WO2001094101A1 - Article moule de polytetrafluoroethylene et son procede de production - Google Patents

Article moule de polytetrafluoroethylene et son procede de production Download PDF

Info

Publication number
WO2001094101A1
WO2001094101A1 PCT/JP2001/004159 JP0104159W WO0194101A1 WO 2001094101 A1 WO2001094101 A1 WO 2001094101A1 JP 0104159 W JP0104159 W JP 0104159W WO 0194101 A1 WO0194101 A1 WO 0194101A1
Authority
WO
WIPO (PCT)
Prior art keywords
molded body
fired
porous
mandrel
compression
Prior art date
Application number
PCT/JP2001/004159
Other languages
English (en)
Japanese (ja)
Inventor
Osamu Shirasaki
Takashi Inaoka
Shuji Tagashira
Yasuhiko Sawada
Original Assignee
Daikin Industries, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daikin Industries, Ltd. filed Critical Daikin Industries, Ltd.
Publication of WO2001094101A1 publication Critical patent/WO2001094101A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00—Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/006—Pressing and sintering powders, granules or fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
    • B29C59/08—Surface shaping of articles, e.g. embossing; Apparatus therefor by flame treatment ; using hot gases
    • B29C59/085—Surface shaping of articles, e.g. embossing; Apparatus therefor by flame treatment ; using hot gases of profiled articles, e.g. hollow or tubular articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C59/00—Surface shaping of articles, e.g. embossing; Apparatus therefor
    • B29C59/08—Surface shaping of articles, e.g. embossing; Apparatus therefor by flame treatment ; using hot gases
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2027/00—Use of polyvinylhalogenides or derivatives thereof as moulding material
    • B29K2027/12—Use of polyvinylhalogenides or derivatives thereof as moulding material containing fluorine
    • B29K2027/18—PTFE, i.e. polytetrafluorethene, e.g. ePTFE, i.e. expanded polytetrafluorethene
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/04—Condition, form or state of moulded material or of the material to be shaped cellular or porous
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/25—Solid
    • B29K2105/251—Particles, powder or granules
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
    • B29L2023/00—Tubular articles

Definitions

  • the present invention relates to a method for producing a large, thick calcined polytetrafluoroethylene (PTFE) molded body, particularly having a length of 400 mm or more.
  • PTFE polytetrafluoroethylene
  • a porous sintered body or a solid body of PTFE with low distortion can be produced, and a large-sized porous sheet obtained by cutting and cutting can be produced. It is useful as a material for permeable membranes and shock absorbing sheets.
  • Sintered PTFE molded products are used in various products by utilizing their excellent heat resistance, chemical resistance, electrical insulation, high-frequency properties, non-adhesion, and low friction. .
  • PTFE Since PTFE has the property that it cannot be melted, it is preformed by compression molding or paste extrusion and then fired to obtain a fired molded body. ing .
  • paste extrusion method sheet-shaped or small-diameter rod-shaped or tube-shaped objects cannot be formed, and large-sized compacts can be obtained exclusively by compression molding. Manufactured from preformed molded products.
  • Preforming and firing by the conventional compression preforming method are performed as follows.
  • PTFE powder is uniformly filled in the annular space of a mold having an annular space, and then pressed from above to obtain a compression-molded body.
  • a cylindrical pre-compression molded body is obtained.
  • a calcined PTFE molded body is manufactured.
  • the obtained cylindrical fired PTFE molded body is processed into a sheet by a scribing machine. Cutting is performed by inserting the core rod of a cutting machine into the center hole of the cylindrical fired molded body, and cutting it to a desired thickness from the outside with a byte. Yes.
  • a large-sized molded body is to be manufactured and processed by this method, it is necessary to first heat it for a long time in order to achieve uniform firing. Then, the PTFE preform formed during the heating and sintering is thermally deformed by its own weight, and the lower part expands. Since this deformation hinders the cutting process, it must be cut off until the surface becomes straight, which is wasteful. In addition, since the center hole of the fired compact also deforms, it is necessary to adjust the hole diameter before applying to the cutting machine.
  • the pre-compacted body is placed horizontally and rotated.
  • a method has been proposed in which firing is carried out in a short time so that the firing is uniform and the deformation is reduced.
  • the concrete method is as follows: (1) Put a pre-compression molded body inside a large metal pipe, and make a pipe so that the cylindrical pre-formed body rolls inside the pipe. (2) passing the shaft through the center hole of the pre-compressed molded body, and firing while rotating the shaft. The method is described.
  • the method (1) required a heating furnace large enough to accommodate a large metal pipe, and the preform rolled inside the pipe.
  • the surface of the molded body after firing may be altered.
  • the method of penetrating the shaft of (2) is specifically described in Example 1 of the W098Z41386 pan fret, and the center hole of the preliminary compression-molded article is described. (25 cm in diameter) through a shaft with an outer diameter of 23 cm and sintering while rotating the shaft to obtain a fired molded body with a core hole diameter of 25 cm.
  • the outer diameter of the shaft during firing is smaller than the diameter of the core hole of the molded product, and the shaft is always rotated in a state of line contact with the inner surface of the core hole. Therefore, it is smaller than the center hole diameter of the molded body after firing.
  • the center pore diameter of the PTFE molded body before and after firing does not change, but generally, If the compression ratio during preforming is increased, the PTFE preform may shrink due to firing. This phenomenon is conspicuous when the porous compact is fired.
  • the inventors of the present invention have noticed this shrinkage phenomenon and, by taking the shrinkage phenomenon into account, actively utilize the shrinkage phenomenon, thereby obtaining a sintered PTFE compact with little deformation even if it is large. This led to the completion of the present invention.
  • An object of the present invention is to provide a large-sized calcined PTFE compact having little deformation during sintering.
  • the present invention also provides a large-sized porous fired PTFE molded body that could not be produced conventionally, and a wide porous PTFE sheet obtained by cutting the same. aimed to . Disclosure of invention
  • the present invention provides a cylindrical pre-pressurizing method by compressing PTFE powder.
  • a pre-compression molded body is produced, and a mandrel is passed through a center hole of the obtained pre-compression molded body, and the pre-compression molded body is supported by supporting the mandrel.
  • the method of manufacturing a cylindrical fired polytetrafluoroethylene molded body that is suspended horizontally and fired the same as the core diameter cD after firing of the pre-compression molded body is used.
  • the present invention relates to a manufacturing method characterized by using a mandrel having a large outer diameter Dm.
  • the outer diameter of the mandrel to be used must be the same as or larger than the core hole diameter of the pre-compressed compact after firing as described above. Further, from the viewpoint of the core hole diameter of the pre-compression molded body before firing, although it differs depending on the solid or porous body, the center hole diameter of the pre-compression molded body before firing is 90 to 110%. %, Especially 95 to 105%.
  • the pre-compression molded body may be hung horizontally while being suspended by a mandrel, and may be calcined. Alternatively, the horizontally hung mandrel may be rotated.
  • the pre-compression molded body may be fired. According to the present invention, it is possible to produce a fired molded body with little deformation without rotating the molded body.
  • a PTFE powder a powder obtained by a suspension polymerization method, which has been fired and then ground.
  • a powder obtained by a suspension polymerization method it is preferable to use a powder obtained by a suspension polymerization method as a raw material PTFE powder and pulverized. Sile .
  • the length Lp of the pre-compression molded body is 400 mm or more, or the ratio LpZ Dp of the length Lp of the pre-compression molded body to the outer diameter Dp is 1 or more.
  • Large PTFE moldings can be manufactured. Further, according to the production method of the present invention, it is a porous cylindrical member having a length L of 400 mm or more, and a cylindrical wall thickness H of 50 mm or more. On the other hand, it is possible to produce a large-sized new calcined PTFE porous compact having a ratio L / H of length to wall thickness H of 1 or more.
  • the present invention also relates to a fired PTFE porous molded article obtained by cutting and cutting the new fired porous PTFE molded article, particularly to a width of 400 mm or more and further to a thickness force of 0 mm. Also for porous PTFE porous sheet of 1mm or more.
  • the present invention further relates to the gas permeable membrane or the buffer sheet, which is the above-mentioned fired PTFE porous sheet.
  • FIG. 1 is a schematic side view showing a suspended state of a pre-compression-molded article produced by the production method of the present invention.
  • the greatest feature of the present invention is that a pre-compressed PTFE compact shrinks during sintering, and a mandrel with a specific outer diameter is placed in the center hole of the pre-compressed compact. As a result, at least after firing, the core hole of the fired molded body and the mandrel are brought into close contact with each other.
  • the pre-compression molded body shrinks during firing and embraces the mandrel. As a result, deformation of the molded body due to heating can be suppressed.
  • the outer diameter of the mandrel to be used is the same as the diameter of the core hole after shrinkage generated by firing the pre-compression molded body. Or something big is needed.
  • the outer diameter of the mandrel is determined experimentally by measuring the shrinkage rate of the pre-compression molded body to be fired by firing in advance.
  • the shrinkage rate of the core hole due to the firing of the pre-compression molded body depends on whether the target molded body is solid or porous, whether the pre-compression molded body Reference, compression ratio, pressure, compression speed, compression time, properties of PTFE powder used (particle size, particle size distribution, molecular weight of PTFE, whether PTFE has been modified, Or fired powder, unfired powder, granulated or not), and the cooling rate during firing, etc., 0 to: 15%, usually 0.1 to 10%. Therefore, it is usually sufficient to use a mandrel having an outer diameter of 90% or more, preferably 95% or more of the center hole diameter of the pre-compression molded body before firing.
  • the upper limit of the outer diameter of the mandrel is determined by whether it can be inserted into the pre-compression molded body. Since the pre-compression molded body expands thermally by heating, it is preferably heated to about 50 to 250 ° C, or expanded mechanically if necessary.
  • a mandrel having an outer diameter of up to 110%, preferably up to 105% of the core hole diameter at the time of preforming of the pre-compression molded body can be used.
  • the reason for introducing a larger mandrel up to the extension may be found in the aforementioned W098Z16696 panfret. This is to accommodate the case of a pre-compression molded body that hardly shrinks during sintering. If a mandrel with an excessively large outer diameter is forcibly inserted, the residual stress in the portion near the mandrel of the molded body increases due to firing, and the density becomes non-uniform. Cracks may occur.
  • the material of the mandrel is a material that can withstand the firing temperature. There is no particular limitation, but usually stainless steel, nickel-plated iron, chrome-plated iron, etc. are preferred. Can be used. If necessary, the mandrel may be a cutting core used in the subsequent cutting process. In this case, the cutting operation can be performed without pulling out the mandrel after firing.
  • PTFE tetrafluoroethylene
  • PTFE includes modified PTFE.
  • a perfluorovinyl ether such as that described in the W ⁇ 98 Z 41386 pamphlet is preferred.
  • the polymerization method may be either a suspension polymerization method or an emulsion polymerization method, but a so-called molding powder obtained by pulverizing particles obtained by suspension polymerization is used. I like it.
  • the particle size of the PTFE powder is a number average particle size of 5 to 600 m, preferably 10 to 150 ⁇ .
  • the PTFE powder used in the present invention may be an unfired product or a fired product (including a semi-fired product). However, when producing a porous compact, it is preferable to use calcined PTFE powder, and when producing a solid compact, it is preferable to use unfired PTFE powder.
  • This PTFE powder is then preformed by compression molding.
  • Compression molding can be carried out under the same molding conditions using the same mold as before. Specifically, when producing a porous molded body, the calcined PTFE powder having a number average particle diameter of 10 to 150 ⁇ m is molded into a mold having an annular space (cavity). It is filled and compressed at a compression pressure of 10 to 100 MPa to a compression ratio of 3 to 6, preferably 4 to 5. When manufacturing solid compacts, number average Unfired PTFE powder having a particle size of 10 to 700 ⁇ m is filled into a mold having an annular space (cavity), and a compression ratio of 2 to 8 at a compression pressure of 10 to 50 MPa is preferable. Compression to 3-6.
  • the mold is not particularly limited as long as it can produce a cylindrical preform having a center hole, but is not limited to the mold according to the production method of the present invention.
  • a large-sized fired molded body can be manufactured.
  • the large (preliminary or fired) compacts of the present invention have a length L of 4 OO mm or more, and the longest depends on the size of the mold and firing furnace. It is about 2000mm.
  • the ratio LpZ between the length Lp and the outer diameter (diameter) Dp is 1 or more, especially those having a length of 2 to 20 and more particularly the length Lp and the wall thickness Hp (outside diameter Dp It can be manufactured with a relatively thin wall thickness ratio of Lp / Hp of 1 or more, especially 4 to 10 (difference in center hole diameter (diameter) cDp).
  • the diameter of the core hole of the pre-compression molded body differs depending on the size (length, outer diameter) of the pre-molded body, etc., but it is usually appropriately selected in the range of 10 to 500 mm.
  • 1 is a pre-compression molded body
  • 2 is a mandrel
  • both ends of the mandrel 2 are supported by a suspension base 3.
  • the pre-compression molded body 1 is separated from the floor 4 of the firing furnace.
  • the production method of the present invention may be fired in the state of horizontal suspension as shown in Fig. 1 or described in the W098 / 41386 Nom fret. In this way, firing may be performed while rotating with a rotating mechanism (not shown in FIG. 1).
  • the sintering is performed at the melting point (pre-sintering) 337 to 347 ° C for baked products, 322 to 332 ° C for baked products), preferably 10 to 60 ° C, preferably 15 to 50 ° C. This can be done by heating for ⁇ 200 hours.
  • the rotation speed depends on the firing temperature, firing time, size of the preform, and the like. It may be appropriately selected according to the conditions, but it is usually 1 to 300 rotations Z time, preferably 10 to 100 rotations Z time. According to the present invention, the rotation can be performed smoothly, at least during firing, because the preform is in a state of embracing (adhering to) the mandrel. In addition, uniform sintering can be achieved, and the amount of deformation can be reduced.
  • the production method of the present invention it is possible to obtain a fired PTFE molded article having a small amount of deformation and uniformly fired.
  • the fired PTFE molded body may be a solid body (specific gravity 2.10 to 2.2) or a porous body (specific gravity 0.8 to 1.8).
  • Solid large molded articles can also be obtained by the methods described in the respective non-flats of the aforementioned WO98Z41386 and WO00 / 16968, but the production method of the present invention According to the method, a material having a smaller deformation amount and being able to be used immediately in a post-process cutting process can be obtained.
  • a large-sized porous fired PTFE molded article was obtained for the first time by the manufacturing method of the present invention. Since the pre-compression molded body for a porous body has low mechanical strength, the amount of deformation is too large in the conventional standing firing method, and it is excessive even in the rotary firing method. When the shaft is in line contact with the shaft, the load concentrates and the deformation becomes large. Therefore, a large-scale porous fired molded product at a practical level cannot be manufactured. I didn't.
  • the length L is 400 mm or more and the wall thickness H is 50 mm or less.
  • a cylindrical porous fired PTFE molded article having a ratio L / H of length L to wall thickness H of 1 or more is a novel material.
  • the obtained cylindrical calcined PTFE molded body is subjected to a scribing U (scube) process in the same manner as in the prior art, and is formed into a sheet shape. Since the sintered compact produced by the conventional manufacturing method has a large amount of deformation during firing, a considerable amount (thickness) is cut out before cutting out a sheet to be a product. In addition, it was necessary to correct the shape of the core hole to a perfect circle according to the core rod of the cutting machine. However, since the solid and porous fired PTFE molded articles obtained by the present invention have a small amount of deformation, the amount to be cut off first can be reduced. Since the center hole is round along the shape of the mandrel where the center hole is round, the cutting machine can be left alone or with a small force [1]. I can do it.
  • a porous fired PTFE sheet obtained by cutting from a large fired PTFE molded body with a length of 400 mm or more has a width of 400 mni or more, and such a wide porous hole is used.
  • High quality fired PTFE sheets have not been obtained in the past.
  • the thickness of the sheet can be adjusted by cutting, and a porous fired PTFE sheet having a thickness of 0.1 mm or more, for example, 0.1 to 1 Omm can be easily obtained. be able to .
  • calcined PTFE sheets can be used for various purposes.
  • heat-resistant insulating tapes such as heat-resistant electric wires, motor vehicles, and generators; corrosion-resistant linings such as chemical plants; piping gaskets. It can be used for molds, mold release films, etc.
  • the porous sheet is a gas permeable membrane utilizing the property of transmitting gas such as a gas-liquid separation membrane, a filter, a gas removal membrane, and a gas generation membrane.
  • a gas-liquid separation membrane such as a gas-liquid separation membrane, a filter, a gas removal membrane, and a gas generation membrane.
  • Packs, cushions, and various seals It can be used for cushioning sheets that use the buffering properties of materials, gaskets, etc .; soundproof covering materials, heat-proofing materials, and polishing pads.
  • Modified PTFE unmodified PTFE (Perfluoro (propylene vinyl ether) manufactured by suspension polymerization method), apparent density 0.42 g / cc, melting point 341 (° C) at 350 to 360 ° C, and then pulverized to an average particle size of 125 m to obtain a calcined PTFE powder.
  • the preformed body Ap 1 has a stainless steel (SUS) pipe with an outer diameter of 48.5 mm (97% of the core hole diameter cDp).
  • SUS stainless steel
  • a pre-formed body Ap2 is passed through a SUS mandrel with an outer diameter of 50.
  • Omm (100% of cDp).
  • 3 was passed through a SUS mandrel with an outer diameter of 50.5 mm (101% of cDp)
  • the preform Ap 4 was passed through an outer diameter of 51.0 mm (102% of cDp). I passed.
  • the preforms Ap3 and AP4 were inserted while heating the preform at 200 ° C. None was inserted into the preformed body Ap5.
  • the preforms Ap:! ⁇ Ap4 with mandrels inserted were suspended horizontally between two suspension stands placed in the firing furnace.
  • the preformed body Ap5 was set up in the firing furnace as it was. In this state, the inside of the baking furnace is heated up to 360 ° C at a heating rate of 50 ° CZ for 50 hours, and fired at 360 ° C for 6 hours, and then cooled at a rate of 50 ° CZ. The temperature was lowered to 80 ° C in the furnace, removed from the furnace, and moved to a constant temperature room at 25 ° C.
  • the size was measured by the following method.
  • Outer diameter Five points are measured at equal intervals in the longitudinal direction of the fired molded body, and the average value is determined.
  • Core hole diameter Measure at two points at both ends and calculate the average value.
  • the outer diameter shrinkage ratio indicates the shrinkage ratio of the outer diameter of the preformed body to the outer diameter Dp of the preformed body.
  • the expansion coefficient in the longitudinal direction represents the expansion coefficient of the length in the longitudinal direction of the fired molded body with respect to the length Lp in the longitudinal direction of the preformed body.
  • the diameter of the pre-compressed compact was smaller than the core hole diameter.
  • the porous fired PTFE molded body (Ap 2 to 4) in which the mandrel was entangled was subjected to cutting to obtain a 0.5 mm thick porous fired PTFE sheet.
  • the sheet is prepared, and its pore size (using POROMETER manufactured by Coulter Electric), hardness (AS KER. C) and tensile strength in the width direction of the cutting sheet and tensile elongation (based on JIS K 6891) ) was measured. The results are also shown in Table 1.
  • each of the porous fired PTFE sheets has sufficient mechanical properties.
  • Unfired PTFE modified PTFE modified with perfluoro (propyl vinyl ether) manufactured by suspension polymerization method
  • This calcined PTFE powder (18,400 g) was filled in a mold having a ring-shaped cavity having an outer diameter of 174 mm and an inner diameter of 50 mm.
  • the packing (apparent) density at this time was 0.45 g Zcc.
  • pre-compression molding was prepared by compressing at a compression molding pressure of 49.6 MPa (500 kgf / cm 2 ) for 60 minutes. The size of the product removed from the mold and left for 1 hour is shown below. Length Lp: 453mm
  • a mandrel (length: 50 mm) of stainless steel (SUS) with an outer diameter of 50 mm (100% of center hole diameter cDp) LOOOmm), and suspended horizontally between two suspension stands placed in the firing furnace. In this state, the temperature was raised to 360 ° C in 13 hours, calcined at 360 ° C for 13 hours, lowered to room temperature in 10 hours, and removed from the furnace. It was removed and moved into a constant temperature room at 25 ° C.
  • SUS stainless steel
  • Example 3 Unsintered PTFE (modified PTFE modified with perfluoro (propylene ether) manufactured by suspension polymerization method) Apparent density 0.42 g / 1075 g of cc, melting point of 341 ° C., average particle diameter of 33 ⁇ m) was filled in a mold having an annular cavity with an outer diameter of 100 mm and an inner diameter of 50 mm. The packing (apparent) density at this time was 0.45 g Zcc. Then, compression was performed at a compression molding pressure of 29.4 MPa (300 kgfXcm 2 ) for 10 minutes to produce a pre-compression molded body. The size of the product removed from the mold and left for 1 hour is shown below.
  • the preformed body Ap 6 has a mandrel (length) of stainless steel (SUS) pipe with an outer diameter of 48.5 mm (97% of the center hole diameter cDp).
  • SUS stainless steel
  • the preform Ap 8 was inserted while heating the preform at 100 ° C. Nothing was inserted into the preform Ap9.
  • the preforms Ap 6 to Ap 8 passed through the mandrel were suspended horizontally between two suspension stands placed in a firing furnace. Reserve The molded body Ap9 was kept standing in the sintering furnace as it was. In this state, the inside of the sintering furnace is heated up to 360 t at a heating rate of 50 Z hours to 360 t, and is held at 360 ° C for 6 hours, followed by sintering, and then a cooling rate of 50 ° CZ time The temperature was lowered to 80 ° C by heating and removed from the furnace and moved into a constant temperature room at 25 ° C.
  • Unmodified PTFE modified with PTFE (Propyl vinyl ether) manufactured by suspension polymerization apparent density 0.42 g / cc (Melting point: 342 ° C.) 138 kg was filled in a mold having an annular cavity with an outside diameter of 418 mm and an inside diameter of 150 mm.
  • the packing (apparent) density at this time was 0.67 g / cc.
  • compression was performed at a compression molding pressure of 19.6 MPa (200 kgf / cm 2 ) for 60 minutes to produce a pre-compression molded body. The size of the sample removed from the mold and left for 1 hour is shown below.
  • SUS stainless steel
  • the firing of a large-sized PTFE molded body can be performed while suppressing deformation.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Casting Or Compression Moulding Of Plastics Or The Like (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Separation Using Semi-Permeable Membranes (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Heating, Cooling, Or Curing Plastics Or The Like In General (AREA)

Abstract

L'invention porte sur un procédé de production d'un article moulé cylindrique de polytétrafluoroéthylène consistant: à soumettre de la poudre de polytétrafluoroéthylène à un moulage par compression donnant une préforme cylindrique, puis à placer un mandrin dans l'alésage central de la préforme, puis à suspendre la préforme dans une position horizontale à l'aide du mandrin lui-même suspendu, puis à cuire la préforme, le mandrin présentant un diamètre extérieur (Dm) égal ou supérieur à celui de l'alésage central (cD) de la préforme après cuisson. L'invention porte également sur un gros article moulé de polytétrafluoroéthylène cuit, sur une feuille large et poreuse de polytétrafluoroéthylène cuit, sur un film perméable aux gaz, et sur une feuille de coussin consistant en la susdite feuille. Ce procédé permet la cuisson de gros articles moulés de polytétrafluoroéthylène, jusqu'alors difficile avec les procédés traditionnels, tout en en supprimant les déformations.
PCT/JP2001/004159 2000-06-06 2001-05-18 Article moule de polytetrafluoroethylene et son procede de production WO2001094101A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2000-168662 2000-06-06
JP2000168662A JP2001341138A (ja) 2000-06-06 2000-06-06 ポリテトラフルオロエチレン成形体およびその製造法

Publications (1)

Publication Number Publication Date
WO2001094101A1 true WO2001094101A1 (fr) 2001-12-13

Family

ID=18671635

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2001/004159 WO2001094101A1 (fr) 2000-06-06 2001-05-18 Article moule de polytetrafluoroethylene et son procede de production

Country Status (2)

Country Link
JP (1) JP2001341138A (fr)
WO (1) WO2001094101A1 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2361671A4 (fr) 2008-09-26 2013-12-18 Nitto Denko Corp Membrane semi-perméable composite et son procédé de fabrication
JP5925409B2 (ja) 2008-10-23 2016-05-25 日東電工株式会社 熱硬化性樹脂多孔シートの製造方法、熱硬化性樹脂多孔シート、及びそれを用いた複合半透膜
JP2012011646A (ja) * 2010-06-30 2012-01-19 Nok Corp ４フッ化エチレン製の製品の製造方法
JP2012121943A (ja) 2010-12-06 2012-06-28 Nitto Denko Corp エポキシ樹脂多孔シートの製造方法
CN106178992A (zh) * 2016-08-23 2016-12-07 李凤荣 一种高分子滤膜的制备方法
BE1024586B1 (nl) * 2016-12-21 2018-04-12 Vanéflon Nv Werkwijze voor het vervaardigen van een polytetrafluorethyleen product en polytetrafluorethyleen product
JP7090064B2 (ja) 2019-12-20 2022-06-23 日東電工株式会社 耐熱緩衝シート及び熱加圧処理方法
WO2021200409A1 (fr) 2020-04-02 2021-10-07 日東電工株式会社 Feuille antiadhésive résistante à la chaleur et procédé de réalisation d'une étape impliquant le chauffage et la fusion de résine

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH05222260A (ja) * 1992-02-13 1993-08-31 Nitto Denko Corp フッ素樹脂組成物および成形物
JPH0615663A (ja) * 1992-07-01 1994-01-25 Nitto Denko Corp 筒状フツ素樹脂成形体とその製造法
JP2877944B2 (ja) * 1990-11-20 1999-04-05 日本バルカー工業株式会社 ポリテトラフルオロエチレン樹脂成形品の製造方法
EP0970799A1 (fr) * 1997-03-19 2000-01-12 Daikin Industries, Ltd. Article en polytetrafluoroethylene moule et son procede de production
WO2000016968A1 (fr) * 1998-09-18 2000-03-30 Daikin Industries, Ltd. Produit moule, sous forme de bloc, a base de polytetrafluoroethylene, et procede de production associe
JP2000334847A (ja) * 1999-06-01 2000-12-05 Nok Corp 焼成素材の製造方法

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2877944B2 (ja) * 1990-11-20 1999-04-05 日本バルカー工業株式会社 ポリテトラフルオロエチレン樹脂成形品の製造方法
JPH05222260A (ja) * 1992-02-13 1993-08-31 Nitto Denko Corp フッ素樹脂組成物および成形物
JPH0615663A (ja) * 1992-07-01 1994-01-25 Nitto Denko Corp 筒状フツ素樹脂成形体とその製造法
EP0970799A1 (fr) * 1997-03-19 2000-01-12 Daikin Industries, Ltd. Article en polytetrafluoroethylene moule et son procede de production
WO2000016968A1 (fr) * 1998-09-18 2000-03-30 Daikin Industries, Ltd. Produit moule, sous forme de bloc, a base de polytetrafluoroethylene, et procede de production associe
JP2000334847A (ja) * 1999-06-01 2000-12-05 Nok Corp 焼成素材の製造方法

Also Published As

Publication number Publication date
JP2001341138A (ja) 2001-12-11

Similar Documents

Publication Publication Date Title
US9464342B2 (en) Titanium, titanium alloy and NiTi foams with high ductility
WO2001094101A1 (fr) Article moule de polytetrafluoroethylene et son procede de production
JP5243235B2 (ja) 金属基複合材料の改善された製造方法
Halldin et al. Powder processing of ultra‐high molecular weight polyethylene I. Powder characterization and compaction
JP2012117125A (ja) 粉末焼結体の製造方法および製造装置
CN105441881A (zh) 铬靶材及其组合的制造方法
JP6403421B2 (ja) 焼結装置および焼結方法
CN113999015A (zh) 一种轻质高强的弹性陶瓷及其制备方法
JP4858545B2 (ja) ポリテトラフルオロエチレン成形体及びその製造方法
JP4429004B2 (ja) 摺動部材用多孔質セラミック焼結体の製造方法とこれにより得られた摺動部材用多孔質セラミック焼結体並びにこれを用いたシールリング
JP2007169789A (ja) 高密度の半製品又は構成要素を製造する方法
JP3613996B2 (ja) ポリテトラフルオロエチレンブロック状成形品およびその製造方法
JPH0593086A (ja) 多孔質ポリテトラフルオロエチレン成形体の製法
JPH0641167B2 (ja) テトラフルオロエチレン樹脂パイプの製造法
RU2336973C2 (ru) Способ изготовления спеченных заготовок из тяжелых сплавов на основе вольфрама
US5683639A (en) Shortened sintering cycle for molded polytetrafluoroethylene articles
JP2004509784A (ja) 冷間等圧プレス成形方法
JP7267391B1 (ja) チタン多孔質体及び、チタン多孔質体の製造方法
RU2414329C1 (ru) Способ изготовления спеченных пористых изделий из псевдосплава на основе вольфрама
KR101947423B1 (ko) 대유량용 다공성 금속 멤브레인의 제조방법
JP5782897B2 (ja) ポリテトラフルオロエチレン成形品の製造方法、ポリテトラフルオロエチレンシートの製造方法
JP2024514249A (ja) フィーチャー付きセラミック物品、例えばセラミックミラーブランクを形成する方法
JPWO2014002127A1 (ja) 長尺軽金属ビレット及びその製造方法
SU1073118A1 (ru) Способ изготовлени изделий из плавких фторполимеров
JP2003245983A (ja) Ｐｔｆｅ多孔体製造方法、ｐｔｆｅ多孔体及びｐｔｆｅ多孔複合体製造方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): CN KR US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR

121 Ep: the epo has been informed by wipo that ep was designated in this application
DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
122 Ep: pct application non-entry in european phase