Pump-type dispensing device

Abstract

Regarding a pump-type dispensing device that returns a head pressed by an elastic piece to its initial state, we propose a technology that can suppress the deformation of the elastic piece. [Solution] The pump-type dispenser 100 comprises a cap attached to the mouth of a container that holds the liquid contents, a pump that is held at the mouth by the cap and driven by the movement of a stem 7a, and a head 12 that has a discharge port 12d for discharging the liquid contents to the outside and is connected to the stem 7a, and either the head 12 or the cap has an extension portion 12e that extends toward the other of the head 12 or the cap, and the other of the head 12 or the cap has a base portion and an elastic piece 10e whose root portion is connected to the base portion and which bends due to the extension portion 12e when the head 12 is advanced toward the cap, and is made of polypropylene having a tensile modulus of elasticity of 1400 MPa or more and 1700 MPa or less.

Description

Technical Field

[0001] The present invention relates to a pump-type discharger.

Background Art

[0002] As a pump-type discharger, there is known one including a cap attached to the mouth of a container, a pump driven by a stem that moves up and down (moves forward and backward) while being held at the mouth by the cap, and a head connected to the stem, and discharging the content liquid in the container from the discharge port of the head by moving the head toward the cap.

[0003] Inside such a pump-type discharger, as shown in Patent Document 1, a coil spring is provided to return the head moved toward the cap to the initial position. In such a pump-type discharger, although most members are made of synthetic resin, the coil spring is made of metal, so there is a problem that it cannot be recycled as a resin product in this state when discarded after use. Also, in order to prevent the members from coming off during normal use, the members are firmly fixed to each other, for example, by fitting. Therefore, it takes time to disassemble the pump-type discharger and separate the coil spring from other members.

[0004] In response to such problems, Patent Document 2 shows a pump-type discharger in which elastic pieces are provided on the cap or the head instead of the coil spring. In the pump-type discharger of Patent Document 2, when the head is lowered toward the cap, the elastic piece is elastically deformed, and when the elastically deformed elastic piece is restored, the head can be raised in the same manner as in the conventional case. Also, the pump-type discharger of Patent Document 2 does not require the work of separating the coil spring at the time of disposal, and since it can be reused as a resin product as it is, it is also excellent in recyclability.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2011-31950 [Patent Document 2] Japanese Patent Publication No. 2024-50382 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, flexible elastic pieces tend to deform easily when repeatedly bent, and when this happens, sufficient restoring force may not be obtained. For this reason, if the elastic piece in a pump-type discharger deforms, the head may not return to its initial upper limit. The inventors of this application have conducted extensive research on this matter and have found that there are differences in deformability depending on the material of the components constituting the elastic piece.

[0007] The present invention focuses on these points and aims to propose a pump-type discharger that returns a head pressed by an elastic piece to its initial state, and that can suppress deformation by specifying the material of the component constituting the elastic piece. [Means for solving the problem]

[0008] The pump-type dispenser of the present invention comprises a cap attached to the mouth of a container holding liquid contents, a pump driven by the movement of a stem held at the mouth by the cap, and a head connected to the stem and having a discharge port for discharging the liquid contents to the outside, wherein the liquid contents in the container are discharged from the discharge port by moving the head toward the cap, and either the head or the cap has an extension portion extending toward the other of the head or the cap, and the other of the head or the cap has a base portion and an elastic piece whose root portion is connected to the base portion and which bends due to the extension portion when the head is advanced toward the cap, and is made of polypropylene having a tensile modulus of elasticity of 1400 MPa or more and 1700 MPa or less. [Effects of the Invention]

[0009] According to the pump-type discharger of the present invention, the deformation of the elastic piece can be suppressed, so that the head can be stably returned to its initial upper limit even after repeated use. [Brief explanation of the drawing]

[0010] [Figure 1] This is a side view cross-sectional view showing one embodiment of the pump-type discharger according to the present invention. [Figure 2] Figure 1 is a perspective view of the peripheral portion of the elastic piece shown. [Figure 3] Figure 1 shows a table of the results of the study using a pump-type discharger. [Modes for carrying out the invention]

[0011] Hereinafter, an embodiment of the pump-type discharger according to the present invention will be described with reference to the drawings. In this specification, the vertical direction is the direction along the central axis O shown in the figure (the central axis of the stem 7a described later), where the side where the pipe 4 is located is "down" and the side where the head 12 is located is "up". The radial direction is the direction perpendicular to the central axis O in a plane perpendicular to the central axis O, and the circumferential direction is the direction of rotation around the central axis O in this plane.

[0012] Figure 1 shows a pump-type dispenser 100, which is one embodiment of the pump-type dispenser according to the present invention. The pump-type dispenser 100 of this embodiment is used by being attached to the mouth of a bottle-shaped container (not shown). The liquid contents to be dispensed by the pump-type dispenser 100 are, for example, cosmetics (such as lotions and toners), shampoos, body soaps, hand soaps, facial cleansers, etc.

[0013] The pump-type discharger 100 consists of a cylinder 1, a valve member 2, a pipe 4, an internal member 5, a piston 6, a cylindrical member 7, a holder 8, a packing 9, a cap body 10, a cap cover 11, a head 12, and a nozzle cover 13. Here, the cylinder 1, valve member 2, internal member 5, piston 6, cylindrical member 7, and holder 8 are components that constitute the "pump" as defined herein, and the cap body 10 and cap cover 11 are components that constitute the "cap" as defined herein. Each component that makes up the pump-type discharger 100 is basically shaped around a central axis O.

[0014] The cap body 10 and head 12 of this embodiment are made of polypropylene (PP). The polypropylene used in the cap body 10 and head 12 may be of any type, such as homopolymer, block copolymer, or random copolymer, but one that has a tensile modulus within a predetermined range is used. A detailed explanation of the polypropylene used in the cap body 10 and head 12 will be given later. The valve member 2, piston 6, and packing 9 are made of elastic, soft synthetic resin (e.g., polyethylene (LDPE, HDPE, foamed PE)), while the other members are made of hard synthetic resin (e.g., polypropylene (PP), polybutylene terephthalate (PBT), polyacetal (POM), polyketone (POK) resin, etc.).

[0015] The cylinder 1 has a disc-shaped bottom wall portion 1a with a central part protruding upward, a cylindrical cylindrical wall portion 1b rising from the outer edge of the bottom wall portion 1a, and a flange wall 1c extending radially outward from the upper part of the cylindrical wall portion 1b. A through hole (suction port 1d) is provided in the central part of the bottom wall portion 1a that protrudes upward. A cylindrical retaining cylinder 1e is provided on the lower surface of the bottom wall portion 1a, surrounding the suction port 1d and extending downward to hold the pipe 4. A through hole (vent port 1f) is provided in the cylindrical wall portion 1b.

[0016] The valve member 2 includes a base portion 2a, a valve body portion 2b that covers the suction port 1d inside the base portion 2a and seats on the upper surface of the bottom wall portion 1a, and an elastically deformable connecting piece 2c that connects the base portion 2a and the valve body portion 2b. The valve member 2 functions as a check valve. When the inside of the cylinder 1 is in a decompressed state, the valve body portion 2b that has been closing the suction port 1d can separate from the bottom wall portion 1a to open the suction port 1d.

[0017] In this embodiment, the base portion 2a has a lid-shaped cylindrical form and has an opening (not shown) through which the content liquid passing through the suction port 1d passes. The base portion 2a is fitted and held on the inner peripheral surface of the cylinder wall portion 1b, whereby the valve member 2 is held inside the cylinder 1.

[0018] The pipe 4 has a hollow shape, and its upper end portion is inserted into the holding cylinder 1e and fitted and held thereto.

[0019] The internal member 5 is arranged inside the cylinder 1 and is a member that moves up and down with respect to the cylinder 1. The internal member 5 includes a cylindrical connecting cylinder 5a and a bottom portion 5b that closes the lower end portion of the connecting cylinder 5a and extends radially outward. Further, a hole (communication port 5c) penetrating the connecting cylinder 5a is provided, and an annular portion 5d is provided on the upper surface of the bottom portion 5b at a position radially outside the connecting portion with the connecting cylinder 5a.

[0020] The piston 6 is inserted through the connecting cylinder 5a and arranged inside the cylinder 1. The piston 6 of this embodiment includes an annular base portion 6a. On the outer edge portion of the base portion 6a, outer sliding pieces 6b extending upward and downward from the base portion 6a are provided. The outer sliding pieces 6b are slidably and liquid-tightly abutted against the inner peripheral surface of the cylinder wall portion 1b. And on the inner edge portion of the base portion 6a, inner sliding pieces 6c extending upward and downward from the base portion 6a are provided. The lower portion of the inner sliding piece 6c is liquid-tightly abutted against the annular portion 5d, and the upper portion of the inner sliding piece 6c is slidably and liquid-tightly abutted against the inner peripheral surface of an enlarged diameter portion 7b described later in the cylindrical member 7.

[0021] The cylindrical member 7 is a member that is generally cylindrical. The cylindrical member 7 includes a stem 7a having a cylindrical shape and a diameter-expanded portion 7b that is connected to the lower end portion of the stem 7a and has a larger diameter than the stem 7a. When the connecting cylinder 5a is inserted into the stem 7a, the two are fitted together, so that the inner member 5 and the cylindrical member 7 move integrally with respect to the cylinder 1.

[0022] The holder 8 has a portion located radially outside the stem 7a and a portion located radially outside the diameter-expanded portion 7b, and includes a holder base 8a that is fitted and held on the inner peripheral surface of the cylinder wall portion 1b. At the upper end portion of the holder base 8a, a flange 8b extending radially outward is provided. The holder 8 prevents the inner member 5, the piston 6, and the cylindrical member 7 from coming out of the cylinder 1.

[0023] The packing 9 is in the shape of an annular plate, is inserted through the cylinder wall portion 1b of the cylinder 1, and is fitted and held therein. When the pump-type discharger 100 is attached to a container (not shown), the packing 9 is sandwiched between the mouth portion of the container and the flange wall 1c. Thereby, problems such as the content liquid overflowing from the mouth portion when the container is tilted, for example, are prevented.

[0024] The cap body 10 has a disk shape and includes a top wall 10a having a through hole at the center. At the outer edge portion of the top wall 10a, a cylindrical peripheral wall 10b extending downward is provided. The upper portion of the inner peripheral surface of the peripheral wall 10b bulges radially inward and can fit and hold the flange wall 1c, whereby the cylinder 1 is held by the cap body 10. Further, on the inner peripheral surface of the cap body 10, an internal thread portion 10c that is screwed into an external thread portion provided at the mouth portion of the container is provided, and by screwing the external thread portion and the internal thread portion 10c together, the cap body 10 can be attached to the container. And on the outer peripheral surface of the peripheral wall 10b, as shown in the partial enlarged view of FIG. 1, a rotation-preventing recess 10d extending in the vertical direction is provided. A plurality of rotation-preventing recesses 10d are provided at intervals in the circumferential direction.

[0025] Furthermore, the cap body 10 is equipped with an elastic piece 10e that extends upward from the upper surface of the top wall 10a and is elastically deformable radially inward. As shown in Figure 2, in this embodiment, multiple elastic pieces 10e (six in this embodiment) are provided at equal intervals in the circumferential direction. As will be described later, the elastic piece 10e is elastically deformed toward the central axis O by the head 12 which is pressed when the contents are discharged, and when the pressing force on the head 12 is released, it restores the head 12 to its original position with a restoring force.

[0026] As shown in Figure 2, the elastic piece 10e comprises a plate-shaped elastic piece body 10f and a reinforcing rib 10g that is narrower than the elastic piece body 10f (shorter in circumferential length than the elastic piece body 10f). As shown in the figure, the reinforcing rib 10g has a thicker thickness (radial length) at its base and a thinner thickness at its tip. In other words, in this embodiment, the elastic piece 10e is more flexible at the tip and less flexible at the base due to the reinforcing rib 10g.

[0027] Furthermore, as shown in Figure 1, the top wall 10a is located radially outward from the elastic piece 10e and includes an annular outer annular wall 10h that protrudes upward from the upper surface of the top wall 10a. In this embodiment, the outer annular wall 10h is located directly above the outer edge of the flange wall 1c, as shown in Figure 1. The top wall 10a is also located radially inward from the elastic piece 10e and includes an annular inner first annular wall 10j that protrudes upward from the upper surface of the top wall 10a. In this embodiment, the inner first annular wall 10j protrudes upward from the edge of a through hole provided in the center of the top wall 10a. The amount of protrusion of the inner first annular wall 10j (length from the upper surface of the top wall 10a to the upper end surface of the inner first annular wall 10j) is approximately the same as the amount of protrusion of the outer annular wall 10h. Furthermore, the top wall 10a is located radially where the inner first annular wall 10j is provided (located directly below the inner first annular wall 10j), and is equipped with an annular inner second annular wall 10k that protrudes downward from the lower surface of the top wall 10a.

[0028] The outer annular wall 10h, the inner first annular wall 10j, and the inner second annular wall 10k described above primarily function to prevent the tilt of the elastic piece 10e from changing when the pump-type discharger 100 is attached to a container (not shown). That is, when the female threaded portion 10c is tightly fastened to the male threaded portion of the container, a strong force is applied to the top wall 10a from the upper end surface of the mouth of the container via the packing 9 and the flange wall 1c, and when it is not tightened tightly, the force applied to the top wall 10a is weaker. Therefore, the force applied to the top wall 10a fluctuates depending on how tightly the female threaded portion 10c is fastened to the male threaded portion, which causes the tilt of the elastic piece 10e to change. On the other hand, in this embodiment, since the top wall 10a is provided with the outer annular wall 10h, the inner first annular wall 10j, and the inner second annular wall 10k, the top wall 10a is less likely to deform, and fluctuations in the tilt of the elastic piece 10e can be suppressed.

[0029] The cap cover 11 has a cylindrical cover periphery wall 11a. The cover periphery wall 11a surrounds the periphery wall 10b and the elastic piece 10e. The lower end of the cover periphery wall 11a is provided with a retaining projection 11b that protrudes radially inward and engages with the lower end of the periphery wall 10b. The inner circumferential surface of the cover periphery wall 11a is provided with a rib 11c that extends in the vertical direction. The lower part of the rib 11c engages with a rotation-preventing recess 10d (see the partially enlarged view of Figure 1), and the cap cover 11 is held in place by the cap body 10 in an anti-rotation manner. The upper part of the rib 11c protrudes radially inward more than the lower part. The lower end surface of this upper part contacts the upper surface of the top wall 10a, and as described above, the retaining projection 11b engages with the lower end of the periphery wall 10b, thereby holding the cap cover 11 in place by the cap body 10 in an anti-rotation manner. The upper end of the cover periphery wall 11a is provided with a ring-shaped cap flange portion 11d that extends radially inward.

[0030] The head 12 is cylindrical and has a cylindrical portion 12a into which a stem 7a is inserted and fitted and held. The top of the cylindrical portion 12a is provided with a top portion 12b having a passage inside that leads to the cylindrical portion 12a. The top portion 12b is provided with a cylindrical nozzle 12c that is cylindrical and extends radially outward, and leads to a passage provided inside the top portion 12b. The tip of the nozzle 12c is provided with a discharge port 12d from which the liquid contents are discharged by a pump-type dispenser 100.

[0031] The head 12 also includes an extension portion 12e that extends downward from the top portion 12b and the nozzle 12c. The extension portion 12e in this embodiment is cylindrical with respect to the central axis O. The lower part of the extension portion 12e is inclined to widen radially outward as it extends downward, and the inner edge of this inclined portion contacts the outer circumferential surface of the elastic piece 10e (elastic piece body 10f). Here, the portion of the extension portion 12e that contacts the elastic piece 10e is referred to as the contact portion 12f.

[0032] The nozzle cover 13 is detachably attached to the head 12. The nozzle cover 13 has a C-shape in plan view and includes a mounting portion 13a that is held by the extension portion 12e, as shown in Figure 1. The nozzle cover 13 is also rectangular in shape and includes a wall portion 13b that covers the bottom, sides, and top of the nozzle 12c and connects to the side of the mounting portion 13a. The tip of the wall portion 13b is provided with a lid wall portion 13c that covers the discharge port 12d. Furthermore, the nozzle cover 13 is plate-shaped and includes a stopper portion 13d that extends downward from the lower surface of the wall portion 13b, inclined toward the central axis O, and interposed between the wall portion 13b and the cap flange portion 11d. The lower end of the stopper portion 13d is provided with a lower wall portion 13e that extends outward in the thickness direction of the stopper portion 13d.

[0033] When the pump-type discharger 100, composed of such components, is attached to a container (not shown), as shown in Figure 1, before the head 12 is pressed, the contact portion 12f of the extension portion 12e is in contact with the elastic piece 10e, causing the elastic piece 10e to elastically deform slightly inward in the radial direction. That is, the head 12 is moved to its upper limit by the slightly bending elastic piece 10e.

[0034] Furthermore, when the nozzle cover 13 is attached to the head 12, the stopper portion 13d is interposed between the wall portion 13b and the cap cover 11. In other words, even if the head 12 is pressed while the nozzle cover 13 is attached, the stopper portion 13d prevents the head 12 from moving toward the cap cover 11.

[0035] Then, when dispensing the liquid contents from the container equipped with the pump-type dispenser 100, the nozzle cover 13 is removed, and the head 12 is pressed from above to lower it. This pushes the stem 7a down together with the head 12. At this time, the contact portion 12f of the extension portion 12e that contacts the elastic piece 10e applies pressure to the elastic piece 10e, causing the elastic piece 10e to bend radially inward.

[0036] As the stem 7a is pushed down, the bottom 5b also descends via the connecting cylinder 5a, releasing the liquid-tight contact between the annular portion 5d and the lower part of the inner sliding piece 6c. As the head 12 is pushed down further, the piston 6 descends along with the cylindrical member 7 and the internal member 5, pressurizing the inside of the cylinder 1. As a result, the liquid inside the cylinder 1 passes through the communication port 5c, through the passages provided inside the connecting cylinder 5a, stem 7a, cylindrical portion 12a, and top portion 12b, and through the inside of the nozzle 12c before being discharged to the outside from the discharge port 12d. When the head 12 is pressed and the piston 6 descends below the vent port 1f, a container (not shown) communicates with the outside through the vent port 1f. This prevents negative pressure from forming inside the container even when the amount of liquid inside decreases, thus preventing the container from deforming and collapsing.

[0037] Subsequently, when the pressure on the head 12 is released, the elastic force of the elastic piece 10e, which had been elastically deformed, acts on the head 12, causing the head 12 to begin rising. As a result, the lower part of the annular portion 5d and the inner sliding piece 6c come into liquid-tight contact again, and the piston 6 rises together with the internal member 5, causing the inside of the cylinder 1 to be depressurized. This causes the valve body 2b to separate from the bottom wall 1a, opening the suction port 1d, and allowing the liquid contents of the container to be drawn into the cylinder 1 through the pipe 4. Subsequently, when the head 12 is pressed, the liquid contents of the cylinder 1 are discharged again from the discharge port 12d.

[0038] Here, we will explain the deformation of the elastic piece 10e. When the liquid contents are repeatedly discharged from the pump-type dispenser 100, the elastic piece 10e bends each time, making it prone to deformation. Since the deformed elastic piece 10e cannot exert sufficient restorative force, there is a risk that the head 12 will not return to its initial upper limit. After repeated investigations by the inventors of this application, it was found that deformation can be suppressed by the material of the component (the cap body 10 in this embodiment) that contains the elastic piece 10e.

[0039] The cap body 10 is made of polypropylene (PP). Polypropylene can be further classified into homopolymer, block copolymer, and random copolymer; any of these types of polypropylene may be used for the cap body 10. Polypropylene is relatively inexpensive and offers excellent mass-producibility when molded, making it a suitable material for forming the cap body 10. The inventors of this application formed the cap body 10 from various types of polypropylene and assembled them as a pump-type dispenser 100 to examine the deformation of the elastic piece 10e. It was found that the tensile modulus of the polypropylene used affected the deformation of the elastic piece 10e. Furthermore, it was found that the difference in tensile modulus also affected the operability of the head 12. This point will be explained with reference to Figure 3.

[0040] Figure 3 shows the results of some of the studies conducted by the inventors regarding polypropylene, the material for the cap body 10. The seven types of materials A to G shown in Figure 3 are all polypropylene, each with a different tensile modulus. Seven types of cap bodies 10 (all identical in shape) were prepared using each of materials A to G and assembled as a pump-type dispenser 100. As shown in Figure 1, the head 12 was pressed at a predetermined speed with the head 12 in the upper position, and after the head 12 moved to its lower limit, the pressure on the head 12 was released and the head 12 was returned to its original position at a predetermined speed. The speed at which the head 12 was pressed and the speed at which the head 12 was returned were set to be relatively slow. For this test, the speed at which the head 12 was returned was set to 100 mm / min. The reason for raising the head 12 relatively slowly is that, at a slower speed than at a faster speed, when the elastic piece 10e deteriorates, the head 12 is less likely to return to its upper limit, making it easier to confirm the deterioration of the elastic piece 10e. The number of times the head 12 is pressed to confirm the deterioration of the elastic piece 10e was determined assuming that the contents of approximately one container equipped with the pump-type dispenser 100 are discharged from the discharge port 12d. In this confirmation, the head 12 was pressed 600 times under the above conditions, and the state of the head 12 when it returned to its upper limit and the operability of the head 12 (whether excessive pressing force was required, etc.) were confirmed from the start to the end of pressing.

[0041] Regarding the "head rise" shown in Figure 3, ○ indicates that the head 12 returned to its upper limit well during 600 presses, △ indicates that there were cases where the head 12 returned to its upper limit and cases where it did not, and × indicates that the head 12 often did not return to its upper limit. Regarding the "head press" shown in Figure 3, ○ indicates that the amount of force required to press the head 12 was appropriate, and △ to × indicates that the amount of force required to press the head 12 was too large.

[0042] As a result of this verification, it was found that when the tensile modulus of elasticity of the polypropylene used as the material for the cap body 10 was 1350 MPa or less, when the head 12 was repeatedly pressed, there were cases where the head 12 returned to its upper limit and cases where it did not, and in many cases the head 12 did not return to its upper limit. Furthermore, when polypropylene with a tensile modulus of elasticity of 2050 MPa or more was used, the amount of force required to press the head 12 became large, which was found to be difficult in terms of operability. On the other hand, when the tensile modulus of elasticity was 1400 MPa or more and 1700 MPa or less, the head 12 stably returned to its initial upper limit even when repeatedly pressed. In other words, it was found that by using polypropylene with a tensile modulus within the above range as the material for the cap body 10 equipped with the elastic piece 10e, the deformation of the elastic piece 10e can be suppressed. Furthermore, when polypropylene with a tensile modulus of elasticity of 1400 MPa or more and 1700 MPa or less was used for the cap body 10, the amount of force required to press the head 12 was appropriate, and operability was also excellent. In particular, when using polypropylene with a tensile modulus of 1450 MPa to 1600 MPa, it was found that even considering various variations, the head 12 stably returned to its initial upper limit, and the operability when pressing the head 12 was also stable.

[0043] Further investigation by the inventors of the present invention revealed that by making the extension portion 12e that bends the elastic piece 10e more difficult to deform, the pressing force when pressing the head 12 becomes more stable, and the pressed head 12 returns to its upper limit more stably. One way to make the extension portion 12e more difficult to deform is to increase the thickness of the extension portion 12e, but the amount of resin required to form the extension portion 12e increases with increasing thickness. In this regard, the inventors of the present invention investigated while considering the amount of resin used, cost, mass productivity when molding with a mold, etc., and found that these points can be optimized by the material of the member having the extension portion 12e (head 12 in this embodiment). Specifically, it was found that the head 12 is made of polypropylene, and the tensile modulus of the polypropylene used in the head 12 is less than or equal to the value of the tensile modulus of the polypropylene used in the cap body 10 having the elastic piece 10e. In other words, polypropylene is relatively inexpensive and has excellent mass productivity when molding with a mold. Furthermore, because the tensile modulus of the extension portion 12e becomes less than or equal to the value of the elastic piece 10e, the extension portion 12e becomes less prone to deformation compared to the elastic piece 10e, and the elastic piece 10e bends as intended. As a result, the pressing force when pressing the head 12 becomes more stable, and the pressed head 12 can be returned to its upper limit more stably.

[0044] When assembling the pump-type discharger 100, if the stem 7a is inserted into the cylindrical portion 12a of the head 12 to fit and hold them together, the force of insertion can sometimes cause the extension portion 12e to rapidly push down the elastic piece 10e, causing it to bend forcefully. In this case, whitening may be observed at the base of the elastic piece 10e. Even if the base of the elastic piece 10e whitens, the head 12 can stably return to its initial upper limit, and the operability when pressing the head 12 is also confirmed to be stable. However, it is preferable to suppress the occurrence of whitening. Upon investigation, it was confirmed that if a homopolymer is used as the polypropylene forming the head 12 that constitutes the elastic piece 10e, the occurrence of such whitening can be suppressed.

[0045] Although one embodiment of the present invention has been described above with reference to the drawings, this embodiment may be modified as follows. For example, the pump described above is just one example, and the present invention also includes the use of other types of pumps.

[0046] Furthermore, the number of elastic pieces 10e and their positions are not limited to the embodiments described above and can be changed as appropriate. The reinforcing ribs 10g may be omitted depending on the shape and number of elastic pieces 10e. In the embodiments described above, the elastic pieces 10e bend toward the central axis O, but they may also bend toward the central axis O. In the embodiments described above, the elastic pieces 10e are provided on the cap body 10 and the extension portion 12e is provided on the head 12, but the extension portion 12e may be provided on the cap body 10 and the elastic pieces 10e on the head 12. When the elastic pieces 10e are provided on the head 12, polypropylene with a tensile modulus of elasticity of 1400 MPa or more and 1700 MPa or less should be used as the material for the head 12.

[0047] (Note) This specification discloses the following technologies in one aspect. The reference numerals listed below correspond to those used in the accompanying drawings, but are provided as examples only and are not intended to limit the inventions of this application.

[0048] (Technology 1) A pump-type dispenser (100) comprising a cap attached to the mouth of a container that holds liquid contents, a pump driven by the movement of a stem (7a) held at the mouth by the cap, and a head (12) connected to the stem (7a) having a discharge port (12d) for discharging the liquid contents to the outside, wherein the liquid contents in the container are discharged from the discharge port (12d) by moving the head (12) toward the cap, Either the head (12) or the cap has an extension (12e) extending toward the other of the head (12) or the cap. A pump-type discharger (100) wherein either the head (12) or the cap has a base portion and an elastic piece (10e) whose root portion is connected to the base portion and which bends due to the extension portion (12e) when the head (12) is advanced toward the cap, and is made of polypropylene having a tensile modulus of 1400 MPa or more and 1700 MPa or less.

[0049] This technology suppresses the deformation of the elastic piece, allowing the head to stably return to its initial upper limit even after repeated use. Furthermore, because the amount of force required to press the head is appropriate, the head offers excellent operability.

[0050] (Technology 2) The pump-type discharger (100) described in Technology 1, wherein the tensile modulus is 1450 MPa or more and 1600 MPa or less.

[0051] This technology allows the head to be stably returned to its initial upper limit, even when considering various variations, and also ensures consistently good operability when pressing the head.

[0052] (Technology 3) A pump-type discharger (100) according to Technology 1 or 2, wherein either the head (12) or the cap is made of polypropylene such that the tensile modulus is less than or equal to the tensile modulus of the other of the head (12) or the cap.

[0053] This technology makes the extended portion that flexes the elastic piece less prone to deformation, allowing the elastic piece to flex as intended. This results in more stable pressing force when pressing the head, and also allows the pressed head to return to its upper limit more stably.

[0054] Although one embodiment of the present invention has been described above, the present invention is not limited to such specific embodiments, and unless otherwise specifically limited in the above description, various modifications and changes are possible within the scope of the spirit of the present invention as described in the claims. For example, the configuration of the above-described embodiment can be added or deleted as appropriate, and the configuration of one embodiment can be provided in other embodiments. Furthermore, the effects in the above-described embodiment are merely illustrative of the effects that may result from the present invention. In other words, the effects of the present invention are not limited to the above-described effects, and additional effects may also be produced in addition to the above-described effects. [Explanation of Symbols]

[0055] 1: Cylinder 1a: Bottom wall part 1b: Cylinder wall 1c: Flange wall 1d: Inlet 1e: Holding tube 1F: Ventilation opening 2: Valve member 2a: Base 2b: Valve body 2c: Connecting piece 4: Pipe 5: Internal components 5a: Connecting tube 5b: Bottom 5c: Communication port 5d: Annular section 6: Piston 6a: base 6b: Outer sliding piece 6c: Inner sliding piece 7: Cylindrical member 7a: Stem 7b: Expanded diameter part 8: Holder 8a: Holder base 8b: Flange 9: Packing 10: Cap body 10a: Ceiling wall 10b: Peripheral wall 10c: Female thread section 10d: Anti-rotation recess 10e: Elastic piece 10f: Elastic piece body 10g: Reinforcement rib 10h: Outer annular wall 10j: Inner first annular wall 10k: Inner second ring wall 11: Cap cover 11a: Cover surrounding wall 11b: Retaining protrusion 11c: Rib 11d: Cap flange section 12: Head 12a: Cylindrical part 12b:Top 12c: Nozzle 12d: Discharge port 12e: Extension part 12f: Contact part 13: Nozzle cover 13a: Mounting part 13b: Wall part 13c: Lid wall part 13d: Stopper part 13e: Lower wall part 100: Pump-type dispensing device O: Central axis

Claims

1. A pump-type dispenser comprising a cap fitted to the mouth of a container holding a liquid, a pump driven by the movement of a stem held at the mouth by the cap, and a head connected to the stem having a discharge port for discharging the liquid to the outside, wherein the liquid inside the container is discharged from the discharge port by moving the head toward the cap, Either the head or the cap has an extension that extends toward the other of the head or the cap. A pump-type discharger, wherein either the head or the cap has a base portion and an elastic piece whose root portion is connected to the base portion and which bends due to the extension portion when the head is advanced toward the cap, and is made of polypropylene having a tensile modulus of 1400 MPa or more and 1700 MPa or less.

2. The pump-type discharger according to claim 1, wherein the tensile modulus is 1450 MPa or more and 1600 MPa or less.

3. The pump-type discharger according to claim 1 or 2, wherein either the head or the cap is made of polypropylene such that the tensile modulus is less than or equal to the tensile modulus of the other of the head or the cap.

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