JP4335844B2 - Radiation treatment method for polymer membrane and fluorine-containing polymer ion exchange membrane - Google Patents

Description

  The present invention relates to a fluorine-containing polymer ion exchange membrane which is a solid polymer electrolyte membrane suitable for a fuel cell and has excellent oxidation resistance and a wide range of ion exchange capacities, and a method and apparatus for producing the same. In particular, the present invention relates to a method and an apparatus for mass-producing a modified fluorine-containing polymer membrane as a base material for a fluorine-containing polymer ion exchange membrane industrially at low cost.

  In a fuel cell using a solid polymer ion exchange membrane, the polymer ion exchange membrane acts as an electrolyte for conducting protons and does not directly mix hydrogen or methanol as a fuel with air or oxygen as an oxidant. Act as a diaphragm for. Therefore, the polymer ion exchange membrane has (1) high ion exchange capacity, (2) resistance to hydroxide radicals, that is, excellent oxidation resistance and durability because of its role as an electrolyte. 3) It is required that the electric resistance can be kept low by keeping the water retention property of the film high and constant. In addition, the polymer ion exchange membrane has (4) excellent mechanical strength and dimensional stability of the membrane because of its role as a diaphragm, and (5) against hydrogen gas, methanol or oxygen gas. Therefore, it is required not to have excessive permeability. Furthermore, in order to put the polymer ion exchange membrane into practical use as an industrial product, (6) it is required that the polymer ion exchange membrane be sufficiently inexpensive and can be mass-produced.

  Early polymer ion exchange membrane fuel cells used hydrocarbon polymer ion exchange membranes produced by copolymerization of styrene and divinylbenzene. However, this ion exchange membrane has poor practicality because of its extremely poor durability due to oxidation resistance. This problem has been solved by DuPont, and a perfluorosulfonic acid membrane developed as “Nafion (registered trademark of DuPont)” has been generally used.

  However, conventional fluorine-containing polymer ion exchange membranes such as “Nafion” have the following drawbacks. That is, (1) the ion exchange capacity is as small as around 1 meq / g, (2) the water retention is insufficient and the ion exchange membrane is dried and the proton conductivity is lowered, and (3) methanol is used as fuel. In this case, membrane swelling and methanol crossover occur. Further, it is known that when a large amount of sulfonic acid groups are introduced for the purpose of increasing the ion exchange capacity, the membrane strength is remarkably lowered and easily broken. Accordingly, in the conventional ion exchange membranes of fluorine-containing polymers, it is necessary to suppress the amount of sulfonic acid groups to such an extent that the membrane strength is maintained. For this reason, only an ion exchange capacity of about 1 meq / g could be achieved. Further, conventional fluorine-containing polymer ion exchange membranes such as “Nafion” are very expensive due to their complicated manufacturing process, which is a major obstacle to practical use. Therefore, it is required to develop a new electrolyte membrane that satisfies the above-mentioned requirements while being low in price, replacing the “Nafion” or the like.

  Attempts have been made for a radiation graft polymerization method in which a solid polymer electrolyte membrane is produced by graft polymerization of a monomer capable of introducing a sulfonic acid group onto a fluorine-containing polymer membrane substrate. However, when a normal fluorine-containing polymer membrane substrate is used, the graft reaction does not proceed to the inside of the membrane and is limited to the membrane surface, so the characteristics as an electrolyte membrane are not improved. In addition, when irradiated with ionizing radiation such as an electron beam or γ-ray, a normal fluorine-containing polymer film substrate deteriorates due to a main chain scission reaction. Furthermore, when a hydrocarbon monomer is used as the graft monomer, there is a problem that the oxidation resistance is low. For example, an ion exchange membrane synthesized by introducing a styrene monomer into an ethylene-tetrafluoroethylene copolymer by a radiation graft reaction and then sulfonating functions as an ion exchange membrane for a fuel cell. Although it is disclosed in the publication, since the styrene graft chain is composed of hydrocarbons, the oxidative degradation of the graft chain occurs when a current is passed through the membrane for a long time, and the ion exchange capacity of the membrane is greatly reduced. have.

  If the fluorine-containing polymer membrane substrate is previously cross-linked, the heat resistance of the membrane is improved and the grafting ratio of the monomer is improved, and further, the decrease in membrane strength due to irradiation for grafting can be suppressed. JP-A-2004-51685 and JP-A-2004-300360 disclose that it is suitable for high-temperature and high-performance ion exchange membranes for fuel cells. In particular, in the radiation grafting reaction of polytetrafluoroethylene (PTFE), an amorphous part is increased by introducing a crosslinked structure into the molecular structure of the membrane substrate, and a graft ratio is low in uncrosslinked polytetrafluoroethylene (PTFE). It is disclosed in Japanese Patent Application Laid-Open Nos. 2004-300360 and 2001-348439 that the above disadvantage can be solved. Thus, by using a fluorine-containing polymer membrane having a crosslinked structure as a substrate, it has excellent oxidation resistance and a wide range of ion exchange capacity, and can be used as a solid polymer electrolyte membrane suitable for fuel cells. It is known that a fluorine-based polymer ion exchange membrane can be formed.

  In general, a fluorine-containing polymer film substrate has excellent heat resistance and chemical resistance, and is widely used as an industrial and consumer resin. However, the fluorine-containing polymer film substrate is highly sensitive to radiation, and molecular chain scission progresses when irradiated with radiation. When the absorbed dose exceeds 50 kGy, mechanical properties deteriorate. Therefore, it could not be used in a radiation environment such as a nuclear facility or outer space. Polytetrafluoroethylene (PTFE), which is a representative of the fluorine-containing polymer film substrate, is extremely sensitive to radiation, and it is known that mechanical properties deteriorate when irradiated with radiation exceeding 1 kGy. In polytetrafluoroethylene (PTFE), it means that molecular cutting occurs preferentially by irradiation and crystallization easily proceeds. However, when polytetrafluoroethylene (PTFE) is irradiated with ionizing radiation in the absence of oxygen at a specific temperature equal to or higher than its crystalline melting point, crosslinking occurs and the characteristics are greatly improved. This is disclosed in Japanese Utility Model Laid-Open No. 7-118423.

  JP-A-6-116423 discloses a method of crosslinking polytetrafluoroethylene (PTFE). This is because ionizing radiation (γ-rays, electron beams, X-rays, neutron beams, high energy) is maintained in a temperature in excess of the crystal melting point (327 ° C.) in an oxygen-free environment, that is, in a vacuum or in an inert gas atmosphere. Ion). The temperature of the polytetrafluoroethylene (PTFE) film substrate at the time of irradiation is desirably around 340 ° C., and the irradiation dose is suitably in the range of 1 kGy to 10 MGy, and in particular when obtaining rubber properties, from 200 kGy It is disclosed that a range of 5MGy is desirable. The polytetrafluoroethylene (PTFE) film that has been subjected to radiation treatment under such conditions is imparted with radiation resistance. Compared with the case of irradiation with ionizing radiation in a room temperature environment in a vacuum, the elongation at break and the strength of the yield point are reduced. It is described that material deterioration such as a decrease is remarkably suppressed.

  In JP-A-11-49867, a tetrafluoroethylene-hexafluoropropylene copolymer (FEP) and a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) are irradiated with ionizing radiation under the same conditions. Discloses that heat resistance and mechanical properties in a radiation environment are improved. Tetrafluoroethylene-hexafluoropropylene copolymer (FEP) or tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) is more than the crystalline melting point in the absence of oxygen, that is, in a vacuum or in an inert gas atmosphere. By irradiating with ionizing radiation (γ-ray, electron beam, X-ray, neutron beam, high-energy ions, etc.) while maintaining within a temperature range from about 20 ° C lower than each crystal melting point about 20 ° C. It is disclosed that the fluorine-containing polymer film substrate is crosslinked. Furthermore, it is disclosed that the temperature of the resin at the time of irradiation is preferably a temperature in the range of about ± 10 ° C., centering on the crystal melting point of each fluorine-containing polymer film substrate. Further, it is disclosed that the irradiation dose is preferably in the range of 1 kGy to 15 MGy, and more preferably in the range of 500 kGy to 10 MGy when imparting rubber properties. These fluorine-containing polymer films treated in this way have improved heat resistance and chemical resistance, and are suitable for equipment sealing materials and packing materials that require these characteristics. In particular, since radiation resistance is imparted, tetrafluoroethylene-hexafluoropropylene copolymer (FEP) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) are used as industrial materials in a radiation environment. become able to.

  Japanese Patent Application Laid-Open No. 7-118423 discloses that when radiation irradiation is continued for a long time at a temperature of 327 ° C. or higher, which is the crystalline melting point of polytetrafluoroethylene (PTFE) in an untreated state, in addition to the crosslinking reaction, It is disclosed that a decomposition reaction or a depolymerization reaction occurs, the monomer is scattered from the surface of polytetrafluoroethylene (PTFE), and the weight is reduced. Polytetrafluoroethylene (PTFE) is crosslinked when irradiated with radiation in a vacuum or in an inert gas at a temperature equal to or higher than its crystalline melting point, but its crystalline melting point decreases as the absorbed dose of radiation increases. Therefore, it is disclosed that the temperature of polytetrafluoroethylene (PTFE) at the time of irradiation may be changed in accordance with the absorbed dose, and crosslinking should be advanced while suppressing thermal decomposition and depolymerization. For example, at the initial stage of irradiation, the temperature is raised to 327 ° C. or higher, desirably 340 ° C. to 350 ° C., but then to 320 to 330 ° C. after irradiation with 50 kGy, to 290 to 300 ° C. after irradiation with 100 kGy, and after 200 kGy irradiation. Examples are disclosed in which the temperature is lowered to 280-290 ° C., to 260-270 ° C. after irradiation with 500 kGy, and to 230-240 ° C. after irradiation with 1 MGy. As a method for lowering the temperature of polytetrafluoroethylene (PTFE), a method of cooling with a refrigerant such as liquid nitrogen or a method of gradually lowering the temperature of an inert gas circulated in the system is disclosed. However, these temperature lowering methods are not specific and accurate temperature management is difficult.

  In the following, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer film substrate at a low oxygen partial pressure while keeping the fluorine-containing polymer film substrate at a temperature within a predetermined set temperature range near its crystal melting point. An example describing a method for producing a modified fluorine-containing polymer film by irradiation in an environment will be described. In JP-A-6-116423, a commercially available polytetrafluoroethylene (PTFE) sheet having a thickness of 1 mm is heated to 340 ° C. in a vacuum (0.01 Torr or less), and γ rays emitted from cobalt-60 are detected. An example of irradiation from 1.7 kGy to 20 kGy, or a polytetrafluoroethylene (PTFE) sheet having a thickness of 0.3 mm is heated to 340 ° C. in a vacuum (0.01 Torr or less), and an electron beam with an energy of 2 MeV is applied from 100 kGy. An example of irradiation up to 2MGy is disclosed. In addition, each of the polytetrafluoroethylene (PTFE) sheets having a thickness of 0.3 mm, 0.5 mm, and 1 mm was irradiated with an electron beam at 370 ° C. in a vacuum. There is a description that the thermal decomposition of (PTFE) proceeds to reduce the thickness of the sheet.

  In JP-A-11-49867, a tetrafluoroethylene-hexafluoropropylene copolymer (FEP) sheet having a thickness of 0.5 mm is heated to 280 ° C. higher than its crystalline melting point (270 ° C.) in an argon stream. An example is disclosed in which radiation resistance is imparted by crosslinking when an electron beam having an energy of 2 MeV is irradiated with 100 kGy. Similarly, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) sheet having a thickness of 0.5 mm is heated to 320 ° C. higher than its crystalline melting point (310 ° C.) in an argon stream, and the energy is 2 MeV. An example in which radiation resistance is imparted by crosslinking by irradiating 300 kGy of the electron beam is disclosed.

In Japanese Patent Laid-Open No. 2001-348439, a 10 cm × 10 cm piece of a polytetrafluoroethylene (PTFE) sheet having a thickness of 0.5 mm and a number average molecular weight of 1 × 10 ⁷ is placed in a heating type irradiation container. ^{-3 After} degassing to about Torr and replacing with argon gas, the temperature of the polytetrafluoroethylene (PTFE) sheet is set to 335 to 345 ° C by heating with an electric heater, and an electron beam with an energy of 2 MeV is 50 kGy, 100 kGy, It is disclosed that a polytetrafluoroethylene (PTFE) sheet that has been irradiated to a dose of 300 kGy, 500 kGy, or 1 MGy, cooled after the irradiation, and finished high-temperature irradiation was taken out.

Japanese Patent Application Laid-Open No. 2002-348389 describes that the following irradiation was performed in order to obtain a long-chain branched polytetrafluoroethylene (PTFE) sheet. That is, a 10 cm x 6 cm piece of a polytetrafluoroethylene (PTFE) sheet having a thickness of 50 μm or 100 μm and a number average molecular weight of 1 × 10 ⁷ is fixed with a frame made of stainless steel, and an electron beam made of a 50 μm thick titanium foil Place in a stainless steel heating type irradiation container with an entrance window, degas the container to about 10 ^-3 Torr and replace with argon gas, and then heat with an electric heater to polytetrafluoroethylene (PTFE) It is disclosed that the temperature of the sheet is set to 335 to 340 ° C. and an electron beam having an energy of 2 MeV is irradiated while flowing an argon gas very slightly. It is disclosed that the dose rate at this time is 0.5 kGy / second, the dose is 100 kGy or 200 kGy, and the irradiation time is 200 seconds or 400 seconds, respectively. After irradiation, the container was cooled and the polytetrafluoroethylene (PTFE) sheet after radiation irradiation was taken out to obtain a long-chain branched polytetrafluoroethylene (PTFE) film.

As disclosed in JP-A-2004-51685, JP-A-2004-14436, JP-A-2003-261697, and JP-A-2003-82129, crosslinked polytetrafluoroethylene (PTFE), that is, long The following irradiation is performed to obtain a chain-branched polytetrafluoroethylene (PTFE) film. A 10cm square of polytetrafluoroethylene (PTFE) film with a thickness of 50μm is placed in a stainless steel autoclave irradiation container (inner diameter 7cmΦ, height 30cm) with a heater, and the inside is degassed to 10 ^-3 Torr with argon gas After that, the temperature of the polytetrafluoroethylene (PTFE) film is set to 340 ° C. (or a temperature range of 300 ° C. to 365 ° C.) by heating with an electric heater, and the dose of cobalt-60 γ rays is 3 kGy / hour. It is described that after irradiation to a dose of 90 kGy at a rate, the polytetrafluoroethylene (PTFE) film after cooling the container and completing irradiation was taken out. The time required for irradiation at this time was 30 hours.

  In the treatment method disclosed above, the fluorine-containing polymer membrane substrate to be treated is a small piece of about 10 cm square, and after being placed in a small volume container and heated together, the ionizing radiation is irradiated. Only an example in which the container is cooled and then the treated fluorine-containing polymer film is taken out is shown. An example of using cobalt-60 gamma rays when performing ionizing radiation irradiation treatment is shown. In this case, since the dose rate is low, it takes 30 hours to irradiate a dose of 90 kGy. I need it. Moreover, although the example which irradiated the electron beam whose energy is 2 MeV is also disclosed, since the dose rate is not so high, about 400 seconds are required for processing of a small piece. Furthermore, it generally takes a long time to cool the container. The reason why the irradiation processing speed could not be increased in such irradiation is that when the dose rate of ionizing radiation is increased, the temperature of the irradiated film substrate increases during irradiation due to the heating effect of ionizing radiation, and the temperature is unevenly distributed. This is because there is a disadvantage that the thermal decomposition partially proceeds. As described above, when a fluorine-containing polymer membrane substrate is subjected to high-temperature radiation treatment, it is possible to treat a large-area fluorine-containing polymer membrane substrate, or when irradiating a large dose rate of ionizing radiation. It is important to be able to keep the polymer membrane substrate at an accurate and uniform temperature.

Furthermore, in order to put the cross-linked fluorine-containing polymer membrane into practical use as an industrial product, it is necessary to increase the processing speed, reduce the price, and achieve high quality by performing advanced management of processing conditions. It is. When the dose rate is increased in order to increase the processing speed when performing the ionizing radiation irradiation process, the heating of the fluorine-containing polymer film substrate by ionizing radiation is superimposed on the temperature of the fluorine-containing polymer film substrate. In addition to the increase in temperature, the temperature distribution changed, and it was difficult to make the quality of the fluorine-containing polymer film after treatment uniform. In particular, when a long and long fluorine-containing polymer film substrate exceeding 30 cm is subjected to radiation treatment, the temperature of the film substrate and the spatial distribution of the temperature and the time change of the temperature immediately after the start of irradiation or during the irradiation It was difficult to manage. For these reasons, it has been difficult to put a crosslinked fluorine-containing polymer membrane, a fluorine-containing polymer ion exchange membrane using the same, and a fuel cell using the same into an industrial product.
JP-A-6-116423 JP 7-118423 A JP-A-9-102322 Japanese Patent Laid-Open No. 11-19190 JP 11-49867 A JP 2001-348439 A JP 2003-82129 A JP 2003-261697 A JP 2004-14436 A JP 2004-51685 A JP 2004-300360 A

  The problem to be solved is that an ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer film substrate in a low oxygen partial pressure environment while maintaining the fluorine-containing polymer film substrate at a temperature within a predetermined set temperature range. In the manufacturing method of fluorine-containing polymer ion exchange membranes including the irradiation process under irradiation, the processing speed is increased and the price is reduced, and the management of the processing conditions is advanced to achieve uniform quality. It is to enable mass production of a large area fluorine-containing polymer ion exchange membrane that is inexpensive and has a long lifetime. It is another object of the present invention to provide an inexpensive and long-life fuel cell that can be used in an automobile or the like. In particular, irradiate ionizing radiation at a large dose rate while keeping a large area fluorine-containing polymer membrane substrate at an optimally determined temperature range at all positions in the irradiation field and throughout the entire irradiation process. Thus, it is intended to provide a method for producing a large amount of a fluorine-containing polymer film having a stable quality cross-linked structure in a short time and at a low cost.

  In the present invention, the above-mentioned problem is achieved by passing a long fluorine-containing polymer membrane substrate through a constant temperature radiation treatment apparatus capable of irradiating the substrate with ionizing radiation while controlling the temperature to an optimum value. It has been solved. At the entrance position and the exit position of the constant temperature radiation processing apparatus, there are provided portions that mechanically hold a part in the longitudinal direction of the fluorine-containing polymer film substrate at room temperature and add a running function. . A heating element is provided inside the constant temperature radiation processing apparatus. This heating element is divided into a large number of heating element elements along the longitudinal direction and width direction of the fluorine-containing polymer film substrate. The surface temperature of each heating element is appropriately controlled spatially and / or temporally, and the fluorine-containing system within a desired range occupying most of the irradiation field, whether during irradiation or immediately before irradiation. The temperature at all positions of the polymer film substrate is uniformly distributed within a set temperature range near the crystal melting point. During the irradiation of the ionizing radiation, an inert gas is blown onto a portion located in the irradiation field of the ionizing radiation to produce a cooling effect that counteracts the heating effect of the ionizing radiation, and thus the desired fluorine-containing polymer film substrate. Temperatures at all positions within the range are uniformly distributed with values within the set temperature range. When the irradiation treatment of a predetermined dose proceeds, the treated portion of the long fluorine-containing polymer film located at the exit portion of the constant temperature radiation processing apparatus is partially cooled and sent out of the constant temperature radiation processing apparatus. In this way, a large amount of a long fluorine-containing polymer film substrate can be subjected to radiation treatment in a short time.

  In the isothermal radiation processing apparatus, at a position where no ionizing radiation is irradiated, or at a timing where no ionizing radiation is irradiated, the surface temperature of the heating element is made uniform within the same element, and is set higher as the element is farther from the irradiation field center. Thus, the temperature of the portion of the fluorine-containing polymer film substrate existing in the irradiation field and its peripheral position is quickly increased to a predetermined set temperature range around the crystal melting point while maintaining a uniform distribution. At the position to irradiate ionizing radiation and the timing to irradiate ionizing radiation, the inert gas is blown from the refrigerant passage located in the vicinity of the irradiation field to the portion located in the irradiation field of the fluorine-containing polymer film substrate, Results are obtained by radiating ionizing radiation having a heat quantity distributed so as to lower the temperature of the fluorine-containing polymer film substrate in a state of being distributed in a bowl-like shape around the irradiation field, and to cancel the heat dissipation. As described above, the temperature of the fluorine-containing polymer film substrate is kept within the predetermined temperature range at any time during irradiation. Further, the spatial distribution and temporal change of the released heat amount coincide with the spatial distribution and temporal change of the heat amount given by the ionizing radiation, respectively, and as a result, one of the set temperature ranges spatially and temporally. A necessary dose can be given in a short time with such a temperature distribution. In the present invention, since the portion located in the irradiation field is cooled so as to have a large cooling rate by blowing the refrigerant locally, the temperature in the irradiation field is stabilized even when ionizing radiation is irradiated at a large dose rate. Can be distributed uniformly. In many cases, the desired range coincides with the irradiation field, but a portion that is not used due to excision after processing may be excluded from the desired range. This is common in any case of the present invention. The set temperature range may be allowed to be set within a temperature range of ± 20 ° C. around the crystal melting point of the fluorine-containing polymer membrane substrate. It is preferable to set a temperature range of about ± 5 ° C. around a specific temperature exceeding the crystalline melting point.

One aspect of the present invention is that the fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction is kept at a temperature within a predetermined set temperature range while the fluorine-containing polymer membrane substrate is ionized by 1 kGy or more. In the method for producing a modified fluorine-containing polymer film including an irradiation step of irradiating radiation in a low oxygen partial pressure environment, the irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction, and the width direction has a radiation field length, the fluorine-containing polymer membrane substrate includes a desired range of the irradiation field substantially matches the magnitude of the ionizing radiation, the irradiation step, the free A first step of heating the desired range of the fluoropolymer membrane substrate to a temperature within the set temperature range, and irradiating a portion occupying the desired range with the ionizing radiation having a predetermined intensity distribution The part has a predetermined heating rate And a second step of cooling the portion with a predetermined cooling rate by blowing an inert gas to the portion occupying the desired range during the irradiation time of the ionizing radiation, The heating in the step is performed by a heating element having a distributed calorific value provided in a non-contact manner facing the fluorine-containing polymer film substrate, and the blowing of the inert gas in the second step is performed as follows: The ionizing radiation which gives heat quantity distributed so that the temperature of the fluorine-containing polymer film substrate is partially decreased with time within the irradiation field width of the irradiation field and the heat distribution is distributed to cancel the heat dissipation. By irradiating, at least one of the blowing intensity distribution of the inert gas and the intensity distribution of the ionizing radiation has the cooling rate and the heating rate changed to the fluorine-containing polymer film. Is a manufacturing method characterized in that it is set or controlled so as to substantially coincide over in the irradiation time at all sites within the desired range of wood. Here, the cooling rate represents a temperature that falls within a unit time in a specific portion, and is a value that collectively represents the temperature decrease rate of the specific portion due to heat conduction, heat radiation, or convection. Similarly, the heating rate represents the temperature rising within a unit time at a specific part. When the present invention is adopted, the temperature of the fluorine-containing polymer film substrate at all positions within a desired range that occupies most of the irradiation field from immediately before the start of the irradiation of the ionizing radiation to immediately after the end of the irradiation is the set temperature. The fluorine-containing polymer membrane substrate having a large area can be accommodated within the range, and high-speed modification treatment can be performed under accurate temperature control.

One aspect of the present invention is that the fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction is kept at a temperature within a predetermined set temperature range while the fluorine-containing polymer membrane substrate is ionized by 1 kGy or more. In the method for producing a modified fluorine-containing polymer film including an irradiation step of irradiating radiation in a low oxygen partial pressure environment, the irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction, and the width direction has a radiation field length, the fluorine-containing polymer membrane substrate includes a desired range of the irradiation field substantially matches the magnitude of the ionizing radiation, the irradiation step, the free A first step of heating the desired range of the fluoropolymer membrane substrate to a temperature within the set temperature range, and irradiating a portion occupying the desired range with the ionizing radiation having a predetermined intensity distribution While heating the part, A second step of cooling the portion by blowing an inert gas to the portion occupying the desired range during the irradiation time of the ionizing radiation, and the heating in the first step is the fluorine-containing polymer film It is made by a heating element having a distributed calorific value provided in a non-contact manner facing the substrate, and the spraying of the inert gas in the second step is performed by setting the temperature of the fluorine-containing polymer film substrate. The radiation intensity of the inert gas is irradiated by irradiating the ionizing radiation which gives heat that is distributed so as to partially cancel the heat dissipation within the irradiation field width of the irradiation field. At least one of the distribution and the intensity distribution of the ionizing radiation is such that the temperature of substantially all the portion within the desired range of the fluorine-containing polymer film substrate is within the set temperature range. On the other hand the set in connection with or controlled by it over in the irradiation time to fit a manufacturing method comprising. In order to set the distribution of the heat generation amount of the heat generating element, the heat generating element may be divided into a large number of heat generating element elements, and the heat generation amounts of these heat generating element element elements may be set appropriately and independently. The setting of the ionizing radiation intensity distribution can be realized by inserting a filter having an appropriate transmittance between the ionizing radiation source and the fluorine-containing polymer film substrate. The inert gas spray strength distribution is set by limiting the distribution range of the inert gas by providing a partition plate formed so that the inert gas does not hit the portion other than the desired range. The inert gas is blown toward a portion occupying the desired range from a plurality of nozzles provided in a portion excluding the range, and the gas pressure in the inert gas passage having the plurality of nozzles is determined as the intensity distribution of the ionizing radiation. This can be done by adjusting appropriately in relation to The inert gas is sprayed in accordance with the irradiation timing of the ionizing radiation. By adopting the present invention, the temperature of the fluorine-containing polymer film substrate at all positions within the desired range from immediately before the start of irradiation with the ionizing radiation to immediately after the end of irradiation can be kept within the set temperature range. The fluorine-containing polymer film substrate having a large area can be modified in a short time under accurate temperature control.

One aspect of the present invention is that the fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction is kept at a temperature within a predetermined set temperature range while the fluorine-containing polymer membrane substrate is ionized by 1 kGy or more. In the method for producing a modified fluorine-containing polymer film including an irradiation step of irradiating radiation in a low oxygen partial pressure environment, the irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction, and the width direction has a radiation field length, the fluorine-containing polymer membrane substrate includes a desired range of the irradiation field substantially matches the magnitude of the ionizing radiation, the irradiation step, the free A first step of heating the desired range of the fluorine-based polymer membrane substrate to a temperature within the set temperature range, and a distributed heat generation provided in a non-contact manner facing the fluorine-containing polymer membrane substrate Part occupying the desired range by a heating element And heating the part by irradiating the part occupying the desired range with the ionizing radiation having a predetermined intensity distribution, and inert to the part occupying the desired range during the irradiation time of the ionizing radiation A second step of cooling the portion by blowing a gas, the heating in the first step is performed by the heating element, and the blowing of the inert gas in the second step is performed by the fluorine-containing step. Radiating the ionizing radiation to give a heat quantity distributed so as to partially reduce the temperature of the system polymer film substrate within the irradiation field width of the irradiation field to partially decrease with time Therefore, at least one of the inert gas spray intensity distribution, the ionizing radiation intensity distribution, and the heat generation amount distribution of the heating element is The temperature of substantially all the portion within the desired range of the fluorine-containing polymer film substrate is set or controlled in relation to the other over the irradiation time so as to be within the set temperature range. This is a manufacturing method. Since the first step of keeping the temperature of the fluorine-containing polymer film substrate within the set temperature range before starting the irradiation of the ionizing radiation is provided, a low temperature state immediately after the start of the irradiation of the ionizing radiation The danger of deteriorating the fluorine-containing polymer membrane substrate by irradiation under the above can be avoided. In this first step, the heating element is divided into a number of heating element elements, and the temperature of the fluorine-containing polymer film substrate is adjusted by appropriately distributing the amount of heat generated by the heating element elements. It is kept at a proper value and uniform. When the present invention is adopted, the temperature of the fluorine-containing polymer film substrate at all positions within the desired range from immediately before the start of the irradiation of the ionizing radiation to immediately after the end of the irradiation may be within the set temperature range. The fluorine-containing polymer film substrate having a large area can be irradiated at high speed under accurate temperature control.

One aspect of the present invention is that the fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction is kept at a temperature within a predetermined set temperature range while the fluorine-containing polymer membrane substrate is ionized by 1 kGy or more. In the method for producing a modified fluorine-containing polymer film including an irradiation step of irradiating radiation in a low oxygen partial pressure environment, the irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction, and the width direction has a radiation field length, the fluorine-containing polymer membrane substrate includes a desired range of the irradiation field substantially matches the magnitude of the ionizing radiation, the irradiation step, the free A first step of heating the desired range of the fluorine-based polymer membrane substrate to a temperature within the set temperature range, and a distributed heat generation provided in a non-contact manner facing the fluorine-containing polymer membrane substrate Part occupying the desired range by a heating element A second step of heating the portion by irradiating the portion occupying the desired range with the ionizing radiation having a predetermined intensity distribution, and the heating elements are arranged in the width direction. The first heat generating element group and the second heat generating element group including the heat generating element, and the first heat generating element group and the second heat generating element group are aligned in the longitudinal direction. The heating in the first step is performed by the heating element, and at least one of the intensity distribution of the ionizing radiation and the calorific value distribution of the heating element in the second step is the fluorine-containing polymer film substrate. The temperature is set or controlled over the irradiation time so that the temperature of substantially all of the portion within the desired range falls within the set temperature range. When the present invention is adopted, the temperature of the fluorine-containing polymer film substrate at all positions within the desired range from immediately before the start of the irradiation of the ionizing radiation to immediately after the end of the irradiation may be within the set temperature range. The fluorine-containing polymer film substrate having a large area can be irradiated at high speed under accurate temperature control.

  One of the present invention, in any one of the above inventions, the fluorine-containing polymer membrane substrate is a first substrate region that is mechanically held at a temperature lower than the set temperature range; A second base material region heated by the heating element; and a third base material region that is irradiated with the ionizing radiation and maintained at a temperature within the set temperature range. The substrate region includes the desired range. The first base material region is preferably kept at room temperature, and can easily hold the fluorine-containing polymer film substrate and run the fluorine-containing polymer film substrate. Can be done continuously. By providing the first base material region on both sides of the third base material region, the fluorine-containing polymer film that has been subjected to the irradiation treatment can be moved and taken out immediately after the end of the processing, and the processing speed Becomes larger. Since the second base material region is heated to a temperature within or near the set temperature range without being irradiated with the ionizing radiation, the fluorine-containing material is irradiated with the ionizing radiation under a low temperature condition. The danger of deteriorating the polymer base material can be avoided. In the second base material region and the third base material region, the heating element provided in the vicinity thereof is divided into a large number of heating element elements, and the respective heat generation amounts of these heating element elements are appropriately set. The temperature is kept at an appropriate value by spatial distribution. When the present invention is employed, a large amount of irradiation processing can be performed efficiently and accurately.

  One of the present invention, in any one of the above inventions, the desired range passes through the isothermal radiation processing apparatus that receives the ionizing radiation, and the isothermal radiation processing apparatus includes the heating element, A first device region that maintains a part of the fluorine-containing polymer film substrate at a temperature lower than the set temperature range and mechanically holds the portion, and a portion that occupies the desired range by the heating element is within the set temperature range. Or a second device region for heating to a temperature close thereto, and a third device region for applying a predetermined dose by irradiating the portion occupying the desired range with ionizing radiation. Is the method. Preferably, the fluorine-containing polymer film substrate is uniformly heated to a temperature within or near the set temperature range without being irradiated with the first device region maintained at room temperature and the ionizing radiation. The second device region and the third device region that performs irradiation with the ionizing radiation are sequentially passed. Accordingly, the temperature of the fluorine-containing polymer film substrate at all positions within the desired range from immediately before the start of the ionizing radiation irradiation to immediately after the irradiation can be kept within the set temperature range, and accurate temperature management is possible. A large amount of irradiation treatment can be performed in a short time under.

One of the present invention is the above invention, wherein the fluorine-containing polymer film substrate includes a fourth substrate region, and the fourth substrate region is the first substrate. a base region located between the region and the second base region, or the containing disposed opposite to the device region located between the first device region and said second device region A temperature of the fluorine-containing polymer film substrate in the fourth substrate region is a first region relative to a distance in a direction toward each of the other substrate regions. Distributed in the second base material region or the third base material region, or arranged opposite to each other in the second device region or the third device region . The temperature of the fluorine-containing polymer film substrate in the substrate region of the fluorine-containing polymer film substrate is Each of the substrate regions is distributed with a second rate of change with respect to the distance in the direction toward the other substrate region, and the magnitude of the first rate of change is the same everywhere in each substrate region. The method is characterized in that it is substantially larger than the magnitude of the change rate of 2. When the present invention is adopted, since the fourth substrate region is heated with a large temperature gradient at a short distance, the fluorine-containing polymer film substrate can be easily held, and an apparatus for processing can be provided. Smaller and lower price. Since the high-temperature part of the fluorine-containing polymer film substrate can be limited to a relatively narrow range including the irradiation field, it is easy to position the processing site during processing, and the processing accuracy and speed can be increased. become able to.

One aspect of the present invention is that the fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction is kept at a temperature within a predetermined set temperature range while a predetermined dose is applied to the fluorine-containing polymer membrane substrate. An isothermal radiation treatment apparatus for irradiating ionizing radiation , wherein the irradiation field of ionizing radiation has an irradiation field width in the longitudinal direction and an irradiation field length in the width direction, and the fluorine-containing polymer film size substrate to match the isothermal radiation treatment device in the retained portion and the set temperature range or the irradiation field and substantially of the ionizing radiation and the heated range heated to near the temperature that is positioned and held The constant-temperature radiation processing apparatus maintains a low temperature at which the held portion can be held and mechanically holds the held portion, and the irradiation field of the irradiation field. In the vicinity, the fluorine-containing high content A second apparatus region for heating the heated range to a temperature within or near the set temperature range by a heating element comprising a plurality of heating element elements provided in a non-contact manner facing the membrane substrate; A third device region that irradiates the ionizing radiation to the desired range and heats it with a predetermined heating rate, and maintains a portion occupying the desired range at a temperature within the set temperature range; and In the third device region, the portion is cooled with a predetermined cooling rate by spraying an inert gas on the portion occupying the desired range during the irradiation time of the ionizing radiation, and the inert gas The spraying dissipates heat so that the temperature of the fluorine-containing polymer film substrate is partially reduced with time within the irradiation field width of the irradiation field, and gives a quantity of heat distributed so as to cancel the heat dissipation. The ionization By irradiating with radiation, at least one of the blowing intensity distribution of the inert gas and the intensity distribution of the ionizing radiation is set to the set temperature at any part within the desired range during the time of irradiation with the ionizing radiation. A device characterized in that it is set or controlled in relation to the other to keep the temperature within a range. In the first apparatus region, it is preferable that the temperature of the fluorine-containing polymer film substrate is kept at room temperature. When the apparatus of the present invention is employed, irradiation with a large dose rate can be easily performed while controlling the temperature of the fluorine-containing polymer film substrate during irradiation with the ionizing radiation to a temperature within the set temperature range. The portion where the processing is completed can be quickly moved out of the processing apparatus and taken out without separately cooling or opening the processing apparatus.

One aspect of the present invention is that in any one of the above-described inventions, the heating element includes a plurality of heating element elements that are spatially divided, and the heating element includes the fluorine-containing system at a central portion in the irradiation field. A first heating element provided opposite to the polymer membrane substrate, and provided opposite to the fluorine-containing polymer membrane substrate at a position away from the center of the irradiation field in the width direction . includes a second heating element, the surface temperature of the second heating element is a method which is characterized in that it is set higher than the surface temperature of the first heating element. When the fluorine-containing polymer film substrate is heated by an integrated heating element having a uniform surface temperature provided opposite to the surface of the fluorine-containing polymer film substrate, the peripheral portion Is lower than the temperature of the central part. This situation does not change when the ionizing radiation is not irradiated or when the ionizing radiation is distributed with a uniform intensity. By controlling only the intensity distribution of the ionizing radiation in a complex manner, the temperature distribution of the fluorine-containing polymer film substrate or other long irradiated object during irradiation can be made uniform, but the temperature immediately after irradiation is set as described above. Not only is it difficult to be within the temperature range, but the absorbed dose is unevenly distributed, which is not preferable. However, when the present invention is adopted, it is easy to make the temperature distribution of the fluorine-containing polymer film substrate uniform in the irradiation field upon heating by the heating element, and to keep the absorbed dose distribution of the ionizing radiation uniform. Easy. Further, the temperature of the fluorine-containing polymer film substrate during irradiation can be controlled using a simple apparatus.

One aspect of the present invention is that in any one of the above-described inventions, the fluorine-containing polymer film substrate has a longitudinal direction and a width direction, and the heating element includes a plurality of heating element elements aligned in the width direction. Including a first heat generating element group and a second heat generating element group, wherein the first heat generating element group and the second heat generating element group are aligned in the longitudinal direction. Is the method . Using a heating element having a simple structure, temperature control of the fluorine-containing polymer film substrate during irradiation can be easily performed. In particular, since the temperature distribution in the longitudinal direction can be easily controlled in a state in which the temperature distribution in the width direction of the fluorine-containing polymer film substrate is kept uniform, the heating element elements aligned in the width direction can have the same time function. Therefore, it is possible to easily irradiate while controlling the temperature of the fluorine-containing polymer film substrate during irradiation with the ionizing radiation to a temperature within the set temperature range.

One aspect of the present invention is that in any one of the above-described inventions, each heating element included in the same heating element group aligned in the width direction is controlled in accordance with the same time function. It is a method . When the present invention is adopted, the temperature control of the fluorine-containing polymer film substrate during irradiation can be easily performed using a heating element and controller having a simple structure. In particular, it is easy to control the temperature distribution in the longitudinal direction while keeping the temperature distribution in the width direction of the fluorine-containing polymer film substrate uniform, and the heating element elements aligned in the width direction can be controlled with the same time function. Since it is controlled, the temperature of the fluorine-containing polymer film substrate during the irradiation of the ionizing radiation can be managed to a temperature within the set temperature range by a simple control method.

One of the present invention, in any one of the invention, the set temperature range in any portion of the fluorine-containing polymer membrane substrate, in the same said any portion of the fluorine-containing polymer membrane substrate The method is characterized in that it is determined so as to decrease while maintaining a predetermined relationship corresponding to the integrated value of the absorbed dose of the ionizing radiation absorbed in the past. Decreasing the set temperature range is either (1) decreasing the dose rate of the ionizing radiation or (2) increasing the cooling rate by the inert gas in accordance with an increase in the integrated value of the past absorbed dose. (3) This can be achieved by reducing the amount of heat generated by the heating element. When the present invention is adopted, even when the integrated value of the absorbed dose of the ionizing radiation absorbed by the fluorine-containing polymer film substrate increases and the crystalline melting point thereof decreases, the integrated value of the absorbed dose and the The relationship with the set temperature range can always be kept at a predetermined best relationship, and high-temperature radiation processing can be performed under optimum temperature conditions.

One of the present invention is the above invention, wherein the fluorine-containing polymer film substrate is a polytetrafluoroethylene film, a tetrafluoroethylene-hexafluoropropylene copolymer film, or a tetrafluoroethylene-perfluoro. It is a method characterized by being one of alkyl vinyl ether copolymer films. When the present invention is adopted, a polytetrafluoroethylene (PTFE) film, a tetrafluoroethylene-hexafluoropropylene copolymer film, or a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film that cannot be used in a radiation environment. Can be used at low cost as an industrial product by modifying it so that it can be used even in a radiation environment. Furthermore, by using these modified fluorine-containing polymer membranes as a base material, it is possible to mass-produce fluorine-containing polymer ion exchange membranes having excellent oxidation resistance and a wide range of ion exchange capacity at low cost. It becomes like this. Furthermore, if this is used, a cheap and durable fuel cell can be provided.

One of the present invention, the use or device by a method according to any one of the invention, substantially all portions in the desired range, while preventing mechanical contact, in the set temperature range While maintaining the temperature, it is obtained by irradiating the ionizing radiation in a low oxygen partial pressure environment and graft-polymerizing various monomers to the produced fluorine-containing polymer film substrate having a crosslinked structure by irradiation. There is a method for producing a fluorine-containing polymer ion exchange membrane, characterized in that a halogen group in a graft chain of a membrane is a sulfonate, and a sulfonate group in the graft chain is subsequently a sulfonate group. By employing the present invention, it becomes possible to mass-produce a fluorine-containing polymer ion exchange membrane having excellent oxidation resistance and a wide range of ion exchange capacity at a low cost. Furthermore, if this is used, a cheap and durable fuel cell can be provided.

One of the present invention, the use or device by a method according to any one of the invention, substantially all portions in the desired range, while preventing mechanical contact, in the set temperature range While maintaining the temperature, it is obtained by irradiating the ionizing radiation in a low oxygen partial pressure environment and graft-polymerizing various monomers to the produced fluorine-containing polymer film substrate having a crosslinked structure by irradiation. And a sulfonic acid group by hydrolyzing an ester group in a graft chain of the membrane in an acidic or alkaline solution. By adopting the present invention, the ion exchange membrane, which is the most important component for enhancing the life and performance of the fuel cell, has excellent oxidation resistance and a wide range of ion exchange capacity, and can be mass-produced at low cost. As a result, high-performance, stable operation and long-life fuel cells can be mass-produced at low cost.

One of the present invention, the use or device by a method according to any one of the invention, substantially all portions in the desired range, while preventing mechanical contact, in the set temperature range A fluorine-containing polymer film having a cross-linked structure produced by irradiating the ionizing radiation in a low oxygen partial pressure environment while maintaining a temperature . By adopting the present invention, a fluorine-containing polymer film having a large area that could not be used in a radiation environment can be modified so that it can be used in a radiation environment and provided as an industrial product at low cost. Furthermore, by using a modified fluorine-containing polymer membrane as a base material, it becomes possible to mass-produce a fluorine-containing polymer ion exchange membrane having excellent oxidation resistance and a wide range of ion exchange capacity at a low cost. . Furthermore, if this is used, a cheap and durable fuel cell can be provided.

One of the present invention, the use or device by a method according to any one of the invention, substantially all portions in the desired range, while preventing mechanical contact, in the set temperature range A fluorine-containing polymer ion produced by using the fluorine-containing polymer film having a crosslinked structure produced by irradiating the ionizing radiation in a low oxygen partial pressure environment while maintaining the temperature. It is an exchange membrane. By adopting the present invention, the ion exchange membrane, which is the most important component for enhancing the life and performance of the fuel cell, can be made to have excellent oxidation resistance and a wide range of ion exchange capacity, and it can be manufactured in large quantities at low cost. As a result, it becomes possible to mass-produce long-lived fuel cells that have high performance and stable operation at low cost.

One of the present invention, the use or device by a method according to any one of the invention, substantially all portions in the desired range, while preventing mechanical contact, in the set temperature range A fluorine-containing polymer ion exchange membrane produced by irradiating the ionizing radiation in a low oxygen partial pressure environment while maintaining the temperature . By adopting the present invention, the ion exchange membrane, which is the most important component for enhancing the life and performance of the fuel cell, has excellent oxidation resistance and a wide range of ion exchange capacity, and can be mass-produced at low cost. As a result, it becomes possible to mass-produce long-lived fuel cells that have high performance and stable operation at low cost.

  When the present invention is adopted, the temperature of the fluorine-containing polymer membrane substrate having a large area is always kept in an optimally defined temperature range over substantially all sites in the irradiation field and throughout the entire processing time. A large dose rate of ionizing radiation can be irradiated in an oxygen-free environment, and a fluorine-containing polymer film having a stable quality cross-linked structure can be produced in a large amount in a short time and at a low cost. Fluorine-containing polymer ions having excellent oxidation resistance and a wide range of ion exchange capacities when using a fluorine-containing polymer membrane having a crosslinked structure of high quality produced by employing the present invention as a base material The exchange membrane can be mass-produced at low cost, and as a result, a long-life fuel cell that operates stably at high performance can be produced at low cost. In addition, the modified fluorine-containing polymer film obtained by the present invention is useful as other industrial material that can be used in a radiation environment or as a medical device material that can be sterilized by radiation because it is given radiation resistance. .

  In a preferred radiation treatment method for a fluorine-containing polymer film substrate according to the present invention, a long fluorine-containing polymer film substrate is subjected to a constant-temperature electron beam treatment apparatus capable of simultaneously performing temperature control and electron beam irradiation. Let it pass. In this constant temperature electron beam processing apparatus, at the entrance position and the exit position, a part to which a part of the longitudinal direction of the fluorine-containing polymer film substrate is mechanically held at a normal temperature and is allowed to run is provided. Is provided. A heating element is provided in the constant temperature electron beam processing apparatus, and the heating element is divided into a large number of heating element elements along the longitudinal direction and the width direction of the fluorine-containing polymer film substrate, The surface temperature of these heating element is appropriately controlled in space and / or time. An inert gas is blown so as to provide a cooling effect that counteracts the heat generation effect of the fluorine-containing polymer film substrate by electron beam irradiation at the timing and timing of electron beam irradiation. In this way, regardless of whether or not during irradiation, the temperature of all the parts located within the irradiation field of the fluorine-containing polymer film substrate is kept substantially uniform, and the predetermined process proceeds. A large amount of processing can be performed in a short time by partially cooling the processed long fluorine-containing polymer film at the outlet position of the constant temperature electron beam processing apparatus and sending it out of the constant temperature electron beam processing apparatus. ing.

  In the constant temperature electron beam processing apparatus, at a position where the electron beam is not irradiated, or at a timing where the electron beam is not irradiated, the surface temperature of each of the heat generating element is set as far as the heat generating element provided away from the center of the irradiation field. By setting it high, the temperature within a predetermined set temperature range around the crystalline melting point in a short time while keeping the temperature of the portion located in and around the irradiation field of the fluorine-containing polymer film substrate uniform. To increase. At the position where the electron beam is irradiated and the timing when the electron beam is irradiated, an inert gas is supplied to the site within the irradiation field of the fluorine-containing polymer film substrate from the refrigerant passage located near the outside of the irradiation field. An electron beam having a calorific value distributed so as to reduce the temperature of the fluorine-containing polymer film substrate by spraying and lowering the temperature in a state distributed in a bowl shape around the irradiation field. As a result, the temperature of the fluorine-containing polymer film substrate is prevented from changing beyond the limit at any timing during irradiation. In addition, the spatial distribution and temporal change of the amount of heat released are substantially the same as the spatial distribution and temporal change of the amount of heat given by the electron beam in the irradiation field. The temperature distribution is uniform in terms of time and time and is within the set temperature range.

  In addition, the melting point of the fluorine-containing polymer film substrate decreases as the absorbed dose increases, and therefore the optimum set temperature range decreases as the integrated value of absorbed dose increases. The optimum cross-linking treatment can be performed at the optimum temperature by changing the value according to the value. Thus, when changing the temperature at the time of irradiation by the integrated value of the absorbed dose, the surface temperature of the heating element, the dose rate of the ionizing radiation, or the Change at least one of the heat dissipation by blowing inert gas according to the integrated value of absorbed dose, and after reaching the predetermined absorbed dose value, stop the electron beam irradiation and only the distance corresponding to the width of the irradiation field After moving the fluorine-containing polymer film substrate in the longitudinal direction and initializing it to cancel the change and returning the temperature of the fluorine-containing polymer film substrate to the set value at the start of irradiation, Repeat the irradiation. At this time, the fluorine-containing polymer film substrate is automatically moved stepwise.

  When the electron beam irradiation dose rate is large, a large amount of inert gas is blown to increase the cooling rate in order to prevent the temperature rise in the portion of the fluorine-containing polymer film substrate located in the irradiation field. It is necessary to let In this case, in order to prevent the fluorinated polymer membrane base material from being subjected to pressure due to the inert gas flux, the fluorinated polymer membrane base material is prevented from being greatly bent. The membrane substrate is provided with an appropriate tension in the longitudinal direction.

  When the integrated value of irradiation dose is not large, the optimum set temperature range can be preset to a constant value. In this case, the temperature setting value of the heating element is kept constant, and the fluorine-containing polymer film substrate is The crosslinking treatment can be performed while moving at a constant speed. Even in this case, if the cooling rate of the fluorine-containing polymer film substrate is increased by increasing the flow rate of the inert gas, etc., the amount of heat generated by the electron beam in proportion to the heat radiation can be increased. Can be irradiated on time.

  As described above, after rapidly heating the irradiation field and the portion located in the vicinity thereof while maintaining the holding portion of the fluorine-containing polymer film substrate at room temperature in the constant temperature electron beam processing apparatus, While irradiating at an irradiation dose rate, the fluorine-containing polymer film substrate is irradiated with a large amount of dose in a short time with the temperature during irradiation kept at an optimum value, and when the irradiation is completed, the treated fluorine-containing polymer A portion of the polymer film located at the outlet of the constant temperature electron beam processing apparatus is partially and rapidly cooled and moved out of the constant temperature electron beam processing apparatus and taken out. In this way, a large amount of the fluorine-containing polymer film substrate can be automatically subjected to radiation treatment at a high speed and in large quantities. Hereinafter, the embodiment and operation of the present invention will be described more specifically and in detail using examples.

With reference to FIG. 1, FIG. 2, FIG. 3, FIG. 4, the radiation treatment method for the fluorine-containing polymer film substrate of the present invention will be described. In these drawings, the same parts are denoted by the same reference numerals. 1 and 2 show an example of a constant temperature electron beam processing apparatus for a fluorine-containing polymer film substrate according to the present invention. 1 is a longitudinal sectional view, and FIG. 2 is a transverse sectional view. In FIG. 1, reference numeral 1 denotes a long and wide fluorine-containing polymer membrane substrate. In this example, polytetrafluoroethylene (PTFE) having a thickness of 100 μm, a width of 30 cm, and a length of 10 m is used. ) A membrane is used. This is initially wound on the reel 2 and moves to a state wound on the reel 3 as the process proceeds. The fluorine-containing polymer film substrate 1 is positioned by the pulley 4 and guided into the constant temperature electron beam processing apparatus 10 , heated to about 340 ° C., and maintained in a temperature range of 340 ± 5 ° C. The electron beam E is irradiated while maintaining. Cooling pulleys 5 and 6 are provided at an inlet portion and an outlet portion of the constant temperature electron beam processing apparatus 10 , and these portions are always kept at room temperature while mechanically holding the fluorine-containing polymer film substrate 1. It operates so as to promote the positioning and running of the fluorine-containing polymer film substrate 1 while maintaining it. Pulleys 7 and 8 are provided outside the exit portion of the constant temperature electron beam processing apparatus 10 . The position of the pulley 7 is fixed, and the fluorine-containing polymer film substrate 1 is positioned. The pulley 8 is movable, and always applies a predetermined tension F1 to the fluorine-containing polymer film substrate 1, and the fluorine-containing high molecular weight located in the constant temperature electron beam processing apparatus 10 is provided. Appropriate tension is always applied to the part of the molecular film substrate 1. The fluorine-containing polymer film substrate 1 that has passed through the pulley 8 is taken up by the reel 3.

The constant temperature electron beam processing apparatus 10 is provided with a processing container 11 having a radiation protection function and a gas containment function, and the inside is filled with an inert gas such as argon or nitrogen. The constant temperature electron beam processing apparatus 10 is provided with a so-called surface irradiation type electron beam irradiation apparatus 12 that irradiates an electron beam E having a flatly distributed intensity. The electron beam irradiation device 12 is a device having a structure disclosed in, for example, Japanese Patent Application Laid-Open No. 11-19190, and is flatly distributed through the first electron beam transmission window 13 and having an energy of about 300 keV and a current of about 10 mA. Can be irradiated with the electron beam. The fluorine-containing polymer film substrate 1 passes through the constant temperature electron beam processing apparatus 10 , and a heating element on the opposite side of the electron beam irradiation apparatus 12 with respect to the fluorine-containing polymer film substrate 1. A heater group 30 for heating is provided. A heat shielding plate 14 is provided between the heater group 30 for heating and the wall of the processing container 11 to prevent the processing container 11 from being overheated. The heating heater group 30 is mechanically held on the heat shield plate 14 via a thermal insulator (not shown). The heat shielding plate 14 is cooled by water cooling or the like as necessary. A second electron beam transmission window 15 and a partition wall 16 for cooling and mechanically supporting the second electron beam transmission window 15 are provided between the fluorine-containing polymer film substrate 1 and the electron beam transmission window 13 in the processing container 11. Yes. The first electron beam transmission window 13 and the second electron beam transmission window 15 are cooled by the inert gas that is guided from the nozzle 17 and flows out of the nozzle 18 flowing between them at a high speed.

At the entrance part and the exit part of the constant temperature electron beam processing apparatus 10 , the heat shielding plate 14 and the partition wall 16 are close to each other in a non-contact manner with the fluorine-containing polymer film substrate 1 interposed therebetween. At these positions, nozzle groups 19 and 20 for spraying an inert gas toward the upper and lower surfaces of the fluorine-containing polymer film substrate 1 shown in the figure are provided, and the fluorine-containing polymer film is flowed by the flow of the inert gas. The fluorine-containing polymer film substrate 1 is cooled while the mechanical contact of the substrate 1 is prevented and held. The partition wall 16 is provided with non-contact thermometer groups 21 and 22 so that the temperature of the surface position of the fluorine-containing polymer film substrate 1 in the directions indicated by the arrows 23 and 24 can be detected. As shown in FIGS. 1 and 2, the central axis of the electron beam E is the Z axis, the intersection of the fluorine-containing polymer film substrate 1 and the Z axis is the origin O, and the constant temperature electron beam processing is performed through the origin O. A direction from the inlet portion to the outlet portion of the apparatus 10 is defined as an X axis, and a direction passing through the origin O and perpendicular to the X axis and the Z axis is defined as a Y axis. In the constant temperature electron beam processing apparatus 10 , the longitudinal direction of the fluorine-containing polymer film substrate 1 is parallel to the X axis, and the width direction of the fluorine-containing polymer film substrate 1 is parallel to the Y axis. The irradiation field Fi of the electron beam E has a width in the X-axis direction of FW and a length in the Y-axis direction of FL.

  It is close to and opposed to the fluorine-containing polymer film substrate 1 and is located on the same side as the second electron beam transmission window 15 and the partition wall 16 with respect to the fluorine-containing polymer film substrate 1 and A partition plate 25 is provided adjacent to the fluorine-containing polymer film substrate 1 in parallel. The structure of the partition plate 25 is shown in FIG. A cut-out hole Win having a width FW1 in the X-axis direction and a width FL in the Y-axis direction with respect to the Z axis is opened. The width FW1 is a value close to the width FW of the irradiation field Fi. Refrigerant passages 26 and 27 are provided in parallel to the partition plate 25 on the side opposite to the fluorine-containing polymer film substrate 1 with respect to the partition plate 25. A large number of refrigerant outlets 26-1 and 27-1 are attached to the refrigerant passages 26 and 27, respectively. The refrigerant passages 26 and 27 and the large number of refrigerant outlets 26-1 and 27-1 are unevenly distributed so as not to prevent the electron beam E from being irradiated on the fluorine-containing polymer film substrate 1 in the range of the irradiation field Fi. Is provided. An inert gas such as nitrogen is introduced into the refrigerant passages 26 and 27, and the inert gas passes through a large number of refrigerant outlets 26-1 and 27-1 at the timing when the electron beam E is irradiated. The portion of the fluorine-containing polymer film substrate 1 that is sprayed toward the molecular film substrate 1 and located in the irradiation field Fi is uniformly cooled. The spatial range in which the inert gas is sprayed onto the fluorine-containing polymer film substrate 1 is limited by the size of the cutout hole Win. The spatial distribution of the inert gas is optimized by adjusting the mounting positions of the large number of refrigerant jets 26-1 and 27-1, the spatial distribution of the hole sizes, and the like. The amount of inert gas blown and the distribution thereof are electron beams so that the temperature of the portion of the fluorine-containing polymer film substrate 1 located in the irradiation field Fi has a cooling effect that does not change by irradiation with the electron beam E. Is controlled according to the strength of the. The temperature of the inert gas sprayed is constant, but may be appropriately controlled.

FIG. 3 (a) shows the refrigerant passages 26, 27, the partition plate 25, the fluorine-containing polymer membrane substrate from the positive direction of the Z-axis by removing a part of the constant temperature electron beam processing apparatus 10 having a positive Z coordinate value. 1 and a plan view of the heater group 30 for heating. FIG. 3B shows a part of a sectional view on the YZ plane corresponding to FIG. FIG. 3C shows a part of a sectional view on the XZ plane corresponding to FIG. The shaded portion in FIG. 3A represents the irradiation field Fi of the electron beam E, the irradiation field width is FW, and the irradiation field length is FL. In the present embodiment, the desired range completely coincides with the irradiation field Fi. 5A and 5B respectively show a plan view and a side sectional view of the heater group 30 for heating. As shown in FIG. 5A, the heater group 30 for heating includes a plurality of heater elements arranged in parallel to the XY plane and a plurality of heater elements arranged in parallel to the XZ plane. All of them are arranged at a certain distance from the fluorine-containing polymer film substrate 1, for example, 2.5 cm. These heater elements are one specific example of the heating element. The heating heater group 30 has X-coordinates of -X2, -X1,0, X1, X2 and Y-coordinates of -Y3, -Y2, -Y1,0, Y1, Y2, Y3, respectively. It is divided into 35 heater elements with a center, which are arranged adjacent to each other at a small distance, for example 2 mm. Here, X1 is 5.8 cm, X2 is 13.8 cm, Y1 is 10.8 cm, Y2 is 15.1 cm, and Y3 is 17.5 cm. These heater elements are composed of five heater element groups including seven heater elements aligned in the Y-axis direction, that is, five heating element groups aligned in the X-axis direction. Each of these heater elements is represented by H (i, j). Here, i represents the above-mentioned suffix in the X-axis direction that represents the center coordinate of the heater element surface, and includes -2, -1, 0, 1, and 2, and j represents the center coordinate of the surface of the heater element. Represents the suffix in the Y-axis direction, and includes -3, -2, -1, 0, 1, 2, 3.

  The heater element H (i, j), i = ± 2, ± 1, 0, j = ± 2, ± 1, 0 has a Z-coordinate of −2.5 cm, and the fluorine-containing polymer membrane substrates 1 to 2 It faces the fluorine-containing polymer film substrate 1 in parallel at a position 5 cm away. The heater element H (i, j), i = ± 2, ± 1, 0, j = ± 3, is at a position away from the center of the irradiation field by −Y3 and Y3 in the Y direction, respectively, and the coordinates in the Z-axis direction are from 0 It extends to -Z1 and is arranged parallel to the XZ plane. The latter serves to make the temperature distribution in the Y-axis direction of the fluorine-containing polymer film substrate 1 uniform. All of these heater elements are divided thermally and electrically so that they can be controlled independently.

  Each of these heater elements H (i, j) is controlled in different manners at two timings. This timing includes rapid heating timing T1 for rapidly heating the fluorine-containing polymer film substrate 1 from an initial temperature, for example, room temperature, to a specified temperature, for example, 340 ° C., and the fluorine-containing polymer film substrate 1 Is a temperature keeping timing T2 for keeping the temperature at a specified temperature, for example, 340 ° C. FIG. 6 shows a distribution example of the calorific value Q (i, j) of each heater element H (i, j) at the rapid heating timing T1. In FIG. 6, the calorific value is represented by area density. FIG. 6A shows the heating value Q (0, j), j = −3, − of the heater element H (0, j), j = −3, −2, −1, 0, 1, 2, 3. 2, -1, 0, 1, 2, 3, and FIG. 6B shows the heater element H (± 1, j), j = −3, −2, −1, 0, 1, 2, 3 , J = −3, −2, −1, 0, 1, 2, 3, and FIG. 6C shows the heater element H (± 2, j), With heat generation amount Q (± 2, j) of j = −3, −2, −1, 0, 1, 2, 3, j = −3, −2, −1, 0, 1, 2, 3, FIG. 6D shows the heater element H (i, 0), i = −2, −1, 0, 1, 2, and the calorific value Q (i, 0), i = −2, −1, 0. 6 (e) shows the heater element H (i, ± 1), the heat value Q (i, ± 1) of i = −2, −1, 0, 1, 2, = −2, −1, 0, 1, 2, and FIG. 6F shows the heating value Q of the heater element H (i, ± 2), i = −2, −1, 0, 1, 2 (I, ± 2), i = −2, −1, 0, 1, 2, and FIG. 6G shows the heater element H (i, ± 3), i = −2, −1, 0, The calorific values Q (i, ± 3) of 1, 2 are i = −2, −1, 0, 1, 2, and so on.

  Similarly, FIG. 7 shows the heat generation amount Q (i, j) of each heater element H (i, j) at the heat retention timing T2. In FIG. 7, the calorific value is represented by area density. FIG. 7A shows the heating value Q (0, j), j = −3, − of the heater element H (0, j), j = −3, −2, −1, 0, 1, 2, 3. 2, -1, 0, 1, 2, 3, and FIG. 7B shows the heater element H (± 1, j), j = −3, −2, −1, 0, 1, 2, 3 , J = −3, −2, −1, 0, 1, 2, 3, and FIG. 7C shows the heater element H (± 2, j), The calorific value Q (± 2, j) of j = −3, −2, −1, 0, 1, 2, 3, and j = −3, −2, −1, 0, 1, 2, 3 FIG. 7 (d) shows the heater element H (i, 0), i = −2, −1, 0, 1, 2 heat generation amount Q (i, 0), i = −2, −1, 0, 1 FIG. 7E shows the heater element H (i, ± 1), i = −2, −1, 0, 1, 2, and the calorific value Q (i, ± 1), i. -F, -1, 0, 1, 2, and FIG. 7 (f) shows the heating value Q (() of the heater element H (i, ± 2), i = -2, -1, 0, 1, 2. i, ± 2), i = −2, −1, 0, 1, 2, and FIG. 7G shows the heater element H (i, ± 3), i = −2, −1, 0, 1 2, the calorific value Q (i, ± 3), i = −2, −1, 0, 1, 2, and so on.

  FIG. 8 shows a time function for controlling the calorific value Q (i, j) of each heater element H (i, j) and a time function for controlling the electron beam intensity. FIG. 8A shows a function Fb (t) expressed by normalizing the heating time t for controlling the electron beam intensity, and FIG. 8B shows the heater element H (i, j), i = −2 to +2. , J = −3 to +3 is a function Fh (t) expressed by normalizing the heating time t. In these figures, the rapid heating timing T1 corresponds to the heating time t between 0 and 12.0 seconds, the heat retention timing T2 corresponds to the heating time t after 12.0 seconds, and the beam irradiation timing T3 corresponds to the heating time. t corresponds to between 24.0 and 44.5 seconds, and between 65.3 and 85.8 seconds, and between 106.6 and 127.1 seconds.

  As described above, the surface temperature Th (i, j, t) of each heater element H (i, j) when the heating value Q (i, j) of each heater element H (i, j) is controlled is determined. This is shown in FIG. Here, t is the heating time, and the value on the vertical axis is expressed in Celsius temperature. FIG. 9A shows the heater element H (0, j), j = ± 3, ± 2, ± 1, 0, surface temperature Th (0, j, t), j = ± 3, ± 2, ± 1. , 0, t = 0 to 145 seconds. FIG. 9B shows a heater element H (± 1, j), j = ± 3, ± 2, ± 1, 0, surface temperature Th (± 1, j, t), j = ± 3, ± 2, ± 1, 0, t = 0 to 145 seconds. FIG. 9C shows a heater element H (−2, j), j = ± 3, ± 2, ± 1, 0, surface temperature Th (−2, j, t), j = ± 3, ± 2, ± 1, 0, t = 0 to 145 seconds. FIG. 9D shows the heater element H (2, j), j = ± 3, ± 2, ± 1,0, surface temperature Th (2, j, t), j = ± 3, ± 2, ± 1 , 0, t = 0 to 145 seconds. When the fluorine-containing polymer film substrate 1 is stationary, Th (−2, j, t) matches Th (2, j, t).

  The spatial distribution of the surface temperature of each heater element H (i, j) at typical heating times t = 11.5 seconds, 21.9 seconds, 24.3 seconds, 29.9 seconds shown in FIG. Is shown in FIG. The value on the vertical axis in FIG. 10 represents the Celsius temperature. FIG. 10A shows the surface temperature Th (0, j, t) of the heater element H (0, j), j = ± 3, ± 2, ± 1, 0. FIG. 10B shows the surface temperature Th (± 1, j, t) of the heater element H (± 1, j), j = ± 3, ± 2, ± 1, 0. FIG. 10C shows the surface temperature Th (± 2, j, t) of the heater element H (± 2, j), j = ± 3, ± 2, ± 1, 0. FIG. 10D shows the surface temperature Th (i, 0, t) of the heater element H (i, 0), i = ± 2, ± 1, 0. FIG. 10E shows the surface temperature Th (i, ± 1, t) of the heater element H (i, ± 1), i = ± 2, ± 1,0. FIG. 10F shows the surface temperature Th (i, ± 2, t) of the heater element H (i, ± 2), i = ± 2, ± 1, 0. FIG. 10G shows the surface temperature Th (i, ± 3, t) of the heater element H (i, ± 3), i = ± 2, ± 1, 0. As can be seen from these figures, the temperature in the same surface of each heater element is distributed almost uniformly.

  As shown in FIGS. 9 and 10, the surface temperature Th (i, j, t) of the heater element H (i, j) is the surface located at the end in the width direction of the fluorine-containing polymer film substrate 1. The temperature is getting higher. The surface temperature of the fluorine-containing polymer film substrate 1 when the fluorine-containing polymer film substrate 1 is heated by thermal radiation with these heater elements H (i, j) is expressed as Tp1 (x, y, t). To do. Here, x represents the position in the X-axis direction, y represents the position in the Y-axis direction, and t represents the time after the start of heating, that is, the heating time. The surface temperature Th (i, j, t) of the heater element H (i, j) is the position in the X direction when the temperature Tp1 (x, y, t) of the fluorine-containing polymer film substrate 1 is within the irradiation field width FW. Regardless of x and heating time t, it is determined to have a uniform temperature distribution in the width direction, that is, the Y direction. As shown in FIGS. 1 (a) and 2 (a), the temperature of the fluorine-containing polymer film substrate 1 is maintained at room temperature in the vicinity of the cooling pulleys 5 and 6. The portion located in the irradiation field Fi of the fluorine-containing polymer film substrate 1 is heated to 340 ± 5 ° C. and is maintained in this temperature range both spatially and temporally.

  In this way, the surface temperature Tp1 (x, y, t) of the fluorine-containing polymer film substrate 1 is kept uniformly in the range of 340 ± 5 ° C. both spatially and temporally within the irradiation field Fi. As shown in FIG. 11A, the intensity distribution in the X-axis direction is an electron beam E having an intensity (300 keV, 0.24 mA) uniformly distributed in the X-axis direction and the Y-axis direction in the irradiation field Fi. When irradiated, the X-axis direction distribution of the temperature Tp2 (x, y, t) of the fluorine-containing polymer film substrate 1 is as shown in FIG. 11B, and is uniform in the Y-axis direction. Distributed. As shown in FIG. 11B, the temperature Tp2 (0, 0, 21 at the center of the irradiation field of the fluorine-containing polymer film substrate 1 at the heating time t = 21.9 seconds immediately before the irradiation with the electron beam E is obtained. .9) is 343.9 ° C., and the temperature Tp2 (0, 0, 24.3 at the center of the irradiation field of the fluorine-containing polymer film substrate 1 at the heating time t = 24.3 seconds immediately after the start of irradiation is shown. ) Is 350.1 ° C., and the temperature Tp2 (0, 0) at the center of the irradiation field of the fluorine-containing polymer film substrate 1 at the heating time t = 29.9 seconds after 5.9 seconds from the start of irradiation. 29.9) is 395.0 ° C., and the temperature Tp2 at the center of the irradiation field of the fluorine-containing polymer film substrate 1 at a heating time t = 42.7 seconds after 18.7 seconds has elapsed since the start of irradiation. (0, 0, 42.7) is 440.7 ° C. That is, the temperature Tp2 (x, y, t) of the fluorine-containing polymer film substrate 1 becomes too high during irradiation, and the pyrolysis of the fluorine-containing polymer film substrate 1 proceeds. The absorbed dose in this case corresponds to 210 kGy.

On the other hand, an inert gas such as nitrogen gas is discharged from a number of refrigerant jets 26-1 and 27-1 attached to the refrigerant passages 26 and 27 shown in FIGS. FIG. 12 shows the temperature Tp3 (x, y, t) of the fluorine-containing polymer film substrate 1 when the electron beam E is not irradiated in a state where a part of the fluorine-containing polymer film substrate 1 is cooled and passed. It shows. In this case, the heat transfer coefficient between the inert gas and the fluorine-containing polymer film substrate 1 is 0.0009 W / (cm ² * deg). 12A shows the Y-axis direction distribution of the temperature Tp3 (x, y, t) of the fluorine-containing polymer membrane substrate 1, and FIG. 12B shows the temperature of the fluorine-containing polymer membrane substrate 1. This is a distribution in the X-axis direction of Tp3 (x, y, t). These figures are distributed so as to be lower at the center position than at the end position within the irradiation field width FW of the irradiation field Fi of the electron beam E at the beam irradiation timing T3 and partially decrease with time. Represents that. The time change of the temperature Tp3 (0, 0, t) of the fluorine-containing polymer film substrate 1 at the irradiation field center in this case is shown in FIG.

  In the state where the fluorine-containing polymer film substrate 1 is partially cooled as described above, at the beam irradiation timing T3 as shown in FIG. 8A, the X-axis direction as shown in FIG. When the electron beam E having a uniform intensity distribution in the Y-axis direction is irradiated, the Y-axis direction distribution Tp0 (0, y, t) of the temperature Tp0 (x, y, t) of the fluorine-containing polymer film substrate 1 is obtained. As shown in FIG. 13 (a), the X-axis direction distribution Tp0 (x, 0, t) is shown in FIG. 13 (b), and the fluorine-containing polymer film substrate at the center of the irradiation field is shown in FIG. The time change of the temperature Tp0 (0, 0, t) of 1 is as shown in FIG. As shown in these figures, the temperature of the fluorine-containing polymer film substrate 1 is within the range of 340 ± 5 ° C. at any position in the irradiation field Fi at any time.

  When the intensity of the electron beam E is determined, the temperature and / or flow rate and / or the flow rate of the inert gas blown to the fluorine-containing polymer film substrate 1 from the large number of refrigerant outlets 26-1, 27-1. The flow velocity is returned to a gas supply control device (not shown) so that the temperature distribution in the direction indicated by the arrows 23 and 24 in FIG. Automatically controlled. In the above-described case, the dose given to the fluorine-containing polymer film substrate 1 by one irradiation for 20.5 seconds corresponds to 210 kGy. While increasing the intensity of the electron beam E, the fluorine-containing polymer film substrate 1 is cooled by an inert gas blown to the fluorine-containing polymer film substrate 1 from a large number of refrigerant jets 26-1 and 27-1. The dose rate given to the fluorine-containing polymer film substrate 1 can be arbitrarily increased without increasing the temperature by increasing the. In this case, at least one of the intensity of the electron beam and the cooling by the inert gas is controlled so that the inflow and outflow of heat to the fluorine-containing polymer film substrate 1 in the irradiation field Fi are equal.

The dose rate R of the electron beam E and a number of refrigerant jets for maintaining the temperature Tp0 (x, y, t) of the fluorine-containing polymer film substrate 1 in the irradiation field Fi at a predetermined set temperature. The relationship between the inert gas blown from 26-1 and 27-1 to the fluorine-containing polymer film substrate 1 and the heat transfer coefficient K between the fluorine-containing polymer film substrate 1 is shown in FIG. ing. In FIG. 15, curve (1) shows the case where the temperature Tp0 (x, y, t) of the portion located in the irradiation field Fi of the fluorine-containing polymer film substrate 1 is kept at 340 ° C., and curve (2) shows When the temperature Tp0 (x, y, t) of the portion located in the irradiation field Fi of the fluorine-containing polymer film substrate 1 is kept at 200 ° C., the curve (3) shows the fluorine-containing polymer film substrate 1 The temperature Tp0 (x, y, t) of the part located in the irradiation field Fi of FIG. In the case of the curves (2) and (3), the temperature control of the heater group 30 must be reset to appropriate values different from those shown in FIGS. As can be seen from these curves, by increasing the heat transfer coefficient K, the temperature Tp0 (x, y, t) of the portion located in the irradiation field Fi of the fluorine-containing polymer film substrate 1 can be determined in advance. The electron beam E can be irradiated in a short time with a large dose rate R in a state where the temperature is within the set temperature range. For example, when the temperature Tp0 (x, y, t) of the fluorine-containing polymer film substrate 1 is maintained at 340 ° C., an appropriate electron can be obtained by setting the heat transfer coefficient K to 0.016 W / (cm ² * deg). The dose rate R of line E is 200 kGy / sec. In this case, the irradiation of 200 kGy is completed in one second. When the irradiation field width FW is 10 cm, the irradiation treatment of the fluorine-containing polymer film substrate 1 of 360 m is completed in one hour.

  As described above, the temperature Tp1 (x, y, t) of the fluorine-containing polymer film substrate 1 is uniformly 340 in the Y-axis direction within the range of the irradiation field Fi before and after irradiation with the electron beam E. Maintaining the temperature in the range of ± 5 ° C. is achieved by optimizing and increasing the surface temperature Th (i, j, t) of the heater element H (i, j) as the distance from the origin increases in the Y-axis direction. During irradiation with the electron beam E, the temperature Tp0 (x, y, t) of the fluorine-containing polymer film substrate 1 is uniformly 340 ± 5 ° C. in the Y-axis direction and the X-axis direction within the range of the irradiation field Fi. Is to keep the surface temperature of the heater element H (i, j) close to the center of the irradiation field Fi at an appropriate level, and the portion of the fluorine-containing polymer film substrate 1 located in the irradiation field Fi. This is achieved by cooling the surface by forced convection of an inert gas and irradiating the same place with an electron beam E having a heat quantity corresponding to the heat quantity released by this cooling. At this time, the X-axis direction of the temperature decrease rate of the fluorinated polymer film substrate 1 that decreases the X-axis direction distribution and the Y-axis direction distribution of the temperature increase rate heated by the electron beam E by blowing an inert gas. Even if the irradiation time of the electron beam E becomes longer by making the distribution and the Y-axis direction distribution match, the temperature Tp0 (x, y, t) of the fluorine-containing polymer film substrate 1 is changed in the X-axis direction. In addition, it can be kept in the range of 340 ± 5 ° C. uniformly in the Y-axis direction. More preferably, the surface temperature of the fluorine-containing polymer film substrate 1 is fed back to automatically control the relationship between the intensity of the electron beam E and the amount of inert gas sprayed over time.

  Although the invention has been described with reference to embodiments and examples, the invention is not limited to the embodiments and examples illustrated herein, and various modifications can be made without departing from the spirit and scope of the invention. It should be understood that various embodiments are possible and that various changes and modifications can be made. For example, in the above embodiment, the case where the temperature of each heater element H (i, j) is preset spatially or temporally is shown, but it can also be automatically controlled using a computer or the like. By changing the time function shown in FIG. 8B according to the integrated value of the absorbed dose, the set temperature range during irradiation according to the integrated value of the absorbed dose received by the fluorine-containing polymer film substrate 1 The temperature at the time of irradiation with ionizing radiation can be optimized over time. The present invention is naturally applicable to the case where various monomers are polymerized with the graph by irradiation of the fluorine-containing polymer film. In the present invention, a fluorine-containing polymer film that has not been subjected to high-temperature radiation treatment is basically referred to as a fluorine-containing polymer film substrate in order to distinguish it from the film after treatment, and the irradiation field includes the above-mentioned irradiation field. This means a spatial range in which the fluoropolymer membrane substrate is irradiated with the ionizing radiation, and does not include a portion where the ionizing radiation protrudes from the fluorine-containing polymer membrane. The electron beam intensity means the power of the absorbed electron beam, and takes a value proportional to the current when the energy is constant. In the embodiments and examples illustrated here, the case of irradiating with an electron beam is described. However, the present invention is not limited to this, and it is a matter of course that the case of irradiating with other ionizing radiation is included.

  When the present invention is adopted, the large-area fluorine-containing polymer membrane substrate is always kept at a temperature within the set temperature range that is optimally determined over substantially the entire range in the irradiation field and throughout the entire processing time. In this state, ionizing radiation can be irradiated at a large dose rate in an oxygen-free environment, and a fluorine-containing polymer film having a stable quality cross-linked structure can be produced in a large amount and at a low cost in a short time. Fluorine-containing polymer having excellent oxidation resistance and a wide range of ion exchange capacity by using as a substrate a low-cost and high-quality fluorine-containing polymer membrane produced by adopting the present invention The ion exchange membrane can be mass-produced at low cost, and as a result, a long-life fuel cell having high performance and stable operation can be produced at low cost, so that the industrial utility value is extremely high. Further, since the modified fluorine-containing polymer film obtained by the present invention is imparted with radiation resistance, the industrial utility value as an industrial material in a radiation environment or a medical device material capable of radiation sterilization is Extremely high.

It is the figure which represented the constant temperature electron beam processing apparatus concerning this invention with the longitudinal cross-sectional view. It is the figure which represented the constant temperature electron beam processing apparatus concerning this invention with the cross-sectional view. It is the top view, the longitudinal cross-sectional view, and the cross-sectional view showing the principal part of the constant temperature electron beam processing apparatus concerning this invention. It is a figure showing the structure of the partition plate which is a part of principal part of the constant temperature electron beam processing apparatus concerning this invention. It is the figure showing the top view and side sectional view of the heater group which are a part of the principal part of the constant temperature electron beam processing apparatus concerning this invention. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the emitted-heat amount of each heater element in the rapid heating timing T1. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the emitted-heat amount of each heater element in the heat retention timing T2. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the normalized time function which controls the emitted-heat amount of each heater element, and the normalized time function which controls the intensity | strength of an electron beam. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the temperature change of the surface of each heater element. It is a figure explaining the effect | action concerning this invention, and is a figure showing the spatial distribution of the surface temperature of each heater element. It is a figure explaining the effect | action concerning this invention, and is a figure which shows temperature distribution in the longitudinal direction of an electron beam intensity distribution and a fluorine-containing polymer film base material at the time of irradiating this electron beam. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the temperature distribution of a fluorine-containing polymer film | membrane base material when not irradiating the electron beam E in the state which sprayed the inert gas to the irradiation field. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the spatial distribution of the temperature of a fluorine-containing polymer film base material, and its time change at the time of irradiating an electron beam in the state which sprayed the inert gas to the irradiation field It is. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the time change of the temperature of a fluorine-containing polymer membrane base material. It is a figure explaining the operation | movement concerning this invention, an effect, and when maintaining the temperature of a fluorine-containing polymer film base material at the predetermined temperature, the dose rate of an electron beam, the inert gas in a radiation field, and a fluorine-containing It is a figure showing the relationship with the heat transfer coefficient between the system polymer film base materials.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluorine-containing polymer film base material 2 Reel 3 Reel 4 Pulley 5 Cooling pulley 6 Cooling pulley 7 Pulley 8 Pulley
10 constant temperature electron beam processing equipment 11 processing container
DESCRIPTION OF SYMBOLS 12 Electron beam irradiation apparatus 13 Electron beam transmission window 14 Heat shielding board 15 Electron beam transmission window 16 Bulkhead 17 Nozzle 18 Nozzle 19 Nozzle group 20 Nozzle group 21 Temperature detector 22 Temperature detector 23 Arrow indicating temperature detection direction 24 Temperature detection direction 25 Partition plate 26 Refrigerant passage 26-1 Refrigerant outlet 27 Refrigerant passage 27-1 Refrigerant outlet
30 Heater Group E Electron Fi Fi Irradiation Field FL Irradiation Field Length FW Irradiation Field Width T1 Rapid Heating Timing T2 Insulation Timing T3 Beam Irradiation Timing Win Cutout Hole

Claims (12)

While maintaining a fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction at a temperature within a predetermined set temperature range, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer membrane substrate in a low oxygen partial pressure environment. In the manufacturing method of a modified fluorine-containing polymer film including an irradiation step of irradiating under,
The irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction and an irradiation field length in the width direction,
The fluorine-containing polymer film substrate includes a desired range having a size substantially corresponding to the irradiation field of the ionizing radiation,
The irradiation step includes a first step of heating the desired range of the fluorine-containing polymer film substrate to a temperature within the set temperature range;
By irradiating the portion occupying the desired range with the ionizing radiation having a predetermined intensity distribution, the portion is heated with a predetermined heating rate, and the portion occupying the desired range during the irradiation time of the ionizing radiation A second step of cooling the part with a predetermined cooling rate by blowing an inert gas on the
The heating in the first step is performed by a heating element having a distributed heating value provided in a non-contact manner facing the fluorine-containing polymer film substrate,
The blowing of the inert gas in the second step is such that the temperature of the fluorine-containing polymer film substrate becomes lower at the center position than at the end position within the irradiation field width of the irradiation field. distributed partly over time by the heat radiation so as to reduce, by irradiating the ionizing radiation to provide the heat distributed to counteract this heat dissipation, the inert gas blowing intensity distribution and the ionizing radiation At least one of the intensity distributions is set so that the cooling rate and the heating rate are substantially matched over the irradiation time in all the sites in the desired range of the fluorine-containing polymer film substrate or A manufacturing method characterized by being controlled. While maintaining a fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction at a temperature within a predetermined set temperature range, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer membrane substrate in a low oxygen partial pressure environment. In the manufacturing method of a modified fluorine-containing polymer film including an irradiation step of irradiating under,
The irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction and an irradiation field length in the width direction,
The fluorine-containing polymer film substrate includes a desired range having a size substantially corresponding to the irradiation field of the ionizing radiation,
The irradiation step includes a first step of heating the desired range of the fluorine-containing polymer film substrate to a temperature within the set temperature range;
By irradiating the portion occupying the desired range with the ionizing radiation having a predetermined intensity distribution and heating the portion, and blowing an inert gas onto the portion occupying the desired range during the irradiation time of the ionizing radiation A second step of cooling the part,
The heating in the first step is performed by a heating element having a distributed heating value provided in a non-contact manner facing the fluorine-containing polymer film substrate,
The blowing of the inert gas in the second step is such that the temperature of the fluorine-containing polymer film substrate becomes lower at the center position than at the end position within the irradiation field width of the irradiation field. distributed partly over time by the heat radiation so as to reduce, by irradiating the ionizing radiation to provide the heat distributed to counteract this heat dissipation, the inert gas blowing intensity distribution and the ionizing radiation At least one of the intensity distributions is related to the other over the irradiation time so that the temperature of substantially all of the fluorine-containing polymer film substrate within the desired range falls within the set temperature range. A manufacturing method characterized by being set or controlled. While maintaining a fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction at a temperature within a predetermined set temperature range, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer membrane substrate in a low oxygen partial pressure environment. In the manufacturing method of a modified fluorine-containing polymer film including an irradiation step of irradiating under,
The irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction and an irradiation field length in the width direction,
The fluorine-containing polymer film substrate includes a desired range having a size substantially corresponding to the irradiation field of the ionizing radiation,
The irradiation step includes a first step of heating the desired range of the fluorine-containing polymer film substrate to a temperature within the set temperature range;
The portion occupying the desired range is heated by a heating element having a distributed calorific value provided in a non-contact manner facing the fluorine-containing polymer film substrate, and the ionizing radiation having a predetermined intensity distribution is heated A second step of heating the portion by irradiating the portion occupying the desired range and cooling the portion by blowing an inert gas to the portion occupying the desired range during the irradiation time of the ionizing radiation. Including
The heating in the first step is performed by the heating element,
The blowing of the inert gas in the second step is such that the temperature of the fluorine-containing polymer film substrate becomes lower at the center position than at the end position within the irradiation field width of the irradiation field. distributed partly over time by the heat radiation so as to reduce, by irradiating the ionizing radiation to provide the heat distributed to counteract this heat dissipation, the inert gas blowing intensity distribution and the ionizing radiation At least one of the intensity distribution and the calorific value distribution of the heating element is irradiated so that the temperature of substantially all of the desired range of the fluorine-containing polymer film substrate falls within the set temperature range. Manufacturing method characterized in that it is set or controlled in relation to the other over time. The fluorine-containing polymer film substrate includes a first substrate region mechanically held at a temperature lower than the set temperature range, and a second substrate region heated by the heating element. And a third base material region that has been irradiated with the ionizing radiation and maintained at a temperature within the set temperature range, and the third base material region includes the desired range. The method according to any one of claims 1 to 3 . The desired range passes through the isothermal radiation processing apparatus that receives the ionizing radiation,
The constant temperature radiation processing apparatus includes the heating element, and a first apparatus region that mechanically holds a part of the fluorine-containing polymer film substrate at a temperature lower than the set temperature range, and
A second device region for heating a portion occupying the desired range by the heating element to a temperature within or near the set temperature range;
Described in any one of claims 1 to 4, characterized in that a third device region provide a predetermined dose by irradiating ionizing radiation to the part occupying the desired range in order Method. Isothermal radiation for irradiating the fluorine-containing polymer film substrate with a predetermined dose of ionizing radiation while maintaining the fluorine-containing polymer film substrate having a longitudinal direction and a width direction at a temperature within a predetermined temperature range. A processing device comprising:
The irradiation field of the ionizing radiation has an irradiation field width in the longitudinal direction and an irradiation field length in the width direction,
The fluorine-containing polymer film substrate and the radiation field of the ionizing radiation and the heated range heated in or near the temperature the set temperature range and the holding portion to be positioned and held within the isothermal radiation treatment apparatus And a desired range of substantially matching sizes,
The constant-temperature radiation processing apparatus maintains a low temperature at which the held part can be held and mechanically holds the held part,
In the vicinity of the irradiation field, the heating range is set within or near the set temperature range by a heating element including a plurality of heating element elements provided in a non-contact manner facing the fluorine-containing polymer film substrate. A second device region for heating to a temperature of
A third device region that irradiates the ionizing radiation to the desired range and heats it with a predetermined heating rate, and maintains a portion occupying the desired range at a temperature within the set temperature range; and
In the third device region, the part is cooled with a predetermined cooling rate by spraying an inert gas on the part occupying the desired range during the irradiation time of the ionizing radiation,
The inert gas spray is partially distributed in such a manner that the temperature of the fluorine-containing polymer film substrate is lower at the center position than at the end position within the irradiation field width of the irradiation field. By radiating the ionizing radiation to give a heat quantity distributed so as to counteract this heat radiation,
At least one of the blowing intensity distribution of the inert gas and the intensity distribution of the ionizing radiation is such that any part within the desired range is maintained at a temperature within the set temperature range during the time of irradiation with the ionizing radiation. A device characterized in that it is set or controlled in relation to the other. The heating element includes a plurality of heating element elements that are spatially divided, and the heating element is provided in a central portion within the irradiation field so as to face the fluorine-containing polymer film substrate. And a second heating element provided to face the fluorine-containing polymer film substrate at a position away from the center of the irradiation field in the width direction,
The method according to any one of claims 1 to 5 , wherein the surface temperature of the second heating element is set higher than the surface temperature of the first heating element. The fluorine-containing polymer film substrate has a longitudinal direction and a width direction, and the heating element includes a first heating element group and a second heating element including a plurality of heating element elements aligned in the width direction. has element group, according to any one of claims 1 to 5 said first heating element group and the second heating element group, characterized in that aligned with the longitudinal direction How. 9. The method according to claim 8 , wherein the heat generation amount of each heat generating element included in the same heat generating element group aligned in the width direction is controlled according to the same time function. The set temperature range in an arbitrary part of the fluorine-containing polymer film substrate is an integrated value of the absorbed dose of the ionizing radiation absorbed in the past in the same arbitrary part of the fluorine-containing polymer film substrate. the method as claimed in any one of claims 1 to claim 5, or claims 7 to 9, characterized in that it is determined to decrease while maintaining the predetermined relationship in response to. The fluorine-containing polymer film substrate is a polytetrafluoroethylene film, a tetrafluoroethylene-hexafluoropropylene copolymer film, or a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film. The method according to any one of claims 1 to 5 or claims 7 to 10 . A method or apparatus according to any one of claims 1 to 11 , wherein substantially all of the desired range is within the set temperature range with mechanical contact prevented. A fluorine-containing polymer film having a crosslinked structure, which is produced by irradiating the ionizing radiation in a low oxygen partial pressure environment while maintaining the temperature.

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