JP2005041108A - Vulcanizing method using vulcanizer and vulcanized product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vulcanizing method for reducing the irregularity of the physical properties such as hardness and the like of a vulcanized molded product. <P>SOLUTION: Pressurized steam is introduced into a vulcanizer filled with an unvulcanized rubber to vulcanize the unvulcanized rubber and the pressure in the vulcanizer is stepwise raised by the introduction of pressurized steam. At least one or more vulcanizing stages are provided and the unvulcanized rubber is vulcanized for a predetermined time under definite vulcanizing pressures respectively set to the respective vulcanizing stages while the raising of pressure to the vulcanizing pressure of each of the respective vulcanizing stages is performed by controlling the pressure in the vulcanizer by the introduction of pressurized steam. The unvulcanized rubber for use in the production of a rubber roller or the like for an office machine is vulcanized by the vulcanizer using pressurized steam as a vulcanizing medium of which the vulcanizing pressure is set to pressure equal to the saturated vapor pressure in the vulcanizer. The definite vulcanizing pressure of at least one stage is set and pressurized steam is supplied into the vulcanizer to raise the pressure in the vulcanizer to the vulcanizing pressure by pressure control to vulcanize the unvulcanized rubber under each of raised vulcanizing pressures in a state that the pressure in the vulcanizer is equal to saturated vapor pressure. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of vulcanizing unvulcanized rubber with a vulcanization can and a vulcanized product vulcanized by the method, and more specifically, the pressure in the vulcanization can is adjusted using pressurized steam as a vulcanization medium. The vulcanization is controlled, and stable vulcanization is performed to reduce variations in physical properties such as hardness of the vulcanized product, and is particularly suitable for vulcanization of rubber rollers and the like in the image forming apparatus.

  Conventionally, rubber products such as rubber rollers used in office automation equipment such as copying machines, printers, facsimiles, and automatic deposit machines have been vulcanized and molded by press vulcanization or vulcanization cans. Various vulcanization methods have been proposed in order to obtain rubber products in which desired performance is well expressed.

  For example, in Japanese Patent Application Laid-Open No. 2002-36245 (Patent Document 1), the present applicant supplies and heats a heating medium made of a high-temperature gas into an elastomer article loaded in a mold in press vulcanization. A gas vulcanization method for an elastomer article that includes a heating process and a pressurizing process that pressurizes the elastomer article and presses the elastomer article against a mold, and alternately repeats a pressure increasing step and a pressure decreasing step during the heating process or the pressing process. is suggesting.

  In JP-A-2002-113735 (Patent Document 2), the raw material composition includes a heating step in which a raw material composition containing a vulcanizing agent and a foaming agent is heated and expanded to form a foam. When heating to a temperature t1 lower than the decomposition temperature of the foaming agent and temporarily holding at this temperature t1, the preheating step for selecting the holding time T2 in the range of 1 to 10 minutes, and the preheating step 15 A method for producing a foam roller having at least a temperature raising step for raising the temperature to a temperature t2 equal to or higher than a decomposition temperature of the foaming agent at an average temperature rise rate of at least ° C./minute, and a foam vulcanization step for holding the temperature t2 for a predetermined time Has been proposed. That is, the vulcanization process is performed in two stages by temperature control, and the above process is performed in a vulcanization can heated with pressurized steam.

JP 2002-36245 A JP 2002-113735 A

  However, Patent Document 1 can suppress the occurrence of poor adhesion between tire members, and is particularly suitable for vulcanization molding of rubber tires. However, the hardness of the vulcanizate may vary by alternately repeating the pressure-increasing step and the pressure-decreasing step while supplying the heating medium into the mold or during pressurization with the pressure medium. In addition, it is difficult to obtain stable performance for use in rubber rollers for office equipment and the like, and there is still room for improvement. Moreover, since it is based on press vulcanization, there is a problem that it is not versatile as compared with a vulcanized can.

  On the other hand, in Patent Document 2, since the vulcanization process is temperature control, the temperature of the vulcanization can itself is transmitted to the temperature sensor unit that controls the vulcanization process, and the accurate temperature inside the vulcanization can cannot be measured. Therefore, there is a problem that the temperature of the vulcanized can itself is increased in temperature control and the physical properties of the vulcanized product vary.

  In addition, if the relationship between the pressure and temperature in the vulcanizing can after the start of vulcanization satisfies the conditions for vaporization of the water present in the rubber, it will cause abnormal foaming, and foamed rubber will lose the balance between foaming and vulcanization. Product characteristics will be affected. Furthermore, in vulcanization with pressurized steam, the vulcanized product will radiate from the vulcanizing can unless the temperature inside the vulcanizing can rises above the temperature of the vulcanizing can itself after the start of steam entry into the vulcanizing can. Sensitive to heat. For this reason, the relationship between the pressure and temperature in the vulcanization can at about 100 ° C., which is the vulcanization start temperature and the foaming start temperature, is particularly important.

  As described above, in the temperature control, there is a problem that the relationship between the pressure and the temperature at the time of temperature rise is not constant due to the influence of the temperature in the vulcanizing can after the start of the steam inlet. Also, the temperature change in the vulcanizing can during steam entry is greatly influenced by the opening and closing interval of the vulcanizing can door and the temperature around the vulcanizing can, and it also affects the temperature change due to the time of day and the annual temperature change. Affected. For example, FIG. 6 shows the relationship between the temperature inside the vulcanization can and time, and the relationship between the pressure inside the vulcanization can and time in the vulcanization process by temperature control. Is 0.624 MPa. As shown in FIG. 6, when the door of the vulcanizing can is repeatedly opened and closed, and the vulcanization is continuously performed three times by temperature control, the unvulcanized product is put in the vulcanizing can and the door is closed to generate steam. The temperature inside the vulcanizing can when entering is changed by vulcanization at 3 degrees.

  In the temperature control, when the rate of temperature increase is constant, the temperature increase time varies depending on the temperature in the vulcanizing can at the time of steam inlet. Even when the temperature raising time is set to be constant, steam is not supplied up to the temperature in the vulcanizing can, so the temperature raising time changes substantially. For this reason, in temperature control, the pressurization time from the time of steam inlet cannot be made constant, which affects the physical properties of the vulcanizate.

  The present invention has been made in view of the above-described problems, and does not detect the temperature of the vulcanization can and raise the pressure in the vulcanization can by temperature control, but detects the pressure in the vulcanization can. However, it is an object of the present invention to provide a vulcanization method that reduces the variation in physical properties such as hardness of a vulcanized product by performing pressure control while performing stable vulcanization.

In order to solve the above problems, the present invention vulcanizes by introducing pressurized steam into a vulcanizing can filled with unvulcanized rubber,
The pressure is increased stepwise by the introduction of the pressurized steam, and at least one vulcanization stage is provided, and vulcanized for a predetermined time at a fixed vulcanization pressure set in each vulcanization stage,
The vulcanization pressure in each vulcanization stage is increased by controlling the pressure in the vulcanization can by introducing the pressurized steam, and the vulcanization pressure is equal to the saturated vapor pressure in the vulcanization can. A vulcanizing method using a vulcanizing can characterized in that the pressure is set to a certain level.

As described above, pressurized steam is introduced into the vulcanizing can, and the pressure inside the vulcanizing can is controlled to control the pressure increase so that the set pressure is reached. In other words, the pressure in the vulcanization can is detected, pressurized steam is introduced to increase the set pressure, the pressure is increased, and vulcanization is performed at a set temperature corresponding to the pressure. The influence of the temperature inside the vulcanizing can and the temperature of the vulcanizing can itself can be reduced. That is, the pressurization time, pressurization speed, vulcanization time, and vulcanization temperature can be arbitrarily set within the pressurized steam supply capacity (0 to 1 MPa), and after setting, the pressurization time and vulcanization time are always controlled by pressure control. It can be kept constant and the vulcanization conditions can be stabilized.
The pressurization time, pressurization speed, vulcanization time, and vulcanization temperature settings can be changed by controlling the introduction of pressurized steam, and based on this, product characteristics such as the hardness of the vulcanizate can be easily changed. You can also.

Furthermore, in the present invention, the vulcanization pressure in the vulcanization stage is set to be approximately the same as the saturated vapor pressure in the vulcanizer, and pressurized steam having a pressure substantially equal to the set vulcanization pressure is set in the pressure increase stage. Then, by introducing the pressurized steam, the inside of the vulcanizing can is quickly increased to a pressure equivalent to the saturated vapor pressure, and vulcanized while maintaining the saturated vapor pressure for a certain time after the pressure increase.
As described above, since the unvulcanized rubber is vulcanized for a predetermined time while being held at a constant pressure equivalent to the saturated vapor pressure, the vulcanization of the rubber can be stabilized. When the rubber is foamed rubber, the balance between foaming and vulcanization can be maintained in a stable state, and a vulcanized product having stable physical properties can be obtained. The state equivalent to the saturated vapor pressure is a range of 0.005 MPa within a range of ± 0 to less than 0.047 MPa from the saturated vapor pressure at each temperature, and a sample having a saturated vapor pressure of less than 0.0047 to 0.119. 0.119 or more and in the range of ± 0.08 MPa.
As described above, in the present invention, by utilizing the relationship between the pressure and temperature of saturated steam, pressurized steam is introduced to increase the set pressure to be the set temperature, and the temperature during vulcanization is increased by pressure control. Therefore, vulcanization can be performed without being affected by the temperature in the vulcanization can at the time of steam inlet or the temperature of the vulcanization can itself.

  In at least one boosting step, the boosting may be continuously performed in two or more steps. Specifically, the pressure is continuously increased in two stages in the first pressure increase stage so as to reach the set pressure in the first vulcanization stage. This becomes close to the pressure of the pressurized steam to be introduced as the set pressure increases, making it difficult to quickly increase the pressure, and is susceptible to the pressure fluctuation of the introduced pressurized steam. Therefore, in order to remove the influence of the pressure fluctuation and keep the boosting speed constant, the boosting speed in the second boosting step is made slower than the first boosting speed.

  This is because, in vulcanization or foaming / vulcanization of unvulcanized rubber, the physical properties of the vulcanizate (electrical properties such as hardness and resistance value) are affected by the application of temperature and pressure up to around 100 ° C. According to. For this reason, in particular, the pressure increase condition from the start of supply of pressurized steam to the first stage vulcanization pressure is important, and the physical property of the vulcanizate is controlled by controlling the pressure increase rate at the initial pressure increase in two stages. It can be further stabilized.

The vulcanization pressure in each of the plurality of vulcanization stages is set higher as the latter stage, but the vulcanization pressure in each vulcanization stage is a constant pressure within the range of 0.01 to 1.0 MPa. It is said.
For example, the vulcanization pressure in the first vulcanization stage is 0.1 to 0.4 MPa, and the vulcanization pressure in the second vulcanization stage is 0.5 to 0.8 MPa.

  The pressure increase rate in each of the plurality of pressure increase steps is 0.001 to 10.00 MPa / min, preferably 0.005 MPa / min to 0.500 MPa / min, and the most preferable range is 0.007 MPa / min. ˜0.3 MPa / min.

  The reduced pressure after vulcanization may be reduced in one stage or stepwise in two or more stages. Further, the decompression speed may be constant or may be changed stepwise.

  Conventional rubbers such as acrylonitrile butadiene rubber, styrene butadiene rubber, butadiene rubber, isoprene rubber, chloroprene rubber, ethylene propylene rubber, ethylene propylene diene rubber, butyl rubber, epichlorohydrin rubber, silicone rubber, fluorine rubber, urethane rubber, natural rubber, etc. One or more known rubbers can be used. Moreover, it is good also as a foaming vulcanizate by mix | blending a conductive filler with a rubber composition, and mix | blending a conductive vulcanizate, a foaming agent, a foaming adjuvant, etc. Furthermore, you may mix | blend various additives, such as a vulcanizing agent, a vulcanization accelerator, a filler, a softening agent, a processing aid, and an anti-aging agent, with a rubber composition.

  The present invention provides a vulcanizate characterized by being vulcanized by the above vulcanization method. Since the vulcanizate has small variations in physical properties such as hardness and electrical resistance, it is particularly suitable as a rubber roller for an image forming apparatus such as a charging roller, a developing roller, a transfer roller, a driving roller, a toner supply roller, and a paper feeding roller. Preferably used.

  As described above, according to the present invention, the temperature of the vulcanization process is controlled by using the relationship between the pressure and temperature of the saturated vapor pressure and the temperature is raised and vulcanized with pressurized steam. The influence of the radiant heat of the main body can be reduced, and the vulcanized material can be vulcanized by pressurized steam heated in a state close to the saturated vapor pressure, and vulcanization and foaming can be stabilized. In addition, the pressure control of the pressurization that correlates with the temperature rise is controlled, so the pressurization time of the vulcanizing can can be stabilized, the pressurization time and pressurization speed can be set arbitrarily, and the inside of the vulcanizing can when pressurized steam is introduced. Vulcanization can be performed without being affected by temperature and vulcanization can temperature.

In addition, since it is not affected by the temperature in the vulcanization can when steam enters, vulcanized products with little variation in physical properties can be continuously produced without the influence of opening and closing of the vulcanization can door. Compared with vulcanization using a temperature-controlled vulcanizer or press vulcanization, the productivity is excellent.
Furthermore, since the vulcanized product vulcanized by the method of the present invention has small variations in physical properties such as hardness and electrical resistance, it can be suitably used as a rubber roller, particularly a transfer roller, used in an image forming apparatus.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a vulcanizer 10 used in the vulcanization method of the present invention.
The vulcanizing device 10 contains a vulcanized can 11 containing unvulcanized rubber and vulcanized using pressurized steam as a vulcanizing medium, a pressure sensor 12 for measuring the pressure in the vulcanized can 11, and a pressure regulator 13. And a temperature sensor 14 for measuring the temperature in the vulcanizing can 11, a temperature measuring device 15, and a pressure and temperature control device 16.

The vulcanizing can 11 includes a main body 11A having an opening at one end and an openable / closable door 11B that closes the opening, and a packing is provided between the main body 11A and the door 11B.
Pressurized steam introduced from the pressurized steam supply means 17 into the vulcanizing can 11 communicates with the diaphragm of the main body 11A of the vulcanized can and communicates with the first supply passage 18A through which pressurized steam is introduced and the packing of the door 11B. Is introduced into the vulcanizing can 11 from the second supply passage 18B.

Further, the pressurized steam is discharged out of the vulcanizing can 11 from the first exhaust passage 19A that communicates with the diaphragm of the main body 11A and exhausts the pressurized steam and the second exhaust passage 19B that communicates with the packing of the door 11B and exhausts the pressurized steam. It is assumed to be configured.
Each supply path 18A, 18B and exhaust path 19A, 19B is provided with a valve B, and the supply / stop of pressurized steam is controlled by opening / closing operation of the valve B.

Hereinafter, the vulcanization method of the first embodiment of the present invention will be described in detail.
First, the kneaded rubber composition containing EPDM and the main component is extruded into a hollow cylindrical shape by an extruder, an unvulcanized rubber roller cut to a fixed size is placed in the vulcanizing can 11 and the door 11B is closed.

  In the present embodiment, a constant vulcanization pressure in two stages of a first stage vulcanization pressure and a second stage vulcanization pressure is set, and pressurized steam is supplied from the pressurized steam supply means 17 into the vulcanization can 11. The vulcanization can be vulcanized by increasing the pressure and raising the temperature inside the vulcanizing can.

Specifically, pressurized steam is supplied into the vulcanizing can 11 from the first supply path 18A and the second supply path 18B, the pressure in the vulcanizing can 11 is measured by the pressure sensor 12, and the pressure regulator 13 and the control are controlled. The valve B is controlled to open and close via the device 16. As a result, as shown in FIG. 2, the pressure inside the vulcanizing can 11 is increased to the first-stage vulcanization pressure Pa at a constant pressure increase time Ta by pressure control. The pressurized steam is introduced into the vulcanizing can 11 so that the heated pressurized steam covers the unvulcanized rubber and maintains the first-stage vulcanization pressure Pa and performs the first-stage vulcanization for a predetermined time Tb. Do.
Next, pressurized steam is further supplied into the vulcanizing can 11, and the pressure inside the vulcanizing can 11 is increased to the second-stage vulcanization pressure Pb at a constant pressure increase rate at time Tc by pressure control. The vulcanization pressure Pb is maintained and the second vulcanization is performed for a predetermined time Td.
The pressure and temperature in the vulcanizing can 11 are measured by the pressure sensor 12 and the temperature sensor 14, and the pressure in the vulcanizing can 11 is increased and vulcanized in a state equivalent to the saturated vapor pressure by the pressure regulator 13 and the control device 16. Has been done.

  After vulcanization, water vapor is discharged from the first exhaust passage 19A, and the inside of the vulcanization can 11 is decompressed at a constant decompression speed at time Te, and further decompressed by changing the decompression speed. After completion of the pressure reduction to a predetermined pressure, the water vapor in the packing is discharged from the second exhaust passage 19B, the door 11B is opened, and the rubber roller, which is a vulcanized product, is taken out from the vulcanizing can 11.

  Thereafter, in this embodiment, a metal shaft with an adhesive attached to the outer peripheral surface is inserted into the hollow portion of the rubber roller, secondary vulcanization (hot air) is performed, and both ends are cut to a predetermined size, The outer peripheral surface is polished by a polishing machine to obtain a rubber roller having a predetermined outer diameter.

The vulcanized product vulcanized by the above method is heated to a temperature corresponding to the pressure by controlling the pressure in the vulcanization can with pressurized steam using the relationship between the pressure and temperature of the saturated vapor pressure. Vulcanized.
For this reason, the influence of the radiant heat from the vulcanizing can 11 can be reduced, and the unvulcanized rubber roller as the vulcanized material can be vulcanized with heated pressurized steam in a state close to the saturated vapor pressure, and vulcanization and foaming can be performed. Can be stabilized. In addition, since the pressure increase is based on pressure control, the pressure increase time of the vulcanizing can 11 can be stabilized, and the influence of the temperature in the vulcanizing can 11 at the time of pressurized steam inlet and the influence of the temperature of the vulcanizing can 11 itself can be reduced. can do. Therefore, a vulcanizate having extremely small variations in hardness and electric resistance can be obtained, and can be suitably used for a rubber roller for office equipment.

FIG. 3 shows a second embodiment of the vulcanization method according to the present invention. By increasing the pressure increase rate from the state of pressure 0 to the first stage vulcanization pressure Pa by pressure control, the pressure is increased stepwise in two stages. ing. For example, after the pressure is increased over time Ta-1, the pressure increase rate can be decreased and the pressure can be increased stepwise to the first stage vulcanization pressure Pa over time Ta-2. Note that the pressure can be reduced at a constant pressure reduction rate.
In the above embodiment, the vulcanization pressure is set to two stages, but the vulcanization pressure may be three stages or more. Further, the pressure may be increased stepwise from the first stage vulcanization pressure to the second stage vulcanization pressure.

Examples of the vulcanization method of the present invention and comparative examples will be described in detail below.
(Experiment 1)
As the unvulcanized rubber, a kneaded rubber composition for a transfer roller in which EPDM, carbon black, zinc oxide, stearic acid, sulfur, a vulcanization accelerator, and a foaming agent were blended in a predetermined amount and kneaded was used. This rubber composition was extruded into a hollow cylindrical shape with an extruder, and an unvulcanized rubber roller cut to a fixed size was put into a vulcanizing can and vulcanized by the following method. The dimensions of the unvulcanized rubber roller were about 250 mm in length, about 5 mm in thickness, about 14 mm in outer diameter, and about 4 mm in inner diameter.

(Example 1)
Two-stage vulcanization was performed by pressure control with a vulcanizer using pressurized steam as in the above embodiment using the same vulcanizing apparatus as in the above embodiment. While the inside of the vulcanizing can was equal to the saturated vapor pressure, the pressure was increased and the vulcanized rubber was vulcanized at each vulcanization pressure. FIG. 4 shows temporal changes in pressure and temperature in the vulcanization can of Example 1.
The first time in the figure also shows the time T1 = 6 minutes for the pressurization stage, the time T2 for the first vulcanization stage = 10 minutes, the time T3 for the second pressure increase stage = 3 minutes, the second vulcanization stage Time T4 = 20 minutes, and reduced pressure time T5 = 11 minutes (two-stage reduced pressure 1 minute + 10 minutes).

The vulcanization pressure P1 in the first vulcanization stage was 0.233 MPa, and the vulcanization pressure P2 in the second vulcanization stage was 0.624 MPa.
The pressure increase rate during the first pressure increase was 0.0388 MPa / min, and the pressure increase rate during the second pressure increase was 0.1303 MPa / min.
As shown in FIG. 4, the temperature in the vulcanization can rises according to the pressure increase in the vulcanization can, and the temperature in the first vulcanization stage is 125 ° C. to 128 ° C. The temperature in the vulcanization stage was 161 ° C to 163 ° C. Since the pressure was controlled to the saturated vapor pressure in the first stage vulcanization stage and the second stage vulcanization stage, the vulcanization temperature hardly changed.

(Comparative Example 1)
Two-stage vulcanization was performed not by pressure control but by temperature control. FIG. 5 shows temporal changes in pressure and temperature in the vulcanization can of Comparative Example 1.
In the figure, T1 = 6 minutes, T2 = 10 minutes, T3 = 3 minutes, T4 = 20 minutes, T5 = 11 minutes (two-stage decompression 1 minute + 10 minutes). The first stage vulcanization temperature t1 was 125 ° C., and the second stage vulcanization temperature t2 was 160 ° C. Note that the pressure at the start of the first stage vulcanization is 0.22 MPa, the pressure at the start of the second stage vulcanization is 6.0 MPa, which is lower than the pressure of the saturated steam, and because of temperature control, the vulcanization stage Since the pressure gradually fluctuated, the temperature at the temperature dropped greatly.

A rubber roller was molded from the vulcanizate produced by the vulcanization method of Example 1 and Comparative Example 1, and Asker C hardness of the rubber roller was measured with an Asker hardness meter (Polymer Meter Co., Ltd.). There were 20 samples each consisting of Example 1 and Comparative Example 1.
As shown in Table 1, the measurement results are shown in Table 1. Example 1 has a standard deviation of 1.5, which is about half of the standard deviation 3.2 of Comparative Example 1 by temperature control, and it can be confirmed that the variation in hardness is very small. It was.

Further, the first stage pressure increase rate in the vulcanization step is 0.0388 MPa / min, 0.033 MPa / min, 0.0178 MPa / min, 0.0155 MPa. The effect on the hardness of the vulcanizate was measured in place of min. The conditions were the same except that the first stage boost time was changed.
The vulcanized vulcanizate with the pressure increasing speed varied was molded into a rubber roller, and the Asker C hardness of the rubber roller was measured with an Asker hardness meter (Polymer Meter Co., Ltd.).
As shown in Table 2, the measurement results showed that the hardness was higher as the first-stage pressure increase rate was slower, and it was confirmed that the pressure increase rate affected the product hardness. Therefore, according to the pressure control of the present invention, it was confirmed that the hardness can be adjusted by adjusting the pressure increasing speed.

It is a schematic block diagram of the vulcanization apparatus which performs the vulcanization method of this invention. It is a figure which shows the relationship between the pressure in a vulcanization can and time of the vulcanization method of 1st Embodiment. It is a figure which shows the relationship between the pressure in a vulcanization can and time of the vulcanization method of 2nd Embodiment. It is a figure which shows the time change of the pressure in the vulcanization can of Example 1, and temperature. It is a figure which shows the time change of the pressure in the vulcanizing can of the comparative example 1, and temperature. It is a figure which shows the time change of the temperature in the vulcanization can of the vulcanization process by the conventional temperature control, and a pressure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vulcanization apparatus 11 Vulcanization can 12 Pressure sensor 13 Pressure regulator 14 Temperature sensor 15 Temperature measuring device 16 Control apparatus 17 Pressurized steam supply means

Claims (5)

Vulcanized by introducing pressurized steam into a vulcanized can filled with unvulcanized rubber,
The pressure is increased stepwise by the introduction of the pressurized steam, and at least one vulcanization stage is provided, and vulcanized for a predetermined time at a fixed vulcanization pressure set in each of these vulcanization stages,
The vulcanization pressure in each vulcanization stage is increased by controlling the pressure in the vulcanization can by introducing the pressurized steam, and the vulcanization pressure is equal to the saturated vapor pressure in the vulcanization can. A vulcanizing method using a vulcanizing can, characterized in that the pressure is set to a certain level.   The vulcanization method using a vulcanizer according to claim 1, wherein the at least one pressurization stage is configured to reach a vulcanization stage in which the pressure is kept constant after the pressure is continuously increased to one or more stages.   The vulcanization pressure in each of the vulcanization stages is a constant pressure within a range of 0.01 to 1.0 MPa, and the pressure increase rate in the pressure increase stage is 0.001 to 10.00 MPa / min. Alternatively, a vulcanizing method using a vulcanizing can according to claim 2.   A vulcanized product obtained by vulcanization by the vulcanization method according to any one of claims 1 to 3.   The vulcanizate according to claim 4, which is formed as a rubber roller used in an image forming apparatus.

Images