JP6226237B2 - Synthetic resin molded product and molding method thereof - Google Patents

Description

  The present invention relates to a synthetic resin molded article having a hinge and a molding method thereof, and more particularly to a synthetic resin molded article and a molding method thereof in which resin leakage hardly occurs near the hinge of an integral connecting portion during two-color molding.

  Conventionally, in a container for dispensing shampoo, rinse or liquid seasoning, etc., the content liquid is fitted with a dispensing cap with a spout into the mouth tube part of the container body, and tilted while pushing the container body from both sides, The contents are poured out from this spout. In this type of pouring cap, since the cap body and the lid are integrally formed at the same time, it is usually the same color. It has also been proposed to improve the aesthetics by forming both the cap body and the lid in different colors (for example, Patent Document 1).

  In Patent Document 1, the cap body and the lid are integrated with each other by separately forming products. However, from the viewpoint of airtightness and fitting strength, it is preferable that the cap body and the lid are integrally formed products. In order to form the cap body and the lid in different colors, it is necessary to perform two-color molding, but the secondary molding in which the lid is integrally connected to the cap body, which is the primary molded product, is required. When this is done, a slight gap is generated between the cap body and the mold in the vicinity of the hinge 16 serving as a connecting portion between the cap body 12 and the upper lid 15 as shown in FIG. And appearance defects sometimes occurred.

JP-A-9-301402

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a synthetic resin molded product in which resin leakage near the hinge of the integral connecting portion hardly occurs during two-color molding and a molding method thereof. It is.

As means for solving the above problems, the invention according to the present invention is
A synthetic resin molded product of primary molding having a member body and a top wall,
An indented step is formed on at least a part of the outer edge of the top wall,
This edge step portion has an edge step groove portion which is a groove portion on the inner side, an edge step side wall which becomes a side wall on the outer side, and an edge step center portion on the center portion, and is recessed on both inner sides of the edge step central portion. It has an edge step central recess .

  This configuration makes it easier for the synthetic resin material in a molten state to enter and fill the edge step groove portion, which is the inner groove portion of the edge step portion, during secondary molding, and the outer edge step side wall can be reliably pressed against the mold. The edge step side wall is in close contact with the mold, and resin leakage from the gap can be prevented.

  In the above structure, the formation of the center part of the edge step can cause abnormal deformation such as turning up during secondary molding to prevent deterioration of hermeticity and fitting strength. The material becomes easy to enter, and stress that presses the center of the edge step against the mold acts.

Moreover, in the synthetic resin molded product of the secondary molding according to the present invention,
A primary molded synthetic resin molded article having a member body and a top wall;
An upper lid that closes the top wall in the closed state;
A hinge for connecting the upper lid to the member main body so as to be freely opened and closed;
In the secondary molded synthetic resin molded product having
The end of the hinge is integrally connected at the edge step groove that is the inner groove of the edge step that is recessed in at least a part of the outer edge of the top wall, and the center of the edge step is the center of the edge step. It is also connected integrally at the edge step center concave part inside the both ends,
The member main body and the upper lid are integrally formed through a hinge.

  With this configuration, the molten synthetic resin material that forms the end of the hinge is filled into the edge step groove portion that is the inner groove portion of the edge step portion, and the molten synthetic resin material is placed on the outer edge step side wall by the holding pressure. The stress which presses against the mold acts, and the edge side wall comes into close contact with the mold. Due to the close contact with the mold, it is possible to prevent resin leakage in the vicinity of the hinge.

  In the structure described above, the synthetic resin material in a molten state is filled and filled by the recess at the center of the edge step, and the stress that presses the center portion of the edge step against the mold acts when holding pressure, and the adhesiveness with the mold is increased and the resin near the hinge Leakage can be prevented.

  In another secondary molded synthetic resin molded product according to the present invention, the member body and the upper lid are formed by two-color molding.

  In the said structure, since the color of a member main body and an upper cover differs, the improvement of the aesthetics as a molded article and the distinguishability of an upper cover can be improved.

In the method for producing a synthetic resin molded product according to the present invention,
A synthetic resin molded product to be a primary molded product having a member body and a top wall;
An upper lid that closes the top wall in the closed state;
A hinge for connecting the upper lid to the member main body so as to be freely opened and closed;
In a method for producing a synthetic resin molded article having
A synthetic resin molded article having an edge step portion that is at least partially recessed at the outer edge of the top wall, an edge step groove portion that becomes a groove portion inside the edge step portion, and an edge step sidewall that becomes a side wall outside is formed. A primary molding process;
A secondary molding step of supplying another resin as the second color and integrally connecting the edge step groove portion is characterized.

  With this configuration, the holding pressure during the secondary molding acts as a stress that presses the outer edge step side wall through the molten synthetic resin material against the mold, and the edge step side wall comes into close contact with the mold, The manufacturing method which prevents the resin leak in the hinge vicinity can be provided.

  In the main configuration of the present invention, the molten synthetic resin material that forms the end of the hinge at the time of secondary molding enters and fills the edge step groove that is the inner groove of the edge step, and the molten state is synthesized by the holding pressure. The stress that the resin material presses the outer edge side wall against the mold acts, and the edge side wall comes into close contact with the mold. By close contact with the mold, resin leakage prevention near the hinge can be achieved.

  In the case where there is an edge step central portion at the center portion of the edge step portion, and there are recessed edge step center concave portions inside the both ends of this edge step center portion, secondary forming is performed by forming the edge step center portion. Occasional abnormal deformation such as turning up can be prevented to prevent deterioration in airtightness and fitting strength, and the synthetic resin material in the molten state can easily enter and be filled by the central recess of the edge step, and the edge step due to the holding pressure The stress that presses the central portion against the mold acts, and the adhesiveness with the mold increases, and the resin leakage near the hinge can be prevented.

  In the case where the member main body and the upper lid are formed by two-color molding, the colors of the member main body and the upper lid are different from each other, and it is possible to achieve improvement in aesthetics as a molded product and improvement in the discrimination of the upper lid.

It is a top view which shows the cap of the synthetic resin molding by this invention. It is a top view which shows the hinge cap of the synthetic resin molding by this invention. It is a longitudinal cross-sectional view of the hinge cap of FIG. (A) is the top view which expands and shows partially the edge step part in the cap of a synthetic resin molded product, (b) is the longitudinal cross-sectional view shown along the AA in (a). . It is a top view which shows the container for cosmetics of the synthetic resin molding by this invention. It is a longitudinal cross-sectional view of the container for cosmetics of FIG. It is explanatory drawing which shows the resin leak of the hinge vicinity which generate | occur | produces when the conventional hinge cap is 2 color-molded.

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

  FIG. 1 is a plan view showing a cap of a synthetic resin molded product according to the present invention, FIG. 2 is a plan view showing a hinge cap, and FIG. 3 is a longitudinal sectional view of the hinge cap. FIG. 4A is an enlarged plan view partially showing an edge step portion in the cap of the synthetic resin molded product, and FIG. 4B is shown along the line AA in FIG. FIG. FIG. 5 is a plan view of a cosmetic container having a hinge, and FIG. 6 is a longitudinal sectional view of the cosmetic container.

  FIG. 1 shows a circular cap of a synthetic resin molded product 1 as a primary molded product, and FIGS. 2 and 3 show a circular hinge cap of a synthetic resin molded product 8 integrally connected by secondary molding. The cap of the synthetic resin molded product 1 is composed of a member main body 2 that is assembled by being erected on the top wall 3 with a nozzle 4a constituting a spout 4 and closely screwed into the mouth tube portion 10a of the container main body 10. A recessed edge step 7 is formed on at least a part of the outer edge of the top wall 3. The edge step 7 has an edge step groove 7a which is a groove on the inside, and a side wall on the outside. An edge step side wall 7b is formed. As shown in FIG. 4, the edge step portion 7 has an edge step center portion 7c at the center portion, and has a recessed edge step center concave portion 7d inside both ends of the edge step center portion 7c.

  An upper lid 5 in which a closure body 5a that is inserted into the nozzle 4a in a closed state and closes the spout 4 is protruded from the member body 2 that is the obtained primary molded product, and the upper lid 5 is attached to the member body 2 Thus, a synthetic resin molded product 8 is formed, in which the hinge 6 that is connected to be freely opened and closed is integrally connected by secondary molding. The hinge cap of the integrally molded product which is such a synthetic resin molded product 8 is used by being attached to the mouth tube portion 10a of the synthetic resin container body 10 filled with the contents indicated by the broken line, for example.

  The member main body 2 is located at a slightly forward position on the top surface of the top wall 3 having a cylindrical shape that is externally screwed into the mouth tube portion 10a of the container main body 10 (a position on the left side opposite to the hinge 6 in FIG. 2). A spout 4 is provided.

  On the inner side of the nozzle 4a, an extraction passage 4b penetrating in the height direction is formed. The inner peripheral surface of the extraction channel 4b is a tapered surface whose diameter is increased upward so that the insertion and removal operations of the closure 5a of the upper lid 5 with respect to the nozzle 4a during the opening / closing rotation operation can be smoothly achieved. ing.

  The upper lid 5 is integrally connected via an hinge 6 with an edge step 7 that is recessed in at least a part of the outer edge of the top wall 3. A closed body 5a made of a thin cylindrical piece projects from the inner surface 5A of the deep dish-shaped upper lid 5 and at a position facing the nozzle 4a in the closed state. The length of the closing body 5a is slightly longer than that of the pouring path 4b, and is formed with a size that allows entry into the deep part of the nozzle 4a when the upper lid 5 is closed.

  In the present invention, the member main body 2 and the upper lid 5 have different colors, and the member main body 2 and the upper lid 5 have different colors by two-color molding in order to improve aesthetics and improve the distinguishability of the upper lid. At the time of molding, the first and second color synthetic resin materials may be the same type or different types. In the present invention, even if the same type of synthetic resin material contains a colorant and the like, the first color and the second color are distinguished as different resins.

Next, a method for manufacturing the hinge cap of the integrally connected two-color molded synthetic resin molded product 8 will be described.
First, as a primary forming step, a cap of a primary molded synthetic resin molded product 1 having a member body 2 and a top wall 3 is injected by injecting a molten synthetic resin material into a predetermined molding die (not shown). It is formed by molding and then releasing the mold. A nozzle 4a constituting the spout 4 is provided on the top wall 3, and a member body 2 is formed below the top wall 3 to be tightly screwed and assembled to the mouth tube portion 10a of the container body 10. Yes. A recessed edge step 7 is formed on at least a part of the outer edge of the top wall 3. The edge step 7 includes an edge step groove 7 a that is a groove on the inside and an edge that forms a side wall on the outside. A step side wall 7b is formed.

  Subsequently, as a secondary forming step, the obtained primary molded synthetic resin molded product 1 is placed in a predetermined molding die (not shown), and another resin having a second color different from the resin used in the primary molding is used. By the secondary molding to be supplied, an upper lid 5 in which a closing body 5a is inserted into the nozzle 4a in a closed state and closes the spout 4 is projected, and the upper lid 5 can be opened and closed freely with respect to the member body 2. A synthetic resin molded product 8 is formed by integrally connecting the hinges 6 to be connected. At the time of the secondary molding, it is important that the end portion of the hinge 6 is integrally connected by the edge step groove portion 7a which is the inner groove portion of the edge step portion 7. Here, the melted synthetic resin material enters the edge step groove portion 7a and sufficiently fills the edge step groove portion 7a, and the stress that the molten synthetic resin material presses the outer edge step side wall 7b against the mold by the subsequent holding pressure. The edge side wall 7b comes into close contact with the mold. Due to the close contact with the mold, it is possible to prevent resin leakage in the vicinity of the hinge.

  Further, the edge step portion 7 may be formed with the edge step central portion 7c at the center portion so as not to cause abnormal deformation such as curling at the time of molding and to reduce the airtightness and fitting strength. By providing the edge step central portion 7c, the edge step groove portion 7a is divided into the right side and the left side, and the stress pressing against the mold is reduced in the vicinity of the edge step center portion 7c. In order to prevent resin leakage due to a decrease in pressing stress at the time of holding pressure, an edge step central recess 7d is provided inside both ends of the edge step center portion 7c, and a synthetic resin material in a molten state enters the edge step center recess 7d. You may make it fully fill and may apply the stress which presses the edge step center part 7c by a holding pressure against a metal mold | die. When the synthetic resin material in the edge step central recess 7d enters, it comes into close contact with the mold, and it is possible to prevent resin leakage near the hinge. Furthermore, you may form a recessed part also inside the both ends of the edge step part 7. FIG.

  Although the embodiment of the hinge cap has been described as having a hinge so far, as another embodiment, as shown in FIGS. 5 and 6, it is also possible to apply the hinge to a circular cosmetic container. . Here too, the aesthetics can be improved by making the member main body 2 and the upper lid 5 different in color by two-color molding.

  As mentioned above, although the structure of this invention and its effect were demonstrated along the Example, embodiment of this invention is not limited to the said Example.

  In the above embodiment, the primary molding step and the secondary molding step are molded by separate molds, that is, the member main body 2 is molded by primary molding, and then cooled, and then the upper lid 5 and the hinge are molded by another mold. 6 is integrally connected by secondary molding, but the member body 2 is primarily molded so that the primary molding process and the secondary molding process are completed in one mold, and then the upper lid 5 and the hinge 6 are It may be integrally connected by secondary molding.

  Furthermore, although the circular hinge cap and the cosmetic container have been described in the above embodiment, the applicable product shape is not limited to this, and may be a rectangular shape, a square shape, a polygonal shape, or the like. Is possible.

  As described above, it provides a hinge that does not cause resin leakage during two-color molding, and has a wide range of applications especially in the field of dispensing caps using hinges that can be freely opened and closed and in the field of cosmetic containers. Be expected.

1; Synthetic resin molded product (primary molded product)
2; member main body 3; top wall 4; spout 4a; nozzle 4b; spout passage 5; upper lid 5A; ; Edge step center portion 7d; edge step center recess 8; synthetic resin molded product (secondary molded product)
10; Container body 10a; Mouth tube portion 11; Resin leakage 12; Cap body 15; Top lid 16;

Claims (4)

A primary molded synthetic resin molded article (1) having a member body (2) and a top wall (3),
An indented step (7) is formed in at least a part of the outer edge of the top wall (3),
The edge step portion (7) has an edge step groove portion (7a) which is a groove portion on the inner side, an edge step side wall (7b) which becomes a side wall on the outer side, and an edge step central portion (7c) at the center portion. A synthetic resin molded product having a recessed edge step central recess (7d) inside both ends of the edge step center (7c) . A primary molded synthetic resin molded article (1) having a member body (2) and a top wall (3);
An upper lid (5) for closing the top wall (3) in a closed state;
A hinge (6) for connecting the upper lid (5) to the member body (2) so as to be openable and closable;
In the secondary molded synthetic resin molded product (8) having
The end of the hinge (6) is integrally connected with an edge step groove (7a) which is an inner groove of the edge step (7) recessed in at least a part of the outer edge of the top wall (3). Furthermore, the edge step central recess (7d) inside the both ends of the edge step central portion (7c), which is the central portion of the edge step portion (7), is also integrally connected,
A synthetic resin molded product, wherein the member main body (2) and the upper lid (5) are integrally molded through the hinge (6). The synthetic resin molded product according to claim 2 , wherein the member main body (2) and the upper lid (5) are formed by two-color molding. A synthetic resin molded article (1) to be a primary molded article having a member body (2) and a top wall (3);
An upper lid (5) for closing the top wall (3) in a closed state;
A hinge (6) for connecting the upper lid (5) to the member body (2) so as to be openable and closable;
In the method for producing a synthetic resin molded article (8) having
An edge step (7) that is recessed at least in part at the outer edge of the top wall (3), an edge step groove (7a) that forms a groove inside the edge step (7), and a side wall on the outside A primary molding step for forming a synthetic resin molded article (1) having an edge step side wall (7b),
A method of manufacturing a synthetic resin molded product, comprising: a secondary molding step of supplying another resin as a second color to the edge step groove (7a) and integrally connecting the resin.

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