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EP-4736998-A1 - STATIC MIXER AND PASTE INJECTOR

EP4736998A1EP 4736998 A1EP4736998 A1EP 4736998A1EP-4736998-A1

Abstract

In order to provide a static mixer and a paste dispenser capable of adjusting the pushing force of a plunger while preventing bubbles from being mixed into a dental material to be discharged, with a simple structure, a static mixer (7) includes a plurality of paste passages (29, 29') that is arranged circumferentially about a central axis (CA) of a syringe (3) and extends in a longitudinal direction (X); an intermediate passage (31); and a mixing passage (33) that extends about the central axis (CA). An inner circumferential surface of each of the plurality of the paste passages (29, 29') includes a tapered portion in a distal surface (29C, 29C'). A tapered portion is formed in a tapered shape that approaches the central axis (CA) from an inflow hole (29A, 29A') toward an outflow hole (29B, 29B'). The inflow hole (29A, 29A') includes an opening area that is greater than that of the outflow hole (29B, 29B').

Inventors

  • KAWANA Mariko
  • NOJIRI YAMATO
  • ATAKA KENSUKE
  • MURAYAMA MOMOE
  • SESHIMO SATOSHI
  • OHDAIRA TOSHIYUKI

Assignees

  • Kuraray Noritake Dental Inc.

Dates

Publication Date
20260506
Application Date
20240624

Claims (9)

  1. A static mixer comprising: a plurality of paste passages that each comprises an inflow hole and an outflow hole and is configured to allow a plurality of types of pastes to respectively pass therethrough, the plurality of types of pastes being individually stored in a syringe extending in a longitudinal direction; an intermediate passage that is configured to guide the plurality of types of the pastes from the outflow holes to a junction position; and a mixing passage that is configured to allow the plurality of types of the pastes merged at the junction position to pass therethrough while the plurality of types of the pastes are mixed therein, wherein the plurality of the paste passages are arranged circumferentially about a central axis of the syringe and extends in the longitudinal direction, wherein an inner circumferential surface of each of the plurality of the paste passages comprises a tapered portion in at least a portion of a distal surface away from the central axis, the tapered portion being formed in a tapered shape that approaches the central axis from the inflow hole toward the outflow hole, and wherein the inflow hole comprises an opening area that is greater than that of the outflow hole.
  2. The static mixer according to claim 1, wherein the tapered portion extends from the inflow hole to the outflow hole.
  3. The static mixer according to claim 1, wherein the tapered portion is formed in a region extending from the inflow hole to a midway position of the paste passage, and wherein the distal surface extends along the central axis in a region extending from the tapered portion to the outflow hole.
  4. The static mixer according to any one of claims 1 to 3, wherein the inner circumferential surface of each of the plurality of the paste passages comprises a proximal surface proximal to the central axis, the proximal surface extending along the central axis.
  5. The static mixer according to claim 1, wherein a center point of the inflow hole is closer to the central axis than that of the inflow hole.
  6. The static mixer according to claim 1, wherein the intermediate passage is provided with a backflow prevention wall that is configured to divide the intermediate passage and to prevent paste that has flowed out of one of the outflow holes from flowing into another of the outflow holes.
  7. The static mixer according to claim 6, wherein the backflow prevention wall comprises a curved surface that directs the paste toward the junction position at an essential portion, and extends along the central axis to the junction position.
  8. The static mixer according to claim 1, wherein the static mixer is used for preparing a dental material by mixing the plurality of types of the pastes and for injecting the dental material.
  9. A paste dispenser comprising the static mixer according to claim 1.

Description

[Technical Field] The present invention relates to a static mixer and a paste dispenser. [Background Art] There is known a dental material that is made of a plurality of types of pastes and is prepared by mixing them just before use. In order to inject such dental material into a predetermined position, there is a paste dispenser that discharges the plurality of types of the pastes while mixing them together. The paste dispenser includes a syringe that stores therein plurality of types of pastes, a plunger that pushes out the pastes, and a static mixer that is attached to a discharge portion of the syringe. For example, Patent Literature 1 and Patent Literature 2 disclose the static mixers. [Prior Art Documents] [Patent Literature] [Patent Literature 1] Japanese Patent Application Publication No. H11-99325[Patent Literature 2] WO2018/057503 [Summary of Invention] [Problem to be solved] The user of the paste dispenser needs to discharge an appropriate amount of dental material little by little by pushing the plunger while holding the syringe in one hand. In other words, if the force required to push the material in the plunger is too large, it is difficult to push the plunger. If the force is too small, the dental material is discharged by an amount more than necessary. It is not possible to properly prepare the dental material if bubbles are mixed therein. Therefore, it is necessary to prevent mixing of bubbles in the flow path of the paste. For example, the static mixer disclosed in Patent Literature 1 includes a stepped portion formed in the paste passage to adjust the force required to push the plunger, as shown in FIG. 2. However, in this case, bubble accumulation tends to occur at the stepped portion. The static mixer disclosed in Patent Literature 2 adjusts the force required to push the plunger by bending the paste passage as shown in FIG. 4. However, in this case, bubble accumulation tends to occur at a change point where the direction of the paste flow changes and that the structure is complicated. An object of the present invention is to provide a static mixer and a paste dispenser capable of adjusting the force required to push the plunger, while preventing bubbles from being mixed into the dental material to be discharged, in a simple structure. [Solution to Problem] A static mixer according to the present invention includes a plurality of paste passages that each includes an inflow hole and an outflow hole and is configured to allow a plurality of types of pastes to respectively pass therethrough, the plurality of types of pastes being individually stored in a syringe extending in a longitudinal direction; an intermediate passage that is configured to guide the plurality of types of the pastes from the outflow holes to a junction position; and a mixing passage that is configured to allow the plurality of types of the pastes merged at the junction position to pass therethrough while the plurality of types of the pastes are mixed therein. In order to achieve the object, the plurality of the paste passages are arranged circumferentially about a central axis of the syringe and extends in the longitudinal direction. An inner circumferential surface of each of the plurality of the paste passages includes a tapered portion in at least a portion of a distal surface away from the central axis. The tapered portion is formed in a tapered shape that approaches the central axis from the inflow hole toward the outflow hole. The inflow hole includes an opening area that is greater than that of the outflow hole. A paste dispenser according to the present invention includes the static mixer. [Effects of Invention] According to the above configuration, the static mixer and the paste dispenser according to the present invention prevent the accumulation of bubbles in the flow path of the paste, thereby suppressing the mixture of bubbles into the dental material. The force required to push the plunger makes it easy to adjust the amount of dental material to be discharged. [Brief Description of Drawings] [FIG. 1] FIG. 1 is a perspective view of a paste dispenser including a static mixer of a first embodiment.[FIG. 2] FIG. 2 is an exploded perspective view of the paste dispenser of the first embodiment.[FIG. 3] FIG. 3 is a sectional view of the static mixer fixed to a tip end portion of a syringe of the first embodiment, the sectional view being taken in the width direction at a position passing through a central axis extending in the longitudinal direction.[FIG. 4A] FIG. 4A is a front view of the syringe of the first embodiment.[FIG. 4B] FIG. 4B is a side view of the syringe of the first embodiment.[FIG. 4C] FIG. 4C is a plan view of the syringe of the first embodiment.[FIG. 4D] FIG. 4D is a bottom view of the syringe of the first embodiment.[FIG. 5] FIG. 5 is a sectional view taken along line V-V shown in FIG. 4C.[FIG. 6] FIG. 6 is an end surface view taken along line VI-VI shown in FIG. 4A.[FIG. 7A] FIG. 7A is a f