JP2005041940A - Oa roller and method for producing oa roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently obtain an OA roller such as a toner supply roller, etc., having an outer peripheral surface composed of a skinless type polyurethane foam layer with foam cells open to the outer peripheral surface. <P>SOLUTION: In the case of obtaining the OA roller having an outer peripheral surface composed of a skinless type urethane foam layer with foam cells open to the outer peripheral surface by molding and foaming a foamable composition comprising a polyol, an isocyanate, water and a foam stabilizer in a mold, a polyol having 0-20 mass % ethylene oxide content is used as the main polyol in the foamable composition. The foamable composition is obtained by mixing 100 parts wt. of the main polyol with 2-20 parts wt. of an auxiliary polyol having 25-100 mass % ethylene oxide content and 2-10 parts wt. of a silicone foam stabilizer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

＊１：三洋化成（株）社製「ＦＴ７０３」（ＥＯ／ＰＯ質量比：１３／８７）
＊２：三洋化成（株）社製「ＦＴ１０３」（ＥＯ／ＰＯ質量比：７５／２５）
＊３：東レ・ダウコーニング・シリコン（株）社製「ＳＲＸ２７４Ｃ」
＊４：花王（株）社製「カオライザー Ｎｏ．３１」
＊５：花王（株）社製「カオライザー Ｎｏ．１」
【００３７】
表１に示されているように、本発明にかかる実施例１〜９のＯＡローラ（トナー供給ローラ）は、表面のスキンレスウレタンフォーム層が良好な物性を有し、良好な性能を確実に発揮し得ると共に、フッ素樹脂コートを施した金型を用いて離型剤を用いることなく、ワンショット法によって５０〜２００ショットの連続成形を行うことができ、非常に効率よく生産し得ることが確認された。一方、比較例１のローラは、シリコーン整泡剤の作用により良好なコーティング耐久性を示すものの、サブポリオールを用いていないためにスキンレスウレタンフォーム層の物性及びローラの性能に劣るものであった。また、比較例２のローラは、良好なスキンレスウレタンフォーム層の物性及びローラ性能が得られるものの、シリコーン整泡剤の使用量が足りないために、コーティング耐久性に著しく劣り、１０ショット毎に金型の洗浄を行う必要が生じて、生産性が非常に悪いものであった。
【図面の簡単な説明】
【図１】トナー供給ローラを用いた現像機構の一例を示す概略図である。
【図２】ローラ表面に形成されたウレタンフォーム層の硬度の測定方法を示す概略図である。
【符号の説明】
１ トナー供給ローラ
２ 現像ローラ
３ 感光ドラム
４ 成層ブレード
５ 転写部
６ 記録媒体
７ クリーニング部
８ クリーニングブレード
ｔ トナー[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a toner supply roller, a developing roller, a charging roller, a transfer roller, a bias roller, a backup roller, a cleaning roller, a supply roller used in an electrophotographic or electrostatic recording type image forming apparatus such as a copying machine, a facsimile machine, and a printer. The present invention relates to an OA roller having a skinless type urethane foam layer used as a paper roller or the like and a manufacturing method thereof, and more specifically, relates to the OA roller that can be efficiently manufactured by a one-shot method and a manufacturing method thereof.
[0002]
[Prior art]
In an electrophotographic or electrostatic recording type image forming apparatus such as a copying machine or a printer, OA rollers such as a toner supply roller, a charging roller, a transfer roller, a bias roller, a backup roller, a cleaning roller, and a paper feed roller are used. ing.
[0003]
As these OA rollers, those in which a urethane foam layer is formed on the outer periphery of a shaft are known. In particular, in a toner supply roller or the like, a skinless foam layer in which foam cells of the urethane foam layer are opened on the outer peripheral surface of the roller. A roller having an outer peripheral surface is used.
[0004]
Conventionally, as a method for producing a roller having such a urethane foam layer, a foamable composition containing a polyol, isocyanate, water, and a foam stabilizer is stirred and injected into a mold having a shaft. Further, there is known a method in which the foamable composition is foamed with the generated carbon dioxide gas and solidified to form a urethane foam layer on the outer periphery of the shaft (Patent Document 1: Japanese Patent Laid-Open No. 2000-320536, Patent Document 2). : Japanese Patent Laid-Open No. 2000-347496, Japanese Patent Laid-Open No. 2000-219717, etc.).
[0005]
[Patent Document 1]
JP 2000-320536 A [Patent Document 2]
JP 2000-347496 [Patent Document 3]
JP-A-2000-219717 [0006]
[Problems to be solved by the invention]
In this case, in order to make the urethane foam layer a skinless foam layer in which foam cells are opened on the outer peripheral surface of the roller, it is necessary to apply a release agent to the inner peripheral surface of the mold every time molding is performed. It is one of the causes of lowering the sex.
[0007]
In addition, by applying water repellency treatment by fluororesin coating and PTFE-containing Ni plating treatment to the inner peripheral surface of the mold to improve the mold releasability of the inner surface of the mold, skinless type urethane can be used without using a release agent. Although it is possible to form a foam layer, even if such a water repellency treatment is applied to the mold, the water repellency (releasability) usually deteriorates in 10 to 15 shots, and a good skinless foam You will not be able to get a layer. For this reason, in order to stably achieve the target product physical properties even when using a water-repellent mold, the mold must be cleaned every time it is molded. In reality, mass production by means of the fact is difficult.
[0008]
The present invention has been made in view of the above circumstances, and an object thereof is to efficiently obtain an OA roller such as a toner supply roller in which an outer peripheral surface is formed of a skinless type polyurethane foam layer in which foamed cells are opened on the outer peripheral surface. To do.
[0009]
[Means for Solving the Problems]
As a result of intensive studies to achieve the above object, the present inventor formed and foamed a foamable composition containing polyol, isocyanate, water and a foam stabilizer in a mold, and the foamed cells were opened on the outer peripheral surface. When an OA roller having an outer peripheral surface formed of a skinless type urethane foam layer is obtained, as a polyol component of the foamable composition, a main polyol having an ethylene oxide content of 0 to 20% by mass and an ethylene oxide content of 25 In combination with ˜100 mass% of the subpolyol, the amount of the subpolyol is 2 to 20 parts by weight with respect to 100 parts by weight of the main polyol, and the silicone foam stabilizer is 100 parts by weight of the main polyol. By adding 2 to 10 parts by weight to the foamable composition, a fluororesin coat or PTFE-containing N With a mold that has been subjected to water repellency treatment such as plating, a skinless type urethane foam layer can be obtained satisfactorily without using a release agent, and more than 50 shots can be continuously performed without cleaning the mold. The present invention has been completed by finding out that an OA roller having a skinless type urethane foam layer can be obtained very efficiently, which can be molded.
[0010]
Therefore, in the present invention, at least the outer peripheral surface is formed of a urethane foam layer obtained by molding and foaming a foamable composition containing polyol, isocyanate, water and a foam stabilizer, and the foamed cells of the urethane foam layer are outer peripheral surfaces. In the OA roller, which is a skinless foam layer opened in the above, the foamable composition for forming the urethane foam layer has an ethylene oxide content of 100 parts by weight of the main polyol having an ethylene oxide content of 0 to 20% by mass. An OA roller characterized by containing 2 to 20 parts by weight of a subpolyol of 25 to 100% by mass and 2 to 10 parts by weight of a silicone foam stabilizer.
[0011]
Furthermore, the present invention provides a shaft or other substrate in a mold, and injects a foamable composition containing a polyol, isocyanate, water and a foam stabilizer into the mold, and the shaft or other substrate is injected into the mold. In the method of manufacturing an OA roller, a urethane foam layer is foam-molded on the outer periphery of the substrate, and an outer peripheral surface is formed of a skinless urethane foam layer having foam cells opened on the outer peripheral surface. While using the thing which gave the water repellent process to the cavity internal peripheral surface, without apply | coating a mold release agent to this cavity internal peripheral surface, ethylene oxide content 0-20 mass% as said foamable composition 2 to 20 parts by weight of a subpolyol having an ethylene oxide content of 25 to 100% by mass and 2 to 10 parts by weight of a silicone foam stabilizer with respect to 100 parts by weight of the main polyol The foamable composition containing injected into the mold to provide a method of manufacturing OA roller, which comprises molding the skinless urethane foam layer.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
As described above, the OA roller of the present invention has a roller outer peripheral surface formed of a skinless type urethane foam layer obtained by molding and foaming a foamable composition containing polyol, isocyanate, water and a foam stabilizer. .
[0013]
There is no restriction | limiting in particular as said polyol component of the said foamable composition, A well-known thing can be used as a raw material polyol for urethane foam manufacture, A polyether-type polyol, a polyester-type polyol, a polyester-polyether-type polyol etc. are rollers. It can be appropriately selected according to the use of the above. For example, when the toner supply roller is used, a polyether polyol is particularly preferably used from the viewpoint of durability although it is not particularly limited.
[0014]
Here, in this invention, as this polyol component, ethylene oxide content (it abbreviates as "EO content") is 0-20 mass%, Preferably it is 10-20 mass%, More preferably, it is 10-15 mass%. The main polyol is used in combination with a subpolyol having an EO content of 25 to 100% by mass, preferably 50 to 85% by mass, more preferably 60 to 85% by mass. In this case, the main polyol and the subpolyol may be the same or different, but it is usually preferable to use the same polyol.
[0015]
The main polyol is not particularly limited, but preferably has a number average molecular weight of 2,000 to 10,000, particularly 5,000 to 8,000, and a primary OH value of 0 to 90, particularly 75 to 90. On the other hand, the subpolyol is not particularly limited, but preferably has a number average molecular weight of 2000 to 10000, particularly 3000 to 6000, and a primary OH value of 10 to 50, particularly 15 to 45. preferable.
[0016]
The mixing ratio of the main polyol and the sub polyol is 2 to 20 parts by weight of the sub polyol with respect to 100 parts by weight of the main polyol. In this case, if the use amount of the subpolyol is less than 2 parts by weight, it becomes difficult to achieve the object of the present invention due to excessive self-reliance, while if it exceeds 20 parts by weight, the disadvantage of cell roughening occurs. Will occur. In addition, the usage-amount of a more preferable subpolyol is 3-15 weight part with respect to 100 weight part of main polyols, Furthermore, 5-10 weight part.
[0017]
Next, the isocyanate component of the foamable composition is not particularly limited, and a known isocyanate can be used. For example, tolylene diisocyanate (TDI), crude TDI, diphenylmethane diisocyanate (MDI), crude MDI, Examples include triphenyl diisocyanate, xylene diisocyanate, polymethylene polyphenylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like, and one or more of these can be used in combination.
[0018]
The blending amount of the isocyanate is appropriately set according to the number of functional groups of the polyol component and the like, and is not limited to the above. However, it is usually preferable that the NCO Index is 80 to 120, particularly 90 to 100. If the index is less than 80, the hardness may be too low and the target hardness for each product may not be obtained. On the other hand, if the NCO index exceeds 120, the hardness will be too high, and the target hardness for each product may be obtained. There may not be.
[0019]
A silicone foam stabilizer is used as the foam stabilizer to be blended in the foamable composition. Examples of silicone foam stabilizers include organopolysiloxanes, modified silicone oils, surfactants, and the like, and more specifically, “SRX274C” manufactured by Toray Dow Corning Silicon Co., Ltd., and the like.
[0020]
The blending amount of the silicone foam stabilizer is 2 to 10 parts by weight with respect to 100 parts by weight of the main polyol, and if it is less than 2 parts by weight, 10 to 15 shots even if a mold subjected to water repellent treatment is used. The water repellency of the mold is lowered to a certain extent, and a skinless type foam layer cannot be obtained satisfactorily, and the object of the present invention cannot be achieved. On the other hand, if it exceeds 10 parts by weight, the autonomy becomes higher than necessary. In addition, a more preferable compounding quantity is 3-9 weight part with respect to 100 weight part of main polyols, Especially 5-8 weight part.
[0021]
A foam stabilizer other than the silicone foam stabilizer can be used in combination with the foamable composition. In this case, examples of other foam stabilizers include alkyl carboxylates and alkylbenzene sulfonates, and the amount of these other foam stabilizers is not particularly limited. It is preferable to set it as 0.1-3 weight part with respect to a part, especially 0.1-1 weight part.
[0022]
In this foamable composition, water is blended as an essential component, and the blending amount of water is usually 1 to 4 parts by weight, particularly 1.5 to 2.5 parts by weight, based on 100 parts by weight of the main polyol. Part.
[0023]
In addition to the polyol component, isocyanate component, foam stabilizer, and water, the foamable composition contains known additives such as catalysts, fillers, antioxidants, ultraviolet absorbers, flame retardants, and conductive agents. An appropriate amount can be added and blended as necessary.
[0024]
In this case, the catalyst is not particularly limited, but an appropriate amount is preferably added and blended from the viewpoint of promoting good foam molding. As the catalyst, both amine-based and tin-based catalysts can be used. As the amine-based catalyst, tetramethylhexamethylenediamine, pentamethyldiethylenetriamine, dimethylcyclohexylamine, bis- (dimethylaminoethyl) ether, tetramethyl Examples include propylenediamine, trimethylaminoethylpiperazine, trimethylethylenediamine, dimethylbenzylamine, methylmorpholine, ethylmorpholine, and triethylenediamine. Examples of tin-based catalysts include stannous octate and dibutyltin dilaurate. The blending amount of these catalysts can be 0.1 to 2 parts by weight, particularly 0.5 to 1.5 parts by weight with respect to 100 parts by weight of the main polyol.
[0025]
The OA roller of the present invention has a skinless type urethane foam layer formed and foamed from the foamable composition and has an outer peripheral surface. In this case, the urethane foam layer constitutes the foamable composition. The components to be mixed and stirred are injected into a mold in which a shaft or other substrate is disposed, and a foamable composition is molded and foamed in the mold, thereby forming an OA on the outer periphery of the shaft or other substrate. It can be formed as a foam layer constituting the surface of the roller.
[0026]
In this case, by using a mold with water repellent treatment such as fluororesin coating or PTFE-containing Ni plating on the inner surface of the cavity as a mold, a foam cell can be easily formed by a one-shot method without requiring a release agent. Can be a skinless foam layer having an opening on the outer peripheral surface. Moreover, there is no need to clean the mold in about 10 to 15 shots, and a good skinless foam layer can be reliably obtained even if continuous molding is performed for 50 to 200 shots. . According to the present invention, the cleaning of the mold can be omitted. Of course, the mold may be cleaned every 10 to 15 shots or every time, in which case the life of the mold is reduced. It can be extended.
[0027]
Here, the water-repellent treatment applied to the cavity inner surface of the mold is not limited to the fluororesin coat or the PTFE-containing Ni plating, and can be appropriately selected as long as it does not depart from the gist of the present invention. .
[0028]
There are no particular restrictions on molding conditions such as molding temperature and compression rate when the foamable composition is molded and foamed in a mold to form a skinless type urethane foam layer. What is necessary is just to set suitably according to the physical property etc. which are requested | required of the composition of a thing, or a urethane foam layer. In addition, the base used as the axis of the roller may be a shaft made of metal or the like, or an intermediate layer made of other foam or elastomer on the outer periphery of the shaft. Preferably, the urethane foam layer is formed directly on the outer periphery of the shaft.
[0029]
As described above, the OA roller of the present invention has a roller outer peripheral surface constituted by a skinless type urethane foam layer in which foamed cells are opened on the outer peripheral surface. In this case, the physical properties of the urethane foam layer are not particularly limited, and are appropriately selected according to the use of the roller. For example, in the case of a toner supply roller, the opening diameter of the foam cell opened on the outer peripheral surface of the roller is preferably 100 to 800 μm, and particularly preferably 200 to 400 μm. 20% or more, particularly 20 to 70%, more preferably 50 to 70%. Further, the hardness is preferably 350 g or less, particularly 50 to 200 g.
[0030]
As shown in FIG. 2, the hardness is measured by supporting both ends of the shaft of the roller 1 and pressing a 50 mm square (thickness 7 mm) pressing plate 10 against the surface of the roller 1 at a speed of 10 mm / min. This is a value obtained by measuring the pressing load at the time of 1 mm displacement as the hardness. In this case, at two locations along the axial direction of the roller 1, each of the four locations is measured by being displaced by 90 ° in the circumferential direction, and the average value of these eight locations is taken as the hardness of the roller.
[0031]
The OA roller of the present invention is a toner supply roller, a charging roller, a transfer roller, a bias roller, a backup roller, a cleaning roller, a paper feed roller, etc. in an electrophotographic or electrostatic recording type image forming apparatus such as a copying machine or a printer. Of these, among these, the toner supply roller is particularly preferably used.
[0032]
In this case, the toner supply roller is a developing mechanism portion of an electrophotographic apparatus or an electrostatic recording apparatus, rotates in contact with the surface of the developing roller, carries the toner in the toner reservoir on the outer peripheral surface, and conveys the toner. The developing mechanism shown in FIG. 1 can be exemplified as a developing mechanism using such a toner supplying roller. That is, in the mechanism of FIG. 1, the developing roller 2 is placed in contact with or close to the photosensitive drum (latent image carrier) 3, and the toner supply roller 1 is further brought into contact with the developing roller 2. The photosensitive drum 3, the developing roller 2, and the toner supply roller 1 are rotated in the directions of the arrows in the drawing, respectively, so that the toner t is removed from the toner reservoir in the toner cassette by the toner supply roller 1. The toner t is supplied to the surface, and the toner t is adjusted to a uniform thin layer by the stratified blade 4, and the developing roller 2 rotates in this state in contact with or close to the photosensitive drum 3. Is attached to the latent image on the photosensitive drum 3 from the developing roller 2, and the latent image is visualized so that development is performed. The OA roller of the present invention is suitably used as the toner supply roller 1. In the figure, reference numeral 5 denotes a transfer portion, where a toner image is transferred to a recording medium 6 such as paper. Reference numeral 7 denotes a cleaning portion, and the surface of the photosensitive drum 3 is transferred by the cleaning blade 8 after being transferred. The toner remaining on the toner is removed.
[0033]
【The invention's effect】
The OA roller of the present invention has an outer peripheral surface formed of a skinless type urethane foam layer formed from the foamable composition having the above specific composition. According to the present invention, the OA roller has excellent physical properties. It can be produced with high productivity by the one-shot method while being held.
[0034]
【Example】
A metal shaft is set in a cylindrical mold (16 mmφ) whose inner peripheral surface is coated with a fluororesin, and a urethane foam foaming composition having the composition shown in Table 1 below is thoroughly stirred in this mold. Then, without using a release agent, a one-shot method was used to form a skinless type urethane foam layer (thickness: 5.5 mm) on the outer periphery of the shaft, thereby producing a toner supply roller. In this case, this operation is continuously repeated without cleaning the mold, and the water repellency (releasability) of the fluororesin coat applied to the inner peripheral surface of the mold is reduced, resulting in a good skinless urethane. The number of shots (coating durability) at which a foam layer could not be obtained was examined. The results are shown in Table 1. The column of “TDI / crude MDI” in Table 1 shows the weight mixing ratio of TDI and crude MDI, and the column of “NCO Index” shows the blending amount of TDI / crude MDI mixture in NCO Index, All other proportions are by weight.
[0035]
Next, for the obtained urethane foam layer of each roller, the hardness according to the above-described measurement method, and the ratio (opening ratio) of the entire opening area of the opening portion of the foam cell opened on the roller outer peripheral surface to the roller outer peripheral surface were examined. . Further, each roller is mounted as a toner supply roller 1 on the developing device having the configuration shown in FIG. 1, and three images are output to determine the presence or absence and degree of image unevenness, ◎: none, ○: almost none, X: Evaluated in three stages: unevenness. The results are shown in Table 1.
[0036]
[Table 1]

* 1: “FT703” manufactured by Sanyo Chemical Co., Ltd. (EO / PO mass ratio: 13/87)
* 2: “FT103” manufactured by Sanyo Chemical Co., Ltd. (EO / PO mass ratio: 75/25)
* 3: “SRX274C” manufactured by Toray Dow Corning Silicon Co., Ltd.
* 4: Kao Riser No. 31 manufactured by Kao Corporation
* 5: Kao Riser No. 1 manufactured by Kao Corporation
[0037]
As shown in Table 1, in the OA rollers (toner supply rollers) of Examples 1 to 9 according to the present invention, the skinless urethane foam layer on the surface has good physical properties and ensures good performance. In addition to being able to exhibit, it is possible to perform 50-200 shots continuous molding by a one-shot method without using a mold release agent using a fluororesin-coated mold, and it can be produced very efficiently confirmed. On the other hand, the roller of Comparative Example 1 showed good coating durability due to the action of the silicone foam stabilizer, but was inferior to the physical properties of the skinless urethane foam layer and the performance of the roller because no subpolyol was used. . In addition, although the roller of Comparative Example 2 can provide good skinless urethane foam layer properties and roller performance, the amount of silicone foam stabilizer used is insufficient, so the coating durability is extremely inferior. The productivity of the mold was very poor because the mold had to be cleaned.
[Brief description of the drawings]
FIG. 1 is a schematic diagram illustrating an example of a developing mechanism using a toner supply roller.
FIG. 2 is a schematic view showing a method for measuring the hardness of a urethane foam layer formed on a roller surface.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Toner supply roller 2 Developing roller 3 Photosensitive drum 4 Laminated blade 5 Transfer part 6 Recording medium 7 Cleaning part 8 Cleaning blade t Toner

Claims (6)

Skinless foaming in which at least the outer peripheral surface is formed of a urethane foam layer obtained by molding and foaming a foamable composition containing polyol, isocyanate, water and a foam stabilizer, and the foam cells of the urethane foam layer are open to the outer peripheral surface. In the OA roller that is the body layer,
The foamable composition for molding the urethane foam layer is 2 to 20 parts by weight of a subpolyol having an ethylene oxide content of 25 to 100% by weight, with respect to 100 parts by weight of a main polyol having an ethylene oxide content of 0 to 20% by weight. And an OA roller comprising 2 to 10 parts by weight of a silicone foam stabilizer. 2. The OA roller according to claim 1, wherein the total area of the opening of the foamed cell of the urethane foam layer is 20% or more of the roller outer peripheral surface. The OA roller according to claim 1 or 2, wherein the urethane foam layer has a hardness of 350 g or less. 4. The urethane foam layer is formed by foaming the outer periphery of the shaft or other substrate by injecting the foamable composition into a mold having a shaft or other substrate disposed thereon. The OA roller according to item 1. Toner supply that rotates in contact with the surface of the developing roller in the developing mechanism of an electrophotographic apparatus or electrostatic recording apparatus, carries the toner in the toner reservoir on the outer peripheral surface, and supplies the toner to the surface of the developing roller The OA roller according to any one of claims 1 to 4, which is a roller. A shaft or other substrate is placed in the mold, and a foamable composition containing polyol, isocyanate, water and a foam stabilizer is injected into the mold, and urethane foam is formed on the outer periphery of the shaft or other substrate. In the method of manufacturing an OA roller, the layer is foam-molded to obtain an OA roller having an outer peripheral surface formed of a skinless urethane foam layer in which foam cells are opened on the outer peripheral surface.
As the above-mentioned mold, while using a water repellent treatment on the inner peripheral surface of the cavity, and without applying a mold release agent to the inner peripheral surface of the cavity, the foamable composition, ethylene oxide content A foamable composition containing 2 to 20 parts by weight of a subpolyol having an ethylene oxide content of 25 to 100% by weight and 2 to 10 parts by weight of a silicone foam stabilizer with respect to 100 parts by weight of a main polyol of 0 to 20% by weight. Is injected into the mold to form the skinless urethane foam layer.

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