JPH0637210B2 - Easy opening lid - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lid that is easily opened, 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. An easy-to-open lid for
In particular, the present invention relates to a lid with an easy opening suitable for a sealed container for retort sterilization.

(Prior Art) Based on the heat-sealing strength of a hermetically sealed container that is hermetically sealed by heat-sealing, for retort sterilization treatment (Ministry of Health and Welfare Notification No. 17 (3) (4) "Heat-sealing strength test"). Peel strength measured by 2.3kg / 15mm
It is obliged that the width is not less than (width) (Ministry of Health and Welfare Notification No. 17 (partially revised in Notification No. 20 of 1982)).

Therefore, the heat-sealing strength of this type of sealed container is usually about 3 kg / 15 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 Application Laid-Open No. 57-114462 proposes a lid which has a score portion formed along the entire inner circumference of the heat seal portion and which is easily opened. 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 attached so that the tip is directly above the score, the score is cut by the tip, and then the tab is pulled up.

However, in the case of the former, it can not be said that the lid cannot be opened easily if there is no knife etc. at hand, so it cannot be said that the lid is easy to open, and in the case of the latter, a knob attached to the lid must be provided. 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 when opening and a picked piece that is adhered, even when heat-sealed with heat-sealing strength to withstand retort sterilization treatment, An object of the present invention is to provide a lid for a hermetically sealed container that is hermetically sealed by heat sealing at low cost and is easy to open.

(Means for Solving the Problems) The lid with an easy opening according to the first aspect of the present invention is a lid with an easy opening for forming an annular heat seal portion between the lid portion and the flange portion of the container body for sealing. The lid is made of a tearable material and has an outwardly projecting tab, and the outer edge of the outer edge of the heat-sealed portion is closer to Tangent and first
A score line or a weakening line is formed on the upstream side in the direction of rotation of the heat seal portion extending at an angle of 50 to 75 degrees to the first side edge of the tab, and the score portion is formed along the vicinity of the inner edge of the heat seal portion. Starting in the vicinity of the radius passing through the base of the second side edge facing the first side edge and extending in the first rotation direction to a position slightly beyond the extension line of the cut line or the weakening line. And the second side edge and the outer peripheral edge of the lid intersect sharply at the base.

The easily openable lid of the second invention of the present invention is an easily openable lid for forming an annular heat seal portion between the lid portion and the flange portion of the container body for sealing, and the lid is tearable. A tangent line of the outer edge of the heat-sealing portion from a point which should be the starting point of tearing of the outer edge of the heat-sealing portion,
A cut line or a weakening line extending to the side edge of the tab at an angle of 50 to 75 degrees is formed on the upstream side in the rotation direction of the first side of the lid parallel to the cut line or the weakening line.
Of the quadrant formed by the second diameter and the second diameter orthogonal to the first diameter, and the quadrant that is symmetric to the quadrant that includes the tab is a position that includes the quadrant and that is the tearing start point when opening. It is characterized in that a non-tearable portion is provided for stopping the progress of the tear line starting from the power point.

The easily openable lid of the third aspect of the present invention is an easily openable lid for forming an annular heat seal portion between the lid body and the flange portion of the container body for sealing, and the lid is tearable. A tangential line of the outer edge of the heat-sealing portion from the point to be the tear starting point of the outer edge of the heat-sealing portion and the first rotation direction. A cut line or a weakening line that extends to the side edge of the tab at an angle of 50 to 75 degrees is formed on the upstream side of the, and the center of a point to be the tear start point of the adjacent tabs. The angle is less than about 180 degrees.

The easily openable lid of the fourth aspect of the present invention is an easily openable 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 is made of a material and has an outwardly projecting tab, and connects two points separated by a small distance, which should be the starting point of tearing of the outer edge of the heat seal part,
A cut line is formed toward the tab side, and in a portion near the point of the cut line, the advancing direction of the tear line starting from the point when opening the heat seal portion is the outer edge at the point. Is extended in a direction that makes an angle of 50 to 75 degrees with the tangent to the heat-sealing portion, and a score portion is formed inside the heat-sealing portion so as to intersect with the traveling direction of the tear line. .

The easily openable lid of the fifth invention of the present invention is an easily openable lid for forming an annular 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 tab that is made of a material and protrudes outward, and from the point that should be the starting point of tearing of the outer edge of the heat-sealed portion to the tangent line of the outer edge at that point and 50-
A cut line or a weakening line is formed to extend to the side edge of the tab at an angle of 75 degrees, and a portion near the point of the heat seal portion is an outwardly convex generally having the point as an apex. It is characterized by having an equilateral triangular shape.

Here, the score line refers to a line having continuous cuts over the entire thickness, and the weak line refers to a so-called perforation (a linear portion having intermittent cuts over the entire thickness) or a score line (in the middle of the thickness). A linear part having a break up to). Hereinafter, the cut line and the weakened line are referred to as a cut line.

The side edge of the tab in the first to third inventions includes the base portion and the central portion of the side edge. In each embodiment, the outer end of the score line is the base portion, but it may be a side edge portion near the base portion.
In the fifth aspect, the tab side edge portion that is the outer end of the cut line is preferably the central portion of the tab side edge or the vicinity thereof. When the cut line or the like is a curve, the angle formed by the tangent line of the cut line or the like at the point to be the tear start point and the tangent line of the outer edge of the heat seal portion at the point is 50 to 75 degrees.

Since many people are right-handed, the first rotation direction is preferably clockwise. However, it may be counterclockwise if necessary. Radial width of heat seal is usually about 2
It is 6 mm.

The maximum value of the heat seal strength of the heat seal portion is usually about 4 kg / 15 mm (width) or less.

When the flange portion is a square with rounded corners, the intersection of both diagonal lines is the center of the lid.

(Operation) In the case of the first to third and fifth inventions, the lid is made of a tearable material, has a tab tab protruding outward, and is heat-sealed with the flange portion of the container body. A cut or weakening line is formed from a point that should be the starting point of tearing of the outer edge of the portion to the side edge of the tab at an angle of 50 to 75 degrees with the tangent line of the outer edge at that point.

When a cut line or the like is formed so that the angle θ of 50 to 75 degrees is on the upstream side with respect to the clockwise direction as shown in FIG. When the side edge 7 on the upstream side with respect to the rotating direction, that is, the side edge on the front right side is picked up and pulled up in the direction in which the cut line 8 extends, the cut line opens upward or the weak line breaks. And open upwards.

Then, at the point 9 which should be the tear start point of the heat seal portion 5, the force (F ₁ ) for tearing the lid 4 along the extension line 8a such as a cut line and the heat seal portion 5 on the left side of the extension line 8a. The force (F ₂ ) for peeling off the portion 5c of the above acts.

Since the lid 4 is made of a tearable material, the resistance to the former force (F ₁ ) is quite small. On the other hand, the width w of the stripping portion 5c (the distance between the extension line 8a and the outer edge 5a of the heat seal portion, which is perpendicular to the extension line 8a) is very small at the point 9, and therefore the resistance to the latter (F ₂ ) is also very small. small. Therefore, tearing along the extension line 8a and peeling of the heat-sealed portion in the portion 5c easily proceed.

Since the width w gradually increases as the tearing and peeling progress, the peeling resistance also gradually increases. The above-mentioned width w is such that the tear is at the intersection 8 of the inner edge 5b of the heat seal portion and the extension line 8a.
The maximum value w _max is reached when a'is reached. When the angle θ is 75 degrees or less, the maximum value w _max is the outer edge 5 of the heat seal portion.
By setting the radial width of the heat-sealed portion to an appropriate value of 2 mm or more with respect to the diameter of a, it can be 7.5 mm or less, for example. Therefore, if the heat seal strength of the heat seal part is 2.3 kg / 15 mm (width) or more, for example, 3 kg /
In case of 15mm (width), the maximum force required for peeling is 1.5k
As a result, the initial peeling from the heat-sealed portion 5c is easily performed.

When the side edge 7 on the front right side of the tab is pinched and pulled up in the clockwise direction (preferably in the case of the first to third inventions, it is preferable to pull up like this), the tear tends to proceed in the direction of the line 8b. , the maximum width w _'max of other factors vertical heat-sealed portion in the same case peel Technical direction (not shown) is smaller than the maximum width w _max of the, thus peel technique becomes easier. And in this case, assuming that the outer edges 5a have the same diameter, compared to when the tearing direction is 8a,
The radial width of the heat seal portion can be increased.

When the angle θ is less than 50 degrees, the tear line starting from the point 9 advances along the outer edge 5a of the heat seal portion 5 and cannot cross the heat seal portion 5, so that the unsealing is not performed. .

In the case of the fourth aspect of the invention, in the portion of the cut line 57 near the point 59, the traveling direction of the tear line starting from the point 59 in the heat seal portion is at an angle of 50 to 75 degrees with the tangent line 10 of the outer edge 5a at the point 59. Since it extends in such a direction, it can be opened satisfactorily for the same reason as above.

After the initial peeling of the heat-sealed part is slightly different depending on the invention, by setting the radial width of the heat-sealed part within an appropriate range, by continuing to pull up the tab, about 1.5 kg. The peeling force described below allows the heat-sealed portion to be easily peeled off.

In the case of the first aspect of the invention, the score portion along the vicinity of the inner edge of the heat seal portion starts from the vicinity of the radius passing through the base portion of the second side edge facing the first side edge of the tab, and the notch is formed. It is formed so as to extend in the first rotation direction to a position slightly beyond an extension line such as a line.

Therefore, when the tab is subsequently pulled in the clockwise direction, the peeling of the heat-sealing portion passes through the base of the left side edge of the tab (corresponding to the second side edge facing the first side edge of the tab). When reaching the vicinity of the radius, the second side edge and the outer peripheral edge of the lid intersect sharply at the base portion, and the base portion easily serves as a starting point of cutting due to the notch effect, so that tearing starts from the base portion in a substantially radial direction. The tear line thus formed merges with the score portion, and thereafter the tear along the score portion progresses, and when the tear of the score portion intersects with the tear line substantially along the extension line such as the score line, the opening is completed. Since the score line is formed along the vicinity of the inner edge of the heat-sealed portion, the lid portion remaining on the flange portion after opening hardly projects inward of the flange portion.

In the case of the second invention, of the quadrant formed by the first diameter of the lid parallel to the score line and the second diameter orthogonal to the first diameter, the quadrant including the tab is center-symmetrical. A non-tearable portion is provided at a position including the quadrant in the position for stopping the progress of the tear line starting from the point which should be the tearing start point when opening.

Upon opening, if the initial tear line traverses the heat-sealed part and then the pulling up of the tab is continued, the traversed tear line advances into the quadrant at the central symmetry position and hits the non-tearable part. It hits and stops progressing. Therefore, this point of collision 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.

In the case of the third aspect of the invention, a plurality of outwardly projecting tabs are provided, and the central angle formed by the point which should be the tear start point of the adjacent tabs is about 180 degrees or less.

When opening, when the first tab is pulled up and the initial tear line has traversed the heat seal portion, and further pulling up of the tab is continued, the lid portion inside the heat seal portion is moved to the initial tear line. Then, the heat seal part is peeled off while being torn in a substantially clockwise direction. However, the point that should be the tear start point of the first tab and the second point on the downstream side
Since the center angle formed with the point where the tear start point of the tab should be about 180 degrees or less, the peeling of the heat seal part is the tear start point of the second tab before the tear line hits the heat seal part. Reach the position before the point that should be. At that point, a full opening can be achieved by pulling up on the second tab in the clockwise direction.

In the case of the fourth aspect of the invention, the score portion is formed inside the heat seal portion so as to intersect with the traveling direction of the tear line starting at the time of opening from the point which should be the tear start point.

When the tab is pulled up just above, the initial tear and the initial peeling proceed from the two points that should be the tear starting points almost at the same time, and when the tab is pulled further, two tabs are almost parallel to this pulling direction. The tear line progresses, intersects the score part, and the score part breaks. After that, only peeling of the heat-sealed portion proceeds. Finally, the whole surface is opened by peeling off the unpeeled portion of the heat-sealed portion between the two points.

In the case of the fifth aspect of the invention, the heat-sealing portion has a portion in the vicinity of the point to be the tear start point, which has a generally isosceles triangular shape with the point as the apex and outwardly convex, such as a score line. The outer edge is preferably at or near the center of the side of the tab.

The part on one side such as the cut line of the tab is pulled up to perform the initial tearing and the initial peeling, after allowing the peeling to proceed a little, and then returning the part to the other side part. When the tab is pulled up, the initial tearing and the initial peeling are performed on the other side portion, and then the tab is pulled up to open the entire surface.

(Example) First, an example of the first invention will be described.

In FIGS. 1 and 3, reference numeral 1 denotes a hermetically sealed container, in which a cup-shaped container main 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. 4).

As shown in FIG. 4, the lid 4 includes a polyethylene terephthalate layer 4x having a thickness of 12 μm and a 2 μm having a thickness of 15 μm from the outer surface side.
A layered body composed of a layer 4y of axially stretched nylon 6, a soft aluminum foil layer 4z having a thickness of 20 μm and a polypropylene layer 4w having a thickness of 50 μm (each layer is bonded to each other by an adhesive layer not shown) The laminate is formed by punching so as to include the tab 6. The tear strength of the laminate is 0.3 kg, and the laminate can be relatively easily torn by the force of fingers.

As shown in FIG. 4, the container body 2 has a thickness of 70 mm from the inner surface side.
μm polypropylene layer 2x, 75 μm thick iron foil layer 2
It consists of y and a polypropylene layer 2z with a thickness of 40 μm. Propylene layer 2 on the inner surface of the flange portion 2a
x is a propylene layer 4w on the inner surface of the lid 4 and 2.3 kg / 15 m
The heat seal portion 5 having a peeling strength of 3 kg / 15 mm (width) or more, which is equal to or larger than m (width), and having a radial width of 3 mm is formed. The heat seal portion 5 is formed slightly inside the outer peripheral edge 4 a of the lid 4.

The lid 4 has a tab 6 protruding outward. A cut line or a weakening line 8 extends from the side edge of the tab 6 on the upstream side in the clockwise direction, that is, from the base portion 7a of the right side edge 7 to the outer edge 5a of the heat seal portion 5.
The cutting line 8 has an angle θ formed on the upstream side in the clockwise direction of the tangent line 10 of the outer edge 5a at the intersection 9 of the cutting line 8 and the outer edge 5a of the heat-sealing portion 5, that is, the point 9 that should be the tear start point. 50 to 75 degrees, more preferably 5
It extends to be 5 to 70 degrees.

On the upper surface of the lid 4, 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. Start from 15 and extend 8a such as notch line 8
It is formed so as to extend in a clockwise direction to a position 16 which slightly exceeds the position.

It is desirable that the score part 11 is formed as deep as possible in a 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, the score unit 11
And the inner edge 5b of the heat seal portion 5 has a radial interval of about 1
It is desirable that it is ˜4 mm.

When opening, when the right side edge 7 of the tab 6 is picked up with the right finger and pulled up in the clockwise direction, as shown in FIG.
Tear in the direction of the arrow 8b (FIG. 2) and initial peeling of the left side portion of the arrow line 8b (corresponding to 5c) occur. After the initial peeling, the heat seal portion 5 is easily peeled in the circumferential direction (since the width of the heat seal portion 5 in the radial direction is 3 mm,
If the heat-sealing strength is 3 kg / 15 mm (width), the force required for peeling is 0.6 kg), and at the same time, the tear progresses along the tear line 17. If the angle θ is less than 50 degrees,
The initial tear line easily advances along the outer edge 5a of the heat seal portion 5, making it difficult to traverse the heat seal portion 5 and making opening difficult. On the other hand, if the angle θ is larger than 75 degrees, as described above, the force required for the initial peeling becomes large, and the initial peeling by the fingers becomes difficult, so that the opening becomes difficult.

The peeling of the heat seal portion 5 is caused by the base portion 12 of the left side edge 12.
When reaching the vicinity of the radius 13 passing through a, as shown in FIG. 6, tearing starts from the base portion 12a in a substantially radial direction,
The tear line 18 merges with the score portion 11, and when the pulling up of the tab 6 in the direction of the arrow is continued, the tear along the score portion 11 advances, and the tear portion 17 tears the tear line 17.
The position is reached to the position 19 where it intersects, and a complete opening is performed as shown in FIG. In addition, 11 'shows a tear mark of the score part 11.

Reference numeral 34 in FIG. 8 shows an example of the lid in the case of the second invention.

The diameter of the lid 35 parallel to the score line 8 of the side edge 7 of the tab 6
Of the four quadrants formed with a diameter 36 orthogonal to the diameter 35, a trapezoidal non-tearable portion 38 is formed in a quadrant 37 that is centrally symmetrical with the quadrant containing the tab 6. The non-tearable portion 38 is, for example, on the upper surface or the lower surface of the lid,
It is formed by adhering plastic film pieces (thickness is, for example, 50 μm) such as polypropylene whose uniaxial stretching direction is the base direction of the trapezoid. 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.
Hereafter, as shown in FIG. 9, it advances into the quadrant 37 by passing above the center O of the lid. If the non-tearable portion 38 does not exist, the tear line 39 crosses the heat seal portion along the phantom line 39 'shown by the alternate long and short dash 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 serves as a kind of fulcrum, and the heat-sealing portion 5 is peeled off in the clockwise direction together with the lid portion inside the heat-sealing portion 5, and finally a complete opening is performed. The score portion may be formed in advance so as to substantially follow the tear line 39.

Reference numeral 44 in FIG. 10 shows an example of the lid in the case of the third invention. In this case, two tabs 6 are provided symmetrically about the center. Therefore, the central angle δ formed by the points 9, 9 that should be the starting points of tearing is 180 degrees.

When the lower tab 6 in the figure is pulled up in the clockwise direction upon opening, the heat seal portion 5 is crossed obliquely leftward and
As shown in the figure, the tear line 45 progresses, but before the tear line 45 hits the heat seal part 5, the heat seal part 5 reaches a position before the cut line 8 on the tab 6 side in the upper part of the figure. It is torn off. Therefore, after that, tab 6 at the top of the figure
Is pulled up in the clockwise direction so that the heat-sealed portion 5 is peeled off over the entire circumference to complete the opening. Two or more tabs 6, for example, three tabs 6 may be provided symmetrically about the center.

Although not shown, a score line or the like is provided at a small distance from the inner edge of the heat seal portion 5 (a radial distance between the score portion 11 and the inner edge of the heat seal portion 5 is about 3 to 20 mm, more preferably about 5 to 10 mm). The score part may be formed along the length of at least about 1/2 of the heat seal part 5 in the peeling direction starting from the vicinity of the extension line of 8. Alternatively, a score portion that is substantially along the tear line 45 may be formed in advance.

The lid 54 in FIG. 12 shows a lid which is easy to open in the fourth aspect of the invention. From the heat-seal portion outer edge 5a, which should be two tearing start points 59, 59 spaced apart at a small interval (preferably about 10 to 25 mm), to the knob tab 56 side,
Two linear cut lines 58, 58 are formed so as to form a predetermined angle θ ′ with the tangent line 10 of the outer edge 5a at each point 59, and the ends 59a, 5 of the cut lines 59, 59 are formed.
9a are connected by an arcuate cut line 57, and a tongue-shaped cut line 55 is formed as a whole. The score line 55 and the knob tab 56 are symmetrical with respect to the extension line of the same diameter 50 of the lid 54. Inside the heat seal portion 5, preferably relatively close to the heat seal portion 5 and starting from the opening points 59, 59 2
The direction of travel 53 of the tear lines 51, 51 (Fig. 13) of the book,
A mountain-shaped score portion 52 is formed at a position intersecting with 53.

When the tab 56 is pulled right above when opening, the tongue-like portion 55a inside the cut line 55 is left as it is, and it extends from the points 59, 59 in a direction substantially close to the direction of the cut lines 58, 58. Forming the tear lines 51a, 51a,
Tear is performed across the heat seal portion 5, and at the same time, initial peeling of the heat seal portion 5 is performed. In this case, in order to smoothly carry out the initial peeling, the w in FIG.
It is preferable to determine the radial width of the heat seal portion 5 so that twice the width corresponding to _max is about 7.5 mm or less.
The angle θ between the initial tear line 51a and the tangent line 10 is 50
The angle θ ′ is set so that it is −75 degrees.

After the tear, as shown in FIG.
If the pulling is continued in the direction of the arrow, the width of the heat seal portion 5 to be peeled off in the direction perpendicular to the diameter 50, which is the pulling direction, gradually decreases, and thus the peeling easily proceeds, When the tear lines 51, 51 are formed along the arrow direction 53 and the tear lines 51, 51 hit the score portion 52,
The score part 52 between the tear lines 51, 51 is torn,
The strip-shaped portion 54a remains. In addition, 52 'shows a tear mark of a score part.

As described above, leaving the portion 5x of the heat seal portion 5 of the strip portion 54a, pulling up the tab until the entire heat seal portion 5 is peeled off, and then pulling up the tongue portion 55a in the circumferential direction. The entire surface is opened by peeling off the portion 5x of the heat seal portion 5.

A lid 64 in FIG. 14 shows a lid which is easy to open in the fifth invention. A portion of the heat-sealing portion 5 corresponding to the knob tab 66 is a generally isosceles triangle shaped portion 5y that is convex toward the tab 66 and has a vertex 69 at a tear starting point. A score line or weakening line 68 extending in the radial direction from the point 69 to the center of the outer edge of the tab 66 is formed, and the tab 66 is divided into a right side portion 66a and a left side portion 66b. As shown in the figure, it is preferable that the score portion 61 extending slightly inward in the radial direction from the point 69 is formed, but the score portion 61 does not necessarily have to be provided. An angle θ formed by the extension line 10 of the outer edge 5a of the triangular shaped portion 5y and the cut line 68 or the like.
Is set to 50 to 75 degrees.

When opening, as shown in FIG. 15, the right side portion 66a (or the left side portion 66b) of the tab 66 may be moved directly upward or counterclockwise (clockwise in the case of the left side portion 66b). Pull up (after cutting it if 68 is a weak line) and perform initial tear and tear.

Next, when the right side portion 66a of the tab is returned and the right side portion 66a and the left side portion 66b are picked up together with fingers and pulled upward, the left side portion 66b is also subjected to initial tearing and initial tearing. Thereafter, as in the case of the fourth aspect of the invention, if the radial width of the heat seal portion 5 is set to an appropriate value, the heat seal portion is smoothly peeled off and the entire surface is opened.

(Effect of the invention) The easily-openable lid of the present invention is such that the applied sealed container can withstand the retort sterilization treatment, and the heat seal strength between the container main body and the flange portion is 2.3 kg / 15 mm (width). Even in the above cases, there is an effect that it can be easily opened without using a knife or the like, and the cost is lower than that of an easily opened lid provided with the adhered tabs. .

[Brief description of drawings]

FIG. 1 is a plan view of a hermetically sealed container in which the container body is hermetically sealed by an easily-openable lid, which is an embodiment of the first invention of the present invention, and FIG. 2 is an enlarged view of an essential part for explaining the P part of FIG. 3, FIG. 3 is a longitudinal sectional view taken along the line III-III of FIG. 1, FIG. 4 is an enlarged view of an essential part of a Q portion of FIG. 3, FIG. 5, FIG. 6 and FIG.
FIG. 8 is a plan view showing the state of the lid shown in FIG. 1 in the initial stage, in the middle, and after the unsealing, and FIG. 8 corresponds to FIG. 1 of the easily opened lid which is an embodiment of the second invention of the present invention. A plan view, FIG. 9 is a plan view showing a state in the middle of opening of the lid of FIG. 8, and FIG. 10 is a plan view corresponding to FIG. 1 of a lid with an easy opening which is an embodiment of the third invention of the present invention. FIG. 11 is a plan view showing a state in which the lid of FIG. 10 is in the process of being opened, and FIG. 12 is a plan view corresponding to FIG. 1 of an easily opened lid which is an embodiment of the fourth invention of the present invention. FIG. 13 is a plan view showing a state in which the lid of FIG. 12 is being opened, and FIG. 14 is a plan view corresponding to FIG. 1 of a lid with an easy opening which is an embodiment of the fifth invention of the present invention, and FIG. FIG. 15 is a plan view showing an initial state of opening the lid of FIG. 14. 2 ... Container body, 2a ... Flange portion, 4 ... Lid with easy opening, 4a ... Outer peripheral edge, 5 ... Heat seal portion, 5a ...
... outer edge, 5b ... inner edge, 5y ... isosceles triangular shape part, 6
... tab tab, 7 ... first side edge, 7a ... base, 8 ...
… Cutting lines, etc. 8a …… Extended lines, 9 …… Points that should be the starting points for tearing, 10 …… Tangential lines, 11 …… Score part, 12
...... Second side edge, 12a ... Base, 13 ... Radius, 15
...... Around the radius, 16 ... A little over the extension line,
34 ... Lid for easy opening, 35 ... First diameter, 36 ...
Second diameter, 37 ... Quadrant in central symmetry, 38
...... Non-tearable part, 39 ...... Tear line, 44 ...... Easy opening lid, 51 ...... Tear line, 52 ...... Score part, 54 ...
… Lid with easy opening, 55… score line, 56… tab, 5
9: A point that should be a tear starting point, 64: A lid that is easy to open, 68 ... A score line, 69: A point that is a tear starting point.

Claims (5)

[Claims] 1. A lid, which is formed of a tearable material and has an easily openable opening, for forming an annular heat-sealing portion with a flange portion of a container body for sealing. Having a tab, from the point to be the tear start point of the outer edge of the heat-sealed portion, on the tangent line of the outer edge at the point, and on the upstream side in the first rotation direction,
A score line or a weakening line is formed that extends to the first side edge of the tab at an angle (θ) of 50 to 75 degrees, and the score portion is formed along the vicinity of the inner edge of the heat seal portion with the first score. It is formed so as to start in the vicinity of a radius passing through the base portion of the second side edge facing the side edge and extend in the first rotation direction to a position slightly beyond the extension line of the cut line or the weakening line. A lid with an easy opening, characterized in that the second side edge and the outer peripheral edge of the lid intersect sharply at the base portion. 2. A lid which is formed of a tearable material, and which is easily opened, for forming an annular heat-sealing portion between a flange portion of a container body and a hermetically sealed portion for sealing. Having a tab, from the point to be the tear start point of the outer edge of the heat-sealed portion, on the tangent line of the outer edge at the point, and on the upstream side in the first rotation direction,
A score line or a weakening line is formed that extends to the side edge of the tab at an angle of 50 to 75 degrees, and has a first diameter of the lid parallel to the score line or the weakening line and a first diameter. In the quadrant formed by the second diameters orthogonal to each other, the tear line starts at a point that should be the tear starting point at the time of unsealing at a position including a quadrant centered symmetrically with the quadrant including the tab. A lid with an easy opening, which is provided with a non-tearable portion for stopping. 3. A lid having an easily openable opening for forming an annular heat seal portion between the lid portion and a flange portion of the container body, the lid being made of a tearable material, and having a plurality of outwardly-extending lids. It has a protruding tab and has a tangential line to the outer edge of the outer edge of the heat seal portion at a tangent to the outer edge at the point and at an upstream side in the first rotation direction of 50 to 75 degrees. A score line or a weakening line that extends at an angle to the side edge of the tab is formed, and the central angle formed by the points that should be the tear starting points of the adjacent tabs is about 180 degrees or less. Features a lid that allows easy opening. 4. A lid having an easily openable opening for forming an annular heat-sealing portion with a flange portion of a container main body for sealing, the lid being made of a tearable material and protruding outward. It has a tab tab, should be a tear start point of the outer edge of the heat seal portion, connects two points spaced apart at a small interval, and a cut line is formed toward the tab side, In the portion near the point of the cut line, the traveling direction of the tear line starting from the point at the time of opening at the heat seal portion forms an angle (θ) of 50 to 75 degrees with the tangent line of the outer edge at the point. A lid with an easy opening, characterized in that a score portion is formed inside the heat seal portion so as to extend in such a direction and intersect with the traveling direction of the tear line. 5. A lid which is formed of a tearable material and which protrudes outward, in a lid having an annular heat-sealing portion formed between the flange portion of the container body and the opening for easy sealing. It has a knob tab, and from the point which should be the tear start point of the outer edge of the heat seal portion to the side edge of the tab at an angle (θ) of 50 to 75 degrees with the tangent line of the outer edge at the point. An extending notch line or a weakening line is formed, and a portion in the vicinity of the point of the heat-sealing portion has a generally isosceles triangular shape with the point as an apex and outwardly convex. Easy-to-open lid.