JP2014177302A - Synthetic resin-made container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cover a container body beautifully with a film in a good yield even when circumferential length differences among parts of the container body are increased to achieve both good gripping properties for a user and capacity enlargement.SOLUTION: A container body 20 comprises: a mouth part 21; a neck part 22; a shoulder part 23; and a trunk part 24. The minimum circumferential length of the neck part 22 is a half of the maximum circumferential length of the trunk part or smaller. A film 30 is formed so as to cover the area from the neck part 22 to the trunk part 24 of the container body 20. At least the outer surface of the neck part 22 of the container body 20 is subjected to a slippage improvement treatment for improving the slippage of the film 22.

Description

  The present invention relates to a synthetic resin container having a container body covered with a heat-shrinkable film.

  Conventionally, various synthetic resin containers have been widely used as containers for storing drugs, beverages, and the like (see, for example, Patent Documents 1 to 6).

  A cylindrical neck portion having a screw portion to which a cap or the like is attached is provided at the upper end portion of the container body of Patent Document 1. A shoulder portion that expands toward the bottom is connected to the lower side of the neck portion, and a trunk portion that extends to the lower end portion with the same diameter is connected to the lower side of the shoulder portion. The shoulder portion and the trunk portion of the container body are covered with a heat-shrinkable film.

  The container main body of patent document 2 also has a neck part, a shoulder part, and a trunk | drum, and it is disclosed covering a shoulder part and a trunk | drum with a heat-shrink film, and covering only a trunk | drum with a heat-shrink film.

  The container main body of patent document 3 also has a neck part, a shoulder part, and a trunk | drum, and it is disclosed covering a trunk | drum with a heat-shrink film. It is disclosed that a longitudinal groove communicating with a holding recess is formed in the body portion of the container main body and that a fine uneven surface is formed.

  The film of Patent Document 4 is also wound around the container body. The portion of the container body where the film is wound is subjected to blasting or the like. The film is provided with a heat-sensitive adhesive layer. When the film is wound around the container body, the film is heated by using a labeling machine so that the heat-sensitive adhesive layer has adhesiveness and is adhered to the container body.

  The outer surface of the container of Patent Document 5 is subjected to an opaque treatment by shot peening. No film is wound around the container body of Patent Document 5.

  On a part of the outer surface of the container of Patent Document 6, a light reflecting layer having a fine uneven pattern is provided.

JP-A-8-244748 International Publication No. 2005/092721 Japanese Patent No. 4877671 JP 2004-18076 A JP 2000-43888 A Japanese Patent Application Laid-Open No. 7-40426

  By the way, the containers that contain the contents will be lined up mainly in stores as products, but what is important at this time is the decorativeness of the containers, the design differentiation from other products, the appeal of the products, etc. It is. Since these are mainly due to the appearance design of the container, there is a demand for a unique design using the widest possible range of the container.

  In addition, it is necessary to change the design of the container for each product in order to have various products. Methods for designing the container include a method of changing the color of the material for molding the container, a method of directly forming a printed layer on the outer surface of the container body by silk printing, pad printing, etc., disclosed in Patent Documents 1 to 4 above. There is a method of preparing a film that has been previously designed according to the product and covering the container body with the film.

  When a container with a dedicated design is set for each product as described above, a considerable number of each container is always kept in stock so that it can be supplied quickly without incurring shortages or shortages of each product. The cost required for storage of the container increases. In addition, if various types of containers are manufactured by changing the materials, setup change time occurs when changing the material or color of the molding machine, resulting in an increase in the number of man-hours. Manufacturing costs increase. In the case of printing as well, there is a problem that the manufacturing cost increases due to the occurrence of the setup change time.

  In order to reduce the cost when arranging various kinds of containers, for example, it is conceivable to make the container main body common and cover the container main body with a film having a different design depending on the product. Thereby, since only one type of container main body needs to be prepared, storage costs and manufacturing costs can be reduced.

  On the other hand, in recent years, the capacity of products has been increasing. Specifically, there is a product with an internal volume of 1000 ml or more, and a hand spray or the like may be attached to such a large-capacity product. In this case, the user operates the hand spray while holding the container. However, because of the large capacity, the user is heavy at the time of use, and therefore it is necessary to improve the ease of holding the container.

  In general, since the hand spray is attached to the upper part of the container, in use, the vicinity of the shoulder is grasped from the part close to the neck of the container. However, the container shapes of Patent Documents 1-3, 5, and 6 are the neck and the trunk. The shoulder portion between the two is rapidly expanding toward the trunk portion, and when the trunk portion is enlarged due to the increase in capacity, the outer diameter of the shoulder portion is also increased. The larger outer diameter of the shoulder means that the perimeter is longer, so it becomes difficult for the fingers to reach the surroundings when the user grasps it, especially for containers that have increased capacity and weight. It becomes difficult to have time. In addition, since it is thought that the container of patent document 4 is a general shape, the same problem may arise.

  Therefore, it is conceivable to shorten the circumferential length of the shoulder portion of the container. However, as described above, since it is necessary to cope with the recent increase in capacity, it is necessary to increase the inner diameter by increasing the outer diameter of the body portion by the amount corresponding to the reduction in the circumference of the shoulder portion. This further increases the circumferential length difference between the shoulder and the trunk.

  When the circumferential length difference between the shoulder and the trunk increases, there are the following problems. That is, when preparing various containers, it is preferable from the viewpoint of cost to prepare a common container body as described above and cover it with a film having a different design. It is common to set the circumference of the film so that the largest body part can be inserted, so the shrinkage rate of the film at the shoulder part is considerably larger than that of the body part. Therefore, it is necessary to apply a large amount of heat in accordance with the site having a large shrinkage rate, and it is difficult to cover a wide range from the body part to the shoulder part of the container body cleanly and with a high yield.

  The present invention has been made in view of the above points, and the object of the present invention is that the difference in circumference is increased depending on the portion of the container main body in order to achieve both ease of gripping by the user and increase in capacity. In such a case, the heat shrinkable film can be mounted on the container body cleanly and with a high yield.

  In order to achieve the above object, according to the present invention, a neck that can be gripped by the user is provided, the difference between the circumference of the neck and the circumference of the torso is set larger than a predetermined value, and the film is outside the neck. Made it easier to slip on the surface.

The first invention is a synthetic resin container in which a synthetic resin container body is covered with a heat shrink film.
The container body includes a cylindrical mouth portion, a neck portion extending from the mouth portion toward the bottom wall side of the container body, a shoulder portion extending from the neck portion toward the bottom wall side of the container body, and the shoulder A body portion extending from the portion to the bottom wall of the container body,
The minimum circumference of the neck is set to 1/2 or less of the maximum circumference of the trunk,
The film is formed so as to cover at least the neck part to the body part of the container body,
The outer surface of at least the neck of the container body is subjected to a slipperiness improving process for improving the slipperiness of the film during heat shrinkage.

  According to this configuration, the minimum circumference of the neck is ½ or less of the maximum circumference of the torso and has a sufficiently large circumference difference, so that the circumference of the neck is made easy for the user to grip. Even if the length is shortened, it is possible to increase the capacity by increasing the circumference of the body portion.

  In addition, since a wide range is covered with a film from the neck part to the body part of the container body, when it is necessary to prepare various kinds of containers with different designs, the container body is made common and only the film is changed. For example, individual designs can be applied over a wide range.

  Furthermore, when the container body is covered with a film, the difference in the shrinkage rate of the film increases correspondingly between the neck and the body with a large difference in circumference, but the outer surface of the neck, which is the portion with the large shrinkage rate, is slippery. By performing the improvement treatment, the film at the time of shrinkage becomes slippery at the site, thereby making it possible to clean the film after shrinkage.

According to a second invention, in the first invention,
The slip improvement process is characterized by forming at least one of a concave portion or a convex portion.

  According to this configuration, it is possible to improve the slipperiness of the film by a simple method of forming a concave portion or a convex portion on the outer surface of the container body.

  Further, when the container main body is obtained by injection blow molding, it is possible to reliably form a concave portion or a convex portion on the outer surface of the container in two stages at the time of injection molding and blow molding. In particular, this method is effective in a portion where the blow ratio at the time of blow molding is small and the embossed transfer at the time of blow molding is weak, and in the case of the container body according to the present invention, each part of the container body Among them, an extremely high effect is obtained at a portion with a short circumference (a range from the neck portion to the shoulder portion), and a sufficient slip improvement effect is exhibited.

According to a third invention, in the first or second invention,
The body portion of the container body is provided with a non-processing portion that has not been subjected to the slip improvement process,
The part which covers the said non-processing part of the said container main body in the said film has translucency, It is characterized by the above-mentioned.

  According to this structure, since the slipperiness improving process is not performed on the non-processing part of the trunk part, the amount of the contents can be easily grasped through the non-processing part. And since this non-processing part is covered with the site | part which has the translucency of a film, it becomes possible for a user to grasp | ascertain the quantity of the content from the outside.

According to a fourth invention, in any one of the first to third inventions,
The film is formed with an air vent hole for venting air between the container body and the film when contracted.

  According to this configuration, since the air between the film and the container body escapes from the air vent hole when the film contracts, the film contracts more finely.

  According to the first invention, since the minimum circumference of the neck of the container main body is set to ½ or less of the maximum circumference of the trunk, when the circumference of the neck is shortened so that the user can easily grip it, It is possible to increase the capacity of the container by sufficiently increasing the circumference of the body portion. Further, since the film covers at least the neck portion to the trunk portion of the container body, various containers having different designs can be prepared at low cost. Furthermore, since the slipperiness improving process is performed on the outer surface of the neck of the container body, the container body can be covered with the film cleanly and with a high yield.

  According to the second invention, since at least one of the concave portion or the convex portion may be formed on the outer surface of at least the neck portion of the container body, the slipperiness of the film can be improved by a simple method.

  According to the third invention, the body portion of the container body is provided with a non-treatment portion that is not subjected to the slip improvement treatment, and the portion covering the non-treatment portion of the container body in the film has translucency. The user can grasp the amount of contents from the outside, and the convenience can be improved.

  According to the fourth invention, since the air vent hole is formed in the film, the film can be further shrunk, the appearance can be improved, and the yield can be improved.

It is a side view of a synthetic resin container with a spray mechanism according to an embodiment of the present invention. It is a front view of a synthetic resin container. It is a side view of a container main body. It is a rear view of a container main body. It is a perspective view of the shrink film before shrinkage. It is a side view of an intermediate molded object. It is a side view which shows the state which covered the container main body with the shrink film before shrinkage | contraction. It is a flowchart which shows the manufacturing process of a synthetic resin container.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  FIG. 1 is a side view of a synthetic resin container 1 with a spray mechanism according to an embodiment of the present invention. The container 1 includes a spray mechanism 10, a container main body 20 shown in FIGS. 3 and 4, and a shrink film 30 having heat shrinkability that covers the container main body 20. In FIG. 1 and FIG. 2, the hatched portion indicates the design portion of the shrink film 30. The container 1 can contain liquids such as various drugs. There are no particular limitations on the type of the contents.

  The spray mechanism 10 has a conventionally well-known structure, and is configured so that the liquid stored in the container 1 can be sprayed in the form of a mist. As shown in FIG. 2, the spray mechanism 10 includes a cap portion 11, a body portion 12 provided integrally with the cap portion 11, a trigger 13, and an injection port 14.

  The cap part 11 is formed in the cylinder shape which covers the screw mouth part 21 of the container main body 20 mentioned later. A screw (not shown) that is screwed into the screw opening 21 is formed on the inner peripheral surface of the cap portion 11. The body portion 12 is provided with a suction pipe (not shown) that extends downward from the cap portion 11 and reaches the container body 20. The body portion 12 has a built-in pump (not shown), and liquid is sucked from the suction pipe by the pump. The trigger 13 operates the pump, and extends while curving downward from the body portion 12 so that the user can put, for example, an index finger (or index finger and middle finger). The injection port 14 is disposed in front of the body portion 12.

  In the description of this embodiment, the front side (also referred to as the front side) of the container 1 refers to the side where the injection port 14 opens, and the back side (also referred to as the rear side) refers to the side where the injection port 14 opens. The left side means the side that is left when the container 1 is viewed from the back side, and the right side is the side that is right when the container 1 is viewed from the back side. To do.

  The container body 20 is a large-capacity type having a capacity of, for example, 900 ml or more, preferably 1000 ml or more. Examples of the material of the container body 20 include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polypropylene ( PP), polyethylene (PE) and the like. Of these, polyethylene terephthalate and polyethylene naphthalate are particularly preferable, and will be described in detail later. These are obtained by injection blow molding, and polyethylene terephthalate is relatively inexpensive and has high chemical resistance. The container body 20 can be formed into a thin wall, and the specific heat, which is a characteristic of the resin itself, is smaller than that of polypropylene or polyethylene. Therefore, the amount of heat required to raise the temperature of the container body 20 when shrinking the shrink film 30 described later. This is particularly preferable because there is an advantage that the shrink film 30 can be processed with a small amount of energy and with a small amount of energy.

  As shown in FIG. 3 and FIG. 4, the container body 20 includes a screw mouth portion 21 having a screw portion 21 a, a neck portion 22 extending from the screw mouth portion 21 toward the bottom wall 25 of the container body 20, and a diameter expanding from the neck portion 22. However, it has the shoulder part 23 extended to the bottom wall 25 side of the container main body 20, and the trunk | drum 24 extended from the shoulder part 23 to the bottom wall 25 of the container main body 20. FIG. The screw mouth portion 21, the neck portion 22, the shoulder portion 23, the body portion 24, and the bottom wall 25 are integrally formed.

  The screw mouth portion 21 has a substantially cylindrical shape, and a screw portion 21a formed of a ridge extending in a spiral shape is formed on the outer peripheral surface thereof. The cap portion 11 of the spray mechanism 10 is screwed into the screw portion 21a.

  The neck portion 22 extends in the up-down direction. An upper surface portion 22 a extending in the horizontal direction is provided at the upper end portion of the neck portion 22. That is, in the container main body 20, a region above the upper surface portion 22 a of the neck portion 22 (region indicated by a symbol A in FIGS. 3 and 4) is the screw mouth portion 21.

  As shown in FIG. 3, a bulging portion 22 b that bulges to the front side is formed on the upper portion of the neck portion 22. The bulging portion 22b is formed so as to be pointed toward the front side, and is formed so that the bulging amount decreases toward the left and right sides of the container body 20.

  The portion of the neck portion 22 below the bulging portion 22b gradually expands in the front-rear direction toward the lower side of the container body 20 in a side view shown in FIG. 3, while in the rear view shown in FIG. After the width is gradually narrowed (squeezed), it is formed to expand.

  The predetermined region below the narrowed portion of the neck portion 22 is configured by a curved surface portion 22c that smoothly extends while being curved so as to expand its diameter downward. The curved surface portion 22 c extends over the entire circumference of the neck portion 22 in the circumferential direction. Accordingly, the lower cross section of the neck portion 22 increases in the front-rear direction of the container body 20 as shown in FIG. 3, and also increases in the left-right direction of the container body 20 as shown in FIG.

  The shoulder portion 23 is connected to the lower end portion of the neck portion 22. The boundary between the neck portion 22 and the shoulder portion 23 is set at a portion where the circumferential length of the neck portion 22 is a predetermined length. That is, the minimum circumferential length above the curved surface portion 22c of the neck portion 22 and below the bulging portion 22b is set in the range of 90 mm to 180 mm in this embodiment. This numerical value is set based on grasping the neck portion 22 by putting the middle finger, the ring finger, the little finger on the neck portion 22 and turning the palm to the neck portion 22 when operating the spray mechanism 10 while holding the container 1. Yes. When the circumference of the neck portion 22 is shorter than 90 mm, when a general adult grasps the neck portion 22 as described above, the neck portion 22 becomes too thin, and it becomes difficult to stabilize the container 1. The content will be reduced. On the other hand, if the circumference of the neck portion 22 is longer than 180 mm, it becomes difficult for the fingers and palms to fully grip the neck portion 22 without turning around the neck portion 22.

  The curved surface portion 22c has a longer circumference than the region above the curved surface portion 22c, but the circumference of the curved surface portion 22c is 30% or more longer than the upper region. This is the boundary with the shoulder 23. That is, in the container main body 20, the region between the upper surface portion 22 a of the neck portion 22 and the boundary between the neck portion 22 and the shoulder portion 23 (the region indicated by symbol B in FIGS. 3 and 4) is the neck portion 22.

  The vertical dimension of the neck portion 22 including the screw mouth portion 21 is preferably 50 mm or greater and 100 mm or less. When the vertical dimension of the screw mouth portion 21 to the neck portion 22 is shorter than 50 mm, the gripping range is too narrow for a general adult to grip with a hand (at least two fingers are difficult to catch), and the container 1 Becomes unstable. In addition, if the vertical dimension of the screw mouth portion 21 to the neck portion 22 is longer than 100 mm, the portion protruding from the hand when the hand is grasped is increased, making it difficult to stabilize the container 1 and corresponding to a large capacity. It will be disadvantageous.

  In addition, when the neck part 22 is grasped by a hand, the neck part 22 is less likely to slip in the vertical direction in the hand by allowing the bulging part 22b of the neck part 22 to be positioned, for example, between the middle finger and the ring finger. In this case, a part of the middle finger is hooked on the cap portion 11 of the spray mechanism 10. Since how to grip the neck portion 22 may differ depending on the user, it is not limited to the above-described gripping method.

  The shoulder portion 23 is connected to the lower end of the curved surface portion 22c of the neck portion 22 and extends downward while being larger than the curved surface portion 22c. The shoulder 23 is also expanded in the front-rear direction of the container main body 20 and the left-right direction of the container main body 20 in the same manner as the curved surface portion 22c. The dimension in the front-rear direction of the shoulder 23 is set longer than the dimension in the left-right direction.

  The boundary between the shoulder portion 23 and the trunk portion 24 is set at a location where the circumference of the shoulder portion 23 hardly changes. That is, the region between the boundary between the neck portion 22 and the shoulder portion 23 in the container body 20 and the portion where the circumference of the shoulder portion 23 hardly changes (the region indicated by the symbol C in FIGS. 3 and 4) is the shoulder. Part 23. The vertical dimension of the shoulder 23 is set shorter than the vertical dimension of the neck 22.

  The longitudinal dimension of the body portion 24 is set longer than the lateral dimension, and has a cross section close to an oval shape that is long in the longitudinal direction as a whole. The maximum peripheral length of the trunk portion 24 is longer than the minimum peripheral length of the portion between the curved surface portion 22c and the bulging portion 22b of the neck portion 22, and is specifically set to be twice or more. As a result, it is possible to increase the internal volume by increasing the maximum peripheral length of the body portion 24 while keeping the minimum peripheral length of the neck portion 22 short to be within the above range. The maximum circumferential length of the body portion 24 is preferably 200 mm or more, and more preferably set to, for example, 300 mm or more and 500 mm or less. The vertical dimension of the body part 24 is set longer than the vertical dimension of the neck part 22. Thereby, an internal volume becomes large.

  In addition, a viewing window portion 24a that allows the amount of contents to be visually recognized from the outside is provided in a part of the body portion 24 in the circumferential direction. In this embodiment, the visual recognition window portion 24 a is located on the back side of the container 1, and continuously extends from the vicinity of the upper end of the trunk portion 24 to the vicinity of the lower end.

  The outer surface of the container body 20 is subjected to a slip property improving process for improving the slip property of the shrink film 30 that is thermally contracted when the container body 20 is covered with the shrink film 30. In this embodiment, the portion on which the slipperiness improving process is performed is the outer surface of the neck portion 22 and the shoulder portion 23, and is a region where fine points are drawn in FIGS. 3 and 4 (indicated by reference numeral 26). The slipperiness improving process may be performed on at least the outer surface of the neck portion 22, and may be performed on the outer surfaces of the shoulder portion 22 and the trunk portion 24.

  That is, when heat shrinking the shrink film 30 using a steam type shrink furnace described later, water vapor may enter between the shrink film 30 and the outer surface of the container body 20. At this time, when the shrink film 30 and the outer surface of the container body 20 are smooth surfaces and are not subjected to the slipperiness improving process, moisture (between the shrink film 30 and the outer surface of the container body 20) Or the water vapor) is in close contact with each other, and the shrink film 30 is attached to the outer surface of the container body 20 in the process of thermal contraction, and air is confined between the container body 20 and the film 30. As a result, the shrink film 30 is wrinkled. This is particularly noticeable when covering the container body 20 having a large difference in circumference as described above.

  In this embodiment, even if moisture (or water vapor) is present between the shrink film 30 and the outer surface of the container main body 20 by the slipperiness improving process, the shrink film 30 is against the outer surface of the container main body 20. By performing the treatment that makes it easy to slip, the shrink film 30 is prevented from being wrinkled.

  Specifically, as the slipperiness improving process, for example, an embossing process for forming an embossing using a mold when the container body 20 is molded, a frame process performed on the outer surface after the container body 20 is molded, and corona discharge And the like. By performing these treatments, at least one of the concave portion and the convex portion or one of them is formed on the outer surface of the container body 20, so that the contact area with the shrink film 30 is reduced.

  When the graining treatment is performed, it is preferable to form the concavo-convex pattern on the molding surface of the mold by physical treatment such as chemical treatment by etching, sand blasting, or polishing treatment that is not mirror finished. The unevenness pattern on the molding surface is transferred to the outer surface of the container main body 20 so that the slipperiness improving process is performed. When sandblasting is performed on the molding surface of the mold, it is preferable to use sand that is coarser than 150th, and it is more preferable to use sand that is 100th or higher.

  The unevenness formed on the molding surface of the mold is preferably 5 or more and 100 or less, more preferably 10 or more and 80 or less in terms of Rz (μm). Note that the upper limit value of Rz is not limited to the above-mentioned value, but is an approximate value that makes the unevenness floating on the surface of the shrink label (film 30) inconspicuous, and is set appropriately in consideration of the appearance shape (designability). do it.

  Etching is effective when forming rough irregularities. By forming irregularities in such a range on the molding surface, the slipperiness improving process can be reliably performed on the outer surface of the container body 20.

  The shrink film 30 is preferably made of a highly shrinkable film as a base material, and a printed layer is preferably formed thereon. However, in consideration of the shape of the container body 20, depending on required characteristics, applications, durability, and the like. What is necessary is just to select a material suitably. As a material for the base material of the shrink film 30, for example, a film made of a polyester resin, a polyolefin resin, a polystyrene resin, or the like is preferably used as the base material.

  As shown in FIG. 5, the shrink film 30 is formed in a cylindrical shape. The shrink film 30 is provided with a translucent portion 31 having translucency at a portion corresponding to the visual recognition window portion 24 a of the container body 20. When the shrink film 30 is thermally shrunk, the translucent part 31 coincides with the visual window part 24 a of the container body 20. The translucent part 31 may be colorless and transparent, or may be translucent. Moreover, since the translucent part 31 should just be able to let sunlight and the light of illumination pass in a normal use environment, it may be colored lightly, for example.

  Part coating may be applied to the end of the shrink film 30. The part coat treatment is configured by applying a heat-sensitive adhesive to a portion that comes into contact with the outer surface of the container body 20 in order to improve heat sealability, and suppresses slipping of the end portion of the shrink film 30. be able to. By performing the part coat treatment, it is possible to suppress the end portion of the shrink film 30 from sliding up during heat shrinkage. In consideration of the finish and the ease of removing the shrink film 30 at the time of disposal of the container 1, it is preferable that the part coat treatment is not performed on portions other than the end portion of the shrink film 30.

  In addition to the above, examples of the base material of the shrink film 30 include resins such as polyvinyl chloride resin, polyamide resin, aramid resin, polyimide resin, polyphenylene sulfide resin, and acrylic resin. These resins may be used alone or in combination of two or more. Alternatively, the shrink film 30 may be configured as a laminated film by laminating the same or different resins. When transparency is required, a polyester film is particularly preferable.

  The shrink film 30 may have a single layer structure made of a single layer film, or may have a laminated structure made of a laminated film in which a plurality of film layers are laminated. In the case of a laminated structure, film layers made of different resins may be laminated, or film layers made of similar resins may be laminated. In the case of a laminated film, a laminated film having a polyester resin as an outer layer and a polyolefin resin or polystyrene resin as an inner layer, or a laminated film having a cyclic olefin resin as an outer layer and a polyethylene resin or a polypropylene resin as an inner layer, Also good.

  The shrink film 30 is preferably a uniaxially, biaxially or multiaxially oriented film from the viewpoint of exhibiting high shrink characteristics. When the shrink film 30 is a laminated film, it is preferable that at least one film layer in the laminated film is oriented. The shrink film is particularly preferably a uniaxial or biaxially oriented film, more preferably a film that is strongly oriented in the uniaxial direction.

  As a method for orienting the shrink film 30, the longitudinal direction, that is, the flow direction (longitudinal direction or MD direction) and the width direction of the production line of the shrink film 30, that is, the direction orthogonal to the longitudinal direction (lateral direction or TD direction). ) Biaxial stretching, uniaxial stretching in the longitudinal direction or width direction, and the like can be used. As the stretching method, a roll method, a tenter method, a tube method, or the like can be used.

  Although it does not specifically limit as a manufacturing method of the shrink film 30, For example, methods, such as melt film forming or solution film forming, can be used. For example, the surface of the shrink film 30 may be subjected to a surface treatment such as a corona discharge treatment or a primer treatment. In the case of producing a shrink film 30 having a laminated structure, for example, a method such as a co-extrusion method or a dry lamination method can be used.

  The thermal shrinkage rate at 90 ° C. for 10 seconds in the main orientation direction of the shrink film 30 is not particularly limited, but is preferably 15 to 90%, more preferably 20 to 85%. The thermal contraction rate (90 ° C., 10 seconds) in the direction orthogonal to the main alignment direction is not particularly limited, but is preferably −3 to 15%. The above-mentioned “main orientation direction” is a direction mainly subjected to a stretching process (a direction having the largest thermal shrinkage), and is generally a longitudinal direction or a width direction, for example, substantially in the width direction. In the case of a uniaxially stretched film, it is the width direction.

  When the shrink film 30 is a transparent film, the haze value (%) of the shrink film 30 (based on JIS K 7105) is preferably less than 10%, more preferably less than 5.0%, and still more preferably less than 2.0%. is there. When the haze value is 10% or more, when printing is shown through the shrink film 30, the printing may become cloudy and the decorativeness may be lowered.

  The thickness of the shrink film 30 is not particularly limited, but is preferably 10 μm to 100 μm, more preferably 12 μm to 80 μm, and still more preferably 15 μm to 60 μm.

  The shrink film 30 is, for example, “Space Clean S7042”, “SV-808” manufactured by Toyobo Co., Ltd., “LX-10S”, “LX-61S” manufactured by Mitsubishi Plastics, Inc. Company-made "Bonnset", Gunze Co., Ltd. "GMLS" (polystyrene film), Gunze Co., Ltd. "FL" (polyolefin film), Mitsubishi Plastics Co., Ltd. "Ecology" (polylactic acid film), “DL” manufactured by Mitsubishi Resin Co., Ltd., “HGS” manufactured by Gunze Co., Ltd. (the laminated film of which the surface layer is a polyester resin and the center layer is a polystyrene resin) can be exemplified.

  The shrink film 30 is provided with a printing layer on at least one side. The print layer may not be provided on the entire surface of the shrink film 30 and may be provided only on a part thereof. The print layer may be provided directly without using another layer such as an anchor coat layer. In addition, you may provide a printing layer on the shrink film 30 via an anchor coat layer as needed.

  For example, the print layer can be constituted by a design composed of only one type among a single color, a plurality of colors, gradation colors, drawings, photographs, characters, or the like, or a design combining two or more of these. The print layer may be a color print layer or a black and white print layer. A protective printing layer (such as a transparent medium protective printing layer or a white protective printing layer) that imparts abrasion resistance or slipperiness may be provided on the surface of the printing layer. The printed layer may constitute various decorations, including display of contents and precautions for use. Moreover, the ink and pigment of a printing layer are not specifically limited.

  In addition to the print layer, the shrink film 30 may be provided with a layer such as an adhesive layer, an ultraviolet ray prevention layer, an anchor coat layer, a primer coat layer, a nonwoven fabric, or paper as necessary.

  The printing layer of the shrink film 30 may be provided so as to be inside the shrink film 30, or may be provided so as to be outside.

  As the main component of the resin forming the print layer, for example, an acrylic resin is preferable. Thereby, safety can be improved. Further, the printing layer may contain a predetermined amount of urethane acrylic resin. Thereby, while the adhesiveness with the base material of the shrink film 30 becomes favorable, moderate softness | flexibility can also be given.

  In the present embodiment, the shrink film 30 is formed in a cylindrical shape, but may be formed so as to be wound. From the viewpoint of excellent designability and followability to the shape of the container body 20, the cylindrical shrink film 30 is preferable, and it is particularly preferable to have a printed layer on the inner side.

  The shrink film 30 is formed with a large number of holes 32 constituting perforations for breaking the shrink film 30 after the container 1 is used (discarded). The holes 32 function as air vent holes for extracting air from between the shrink film 30 and the outer surface of the container body 20 when the shrink film 30 is contracted.

  Next, the case where the container 1 configured as described above is manufactured will be described based on the flowchart of FIG. First, in step S1, a resin material constituting the container body 20 is injection-molded (preformed) to obtain a cylindrical intermediate molded body 40 as shown in FIG. In this injection molding step, although not shown, a conventional injection molding machine and a molding die for injection molding are used. The intermediate molded body 40 obtained from the mold for injection molding includes a screw mouth portion constituting portion 41 that becomes the screw mouth portion 21 of the container body 20, a neck portion constituting portion 42 that becomes the neck portion 22 of the container body 20, and the container body 20. A shoulder component 43 serving as the shoulder 23, a trunk component 44 serving as the barrel 24 of the container body 20, and a bottom wall component 45 serving as the bottom wall 25. The code | symbol 41a is a part used as a screw thread.

  The molding surface of the molding die for molding the intermediate molded body 40 is subjected to a graining process on the portions of the intermediate molded body 40 where the neck portion constituting portion 42 and the shoulder portion constituting portion 43 are molded. As a result, a concavo-convex pattern is formed on the outer surfaces of the neck component 42 and the shoulder component 43 of the intermediate molded body 40. The formation range of the concavo-convex pattern is a range in which fine dots are drawn in FIG. The formation of the concavo-convex pattern constitutes the slip improvement process of the container body 20 and is the primary process of the slip improvement process.

  By forming the concavo-convex pattern at the time of injection molding, the concavo-convex pattern can be surely formed. Therefore, even after subsequent blow molding, the concavo-convex pattern on the outer surface is hard to disappear, and the concavo-convex pattern can be clearly left. In particular, this method is effective in a portion where the blow ratio at the time of blow molding is small and the texture transfer at the time of blow molding is weak. In the case of the container body 20 according to the present invention, the container body 20 Among each part, a very high effect is obtained in a part with a short circumference (a range from the neck part 22 to a part of the shoulder part 23), and a sufficient slip improvement effect is exhibited. In the present embodiment, at least the neck portion 22 of the container body 20 is subjected to a texture process.

  The area indicated by A ′ in FIG. 6 corresponds to the area indicated by A in FIG. 3, the area indicated by B ′ in FIG. 6 corresponds to the area indicated by B in FIG. 3, and the area indicated by C in FIG. A region indicated by 'corresponds to a region indicated by C in FIG. 3, and a region indicated by D ′ in FIG. 6 corresponds to a region indicated by D in FIG. 3.

  Then, it progresses to step S2 and the intermediate molded body 40 heated is blow-molded. In this blow molding process, a blow mold (not shown) for molding the container body 20 is prepared, and the intermediate molded body 40 is placed inside the blow molded mold and heated inside the intermediate molded body 40. Inject high-pressure air.

  The molding surface of the blow molding die is subjected to embossing at the site where the neck portion 22 and the shoulder portion 23 of the container body 20 are molded. Thereby, an uneven pattern is formed on the outer surfaces of the neck portion 22 and the shoulder portion 23 of the container body 20. The formation of the concavo-convex pattern constitutes a slip improvement process of the container body 20 and is a secondary process of the slip improvement process. The slip improvement process is completed through this secondary process. The above is the injection blow molding method.

  Thereafter, the process proceeds to step S3, and the shrink film 30 is attached to the container body 20 as shown in FIG. This process can be performed continuously by, for example, transporting a large number of container bodies 20 by a transport conveyor (not shown) and covering each container body 20 with the shrink film 30 during the transportation.

  Subsequently, it progresses to step S4 and moves to the shrink process which shrinks the shrink film 30 by heat. In the shrink process, a steam type shrink furnace (not shown) is used. The said conveyance conveyor can convey the container main body 20 and the shrink film 30 to the heating chamber of a steam type shrink furnace.

  A steam generator for generating steam is provided in the heating chamber. Water vapor comes into contact with the container main body 20 and the shrink film 30 passing through the heating chamber, whereby the container main body 20 and the shrink film 30 are heated. The heating temperature with water vapor is preferably set appropriately in the range of 65 ° C to 100 ° C. Moreover, you may perform a shrink process using superheated steam. The temperature of the superheated steam can be set to 150 ° C. to 200 ° C., for example.

  As the shrink film 30 is heated, it begins to shrink. At this time, since the minimum circumference of the neck 22 of the container body 20 is ½ or less of the maximum circumference of the body 24 and the difference in circumference is large, the shrinkage rate of the portion corresponding to the neck 22 in the shrink film 30 Is larger than the portion corresponding to the body portion 24. When the portion of the shrink film 30 corresponding to the neck portion 22 contracts, at least the outer surface of the neck portion 22 is formed with projections and depressions so that the contact area is reduced. Even if moisture (or water vapor) exists between the outer surface of the neck portion 22, the shrink film 30 does not stick to the outer surface, and the shrink film 30 at the time of shrinkage easily slips on the outer surface. . As a result, the shrink film 30 after shrinkage is difficult to be wrinkled and is in a clean state.

  When the shrink film 30 contracts, since the holes 32 are provided in the shrink film 30, air between the shrink film 30 and the container body 20 can be smoothly extracted from the holes 32. As a result, the shrink film 30 shrinks even more cleanly. The container 1 is obtained through the above steps.

  When the container 1 obtained as described above is used, the minimum circumferential length of the neck portion 22 of the container body 20 is set to ½ or less of the maximum circumferential length of the body portion 24. Easy to grip the neck 22. Thereby, it becomes possible to stably hold the large-capacity and heavy container 1 for a long time.

  Further, the amount of the contents of the container 1 can be seen from the outside through the viewing window 24 a and the light transmitting part 31.

  As described above, according to the container 1 according to this embodiment, even if the circumference of the neck portion 22 is shortened so that the user can easily grasp it, the circumference of the trunk portion 24 is lengthened to increase the capacity. be able to. And since the shrink film 30 covers from the neck part 22 to the trunk | drum 24 of the container main body 20, the various containers 1 from which a design differs can be prepared at low cost. Furthermore, since the slipperiness improving process is performed on the outer surface of the neck portion 22 of the container body 20, the container body 20 can be covered with the shrink film 30 cleanly and with a high yield.

  Further, since the slipperiness improving process is performed by forming the irregularities, the slipperiness of the shrink film 30 can be improved by a simple method.

  Moreover, the window part 24a for visual recognition which does not perform a slipperiness improving process is provided in the trunk | drum 24 of the container main body 20, and the site | part which covers the window part 24a for visual recognition of the container main body 20 in the shrink film 30 has translucency. Therefore, the user can grasp the amount of contents from the outside, and the convenience can be improved.

  Further, since the holes 32 can be formed in the shrink film 30 so that air can be extracted, the shrink film 30 can be contracted more cleanly, the appearance can be improved, and the yield can be improved.

  The above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  Examples of the present invention will be described below, but the present invention is not construed as being limited to the examples.

  In Table 1, the evaluation about the state (finished state) which shrunk the shrink film 30 about the comparative example and Examples 1-6 of this invention is shown.

  In Table 1, “I” in the “Manufacturing method” column is the case of injection blow molding without any embossing on the mold, and “II” is the entire embossing process only on the blow mold by injection blow molding. "III" means that a part of the injection mold (corresponding to the neck portion 22 of the container body 20) is subjected to the embossing process by the injection blow molding, and the entire blow mold is embossed. “IV” is a case where the container body 20 obtained by the manufacturing method “I” is directly sandblasted, and “V” is a multilayer direct blow molding method.

  In Table 1, “XX” in the “Finished” column means that the occurrence rate of defective products with wrinkles on the shrink film is 10% or more, and “O” means that the occurrence rate is 1% or more. This is a case of less than 3%, and “◎” means a case where the occurrence rate is less than 1%.

  The measuring instrument for the surface roughness Rz (μm) of the container body uses a surface roughness measuring instrument “Surfcom 130A (manufactured by Tokyo Seimitsu Co., Ltd.)”, which is a contact type with a tip radius of 2 μm, a material of diamond, and a measuring force of 0.75 mN. Rz is the unevenness average value of the measurement section of 5 mm (average value of 10 high points and 10 low points selected by the measuring device).

  As is clear from Table 1, in the comparative example, the die is not subjected to the graining process, and the container body is not subjected to the sandblasting process. Is expensive. This is because Rz (μm) is a low value of about 1.5, the outer surface of the container body is not slippery, air does not escape smoothly between the container body film, and wrinkles occur in the film. This is because it becomes easier.

  On the other hand, in Examples 1-6, since the value of Rz (μm) is larger than that of the comparative example, air is smoothly trapped without being trapped between the container body and the film, and wrinkles to the film There is no occurrence of, and it is finished neatly. Further, when Examples 5 and 6 are compared, the steam output is smaller in Example 6, but the yield is good because the occurrence rate of defective products is less than 3% when looking at the finished product.

  As described above, the synthetic resin container according to the present invention can contain, for example, a chemical solution or the like.

DESCRIPTION OF SYMBOLS 1 Synthetic resin container 10 Spray mechanism 20 Container main body 21 Screw mouth part 22 Neck part 23 Shoulder part 24 Trunk part 24a Window part for visual recognition (non-processing part)
25 Bottom wall 30 Shrink film 31 Translucent part 32 Hole (air vent hole)
40 Intermediate molded body

Claims (4)

In a synthetic resin container in which a synthetic resin container body is covered with a heat shrink film,
The container body includes a cylindrical mouth portion, a neck portion extending from the mouth portion toward the bottom wall side of the container body, a shoulder portion extending from the neck portion toward the bottom wall side of the container body, and the shoulder A body portion extending from the portion to the bottom wall of the container body,
The minimum circumference of the neck is set to 1/2 or less of the maximum circumference of the trunk,
The film is formed so as to cover at least the neck part to the body part of the container body,
A synthetic resin container, wherein at least an outer surface of the neck part of the container body is subjected to a slip property improving process for improving the slip property of the film during heat shrinkage. In the synthetic resin container according to claim 1,
The above-mentioned slipperiness improving process forms at least one of a recessed part or a convex part, The synthetic resin container characterized by the above-mentioned. In the synthetic resin container according to claim 1 or 2,
The body portion of the container body is provided with a non-processing portion that has not been subjected to the slip improvement process,
A synthetic resin container characterized in that a portion of the film covering the non-processed portion of the container body has translucency. In the synthetic resin container according to any one of claims 1 to 3,
A synthetic resin container, wherein the film is formed with an air vent hole for venting air between the container body and the film when contracted.

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