JP2004151499A - Toner supply roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner supply roller whose roller performance is stabilized, which has properties such as proper open cell ratio, impact resistance and compression set and with which an image of high quality without having density unevenness can be obtained. <P>SOLUTION: The toner supply roller whose surface layer is at least formed of a polyurethane foam obtained by using a long chain polyol and polyisocyanate, is characterized in that the long chain polyol component incorporates a polyoxyethylene polyoxypropylene polyol where ethylene oxide is added and polymerized by 60-95 mol% at random. <P>COPYRIGHT: (C)2004,JPO

Description

配合量＝質量部
【００７６】
１）分子量３５００、官能基数３、水酸基４８ｍｇＫＯＨ／ｇ含有、エチレンオキシドを７０モル％ランダム付加
２） 分子量３０００、官能基数３、水酸基５５．２ｍｇＫＯＨ／ｇ含有、エチレンオキシドを２０モル％ランダム付加
３） 三洋化成工業（株）製ポリエーテルポリオール、分子量７０００、官能基数３、水酸基２４．３ｍｇＫＯＨ／ｇ含有
４） 東ソー（株）製アミン触媒
５） 東ソー（株）製アミン触媒
６） 日本ユニカー（株）製シリコーン整泡剤
７） 三井武田ケミカル（株）製ＴＤＩ、ジフェニルメタンジイソシアネート混合体、ＮＣＯ＝４０％
８）三井武田ケミカル（株）製ＴＤＩ、ジフェニルメタンジイソシアネート混合体、ＮＣＯ＝４５％
９）日本ポリウレタン（株）製ＴＤＩ、ジフェニルメタンジイソシアネート混合体、ＮＣＯ＝３６％
比較例１、２では、画像耐久試験中にベタ黒画像に濃度ムラまたは色抜けが周期的に発生した。
【００７７】
これに対し実施例１〜３では、湿熱圧縮永久歪率１４％以下、セル開口が十分であり、収縮もなく、画像耐久試験では問題なく良好な画像が得られた。実施例４では、湿熱圧縮永久歪率１７％、セル開口が十分であり、収縮が少々あるがクラッシングで容易に戻り、画像耐久試験では問題なく良好な画像が得られた。実施例５では、湿熱圧縮永久歪率１６％、セル開口が１部不十分ではあるが、収縮はなく、画像耐久試験では問題なく良好な画像が得られた。本結果より本実施例に示したトナー供給ローラは、耐久性に優れていることがわかる。
【００７８】
【発明の効果】
本発明により、適正な連続気泡率、反発弾性および圧縮永久歪などの物性を有し、色抜けや濃度ムラのない高品質の画像が得られ、ローラ性能が経年変化のない安定したトナー供給ローラが得られた。
【図面の簡単な説明】
【図１】本発明の画像形成装置部品をトナー供給ローラとして装着した電子写真方式の画像形成装置の一例を示す説明図である。
【図２】トナー供給ロールのポリウレタンフォーム層の湿熱圧縮永久歪の測定方法を示す説明図であって、（ａ）は平面説明図、（ｂ）は側面説明図である。
【符号の説明】
１．画像形成体
２．現像ローラ
３．トナー供給ローラ
４．層規制ブレード
５．転写ローラ
６．クリーニングブレード
７．帯電ローラ
８．記録媒体
９．スキン層
１０．芯金
１１．ポリウレタンフォーム層
１２．スリーブ（φ１６ｍｍ）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a toner supply roller.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, image forming apparatuses such as copying apparatuses, image recording apparatuses, printers, and facsimile machines develop an electrostatic latent image formed on an image carrier made of an electrophotographic photosensitive member or an electrostatic recording derivative by a developing device. And visualization as a toner image.
[0003]
Such a developing device has a built-in toner supply roller composed of a soft elastic roller for supplying a predetermined toner (developer) contained in the hopper to the image carrier.
[0004]
In recent years, the demand for digitized images has increased, and accordingly, higher definition and higher quality images have been demanded. As a result, it is necessary to improve color images and electrophotographic images. An elastic roller made of polyurethane foam (sponge) has been used as a toner supply roller in such a developing device.
[0005]
Conventionally, flexible polyurethane foams have been widely used for furniture, bedding, vehicles, and the like, and particularly for cushioning materials of automobiles, etc., by making use of their excellent cushioning properties as disclosed in Japanese Patent Application Laid-Open No. 8-245746. Was.
[0006]
As a method for producing a cushion material made of this flexible polyurethane foam, a method is known in which water is used in combination with a low-boiling fluorine compound such as Freon 11 or Freon 123 as a foaming agent.
[0007]
In addition, a molding method is mainly used for a seat cushion of an automobile or the like.
[0008]
The polyurethane toner supply roller is manufactured, for example, by the following method.
[0009]
To manufacture the toner supply roller, a molding die for a toner conveying roller is prepared, and a composition containing a polyisocyanate and a polyol component (polyol, foam stabilizer, catalyst, water, etc.) is prepared in the molding die by a one-shot manufacturing method. After mixing, the mixture is poured, foamed in a mold, and then the molded product is released from the mold.
[0010]
From the viewpoints of conductivity and heat resistance, for example, as disclosed in JP-A-9-8735, a polyoxyethylene polyoxypropylene polyol obtained by random addition polymerization of 3 to 50% by mass of ethylene oxide is used as a conductive member. -Is used.
[0011]
[Problems to be solved by the invention]
A toner supply roller using a conventional molding die shrinks if left as it is after demolding, and the surface condition is non-uniform.
[0012]
In order to solve this problem, crushing is performed to forcibly break the cell membrane and increase the open cell ratio, thereby preventing the shrinkage. As the crushing method, there are a roller crushing method and a vacuum crushing method. However, when the open cell ratio is low, the cell state is not sufficiently destructed, the shrinkage is large, and the shape does not return sufficiently, so that the surface state is not good. The image becomes uniform, and color loss or uneven density occurs in the image.
[0013]
In addition, when foaming is carried out with water alone without using a low boiling point fluorine compound, physical properties such as rebound resilience and compression set of the obtained flexible polyurethane foam are deteriorated, durability is impaired, and color loss occurs in images. Is generated periodically. In addition, if the number of water parts is reduced to such an extent that physical properties such as rebound resilience and compression set of the obtained flexible polyurethane foam are not deteriorated, foaming becomes insufficient and cell opening property is impaired, and non-supply of toner causes uneven density in an image. There was a problem of doing.
[0014]
The present invention provides a stable toner supply roller that has physical properties such as an appropriate open cell ratio, rebound resilience, and compression set, is capable of obtaining a high-quality image without color omission and density unevenness, and whose roller performance does not change over time. It is intended to provide.
[0015]
[Patent Document 1]
JP-A-8-245746
[Patent Document 2]
JP-A-9-87354
[0016]
[Means for Solving the Problems]
The present invention includes the following aspects.
(1) In a toner supply roller in which at least a surface layer is formed of a polyurethane foam obtained by using a long-chain polyol and a polyisocyanate, polyoxyethylene polyoxypropylene polyol obtained by random addition polymerization of 60 to 95 mol% of ethylene oxide. Is used in the above long-chain polyol component.
(2) The toner supply roller according to (1), wherein the polyoxyethylene polyoxypropylene polyol has an average number of functional groups of 2 to 6.
(3) The toner supply roller according to (1) or (2), wherein the terminal ethylene oxide of the polyoxyethylene polyoxypropylene polyol is contained in an amount of 3 to 20 mol%.
(4) The toner supply roller according to any one of (1) to (3), wherein the polyoxyethylene polyoxypropylene polyol is contained in the long-chain polyol component in an amount of 0.5 to 10% by mass. .
(5) The toner supply roller according to any one of (1) to (4), wherein the polyoxyethylene polyoxypropylene polyol contains a hydroxyl group in an amount of 20 to 70 mgKOH / g.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
The present invention relates to a toner in which the surface layer is formed of a polyurethane foam obtained by using a polyisocyanate and a long-chain polyol containing polyoxyethylene polyoxypropylene polyol obtained by random addition polymerization of ethylene oxide at 60 to 95 mol%. A supply roller is provided.
[0018]
According to the present invention, a toner having a proper open cell ratio, physical properties such as rebound resilience and compression set, a high-quality image without color omission and density unevenness, and stable roller performance without aging can be obtained. A supply roller can be provided.
[0019]
Next, embodiments of the present invention will be described in detail.
[0020]
Ethylene oxide (hereinafter abbreviated as EO) addition polyols are roughly classified into three types.
[0021]
The first is a type in which EO is added only to the terminal (immediately before the hydroxyl group), the second is a type in which EO is added only to the inside, and the third is a type in which EO is added to both the terminal and the inside.
[0022]
The EO-terminal-added polyol is a polyol in which EO is added before a hydroxyl group in order to increase the reactivity (resinification) of polyoxypropylene glycol with isocyanate, and is a polyol having a high degree of primary conversion of the hydroxyl group. Except for the terminal part, it is propylene oxide (hereinafter referred to as PO) and is rich in PO, so that it has better compatibility with isocyanate than water, and the hydroxyl group with increased reactivity easily reacts with isocyanate and has high closed-cell properties ( Polyurethane foam (of strong resin) is easily formed.
[0023]
On the other hand, since the EO internal addition polyol is EO-rich except for the terminal portion, it has excellent compatibility with water, and since the hydroxyl group is secondary, the reaction of water-isocyanate is prioritized. That is, because of strong gasification (high open cell properties), the EO internal addition polyol is rarely used alone. Further, since the reactivity of the hydroxyl group is low, it is hardly used for molds requiring high reactivity. In most cases, a small amount of a slab foam modifier is added and used.
[0024]
The EO random addition polyol is a polyol in which the reactivity of the hydroxyl group is increased by adding EO to the terminal, and at the same time, EO is also added inside to improve the closed cell properties. The balance between gasification and resinization differs depending on the EO addition rate and arrangement at the end and inside.
[0025]
In a toner supply roller in which at least a surface layer is formed of a polyurethane foam obtained by using a long-chain polyol and an isocyanate, a polyol to which 60 to 95% of EO is added at random is contained in a long-chain polyol component. Has been found to improve the low open cell properties of, and obtain an appropriate open cell ratio.
[0026]
For example, the polyoxyethylene polyoxypropylene polyol used in the present invention may be prepared by using a compound having two or more active hydrogen groups used for obtaining a long-chain polyol alone or an arbitrary mixture as an initiator. Molar%, preferably 65 to 90 mole%, is obtained by random addition polymerization.
[0027]
When ethylene oxide is contained in the long-chain polyol in an amount of 60 mol% or more, the internal EO is low, so that the polyol does not become a low open cell polyol. Therefore, sufficient open cell properties are obtained and the opening property is not impaired. It is not necessary to add a large amount of raw materials to obtain a proper cell opening property.
[0028]
If ethylene oxide is contained in an amount of 95 mol% or less in the long-chain polyol, the polyol does not become a highly open-cell polyol due to the high internal EO. Although high open cell properties can be obtained by adding a small amount of polyol, unless the content is more than 95 mol% in the long-chain polyol, the cell itself will not be coarsened and some cell coalescence will not occur. A toner supply roller having a predetermined stable cell opening property can be obtained.
[0029]
The polyoxyethylene polyoxypropylene polyol used in the present invention preferably has an average number of functional groups (MW (molecular weight) / EW (equivalent)) of 2 to 6, and more preferably 2.5 to 4.0. .
[0030]
If the average number of functional groups is 2 or more, the foam is sufficiently foamed, and if it is 6 or less, the obtained polyurethane foam does not become hard. If it exceeds 6, the hardness of the polyurethane foam increases, and the toner deteriorates.
[0031]
In the polyoxyethylene polyoxypropylene polyol used in the present invention, the terminal ethylene oxide is preferably 3 to 20 mol%, more preferably 5 to 15 mol%.
[0032]
If it is 3 mol% or more, it reacts and foams sufficiently, and if it is 20 mol% or less, the primary ratio of hydroxyl groups increases, resinification improves, closed cell properties increase, shrinkage increases, and it becomes difficult to obtain a normal foam. Not even.
[0033]
The polyoxyethylene polyoxypropylene polyol used in the present invention is preferably 0.5 to 10% by mass, more preferably 1 to 3% by mass, when the total amount of the polyol component in the long-chain polyol component is 100% by mass. %. Within this range, the cells of the polyurethane foam become open cells, which facilitates crushing and at the same time improves compression set.
[0034]
When the content is 0.5% by mass or more, the above effect is sufficiently obtained, and when the content is 10% by mass or less, the mixing does not become uneven.
[0035]
The polyoxyethylene polyoxypropylene polyol used in the present invention preferably contains 20 to 70 mg KOH / g of hydroxyl groups (hereinafter abbreviated as OH value). When the OH value is 20 or more, the reaction is sufficiently performed, and when the OH value is 70 or less, the resin is hardened and the cell is hardly opened, and the cell is not hardened.
[0036]
The long-chain polyol is not particularly limited, and may be appropriately selected from conventionally known various polyols and used. Examples of the polyol include polyethylene adipate (PEA), polybutylene adipate (PBA), polyhexylene adipate (PHA), a copolymer of ethylene adipate and butylene adipate, dimer acid-based polyol, castor oil-based polyol, and polycaprolactone. Examples include polyester polyols such as polyols and polyether polyols such as polyoxyalkylene glycols.
[0037]
These polyols include, for example, ethylene glycol, propanediol, butanediol, diethylene glycol, dipropylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, decamethylene glycol, neopentyl glycol, 3-methyl-1,5- Pentanediol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sugar alcohols such as sucrose, glucose, bisphenol A, ethylenediamine, propylenediamine, diethylenetriamine, toluenediamine, metaphenylenediamine, diphenylmethanediamine, xylylenediamine, etc. EO using one or more compounds having two or more active hydrogens as an initiator PO, butylene oxide, amylene oxide, glycidyl ethers, methyl glycidyl ether, t- butyl glycidyl ether, are prepared by addition polymerization by a known method monomers one or more of such phenyl glycidyl ether. Preferably, it is obtained by addition polymerization of EO, PO, etc., and has a molecular weight of 2,000 to 10,000, a functional group of 2 to 4, more preferably 2.5 to 3.5, and an ethylene oxide terminal content of 5 to 30 mol%. , More preferably 10 to 25 mol%.
[0038]
It is preferable to use these polyols singly or as a mixture, adjusting the molecular weight to 2,000 to 10,000. That is, if it is 2000 or more, there is no tendency that the hardness is increased and the deterioration of the toner is accelerated and the durability is inferior. If the molecular weight is 10,000 or less, the viscosity of the polyol becomes high, and there is no tendency that the workability during the reaction deteriorates.
[0039]
When a polyether polyol is used among the above polyols, it is suitable for the production of a soft and highly elastic polyurethane having excellent resistance to wet heat. Further, the use of a polyether polyol containing 5 mol% or more of ethylene oxide is preferable because of good moldability. Further, it may be used as a prepolymer previously polymerized with polyisocyanate.
[0040]
At least a part of the polyether polyol can be replaced by a so-called polymer polyol (trade name: Mitsui Takeda Chemical) modified by polymerization of an ethylenically unsaturated monomer in the polyether polyol.
[0041]
By partially using the above polymer polyol, it is possible to improve the air permeability and the hardness without lowering the wet heat durability of the foam.
[0042]
The ethylenically unsaturated monomer is not particularly limited, but includes acrylonitrile, styrene, methyl methacrylate, vinylidene chloride, and the like, and these polymers are usually dispersed in the form of fine particles having a diameter of 0.1 to 10 μm.
[0043]
The polyisocyanate is not particularly limited and may be appropriately selected from conventionally known polyisocyanates.
[0044]
Examples of the polyisocyanate include aromatic polyisocyanates and derivatives thereof such as toluene diisocyanate (hereinafter abbreviated as TDI) and diphenylmethane diisocyanate, aliphatic polyisocyanates and derivatives thereof such as hexamethylene diisocyanate, and alicyclic rings such as isophorone diisocyanate. Examples include the formula polyisocyanate and derivatives thereof.
[0045]
Examples of the polyisocyanate derivative include a polynuclear compound, a urethane-modified product modified with a polyol, a dimer formed by uretdione, an isocyanurate-modified product, a carbodiimide-modified product, a uretonimine-modified product, an allohanate-modified product, a urea-modified product, and a buret-modified product. Things can be mentioned.
[0046]
Among these polyisocyanates, those containing an aromatic polyisocyanate such as TDI or diphenylmethane diisocyanate or a derivative thereof as a main component are preferable because the resulting toner supply roller has low hardness and improved wet heat durability.
[0047]
In the present invention, one kind of aromatic polyisocyanate such as TDI and diphenylmethane diisocyanate and derivatives thereof may be used, or two or more kinds thereof may be used in combination. Further, if desired, an aliphatic polyisocyanate such as hexamethylene diisocyanate and an alicyclic polyisocyanate such as isophorone diisocyanate together with the aromatic polyisocyanate such as TDI and diphenylmethane diisocyanate and derivatives thereof as long as the object of the present invention is not impaired. Isocyanates and their derivatives can be used in combination. The amount of these polyisocyanates is not particularly limited, but is preferably set so that the NCO index is 60 to 120%, and more preferably 70 to 105%.
[0048]
When the content is 60% or more and 120% or less, unreacted components do not exude or change with time.
[0049]
Examples of the foam stabilizer used together with the polyisocyanate and the long-chain polyol include water-soluble polyether siloxane from polydimethyl siloxane and EO / PO, a sodium salt of sulfonated ricinoleic acid, and polysiloxane and polysiloxane. Examples thereof include a mixture with an oxyalkylene copolymer. Among them, a water-soluble polyether siloxane is preferable as the polyether polyol-based foam stabilizer.
[0050]
Hot-molded foams tend to gel faster than slab foams, and tend to have poor air permeability of polyurethane foams due to overpacking in the mold. For this reason, a foam stabilizer which is basically similar to that for slabs, but has a slightly lower foam regulating power and a higher air permeability is selected.
[0051]
In addition, since the high elastic foam has a high viscosity and high reactivity of the system, when a normal foam stabilizer for flexible foam is used, foam stabilization becomes excessive, the degree of communication decreases, and the foam shrinks. Is generated. For this purpose, low molecular weight copolymers are used.
[0052]
What added an organic functional group instead of the polyether chain may be used. The amount of the foam stabilizer used is 0.1 to 3.0% by mass based on the total amount of the compound having active hydrogen and the polyisocyanate.
[0053]
Blowing agents used with the above polyisocyanates and polyols include water, trichloromonofluoromethane, dichlorodifluoromethane, methylene chloride, trichlorofluoromethane, n- and iso-pentane, especially industrial mixtures thereof, n- and iso-butane. , Liquid hydrocarbons such as propane, ethers such as furan, dimethyl ether and diethyl ether, ketones such as acetone and methyl ethyl ketone, carboxylic acid alkyl esters such as methyl formate, dimethyl oxalate and ethyl acetate, and carbon dioxide And the like are used alone or as a mixture, but it is preferable to use water alone from the viewpoint of environmental protection.
[0054]
The amount of the foaming agent used is preferably 1.0 to 5.0 parts by mass based on 100 parts by mass of the polyol used. When the amount is 1.0 part by mass or more, no skin is formed, and when the amount is 5.0 parts by mass or less, a large amount of aromatic polyurea is generated, physical properties such as compression set are deteriorated, and durability is impaired. Nothing.
[0055]
The catalyst used in the present invention is a known catalyst and is not particularly limited. Examples of the amine catalyst include 1,2-dimethylimidazole, triethylamine, tripropylamine, tributylamine, hexadecyldimethylamine, N- Methylmorpholine, N-ethylmorpholine, N-octadecylmorpholine, diethylenetriamine, N, N, N ', N'-tetramethylethylenediamine, N, N, N', N'-tetramethylpropylenediamine, N, N, N ' , N'-tetramethylbutanediamine, N, N, N ', N'-tetramethyl-1,3-butanamine, N, N, N', N'-tetramethylhexamethylenediamine, bis [2- (N .N-dimethylamino) ethyl] ether, N, N-dimethylbenzylamine, N, N-dimethyl Rohexylamine, N, N, N ', N', N ", N" -pentamethyldiethylenetriamine, triethylenediamine, salts of triethylenediamine, oxyalkylene adducts of amino groups of primary and secondary amines, 1,8 Azacyclo compounds such as -diazabicyclo (5,4,0) undecene-7,1,5-diazabicyclo (4,3,0) nonene-5, N, N-dialkylpiperazines, various N, N ', N "-Trialkylaminoalkylhexahydrotriamines and the like, and organometallic urethanization catalysts include tin acetate, tin octylate, tin octetate, tin oleate, tin laurate, dibutyltin dichloride, dibutyltin dilaurate, Dibutyltin diacetate, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetrakis 2-ethylhexyloxy) titanium, lead naphthenate, nickel naphthenate, cobalt naphthenate, etc., and an organic acid salt catalyst (carboxylate, borate, etc.) having reduced initial activity of an amine catalyst and an organometallic catalyst. ).
[0056]
These catalysts are used alone or as a mixture, and the amount of the catalyst used is suitably 0.001 to 10% by mass based on the compound having active hydrogen.
[0057]
The structure of the crosslinking agent used if necessary is not particularly limited, but diols such as alkylene glycol and 1,4-butanediol (1,4BD), triols such as glycerin and trimethylolpropane (TMP), and pentane Tetraols such as erythritol, diamines such as ethylenediamine (EDA), amino alcohols such as diethanolamine (DEA) and triethanolamine (TEA) can be used alone or in combination.
[0058]
In addition, as the conductive material for providing conductivity as necessary, a general conductivity-imparting agent can be used, and for example, an ionic conductive material can be used.
[0059]
Examples of the ion conductive agent include quaternary ammonium salts and the like, and are used alone or in combination.
[0060]
The compounding amount of these conductive materials is usually in the range of 0.5 to 50 parts by mass, preferably 0.5 to 10 parts by mass, based on 100 parts by mass of the polyol used.
[0061]
That is, when the amount of the conductive agent is 0.5 parts by mass or more, the electric resistance decreases. When the amount is 10 parts by mass or less, the electric resistance does not increase and the ionic conductive agent does not bloom on the surface.
[0062]
As other additives, a flame retardant, a colorant, an antioxidant, an ultraviolet absorber, an antioxidant, an antioxidant, and the like can be used as needed.
[0063]
From the ease of mixing operation and the characteristics of the obtained toner supply roller, the preferred combination of polyisocyanate, polyol and foam stabilizer is a mixture of diphenylmethane diisocyanate and TDI as the polyisocyanate, and polyether as the polyol. A combination using a water-soluble polyether siloxane as the polyol and the foam stabilizer.
[0064]
In addition, the polyurethane molded product preferably has a wet heat permanent distortion rate of 15% or less. That is, the obtained toner supply roll exhibits particularly excellent wet heat durability within the above range. The term "moisture heat permanent distortion ratio" as used herein means, as shown in FIG. 2 (a), that the toner supply roller is supported at the metal core portions at both ends thereof, and that the polyurethane foam layer has a sleeve of φ16 mm. In the state of displacement (compression) of 5 mm, it was left for 72 hours at a temperature of 40 ° C. and a humidity of 95% RH, and showed a degree of restoration after 30 minutes had passed after removal and release (JIS K 6202: C). _S = (T ₀ -T ₁ ) /1.5×100, C _S : Compression set (%), t ₀ : Radius (mm) of the first molded product, t ₁ : Radius (mm) of the molded article after the test. The measurement point was measured at the median as shown in FIG. 2 (b).
[0065]
The method for manufacturing the toner supply roller of the present invention is not particularly limited, and may be a conventional method. An example is as follows. First, after uniformly mixing the long-chain polyol, polyisocyanate, catalyst, foaming agent and optionally used foam stabilizer, water, other auxiliaries, and the like, heating and reaction-curing the present invention, A toner supply roller is obtained. The temperature and time for mixing the raw materials are not particularly limited, but the mixing temperature is usually in the range of 10 to 90 ° C, preferably 20 to 60 ° C, and the mixing time is usually 1 second to 10 minutes, preferably Is about 3 seconds to 5 minutes.
[0066]
In addition, when heating and reacting and curing, a toner supply roller made of polyurethane foam can be manufactured by foaming by a conventionally known method. The foaming method here is not particularly limited, and any method such as a method using a foaming agent and a method of mixing bubbles by mechanical stirring can be used. The expansion ratio may be determined as appropriate, and is not particularly limited.
[0067]
The image forming apparatus component of the present invention uses the polymer material for the image forming apparatus component thus obtained, and when the image forming apparatus component is a roller, it is usually plated with iron. And a core metal made of stainless steel or the like is coated with the above-mentioned polyurethane foam.
[0068]
There is no particular limitation on the joining method of the metal member and the polyurethane member. However, a method in which the metal member is disposed in advance in a mold (molding mold) and the polyurethane composition is cast and cured, or the polyurethane member is formed into a predetermined shape. A method of bonding after molding can be used. In either method, an adhesive layer can be provided between the metal member and the polyurethane foam as required, and a known material such as an adhesive or a hot melt sheet can be used as the adhesive layer.
[0069]
There is no particular limitation on the method of forming the polyurethane member of the present invention, and in addition to a known method, for example, a method of casting a mold having a predetermined shape as described above, a method of cutting a block to a predetermined size by cutting, polishing, and the like. It is possible to use a method of processing to a predetermined size, a method of appropriately combining these methods, or the like.
[0070]
FIG. 1 is an explanatory view showing an example of an electrophotographic image forming apparatus equipped with a toner supply roller of the present invention, and shows an image forming body 1 holding a toner supply roller 3 and an electrostatic latent image according to the present invention. Between the developing roller 2 and the image forming body 1, the outer peripheral surface of which is disposed close to the surface of the image forming body 1, and the transfer roller 5 is brought into contact with the image forming body 1 via a recording medium 8 such as paper. The structure shown is shown. The toner is supplied to the surface of the developing roller 2 by the toner supply roller 3 by rotating the toner supply roller 3, the developing roller 2, and the image forming body 1 in the direction of the arrow, and is formed into a uniform thin layer by the layer regulating blade 4. After that, the latent image adheres to the latent image on the image forming body 1, and the latent image is visualized. Then, by generating an electric field between the image forming body 1 and the transfer roller 5, the toner image on the image forming body 1 is transferred to the recording medium 8. Reference numeral 6 denotes a cleaning roller which removes toner remaining on the surface of the image forming body 1 after transfer. Reference numeral 7 denotes a charging roller.
[0071]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
[0072]
(Examples 1 to 5, Comparative Examples 1 and 2)
First, a polyol component (polyoxyethylene polyoxypropylene polyol, long-chain polyol, foam stabilizer, catalyst, water, etc.) having the composition shown in Table 1 below and a polyisocyanate were adjusted to a liquid temperature of 25 ° C. Then, the two liquids were blended so as to have the respective NCO indexes, and the mixture was stirred for 5 seconds with a stirring blade, and then poured into a mold for a toner supply roll adjusted to a temperature of 60 ° C. to produce a toner supply roll. And various physical properties were evaluated. Regarding the cell opening properties, those having openings over the entire surface were indicated by ○, those with partial skin formation were indicated by Δ, and those with half or more skin formation were indicated by x.
[0073]
In addition, each toner supply roll is incorporated into each toner cartridge of cyan, magenta, yellow, and black of a full-color laser beam printer (contact development system), and continuously outputs 4000 continuous text pages for continuous durability. The solid images of each color were formed and evaluated according to the following methods. The results are shown in Table 1 below.
[0074]
(Image evaluation)
The printed solid image was visually observed and evaluated. Good samples were indicated by "O", and samples having defects (color loss, density unevenness) were indicated by "X". Color loss refers to a case where toner is not supplied to a place where an image is present. Density unevenness means that a solid image becomes non-uniform.
[0075]
[Table 1]

Compounding amount = parts by mass
[0076]
1) Molecular weight 3500, number of functional groups 3, containing hydroxyl group 48mgKOH / g, random addition of ethylene oxide 70mol%
2) 3000 molecular weight, 3 functional groups, containing 55.2 mg KOH / g hydroxyl group, random addition of 20 mol% ethylene oxide
3) Sanyo Kasei Kogyo Co., Ltd. polyether polyol, molecular weight 7000, 3 functional groups, containing 24.3 mg KOH / g hydroxyl group
4) Amine catalyst manufactured by Tosoh Corporation
5) Amine catalyst manufactured by Tosoh Corporation
6) Silicone foam stabilizer manufactured by Nippon Unicar Co., Ltd.
7) TDI manufactured by Mitsui Takeda Chemical Co., Ltd., diphenylmethane diisocyanate mixture, NCO = 40%
8) TDI manufactured by Mitsui Takeda Chemical Co., Ltd., diphenylmethane diisocyanate mixture, NCO = 45%
9) TDI manufactured by Nippon Polyurethane Co., Ltd., diphenylmethane diisocyanate mixture, NCO = 36%
In Comparative Examples 1 and 2, density unevenness or color omission occurred periodically in the solid black image during the image durability test.
[0077]
In contrast, in Examples 1 to 3, the wet heat compression set was 14% or less, the cell openings were sufficient, there was no shrinkage, and good images were obtained without any problem in the image durability test. In Example 4, the wet heat compression set ratio was 17%, the cell opening was sufficient, and although the shrinkage was a little, it easily returned by crushing, and a good image was obtained without any problem in the image durability test. In Example 5, although the wet heat compression set ratio was 16% and the cell opening was insufficient for one part, there was no shrinkage, and a good image was obtained without any problem in the image durability test. From this result, it can be seen that the toner supply roller shown in this embodiment has excellent durability.
[0078]
【The invention's effect】
According to the present invention, a stable toner supply roller having proper open cell ratio, rebound resilience, compression set, and other physical properties, obtaining a high-quality image without color omission or density unevenness, and having no roller performance aging. was gotten.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram illustrating an example of an electrophotographic image forming apparatus in which an image forming apparatus component of the present invention is mounted as a toner supply roller.
FIGS. 2A and 2B are explanatory diagrams illustrating a method of measuring the wet heat compression set of a polyurethane foam layer of a toner supply roll, wherein FIG. 2A is a plan explanatory diagram and FIG.
[Explanation of symbols]
1. Image forming body
2. Developing roller
3. Toner supply roller
4. Layer control blade
5. Transfer roller
6. Cleaning blade
7. Charging roller
8. recoding media
9. Skin layer
10. Mandrel
11. Polyurethane foam layer
12. Sleeve (φ16mm)

Claims (1)

In a toner supply roller in which at least the surface layer is formed of a polyurethane foam obtained by using a long-chain polyol and a polyisocyanate, polyoxyethylene polyoxypropylene polyol obtained by random addition polymerization of ethylene oxide at 60 to 95 mol% is used. A toner supply roller used by being contained in a chain polyol component.

Images