JPH04267744A - Fluororesin-lined chemical container and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a chemical container high in chemical resistance by providing a fluororesin lining layer constituted of a first resin layer mixed with fine particles and a second resin layer formed thereon for suppressing the deposition of the fine particles. CONSTITUTION:A chemical container which comprises a stainless steel made container body 1; a cylindrical neck part 10 made of tetrafluoroethylene resin mounted at a neck part 2 of the container body 1 integrally therewith; a contacting face 13 formed on the top surface of the cylindrical neck part 10; a flange 5 of a pour-out cylinder 20 disposed in contact with the contacting face; an O-ring mounting surface 11 provided on the side wall 12 of the cylindrical neck part 10 in a stepped form for mounting thereon an O-ring 30 consisting of an elastic material; a lining layer 3 consisting of a two-layer structure formed on the inner surface of the container body 1; a first resin layer 3a, the first resin layer being mixed with fine particles 6 upon formation, thereby suppressing the formation of air bubbles; and a second resin layer 3b formed thereon, the second resin layer being capable of suppressing the deposition of the fine particles, whereby a chemical container high in chemical resistance can be obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical-resistant metal container and a method for manufacturing the same.

0002

[Prior Art] In order to impart chemical resistance to this type of metal container, a synthetic resin inner bag is inserted into the container body, the inner surface of the container body is lined with resin by electrostatic coating, or Measures such as attaching a sheet of synthetic resin to the inner surface of the container body using plastic welding have been used.

[0003] However, when an inner bag is used, there is a high possibility that the inner bag does not come into close contact with the inner surface of the main body of the container, and the chemicals will penetrate into the metal container side.

[0004] Furthermore, the electrostatic coating had a layer thickness of 0.5 mm or less, and its corrosion resistance was insufficient. In addition, seat lining can introduce impurities into the welded area,
There was a problem in that the chemical resistance of this part deteriorated.

[0005] In view of the above-mentioned problems, the present inventors have
No. 338,899 proposes a technique in which a heat-melting fluororesin is injected into a metal container body while rotating the container body in a heated state to form a lining.

[0006]

[Problems to be Solved by the Invention] By the way, during the rotational lining, the heat-melting fluororesin may foam, and bubble spaces may be scattered in the resin layer produced. If such air bubble spaces exist in the resin layer, the corrosion resistance of this portion will decrease, causing deterioration of container performance.

[0007] Therefore, it is considered that inorganic powder or metal powder such as glass, silicon, zinc, aluminum (Al), copper (Cu), etc. is mixed into the fluororesin to suppress the generation of bubbles.

However, in such containers for chemicals, when the resin layer is formed by mixing the fine powder into the resin, the mixed fine powder precipitates near the surface of the layer, which may affect the characteristics of the stored medicine. The present inventors have newly discovered that there is a possibility that the corrosion resistance may be deteriorated due to chemical changes in the fine powder itself caused by chemicals.

[0009] An object of the present invention is to provide a technique for obtaining a chemical container with high chemical resistance by preventing the generation of air bubbles in the resin layer and suppressing the precipitation of fine powder material on the surface of the resin layer. be.

0010

[Means for Solving the Problems] The present invention provides a chemical container in which a lining layer is formed on the inner surface of the container by spin-coating a heat-melting fluororesin inside the container body, the lining layer being at least The gist of the present invention is a fluororesin-lined chemical container comprising a first resin layer mixed with fine powder and a second resin layer formed on the first resin layer to suppress precipitation of the fine powder material.

[0011]

[Operation] According to the above-mentioned means, by mixing fine powder into the resin when forming the first resin layer, the free movement of the fine powder in the molten resin causes air bubbles in the resin to be removed from the outside. This prevents air bubbles from remaining in the resin.

[0012] Furthermore, by forming a second resin layer on top of the first resin layer mixed with the fine powder, precipitation of the fine powder material can be suppressed.

[0013]

[Example] The chemical container of the present invention has a container body 1 made of stainless steel and having an internal volume of 100 liters, and the opening 2 of the container body 1 is made of polytetrafluoroethylene resin (PTFE). The formed mouth cylinder 10 is the container body 1.
It is fitted into one piece. The spout cylinder 10 has a contact surface 13 formed on its upper surface, and has a structure in which a collar 5 of a spout cylinder 20, which will be described later, comes into contact with this contact surface 13. An O-ring mounting surface 11 is formed in a step-like manner on the inner peripheral surface of the mouth cylinder 10 (mouth cylinder side wall 12), and this O-ring mounting surface 11 is made of an elastic material such as synthetic rubber. An O-ring 30 made of is placed thereon.

A lining layer 3 having a two-layer structure is formed on the inner surface of the container body 1.

Next, a method for manufacturing and assembling the drug container will be explained step by step. First, the container body 1 is placed on a pair of support rollers (not shown) and rotated around the axis of the container body 1 while being heated to about 370° C. to 410° C.

During this rotation, a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene (PFA), which is a heat-melting fluororesin, is injected from the open port 2. This PFA contains glass, silicon, zinc, aluminum (Al), copper (Cu).
Fine powder 6 made of inorganic powder such as or metal powder is mixed.

In the resin lining, bubbles are generated in the molten PFA, and the bubbles adhere to the fine powder 6 that is freely moving in the PFA and are emitted to the outside. Therefore, no air bubbles remain in PFA.

[0018] The amount of the fine powder 6 mixed in the PFA can range from about 0.1% to 30%, and more preferably about 5% is most effective for removing air bubbles. It is.

Next, by cooling the container body 1 and hardening the PFA, a layer with a thickness of 2 mm is formed on the inner surface of the container body 1.
A first resin layer 3a is obtained.

Next, while rotating the container body 1, it is again
After heating to about 70° C. to 410° C., PFA is injected into the container body 1 in the same manner as described above. This second PFA injection does not contain the fine powder 6 used in the first PFA injection. Furthermore, a smaller amount of PFA may be injected than the first PFA.

[0021] In such second resin lining, a layer thickness of 0.5 mm to 0.5 mm is applied to the surface of the first resin layer 3a.
A second resin layer 3b of 1.0 mm is obtained.

Since the second resin layer 3b has a smaller layer thickness than the first resin layer 3a, the generation of bubbles itself is extremely small. Therefore, when forming the second resin layer 3b, it is not necessary to mix the fine powder 6 into the PFA.

Furthermore, the reason why the layer thickness is set to 0.5 mm to 1.0 mm is because the layer thickness within this range is necessary and sufficient to suppress the precipitation of the fine powder material from the first resin layer 3a. be.

The container body 1, on which the lining layer 3 consisting of the first and second resin layers 3a and 3b is formed on the inner surface as described above, is further coated with a thickness of 0.2 mm on the outer surface thereof.
A resin coating 4 made of polyethylene resin is formed.

The resin coating 4 is formed by inserting a support (not shown) into the container body 1 and applying the polyethylene resin while rotating the support.

[0026]The coating thickness needs to be at least 0.1 mm or more, and as the material, polypropylene (PP), polyvinyl chloride (PVC), etc. can be used in addition to the polyethylene (PE).

Next, the pouring tube 20 is fitted into the mouth tube 10 of the container body 1. The outer peripheral surface of the pouring tube 20 has a stepped O-ring pressing surface 21 at a position corresponding to the O-ring mounting surface 11 of the mouth tube 10.
By press-fitting, the O-ring 30 is pressed against the mouth cylinder side wall 1 by the urging force from the O-ring mounting surface 11 and the O-ring pressing surface 21.
2 and the spout cylinder side wall 22, and urges both side walls.

In this way, the O-ring 30 is urged into close contact with the four surfaces of the O-ring mounting surface 11, the O-ring pressing surface 21, the spout cylinder side wall 12, and the spout cylinder side wall 22, so that the spout cylinder 1
0 and the dispensing cylinder 20 are sealed, and leakage of the chemical liquid inside is completely prevented.

[0029] Furthermore, when the spouting cylinder 20 is press-fitted into the mouth cylinder 10, the flange 5 of the spouting cylinder 20 comes into contact with the contact surface 13, so that the press-fitting beyond a certain level is inhibited. This can prevent the O-ring 30 from collapsing due to overpressure.

Generally, the O-ring 30 may be crushed by excessive pressure, which may actually deteriorate the sealing performance. Since more press-fitting is prevented,
There are no such concerns.

Finally, the cap 35 is screwed onto the spout cylinder 10 to prevent the spout cylinder 20 from falling off.

As described above, according to this embodiment, the lining layer 3 has a laminated structure, and by mixing the fine powder 6 into the resin when forming the first resin layer 3a, Generation of bubbles is suppressed. Further, by forming the second resin layer 3b on top of the first resin layer 3a, precipitation of the fine powder material is suppressed.

Furthermore, when press-fitting the dispensing tube 20 into the spout 2, the O-ring 30 is biased in all directions and is prevented from being press-fitted more than necessary. It is possible to prevent sealing defects caused by crushing of the O-ring due to pressure, and to provide a chemical container with high sealing reliability.

[0034]

According to the present invention, the lining layer 3 has a laminated structure of a first resin layer mixed with fine powder 6 and a second resin layer that suppresses precipitation of the fine powder material.
A chemical container with high chemical resistance can be provided.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the schematic structure of a drug container that is an embodiment of the present invention.

FIG. 2 is a sectional view showing the vicinity of the opening of the drug container in the example.

FIG. 3 is a partial cross-sectional view showing a part of the medicine container in the example.

[Explanation of symbols]

1. Container body 2. Mouth 3. Lining layer 3a...Resin layer 3b...resin layer 4. Resin coating 5. Tsuba 6. Fine powder 10... Mouth tube 11... O-ring mounting surface 12... Mouth cylinder side wall 13... Contact surface 20... pouring tube 21... O-ring pressing surface 22... Pour tube side wall 30...O-ring 35...cap

Claims (4)

[Claims] 1. A chemical container comprising a lining layer formed on the inner surface of the container by spin-coating a heat-melting fluororesin inside a metal container body, the lining layer comprising at least a first resin mixed with fine powder. A fluororesin-lined chemical container comprising a second resin layer and a second resin layer formed on the first resin layer to suppress precipitation of the fine powder. [Claim 2] A first material made of the heat-melting fluororesin.
The fluororesin-lined chemical container according to claim 1, wherein the second lining layer is made of a copolymer of tetrafluoroethylene and perfluoroalkoxyethylene. 3. A container body made of metal, a mouth tube made of synthetic resin provided at the mouth of the container body, and a spout that is fitted into the mouth tube and communicates the space inside the container body with the outside. It consists of a tube and a cap screwed onto the mouth tube to prevent the dispensing tube from falling off, and the inner surface of the container body has a first tube mixed with fine powder to prevent foaming during lining.
A lining layer consisting of a resin layer and a second resin layer formed on the first resin layer to suppress precipitation of the fine powder is formed, and the mouth tube has a stepped shape formed on its inner wall. The dispensing tube is provided with an O-ring pressing surface corresponding to the O-ring placing surface on the outer periphery of the pouring tube, and the O-ring pressing surface is connected to the O-ring pressing surface. The O-ring installed between the spouts is elastically deformed in the horizontal direction of the spout by being press-fitted into the mouth cylinder of the spouting cylinder, and airtightly closes the contact area between the spout cylinder and the spout cylinder. The fluororesin-lined chemical container according to claim 1 or 2, characterized in that: 4. Forming a first lining layer on the inner surface of the container body by injecting a first heat-melting fluororesin mixed with fine powder into a container body made of metal and rotating the container body under heating. After that, a second heat-melting fluororesin is injected into the container body and the container body is rotated under heating to form a second lining layer on the inner surface of the container body above the first lining layer. A method for manufacturing a fluororesin-lined chemical container, characterized by: