JP7837764B2 - Plastic molded body - Google Patents

Description

This invention relates to a plastic molded body comprising a main body fixed to a container and a top lid that covers the main body and can seal the container.

Conventionally, as a plastic molded body for closing the opening of a container or a dispensing cap, a plastic molded body consisting of a main body fixed to the container and an upper lid that locks onto the main body and blocks the dispensing nozzle, is known from Patent Document 1, etc.

The plastic molded body (hinged cap with sorting function 1) described in Patent Document 1 has a main body (cap body 2) and an upper lid (3), an annular wall (16) hanging down from the top surface (top plate 14) of the upper lid (3), a dispensing nozzle (dispensing cylinder 12) is provided on the top plate portion (top plate 6) of the main body (cap body 2), and a beak-shaped portion (12a) is formed on a part of the upper part of the dispensing nozzle (dispensing cylinder 12) opposite to the hinge (4), which is formed to protrude upward and radially outward.
This plastic molded body (a hinged cap with a sorting function 1) has a planned opening (5) formed on the top plate (top plate 6), and the liquid contents of the container can be poured out through the opening created by cutting out the planned opening (5).

Furthermore, the beak-shaped portion (12a) is provided to improve the ease of pouring when dispensing liquid contents.
Furthermore, when the top lid (3) is closed, the outer surface of the annular wall (16) comes into close contact with the circumferentially uniform straight section of the lower inner surface of the dispensing nozzle (dispensing cylinder 12). Therefore, after cutting out the opening portion (5) and dispensing the liquid contents, the plastic molded body (hinged cap with separation function 1) is sealed by the contact surface between the annular wall (16) and the dispensing nozzle (dispensing cylinder 12), preventing leakage of the liquid contents.

Furthermore, a plastic molded body in which an enlarged diameter surface (liquid-cutting edge 2) forming an outwardly curved flange is provided around the entire circumference of the upper part of the dispensing nozzle (dispensing outlet 1) is also known, as described in Patent Document 2, etc.

The plastic molded body described in Patent Document 2 has a main body (cap body 9) to which the top lid (outer cap 10) is hinged. When the top lid (cap 10) is closed, the outer surface of the annular wall provided on the top lid (outer cap 10) comes into close contact with the inner surface of the dispensing nozzle (dispensing outlet 1), thereby sealing the plastic molded body.

Japanese Patent Publication No. 2009-298447 Japanese Unexamined Patent Publication No. 53-144966

However, the hinge caps with sorting functions known from the above-mentioned patent documents still had room for improvement.

In other words, the hinge cap with a sorting function known from the above-mentioned patent documents, etc., is sealed by inserting the outer surface of the annular wall into the lower inner surface of the pouring cylinder or spout after the opening portion has been cut out, so it is necessary to form a long annular wall. However, if the enlarged diameter surface is provided around the entire circumference of the pouring cylinder or spout so as not to restrict the direction of dispensing of the contents, the annular wall on the hinge side may interfere with the tip of the enlarged diameter surface, making it impossible to close the top lid, thus impairing the so-called top lid covering ability.
Furthermore, because the hinge cap with a sorting function is sealed by the tight contact between the straight sections of the outer surface of the annular wall and the inner surface of the dispensing cylinder and spout, the contact surfaces between them increase, and there was a risk that the annular wall and the dispensing cylinder and spout would become excessively tight, increasing the burden on the user when opening and closing the top lid.
Furthermore, forming a long annular wall would increase the amount of resin required for molding, potentially leading to higher costs.

This invention aims to solve these problems by providing a plastic molded product with a simple structure that allows the top lid to be securely closed to seal the dispensing nozzle, can be opened and closed without burdening the user, and can suppress increases in manufacturing costs.

The present invention provides a plastic molded body comprising a main body fixed to a container and a top lid that covers the main body and can close the container, wherein the main body is provided with a top plate portion and a skirt portion hanging down from the top plate portion, and a cylindrical dispensing nozzle protruding from the top plate portion is provided on the upper surface side of the top plate portion, and the inner circumferential surface of the upper part of the dispensing nozzle has an expanding diameter surface that gradually widens as it goes upward along its entire circumference, and the top lid is provided with a top surface and a circumferential wall hanging down from the outer edge of the top surface, and the top lid is provided with the top surface The lid further has a protruding portion that projects downward from the inside of the circumferential wall, and an elastic sealing piece is provided at the lower part of the protruding portion, connected via a thin-walled portion formed to be thin, and an annular sealing surface is formed on the inner surface side of the elastic sealing piece that can adhere closely to the inner circumferential surface of the dispensing nozzle, and the elastic sealing piece is configured to be reversible in the upward direction, and a reversal assist extension is provided at the lower end of the elastic sealing piece, so that when the top lid is placed over the main body, the annular sealing surface comes into contact with the enlarged diameter surface, thereby solving the above problem.

According to the plastic molded article of claim 1, a thin-walled portion is provided between the protrusion and the elastic sealing piece. By bending the thin-walled portion, the elastic sealing piece can be reversed, and the elastic sealing piece can be positioned on the outer circumferential surface side of the protrusion.
This allows for a reduction in the outer diameter of the protruding part, thereby suppressing interference between the protruding part and the dispensing nozzle.
Furthermore, when the annular sealing surface comes into contact with the enlarged diameter surface, an elastic sealing piece is sandwiched between the protrusion and the dispensing nozzle, generating a repulsive force. This increases the adhesion between the annular sealing surface and the enlarged diameter surface, ensuring reliable sealing of the dispensing nozzle and improving vibration and drop impact resistance.
Furthermore, since the plastic molded body can be sealed by bringing the annular sealing surface into contact with the enlarged diameter surface provided on the top of the dispensing nozzle, there is no need to form a long protrusion. Even if the enlarged diameter surface is provided uniformly in the circumferential direction on the top of the dispensing nozzle to facilitate pouring of the contents and to avoid restricting the direction of dispensing of the contents, the protrusion does not interfere with the enlarged diameter surface when closing the top lid. The elastic sealing piece inverts to follow the shape of the top of the dispensing nozzle, so a seal can be formed between the annular sealing surface and the enlarged diameter surface without impairing the so-called top lid fit.
Furthermore, since it is not necessary to form the protruding portion long enough to reach the bottom of the dispensing nozzle, the amount of resin required for molding can be suppressed, thereby suppressing an increase in manufacturing costs.
Furthermore, since the inner circumferential surface of the enlarged diameter gradually widens towards the top, when the top lid is closed, the elastic sealing piece is positioned so as to be sandwiched diagonally between the protruding portion and the enlarged diameter surface.
This prevents excessive compression of the elastic seal piece compared to the case where the elastic seal piece is sandwiched from the side between the protruding part and the straight part of the dispensing nozzle, prevents excessive adhesion between the annular seal surface and the enlarged diameter surface, reduces the burden on the user when opening, and allows the annular seal surface to be easily separated from the enlarged diameter surface.
Furthermore, when the annular sealing surface is brought into contact with the enlarged diameter surface while the plastic molded body is still warm immediately after molding, the thin-walled portion is more easily deformed, allowing the elastic sealing piece to be easily reversed and positioned on the outer circumferential surface of the protrusion. Moreover, by cooling the thin-walled portion while it is still deformed, the elastic sealing piece can be retained on the outer circumferential surface side of the protrusion.
Furthermore, the protruding portion, the elastic sealing piece, and the thin-walled portion can be integrally molded, preventing the elastic sealing piece from remaining inside the dispensing nozzle when the protruding portion is removed, thus preventing opening failures. This reduces the increase in the number of parts and suppresses increases in manufacturing costs.
Furthermore, since the lower part of the elastic seal piece is provided with an inversion assist extension, when placing the top lid on the main body, simply moving the elastic seal piece connected to the inversion assist extension while bringing the inner surface of the inversion assist extension into contact with the top of the dispensing nozzle will automatically bend its thin-walled portion and invert it, allowing it to be easily moved to the outer surface of the protruding portion.

According to the configuration described in claim 2, the outer diameter of the protrusion is formed to be larger than the smallest inner diameter of the enlarged surface, thereby preventing the protrusion from entering below the enlarged surface of the dispensing nozzle and ensuring that the annular sealing surface comes into contact with the enlarged surface from above.
This makes it possible to more reliably prevent excessive compression of the elastic sealing piece and prevent excessive adhesion between the annular sealing surface and the enlarged diameter surface.
According to the configuration described in claim 3, since the enlarged diameter surface is formed in an R-shape, the contact area between the annular sealing surface and the enlarged diameter surface can be further reduced, preventing excessive adhesion between the annular sealing surface and the enlarged diameter surface, and reducing the burden on the user when opening, allowing the annular sealing surface to be easily detached from the enlarged diameter surface.

According to the configuration described in claim 4, the inner circumferential surface of the dispensing nozzle is provided with a cylindrical surface that extends vertically and has a uniform inner diameter, and the enlarged diameter surface is connected to the upper end of the cylindrical surface. Therefore, even when the annular sealing surface comes into contact with the lower end of the enlarged diameter surface, the annular sealing surface does not interfere with the cylindrical surface below the enlarged diameter surface, and the close contact between the annular sealing surface and the enlarged diameter surface can be stabilized.
According to the configuration described in claim 5, when the top lid is placed over the main body, the inclination angle of the enlarged diameter surface that contacts the annular sealing surface is 20 degrees or more and 80 degrees or less when viewed from the top plate portion. This ensures that excessive pressure on the elastic sealing piece is prevented while maintaining adequate sealing performance, preventing excessive adhesion between the annular sealing surface and the enlarged diameter surface, and reducing the burden on the user when opening, allowing the annular sealing surface to be easily detached from the enlarged diameter surface.

According to the configuration described in claim 6 , since the reversal assist extension has a notch that opens downwards, the reversal assist extension can be opened more easily, and when placing the top cover on the main body, the elastic sealing piece can be reversed and moved to a position where the annular sealing surface can contact the enlarged diameter surface.

According to the configuration described in claim 7 , since the main body and the top lid are integrally molded, the number of molds to be manufactured can be reduced, and cost increases can be suppressed.
Furthermore, since the main body and the top lid are connected via a hinge, the operation of the top lid during opening and closing can be stabilized, and the annular sealing surface can be more reliably brought into contact with the enlarged diameter surface.

A perspective view of a plastic molded body 100 according to one embodiment of the present invention. A top view of a plastic molded body 100 according to one embodiment of the present invention. A side cross-sectional view of a plastic molded body 100 according to one embodiment of the present invention. A side cross-sectional view showing a plastic molded body 100 according to one embodiment of the present invention, with the endless score 128 fractured. A side cross-sectional view showing a plastic molded body 100 according to one embodiment of the present invention in the process of being closed. A side cross-sectional view showing the state of a plastic molded body 100 after it has been sealed, according to one embodiment of the present invention. An enlarged view of part A showing the state of a plastic molded body 100 according to one embodiment of the present invention after it has been sealed. A side cross-sectional view showing the state of a plastic molded body 100 after opening, according to one embodiment of the present invention. A side cross-sectional view showing the state of a plastic molded body 100 according to one embodiment of the present invention, after the plug has been closed and before the endless score 128 is broken.

A plastic molded article 100 according to one embodiment of the present invention will be described below with reference to the drawings.
Note that the container in which the plastic molded body 100 is fixed is not shown.
As shown in Figures 1 to 3, the plastic molded body 100 has a cap body 110 which is the main body fixed to the container, and an upper lid 120 which covers the cap body 110 and can close the container.

The cap body 110 is provided with a top plate portion 111, a locking ring 119 protruding in a ring shape from above the top plate portion 111, a skirt portion 114 hanging down from the outer peripheral edge of the top plate portion 111, an endless score 128 formed in a circular shape below the top plate portion 111, and a fitting cylinder 113 hanging down from inside the skirt portion 114 and outside the endless score 128. A fitting portion 115 protruding radially inward is formed on the lower inner circumference side of the skirt portion 114.
The cap body 110 fits onto the mouth of the container by sandwiching it between the skirt portion 114 and the fitting cylinder 113, and is secured in place by the fitting portion 115.

On the upper surface of the top plate portion 111, a dispensing nozzle 116 is provided that extends upward so as to surround the endless score 128. The inner circumferential surface of the dispensing nozzle 116 has a cylindrical surface 133 with a uniform inner diameter formed by a straight surface that extends almost vertically upward from the lower end, and an R-shaped enlarged diameter surface 117 that gradually widens in diameter from the upper end of the cylindrical surface 133 towards the top, extending around the entire circumference.
Furthermore, the cylindrical surface 133 is formed to a height of more than half the vertical length of the dispensing nozzle 116, and the enlarged diameter surface 117 is formed to the same height all around.

The top cover 120 is provided with a top surface 121 and a circumferential wall 122 that hangs down from the outer edge of the top surface 121. An outer ring 130 is formed inside the circumferential wall 122, and a protrusion 123 is formed inside the outer ring 130.
A locking portion 134 is formed on the inner circumferential surface of the circumferential wall 122, which can engage with the locking ring 119.
An elastic sealing piece 125 is provided at the lower part of the protrusion 123, that is, at the tip side not connected to the top surface 121, along the outer surface of the protrusion 123, and the protrusion 123 and the elastic sealing piece 125 are connected by a thin-walled portion 124.
Furthermore, the elastic sealing piece 125 is formed to gradually widen in diameter from the thin-walled portion 124 side toward the end side not connected to the thin-walled portion 124, that is, in the direction away from the outer surface of the protruding portion 123.

The elastic sealing piece 125 has an annular sealing surface 126 that is formed to protrude radially inward in a curved shape, and the tip side of the elastic sealing piece 125 is provided with a reversal assist extension 127 that is spaced apart circumferentially by a notch 129.
The cap body 110 and the top lid 120 are integrally molded parts connected by a hinge 132, and an opening flange 131 is formed on the circumferential wall 122 of the top lid 120 on the side opposite to the connection with the hinge 132.

Next, the closing and opening of the plastic molded body 100 according to one embodiment of the present invention will be explained with reference to Figures 3 to 8.

First, when the pull ring 118 is pulled upward from the state shown in Figure 3, the endless score 128 breaks, and as shown in Figure 4, an opening 112 for pouring out the liquid is formed in the top plate portion 111.
Next, as the top cover 120 is placed over the cap body 110 with the hinge 132 as the pivot point, the inner side (annular sealing surface 126) of the elastic sealing piece 125 on the hinge 132 side begins to come into contact with the enlarged diameter surface 117, as shown in Figure 5.
At this time, since the elastic sealing piece 125 is connected to the protruding portion 123 and the thin-walled portion 124, the elastic sealing piece 125 begins to tilt outward and invert as the thin-walled portion 124 deforms.
Furthermore, since the tip end of the elastic sealing piece 125 is provided with an inversion assist extension 127, the inside of the elastic sealing piece 125 is more likely to come into contact with the enlarged diameter surface 117, making inversion even easier.

As the top cover 120 is placed over the cap body 110, the elastic sealing pieces 125 successively come into contact with the enlarged diameter surface 117 from the side closest to the hinge 132, causing them to bend outward and flip over, so that the annular sealing surface 126 faces outward.
As the top lid 120 is placed over the cap body 110, the protruding portion 123 is positioned above the dispensing nozzle 116, and the annular sealing surface 126 and the enlarged diameter surface 117 gradually come into contact. When the top lid 120 is completely placed over the cap body 110, as shown in Figure 6, the locking ring 119 and the locking portion 134 engage, locking the top lid 120 to the cap body 110, and the elastic sealing piece 125 (annular sealing surface 126) is sandwiched between the enlarged diameter surface 117 and the outer surface of the protruding portion 123, making tight contact with the enlarged diameter surface 117 around its entire circumference.

As a result, the circumferentially continuous annular sealing surface 126 can be tightly fitted to the enlarged diameter surface 117 without any gaps in the circumferential direction, thereby sealing the opening 112 that communicates with the dispensing nozzle 116 and preventing leakage of the liquid contents.
Furthermore, even if the enlarged diameter surface 117 is temporarily deformed due to vibration or impact from dropping, the elastic sealing piece 125 also deforms in accordance with the deformation of the enlarged diameter surface 117, so that the contents do not leak out from between the annular sealing surface 126 and the enlarged diameter surface 117.
Furthermore, if the elastic sealing piece 125 is made of a material that is easily elastically deformable, the adhesion between the enlarged diameter surface 117 and the annular sealing surface 126 can be made stronger, further preventing leakage of the liquid contents inside the container.

Furthermore, by bending the thin-walled portion 124 to invert the elastic sealing piece 125 and positioning the elastic sealing piece 125 on the outer peripheral surface side of the protruding portion 123, the outer diameter of the protruding portion 123 can be made smaller, thus suppressing interference between the protruding portion 123 and the dispensing nozzle 116 when the cap is closed.
Furthermore, since the annular sealing surface 126 is brought into contact with the enlarged diameter surface 117 provided on the upper part of the dispensing nozzle to close the cap, there is no need to make the protruding portion 123 long enough to reach below the dispensing nozzle. Even if the enlarged diameter surface 117 is provided uniformly in the circumferential direction, the protruding portion 123 will not interfere with the enlarged diameter surface 117 when closing the cap, and a seal between the annular sealing surface 126 and the enlarged diameter surface 117 can be reliably formed.
Furthermore, since it is not necessary to form a long protrusion 123, the increase in the amount of resin required for molding can be suppressed, and thus the increase in manufacturing costs can be suppressed.

Furthermore, since the inner circumferential surface of the enlarged diameter surface 117 is formed in an R-shape that gradually widens as it extends upward, when the top cover 120 is closed, the elastic sealing piece 125 is positioned so as to be sandwiched diagonally between the protrusion 123 and the enlarged diameter surface 117, as shown in Figure 7.
This prevents excessive compression of the elastic sealing piece 125 compared to the case where the elastic sealing piece 125 is sandwiched from the side between the protruding portion 123 and the straight portion of the dispensing nozzle 116, prevents excessive adhesion between the annular sealing surface 126 and the enlarged diameter surface 117, reduces the burden on the user when opening, and allows the annular sealing surface 126 to be easily separated from the enlarged diameter surface 117.
Furthermore, when the top lid 120 is placed over the cap body 110, if the inclination angle B of the enlarged diameter surface 117 at the position in contact with the annular sealing surface 126 is between 20 degrees and 80 degrees, it is possible to maintain adequate sealing performance while preventing excessive compression of the elastic sealing piece 125, and to prevent excessive adhesion between the annular sealing surface 126 and the enlarged diameter surface 117.

When opening the bottle, the opening flange 131 is pushed upward to detach the top lid 120, thereby releasing the engagement between the locking ring 119 and the locking portion 134, and gradually separating the annular sealing surface 126 from the enlarged diameter surface 117.
Furthermore, if the inclination angle B of the enlarged diameter surface 117 at the position in contact with the annular sealing surface 126 is between 20 and 80 degrees, as described above, excessive adhesion between the annular sealing surface 126 and the enlarged diameter surface 117 is prevented, thereby reducing the burden on the user when opening and allowing the annular sealing surface 126 to be easily detached from the enlarged diameter surface 117.
Because the thin-walled portion 124 is bent and shaped when the cap is closed, the elastic sealing piece 125 remains in an inverted state when the cap is opened, as shown in Figure 7.

Furthermore, by sealing the plastic molded body 100 immediately after molding, the thin-walled portion 124, which is not yet cooled, is easily bendable, allowing the elastic seal piece 125 to be easily reversed. Compared to sealing the plastic molded body 100 after it has cooled, it is easier to shape the thin-walled portion 124.
Furthermore, the cap body 110 is not particularly limited in form as long as it is fixed to the container, and includes not only configurations that fit and fix to the mouth of a container such as a PET bottle, but also those formed in a spout shape that is welded and fixed to the mouth of a container such as a pouch.
An example of the manufacturing process for a plastic molded article 100 according to one embodiment of the present invention will be described.
First, the plastic molded body 100 is injection molded from polyethylene in the state shown in Figure 3. Immediately afterward, while the plastic molded body 100 has not yet cooled, the top lid 120 is closed and locked to the cap body 110 as shown in Figure 9, and the elastic seal piece 125 is inverted while the thin-walled portion 124 is still soft.
The plastic molded body 100, with the top lid 120 closed and locked to the cap body 110, is fixed to the mouth of the container filled with contents in the state shown in Figure 9, thereby sealing the container.

Next, an example of the procedure for removing the contents from the dispensing nozzle 116 of the plastic molded body 100 fixed to the mouth of the container will be described.
To remove the contents, first, the top lid 120 is detached from the cap body 110, the annular sealing surface 126 is detached from the enlarged diameter surface 117, and the pull ring 118 is pulled upward to break the endless score 128 and form the opening 112.

At this point, since time has passed since injection molding and the plastic molded body 100 has cooled sufficiently, the thin-walled portion 124 remains in a bent state, and as shown in Figure 8, the elastic sealing piece 125 does not return to its position immediately after injection molding, but remains in an inverted state.
After removing the contents and returning the container to an upright position, the top lid 120 is placed back onto the cap body 110, so that the annular sealing surface 126 adheres tightly to the enlarged diameter surface 117, as shown in Figure 6, completing the resealing process.

Although embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design modifications can be made without departing from the scope of the claims.

In the embodiments described above, the plastic molded body was described as an integrally molded product in which the cap body and the top lid are connected by a hinge. However, the configuration of the plastic molded body is not limited to this. For example, the cap body and the top lid may be made as separate parts without a hinge, or the cap body and the top lid may be connected by a pin instead of a hinge, and the cap may be made to open and close with the pin as the pivot point.
Furthermore, although the above-described embodiment was explained as having the same height around its entire circumference, the configuration of the enlarged diameter surface is not limited to this, and for example, only the hinge-forming portion of the enlarged diameter surface may be formed at a lower height.

Furthermore, in the embodiments described above, the tip side of the elastic sealing piece is provided with reversal assist extensions that are spaced apart circumferentially by notches. However, the configuration around the elastic sealing piece is not limited to this, and for example, the reversal assist extensions may be formed uniformly in the circumferential direction without notches.
Furthermore, in the embodiments described above, the cylindrical surface was described as being formed as a straight surface extending almost vertically upward from the lower end of the inner circumferential surface of the dispensing nozzle. However, the configuration of the cylindrical surface is not limited to this, and for example, it may be formed to extend upward from a position above the lower end of the inner circumferential surface of the dispensing nozzle.

100 ... Plastic molded body 110 ... Cap body 111 ... Top plate portion 112 ... Opening 113 ... Fitting cylinder 114 ... Skirt portion 115 ... Fitting portion 116 ... Dispensing nozzle 117 ... Enlarged diameter surface 118 ... Pull ring 119 ... Locking ring 120 ... Top cover 121 ... Top surface 122 ... Circumferential wall 123 ... Protrusion 124 ... Thin-walled portion 125 ... Elastic seal piece 126 ... Annular seal surface 127 ... Reversal assist extension portion 128 ... Endless score 129 ... Notch portion 130 ... Outer ring 131 ... Opening flange 132 ... Hinge 133 ... Cylindrical surface 134 ... Locking part

Claims (7)

A plastic molded body having a main body fixed to a container and a top lid that covers the main body and can close the container,
The main body is provided with a top plate and a skirt portion that hangs down from the top plate.
A cylindrical dispensing nozzle is provided on the upper surface of the top plate portion, protruding from the top plate portion.
The inner circumferential surface of the upper part of the aforementioned dispensing nozzle has an expanding surface that gradually widens in diameter as it extends upward,
The top cover is provided with a top surface and a peripheral wall that hangs down from the outer edge of the top surface.
The top cover further has a projection that protrudes downward from the inside of the circumferential wall of the top surface,
An elastic sealing piece is provided at the lower part of the protrusion, connected via a thin-walled portion formed to be thin.
An annular sealing surface is formed on the inner surface of the elastic sealing piece, which is capable of adhering closely to the inner circumferential surface of the dispensing nozzle.
The elastic sealing piece is configured to be able to invert its inner and outer surfaces upward,
The lower end of the elastic sealing piece is provided with an inversion assist extension.
A plastic molded body characterized in that when the top cover is placed over the main body, the annular sealing surface comes into contact with the enlarged diameter surface. The plastic molded article according to claim 1, characterized in that the outer diameter of the protruding portion is larger than the smallest inner diameter of the enlarged surface. The enlarged diameter surface is formed in an R-shape, characterized in that it is a plastic molded article according to claim 1 or 2. The inner circumferential surface of the aforementioned dispensing nozzle is provided with a cylindrical surface that extends vertically and has a uniform inner diameter.
The plastic molded article according to any one of claims 1 to 3, characterized in that the enlarged diameter surface is connected to the upper end of the cylindrical surface. The plastic molded body according to any one of claims 1 to 4, characterized in that when the top cover is placed over the main body, the inclination angle of the enlarged diameter surface at the position that contacts the annular sealing surface is 20 degrees or more and 80 degrees or less when viewed from the top plate portion . The plastic molded article according to any one of claims 1 to 5 , characterized in that the inversion assist extension portion has a notch portion that is open downwards. The plastic molded body according to any one of claims 1 to 6 , characterized in that the main body and the top lid are integrally molded and connected via a hinge.