JP5930874B2 - Method for manufacturing elastic member - Google Patents

Description

The present invention, in the electrophotographic copying apparatus, relates to the production how the elastic member can be suitably used as a fixing member.

In a fixing device used in a toner image forming apparatus using an electrophotographic method, in order to efficiently heat paper on which unfixed toner is placed, a heat insulating layer is provided on a pressure member disposed opposite to a heating roller or the like. Has been done.
As such a pressure member, a member having a porous silicone rubber elastic layer may be used. As a method for forming such a porous silicone rubber elastic layer, Reference 1 discloses an emulsion obtained by mixing an uncrosslinked material of addition-curable liquid silicone rubber and water with a thickener, an emulsifier and the like. In the mold, and then, the silicone rubber is cross-linked in the mold and cured, and the water contained in the silicone rubber elastic layer in a dispersed state is removed.

JP 2008-214625 A International Publication No. 09/142151

The inventors of the present invention have studied repeatedly with the recognition that the method according to Patent Document 1 is a method capable of efficiently forming a homogeneous porous silicone rubber elastic layer. In the process, the present inventors have found the following new problem.
That is, when a porous silicone rubber elastic layer is formed by the above-described method, a porous silicone rubber elastic layer having inferior surface smoothness having a concave portion on the surface may be obtained.

  Here, in Patent Document 2, an emulsified sponge-forming silicone rubber composition containing water is injected into a mold and cured to form a hydrous silicone rubber, and then water is removed from the hydrous silicone rubber. A method for obtaining a silicone rubber sponge molded article having fine and uniform open cells is described. In [0049] of Patent Document 2, when the sponge-forming silicone rubber composition is injected into the cavity of the mold for casting, the injection speed and the shape of the injection hole are appropriately selected. It is described that separation and precipitation of water and a thickener in a sponge-formable silicone rubber composition due to shearing can be prevented.

From the above description of Patent Document 2, the inventors of the present invention described the formation of the recesses on the surface of the porous silicone rubber elastic layer when the emulsified silicone rubber composition containing water is injected into the mold. Further, it was presumed that the emulsified state of the silicone rubber composition was partially lowered and water was partially agglomerated.
Although it is disclosed in Patent Document 2 that the emulsified state can be maintained by controlling the injection speed of the silicone rubber composition into the mold, the injection speed of the silicone rubber composition into the mold is controlled. It was difficult to control each time from the viewpoint of mass productivity.

Accordingly, an object of the present invention is to provide a method capable of stably producing an elastic member having a porous silicone rubber elastic layer having excellent surface smoothness and having fine cells present more uniformly. There is.
Another object of the present invention is to provide a pressure member for fixing having a loss tangent under a predetermined condition larger than that of the prior art and excellent in paper conveyance performance.

According to the present invention, there is provided a method for producing an elastic member having a porous silicone rubber elastic layer,
(1) Polydiorganosiloxane having both ends of a molecular chain blocked with alkenyl groups and having no alkenyl group in the side chain of the molecular chain, polydiorganosiloxane having two or more alkenyl groups in the side chain of the molecular chain in one molecule Injecting an emulsified siloxane mixture into the mold cavity, comprising a polyorganosiloxane having at least two silicon-bonded hydrogen atoms, water, an inorganic thickener, and an emulsifier;
(2) cross-linking the emulsified siloxane mixture injected into the cavity at a temperature lower than the boiling point of water to form a water-containing silicone rubber, and (3) water-containing silicone rubber Heating to a temperature higher than the boiling point to remove water to form a porous silicone rubber elastic layer,
The step (1)
There is provided a method for producing an elastic member, which includes a step of applying a shear stress of 200 Pa or more to the siloxane mixture flowing in a pipe for sending the siloxane mixture to the cavity .

  Further, according to the present invention, a porous silicone rubber elastic layer is provided on the surface, and the silicone rubber elastic layer has a temperature of 5 mm in width, 5 mm in length, and 3 mm in thickness cut out from the silicone rubber elastic layer. There is provided a pressure member for a fixing device having a tan δ of 0.08 or more when dynamic viscoelasticity is measured at 200 ° C., an amplitude of 2 μm, a vibration frequency of 10 Hz, and a load of 350 g.

  According to the present invention, an elastic member excellent in surface smoothness can be stably produced. In addition, according to the present invention, it is possible to obtain a pressure member for a fixing device having a stable paper conveyance performance.

It is a figure which shows typically the elastic member which has the porous silicone rubber elastic layer manufactured by the manufacturing method of this invention. It is the schematic of the pressure roller (pressure member) of the fixing device using the elastic member which has the porous silicone rubber elastic layer manufactured by the manufacturing method of this invention. It is a cross-sectional schematic diagram between A-A 'in FIG. It is the schematic which shows the apparatus which manufactures the elastic member which has a porous silicone rubber elastic layer by the manufacturing method of this invention. It is a figure which shows the relationship between the shear rate of a siloxane mixture of an emulsified state, and a shear stress.

The details of the present invention will be described below with reference to the drawings.
In FIG. 1, 1 is an elastic member, 2 is an addition-curable silicone rubber, and 3 is a hole. The hole 3 has a spherical shape or an indefinite shape, and has a diameter or a side of about several μm to several tens of μm. The addition-curable silicone rubber 2 can be obtained by reacting the following three materials with a hydrosilylation reaction (crosslinking reaction) catalyst interposed therebetween.
1) a polydiorganosiloxane having both ends of the molecular chain blocked with alkenyl groups and having no alkenyl groups in the side chains of the molecular chain,
2) a polydiorganosiloxane having two or more alkenyl groups in the side chain of the molecular chain, and 3) a polyorganosiloxane having at least two silicon-bonded hydrogen atoms in one molecule. Speaking of an uncrosslinked state, the elastic member 1 mixes an uncrosslinked material with water, an emulsifier, a thickener, etc. to make an emulsified state, and then proceeds with a hydrosilylation reaction (crosslinking reaction) by means such as heating. -It can be obtained by dehydrating the cured product.

  2 and 3, 10 is a pressure roller as an elastic member, 21 is a substrate, 22 is a primer layer, 23 is a porous silicone rubber elastic layer, and 24 is a release layer. The release layer 24 is fixed to the peripheral surface of the silicone rubber elastic layer 23 by a cured silicone rubber adhesive layer (not shown).

  The pressure roller 10 is used in pressure contact with a heating body (not shown). A nip portion serving as a heating / pressurizing region is formed between the heating member and the pressure roller 10, and an image support such as a sheet (an image formed with unfixed toner) is sandwiched and conveyed in the nip portion. Thus, the unfixed toner image on the image support is heated and pressurized. As a result, the toner is melted and mixed, and then cooled to fix the image on the image support.

FIG. 4 is a schematic view showing a part of a method for producing an elastic member having a porous silicone rubber elastic layer according to the present invention. In FIG. 4, 40 is a cavity, 41 is a substrate having a primer layer, 42 is an emulsified siloxane mixture mainly composed of an uncrosslinked material and water, 43 is a pipe for injecting the siloxane mixture 42 into the cavity, It is connected to the measuring instrument 50 via the valve 52.
The emulsified siloxane mixture 42 is introduced into the measuring instrument 50 having an inner diameter of 40 mm by a method (not shown), and is then transferred to the cavity 40 via the pipe 43 by pushing down the pusher 51 attached to the measuring instrument 50. be able to.

  At this time, the shear rate acting on the emulsified siloxane mixture 42 injected into the cavity 40 can be controlled by controlling the moving speed of the pusher 51 and the inner diameter of the pipe 43. After confirming that the emulsified siloxane mixture 42 injected into the cavity 40 flows out from the opening 44 provided at the end of the cavity opposite to the injection port, the opening 44 is sealed with a stopper (not shown). Then, the inlet of the cavity 40 removed from the pipe 43 is also sealed to keep the inside of the cavity 40 sealed. Subsequently, the temperature is raised to a temperature lower than the boiling point of water, and the silicone rubber uncrosslinked component in the emulsified siloxane mixture is crosslinked. Finally, the water-containing silicone rubber taken out from the cavity 40 can be heated to a temperature higher than the boiling point of water and dehydrated to form an elastic member having a porous silicone rubber elastic layer.

  By the way, the pressure member that constitutes the fixing device of the electrophotographic apparatus is required to have the ability to stably convey the paper introduced into the nip. Then, according to the study by the present inventors, a pressure having a porous silicone rubber elastic layer whose loss tangent tan δ when measured under a predetermined condition is larger than tan δ of a conventional porous silicone rubber elastic layer. It has been found that the member exhibits stable paper transport performance.

  That is, the porous silicone rubber elastic layer according to the present invention is a dynamic sample at a temperature of 200 ° C., an amplitude of 2 μm, a vibration frequency of 10 Hz, and a load of 350 g from the silicone rubber elastic layer. Tan δ (loss tangent) when measuring the viscoelasticity is 0.08 or more. Such a pressure member for a fixing device having a high-loss tangent silicone rubber elastic layer on the surface thereof is excellent in paper transportability.

  The reason why such a pressure member has stable paper transportability can be inferred as follows. Tan δ is a ratio of storage elastic modulus and loss elastic modulus, and a viscoelastic body having a large tan δ exhibits a more viscous property than a viscoelastic body having a small tan δ. Considering the case where the paper stays in the nip of the fixing device, it can be considered that the paper receives a force of a low frequency and a high load. Therefore, it can be inferred that the sheet adheres well to the elastic member having a large tan δ in the nip (that is, low frequency and high load) and the conveyance is stable.

And the pressurization member which has such a stable paper conveyance performance can be manufactured with the manufacturing method of the elastic member which has the porous silicone rubber elastic layer which concerns on this invention.
The reason is that according to the present invention, the emulsified state is maintained in the process of filling the siloxane mixture in the emulsified state into the cavity and curing, so that the surface smoothness is high and the pores are highly uniformly dispersed. This is considered to be because the obtained porous silicone rubber elastic layer is obtained.

Moreover, the present inventors consider the reason why an elastic member having good surface smoothness can be obtained by the method for producing an elastic member having a porous silicone rubber elastic layer according to the present invention as follows.
That is, as described above, the occurrence of the concave portion on the surface of the porous silicone rubber elastic layer is caused by the emulsified state of the silicone rubber composition when the silicone rubber composition containing water is injected into the mold. This is thought to be due to partial destruction and partial aggregation of water. In the process of breaking the emulsified state, in the process in which the siloxane mixture in the emulsified state flows through the flow path or the like sent to the cavity, the water that is dispersed in the siloxane is generated by the frictional force received from the flow path wall. Conceivable. Therefore, the emulsified state of the siloxane mixture can be maintained by applying a shear stress superior to the aggregation of water due to the frictional force.

  The emulsified siloxane mixture 42 used in the present invention exhibits non-Newtonian fluid characteristics, and the shear rate and the shear stress are in the relationship shown in FIG. Therefore, even when the water component is aggregated, the present inventors can apply a shear stress that reconstructs the emulsified state to inject into the cavity and undergo crosslinking / curing / dehydration. We thought it was possible to prevent the decline. And according to examination of the present inventors, such a shear stress acquired the knowledge that it was 200 Pa or more. That is, when the siloxane mixture in an emulsified state is filled into the cavity, by applying a shear stress of 200 Pa or more to the siloxane compound, the destruction of the emulsified state in the transfer process of the siloxane mixture to the cavity is suppressed, and as a result As described above, a pressure member having excellent surface smoothness and high paper conveyance performance can be stably produced.

EXAMPLES The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to these examples.
(1) Substrate Various types of substrates can be used for the elastic member of the present invention. When the elastic member of the present invention is used as a fixing device pressure roller, an appropriate pressure is applied. Therefore, it is preferable to use a base material made of a metal material. In particular, a base material in which a free-cutting steel (SUM material) excellent in pressurization and workability is processed into a desired shape to form a cored bar and electroless nickel plating for rust prevention is applied to the surface is preferable. Can be adopted.
If a part of the nickel component is modified into nickel oxide NiO and used, it is more preferable because adhesion with a porous silicone rubber elastic layer described later is improved.

(2) Adhesive layer (primer) made of silane coupling agent
The silane coupling agent has two or more kinds of reactive groups in the molecule, that is, a hydrolyzable group (eg, alkoxy group) that is compatible with inorganic substances, and an organic functional group imparting adhesiveness to organic components. Hold in. It can be combined with an organic component by an organic functional group that reacts and bonds with glass or metal by a hydrolyzable group and imparts adhesion to the organic component. In consideration of adhesiveness to silicone rubber, examples of the organic functional group include a vinyl group, a methacryl group, an epoxy group, and a SiH group. Various types of adhesive layers composed of silane coupling agents applicable to the present invention can be applied. To give an example, nickel or an alkoxy group that is hydrolyzed and condensed with NiO disposed on nickel plating and an SiH group that adheres to the vinyl group of the liquid uncrosslinked silicone rubber by an addition reaction are included in the molecule. At the same time. In the present invention, when the porous silicone rubber is cut out from the elastic member and the viscoelastic properties are measured, the adhesive layer (2) made of the silane coupling agent is not disposed, and the porous silicone is removed from the substrate. The rubber was easily cut out.

(3) Emulsified siloxane mixture In preparing an elastic member having a porous silicone rubber elastic layer, first, it is composed of addition-curing silicone rubber stock solutions A and B, water and an inorganic thickener. C liquid was prepared.
(3-A) Polydiorganosiloxane having both ends of the molecular chain blocked with alkenyl groups and having no alkenyl group in the molecular chain side chain, and polydiorganosiloxane A liquid having two or more alkenyl groups in the molecular chain side chain A small amount of a platinum compound as a hydrosilylation reaction (crosslinking reaction) catalyst was previously contained therein. The liquid A contained a composition mainly composed of a polysiloxane compound having a vinyl group (unsaturated aliphatic group) as one of the addition reaction sites in the siloxane bond side chain. This composition is composed of a polydiorganosiloxane having both ends of a molecular chain blocked with alkenyl groups and having no alkenyl group in the side chain of the molecular chain, and a polydiorganosiloxane having two or more alkenyl groups in the side chain of the molecular chain. It is configured. In addition, since A liquid is a colorless and transparent and highly viscous liquid, and it may be difficult to distinguish from B liquid described later, a coloring material such as bengara that does not impair the function of silicone rubber can be mixed in advance. .

(3-B) Polyorganosiloxane having at least two silicon atom-bonded hydrogen atoms in one molecule Composition containing mainly a polysiloxane compound having silicon atom-bonded hydrogen as another addition reaction site in solution B The product was included. This composition is composed of a polyorganosiloxane having at least two silicon-bonded hydrogen atoms in one molecule. In addition, since B liquid is a colorless and transparent and highly viscous liquid, and it may be difficult to distinguish from the above-mentioned A liquid, a coloring material such as bengara that does not impair the function of silicone rubber can be mixed in advance. .

(3-C) Water, thickener Water that is the main component of the liquid C is for making the silicone rubber porous by removing the siloxane mixture in an emulsified state in the curing and dehydrating step after crosslinking. It is. The water may be clean, but ion exchange water is generally used. Here, since water has a lower viscosity than the A and B liquids, it is preferable to use a thickener to facilitate mixing and dispersion. As the thickener, there are various types of inorganic and organic types. In the present invention, an inorganic thickener is preferably used. Among these, it is preferable to use an inorganic thickener (trade name: Bengel W-200U, manufactured by Hojun Co., Ltd.) made of an organic polymer composite hydrophilic purified bentonite containing a smectite group clay mineral because the viscosity of the liquid C can be easily adjusted. In this example, the liquid C is composed of a gel-like liquid material obtained by adding 99 parts by weight of ion-exchanged water to 1 part by weight of the inorganic thickener and stirring it sufficiently.

(3-D) Emulsifier In order to form an emulsified siloxane mixture composed of three liquids, A liquid, B liquid, and C liquid, emulsifier D is added to a mixed liquid obtained by mixing these three liquids in a desired ratio. Various types of emulsifiers D can be employed, and any of anionic, cationic, zwitterionic and nonionic types may be used. Among them, it is particularly preferable to employ a nonionic surfactant because it has little influence on the hydrosilylation reaction catalyst. The emulsifier preferably has an HLB (Hydrophile-Lipophile Balance) value of 1.5 or more and less than 6. Moreover, the compounding quantity of an emulsifier is 0.2-3 weight part with respect to 100 weight part of C components. The emulsifier D can also be added after mixing three liquids of liquid A, liquid B and liquid C. Moreover, after adding an emulsifier to any one or several liquid of A liquid, B liquid, or C liquid, 3 liquids, A liquid, B liquid, and C liquid, can also be mixed.

  The density of the porous silicone rubber to be formed can be determined by controlling the ratio of the C liquid to the A liquid and the B liquid. Table 1 shows preparation examples (units are parts by weight) of materials used in the examples. These raw materials were put into a planetary mixer and stirred sufficiently to obtain an emulsified siloxane mixture.

(4) Production of elastic member (4-1) Step of injecting emulsified siloxane mixture into mold cavity As shown in FIG. 4, a cavity 40 in which a base material 41 is disposed and a meter 50 are piped. 43 connected. Next, the emulsified siloxane mixture 42 prepared in (3) was introduced into the meter 50. Then, the pusher 51 was pushed down to transfer the emulsified siloxane mixture 42 to the cavity 40. The moving speed of the pusher 51 and the inner diameter (pipe diameter) of the narrowest portion of the pipe 43 are as shown in conditions a to c shown in Table 2. After confirming that the emulsified siloxane mixture 42 injected from the injection port 45 flows out from the opening 44 provided on the opposite side of the injection port 45, both the opening 44 and the injection port 45 are sealed together, and Removed.
(4-2) Step of forming silicone rubber Next, the cavity 40 containing the base material 41 and the emulsified siloxane mixture 42 was placed in a hot air circulation oven, and held at a temperature of 90 ° C. for 60 minutes for crosslinking. .
(4-3) Step of forming a porous silicone rubber elastic layer After completion of crosslinking and cooling, the water-containing silicone rubber elastic member (including the base material 41) taken out from the cavity 40 is placed in a hot air circulation oven, and the temperature is 200 ° C. For 4 hours to cure and dehydrate. Thus, an elastic member having a porous silicone rubber elastic layer was produced.

(5) Dynamic viscoelasticity Viscoelasticity of a sample 5 mm wide, 5 mm long and 3 mm thick cut out from the elastic layer using a compression jig with a dynamic viscoelasticity measuring device (DVE rheometer, manufactured by Rheology Co., Ltd.). Characteristics were measured. The measurement was carried out under the condition of applying a sinusoidal wave with an amplitude of 2 μm at a load of 350 g at 10 Hz in an environment of 200 ° C., and a tan δ value was obtained from the dynamic response at this time.

<Example 1>
In this embodiment, the elastic member of the present invention was used as a fixing roller pressure roller for A3 paper.
(Example 1-1) (“Example 1-1” means “Step 1 of Example 1.” The same applies to the following.)
Free-cutting steel (SUM) was processed into the following shape, and two metal cores having electroless nickel plating (thickness of 3 to 6 μm) on the outer surface were prepared as the base material 41.
First bearing part: outer diameter 8 mm × length 22 mm,
Parts other than the bearing part: outer diameter 23 mm × length 325 mm,
Second bearing part: outer diameter 8 mm × length 53 mm.

(Example 1-2)
A primer (trade name: DY35-051, Toray Dow Corning Co., Ltd.) was applied to one of the two substrates by a known method. The remaining one was used as is in Example 1-3.
(Example 1-3)
Using the apparatus of FIG. 4, the emulsified siloxane mixture 42 prepared in Preparation Example 1 was transferred to the cavity 40 in which the base material 41 was disposed under the condition c in Table 2.
The emulsified siloxane mixture 42 injected into the cavity 40 was sealed after confirming that it flowed out from the opening 44, and then the inlet of the cavity 40 removed from the pipe 43 was sealed to seal the inside of the cavity 40. Sealed. Subsequently, the mixture was heated at 90 ° C. for 60 minutes to crosslink the silicone rubber uncrosslinked component in the emulsified siloxane mixture. Finally, the water-containing silicone rubber taken out from the cavity 40 was heated at a temperature of 200 ° C. for 4 hours, cured and dehydrated to obtain an elastic member having a porous silicone rubber elastic layer. The surface smoothness of the obtained elastic member was evaluated by visually observing the surface of the porous silicone rubber elastic layer. The obtained elastic member had good surface smoothness, and unevenness and rubber peeling were not seen on the elastic member surface.

(Example 1-4-1)
Among the elastic members obtained in Example 1-3, a tube-shaped fluororesin film (thickness 50 μm; manufactured by Gunze Co., Ltd.) is coated on the elastic member obtained by applying a primer to the base material 41 by a known method. Completed the pressure roller.
(Example 1-4-2)
Of the elastic member obtained in Example 1-3, the porous silicone rubber elastic layer of the elastic member that was not coated with the primer on the base material 41 was cut out, and the dynamic viscoelastic property was measured under the above conditions. Was 0.08.
(Example 1-5)
The pressure roller completed in Example 1-4-1 is set in a fixing device of an electrophotographic image forming apparatus (LBP5910; Canon Inc.), and the cardboard is used in an atmosphere of high temperature and high humidity (45 ° C., 90%). When 100 test prints were made, all sheets could be transported without any problems.

<Comparative Example 1>
(Comparative Example 1-1) to (Comparative Example 1-2)
The same as Example 1-1 and Example 1-2.
(Comparative Example 1-3)
A pressure roller as an elastic member was prepared in the same manner as in Example 1 except that the condition c in Table 2 was changed to the condition a. The obtained elastic member had poor surface smoothness, and unevenness and rubber peeling were observed on the elastic member surface.
(Comparative Example 1-4-1)
Of the elastic members obtained in Comparative Example 1-3, the elastic member obtained by applying a primer to the base material 41 was coated with the same tube-shaped fluororesin film as in Example 1 by a known method to complete a pressure roller. .
(Comparative Example 1-4-2)
Of the elastic member obtained in Comparative Example 1-3, the porous silicone rubber elastic layer of the elastic member in which the primer was not applied to the base material 41 was cut out, and the dynamic viscoelastic property was measured under the above conditions, and tan δ Was 0.03.
(Comparative Example 1-5)
The pressure roller completed in Comparative Example 1-4-1 was set in a fixing device of an electrophotographic image forming apparatus (LBP5910; Canon Inc.), and the cardboard 100 was used in a high-temperature and high-humidity atmosphere as in Example 1. When I test printed the sheets, the paper often slipped.

<Example 2>
(Example 2-1)
Free-cutting steel (SUM) was processed in the same manner as in Example 1, and a cored bar having an electroless nickel plating of 3 to 6 μm on its outer surface was prepared as the base material 41.
(Example 2-2)
The same primer as Example 1 was apply | coated to the base material of Example 2-1 by a well-known method.
(Example 2-3)
A pressure roller as an elastic member was prepared in the same manner as in Example 1 except that Preparation Example 1 was changed to Preparation Example 2 and condition c in Table 2 was changed to condition b. The obtained elastic member had good surface smoothness, and unevenness and rubber peeling were not seen on the elastic member surface.
(Example 2-4)
The elastic member obtained in Example 2-3 was coated with the same tube-shaped fluororesin film as in Example 1 by a known method to complete a pressure roller.
(Example 2-5)
The pressure roller completed in Example 2-4 was set in a fixing device of an electrophotographic image forming apparatus (LBP5910; Canon Inc.), and 100 sheets of cardboard were placed in a high temperature and high humidity atmosphere as in Example 1. As a result of test printing, all the paper could be transported without problems.

<Example 3>
(Example 3-1)
Free-cutting steel (SUM) was processed in the same manner as in Example 1, and a cored bar having an electroless nickel plating of 3 to 6 μm on its outer surface was prepared as the base material 41.
(Example 3-2)
The same primer as Example 1 was apply | coated to the base material of Example 3-1 by a well-known method.
(Example 3-3)
A pressure roller as an elastic member was prepared in the same manner as in Example 2 except that the condition b in Table 2 was changed to the condition c. The obtained elastic member had good surface smoothness, and unevenness and rubber peeling were not seen on the elastic member surface.
(Example 3-4)
The elastic member obtained in Example 3-3 was coated with the same tube-shaped fluororesin film as in Example 1 by a known method to complete a pressure roller.
(Example 3-5)
The pressure roller completed in Example 3-4 was set in a fixing device of an electrophotographic image forming apparatus (LBP5910; Canon Inc.), and 100 sheets of thick paper were placed in a high temperature and high humidity atmosphere as in Example 1. As a result of test printing, all the paper could be transported without problems.
The above results are summarized in Tables 3 and 4.

DESCRIPTION OF SYMBOLS 1 Elastic member 2 Addition-curing type silicone rubber 3 Hole 10 Pressure roller 21 Base material 22 Primer layer 23 Porous silicone rubber elastic layer 24 Release layer 40 Cavity 41 Base material 42 with a primer layer Emulsified siloxane mixture 43 Piping 44 Cavity opening 50 Meter 51 Pusher 52 Valve

Claims (3)

A method for producing an elastic member having a porous silicone rubber elastic layer,
(1) Polydiorganosiloxane having both ends of a molecular chain blocked with alkenyl groups and having no alkenyl group in the side chain of the molecular chain, polydiorganosiloxane having two or more alkenyl groups in the side chain of the molecular chain in one molecule Injecting an emulsified siloxane mixture into the mold cavity comprising a polyorganosiloxane having at least two silicon-bonded hydrogen atoms, water, an inorganic thickener, and an emulsifier;
(2) cross-linking the emulsified siloxane mixture injected into the cavity at a temperature lower than the boiling point of water to form a water-containing silicone rubber, and (3) water-containing silicone rubber Heating to a temperature higher than the boiling point to remove water to form a porous silicone rubber elastic layer,
The step (1)
The manufacturing method of the elastic member characterized by including the process of giving the shear stress of 200 Pa or more with respect to this siloxane mixture which is flowing in the piping for sending this siloxane mixture to this cavity .   The method for producing an elastic member according to claim 1, wherein the shear stress is 280 Pa or more and 440 Pa or less.   The manufacturing method of the elastic member of Claim 1 or 2 which provides the said shear stress with respect to the said siloxane mixture by controlling the internal diameter of the said piping.