JP2007022547A - Fluororesin box-shaped hollow container, and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a large-sized fluororesin box-shaped hollow container which has superior chemical resistance, strength, heat resistance, and stain resistance. <P>SOLUTION: The fluororesin box-shaped hollow container 20 includes a bottom board 18 made of a polytetrafluoroethylene resin, and at least three side boards 19 made of a polytetrafluoroethylene resin, which side boards 19 are integral to the bottom board 18 and are folded to be connected together. Adjacent side boards 19 are welded to each other via a fluororesin. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a fluororesin container and a method for producing the same, and in particular, a fluororesin container that is excellent in chemical resistance, strength, and non-contamination, and can be used for semiconductor manufacturing, liquid crystal display manufacturing, pharmaceutical manufacturing, and the like. Regarding the method.

  Conventionally, in the fields of semiconductor manufacturing, liquid crystal display (LCD) manufacturing, pharmaceutical manufacturing, etc., various corrosive chemicals are frequently used in the manufacturing process, and storage containers, processing containers, cleaning containers, etc. are used for handling these chemicals. It is used. In addition, in these manufacturing processes, a high level of chemical resistance and non-contamination are required because they dislike foreign substances due to the characteristics of the product. Accordingly, the container used in the process is required to have chemical resistance and non-contamination, and in addition, since high temperature chemicals are used, strength, heat resistance and the like are also required to prevent liquid leakage.

  By the way, as materials excellent in chemical resistance and heat resistance, for example, PTFE (tetrafluoroethylene resin), PFA (tetrafluoroethylene-perfluorovinyl ether copolymer resin), PFEP, ETFE, PCTFE, PVDF, ECTFE, There is a PVF fluororesin, and among these fluororesins, PTFE has the highest heat resistance and chemical resistance. Therefore, in these fields, conventionally, as the storage container, the processing container, and the cleaning container, the entire container is composed of a fluororesin such as PTFE, PFA, etc. excellent in chemical resistance, heat resistance, etc., and has an internal volume of 20-100. A relatively small container of about 1 liter is used. Among these fluororesin containers, for example, PTFE containers are manufactured by a method of welding sheet materials, or by an integral molding method such as isotactic molding, and PFA containers are manufactured by integral molding by injection molding. ing.

  However, in recent years, semiconductor products, LCDs, etc. have been increased in size and mass production of processed materials has progressed. With this, large-scale semiconductors, LCDs, etc. can be processed, and a large amount of semiconductors can be processed at once. There is a need for large containers that can be processed. Therefore, it is conceivable to increase the size of the fluororesin container as one means for meeting such a demand. However, the fluororesin is superior in chemical resistance and high heat resistance to a general-purpose resin such as polyvinyl chloride (PVC), but is inferior in strength. In addition, if the thickness of the fluororesin container is increased in order to increase the strength, the specific gravity is the highest among the synthetic resins, so that the container becomes heavier, inferior in handleability, and extremely expensive. In particular, if an attempt is made to manufacture a container having the entire container made of PTFE by the above-mentioned welding method, when the container is enlarged, the surface area to be welded is large, and the possibility of liquid leakage from the weld surface is high.

  Moreover, if it is going to manufacture a container made from a large and high intensity | strength PTFE, the load concerning a welding area will become large because the thickness of the sheet | seat material etc. to be used becomes thick. Further, when the container is used, that is, in a state where the container is filled with a chemical solution, a larger load is applied to the welded portion, and the probability of causing deformation during use is increased.

  PTFE resin has a relatively large coefficient of thermal expansion among the resins, and expands and contracts as the temperature changes. Therefore, PTFE containers, particularly when used in fields where temperature is applied, such as semiconductor manufacturing processes, are prone to breakage at the welds when subjected to repeated temperature changes and repeated expansion and contraction. However, the thick PTFE container has a problem that it tends to break at such a weld. Therefore, it is difficult to manufacture a large fluororesin container having the same quality as that of the conventional product, in particular, the same strength, by the welding method similar to the conventional one.

In order to solve the above problems, a method has been proposed in which the outer side of the fluororesin container is made of a thermoplastic resin such as polyvinyl chloride (PVC) (Patent Document 1).
FIG. 5 shows a perspective view of a conventional PTFE box-type hollow container. The hollow container 1 is composed of one bottom plate 2 and four side plates 3. The hollow container 1 is manufactured as follows. That is, first, a total of five sheet-like materials to be the bottom plate 2 and the side plate 3 are cut out, and then a groove portion screw mounting hole (not shown) for welding is processed into each sheet-like material. Next, the bottom plate 2, the side plate 3, and the side plates 3 are temporarily fixed with PTFE resin screws 4 to form a hollow box shape. However, FIG. 5 shows a state where the bottom plate 2 is turned up for convenience. Subsequently, the bottom plate 2, the side plate 3, and the side plates 3 are welded together using a PFA resin welding rod to produce the PTFE box-type hollow container 1. However, the number 5 of FIG. 5 shows a welding part.
JP 10-278141 A

  The present invention seeks to solve the problems associated with the prior art as described above, and is excellent in chemical resistance, strength, heat resistance, non-contamination, and particularly weak in strength when enlarged. An object of the present invention is to provide a fluororesin box-type hollow container that can be used for semiconductor devices, liquid crystal display manufacturing, pharmaceutical manufacturing, and the like, and a method for manufacturing the same.

  (1) A fluororesin box-type hollow container according to the present invention includes a bottom plate made of tetrafluoroethylene resin, and at least three side plates made of ethylene tetrafluoride resin that are integrally bent and connected to the bottom plate. And adjacent side plates are welded together with a fluororesin.

  (2) The fluororesin box-type hollow container manufacturing method according to the present invention includes a box-shaped hollow container cut out in a developed view, and at least three bottom plate formation planned portions and the bottom plate formation planned portion are integrally connected. Forming a sheet-like member having a side plate formation scheduled portion, forming a bending groove at a boundary between the bottom plate formation scheduled portion and the side plate formation scheduled portion, and bending the sheet-like member starting from the groove. And a step of welding adjacent side plate formation scheduled portions to form a box-shaped hollow container composed of a bottom plate and a side plate.

  According to the present invention, a fluororesin box-type hollow container excellent in chemical resistance, strength, heat resistance, and non-contamination can be obtained. Further, according to the present invention, a large box-shaped hollow container made of a fluororesin can be obtained by increasing strength and reliability, and can be used for manufacturing semiconductor devices, liquid crystal displays, pharmaceuticals, and the like.

Hereinafter, the present invention will be described in more detail.
In the present invention, the side plate is bent at approximately 90 degrees with respect to the bottom plate starting from the bending groove. Here, the number of side plates is usually four, and in this case, the side plates are preferably screwed together from the viewpoint of reinforcement. However, the number of side plates is not limited to four, and may be three or five or more. In this case, the bottom plate also needs to be triangular or pentagonal depending on the number of side plates.

  In the present invention, the shape and depth of the bending groove are not particularly limited, and examples thereof include a V-shaped cut, an arc-shaped cut, and a simple linear cut, which can be employed depending on the application. The bending direction starting from the groove may be folded inward or folded outward. However, from the viewpoint of non-contamination, it is preferable to bend the groove outward because there is no cut inside the container. In this case, after bending from the groove, the PFA resin welding rod or the like is used along the bent portion. It is preferable to reinforce. Further, in order to facilitate folding and prevent whitening of the bent portion, the surface of the bent portion has a surface of the bent portion of about 300 at a starting portion of the bend using a hot-air welding gun before the bending process. It is preferable to heat so that it may become about degreeC.

  In the present invention, the sheet-like member is prepared by, for example, producing a preformed product by compressing a molded powder of PTFE resin in a mold at a pressure of usually about 20 MPa at room temperature, and the preformed product is usually at a melting point or higher. It can be obtained by compression molding similar to powder metallurgy peculiar to PTFE resin that is fired in a furnace at 360 ° C. or higher. The PTFE resin used at this time is not limited, but PTFE resin molding powder composed of 100% PTFE resin produced by so-called suspension polymerization, or other fluororesin containing 1% by mass or less thereof. Any of the PTFE resin molding powder modified with the above can be used.

  In the present invention, welding between adjacent side plate formation scheduled portions can be performed with a PFA resin rod using, for example, a hot-air welding gun for plastic welding. Moreover, it is preferable to weld also the boundary part (groove part) of a baseplate formation plan part and a side plate formation plan part from a viewpoint of intensity | strength.

Specific examples will be described below.
Example 1
A fluororesin box-type hollow container according to Example 1 will be described with reference to FIGS.
First, a preformed product was manufactured by compressing a PTFE resin molding powder in a mold at a room temperature at a pressure of about 20 MPa. Here, as the PTFE resin, PTFE resin molding powder composed of 100% PTFE resin produced by suspension polymerization was used. Next, a PTFE resin sheet 11 was produced by compression molding similar to powder metallurgy unique to PTFE resin, in which the preformed product was fired in a furnace having a melting point or higher, usually 360 ° C. or higher. Subsequently, a bending groove 14 is formed at the boundary between the bottom plate formation planned portion 12 and the side plate formation planned portion 13 of the PTFE resin sheet 11 and the side plate formation planned portion adjacent to the corner portion X of the bottom plate formation planned portion 12. 13 were cut. Further, through holes 15 for screw insertion were formed along two opposing sides of the side plate formation scheduled portion 13, and an opening hole 16 for screw installation was formed (shown in FIG. 1A).

  Next, the side plate formation scheduled portion 13 is bent 90 degrees in the direction of the arrow with respect to the bottom plate formation planned portion 12 so that the groove 14 is on the outer side along the folding groove 14 (FIG. 1B). (Illustrated). Subsequently, the side plate formation scheduled portions 13 were fixed with screws 17. Further, the side plate formation scheduled portions 13 were welded with a PFA resin rod using a hot-air welding gun for plastic welding. As a result, a box-shaped hollow container 20 including a bottom plate 18 having a thickness of 20 mm and four side plates 19 having a thickness of 20 mm integrated with the bottom plate 18 was manufactured (shown in FIG. 1C). In addition, the number 21 in FIG.1 (C) shows the welding part made from PFA resin.

  As described above, the fluororesin box-type hollow container 20 according to Example 1 includes the bottom plate 18 made of ethylene tetrafluoride resin and the four pieces integrally connected to the bottom plate 18 and bent at four positions. A side plate 19 made of ethylene tetrafluoride resin is provided, and adjacent side plates 19 are reinforced with a welded portion 20 made of PFA resin and screws 17. According to the hollow container having such a configuration, since the bottom plate 18 and the side plate 19 are made of PTFE, it has excellent chemical resistance, heat resistance, and non-contamination property. Since it is small (half), it is possible to overcome the weakness of strength, especially when the size is increased, and the cost can be reduced because there are few welding processes. Therefore, it is possible to contribute to the progress of the recent increase in size of semiconductor products, LCDs, etc. and the mass production of objects to be processed.

  In the hollow container of FIG. 1, the boundary portion (folding groove portion) between the bottom plate 18 and the side plate 19 can be welded with a PFA resin rod. Thereby, the intensity | strength of a hollow container can be improved further. Further, although not shown in FIG. 1, a liquid outlet for taking out liquid or the like stored in the hollow container is formed at or near the bottom of the hollow container.

(Example 2)
A fluororesin box-type hollow container according to Example 2 will be described with reference to FIG. However, the same members as those in FIG. The second embodiment is characterized in that the four side plate formation scheduled portions 19 are bent so that the bending grooves are inside.
According to the hollow container 22 of FIG. 2, the welded portion 20 is located on the inner side, so that there is an advantage that it is excellent in terms of appearance.

(Example 3)
A fluororesin box-shaped hollow container according to Example 3 will be described with reference to FIGS. 4A is a plan view of the hollow container, FIG. 4B is a front view of FIG. 4A, and FIG. 4C is a cross-sectional view taken along line XX of FIG. Indicates. However, the same members as those in FIG.

  The hollow container 23 of FIG. 4 includes a container main body 24 including a bottom plate 18 and a side plate 19, and an overflow portion 25 provided on the upper peripheral edge of the container main body 24. The overflow portion 25 is provided on the upper portion of the container body 24 by welding or the like so that the upper surface thereof is higher than the upper surface of the container body 24. A plurality of V-shaped grooves 26 cut at an angle (α) of 90 ° are formed on the upper edge of the side plate 19. When the liquid overflows from the container main body 24, it flows from the V-shaped groove 26 to the overflow portion 25. The overflow portion 25 is provided with a liquid outlet 27 for flowing the overflowed liquid. A liquid outlet 28 is also provided at the bottom of the container body 24.

  According to the hollow container of FIG. 3, since the overflow part 25 is provided, the liquid overflowed from the container body 24 can be processed without being scattered around, and contamination of peripheral devices can be avoided.

Example 4
A fluororesin box-shaped hollow container according to Example 4 will be described with reference to FIG. FIG. 3 is a development view of a sheet-like member for producing the hollow container of Example 4. The hollow container 27 of Example 4 includes a hexagonal bottom plate formation scheduled portion 29 and six side plate formation planned portions 30, and after the side plate formation planned portion 30 is bent at a boundary portion with the bottom plate formation planned portion 29, It is comprised by welding the baseplate formation scheduled parts.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Specifically, the shape of the container is not limited to the quadrangular shape as shown in FIGS. 1 and 2 or the hexagonal shape as shown in FIG. 3, but may be a multi-angle shape such as a triangular shape. Furthermore, you may combine suitably the component covering different embodiment.

Explanatory drawing which shows the manufacturing method of the fluororesin box-shaped hollow container which concerns on Example 1 of this invention in order of a process. The perspective view of the fluororesin box-shaped hollow container which concerns on Example 2 of this invention. Explanatory drawing of the fluororesin box-shaped hollow container which concerns on Example 4 of this invention. The expanded view of the fluororesin box-type hollow container which concerns on Example 3 of this invention. The perspective view of the conventional PTFE box-shaped hollow container.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... PTFE resin sheet, 12, 29 ... Bottom plate formation scheduled part, 13, 30 ... Side plate formation scheduled part, 14 ... Bending groove, 15 ... Through hole, 16 ... Opening hole, 17 ... Screw, 18 ... Bottom plate, 19 ... Side plate, 21 ... welded part, 20, 22, 23 ... box-shaped hollow container, 24 ... container body, 25 ... overflow part, 26 ... V-shaped groove, 27, 28 ... liquid outlet.

Claims (4)

A bottom plate made of ethylene tetrafluoride resin, and at least three side plates made of ethylene tetrafluoride resin that are integrally bent and connected to the bottom plate, and the adjacent side plates are welded together by fluororesin A fluororesin box-type hollow container. The fluororesin box-type hollow container according to claim 1, wherein there are four side plates, and the side plates are screwed together. A step of forming a sheet-shaped member having a bottom plate formation scheduled portion and at least three side plate formation planned portions integrally connected to the bottom plate formation planned portion by cutting out the box-shaped hollow container into a developed view; Forming a folding groove at the boundary between the portion and the side plate formation scheduled portion, bending the sheet-like member from the groove to form a box shape, and welding adjacent side plate formation scheduled portions to each other. And a step of forming a box-shaped hollow container comprising a bottom plate and a side plate. 4. The fluororesin box according to claim 3, further comprising a step of screwing the side plate formation scheduled portions together before welding after bending the side plate formation scheduled portions and having four side plate formation scheduled portions. A method for producing a hollow mold container.

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