is the center position of the region on the right side of the hinge in FIGS. 19 and 20. Point B is located at the center of the pair of long side end portions facing each other in FIGS. 19 and 20, and is located 40 mm to the left from the right side short side end portion.
Table 1 shows the results of measurement with the span L between the tables as 500 mm, and Table 2 shows the results of measurement with the span L as 600 mm. When the span L was set to 600 mm, the resin panel might be damaged, so the load was limited to 40 kg.

As shown in Table 1, when the span L between the tables is 500 mm, the displacement of the center A point of the resin panel of the example is close to that of Comparative Example 1 (foaming ratio: 30 times), and the edge It can be seen that the displacement of point B in the vicinity of the portion is close to that of Comparative Example 2 (foaming ratio: 20 times). Here, when the resin panel is placed on the table as shown in FIGS. 19 and 20, the vicinity of the short side end portion of the resin panel (that is, the region including the point B) has the highest structural rigidity. Since it is a region that tends to be low, in the resin panel of the example, the foaming ratio is reduced to 20 times as a whole in the region having the lowest rigidity while being lighter than the foaming ratio of 20 times as a whole. It means that it could be made equivalent to the one.
Further, when the displacement difference between points A and B is compared, the displacement difference of the resin panel of the example is smaller than that of Comparative Examples 1 to 3 excluding Comparative Example 4 including the reinforcing material. It can be seen that the part can be selectively reinforced.

As shown in Table 2, the same result was obtained when the span L between the tables was set to 600 mm. That is, the displacement of point A in the center of the resin panel of the example is close to that of Comparative Example 4 (foaming ratio: 30 times), and the displacement of point B near the end is that of Comparative Example (foaming ratio: 20 times). You can see that it is close. Further, when the displacement difference between points A and B is compared, it can be seen that the displacement difference of the resin panel of the example is smaller as a whole than that of Comparative Examples 1 to 3 excluding Comparative Example 4 including the reinforcing material.

1 ... Resin panel S ... Skin material sheet 1a ... Front surface 1b ... Back surface 1c ... Long side side wall surface 1d ... Short side side wall surface 2,2A, 2B, 2C, 2D, 2E ... Interior material (foam) Example)
2c ... Long side side wall surface 2d ... Short side side wall surface 21,21A, 21B, 21C, 21D, 21E, 22, 22A, 22B, 22C, 22D, 22E, 23, 23A, 23D, 23E, 24E, 25E, 26E ... Foaming part 21Ch ... Handle 3 ... Reinforcing material 70 ... Mold clamping device 71A, 71B ... Dividing mold 72A, 72B ... Forming surface 74A, 74B ... Pinch-off part 75A, 75B ... Sliding part P ... Molten resin sheet ST ... Stand H ... Connecting region J1 ... First foamed portion J2 ... Second foamed portion J1p, J2p ... Protrusions J1h, J2h ... Holes

Claims (5)

It is a plate-shaped foam
It is provided with a first foaming region having a first foaming ratio and a second foaming region having a second foaming ratio lower than the first foaming ratio.
The second foam region is formed at least partially along the periphery of the foam, or is formed so as to cross from one part of the periphery of the foam to another.
The first foamed portion having the first foamed region and the second foamed portion having the second foamed region are connected to each other.
The first foamed portion and the second foamed portion have irregularities along the sides facing each other.
The unevenness of the first foamed portion and the second foamed portion is unevenness in a direction facing each other, and the foam is connected by fitting these unevennesses. It is a plate-shaped foam
It is provided with a first foaming region having a first foaming ratio and a second foaming region having a second foaming ratio lower than the first foaming ratio.
The second foam region is formed at least partially along the periphery of the foam, or is formed so as to cross from one part of the periphery of the foam to another.
The first foamed portion having the first foamed region and the second foamed portion having the second foamed region are connected to each other.
The unevenness of the first foamed portion and the second foamed portion is formed as a stepped portion in the thickness direction.
A protrusion is formed on at least one of the stepped portion between the first foamed portion and the second foamed portion, and the first foamed portion and the second foamed portion are connected by engaging the protrusion. A foam characterized by. The second foamed region is characterized in that the cross-sectional thickness is not uniform.
The foam according to claim 1 or 2. A hinge is formed in at least a part of the second foamed region.
The foam according to claim 3. A resin panel in which the foam according to any one of claims 1 to 4 is covered with a skin material sheet.

Images