JP2002023531A - Member for image forming device and image forming device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a member for image forming device which is made by using polyurethane foam which has not coarse cells but has uniformly fine cells, and an image forming device provided with the same. SOLUTION: This member for image forming device uses polyurethane foam which is made by foaming and curing a polyurethane forming material which includes a silicone based foam regulating agent consisting of a polyether polyol (A) which is made by performing addition polymerization of ethylene oxide or ethylene oxide and propylene oxide to glycerol, has 1,000-15,000 Mw and has the proportion of primary hydroxy group in terminal hydroxy groups of >=50 mol%, a polyisocyanate compound (B) and polyorganosiloxane-polyalkylene oxide copolymer which has a polyorganosiloxane segment of 400-3,000 Mw and a polyoxyalkylene segment of 1,000-7,000 Mw in the proportion of 95 to (5-50) to 50 in segment ratio. An image forming device is provided with this member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member for an image forming apparatus, and more particularly, to a member using a polyurethane foam having uniform and fine cells without coarse cells. The present invention relates to a member for an image forming apparatus having good performance, which is used as a transfer member, a toner supply member, a cleaning member, a sheet feeding member, and the like, and an image forming apparatus including the same.

[0002]

2. Description of the Related Art In recent years, with the development of electrophotographic technology, image forming apparatuses such as dry electrophotographic apparatuses have been used for charging, developing, and the like.
Polymer members have been attracting attention as members of parts used for transfer, toner supply, cleaning, etc., and generally have elasticity such as a charging roller, a developing roller, a transfer roller, a toner supply roller, and a cleaning roller. It is used in the form of a roller. In processes such as charging and transfer using an elastic roller, this polymer member has the advantage that compared to conventional corotron chargers, the required image forming body charging potential and toner transfer amount can be obtained with a lower power supply voltage. is there. For the polymer members used for these purposes, polymer elastomers or foams such as rubber or polyurethane are usually used, and these have low hardness and contaminate image forming bodies and transfer materials. In many cases, it is required to have a predetermined resistance value in a medium resistance region of 10 ⁴ to 10 ¹⁰ Ω.

However, in order to reduce the hardness of rubber or polyurethane elastomers, it is necessary to incorporate a plasticizer such as dioctyl phthalate or an oil such as aroma oil, and as a result, does not contaminate the image forming body. It is difficult to meet the demand. Therefore, a foam obtained by foaming ethylene-propylene-diene rubber (EPDM) or silicone rubber with a foaming agent such as 4,4'-oxybis (benzenesulfonylhydrazide), or a polyurethane foamed with a foaming agent such as water or Freon is used. Advantageously, foams are used, in particular polyurethane foams. It is required that the polyurethane foam used for each member for the above-mentioned image device has no coarse cells and has uniform and fine cells. The size of the coarse cell that causes an image defect varies depending on the type of each member attached to the image apparatus. For example, in a transfer member, the maximum cell diameter is generally 900 μm or less, and the average cell diameter is 300 μm or less. In this case, a good image is obtained, and if it deviates from this range, image unevenness occurs.

[0004]

Under such circumstances, the present invention uses a polyurethane foam having uniform and fine cells without coarse cells, and comprises a charging member, a developing member, An object of the present invention is to provide a member for an image forming apparatus having good performance, which is used as a transfer member, a toner supply member, a cleaning member, and a sheet feeding member, and an image forming apparatus including the same. Things.

[0005]

Means for Solving the Problems The present inventors have conducted intensive studies to develop a member for an image forming apparatus using a polyurethane foam having uniform and fine cells without coarse cells. It has been found that the object can be achieved by using a molding material containing a polyether polyol having a specific structure, a polyisocyanate compound, and a silicone-based foam stabilizer having a specific structure. The present invention has been completed based on such findings. That is, the present invention relates to (A) glycerin obtained by addition polymerization of ethylene oxide or ethylene oxide and propylene oxide, and having a weight average molecular weight of 1
A polyether polyol having a ratio of primary hydroxyl groups in the terminal hydroxyl group of at least 50 mol%, (B) a polyisocyanate compound, and (C) a polyorganosiloxane segment having a weight average molecular weight of 400 to 3000 and a weight average A polyoxyalkylene segment having a molecular weight of 1,000 to 7000, and a segment ratio of 95:
Image formation using a polyurethane foam obtained by foaming and curing a polyurethane molding material containing a silicone-based foam stabilizer comprising a polyorganosiloxane-polyalkylene oxide copolymer having a ratio of 5 to 50:50. An object of the present invention is to provide an apparatus member and an image forming apparatus having the same.

[0006]

DETAILED DESCRIPTION OF THE INVENTION In the polyurethane molding material of the present invention, as the polyether polyol (A), glycerin obtained by addition polymerization of ethylene oxide or ethylene oxide and propylene oxide is used. The ethylene oxide or the number of moles of ethylene oxide and propylene oxide added is such that the weight average molecular weight of the resulting polyether polyol is 1000 to 150.
00 is selected. When the weight average molecular weight is out of the above range, a polyurethane foam having desired physical properties cannot be obtained. The preferred weight average molecular weight is 2
000-8000.

In this polyether polyol, the ratio of primary hydroxyl groups in terminal hydroxyl groups is 50 mol% or more. When the proportion of the primary hydroxyl group is less than 50 mol%, there is no coarse cell, and it is difficult to obtain a polyurethane foam having uniform and fine cells, and the object of the present invention cannot be achieved. The preferred proportion of this primary hydroxyl group is at least 50 mol%,
0 mol% or more is preferable. Incidentally, the primary reduction ratio of terminal hydroxyl groups by measurement of the proton nuclear magnetic resonance spectra ⁽¹ H-NMR), can be quantified. The alkylene oxide to be added to glycerin may be ethylene oxide alone or a combination of ethylene oxide and propylene oxide. When ethylene oxide and propylene oxide are combined and subjected to addition polymerization, their use ratio is not particularly limited, but it is necessary to carry out addition polymerization by a method such that the ratio of primary hydroxyl groups in terminal hydroxyl groups becomes 50 mol% or more. It is. In addition,
The content of the ethylene oxide component in the polyether polyol is usually in the range of 3 to 50% by weight. Also,
The arrangement of the oxyethylene and oxypropylene groups in the molecular chain is preferably random.

In the present invention, as the component (A), one kind of the above polyether polyols may be used, or two or more kinds thereof may be used in combination. In the polyurethane molding material, examples of the polyisocyanate compound used as the component (B) include various aromatic polyisocyanate compounds such as diphenylmethane diisocyanate and tolylene diisocyanate or derivatives thereof, and various aliphatic polyisocyanate compounds such as hexamethylene diisocyanate. Examples thereof include derivatives thereof, alicyclic polyisocyanate compounds such as isophorone diisocyanate, and derivatives thereof. Among these polyisocyanate compounds, various aromatic polyisocyanate compounds and derivatives thereof are particularly preferable because the cell diameter is stabilized when foaming and curing are performed by using both inert gas and mechanical stirring.

As the aromatic polyisocyanate compound, there are polynuclear compounds, and pure diphenylmethane diisocyanate obtained from diaminodiphenylmethane, polymeric diphenylmethane diisocyanate obtained from a polynuclear compound of diaminodiphenylmethane, and the like can be used. The number of functional groups of the polymeric diphenylmethane diisocyanate is not particularly limited, but a mixture of pure diphenylmethane diisocyanate and various types of polymeric diphenylmethane diisocyanate is used, and the average number of functional groups is preferably 2.05 to 2.05.
4.00, more preferably 2.50 to 3.50. In addition, any polyisocyanate compound can be used as a derivative, such as a modified urethane modified with a polyol or the like, a dimer formed by forming uretdione, a modified isocyanurate, a modified carbodiimide / uretonimine, a modified alohanaate, a modified urea, or a buret. Modified products are used, but urethane modified products and carbodiimide / uretonimine modified products are particularly preferable. These polyisocyanate compounds may be used alone or in combination of two or more. In addition, several kinds of diphenylmethane diisocyanates and derivatives thereof can be used by blending. In addition, within the range not impairing the advantages of the present invention, other aromatic polyisocyanate compounds such as tolylene diisocyanate and various aliphatic polyisocyanate compounds such as hexamethylene diisocyanate and alicycles such as isophorone diisocyanate together with diphenylmethane diisocyanate and derivatives thereof. It does not prevent the combined use of an aromatic polyisocyanate compound or a derivative thereof. The component (A) and the component (B) have an NCO group / OH group molar ratio of 0.9 to 1.5, preferably 1.0 to 1.2.
Is advantageously used in such a ratio as to fall within the range.

The silicone-based foam stabilizer (C) in the polyurethane molding material may have a weight average molecular weight of 400.
A polyorganosiloxane segment having a weight average molecular weight of 1,000 to 7000 and a segment ratio of 95: 5 to 50:50,
Preferably, a polyorganosiloxane-polyalkylene oxide copolymer having a ratio of 90:10 to 60:40 is used. Here, the segment ratio refers to the ratio of the total number of repeating units constituting each segment. By using such a silicone-based foam stabilizer,
When foaming and curing are performed by using both inert gas introduction and mechanical stirring, the cell diameter is stabilized, and a desired polyurethane foam is obtained. The polyorganosiloxane constituting the above-mentioned polyorganosiloxane-polyalkylene oxide copolymer is not particularly limited, and various ones can be used.From the viewpoints of effects and economy, polydimethylsiloxane is preferred. is there.

On the other hand, as polyalkylene oxide,
An ethylene oxide addition polymer or a co-addition polymer of ethylene oxide and propylene oxide is preferred. In the case of a co-addition polymer of ethylene oxide and propylene oxide, it is preferable that ethylene oxide is used in a proportion of 50 to 100 mol% and propylene oxide in a proportion of 50 to 0 mol%. This silicone-based foam stabilizer may be used alone or in combination of two or more. Also,
If desired, an ionic surfactant such as a cationic, anionic or amphoteric surfactant or a nonionic surfactant such as various polyethers or polyesters may be used together with the foam stabilizer. In general, the amount of the silicone foam stabilizer is preferably in the range of 0.1 to 10 parts by weight, more preferably 0.5 to 10 parts by weight, per 100 parts by weight of the polyether polyol (A).
A range of from 5 to 5 parts by weight is preferred. When the member for an image forming apparatus of the present invention is used as a conductive member, a conductivity-imparting agent can be added to the polyurethane molding material as the component (D).

As the conductivity-imparting agent, a carbon conductive agent or an ionic conductive agent can be used. Examples of the carbon conductive agent include gas black such as electrified black, Ketjen black, acetylene black, oil furnace black including ink black, thermal black, channel black, and lamp black. Examples of the ion conductive agent include, for example, tetraethylammonium, tetrabutylammonium, dodecyltrimethylammonium such as lauryltrimethylammonium, octadecyltrimethylammonium such as stearyltrimethylammonium, hexadecyltrimethylammonium, benzyltrimethylammonium,
Perchlorates such as denatured aliphatic dimethylethylammonium, chlorates, hydrochlorides, bromates, iodates, borofluorides, sulfates, alkyl sulfates, carboxylates, sulfonates, etc. Ammonium salts: Perchlorates, chlorates, hydrochlorides, bromates, iodates, borofluorides, trifluoromethyl sulfates of alkali metals or alkaline earth metals such as lithium, sodium, calcium and magnesium Salts, sulfonates and the like. Of these, quaternary ammonium salts of alkyl sulfates and quaternary ammonium salts of polybasic carboxylic acids are particularly preferred because of a small increase in resistance during continuous energization.

These conductive agents may be used alone or in combination of two or more. The amount is not particularly limited and is appropriately selected according to various situations.
Usually, the polymer material 10 constituting the polyurethane foam
0.1 to 40 parts by weight, preferably 0.1 to 40 parts by weight, based on 0 parts by weight.
It is blended at a ratio of 3 to 20 parts by weight. The polyurethane molding material used in the present invention may optionally contain a urethane reaction catalyst or an inorganic powder such as magnesium carbonate, calcium carbonate or magnesium oxide. As the urethane reaction catalyst, for example, triethylamine,
Monoamines such as dimethylcyclohexylamine, tetramethylethylenediamine, tetramethylpropanediamine, diamines such as tetramethylhexanediamine,
Triamines such as pentamethyldiethylenetriamine, pentamethyldipropylenetriamine and tetramethylguanidine; cyclic amines such as triethylenediamine, dimethylpiperazine, methylethylpiperazine, methylmorpholine, dimethylaminoethylmorpholine and dimethylimidazole; dimethylaminoethanol and dimethylamino Ethoxyethanol, trimethylaminoethylethanolamine, methylhydroxyethylpiperazine,
Alcohol amines such as hydroxyethylmorpholine,
Ether amines such as bis (dimethylaminoethyl) ether, ethylene glycol bis (dimethyl) aminopropyl ether, stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker peptide, dibutyltin thiocarboxylate, dibutyltin dimaleate Known catalysts such as organic metal compounds such as dioctyltin marker peptide, dioctyltin thiocarboxylate, phenylmercury propionate and octenoate can be used alone or in combination of two or more. When foaming and curing are performed by introducing inert gas and mechanical stirring in combination among these, from the viewpoint of stabilizing the cell diameter, in particular, stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin marker peptide, Organic metal compounds such as dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin marker peptide, dioctyltin thiocarboxylate, phenylmercuric propionate and octenoate are preferred.

As a method for producing a polyurethane foam, for example, a polyether polyol of the component (A),
The polyurethane molding material containing the polyisocyanate compound of the component (B), the silicone foam stabilizer of the component (C) and, if desired, the conductivity-imparting agent of the component (D) and the urethane reaction catalyst is inertized with mechanical stirring. Gas is introduced to mix bubbles, and this is poured into a predetermined mold or the like or foamed freely in a block shape, and then heat-cured, or a polyether polyol is previously isocyanated, Ethylene glycol or 1,4
A prepolymer method of foaming and curing in the same manner as described above using a chain extender such as butanediol and trimethylolpropane can be used. In the polyurethane foam thus obtained, the maximum cell diameter was 900 μm.
The above coarse cells do not substantially exist, and the average cell diameter is usually in the range of 160 to 280 μm. The bulk density is
It is good to be about 0.2 to 0.7 g / milliliter.

The shape of the member for an image forming apparatus of the present invention is not particularly limited, and may be used in the form of a roller, a drum, a blade or the like depending on the application. When the member for an image forming apparatus of the present invention is a conductive member, the member is usually a metal member obtained by plating steel such as sulfur free-cutting steel with zinc or the like, or a metal member such as aluminum or stainless steel. , A polyurethane foam containing a part or the whole thereof containing a conductivity-imparting agent (hereinafter referred to as a conductive polyurethane foam).
The surface of the conductive polyurethane foam formed by coating the metal member may be coated with a conductive, semiconductive, or insulating paint, if necessary. Specifically, when the member for an image forming apparatus is a medium-resistance elastic conductive roller, a core obtained by plating zinc or the like on sulfur free-cutting steel or the like is cylindrically formed of the conductive polyurethane foam. And, if necessary, a conductive, semi-conductive or insulating paint applied to the outside thereof.

The joining method of the metal member and the conductive polyurethane foam is not particularly limited. However, a method in which the metal member is disposed in a mold in advance and the polyurethane molding material is cast and cured, or the method in which the conductive polyurethane foam is used. For example, a method of forming a predetermined shape and then bonding the same can be used. In either method, an adhesive layer can be provided between the metal member and the conductive polyurethane foam as needed.As the adhesive layer, a known material such as an adhesive made of a conductive paint or a hot melt sheet can be used. Can be used. There is no particular limitation on the method of forming the conductive polyurethane foam, and a known method, for example, in addition to the method of casting a mold having a predetermined shape as described above, a method of cutting a block into predetermined dimensions by cutting, A method in which predetermined dimensions are obtained by polishing treatment, a method in which these methods are appropriately combined, or the like can be used. The type of the member for an image forming apparatus of the present invention is not particularly limited,
For example, when used in an electrophotographic apparatus, a charging member,
Examples include a developing member, a toner supply member, a transfer member, a cleaning member, and a paper supply member.

FIG. 1 is an explanatory view showing an example of an electrophotographic image forming apparatus in which a member for an image forming apparatus according to the present invention is mounted as a transfer roller, and holds a toner supply roller 3 and a latent electrostatic latent image. The developing roller 2 is disposed between the developing roller 2 and the formed image forming body 1 in a state where the outer peripheral surface thereof is close to the surface of the image forming body 1. 2 shows a structure in which a transfer roller 5 according to the present invention is brought into contact. 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 the uniform thin layer is formed by the layer regulating blade 4. Then, the latent image is adhered 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.
The toner remaining on the surface of the image forming body 1 after the transfer is removed. Reference numeral 7 denotes a charging roller.

[0018]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 Propylene oxide and ethylene oxide were randomly added to glycerin, and the content of oxyethylene units was 18
% By weight, the number of functional groups is substantially 3, and the weight average molecular weight is 500
0, the content of primary hydroxyl groups in terminal hydroxyl groups is 80 mol%,
A polyether polyol having an OH value of 35 mgKOH / g was produced. 100 parts by weight of this polyether polyol,
23 parts by weight of a mixture of diphenylmethane diisocyanate, urethane-modified diphenylmethane diisocyanate and carbodiimide-modified diphenylmethane diisocyanate (isocyanate group content: 26% by weight), 0.8 parts by weight of modified aliphatic dimethylethylammonium ethyl sulfate as an ion conductive agent, silicone Polydimethylsiloxane-poly (ethylene oxide / propylene oxide) copolymer which is a system foam stabilizer [weight average molecular weight of polydimethylsiloxane segment 700, weight average molecular weight of polyoxyalkylene segment 3000, segment ratio thereof: 80:20] 4 0.0 parts by weight and 0.005 parts by weight of dibutyltin dilaurate as a catalyst were mixed while being foamed by mechanical stirring, and the mixture was mixed with a metal shaft having a diameter of 6 mm. After the cast to provided a mold, 100
At 10 ° C. for 10 hours, diameter 16.5 mm and length 2
A 15 mm polyurethane foam roller was produced.
Bulk density of foam part 0.4 g / milliliter, Asker C hardness 30 °, average cell diameter 210 μm, diameter 700 μm
m or more cells did not exist.

The above roller was incorporated as a transfer roller in the image forming apparatus shown in FIG. 1 for temperature and 1 for humidity
When a grayscale, black solid, or white solid image was printed in an environment of 5 ° C. and 10%, a good image was obtained without image unevenness. Comparative Example 1 A roller made of polyurethane foam was produced in the same manner as in Example 1 except that the polyether polyol used had a primary hydroxyl group content of 1 mol% in the terminal hydroxyl groups. . Bulk density of foam part 0.4g / ml, Asker C
There were cells having a hardness of 30 °, an average cell diameter of 270 μm, and a diameter of 900 μm or more. When an image was printed using this polyurethane foam roller in the same manner as in Example 1, image unevenness occurred, and a good image was not obtained.

Comparative Example 2 The procedure of Example 1 was repeated, except that a foam stabilizer having a siloxane / ether segment ratio of 0: 100 (ie, a poly (ethylene oxide / propylene oxide) copolymer) was used. In the same manner as in Example 1, a roller made of polyurethane foam was produced. Bulk density of foam part 0.4
g / milliliter, Asker C hardness 30 °, average cell diameter 350 μm, and cells having a diameter of 900 μm or more were present. When an image was printed using this polyurethane foam roller in the same manner as in Example 1, image unevenness occurred, and a good image was not obtained.

[0021]

According to the present invention, a member for an image forming apparatus using a polyurethane foam having uniform and fine cells without coarse cells can be easily obtained. The member for an image forming apparatus of the present invention is used, for example, as a charging member, a developing member, a transfer member, a toner supply member, a cleaning member, and a paper supply member.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of an electrophotographic image forming apparatus in which a member for an image forming apparatus of the present invention is mounted as a transfer roller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming body 2 Developing roller 3 Toner supply roller 4 Layer regulating blade 5 Transfer roller 6 Cleaning roller 7 Charging roller 8 Recording medium

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 75/08 C08L 75/08 3J103 F16C 13/00 F16C 13/00 A 4J002 B 4J034 G03G 15/02 101 G03G 15/02 101 15/08 501 15/08 501D 501A 21/10 21/00 312 F term (reference) 2H003 BB11 BB16 CC05 2H032 AA05 BA19 BA23 2H034 BC01 BC02 BC03 BC04 BC05 2H077 AC04 AD06 AD13 FA13 FA22 FA27 3F343 FA02 FB01 JA11 JD37 3J103 AA02 AA13 AA14 AA32 AA51 BA41 FA14 FA15 FA18 GA02 GA52 GA64 GA73 GA74 HA03 HA05 HA12 HA18 HA20 HA32 HA33 HA37 HA41 HA47 HA48 HA54 4J002 CK041 DA036 DE196 DG046 DK006 EN136 EV256 FD116 GT03 4DG03 DG09 DB03 HC03 HC12 HC17 HC22 HC34 HC35 HC61 HC64 HC65 HC67 JA01 MA01 MA02 MA14 MA15 MA24 NA08 NA09 QC01 QD03 RA07

Claims (7)

[Claims] 1. A polyether obtained by addition polymerization of (A) glycerin with ethylene oxide or ethylene oxide and propylene oxide, having a weight average molecular weight of 1,000 to 15,000 and a proportion of primary hydroxyl groups in terminal hydroxyl groups of 50 mol% or more. Polyol, (B) polyisocyanate compound, and (C) weight average molecular weight of 400 to 3000
A polyorganosiloxane segment comprising a polyorganosiloxane segment and a polyoxyalkylene segment having a weight average molecular weight of 1,000 to 7000 at a segment ratio of 95: 5 to 50:50. A member for an image forming apparatus, wherein a polyurethane foam obtained by foaming and curing a polyurethane molding material is used. 2. The member for an image forming apparatus according to claim 1, wherein the polyisocyanate compound of the component (B) is an aromatic polyisocyanate compound. 3. The silicone foam stabilizer of component (C) is a polydimethylsiloxane-polyethylene oxide copolymer and / or a polydimethylsiloxane-poly (ethylene oxide / propylene oxide) copolymer.
Or the member for an image forming apparatus according to 2. 4. The polyurethane molding composition further comprises (D)
The member for an image forming apparatus according to claim 1, further comprising a conductivity imparting agent as a component. 5. The member for an image forming apparatus according to claim 4, wherein the conductivity imparting agent is an ion conductive agent. 6. A charging member, a developing member, a transfer member,
The member for an image forming apparatus according to claim 1, wherein the member is used as a toner supply member, a cleaning member, or a paper supply member. 7. An image forming apparatus comprising the member for an image forming apparatus according to claim 1.