JP2013193381A - Molding die for molding cleaning blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a molding die for molding a cleaning blade, which allows easy separation of the cleaning blade and exhibits superior durability in repeatedly manufacturing the cleaning blade.SOLUTION: A molding die 2 for molding a cleaning blade is used to mold the cleaning blade having a rubber elastic body. At least a portion in contact with the rubber elastic body comprises a material mainly composed of fully aromatic polyester.

Description

  The present invention relates to a mold for forming a cleaning blade.

  Conventionally, in electrophotographic copying machines, printers, facsimiles, etc., a cleaning blade in which a rubber elastic body is fixed to a support member is used as a cleaning means for removing residual toner on the surface of a photoreceptor. . The cleaning blade is formed by, for example, injecting a resin solution such as urethane rubber into a metal mold and heat-curing it.

  As a mold used for molding, for example, Patent Document 1 discloses that a flexible mold is composed of a support made of a composite material of a polymer material and a reinforcing material, and a microstructure surface supported by the support. A mold configured to have a shaping layer provided for the above is disclosed.

  Patent Document 2 discloses a split mold for producing a ring-shaped seamless molded body by applying a resin solution for a molded body to an outer peripheral surface or an inner peripheral surface and firing the resin solution. The convex part of the mold member and the concave part of the other mold member are connected by fitting fitting with an intermediate member made of a material different from the mold material sandwiched between them. A mold is disclosed.

  Patent Document 3 discloses a method of forming a release layer having a main chain of polysilazane or polysiloxane and hardness of 55 ° to 85 ° in JIS A type on the inner surface of the mold. .

JP 2011-084071 A JP 2009-178960 A Japanese Patent No. 4379674

  The subject of this invention is providing the shaping | molding die for a cleaning blade shaping | molding which is excellent in the peeling property of a cleaning blade, and excellent in the durability at the time of manufacturing a cleaning blade repeatedly.

In order to achieve the above object, the following invention is provided.
The invention according to claim 1
Used to form a cleaning blade with a rubber elastic body,
In addition, the cleaning die is a molding die for forming a cleaning blade, wherein at least a portion in contact with the rubber elastic body is made of a material mainly composed of wholly aromatic polyester.

The invention according to claim 2
The wholly aromatic polyester is a polymer having a structural unit derived from an aromatic hydroxycarboxylic acid, a structural unit derived from an aromatic diol, and a structural unit derived from an aromatic dicarboxylic acid in the structure. Item 2. A mold for forming a cleaning blade according to Item 1.

The invention according to claim 3
The molding die for cleaning blade molding according to claim 1 or 2, wherein at least a ten-point average surface roughness Rz (JIS-B0601 (1994)) in contact with the rubber elastic body is 2 µm or more and 20 µm or less. It is.

  According to the first aspect of the present invention, the cleaning blade is excellent in releasability of the cleaning blade as compared with the case where the portion in contact with the rubber elastic body is not made of a material mainly composed of wholly aromatic polyester, and the cleaning blade is repeatedly applied There is provided a molding die for forming a cleaning blade that is excellent in durability at the time of manufacturing.

  According to the invention of claim 2, the wholly aromatic polyester has a structural unit derived from an aromatic hydroxycarboxylic acid, a structural unit derived from an aromatic diol, and a structural unit derived from an aromatic dicarboxylic acid in the structure. As compared with a case where the polymer is not a polymer having the above, there is provided a molding die for forming a cleaning blade which is excellent in releasability of the cleaning blade and excellent in durability when the cleaning blade is repeatedly produced.

  According to the invention of claim 3, the ten-point average surface roughness Rz (JIS-B0601 (1994)) in contact with the rubber elastic body is not in the range of 2 μm or more and 20 μm or less. A mold for forming a cleaning blade having excellent properties is provided.

It is a perspective view which shows the whole image of a shaping | molding die. It is a front view which shows the whole image of a shaping | molding die. It is a top view which shows the whole mold. It is a schematic sectional drawing which shows the master type | mold used for manufacture of a shaping | molding die.

  Hereinafter, embodiments of the present invention will be described in detail.

<Molding tool for cleaning blade molding>
The molding die for forming a cleaning blade according to the present embodiment is a material that is used for molding a cleaning blade having a rubber elastic body, and at least a portion in contact with the rubber elastic body is a wholly aromatic polyester as a main component. Composed.

  The molding die according to the present embodiment is made of a material mainly composed of wholly aromatic polyester as the part that contacts the rubber elastic body of the cleaning blade, so that the cleaning blade can be easily peeled off from the molding die, Moreover, it is excellent in durability when it is repeatedly used for producing a cleaning blade.

  First, since the wholly aromatic polyester is excellent in releasability, it is considered that releasability from the formed cleaning blade is ensured without using a release agent. As a result, when the release agent is used, the cleaning blade is contaminated by the deteriorated product of the release agent, the photoconductor is in contact with the cleaning blade, and the plate has rigidity due to the deteriorated product. Adhesion failure with the support material is suppressed. Further, the cost can be reduced by omitting the mold release agent coating process and the mold cleaning process for cleaning the mold release agent.

  In addition, the wholly aromatic polymer has high heat resistance because the temperature at which it changes from a solid to a liquid crystal state is 300 ° C. or higher. In addition, the wholly aromatic polymer exhibits a uniform molecular orientation compared to other aromatic polymers, and thus has a self-reinforcing effect, exhibits rigidity comparable to that of metals (aluminum, etc.), and is excellent in durability. It is considered a thing.

The wholly aromatic polyester is a resin that exhibits liquid crystallinity in a specific temperature range (thermotropic), and is called a liquid crystal polymer (LCP). Fully aromatic polyester has low linear expansion among resins and is equivalent to metal (10 ^-5 / ° C). Therefore, when heated by using a material mainly composed of wholly aromatic polyester in the mold It is considered that a cleaning blade in which the dimensional change of the mold is suppressed and the dimensional tolerance is suppressed is provided.

  Further, the wholly aromatic polyester has a specific gravity in the range of 1.3 or more and 1.8 or less, and is lighter than the specific gravity (mass) of 7.7 or more and 8 or less of the stainless steel material that is representative of metal mold materials. It is excellent in the transportability of the mold and can be moved easily.

  Furthermore, since fully aromatic polyester has a high molecular orientation, it is considered to have excellent thermal conductivity compared to other resins, and heat is efficiently supplied to the resin for forming the blade for cleaning. It is suitable for a mold for forming a blade for cleaning that is required to be performed.

-Structure of a shaping | molding die Here, the structure of the shaping | molding die for cleaning blade shaping | molding is demonstrated using figures. FIG. 1 is a perspective view showing an overall image of a mold, FIG. 2 is a front view thereof, and FIG. 3 is a top view thereof.
As shown in FIGS. 1 to 3, the mold 2 includes a cavity (dent) 4 that stores a resin solution for a cleaning blade, and a plate-like body that serves as a support member that supports a rubber elastic body portion of the cleaning blade. And a support member installation portion 6 for installation.

-Fully Aromatic Polyester The mold according to the present embodiment is formed of a material whose main component is a fully aromatic polyester in the portion of the cleaning blade that contacts the rubber elastic body. The “main component” means that it is contained as the most abundant component among the materials used for the portion of the cleaning blade in contact with the rubber elastic body, and the content is preferably 50% by mass or more.

  The wholly aromatic polyester used in the mold is also called liquid crystal polymer (LCP), and is a synthetic resin that exhibits liquid crystal-like properties in which the linear chain of molecules is regularly arranged in a molten state and belongs to a thermoplastic resin. . A copolymer obtained by polymerizing a plurality of monomers and all the various components are aromatic is called a wholly aromatic polyester.

As a wholly aromatic polyester,
A structural unit derived from an aromatic hydroxycarboxylic acid A structural unit derived from an aromatic diol A preferred example includes a structural unit derived from an aromatic dicarboxylic acid, that is, an aromatic hydroxycarboxylic acid and an aromatic diol Polymers with aromatic dicarboxylic acids are preferred.

Examples of the aromatic hydroxycarboxylic acid include parahydroxybenzoic acid, metahydroxybenzoic acid, 2-hydroxy-6-naphthoic acid, 2-hydroxy-3-naphthoic acid, 1-hydroxy-4-naphthoic acid, and 6-hydroxy. 2-naphthoic acid, 4-hydroxy-4'-carboxydiphenyl ether, 2,6-dichloro-parahydroxybenzoic acid, 2-chloro-parahydroxybenzoic acid, 2,6-difluoro-parahydroxybenzoic acid, 4-hydroxy -4'-biphenyl carboxylic acid and the like. Among these, it is more preferable to use parahydroxybenzoic acid and 6-hydroxy-2-naphthoic acid because the characteristics and melting temperature of the wholly aromatic polyester can be easily adjusted. preferable.
Aromatic hydroxycarboxylic acids may be used alone or in combination of two or more. In addition, from the viewpoint of further increasing the thermal conductivity of the mold, a heat conductive filler such as aluminum nitride powder, boron nitride powder, or alumina may be included.

Examples of the aromatic diol include hydroquinone, resorcin, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 4,4′-dihydroxybiphenyl, 3, 3'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxybiphenyl ether and the like. Among these, hydroquinone and 4,4'-dihydroxybiphenyl are used. It is more preferable from the viewpoint of the characteristics of the wholly aromatic polyester obtained.
Aromatic diols may be used alone or in combination of two or more.

Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 4,4 '-Dicarboxybiphenyl and the like can be mentioned. Among these, terephthalic acid and isophthalic acid are used because it is easy to adjust the mechanical properties, heat resistance, melting temperature, and moldability of the wholly aromatic polyester to an appropriate level. preferable.
Aromatic dicarboxylic acids may be used alone or in combination of two or more.

Since the wholly aromatic polyester has a strong molecular orientation, the warp in the flow vertical (TD) direction is large, and it may be deformed when the mold is manufactured. Therefore, it is preferable to add a filler as a molecular orientation relaxation material and a rigidity reinforcing material from the viewpoint of reducing warpage.
Examples of the filler include fibers for resin reinforcing materials such as glass fiber, carbon fiber, aramid fiber, LCP fiber, inorganic filler such as wollastonite, sepiolite, mica, talc, potassium titanate whisker, aluminum borate whisker, carbonic acid Examples include whiskers such as calcium whiskers, magnesium sulfate whiskers, zonotlite, and zinc oxide whiskers. Among these, glass fiber and carbon fiber are preferable from the viewpoint of high mechanical strength, and inexpensive glass fiber is more preferable.
The filler may be used alone or in combination of two or more.

-Other resins In the mold for molding the cleaning blade, the portion of the cleaning blade that contacts the rubber elastic body is composed of a material mainly composed of wholly aromatic polyester as described above. Other resins may be included. Other resins include PEEK (polyetheretherketone), PFA (tetrafluoroethylene-perfluoroalkoxyethylene copolymer), PTFE (tetrafluoroethylene), polyimide, PES (polyethersulfone), PSF ( Polysulfone), PPSU (polyphenylsulfone), PPS (polyphenylene sulfide), PAR (polyarylate), POM (polyacetal) and the like.
However, it is more preferable that the material constituting the portion in contact with the rubber elastic body of the cleaning blade of the mold contains only wholly aromatic polyester as the resin.

  The mold may be entirely composed of a material mainly composed of wholly aromatic polyester, and the portion of the cleaning blade that does not contact the rubber elastic body is made of another material (for example, metal (SUS, etc.) or resin. Etc.).

-Manufacturing method of a shaping | molding die Here, the manufacturing method of the shaping | molding die comprised with the material which has wholly aromatic polyester as a main component as a whole is demonstrated, giving an example using figures.
The molding die according to the present embodiment is manufactured using, for example, a master die composed of an upper die 12 and a lower die 14 made of metal (SUS304) shown in FIG. The lower mold 14 in the master mold has a resin reservoir 16 for injecting a material mainly composed of wholly aromatic polyester, and the resin reservoir 16 is formed with a cavity for forming the cavity 4 in the molding die. A support member installation part forming part 6 ′ for forming the part 4 ′ and the support member installation part 6 is formed.
After injecting the material mainly composed of wholly aromatic polyester into the resin reservoir 16 of the lower mold 14 with an injection molding machine in a molten state, the upper mold 12 and the lower mold 14 are engaged with each other. The mold is manufactured by cooling and solidifying.

-Surface roughness The surface roughness of the portion of the molding die that contacts the rubber elastic body of the cleaning blade is preferably 2 μm or more and 20 μm or less in terms of 10-point average surface roughness Rz (JIS-B0601 (1994)). Molding molds of less than 2 μm are difficult to produce, and if it is 20 μm or less, the resin for forming the cleaning blade does not easily enter the irregularities on the surface of the mold, and an anti-anchor effect is obtained, resulting in improved peelability.

  The surface roughness of the part of the mold that contacts the rubber elastic body of the cleaning blade is controlled by the resin temperature, injection pressure, and mold temperature when the mold is manufactured by the injection molding machine. Adjusted by.

-Manufacture of a cleaning blade using a molding die Manufacture of a cleaning blade using a molding die according to the present embodiment is performed, for example, by the following method. That is, after the mold 2 is heated, a resin solution for forming a cleaning blade is poured into the cavity 4 of the mold 2. After injection, for example, a rubber plate fixed to the indicating member is obtained by inserting and setting a heated plate-like body into the indicating member setting portion 6 after being applied, further curing by heating, and removing from the mold 2 A cleaning blade having an elastic body is manufactured.

As the rubber elastic body in the cleaning blade, for example, a thermosetting resin is used, and urethane rubber is particularly preferably used. As a material for a rubber elastic body using urethane rubber, it is preferable to use a mixture obtained by mixing, for example, a polyol, an isocyanate, a crosslinking agent, a catalyst, a chain extender and the like.
Further, the cleaning blade may be in a mode in which the rubber elastic body is instructed by the support member or in a mode in which the support member is not provided. As the support member, it is preferable to use a plate having rigidity.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples.

[Example 1]
-Making mold-
The following compound was prepared as a wholly aromatic polyester compound (LCP1).
“Xydar MG350,
(Made by Solvay Advance Polymer, deflection temperature under load: 256 ° C) "
Compound composition: Totally aromatic polyester / glass fiber / talc
= 50/13/37 mass%

Next, a mold was produced by the following method.
A master mold comprising an upper mold 12 made of metal (SUS304) and a lower mold 14 made of metal (SUS304) and having a cleaning blade-shaped resin reservoir 16 shown in FIG. 4 was prepared. Next, the wholly aromatic polyester compound (LCP1) heated and melted in the resin reservoir 16 of the lower mold 14 is cast using an injection molding machine, and the upper mold 12 and the lower mold 14 are engaged with each other. After that, by cooling and solidifying, a mold for forming a cleaning blade was produced.

  In addition, the surface roughness of the portion in contact with the cleaning blade (rubber elastic body) in the above-mentioned mold depends on the resin temperature, injection pressure, and mold temperature when the mold is produced by an injection molding machine as shown in Table 1 below. Controlled. As the injection molding machine, FE360S100ASE (manufactured by Nissei Plastic Co., Ltd.) having a clamping force of 360 tons was used.

-Measurement of surface roughness-
The 10-point average roughness Rz (JIS-B0601 (1994)) of the portion of the mold that comes into contact with the cleaning blade (rubber elastic body) is 0 using a surface roughness measuring device Surfcoder SE3500 manufactured by Kosaka Laboratory. Measured at a feed rate of .05 mm / s.
The results are shown in Table 1 and Table 2 below.

-Production of cleaning blade using mold-
A mixed solution for forming a cleaning blade was prepared by the following method.
Polycaprolactone polyol (Daicel Chemical Industries, Plaxel 205, average molecular weight 529, hydroxyl value 212 KOHmg / g) and polycaprolactone polyol (Daicel Chemical Industries, Plaxel 240, average molecular weight 4155, hydroxyl value 27 KOHmg / g) And as a hard segment material of a polyol component. In addition, an acrylic resin containing 2 or more hydroxyl groups (Act Flow UMB-2005B, manufactured by Soken Chemical Co., Ltd.) was used as the soft segment material. The hard segment material and the soft segment material were mixed at a ratio of 8: 2 (mass ratio).

  Next, 4,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT, hereinafter referred to as “MD1”) as an isocyanate compound with respect to 100 parts by mass of the mixture of the hard segment material and the soft segment material. 6.26 parts by mass was added and reacted at 70 ° C. for 3 hours under a nitrogen atmosphere. The amount of the isocyanate compound used in this reaction is selected so that the ratio of isocyanate group to hydroxyl group (isocyanate group / hydroxyl group) contained in the reaction system is 0.5.

  Subsequently, 34.3 parts by mass of the isocyanate compound was further added and reacted at 70 ° C. for 3 hours in a nitrogen atmosphere to obtain a prepolymer. The total amount of isocyanate compound used when using the prepolymer was 40.56 parts by mass. Next, this prepolymer was heated to 100 ° C. and degassed for 1 hour under reduced pressure. Thereafter, 7.14 parts by mass of a mixture of 1,4-butanediol and trimethylolpropane (mass ratio = 60/40) is added to 100 parts by mass of the prepolymer, and it is sufficiently not to foam for 3 minutes. By mixing, a liquid mixture for forming a cleaning blade was obtained.

  After heating (110 degreeC) the shaping | molding die for cleaning blade shaping | molding obtained by the said method, the said liquid mixture was inject | poured into the cavity of the shaping | molding die. After the injection, an adhesive composed of a phenol resin containing a hydroxyl group is applied and a rigid plate heated to the same temperature as the mold is inserted, and cured on a hot plate controlled for 5 minutes, Thereafter, the mold was removed and a cleaning blade was formed.

[Example 2]
As shown in Table 1 above, the part in contact with the cleaning blade (rubber elastic body) in the mold for cleaning blade molding by changing the resin temperature, injection pressure, and mold temperature at the time of mold forming by the injection molding machine A cleaning blade was prepared by the method described in Example 1 except that a cleaning blade forming mold having a surface roughness of 1 in the numerical values shown in Table 1 was prepared.

Example 3
As shown in Table 1 above, the part in contact with the cleaning blade (rubber elastic body) in the mold for cleaning blade molding by changing the resin temperature, injection pressure, and mold temperature at the time of mold forming by the injection molding machine A cleaning blade was prepared by the method described in Example 1 except that a cleaning blade forming mold having a surface roughness of 1 in the numerical values shown in Table 1 was prepared.

[Comparative Example 1]
First, the compound shown below was prepared as an aromatic polyester compound (LCP2).
“Rodrun LC5030G (manufactured by Unitika Ltd., deflection temperature under load 210 ° C.)”
Compound composition: Aromatic polyester / glass fiber
= 70/30% by mass

  In the production of the mold of Example 1, the compound used was changed to the above aromatic polyester compound (LCP2), and as shown in Table 1, the resin temperature and injection pressure when producing the mold with an injection molding machine, gold A mold for cleaning blade molding in which the surface temperature of the portion in contact with the cleaning blade (rubber elastic body) in the mold for molding the cleaning blade is changed as shown in Table 1 by changing the mold temperature. A cleaning blade was produced by the method described in Example 1 except that it was produced.

[Comparative Example 2]
A mold for forming a cleaning blade made of metal (SUS304) was produced. A specific manufacturing method is as follows. It was manufactured by cutting directly into a mold base material (SUS304) to a blade shape by NC processing using a ball end mill. Thereafter, blasting was performed on the portion in contact with the blade, and the 10-point average surface roughness Rz was set to 8 μm.

  Next, using a mold for forming a cleaning blade made of this metal (SUS304), a release agent (trade name: Fleet 410, manufactured by Neos Co., Ltd.) is applied to a portion in contact with the cleaning blade (rubber elastic body). A cleaning blade was prepared by the method described in Example 1 without performing the above.

[Comparative Example 3]
A mold for forming a cleaning blade made of metal (SUS304) was produced. A specific manufacturing method is as follows. It was manufactured by cutting directly into a mold base material (SUS304) to a blade shape by NC processing using a ball end mill. Thereafter, blasting was performed on the portion in contact with the blade, and the 10-point average surface roughness Rz was set to 10 μm.

  Next, a mold release agent (manufactured by Neos Co., Ltd., trade name: Fleet 410) was applied to a portion in contact with the cleaning blade (rubber elastic body) using a mold for cleaning blade molding made of this metal (SUS304). A cleaning blade was prepared by the method described in Example 1 above.

〔Evaluation test〕
<Peelability (demoldability)>
The peelability at the time of demolding of the cleaning blade injected into the mold cavity, cured and molded was evaluated according to the following evaluation criteria.
A: Light peeling (= After peeling, the blade is observed 10 times using a digital video micro VHS-9000 (manufactured by Keyence Corporation), and there is no scratch or chipping.)
○: Heavy peeling (= After peeling, the blade was observed 10 times using Digital Video Micro VHS-9000 (manufactured by Keyence Corporation), and scratches and chips less than 50 μm were generated.)
Δ: After peeling, the blade was observed 10 times using a digital video micro VHS-9000 (manufactured by Keyence Corporation), and scratches and chips of 50 μm or more were generated.
×: Unable to peel

<Image evaluation>
A cleaning blade was prepared 50 times using the same mold by the methods described in the examples and comparative examples. The cleaning blade produced for the 50th time is incorporated into DocuCenter Color f450 (manufactured by Fuji Xerox Co., Ltd.), an image is formed by this image forming apparatus, and the initial tenth output image is used as an image evaluation sample. The presence or absence of streak was evaluated according to the following criteria.
A: Color streak has not occurred.
○: Color streak cannot be visually confirmed, but can be slightly confirmed with a magnifying glass.
Δ: Slight color streak stains can be visually confirmed.
X: A clear color streak stain can be visually confirmed.

<Die mold durability>
A cleaning blade was prepared 50 times using the same mold by the methods described in the examples and comparative examples. After molding 50 times, the presence of damage in the portion in contact with the cleaning blade in the mold was confirmed with a loupe and evaluated according to the following criteria.
○: No damage occurred.
X: There is fine damage.

  The results are also shown in Table 2.

It was found that those using the molds of Examples 1 to 3 gave favorable results in peelability and image quality, and a cleaning blade having excellent cleaning properties. However, since Example 3 has a large surface roughness, it is considered that the peelability is inferior to that of Examples 1 and 2, but it was at a level with no practical problem.
Comparative Example 1 has no problem in peelability and image quality, but is inferior in mold durability.
In Comparative Example 2, since the release agent was not applied, the cleaning blade could not be peeled from the mold.
In Comparative Example 3, the releasability is improved because a release agent is applied to Comparative Example 2. However, when continuous molding is performed, the edge portion in the mold cavity and the like are separated from urethane. A reaction product with the mold was adhered, the peelability was poor, and the edge portion was chipped, and a good image could not be obtained.

2 Mold 4 Cavity (dent)
4 'Cavity forming part 6 Indicating member installing part 6' Indicating member installing part forming part 12 Upper mold 14 Lower mold 16 Resin pool

Claims (3)

Used to form a cleaning blade with a rubber elastic body,
A molding die for forming a cleaning blade, wherein at least a portion in contact with the rubber elastic body is made of a material mainly composed of wholly aromatic polyester.   The wholly aromatic polyester is a polymer having a structural unit derived from an aromatic hydroxycarboxylic acid, a structural unit derived from an aromatic diol, and a structural unit derived from an aromatic dicarboxylic acid in the structure. Item 2. A molding die for molding a cleaning blade according to Item 1.   The molding die for cleaning blade molding according to claim 1 or 2, wherein at least a ten-point average surface roughness Rz (JIS-B0601 (1994)) in contact with the rubber elastic body is 2 µm or more and 20 µm or less. .

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