JP5973744B2 - Synthetic resin cap - Google Patents

Description

  The present invention relates to a synthetic resin cap for closing a mouth of a cosmetic container.

  Conventionally, a synthetic resin cap for closing a container mouth is manufactured by compression molding a synthetic resin material with a mold. Specifically, the gap between the outer surface mold that molds the outer surface of the cap and the inner surface mold that molds the inner surface of the cap is filled with a synthetic resin material of a molten material and cured, and the outer surface mold is removed. The completed cap is obtained by forcibly pulling out the inner mold from the cap.

  By the way, in a synthetic resin cap generally used for a beverage container or the like, a part of a screw portion formed on the inner peripheral surface of the cap is cut into a vertical groove shape to divide the screw portion in the circumferential direction, and the gas in the container A so-called vent slot for punching is formed (Patent Document 1 and Patent Document 2). This vent slot is originally provided for the purpose of degassing, but by dividing the threaded portion and making it non-continuous, when the inner mold is pulled out from the cap during molding, the cap expands in the diameter direction. There was also an advantage that the removal work becomes easy.

  However, depending on the relationship between the threaded portion and the vent slot, the following problems may occur during manufacture or use. In other words, when the circumferential length of the screw part is increased while the circumferential length of the vent slot is shortened, the tightening force of the screw during use is improved, but when the inner mold is pulled out during manufacture, the cap Deformation hardly occurs in the diameter-expanding direction, and it may be difficult to remove from the mold, and if it is forcibly pulled out, there may be a molding defect such as deformation of the screw part. Also, if the circumferential length of the threaded portion is shortened while the circumferential length of the vent slot is increased, the ease of pulling out from the mold is improved, but the screw tightening force during use may be reduced. there were.

  In addition, if the body material is made of glass in a container such as cosmetics, the dimensional accuracy of processing is inferior to that of synthetic resin, so sealing with a cap at the time of closure may be insufficient, and conventional beverage caps With this structure, there is a possibility that sufficient sealing cannot be maintained.

JP 2003-261155 A JP-A-10-1150

  The present invention provides a synthetic resin cap that overcomes the drawbacks of conventional synthetic resin caps, is easy to be removed from the mold during molding, and that there is no risk of lowering the clamping force, and that can maintain a sufficient degree of sealing. is there.

  The present invention solves the above-described problem, and includes a top plate portion and a peripheral wall portion that hangs down from the periphery thereof, and an inner surface of the peripheral wall has a screw portion that can be screwed to the container mouth portion. The threaded portion is formed so as to be alternately arranged in the circumferential direction with the non-threaded portion not provided with the thread, and further, the circumferential length of the threaded portion and the non-threaded portion is formed to be the same. Synthetic resin cap.

  According to the synthetic resin cap of the present invention, since the circumferential length of the threaded portion and the non-threaded portion is the same, the ease of pulling out from the mold and the tightening force of the screw during use are improved. Both reduction prevention can be achieved.

  In addition, the synthetic resin cap of the present invention having a rib on the back of the top plate can easily attach a packing to the back of the top plate, and can maintain high sealing performance regardless of the material of the container body. it can.

A-A 'sectional view of a synthetic resin cap according to the present invention Bottom view of the synthetic resin cap according to the present invention The partially expanded sectional view of the state which attached the packing to the synthetic resin cap which concerns on this invention Graph showing the visible light transmittance of the synthetic resin cap according to the present invention

  Hereinafter, an example of an embodiment of a synthetic resin cap according to the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of the synthetic resin cap of the present invention, taken along the line A-A ′, and FIG. In the figure, 1 is a synthetic resin cap, 11 is a top plate portion, 12 is a peripheral wall, 13 is a screw portion, 14 is a screw thread, 15 is a non-screw portion, 16 is a rib portion, and 161 is a protruding portion.

  As shown in FIG. 1, the synthetic resin cap 1 of the present invention includes a top plate portion 11 and a peripheral wall 12 that hangs down from the peripheral edge thereof, and is formed on the inner peripheral surface of the peripheral wall 12 so as to be screwable with a container mouth portion. And has a threaded portion 13. The screw portion 13 is divided in the circumferential direction by the non-screw portion 15.

  The screw portion 13 of this embodiment is formed by projecting a screw thread 14 in two upper and lower stages on a rectangular peripheral wall portion formed thicker than other portions of the peripheral wall 12. A plurality of such screw portions 13 are provided discontinuously on the inner peripheral surface of the peripheral wall 12, and a non-screw portion 15 in which no screw thread 14 is formed is formed between the adjacent screw portions 13. As described above, the plurality of screw portions 13 and the non-screw portions 15 are formed on the inner peripheral surface of the synthetic resin cap 1 so as to be alternately arranged in the circumferential direction.

  The screw portion 13 may have the same thickness as the other peripheral walls 12, but by forming the screw portion 13 thicker than the non-screw portion 15 as in this embodiment, the strength of the screw thread 14 is improved and the cap is made of gold. This is preferable because the deformation and distortion of the screw thread 14 can be minimized when being pulled out from the mold. Furthermore, by forming the peripheral wall 12 of the non-threaded portion 15 thin with respect to the threaded portion 13, the cap is easily deformed in the diameter-expanding direction when being pulled out from the mold, and the removal from the mold is facilitated. preferable.

  As shown in FIG. 2, the synthetic resin cap 1 of the present invention is formed such that the circumferential length W1 of the screw portion 13 and the circumferential length W2 of the non-screw portion 15 are the same. . Thus, by forming the circumferential length W1 of the threaded portion 13 and the circumferential length W2 of the non-threaded portion 15 in the same manner, when the inner mold is pulled out from the cap during molding, the cap expands in the diameter increasing direction. It can be easily deformed and removed easily, and the tightening force of the screw during use can be sufficiently maintained.

  There is no particular limitation on the number of the screw part 13 and the non-screw part 15 provided that the circumferential lengths thereof are the same. It is preferable to provide in a range of locations, and in particular, it is desirable to provide 8 locations as in this embodiment.

  A rib portion 16 for attaching a packing may be provided on the upper portion of the non-screw portion 15. As shown in FIG. 3, the rib portion 16 is formed so as to protrude from the upper peripheral wall 12 of the non-screw portion 15 toward the center of the synthetic resin cap 1, and the synthetic resin cap is formed below the other rib portion 16 portion. 1 has a protruding portion 161 that further protrudes in the center direction. The packing 2 attached to the synthetic resin cap 1 of this embodiment is formed in a disc shape that is the same as or slightly larger than the cap inner diameter φ1 obtained by subtracting the protruding height of the rib portion 16 in the cap center direction. The packing 2 can be attached to the synthetic resin cap 1 by inserting the packing 2 from the opening side of the cap, getting over the protruding portion 161 and pushing it into the rib portion 16 at the upper portion of the protruding portion 161. As a result, the packing 2 is held on the back surface of the top plate portion 11 without being easily removed by being blocked by the protruding portion 161 while the peripheral portion is held by the rib portion 16, and therefore by the bonding or other fixing means The packing 2 can be easily attached. The rib portion 16 is preferably provided one for each non-threaded portion 15, but if it is sufficient to fix and maintain the packing 2, for example, one location for two non-threaded portions 15. You may provide the rib part 16 one by one.

  In this way, by attaching the packing 2 to the back side of the top plate portion 11 of the synthetic resin cap 1, even if there is a slight deviation in the dimensional accuracy of the mouth portion of the container body, the mouth portion is in close contact with the mouth portion. Can be maintained. The material of the packing 2 is not limited as long as it has a certain degree of elasticity and can maintain the airtightness in the container, but a low foam polyethylene sheet is preferable.

The synthetic resin cap 1 can use polypropylene, polyethylene terephthalate, or the like as its material. In addition, the colored cap as a whole has a lower visible light transmittance than the uncolored one, and especially the black colored one has a very low light transmittance. This is preferable because the influence of the above can be reduced. Furthermore, it is preferable to attach the packing 2 to the synthetic resin cap 1 because the light transmittance is lower than when the packing 2 is not attached.

  Next, the present invention will be described in more detail with reference to examples.

Example Synthetic resin caps according to the present invention, which are prepared with white and black coloring as a whole, and in the state where the packing is attached and the state where the packing is not attached, respectively, and visible light transmittance under the following conditions: Was measured. The results are shown in FIG.

<Devices used>
UV-Vis spectrophotometer: UV-2500PC (Shimadzu Corporation)
Integrating sphere reflector: ISR-260 (Shimadzu Corporation)
<Measurement conditions>
Measured value: Transmittance Scanning speed: Medium speed Slit width: 5.0nm
Sampling pitch: 0.5nm
Measurement temperature: room temperature

  As can be seen from the results of FIG. 4, it was found that the visible light transmittance was significantly lower in the black colored one than in the white colored one. Further, it was found that the same color of the one with packing and the one without packing had a lower transmittance. For example, it was confirmed that the white coloring without packing was higher than the standard value of the transmittance of kojic acid, which is one of the components of cosmetics, while the one with packing of the same color, It was confirmed that it was lower than the reference value.

DESCRIPTION OF SYMBOLS 1 ... …… Synthetic resin cap 2 ......... Packing 11 ......... Top plate part 12 ......... Perimeter wall 13 ......... Screw part 14 ......... Screw thread 15 ......... Non-screw part 16 ......... Rib part 161 ......... Projection part W1 ......... Circumferential length of the screw part W2 ......... Circumferential length of the non-screw part φ1 ... ... Cap inner diameter obtained by subtracting the projection height of the rib part toward the cap center

Claims (4)

A top plate portion and a peripheral wall portion that hangs down from the periphery of the top plate portion, and an inner peripheral surface of the peripheral wall has a screw portion that can be screwed to the container mouth portion, and the screw portion is not provided with a thread. it six absence each to be disposed alternately in the threaded portion and the circumferential direction are formed 12 places, further, is formed so as circumferential length of the threaded portion and the unthreaded portion is equal Rutotomoni, wherein A synthetic resin cap characterized in that a rib portion projecting in the center direction of the cap is provided on the upper portion of the non-screw portion so as to extend in the vertical direction .   2. The synthetic resin cap according to claim 1, wherein the screw portion includes a peripheral wall portion formed thicker than a non-screw portion and a screw thread formed on the peripheral wall portion. The synthetic resin cap according to claim 1 or 2 , wherein a protruding portion that further protrudes in a center direction of the cap is formed on the rib portion , and a packing is attached to the back surface of the top plate portion by the protruding portion .   The synthetic resin cap according to any one of claims 1 to 3, wherein the entire synthetic resin cap is colored black.

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