JP2001088217A - Method and fusion jig for producing square container made of fluoroplastic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce a square container consisting of floroplastic resin not carrying over a chemical soln., having excellent washing properties and high strength, suitable for preserving the chemical soln. for high purity and prevented from following thermal expansion or a shrink speed to generate deformation. SOLUTION: A modified polytetrafluoroethylene raw material obtained by copolymerizing a small amt. of a degree not imparting meld flow properties of a monomer with polytetrafluoroethylene is subjected to compression molding and the molded one is heated and baked to obtain a plate-shaped member, and a square fluoroplastic resin container of which one surface is opened is produced from several plate-shaped members. In this square container manufacturing method, one of the plate-shaped members is used as a bottom plate 16 and side plates 12, 13, 14, 15 being the plate-shaped members are erected on the upper surface of the bottom plate to be assembled into a container shape of which one surface is opened and the peripheries of the erected side plates 12, 13, 14, 15 are tightened by a grasping means A capable of permitting deformation to form a container main body 11 which is, in turn, fused and integrated in an oven.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ozone water producing apparatus used for storing various kinds of high-purity chemicals used in processes for treating semiconductor wafers, liquid crystal substrates, etc., and for sterilization and cleaning for medical use. The present invention relates to a method for manufacturing a fluororesin rectangular container suitable for being inserted into the inner wall of the rectangular container for storing a chemical solution, and a fusion jig for manufacturing a fluororesin rectangular container.

[0002]

2. Description of the Related Art Fluororesins are widely used as materials for high-purity chemical liquid storage containers used in semiconductor manufacturing processes, medical treatments, etc. because of their excellent chemical resistance, heat resistance and purity. The fluororesin cannot be melt-molded, and the raw material powder is compacted to form a preform, and this preform is
PTFE (polytetrafluoroethylene) molded by heating and baking above the melting point, PFA (polytetrafluoroethylene / perfluoroalkylvinyl ether copolymer) that can be melt-molded, FEP (tetrafluoroethylene / hexafluoropropylene copolymer) ETFE (ethylene / tetrafluoroethylene copolymer), PVDE
(Polyvinylidene fluoride).

[0003] In such a fluororesin, in terms of productivity, a molten resin (PF) which can be extruded and injection-molded.
A, FEP, etc.) are advantageous, but in terms of the above characteristics, P
Since it does not reach TFE, there is still a high demand for a container made of PTFE. However, since PTFE cannot be injection-molded or the like as described above, it is technically difficult to integrally mold such a container. Therefore, for example, many of the PTFE square containers first compress the raw material powder into a plate to form a pre-formed body, and then fire the plurality of plate-shaped pre-formed bodies. It is formed by PFA welding the butted end faces of the assembled plate-shaped members while assembling them in the shape.

FIG. 5 shows an example of a conventional rectangular container manufactured as described above. In this rectangular container 1, a container body 2 provided with a drug solution storage part 2a is formed in a rectangular shape, and a lid (not shown) is attached to an open end 2b thereof. And
As shown in FIGS. 5 and 6, the container body 2 is composed of side plates 3, 4, 5, and 6, and a bottom plate 7, and the A portion is welded.

The rectangular container 1 to which the container body 2 is welded by PFA has the following problems. That is, in the rectangular container 1 usually made of PTFE, since the side plates 3, 4, 5, 6 and the bottom plate 7 are welded at the portion A as described above, dust easily accumulates at the bead portion at the welding location. Therefore, there are problems in terms of retention of particles, maintenance of cleanliness, and cleanability.

[0006] Further, if there is a poor welding, a high-purity chemical solution is impregnated through the gap, or the chemical solution remains even after repeated washing with pure water. Is carried over, and this chemical solution is mixed with a new chemical solution. On the other hand, it is conceivable to use modified PTFE for the purpose of developing a container having no welded portion. That is, it is known that a molded article made of modified PTFE is easily self-fused.
Therefore, plate-shaped members 3, 4, using modified PTFE as a raw material.
5, 5 and 7 are prepared, and as shown in FIG.
If it is assembled inside and heated in the state of pressing in the direction of the arrow, it is possible to heat-bond all the joint surfaces at the same time, but in that case, thermal expansion occurs due to heating, and there is no escape area for the expansion Therefore, the bending 9 occurred in the side plate as shown in FIG. 9, and good results could not be expected.

In view of such circumstances, the present invention has excellent cleaning properties without carrying over a chemical solution, has high strength, is suitable for storage of a high-purity chemical solution, and further follows the rate of thermal expansion and contraction. To provide a method of manufacturing a rectangular container made of fluororesin which does not partially deform and a fusion jig for manufacturing a rectangular container made of fluororesin suitable for manufacturing such a rectangular container. The purpose is.

[0008]

According to the present invention for achieving the above object, modified polytetrafluoroethylene is used as a raw material. Modified polytetrafluoroethylene is a polytetrafluoroethylene that is modified by copolymerizing a small amount of another monomer that does not provide melt fluidity, and is capable of self-fusion. . The present invention is a method for producing a fluororesin container, which comprises compression-molding this raw material, heating and firing to form a plate-like member, and producing a rectangular container having one side open from the obtained plate-like member. One of the plate-like members is used as a bottom plate, and a side plate is erected on the upper surface of the bottom plate to assemble into a container shape having one open side. Then, the container body is clamped by a clamping means capable of permitting deformation, and the container body is fused and integrated in the furnace by the clamping means.

According to such a method, it is possible to reduce as much as possible the places where particles easily accumulate. In addition, the dimensional accuracy could be improved. Furthermore, even if it is thermally deformed, there is a relief area in the deformation, so that partial bending or the like does not occur, the strength is sufficiently strong, and a rectangular container having no welded portion can be manufactured. Further, the present invention is characterized in that a regulating means for regulating an inward deformation generated at the time of heat fusion is provided inside the raised side plate.

According to such a configuration, it is possible to prevent deformation in the inward direction during heat fusion. Further, the holding means includes an L-shaped member which is inserted into a corner of the container body,
A bracket provided on the L-shaped member at a predetermined interval, a rod-shaped member extending between the brackets of the two L-shaped members, and spring members mounted on both ends of the rod-shaped member are provided. Features.

According to such a configuration, the plate-like members can be butted against each other without any gap, and the welding can be performed in a state where the necessary pressure is applied to the joint. Therefore, according to the method of the present invention, it has become possible to provide a rectangular container suitable for storing a chemical solution used for manufacturing a liquid crystal semiconductor or medical treatment. Further, the fusion jig for producing a fluororesin rectangular container according to the present invention is attached to each corner of a rectangular container assembled from a fluororesin plate-shaped molded body, and these fluororesin plate members are joined together. What is claimed is: 1. A fusion jig for manufacturing a rectangular container made of a fluororesin, which is used at the time of heat fusion, comprising: an L-shaped member vertically extended over a corner portion of a shape container main body; And a rod-shaped member having a spring member attached to both ends thereof, and a bar-shaped member inserted between a pair of brackets facing each other. The action of the spring member allows the plate member of the fluororesin to be formed. At the time of assembly, keep the assembly state,
And the load required for fusion is applied to the fusion portion of the fluororesin plate-like body, and during heat fusion and subsequent cooling,
It is characterized by having a holding means capable of permitting deformation following the thermal expansion or contraction of the fluororesin plate-like formed body caused by heating and cooling.

Thus, when expanded in the fusion-sintering furnace, the expanded portion can be released, so that there is no partial deformation. Here, it is preferable that a regulating body which is substantially the same as the inner size of the container and which can be inserted into the inner wall of the rectangular container is provided inside the rectangular container, and that the regulating body regulates inward expansion. Thereby, inward deformation accompanying expansion in the furnace can also be prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a rectangular container 10 according to one embodiment of the present invention. This square container 1
Reference numeral 0 denotes a container body 11 provided with a medicinal solution storage section 11a, and a lid (not shown) attached to the opening 11b of the container body 11.

The container body 11 is made of modified PTFE having excellent heat resistance, chemical resistance and cleanliness. Modified PTFE is made of tetrafluoroethylene (TF
It can be produced by copolymerizing and modifying a small amount (for example, about 0.5 mol% or less) of another co-homopolymer that does not give melt flowability to the homopolymer of E). it can. Examples of such a copolymer include hexafluoropropylene, perfluoro (alkyl vinyl ether), perfluoro (alkoxyalkyl vinyl ether), trifluoroethylene, and perfluoroalkylethylene.

In order to form the above-mentioned container body 11 using such modified PTFE, first, the raw material powder of the modified PTFE is uniformly pressed and compressed into a plate-shaped preform, which is heated at a temperature not lower than the melting point. And baking, the plate-like member 1
In addition to forming 2, 13, 14, and 15, a plate-like member 16 slightly larger than this is formed. In addition, the plate-like member 16 which is slightly larger than the plate-like members 12, 13 as side plates is used.
It is a bottom plate that holds 14 and 15. Then, as shown in FIG. 1, a container body 1 assembled in a box shape with one side opened.
The holding means A for positioning and fixing is set around 1.

As shown in FIGS. 2 to 4, the holding means A has an L-shaped member 20 which is vertically arranged at a corner of the container body 11, and is provided at a predetermined distance from the L-shaped member 20. Brackets 17 and 18 and L-shaped member 2 adjacent to each other
A bar-shaped member 36 extending between 0 and 20;
6 is constituted by a combination with spring members 21 and 21 attached to both ends.

That is, as shown in FIG. 3, the L-shaped member 20 has a pair of brackets 17, 18 in a direction orthogonal to each other with a predetermined space therebetween. A hole 19 is formed. In addition, in FIG. 2, when four corner portions are respectively B1, B2, B3, and B4 in FIG.
And B3 have the same shape, and the brackets B2 and B4 have the same shape.

The rod-shaped member 36 is inserted into the hole 19 between the brackets 17 or the brackets 18 at these symmetric positions. Then, as shown in FIG. 4, the bar-shaped member 36 has these brackets 17 or 18 as one spring receiver, and the other spring receiver 23 is disposed outside thereof, and the spring member 21 is fitted therebetween. are doing. In the container body 10 whose periphery is tightened at a plurality of places by such a holding means A, the butted portions between the members are closely engaged,
The butted portion does not shift.

On the other hand, a rectangular tubular restricting body 30 as shown in FIG. 7 can be set in such a holding means A. The restricting body 30 constitutes a restricting means for restricting inward deformation when the plate-shaped formed body of fluororesin is fired in a furnace. The restricting body 30 is made of metal and has a bar-shaped member 31 to be held and lifted by hand at an upper part, and is set to have a size to substantially abut the inside of the container body 10, and the height thereof is higher than the height of the container body 10. It is formed high. By setting such a regulating body 30, it is possible to prevent inward deformation.

The welding jig suitable for carrying out the method according to the present invention comprises the holding means A and the regulating body 30, but this regulating body 30 is not always necessary. Then, the container body 11 whose periphery is tightened by the holding means A and the regulating body 30 is stored in the furnace as it is and fused. At the time of fusion, in the furnace, the sintering temperature is raised at a constant speed to, for example, 355 ° C., and sintering is performed at that temperature until the sintering is completed uniformly over the entire temperature. Now cool to room temperature and complete the cooling.

The box unit fired in the furnace is taken out of the furnace, and the holding means A and the regulating body 30 are removed. At this time, even if the modified PTFE tries to expand during heating or shrink during cooling in the furnace, the holding means A
Can freely follow the change, and there is no possibility of partial bending. Further, since the regulating body 30 exists inside, it is possible to prevent inward deformation. This ensures the dimensional accuracy of the inside, which is important for the container.

An embodiment in which a 300 mm square tank is prepared using the above jig will be described below. The thickness of the square tank was 12 mm. Further, as shown in FIG. 2, three holding means A are arranged between the upper and lower sides with a predetermined space therebetween. The tightening pressure was set to 300 g / mm based on the fact that the square tank was 300 mm. By applying such a pressure, the pressure required for self-fusion of the modified PTFE can be applied to the fusion surface. After tightening under these conditions, it is housed in a heating furnace and stored at 360 ° C for 3 hours.
After fusion for a time, a desired container body 11 could be obtained.

Further, the obtained container body 11 was excellent in dimensional accuracy and could be formed into a desired shape. Further, the container body 1 made of the modified PTFE manufactured as described above is used.
In No. 1, since there is no welded portion, the surface smoothness of the inner surface is excellent, and even when the chemical liquid comes into contact, the surface is smooth, so that the chemical liquid component, dust, etc. do not remain on the surface, It has excellent cleanliness, reduces the number of washings,
It has become possible to reduce costs. The modified P
TFE has excellent chemical resistance such as gas and chemical liquid permeation resistance,
Moreover, since impurities are hardly eluted, it is extremely suitable as a storage container for chemical liquids in liquid crystal, semiconductor, medical fields and the like. Further, according to such a container manufacturing method, it is possible to manufacture a large number of containers in a short time, and it is possible to contribute to a reduction in use of material costs.

As described above, the method for manufacturing the rectangular container made of fluororesin and the fusion jig for manufacturing the rectangular container made of fluororesin according to one embodiment of the present invention have been described. However, the present invention is not limited to the above embodiment. For example, the rectangular container is not limited to a quadrangle. In such a case, adjusting the opening angle of the L-shaped member or the like can cope with this. Further, the number of holding means is not limited to three, but can be increased or decreased according to the size of the container.

Further, the regulating body 30 is not always necessary. Such containers can also be used in a wide range.

[0026]

As described above, according to the method of the present invention, since the welded portion does not exist in the rectangular container made of modified PTFE, the mechanical strength can be increased. Further, since there is no welded portion, the chemical solution does not seep into the gap. Furthermore, dimensional accuracy could be maintained because there was no bending or the like. In addition, since there is no welded portion, it is possible to reduce the number of locations where a chemical solution or the like is permeated as much as possible, thereby eliminating carryover of the chemical solution and improving the cleaning property.

Further, according to the fusion jig of the present invention, the above-described method can be performed with a simple structure, and a rectangular container with little dimensional change and no bending can be manufactured. Was.

[Brief description of the drawings]

FIG. 1 is a perspective view of a container body of a rectangular container according to an embodiment of the present invention.

FIG. 2 is a perspective view of a holding means according to the present invention.

FIG. 3 is a perspective view of an L-shaped member constituting the holding unit shown in FIG. 2;

FIG. 4 is an enlarged perspective view showing a part of the container body tightened by the holding means shown in FIG. 2;

FIG. 5 is a side sectional view of a conventional container body.

FIG. 6 is a plan view of FIG. 5;

FIG. 7 is a perspective view of a regulating body used in one embodiment of the present invention.

FIG. 8 is a side sectional view of another conventional method for manufacturing a rectangular container.

FIG. 9 is a plan view showing a defect at the time of manufacturing in FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Rectangular container 11 Container main body 12, 13, 14, 15 Plate-shaped member 16 Bottom plate 17, 18 Bracket 21 Spring member 36 Bar-shaped member A Holding means

Continued on the front page (72) Inventor Toshikazu Tsuruta 1043 Asakawahara, Oji Omachi, Nagano City, Nagano Pref.

Claims (5)

[Claims] 1. A modified polytetrafluoroethylene raw material obtained by copolymerizing and modifying a small amount of another monomer that does not give melt flowability to polytetrafluoroethylene, compression-molding, heating and firing. A method of manufacturing a fluororesin container for forming a rectangular container having one side open from the obtained plate-like member while forming a plate-like member by using the obtained plate-like member, wherein one of the plate-like members is a bottom plate, The side plate is set up on the upper surface of the container and assembled into a container shape with one side open.Following the expansion and contraction that occurs when the raised side plate is heat-sealed, the side plate is clamped by clamping means capable of allowing deformation. A method for producing a rectangular container made of fluororesin, wherein the container body is fused in a furnace by means and integrated. 2. The fluororesin square container according to claim 1, wherein a restricting means for restricting an inward deformation generated at the time of heat fusion is disposed inside the raised side plate. Manufacturing method. 3. The holding means includes an L-shaped member vertically extended to a corner of the container body, a bracket provided at a predetermined distance from the L-shaped member, and a bracket for the two L-shaped members. The method for producing a fluororesin rectangular container according to claim 2, further comprising: a rod-shaped member that is inserted between the brackets; and spring members that are attached to both ends of the rod-shaped member. 4. Manufacturing of a fluororesin rectangular container which is attached to each corner of a rectangular container assembled from a fluororesin plate-like molded member and is used when these fluororesin plate members are heat-sealed to each other. An L-shaped member vertically extending over a corner of the rectangular container body, a bracket provided at a predetermined distance from the L-shaped member, and a spring member at both ends. And a rod-shaped member mounted between a pair of opposed brackets. By the action of the spring member, at the time of assembling the fluororesin plate-shaped member, the assembled state is maintained, and A load required for adhesion is applied to the fused portion of the fluororesin plate-like body, and at the time of heat fusion and subsequent cooling, heat expansion and cooling of the fluororesin plate-like formed body caused by heating and cooling. Shrinkage Fusion jig fluororesin rectangular container manufacturing, characterized in that it comprises a clamping means that can tolerate variations follow to. 5. The method according to claim 5, further comprising a restricting body which is substantially the same as the inner dimension of the container and which can be inserted into the inner wall of the rectangular container, wherein the restricting body restricts inward expansion. The fusion jig for producing a fluororesin rectangular container according to claim 4.