JP6083739B2 - Conductive roller, manufacturing method thereof, developing device, and image forming apparatus - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive roller, a manufacturing method thereof, a developing device, and an image forming apparatus, and more specifically, a conductive roller that hardly contaminates the environment with a volatile organic compound, a manufacturing method thereof, and a contaminated environment with a volatile organic compound. The present invention relates to a developing device and an image forming apparatus that are less likely to occur.

  Blue Angel is a kind of eco-label and is an important indicator for knowing the attitude of products and companies that consider environmental protection to the environment. The blue angel ecolabel is affixed to environmentally friendly products in Germany. In Japan, the Eco Mark is attached to products that consider environmental conservation. The blue angel pioneered the Japanese Eco Mark and became a model.

  Thus, in Germany and Japan, awareness of the environmental impact of manufactured products is increasing, and it is expected that demand for environmentally friendly products will increase in other countries in the future.

  Therefore, products exported from Japan to each country are strongly required to conform to the Blue Angel standard that does not adversely affect the environment.

  Copiers (copiers) are subject to Blue Angel. Blue Angel requires that the amount of volatile organic compounds (VOC) emitted from the entire copier be reduced. The VOC discharged from the entire copying machine is the total VOC discharged from each part of the copying machine.

  Patent Document 1 states that “in a roller for a fixing device in which at least one silicone sponge elastic body layer is provided around a shaft body, the silicone sponge elastic body layer uses a dispersion accelerator that does not contain a phenyl group as a dispersion accelerator for a filler. And a fixing roller characterized by using a silicone sponge obtained by vulcanizing and foaming a thermosetting silicone rubber composition based on a diorganopolysiloxane that does not contain a phenyl group. Aiming to reduce the amount of VOC discharged from the rollers, as a result, “benzene is applied to the silicone sponge elastic body provided on the shaft peripheral surface of the fixing unit roller of the heat fixing device used in copying machines, printers, facsimiles, etc. Since a silicone sponge that does not occur is used, the use of this OA device It is possible to suppress the occurrence of benzene from wearing dexterity roller, it is possible to suppress the deterioration of the environment "is (see paragraph number 0014 of Patent Document 1).

  Patent Document 2 relates to “an apparatus for removing VOC (volatile organic compound) generated in an image forming apparatus such as a copying machine or a printer” (see Paragraph No. 0001 of Patent Document 2). An airflow formed to flow in a horizontal direction, and a device having a noise source therein, is arranged so as to block the airflow and removes a predetermined substance contained in the air and has a sound absorbing effect And an apparatus in which the plate-like filter is disposed so as to be horizontal to the outer wall and between the noise source and the outer wall "(see claim 1 of Patent Document 2) To do.

  The invention described in Patent Document 1 is characterized in that a dispersion accelerator containing no phenyl group is used in order to reduce the amount of VOC discharged from the fixing device roller, such as benzene. The invention according to the present invention is characterized in that a special filter for removing generated VOC is attached.

  Patent Document 3 states that “the environment in which carbon black is uniformly dispersed by suppressing the entrainment of bubbles due to the thickening of the urethane raw material at the initial stage of the urethane reaction and curing the urethane before the carbon black is re-aggregated by heating. The object is to provide a conductive roll with little dependency ”(see paragraph No. 0006 of Patent Document 3).“ •• The conductive elastic layer comprises at least a polyol mainly composed of a polyether polyol and a diisocyanate. , A conductive roll obtained by reacting a tetravalent organotin compound having a tin content of 18.7% by weight or less as a catalyst. "(See claim 1 of Patent Document 3) Has been.

In Patent Document 4, an object is to provide “a method for producing a polyurethane foam roller having stable hardness and excellent surface properties” (see paragraph No. 0008 of Patent Document 4). A polyurethane foam roller comprising a step of molding a polyurethane foam layer using a mold that supports both ends, and firing, curing and releasing the raw material components in the cylindrical mold and then crushing the polyurethane foam layer. In the production method, after the crushing treatment, aging is performed for 10 minutes to 10 hours at 15 to 80 ° C. in an environment of 5 to 40 g / m ^{3 of} water vapor, and drying is performed for 5 minutes to 5 hours at 80 to 300 ° C. A process for producing a polyurethane foam roller characterized in that it is performed "(see claim 1 of Patent Document 4) is disclosed.

  The invention in Patent Document 3 is characterized in that a conductive elastic layer is formed by reacting a polyol and a diisocyanate using an organotin compound as a catalyst. In the invention in Patent Document 4, a polyurethane foam layer is provided. The raw material component to be formed is characterized by performing aging treatment and drying treatment after firing, curing and demolding in a cylindrical mold, crushing treatment.

JP 2006-350118 A JP 2011-17895 A Japanese Patent No. 4730766 Japanese Patent No. 4807869

  The present invention provides a conductive roller capable of reducing the discharge amount of VOC from the conductive roller despite the fact that it is a conductive roller obtained using a substance causing VOC, It is an object of the present invention to provide a method for manufacturing such a conductive roller, and to provide a developing device and an image forming apparatus using the conductive roller that emits less VOC.

Means for solving the problems are as follows:
(1) A conductive roller comprising an elastic layer formed on an outer peripheral surface of a shaft body and a urethane coat layer formed by applying urethane resin to the outer peripheral surface of the elastic layer,
A conductive roller characterized in that the amount of volatile organic compounds released from the conductive roller is 100,000 μg / m ³ or less,
(2) The conductive roller according to (1), wherein the volatile organic compound released from the conductive roller is butyl acetate,
(3) A method for producing a conductive roller comprising: an elastic layer formed on an outer peripheral surface of a shaft body; and a urethane coat layer formed by applying urethane resin to the outer peripheral surface of the elastic layer,
The urethane coat layer formed on the outer peripheral surface of the elastic layer is heated at 120 to 170 ° C. for 15 minutes to 2 hours, and then allowed to stand at room temperature for 4 to 72 hours, and then 120 to 170 ° C. It is a manufacturing method of a conductive roller characterized by heating for 15 minutes to 2 hours,
(4) A developing device comprising the conductive roller according to (1) or (2),
(5) An image forming apparatus comprising the developing device according to (4).

  According to the present invention, it is possible to provide a conductive roller that emits less volatile organic compound (VOC), particularly butyl acetate, and provides a method of manufacturing a conductive roller that emits less VOC. By providing the conductive roller according to the present invention, it is possible to provide a developing device with a small amount of VOC released from the developing device itself, and to incorporate a developing device with a small amount of VOC released. Therefore, it is possible to provide an image forming apparatus with a reduced VOC emission amount as a whole.

FIG. 1 is a perspective view showing an example of a conductive roller according to the present invention. FIG. 2 is a schematic view showing an example of an image forming apparatus according to the present invention.

  For example, as shown in FIG. 1, the developing roller according to the present invention includes an elastic layer 3 formed on the outer peripheral surface of the shaft body, and a urethane coat layer 4 formed of urethane resin on the outer peripheral surface of the elastic layer 3. And comprising.

In this conductive roller 1, the amount of volatile organic compound (VOC) released therefrom is 100,000 μg / m ³ or less, particularly 50,000 μg / m ³ or less.

The amount of VOC released can be measured, for example, as follows.
In this conductive roller 1, the diameter of the shaft body 2 is 7.5 mm, the shaft core length is 280 mm, the diameter of the elastic layer 3 is 16 mm, the shaft core length is 230 mm, and the thickness of the urethane coat layer 4 is 20 μm. .

  First, one conductive roller having the above dimensions is used as a simple gas collection bag (for example, a smart bag PA manufactured by GL Science Co., Ltd., an internal volume of 10 L) (hereinafter referred to as “collection bag”). Store. Next, the collection bag containing the conductive roller is placed in a heating apparatus heated to 50 ° C. and held for 2 hours, and the gas discharged from the conductive roller is filled in the collection bag. After the elapse of 2 hours, the collection bag is taken out from the heating device, and the collection bag is opened at one end of an adsorption tube (for example, Tenax TA, particle size 60/80 mesh, filling amount 150 mg, manufactured by GL Sciences Inc.). And attach the other end opening of the adsorption tube to the metering pump. The metering pump is driven to introduce the collection gas in the collection bag into the adsorption tube at a suction speed of 100 mL / min, and the gas in the collection bag is adsorbed by the adsorbent in the adsorption tube.

  Next, an adsorption tube having an adsorbent that has adsorbed the collected gas is loaded into a heat desorption apparatus and heated to desorb the collected gas adsorbed by the adsorbent. The desorbed collected gas is introduced into a cooled cold trap and temporarily held, and then the cold trap is rapidly heated to re-desorb the collected gas held in the cold trap. The re-desorbed collected gas is introduced into a column in the gas chromatograph apparatus, and the volatile organic compound (VOC) is quantitatively analyzed.

  Examples of the volatile organic compound (VOC) include hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and tetradecamethyl. When quantitatively analyzing low-molecular cyclic siloxanes such as cycloheptasiloxane (D7) and butyl acetate, for example, VOC gas can be quantitatively analyzed with the following apparatus and conditions.

  In the following gas chromatograph, in the process in which the collected gas passes through the column, the components in the collected gas travel through the column at different rates depending on the size of each molecule, and are separated into individual components. Are sequentially introduced into the mass spectrometer. The individual components of the trapped gas introduced into the mass spectrometer are ionized, and the number of ions for each specific mass / charge ratio is displayed as a mass spectrum pattern and compared with the mass spectrum pattern of a known substance. Thus, the qualitative analysis of the components of the collected gas can be performed. Moreover, quantitative analysis can be performed by preparing a calibration curve in advance using a known substance and a standard substance having a known concentration.

Thermal desorption device: Perkin Elmer, Turbo Matrix ATD
Heat desorption condition: set temperature 270 ° C. Heating time 15 minutes Cold trap condition: −10 ° C.
Analyzer: Shimadzu Corporation gas chromatograph GC-MS QP-2010plus
Column: Agilent Technology Co., Ltd. micropolar column DB-5ms
Length 30m, inner diameter 0.32mm, film thickness 0.25μm
Measurement temperature: heating to 40 ° C. for 5 minutes, then to 300 ° C. at a heating rate of 10 ° C./min,
Heat at 300 ° C. for 4 minutes.

Detector voltage: 0.5-1 kV
Split ratio: 50-5000

When the discharge amount of VOC discharged by the conductive roller according to the present invention is 100,000 μg / m ³ or less, the conductive roller can reduce the load on the environment.

The measurement of the amount of VOC released by the conductive roller may be at the latest when the conductive roller is manufactured and shipped. Further, it may be the time when the conductive roller is completed in the manufacturing process of the conductive roller. If the discharge amount of VOC measured at the time when the conductive roller is completed is 100,000 μg / m ³ or less, the discharge amount of VOC further decreases with the passage of time to the shipping stage. There is no need to measure the amount released.

  An example of the conductive roller according to the present invention will be described. As shown in FIG. 1, the conductive roller as an example of the conductive roller according to the present invention includes a shaft body 2, an elastic layer 3 formed on the outer peripheral surface of the shaft body 2, and an outer peripheral surface of the elastic layer 3. And a urethane coat layer 4 formed on the surface.

  The shaft body 2 is basically the same as the shaft body in a conventionally known conductive roller. The shaft body 2 is a so-called “core metal” composed of iron, aluminum, stainless steel, brass, or the like, and has good conductive characteristics. The shaft body 2 may be a shaft body made conductive by plating an insulating core body such as a thermoplastic resin or a thermosetting resin.

  The elastic layer 3 is basically the same as the elastic layer in a conventionally known conductive roller. The elastic layer 3 is formed by curing a conductive composition described later on the outer peripheral surface of the shaft body 2, and preferably has a JIS A hardness of 20 to 70. When the elastic layer 3 has a JIS A hardness (JIS K6301) of 20 to 70, the contact area between the conductive roller 1 and the contacted body can be increased, and the resilience and compression of the elastic layer 3 can be increased. Excellent permanent set.

The elastic layer 3 preferably has a volume resistivity in the range of 10 ¹ to 10 ⁷ Ω · cm and / or an electrical resistivity in the range of 10 ¹ to 10 ⁹ Ω. When the volume resistivity and / or the electrical resistivity of the elastic layer 3 are within the above ranges, the developer is supported and supplied as desired when the conductive roller 1 is mounted on the image forming apparatus, and the desired quality is obtained. It is possible to contribute to forming an image having The volume resistivity can be measured according to a method defined in JIS K6911 (applied voltage is 100 V). The electrical resistivity is measured by, for example, using an electrical resistance meter (trade name: ULTRA HIGH RESISTANCE METER R8340A, manufactured by Advantest Co., Ltd.), placing the conductive roller 1 horizontally, a thickness of 5 mm, a width of 30 mm, and conductivity. The shaft body 2 is made such that a gold-plated plate having a length on which the entire elastic layer 3 of the conductive roller 1 can be placed is used as an electrode, and a load of 500 g is supported on both ends of the shaft body 2 in the conductive roller 1. DC100V is applied between the electrode and the electrode, the value of the electric resistance meter after 1 second is read, and this value can be measured in accordance with a method for setting the electric resistance value.

  The thickness of the elastic layer 3 is preferably 1 mm or more in that a uniform nip width between the contacted body and the elastic layer 3 can be secured in the contact state with the contacted body. It is especially preferable that it is 4 mm or more. On the other hand, the upper limit of the thickness of the elastic layer 3 is not particularly limited as long as the outer diameter accuracy of the elastic layer 3 is not impaired. Generally, if the thickness of the elastic layer 3 is excessively increased, the production cost of the elastic layer 3 increases. In consideration of practical production costs, the thickness of the elastic layer 3 is preferably 30 mm or less, and more preferably 20 mm or less. The thickness of the elastic layer 3 is appropriately selected according to the hardness of the elastic layer 3, such as JIS A hardness, in order to achieve a desired nip width.

  The conductive composition forming the elastic layer 3 contains rubber, a conductivity imparting agent, and various additives as desired. Examples of the rubber include silicone or silicone-modified rubber, nitrile rubber, ethylene propylene rubber (including ethylene propylene diene rubber), styrene butadiene rubber, butadiene rubber, isoprene rubber, natural rubber, acrylic rubber, chloroprene rubber, butyl rubber, and epichlorohydrin. Examples thereof include rubbers such as rubber, urethane rubber, and fluorine rubber. Silicone or silicone-modified rubber or urethane rubber is preferable, and silicone or silicone-modified rubber is particularly preferable in terms of excellent heat resistance and charging characteristics. These rubbers may be liquid or millable. The electroconductivity imparting agent is not particularly limited as long as it has electroconductivity, and examples thereof include electroconductive powder such as electroconductive carbon, carbon for rubber, metal, and electroconductive polymer. Various additives include, for example, auxiliary agents such as chain extenders and crosslinking agents, catalysts, dispersants, foaming agents, anti-aging agents, antioxidants, fillers, pigments, colorants, processing aids, softening agents, Examples thereof include a plasticizer, an emulsifier, a heat resistance improver, a flame retardant improver, an acid acceptor, a heat conductivity improver, a release agent, and a solvent.

Preferred examples of the conductive composition include addition curable millable conductive silicone rubber compositions and addition curable liquid conductive silicone rubber compositions. This addition-curable millable conductive silicone rubber composition has (A) average composition formula: R _n SiO _{(4-n) / 2} (R may be the same or different, substituted or unsubstituted monovalent carbonization A hydrogen group, preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, more preferably 1 to 8 carbon atoms, and n is a positive number of 1.95 to 2.05). It contains a polysiloxane, (B) a filler, and (C) a conductive material other than those belonging to the component (B). These components (A) to (C) are basically the same as the components in the “addition-curable millable conductive silicone rubber composition” described in, for example, JP-A-2008-058622. The addition-curable liquid conductive silicone rubber composition comprises (D) an organopolysiloxane containing at least two alkenyl groups bonded to silicon atoms in one molecule, and (E) bonded to silicon atoms in one molecule. An organohydrogenpolysiloxane containing at least two hydrogen atoms; (F) an inorganic filler having an average particle size of 1 to 30 μm and a bulk density of 0.1 to 0.5 g / cm ³ ; and (G) a conductive material. An addition-curable liquid conductive silicone rubber composition containing a property-imparting agent and (H) an addition reaction catalyst. These components (D) to (H) are basically the same as the components in the “addition-curable liquid conductive silicone rubber composition” described in JP-A-2008-058622, for example.

  The urethane coat layer 4 is formed as an outermost layer of the conductive roller 1 with a layer thickness of preferably 0.1 to 50 μm, more preferably 10 to 25 μm. This urethane coat layer is formed by curing urethane resin on the outer peripheral surface of the elastic layer 3.

  The suitable urethane coat layer 4 may contain various additives ordinarily used in various urethane resin compositions, if desired, in addition to the urethane resin. As such an additive, for example, a conductivity imparting agent such as carbon black, and other components such as an auxiliary agent in the urethane resin composition described later may be contained as optional components. The urethane coat layer 4 does not substantially contain “binder resin and conductive resin particles dispersed in the binder resin” described in JP-A-2005-315979. Here, “substantially does not contain” means not only the case where the conductive resin particles are not contained in the urethane coat layer 4 at all, but also a trace amount, for example, 100 mass of urethane resin. The case where it is contained at 5 parts by mass or less with respect to parts is also included. When the urethane coat layer 4 contains carbon black, the DBP adsorption amount of the carbon black is preferably less than 100 mL / 100 g. This DBP adsorption amount can be measured according to JIS K6217-4.

  The urethane resin contained in the urethane coat layer 4, that is, the urethane resin serving as a base resin for forming the urethane coat layer 4 may be a known urethane resin, and is usually obtained from a polyol and a polyisocyanate. The polyol is preferably a polyester polyol or a polyether polyol. Examples of the polyisocyanate include aliphatic polyisocyanates and aromatic polyisocyanates.

  The urethane resin composition that forms the urethane coat layer 4 contains a urethane adjusting component that is a precursor for forming a urethane resin, and various additives as desired. Therefore, the urethane coat layer 4 is formed by applying and curing a urethane resin composition containing a urethane adjusting component and optionally various additives on the outer peripheral surface of the elastic layer 3.

  The urethane adjusting component may be any component that can form polyurethane, and examples thereof include a mixture of a polyol and an isocyanate.

  The polyol may be any of various polyols usually used for preparing polyurethanes, preferably having at least two hydroxyl groups in the molecule. Such a polyol is preferably at least one polyol selected from polyether polyols and polyester polyols. The polyol is preferably a diol, and therefore more preferably a polyester diol or a polyether diol, and particularly preferably a polyester diol.

  Examples of the polyether polyol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, and polypropylene glycol-ethylene glycol, polytetramethylene ether glycol, copolymer polyols of tetrahydrofuran and alkylene oxide, and various modified products thereof. And the like. Examples of the polyester polyol include condensation-type polyester polyols, lactone-type polyester polyols, polycarbonate polyols, and mixtures thereof obtained by condensation of dicarboxylic acids such as adipic acid and polyols such as ethylene glycol and hexanediol. It is done. The polyether polyol and the polyester polyol may be used alone or in combination of two or more, or a polyether polyol and a polyester polyol may be used in combination. The polyol is preferably a polyester polyol because it is excellent in thermal stability. The polyol preferably has a number average molecular weight of 1000 to 8000, more preferably 1000 to 5000, and more preferably 800 to 15000 in terms of excellent compatibility with polyisocyanate and the like described later. It preferably has an average molecular weight, and more preferably has a number average molecular weight of 1000 to 5000. The number average molecular weight is a molecular weight when converted to standard polystyrene by gel permeation chromatography (GPC).

  The polyisocyanate may be any of various polyisocyanates usually used in the preparation of polyurethane having at least two isocyanate groups in the molecule, and examples thereof include aliphatic polyisocyanates, aromatic polyisocyanates and these polyisocyanates. Derivatives and the like. The polyisocyanate is preferably an aliphatic polyisocyanate, preferably a diisocyanate, in view of excellent storage stability and easy control of the reaction rate, and also after a long period of standby or shutdown of the image forming apparatus. In addition, an aliphatic polyisocyanate is preferable in that a high-quality image can be formed even in a low humidity environment, and therefore an aliphatic diisocyanate is particularly preferable.

  Examples of the aromatic polyisocyanate include xylylene diisocyanate (XDI), diphenylmethane diisocyanate (MDI), toluene diisocyanate (also referred to as tolylene diisocyanate, TDI), 3,3′-bitolylene-4,4′-diisocyanate, 3 , 3′-dimethyldiphenylmethane-4,4′-diisocyanate, 2,4-tolylene diisocyanate uretidinedione (a dimer of 2,4-TDI), xylene diisocyanate, naphthalene diisocyanate (NDI), paraphenylene diisocyanate (PDI) ), Tolidine diisocyanate (TODI), metaphenylene diisocyanate and the like. Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), orthotoluidine diisocyanate, lysine diisocyanate methyl ester, isophorone diisocyanate (IPDI), norbornane diisocyanate methyl, trans Examples include cyclohexane-1,4-diisocyanate and triphenylmethane-4,4 ′, 4 ″ -triisocyanate. Examples of the derivatives include polynuclear polyisocyanates, urethane-modified products modified with polyols (including urethane prepolymers), dimers formed by uretidione formation, isocyanurate-modified products, carbodiimide-modified products, uretonimine-modified products, and allophanate-modified products. Products, urea-modified products, and burette-modified products. Polyisocyanate can be used alone or in combination of two or more. The polyisocyanate preferably has a molecular weight of 500 to 2000, more preferably 700 to 1500.

  When the polyol and the polyisocyanate are contained, the mixing ratio of the polyol and the polyisocyanate is not particularly limited, but the number of moles of the hydroxyl group (OH) contained in the polyol and the isocyanate group ( The ratio [NCO / OH] to the number of moles of (NCO) is preferably 0.7 to 1.15. This ratio [NCO / OH] is more preferably 0.85 to 1.10 in that the hydrolysis of the polyurethane can be prevented. However, in practice, an amount corresponding to 3 to 4 times the appropriate molar ratio may be blended in consideration of work environment and work errors.

  In the urethane resin composition, in addition to the urethane adjusting component, an auxiliary agent usually used in the reaction between the polyol and the polyisocyanate, for example, a chain extender or a crosslinking agent may be used in combination. Examples of chain extenders and crosslinking agents include glycols, hexanetriol, trimethylolpropane, and amines.

  The urethane resin composition is obtained by mixing a urethane adjusting component and, if desired, a solvent, an auxiliary agent and the like by an appropriate method. Examples of the solvent include alcohols such as methanol and ethanol, aromatic solvents such as xylene and toluene, volatile solvents such as ester solvents such as ethyl acetate and butyl acetate, and water.

  A method for manufacturing a conductive roller according to the present invention will be described below by taking the conductive roller 1 as an example.

  The conductive roller 1 is manufactured by forming the elastic layer 3 on the outer peripheral surface of the shaft body 2 and further forming the urethane coat layer 4 on the outer peripheral surface of the elastic layer 3. In order to manufacture the conductive roller 1, first, the shaft body 2 is prepared. For example, the shaft body 2 is prepared in a desired shape by a known method. The shaft body 2 may be coated with a primer before the elastic layer 3 is formed. Although there is no restriction | limiting in particular as a primer apply | coated to the shaft body 2, The resin similar to the material which forms the primer layer which adhere | attaches or closely_contact | adheres the elastic layer 3 and the urethane coat layer 4, and a crosslinking agent are mentioned. The primer is dissolved in a solvent or the like as desired, and is applied to the outer peripheral surface of the shaft body according to a conventional method such as a dipping method or a spray method.

  The elastic layer 3 is formed by heat curing the conductive composition on the outer peripheral surface of the shaft body 2. For example, the elastic layer 3 is formed on the outer peripheral surface of the shaft body 2 by performing heat curing and molding simultaneously or continuously by a known molding method. The method for curing the conductive composition may be any method that can apply heat necessary for curing the conductive composition, and the method for forming the elastic layer 3 may be continuous vulcanization by extrusion, pressing, molding by injection, etc. There is no particular limitation. For example, when the conductive composition is an addition curable millable conductive silicone rubber composition, for example, extrusion molding or the like can be selected, and the conductive composition is an addition curable liquid conductive silicone rubber composition. In this case, for example, a molding method using a mold can be selected. The heating temperature for curing the conductive composition is 100 to 500 ° C., particularly 120 to 300 ° C., in the case of an addition-curable millable conductive silicone rubber composition, and the time is several seconds to 1 hour, particularly 10 seconds or more. ~ 35 minutes or less is preferable, and in the case of an addition-curable liquid conductive silicone rubber composition, it is 100 to 300 ° C, particularly 110 to 200 ° C, and the time is 5 minutes to 5 hours, particularly 1 to 3 hours. Is preferred. In addition, in the case of an addition-curable millable conductive silicone rubber composition, the curing conditions are about 100 to 200 ° C. for about 1 to 20 hours, and in the case of an addition-curable liquid conductive silicone rubber composition, 120 Secondary vulcanization may be carried out at about 250 ° C. under curing conditions for about 2 to 70 hours. In addition, the conductive composition can be foamed and cured by a known method to easily form a sponge-like elastic layer having bubbles.

  The elastic layer 3 formed in this way has its surface polished and ground as desired to adjust the outer diameter, surface state, and the like. Further, the primer layer may be formed on the elastic layer 3 formed in this way before the urethane coat layer 4 is formed.

  The urethane coat layer 4 is formed by coating the urethane resin composition on the outer peripheral surface of the elastic layer 3 thus formed or the primer layer formed as desired, and then applying the urethane resin composition. An object is formed by heat curing or moisture curing. The application of the urethane resin composition is, for example, a coating method of coating a urethane resin composition coating solution, a dipping method of immersing the elastic layer 3 or the like in the coating solution, or spraying the coating solution onto the elastic layer 3 or the like. It is performed by a known coating method such as a spray coating method. The urethane resin composition may be applied as it is, or applied to the urethane resin composition, for example, alcohols such as methanol and ethanol, aromatic solvents such as xylene and toluene, and ester solvents such as ethyl acetate and butyl acetate. You may apply the coating liquid which added volatile solvents, such as these, or water. The urethane resin composition thus coated may be cured by any method that can add heat or moisture necessary for curing the urethane resin composition. For example, the urethane resin composition is coated. And a method of heating the elastic layer 3 and the like with a heater, a method of leaving the elastic layer 3 and the like coated with the urethane resin composition under high humidity, and the like. The heating temperature when the urethane resin composition is heat-cured is, for example, 100 to 200 ° C., particularly 120 to 160 ° C., and the heating time is preferably 10 to 120 minutes, particularly preferably 30 to 60 minutes. Instead of the coating, the urethane resin composition is laminated on the outer peripheral surface of the elastic layer 3 or the primer layer by a known molding method such as extrusion molding, press molding, injection molding or the like, or after the lamination. A method of curing the laminated urethane resin composition or the like can be employed.

  In the method for manufacturing a conductive roller according to the present invention, after the conductive roller is manufactured as described above, primary drying is performed by heating the conductive roller at 120 to 170 ° C. for 15 minutes to 2 hours. Then, the heating is stopped and the mixture is left at room temperature for 4 to 72 hours, and then subjected to secondary drying in which heating is performed at 120 to 170 ° C. for 15 minutes to 2 hours.

  There is no restriction | limiting in particular as the heating method in the said primary drying, For example, the nichrome wire etc. which red-heated by the heating dryer, the dryer, and electricity supply can be mentioned.

  During the primary drying period, volatile organic compounds such as butyl acetate and low molecular weight siloxane present in the elastic layer and the urethane coat layer of the conductive roller move through the elastic layer and the urethane coat layer. It diffuses from the surface to the outside of the urethane coat layer. As a result, there is a concentration gradient in which the concentration of the volatile organic compound decreases from the portion close to the shaft body of each of the elastic layer and the urethane coat layer, that is, from the deep portion in the elastic layer and the urethane coat layer toward the surface of the urethane coat layer. Occur.

  Heating is stopped after 15 minutes to 2 hours of primary drying, and if left at room temperature for 4 to 72 hours, it exists in the deep part of each elastic layer and urethane coat layer during the heating stop period. The volatile organic compound that has been diffused to the surface of the urethane coat layer disappears, or the concentration gradient of the volatile organic compound disappears or becomes smaller in each of the elastic layer and the urethane coat layer. In other words, there is almost no difference between the concentration of the volatile organic compound in the deep part of each of the elastic layer and the urethane coat layer and the concentration of the volatile organic compound in the part close to the surface of the urethane coat layer. Become. The concentration of the volatile organic compound in each of the elastic layer and the urethane coat layer after stopping the heating for 4 to 72 hours is much higher than the concentration of the volatile organic compound in each of the elastic layer and the urethane coat layer immediately before the primary drying. It has dropped to. And the density | concentration of the reduced volatile organic compound is substantially constant in the deep part of an elastic layer and a urethane coat layer, and the surface part of a urethane coat layer. Therefore, even if the heating stop period exceeds 72 hours, the concentration of the volatile organic compound in each of the elastic layer and the urethane coat layer does not decrease so much.

  When the conductive roller is subjected to secondary drying after the end of the heating stop period, volatile organic compounds such as butyl acetate and low molecular weight siloxane present in the elastic layer and the urethane coat layer are diffused and moved again by heat, and the urethane coat layer. Volatile organic compounds existing in the deep part of the resin move to the surface part of the urethane coat layer, and volatile organic compounds present on the surface part of the urethane coat layer are released from the surface to the outside of the urethane coat layer.

  As a result, after the secondary drying, the concentration of the volatile organic compound in the region close to the surface of the urethane coat layer becomes almost zero, and the concentration of the volatile organic compound in the deep part of the urethane coat layer also decreases considerably.

In the present invention, when the release amount of butyl acetate is particularly large among the volatile organic compounds present in the conductive roller, butyl acetate is adopted as an index of the release amount of the volatile organic compound. That is, when the amount of butyl acetate released from the conductive roller is 100,000 μg / m ³ or less, the amount of low-molecular siloxane, toluene, and other volatile organic compounds released from the conductive roller is small. .

  Next, an example of a developing device (hereinafter, also referred to as a developing device according to the present invention) including the conductive roller 1 according to the present invention, and an image forming apparatus (hereinafter referred to as a developing device of this example) An example of the image forming apparatus according to the present invention will be described with reference to FIG.

  As shown in FIG. 2, the image forming apparatus 10 includes developing devices 20B, 20C, 20M, and 20Y according to the present invention. In the developing devices 20B, 20C, 20M and 20Y and the image forming apparatus 10, the conductive roller 1 is mounted as a developer carrier 23B, 23C, 23M and 23Y, that is, as a developing roller. As shown in FIG. 2, the image forming apparatus 10 includes a plurality of image carriers 11B, 11C, 11M, and 11Y that are provided in the developing units B, C, M, and Y of the respective colors in series on the transfer conveyance belt 6. Therefore, the developing units B, C, M, and Y are arranged in series on the transfer conveyance belt 6 wound around the two support rollers 42. The developing unit B includes an image carrier 11B such as a photosensitive member (also referred to as a photosensitive drum), a charging unit 12B such as a charging roller, an exposure unit 13B, a developing device 20B, and an image carrying belt 6. A transfer unit 14B that contacts the body 11B, such as a transfer roller, and a cleaning unit 15B are provided. The developing units C, M, and Y are basically configured in the same manner as the developing device B.

  The developing device 20B adjusts the thickness of the casing 21B that accommodates the one-component non-magnetic developer 22B, the developer carrier 23B that supplies the developer 22B to the image carrier 11B, for example, the developing roller, and the thickness of the developer 22B. Developer amount adjusting means 24B, for example, a blade is provided. The developing device 20B is mounted on the image forming apparatus 10 such that the conductive roller 1 as the developer carrier 23B is in contact with or pressure contact with the image carrier 11B. The nip width between the conductive roller 1 and the image carrier 11B at this time is normally adjusted so that the circumferential length of the conductive roller 1 is 0.1 to 2 mm. The developing devices 20C, 20M, and 20Y are basically configured similarly to the developing device 20B.

  The developers 22B, 22C, 22M, and 22Y used in the image forming apparatus 10 are all developers that can be charged by friction, and may be, for example, a dry developer or a wet developer, and nonmagnetic development. An agent or a magnetic developer may be used. One component non-magnetic black developer 22B, cyan developer 22C, magenta developer 22M and yellow developer 22Y are accommodated in the housings 21B, 21C, 21M and 21Y of the developing units.

  The fixing unit 30 is disposed downstream of the developing unit Y in the conveyance direction of the recording medium 16. The fixing unit 30 includes a fixing roller 31, an endless belt support roller 33 disposed in the vicinity of the fixing roller 31, a fixing roller 31, and an endless belt support roller in a housing having an opening 35 through which the recording medium 16 passes. 33, an endless belt 36 wound around 33, and a pressure roller 32 disposed opposite to the fixing roller 31. The fixing roller 31 and the pressure roller 32 are in contact with or pressed against each other via the endless belt 36. It is a pressure heat fixing device which is supported in a freely rotatable manner. At the bottom of the image forming apparatus 10, a cassette 41 that houses the recording medium 16 is installed.

  The image forming apparatus 10 forms a color image on the recording body 16 as follows. First, in the developing unit B, an electrostatic latent image is formed by the exposure unit 13B on the surface of the image carrier 11B charged by the charging unit 12B, and the black electrostatic latent image is developed by the developer 22B supplied by the developer carrier 23B. The image is developed. The black electrostatic latent image is transferred to the surface of the recording medium 16B when the recording medium 16 passes between the transfer means 14B and the image carrier 11B. Next, in the same manner as in the developing unit B, a cyan image, a magenta image, and a yellow image are superimposed on the recording medium 16 in which the electrostatic latent image is visualized as a black image by the developing units C, M, and Y, respectively. A color image is visualized. Next, the recording body 16 in which the color image is visualized is fixed to the recording body 16 by the fixing unit 30 as a permanent image. In this way, a color image can be formed on the recording medium 16.

  Since each of the developing devices 20B, 20C, 20M, and 20Y includes the conductive roller 1 as the developer carrier 23B, 23C, 23M, and 23Y, the image forming apparatus 10 can contribute to forming a high-quality image. At the same time, the amount of VOC emissions can be reduced.

  The tandem type image forming apparatus 10 can form a high-quality image when the conductive roller 1 is mounted as the developer carrier 23 and the conductive roller 1 is mounted as the developer carrier 23. , VOC emissions can be reduced. Further, even if the tandem type image forming apparatus 10 is on standby or stopped for a long period of time, the uniformity of the urethane coat layer 4 of the conductive roller 1 is not impaired. Even if it continues for a long time, a high quality image substantially free of white streaks can be formed.

  The image forming apparatus 10 is an image forming apparatus such as a copying machine, a facsimile machine, or a printer. The image forming apparatus 10 has been described with reference to an example in which the conductive roller according to the present invention is used as a developing roller as an example of the developer carrier 23. However, the conductive roller according to the present invention is used as a developer supply roller. Even if a roller is used, a high-quality image can be formed in the same manner, and the VOC discharge amount can be further reduced.

  The conductive roller, the developing device, and the image forming apparatus according to the present invention are not limited to the above-described examples, and various modifications can be made within a range in which the object of the present invention can be achieved. For example, the conductive roller according to the present invention may have another layer between the elastic layer and the urethane coat layer. Examples of the other layer include a primer layer that adheres or adheres the elastic layer and the urethane coat layer. Examples of materials for forming the primer layer include alkyd resins, phenol-modified / silicone-modified alkyd resin modified products, oil-free alkyd resins, acrylic resins, silicone resins, epoxy resins, fluororesins, phenol resins, polyamide resins, urethanes. Examples thereof include resins and mixtures thereof. Moreover, as a crosslinking agent which hardens and / or bridge | crosslinks these resin, an isocyanate compound, a melamine compound, an epoxy compound, a peroxide, a phenol compound, a hydrogen siloxane compound etc. are mentioned, for example. The primer layer is formed with a thickness of 0.1 to 10 μm, for example.

  The image forming apparatus 10 is an electrophotographic image forming apparatus. However, in the present invention, the image forming apparatus is not limited to the electrophotographic system, and may be, for example, an electrostatic image forming apparatus. . Further, the image forming apparatus provided with the conductive roller according to the present invention is not limited to a tandem color image forming apparatus in which a plurality of image carriers having developing units of respective colors are arranged in series on a transfer conveyance belt. For example, a monochrome image forming apparatus provided with a single developing unit, a four-cycle color image forming apparatus that sequentially repeats primary transfer of a developer image carried on an image carrier onto an endless belt may be used. The developer used in the image forming apparatus is a one-component non-magnetic developer. However, in the present invention, a one-component magnetic developer or a two-component non-magnetic developer may be used. Also, a two-component magnetic developer may be used. The fixing unit 30 may be a heat roller fixing device, a heat fixing device, a pressure fixing device, or the like.

Example 1
An electroless nickel-plated shaft body (SUM22, diameter 7.5 mm, length 280 mm) was washed with ethanol, and a silicone primer (trade name “Primer No. 16”, Shin-Etsu Chemical Co., Ltd.) on its surface Applied). The primer-treated shaft body 2 was fired at a temperature of 150 ° C. for 10 minutes using a gear oven, and then cooled at room temperature for 30 minutes or more to form a primer layer on the surface of the shaft body 2.

100 parts by weight of methyl vinyl silicone raw rubber (trade name “KE-78VBS”, manufactured by Shin-Etsu Chemical Co., Ltd.), 20 parts by weight of dimethyl silicone raw rubber (trade name “KE-76VBS”, manufactured by Shin-Etsu Chemical Co., Ltd.), and carbon 10 parts by weight of black (trade name “Asahi Thermal”, manufactured by Asahi Carbon Co., Ltd.) and fumed silica-based filler (trade name “AEROSIL OX-50”, average primary particle size 40 nm, bulk density 1.3 g / cm ³ 15 parts by mass of Nippon Aerosil Co., Ltd., 0.5 parts by mass of a platinum-based catalyst (trade name “C-19A”, manufactured by Shin-Etsu Chemical Co., Ltd.), and organohydrogenpolysiloxane (trade name “C-19B”) ”, Manufactured by Shin-Etsu Chemical Co., Ltd.), 2.0 parts by mass, kneaded with a pressure kneader, and addition-curable millable conductive silicone rubber composition It was prepared.

  Next, the shaft body 2 on which the primer layer is formed and the addition-curable millable conductive silicone rubber composition are integrally extracted with a crosshead type extruder, and heated at 250 ° C. for 30 minutes using a gear oven. did. Thereafter, using a gear oven, secondary heating was performed at 200 ° C. for 4 hours, and the mixture was allowed to stand at room temperature for 24 hours. Next, the surface of the elastic layer 3 was polished by a cylindrical grinder so that the formed elastic layer 3 had a diameter of 16 mm. The axial length of the formed elastic layer 3 was 230 mm.

  Also, the polyol and polycarboxylic acid shown below were prepared, and these were polymerized so that the molar ratio (OH / COOH) of the OH group of the polyol to the COOH group of the polycarboxylic acid was 8/7. A polyol was prepared.

  The polyester polyol was synthesized as follows. That is, 709 parts by mass of 1,6-hexanediol and 212 parts by mass of 1,2,4-butanetriol, adipic acid were added to a separable flask in which a cooling pipe, a thermometer, a moisture receiver, a nitrogen introduction pipe and a decompression device were set. 472 parts by mass, 498 parts by mass of isophthalic acid, 0.5 part by mass of p-toluenesulfonic acid, and 50 parts by mass of toluene were charged, and the mixture was heated to 180 ° C. over 2 hours while stirring nitrogen and stirred. During the heating, the whole was melted and mixed, and the mixture of water and toluene flowed out. After raising the temperature to 180 ° C., dehydration condensation was performed at the same temperature for 2 hours. Subsequently, the pressure in the flask was gradually reduced to 20 mmHg, and dehydration condensation was subsequently performed while toluene was distilled off at this pressure for 1 hour. Thereafter, it was cooled to obtain a polyester polyol.

Next, a urethane resin composition for forming the urethane coat layer 4 having the following composition was prepared.
-28 parts by mass of the polyester polyol (molar ratio of hexamethylene diisocyanate and polyester polyol described later (NCO / OH = 1.1 / 1)
・ 5 parts by mass of carbon black (trade name “Toka Black # 5500”, manufactured by Tokai Carbon Co., Ltd.) ・ 4 parts by mass of small diameter silica (average particle size 1.5 μm, trade name “ACEMATT OK-607”, manufactured by Degussa) (9.5 parts by mass with respect to 100 parts by mass of the polyurethane adjusting component)
・ 0.03 parts by mass of dibutyltin diuraurate (trade name “di-n-butyltin dilaurate”, Showa Chemical Co., Ltd.) • 14 parts by mass of hexamethylene diisocyanate (trade name “Duranate TPA-100”, manufactured by Asahi Kasei Corporation)

  300 parts by mass of butyl acetate is added to 100 parts by mass of the urethane resin composition thus prepared to prepare a coating liquid, and this coating liquid is applied to the outer peripheral surface of the elastic layer 3 by a spray coating method. The urethane coat layer 4 having a layer thickness of 20 μm was formed by heating at 160 ° C. for 30 minutes. In this way, three conductive rollers were manufactured.

  Three conductive rollers were placed in a heating furnace and heated at 160 ° C. for 30 minutes as primary drying.

  After the heating time had elapsed, heating was stopped, and the three conductive rollers were removed from the heating furnace and placed in a non-heated state for 24 hours at room temperature.

After leaving the three conductive rollers at room temperature for 24 hours, the three conductive rollers were charged into the heating furnace and subjected to heat treatment at 160 ° C. for 30 minutes as secondary drying.
Thus, the conductive roller of Example 1 was manufactured.

  For each of the three conductive rollers produced, the amount of volatile organic compound released was quantified as follows (quantification of emitted gas).

  That is, one conductive roller was stored in a simple gas collection bag (manufactured by GL Sciences Inc., smart bag PA, internal volume 10 L) (hereinafter referred to as “collection bag”). The collection bag containing the conductive roller was placed in a heating apparatus heated to 50 ° C. and held for 2 hours. After the elapse of 2 hours, the collection bag is taken out from the heating device, and the collection bag is attached to one end opening of an adsorption tube (manufactured by GL Sciences, Tenax TA, particle size 60/80 mesh, filling amount 150 mg). The other end opening of the adsorption tube was attached to a metering pump. The metering pump was driven to introduce the collected gas in the collection bag into the adsorption tube at a suction rate of 100 mL / min. The gas in the collection bag was adsorbed on the adsorbent in the adsorption tube.

  The adsorption tube with the adsorbent that adsorbs the collected gas is loaded into the following heat desorption device, the collected gas is desorbed, and the desorbed collected gas is introduced into the column in the following analytical device to make it volatile. As an organic compound (VOC), hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), tetradecamethylcycloheptasiloxane ( D7) and butyl acetate were quantitatively analyzed.

Thermal desorption device: Perkin Elmer, Turbo Matrix ATD
Heat desorption condition: set temperature 270 ° C. Heating time 15 minutes Cold trap condition: −10 ° C.
Analyzing apparatus: manufactured by Shimadzu Corporation, GC-MS QP-2010plus
Column: Agilent Technology Co., Ltd. micropolar column DB-5ms
Length 30m, inner diameter 0.32mm, film thickness 0.25μm
Measurement temperature: heating to 40 ° C. for 5 minutes, then to 300 ° C. at a heating rate of 10 ° C./min,
Heat at 300 ° C. for 4 minutes.

Detector voltage: 0.5-1 kV
Split ratio: 50-5000

As a result of arithmetically averaging the values obtained by quantifying the release amount of the volatile organic compound for each of the three conductive rollers, the collection amount of butyl acetate is 57800 μg / m ³ and the collection amount of D3 is 400 μg. / ^m is ^3, the amount of collected D4~D7 is 28600Myug / ^{m 3,} the total amount of the detected collected gas was 86800Myug / ^{m 3.}
(Comparative Example 1)
Three conductive rollers were produced in the same manner as in Example 1 except that the conductive roller similar to the conductive roller in Example 1 was not left at room temperature and not subjected to secondary drying.

  The discharged gas was quantified for the conductive roller after the primary drying.

As a result of arithmetically averaging the quantitative values of the gas discharged from each of the three conductive rollers, the amount of butyl acetate collected as the substance released from the conductive roller was 292000 μg / m ³ and the amount of D3 collected was 420 μg. / ^m is ^3, the amount of collected D4~D7 is 42800Myug / ^{m 3,} the total amount of the detected collected gas was 335220Myug / ^{m 3.}

(Comparative Example 2)
The conductive roller similar to the conductive roller in the first embodiment is subjected to 3 conductive rollers in the same manner as in the first embodiment except that heating is performed at 160 ° C. for 60 minutes and secondary drying is not performed as primary drying. The book was manufactured.

  The discharged gas was quantified for the conductive roller after standing at room temperature for 24 hours.

As a result of arithmetically averaging the quantitative values of the gas discharged from each of the three conductive rollers, the collected amount of butyl acetate as the substance released from the conductive roller is 82100 μg / m ³ and the collected amount of D3 is 550 μg. / ^m is ^3, the amount of collected D4~D7 is 43700Myug / ^{m 3,} the total amount of the detected collected gas was 126350Myug / ^{m 3.}

As shown in Example 1, Comparative Example 1 and Comparative Example 2, compared to the conductive rollers of Comparative Example 1 and Comparative Example 2 which were not allowed to stand at room temperature and / or secondary dried, Example 1 The conductive roller has a small amount of collected butyl acetate, D3, D4 to D7, and the total amount of collected gas detected is 100,000 μg / m ³ or less, and the discharge amount of VOC from the conductive roller is small. There were few.

DESCRIPTION OF SYMBOLS 1 Conductive roller 2 Shaft body 3 Elastic layer 4 Urethane coat layer 6 Transfer conveyance belt 10 Image forming apparatus 11B, 11C, 11M, 11Y Image carrier 12B, 12C, 12M, 12Y Charging means 13B, 13C, 13M, 13Y Exposure means 14B, 14C, 14M, 14Y Transfer means 15B, 15C, 15M, 15Y Cleaning means 16 Recording body 20 Developing devices 21B, 21C, 21M, 21Y, 34 Housings 22B, 22C, 22M, 22Y Developers 23B, 23C, 23M, 23Y developer carrier 24B, 24C, 24M, 24Y developer regulating member 30 fixing means 31 fixing roller 32 pressure roller 33 endless belt support roller 35 opening 36 endless belt 41 cassette 42 support rollers B, C, M, Y development unit

Claims (1)

A method for producing a conductive roller comprising: an elastic layer formed on an outer peripheral surface of a shaft body; and a urethane coat layer formed by applying a urethane resin to the outer peripheral surface of the elastic layer,
The urethane coat layer formed on the outer peripheral surface of the elastic layer is heated at 120 ° C. to 170 ° C. for 15 minutes to 2 hours, then left at room temperature for 4 hours to 72 hours, and then 120 ° C. A method for producing a conductive roller, comprising heating at ~ 170 ° C for 15 minutes to 2 hours.

Images