JP4078406B2 - Method for manufacturing syringe cylinder - Google Patents

Description

（実施例２）
次に、シリコンオイル（ポリジメチルシロキサン）の粘度と、摺動性及び外観についての実験結果を示す。

以上から、摺動性と外観とを共にクリアする領域として、シリコンオイルがポリジメチルシロキサンの場合、その粘度が５００〜３０,０００センチストークスであり、塗布量が０.００１〜０.０５ｇ／１００cm²であることが分かる。
【００３６】
【発明の効果】
本発明によれば、ピストンの先端に装着されているゴム摺動体が摺接するシリンダの少なくとも円筒内周面にシリコンオイル由来の潤滑薄層が一体的に形成されているので、ゴム摺動体を移動させたとしても潤滑薄層の剥離がほとんどなく、注射液への混入がない。
また、シリコンオイルの塗布領域を凸部の円柱外周面に限定すれば、シリコンオイルの塗布面積を最小限にする事が出来るだけでなく、従来のようなシリコンオイルの溜まりが発生せず、安全性を高める事ができる。
また、本発明方法によれば、凸部の表面へのシリコンオイルの塗布だけで潤滑薄層の形成が可能になり、細菌付着やエンドトキシンなどの非常に少ない安全なシリンダを自動化によって大量生産する事が可能になる。
また、型開後、雄金型に付着しているシリンダの表面に印刷するようにすれば、（ｉ）印刷インクの速乾による印刷工程の短縮と、（ｉｉ）細菌の付着・増殖を抑制する事が同時に行えるという利点がある。
【図面の簡単な説明】
【図１】本発明にかかる射出成形機の概略断面図
【図２】丸で囲んだ部分を更に拡大した図を有する図面で、本発明において、型開状態で凸部にシリコンオイルを塗布した状態の要部拡大正断面図
【図３】型締状態の要部拡大断面図
【図４】型締状態で混練溶融樹脂が金型キャビティに射出されている途中段階の要部拡大断面図
【図５】丸で囲んだ部分を更に拡大した図を有する図面で、型締状態で混練溶融樹脂が金型キャビティに充填された状態の要部拡大断面図
【図６】片開き状態の要部拡大断面図
【図７】片開き後、シリンダの外面に印刷を施している状態の要部拡大断面図
【図８】印刷完了シリンダを離型している状態の要部拡大断面図
【図９】他の本発明方法で、凸部に既製シリンダを装着しようとしている場合の要部断面図
【図１０】凸部に既製シリンダを装着した場合の要部断面図
【図１１】本発明にかかるシリンダの円筒内周面の部分拡大断面斜視図
【図１２】（ａ）…本発明方法で形成された潤滑薄層が内周面全面に形成されているシリンダの断面図
（ｂ）…本発明方法で形成された潤滑薄層が円筒内周面だけに形成されているシリンダの断面図
【図１３】丸で囲んだ部分を更に拡大した図を有する図面で、従来例の注射器のシリンダの断面図
【符号の説明】
（Ａ）…射出成形機
（１）…シリンダ
（１ａ）…円筒内周面 （１ｂ）…底面 （１ｃ）…ピストン （１ｄ）…ゴム摺動体
（２）…シリコンオイル
（２ａ）…シリコンオイル由来の潤滑薄層
（２ｂ）…サブミクロン厚の島状部分[0001]
[Industrial application fields]
The present invention relates to a cylinder of a syringe in which a thin lubricating layer derived from silicon oil is integrally formed on a cylinder inner peripheral surface of the cylinder, and a method for manufacturing the same.
[0002]
[Prior art]
Recently, disposable medical devices have become extremely popular in the medical field due to health and safety issues and manpower issues. Disposable syringes have become the best, especially after the AIDS and infectious disease issues have become social issues. Yes. Conventionally, syringe cylinders were made of glass, but when it became urgent to adopt disposable syringes for drug injection, the use of plastic cylinders, especially polypropylene cylinders and polycarbonate cylinders, was considered. I came. Even in the case of a glass cylinder, when using a rubber sliding body, of course, in the case of resin, the rubber sliding body attached to the tip of the piston by applying silicone oil to the cylinder inner peripheral surface is smooth. Must slide to.
[0003]
However, since it has begun to be pointed out in the United States that silicone oil may cause damage when entering the human body, according to Ministry of Health and Welfare Notification No. 442, the application amount is 8 mg / min for a disposable syringe of 5 ml capacity or less. Below this, even large-sized syringes are strictly determined to be 15 mg / tube or less, and those that show a coating amount higher than this are discarded as defective products. However, since the silicon oil is applied manually by the operator by impregnating the cotton swab or sponge with silicon oil (2) one by one, not only uneven coating is likely to occur, but also the cylinder ( The silicone oil (2) applied to the bottom surface (1b) of 1) accumulates, and the accumulated silicone oil (2) and the thick and fluid part produced by the coating unevenness are mixed with the injection solution for injection. There was also a problem of being.
[0004]
Furthermore, the most important thing in the manufacture of medical devices is that the final product is required to have not only bacteria, but also endotoxins resulting from infectious diseases, such as endotoxins resulting from the bodies of Gram-negative bacteria. ing.
Therefore, the molded cylinder (1) is frequently sterilized and washed with ultrapure water for each step, and requires a great deal of effort to minimize the adhesion of bacteria.
However, the conventional method uses sterile silicone oil and a cylinder (1) that is almost completely disinfected, paying attention to the clothes and other items of the worker in a clean room that is almost free of bacteria, and how to apply it. Even if it pays, adhesion of bacteria is inevitable as long as the application work is manual. Once attached, the bacteria grow at the place of attachment. This growth increases the number of bacteria (especially on the surface where silicone oil is applied), so even if sterilized after application, the number of bacteria that die by this sterilization increases, and the probability of endotoxin adherence generated from the large number of dead bodies also increases. Naturally it will increase.
In addition, there is a possibility that the number of bacteria that have increased due to growth can be avoided even if sterilization is performed later.
In addition, since the work is performed manually, there is a problem that not only the product is uneven, but the work efficiency is remarkably bad.
[0005]
[Problems to be solved by the invention]
The present invention has a lubricating thin layer derived from silicon oil that is extremely thin and formed integrally on the inner peripheral surface of a cylinder. The mixing of silicon oil into a chemical solution is extremely less than in the conventional example. In the development of an innovative syringe cylinder that has never been achieved, secondly, the cylinder having the lubricating thin layer or the lubricating thin layer is efficiently maintained while suppressing the growth of bacteria or maintaining sterility. The development of a method for manufacturing a cylinder or a lubrication thin layer of a syringe that can be manufactured by
[0006]
[Means for Solving the Problems]
“Claim 1” states that “polydimethylsiloxane (2) is applied to the surface of the convex part (3a) of the male mold (3) for forming the cylinder, and then the mold is clamped, and then the polypropylene resin (13), polycarbonate resin ( 13) or aromatic polyolefin resin (13) is injected into the mold cavity (4), and is generated on the inner peripheral surface of the cylinder (1) formed of the resin (13) by heating and pressing during injection molding. and a method of manufacturing a syringe cylinder according to claim integrally formed "that the polydimethylsiloxane derived lubricating thin layer of (2a).
[0007]
According to the cylinder manufactured by the manufacturing method of the present invention , the silicon oil (2) is simply applied as in the prior art and is not integrated with the cylindrical inner peripheral surface (1a) of the cylinder (1), and the piston ( When the rubber sliding body (1d) attached to the tip of 1c) is moved, a part of the rubber sliding body (1d) adheres to it, and the part that is thickly coated and maintains fluidity is scraped off and mixed into the injection solution. Unlike such, the cylindrical inner peripheral surface of the lubricating thin layer from polydimethylsiloxanes to form the Jun slipping layer (2a) is a cylinder (1) (1a), of course, its bottom surface (1b) and needle attachment projections ( 1e) is formed integrally with the entire inner peripheral surface including the inner peripheral surface (1f) . Therefore , even if the rubber sliding body (1d) attached to the tip of the piston is moved in the cylinder (1), the bottom surface (1b) as well as the thin lubricating layer (2a) of the cylindrical inner peripheral surface (1a) In addition, the lubricating thin layer (2a) on the inner peripheral surface (1f) of the injection needle mounting projection (1e) hardly peels off and hardly mixes with the injection solution, which is extremely hygienic.
[0008]
In this case, the material of the cylinder (1) is polypropylene resin, polycarbonate resin or aromatic polyolefin resin. Further, silicone oil (2), one which will be described later in the current Pharmaceutical Affairs Law, only polydimethylsiloxane that has been approved.
The lubricating thin layer (2a) is formed by using both heating and pressing. The heating and pressurizing method is performed by injection molding as described later.
[0011]
Further, the surface of the convex portion (3a) of the male mold (3) for forming a cylinder “in this case, not only the outer circumferential surface but also the outer circumferential surface of the tip surface (3c) and the pin portion (3b) are included. The cylinder (1) in which the thin lubricating layer (2a) derived from polydimethylsiloxane is firmly and integrally formed on the entire inner peripheral surface is obtained simply by adding a process of applying polydimethylsiloxane (2) to I can do things. Further, since this thin lubricating layer (2a) is formed by pressurization and heating (for example, the molten resin temperature during filling is 200 to 350 ° C. and the filling pressure is 300 to 2000 kgf / cm ² ), the conventional coating method is used. It can be made much thinner and the amount of polydimethylsiloxane (2) applied can be minimized. A mechanism for producing such an effect will be described later.
[0012]
Furthermore, since it is to injection mold after applying polydimethylsiloxane (2), even when the coating of polydimethyl siloxane (2) at elevated temperature and pressure immediately after coating of polydimethylsiloxane even bacteria were adhered (2) Because of injection molding, the attached bacteria will die soon before they grow, increasing the safety compared to the conventional example, and the cylinder (1) for injection molding with the polydimethylsiloxane (2) attached The inner diameter of the cylinder includes a lubricating thin layer (2a). Unlike the case where the polydimethylsiloxane (2) is applied after molding , the dimensional accuracy of the inner diameter of the cylinder (1) becomes very high.
[0015]
“Claim 2” is another example of the manufacturing method of the cylinder (1) of the syringe. “ Polydimethylsiloxane (2) is applied to the surface of the projection (3a) of the male mold (3) for forming the cylinder”. Then, after clamping, a polypropylene resin (13) , a polycarbonate resin (13) or an aromatic polyolefin resin (13) is injected into the mold cavity (4) , and the cylinder (1) formed of the resin (13 ) A thin lubricating layer (2a) derived from polydimethylsiloxane generated by heating and pressurizing during injection molding is integrally formed on the inner peripheral surface of the mold and attached to the male mold (3) after the mold is opened . It prints on the surface of the cylinder (1) ".
[0016]
According to this, in addition to the above case, printing is performed on the surface of the high temperature cylinder (1) adhering to the male mold (3) , so that (i) the printing ink dries quickly and the printing process is shortened. (Ii) Even if there is bacteria attached to the outer surface of the cylinder (1) during printing, it will be instantly killed by heat, so even in this process, the growth of bacteria should be suppressed or kept sterile. Can be very hygienic.
[0020]
【Example】
The present invention will be described below with reference to the illustrated embodiments. FIG. 1 shows a general injection molding machine (A) for producing a cylinder (1) of the present invention, in which a nozzle (7) of an injection tube part (6) is connected to a female mold (5). A screw (8) is disposed in the injection cylinder (6) so as to be rotatable and slidable back and forth. An injection cylinder (9) and a drive unit (10) are connected to the screw (8), and the screw (8) is slid back and forth in the injection cylinder (9), via a gear mechanism (11). The screw (8) is rotated by the drive unit (10). A hopper (12) is installed at the rear end of the injection tube portion (6) so as to continuously supply the raw resin (13). A heater (14) is wound around the injection cylinder portion (6) so as to heat and melt the raw material resin (13) being passed.
[0021]
The main components of the mold (K) in the illustrated embodiment are the male mold (3), the female mold (5), and the protruding cylinder (15), and the inner surface shape of the cylinder (1) from the male mold (3) A protrusion (3a) is formed to form a recess, and a corresponding recess (5a) is formed in the female die (5) to form the outer surface of the cylinder (1). .
[0022]
(R) is a robot apparatus, which is attached to the injection molding machine (A) .For example, the oil application device (16), the printing device (17), and the take-out device (20) can be moved to predetermined positions. . Although a human hand may be used instead of the robot apparatus (R), it is preferable to use the robot apparatus (R) as the take-out apparatus (20) at a minimum.
The entire apparatus is generally installed in a clean room where the number of bacteria is strictly controlled.
[0023]
The resin raw material (13) used for the cylinder (1) must satisfy various conditions stipulated by the Pharmaceutical Affairs Law such as water permeability, transparency, and heat resistance depending on its use. A group polyolefin is used.
[0024]
Next, the operation of the present invention will be described. First, the robot device (R) is operated, and silicon oil (2) is applied to the outer peripheral surface of the convex portion (3a) of the male die (3) of the die (K) that is opened by the oil application device (16). ) Is applied in an appropriate amount. The application region may be the entire outer surface of the convex portion (3a) including the outer peripheral surface of the cylinder (3d), the tip surface (3c) and the pin portion (3b), or the pin portion (3b) or the tip surface (3c). Although it may be an excluded portion, at least the outer peripheral surface of the cylinder (3d) is applied.
[0025]
The method of applying the silicone oil (2) is not particularly limited, and in this embodiment, a cylindrical shape impregnated with the silicone oil (2) using a robotic device (R) such as the oil application device (16). The convex part (3a) is surrounded and pressed with a cloth, paper, sponge (16a) or the like, and silicon oil (2) is applied to the outer peripheral surface including at least the cylindrical outer peripheral surface (3d) of the convex part (3a). When the application of silicon oil (2) is finished, the mold is closed, and a mold cavity (4) is formed in the mold (K).
[0026]
On the other hand, the raw material resin (13) is put into the hopper (12), and the drive unit (10) is operated to rotate the screw (8). As the screw (8) rotates, the raw material resin (13) is heated to, for example, 200 to 350 ° C. by the heater (14), melted and kneaded, and stored in the tip portion of the injection cylinder (6). At the same time, the screw (8) is gradually retracted, and when the measurement of the melt-kneaded resin stored at the tip of the injection cylinder (6) is completed, the injection cylinder (9) is operated to project the screw (8) forward. The metering resin at the tip of the injection cylinder (6) is injected into the mold (K) at 300 to 2000 kgf / cm ² .
[0027]
The injected melt-kneaded resin (13) passes through the runner (18) and gate (19) of the mold (K) and is pressed into the mold cavity (4) at high speed and high pressure. The melt-kneaded resin (13) press-fitted into the mold cavity (4) is momentarily pressed strongly against the silicone oil (2) applied to the outer surface of the convex part (3a) of the male mold (3). Fill the mold cavity (4). At this time, the temperature of the silicone oil (2) is instantaneously raised to the temperature of the melt-kneaded resin (13), and at the same time, the silicone oil (2) is uniformly extended to the surface of the convex portion (3a) and sticks to the inner peripheral surface of the melt-kneaded resin (13). Thereafter, the melt-kneaded resin (13) is solidified to form a cylinder (1), and a thin lubricating oil layer (2a) derived from silicon oil is integrally formed at least on the inner peripheral surface (1a) of the cylinder.
The forming range of the lubricating thin layer (2a) corresponds to the application region of the silicon oil (2).
[0028]
In this process, the mold (K) and the melt-kneaded resin (13) are generally kept above the sterilization temperature, so that bacteria adhere to the convex part (3a) and the cylinder (1) during this injection molding. In the unlikely event that it adheres at the time of application, it will die instantly due to high temperature, so it will be killed due to the high temperature, so that bacteria will not adhere and multiply throughout the manufacturing process of the cylinder (1). The generation of endotoxin and the like can be minimized or decomposed, and the safety can be dramatically improved as compared with the conventional production method.
[0029]
Here, the presumed mechanism of the formation process of the lubricating oil thin layer (2a) derived from silicon oil will be described. No matter how precisely polishing or other processing is performed on the cavity surface forming the mold cavity (4), the present technology has extremely fine irregularities on the submicron range (for example, 0.5 to 0.02 μm). . Now, when silicon oil (2) is applied to the convex part (3a), the high-viscosity silicone oil (2) enters the recess on the submicron level remaining on the surface of the convex part (3a) due to its surface tension. Don't go. (See Figure 2 (b))
Therefore, when injection molding is performed at a high temperature and a high pressure as described above, the pressure of the high temperature injection resin causes the silicone oil (2) to be pressed and spread on the surface of the convex portion (3a), and at the same time, a part of it is pushed into the concave portion. A thin lubricating layer (2a) having a convexity (3a) is uniformly formed on the entire outer peripheral surface including at least the cylindrical outer peripheral surface (3d), and this includes an inner surface including at least the cylindrical inner peripheral surface (1a) of the cylinder (1). It adheres integrally to the peripheral surface. (See Fig. 5 (b))
As a result, as shown in FIG. 12, a thick portion (2b) of submicron level (for example, 0.5 to 0.02 μm) is uniformly formed in an island shape on the inner peripheral surface of the lubricating thin layer (2a). This submicron thick island (2b) helps the majority of the smooth sliding of the rubber slide (1d). As a result, the amount of silicone oil (2) applied is much smaller than that of the conventional example.
[0030]
This thin lubricating oil layer (2a) derived from silicone oil is not simply applied so that part or all of it can be easily wiped off with a cloth or the like. A thin layer is formed in a strong and integrated manner on the cylindrical inner peripheral surface (1a) of the cylinder (1).
[0031]
When the molding of the cylinder (1) with the lubricating thin layer (2a) is completed in this way, the mold is opened to expose the cylinder (1) attached to the male mold (3) to the outside, and then the robot apparatus. Operate (R) to move the printing device (17) directly above the cylinder (1), lower the printing pad (17a) of the printing device (17), and apply it on the printing pad (17a). The printed pattern is transferred and printed on the surface of the cylinder (1).
Even at this time, the surface of the cylinder (1) is kept at a sufficiently high sterilization temperature, so that the growth of bacteria can be prevented, and the printed ink can be dried quickly and can be taken out in a short time. When printing is finished, the printing pad (17a) is pulled up and separated from the cylinder (1), and then the protruding device (15a) is operated to protrude the protruding cylinder (15) and fit into the convex part (3a). Remove the existing cylinder (1). Thereafter, the robot device (R) is operated to move the take-out device (20) directly above the runner portion (21) of the injection-molded product, and then the take-out device (20) is lowered to move the runner portion (21 ) And remove it from the mold (K).
The mass production under the aseptic condition of the syringe cylinder (1) is carried out by repeating the above operation.
[0032]
9 and 10 show a case where the lubricating thin layer (2a) is formed using the molded cylinder (1). First, at least a mold (30) for forming a thin lubricating layer (2a) that is substantially the same shape as the inner peripheral shape of a cylinder (1) for a syringe is prepared. Since it is the cylindrical inner peripheral surface (1a) of the cylinder (1) that requires a thin lubricating layer (2a), the forming die (30) only matches the cylindrical inner peripheral surface (1a) of the cylinder (1). It is enough if it has the shape to do. In the illustrated embodiment, an example having up to the pin portion (30b) is described.
[0033]
First, silicon oil (2) is applied to the surface of the convex portion (30a) "at least the outer circumferential surface of the cylinder (30d)", and then the convex portion (30a) is inserted into the syringe cylinder (1) and heated. Alternatively, pressurization or heating / heating is performed, and the resulting thin lubricating oil layer (2a) derived from silicon oil is integrally formed on the inner peripheral surface of the cylinder (1).
As a pressurizing method, a female die (not shown) may be fitted to the outside of the cylinder (1) for pressurization, and the method is not limited.
As a heating method, a heater (not shown) may be mounted inside the convex portion (30a), or the convex portion (30a) may be heated by heat transfer from a mold (30), for example.
[0034]
In this case as well, at least the cylindrical inner peripheral surface (1a) of the formed cylinder (1), and possibly the entire inner peripheral surface including the bottom surface (1b) and the inner peripheral surface (1f) of the injection needle mounting projection (1e). A thin lubricating oil layer (2a) derived from silicone oil can be formed integrally.
[0035]
Example 1
Next, the application amount of silicon oil (polydimethylsiloxane), and the experimental results on the slidability and appearance are shown. Cylinder oil was applied to the convex portion, and injection molding was performed as described above using polycarbonate as the raw material resin. If a thin lubricating layer is formed on the cylinder inner peripheral surface of the cylinder, the slipperiness of the butyl rubber sliding body attached to the tip of the syringe piston is remarkably improved, but if the amount of application to the convex part is too large, the cylinder will become cloudy. Appearance is poor and, on the contrary, if the coating amount is too small, the appearance is good but the slipperiness is impaired. Therefore, the relationship between the amount of silicon oil applied, slidability, and appearance was examined as follows.

(Example 2)
Next, experimental results on the viscosity, slidability, and appearance of silicon oil (polydimethylsiloxane) are shown.

From the above, as a region where both slidability and appearance are cleared, when the silicone oil is polydimethylsiloxane, the viscosity is 500 to 30,000 centistokes and the coating amount is 0.001 to 0.05 g / 100 cm. It turns out that it is ² .
[0036]
【The invention's effect】
According to the present invention, since the lubricating thin layer derived from silicon oil is integrally formed on at least the cylinder inner peripheral surface of the cylinder in sliding contact with the rubber sliding body attached to the tip of the piston, the rubber sliding body is moved. Even if it is made, there is almost no peeling of a lubrication thin layer, and there is no mixing in an injection solution.
In addition, if the silicone oil application area is limited to the cylindrical outer peripheral surface of the convex part, not only the silicone oil application area can be minimized, but there is no accumulation of silicon oil as in the past, and safety is ensured. You can increase the sex.
In addition, according to the method of the present invention, it is possible to form a thin lubricating layer only by applying silicone oil to the surface of the convex portion, and mass production by automation of very safe cylinders with very few bacteria, endotoxins, etc. Is possible.
In addition, if the printing is performed on the surface of the cylinder attached to the male mold after the mold is opened, (i) the printing process is shortened by quick drying of the printing ink, and (ii) the bacteria adherence and proliferation are suppressed. There is an advantage that it can be done at the same time.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view of an injection molding machine according to the present invention. FIG. 2 is a drawing having a further enlarged view of a circled portion. In the present invention, silicon oil is applied to convex portions in a mold open state. Fig. 3 is an enlarged cross-sectional view of the main part in the mold-clamped state. Fig. 4 is an enlarged cross-sectional view of the main part in the middle of the injection of the kneaded molten resin into the mold cavity. FIG. 5 is a drawing having a further enlarged view of a circled portion, and is an enlarged cross-sectional view of the main part in a state where the mold cavity is filled with the kneaded molten resin in the mold-clamped state. Enlarged cross-sectional view [Fig. 7] Enlarged cross-sectional view of the main part in a state where printing is performed on the outer surface of the cylinder after half-opening. [Fig. ] Cross-sectional view of the main part when an off-the-shelf cylinder is to be mounted on the convex part by another method of the present invention [Fig. FIG. 11 is a partially enlarged cross-sectional perspective view of a cylindrical inner peripheral surface of a cylinder according to the present invention. FIG. 12A is formed by the method of the present invention. FIG. 13B is a cross-sectional view of a cylinder in which a thin lubricating layer is formed on the entire inner peripheral surface. FIG. 13B is a cross-sectional view of a cylinder in which the thin lubricating layer formed by the method of the present invention is formed only on the inner peripheral surface. ] A cross-sectional view of a cylinder of a conventional syringe with an enlarged view of a circled portion .
(A) ... Injection molding machine (1) ... Cylinder (1a) ... Cylindrical inner peripheral surface (1b) ... Bottom face (1c) ... Piston (1d) ... Rubber sliding body (2) ... Silicon oil (2a) ... Derived from silicon oil Lubricant thin layer (2b) ... Submicron thick islands

Claims (2)

Polydimethylsiloxane was applied to the convex surface of the male mold for cylinder formation, and after mold clamping, polypropylene resin, polycarbonate resin or aromatic polyolefin resin was injected into the mold cavity and formed with the resin. the inner peripheral surface of the cylinder, the manufacturing method of the syringe cylinder, characterized in that integrally formed lubricating thin layer from the polydimethylsiloxane produced by heating and pressurizing during injection molding. Polydimethylsiloxane was applied to the convex surface of the male mold for cylinder formation, and after mold clamping, polypropylene resin, polycarbonate resin or aromatic polyolefin resin was injected into the mold cavity and formed with the resin. On the inner peripheral surface of the cylinder, the lubricating thin layer derived from polydimethylsiloxane generated by heating and pressurizing during injection molding is integrally formed. After opening the mold, the cylinder surface is attached to the male mold. A method of manufacturing a cylinder of a syringe characterized by printing.

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