Plastic molded body

Abstract

To provide a plastic molding body capable of sealing a pour-out nozzle by surely closing an upper lid, capable of opening / closing without any burden on the user, and capable of suppressing an increase in manufacturing cost, with a simple configuration.SOLUTION: A plastic molding body 100 comprises a cap body 110 and an upper lid 120. A pour-out nozzle 116 is provided on an upper face side of a top plate part 111 in the cap body 110. An inner peripheral face above the pour-out nozzle 116 is provided with a diameter enlargement face 117 that gradually enlarges a diameter toward an upper side over the entire circumference. The upper lid 120 is provided with a top face 121, and a protrusion 123 protruding to a lower portion of the top face 121. A lower portion of the protrusion 123 is provided with an elastic seal piece 125. An inner face side of the elastic seal piece 125 has an annular seal face 126 formed therein. The elastic seal piece 125 is configured to have reversible inner and outer faces. When the upper lid 120 is covered on the cap body 110, the annular seal face 126 is brought into contact with the diameter enlargement face 117.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a plastic molded body composed of a main body fixed to a container and an upper lid that covers the main body and can close the container.

Background Art

[0002] Conventionally, as a plastic molded body for closing a container mouth or a discharge cap, etc., a plastic molded body in which a main body fixed to a container and an upper lid that is locked to the main body and closes a pouring nozzle are hinge-connected is known from Patent Document 1 etc.

[0003] The plastic molded body (hinged cap 1 with sorting function) described in this Patent Document 1 has a main body (cap main body 2) and an upper lid (3). An annular wall (16) hangs down from the top surface (top plate 14) of the upper lid (3). A pouring nozzle (pouring cylinder 12) is provided on the top plate portion (top plate 6) of the main body (cap main body 2). A beak-shaped portion (12a) that protrudes upward and radially outward is formed on a part of the upper portion of the pouring nozzle (pouring cylinder 12) on the side opposite to the hinge (4). In this plastic molded body (hinged cap 1 with sorting function), an opening planned portion (5) is formed on the top plate portion (top plate 6), and the liquid content in the container can be poured out through an opening generated by cutting out the opening planned portion (5).

[0004] Also, the beak-shaped portion (12a) is provided to improve the pouring property when pouring the liquid content. When the upper lid (3) is closed, the outer peripheral surface of the annular wall (16) adheres closely to a straight portion formed uniformly in the circumferential direction on the inner peripheral surface of the lower portion of the pouring nozzle (pouring cylinder 12). Therefore, after cutting out the opening planned portion (5) and pouring out the liquid content, the plastic molded body (hinged cap 1 with sorting function) is sealed by the close contact surface between the annular wall (16) and the pouring nozzle (pouring cylinder 12), preventing the leakage of the liquid content.

[0005] Furthermore, plastic molded bodies in which an enlarged diameter surface (liquid cut-off edge 2) forming an outwardly curved flange is provided around the entire circumference of the upper part of the dispensing nozzle (dispensing outlet 1) are also known from Patent Document 2, etc.

[0006] The plastic molded body described in Patent Document 2 has a main body (cap body 9) to which an upper lid (outer cap 10) is hinged. When the upper lid (cap 10) is closed, the outer surface of the annular wall provided on the upper 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. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2009-298447 [Patent Document 2] Japanese Patent Application Publication No. 53-144966 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, the hinge caps with sorting functions known from the above-mentioned patent documents still had room for improvement.

[0009] 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.

[0010] The present invention aims to solve these problems by providing a plastic molded body with a simple structure that can securely close the top lid to seal the dispensing nozzle, can be opened and closed without burdening the user, and can suppress increases in manufacturing costs. [Means for solving the problem]

[0011] 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, a cylindrical dispensing nozzle protruding from the top plate portion is provided on the upper surface side of the top plate portion, the inner circumferential surface of the upper part of the dispensing nozzle has an expanding surface that gradually widens in diameter as it extends upward, the top lid is provided with a top surface and a circumferential wall hanging down from the outer edge of the top surface, the top lid further has a projection that protrudes downward from the inside of the circumferential wall of the top surface, an elastic sealing piece connected via a thin-walled portion is provided at the lower part of the projection, an annular sealing surface that can adhere closely to the inner circumferential surface of the dispensing nozzle is formed on the inner surface side of the elastic sealing piece, and the elastic sealing piece is configured to be reversible inward and outward. The lower end of the elastic sealing piece is provided with an inversion assist extension. The problem is solved when the upper cover is placed over the main body, and the annular sealing surface comes into contact with the enlarged diameter surface. [Effects of the Invention]

[0012] According to the plastic molded article of claim 1, a thin-walled portion is provided between the protrusion and the elastic sealing piece, so that the elastic sealing piece can be bent to invert the elastic sealing piece and position it 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.

[0013] 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.

[0014] 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.

[0015] Claim 6 According to the configuration described, the reversal assist extension has a notch that opens downwards, making it easier to open the reversal assist extension. When placing the top cover on the main body, it becomes even easier to reverse the elastic sealing piece and move it to a position where the annular sealing surface can contact the enlarged diameter surface.

[0016] Claim 7According to the configuration described in , since the main body and the upper lid are integrally formed, the number of molds to be produced can be reduced, and the cost increase can be suppressed. In addition, since the main body and the upper lid are connected via a hinge, the operation of the upper lid during opening and closing can be stabilized, and the annular seal surface can be more reliably brought into contact with the diameter-expanded surface.

Brief Description of the Drawings

[0017] [Figure 1] Perspective view of the plastic molded body 100 according to an embodiment of the present invention. [Figure 2] Top view of the plastic molded body 100 according to an embodiment of the present invention. [Figure 3] Side cross-sectional view of the plastic molded body 100 according to an embodiment of the present invention. [Figure 4] Side cross-sectional view showing the state where the endless score 128 of the plastic molded body 100 according to an embodiment of the present invention is broken. [Figure 5] Side cross-sectional view showing the state of the plastic molded body 100 according to an embodiment of the present invention during closing. [Figure 6] Side cross-sectional view showing the state of the plastic molded body 100 according to an embodiment of the present invention after closing. [Figure 7] Enlarged view of part A showing the state of the plastic molded body 100 according to an embodiment of the present invention after closing. [Figure 8] Side cross-sectional view showing the state of the plastic molded body 100 according to an embodiment of the present invention after opening. [Figure 9] Side cross-sectional view showing the state of the plastic molded body 100 according to an embodiment of the present invention after closing before breaking the endless score 128.

Mode for Carrying Out the Invention

[0018] Hereinafter, the plastic molded body 100 according to an embodiment of the present invention will be described based on the drawings. Note that the container to 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.

[0019] 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.

[0020] 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 its 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.

[0021] 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 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.

[0022] 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.

[0023] 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.

[0024] First, when the pull ring 118 is pulled upward from the state shown in Figure 3, the endless score 128 breaks, and an opening 112 for pouring out the liquid contents is formed in the top plate portion 111, as shown in Figure 4. Next, as shown in Figure 4, when 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. 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.

[0025] 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 protrusion 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 protrusion 123, making tight contact with the enlarged diameter surface 117 around its entire circumference.

[0026] 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 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 to follow the deformation of the enlarged diameter surface 117, so that the contents do not leak 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.

[0027] 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 protrusion 123, the outer diameter of the protrusion 123 can be made smaller, thus suppressing interference between the protrusion 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, thereby suppressing an increase in manufacturing costs.

[0028] 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.

[0029] 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 seal piece 125 remains in an inverted state when the cap is opened, as shown in Figure 7.

[0030] 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. This makes it easier to shape the thin-walled portion 124 compared to sealing the plastic molded body 100 after it has cooled. 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.

[0031] 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.

[0032] 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.

[0033] 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 present invention as described in the claims.

[0034] 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.

[0035] 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. [Explanation of Symbols]

[0036] 100 ··· Plastic molded product 110 ··· Cap body 111...Top plate part 112 ··· Opening 113 ··· Fitting tube 114... Skirt section 115 ··· Mating part 116 ··· Dispensing nozzle 117... Expanded diameter surface 118 ··· Pull ring 119... Locking ring 120...Top lid 121 ··· Top surface 122 ··· Perimeter wall 123... protrusion 124 ··· Thin-walled section 125 ··· Elastic seal piece 126 ··· Annular sealing surface 127 ··· Reversal assist extension 128 ··· Endless score 129... Notch 130 ··· Outer ring 131 ··· Opening guard 132... Hinge 133 ··· Cylindrical surface 134... Locking part

Claims

1. 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.

2. The plastic molded article according to claim 1, characterized in that the outer diameter of the protruding portion is formed to be larger than the portion with the smallest inner diameter among the enlarged surfaces.

3. The plastic molded article according to claim 1 or 2, characterized in that the enlarged diameter surface is formed in an R-shape.

4. 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.

5. 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.

6. 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.

7. 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.

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