JP2018095686A - Method for producing silicone rubber molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a silicone rubber molding that can reduce volatile compounds and ultrafine particles discharged outside from an electrophotographic image formation device with efficiency and at low cost, and can also prevent stains on an output image and destruction of a silicone rubber molding.SOLUTION: A method for producing a silicone rubber molding has the step for cleaning a silicone rubber molding by the steam of an organic solvent.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for producing a silicone rubber molded body. More specifically, the present invention can efficiently and inexpensively suppress volatile compounds and ultrafine particles discharged outside the electrophotographic image forming apparatus, and can reduce the contamination of the output image and the destruction of the molded silicone rubber. The present invention relates to a method for producing a molded silicone rubber.

  By using an electrophotographic image forming apparatus (hereinafter also referred to as “image forming apparatus”) such as a printer, a copier, a facsimile machine, or a composite machine of these, ultra fine particles having a particle diameter of less than 100 nm are discharged from the image forming apparatus. It has been pointed out. Since there is concern about the effects of such ultrafine particles on the health, there is a movement to standardize the amount of ultrafine particles emitted based on the Blue Angel Mark standard.

  As an image forming apparatus capable of removing such ultra fine particles, an image provided with electrostatic dust collecting means for electrostatically collecting fine particle dust generated in the image forming apparatus or cyclone dust collecting means for collecting by a cyclone method. A forming apparatus has been proposed (see, for example, Patent Document 1).

  In addition to the means for removing with a filter in this way, the study of reducing the ultrafine particles themselves generated from the heating means has also been conducted in the past, and the low-molecular siloxane in the rubber compound is reduced in advance by vacuum heat treatment. Proposals have been made, and there is also a proposal to extract a solvent after vacuum heat treatment (see, for example, Patent Document 2).

  Furthermore, Patent Document 3 proposes to remove cyclic dimethylpolysiloxane and low molecular weight dimethylpolysiloxane remaining in silicone rubber products by immersing them in an organic solvent having a low solubility coefficient and a low boiling point, and subjecting them to ultrasonic treatment. It has also been made.

Further, when the solubility parameter exceeds 19.0278 MPa ^1/2 (9.3 (cal / cm ³ ) ^1/2 ) and is 30.69 MPa ^1/2 (15.0 (cal / cm ³ ) ^1/2 ) or less. It has also been proposed to reduce low molecular siloxanes such as organopolysiloxane low molecular weight substances contained in silicone rubber moldings by immersing them in an organic solvent having a boiling point in the range of 50 to 90 ° C. Using an organic solvent having a slightly larger solubility parameter than that of the rubber molded body, the silicone rubber molded body is treated while suppressing swelling (for example, see Patent Document 4).

  However, it is difficult to install the electrostatic dust collecting means or the cyclone dust collecting means in the image forming apparatus as in Patent Document 1 due to the space problem of the image forming apparatus, and the structure is complicated. Therefore, practical application has been difficult. Further, it is difficult to completely remove the remaining low-molecular siloxane only by vacuum heat treatment as in Patent Document 2, and further, immersion treatment with an organic solvent having a solubility parameter similar to that of low-molecular siloxane as in Patent Document 3 is not possible. If the low molecular weight component is dissolved, it may lead to physical destruction and the durability of the molded silicone rubber may be lowered.

  Furthermore, only organic solvents with relatively large solubility parameters as in Patent Document 4 and slightly low compatibility with silicone rubber have a weak ability to dissolve low-molecular-weight siloxane, and sufficiently reduce the discharge of volatile compounds and ultrafine particles. Can not exert the effect.

JP 2010-2803 A JP-A-6-25431 Japanese Examined Patent Publication No. 7-62084 JP 2005-139394 A

  The present invention has been made in view of the above-described problems and circumstances, and a solution to the problem is that volatile compounds and ultrafine particles discharged outside the electrophotographic image forming apparatus can be efficiently and inexpensively suppressed, and an output image can be obtained. It is an object of the present invention to provide a method for producing a silicone rubber molded product that can reduce the contamination of the molded product and the destruction of the molded silicone rubber product.

In order to solve the above-mentioned problems, the present inventor, in the process of studying the cause of the above-mentioned problems, cleans the silicone rubber molding with an organic solvent vapor, thereby volatilizing the liquid discharged outside the electrophotographic image forming apparatus. The present invention has found that it is possible to provide a method for producing a silicone rubber molded body capable of efficiently and inexpensively suppressing the active compound and the ultrafine particles, and reducing the contamination of the output image and the destruction of the silicone rubber molded body. It came.
That is, the said subject which concerns on this invention is solved by the following means.

  1. A method for producing a silicone rubber molding, comprising a step of washing the silicone rubber molding with an organic solvent vapor.

2. The organic solvent contains an organic solvent having a solubility parameter in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ). The manufacturing method of the silicone rubber molding of Claim 1 to do.

3. The organic solvent has a solubility parameter in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ) and a boiling point of 35 to 150 ° C. The manufacturing method of the silicone rubber molding as described in 1 or 2 characterized by containing the organic solvent which is in the range of these.

  4). 4. The method according to claim 1, wherein the step of cleaning the silicone rubber molded body with a vapor of an organic solvent is performed under a pressure environment within a range of 102 to 800 kPa. Manufacturing method of silicone rubber molding.

5. After the step of washing the silicone rubber molding with an organic solvent vapor,
The silicone according to any one of items 1 to 4, further comprising a step of applying a physical pressure to the silicone rubber molded body to release the organic solvent from the silicone rubber molded body. Manufacturing method of rubber molding.

6). Releasing the organic solvent from the silicone rubber molded body,
After further washing the silicone rubber molded body with the vapor of the organic solvent, applying an organic solvent to the silicone rubber molded body to repeatedly release the organic solvent from the silicone rubber molded body is an organic solvent squeezing step. 6. A method for producing a silicone rubber molded article according to item 5, characterized by comprising:

7). After the organic solvent squeezing step,
7. The method for producing a silicone rubber molded article according to item 6, further comprising a step of drying the silicone rubber molded article by vacuum heating.

By the above-described means of the present invention, volatile compounds and ultrafine particles discharged outside the electrophotographic image forming apparatus can be efficiently and inexpensively suppressed, and the contamination of the output image and the destruction of the silicone rubber molding can be reduced. A method for producing a silicone rubber molded body can be provided.
The expression mechanism or action mechanism of the effect of the present invention is not clear, but is presumed as follows.

  Conventional methods were a method of washing with a solvent whose solubility parameter (hereinafter also referred to as “SP value”) is close to that of low-molecular-weight siloxane, and a method of washing with an amount of solvent that does not swell the silicone rubber molding. .

The former method has a high cleaning effect because the SP value of the solvent is close to that of low-molecular siloxane, but the silicone rubber molding is excessively swollen and greatly deformed. For this reason, the silicone rubber part is peeled off from the cored bar part, and the durability is adversely affected. In addition, since this method uses a large amount of solvent, there is a problem that the load on the environment is large.
However, the method for producing a silicone rubber molded body of the present invention succeeds in reducing the amount of use by washing with an organic solvent as a vapor, and as a result, the load on the environment can be minimized. .

  Further, the latter method has a problem that the cleaning effect is low and a sufficient cleaning effect cannot be obtained by itself. In order to solve this problem, the present invention can wash an organic solvent having an SP value close to that of low-molecular-weight siloxane with a small amount of steam to such an extent that a cleaning effect equivalent to that of the former method is exhibited. Therefore, according to the method for producing a silicone rubber molded body of the present invention, the low molecular weight siloxane in the silicone rubber molded body is melted without excessively swelling the silicone rubber molded body, and thus the silicone rubber molded body. The low molecular weight siloxane can be sufficiently reduced.

  Furthermore, in the present invention, physical deformation may be applied and squeezing may be performed, or steam cleaning with an organic solvent may be repeated. In this way, the low-molecular siloxane in the silicone rubber can be further washed out, and the low-molecular siloxane in the silicone rubber molding can be further reduced.

1 is a diagram showing a schematic configuration of an electrophotographic image forming apparatus according to the present invention. The figure which shows schematic structure of an example of the silicone rubber molding which concerns on this invention Explanatory drawing which shows an example of the chamber cleaned with the vapor | steam of an organic solvent The figure which shows the one aspect | mode for applying a physical pressure to a silicone rubber molding The figure which shows the other aspect for applying a physical pressure to a silicone rubber molding

  The method for producing a silicone rubber molded body of the present invention includes a step of washing the silicone rubber molded body with an organic solvent vapor. This feature is a technical feature common to or corresponding to the claimed invention. As a result, the present invention can efficiently and inexpensively suppress volatile compounds and ultrafine particles discharged outside the electrophotographic image forming apparatus, and can reduce the contamination of the output image and the destruction of the molded silicone rubber. .

As an embodiment of the present invention, as the organic solvent, an organic solvent having a solubility parameter in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ) It is preferable to contain a solvent. Thereby, a higher cleaning effect can be exhibited.

As an embodiment of the present invention, the organic solvent has a solubility parameter in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ), And it is preferable to contain the organic solvent whose boiling point exists in the range of 35-150 degreeC. Thereby, a higher cleaning effect can be exhibited.

  As an embodiment of the present invention, it is preferable that the step of cleaning the silicone rubber molded body with an organic solvent vapor is performed in a pressure environment within a range of 102 to 800 kPa. Thereby, a higher cleaning effect can be exhibited.

As an embodiment of the present invention, after the step of washing the silicone rubber molding with an organic solvent vapor,
It is preferable to have a step of applying a physical pressure to the silicone rubber molded body to release the organic solvent from the silicone rubber molded body. Thereby, a higher cleaning effect can be exhibited.

As an embodiment of the present invention, the step of releasing the organic solvent from the silicone rubber molded body,
After further washing the silicone rubber molded body with the vapor of the organic solvent, applying an organic solvent to the silicone rubber molded body to repeatedly release the organic solvent from the silicone rubber molded body is an organic solvent squeezing step. It is preferable to have. Thereby, a higher cleaning effect can be exhibited.

As an embodiment of the present invention, after the organic solvent extraction step,
It is preferable to have a step of drying the silicone rubber molding by vacuum heating. Thereby, an organic solvent can be more effectively released from a silicone rubber molding.

  Hereinafter, the present invention, its components, and modes and modes for carrying out the present invention will be described in detail. In addition, in this application, "-" is used in the meaning which includes the numerical value described before and behind that as a lower limit and an upper limit.

≪Outline of manufacturing method of silicone rubber moldings≫
The method for producing a silicone rubber molded body of the present invention includes a step of washing the silicone rubber molded body with an organic solvent vapor.
In the following, first, an electrophotographic image forming apparatus (hereinafter also simply referred to as “image forming apparatus”) capable of using a silicone rubber molded body produced by the method for producing a silicone rubber molded body of the present invention has been described. The method for producing the silicone rubber molded body of the present invention will be described later.

[Electrophotographic image forming apparatus]
FIG. 1 shows a schematic configuration of a color tandem type image forming apparatus 100 according to a preferred embodiment of the present invention. This image forming apparatus is a multifunction peripheral having functions such as a scanner, a copy, and a printer, and is called an MFP (Multi Function Peripheral or Multi Function Printer).

As shown in FIG. 1, the image forming apparatus 100 includes an annular intermediate transfer belt 108 that moves in the circumferential direction and is wound around two rollers 102 and 106 at the approximate center in the main body casing 101.
Of the two rollers 102 and 106, one roller 102 is disposed on the left side in the figure, and the other roller 106 is disposed on the right side in the figure. The intermediate transfer belt 108 is supported by these rollers 102 and 106 and is driven to rotate in the arrow X direction.

  Below the intermediate transfer belt 108, image forming units 110Y, 110M, 110C, and 110K corresponding to yellow (Y), magenta (M), cyan (C), and black (K) toners in order from the left in the drawing. Are arranged side by side.

The image forming units 110Y, 110M, 110C, and 110K are configured in the same manner except for the difference in toner colors that they handle.
For example, the yellow image forming unit 110 </ b> Y includes a photosensitive drum 190, a charging device 191, an exposure device 192, a developing device 193 that performs development using toner, and a cleaner device 195. .
A primary transfer roller 194 is provided at a position facing the photosensitive drum 190 with the intermediate transfer belt 108 interposed therebetween.
At the time of image formation, the surface of the photosensitive drum 190 is first uniformly charged by the charging device 191, and then the surface of the photosensitive drum 190 is exposed by the exposure device 192 to form a latent image there. Next, the latent image on the surface of the photosensitive drum 190 is developed by the developing device 193 to become a toner image. This toner image is transferred to the intermediate transfer belt 108 by applying a voltage between the photosensitive drum 190 and the primary transfer roller 194. Transfer residual toner on the surface of the photosensitive drum 190 is cleaned by a cleaner device 195.

  As the intermediate transfer belt 108 moves in the arrow X direction, four color toner images are formed as an output image on the intermediate transfer belt 108 by the image forming units 110Y, 110M, 110C, and 110K.

On the left side of the intermediate transfer belt 108, a cleaning device 125 that removes residual toner from the surface of the intermediate transfer belt 108 and a toner collection box 126 that collects the toner removed by the cleaning device 125 are provided.
A secondary transfer roller 112 is provided on the right side of the intermediate transfer belt 108 with a conveyance path 124 for paper interposed therebetween. A transport roller 120 is provided in a position corresponding to the upstream side of the secondary transfer roller 112 in the transport path 124. An optical density sensor 115 for detecting a toner pattern on the intermediate transfer belt 108 is provided.

A fixing device 130 for fixing the toner to the sheet is provided at the upper right portion in the main body casing 101.
The fixing device 130 includes a pair of fixing rollers extending perpendicularly to the paper surface in FIG. One of the fixing rollers is a heating roller 132, and the other is a pressure roller 131.
The heating roller 132 is heated to a predetermined target temperature (for example, a fixing temperature within a range of 180 to 200 ° C.) by the heater 133. The pressure roller 131 is urged toward the heating roller 132 by a spring (not shown). Thereby, the pressure roller 131 and the heating roller 132 form a nip portion for fixing.
The sheet 90 on which the toner image has been transferred passes through the nip portion, whereby the toner image is fixed on the sheet 90. The temperatures of the pressure roller 131 and the heating roller 132 are detected by temperature sensors 135 and 136, respectively.

Under the main body casing 101, paper feed cassettes 116A and 116B for storing paper 90 are provided in two stages. FIG. 1 shows a state in which the sheet 90 is stored only in the sheet feeding cassette 116A.
Each of the paper feed cassettes 116A and 116B is provided with a paper feed roller 118 for feeding the paper and a paper feed sensor 117 for detecting the fed paper.

  In the main body casing 101, a control unit 200 including a CPU (Central Processing Unit) that controls the operation of the entire image forming apparatus is provided.

At the time of image formation, the paper 90 is fed one by one from the paper feed cassette 116A to the transport path 124 by the paper feed roller 118 under the control of the control unit 200. The sheet 90 sent out to the transport path 124 is sent to the toner transfer position between the intermediate transfer belt 108 and the secondary transfer roller 112 by the transport roller 120 at a timing by the registration sensor 114.
On the other hand, as described above, the four color toner images are formed on the intermediate transfer belt 108 by the respective image forming units 110Y, 110M, 110C, and 110K, and are formed on the sheet 90 fed to the toner transfer position. The four color toner images on the transfer belt 108 are transferred by the secondary transfer roller 112.
The sheet 90 on which the toner image is transferred is conveyed through a nip formed by the pressure roller 131 and the heating roller 132 of the fixing device 130 and is heated and pressurized. As a result, the toner image is fixed on the sheet 90.
Finally, the sheet 90 on which the toner image is fixed is discharged by a discharge roller 121 through a discharge path 127 to a discharge tray portion 122 provided on the upper surface of the main body casing 101.
Note that the image forming apparatus 100 is provided with a switchback conveyance path 128 for sending the paper sheet 90 to the toner transfer position again in the case of duplex printing.

[Fixing roller (pressure roller)]
As described above, the pressure roller 131 constitutes one of the fixing rollers, and here is a silicone rubber roller.

(Silicone rubber molding)
As shown in FIG. 2, the pressure roller 131 is mainly composed of a cylindrical silicone rubber molded body 10.
As an example of the silicone rubber molding 10 according to the present invention, a cylindrical cored bar 12, a solid rubber layer 14 provided so as to cover the outer peripheral surface of the cored bar 12, and an outer peripheral surface of the solid rubber layer 14 are covered. And having a three-layer structure with the sponge rubber layer 16 provided as described above. The solid rubber layer 14 and the sponge rubber layer 16 are made of silicone rubber. Here, a roller body (a three-layer structure of the core metal 12, the solid rubber layer 14, and the sponge rubber layer 16) including this is molded into a silicone rubber. The name is 10. The silicone rubber molded body 10 is an example of a silicone rubber molded body according to the present invention.

The cored bar 12 is made of a metal material such as aluminum, iron, or SUS.
The thickness of the cored bar 12 is about 0.1 to 5 mm here, but is more preferably about 0.1 to 1.5 mm in view of weight reduction and warm-up time.
The diameter of the cored bar 12 is set to about 10 to 50 mm here.

The solid rubber layer 14 and the sponge rubber layer 16 are made of silicone rubber as described above.
Silicone rubber has heat resistance to the fixing temperature and elasticity for ensuring the size of the area where the paper 90 is pressed (length of the nip portion).
The solid rubber layer 14 is a solid hard layer. The thickness of the solid rubber layer 14 is preferably in the range of 5 to 10 mm, and is set to about 7 to 8 mm here.
On the other hand, the sponge rubber layer 16 is a sponge-like soft layer containing an infinite number of microballoons. The thickness of the sponge rubber layer 16 is desirably in the range of 5 to 100 μm, and is set to about 80 to 90 μm here.

≪Method for producing molded silicone rubber≫
Then, the manufacturing method of the silicone rubber molding 10 is demonstrated.
This manufacturing method is basically a method of cleaning the silicone rubber molded body 10 immediately after the solid rubber layer 14 and the sponge rubber layer 16 are formed on the core metal 12, and is the final manufacturing process of the silicone rubber molded body 10. This assumes processing performed in stages.

The method for producing a silicone rubber molded body of the present invention includes the step of (i) cleaning the silicone rubber molded body with an organic solvent vapor.
In addition, the manufacturing method of the silicone rubber molding of the present invention includes the step (i) of washing the silicone rubber molding with an organic solvent vapor,
(Ii) Step of releasing organic solvent from silicone rubber molded body (ii-i) Organic solvent squeezing step (iii) It is preferable to further include a step of drying the silicone rubber molded body.

[(I) Process of washing with vapor of organic solvent]
In the step of washing with steam, it is necessary that the silicone rubber molding is kept in contact with the vapor of the organic solvent. In addition, as cleaning continues, the concentration of low-molecular siloxane in the organic solvent gradually increases, and the efficiency of extracting low-molecular siloxane from the silicone rubber molded body decreases. Is preferable. Furthermore, since the cleaning effect is high when the temperature is high, it is preferable that the organic solvent is heated and permeated in a vapor state. The heated temperature range is preferably room temperature or higher and higher than the boiling point of the solvent used.

  The time for washing with steam depends on the thickness of the silicone rubber molding, but it is preferably exposed to steam for 30 to 60 minutes.

  In the present invention, the reduction of the low molecular siloxane by washing the silicone rubber molding using the organic solvent as described above is to reduce the content of the low molecular siloxane having a polymerization degree of 10 or less to a detection limit or less. In addition, the content of the low molecular siloxane having a polymerization degree of 11 to 20 is set to 1000 ppm or less. Furthermore, it is more preferable if the low molecular weight siloxane having a polymerization degree of 11 to 20 is 500 ppm or less, and most preferable if it can be reduced to a detection limit or less.

  The silicone rubber product produced by washing the silicone rubber molding as described above sufficiently reduces not only low molecular siloxanes having a polymerization degree of 10 or less but also low molecular siloxanes having a polymerization degree of 11 to 20. Therefore, the risk of causing silicone troubles such as contact failure when used in electrical and electronic equipment is extremely reduced. The same applies when the silicone rubber product thus produced is in the form of a film or sheet.

  In addition, it is preferable to perform the process of wash | cleaning a silicone rubber molding with the vapor | steam of an organic solvent in the pressure environment within the range of 102-800 kPa. Thereby, a higher cleaning effect can be exhibited.

The step of cleaning the silicone rubber molded body with the vapor of the organic solvent will be further described with reference to FIG. 3 as a specific method.
FIG. 3 shows a chamber 19 for cleaning the molded silicone rubber with an organic solvent vapor.
The silicone rubber molded body 310 is subjected to vapor cleaning with the vapor of the organic solvent 340 in the chamber 319. The method of cleaning with vapor in the chamber 319 is not particularly limited. For example, the method may be performed by heating the liquid organic solvent 340 to generate vapor of the organic solvent, or spraying the vapor of the organic solvent. It may be. In the example of FIG. 3, the organic solvent 340 is placed in the tray 330 below the chamber 319, and the chamber 319 is filled with vapor of the organic solvent 340 generated by heating the chamber 319.
In the example of FIG. 3, the silicone rubber molded body 310 is fixed to a height at which the silicone rubber molded body 310 is not immersed in the organic solvent 340 in the tray 330 by a support body 320 having a concave portion on which the core metal 312 can be placed.

  In addition, when performing the process which wash | cleans a silicone rubber molded object with the vapor | steam of an organic solvent in the pressure environment within the range of 102-800 kPa, a vapor | steam is sprayed or the liquid organic solvent is heated with the said chamber sealed. The pressure in the chamber may be raised by generating steam.

(Organic solvent)
The organic solvent for washing the silicone rubber molded body must satisfy the following conditions in order to efficiently wash and reduce the content of the low molecular siloxane.
First, the SP value of the organic solvent is an index indicating the polarity of a substance and is a value indicating an affinity between substances. The closer the solubility parameter (SP value; Solubility Parameter) between the low-molecular siloxane and the organic solvent, the easier it is for the organic solvent to enter between the molecules of the low-molecular siloxane. This increases the cleaning effect.
The SP value of the low molecular weight siloxane is about 14.9358 to 15.5496 MPa ^1/2 (7.3 to 7.6 (cal / cm ³ ) ^1/2 )). If the value is 19.0278 MPa ^1/2 (9.3 (cal / cm ³ ) ^1/2 ) or less, it is close to the SP value of the low-molecular siloxane, and the volume expansion coefficient is large and the cleaning effect is enhanced. Soaking the silicone rubber molded body in such an organic solvent will erode the excess solvent, so that the physical properties and preferred shape of the silicone rubber may not be maintained. This fear can be avoided because it is washed.
In addition, since the solubility of a low molecular siloxane will also become high when it heats more than the boiling point of an organic solvent, and the washing | cleaning effect becomes still higher, it is preferable that the boiling point of an organic solvent exists in the range of 35-150 degreeC.
The SP value according to the present invention is a value calculated by Fedors' method (for example, “SP value basics / application and calculation method” (see Hideki Yamamoto, published by Information Technology Corporation, 2005)).

Examples of the organic solvent satisfying the above conditions include n-hexane, n-octane, cyclohexane, ethyl acetate, benzene, toluene, xylene, methyl ethyl ketone, chloroform, methyl acetate, 1,2-dichloroethane, acetone, isopropyl alcohol. , Acetonitrile, ethanol, methanol, 3-methylbutyl acetate and the like. Preferably, n-hexane, cyclohexane, toluene, and xylene are used, and more preferably, n-hexane, cyclohexane, and toluene are suitable for easy handling.
These organic solvents may be a mixture of two or more, but may be used alone.

The SP value of the organic solvent is preferably in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ). Regarding the boiling point, in order to diffuse and release the organic solvent in which the low-molecular-weight siloxane is dissolved out from the inside of the silicone rubber, the boiling point is preferably not too high, and is preferably in the range of 35 to 200 ° C. It is preferably within the range of 170 ° C, more preferably within the range of 35 to 150 ° C.
When the organic solvent remains in the silicone rubber, it is preferable that the boiling point of the solvent is lower because a stable image cannot be produced when the silicone rubber molding is used as a part of an electrophotographic image forming apparatus, and unevenness may occur. Since the organic solvent is preferably liquid at normal temperature, its boiling point is preferably 35 ° C. or higher.

As an organic solvent, the SP value is in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ) as described above, and the boiling point is 35. It is preferable to contain the organic solvent which exists in the range of -150 degreeC. Thereby, a higher cleaning effect can be exhibited.

<Adsorption (swelling) amount of organic solvent in washing>
When the change in the mass of the silicone rubber molded body before and after cleaning with the vapor of the organic solvent is measured, the amount of adsorption of the organic solvent is 20 of the unit mass of the silicone rubber molded body, compared with the mass before cleaning. It is more effective to perform the solvent treatment so that the increase after ˜50%, that is, the mass after washing becomes 120 to 150% by mass as compared with the mass before washing. More preferably, the increase is 30 to 50% of the unit mass, and further preferably 40 to 50% of the unit mass.

[(Ii) Step of releasing organic solvent from molded silicone rubber]
It is preferable that after the step of washing the silicone rubber molded body with an organic solvent vapor, a physical pressure is applied to the silicone rubber molded body to release the organic solvent from the silicone rubber molded body. Thereby, a higher cleaning effect can be exhibited.

(About physical pressure)
A physical pressure is applied to the silicone rubber molding 10 washed with the vapor of the organic solvent.
For example, as shown in FIG. 4, the silicone rubber molded body 10 is forcibly passed through a metal squeezing ring 20 having a slightly smaller diameter, and physical pressure is applied to the silicone rubber molded body 10. As shown in FIG. 5, physical pressure may be applied to the silicone rubber molded body 10 by rotating the pressure roller 30 while being pressed against the silicone rubber molded body 10.

((Ii-i) organic solvent extraction process)
Further, in the step of releasing the organic solvent from the silicone rubber molded body, the silicone rubber molded body is further washed with vapor of the organic solvent, and then physical pressure is applied to the silicone rubber molded body to remove the organic solvent. It is preferable to have an organic solvent squeezing step that repeats the release from the silicone rubber molded body. Thereby, a volatile compound and an ultrafine particle can be more effectively released from a silicone rubber molding, and a higher cleaning effect can be exhibited.
Specifically, the silicone rubber molding 10 is washed with an organic solvent vapor, and after applying physical pressure to the silicone rubber molding to release the organic solvent from the silicone rubber molding,
(A) After further cleaning the silicone rubber molded body with a new organic solvent vapor (b) One set of (a) and (b), wherein physical pressure is applied to release the organic solvent from the silicone rubber molded body The organic solvent squeezing step may be repeated.

(Process to dry the molded silicone rubber)
In the present invention, after the step of releasing the organic solvent from the silicone rubber molded body, it is preferable to have a step of drying the silicone rubber molded body in order to remove the organic solvent remaining in the silicone rubber molded body. A method for drying is not particularly limited, and a known method can be applied. Among them, a step of drying the silicone rubber molded body by vacuum heating is preferable. Thereby, an organic solvent can be more effectively released from a silicone rubber molding.
In addition, although the process of drying this silicone rubber molding is based also on the thickness of a silicone rubber molding, it is preferable to leave for 10 minutes-3 hours in an environment of 50-130 degreeC.

<< Method for Forming Electrophotographic Image Forming Apparatus >>
Next, a method for manufacturing the image forming apparatus 100 will be described.
This manufacturing method is basically a method in which the pressure roller 131 is manufactured using the cleaned silicone rubber molded body 10 and installed in the image forming apparatus 100, and the final assembly of the image forming apparatus 100 is performed. Is assumed.

The manufacturing method of the image forming apparatus 100 according to the present invention is mainly as follows.
(I) a step of manufacturing the pressure roller 131 using the silicone rubber molded body 10 according to the present invention;
(Ii) a step of installing the pressure roller 131 at a predetermined position of the image forming apparatus 100 is preferable.
In particular, in the manufacturing process of the pressure roller 131, the surface of the silicone rubber molded body 10 may be polished or the silicone rubber molded body 10 may be cut into a predetermined length.

  The embodiments to which the present invention can be applied are not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit of the present invention.

  In the conventional method, the silicone rubber molded body is swollen and washed by immersing it in a solvent, and is not a method of washing with solvent vapor. Therefore, the silicone rubber molded body is excessively swollen. As a result, the original shape may not be maintained. In this respect, the above-described present invention can minimize the deformation of the silicone rubber while using a small amount of low molecular weight siloxane and an organic solvent having a close SP value, and further, it is effective from the inside of the silicone rubber molding. In particular, low molecular siloxane can be removed.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "mass part" or "mass%" is represented.

  In the image forming apparatus as shown in FIG. 1, the fixing roller is the following sample (silicone rubber molding).

(1) Preparation of sample <Preparation of silicone rubber molding>
10 parts by mass of a curing agent (trade name: Cat. 1602, manufactured by Shin-Etsu Chemical Co., Ltd.) is added to 100 parts by mass of a two-component room temperature curing type silicone rubber (trade name: KE 1602, manufactured by Shin-Etsu Chemical Co., Ltd.) By mixing, a silicone rubber mixture C was obtained.
15 parts by mass of expanded expander 461 was added to the silicone rubber mixture C and mixed with a stirrer for 30 minutes to obtain a silicone rubber mixture D. The EXPANSEL 461 is a microballoon manufactured by Kema Nobel, whose outer shell is a copolymer of vinylidene chloride and acrylonitrile, and melts at 110 ° C. The unexpanded sphere was 10 to 16 μm. Here, the spheroid was heated at 100 ° C. for 10 minutes to form an expanded microballoon having a sphere of 40 to 60 μm.

Apart from the preparation of the silicone rubber mixtures C and D, an adhesive is applied to an aluminum core (length 370 mm, diameter 25 mm) so that the core is centered on a paper tube 15 mm thicker than the core. And a bottom lid was installed.
Thereafter, between the paper tube and the cored bar, the silicone rubber mixture C (not containing the microballoon) was poured and allowed to stand overnight at room temperature to complete the curing. Thereafter, the paper tube was removed and a solid rubber layer was formed.
Thereafter, a silicone rubber mixture D (including microballoons) is applied to the solid rubber layer to a thickness of 100 μm and left to stand overnight, and then the surface is polished with a polishing machine to obtain a microballoon of about 40 to 60 μm. Countless embedded sponge rubber layers were formed.
By such treatment, a silicone rubber molded body (copier roll, rubber layer surface length 340 mm, see FIG. 2) having a two-layer structure in which the outer layer is sponge rubber and the inner layer is solid rubber was obtained. The hardness of this silicone rubber molding was 55 degrees with an Asker C-type hardness meter.

<Step of washing the molded silicone rubber with an organic solvent>
As described in Table I, the process was performed by simple dipping treatment or solvent vapor treatment. Specifically, these processes are as follows.

(Step of cleaning by dipping in an organic solvent (simple dipping treatment))
The organic solvent described in Table I was put in a container, and the silicone rubber molding was immersed in the organic solvent for 30 minutes.

(Process for cleaning with organic solvent vapor (solvent vapor treatment))
In this step, the silicone rubber molding was washed with an organic solvent vapor.
Specifically, an organic solvent was placed in a tray below the chamber, the chamber was heated at the treatment temperature shown in Table I, the inside of the chamber was filled with vapor of the organic solvent, and the treatment was performed for 1 hour. Thereafter, the temperature was lowered to room temperature, the tray inside the chamber was taken out, and the vapor of the organic solvent was discharged out of the chamber.
The type of organic solvent used, the processing temperature, and the pressure in the chamber were as shown in Table I. The SP value of the organic solvent is a value calculated by the Fedors method.

<Process for releasing organic solvent from molded silicone rubber (physical squeezing)>
A step of forcibly passing the silicone rubber molded body washed with an organic solvent through a squeezing ring having an inner diameter of 40 mm and squeezing excess organic solvent from the silicone rubber molded body to release the organic solvent from the silicone rubber molded body. Went.
For Examples 5 and 7 to 10,
(A) After further cleaning the silicone rubber molded body with a new organic solvent vapor (b) One set of (a) and (b), wherein physical pressure is applied to release the organic solvent from the silicone rubber molded body 5 sets of the organic solvent squeezing process were performed.

<Step of drying the molded silicone rubber>
The step of drying the silicone rubber molding was as described in Table I. In addition, the following operation was performed in normal-pressure heat drying and vacuum heat drying.

(Normal pressure heat drying)
The silicone rubber molding was manufactured by putting it in a thermostat at 80 ° C. and drying it for 1 hour.

(Vacuum heat drying)
The silicone rubber molding was placed in a vacuum dryer (ADP model 300 manufactured by Yamato Kagaku) and heated at 1.33 kPa and 100 ° C. for 1 hour to be vacuum dried.

(2) Evaluation of sample The fixing roller (pressure roller) of the image forming apparatus (bizhub C754 manufactured by Konica Minolta) was rearranged with the silicone rubber molded body samples of Comparative Example 1 and Examples 1 to 10 prepared above, It was set in a stainless steel chamber with a volume of 1 m ³ and set to ventilate 67 L / min in the chamber. After ventilating the chamber for about 1 hour, a printing operation was performed for 10 minutes, and volatile organic compounds and ultrafine particles discharged from the apparatus during the printing operation were sampled. A toner having a volume average particle diameter of 8 μm was used.
The results are shown in Table II.

(2.1) Volatile compounds The Tenax tube (Tenax: registered trademark) captures air in the chamber at a suction speed of 100 mL / min, and continuously samples the volatile compounds for about 2 hours after stopping the printing operation. Went. Volatile compounds collected from the Tenax tube were desorbed with a heat desorption apparatus, and the amount of the volatile compounds desorbed with a gas chromatograph mass spectrometer (GC-MS) was measured. The total amount of volatile compounds discharged from the apparatus (TVOC) was calculated by the calculation formula of the emission rate of Blue Angel Mark (standard of BAM (German Federal Research Institute for Materials)). The case where it is 100 mg / h or more is regarded as a practically problematic level.

(2.2) Total number of ultrafine particles Ultrafine particles G discharged into the chamber were continuously measured with a fine particle measuring instrument (model CPC3007) manufactured by TSI. The total number of ultrafine particles having a particle diameter in the range of 10 to 1000 nm observed from the start of printing to the time corresponding to 3 ventilation after the end of printing was measured. The case of 1 × 10 ⁷ pieces / mL or more is regarded as a practically problematic level.

(2.3) Number of image stains The fixing roller (pressure roller) of the image forming apparatus (bizhub C754 manufactured by Konica Minolta) was replaced with the silicone rubber molded body samples of Comparative Example 1 and Examples 1 to 10 prepared above. As the first printing after printing, image stains that can be observed like spots when the solid image was output on J paper (A4) were counted. A case where the image contamination per sheet is 100 or more is regarded as a practically problematic level.

(2.4) Physical destruction The silicone rubber molding was visually observed and evaluated according to the following criteria.
A: No peeling from the core metal B: Partial peeling from the core metal C: Complete peeling from the core metal

(Summary)
As is apparent from the above results, according to the method for producing a silicone rubber molded body of the present invention, it is possible to efficiently suppress volatile compounds and ultrafine particles discharged outside the electrophotographic image forming apparatus, and stain the output image. It was also shown that the breakage of the silicone rubber molding can be reduced.
Further, according to the present invention, since it is possible to suppress discharge of volatile compounds and the like without having a dust collecting means or the like, it is inexpensive.

10 Silicone rubber molding 12 Core metal 14 Solid rubber layer 16 Sponge rubber layer 131 Pressure roller

Claims (7)

  A method for producing a silicone rubber molding, comprising a step of washing the silicone rubber molding with an organic solvent vapor. The organic solvent contains an organic solvent having a solubility parameter in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ). The manufacturing method of the silicone rubber molding of Claim 1. The organic solvent has a solubility parameter in the range of 14.322 to 19.0278 MPa ^1/2 (7.0 to 9.3 (cal / cm ³ ) ^1/2 ) and a boiling point of 35 to 150 ° C. The manufacturing method of the silicone rubber molding of Claim 1 or Claim 2 containing the organic solvent which is in the range of these.   The step of cleaning the silicone rubber molded body with a vapor of an organic solvent is performed under a pressure environment within a range of 102 to 800 kPa, according to any one of claims 1 to 3. Manufacturing method of silicone rubber molding. After the step of washing the silicone rubber molding with an organic solvent vapor,
The silicone according to any one of claims 1 to 4, further comprising a step of applying a physical pressure to the silicone rubber molded body to release the organic solvent from the silicone rubber molded body. Manufacturing method of rubber molding. Releasing the organic solvent from the silicone rubber molded body,
After further washing the silicone rubber molded body with the vapor of the organic solvent, applying an organic solvent to the silicone rubber molded body to repeatedly release the organic solvent from the silicone rubber molded body is an organic solvent squeezing step. The method for producing a silicone rubber molded body according to claim 5, comprising: After the organic solvent squeezing step,
The method for producing a silicone rubber molded body according to claim 6, further comprising a step of drying the silicone rubber molded body by vacuum heating.

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