JP2008080700A - Elastomer molding method and blade member for elctrophotography - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastomer molding method using a molding die that keeps good releasability and demoldability over a long period of time, and to provide a blade member for electrophotography manufactured by the method. <P>SOLUTION: In the elastomer molding method which makes a liquid elastomer raw material cure by being charged into a molding die with a mold release layer, the method is characterized by using, as the molding die, one having on its inner wall surface the mold release layer which is formed with a liquid curable silicone and in which the content of the components volatile at the curing temperature of the liquid elastomer raw material is ≤0.5 mass%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an elastomer molding method in which a liquid elastomer raw material is charged into a mold having a release layer and cured, and an electrophotographic blade member produced by the molding method.

  With the recent progress of electrophotographic technology, fine toner having a particle size of about 10 μm has been used. Accordingly, in the electrophotographic apparatus, it is necessary to remove a fine toner residue from the photoreceptor. In order to realize this, a very high dimensional accuracy is required for the blade member for the cleaning blade and the developing blade of the electrophotographic apparatus.

  The developing blade is made in the same configuration as the cleaning blade, but high precision is essential, and very precise dimensional control technology is required to form a uniform toner layer on the developer carrier. It becomes. For example, the thickness of the blade member of the developing blade is an important factor that determines the contact pressure with the developer carrier, and this is important for stably forming a precise image in order to determine the coat amount of the toner. is there. Therefore, it can be said that establishment of a production method with high thickness accuracy of an elastomer sheet used for manufacturing these members is an important issue.

  As described above, the blade members of the cleaning blade and the developing blade used in the electrophotographic apparatus are required to have high dimensional accuracy, and moreover, both exhibit wear resistance in order to perform their functions by rubbing against the rotating member. High material is preferred, and polyurethane is often used.

  Centrifugal molding is an example of a method for molding an elastomer such as a cleaning blade for an electrophotographic apparatus or a blade member of a developing blade that requires a highly accurate thickness. As an advantage of the centrifugal molding method, first, it can be mentioned that the thickness can be made highly accurate. In addition to this, the thickness can be freely controlled by the amount of liquid elastomer raw material charged into the mold, the same equipment can be used for materials with different prescriptions such as curing speed and hardness, and versatility is high. Can be mentioned.

  As an example of a molding method having a high accuracy and a releasability using the centrifugal molding method, a molding method disclosed in Patent Document 1 can be exemplified. The molding method disclosed in Patent Document 1 relates to a method of manufacturing a belt for an electrophotographic apparatus by a centrifugal molding method. This member also requires both thickness accuracy and productivity. In the molding method described in Patent Document 1, an endless belt is manufactured by providing a release layer on the inner surface of a centrifugal mold and then centrifugally forming an endless film on the release layer using a liquid material.

  There is a limit to the mechanical approach to forming a constant thickness elastomer by centrifugal molding. There is a demerit that the inaccuracy of the mechanical accuracy such as the horizontal accuracy of the molding die installation and the molding die fluttering directly becomes the thickness accuracy variation of the molded product.

  In order to solve this problem, it is necessary to design a molding machine with very high accuracy, and the capital investment and maintenance work are enormous. Therefore, in the molding method described in Patent Document 1, a liquid curable material is put into a centrifugal molding machine and cured in a rotating molding machine to obtain a release layer first. In the molding method described in Patent Document 1, a release layer is formed by introducing a liquid material to absorb the flare in the mechanical device, and there is no need for a highly precise and time-consuming design. It is possible to suppress.

  Further, as an improvement on this, Patent Document 2 discloses an elastomer molding method using a centrifugal mold having a holding layer releasably bonded in a mold and a release layer. In this method, a holding layer bonded in a peelable manner is formed on the inner peripheral surface using a thermosetting epoxy resin, and a release layer formed from a thermosetting polyorganosiloxane is provided thereon. A molding die is used. By providing such a holding layer and a release layer, an efficient method of molding an elastomer is obtained. Unlike the manufacturing method described in Patent Document 1, by providing a holding layer that can be peeled once as in the manufacturing method described in Patent Document 2, the horizontal accuracy of the surface of the resulting elastomer is further increased. As a result, the obtained elastomer molded body is not only more preferable for electrophotographic apparatus, but also has a mold release property that is adhesive to metal by a simple operation of removing the holding layer after repeated use of a centrifugal mold. The layer can be easily removed, making it highly productive.

  In these production methods, the present inventors show good production performance in several molding processes, but with this production method in view of mass production, continuous production over a long period of 10 days or more. In this case, it has been found that the mass production processability gradually decreases. That is, when this batch production is repeated for several tens of times for a long period of time, it has become clear that the elastomer molded body is deformed, causing problems such as tearing and demolding failure, and the yield gradually decreases.

Japanese Patent Publication No. 2000-158555 Japanese Patent Publication No. 2004-025846

  The present invention has been made in view of the above-described state of the art, and an elastomer molding method using a mold that continues good releasability and demolding over a long period of time, and an electrophotographic blade produced by the method The purpose is to provide materials.

In the elastomer molding method in which a liquid elastomer raw material is charged into a mold having a release layer and cured, the curing temperature of the liquid elastomer raw material formed using liquid curable silicone as the mold This is achieved by an elastomer molding method characterized by using a molding die having a release layer on the inner wall surface, the content of which is volatilized in (2) being 0.5% by mass or less.
Moreover, the said subject is achieved by the braid | blade member for electrophotography produced with the elastomer shaping | molding method of the said invention.

  According to the elastomer molding method of the present invention, the elastomer can be easily peeled off from the mold by a simple means and can be efficiently removed, and defects such as tearing at the time of removal can be reduced. Further, the mold can be used repeatedly over a long period of time, and stable productivity can be obtained. Furthermore, it is possible to produce a uniform elastomer with high dimensional accuracy, and in particular, it exhibits superiority in the production of blade members such as cleaning blades and developing blades for electrophotography. Moreover, the elastomer molding method of the present invention is not limited to the centrifugal molding method, and can be applied to other molding methods. Furthermore, the electrophotographic blade member produced by the molding method of the present invention is suitably used for an electrophotographic cleaning blade or a developing blade.

  The elastomer molded body molded by the elastomer molding method of the present invention usually has a shape such as a sheet shape or an endless sheet shape. In particular, an elastomer molded body having a sheet shape and an endless sheet shape is suitable as a blade member for electrophotography. The electrophotographic blade member obtained by the elastomer molding method of the present invention is cut and integrated with a plate-like holding member and used as a cleaning blade or a developing blade. At this time, the dimensional accuracy of the thickness is a very important factor. According to the elastomer forming method of the present invention, an electrophotographic blade member having required dimensional accuracy can be provided.

  When used as a blade of a cleaning blade, this blade plays a role of scraping and cleaning toner remaining without being transferred onto the photosensitive drum. With recent advances in electrophotographic technology, the toner becomes as fine as about 10 μm, and a toner having a particle size has also been developed. In order to efficiently clean the toner, a very high thickness dimension accuracy is required. The accuracy of the thickness dimension here is of course the accuracy in the longitudinal direction per blade, but in view of mass productivity, large-sized elastomer molding is a sheet-like electrophotographic blade member before cutting. There is no variation in body dimensions, and yield is a problem unless it is highly accurate. According to the elastomer forming method of the present invention, it is possible to provide an electrophotographic blade member having dimensional accuracy required as a blade member of such a cleaning blade.

  On the other hand, even when used as a blade of a developing blade, the required characteristic of dimensional accuracy is high due to its role. Since it is a functional member that forms a fine toner layer in contact with the developer carrier, the thickness determines the contact pressure with the developer carrier and is an important factor for good image formation and stabilization of image formation. It becomes. Because of this, accuracy and control technology to an arbitrary thickness are important. Even in the developing blade, it is natural that the accuracy within one blade is important, and the thickness accuracy of a large-sized elastomer molded body that is a sheet-like electrophotographic blade member before cutting during production is also constant. However, it is the same as the cleaning blade that is important for production efficiency. According to the elastomer forming method of the present invention, it is possible to provide an electrophotographic blade member having dimensional accuracy required as a blade member of such a developing blade.

  The elastomer molding method of the present invention is an elastomer molding method in which a liquid elastomer raw material is charged and cured in a mold having a release layer. And as a shaping | molding die, it has a mold release layer formed on the inner wall surface using liquid curable silicone, and the content of the component which volatilizes at the curing temperature of the liquid elastomer raw material is 0.5% by mass or less It is characterized by using a mold. In the elastomer molding method of the present invention, it is preferable to use a molding die further having a holding layer that is releasably bonded to the inner wall surface of the molding die.

  The holding layer is preferably composed of a thermosetting resin having a heat resistant temperature of not less than the curing temperature of the liquid elastomer raw material, generally about 150 ° C. In particular, if it does not exhibit rubber-like elasticity over the range of room temperature to 150 ° C., it is advantageous when removing the holding layer together with the release layer from the mold. Examples of such a thermosetting resin include a polyimide resin, a polyurethane resin, a phenol resin, and an epoxy resin. In particular, a thermosetting epoxy resin that maintains appropriate adhesion with the inner wall surface of the mold and can be releasably bonded to the inner wall surface of the mold is preferable.

  The holding layer preferably has a layer thickness of 0.5 to 5.0 mm. When the thickness of the holding layer is 0.5 mm or more, the strength of the holding layer is large, and the holding layer can be easily removed from the mold together with the release layer. Further, when the thickness of the holding layer is 5 mm or less, the heat conduction efficiency from the mold to the liquid elastomer raw material is improved via the holding layer and the release layer, and the liquid elastomer raw material can be quickly cured.

  The holding layer can be formed by supplying a liquid thermosetting resin material into a mold, forming a thermosetting resin material layer having a uniform layer thickness on the inner wall surface of the mold, and curing the material layer. In order to form a thermosetting resin material layer having a uniform layer thickness, the viscosity of the thermosetting resin material is preferably 2 Pa · s or less. Further, in order to improve the uniformity of the layer thickness of the holding layer, after forming a single holding layer on the inner wall surface of the mold, the air surface side (referred to as the surface side in contact with the atmosphere) is further provided. It is preferable to provide an additional retaining layer. For example, when scratches are found on the inner wall surface of the mold, if the retaining layer is formed on the inner wall surface, the scratches may be transferred, but this problem is resolved by going through such a procedure. Thus, a highly accurate holding layer can be formed.

  Further, a release agent may be applied to the inner wall surface of the mold in advance in order to make the adhesion between the inner wall surface of the mold and the holding layer appropriate. As such a release agent, a silicone release agent, a fluorine release agent, a wax, or the like can be used. When the holding layer is made of an epoxy resin, it is preferable to use a release agent for epoxy resin (for example, KS707 manufactured by Shin-Etsu Chemical Co., Ltd.). When the release agent is applied in advance as described above, the holding layer can be easily peeled together with the release layer when the release layer becomes unusable. Thereby, productivity and quality can be improved. The release agent is usually effective when applied with a layer thickness of about 0.5 to 1.0 mm.

  The release layer preferably has heat resistance equal to or higher than the curing temperature of the liquid elastomer raw material, and usually preferably has heat resistance equal to or higher than 150 ° C. The layer thickness per layer of the release layer is usually preferably from 0.3 mm to 3 mm, and more preferably from 0.5 mm to 2 mm. When the layer thickness per layer of the release layer is 0.3 mm or more, a release layer having a uniform layer thickness can be easily formed on the holding layer. In addition, when the layer thickness per layer of the release layer is 3 mm or less, it is possible to prevent delamination due to a decrease in adhesion of individual release layers when a plurality of release layers are laminated. it can. In addition, when a plurality of release layers are laminated, it is usually preferable that the thickness of the entire release layer be 3 mm to 20 mm. When the layer thickness of the entire release layer is 3 mm to 20 mm, the heat conduction efficiency is good and the liquid elastomer raw material can be easily cured. In addition, a release layer having excellent physical properties can be easily produced.

  The liquid curable silicone used for forming the release layer is liquid and curable. The millable type is not suitable in the present invention. When liquid curable silicone is used, it is put into a mold and, for example, molded with an elastomer having a stable wall thickness that is difficult to control by mechanical dimensions by allowing it to stand or rotate and cure while applying centrifugal force. A release layer that enables the body to be obtained can be formed. When the liquid curable silicone is used, a molding die capable of forming an elastomer having excellent dimensional stability is realized not only in a centrifugal molding method but also in other molding methods.

  There are two types of curable silicones: a type in which a silicone resin thin film is baked and a liquid type curable type. Either type can be used to form a release layer with good release properties, but the surface properties have a certain layer thickness. In order to obtain an excellent release layer, a liquid curable type is more preferable.

  Furthermore, the liquid curable silicone includes types such as a one-component curable type, a two-component curable type, and a three-component curable type, and the effects of the present invention can be exhibited in any type. However, the one-component curable type is difficult to store and handle and must be stored in a cool and dark place. When a release layer is formed on a large mold as in the present invention, a large amount of liquid curable silicone is required. Therefore, in consideration of mass productivity, the reaction can be started with an arbitrary setup. A mold or a three-component curable mold is more preferable.

  There are two types of curable silicones of two or more liquids: an addition curable type and a condensation curable type. As described above, either type may be used as long as a release layer having a content of a component volatilized at the curing temperature of the liquid elastomer raw material is 0.5% by mass or less can be formed. However, the mold release layer on the inner wall surface of the mold must exhibit surface accuracy and be easily removable after use. As the condensation type silicone, it is more preferable to select an addition curing type because there is a possibility that the time until complete curing varies depending on the layer thickness of the release layer to be formed. Addition-curing silicone has a very fast reaction rate at the time of thermosetting, and may be cured before evenly spreading over the entire wall surface of the mold on which the release layer is to be provided. In such a case, a reaction retarder may be added to the addition-curable silicone at an appropriate time. Examples of the reaction retarding agent that can be suitably used in the present invention include control agent No. 6-10 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.).

In the present invention, the content of the component that volatilizes at the curing temperature of the liquid elastomer raw material contained in the release layer can be measured as follows.
A mold is prepared, and liquid curable silicone for forming a release layer is poured into the mold. A release layer test piece is prepared by heating and curing the liquid elastomer material at the same temperature and time as the curing temperature and time. The mass of the release layer test piece is measured, and the mass at this time is defined as an initial release layer test piece mass W1. Next, this release layer test piece is put into an electric furnace having the same temperature as the curing temperature of the liquid elastomer raw material, and the change with time in mass is measured. Heating is continued until the mass of the release layer test piece stops decreasing, and the time until the mass stops decreasing is determined, and the mass of the release layer test piece at the time when the time has elapsed is measured. The mass at this time is defined as a release layer test piece mass W2 after the component volatilized at the curing temperature of the liquid elastomer raw material is volatilized. And what is necessary is just to obtain | require content (DELTA) W (mass%) of the component which volatilizes at the curing temperature of the liquid elastomer raw material of a mold release layer by a following formula.
ΔW (mass%) = [(W1-W2) / W1] × 100

Next, the details of the problem to be solved by the present invention will be described.
FIG. 1 is a schematic diagram showing an outline of an example of a centrifugal mold. The centrifugal mold 10 shown in FIG. 1 has a cylindrical shape, and has a concave inner wall surface (sometimes referred to as an inner peripheral surface) 10a on the inner periphery. A liquid elastomer raw material is put into this molding die and heated and cured to form an elastomer molded body.

  FIG. 2 shows a schematic view of a cross section in the vicinity of the inner peripheral surface end portion 10b of the mold when an elastomer molded body is formed using the centrifugal mold. The inner peripheral surface end wall surface of the mold is composed of the inner peripheral surface 10a of the centrifugal mold 10 and the inner wall surface of the inner peripheral surface end portion 10b. A releasable holding layer 11 and a release layer 12 are provided on the inner peripheral surface of the mold. As a result, horizontal accuracy and peelability, and good mold release properties at the time of production are expressed, and the elastomer molded body 13 is molded, released from the mold, and produced.

  The release layer 12 formed on the holding layer 11 often has a polydimethylsiloxane structure as a main component. In general, the molecular chain becomes longer due to polymerization, and these are formed by crosslinking or modification with a functional group. It is known that both the growth reaction of a polymer molecular chain and the formation reaction of a cyclic body having a cyclic siloxane structure occur in the step of forming a release layer using a liquid curable silicone. Thus, it is a general characteristic in the curing reaction of the liquid curable silicone that a low molecular weight and volatile cyclic component is mixed. Such a low molecular weight volatile component remains in a commercially available liquid curable silicone.

  After forming the holding layer 11 on the inner peripheral surface 10a of the centrifugal mold 10 and forming the release layer 12 on the inner peripheral surface of the holding layer 11, the liquid elastomer raw material is charged into the centrifugal mold and cured. As a result, as shown in FIG. 2, a release layer 12 that extends to the inner wall surface of the inner peripheral surface end portion 10b is formed. Thus, if the release layer 12 reaches the inner wall surface of the inner peripheral surface end portion 10b, the elastomer molded body 13 can be molded without any problem. If the liquid elastomer raw material is a thermosetting type, the centrifugal mold 10, the holding layer 11 and the release layer 12 are always exposed to the curing temperature of the liquid elastomer raw material during molding. For example, when the liquid elastomer raw material is polyurethane, the curing temperature is usually 100 to 160 ° C. If the elastomer molding is repeated for a long time, the release layer 12 is also exposed to this temperature during this period. This was thought to be the cause of the above-mentioned problems.

When a release layer formed from a liquid curable silicone is exposed to a high temperature, not only low molecular weight components (mainly trimers of 10 to 10 trimers called D _{3 to} D ₁₀ ) but also low molecular weight components Even larger molecular weight components may be volatilized. These volatile components do not volatilize immediately and gradually volatilize over several days, causing mass loss at the same time. For example, even if the release layer 12 is formed of a two-component curable silicone, the mass gradually decreases when exposed to the curing temperature of the liquid elastomer raw material for a long time. The release layer causing mass reduction causes dimensional shrinkage at the same time. Therefore, when the content of the component that volatilizes at the curing temperature of the liquid elastomer raw material is large in the release layer 12 formed using the two-component curable silicone, it can be said that the dimensional shrinkage is correspondingly large. Then, even when the release layer 12 is filled up to the inner peripheral surface end portion 10b as shown in FIG. 2 at an initial stage, the low molecular weight component volatilizes and the mass decreases when exposed to the curing temperature for a long time. Wake up. Along with this, the mold release layer 12 undergoes dimensional shrinkage, and a shrinkage gap 14 may be generated between the mold release layer 12 and the inner peripheral surface end portion 10b of the mold even though it is small as shown in FIG. It became clear as an observation fact.

  When molding is performed with the molding die in such a state, as shown in FIG. 4, the liquid elastomer raw material enters the shrinkage gap in the vicinity of the inner peripheral surface end portion 10b of the molding die and is cured to generate burrs 14a.

  As a result, as shown in FIG. 5, the burr 14 a fixed when the elastomer molded body 13 is peeled becomes a portion that is difficult to peel. This sometimes causes breakage of the elastomer molded body 13 during demolding or defective release. When such a phenomenon occurs, as shown in FIG. 6, the residual burrs 14 b broken from the elastomer molded body adhere to the shrinkage gap 14. When such minute residual burrs are present, the releasability from the inner peripheral surface end portion 10b of the mold becomes poor, and when the elastomer is continuously molded over a long period of time, the releasability and workability deteriorate. It causes a defect.

  In order to obtain good processability and mass productivity over a long period of time without causing such problems, even if the state shown in FIG. 2 is exposed to the curing temperature of the liquid elastomer raw material, it can be continued over a long period of time. Things are necessary. That is, it is ideal that the release layer does not shrink as shown in FIG. 3 even when exposed to the curing temperature of the liquid elastomer raw material for a long time. The smaller the volatile low molecular weight component, the more the workability is. It can be understood that this is advantageous.

  Liquid curable silicones generally remove such low molecular weight components during purification, but complete removal is virtually impossible. On the other hand, when a release layer formed using liquid curable silicone is used as a release layer in a mold, there is a concern that the molecular weight component that does not volatilize at room temperature may be volatilized to cause mass reduction or shrinkage. Is done.

  Therefore, as a result of intensive studies, the present inventors have determined that if the content of the component that volatilizes at the curing temperature of the liquid elastomer raw material of the release layer formed using liquid curable silicone is 0.5% by mass or less, long-term It was found out that good releasability could be secured over the period.

  Next, the present invention will be further described with reference to examples.

In this example, a liquid elastomer raw material prepared by the method described below was used.
As the polyurethane prepolymer, Coronate 4387 (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd .; isocyanate value 6.2%), which is an MDI-polybutylene adipate-based polyurethane prepolymer, was prepared. Further, as a curing agent, 1,4-butanediol and trimethylolpropane were mixed at 70:30, and 1000 ppm of TEDA (triethylenediamine) was added thereto. The polyurethane prepolymer is melted in an electric furnace at 80 ° C. and preheated (approximately 8 hours) until completely transparent, and then the curing agent is adjusted so that the molar ratio of hydroxyl groups to isocyanate groups is 0.95. A liquid elastomer raw material was prepared by mixing.

  In this example, the content of the component that volatilizes at the curing temperature of the liquid elastomer raw material in the release layer formed using the liquid curable silicone was measured as follows.

A mold having dimensions of 50 mm × 80 mm × 5 mm was prepared. Each liquid curable silicone used in this example was poured into this mold and cured by heating for 1 hour at 130 ° C., which is the curing temperature of the liquid elastomer raw material used in this example. Was made. The temperature was returned to room temperature, and the mass of the release layer test piece was measured. The mass at this time was defined as an initial release layer test piece mass W1. Next, this release layer test piece was placed in an electric furnace at 130 ° C., which is the curing temperature of the liquid elastomer raw material used in this example, and the change with time in mass was measured. It was found that the weight of the release layer test piece stopped decreasing in about 10 days. Therefore, the mass of the release layer test piece after heating at 130 ° C. for 10 days was defined as the release layer test piece mass W2 after the component volatilized at the curing temperature of the liquid elastomer raw material used in this example. The content ΔW (mass%) of the component that volatilizes at the curing temperature of the liquid elastomer raw material of the release layer formed using each liquid curable silicone used in this example was determined by the following formula.
ΔW (mass%) = [(W1-W2) / W1] × 100

(Example 1)
A centrifugal molding machine equipped with a molding die having a diameter of 400 mm and a depth of 250 mm was prepared. The mold is heated to 130 ° C., an epoxy mold release agent (trade name: KS707 manufactured by Shin-Etsu Chemical Co., Ltd.) is applied, and a liquid thermosetting epoxy resin is poured into a centrifugal molding machine rotated at 800 rpm. Then, the holding layer having a layer thickness of 1 mm was formed on the inner wall surface of the molding die. Separately, two liquid addition curing type silicone (trade name: XE15-C2617AB manufactured by GE Toshiba Silicone Co., Ltd.) is stirred and mixed, and then subjected to vacuum defoaming for 1 hour to form a liquid curing type for forming a release layer. Silicone was prepared. This was put into a molding die having a holding layer heated to 130 ° C. and rotated at 800 rpm, and cured by heating for 1 hour to form a release layer having a layer thickness of 1 mm.

  Next, the liquid elastomer raw material was poured into the molding die maintained at a temperature of 130 ° C., heated for 50 minutes to be cured and demolded to obtain a polyurethane sheet having a layer thickness of 1 mm. Thereafter, the operation of curing and demolding the liquid elastomer raw material again was repeated, and continuous productivity was evaluated. This operation was continuously repeated for 10 days or more, and it was confirmed that the mold could be removed without any problem for 100 shots or more.

  On the other hand, the release layer test piece formed by using the above-mentioned two-component addition-curable silicone (trade name: XE15-C2617AB GE Toshiba Silicone Co., Ltd.), measured by the above method, contains a component that volatilizes at 130 ° C. The amount was 0.25% by mass.

(Example 2)
A polyurethane sheet was obtained in the same manner as in Example 1 except that XE15-C2618AB (trade name, manufactured by GE Toshiba Silicone Co., Ltd.) was used as the two-component addition-curable silicone. The operation was continuously repeated for 10 days or more, and it was confirmed that the mold could be removed without any problem for 120 shots or more. Moreover, content of the component which volatilizes at 130 degreeC of the release layer test piece formed using the 2 liquid addition hardening type silicone in the present Example measured by the said method was 0.19 mass%.

(Comparative Example 1)
A polyurethane sheet was obtained in the same manner as in Example 1 except that CY52-005 (trade name, manufactured by Toray Dow Corning Co., Ltd.) was used as the two-component addition-curable silicone. However, at the stage of the fifth day (45 shots), the state became as shown in FIGS. 5 to 6 and further molding was impossible. Moreover, content of the component which volatilizes at 130 degreeC of the release layer test piece formed using the two-component addition curable silicone in this comparative example measured by the above method was 0.52% by mass.

(Comparative Example 2)
A polyurethane sheet was obtained in the same manner as in Example 1 except that TSE3455T (trade name, manufactured by GE Toshiba Silicones Co., Ltd.) was used as the two-component addition-curable silicone. However, at the stage of the 5th day (43 shots), the state shown in FIGS. 5 to 6 was reached, and further molding was impossible. Moreover, content of the component which volatilizes at 130 degreeC of the release layer test piece formed using the two-component addition hardening type silicone of this comparative example measured by the said method was 0.55 mass%.

  As shown in Table 1, the molding methods of Examples 1 and 2 were sufficiently capable of withstanding continuous production, but the molding methods of Comparative Examples 1 and 2 resulted in low continuous productivity. .

It is a schematic diagram of an example of the centrifugal mold in this invention. It is a cross-sectional schematic diagram of the inner peripheral surface end part vicinity of an example of the shaping | molding die in this invention. It is a cross-sectional schematic diagram of an example of the shaping | molding die which the shrinkage | contraction gap generate | occur | produced between the mold release layer and the inner peripheral surface terminal part. It is a schematic diagram which shows an example of the burr | flash of the elastomer molded object which generate | occur | produced by the shrinkage | contraction clearance gap between a mold release layer and a shaping | molding die internal peripheral surface end part. It is a schematic diagram showing an example of a defect caused by a burr of an elastomer molded body generated by a shrinkage gap generated between a release layer and a mold inner peripheral surface end portion. It is a schematic diagram which shows an example of the residual burr | flash of the shrinkage | contraction clearance gap between a mold release layer and a shaping | molding die internal peripheral surface end part.

Explanation of symbols

10 Centrifugal Mold 10a Inner Wall (Inner Surface)
10b Inner peripheral surface end portion 11 Holding layer 12 Release layer 13 Elastomer molded body 14a Burr 14b formed at the end of the elastomer molded body Residual burr 14 Shrinkage gap

Claims (6)

  In an elastomer molding method in which a liquid elastomer raw material is charged into a mold having a release layer and cured, the component that is formed using liquid curable silicone as the mold and volatilizes at the curing temperature of the liquid elastomer raw material An elastomer molding method characterized by using a mold having a release layer on the inner wall surface with a content of 0.5% by mass or less.   The method for molding an elastomer according to claim 1, wherein a molding die further having a holding layer releasably bonded to the inner wall surface of the molding die is used as the molding die.   The elastomer molding method according to claim 1 or 2, wherein the liquid elastomer raw material contains a polyurethane prepolymer as a main component.   4. The elastomer molding method according to claim 2, wherein the holding layer is a holding layer formed using a thermosetting epoxy resin.   The method for molding an elastomer according to claim 1, wherein the mold is a centrifugal mold.   An electrophotographic blade member produced by the elastomer molding method according to claim 1.

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