JPH0714735B2 - Easy-to-open lid - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lid that is easy to open, and more specifically, an annular heat seal portion is formed between the lid body and a flange portion of the container body to seal the container body. It is an easy-to-open lid for
In particular, the present invention relates to a lid which is suitable for a sealed container for retort sterilization and which can be easily opened.

(Prior Art) Based on the heat-sealing strength of a hermetically sealed container whose heat-sealing lid is used for retort sterilization treatment (Ministry of Health and Welfare Notification No. 17 (3) (4) "heat sealing strength test") Peel strength measured by 2.3 kg / 15 mm (width)
It is obliged that it be more than the above (Ministry of Health and Welfare Notification No. 17 (partly revised in Notification No. 20 of 1982)).

Therefore, the heat-sealing strength of this type of sealed container is usually about 3 kg / mm (width). On the other hand, when an ordinary adult tries to peel off the heat-sealed part with fingers, the peeling resistance when it can be easily peeled off is about 1.5 kg or less.

Therefore, it is not possible to pull up the normal tongue-shaped knob tab provided on the outside of the heat-sealing portion of the lid inward in the radial direction to peel off the heat-sealing portion, because the initial peeling resistance exceeds the above value. Possible or difficult.

As a countermeasure against this, Japanese Patent Laid-Open No. 57-114462 proposes an easy-to-open lid in which a score portion is formed along the entire inner circumference of the heat seal portion. As a means of tearing and opening this score part, after making a cut with a knife etc. in a part of the score part, pull up by pulling up the part near the center of the cut part with your finger, or inside the score part, the sharp It is shown that the tab is adhered so that the cutting edge is right above the score part, the score part is cut by the cutting edge, and then the tab is pulled up.

However, in the case of the former, it can be said that it is not easy to open if there is no knife etc. at hand, it is difficult to open, and in the case of the latter, it is necessary to provide a knob attached to the lid. However, there is a problem that the cost becomes high.

(Problems to be Solved by the Invention) The present invention does not require a blade or the like for opening or a picked piece that is adhered even when heat-sealed at a heat-sealing strength to endure retort sterilization treatment, and is low cost. Another object of the present invention is to provide a lid which can easily open a hermetically sealed container hermetically sealed by heat sealing.

(Means for Solving the Problem) The lid which is easy to open according to the first aspect of the invention is easy to open for forming a ring-shaped heat seal portion between the lid portion and the flange portion of the container main body for sealing. In the lid, the lid is made of a tearable material and has an outwardly projecting tab, and a base of a side edge of the tab upstream of a peeling direction of the heat seal portion. 50 to 75 near the tangent line of the outer edge at the intersection of the extension line of the near portion and the outer edge of the heat seal portion, and the upstream side in the peeling direction.
And a score portion along the vicinity of the inner edge of the heat-sealing portion, which extends at an angle of degrees, passes through the base of the side edge of the tab on the downstream side with respect to the peeling direction. It is characterized in that it is formed so as to extend in the peeling direction to a position starting from a portion and slightly beyond an extension line in the vicinity of the base portion of the side edge on the upstream side.

The easily-openable lid according to claim 2 is a lid that can be torn in an easily-openable lid for sealing by forming an annular heat-sealing portion with the flange portion of the container body. The tab has a tab that is made of a material and protrudes outward, and the tab near the base of the side edge on the upstream side with respect to the peeling direction of the heat seal portion is 50 to 75 on the tangent line of the outer edge at the intersection of the extension line and the outer edge of the heat seal portion and on the upstream side in the peeling direction.
And the score portion passes through an extension line in the vicinity of the base of the side edge on the upstream side of the tab at a small distance from the inner edge of the heat seal portion. Is formed along the length of at least about 1/2 of the heat-sealed portion in the peeling direction.

The easily-openable lid according to claim 3 is an easily-openable lid for forming a ring-shaped heat-sealing portion with a flange portion of a container body for sealing, and the lid is tearable. The tab has a tab that is made of a material and protrudes outward, and the tab near the side edge on the upstream side with respect to the peeling direction of the heat seal portion is an extension line of the tab. And the tangent of the outer edge at the intersection of the outer edge of the heat-sealed portion and the upstream side in the peeling direction, the side extending at an angle of 50 to 75 degrees and located on the upstream side of the tab. Within the quadrant formed by the diameter of the lid parallel to the vicinity of the base of the rim and the diameter of the lid orthogonal to the diameter,
In the quadrant located centrally symmetrical to the quadrant including the tab, a non-tearable portion for stopping the progress of the tear line starting from the base of the upstream side edge when opening is provided. To do.

The easy-open lid according to claim 4 is an easy-open lid for forming a ring-shaped heat seal portion between the lid body and the flange portion of the container body for sealing, and the lid is tearable. It has a plurality of tabs made of a material and projecting outward, and the tab near the base of the side edge on the upstream side with respect to the peeling direction of the heat-sealing portion is near the tab. A tangent to the outer edge at the intersection of the extension line of the portion and the outer edge of the heat-sealed portion, and on the upstream side in the peeling direction,
It is extended so as to form an angle of 50 to 75 degrees, and the central angle formed by the base portions of the adjacent tabs is about 180 degrees or less as viewed from the side where the peeling of the heat seal portion progresses. And

Since most people are right-handed, the peeling direction is usually clockwise. However, it may be counterclockwise if necessary. In the following (actions) and (examples),
A case where the peeling direction is clockwise will be described.

The radial width of the heat seal is usually about 2-6 mm.
The maximum heat seal strength of the heat seal part is about 4 kg /
It is 15 mm (width).

In the lid which is easy to open according to the third aspect of the invention, when the flange portion is a quadrangular corner, the intersection of both diagonal lines is the center of the lid.

(Operation) The easily-openable lid described in each claim is made of a tearable material and has a tab tab protruding outward, and the tab tab peeling direction of the heat seal portion. In the vicinity of the base of the side edge on the upstream side with respect to the tangent line of the outer edge at the intersection of the extension line and the outer edge of the heat seal portion, on the upstream side in the peeling direction, an angle of 50 to 75 degrees is formed. It extends like an eggplant.

When unpacking, with the finger of the right hand, the side edge on the upstream side with respect to the peeling direction, that is, the clockwise direction, that is, the side edge on the front right side is pinched and pulled up in the clockwise direction with the right finger, From the base of the side edge, the initial tear progresses substantially along the direction of the extension line of the vicinity of the base of the side edge, and the initial tear line strikes the outer edge of the heat seal portion (in the vicinity of the base, the outer peripheral edge of the lid). Is on the outside of the heat-sealed part with some space).

The radial width of the heat seal is usually about 2 to 6 mm, so the heat seal strength of the heat seal is 2.3 kg / 15 mm.
In case of (width) or more, for example, 3kg / 15mm (width), the force required to peel the heat seal part in the circumferential direction is 0.4 to 1.0.
It is kg and can be easily peeled off with fingers.

On the other hand, the tangent line at the outer edge of the heat seal at the point where the initial peeling line hit the outer edge of the heat seal (corresponding to the intersection of the extension line near the base and the outer edge of the heat seal) The tear lines intersect at an acute angle of 50 to 75 degrees on the upstream side in the clockwise direction.

Therefore, if the pulling of the right finger is further continued, the tear line crossing the heat seal part in the oblique left direction and the peeling of the heat seal part in the clockwise direction starting from the crossing tear line part occur almost at the same time. .

If the intersecting angle is less than 50 degrees, the initial tear line advances along the outer edge of the heat seal portion and cannot cross the heat seal portion, so that the unsealing is not performed. On the other hand, if the angle is larger than 75 degrees, the peeling force of the heat seal part is applied, and the width of the left side part of the initial tear line is
Since it exceeds 15 mm, the force required for peeling exceeds 3.0 kg, making it difficult to peel off the heat seal part with fingers.
Therefore, the progress of the initial tear line stops at the outer edge, and the opening is not performed (see page 21, lines 6 to 16, and the experimental example described later).

In the case of the lid that can be easily opened according to claim 1, the score portion is formed along the vicinity of the inner edge of the heat seal portion,
Starting from the vicinity of the radius passing through the base of the side edge on the downstream side with respect to the peeling direction, to a position that slightly exceeds the extension line of the vicinity of the base of the side edge on the upstream side with respect to the peeling direction , The peeling direction, that is, the clockwise direction.

Therefore, if the tab is pulled up in the clockwise direction subsequently, when the peeling of the heat-sealing part reaches near the radius passing through the base of the left side edge of the tab (the side edge on the downstream side with respect to the peeling direction). , Tearing starts almost in the radial direction from the base, the tear line formed merges with the score part, the tearing along the score part proceeds thereafter, and the tearing of the score part is near the base of the right side tab side edge. The opening is completed at the time when it intersects with the extension line, that is, the tear line that is substantially along the extension line.

As described above, at the initial stage of opening, that is, after the merging, since only the score part needs to be torn, only a small force is required for opening as a whole.

Since the score portion is formed along the vicinity of the inner edge of the heat seal portion, the lid portion remaining on the flange portion after opening hardly protrudes inward of the flange portion.

In the case of the easily-openable lid according to claim 2, the score portion has a small distance from the inner edge of the heat seal portion, and the score portion of the base portion of the side edge upstream of the tab peeling direction. The heat-sealing portion is formed along the extension line in the vicinity of the heat-sealing portion in the peeling direction along at least about 1/2 of the length.

When opening, when the initial tear line crosses the heat seal part and the pulling up of the tab is continued further, the crossing tear line merges with the score part, and thereafter, with the pulling up of the tab in the clockwise direction, After the peeling of the heat seal portion and the tearing of the score portion proceed at the same time and the tearing of the score portion reaches its end point, only the peeling of the heat seal portion is performed and the opening is completed.

If the space between the inner edge of the heat seal and the score is too small, tearing progresses in the direction of arrow A (Fig. 12), making it impossible to open by tearing. If the portion does not pass through the extension line, or even if it passes through, the tearing progresses in the direction of arrow B (Fig. 12), and there is a possibility that the arrow-tightening cannot be opened.

On the other hand, if the score portion is only along the length less than about 1/2 of the total length of the heat seal portion, for example, the arrow C in FIG.
There is a risk that tearing will progress in the direction and the opening will not be possible.

As described above, since the entire length of the heat seal portion is peeled off when opening, the appearance of the upper surface of the flange portion after opening is more beautiful than that of the lid which is easy to open according to claim 1. (See Figures 6 and 14).

In the case of the easily-openable lid according to claim 3, the diameter of the lid parallel to the vicinity of the base of the side edge on the upstream side with respect to the stripping direction of the tab, and the diameter orthogonal to this diameter. Among the quadrants formed by, in the quadrant that is located symmetrically with the quadrant containing the tab, there is a non-tearable part to stop the progress of the tear line starting from the base of the tab side edge on the upstream side when opening. It is provided.

Upon opening, if the initial tear line traverses the heat-sealed part and then the pulling of the tab is continued, the traversed tear line advances in the direction of the quadrant located in the center symmetry and hits the non-tearable part. Upon hitting, the progress stops. The hit point serves as a kind of fulcrum, and the heat seal part is peeled off in the clockwise direction together with the lid part inside the heat seal part to complete the opening. Therefore, as compared with the lid that can be easily opened according to claims 1 and 2, the labor for forming the score portion is not necessarily required.

In the case of the lid which can be easily opened according to claim 4, a plurality of outwardly projecting tabs are provided, and the base portions of the adjacent tabs as viewed from the side where the peeling of the heat seal portion progresses. The central angle of is less than about 180 degrees.

When opening, the first (first) tab is pulled up, and after the initial tear line has crossed the heat seal part, if the tab is further pulled up, the lid part inside the heat seal part is Following the tear line, the heat seal is peeled off while tearing in a generally clockwise direction.

And the base of the first tab and the next (second
The center angle of the base of the tab, which is viewed from the side where the peeling proceeds, is about 180 degrees or less.Before the tear line hits the heat seal part, peel off the heat seal part from the next tab. Reach the base position of. At that point, a full opening can be made by pulling the next tab up in the clockwise direction. Therefore, also in this case, it is not always necessary to form the score portion. Moreover, the scope of claims 3
It is not necessary to provide a non-tearable portion as in the case of the lid which can be easily opened.

If the center angle exceeds about 180 degrees, the tear line of the first tab hits the heat seal part before the peeling of the heat seal part by the first tab reaches the position of the base part of the next tab, and heat is applied. Since the seal portion is crossed, only the lid portion on the left side of the tear line is opened, and the lid portion on the right side remains heat-sealed, resulting in an incomplete opening.

(Embodiment) First, a lid which is easy to open according to claim 1 will be described.

In FIGS. 1 and 2, reference numeral 1 denotes a hermetically sealed container, in which a cup-shaped container body 2 having a flange portion 2a is filled with contents 3, and then a flange 4 is heat-sealed with a lid 4 to form a circle. It is formed by forming an annular heat seal portion 5 (see FIG. 3) for sealing.

As shown in FIG. 3, the lid 4 has a polyethylene terephthalate layer 4x having a thickness of 12 μm from the outer surface side, a biaxially stretched nylon 6 layer 4y having a thickness of 15 μm, a soft salminium foil layer 4a having a thickness of 20 μm, and a thickness of 50 μm. It is formed by punching a laminated body composed of the polypropylene layer 4w (each layer is adhered to each other by an adhesive layer (not shown)) so as to have a tab 6 to be described later, and the tear strength of this laminated body is
It is 0.3 kg and can be torn relatively easily with the force of fingers.

As shown in FIG. 3, the container body 2 has a thickness of 70 μm from the inner surface side.
m polypropylene layer 2x, 75 μm thick iron foil layer 2y and 40 μm thick polypropylene layer 2z. The inner polypropylene layer 2x of the flange portion 2a has a thickness of 2.3 kg / mm (width) or more, together with the inner polypropylene layer 4w of the lid 4.
For example, with a peel strength of 3 kg / mm (width), a radial width of 3 m
The m heat seal portion 5 is formed. The heat seal portion 5 is formed slightly inside the outer peripheral edge 4a of the lid 4.

The lid 4 has a tab 6 protruding outward. The side edge of the tab 6 on the upstream side in the clockwise direction, that is, the portion 7b near the base portion 7a of the right side edge 7 in the drawing is at the intersection 9 of the extension line 8 and the outer edge 5a of the heat seal portion 5. The angle θ formed on the upstream side in the clockwise direction of the tangent line 10 of the outer edge 5a is 50 to
It extends to more than 75 degrees, preferably 55 to 70 degrees.
The left side edge 12 in the figure, which faces the side edge 7, extends parallel to the side edge 7.

On the upper surface of the lid 7, along the vicinity of the inner edge 5b of the heat seal portion 5, the score portion 11 is near the radius 13 passing through the base portion 12a of the side edge 12 on the downstream side with respect to the clockwise direction of the tab. It starts from 15 and extends in the clockwise direction to a position 16 slightly beyond the extension line 8 of the base vicinity portion 7b of the side edge 7.

It is desirable that the score portion 11 is formed as deep as possible within the range where the aluminum foil layer 4z is not exposed. Although not shown, the score portion may be formed on the inner surface side of the lid 4, or on both sides of the outer surface and the inner surface. Also score section 11
And the inner edge 5b of the heat seal portion 5 has a radial interval of about 1 to
4mm is desirable.

When opening, when the right side edge 7 side of the tab 6 is picked up by the right finger and pulled up in the clockwise direction, as shown in FIG. 4, it extends substantially along the direction of the extension line 8 from the base portion 7a. The initial tearing progresses, and the initial tear line 17a hits the outer edge 5a of the heat seal portion 5.

In this heat-sealing portion 5, only the radial peeling force is applied only to the portion on the left side of the initial tear line 17a having a circumferential width of about several mm (for example, 3 mm). If the heat seal strength is 3 kg / 15 mm (width), the force required to peel off 3 mm is 0.6 kg, so the above-mentioned width part can be easily peeled off, and at the same time, the heat seal part 5 is slanted to the left. After traversing, the tear progresses in a substantially radial direction, forming a tear line 17.

When the angle θ is smaller than 50 degrees, the initial tear line 17a advances along the outer edge 5a of the heat seal portion 5 and cannot cross the heat seal portion 5, so that the opening is not performed. On the other hand, if the angle θ is larger than 75 degrees, the heat seal part 5
Since the width of the left part of the initial tear line 17a exceeds 15 mm and the force required for peeling exceeds 3.0 kg, it becomes difficult to peel off the heat-sealed portion 5 with fingers, and therefore the initial tear The progress of the line 17a is stopped at the outer edge 5a, and the opening is stopped.

Then, when the tab 6 is pulled up in the direction of the arrow in FIG. 4, a peeling force is applied to the heat seal portion 5 in the circumferential direction,
Radial width of heat seal part 5 is small (3m in this case)
m), so the heat-sealed part can be easily peeled off.

When the peeling of the heat seal portion 5 reaches near the radius 13 passing through the base portion 12a of the left side edge 12, as shown in FIG.
The tear started in the radial direction from the base 12a and the tear line 1
8 merges with the score part 11, and if the tab 6 is continuously pulled up in the direction of the arrow, tearing along the score part 11 progresses, and this tearing progresses to a position 19 where the score part 11 intersects the tear line 17. , A full opening is performed as shown in FIG.
In addition, 11 'shows the tear mark of the score part 11.

As shown in FIG. 7, the base portion 7a is closer to the base portion of the side edge 7 than the base portion 7a.
By forming the score portion 20 extending in the extension line direction of 7b to the vicinity of the outer edge 5a of the heat seal portion 5, initial tearing when pulling up the tab 6 is facilitated. If a score line is formed instead of the score portion 20 or a notch 21 extending in the extension line direction is formed as shown in FIG. 8, the initial tear is not necessary.

As shown in FIG. 9, when the left end edge 22a forms the heat seal portion 22 extending from the base portion 7a along the extension line,
Initial tearing becomes easier. Further, as shown in FIG. 7, when a score portion 23 (which may be a score line, a notch or the like) extending from the base portion 12a of the side edge 12 to the vicinity of the outer edge 5a of the heat seal portion in a substantially radial direction is formed, It becomes easy to form the tear line 18 passing through the base portion 12a. FIG. 10 shows an example in which the outer edge 5a of the heat seal portion 5 substantially coincides with the outer peripheral edge 4a of the lid 4.

As shown in FIG. 11, when the portion 7'b near the base 7'a of the side edge 7'on the upstream side with respect to the clockwise direction of the knob tab 6'is curved, the base 7'a of this curve is formed. Tangent line at 8 '
Corresponds to the extension line 8. Although not shown, in the case where the heat-sealing portion is a square with rounded corners and the heat-sealing portion intersecting with the extension line 8 of the base vicinity portion 7b is a linearly extending portion, the outer edge of the heat-sealing portion is a tangent line. Corresponds.

Next, the lid 24 shown in FIG. 12 which is an embodiment of the lid which can be easily opened according to the second aspect of the present invention will be described. The same reference numerals as those in FIGS. 1 and 2 denote the same parts. The same applies to the drawings starting from FIG.

The score portion 11 of the lid 24 is spaced from the inner edge 5b of the heat seal portion 5 at a small distance, and starts from the extension line 8 of the proximal portion 7b of the side edge 7 of the tab, and extends in the clockwise direction at least at the inner edge 5b. It is formed along a length of about 1/2, more preferably at least about 2/3.

The radial distance d between the score portion 11 and the inner edge 5b is about 3 to 20 mm,
More preferably, it is about 5 to 10 mm. The score part 11 may be formed over the entire circumference. Further, the distance d may fluctuate within the above range in the circumferential direction.

When opening, when the tab 6 is pulled up in the same manner as in the case of the lid 4 in FIG. 1, an extension line 8 is formed as shown in FIG.
A tear line 25 that crosses the heat-sealed portion 5 obliquely leftward is formed substantially along the line, and the tear line 25 strikes the score portion 11 at the intersection point 26. When the tab is continuously pulled up in the clockwise direction as it is, the score portion 11 is torn from the intersection point 26 as a starting point and a tear mark 11 ′ is formed while forming a tear mark 11 ′.
The outer lid part is peeled off.

In this way, the tearing of the score part 11 is the end point of the score part 11.
After reaching 27, the tongue-shaped lid inside the score part 11 is almost free without being restrained, so even if the tab 6 is further pulled in the clockwise direction, the end point 27 is reached. The heat seal portion 5 is peeled off together with the entire lid without tearing the lid over and the flange portion 2a is exposed completely over the entire circumference as shown in FIG.

Next, a description will be given of the lid 34 shown in FIG. 15 which is an embodiment of the lid which can be easily opened according to claim 3.

The diameter of the lid 34 parallel to the vicinity of the base of the side edge 7 of the tab 6
35 and a quadrant that is centrally symmetric with the quadrant containing the tab 6 among the four quadrants formed in the diameter 36 that is orthogonal to the diameter 35
A trapezoidal non-tearable portion 38 is formed inside 37.

The non-tearable portion 38 is formed, for example, by adhering a plastic piece (having a thickness of, for example, 50 mm) of polypropylene or the like whose uniaxially extending direction is the trapezoidal bottom side to the upper surface or the lower surface of the lid. The front line 38a of the non-tearable portion 38 is preferably provided near the lid center O.

In this case, since the score portion is not formed, when the tab 6 is pulled up and the heat seal portion 5 is peeled in the clockwise direction, the tear line 39 crossing the heat seal portion in the oblique left direction.
Then proceeds through the upper part of the lid center O into the quadrant 37, as shown in FIG.

If the non-tearable portion 38 does not exist, the tear line 39 crosses the heat seal portion along the imaginary line 39 'shown by the one-dot chain line, and the subsequent peeling of the heat seal portion 5 becomes difficult or impossible. However, when the non-tearable portion 38 is provided, the tearing stops at the intersection 40 of the tear line 39 and the front line 38a, and thereafter, the intersection 40 becomes one kind of fulcrum, and the heat seal portion 5 is a watch. It is peeled off in the circumferential direction, and finally, as in the case of the lid 24 which is easy to open according to the second aspect of the invention, a complete opening as shown in FIG. 14 is performed. The score portion may be formed in advance so as to substantially follow the tear line 39.

The non-tearable portion 38 may extend slightly to the quadrant next to the quadrant 37.

Next, a description will be given of the lid 44 shown in FIG. 17 which is an embodiment of the lid which can be easily opened according to claim 4. In this case, two tabs 6 are provided with center symmetry. Therefore, the central angle δ formed by the base portions 7a, 7a of the tabs 6, 6 as viewed from the side where the peeling progresses is 180 degrees.

When opening the tab, pull the tab 6 at the bottom of the drawing clockwise in the clockwise direction to cross the heat seal portion 5 obliquely leftward and
The tear line 45 progresses as shown in Fig. 18, but the tear line
Before 45 hits against the heat-sealing portion 5, the heat-sealing portion 5 is peeled off to the position of the extension line 8 of the base-neighboring portion 7b of the tab 6 in the upper part of the figure.

Therefore, after that, the tab 6 on the upper side of the drawing is pulled up in the clockwise direction to peel off the heat seal portion 5 over the entire circumference, and the lid 24 according to claim 2 is easily opened.
As in the case of, the complete opening as shown in FIG. 14 is performed. Two or more tabs 6, for example, three tabs 6 may be provided symmetrically about the center.

Although not shown, a score portion corresponding to the score portion 11 in FIG. 12 or a score portion substantially along the tear line 45 may be formed in advance.

Next, in the vicinity of the base 7a of the side edge 7 on the upstream side of the tab 6
7b and the tangent line 10 of the outer edge 5a of the heat-sealing portion of the base portion 7a
An example of an experiment conducted to investigate the influence of the angle θ formed on the upstream side in the peeling direction on the unsealing property will be described.

70μm thick polypropylene layer 2x from inside, thickness 75μ
40 mm in height, upper end of the trunk from a laminate composed of an iron foil layer 2y of m and a polypropylene layer 2z of 40 μm in thickness (each layer is adhered to each other by an adhesive layer not shown: see FIG. 3) A container body 2 of the type shown in FIG. 2 having an outer diameter of 64 mm, a diameter of the grounding portion of 54 mm, and a width of the flange portion 2a of 6 mm was formed by drawing.

From the outer surface side, a polyethylene terephthalate layer 4x having a thickness of 12 μm, a biaxially stretched nylon 6 layer 4y having a thickness of 15 μm, and a thickness
20 μm soft aluminum foil layer 4a and 50 μm thick
From the laminated body consisting of the polypropylene layer 4w (each layer is adhered to each other by an adhesive layer (not shown)), the angle θ is 35 degrees, 45 degrees, 60 degrees, 80 degrees and 90 degrees A lid 4 of the type shown in FIG. 1 was punched and formed. The radial distance between the inner edge 5b of the heat seal portion 5 and the score portion 11 was 2 mm.

Each lid 4 was heat-sealed to the flange portion 2a of the container body 2 to produce the hermetically sealed container 1 having the heat-sealed portion 5 having a radial width of 3 mm. The outer edge 5a of the heat seal portion 5 and the lid 4
The radial distance from the outer peripheral edge 4a was 3 mm. The peel strength of the heat seal part 5 was 3.8 kg / 15 mm (width).

In the case of the lid 4 shown in FIG. 19 where the angle θ is 35 degrees, when the right side edge 7 side of the knob tab 6 is pinched with the right finger and pulled up in the clockwise direction, the extension line of the side edge 7 is formed. Along the base 7a
It was easily torn from intersection 9 to. However, it is considered that the angle formed between the tangent line 10 and the side edge 7 is small and the wedge effect is large, and the peeling strength of the heat seal portion 5 is large, but the tear line 17 does not cross the heat seal portion 5 and the As shown in the figure, the tear progresses from the intersection 9 along a part of the outer edge 5a of the heat-sealing portion 5, and finally only the knob tab 6 is covered.
It was torn and could not be opened.

In the case of the lid 4 having the angle θ of 45 degrees, the heat seal part 5 was slightly peeled off, but the tear line 17 could not cross the heat seal part 5, and the tear was part of the heat seal part 5 and its part. After proceeding along the circumferential direction of the outer edge 5a, the opening could not be performed.

In the case of the lid 4 having the angle θ of 60 degrees, satisfactory opening was performed in the order shown in FIGS. 4, 5, and 6.

In the case of the lid 4 shown in FIG. 21 in which the angle θ is 80 degrees, when the side edge 7 side on the right side of the tab 6 is picked with the right finger and pulled up in the clockwise direction, the extension line of the side edge 7 is formed. Teared along from base 7a to intersection 9. However, since the angle θ is considerably large, as shown in FIG. 22, the heat-sealing portion 5 extends over a considerably long circumferential width on the left side of the tear line 17 (knob tab 6).
The peeling force in the radial direction is applied to the circumferential width part (about 6 mm, which is about half the width of the tape), so it seems that the force required for peeling has increased, but for ordinary women and children it is opened. I couldn't.

In the case of the lid 4 having the angle θ of 90 degrees, as shown in FIG. 23, since the tabs 6 are pulled up toward the center of the lid 4, after the tear lines 17 and 17 'are formed, the tabs 6 are pulled. The heat seal portion 5 must be peeled off over the entire width where 6 contacts the outer edge 5a of the heat seal portion 5. Therefore, the force required for peeling was large, and even ordinary adults could not open the package.

(Effect of the invention) The lid which is easy to open according to the claims is such that the applied sealed container is resistant to the retort sterilization treatment,
Heat seal strength with the flange of the container body is 2.3k
Even if it is g / 15 mm (width) or more, it can be easily opened without using a knife or a stick having a sharp edge that is adhered, and an easy-to-open lid provided with the above-mentioned adhered grip. Compared with this, there is an effect that the cost is low.

The easy-to-open lid described in claim 1 has an advantage that the opening as a whole requires only a small amount of force for opening since the opening only requires tearing the score portion. .

The lid which is easy to open according to the second aspect of the present invention has an advantage that the upper surface of the flange portion after opening is beautiful because the entire length of the heat seal portion is peeled off when opening.

The easily-openable lid described in claim 3 has an advantage that, in addition to the advantage of the easily-openable lid described in claim 2, the labor for forming the score portion is not necessarily required.

In addition to the merit of the easy-open lid described in claim 3, the easy-open lid described in claim 4
It has the advantage that it does not require the trouble of providing a non-tearable part.

[Brief description of drawings]

FIG. 1 is a plan view of a hermetically sealed container in which a container body is hermetically sealed by an easily-openable lid, which is an embodiment of the invention described in claim 1, and FIG. 2 is II-II of FIG. Fig. 3 is a longitudinal sectional view taken along the line, Fig. 3 is an enlarged view of a main part of the p portion in Fig. 2, and Figs. 4, 5, and 6 are respectively the initial stage of opening the lid of Fig. 1,
Plan views showing states on the way and after completion, FIG. 7, FIG.
FIGS. 9, 9, 10 and 11 are first, second, third, fourth and fifth modes, respectively, which are different from FIG. 1 in the vicinity of the tab of the easily-openable lid of the present invention. And FIG. 12 is a plan view corresponding to FIG. 1 of a lid which is an embodiment of the invention described in claim 2 and which is easy to open, FIGS. 13 and 14
12A and 12B are plan views showing the state of the lid of FIG. 12 during and after the opening of the lid, and FIG. 15 is a plan view of the lid which is easy to open, which is an embodiment of the invention described in claim 3. Corresponding plan view, FIG. 16 is a plan view showing a state in which the lid of FIG. 15 is being opened, and FIG. 17 is a plan view corresponding to FIG. 1 of the easy-open lid of claim 4. FIG. 18 is a plan view showing the state of the lid of FIG. 17 in the process of being opened, FIG. 19 is a plan view corresponding to FIG. 1 of the lid which is the first comparative example, and FIG. 20 is of FIG. FIG. 21 is a plan view showing a state after the tab of the lid is pulled up, FIG. 21 is a plan view corresponding to FIG. 1 of the lid which is a second comparative example, and FIG.
21 is a plan view showing the state after pulling up the tab of the lid shown in FIG. 21, and FIG. 23 is a plan view showing the state after pulling up the tab of the lid which is the third comparative example. is there. 2 ... Container body, 2a ... Flange part, 4 ... Easy-to-open lid, 5 ... Heat seal part, 5a ... Outer edge, 5b ... Inner edge,
6, 6 '... knob tab, 7 ... upstream side edge, 7a ...
... Base part, 7b ... Near part of base part, 8,8 '... Extension line, 9
...... Intersection point, 10 tangent line, 11 ...... score part, 12 ...... downstream side edge, 12a ...... base part, 13 ...... radius, 15 ...... radius part, 16 ...... extension line slightly Crossing position, 24 …… Easy-to-open lid, 35 …… Diameter, 36 …… Diameter, 37 …… Centrally symmetrical quadrant, 38 …… Non-tearable part, 39 …… Tear line, 44
…… A lid that is easy to open.

Claims (4)

[Claims] 1. A lid which is made of a tearable material and which protrudes outward in an easily opened lid for forming a ring-shaped heat seal portion between the flange portion of a container body and a hermetic seal. The tab has a tab, and the tab near the base of the side edge on the upstream side with respect to the peeling direction of the heat-sealing portion has an extension line of the neighborhood and the outer edge of the heat-sealing portion. The tangent line of the outer edge at the intersection point of, and on the upstream side in the peeling direction, extending to form an angle of 50 to 75 degrees, and the score portion along the vicinity of the inner edge of the heat seal portion, , Starting from the vicinity of the radius passing through the base of the side edge on the downstream side with respect to the peeling direction to a position slightly beyond the extension line in the vicinity of the base of the side edge on the upstream side, An easy-to-open lid characterized by being formed so as to extend in the peeling direction . 2. A lid, which is made of a tearable material and which projects outward, in a lid that is easy to open for forming an annular heat seal portion between the flange portion of the container body and the container for sealing. The tab has a tab, and the tab near the base of the side edge on the upstream side with respect to the peeling direction of the heat-sealing portion has an extension line of the neighborhood and the outer edge of the heat-sealing portion. The tangent line of the outer edge at the intersection point of, and on the upstream side in the peeling direction, extending to form an angle of 50 to 75 degrees, and the score portion, with a small distance from the inner edge of the heat seal portion, The tab is formed along an extension line in the vicinity of the base portion of the side edge on the upstream side, along the length of at least about 1/2 of the heat seal portion in the peeling direction. A lid that is easy to open. 3. A lid which is easy to open for forming a ring-shaped heat-sealing portion between a flange portion of a container body and a hermetically sealed portion, the lid being made of a tearable material and protruding outward. A tab near the side edge of the tab on the upstream side with respect to the peeling direction of the heat-sealing portion is located at the intersection of the extension line of the neighborhood and the outer edge of the heat-sealing portion. And a tangent line of the outer edge of the tab, on the upstream side in the peeling direction, extending to form an angle of 50 to 75 degrees, and parallel to the vicinity of the base of the side edge on the upstream side of the tab. Of the quadrant formed by the diameter of the lid and the diameter of the lid that is orthogonal to the diameter, in the quadrant that is centrally symmetrical with the quadrant that includes the tab, start from the base of the side edge on the upstream side when opening. A non-tearable part is provided to stop the progress of the tear line. A lid that is easy to open characterized in that. 4. An easy-to-open lid for forming an annular heat-sealing portion with a flange portion of a container body for sealing, the lid being made of a tearable material and protruding outward. The tab has a plurality of tabs, and the portion of the tab near the base of the side edge on the upstream side with respect to the peeling direction of the heat seal portion has an extension line of the neighborhood portion and the heat seal portion. The tangent line of the outer edge at the intersection with the outer edge and the upstream side in the peeling direction extend so as to form an angle of 50 to 75 degrees, and are seen from the side where the peeling of the heat seal portion progresses, the adjacent The center angle of the base of the mating tab is about 180
An easy-to-open lid characterized by a degree of less than 100 degrees.