JP4755787B2 - Method for producing foamed elastic roller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a foamed elastic roller. More specifically, the present invention relates to a foamed elastic roller having a foamed elastic body layer having an arbitrary irregular surface on the surface, which is useful as a toner supply roller used in an image forming apparatus. Thus, the present invention relates to a method for efficiently manufacturing.
[0002]
[Prior art]
In general, image forming apparatuses such as dry electrophotographic apparatuses use a roller having a foamed elastic layer formed on the outer periphery of a rotating shaft, such as a toner supply roller, a developing roller, a transfer roller, a cleaning roller, and a paper feed roller. .
As a method for manufacturing these so-called foamed elastic rollers, an integral foam molding method in which a foam-forming material is poured into a cylindrical foaming mold with a rotating shaft set and foam-cured is excellent in productivity. Therefore, it is generally used.
On the other hand, the foamed elastic roller, particularly the toner supply roller, is often required to have a concavo-convex shape on the surface of the foamed elastic layer in order to improve toner transportability and scraping.
[0003]
In response to such a demand, the inner surface of the foam mold may be formed into a concave and convex shape, and the shape may be shaped on the surface of the foamed elastic layer, so that a concave groove that extends linearly in the roll axis direction is formed on the inner surface. There is also proposed a method using a foaming mold, but the shape is limited because a roller is extruded from a cylindrical foaming mold and the shape is limited. It was not possible to shape the surface.
[0004]
[Problems to be solved by the invention]
Under such circumstances, the present invention provides a method for efficiently producing a foamed elastic roller having a foamed elastic layer having an irregular surface on the surface by an integral foaming method using a foaming mold. It is intended.
[0005]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the inventors of the present invention, when producing a foamed elastic layer roller by in-mold foaming, have a surface before the foamed elastic layer is completely cured by heating. Remove the roller from the foaming mold in a formable state and place it in a split mold for forming with an uneven inner surface, or further heat or heat and humidify after winding the wire around the surface A method of manufacturing a foamed elastic roller characterized by the above.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
In the method of the present invention, a foam roller provided with a rotating shaft and a foamed elastic layer having an irregular surface on its outer periphery and having an irregular surface is manufactured by an integral foam molding method.
The foamed elastic layer in the foam roller is not particularly limited and may be any of polyurethane foam layer, silicone rubber foam layer, EPDM foam layer, etc. A foam layer (a roller in which a polyurethane foam layer is provided on the outer periphery of a rotating shaft is hereinafter referred to as a polyurethane foam roller) is preferable from the viewpoint of performance and the like.
In the production of the polyurethane foam roller, as the polyurethane foam forming material, a material containing a polyol component, a polyisocyanate component, a foaming agent and optionally used conductivity imparting agent, catalyst, foam stabilizer and the like 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.
[0007]
There is no restriction | limiting in particular as a polyol component used for manufacture of a polyol or a prepolymer, Polyether polyol, polyester polyol, hydrophobic polyol, etc. can be mentioned. Here, as the polyether polyol, polyols such as polyols obtained by addition polymerization of ethylene oxide or propylene oxide to glycerin or the like, polytetramethylene glycol, ethylene glycol, propanediol, butanediol and the like are preferably used. Polyester polyols include condensed polyester polyols obtained by condensation of dicarboxylic acids with diols and triols, lactone polyester polyols obtained by ring-opening polymerization of lactones based on diols and triols, and polyether polyols with lactone ends. A polyol such as an ester-modified polyol modified with an ester is preferably used. 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.
[0008]
On the other hand, polyisocyanate components used for the production of polyisocyanates or prepolymers include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), crude diphenylmethane diisocyanate (crude MDI), isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate; Diisocyanate; polyisocyanates having no unsaturated bond such as hexamethylene diisocyanate, and their modified products by isocyanurate, carbodiimide, glycol, and the like. These polyisocyanate components may be used singly or in combination of two or more.
[0009]
Next, as the foaming agent, a physical foaming agent generally having a boiling point in the range of 20 to 60 ° C. is preferably used in consideration of ease of handling in the production process, ease of vaporization and foaming. When this foaming agent is used as a raw material for polyurethane foam, the foaming agent alone has a low viscosity, and it is difficult to obtain a stable flow rate with a foaming machine. It is advantageous.
Examples of such foaming agents include n-pentane, isopentane, cyclopentane, methylene chloride, Freon 134a (1,1,1,2-tetrafluoroethane), Freon 245fa (1,1,1,3,3- Pentafluoropropane), Freon 365mfc (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), water and the like. These may be used alone or in combination of two or more.
[0010]
Next, in the polyurethane foam forming material of the present invention, examples of the conductivity imparting agent used as desired 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. Examples of ionic conductive agents include dodecyltrimethylammonium such as tetraethylammonium, tetrabutylammonium, and lauryltrimethylammonium, octadecyltrimethylammonium such as stearyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium, and modified aliphatic dimethylethylammonium. Ammonium salts such as chlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, sulfate, alkyl sulfate, carboxylate, sulfonate; lithium, sodium, calcium, Perchlorate, chlorate, hydrochloride, bromate, iodate, borofluoride, trifluoromethyl sulfate, sulfo of alkali metal or alkaline earth metal such as magnesium Such as salts, and the like.
[0011]
These conductivity-imparting agents may be used singly or in combination of two or more. Further, the blending amount thereof is not particularly limited and is appropriately selected according to various situations. Usually, it is 0.1 to 40 parts by weight, preferably 0.3 to 20 parts by weight with respect to 100 parts by weight of the polymer material. It is blended at a ratio of Moreover, filler-type conductive agents, such as a metal powder and a metal oxide powder, can be added with said carbon black and an ionic conductive agent.
Further, in the polyurethane foam-forming material, the catalyst used as desired includes, for example, organometallic catalysts such as dibutyltin dilaurate, dibutyltin diacetate, stannous octoate, dibutyltin marker butylide, dibutyltin thiocarboxylate, dibutyltin dimaleate. Neat, dioctyltin marker butyl, 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 or in combination of two or more.
[0012]
Further, in the polyurethane foam-forming material, the foam stabilizer used as desired includes, for example, polyether silicone oil, nonionic surfactant, ionic surfactant and the like, and these may be used alone. Two or more kinds may be used in combination.
In the method of the present invention, a cylindrical mold made of resin, ceramics or metal is suitable as the foaming mold. In the case of using a resin foam mold, one having resistance to the foam-forming material cast therein is used. When the foam-forming material is the polyurethane foam-forming material, the resin-based foam mold is preferably a foam mold made of, for example, polypropylene or polyethylene.
In addition, the foaming mold which coat | covered the fluororesin on the inner surface has the effect which prevents that a skin layer remains on the surface of a foaming elastic body, and can be used suitably also in the method of this invention.
Examples of the rotating shaft include a metal member obtained by plating a steel material such as sulfur free-cutting steel with zinc or the like, and a metal member such as aluminum, stainless steel, or magnesium alloy.
[0013]
Next, the manufacturing method of the foam roller of this invention is demonstrated based on FIG.
FIG. 1 shows the process in the present invention until the final product is obtained by taking out the roller from the foaming mold, putting it in a split mold for shaping, and further heating or heating and humidifying. It is sectional drawing in a surface orthogonal to.
(1) is a roller taken out from the foaming mold, 1 represents a rotating shaft, and 2 represents a foamed elastic layer.
The roller (1) is placed in a split mold having an uneven inner surface made of 3a and 3b, as in (2), and heating or heating and humidification are performed as the state (3). I do.
The roller can be easily taken out by opening the split mold, and a foamed elastic body roller having a concavo-convex shape on the surface as shown in (4) is obtained.
The uneven shape on the inner surface of the split mold for shaping can be any shape according to requirements.
FIG. 2 is a plan view showing an example of a foamed elastic roller obtained by the method of the present invention, and can have various shapes such as (a), (b), (c) and (d).
[0014]
1 will be described. First, after setting the rotating shaft in the foaming mold, a predetermined amount of the foam-forming material is cast, and usually 15 to 110 ° C., preferably 20 to Initiate foaming of the foam-forming material at a temperature in the range of 100 ° C. After the void in the mold is filled with the foam, heating is started.
A chemical reaction occurs with heating and curing begins, but the roll is taken out from the foaming mold in the middle of the process to obtain the state of (1) in FIG.
If the curing in the foaming mold proceeds excessively, it will not be shaped even if it is put into a split mold and then heated. Therefore, in the state where the surface can be shaped, the curing rate in the foaming mold is preferably 70. In a state where it becomes ˜95%, it is necessary to take out the roller from the foaming mold. From the viewpoint of operability such as ease of demolding from the foaming mold, it is particularly preferable to take out from the foaming mold when the curing rate is 80 to 90%.
The curing rate is the ratio of the tensile strength measured according to JIS K 6400 to the tensile strength of the completely cured foamed elastic layer, and the cure rate of the completely cured foamed elastic layer is 100. %.
The heating temperature in the foaming mold and the split mold is suitably 40 to 120 ° C.
In addition, when heating in the split mold, the reaction can be accelerated by performing humidification at the same time.
[0015]
【Example】
EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.
Example 1
(1) 70 parts by weight of a polyether polyol having an average molecular weight of 5000 and 3 functional groups, (2) 30 parts by weight of a styrene graft type polymer polyol, (3) 0.3 parts by weight of triethylenediamine, (4) N-methylmorpholine 0.2 parts by weight, (5) 1.5 parts by weight of water, (6) 1.5 parts by weight of silicone foam stabilizer, and (7) isocyanate having a weight ratio of TDI-80 / polymeric MDI of 50/50, index 105 A polyurethane foam-forming material was prepared by blending in such an amount as follows.
This polyurethane foam-forming material started foaming in 10 seconds at a temperature of 25 ° C. after stirring and injecting in a free foaming experiment performed in a cup separately, and finished foaming in 90 seconds. The density at that time was 0.10 g / ml.
An iron rotating shaft (diameter 6 mm, length 260 mm) is set in a cylindrical stainless steel foaming mold having an inner diameter of 18 mm and a length of 250 mm, and 6.5 g of the polyurethane foam forming material is injected from the foaming machine. And foamed at 25 ° C. for 90 seconds.
Thereafter, heating was started at 90 ° C., and when 10 minutes had elapsed, the roller was removed from the mold, immediately placed in a split mold, and further heated at 100 ° C. for 20 minutes.
The degree of cure of the foamed elastic body when it is removed from the foaming mold is 88%, and a large number of ridge grooves having a height of 300 μm and a pitch in the roll axis direction of 1500 μm are formed on the inner surface of the split mold. Has been.
When the split was opened and the roller was taken out, a polyurethane foamed elastic roller with a shaft having a concavo-convex shape as shown in FIG. 2B on the surface was obtained.
This foamed elastic roller was suitable for an image forming apparatus.
[0016]
Example 2
The foamed elastic roller was obtained in the same manner as in the Example except that the removed roller was placed in a split mold and heated at 50 ° C. for 10 minutes under a humidity of 85%. It was suitable for.
[0017]
【The invention's effect】
By using the roller mold of the present invention and the roller mold manufactured by the method of the present invention, it is possible to manufacture a foamed elastic roller roller having an arbitrary uneven shape on the surface, which is suitable for an image forming apparatus.
[Brief description of the drawings]
In the method of the present invention, a roll showing a process from taking out a roller from a foaming mold, putting it into a split mold for shaping, and further heating or heating and humidifying to obtain a final product. It is sectional drawing in the surface orthogonal to an axial direction.
FIG. 2 is a plan view showing an example of a foamed elastic roller obtained by the method of the present invention.
[Explanation of symbols]
1 Rotating shaft 2 Elastic foam layers 3a, 3b

Claims (7)

When manufacturing a roller having a foamed elastic layer provided on the outer periphery of the rotating shaft by a method in which the rotating shaft is set in a foaming mold, the foam-forming material is cast and foamed, and then heated and cured, Before the curing of the foamed elastic layer is completed, the roller is removed from the foaming mold in a state where the surface can be shaped, and placed in a split mold for shaping having an uneven inner surface, and further heated or heated. And a method of manufacturing a foamed elastic roller characterized by performing humidification. When manufacturing a roller having a foamed elastic layer provided on the outer periphery of the rotating shaft by a method in which the rotating shaft is set in a foaming mold, the foam-forming material is cast and foamed, and then heated and cured, The roller is removed from the foaming mold in a state where the surface can be shaped before the foamed elastic body layer is cured by heating, and after the wire is wound around the surface, heating or heating and humidification are further performed. A method for producing a foamed elastic roller. Curing rate of the foamed elastic layer (the ratio of the tensile strength measured according to JIS K 6400 to the tensile strength of the completely cured foamed elastic layer, and the curing rate of the completely cured foamed elastic layer) 3. The method for producing a foamed elastic body roller according to claim 1, wherein the foamed elastic body roller is taken out from the foaming mold in a state where the ratio is 70 to 95%. 4. The method for producing a foamed elastic body roller according to claim 3, wherein the foamed elastic body layer is taken out from the foaming mold in a state where the curing rate of the foamed elastic body layer is 80 to 90%. The method for producing a foamed elastic roller according to claim 1 or 2, wherein heating at a temperature of 40 to 120 ° C or heating at a temperature of 30 to 60 ° C and humidification at a humidity of 80 to 95% are performed. The method for producing a foam elastic body roller according to claim 1 or 2, wherein the foam elastic body layer is a polyurethane foam layer. The method for producing a foamed elastic roller according to any one of claims 1 to 6, wherein the foamed elastic roller is a toner supply roller.

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