Cap and delaminatable container

Abstract

A cap with improved usability is provided. The present invention provides a cap including a cap body to be fitted to a mouth of a container, wherein the cap is configured to include: a valve seat having a flow aperture; a valve body to be separated from or seated on the valve seat so as to open and close the flow aperture; and a biasing member to bias the valve body in a seating direction, and configured to increase a flow area in which contents flow with an increase in a displacement of the valve body, and the cap further includes a displacement restricting section to restrict the displacement of the valve body.

Description

TECHNICAL FIELD

The present invention relates to a cap including a check valve and a delaminatable container including the cap.

BACKGROUND ART

Conventionally, delaminatable containers are known that include a container body having an outer shell and an inner bag, the inner bag to be shrunk with a decrease in contents. Such a delaminatable container is usually provided with a cap having a check valve as described in PTL 1 and is configured to open the check valve and discharge the contents by squeezing the container body and close the check valve by stopping squeezing.

CITATION LIST

Patent Literature

PTL 1: JP 2013-241197A

SUMMARY OF INVENTION

Technical Problem

However, the cap in PTL 1 has a risk of degradation of usability due to discharge of more than an expected amount of the contents or occurrence of more than estimated pulsation of the contents depending on the degree of squeezing.

The present invention has been made in view of such circumstances and is to provide a cap with improved usability.

Solution to Problem

The present invention provides a cap comprising a cap body to be fitted to a mouth of a container, wherein the cap is configured to include: a valve seat having a flow aperture; a valve body to be separated from or seated on the valve seat so as to open and close the flow aperture; and a biasing member to bias the valve body in a seating direction, and configured to increase a flow area in which contents flow with an increase in a displacement of the valve body, and the cap further includes a displacement restricting section to restrict the displacement of the valve body.

The present inventor made an intensive review to find that such a cap as in PTL 1 has a structure to increase the flow area in which the contents flow with an increase in the displacement of the valve body of the check valve, and when the container body is squeezed too strong, the valve body is opened widely to discharge more than an expected amount of the contents or to create more than estimated pulsation of the contents as a result of closing the valve body in reaction to wide opening, causing degradation of usability and thus has come to complete the present invention of restricting the displacement of the valve body.

Various embodiments of the present invention are described below as examples. The embodiments described below may be combined with each other.

Preferably, the displacement restricting section restricts the displacement of the valve body to be 0.8 times or less a diameter of the flow aperture.

Preferably, the displacement restricting section restricts the displacement of the valve body to 1.5 mm or less.

Preferably, the displacement restricting section restricts the displacement of the valve body from 0.4 to 0.8 mm.

Preferably, the biasing member is formed of a plurality of elastic pieces radially extending from an outer circumferential portion of the valve body.

Preferably, the cap body includes: an inner tube section having the valve seat; and a discharge portion mounted to the inner tube section and having an outlet, the inner tube section and the discharge portion forming an intermediate space, and the cap is configured to displace the valve body in the intermediate space.

Preferably, the displacement restricting section is formed of a plurality of projections formed on a surface on a side of the intermediate space of the discharge portion.

Preferably, the displacement restricting section is formed of a spacer disposed between the discharge portion and the check valve.

The present invention also provides a delaminatable container including a container body having an outer shell and an inner bag, the inner bag to be shrunk with a decrease in the contents, wherein the cap of any of the above configurations is fitted to a mouth of the container body.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view of a delaminatable container 1 according to a first embodiment of the present invention.

FIG. 2A is a cross-sectional view taken along A-A in FIG. 1, and FIG. 2B is an enlarged cross-sectional view of a cap 2 of the delaminatable container 1 in FIG. 2A and illustrates a state where a cap cover 22 is opened.

FIG. 3A is a front view of a check valve 25 of the cap 2, FIG. 3B is a perspective view of a discharge member 26 of the cap 2 taken from above, and FIG. 3C is a perspective view of the discharge member 26 taken from below.

FIG. 4A is an enlarged cross-sectional view of a cap 2 according to a modification of the present invention, and FIG. 4B is a perspective view illustrating a discharge member 26 and a spacer 27 of the cap 2 in FIG. 4A.

DESCRIPTION OF EMBODIMENTS

Embodiments of the present invention are described below. Various characteristics in the embodiments described below may be combined with each other. Each characteristic is independently inventive.

As illustrated in FIGS. 1 and 2A, a delaminatable container 1 in an embodiment of the present invention includes a cap 2 and a container body 3. The container body 3 is provided with a valve member 5, a storage portion 7 to store the contents, and a mouth 9 to discharge the contents from the storage portion 7. In the present embodiment, the cap 2 is press fitted, and as illustrated in FIG. 2A, the cap 2 is mounted by engaging an engagement section 9e formed in the mouth 9 of the container body 3 with an engaged section 24e formed in the cap 2. Noted that the cap 2 may be mounted by threading.

As illustrated in FIG. 2A, the container body 3 includes an outer layer 11 and an inner layer 13 in the storage portion 7 and the mouth 9, where the outer layer 11 constitutes an outer shell 12 and the inner layer 13 constitutes an inner bag 14. Due to delamination of the inner layer 13 from the outer layer 11 with a decrease in the contents, the inner bag 14 separates from the outer shell 12 to be shrunk. Preliminary delamination is sometimes performed to delaminate the inner layer 13 from the outer layer 11 before storage of the contents in the storage portion 7. In this case, the inner layer 13 is contacted with the outer layer 11 by blowing air or storing the contents in the storage portion 7 after preliminary delamination. The inner layer 13 then separates from the outer layer 11 with a decrease in the contents. Meanwhile, when preliminary delamination is not performed, the inner layer 13 is delaminated from the outer layer 11 in discharge of the contents to separate from the outer layer 11.

The valve member 5 is, as illustrated in FIGS. 2A and 2B, inserted into a fresh air inlet 15 formed in the storage portion 7 to regulate entrance and exit of air between the outside and a space G between the outer shell 12 and the inner bag 14. The configuration examples of the valve member 5 include a configuration where a gap between the valve member 5 and an edge of the fresh air inlet 15 is opened and closed by movement of the valve member 5 for opening and closing of the fresh air inlet 15 by the valve member 5 and a configuration where the valve member 5 itself is provided with a through hole and an on-off valve, which acts to open and close the through hole for opening and closing of the fresh air inlet 15. In addition, configurations without providing the valve member 5 are allowed to regulate entrance and exit of air by placing a filter on the fresh air inlet 15 or by simply closing the fresh air inlet 15 with a finger or the like for discharging the contents. The fresh air inlet 15 may be provided in the mouth 9 to use a cap having a check valve in communication with the fresh air inlet 15.

The valve member 5 in any of the above configurations is configured to allow compression of the inner bag 14 by closing the fresh air inlet 15 when the outer shell 12 is compressed to introduce fresh air into the space G when the compressive force to the outer shell 12 is released.

The storage portion 7 is covered with a shrink film after the valve member 5 is mounted. At this point, to avoid interference of the valve member 5 with the shrink film, the valve member 5 is mounted to a valve member mounting recess 7a provided in the. In addition, not to tightly close the valve member mounting recess 7a with the shrink film, an air circulation groove 7b is provided that extends in the direction from the valve member mounting recess 7a to the mouth 9 (refer to FIG. 1).

Regarding the layer structure of the container body 3, the outer layer 11 is formed thicker than the inner layer 13 so as to increase the restorability thereof. The outer layer 11 is formed of, for example, low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, an ethylene-propylene copolymer, or a mixture thereof, or the like. The outer layer 11 may have a multilayer structure. The inner layer 13 preferably has a multilayer structure. Examples of the layer in contact with the outer layer 11 include an EVOH layer 13a of an ethylene-vinyl alcohol copolymer (EVOH) resin, and examples of the layer in contact with the contents include an inner surface layer 13b of polyolefin, such as low-density polyethylene, linear low-density polyethylene, high-density polyethylene, polypropylene, an ethylene-propylene copolymer, and a mixture thereof. The adhesion layer 13c is preferably used between the EVOH layer and the inner surface layer.

Then, referring to FIG. 2B and FIGS. 3A to 3C, the cap 2 is described. The cap 2 in the present embodiment includes, as illustrated in FIG. 2B, a cap body 21 and a cap cover 22, which are formed of a synthetic resin. The cap body 21 and the cap cover 22 are connected by a hinge 23 to allow opening and closing of the cap cover 22. The cap body 21 is composed of three members of a main cap member 24, a check valve 25, and a discharge member 26 as the discharge portion. The synthetic resin to form the check valve 25 is more elastic than the synthetic resin forming the other members. For example, the check valve 25 is formed of a polyethylene elastomer and the other members are formed of polypropylene.

The main cap member 24 is configured with a cylindrical outer tube section 24o, a cylindrical inner tube section 24i concentrically disposed inside the outer tube section 24o, and an annular portion 24r connecting upper ends of the outer tube section 24o and the inner tube section 24i with each other. The outer tube section 24o has a lower inner circumferential surface having the engaged section 24e formed to be engaged with the engagement section 9e of the mouth 9. The inner tube section 24i has a lower inner circumferential surface, where an annular valve seat 24s is formed that extends diagonally above toward the radial center and has a flow aperture 24h at the center. The valve seat 24s has an inner circumferential surface 24s1 in a tapered shape inclined above. The inner tube section 24i has an upper inner circumferential surface, where a fitting recess 24f is formed over the entire circumference.

The check valve 25 is, as illustrated in FIGS. 2B and 3A, formed of a valve body 25b, four elastic pieces 25p, and a circular outer frame 25f. The valve body 25b is a member in a domical shape having an upwardly curved cross-sectional shape (refer to FIG. 2B) and having a circular plan view (refer to FIG. 3A) and has a spherical convexity 25s formed at the center of its upper surface. The valve body 25b has an outer circumferential portion 25b1 in a tapered shape inclined below to be seated on the inner circumferential surface 24s1 of the valve seat 24s and is configured to open and close the flow aperture 24h by the valve body 25b being separated from or seated on the valve seat 24s. The flow aperture 24h and the corresponding valve body 25b do not have to be in a circular shape and may be in in a polygonal shape or an annular shape. Each elastic piece 25p extends, as illustrated in FIG. 2B, diagonally above in a somewhat curved manner radially from the outer circumferential portion of the valve body 25b and is connected to an upper end of an inner circumferential surface of the outer frame 25f. The four elastic pieces 25p are provided every 90° over the entire circumference, and four openings 25o to flow the contents are formed of two of the adjacent elastic pieces 25p, the outer frame 25f, and the valve body 25b. The four elastic pieces 25p bias the valve body 25b in the seating direction as the biasing member. The number of elastic pieces 25p is not limited to four and may be two, three, five or more. Noted that, to transfer the biasing force to the valve body 25b, the elastic pieces 25p preferably extend radially. The outer frame 25f is disposed to abut on an inner wall surface of the inner tube section 24i in an upper area of the valve seat 24s of the main cap member 24. In the present embodiment, the valve body 25b, the elastic pieces 25p, and the outer frame 25f of the check valve 25 are formed integrally as a single piece.

The discharge member 26 is provided with, as illustrated in FIGS. 2B, 3A, and 3B, a tubular support section 26s fitted to the inner tube section 24i of the main cap member 24, a tubular guide section 26g disposed concentrically with the tubular support section 26s and having an outlet 26m, and a sheet disk section 26d integrally connecting the tubular guide section 26g and an upper edge of the tubular support section 26s as a single piece. On the upper edge of the tubular support section 26s, a flange 26b outwardly extending in a radial direction is formed and configured to engage with an inner edge of the annular portion 24r of the main cap member 24. The tubular support section 26s has an outer circumferential surface with an annular rib 26r formed over the entire circumference to be fitted to the fitting recess 24f of the main cap member 24. When the main cap member 24 is fitted to the discharge member 26, a lower surface of the tubular support section 26s abuts on an upper surface of the outer frame 25f of the check valve 25 to fix the check valve 25. In this state, the valve seat 24s and the inner tube section 24i of the main cap member 24 and the discharge member 26 form an intermediate space S (refer to FIG. 2B) to allow displacement of the valve body 25b in the intermediate space S.

In addition, the discharge member 26 in the present embodiment is provided with, as illustrated in FIGS. 2B and 3B, a plurality of projections 26p protruding toward the valve body 25b in a position facing the valve body 25b on a surface on the intermediate space S side. In the present embodiment, six projections 26p are provided at regular intervals over the entire circumference (refer to FIG. 3B). The projections 26p function as the displacement restricting section to restrict the maximum displacement in the intermediate space S of the valve body 25b of the check valve 25, and for example, preferably restricts the maximum displacement with reference (zero displacement) to the valve body 25b seated on the valve seat 24s to be 0.8 times or less a diameter of the flow aperture 24h (that is, inner diameter of valve seat 24s) and even more preferably to be 0.4 times or less. The displacement is preferably restricted to be from 0.01 times to 0.2 times the diameter of the flow aperture 24h, preferably from 0.05 times to 0.1 times, more preferably from 0.06 times to 0.09 times, and even more preferably from 0.07 times to 0.08 times. Specifically, this value is, for example, 0.05, 0.055, 0.06, 0.065, 0.07, 0.075, 0.08, 0.085, 0.09, 0.095, 0.1, 0.2, 0.4, and 0.8 times or it may be in a range between any two values exemplified here. Such an actual displacement is preferably 1.5 mm or less, preferably from 0.4 to 0.8 mm, more preferably from 0.5 to 0.7 mm, and even more preferably from 0.65 to 0.75 mm. Specifically, this value is, for example, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, and 0.8 mm or it may be in a range between any two values exemplified here. Naturally, the maximum displacement may be reduced by increasing the degree of protrusion of the projections 26p and the maximum displacement may be increased by reducing the degree of protrusion of the projections 26p. The number of projections 26p is not limited to six as long as operations of the valve body 25b is restricted, and may be five or less or seven or more. Noted that sufficient gaps are preferably provided between the projections 26p to allow discharge of the contents even when the valve body 25b gets close to or abuts on the projections 26p.

Then, operations of the cap 2 according to the present embodiment are described.

For discharging the contents, the cap cover 22 is opened to expose the discharge member 26, the container body 3 is tilted to direct the tubular guide section 26g below, and the storage portion 7 of the container body 3 is squeezed. The valve body 25b is lifted from the valve seat 24s due to pressure rise in the storage portion 7 (inner bag 14), causing opening of the check valve 25 to discharge the contents in the storage portion 7 through the flow aperture 24h and the intermediate space S from the outlet 26m.

Then, after a required amount of the contents is discharged, the container body 3 is returned to an upright position and the squeezing of the storage portion 7 is stopped, thereby reducing the internal pressure of the storage portion 7 and closing the check valve 25 due to the biasing force of the elastic pieces 25p. Accordingly, an incoming flow of fresh air from the flow aperture 24h into the storage portion 7 (inner bag 14) is prevented, and fresh air thus does not enter the inner bag 14 to inhibit content degradation.

When a sudden force happens to be applied without realizing how strong it should be for discharging the contents by squeezing the storage portion 7 of the container body 3, the valve body 25b sometimes moves a lot to discharge more than an expected amount of the contents. There is another problem that squeezing with a weaker force after applying a sudden force causes sudden closing of the valve body 25b in reaction to wide opening the valve body 25b due to the biasing force of the elastic pieces 25p and repeating this cycle creates pulsation that results in degradation of usability. However, the cap 2 in the present embodiment has the discharge member 26 provided with the projections 26p to restrict the maximum displacement of the valve body 25b to the predetermined amount described above, thereby preventing opening of the valve body 25b more than necessary to allow improving the usability. In the present embodiment, the projections 26p are integrally formed with the discharge member 26 as a single piece and thus the displacement restricting section is readily configured only by changing the die shape of the discharge member without incorporating another member.

The present invention is allowed to be carried out in the following embodiments.

Although the projections 26p formed in the discharge member 26 are used as the displacement restricting section to restrict the displacement of the valve body 25b in the above embodiment, the displacement restricting section is not limited to such a configuration. For example, as illustrated in FIGS. 4A and 4B, a spacer 27 having a through hole 27h, as a separate member from the discharge member 26, is placed on the surface on the intermediate space S side of the discharge member 26 to configure the displacement restricting section with projections 27p formed with the spacer 27. Specifically, the spacer 27 has a thin annular portion 27d with an outer diameter approximately identical to the inner diameter of the tubular support section 26s of the discharge member 26, a plurality of arms 27a extending from the inner circumferential surface of the annular portion 27d toward the radial center, and projections 27p axially protruding from the ends of the respective arms 27a. The arms 27a and the projections 27p are formed at regular intervals over the entire circumference. Use of the spacer 27 in such a configuration as the displacement restricting section allows restriction of the displacement of the valve body 25b to improve the usability during discharge of the contents. In addition, by preparing a plurality of spacers 27 that are different in the length of the projections 27p and changing the spacer 27 to be mounted to the discharge member 26 in accordance with the application of the container and the type of contents, the cap 2 with appropriate usability in accordance with intended use is readily manufactured without changing the shapes of the other members.

In addition, as the displacement restricting section to restrict the displacement of the valve body 25b, projection(s) formed on a surface on the discharge member 26 side of the valve body 25b may be used. In this case, the projection on the valve body 25b side abuts on the surface on the intermediate space S side of the discharge member 26 to restrict the displacement of the valve body 25b itself.

The cap 2 of the present invention may be used for containers other than the delaminatable container 1, for example, a monolayer container in which the entire container is shrunk with discharge of the contents.

EXAMPLES

The present invention is described below further in detail using Test Examples. The present invention is, however, not at all limited to Test Examples below. In the following tests, the cap 2 had the outlet 26m with a diameter of 4.0 mm, the flow aperture 24h (valve body 25b) with a diameter of 8.0 mm. The contents were a liquid (soy sauce), and the container body 3 had a volume of 360 ml. In the tests, 11 test subjects performed discharge of the contents (liquid) in the container body 3 twice per subject and evaluated Samples having displacement restricting section (projections 26p) that caused the valve bodies 25b to have the four maximum displacements below and Comparative Example having no displacement restricting section from three perspectives of “whether the contents were discharged in an intended position”, “whether the contents were discharged in a satisfactory manner”, and “whether the contents were discharged in an appropriate amount”. The evaluation was made in five grades (from 1 as poor to 5 as good).

• Sample 1 0.4 mm (0.05 times of the flow aperture diameter)
• Sample 2 0.5 mm (0.0625 times of the same)
• Sample 3 0.6 mm (0.075 times of the same)
• Sample 4 0.7 mm (0.0875 times of the same)
• Comparative Example 2.0 mm or more

	TABLE 1
		Discharged	Discharged	Discharged
	Maximum	in	in	in
	Displacement of	Intended	Satisfactory	Appropriate
	Valve Body 25b	Position?	Manner?	Amount?
Sample 1	0.4 mm	2.0	1.5	1.7
Sample 2	0.5 mm	3.6	3.4	3.5
Sample 3	0.6 mm	3.8	4.0	4.0
Sample 4	0.7 mm	3.8	3.7	3.7
Com-	2 mm or more	2.2	2.0	2.7
parative
Example
Poor 1 < 2 < 3 < 4 < 5 Good

Table 1 shows results of the above tests. Each value in Table 1 was obtained by rounding off an average of the evaluations by the 11 subjects to the first decimal place. As shown in Table 1, from any of the three perspectives, the scores get better with each increase in displacement within the maximum displacement ranging from 0.4 mm to 0.6 mm and the scores for 0.7 mm are somewhat worse than those for 0.6 mm. In comparison with Comparative Example, only for the maximum displacement of 0.4 mm, the results were worse than Comparative Example and the users felt discomfort. This is considered because the amount of discharge was not as much as expected relative to the degree of squeezing. The above findings indicate that the maximum displacement of the valve body 25b is preferably from 0.4 to 0.8 mm, more preferably from 0.5 to 0.7 mm, and even more preferably from 0.55 to 0.65 mm. Similarly, the maximum displacement of the valve body 25b is preferably from 0.05 times to 0.1 times the diameter of the flow aperture 24h, more preferably from 0.06 times to 0.09 times, and even more preferably from 0.07 times to 0.08 times.

REFERENCE SIGNS LIST

• 1: Delaminatable Container, 2: Cap, 3: Container Body, 5: Valve Member, 7: Storage Portion, 9: Mouth, 15: Fresh Air Inlet, 21: Cap Body, 24: Main Cap Member, 24h: Flow Aperture, 24i: Inner Tube Section, 24o: Outer Tube Section, 24r: Annular Portion, 24s: Valve Seat, 25: Check Valve, 25b: Valve Body, 25f: Outer Frame, 25p: Elastic Piece, 26: Discharge Member, 26d: Disk Section, 26g: Tubular Guide Section, 26m: Outlet, 26p: Projection, 26s: Tubular Support Section, S: Intermediate Space.

Claims

1. A cap comprising a cap body to be fitted to a mouth of a container, wherein the cap is configured to include: a valve seat having a flow aperture; a valve body to be separated from or seated on the valve seat so as to open and close the flow aperture; and a biasing member to bias the valve body in a seating direction, whereinthe cap is configured to form a flow path through which contents flow immediately after the valve body starts to be displaced, and configured to expand the flow path proportionally as the displacement of the valve body increases, andthe cap further includes a displacement restricting section to restrict the displacement of the valve body when discharging the contents, whereinthe displacement restricting section restricts the displacement of the valve body to be 0.09 times or less a diameter of the flow aperture.

2. The cap of claim 1, wherein the displacement restricting section restricts the displacement of the valve body to 1.5 mm or less.

3. The cap of claim 1, wherein the displacement restricting section restricts the displacement of the valve body from 0.4 to 0.8 mm.

4. The cap of claim 1, wherein the biasing member is formed of a plurality of elastic pieces radially extending from an outer circumferential portion of the valve body.

5. The cap of claim 1, wherein the cap body includes: an inner tube section having the valve seat; and a discharge portion mounted to the inner tube section and having an outlet, the inner tube section and the discharge portion forming an intermediate space, and the cap is configured to displace the valve body in the intermediate space.

6. The cap of claim 5, wherein the displacement restricting section is formed of a plurality of projections formed on a surface on a side of the intermediate space of the discharge portion.

7. The cap of claim 5, wherein the displacement restricting section is formed of a spacer disposed between the discharge portion and the valve body.

8. A delaminatable container comprising a container body having an outer shell and an inner bag, the inner bag to be shrunk with a decrease in the contents, whereina cap body to be fitted to a mouth of a container,wherein the cap is configured to include: a valve seat having a flow aperture; a valve body to be separated from or seated on the valve seat so as to open and close the flow aperture; and a biasing member to bias the valve body in a seating direction,wherein the cap is configured to form a flow path through which contents flow immediately after the valve body starts to be displaced, and configured to expand the flow path proportionally as the displacement of the valve body increases, andthe cap further includes a displacement restricting section to restrict the displacement of the valve body when discharging the contents,wherein the displacement restricting section restricts the displacement of the valve body to be 0.09 times or less a diameter of the flow aperture.

9. The cap of claim 1, wherein the valve body is a member in a domical shape having an upwardly curved cross-sectional shape, and the displacement restricting section restricts the displacement of the valve body by abutting on the upper surface of the valve body.

10. The cap of claim 1, wherein the valve seat has an inner circumferential surface in a tapered shape, increasing in diameter in a direction of the flow path approaching a discharge member, wherein the valve body has an outer circumferential portion in a tapered shape, decreasing in diameter in a direction of the flow path approaching the discharge member, to be seated on the inner circumferential surface of the valve seat.