JP2023116284A - syringe for paste - Google Patents

Abstract

To provide a syringe for paste even when a paste has a storage elastic modulus of substantially 500 to 1500 Pa, capable of discharging the paste through a nozzle part of a syringe outer cylinder by applying appropriate force to a pusher, and capable of avoiding such a case as much as possible that the paste flows back through a gap between an inner peripheral surface of a main part of the syringe outer cylinder and an outer peripheral surface of a pushing part of the pusher and is lost.SOLUTION: A syringe for paste comprises a syringe outer cylinder including a cylindrical main part and a nozzle part extending from a tip of the main part, and a pusher including a pushing part for acting on a paste to be stored in the syringe outer cylinder to discharge the paste through the nozzle part. A difference (MD-PD) between an inside diameter MD of the main part of the syringe outer cylinder and an outside diameter PD of the pushing part of the pusher is 0.03 to 0.40 mm, and a ratio (ND/MD) between the inside diameter MD of the main part of the syringe outer cylinder and the inside diameter ND of the nozzle part is 0.15 to 0.70.SELECTED DRAWING: Figure 1

Description

The present invention relates to a syringe comprising a syringe outer cylinder and a plunger, more specifically, a powder-liquid mixture in which a powder material containing a non-crosslinked resin as a main component and a liquid material containing a radically polymerizable monomer as a main component are mixed. The present invention relates to a paste syringe for pastes such as denture base relining materials.

In Patent Document 1 below, when forming a denture from a standard denture, a powder containing a non-crosslinked resin such as polyethyl methacrylate as a main component and a liquid containing a radically polymerizable monomer such as a methacrylate-based monomer as a main component materials to form a paste that is used as a powder-liquid mixed denture base relining material and applied to a reference denture. Further, Patent Documents 2 and 3 below describe in detail preferred examples of a powder material containing a non-crosslinked resin as a main component and a liquid material containing a radically polymerizable monomer as a main component.

The present inventors have investigated the use of a syringe to mix the powder material and the liquid material to form a paste for convenient use. Specifically, the powder material and the liquid material are introduced into the syringe outer cylinder with the pusher removed from the syringe outer cylinder and the nozzle portion of the syringe outer cylinder closed, and an appropriate mixing tool such as a mixing spatula is inserted into the syringe outer cylinder. A powder material and a liquid material are mixed by inserting into the outer cylinder to generate a paste. After that, the nozzle portion of the syringe outer cylinder is unsealed, and a plunger is combined with the syringe outer cylinder.

Japanese Patent Application Laid-Open No. 2021-187780 Republished patent WO2018/016602 JP 2020-45459 A

The paste used as the powder-liquid mixed denture base relining material should normally have a viscosity of about 500 to 1500 Pa in storage modulus at room temperature (i.e., 15 to 25° C.) and be applied to the required site of the standard denture. be On the other hand, in a general syringe, a sealing member such as a rubber ring is arranged on the outer peripheral surface of the pushing portion of the pusher, and the inner peripheral surface of the main portion of the syringe outer cylinder and the outer circumference of the pushing portion of the pusher are arranged. The faces are closely attached. According to experiments by the present inventors, in the case of such a general syringe, even if a considerable force is applied to the pusher, it is impossible to discharge a paste with a storage elastic modulus of about 500 to 1500 Pa. It was possible. In addition, even when the ratio (ND/MD) of the inner diameter MD of the main part of the syringe outer cylinder and the inner diameter ND of the nozzle part is too small, the storage elastic modulus is about 500 to 1500 Pa unless an excessive force is applied to the plunger. It was not possible to eject a paste of viscosity.

The present invention has been made in view of the above facts, and even if the paste has a storage elastic modulus of about 500 to 1500 Pa, it can be discharged through the nozzle part of the syringe outer cylinder by applying an appropriate force to the plunger. In addition, it is possible to prevent the paste from flowing back through the gap between the inner peripheral surface of the main part of the syringe outer cylinder and the outer peripheral surface of the pressing part of the plunger and being lost as much as possible. Another object of the present invention is to provide an improved paste syringe.

As a result of intensive studies and experiments, the present inventors set the difference (MD-PD) between the inner diameter MD of the main part of the syringe outer cylinder and the outer diameter PD of the pushing part of the pusher to an appropriate value, and the syringe It has been found that the above main technical problems can be achieved by setting the ratio (ND/MD) between the inner diameter MD of the main portion of the outer cylinder and the inner diameter ND of the nozzle portion to an appropriate value.

That is, according to the present invention, as a paste syringe that achieves the above main technical problems,
A syringe outer cylinder including a cylindrical main portion and a nozzle portion extending from the tip of the main portion; A syringe for paste comprising a pusher including a pushing portion,
The difference (MD-PD) between the inner diameter MD of the main portion of the syringe barrel and the outer diameter PD of the pushing portion of the plunger is 0.03 to 0.40 mm,
The ratio (ND/MD) between the inner diameter MD of the main portion of the syringe barrel and the inner diameter ND of the nozzle portion is 0.15 to 0.70.
There is provided a paste syringe characterized by:

The inner peripheral surface of the main part of the syringe outer cylinder and the outer peripheral surface of the pressing part of the plunger are not limited to a cylindrical shape, and may be an elliptical cylindrical shape or a regular polygonal cylindrical shape. means the major axis or the minor axis in the case of an elliptical cylindrical shape, and the length between opposing side surfaces in the case of a regular polygonal cylindrical shape. The inner peripheral surface of the nozzle portion is not limited to a cylindrical shape, and may be tapered truncated cone shape or the like, but the term "inner diameter" means the minimum inner diameter of the tip when tapered truncated cone shape.

Preferably, said difference (MD-PD) is between 0.04 and 0.35 mm and said ratio (ND/MD) is between 0.16 and 0.45. The volume of the main portion of the syringe barrel is preferably 20-80 mL. The inner peripheral surface of the main portion of the syringe barrel and the outer peripheral surface of the pushing portion of the plunger are preferably cylindrical, and the inner peripheral surface of the nozzle portion of the syringe barrel is cylindrical or Advantageously, it has a tapered frusto-conical shape. The paste is a powder-liquid mixed denture base lining material that is a mixture of a powder material whose main component is a non-crosslinked resin and a liquid material whose main component is a radically polymerizable monomer. A pressure of 500 to 1500 Pa is particularly suitable.

As will be clearly understood from Examples and Comparative Examples to be described later, according to the paste syringe of the present invention, even when the paste has a storage elastic modulus of about 500 to 1500 Pa, the syringe can be obtained by applying an appropriate force to the plunger. The paste can be discharged through the nozzle part of the outer cylinder, and the paste can flow back through the gap between the inner peripheral surface of the main part of the syringe outer cylinder and the outer peripheral surface of the pushing part of the plunger, and can be lost. can be effectively avoided.

1 is an exploded front view, partially in cross-section, of a preferred embodiment of a syringe constructed in accordance with the present invention; FIG. FIG. 2 is a cross-sectional view of the main portion of the syringe barrel of the syringe illustrated in FIG. 1, taken along line II-II in FIG. 1; FIG. 2 is a cross-sectional view of the nozzle portion of the syringe barrel in the syringe illustrated in FIG. 1, taken along line III-III in FIG. 1; FIG. 2 is a bottom view of the plunger in the syringe illustrated in FIG. 1; FIG. 2 is a front view, partly in cross section, for explaining the manner of use of the syringe illustrated in FIG. 1 ;

Reference will now be made in more detail to the accompanying drawings which illustrate preferred embodiments of syringes constructed in accordance with the present invention.

Referring to FIG. 1, a syringe, generally designated 2, comprises a syringe barrel 4, a plunger 6 and a closure 8. As shown in FIG. Syringe barrel 4, pusher 6 and closure 8 can be made of a suitable synthetic resin such as polyethylene or polypropylene. Syringe barrel 4, pusher 6 and closure 8, particularly syringe barrel 4, are conveniently transparent or translucent.

Syringe barrel:
2 and 3 together with FIG. 1, the syringe barrel 4 includes a main portion 10 and a nozzle portion 12 extending from the tip of the main portion 10 (lower end in FIG. 1). The main portion 10 of the illustrated syringe outer cylinder 4 has a cylindrical shape and has a cylindrical inner peripheral surface and a cylindrical outer peripheral surface. The inner peripheral surface and the outer peripheral surface of the main portion 10 are not limited to a cylindrical shape, and may be an elliptical cylindrical shape or a regular polygonal cylindrical shape such as a regular hexagonal cylinder. Instead, for example, the inner peripheral surface may have a cylindrical shape and the outer peripheral surface may have a regular polygonal cylindrical shape. If the paste contained in the main part 10 of the syringe barrel 4 is a powder-liquid mixing type denture base lining material (this powder-liquid mixing type denture base lining material will be referred to later), the required discharge amount, etc. , the volume of the main part 10 of the syringe outer cylinder 4 is 20 to 80 mL, particularly about 25 to 50 mL, the inner diameter of the main part 10 of the syringe outer cylinder 4 is about 20 to 40 mm, and the length is 50 to 130 mm. In particular, it is convenient to be about 70 to 100 mm. A protruding flange 14, which may be substantially elliptical, is attached to the base end (upper end in FIG. 1) of the main portion 10. As shown in FIG. The nozzle portion 12 in the illustrated syringe outer cylinder 4 has a cylindrical shape, and has a cylindrical inner peripheral surface and a cylindrical outer peripheral surface. If desired, the inner and/or outer peripheral surface of the nozzle portion 12 can be tapered frusto-conical (ie, inverted frusto-conical). The nozzle portion 12 extends from the tip of the main portion 10 concentrically with the main portion 10, and the tip of the main portion 10 and the base end of the nozzle portion 12 (upper end in FIG. 1) form an annular connecting wall 16. connected by The nozzle portion 12 does not necessarily have to be concentric with the main portion 10 , and can be eccentric with respect to the main portion 10 and extend from the tip of the main portion 10 .

Pusher:
The illustrated pusher 6 has a pushing portion 18 positioned at the tip (lower end in FIG. 1), an operating portion 20 positioned at the base end (upper end in FIG. 1), and a connecting portion connecting the pushing portion 18 and the operating portion 20. 22. The pushing portion 18 has a thin disk shape having an outer peripheral surface corresponding to the inner peripheral surface of the main portion 10 of the syringe outer cylinder 4, and therefore, in the shown pusher 6, the outer peripheral surface is cylindrical. The bottom surface of the pressing portion 18, that is, the pressing surface that acts on the paste contained in the main portion 10 of the syringe barrel 4 (this paste will be further referred to later), has a concentric cylindrical shape projecting downward. A protrusion 24 is provided. In the pusher 6 shown in the figure, the operating portion 20 is also shaped like a thin disc, and has an outer diameter slightly larger than the outer diameter of the main portion 10 of the syringe outer cylinder 4 . The connecting portion 22 is formed of four elongated thin plate pieces 26 (only three elongated thin plate pieces 26 are shown in FIG. 1) arranged at angular intervals of 90 degrees. The inner edges of the elongated thin plate pieces 26 are connected to each other, the lower edges are connected to the upper surface of the pushing portion 18 , and the upper edges are connected to the lower surface of the operating portion 20 . The outer edges of the four elongated thin plate pieces 26 are located radially inside the outer peripheral edge of the pushing portion 18 .

Closure device:
As shown in FIG. 1, the closure 8 in the illustrated embodiment projects upwardly from a circular bottom wall 28, a cylindrical side wall 30 extending upwardly from the periphery of the bottom wall 28, and a center of the bottom wall 28. It has a cylindrical sealing pin 32 . The inner diameter of the side wall 30 is substantially the same as the outer diameter of the nozzle portion 12 of the syringe outer cylinder 4, and the outer diameter of the blocking pin projection 32 is substantially the same as the inner diameter of the nozzle portion 12 of the syringe outer cylinder 4, It is convenient that the protruding length of the blocking pin 32 is substantially the same as the length of the nozzle portion 12 of the syringe outer cylinder 4 .

Difference between the inner diameter MD of the main part of the syringe barrel and the outer diameter PD of the pushing part of the plunger:
In the syringe 2 configured according to the present invention, the difference (MD-PD) between the inner diameter MD of the main portion 10 of the syringe outer cylinder 4 and the outer diameter PD of the pushing portion 18 of the pusher 6 is 0.03 to 0.40 mm. , preferably 0.04 to 0.35 mm, particularly preferably 0.05 to 0.30 mm. As will be clearly understood from the examples and comparative examples described later, if the difference (MD-PD) is too small, the pusher 6 is operated to push out the paste from the main portion 10 of the syringe outer cylinder 4 through the nozzle portion 12. If the difference (MD-PD) is too large, the main part of the syringe outer cylinder 4 is pushed out from the main part 10 of the syringe outer cylinder 4 through the nozzle part 12 by operating the pusher 6. There is a tendency for the paste to flow back through the gap between the inner peripheral surface of the pusher 10 and the outer peripheral surface of the pressing portion 18 of the pusher 6, resulting in a wasteful loss of the paste. As described above, the inner peripheral surface of the main portion 10 of the syringe outer cylinder 4 and the outer peripheral surface of the pressing portion 18 of the pusher 6 are not limited to cylindrical shapes, and may be elliptical cylindrical shapes or regular polygonal cylindrical shapes. The terms "inner diameter" and "outer diameter" refer to the major axis or minor axis in the case of an elliptical cylinder, and to the length between opposing side surfaces in the case of a regular polygonal cylinder.

The ratio of the inner diameter MD of the main portion of the syringe barrel to the inner diameter ND of the nozzle portion (ND/MD):
In the syringe 2 constructed according to the present invention, the ratio (ND/MD) of the inner diameter MD of the main portion 10 of the syringe outer cylinder 4 to the inner diameter ND of the nozzle portion 12 is 0.15 to 0.70, preferably 0.70. It is important that it is between 16 and 0.45, particularly preferably between 0.17 and 0.35. As is clear from the examples and comparative examples to be described later, if the ratio (ND/MD) is too small, it is difficult to operate the plunger 6 to push out the paste from the main portion 10 of the syringe outer cylinder 4 through the nozzle portion 12. If the ratio (ND/MD) is too large, the cross-sectional area of the paste discharged through the nozzle part 12 becomes too large, which is inconvenient for use as a powder-liquid mixed denture base relining material. As described above, the inner peripheral surface of the nozzle portion 12 is not limited to a cylindrical shape, and may be tapered truncated cone shape or the like. do.

Style of use of the syringe:
Next, mainly with reference to FIG. 5, the mode of use of the syringe 2 will be described. When producing the powder-liquid mixed denture base lining material, the plunger 6 is separated from the syringe outer cylinder 4 . Then, as shown in FIG. 5, the sealing member 8 is attached to the nozzle portion 12 of the syringe outer cylinder 4. More specifically, the side wall 30 of the sealing member 8 is fitted onto the outer peripheral surface of the nozzle portion 12, and the sealing pin 32 is attached to the nozzle portion. 12, and the inner surface of the bottom wall 28 is brought into contact with the tip surface of the nozzle portion 12, thus closing the nozzle portion 12. As shown in FIG. Next, a required amount of powder material and liquid material (not shown) is poured into the main part 10 through the opening located at the proximal end (upper end in FIG. 5) of the main part 10 of the syringe barrel 4 in this order or in reverse order. are inserted in sequence. The powder material for producing the powder-liquid mixed denture base relining material is a powder material mainly composed of a non-crosslinked resin such as polyethyl methacrylate, and the liquid material is a radically polymerizable monomer such as a methacrylate monomer. is the main component of the liquid material. Details of such powder materials and liquid materials are described in detail in the above-mentioned Patent Documents 2 and 3, and therefore the descriptions thereof are cited and the description thereof is omitted in this specification. Since the nozzle portion 12 of the syringe outer cylinder 4 is closed by the closing member 8 , the powder material and the liquid material introduced into the main portion 10 do not flow down through the nozzle portion 12 . Next, an appropriate mixing tool (not shown) such as a mixing spatula is inserted into the main portion 10 of the syringe outer cylinder 4 to mix the charged powder material and the liquid material. Thus, a paste, that is, a powder-liquid mixed denture base lining material is produced in the main portion 10 of the syringe barrel 4 .

After that, as indicated by a two-dot chain line in FIG. to release the blockage of the nozzle portion 12 . Then, the forefinger and the middle finger are put on the overhanging flange 14 of the syringe outer cylinder 4 and the thumb is engaged with the operating portion 20 of the pusher 6 to apply a pressing force to the pusher 6 so that the inside of the main portion 10 of the syringe outer cylinder 4 is pushed. Then, the pusher 6 is gradually advanced to press the paste in the main part 10 by the pushing part 18 of the pusher 6, and the paste is discharged through the nozzle part 12 to a desired site, for example, the floor surface (back surface) of the reference denture. . A protrusion 24 attached to the lower surface of the pushing portion 18 can enter the nozzle portion 12 and discharge the paste without substantially leaving the paste in the nozzle portion 12 .

Examples and Comparative Examples Syringes used:
A syringe configured as illustrated in FIGS. 1-5 was used. The volume of the syringe outer cylinder is 37 mL, and the inner diameter MD of the main part of the syringe outer cylinder, the inner diameter ND of the nozzle part of the syringe outer cylinder, the outer diameter PD of the pushing part of the pusher, and the inner diameter MD of the main part of the syringe outer cylinder. The difference between the outer diameter PD of the pushing part of the plunger (MD-PD) and the ratio of the inner diameter MD of the main part of the syringe outer cylinder and the inner diameter ND of the nozzle part of the syringe outer cylinder (ND/MD) are shown in Table 1. It was as described.

Powder-liquid mixed denture base lining material used:
The symbol "HL" shown in Table 1 indicates a powder-liquid mixed denture base lining material sold by Tokuyama Dental Co., Ltd. under the trade name "Tokuyama Hikari Liner", and the symbol "R3" is a product of Tokuyama Dental Co., Ltd. It shows a powder-liquid mixed denture base relining material sold under the name "Tokuya Rebase III First".

Input and mixing of powder and liquid materials:
A liquid material (4.8 mL) is added with a stopper attached to the nozzle part of the syringe outer cylinder from which the plunger has been removed, and then powder material (8.6 g for HL, 9.6 g for R3). After that, the powder material and the liquid material were mixed for 30 seconds using a mixing spatula sold by Tokuyama Dental Co., Ltd. under the trade name "Spatula No. 001". After that, the plunger was combined with the syringe outer cylinder, and the sealing tool was removed from the syringe outer cylinder.

Paste storage modulus (time from mixing to discharge):
When the powder material and the liquid material are mixed, they gradually become a paste, and the viscosity gradually increases with the passage of time. Therefore, the change in the storage modulus of the paste with the lapse of time after mixing the powder material and the liquid material was measured using a viscoelasticity measuring device sold by Anton Paar GmbH under the trade name "MCR302". did. Then, based on the obtained measured value, the elapsed time from the mixing of the powder material and the liquid material is measured, and when the storage elastic modulus Pa of the paste reaches the value described in Table 1, the plunger is manually operated. Then, an attempt was made to discharge the paste through the nozzle.

The symbol "○" in Table 1 indicates that the paste could be discharged by manually operating the pusher, and the symbol "×" in Table 1 indicates that the paste was discharged by manually operating the pusher. It was extremely difficult or impossible. The symbol "AA" in the paste loss column in Table 1 indicates that the paste loss due to backflow was less than 10%, and the symbol "A" indicates that the paste loss due to backflow was 10% or more and less than 20%. The symbol "B" indicates that the paste loss due to backflow was 20% or more and less than 50%, and the symbol "C" indicates that the paste loss due to backflow was 50% or more.

From Table 1, the difference (MD-PD) between the inner diameter MD of the main part of the syringe barrel and the outer diameter PD of the pushing part of the pusher is 0.03 to 0.40 mm, especially 0.04 to 0.35 mm, especially is 0.05 to 0.30 mm, and the ratio (ND/MD) of the inner diameter MD of the main portion of the syringe barrel to the inner diameter ND of the nozzle portion of the syringe barrel is 0.15 to 0.70, particularly 0.70. When it is 16 to 0.45, particularly 0.17 to 0.35, paste having a storage elastic modulus of 500 to 1500 Pa can be discharged smoothly by manual operation of the plunger, and paste loss can be minimized. It is understood to avoid as much as possible (losses can be reduced to less than 20%, especially less than 10%).

2: Syringe 4: Syringe outer cylinder 6: Pusher 8: Closure tool 10: Main part of syringe outer cylinder 12: Nozzle part of syringe outer cylinder 18: Pusher part of plunger

Claims (7)

A syringe outer cylinder including a cylindrical main portion and a nozzle portion extending from the tip of the main portion; A syringe for paste comprising a pusher including a pushing portion,
The difference (MD-PD) between the inner diameter MD of the main portion of the syringe barrel and the outer diameter PD of the pushing portion of the plunger is 0.03 to 0.40 mm,
The ratio (ND/MD) between the inner diameter MD of the main portion of the syringe barrel and the inner diameter ND of the nozzle portion is 0.15 to 0.70.
A paste syringe characterized by: A paste syringe according to claim 1, wherein said difference (MD-PD) is between 0.04 and 0.35 mm. 3. The paste syringe according to claim 1, wherein said ratio (ND/MD) is from 0.16 to 0.45. 4. The paste syringe according to any one of claims 1 to 3, wherein the volume of the main portion of the syringe barrel is 20 to 80 mL. 5. The paste syringe according to any one of claims 1 to 4, wherein the inner peripheral surface of the main portion of the syringe outer cylinder and the outer peripheral surface of the pressing portion of the plunger are cylindrical. 6. The paste syringe according to any one of claims 1 to 5, wherein the inner peripheral surface of the nozzle portion of the syringe outer cylinder has a cylindrical shape or a tapered truncated cone shape. The paste is a powder-liquid mixed denture base lining material that is a mixture of a powder material whose main component is a non-crosslinked resin and a liquid material whose main component is a radically polymerizable monomer. 7. The syringe for paste according to any one of claims 1 to 6, which is 500 to 1500 Pa.

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