JP4784982B2 - Cap material and container with cap - Google Patents

Description

  The present invention relates to a cap material and a cap-equipped container used for bottle cans, glass bottles, PET bottles, and the like.

  In recent years, openable and closable containers such as glass bottles, PET bottles, and aluminum bottle cans have been widely used as containers for beverages such as soft drinks. Cap materials used in these containers are liners mainly composed of synthetic resin on cap bodies formed by injection molding synthetic resin and cap bodies formed by drawing aluminum plates or iron plates. The cap material is widely provided and used as a cap that can be opened and closed by screwing this cap material into a container having a male screw portion at the bottle mouth portion.

  The liner that is placed on the inner surface of the top plate of the cap body can be a resin that is bonded to the center of the inner surface of the top plate of the cap body after inserting a pre-formed disk, or resin on the cap body such as PVC sol. Into which the melted resin is adhered at the same time as the gelation, and the molten resin is put into the cap body and embossed. And most of these liners are bonded to the inner surface of the top plate portion of the cap body, and when rotating the cap, it is necessary to rotate the liner simultaneously with the cap. Here, if the liner and the liner contact portion at the opening of the bottle mouth are firmly attached, the frictional resistance between them is large, so the torque required for opening (hereinafter referred to as opening torque) There is a problem that the opening operation becomes difficult due to the increase in size. Therefore, in order to reduce the plug opening torque, it is necessary to improve the lubrication between the liner and the contact portion between the liner at the opening of the bottle mouth, and a lubricant added to the liner is provided.

  However, when a liner to which a lubricant has been added is used, the liner to which the lubricant has been added is in direct contact with the filler in the bottle container, so that a portion of the lubricant falls on the filler and floats on the surface of the filler. There was a risk of being recognized as a foreign object and degrading quality.

In order to solve such a problem, in Patent Document 1, the liner has a two-layer structure of a functional layer and a support layer, and the sheet-like liner is attached to the inner surface of the top plate portion of the cap body in a non-bonded state. The proposed cap has been proposed.
JP 2004-217295 A

  However, the liner used in the cap described in Patent Document 1 is configured by laminating a functional layer made of an elastomer or the like and a support layer having a certain bending strength, and the thickness of the support layer is the liner. The thickness is 4% to 50% of the total thickness. Therefore, the thickness of the functional layer constituted by the elastomer occupies 50% to 96% of the whole, and the liner as a whole has elasticity and its deformation resistance is small.

  When the cap material equipped with the above liner is screwed into the bottle mouth of the bottle container, the deformation of the liner is small, so the liner is greatly deformed and bites around the bottle mouth. There is a problem that the contact area between the mouth portion and the liner is increased, and the opening torque when the cap is rotated to open the opening becomes very large.

  In addition, when selling bottle cans with caps to about 40-70 ° C. in the market, the internal pressure of the bottle cans increases and the liner is strongly pressed against the inner surface of the top plate of the cap body. When the liner is deformed greatly, the liner adheres to the top plate of the cap body, the frictional resistance between the liner and the cap material increases, and there is a problem that the opening torque increases and the opening is difficult. .

  In addition, when the glass bottle is heated and filled with a filler and sealed with a cap, the inside of the glass bottle becomes a negative pressure, that is, a decompression bottle. However, when the cap is rotated, only the cap body is separated from the glass bottle, and the liner is dropped from the cap body.

In addition, since elastomers generally have high permeability to oxygen and odorous substances, the quality deteriorates due to oxygen that has passed through the functional layer of the liner when the filler is stored for a long time, and TCA (Trichloroanisote) There is a problem in that odorous substances such as the like enter the bottle container through the functional layer of the liner, the odor is transferred to the filling, and the flavor property is impaired.
Further, when the thickness of the functional layer that is an elastomer exceeds 50% of the total thickness of the liner, when the cap material is fitted into the bottle, the functional layer expands outward in the circumferential direction, and the cap material Since the contact between the cylindrical portion and the functional layer is increased, there has been a problem that the opening torque is increased.
The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a cap material and a container with a cap that have a small opening torque and are easy to open and have excellent sealing performance.

  In order to solve the above-mentioned problems, the present invention provides a cap body having a disk-shaped top plate portion and a peripheral wall portion substantially hanging from the periphery of the top plate portion, and an inner surface of the top plate portion of the cap body In the cap material provided with a sheet type liner disposed along the sealing layer, the liner has a sealing layer made of an elastomer and having a sealing function, a hardness higher than that of the sealing layer, and the top plate portion. An inner surface and a sliding layer that slides are laminated, and the thickness of the sliding layer is 55% to 95% of the thickness of the liner.

  In the cap material configured as described above, the liner is provided with a sliding layer that slides opposite the inner surface of the top plate portion of the cap body, so that the inner surface of the top plate portion of the cap body and the liner are prevented from sticking. Opening torque can be reduced. Moreover, since the sealing layer which has a sealing function is provided in the liner, the opening part of a bottle mouth part can be sealed with a liner.

  Further, the thickness of the sliding layer having a hardness higher than that of the sealing layer is 55% to 95% of the thickness of the entire liner, and the deformation resistance of the entire liner is large. The contact area can be reduced, and the opening torque can be reduced. Even when the inside of the glass bottle has a negative pressure, since the deformation resistance of the entire liner is large, it is possible to prevent the liner from being deformed and sticking to the glass bottle, and to prevent the liner from dropping off when the bottle is opened.

  In addition, since the thickness of the sliding layer is 95% or less and the thickness of the sealing layer can be 5% or more, the thickness of the sealing layer can be secured, the sealing layer is deformed along the bottle mouth, and the bottle container is Can be sealed. On the other hand, since the thickness of the sliding layer is 55% or more of the entire liner and the thickness of the sealing layer is 45% or less of the entire liner, the deformation margin of the sealing layer in the sealed state is small, and the bottle After the container is sealed, the liner is hardly elastically deformed, and the sealed state can be maintained. Furthermore, even when the cap material is fitted to the bottle container, the expansion of the sealing layer on the outer circumferential side of the liner is suppressed, and the contact area between the inner wall surface of the cap material cylindrical portion and the sealing layer is prevented. And the opening torque can be reduced.

  Moreover, since the thickness of the sliding layer is set to 60% to 80% of the thickness of the liner, the thickness of the sealing layer is set to 20% or more, and the thickness of the sealing layer can be sufficiently secured. The container can be sealed. Also, the deformation resistance of the liner is prevented from becoming extremely large, and for example, the present invention can be applied to a cap that seals the bottle mouth portion by squeezing and deforming the liner.

  Furthermore, by making the thickness of the sliding layer 60% to 70% of the thickness of the liner, it is possible to seal the bottle container more stably and provide a cap material with excellent openability. can do.

In addition, by providing an intermediate layer partly or entirely between the sliding layer and the sealing layer, the sealing performance of the bottle mouth and the frictional resistance with the inner surface of the top plate of the cap body are affected. In addition, new properties can be added to the liner.
For example, when the intermediate layer is a barrier film such as aluminum, PET (polyethylene terephthalate), EVOH (ethylene vinyl alcohol copolymer), PVDC (polyvinylidene chloride), PA (polyamide), oxygen is externally applied. Mixing into the bottle container is prevented, and deterioration of the quality of the filler due to oxygen can be prevented. Moreover, it can prevent that TCA etc. penetrate | invade in a bottle container, an odor moves to a filling, and flavor property is impaired.

  In addition, by forming the intermediate layer by applying ink, it is possible to display letters, figures, etc. with ink between the sliding layer and the sealing layer. The above information can be displayed on the liner by printing such information and making the sealing layer and the sliding layer transparent or translucent. Furthermore, since the ink for displaying such information is provided between the sliding layer and the sealing layer, the ink does not come into contact with the filling in the bottle container and is excellent in hygiene.

  Further, by adding a lubricant to the sliding layer, the frictional resistance between the liner and the inner surface of the top plate portion of the cap body is reduced by the lubricant, the opening torque can be reduced, and the opening can be easily performed. it can.

  Further, the sliding layer is made of polypropylene or a polymer of polypropylene, and the sealing layer is made of a blend material of polypropylene and elastomer or a blend of polypropylene polymer and elastomer, whereby the sliding layer and The sealing layer is made of the same polypropylene-based material, and the sheet waste after punching generated when the liner is punched can be reused as a raw material for the sliding layer. Therefore, generation | occurrence | production of a waste can be reduced, while being able to make an environmental load small, the manufacturing cost can be reduced. In this specification, the polymer includes a copolymer.

  Here, since the sealing layer, which is an elastomer, comes into contact with the filling of the bottle container, it is necessary to strictly control the characteristics such as hygiene and elasticity. However, since the sliding layer does not come into contact with the filling, the characteristics are strictly limited. There is no need for management, and there is no problem even if a small amount of the polymer or blend material of polypropylene constituting the sealing layer is mixed. Furthermore, since the thickness of the sliding layer is 55% to 95% of the entire liner, even if the sheet waste after punching is used as a raw material, the amount of the polypropylene polymer or blend material constituting the sealing layer is mixed. And the effect on the characteristics of the sliding layer is small.

  Here, when the sealing layer and the bottle mouth part are firmly fixed, a large force is required when the liner is separated from the bottle mouth part, so that the cap opening property is deteriorated. Therefore, in order to improve the openability of the cap, it is preferable to add an antiblocking agent or a fatty acid amide alone or both to the sealing layer. As an anti-blocking agent, for example, talc, mica, kaolin, diatomaceous earth, or the like is added to the sealing layer in an amount of 0.3 to 5.0% by weight, thereby forming irregularities on the surface of the sealing layer and fixing the sealing layer to the bottle mouth. Can be prevented. Further, by adding 0.01 to 1.0% by weight of fatty acid amide, the surface of the sealing layer becomes slippery and sticking between the sealing layer and the bottle mouth can be prevented.

  Moreover, the cap material of the present invention can be used as a cap for bottle containers such as aluminum bottle cans, PET bottles, tin three steel bottle cans and glass bottles by forming the cap body from aluminum, synthetic resin, tinplate or tin-free steel. Can be used.

  In addition, the cap material is configured to rotatably support the liner by a liner support portion provided in the vicinity of the top plate portion of the cap body, so that when the cap is rotated, the liner is used together with the cap. There is no need to rotate, the opening torque can be greatly reduced, and opening is easy.

  A container with a cap in which the cap material according to any one of claims 1 to 10 is disposed in a bottle mouth portion, and an internal thread portion is formed on the inner surface of the peripheral wall portion to be screwed to the bottle mouth portion. When the cap screwed into the mouth is rotated to open the cap, the side that contacts the inner surface of the top plate portion of the cap body and the inner surface of the top plate portion of the liner serves as a sliding layer. Since the hardness of the moving layer is high and the deformation resistance of the entire liner is large, the liner is not firmly fixed to the inner surface of the top plate of the cap body, and the cap and liner can be moved relative to each other when the cap is rotated. Since the inner surface of the top plate portion of the cap body and the sliding layer of the liner slide, there is no need to slide the sealing layer of the liner and the contact portion between the sealing layer at the opening of the bottle mouth portion, and the cap It can be rotated, cap removal torque is reduced, it is possible to easily unplugging operation.

  As described above, according to the present invention, it is possible to provide a cap material and a cap-equipped container having a small opening torque and being easy to open and having excellent sealing performance.

A first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a cap material 10 according to the first embodiment of the present invention, and FIG. 2 shows a liner 20 used for the cap material 10.
The cap material 10 includes a cap main body 11 made of an aluminum material and a liner 20 attached to the cap main body 11.
The cap body 11 includes a disk-shaped top plate portion 12 and a peripheral wall portion 13 that is substantially suspended from the periphery of the top plate portion 12. An uneven portion 14 having a liner support portion 14 a protruding toward the inner surface side of the peripheral wall portion 13 is formed above the peripheral wall portion 13.

The liner 20 includes a sealing layer 21 made of a blend material in which a polypropylene polymer and an elastomer are blended within a predetermined ratio, and a sliding layer 22 made of a polypropylene (PP) plastic layer. The thickness of the sliding layer 22 is 65% of the total thickness of the liner 20. Here, the hardness of the sealing layer 21 is 30 or less in Shore D (JIS K 6253) (80 or less in Shore A (JIS K 6253)), and the hardness of the sliding layer 22 is 40 or more in Shore D. .
Here, 0.2% by weight of fatty acid amide is added to the sealing layer 21, and the surface of the sealing layer 21 is made slippery.
The liner 20 is disposed so that the sliding layer 22 made of a plastic layer faces the inner surface of the top plate 12. The liner 20 is not joined to the inner surface of the top plate portion 12 but is held by the liner support portion 14 a on the inner surface side of the concavo-convex portion 14.

  FIG. 3 shows a bottle can 30 with a cap as an example of a container with a cap in which the cap material 10 is used. The bottle can 30 with a cap has a configuration in which a cap 40 is screwed to a metal bottle can 31 (hereinafter referred to as a bottle can 31) formed of an aluminum alloy or the like. The bottle can 31 has a reduced diameter portion 33 that decreases in diameter upward from a cylindrical can body 32, and includes a cap portion 34 above the reduced diameter portion 33. A male thread part 35, a bulging part 36, and a curl part 37 are formed in the base part 34.

The cap material 10 is used by being attached to the cap part 34 of the bottle can 31. That is, the cap material 10 is put on the base part 34 of the bottle can 31, and the periphery of the base part 34 is rotated in a state where the screw forming roller of the capping device is pressed against the peripheral wall part 13 of the cap material 10. By rolling along the male threaded portion 35 of 34, the inner surface of the peripheral wall 13 of the cap material 10 is attached to the base 34 while forming a female screw corresponding to the male threaded portion 35 of the base 34. Used as cap 40.
That is, the cap 40 is attached to the bottle can 31 and the female thread 41 is formed on the peripheral wall 13 of the cap 10 is referred to as a cap 40.

  The cap 40 is formed with a top plate portion 12, a female screw portion 41, a pill fur proof portion 42, and a bridge portion 43, and a liner 20 as a sealing material is disposed on the inner surface of the top plate portion 12. Above the cap 40, an uneven portion 14 is formed by repeating a liner support portion 14a protruding toward the inner surface side of the peripheral wall surface 13 in the circumferential direction. In the state where the male screw part 35 of the bottle can 31 and the female screw part 41 of the cap 40 are screwed together and the lower end of the pill fur proof part 42 is wound under the bulging part 36, the cap 40 is used in the bottle can 31. The cap part 34 of the bottle can 31 and the sealing layer 21 of the liner 20 are in close contact with each other to be sealed.

  When opening the bottle can 31 to which the cap 40 is attached, the cap 40 is rotated while the bottle can 31 is held at a fixed position. By this rotation, the pill fur proof portion 42 engaged with the bulging portion 36 of the bottle can 31 is separated by the bridge portion 43, and the portion other than the pill fur proof portion 42 of the cap 40 is the male portion of the base portion 34. It moves upward along the screw part 35. Along with this, the liner 20 held by the liner support portion 14a of the concavo-convex portion 14 also moves upward, and the liner 20 and the base portion 34 are separated and opened.

  In this opening operation, the cap 40 having the above-described configuration has the sliding layer 22 on the side contacting the inner surface of the top plate 12 of the cap body 11 and the inner surface of the top plate 12 of the liner 20. In addition to being small, the hardness of the sliding layer 22 is high, and the deformation resistance of the entire liner 20 is large. Therefore, the liner 20 is not firmly fixed to the inner surface of the top plate portion 12 of the cap body 11, and When the cap 40 is rotated, the inner surface of the top plate portion 12 of the cap body 11 and the sliding layer 22 of the liner 20 slide, so that the sealing layer 21 of the liner 20 and the opening portion of the base portion 34 are opened. It is not necessary to slide the contact portion with the liner 20 in the case, the cap 41 can be rotated, the opening torque is reduced, and the opening operation is easily performed. It can be.

Furthermore, since the thickness of the sliding layer 22 is 65% of the entire thickness of the liner 20, the ratio of the sealing layer 21 made of elastomer is low, the deformation resistance of the liner 20 as a whole is large, and the base portion 34. The contact area between the liner 20 and the liner 20 can be reduced, and the opening torque can be reduced.
Moreover, even when the inside of the bottle can 31 becomes a negative pressure, the liner 20 is prevented from being deformed and entering the base part 34, and the filling material can be prevented from splashing outside when the bottle is opened.

  Further, since the sealing layer 21 and the sliding layer 22 of the liner 20 are made of the same polypropylene material, the sheet waste after punching generated when the liner 20 is punched and molded is used as the raw material of the sliding layer 22. Can be reused. Therefore, generation | occurrence | production of a waste can be reduced, an environmental load can be made small, and the manufacturing cost of the liner 20 can be reduced.

  Furthermore, 0.2% by weight of fatty acid amide is added to the sealing layer 21 to prevent the sealing layer 21 and the base part 24 from sticking, and the liner 20 is separated from the base part 34 when the cap 40 is opened. When this is done, a large force is not required, and the opening of the cap 40 is improved.

Next, a second embodiment of the present invention will be described. FIG. 4 shows a liner 50 attached to the cap material 10 of the second embodiment.
In the liner 50 attached to the cap member 10 of the second embodiment, an aluminum sheet 51 is inserted as an intermediate layer between the sliding layer 22 and the sealing layer 21. The sliding layer 22 is added with a fatty acid derivative such as an unsaturated fatty acid amide or a saturated fatty acid bisamide as a lubricant.

  Since the lubricant is added to the sliding layer 22 when the cap 40 composed of the cap material 10 is opened, the frictional resistance between the liner 50 and the top plate portion 12 is reduced, and the cap 40 and the liner 50 can be moved relative to each other. Therefore, when the cap 40 is rotated, the cap 40 can be rotated without rotating the liner 50 together with the cap 40, the opening torque is reduced, and the bottle can 31 can be easily opened. .

  Moreover, since the aluminum sheet 51 which suppresses permeation | transmission of oxygen and an odorous substance is inserted as an intermediate | middle layer, permeation | transmission of oxygen and TCA is prevented, The quality deterioration of the filling material by oxygen mixing, and the deterioration of the flavor property by odor transfer are prevented. Can be prevented.

A third embodiment of the present invention will be described. 5A and 5B show a liner 60 to be attached to the cap material 10 of the third embodiment.
In the liner 60 attached to the cap material 10 of the third embodiment, ink 61 is inserted as an intermediate layer between the sliding layer 22 and the sealing layer 21, and the ink 61 is used for sales promotion by the ink 61. Is displayed. Further, the sealing layer 21 or the sliding layer 22 is transparent or translucent.

In the cap material 10 described above, since the information display for sales promotion is displayed by the ink 61 existing as an intermediate layer between the sliding layer 22 and the sealing layer 21, contact between the ink 61 and the filler can be prevented, It is possible to reliably prevent the ink 61 from being mixed into the filling.
Further, since the ink 61 is not exposed on the surface of the liner 60, even if a child removes the liner 60 and licks it, for example, the ink 61 does not come into contact with the liner 60 and is particularly excellent in hygiene.

In addition, in this embodiment, although demonstrated using the bottle can with an aluminum cap, it is not limited to this, For example, the thing with which the metal cap was mounted | worn with a glass bottle, or resin-made PET containers A cap may be attached.
In addition, although an aluminum sheet is inserted as the intermediate layer, a film such as PET, EVOH, PVDC, PA, or the like that can prevent transmission of oxygen and odorous materials may be inserted.

Furthermore, in the present embodiment, the thickness of the sliding layer 22 has been described as 65% of the total thickness of the liner 20, but is not limited thereto, and may be in the range of 55% to 95%. Preferably, it may be within the range of 60% to 80%, more preferably within the range of 60% to 70%.
In addition, although the sliding layer is made of polypropylene, the present invention is not limited to this. For example, HDPE (high density polyethylene), L-LDPE (linear low density polyethylene), PET, PBT (polyethylene) It may be composed of butylene terephthalate), PA, PC (polycarbonate), PS (polystyrene) resin, or the like.

  In addition, although the sealing layer has been described as being composed of a blend material of a polypropylene polymer and an elastomer, the present invention is not limited thereto, and examples thereof include EVA (ethylene vinyl acetate copolymer) and HSBR (hydrogenated styrene). Styrene such as butadiene copolymer), SIS (styrene isoprene styrene copolymer), SBR (styrene butadiene rubber), SEBS (hydrogenated styrene ethylene butylene styrene copolymer), SEPS (styrene ethylene propylene styrene copolymer) -Based elastomers, olefin-based elastomers such as HDPE / EPDM (ethylene propylene diene terpolymer) and oil blends, blends of these, and plasticized PVC that is a blend of PVC (polyvinyl chloride) and plasticizers Polyester elastomer, polyamid Elastomer or be constituted by other elastomers well, blend materials of polypropylene and SEBS and oil blend material or a polypropylene polymer and SEBS and the oil (liquid paraffin) are very suitable.

  Furthermore, although it demonstrated by what added 0.2 weight% of fatty acid amide to the sealing layer 21, it is not limited to this, The addition amount of a fatty acid amide exists in the range of 0.01-1.0 weight%. I just need it. Moreover, you may add an antiblocking agent instead of a fatty acid amide or in addition to a fatty acid amide. Here, for example, talc, mica, kaolin, diatomaceous earth, or the like may be added as an antiblocking agent in an amount of 0.3 to 5.0% by weight.

Below, the result of the comparative test conducted in order to confirm the effect of this invention is demonstrated.
In the comparative test, a 0.22 mm thick aluminum plate coated with a synthetic resin paint on the inner and outer surfaces was molded into the cap body of a 28 mm PP cap, and a cap was inserted by inserting a liner that changed the thickness of the sliding layer and sealing layer. Then, hot water at 80 ° C. was filled in a glass bottle with an inner volume of 180 ml and a diameter of 28 mm, and the cap was plugged with the cap. After leaving this at room temperature (20 ° C.), the sealing property, the opening torque, and the state of the liner falling off were examined. The liner diameter was 27.5 mm, and the liner stopper inner diameter was 26.5 mm. The liner was set on the cap body with the sliding layer facing the inner surface of the top plate portion of the cap body. The test results are shown in Table 1.
Here, the sliding layer was made of HDPE, and the sealing layer was made of EVA.

  In the example of the present invention, the opening torque was as low as 80 N · cm or less, and no liner was removed. On the other hand, in the comparative example, the opening torque was 85 N · cm or more, and the liner was dropped. In particular, in the case where there was no sliding layer, the opening torque was very high at 330 N · cm, and the liners were also removed in all 10 pieces.

In the next comparative test, an aluminum plate with a thickness of 0.22 mm, the inner and outer surfaces of which were coated with a synthetic resin paint, was molded into the cap body of a 28 mm PP cap, and a liner with a changed thickness of the sliding layer and sealing layer was inserted. The cap was filled with gas water (internal pressure: 3 volumes) in a glass bottle with an internal volume of 180 ml and a diameter of 28 mm, and the cap was plugged with the cap. After leaving this at room temperature (20 ° C.), the sealing property, the opening torque, and the state of the liner falling off were examined. The liner diameter was 27.5 mm, and the liner stopper inner diameter was 26.5 mm. The liner was attached to the cap body with the sliding layer facing the inner surface of the top plate portion of the cap body. The test results are shown in Table 2.
Here, the sliding layer was made of HDPE, and the sealing layer was made of HSBR.

  In the example of the present invention, the opening torque was as low as 77 N · cm or less, and the liner did not fall off. On the other hand, in the comparative example, the opening torque was about 80 N · cm, which was relatively low, but the liner was removed. In particular, when the sliding layer was 10%, all 10 liners were observed to fall off.

In the next comparative test, an aluminum plate with a thickness of 0.25 mm, the inner and outer surfaces of which were coated with a synthetic resin paint, was molded into the cap body of a 38 mm PP cap, and a liner with a changed thickness of the sliding layer and sealing layer was inserted. The cap was filled with hot water of 80 ° C. in an aluminum bottle can having an internal volume of 300 ml (total amount of 340 ml), and a certain amount of liquid nitrogen was dropped into the head space and immediately capped with the cap. The aluminum bottle can thus in a pressurized state was retorted (120 ° C., 30 minutes) and allowed to stand at room temperature (20 ° C.), and the sealing performance, opening torque, and liner dropping were examined. The test results are shown in Table 3.
Here, the sliding layer was made of polypropylene, and the elastomer of the sealing layer was made of a blend material obtained by mixing polypropylene, SEPS (styrene ethylene propylene styrene block copolymer) and liquid paraffin.

  In the example of the present invention, the opening torque was lower than that of the comparative example, and the liner did not fall off. On the other hand, in the comparative example, the opening torque was relatively high, and the liner dropped out. Here, in the example of the present invention in which the sliding layer was 1.3 mm and the sealing layer was 0.3 mm, the liner itself was as thick as 1.6 mm, and thus the sealing state was incomplete. In addition, when the sliding layer is 0.3 mm, the sealing layer is 0.2 mm, and the sliding layer is 0.2 mm and the sealing layer is 0.1 mm, the liner itself is thin. Was incomplete.

In the next comparative test, a tin plate having a thickness of 0.24 mm, the inner and outer surfaces of which were baked and coated with a synthetic resin paint, was formed into a 42 mm screw cap, and a liner in which the thicknesses of the sliding layer and the sealing layer were changed was inserted. This was plugged into a glass bottle (with an internal volume of 300 ml) filled with 90 ° C. hot water. The closing torque at this time was 200 N · cm. After cooling this to room temperature (20 ° C.), the sealing performance, opening torque, and liner dropping were examined. The test results are shown in Table 4.
Here, the sliding layer was made of polypropylene, and the elastomer of the sealing layer was made of a blend material obtained by mixing polypropylene, SEPS, and liquid paraffin.

  In the example of the present invention, the opening torque was lower than that of the comparative example, and the liner did not fall off. On the other hand, in the comparative example, the opening torque was relatively high, and the liner dropped out. In particular, in the case where there was no sliding layer, the opening torque was as high as 420 N · cm, and the liners were also removed in all ten.

  From the results of the above comparative tests, it was confirmed that if the liner of the present invention example was used, it was possible to provide a cap material excellent in sealing performance and openability.

It is a fragmentary sectional view of the cap material which is the 1st embodiment of the present invention. It is explanatory drawing of the liner used for the cap material of FIG. It is a fragmentary sectional view of a bottle can with a cap. It is explanatory drawing of the liner used for the cap material which is the 2nd Embodiment of this invention. It is explanatory drawing of the liner used for the cap material which is the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cap material 11 Cap main body 12 Top plate part 13 Perimeter wall part 20, 50, 60 Liner 21 Sealing layer 22 Sliding layer 34 Base part (bottle mouth part)
40 Cap 51 Aluminum sheet (barrier film, intermediate layer)
61 ink

Claims (11)

A cap body having a disk-shaped top plate portion, a peripheral wall portion substantially hanging from the periphery of the top plate portion, and a sheet type liner disposed along the inner surface of the top plate portion of the cap body. In the cap material provided,
The liner is formed by laminating a sealing layer made of an elastomer and having a sealing function, and a sliding layer having a higher hardness than the sealing layer and sliding with the inner surface of the top plate portion,
The cap material, wherein a thickness of the sliding layer is 55% to 95% of a thickness of the liner.   The cap material according to claim 1, wherein the thickness of the sliding layer is 60% to 80% of the thickness of the liner.   The cap material according to claim 1 or 2, wherein the thickness of the sliding layer is 60% to 70% of the thickness of the liner.   The cap material according to any one of claims 1 to 3, wherein an intermediate layer is provided at least at a part between the sliding layer and the sealing layer.   The cap material according to claim 4, wherein the intermediate layer is a barrier film.   The cap material according to claim 4, wherein the intermediate layer is formed by applying ink.   The cap material according to any one of claims 1 to 6, wherein a lubricant is added to the sliding layer. The sliding layer is made of polypropylene or a polypropylene polymer,
The cap material according to any one of claims 1 to 7, wherein the sealing layer is made of a blend material of polypropylene and an elastomer or a blend material of a polymer and an elastomer of polypropylene.   The cap material according to any one of claims 1 to 8, wherein the cap body is made of aluminum, synthetic resin, tinplate, or tin-free steel.   10. The cap material according to claim 1, wherein the cap material is configured to rotatably support the liner by a liner support portion provided in the vicinity of the top plate portion of the cap body. Cap material according to.   A container with a cap in which the cap material according to any one of claims 1 to 10 is disposed in a bottle mouth portion, and an internal thread portion is formed on the inner surface of the peripheral wall portion to be screwed to the bottle mouth portion.

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