JP2002326239A - Roller mold and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a roller mold for manufacturing a foam roller having surface roughness suitable for an image forming apparatus, and a method for manufacturing the same. SOLUTION: In manufacturing the roller mold having a fluoroplastic coating layer with a surface roughness Rz of >20-2,000 μm provided to the inner surface thereof, granular fluoroplastic is applied to the inner surface of the roller mold by dry spraying to form the coating layer or a coating material prepared by dispersing granular fluoroplastic in a solvent solution for fluoroplastic is applied to the inner surface of the roller mold and the coated roller mold is dried to form the coating layer. Alternatively, a coating material, which is prepared by dispersing a granular substance capable of disappearing by dissolution or melting in the solvent solution for fluoroplastic, is applied to the inner surface of the roller mold to be dried and the granular substance is allowed to disappear by dissolution or melting to form the coating layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold used for manufacturing a foam roller and a method for manufacturing the same. More specifically, the present invention relates to a roller mold useful for manufacturing a foam roller having a surface roughness suitable for an image forming apparatus, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In general, an image forming apparatus such as a dry electrophotographic apparatus uses a roller having a foamed elastic layer formed on the outer periphery of a rotating shaft, such as a developing roller, a transfer roller, a cleaning roller, and a paper feed roller. I have. These so-called foam rollers are generally manufactured by an integral foam molding method in which a foam-forming material is poured into a cylindrical mold in which a rotating shaft is set and foam-hardened. This method
After demolding, it does not require cutting or grinding, so it has excellent productivity, but a thin film generally called a skin layer is formed on the surface of the foam elastic layer provided on the outer circumference of the rotating shaft. As a result, the performance is impaired, and it is necessary to remove the skin layer by polishing or the like.

[0003] In response to such a demand, a "mold having a fluororesin coating layer formed on the inner surface of the mold and processed (shot blasting) so that the fluororesin coating layer has a surface roughness: Rz of 5 to 20 µm. Is also adjusted so that a concave groove corresponding to a plurality of ridges providing an uneven surface structure is formed on the inner surface of the mold, and the surface roughness Rz is 5 to 20 μm. In addition, methods using a "mold having a coating layer of a silicone-based or fluorine-based release agent" are proposed. However, neither method can provide a roller having a satisfactory rough surface. It should be noted that, as in the latter method, it is necessary to accurately process the groove on the inner surface of the mold.
It is very difficult because the mold is cylindrical and has a small diameter.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a roller mold useful for producing a foam roller having an appropriate surface roughness under such circumstances, and a method for producing the same. Is what you do.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, it has been found that the above-mentioned object can be achieved.
A roller mold provided with a fluororesin coating layer having a z of more than 20 μm and not more than 2000 μm (first invention) and a method of forming a coating layer by dry spraying particulate fluororesin on the inner surface of a cylindrical member (second method) Invention), a method of forming a coat layer by applying and drying a coating material in which a particulate fluororesin is dispersed in a solvent solution of a fluororesin on the inner surface of a cylindrical member (third invention), and a method of forming a cylindrical member. After coating and drying the inner surface of a solvent solution of a fluororesin in which a particulate material insoluble or hardly soluble in the solvent and dissolvable or dissolvable particulate material is dispersed and dried, the particulate material is dissolved or melted. (4th invention) inventing a method of forming a coat layer by eliminating the above.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION According to a first aspect of the present invention, the inner surface of a cylindrical member has a surface roughness Rz exceeding 20 μm and 2000 μm
A roller mold comprising the following fluororesin coating layer. The cylindrical member is not particularly specified. In addition to metals such as iron, copper, aluminum, and stainless steel, polycarbonate, polyamide, and polyacetate can be used.
, Polybutylene terephthalate, polyphenylene oxide, polyphenylene ether, polyethersulfone, polysulfone, polyphenylene sulfide, and other engineering plastics and ceramics, but stainless steel is most suitable in terms of strength and cost. It is.

[0007] As the fluororesin for forming the coat layer,
Any known materials can be used. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FE)
P), tetrafluoroethylene-pafluoro (alkyl vinyl ether) copolymer (PFA), tetrafluoroethylene-hexafluoropropylene-pafluoro (propyl vinyl ether) terpolymer (EPE), polychlorotrifluoroethylene (PCTFE), Examples include polyvinylidene fluoride (PVDF), ethylene-tetrafluoroethylene alternating copolymer (ETFE), ethylene-chlorotrifluoroethylene alternating copolymer (ECTFE), and polyvinyl fluoride (PVF). Polytetrafluoroethylene is particularly preferred from the viewpoints of properties, release properties, stability, chemical resistance and the like.

In the first invention, the surface roughness Rz of the fluororesin coating layer formed on the inner surface of the cylindrical member is 20 μm.
m and 2000 μm or less, particularly preferably more than 20 μm and 200 μm or less. When the surface roughness Rz of the fluororesin coating layer is 20 μm or less, the surface of the foamed elastic body of the obtained roller is too smooth to obtain the desired roughness, while the surface roughness Rz is 20 μm.
If the thickness exceeds 00 μm, the foamed elastic body formed in the mold cannot be removed from the mold.

A second invention of the present invention is a method for forming a coating layer by dry spraying a particulate fluororesin on the inner surface of a cylindrical member. FIG. 1 is a view showing a lower end face when a roller mold manufactured by the method of the second invention is cut along a plane parallel to a cylindrical axis. Cylindrical member 1
A coating layer 2 made of a fluororesin is formed on the surface (inner surface) of the substrate, and the surface of the coating layer 2 has a large number of irregularities 3, so that a solvent solution of the fluororesin is applied and dried. Has a clearly different surface shape from the coat layer formed by the above method. In the second invention, the types of the cylindrical member and the fluororesin are the same as those in the first invention, but the coating layer is formed by dry spraying a particulate fluororesin. Here, dry spray is different from the usual coating method of completely dissolving the resin in the solvent and applying it, or reducing the amount of the solvent to the particulate resin, using a highly volatile solvent, or By increasing the amount of air compared to the amount of raw materials when spraying, it means that the solvent disappears before reaching the surface to be coated when spraying, resulting in a coating method with a rough surface layer I do. The size of the particulate fluororesin may be a size usually used for dry spraying. As a result, the surface roughness Rz of the coating layer is 20 to 2000 μm.
m, preferably 20 to 200 μm.

A third invention of the present invention is a method for forming a coat layer by applying a coating material in which a particulate fluorine resin is dispersed in a solvent solution of a fluorine resin on the inner surface of a cylindrical member and drying the coating material. . FIG. 2 is a view showing a roller mold manufactured by the method of the third invention, similarly to FIG. A coating layer 2 made of a fluororesin is formed on the surface of the metal 1. On the surface of the coating layer 2, a particulate fluororesin 4 dispersed in a coating material protrudes to form an uneven surface. In the third aspect, the types of the cylindrical member and the fluororesin are the same as in the first aspect, but it is preferable to use two types of fluororesins having different solubility in a solvent. That is, it is a fluororesin that is soluble in a specific solvent and a particulate fluororesin that is insoluble or hardly soluble in the solvent, and may be appropriately selected depending on the combination with the solvent. As the solvent, any of those commonly used for fluororesins can be used, and may be appropriately selected in combination with two kinds of fluororesins. As a result, the size of the particulate fluororesin is such that the surface roughness Rz of the coating layer is 20%.
It is appropriate to choose to be ２０００2000 μm, preferably 20-200 μm.

According to a fourth aspect of the present invention, there is provided a coating material in which a particulate material insoluble or hardly soluble in a solvent of a fluororesin and dispersible by melting or melting is dispersed on the inner surface of a cylindrical member. This is a method of forming a coat layer by dissolving or melting the particulate matter after coating and drying. 3 (a) and 3 (b) are views showing the steps of the method of the fourth invention in the same manner as in FIG. At the stage where the coating material is applied to the inner surface of the cylindrical member and dried, as shown in FIG. 3A, the particulate matter 5 exists in a state protruding from the coating layer. By dissolving or melting the substance,
As shown in (b), many holes 6 are formed in the coat layer. In the fourth aspect, the types of the cylindrical member and the fluororesin are the same as in the first aspect.

On the other hand, the particulate matter dispersed in the solvent solution of the fluororesin is insoluble or hardly soluble in the solvent of the fluororesin, and is dissolved in a solvent which does not dissolve the fluororesin, or the melting temperature of the fluororesin. It must be a substance that can be eliminated by melting at the following temperature. As such a substance, various substances can be used, but thermoplastic resins such as polystyrene, polyvinyl chloride, and polyamide, and vinyl acetate are suitable.Especially, using polystyrene particles, the substance is dissolved in methylene chloride and disappears. It is preferable to employ a method of causing the workability and cost. As a result, the size of the particulate matter is such that the surface roughness Rz of the coating layer is 20 to 2000 μm, preferably 20 to 2000 μm.
It is appropriate to select to be 200 μm. still,
The shape shown in FIG. 3A is the same as that of the third invention shown in FIG. 2, but in the case of the fourth invention in which the particulate matter is further reduced to the shape of FIG. Is preferable since Rz can be selected in a wide range and Rz can be easily adjusted in various ways.

[0013] The roller mold of the first invention and the second to fourth embodiments
The roller mold manufactured by the method of the present invention is suitable for manufacturing a foam roller by an integral foam molding method. less than,
A method for manufacturing the foam roller will be described by taking a case where the foam elastic layer is a polyurethane foam as an example.
First, after setting a rotating shaft in a roller mold coated with a fluorine-based or silicone-based release agent, a predetermined amount of a polyurethane foam-forming material is cast, usually 15 to 80.
Initiate foaming at a temperature in the range of from 0 ° C, preferably from 20 to 65 ° C. Next, after the cavity in the mold is filled with the polyurethane foam, curing is performed at a temperature of about 70 to 120 ° C., and then the mold is removed, whereby a foam roller is obtained.

Examples of the rotating shaft include a metal member obtained by plating steel such as sulfur free-cutting steel with zinc or the like, and a metal member such as aluminum, stainless steel, and magnesium alloy. The foamed elastic layer in the foamed roller is not particularly limited, and may be any of a polyurethane foamed layer, a silicone rubber foamed layer, an EPDM foamed layer, and the like. The roller provided with a polyurethane foam layer is hereinafter referred to as a polyurethane foam roller.) From the viewpoint of performance and the like. In the production of the polyurethane foam roller, a polyurethane foam-forming material containing a polyol component, a polyisocyanate component, a foaming agent, and a conductivity imparting agent, a catalyst, a foam stabilizer and the like used as desired is used. . In the polyurethane foam-forming material, the polyol component and the polyisocyanate component may be contained in the form of a prepolymer obtained by reacting them.

The polyol component used for producing the polyol or the prepolymer is not particularly limited, and examples thereof include a polyether polyol, a polyester polyol, and a hydrophobic polyol. Here, as the polyether polyol, a polyol obtained by addition-polymerizing ethylene oxide or propylene oxide to glycerin or the like, or a polyol such as polytetramethylene glycol, ethylene glycol, propanediol, or butanediol is preferably used. As the polyester polyol, a condensation-based polyester polyol obtained by condensation of a dicarboxylic acid and a diol or a triol, a lactone-based polyester polyol obtained by ring-opening polymerization of a lactone based on a diol or a triol, and a polyether polyol having a lactone terminal. A polyol such as an ester-modified ester-modified polyol is preferably used. Further, as the hydrophobic polyol, polyisoprene polyol, polybutadiene polyol, hydrogenated polybutadiene polyol, or the like is used. These polyol components may be used alone or in combination of two or more.

On the other hand, the polyisocyanate component used for producing a polyisocyanate or a prepolymer includes tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate (crude MDI), isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate; Examples include hydrogenated tolylene diisocyanate; polyisocyanates having no unsaturated bond such as hexamethylene diisocyanate, and modified products thereof with isocyanurate, carbodiimide, glycol, and the like. These polyisocyanate components may be used alone or in combination of two or more.

Next, considering the ease of handling in the production process, the ease of vaporization and foaming, etc., as the foaming agent,
Generally, a physical foaming agent having a boiling point in the range of 20 to 60 ° C is preferably used. When this foaming agent is used as a raw material of a polyurethane foam, it is difficult to obtain a stable flow rate by using a foaming agent alone and to obtain a stable flow rate with a foaming machine. It is advantageous. Examples of such a foaming agent include n-pentane, isopentane, cyclopentane, methylene chloride, Freon 134a (1,1,1,2-tetrafluoroethane), and Freon 245fa (1,1,1,1).
3,3-pentafluoropropane), CFC 365mf
c (1,1,1,3,3-pentafluorobutane), Freon 356, Freon 141b (1,1-dichloro-1-
Fluoroethane), Freon 142b (1-chloro-1,
1-difluoroethane), Freon 22 (chlorodifluoromethane), and water. These may be used alone or in combination of two or more.

Next, in the polyurethane foam forming material of the present invention, examples of the conductivity-imparting agent that may be used include carbon black and ionic conductive agents. Examples of carbon black include gas black such as electrified black, Ketjen black, and acetylene black, oil furnace black including ink black, thermal black, channel black, and lamp black. As the ion conductive agent,
For example, tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium such as lauryltrimethylammonium, octadecyltrimethylammonium such as stearyltrimethylammonium,
Perchlorates, chlorates, hydrochlorides, bromates, such as hexadecyltrimethylammonium, benzyltrimethylammonium, modified aliphatic dimethylethylammonium,
Ammonium salts such as iodate, borofluoride, sulfate, alkyl sulfate, carboxylate and sulfonate; perchlorates of alkali metals or alkaline earth metals such as lithium, sodium, calcium and magnesium Chlorate, hydrochloride, bromate, iodate, borofluoride, trifluoromethyl sulfate, sulfonate and the like.

These conductivity imparting agents may be used alone or in combination of two or more. The amount is not particularly limited and may be appropriately selected depending on various circumstances. Usually, the amount is 0.1 to 100 parts by weight of the polymer material.
-40 parts by weight, preferably 0.3-20 parts by weight. In addition, a filler-based conductive agent such as a metal powder or a metal oxide powder can be added together with the carbon black and the ionic conductive agent. In the polyurethane foam-forming material, as a catalyst optionally used, for example, organometallic catalysts such as dibutyltin dilaurate, dibutyltin diacetate, stannas octoate, dibutyltin marker butide, dibutyltin thiocarboxylate, and dibutyltin dimaleate Neat, dioctyltin marker butide, dioctyltin thiocarboxylate, phenylmercury, silver propionate, tin octenoate, amine-catalyzed triethylamine, N, N, N'N'-tetramethylethylenediamine, triethylenediamine, N
-Methylmorpholine, dimethylaminoethanol, bis (2-dimethylaminoethyl) ether, 1,8-diazabicyclo (5,4,0) -undecene-7 and the like are preferably used. These catalysts may be used alone,
Two or more kinds may be used in combination.

Further, in the polyurethane foam-forming material, examples of the foam stabilizer optionally used include a polyether silicone oil, a nonionic surfactant, an ionic surfactant and the like. Or two or more of them may be used in combination.

[0021]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 A cylindrical stainless steel having an inner diameter of 18 mm and a length of 250 mm was heated to 60 ° C., and its inner surface was dry-sprayed with 20 μm-diameter particulate polytetrafluoroethylene and dried. As a result, a roller mold A having an inner surface on which a coat layer having an average thickness of 25 μm and a surface roughness Rz of 22 μm was formed was obtained.

Example 2 30 g of polytetrafluoroethylene was placed on the inner surface of the same cylindrical stainless steel used in Example 1 as toluene 7.
A coating solution in which 6 g of particulate polytetrafluoroethylene having a diameter of 30 μm was dispersed in a solution dissolved in 0 g was applied by spraying, and dried at 200 ° C. for 30 minutes. As a result, the inner surface had an average thickness of 20 μm and a surface roughness Rz of 25 μm.
The roller mold C on which the m coat layer was formed was obtained.

Example 3 30 g of polytetrafluoroethylene was placed on the inner surface of the same cylindrical stainless steel used in Example 1 as toluene 7.
Spraying a coating solution in which 1.5 g of 100 μm-diameter particulate polystyrene was dispersed in a solution dissolved in 0 g, drying at 200 ° C. for 30 minutes, and immersing in methylene chloride to expose the polyethylene exposed on the surface. It was dissolved and removed. . As a result, a roller mold C having an inner surface on which a coat layer having an average thickness of 20 μm and a surface roughness Rz of 50 μm was formed was obtained.

Preparation Example 1 70 parts by weight of a polyether polyol having an average molecular weight of 5,000 and a number of functional groups of 3, 70 parts by weight of a styrene graft type polymer polyol, and 0.1 part of triethylenediamine.
3 parts by weight, 0.2 part by weight of N-methylmorpholine,
1.5 parts by weight of water, 1.5 parts by weight of silicone foam stabilizer and 50 parts by weight of TDI-80 / polymeric MDI
A polyurethane foam-forming material was prepared by blending an isocyanate of / 50 at an index of 105. In a free foaming experiment in a cup, which was separately performed, the polyurethane foam-forming material started foaming at 25 ° C. for 10 seconds after stirring and pouring, and completed foaming in 90 seconds. The density at that time was 0.10 g / milliliter.

Molding Examples 1 to 3 Roller molds A, B and C obtained in Examples 1 to 3
An iron shaft (diameter 6 mm, length 260 mm), an upper lid and a lower lid having a shaft holding hole at the center were prepared. First, a lower lid was attached to one opening of the roller mold, and a cylindrical mold was set up with a shaft inserted into a shaft holding hole of the lower lid. Next, the polyurethane foam-forming material obtained in Preparation Example 6.
5 g was injected from a foaming machine, and the upper lid was immediately attached to the opening of the roller mold such that the end of the shaft was inserted into the shaft holding hole. After foaming at 25 ° C for 90 seconds, 9
Cure at 0 ° C. for 20 minutes. Next, remove the mold and measure 18m in diameter.
Polyurethane foam rollers A, B and C having a shaft of m and a length of 220 mm were prepared. Each of these foam rollers had a surface with a roughness of 20 to 40 μm, and was suitable for an image forming apparatus.

[0026]

By using the roller mold of the present invention and the roller mold manufactured by the method of the present invention, a foam roller having a surface roughness suitable for an image forming apparatus can be manufactured.

[Brief description of the drawings]

FIG. 1 is a view showing a lower end face of a roller mold manufactured by a method of a second invention when cut along a plane parallel to a cylindrical axis.

FIG. 2 is a view showing a lower end face of a roller mold manufactured by the method of the third invention when cut along a plane parallel to a cylindrical axis.

FIG. 3 is a diagram showing a lower end surface of the roller mold in a state in the middle of manufacture (a) and in a state after completion (b), when cut along a plane parallel to a cylindrical axis according to the method of the fourth invention. is there.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical member 2 Coat layer 3 Unevenness 4 Particulate fluorine resin 5 Particulate matter 6 Hole

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 21/10 B29K 105: 04 4F204 // B29K 105: 04 B29L 31:08 B29L 31:08 G03G 21/00 312 F term (reference) 2H077 AD06 FA01 FA22 FA27 2H134 GA01 HA01 HA17 HA18 KD08 KD12 KE02 KH10 2H200 FA13 HB12 HB22 HB45 HB46 HB47 LC03 MA02 MA08 MA13 MA20 MB01 MC06 3J103 AA01 AA13 AA21 GA12 GA41 HA48 4F202 AA13 AA16 AG03 AG20 AH04 CA01 CB01 CB11 4F204 EA01 EB01 EB11 EB25 EF25 EL01

Claims (10)

[Claims] 1. A roller mold for forming an elastic foam layer on the outer periphery of a rotating shaft by foam molding of a foam-forming material, wherein the inner surface of a cylindrical member has a surface roughness Rz of 20 μm.
A roller mold comprising a fluororesin coating layer having a thickness of over 2000 μm. 2. The roller mold according to claim 1, wherein the surface roughness Rz of the inner surface is more than 20 μm and 200 μm or less. 3. A method for manufacturing a roller mold for forming a foamed elastic layer on the outer periphery of a rotating shaft by foam molding of a foam-forming material, wherein a particle-like fluororesin is dried on an inner surface of a cylindrical member. A method for producing a roller mold, comprising forming a coat layer by spraying. 4. The method according to claim 3, wherein the particulate fluororesin is polytetrafluoroethylene. 5. A method for producing a roller mold for forming a foamed elastic material layer on the outer periphery of a rotating shaft by foam molding of a foam-forming material, the method comprising: A method for manufacturing a roller mold, comprising forming a coat layer by applying and drying a coating material in which a fluorinated resin is dispersed. 6. The method for producing a roller mold according to claim 7, wherein the fluororesin and the particulate fluororesin in the coating material are polytetrafluoroethylene. 7. A method for producing a roller mold for forming a foamed elastic layer on the outer periphery of a rotating shaft by foam molding of a foam-forming material, wherein a solvent solution of a fluororesin is formed on an inner surface of a cylindrical member. After coating and drying a coating material in which a particulate material that is insoluble or hardly soluble in a solvent and that can be eliminated by dissolution or melting is applied and dried, the coated layer is formed by dissolving or dissolving the particulate material. A method for manufacturing a roller mold, comprising: 8. The method according to claim 7, wherein the fluororesin in the coating material is polytetrafluoroethylene and the particulate matter is polystyrene particles, and the particulate matter is dissolved and eliminated with methylene chloride. 9. The coating layer having a surface roughness Rz of 20 to 200.
The method for producing a roller mold according to claim 3, wherein the thickness is 0 μm. 10. The coating layer having a surface roughness Rz of 20 to 20.
The method for producing a roller mold according to claim 3, wherein the thickness is 0 μm.