JP3747095B2 - Conductive roller and method and apparatus for manufacturing the same - Google Patents

Description

【００４７】
【表２】

【００４８】
【発明の効果】
以上説明したことから明らかなように、この発明にかかる導電性ローラの製造方法および製造装置には、次のような優れた効果がある。
(1) 本発明にかかる製造方法では、モールドの上端開口から混合液を円滑に注入することができ、また材料のロスが生じることがなく、また繰り返しモールドを使用する際の清掃作業がほとんど不要で、自動化が容易であるうえに、計量・混合装置等から吐出させて混合液を注入するときにも、同装置に背圧が作用せず、高い計量精度が維持できる。
【００４９】
(2) また請求項１記載の製造方法では、モールドの内周面全体にわたり混合液が付着し、肉厚がほぼ一定で薄く、硬度が一定したスキン層を形成できるとともに、内側の発泡体部のセル径も均一になって硬度むらが生じない。しかも、モールドの内周面に沿って混合液が注入されるから、芯金をモールドの下端開口から一部挿入した状態でも、芯金の上端部を混合液で汚すことがない。
【００５０】
(3) 請求項２記載の製造方法では、エアローディング作用を行うことになるので、粘性度の高い性状の混合液の流動性が良好になって混合液を円滑にかつ短時間でモールド内に注入することができる。
【００５１】
(4) 請求項３記載の製造方法では、ローラの上端側にバリが生じにくくなる。
【００５２】
(5) 請求項４記載の製造方法では、所定の密度（０．２〜０．６ｇ／ｃｍ3 ）を有する特に帯電ローラとして好適な導電性ローラが得られる。
【００５３】
(6) 本発明にかかる導電性ローラは、自己形成されるポーラスでなく平滑で薄いスキン層が内側の発泡体と境を明確にして形成され、低密度で均一なセル径を保ち、非帯電レベルでかつ電気抵抗値を比較的狭い範囲内に制御でき、また弾力性に富み感光体との接触状態で感光体を傷つけることがなく、変質を生じさせたりすることがなく、また接触面積を増してグリップ性を向上でき、しかも常時接触しても永久変形しにくく、高電圧を印加したときの帯電音の防止が十分に図られる。
【００５４】
(7) 本発明にかかる製造装置では、上記した本発明にかかる各製造方法を確実に実施することができ、精度の高い導電性ローラを効率よく生産でき、自動化が容易である。
【００５５】
(8) 請求項６記載の製造装置では、モールド内に混合液が発泡して液面が上端開口に達する直前にセンサーが検知し、開閉型締め機構が上蓋を自動的に閉塞しモールド内圧に打ち勝つように型締めする。
【図面の簡単な説明】
【図１】本発明にかかる導電性ローラの製造装置の実施例を示す側面図である。
【図２】図１の製造装置の主要部を示す正面図である。
【図３】図１の製造装置の一部を拡大して示す概要図である。
【図４】本発明にかかる導電性ローラの実施例を示す、一部を切り欠いて断面で表した斜視図である。
【符号の説明】
２ モールド
３ 下蓋
４ 上蓋
５ 保持フレーム
６ 保持板
７ モールド保持機構
１０・１５ 開閉型締め機構
１２ ガイド管
１３ 送り出し装置
１４ｃ・１７ シャフト
１８ 昇降機構
Ａ 導電性ローラ
Ｃ 芯金[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a conductive roller used for electrostatically controlling an object such as a toner conveying roller, a charging roller, a transfer roller, and a cleaning roller in a printer for electrophotography and electrostatic recording.La'sThe present invention relates to a manufacturing method and a manufacturing apparatus.
[0002]
[Prior art]
Conventionally, the corona discharge method has been used in the electrophotographic process, but recently, the charging / transfer method using a roller that contacts the photoconductor can significantly reduce the amount of ozone generated in the charging / transfer process. It is being adopted instead of the method. In addition, the conductive roller used in the roller charging / transfer system as described above can control the electrical resistance value within a relatively narrow range at a non-charging level, does not damage the photoconductor, increases the contact area, and improves grip performance. An elastic roller having conductivity is generally used because it can be improved, and is not easily permanently deformed even when it is always in contact. Furthermore, among the elastic bodies having conductivity, the foam roller is particularly effective in reducing the compression strength against the photosensitive member and preventing charging noise when a high voltage is applied. More and more people are hiring.
[0003]
For example, Japanese Patent Application Laid-Open No. 5-035110 discloses a prior art related to this type of foam roller. In the method for producing a roller described in the publication, a mixture containing two or more active hydrogen-containing compounds, two or more isocyanate group-containing compounds and a catalyst, and a foam stabilizer is foamed by a foaming injector, The mixed solution is poured from the bottom of the mold in a state where the core shaft is loaded into the cylindrical mold, and the mold is filled with foam and heated at 80 ° C. for 10 minutes for curing. By doing so, a skin layer is formed on the outer peripheral surface, and urethane coating is applied to the surface of the skin layer.
[0004]
[Problems to be solved by the invention]
However, the roller and the manufacturing method thereof described in the above publication have the following disadvantages.
[0005]
(1) Since the liquid mixture is injected (press-injected) from the bottom of the mold, not only the material remaining in the press-in path is wasted, but also processes such as cleaning and mold release processing when the same mold is used repeatedly. This is a cause of defects and difficult to automate.
[0006]
{Circle around (2)} When press-fitting from the bottom of the mold, back pressure is applied to the attached measuring / mixing device due to the resistance of the press-fitting path, and the measuring accuracy deteriorates.
[0007]
(3) When manufacturing a roller with a small outer diameter of 20 mm or less and a thin wall thickness of 3 to 5 m, the boundary between the skin layer and the internal foam (foam) part is unclear and overall high. It becomes dense and the hardness becomes too high. Further, since the mixed solution is injected in a state where the core metal is completely inserted into the mold, it cannot be smoothly injected or the injection becomes difficult.
[0008]
(4) If a roller with a small outer diameter and a small wall thickness is to be manufactured, it cannot be expected that the mixed solution will accelerate hardening due to the exothermic reaction, and the reaction time will be long, and demolding will take a long time. , Production efficiency is bad.
[0009]
The present invention has been made in view of the above points, and has a skin layer having a small outer diameter, a small thickness, and a uniform thickness over the entire circumference on the outer peripheral surface, and a clear boundary with the inner foam portion. Easily demolded and highly conductive conductive lowLa'sAn object of the present invention is to provide a manufacturing method and a manufacturing apparatus.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, a method for producing a conductive roller according to the present invention comprises a liquid compound containing two or more active hydrogens and a liquid compound and catalyst having two or more isocyanate groups, a foam stabilizer, and a conductivity. A predetermined amount of liquid mixture containing a substance is injected into a cylindrical mold with the lower end closed and the upper end open, with a core metal heated from the lower end side partially inserted.In addition, when injecting the mixed liquid, by inclining and rotating the mold, the mixed liquid is continuously injected spirally and without gaps along the inner peripheral surface of the mold. Stand up the mold,In the process of raising the core metal along the axial core portion of the mold and partially projecting the upper end portion thereof from the mold, the mixed liquid is foamed by chemical foaming and at the same time the outer peripheral surface thereof isLet it hardenForms a smooth skin layerIt is characterized byIs.
[0011]
According to the manufacturing method according to the present invention having the above-described configuration, the mixed liquid can be injected relatively smoothly from the upper end opening of the mold even when a roller having a small outer diameter and a thin wall is manufactured. Further, since the liquid mixture is directly injected from the upper end opening of the mold, there is no loss of material, cleaning work when using the mold repeatedly is almost unnecessary, and automation is easy. In addition, since the mixed solution is injected with the upper end of the mold open, when the mixed solution is injected by discharging from the weighing / mixing device, etc., no back pressure is applied to the device and high measuring accuracy is maintained. it can.
[0013]
Moreover, according to the manufacturing method of the said Claim 1,When injecting the mixed liquid into the mold, the mixed liquid is continuously spirally injected along the inner peripheral surface of the mold without any gaps, and the inner peripheral surface of the mold is uneven.
Can be wetted with the liquid mixture, so that the liquid mixture adheres to the entire inner peripheral surface of the mold, and a skin layer with a substantially constant and thin wall thickness can be formed. However, it becomes uniform and does not cause unevenness of hardness. In addition, since the mixed solution is injected along the inner peripheral surface of the mold, even if the cored bar is partially inserted from the lower end opening of the mold, the head (upper end) of the cored bar is not soiled with the mixed solution.
[0014]
Claim2As described, when stirring and mixing the two kinds of liquid compounds, a small amount of inert gas is supplied into the mixing chamber, and a part of the mixed solution before being injected into the mold is made into a foam beforehand. You can also.
[0015]
Claim2According to the described manufacturing method, since an inert gas is supplied into the mixing chamber and foamed, so-called air loading action is performed, the fluidity of the liquid mixture having high viscosity is improved. The mixed liquid can be poured into the mold smoothly and in a short time.
[0016]
Claim3As described, when the mixed liquid injected into the mold expands in the mold by chemical foaming, the upper lid can be closed by closing the upper lid immediately before reaching the vicinity of the upper end opening of the mold.
[0017]
Claim3According to the described manufacturing method, burrs are hardly generated on the upper end side of the roller.
[0018]
Claim4As described, the injection amount of the mixed solution into the mold is set so that the pack ratio (density of the molded product / density at the time of free foaming) is in the range of 1.01 to 4.50. Is desirable.
[0019]
Claim4According to the described manufacturing method, a mixed solution of a fraction of the total volume (usually about 1/4 to 1/3) is injected into the mold, and the mixed solution foams and expands in the mold. Thus, a conductive roller having a target density (0.2 to 0.6 g / cm @ 3) can be obtained.
[0022]
Claim5The conductive roller manufacturing apparatus described above includes a cylindrical mold having both upper and lower ends opened, a mold holding mechanism capable of rotating the mold in a rotatable manner and tilting in a substantially vertical state and an inclined state, and the mold. A mold rotation mechanism that rotates the core, a lower lid provided with an insertion hole for a cored bar, an upper lid provided with an insertion hole for a centering shaft for the cored bar, and the upper and lower lids are self-holding by chemical foaming with a force higher than the internal pressure. A lid opening / closing mold clamping mechanism provided with a mechanism for causing the mixture to be mixed, and a mixing foaming machine that stirs and mixes two or more compounds and discharges them from the upper end opening into the mold.
[0023]
Claim5According to the manufacturing apparatus of the present invention having the above-described configuration, the lower end opening of the mold is closed with the lower lid, a part of the core metal is inserted from the insertion hole of the lower lid, and the mold is inclined slightly in the horizontal direction. In this state, a mixed liquid obtained by stirring and mixing two or more kinds of compounds from the mixing foamer was discharged along the inner peripheral surface while rotating the mold into the mold from the upper end opening, and a predetermined amount of the mixed liquid was injected. After that, the rotation of the mold is stopped and the mold is erected almost vertically, and the cored bar is raised in the mold, and at the same time, the shaft is inserted into the mold from the insertion hole of the upper lid and lowered to make contact with the cored bar. Then, while supporting the cored bar with the shaft, the two are raised together to extract the shaft, and the upper end of the cored bar projects upward from the insertion hole of the upper lid. In this state, the mixed liquid in the mold expands by chemical foaming to become a foam, and the mixed liquid on the outer peripheral surface is made into a resin to form a skin layer. And when the liquid mixture reaches near the upper end opening of the mold, the upper lid is tightly closed. Then, the mold is sent to the next step with the upper and lower lids closed, and heated at a predetermined temperature to carry out post-crosslinking, and then cooled to remove the upper and lower lids, and the molded product in the mold is taken out.
[0024]
Claim6As described, a sensor for detecting that the liquid level due to chemical foaming of the mixed liquid reaches the vicinity of the upper end opening of the mold is provided, and the opening and closing mold clamping mechanism is closed when the sensor is detected. Can do.
[0025]
Claim6According to the described manufacturing apparatus, the sensor detects immediately before the liquid mixture foams in the mold and the liquid level reaches the upper end opening, and the mold is such that the open / close mold clamping mechanism automatically closes the upper lid and overcomes the mold internal pressure. Tighten.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of a conductive roller, a manufacturing method thereof, and a manufacturing apparatus according to the present invention will be described below with reference to the drawings.
[0027]
1 is a side view showing an embodiment of a manufacturing apparatus for conductive rollers, FIG. 2 is a front view showing the manufacturing apparatus of FIG. 1, and FIG. 3 is a schematic diagram showing an enlarged part of the manufacturing apparatus of FIG. .
[0028]
As shown in FIGS. 1 and 2, the mold injection device 1 includes a cylindrical mold 2 that does not have a dividing line, a lower lid 3, and an upper lid 4. The center hole 2c of the mold 2 has an inner diameter corresponding to the outer diameter of the conductive roller A, and its inner peripheral surface is finished to a super mirror surface. The mold 2 is rotatably supported at the tip end portion of an upper and lower side-viewing L-shaped holding frame 5 via a bearing 5a. Each holding frame 5 is fixed to a holding plate 6. This holding plate 6 can be tilted to a support column 8 erected in the vertical direction of the mold holding mechanism 7 as shown in FIG. It is attached to. In this example, it tilts between a vertical position and a position inclined 35 ° counterclockwise from the same position, but positioning pins 9 are provided for positioning the holding plate 6 at each position.
[0029]
An open / close mold clamping mechanism 10 is disposed below the holding plate 6 to move the lower lid 3 up and down by a motor 11 to open and close the lower end opening 2a of the mold 2 and mold-clamp the lower lid 3 at a predetermined pressure or higher. . As shown in FIG. 2, the open / close mold clamping mechanism 10 is mounted to be tiltable via an auxiliary plate 6a as shown in FIG. In this example, the auxiliary plate 6a is inclined between the vertical position and a position inclined 35 ° counterclockwise from the same position as the holding plate 6, but in order to position the open / close clamping mechanism 10 at each position. Positioning pins 10b are provided.
[0030]
The lower lid 3 is formed in a truncated-conical taper shape whose outer diameter is gradually reduced upward, and an insertion hole 3a for the cored bar C is formed in the center thereof. On the lower end side of the lower lid 3, a guide tube 12 having a guide hole 12a continuous to the insertion hole 3a is disposed in the open / close clamping mechanism 10 via an L-shaped support 12b. An adapter case 3g is rotatably mounted via a bearing 3k. A cylindrical holding body 3d is detachably fitted in the upper opening of the adapter case 3g, and is fixed by a ball plunger type fastener 3h. The lower lid 3 is slidably disposed in the holding body 3d, and is urged upward with respect to the holding body 3d by a spring 3e. An annular groove 3i is formed on the outer periphery of the upper end portion of the holding body 3d. Reference numeral 3f denotes a ring for preventing the lower lid 3 from coming off. With this configuration, the lower lid 3 moves up and down integrally with the guide tube 12. Further, a feed mechanism 13 for the cored bar C inserted from the lower end of the guide hole 12a to the insertion hole 3a is disposed in front of them in parallel with the mold 2, the guide tube 12, and the like. The delivery mechanism 13 includes an air cylinder 14 fixed on the open / close clamping mechanism 10 via a bracket 13a, and a delivery shaft 14c connected to the lower end of the piston rod 14a via a connector 14b. The delivery shaft 14c is inserted from the lower end of the guide hole 12a, and feeds the metal core C upward by the air cylinder 14. Corresponding to the taper shape of the lower lid 3, the lower end opening 2 a of the mold 2 is formed in a taper. The lower lid 3 and the guide tube 12 are arranged so that the insertion hole 3a and the guide hole 12a are located on an extension line of the center hole 2c of the mold 2.
[0031]
Around the lower end opening 2a of the mold 2, there is provided a fixing mechanism 25 provided with a plurality of spheres 2f that can be fitted into the annular groove 3i of the holding body 3d so as to be freely movable in and out. The fixing mechanism 25 includes a cylindrical holding cylinder 2d mounted on the outer periphery of the lower end opening 2a of the mold 2, and each of the spheres 2f is accommodated in a plurality of holding holes 2e formed in the lower end portion of the holding cylinder 2d. Has been. An outer cylinder 2g that pushes each spherical body 2f inwardly is arranged on the outer periphery of the holding cylinder 2d, and an inner cylinder 2h that pushes each spherical body 2f outwardly is slidable in the vertical direction on the inner circumference of the holding cylinder 2d. The outer cylinder 2g is urged downward by the spring 2i, and the inner cylinder 2h is urged downward by the spring 2j. Normally, in the state on the left side of FIG. 3, each sphere 2f in the holding hole 2e is pushed outward by the inner cylinder 2h, and the sphere 2f is held by the lower end of the outer cylinder 2g. A fixing mechanism 25 ′ is also provided around the upper end opening 2 b of the mold 2. The fixing mechanism 25 ′ includes a plurality of spherical bodies 2 f that can be fitted in an annular groove 4 i of a holding body 4 d to be described later. Since the fixing mechanism 25 'has the same structure as the fixing mechanism 25, the same reference numerals are used and the description is omitted.
[0032]
On the other hand, an open / close mold clamping mechanism 15 is disposed at the upper end of the support column 8 to raise and lower the upper lid 4 by a motor 16 to open and close the upper end opening 2b of the mold 2 and to mold the upper lid 4 with a predetermined pressure or more. Yes. The upper lid 4 is formed in a truncated frustoconical taper whose outer diameter is gradually reduced downward, and an insertion hole 4a for a centering shaft 17 is formed in the center thereof. Corresponding to the tapered shape of the upper lid 4, the upper end opening 2 b of the mold 2 is tapered. The upper lid 4 is arranged so that the insertion hole 4 a is located on the extension line of the center hole 2 c of the mold 2. An elevating mechanism 18 for the centering shaft 17 is disposed immediately above the upper lid 4. In this example, the elevating mechanism 18 is an air cylinder 18a fixed on the open / close clamping mechanism 15 via a bracket. And the centering shaft 17 connected to the lower end of the piston rod 18b via a connecting tool 18c.
[0033]
As shown in FIG. 1, an adapter case 4g having a center hole that constitutes a guide hole 18d of the centering shaft 17 is rotatably mounted on an L-shaped support 17b, and is placed in an upper opening of the adapter case 4g. A cylindrical holding body 4d is detachably fitted and fixed by a ball plunger type fastener 4h. The upper lid 4 is slidably disposed in the holding body 4d and is urged upward with respect to the holding body 4d by a spring (not shown). An annular groove 4i is formed on the outer periphery of the upper end portion of the holding body 4d. With this configuration, the upper lid 4 moves up and down integrally with the open / close mold clamping mechanism 15. Further, a driven gear 20b is detachably fitted around the middle position in the length direction of the mold 2, and the motor 20 having a drive gear 20a meshing with the driven gear 20b is attached to the holding plate 6 via the bracket 21. It is attached. A mold rotation mechanism 19 is configured by these components. Further, a sensor (not shown) is provided near the upper end opening 2 b of the mold 2 to detect the position of the upper surface of the mixed liquid injected into the mold 2.
[0034]
As shown in detail in FIG. 3, a conical centering hole C ′ is formed at the center of the upper end surface of the cored bar C, and a centering protrusion 17a (FIG. 1) corresponding to the centering hole C ′ is formed. The shaft 17 projects from the center of the lower end surface.
[0035]
The mold injection apparatus 1 includes a quantitative mixing foaming machine (not shown). This foaming machine has two inlets at the upper end and a discharge outlet at the lower end in the mixing chamber. The stirring rotor is rotatably supported through a bearing, and two or more kinds of liquid materials such as a main agent and a curing agent are mixed and stirred to be discharged. Measure liquid compounds containing two or more isocyanate groups and liquid compounds containing two or more active hydrogens, and additives such as catalysts, foam stabilizers, and conductive substances as liquid mixtures, and determine from the inlet. The mixture is introduced into the mixing chamber of the mixing foaming machine, and the mixed liquid stirred and mixed is discharged into the mold 2. In this example, in order to form a uniform cell, a small amount of an inert gas such as nitrogen gas or air is injected into the mixing chamber, and a part of the mixed solution is previously made into a foam before being discharged into the mold 2. You can also
[0036]
As the liquid compound having two or more isocyanate groups, polyisocyanate compounds used for general flexible urethane foams and polyurethane elastomers are used. That is, tolylene diisocyanate (TDI), crude TDI, 4,4′diphenylmethane diisocyanate (MDI), crude MDI, alicyclic polyisocyanate having 2 to 18 carbon atoms, and mixtures and modifications of these polyisocyanates, for example, parts For example, prepolymers obtained by reacting with polyols are used.
[0037]
As liquid compounds containing two or more active hydrogens, polyols used in general flexible urethane foams and polyurethane elastomers, that is, polyether polyols having a hydroxyl group at the terminal, polyester polyols, and copolymers of both are used. General polyols such as a polyether polyester polyol and a so-called polymer polyol obtained by polymerizing an ethylenically unsaturated monomer in the polyol are used.
[0038]
As the catalyst, an amine-based catalyst or an organometallic catalyst used in the production of a general flexible urethane foam can be used. However, after stirring and mixing, it is injected into the mold 2 and the time until the core C is moved upward is used. Temperature-sensitive (retarding) catalyst to prevent an undesirable increase in viscosity in the interior and to form a skin layer with a clear and smooth surface on the outer peripheral surface with the inner foam part It is desirable to use In particular, organic acid salts of 1,8-diazabicyclo (5,4,0) undecene-7 (DBU) and 1,5-diazabicyclo (4,3,0) nonene-5 (DBN) have high resinization activity. It may be used in combination with an organometallic catalyst or F22 (Tosoh) Thus, by using both catalysts together, while ensuring the cream time (time until foaming starts) necessary for the work, it is rapidly foamed by receiving heat from the cored bar C as described later. While making it harden | cure both, the skin layer with a smooth surface can be formed.
[0039]
There are various types of organic acids that form salts with DBU or DBN as described above, and the stronger the acid, the higher the catalyst activation temperature, so that it is appropriately selected in relation to the molding conditions. For the production of the conductive roller of the present invention, a chain extender, a silicone foam stabilizer, a flame retardant, an organic / inorganic filler, a pigment, etc. used in ordinary polyurethane foams are used if necessary. Good.
[0040]
Next, an operation procedure for manufacturing the conductive roller A using the above-described material using the manufacturing apparatus according to this embodiment will be described.
(1) Set the lower lid 3 on the open / close clamping mechanism 10.
(2) The open / close mold clamping mechanism 10 is tilted 35 ° counterclockwise with respect to the holding plate 6.
(3) The outer peripheral surface of the cored bar C is treated with an adhesive, and the cored bar C is heated to a predetermined temperature (about 70 to 80 ° C.), and then inserted into the insertion hole 3a of the lower lid 3 from above. Then, it is inserted until it hits the shaft 14c of the cored bar feed mechanism 13.
(4) The opening / closing mold clamping mechanism 10 is tilted clockwise with respect to the holding plate 6 together with the core metal feeding mechanism 13 to return to the original vertical state.
(5) The lower lid 3 is raised by the open / close mold clamping mechanism 10, the lower end opening 2 a of the mold 2 is closed with the lower lid 3, and the lower lid 3 is pressed upward with a predetermined pressure to clamp the mold.
[0041]
(6) The core bar C is pushed up by a predetermined length by the shaft 14 c of the core bar feed mechanism 13, and a part of the core bar C is inserted into the mold 2.
(7) The holding plate 6 is inclined 35 ° counterclockwise with respect to the support column 8 around the support shaft 8a. As a result, the mold 2 and the open / close mold clamping mechanism 10 and the core metal feeding mechanism 13 are inclined by 35 ° counterclockwise.
(8) The mold 2 is rotated by the motor 20 via the drive gear 20a and the driven gear 20b.
(9) The mixed solution is injected from the upper end opening 2b of the mold 2 along the inner peripheral surface of the mold. At this time, the mixed liquid flows in a spiral shape without gaps in the longitudinal direction and wets the inner peripheral surface of the mold, so that the mixed liquid does not adhere to the upper end portion of the partially inserted cored bar C.
[0042]
(10) After a predetermined amount of the mixed liquid is injected into the mold 2, the holding plate 6 is rotated clockwise with respect to the support column 8 about the support shaft 8a. Thereby, the mold 2 and the open / close mold clamping mechanism 10 and the core metal feed mechanism 13 are returned to the original vertical direction.
(11) The core bar C is immediately moved upward in the mold 2 by the core bar feed mechanism 13 through the shaft 14c, and at the same time, the centering shaft 17 is moved from the insertion hole 4a of the upper lid 4 into the mold 2 by the lifting mechanism 18. Insert and lower, but align with the upper end of the core C and center. In this state, the core bar C is raised together with the centering shaft 17 until its upper end protrudes upward from the upper end opening 2b of the mold 2 by a predetermined length. (12) The mixed liquid injected into the mold 2 is heated by the heat of the core bar C, and is rapidly foamed by the action of the catalyst to form a foam. On the other hand, since the mold 2 is at room temperature (30 ° C. or lower), the mixed liquid that comes into contact with the inner peripheral surface of the mold 2 is cooled by being deprived of heat by the mold 2 and is made resin instead of foaming.( Curing)Is promoted to form a skin layer having a smooth surface with a predetermined thickness (about 10 to 50 μm) with a clear boundary with the inner foam. In addition, it is desirable to attach a cooling means to the periphery so that the temperature of the mold 2 can be maintained at 30 ° C. or lower even when heated by a chemical (exothermic) reaction of the urethane mixed solution in the mold 2.
(13) The shafts 14 c and 17, which are partially inserted into the insertion hole 3 a of the lower lid 3 and the insertion hole 4 a of the upper lid 4, are extracted via the feed mechanism 13 and the lifting mechanism 18.
(14) The mold 2 is removed in a state where the upper and lower end openings 2a and 2b of the mold 2 are closed with the upper and lower lids 3 and 4 and sent to the next process to perform post-crosslinking at a predetermined temperature. The upper and lower lids 3 and 4 are fixed by the fixing mechanisms 25 and 25 ′ around the upper end opening 2 b and the lower end opening 2 a of the mold 2 in a state where the upper and lower end openings 2 a and 2 b of the mold 2 are closed. Loosen 3h and 4h and remove from adapter case 3g and 4g.
(15) Set in a mold disassembling apparatus (not shown), the upper and lower lids 3 and 4 are removed by pushing up the outer cylinder 2g of the fixing mechanism 25 and 25 'against the spring 2i, and the conductive roller A in the mold 2 is removed. Take out.
[0043]
As described above, the conductive roller A as shown in FIG. 4 can be manufactured. The conductive roller A has a cylindrical foam B around the core bar C and a skin layer on the outer peripheral surface thereof. S is formed integrally. The density of the foam (foam part) can be adjusted by changing the formulation of the conductive roller A when forming the foam and the packing ratio into the mold 2 (the density of the molded product / the density during free foaming). In this example, the density of the foam is 0.2 to 0.6 g / cm by setting the pack rate within the range of 1.01 to 4.50.^Three become.
[0044]
Further, the surface of the conductive roller A may be coated after demolding. However, in this case, the paint has a JIS-A hardness of 70 or less and a coating thickness of 300 μm or less (so that the surface hardness does not increase). Preferably, 50-200 micrometers is good.
[0045]
【Example】
The conductive roller of the present embodiment is used as a charging roller. In FIG. 4, the outer diameter of the main body of the roller A is 12 mm, the length of the main body is 225 mm, the outer diameter of the cored bar C is 6 mm, and the length is 250 mm. ing. Table 1 shows the formulation and molding conditions of Examples 1 to 3 and Comparative Examples 1 to 4. Further, Table 2 shows the characteristics of the rollers of Examples 1 to 3 and Comparative Examples 1 to 4 and the evaluation results with an actual machine (laser printer).
[0046]
[Table 1]

[0047]
[Table 2]

[0048]
【The invention's effect】
As is clear from the above explanation, the conductive low according to the present invention is used.La'sThe manufacturing method and the manufacturing apparatus have the following excellent effects.
(1) In the manufacturing method according to the present invention, the liquid mixture can be smoothly injected from the upper end opening of the mold, there is no material loss, and almost no cleaning work is required when using the mold repeatedly. Thus, in addition to being easy to automate, when a liquid mixture is injected by being discharged from a measuring / mixing device or the like, back pressure does not act on the device, and high measuring accuracy can be maintained.
[0049]
(2) Claims1In the manufacturing method described above, the liquid mixture adheres to the entire inner peripheral surface of the mold, and a skin layer having a substantially constant and thin wall thickness and a constant hardness can be formed, and the cell diameter of the inner foam portion is also uniform. Hardness unevenness. And since a liquid mixture is inject | poured along the internal peripheral surface of a mold, even if it inserts a core metal partially from the lower end opening of a mold, the upper end part of a metal core is not soiled with a liquid mixture.
[0050]
(3) Claims2In the described manufacturing method, an air loading operation is performed, so that the fluidity of the liquid mixture having a high viscosity is improved, and the liquid mixture can be poured into the mold smoothly and in a short time.
[0051]
(4) Claims3In the manufacturing method described, burrs are less likely to occur on the upper end side of the roller.
[0052]
(5) Claim4With the described production method, a conductive roller having a predetermined density (0.2 to 0.6 g / cm @ 3) and particularly suitable as a charging roller can be obtained.
[0053]
(6) The conductive roller according to the present invention is a self-formed porous, smooth and thin skin layer formed with a clear boundary with the inner foam, maintains a uniform cell diameter at a low density, and is non-charged. Level and electric resistance value can be controlled within a relatively narrow range, and it is highly elastic and does not damage the photoconductor in contact with the photoconductor. In addition, the grip performance can be improved, and it is difficult to be permanently deformed even if it is always in contact, and it is possible to sufficiently prevent charging noise when a high voltage is applied.
[0054]
(7) In the manufacturing apparatus according to the present invention, the above-described manufacturing methods according to the present invention can be surely performed, highly accurate conductive rollers can be efficiently produced, and automation is easy.
[0055]
(8) Claim6In the described manufacturing apparatus, the sensor detects immediately before the liquid mixture foams in the mold and the liquid level reaches the upper end opening, and the open / close mold clamping mechanism automatically closes the upper lid and clamps the mold so as to overcome the mold internal pressure. .
[Brief description of the drawings]
FIG. 1 is a side view showing an embodiment of a conductive roller manufacturing apparatus according to the present invention.
2 is a front view showing a main part of the manufacturing apparatus of FIG. 1. FIG.
3 is an enlarged schematic view showing a part of the manufacturing apparatus of FIG. 1. FIG.
FIG. 4 is a perspective view of a conductive roller according to an embodiment of the present invention, partly cut away and shown in cross section.
[Explanation of symbols]
2 Mold
3 Lower lid
4 Top cover
5 Holding frame
6 Holding plate
7 Mold holding mechanism
10.15 Opening and closing mold clamping mechanism
12 Guide tube
13 Delivery device
14c / 17 shaft
18 Lifting mechanism
A Conductive roller
C cored bar

Claims (6)

In a cylindrical mold in which a liquid compound containing two or more active hydrogens and a liquid compound containing two or more isocyanate groups, a mixed liquid containing a catalyst, a foam stabilizer, and a conductive substance are closed at the lower end and opened at the upper end. And injecting a predetermined amount in a state in which the core metal heated from the lower end side is partially inserted ,
When injecting the mixed solution, the mold is tilted and rotated to continuously inject the mixed solution spirally along the inner peripheral surface of the mold without any gaps. Let
In the process of raising the core metal along the axial core portion of the mold and partially projecting the upper end portion thereof from the mold, the mixed solution is foamed by chemical foaming and at the same time the outer peripheral surface thereof is cured and smoothed. A method for producing a conductive roller, comprising forming a skin layer. 2. The conductive material according to claim 1, wherein when the two kinds of liquid compounds are stirred and mixed, a part of the mixed solution before supplying the trace amount of inert gas into the mixing chamber and injecting into the mold is made into a foam in advance. Manufacturing method of the adhesive roller. 3. The conductive roller according to claim 1 , wherein when the mixed liquid injected into the mold expands in the mold by chemical foaming, the upper lid is closed and the upper end opening is closed immediately before reaching the vicinity of the upper end opening of the mold. Production method. The injection amount into the mold inside of the mixed solution, (density of density / free foaming upon molding) pack ratio of claims 1 to 3 was set to be in the range of 1.01 to 4.50 The manufacturing method of the electroconductive roller in any one. Cylindrical mold with both upper and lower ends open, a mold holding mechanism that can hold the mold in a rotatable manner, and can tilt in a substantially vertical state and an inclined state, a mold rotating mechanism that rotates the mold, and a cored bar Opening and closing mold closure of the lid with a lower lid provided with an insertion hole, an upper lid provided with an insertion hole for a centering shaft for the cored bar, and a mechanism for self-holding the upper and lower lids by chemical foaming with a force greater than the internal pressure An apparatus for producing a conductive roller, comprising: a mechanism; and a mixing and foaming machine that stirs and mixes two or more kinds of compounds and discharges them from the upper end opening into the mold. 6. A conductive material according to claim 5 , wherein a sensor is provided for detecting that a liquid surface due to chemical foaming of the mixed liquid reaches the upper end opening of the mold, and the upper and lower mold clamping mechanism is closed when the sensor is detected. Manufacturing equipment.

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