JP4178150B2 - Radiation treatment method for polymer membrane, modified polymer membrane and fuel cell - 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. Due to its role as a polymer ion exchange membrane, it has a high ion exchange capacity as an electrolyte, excellent resistance to hydroxyl radicals, that is, oxidation resistance, and water retention of the membrane to keep electric resistance low. Is required to be constant and high. On the other hand, because of its role as a diaphragm, it is required that the film has excellent mechanical strength and dimensional stability, and does not have excessive permeability to hydrogen gas, methanol, or oxygen gas.

  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. Thereafter, a perfluorosulfonic acid membrane “Nafion (registered trademark of DuPont)” developed by DuPont to overcome this drawback has been generally used.

  However, conventional fluorine-containing polymer ion exchange membranes such as “Nafion” are excellent in the durability and stability, but the ion exchange capacity is as small as about 1 meq / g, and the water retention is not good. The ion exchange membrane is sufficiently dried and proton conductivity is lowered, and when methanol is used as a fuel, there are drawbacks such as membrane swelling and methanol crossover. Further, if an attempt is made to introduce a large number of sulfonic acid groups for the purpose of increasing the ion exchange capacity, since the polymer chain does not have a cross-linked structure, the membrane strength is remarkably lowered and the membrane easily breaks. 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. In addition, conventional fluorine-containing polymer ion exchange membranes such as “Nafion” are very difficult because the synthesis of the monomers is difficult and complicated, and the process of polymerizing them to produce a polymer membrane is also very complicated. Expensive. This is a major obstacle when a conventional proton exchange membrane fuel cell is mounted on an automobile or the like for practical use. Therefore, it is required to develop a low-cost and high-performance electrolyte membrane 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, in a normal fluorine-containing polymer membrane substrate, 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, the hydrocarbon-based monomer as the graft monomer has a problem of low oxidation resistance. 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 a resin for industrial and private use. 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. Although the fluorine-containing polymer film substrate is a typical collapsible polymer film against radiation, it has not been possible to impart radiation resistance by a conventional method such as thermochemical reaction. Polytetrafluoroethylene (PTFE), which is a representative of the fluorine-containing polymer membrane substrate, is extremely sensitive to radiation, and its mechanical properties deteriorate when irradiated with radiation exceeding 1 kGy. The resin below could not be used. This is because in polytetrafluoroethylene (PTFE), molecular cutting occurs preferentially by irradiation and crystallization easily proceeds. When polytetrafluoroethylene (PTFE) is irradiated with ionizing radiation in the absence of oxygen at a temperature equal to or higher than its crystalline melting point, crosslinking occurs, and the characteristics are greatly improved, as disclosed in JP-A-6-116423 and JP-A-7-118423. It is disclosed in the gazette.

  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, but in order to obtain rubber characteristics, it is particularly in the range of 200 kGy to 5 MGy. It is disclosed that a range is desirable. Polytetrafluoroethylene (PTFE) film treated under such conditions is given radiation resistance, and material degradation such as elongation at break and strength at yield point compared to when irradiated with ionizing radiation in a vacuum at room temperature. Is significantly 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) in the absence of oxygen, i.e. in vacuum or in an inert gas atmosphere, to prevent oxidation during irradiation Ionizing radiation (gamma rays, electron beams, X-rays, neutron rays, high-energy ions, etc.) within a temperature range from about 20 ° C. lower than each crystal melting point to about 20 ° C. higher than each crystal melting point It is disclosed that these fluorine-containing polymer film substrates are crosslinked by irradiating with. 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 crystalline 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 in order to impart rubber characteristics. 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) can be used as industrial materials in a radiation environment. It becomes like this.

  Japanese Patent Application Laid-Open No. 7-118423 discloses a thermal decomposition reaction and a depolymerization reaction in addition to a crosslinking reaction when radiation irradiation is continued at a temperature of 327 ° C. or more which is an initial crystal melting point of polytetrafluoroethylene (PTFE). And the monomer is scattered from the surface of polytetrafluoroethylene (PTFE), and the weight is reduced. When polytetrafluoroethylene (PTFE) is irradiated with radiation in a vacuum or an inert gas at a temperature equal to or higher than its crystalline melting point, it crosslinks, but the crystalline melting point decreases as the radiation dose increases. Therefore, it is disclosed that the temperature of polytetrafluoroethylene (PTFE) at the time of irradiation may be changed in accordance with the irradiation dose to advance the crosslinking 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 320 to 330 ° C. after 50 kGy irradiation, 290 to 300 ° C. after 100 kGy irradiation, and 280 to 200 kGy irradiation. Examples are disclosed in which the temperature is lowered to 260-270 ° C. after irradiation at 290 ° C. and 500 kGy, and 230-240 ° C. after irradiation at 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, accurate temperature management is difficult with these temperature reduction methods.

  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 maintaining the fluorine-containing polymer film substrate at a temperature within a predetermined set temperature range equal to or higher than its crystalline 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 irradiated from cobalt-60 are 1 Example of irradiation from 0.7 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 to 2 MGy An example of irradiation up to 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 is disclosed in which radiation resistance is imparted by crosslinking when irradiated with 300 kGy of the electron beam.

In JP 2001-348439 A, a 10 cm × 10 cm piece of a polytetrafluoroethylene (PTFE) sheet having a thickness of 500 μm and a number average molecular weight of 1 × 10 ⁷ is placed in a heating type irradiation container, and the inside of the container is about 10 ⁻³ Torr. After degassing 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, 300 kGy, 500 kGy, Alternatively, it is disclosed that a polytetrafluoroethylene (PTFE) sheet that has been irradiated to a dose of 1 MGy, and after irradiation was cooled to finish 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 × 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 SUS frame, and has an electron beam incident window made of a 50 μm thick titanium foil. In a heated SUS irradiation container, the inside of the container is degassed to about 10 ⁻³ Torr and replaced with argon gas, and then heated with an electric heater to adjust the temperature of the polytetrafluoroethylene (PTFE) sheet to 335 It is disclosed that an electron beam with an energy of 2 MeV was irradiated while flowing argon gas at a slight temperature of ˜340 ° C. At this time, the current is 0.5 mA, the dose rate 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 10 cm square of polytetrafluoroethylene (PTFE) film with a thickness of 50 μm is placed in a SUS autoclave irradiation container (inner diameter 7 cmΦ, height 30 cm) equipped with a heater, and the inside of the container is degassed to 10 ⁻³ Torr and turned into argon gas. Substitution, and then heating with an electric heater to set the temperature of the polytetrafluoroethylene (PTFE) film to 340 ° C. (or a temperature range of 300 ° C. to 365 ° C.), and the dose rate of 3 kGy / hour of cobalt-60 γ-rays After that, the polytetrafluoroethylene (PTFE) film was taken out after cooling to the dose of 90 kGy and cooling the container. 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, it is subjected to ionizing radiation irradiation treatment, and then The container is cooled and the treated fluorine-containing polymer film is taken out. 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 predetermined dose. Is needed. 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. In such irradiation, when the dose rate of ionizing radiation is increased, the temperature of the film substrate to be irradiated rises during irradiation due to the heating effect of ionizing radiation, resulting in inconvenience that thermal decomposition 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 the fluorine-containing polymer membrane substrate is irradiated with ionizing radiation. It is important to be able to accurately control the temperature of the material.

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 when performing ionizing radiation treatment, the heating of the fluorine-containing polymer membrane substrate by ionizing radiation is superimposed on the temperature of the fluorine-containing polymer membrane substrate to increase the temperature. It was difficult to make the quality of the fluorine-containing polymer film after the treatment uniform. In particular, when processing a long and long fluorine-containing polymer membrane substrate exceeding 30 cm, the temperature and temperature distribution of the membrane substrate and the temporal change in temperature before and after irradiation, particularly during irradiation, are managed. It was difficult. For these reasons, the crosslinked fluorine-containing polymer film has not been put to practical use as 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 1 kGy is applied to the fluorine-containing polymer membrane substrate while keeping the wide and long fluorine-containing polymer membrane substrate at a temperature within a predetermined set temperature range around its crystalline melting point. When producing modified fluorine-containing polymer membranes by irradiating the above ionizing radiation in a low oxygen partial pressure environment, the processing speed is increased and the price is reduced, and the processing conditions are advanced and quality is controlled. By achieving homogenization, the cross-linked fluorine-containing polymer film is put to practical use as an industrial product. In addition, a fluorine-containing polymer membrane that is inexpensive and has a large cross-section as a base material is provided as a base material, and it has excellent oxidation resistance and a wide range of ion exchange capacity as a solid polymer electrolyte membrane suitable for a fuel cell. An object of the present invention is to provide a low-cost and long-life fuel cell that can be mass-produced at a low cost and can be mounted on an automobile or the like. In particular, stable irradiation is achieved by irradiating ionizing radiation with a large area fluorine-containing polymer film substrate kept at a predetermined temperature range at all positions in the irradiation field and throughout the entire irradiation process. It is to provide a method for producing a large amount of a fluorine-containing polymer film having a cross-linked structure of a high quality in a short time and at a low cost.

  The present invention allows a long fluorine-containing polymer membrane substrate to pass through a high-temperature radiation processing apparatus capable of temperature control and ionizing radiation irradiation, and the fluorine-containing high polymer film at the inlet position and the outlet position of the high-temperature radiation processing apparatus. A part of the molecular film substrate in the longitudinal direction is kept mechanically at room temperature and is given a running function. A heating element is provided in the high-temperature radiation processing apparatus, and the heating element is a fluorine-containing polymer film base. A plurality of heating element elements are divided and arranged along the longitudinal direction and the width direction of the material, and the surface temperature of these heating element elements is appropriately controlled spatially and / or temporally, during irradiation and Regardless of before or after irradiation, the temperature of all positions of the fluorine-containing polymer film substrate within the desired range in the irradiation field is made uniform, and if a predetermined treatment proceeds, a long and modified fluorine-containing fluorine The exit of the polymer membrane It cooled and has to be a large amount of processing in a short time by sending out a high temperature radiation treatment apparatus.

  In the high-temperature 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 set higher stepwise as the distance from the irradiation center increases. The temperature of the portion of the fluorine-containing polymer film substrate existing at the peripheral position is uniformly increased to a predetermined temperature range around the crystal melting point in a short time. At the position to irradiate ionizing radiation and the timing to irradiate ionizing radiation, the surface temperature of the heating element located in the vicinity of the irradiation field is lowered so that the temperature of the fluorine-containing polymer film substrate is focused on the irradiation field. As a result, the temperature of the fluorine-containing polymer film substrate does not change at any timing during irradiation by irradiating with ionizing radiation having a heat quantity that cancels this heat dissipation by radiating heat so that it is distributed in a bowl-like manner I am doing so. In addition, the spatial distribution and temporal change of the amount of released heat coincided with the distribution of the amount of heat given by the ionizing radiation and the temporal change, respectively, resulting in a uniform temperature distribution in space and time. The necessary dose can be given in a short time in the state. In the present invention, in any case, since local cooling such as blowing the refrigerant locally is not required, stable management of the temperature distribution can be performed. In addition, since the cooling is performed by using natural convection of an inert gas, temperature management is facilitated. 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 maintained at a temperature within a predetermined set temperature range around the crystal melting point. In the method for producing a modified fluorine-containing polymer film by irradiating ionizing radiation of 1 kGy or more in a low oxygen partial pressure environment, a heating element having a calorific value distributed in the longitudinal direction and the width direction , In the vicinity of the irradiation field of the ionizing radiation provided extending in the width direction, the heating element is provided in a non-contact manner facing the surface of the fluorine-containing polymer film substrate , and the heating elements are aligned in the width direction. A first heating element group and a second heating element group each including a plurality of heating element elements, and the first heating element group and the second heating element group are aligned in the longitudinal direction. and is, the fluorine-containing polymer The substrate includes a desired size range which matches with said irradiation field and substantially all of the sites within the desired range of the fluorine-containing polymer membrane substrate, the set temperature by the heating element after being heated to a temperature in the range, by the ionizing radiation with a predetermined intensity distribution while being cooled with a predetermined cooling rate is heated with a predetermined heating rate, the intensity of the ionizing radiation distribution or / and the calorific value of the distribution of the heating element, that the said cooling rate and the heating rate Ru is always set so as to substantially match or control over in the irradiation time at all sites within the desired range It is a characteristic method. Here, the cooling rate represents the temperature at which the specific portion decreases within a unit time, and is a generic value of the temperature decrease rate at 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 modified 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 maintained at a temperature within a predetermined set temperature range around the crystal melting point. In the method for producing a modified fluorine-containing polymer film by irradiating ionizing radiation of 1 kGy or more in a low oxygen partial pressure environment, a heating element having a calorific value distributed in the longitudinal direction and the width direction , In the vicinity of the irradiation field of the ionizing radiation provided extending in the width direction, the heating element is provided in a non-contact manner facing the surface of the fluorine-containing polymer film substrate , and the heating elements are aligned in the width direction. A first heating element group and a second heating element group each including a plurality of heating element elements, and the first heating element group and the second heating element group are aligned in the longitudinal direction. and is, the fluorine-containing polymer The substrate includes a desired size range which matches with said irradiation field and substantially all of the sites within the desired range of the fluorine-containing polymer membrane substrate, the set temperature by the heating element After being heated to a temperature within the range, at the position where the ionizing radiation is irradiated, the surface temperature of the heating element located in the vicinity of the irradiation field is lowered to reduce the temperature of the fluorine-containing polymer film substrate. Radiating and cooling so as to be distributed and reduced in a bowl-like shape with the irradiation field as the center , releasing the first amount of heat per unit volume , and receiving the ionizing radiation having a predetermined intensity distribution The second heat quantity is received per unit volume, and the intensity distribution of the ionizing radiation or / and its change over time or / and the calorific value distribution of the heating element are integrated values within the specific irradiation time of the first heat quantity. And the second heat Set of the integrated value within the irradiation time and the same time so as to substantially match, or a method characterized by that are controlled. 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 elements may be set 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 time change of the ionizing radiation intensity can be set by electrically controlling the generation intensity of the ionizing radiation source. 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 membrane substrate having a large area can be modified 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 maintained at a temperature within a predetermined set temperature range around the crystal melting point. In the method for producing a modified fluorine-containing polymer film by irradiating ionizing radiation of 1 kGy or more in a low oxygen partial pressure environment, a heating element having a calorific value distributed in the longitudinal direction and the width direction , In the vicinity of the irradiation field of the ionizing radiation provided extending in the width direction, the heating element is provided in a non-contact manner facing the surface of the fluorine-containing polymer film substrate , and the heating elements are aligned in the width direction. A first heating element group and a second heating element group each including a plurality of heating element elements, and the first heating element group and the second heating element group are aligned in the longitudinal direction. and is, the fluorine-containing polymer The substrate wherein radiation field and includes a substantially magnitude of desired scope consistent, calorific value and / or its distribution of the heating element is or are controlled set according to a predetermined time function, the time function The first timing when the heating element heats all the sites within the desired range to a temperature within the set temperature range, the temperature rise due to irradiation of the ionizing radiation at all the sites within the desired range, and the And a second timing that substantially cancels the temperature drop due to cooling of the fluorine-containing polymer film substrate, and at this second timing, the heating element located in the vicinity of the irradiation field the lowering of the surface temperature of the temperature of the fluorine-containing polymer membrane substrate, about said irradiation field, is the method comprising Rukoto is radiating to lower distributed semi-cylindrical Since the timing for keeping the temperature of the fluorine-containing polymer film substrate within the set temperature range is provided before starting the irradiation of the ionizing radiation, the irradiation is performed at a low temperature immediately after the start of the irradiation of the ionizing radiation. You can avoid danger. At this heating timing, the heating element is divided into a large number of heating element elements, and the respective calorific values of these heating element elements are appropriately distributed in space so that the temperature of the fluorine-containing polymer film substrate is set appropriately. The value is kept uniform. At the timing of the cancellation, the temperature of the fluorine-containing polymer film substrate is kept uniform at an appropriate value by appropriately resetting the heat generation amount and the spatial distribution of the heating element. 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 irradiation of the ionizing radiation to immediately after the irradiation can be kept within the set temperature range. The fluorine-containing polymer membrane substrate having a large area can be modified 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 maintained at a temperature within a predetermined set temperature range around the crystal melting point. In a method for producing a modified fluorine-containing polymer film by irradiating ionizing radiation of 1 kGy or more in a low oxygen partial pressure environment, a heating element having a predetermined calorific value distributed in the longitudinal direction and the width direction Is provided in a non-contact manner in the vicinity of the irradiation field of the ionizing radiation so as to face the surface of the fluorine-containing polymer film substrate , and each of the heating elements includes a plurality of heating element elements aligned in the width direction. A first heat generating element group and a second heat generating element group, the first heat generating element group and the second heat generating element group are aligned in the longitudinal direction, and the fluorine-containing system the radiation field and substantially the polymer membrane substrate It includes the size of the desired range that matches, the fluorine-containing polymer membrane substrate has a first substrate region held is maintained at a temperature lower than the set temperature range, by the heating element A second substrate region heated to a temperature within or near the set temperature range; and a third substrate region maintained at a temperature within the set temperature range by being irradiated with the ionizing radiation. and de, the third base region contains the desired range, in every part of the said desired range, the temperature due to the heating of the heating element is due to illumination of it when Then the ionizing radiation to decrease The amount of heat generated by the heating element and / or its distribution and / or the intensity of the ionizing radiation so that the temperature rises and the temperature is maintained within the set temperature range during the time of receiving the ionizing radiation. Is set or controlled A method characterized by that. The first base material region is preferably kept at room temperature, and the fluorine-containing polymer film base material can be easily held and its running action can be imparted, so that the irradiation treatment can be performed continuously. By providing the first base material region on both sides of the third base material region, the fluorine-containing polymer film after the irradiation treatment can be taken out immediately, and the processing speed is increased. Since the second base material region is heated to the temperature within or near the set temperature range without being irradiated with the ionizing radiation, the risk of irradiating the ionizing radiation under a low temperature state can be avoided. . In the second base material region and the third region, the heating element provided in the vicinity thereof is divided into a number of heating element elements, and the respective heat generation amounts of these heating element elements are appropriately distributed in space. Therefore, the temperature is kept uniform at an appropriate value. When the present invention is employed, a large amount of irradiation processing can be performed efficiently and accurately.

One aspect of the present invention is that the fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction is maintained at a temperature within a predetermined set temperature range around the crystal melting point. In the method for producing a modified fluorine-containing polymer film by irradiating ionizing radiation of 1 kGy or more in a low oxygen partial pressure environment, the fluorine-containing polymer film substrate is substantially the same as the irradiation field of the ionizing radiation. And a portion within the desired range passes through the processing apparatus that is irradiated with the ionizing radiation, and the processing apparatus includes the fluorine-containing polymer film substrate . A first device that includes a heating element provided in a non-contact manner facing the surface , and that mechanically holds a part of the fluorine-containing polymer film substrate at a temperature lower than the set temperature range Area and front by said heating element Third device area to which the second device region for heating the portion of the desired range to the set temperature within or close to the temperature thereof, and irradiating the ionizing radiation to a portion within the desired range predetermined dose The heating element includes a first heating element group and a second heating element group each including a plurality of heating element elements aligned in the width direction, and the first heating element and the body element group and the second heating element group aligned in the longitudinal direction, when the portion in the desired range is located in the third device region part in said desired range is cooled so as to keep the temperature of any site within the desired range within the set temperature range temperature Te is the temperature raised due to the irradiation of the ionizing radiation to compensate for it when Then the temperature drop to drop, the ionizing radiation Intensity distribution of and / or said A method characterized in that calorific value of the distribution of the thermal body is adapted to be set or controlled. The fluorine-containing polymer film substrate is preferably heated uniformly to a temperature within or near the set temperature range without being irradiated with the ionizing radiation, and the first device region maintained at room temperature. The second device region and the third device region that receives 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 reforming 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 fluorine-containing polymer membrane substrate located between the first device region and said second device region a base material region, in the fourth base region temperature of the fluorine-containing polymer film substrate have a first rate of change with respect to the distance in the direction towards the other substrate regions of the their respective The fluorine-containing polymer film bases that are distributed in the second substrate region or the third substrate region, or are located in the second device region or the third device region, respectively. in the substrate region of the timber, the direction the temperature of the fluorine-containing polymer film substrate toward the other substrate regions of the their respective Distance and a second rate of change and distribution for the magnitude of the first rate of change, the everywhere within each substrate region substantially than the magnitude of the second rate of change It is a method characterized by the fact that it is larger. When the present invention is adopted, the fourth substrate region is heated while maintaining a large temperature gradient in a narrow range, so that 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 portion can be limited to a relatively narrow range including the irradiation field, it is easy to position the portion to be processed during processing, and the processing can be accurately and speeded up.

One of the invention, the said long while keeping the temperature within the preset temperature range set the fluorine-containing polymer membrane substrate, or other longitudinal direction and elongated irradiated body extending in the width direction in advance a processing apparatus for irradiating an ionizing radiation of a predetermined dose of irradiation, the long irradiation object includes a holding portion which is positioned and held in the processing unit, in the set temperature range or near the temperature a heating range to be heated, the includes a size of the desired scope consistent radiation field and substantially of ionizing radiation, wherein the processing unit, the retaining portion with keeping the holding portion to a lower temperature can be maintained and a first device region for mechanically holding, a plurality of heating element disposed in line in the width direction to be opposed to the surface of the elongated object to be irradiated in a non-contact in the vicinity of the irradiation field portion within the heating range by the heating element consisting of And a second device region is heated to the set temperature within or close to the temperature thereof, the portion the set temperature range within the desired range to give a heat generation due to irradiation of the ionizing radiation to a portion within the desired range includes a third device region to keep the temperature of the inner, the in the third device region, the calorific value of the distribution of the heating element is heating value of the heating element in the second device region The distribution is set differently, and when the temperature of the portion within the desired range heated by the heating element is about to decrease, due to the irradiation of the ionizing radiation with the intensity distributed to compensate for the temperature decrease the temperature of a portion within a desired range so as to increase, during the period for receiving the irradiation of the ionizing radiation, the desired range while maintaining any part within the desired range to a temperature within the set temperature range Is a device which is characterized in that so as to provide a predetermined dose portion of the inner. In the first apparatus region, it is preferable that the temperature of the fluorine-containing polymer film substrate or other long object to be irradiated is kept at room temperature. In the third device region, each of the heating element elements distributed in the longitudinal direction and / or the width direction so that the temperature distribution at the time when the temperature heated by the heating element decreases is optimized. It is preferable to set or control the calorific value distribution. In addition, when the intensity distribution of the ionizing radiation is optimized at the time, since the temperature response speed is high, more accurate control can be performed. When the apparatus of the present invention is employed, the irradiation of the fluorine-containing polymer film substrate or other long object to be irradiated during the irradiation of the ionizing radiation is easily performed while managing the temperature within the set temperature range. be able to.

One of the present invention, in any one of the above invention, the heating so that the change rate relative to the distance the temperature of the long object to be irradiated at any site within the desired range is always smaller than a predetermined value The apparatus is characterized in that the distribution of the calorific value of the body is controlled over time. Dividing the heating element into a number of heating element elements and controlling the heating value distribution of the heating elements over time by controlling the heating value of each heating element spatially and temporally. Can do. In particular, it is effective to control the calorific value so that the temperature distribution is uniform before and during the irradiation of the ionizing radiation. The predetermined rate of change value is determined so that the temperature of every part within the desired range falls within the set temperature range. By adopting the present invention, it becomes easy to manage the temperature distribution of the fluorine-containing polymer film substrate or other long irradiated object during the irradiation of the ionizing radiation, and all necessary even if the processing time is long Irradiation treatment can be performed at a precisely controlled temperature in the region. In particular, it becomes possible to accurately manage the temperature distribution immediately after the start and end of the irradiation process.

One aspect of the present invention is that the fluorine-containing polymer membrane substrate having a longitudinal direction and a width direction is maintained at a temperature within a predetermined set temperature range around the crystal melting point. In the method for producing a modified fluorine-containing polymer film by irradiating ionizing radiation of 1 kGy or more in a low oxygen partial pressure environment, a heating element having a calorific value distributed in the longitudinal direction and the width direction, In the vicinity of the irradiation field of the ionizing radiation provided extending in the width direction, it is provided in a non-contact manner facing the surface of the fluorine-containing polymer film substrate, and the heating elements are aligned in the width direction. A first heating element group and a second heating element group each including a plurality of heating element elements, and the first heating element group and the second heating element group are arranged in the longitudinal direction. Fluorine-containing high The sub-film substrate includes a desired range of a size that substantially matches the irradiation field, and either the first heating element group or the second heating element group is within the irradiation field. A first heating element provided opposite to the surface of the fluorine-containing polymer membrane substrate in the center, and a position of the fluorine-containing polymer membrane substrate located at the end in the width direction. A second heat generating element provided opposite to the surface, and the surface temperature of the second heat generating element is set higher than the surface temperature of the first heat generating element. It is a method characterized by maintaining the temperature of every part within the range within the set temperature range. By adopting the present invention and optimizing the amount of heat generated by each heating element, the portion within the desired range can be easily and accurately maintained at the temperature within the set range.
One of the present invention, in any one of the above invention, wherein the plurality of heat generating element contained in either the first heating element group or said second heating element group of the illumination within the field a first heating element provided opposite to the surface of the fluorine-containing polymer membrane substrate at the center, of the fluorine-containing polymer membrane substrate positioned more ends in the width direction opposite to the surface a second heating element and the cage containing Marete provided in, that the surface temperature of the second heating element is set higher than the surface temperature of the first heating element It is a characteristic method . When the fluorine-containing polymer film substrate is heated by a heating element having a uniform surface temperature provided opposite to the surface of the fluorine-containing polymer film substrate , It becomes 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 uniformly distributed in intensity. The temperature distribution of the fluorine-containing polymer film substrate during irradiation can be made uniform by controlling only the intensity distribution of the ionizing radiation in a complicated manner, but it is difficult to keep the temperature immediately after irradiation within the set temperature range. This is not preferable because the absorbed dose is unevenly distributed. However, when the present invention is adopted, the temperature distribution of the fluorine-containing polymer film substrate during heating by the heating element can easily achieve a uniform temperature distribution in the irradiation field, and the absorbed dose of the ionizing radiation can be made uniform. Easy to keep. 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 inventions, the difference between the surface temperature of the second heating element and the surface temperature of the first heating element is the difference between the surface temperature of the fluorine-containing polymer film substrate . The method is characterized in that it can be changed according to the moving speed. When the present invention is adopted, when the moving speed of the fluorine-containing polymer film substrate changes, the surface temperature of the second heating element and the first temperature in the moving direction of the fluorine-containing polymer film substrate are changed. since different difference between the surface temperature of the first heating element is changed, it is contained in the set temperature range regardless of the temperature of the fluorine-containing polymer membrane substrate in its moving speed.

One of the present invention, in any one of the above invention, the heating element has a first heating element group and the second heat generating element groups each comprising a plurality of heating element aligned in the width direction The first heat generating element group and the second heat generating element group are aligned in the longitudinal direction, and the surface temperature of these heat generating element elements is in the width direction of the fluorine-containing polymer film substrate, The method is characterized in that the temperature of the surface of the heating element located at the end is higher . When the present invention is adopted, temperature control of the fluorine-containing polymer film substrate during irradiation can be easily performed using a heating element having a simple structure. In particular, since the temperature distribution in the longitudinal direction can be easily controlled in a state where 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 be controlled with the same time function. will be controllable, it can be easily irradiated while controlling the temperature of the fluorine-containing polymer membrane substrate during irradiation of the ionizing radiation at a temperature within the preset temperature range.

One of the present invention, in any one of the invention, aligned in the width direction, the same of the contained in the heat-generating element group, wherein each heating element is heating value thereof is controlled according to the same time function It is the method characterized by this. By adopting the present invention, it is possible to accurately irradiate while controlling the temperature of the fluorine-containing polymer film substrate during the irradiation of the ionizing radiation to a temperature within the set temperature range using a simple control device. . In particular, it becomes easy to keep the temperature of the fluorine-containing polymer film substrate at a temperature within the set temperature range before and after the start of irradiation with the ionizing radiation.

One of the present invention, in any one of the invention, the set temperature range at a particular portion of the long irradiation object, the ionizing radiation absorbed in the past at the specified portion of the elongated object to be irradiated It is an apparatus characterized in that it decreases while maintaining a predetermined relationship corresponding to the integrated value of the absorbed dose. When the present invention is adopted, even when the integrated value of the absorbed dose of the ionizing radiation absorbed by the long object is increased, the integrated value of the absorbed dose and the set temperature range even when the crystalline melting point is lowered. The high temperature radiation treatment can be carried out under the optimum temperature condition.

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 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 can be provided at low cost as an industrial product. In addition, by using a modified polytetrafluoroethylene (PTFE) membrane as a base material, a large amount of modified polytetrafluoroethylene ion exchange membranes having excellent oxidation resistance and a wide range of ion exchange capacities at low cost It becomes possible to produce. Furthermore, if this is used, a cheap and durable fuel cell can be provided.

One of the present invention, by the method of any one of the invention, or a modified fluorine-containing polymer film produced using the apparatus. 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. In addition, the fluorine-containing polymer film modified so that it can be used even in a radiation environment is inexpensive and can be supplied in large quantities, and is useful as an industrial product.

  One aspect of the present invention is a fuel cell manufactured by using the modified fluorine-containing polymer membrane manufactured by any of the above-described methods or using an apparatus. 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, when the fluorine-containing polymer membrane substrate is cross-linked by irradiating with ionizing radiation at a high temperature in the absence of oxygen, the temperature of the large-area fluorine-containing polymer membrane substrate is set within the irradiation field. A large amount of fluorine-containing polymer film having a stable quality cross-linked structure can be irradiated in a short period of time with ionizing radiation in a state where it is always kept within a predetermined temperature range over the entire region of the treatment. And can be produced inexpensively. 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 the radiation treatment method for a polymer film substrate according to the present invention, a long fluorine-containing polymer film substrate is passed through a high temperature electron beam processing apparatus capable of temperature control and electron beam irradiation. At the entrance position and exit position of the high temperature electron beam processing apparatus, a part of the longitudinal direction of the fluorine-containing polymer film substrate is mechanically held at room temperature and a running function is given. A heating element is provided in the high-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, By appropriately controlling the surface temperature of these heating element elements spatially and / or temporally, all the parts located in the irradiation field of the fluorine-containing polymer film substrate during irradiation and before and after irradiation By substantially cooling the exit temperature of the elongate fluorine-containing polymer film and feeding it out of the high-temperature electron beam processing apparatus, when the predetermined process proceeds, A large amount of processing can be performed in a short time.

  In the high temperature electron beam processing apparatus, at the position where the electron beam is not irradiated, or at the timing where the electron beam is not irradiated, by setting the surface temperature of the heating element higher in a stepped manner as the distance from the center of the irradiation field increases, While keeping the temperature of the portion located in the irradiation field of the fluorine-containing polymer film substrate and its peripheral position uniform, the temperature is raised in a short time to a temperature within a predetermined set temperature range around the crystal melting point. At the electron beam irradiation position and the electron beam irradiation timing, the temperature of the heating element located in the vicinity of the irradiation field is lowered so that the temperature of the fluorine-containing polymer film substrate is centered on the irradiation field. As a result, the fluorine-containing polymer film substrate is heated by irradiating with an electron beam having a quantity of heat that cancels this heat dissipation, and as a result, the fluorine-containing polymer film substrate is heated at any timing during irradiation. The temperature is kept from changing. In addition, the spatial distribution and temporal change of the amount of released heat coincide with the spatial distribution and temporal change of the amount of heat given by the electron beam in the irradiation field, and as a result, spatial and temporal changes in the irradiation field. The temperature distribution is uniform.

  Also, as the absorbed dose increases, the crystalline melting point decreases, and therefore the optimum temperature range decreases with the absorbed dose. Therefore, the surface temperature of the heating element is changed according to the integrated value of the absorbed dose, and is always optimal at the optimum temperature. Can be cross-linked. Thus, when the temperature at the time of irradiation is changed by the integrated value of the absorbed dose, the surface temperature of the heating element according to the integrated value of the absorbed dose with the fluorine-containing polymer film substrate stationary. Control, after reaching a predetermined absorbed dose value, stop the irradiation of the electron beam and move the fluorine-containing polymer film substrate in the longitudinal direction by a distance corresponding to the width of the irradiation field. The temperature setting of the body element is initialized to return the temperature of the fluorine-containing polymer film substrate to the set value at the start of irradiation, and then the irradiation is repeated. At this time, the fluorine-containing polymer film substrate is automatically moved stepwise.

  When the allowable temperature range at the time of electron beam irradiation is set to be narrow, the periphery of the irradiation field is surrounded by appropriately modulating the electron beam intensity distribution along the longitudinal direction of the fluorine-containing polymer film substrate. The temperature of can be the same as the temperature of other parts. In this case, since the irradiation dose rate is different between the periphery of the irradiation field and the central part of the irradiation field, the absorbed dose becomes non-uniform in position when the fluorine-containing polymer film substrate is irradiated stationary. In order to improve this, the fluorine-containing polymer film substrate may be moved at an appropriate speed during irradiation. Further, when the temperature distribution in the longitudinal direction of the fluorine-containing polymer film substrate is optimized by subdividing each of the heating element elements along the longitudinal direction and controlling the heat generation amount with higher accuracy, The modulation of the electron beam intensity distribution can be made unnecessary.

  When the irradiation dose is not large, the optimum temperature range can be preset to a constant value. In this case, the temperature of the heating element is kept constant and the fluorine-containing polymer film substrate is moved at a constant speed. The cross-linking treatment can be performed. 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. A large dose can be irradiated in time.

  As described above, after rapidly heating the irradiation field and its vicinity while keeping the holding part of the fluorine-containing polymer film substrate at room temperature in the high-temperature electron beam processing apparatus, a large irradiation dose rate The fluorine-containing polymer film substrate is irradiated with a large amount of dose in a short time in a state where the temperature is kept constant while irradiating with, and when the irradiation is completed, the high-temperature electron beam of the fluorine-containing polymer film substrate A portion located at the processing apparatus outlet is partially cooled rapidly and taken out of the high temperature electron beam processing apparatus. In this way, the fluorine-containing polymer film substrate having a large area can be automatically crosslinked in a large amount at a high speed. Hereinafter, the embodiment and operation of the present invention will be described more specifically and in detail using examples.

The radiation treatment method for the fluorine-containing polymer film substrate of the present invention will be described with reference to FIGS. In these drawings, the same parts are denoted by the same reference numerals. 1 and 2 show an example of a high-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 moves so as to be wound around the reel 3 from the state wound around the reel 2. The fluorine-containing polymer film substrate 1 is positioned by the pulley 4 and guided into the high-temperature electron beam processing apparatus 10 and heated to about 340 ° C., and then the temperature is kept within the range of 340 ± 5 ° C. The electron beam is irradiated while maintaining. Cooling pulleys 5 and 6 are provided at an inlet portion and an outlet portion of the high-temperature electron beam processing apparatus 10 , which mechanically hold the fluorine-containing polymer film substrate 1 and keep this portion at a normal temperature. 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 at the exit of the high 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 a predetermined force F1 is always applied to the fluorine-containing polymer film substrate 1, and an appropriate tension is applied to a portion in the high-temperature electron beam processing apparatus 10 . Is supposed to give. The fluorine-containing polymer film substrate 1 that has passed through the pulley 8 is taken up by the reel 3.

The high-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 high 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 whose intensity is distributed in a planar shape. The electron beam irradiation apparatus 12 is an apparatus having a structure disclosed in, for example, Japanese Patent Application Laid-Open No. 11-19190, and is an electron having an energy of about 300 keV and a current of about 10 mA distributed in a plane through the electron beam transmission window 13. Can be irradiated with a line. The fluorine-containing polymer film substrate 1 passes through the high-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 supported by the heat shielding 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 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 high-temperature electron beam processing apparatus 10 , the heat shielding plate 14 and the partition 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 a non-contact thermometer (not shown) so that the temperature of the surface position of the fluorine-containing polymer film substrate 1 in the directions indicated by arrows 21 and 22 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 high-temperature electron beam treatment passes 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 high-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.

FIG. 3A is a plan view of the fluorine-containing polymer film substrate 1 and the heater group 30 as viewed from the Z-axis direction by removing a portion of the high-temperature electron beam processing apparatus 10 having a positive Z coordinate value. Represents. FIG. 3B shows a cross-sectional view in the YZ plane of 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. 4A and 4B respectively show a plan view and a side sectional view of the heater group 30 for heating. As shown in FIG. 4A, the heating heater group 30 includes a plurality of heater elements parallel to the XY plane and a plurality of heater elements parallel to the XZ plane. They are arranged with a certain distance Z1 from the molecular film substrate 1, for example, 2.5 cm. These heater elements are one specific example of the heating element. The heater group 30 has a surface with X coordinates of -X2, -X1, 0, X1, and X2 and Y coordinates of -Y3, -Y2, -Y1, 0, Y1, Y2, and 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. This heater group is 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 suffix in the X-axis direction representing the center coordinate of the heater element surface, -2, -1, 0, 1 and 2 are included, and j represents the center coordinate of the heater element surface. The suffix in the Y-axis direction is represented, and -3, -2, -1, 0, 1, 2, 3 are included.

  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 film 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 located in the Y direction from the irradiation field center by −Y3 and Y3, respectively, and the coordinates in the Z direction are from 0 to − 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 these heater elements are each thermally and electrically divided and are controlled independently.

  Each of these heater elements is controlled in a different manner at three 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 Temperature maintaining timings T2 and T4 for maintaining the temperature at a specified temperature, for example, 340 ° C., a partial cooling timing T3 for lowering the temperature in a part of the fluorine-containing polymer film substrate 1, and an electron beam E. And a beam irradiation timing T5 for irradiating the film substrate 1. FIG. 5 shows the distribution of the amount of heat generated by each heater element at the rapid heating timing T1. In FIG. 5, the heat generation amount is represented by area density. FIG. 5A 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. 5B shows the heater element H (± 1, j), j = −3, −2, −1, 0, 1, 2, 3 , Q = ± 1, j, j = −3, −2, −1, 0, 1, 2, 3, and FIG. 5C 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, Yes, FIG. 5 (d) shows the heater element H (i, 0), i = −2, −1, 0, 1, 2, and the calorific value Q (i, 0), i = −2, −1, 0. 5 (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. 5 (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. 5G 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, the amount of heat generated by each heater element at the heat retention timings T2 and T4 is shown in FIG. 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), 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. 6D shows the heater element H (i, 0), i = −2, −1, 0, 1, 2, and the heat generation amount Q (i, 0), i = −2, −1, 0, 1 6 (e) shows the heater element H (i, ± 1), i = −2, −1, 0, 1, 2, and the calorific value Q (i, ± 1), i. −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, 1 2, the calorific value Q (i, ± 3), i = −2, −1, 0, 1, 2, and so on.

  Similarly, the amount of heat generated by each heater element at the partial cooling timing T3 is shown in FIG. 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), With heat generation amount Q (± 2, j) of j = −3, −2, −1, 0, 1, 2, 3, j = −3, −2, −1, 0, 1, 2, 3, Yes, FIG. 7D shows the heating value Q (i, 0) of the heater element H (i, 0), i = −2, −1, 0, 1, 2, i = −2, −1, 0. 7 (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. 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, The calorific values Q (i, ± 3) of 1, 2 are i = −2, −1, 0, 1, 2, and so on.

  FIG. 8 shows a time function for controlling the amount of heat generated by each heater element H (i, j) and a time function for controlling the electron beam irradiation dose. FIG. 8A shows a function Fb (t) of the heating time t for controlling the electron beam irradiation dose. FIG. 8B shows the heater element H (0, j), j = −1, 0, 1, FIG. 8C is a function Fh1 (t) of the heating time t for controlling the calorific value Q (0, j), j = −1, 0, 1. FIG. 8C shows the heater element H (0, j), j = FIG. 8D is a function Fh2 (t) of the heating time t for controlling the calorific value Q (0, j), j = ± 3, ± 2 of ± 3, ± 2, and FIG. 1, j), a function of the heating time t for controlling the calorific value Q (± 1, j), j = ± 3, ± 2, ± 1, 0, where j = ± 3, ± 2, ± 1, 0 Fh3 (t), FIG. 8 (e) shows heater element H (± 2, j), j = ± 3, ± 2, ± 1, 0, calorific value Q (± 2, j), j = ± A function Fh4 of the heating time t for controlling 3, ± 2, ± 1, 0 ( ) It is. These function values are optimized to different values as the cooling rate of the fluorine-containing polymer film substrate 1 changes. The time function Fh4 (t) may coincide with the time function Fh3 (t). In these figures, the rapid heating timing T1 corresponds to a heating time t between 0 and 12.0 seconds. Similarly, the heat retention timing T2 has a heating time t of 12.0 seconds to 22.5 seconds, and the heat retention timing T4 has a heating time t of 41.3 seconds to 63.8 seconds, and 82.6 seconds. Corresponds to between 10 to 105.1 seconds and 123.9 to 146.4 seconds. Similarly, the partial cooling timing T3 includes heating times t between 22.5 seconds and 41.3 seconds, between 63.8 seconds and 82.6 seconds, and between 105.1 seconds and 123.9 seconds. It corresponds to. Similarly, the beam irradiation timing T5 is between the heating time t between 24.0 seconds and 44.5 seconds, between 65.3 seconds and 85.8 seconds, and between 106.6 seconds and 127.1 seconds. Equivalent to.

  When the heating value Q (i, j) of each heater element H (i, j) is controlled as described above, the temperature Th (i, j) at the heating time t of the surface of each heater element H (i, j) is controlled. j, t) are represented in FIG. FIG. 9A shows the surface temperature Th (0, j, t) of the heater element H (0, j), j = ± 3, ± 2, ± 1, 0, j = ± 3, ± 2, ± 1, 0, t = 0 to 145 seconds. FIG. 9B shows the surface temperature Th (± 1, j, t) of the heater element H (± 1, j), j = ± 3, ± 2, ± 1, 0, j = ± 3, ± 2. , ± 1, 0, t = 0 to 145 seconds. FIG. 9C shows the surface temperature Th (2, j, t) of the heater element H (2, j), j = ± 3, ± 2, ± 1, 0, j = ± 3, ± 2, ± 1, 0, t = 0 to 145 seconds. FIG. 9D shows the surface temperature Th (−2, j, t) of the heater element H (−2, j), j = ± 3, ± 2, ± 1, 0, 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 the representative heating times t = 11.5 seconds, 21.9 seconds, 24.3 seconds, 29.9 seconds shown in FIG. This 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 is higher at the surface located at the end in the width direction of the fluorine-containing polymer film substrate 1. 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 is Tp (x, y, t). 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 is such that the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 is the X-direction position x and the heating time t within the irradiation field width FW. Regardless of the relationship, the temperature distribution is determined to be uniform 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. When there is no partial cooling timing T3 shown in FIGS. 8 and 9 and each heater element H (i, j) is controlled so that the heat retaining timings T2 and T4 continue following the rapid heating timing T1, The portion located in the irradiation field Fi of the system polymer film substrate 1 is heated to 340 ± 5 ° C. and kept in this temperature range both spatially and temporally.

  In this way, the surface temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 is kept uniformly within the range of 340 ± 5 ° C. both spatially and temporally within the irradiation field Fi. When the electron beam E having an intensity (300 keV, 0.24 mA) uniformly distributed in the irradiation field Fi as shown in FIG. The X-axis direction distribution of the temperature Tp (x, y, t) of the polymer-based polymer film substrate 1 is as shown in FIG. 11B, and is uniformly distributed in the Y-axis direction. As shown in FIG. 11B, the temperature Tp (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 electron beam E irradiation. .9) is 343.9 ° C., and the temperature Tp (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 irradiation. Is 350.1 ° C., and the temperature Tp (0, 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 Tp (at the center of the irradiation field of the fluorine-containing polymer film substrate 1 at the heating time t = 42.7 seconds after the passage of 18.7 seconds from the start of irradiation) 0, 0, 42.7) is 440.7 ° C. That is, the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 becomes too high during irradiation, and thermal decomposition of the fluorine-containing polymer film substrate 1 proceeds. The absorbed dose in this case corresponds to 210 kGy.

  X-axis of temperature Tp (x, y, t) of fluorine-containing polymer film substrate 1 when the X-axis direction distribution in irradiation field Fi of electron beam E is changed as shown in FIG. The direction distribution is as shown in FIG. 12B, and changes gently within the width FW of the irradiation field Fi. The time change of the temperature Tp (0, 0, t) of the fluorine-containing polymer film substrate 1 at the irradiation field center in this case is shown in FIG. Even in this case, the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 is uniformly distributed in the Y-axis direction. Thus, by modulating the X-axis direction distribution in the irradiation field Fi of the electron beam E, the X-axis direction distribution of the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 can be arbitrarily set. Can be changed. Adjustment of the X-axis direction distribution in the irradiation field Fi of the electron beam E can be achieved by providing an appropriate filter in the passage of the electron beam E.

  On the other hand, as shown in FIGS. 8 and 9, the fluorine-containing polymer film substrate in the case where the electron beam E is not irradiated in a state where each heater element H (i, j) is controlled so that the partial cooling timing T3 occurs. A temperature Tp (x, y, t) of 1 is shown in FIG. FIG. 13A shows the Y-axis direction distribution of the temperature Tp (x, y, t) of the fluorine-containing polymer membrane substrate 1, and FIG. 13B shows the temperature of the fluorine-containing polymer membrane substrate 1. This is a distribution in the X-axis direction of Tp (x, y, t). These figures show that the temperature is partially decreased with the heating time t within the irradiation field width FW of the irradiation field Fi of the electron beam E at the partial cooling timing T3. The time change of the temperature Tp (0, 0, t) of the fluorine-containing polymer film substrate 1 at the center of the irradiation field in this case is shown in FIG.

  When the electron beam having the intensity distribution shown in FIG. 12 (a) is irradiated at the beam irradiation timing T5 which roughly matches the partial cooling timing T3 as shown in FIG. 8 (a), the fluorine-containing polymer film The Y-axis direction distribution Tp (0, y, t) of the temperature Tp (x, y, t) of the substrate 1 is as shown in FIG. 14A, and the X-axis direction distribution Tp (x, 0, t) is As shown in FIG. 14B, the time change of the temperature Tp (0, 0, t) of the fluorine-containing polymer film substrate 1 at the center of the irradiation field 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. As shown in FIG. 14A, the X-axis direction distribution Tp (x, 0, t) is within a range of 340 ± 5 ° C. within the irradiation field Fi, and in a portion located in the immediate vicinity of the irradiation width FW. As the irradiation time becomes longer, the temperature of the fluorine-containing polymer film substrate 1 is slightly lowered. This is due to the difference in temperature distribution outside the irradiation field width FW in FIGS. 12B and 13B. In this part, since the fluorine-containing polymer film substrate 1 is not irradiated with the electron beam E, there is no problem.

In order to reduce the change over time of the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1, the intensity of the electron beam E is changed with time as shown in FIG. . Also in this case, the spatial distribution of the intensity of the electron beam E is kept constant as described above. The time change of the intensity of the electron beam E can be automatically controlled by measuring the temperature in the direction indicated by the arrow 16 in FIG. 1A with a non-contact thermometer and performing feedback control to the electron beam irradiation device 12. . The dose given to the fluorine-containing polymer film substrate 1 by one irradiation for 20.5 seconds described above corresponds to 236 kGy, and the dose can be arbitrarily increased by repeatedly irradiating.

  As described above, the temperature Tp (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 of the heater element H (i, j) in the Y-axis direction as the distance from the origin increases. Maintaining the temperature Tp (x, y, t) uniformly in the range of 340 ± 5 ° C. in the X-axis direction optimizes the surface temperature of the heater element H (i, j) as the distance from the origin in the X-axis direction increases. Achieved by increasing. During irradiation with the electron beam E, the temperature Tp (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 partially reduce the surface temperature of the heater element H (i, j) in the vicinity of the center of the irradiation field Fi, and the surface of the fluorine-containing polymer film substrate 1 is subjected to thermal radiation and natural convection. This is achieved by irradiating the electron beam E having a heat quantity corresponding to the heat quantity released by this cooling. At this time, even when the irradiation time of the electron beam E becomes long, the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 is uniformly in the range of 340 ± 5 ° C. in the X-axis direction. Maintaining the X-axis direction distribution of the temperature rise heated by the electron beam E by appropriately distributing the intensity at the end of the irradiation field width FW in the X-axis direction of the electron beam E, the heater element H (i, j This is achieved by matching the temperature decrease of the fluorine-containing polymer film substrate 1 that is decreased by the calorific value Q (i, j) of X) in the X-axis direction. The temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 is always kept within the range of 340 ± 5 ° C. over time within the range of the irradiation field width FW immediately after the start of irradiation with the electron beam E. This is achieved by appropriately setting the electron beam intensity immediately before the end of irradiation. More preferably, the surface temperature of the fluorine-containing polymer film substrate 1 is fed back to automatically control the intensity of the electron beam E over time.

  The case where the electron beam E is irradiated while the fluorine-containing polymer film substrate 1 is stationary has been described above. In this case, the X-axis direction distribution of the electron beam intensity is as shown in FIG. Therefore, there is a portion where the irradiated dose is not uniform in the X-axis direction. If this non-uniformity in the X-axis direction of the irradiation dose is not allowed, the X-axis direction distribution of the electron beam intensity is made uniform as shown in FIG. 11A, and the heater element H (i, j) is moved in the X-axis direction. And can be improved by optimizing the temperature distribution in the X-axis direction at the partial cooling timing T3. Alternatively, the absorbed dose can be made uniform by moving the fluorine-containing polymer film substrate 1 in the X-axis direction at an appropriate speed during irradiation with the electron beam E. Furthermore, this can be achieved by controlling the moving speed of the fluorine-containing polymer film substrate 1 in conjunction with the intensity of the electron beam E to make the absorbed dose per unit distance uniform. The fluorine-containing polymer film substrate 1 is moved in the X-axis direction at the beam irradiation timing T5, the fluorine-containing polymer film substrate 1 is stopped at the heat retention timing T4, and the heater element H (i, j ) To return the temperature of the fluorine-containing polymer film substrate 1 uniformly, and by repeating these alternately, the tape-like long fluorine-containing polymer film substrate 1 can be subjected to an arbitrary uniform dose at a uniform temperature. Electron beam irradiation can be performed. The absorbed dose per unit area can be arbitrarily determined by lengthening the beam irradiation timing T5.

In the above, the rapid heating timing T1, the warming timings T2 and T4, and the partial cooling are performed by changing the time function for controlling the calorific value Q (i, j) while keeping the spatial distribution of each heater element H (i, j) constant. In the embodiment, the surface temperature Th (i, j) of each heater element H (i, j) is changed at the timing T3. However, the surface temperature Th (i, j) of each heater element H (i, j) is shown. ) Are set spatially different in the direction of the X axis, a rapid heating space, a heat retaining space, and a partial cooling space are provided in this order, and the relative relationship of the surface temperature Th (i, j) of the heater element in these spaces And the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 is uniformly set to 340 ± 5 by adjusting the moving speed of the fluorine-containing polymer film substrate 1. It can be kept in the range of ° C. Further, a beam irradiation space is provided, which is approximately coincident with the partial cooling space. The spatial distribution of the temperature of each heater element H (i, j) in this case is shown in FIG. 16A as the temperature of the fluorine-containing polymer film substrate 1 heated by each heater element H (i, j). FIG. 16 (b) shows the spatial distribution, FIG. 16 (c) shows the spatial distribution of the temperature of the fluorine-containing polymer film substrate 1 heated by electron beam irradiation, and heating by each heater element H (i, j). FIG. 16D shows the spatial distribution of the temperature of the fluorine-containing polymer film substrate 1 when heating by electron beam irradiation is superimposed. Also in this embodiment, the amount of heat released from the fluorine-containing polymer film substrate 1 within the unit time in the partial cooling space and the amount of heat given by the electron beam E within the unit time are the fluorine-containing polymer film substrate 1. It always coincides at any position within the irradiation field Fi.

  The relationship between the X-axis direction length Xs of each space, the moving speed v of the fluorine-containing polymer membrane substrate 1 and the time t is set to t = Xs / v, so that the fluorine-containing high height similar to that in Example 1 is obtained. The temperature Tp (x, y, t) of the molecular film substrate 1 can be realized. In this embodiment, since the temperature Tp (x, y, t) of the fluorine-containing polymer film substrate 1 can be kept within a certain range even if the moving speed v of the fluorine-containing polymer film substrate 1 is changed, the irradiation dose In order to change, the moving speed v may be changed. The irradiation dose rate of the electron beam E can be optimized by changing the setting of the surface temperature of the heater element H (i, j) in the partial cooling space.

  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. Irradiation is performed by changing the set temperature range during irradiation according to the accumulated dose received by the fluorine-containing polymer film substrate 1 by changing the time function shown in FIG. 8 according to the accumulated value of the absorbed dose. The temperature of the hour can be optimized over time. 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 is the fluorine-containing polymer film. It means a spatial range where the polymer film substrate is irradiated with the ionizing radiation, and does not include a portion where the ionizing radiation protrudes from the fluorine-containing polymer film. Further, in the present invention, the cooling is expressed including the case where the amount of heat in a specific part is reduced by heat conduction in addition to radiation by radiation or convection. 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.

  When the present invention is employed, when a fluorine-containing polymer membrane substrate is cross-linked by irradiating with ionizing radiation at a high temperature in an oxygen-free environment, a large-area fluorine-containing polymer membrane substrate is applied to all the irradiation fields. It is possible to irradiate ionizing radiation in a state that is always kept within a predetermined temperature range over a position and throughout the entire processing time, and in a short time a large amount of fluorine-containing polymer film having a stable quality cross-linked structure Moreover, it can be produced at 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 Since the exchange membrane can be mass-produced at a low cost, and as a result, a long-life fuel cell having high performance and stable operation can be produced at a low cost, 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 expensive.

It is the figure which represented the high temperature electron beam processing apparatus concerning this invention with the longitudinal cross-sectional view. It is the figure which represented the high temperature electron beam processing apparatus concerning this invention with the cross-sectional view. It is the top view and sectional drawing showing the heater group for a heating which comprises the high temperature electron beam processing apparatus concerning this invention. It is the figure showing the top view and sectional side view of the heater group for a heating 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 heat retention timing T2, T4. 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 partial cooling timing T3. It is a figure explaining the effect | action concerning this invention, and is a figure which shows the time function which controls the emitted-heat amount of each heater element, and the time function which controls an electron beam irradiation dose. 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 X-axis direction distribution of the electron beam intensity and the temperature of a fluorine-containing polymer film base material at the time of irradiating this. It is a figure explaining the effect | action concerning this invention, and is a figure which shows X-axis direction distribution of the electron beam intensity and the temperature of a fluorine-containing polymer film base material at the time of irradiating this. It is a figure explaining the effect | action concerning this invention, and shows the temperature distribution of the fluorine-containing polymer film | membrane base material 1 when not irradiating the electron beam E in the state which controlled each heater element so that the partial cooling timing T3 may arise. FIG. 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 membrane base material during an electron beam irradiation, and its time change. 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 showing the other Example concerning this invention, and is a figure which shows the spatial distribution of the surface temperature of each heater element, and the spatial distribution of the temperature of a fluorine-containing polymer film | membrane base material.

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 High-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 Arrow which shows temperature detection direction 22 Arrow which shows temperature detection direction
30 Heater group E Electron beam Fi Irradiation field FL Irradiation field length FW Irradiation field width T1 Rapid heating timing T2 Thermal insulation timing T3 Partial cooling timing T4 Thermal insulation timing T5 Beam irradiation timing

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 around its crystalline melting point, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer membrane substrate. In a method for producing a modified fluorine-containing polymer film by irradiation in a low oxygen partial pressure environment,
A heating element having a calorific value distributed in the longitudinal direction and the width direction is opposed to the surface of the fluorine-containing polymer film substrate in the vicinity of the irradiation field of the ionizing radiation provided extending in the width direction. Is provided in a non-contact manner,
The heating element has a first heating element group and a second heating element group each including a plurality of heating element elements aligned in the width direction, and the first heating element group and the second heating element group. Body elements are aligned in the longitudinal direction;
The fluorine-containing polymer film substrate includes a desired range having a size substantially corresponding to the irradiation field,
All parts of the body within the desired range of the fluorine-containing polymer film substrate, after being heated to a temperature within the preset temperature range by the heating element,
By the ionizing radiation with a predetermined intensity distribution while being cooled with a predetermined cooling rate is heated with a predetermined heating rate,
Intensity distribution and / or the calorific value of the distribution of the heating element of the ionizing radiation is always set so as to substantially match over in the irradiation time and the heating rate and the cooling rate at all sites within the desired range method characterized by that Ru is by 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 around its crystalline melting point, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer membrane substrate. In a method for producing a modified fluorine-containing polymer film by irradiation in a low oxygen partial pressure environment,
A heating element having a predetermined calorific value distributed in the longitudinal direction and the width direction is provided in contact with the surface of the fluorine-containing polymer film substrate in the vicinity of the irradiation field of the ionizing radiation. ,
The heating element has a first heating element group and a second heating element group each including a plurality of heating element elements aligned in the width direction, and the first heating element group and the second heating element group. Body elements are aligned in the longitudinal direction;
The fluorine-containing polymer film substrate includes a desired range having a size substantially corresponding to the irradiation field,
The fluorine-containing polymer film substrate is heated to a temperature within or near the set temperature range by the first substrate region maintained at a temperature lower than the set temperature range and the heating element. A second base material region, and a third base material region that is irradiated with the ionizing radiation and maintained at a temperature within the set temperature range,
The third base material region includes the desired range,
In any part within the desired range, when the temperature due to heating of the heating element is going to decrease, the temperature due to irradiation with the ionizing radiation rises, and during the time of receiving the irradiation with ionizing radiation, the temperature is increased. as kept within the preset temperature range, wherein the amount of heat generation and / or distribution and / or the intensity of the ionizing radiation that of the heating element is set, or that are 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 around its crystalline melting point, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer membrane substrate. In a method for producing a modified fluorine-containing polymer film by irradiation in a low oxygen partial pressure environment,
The fluorine-containing polymer film substrate includes a desired range having a size substantially corresponding to the irradiation field of the ionizing radiation,
The portion within the desired range passes through the processing apparatus that receives the ionizing radiation,
The processing apparatus includes a heating element provided in a non-contact manner so as to face the surface of the fluorine-containing polymer film substrate, and a part of the fluorine-containing polymer film substrate is placed in the set temperature range. A first device region that is maintained at a lower temperature and mechanically held; a second device region that heats a portion within the desired range to a temperature within or near the set temperature range by the heating element; and a third device area to which a predetermined dose in order to irradiate the ionizing radiation to a portion of the desired range,
The heating element includes a first heating element group and a second heating element group each including a plurality of heating element elements arranged in the width direction, and the first heating element group and the second heating element. Body elements are aligned in the longitudinal direction;
Wherein when the portion in the desired range is positioned at the third device area, due to the irradiation of the ionizing radiation as part is cooled temperature within the desired range supplement the try when Then the temperature drop decreases The intensity distribution of the ionizing radiation and / or the calorific value distribution of the heating element is set or controlled so that the temperature of any part within the desired range is kept within the set temperature range by increasing the temperature of the heating element. A method characterized by that. Fluorine-containing polymer membrane substrate, or other longitudinal direction and the width direction and in the long irradiation object in the predetermined dose while keeping the temperature within a predetermined set temperature range elongate irradiated body extending A processing apparatus for irradiating ionizing radiation,
Said elongate the irradiated body, and a holding portion which is positioned and held in the processor, the set temperature range or heating range to be heated to near the temperature, radiation field substantially coincides with the ionizing radiation And a desired range of sizes to be
The processing apparatus includes a first device region for mechanically holding said retaining portion with keeping the holding portion to a lower temperature can be held to face the surface of the elongated object to be irradiated in the vicinity of the irradiation field And a second device region that heats a portion within the heating range to a temperature within or near the set temperature range by a heating element including a plurality of heating element elements arranged in a non-contact manner in the width direction. If, it includes a third device region to keep the part in the desired range to give a heat generation due to irradiation of the ionizing radiation to a portion within the desired range to a temperature within the preset temperature range,
In the third device region, the distribution of the amount of heat generated by the heating element is set differently from the distribution of the amount of heat generated by the heating element in the second device region, and is heated by the heating element. wherein the temperature at the portion within the desired range due to the irradiation of the ionizing radiation distributed intensity such that the temperature did compensate for trying the result the temperature drop decreases in portions in the desired range increases with the An apparatus characterized in that a predetermined dose is given to a portion within the desired range while maintaining all portions within the desired range at a temperature within the set temperature range during a period of receiving ionizing radiation. As time control the heating value of the distribution of the elongated object to be irradiated the heating element such that the change rate relative to the distance the temperature is always smaller than a predetermined value of at any site within the desired range The apparatus according to claim 4 , wherein: 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 around its crystalline melting point, ionizing radiation of 1 kGy or more is applied to the fluorine-containing polymer membrane substrate. In a method for producing a modified fluorine-containing polymer film by irradiation in a low oxygen partial pressure environment,
A heating element having a calorific value distributed in the longitudinal direction and the width direction is opposed to the surface of the fluorine-containing polymer film substrate in the vicinity of the irradiation field of the ionizing radiation provided extending in the width direction. Is provided in a non-contact manner,
The heating element includes a first heating element group and a second heating element group each including a plurality of heating element elements aligned in the width direction, and the first heating element group and the second heating element group The heating element groups are aligned in the longitudinal direction;
The fluorine-containing polymer film substrate includes a desired range having a size substantially corresponding to the irradiation field,
Either the first heat generating element group or the second heat generating element group is provided in a central portion within the irradiation field so as to face the surface of the fluorine-containing polymer film substrate. A heating element, and a second heating element disposed opposite to the surface of the fluorine-containing polymer film substrate at a more end in the width direction,
By setting the surface temperature of the second heat generating element higher than the surface temperature of the first heat generating element, the temperature of every part within the desired range is maintained within the set temperature range. Method. Wherein the plurality of heat generating element contained in either the first heating element group or said second heating element group, the surface of the fluorine-containing polymer membrane substrate at the center portion of the irradiation cortex And a second heat generating element provided opposite to the surface of the fluorine-containing polymer film substrate located at the end in the width direction. door is cage containing Marete,
Method according to any one of claims 1 to 3 surface temperature of the second heating element is characterized in that it has been set higher than the surface temperature of the first heating element. The difference between the surface temperature of the second heating element and the surface temperature of the first heating element can be changed in accordance with the moving speed of the fluorine-containing polymer film substrate. The method according to any one of claims 6 to 7 . The heating element has a first heating element group and the second heat generating element groups each comprising a plurality of heating element aligned in the width direction, the first heat generating element group and the second heating The body element groups are aligned in the longitudinal direction, and the surface temperature of these heating element elements is the surface temperature of the heating element elements located at the ends in the width direction of the fluorine-containing polymer film substrate. claims 1 to 3, characterized in that the temperature becomes higher, or the method described in any one of claims 6 to 8. The aligned in the width direction, it included in the same said heat generating element groups, wherein each heating element is claims 1 to 3, characterized in that the heating value thereof in accordance with the same time function is controlled, Alternatively, the method according to any one of claims 6 to 9 . The set temperature range in a specific portion of the long irradiated body is determined in advance corresponding to an integrated value of the absorbed dose of the ionizing radiation absorbed in the past in the specific portion of the long irradiated body . 6. A device according to any one of claims 4 to 5 , characterized in that it drops while maintaining a relationship. The fluorine-containing polymer film substrate is a polytetrafluoroethylene film, a tetrafluoroethylene-hexafluoropropylene copolymer film, or a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer film. method according to any one of claims 1 to 3, or claims 6 to 10 and.

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