JPS5999474A - Electrophotographic copying machine - Google Patents

Abstract

PURPOSE:To display excellent cleaning functions even at high temperature and high humidity for a long period and to form an excellent copy picture by providing a cleaning blade made of specific urethane rubber. CONSTITUTION:An electrophotographic copying machine is equipped with a photosensitive body and the cleaning blade which cleans the surface of the photosensitive body by rubbing. The cleaning blade uses urethane rubber obtained by reacting polyisocyanate with polylactone ester [obtained by adding 1mol polymerization initiating agent (e.g. ethylene glycol) to 2-35mol lactone compound (shown by formula I or II) of the same or different kind consisting of >=8-membered ring incorporating an ester component of the lactone compound and performing ring-opening addition polymerization to 1,000-4,000 mean molecular weight] and cured. Consequently, excellent cleaning functions are displayed even at high humidity and high temperature for a long period and excellent copy pictures are obtained.

Description

[Detailed description of the invention] The present invention relates to an electrophotographic copying machine.

In general, electrophotographic copying machines, especially electrophotographic copying machines that use plain paper as recording paper, develop a latent image formed on a photoreceptor with toner.Toner 1.1! By transferring the toner onto recording paper, the photoreceptor can be used repeatedly. Therefore, as the final step of each electrophotographic process, the photoreceptor is cleaned to remove any residual toner that has adhered to it. It is necessary to remove it. As an example of such a cleaning method, there is a known cleaning method in which a cleaning blade made of an elastic material is brought into contact with the photoreceptor and rubbed relative to the photoreceptor29, and this method is extremely simple in construction. It is advantageous.

Conventionally, the blade cleaning method used
The materials for the /-board include urethane rubber, silicone rubber,
Fluororubber, chloroprene rubber, butadiene rubber, etc. are known, but urethane rubber is extremely useful in terms of its mechanical properties, especially its wear resistance, compared to other rubbers. It is.

Conventionally, in cleaning blades, for example, urethane rubber obtained by reacting polyethylene adipate ester, polyoxypropylene glycol, caprolactone ester, etc. with polyisocyanate can be used as a material, as disclosed in JP-A-54-1048.
It is described in Publication No. 40. However, all substances belonging to this group of substances are not suitable for use as a cleaning blade, regardless of their structure, molecular weight, etc. Currently, in 2, polyethylene adipate ester raw materials are used as polyisocyanate raw materials such as 4゜4'-dimethylene diisocyanate and 1,5-naphthylene diisocyanate, and these are used as curing agents such as 1,4-butanediol. However, this cleaning blade has low moisture resistance and undergoes hydrolysis in a high temperature and high humidity atmosphere, resulting in deterioration of its physical properties. There are disadvantages in obtaining the desired cleaning effect over a long period of time in a humid atmosphere.

The present invention was developed based on these circumstances, and its purpose is to provide a high temperature and high humidity atmosphere. The cleaning blade will perform a good cleaning function over a long period of time, forming good copy images.
To provide electronic photocopying machines.

This purpose is to provide an electrophotographic copying machine comprising a photoreceptor and a cleaning blade that cleans the surface of the photoreceptor by rubbing against the surface of the photoreceptor, the cleaning blade comprising a multi-membered ring of 8 negative or more. This is achieved by an electronic copying machine characterized in that it is made of a urethane rubber material obtained by complete reaction and curing of a polylactone ester containing an ester component of a lactone compound, and a polyisocyanate.

The present invention will now be explained in detail with reference to the drawings. In the second aspect of the present invention, as shown in FIG. A photoreceptor drum 11 is provided to rotate in the direction of arrow A, and the outer peripheral area of the photoreceptor drum 11 is provided with a charging device 12 for charging the photosensitive layer, a document light image exposure device 13 for forming an electrostatic charge image, and A developing device 14 for developing an electrostatic image is arranged in this order in the rotating direction of the source drum 110, and following the developing device 14, a transfer paper feeding row 2 is provided.
A transfer electrode 16 for electrostatically transferring the toner image formed by development onto the transfer paper fed along the path P by the photosensitive drum 11 and a separation member for separating the transfer paper from the photosensitive drum 11. The electrodes 17 are provided in this order, and the exposure mechanism 1 for erasing the charge is provided along the rotational direction of the photoreceptor drum 110.
8 is provided, and in the area following this, the cleaning blade 19 is held by the holder 20 so that its tip edge part extends over the entire width of the photoreceptor drum 11, for example, from 15 to 25 gji.
The material of the cleaning blade 19 is obtained by curing a polylactone ester containing an ester component of a lactone compound consisting of a multi-membered ring of 8 or more members by reaction with polyisocyanate.
An electrophotographic copying machine is constructed using a urethane rubber material. Reference numeral 21 denotes a collection container for toner scraped off by the cleaning blade 19 f'.

The present invention is characterized in that the cleaning blade 19 is made of urethane rubber obtained from a specific polylactone ester. In the present invention, as described above, since the cleaning blade 19 is made of a specific urethane rubber,
The cleaning blade has good physical properties, especially its moisture resistance.

Even in a high temperature and high humidity atmosphere, a good and stable masquerading effect can be obtained over a long period of time, and a long-lasting copy image can be formed.

The reason why such excellent effects are obtained is not necessarily clear, but the inclusion of the lactone ring as a component allows the urethane rubber to have good physical properties. This is presumed to be because the presence of a ring compound reduces the number of hydrolyzable groups9, resulting in improved moisture resistance.

In the urethane rubber used as the material of the cleaning blade in the present invention, preferable properties are obtained if the proportion of the ester component of the lactone compound consisting of a multi-membered ring of 8 or more members in the polylactone ester that is the raw material for the component is as low as 9%. It is preferable to use a polylactone ester containing at least 30 liters or more by weight.

The polylactone ester containing an ester of a lactone compound consisting of a multi-membered ring of 8 or more members, which is the raw material for the urethane rubber used as the material for the above-mentioned cleaning blade, has an average molecular weight in the range of 1000 to 4000. preferable. The method for measuring the average molecular weight is to add an acetylation reagent consisting of acetic anhydride and pyridine to polylactone ester, and acetylate it at a specified reaction temperature and for a certain period of time, resulting in vinegar +! This value is obtained by quantifying the terminal OH group based on the amount of potassium hydroxide required to neutralize 2 and measuring the number average molecular weight.

In addition, in practice, the above polylactone ester is obtained as a mixture of various components with different bonding states, so it is neither necessary nor appropriate to define it according to the structural formula of %. If it is represented by general formula [I],
11 is considered to be as follows.

General formula [I] ) i 0-fXl-1-rrr-R-5X, CarOi
- in the formula, Xl and X2 are cleavage residues of a lactone ring consisting of 9 or more negative multi-membered rings, and may be the same or different, and the sum of m and n is 2 to 35. The range is such that nln is 1=3 to 3:1. R is a linking group for X, , X2 and is a divalent organic group having about 300 or less carbon atoms. Further, the average molecular weight (molecular weight based on the above measurement method) of the compound represented by the general formula [■] is preferably 1,000 to 4,000, and the lid containing the lactone ester component (XI, 1X2) is preferably 1 or 30[ It is more than ryoga.

In order to produce a polylactone ester as shown in the general formula [1] above, a lactone compound consisting of 9 or more 8-membered rings of the same or different type must be added at a rate of 2 to 35 [1 mole per mole of polymerization]. Add initiator, temperature 150-300℃
Ring-opening addition polymerization under the conditions of
4000 polylactone ester [obtained]. Examples of the polymerization initiator include -OH group, -NH group, or -
An organic compound having at least two active hydrogen groups, such as 8 to 4 groups, is used. [The above general formula [1] K
The lactone compound for forming the lactone ring cleavage residue group is a lactone compound consisting of a multi-membered ring of 8 or more members, and the following can be mentioned as specific examples of the lactone compound.

591- (ni-undecalactone) (λ-dodecalactone) (μ-tridecalactone) (ν-tetratecalactone) (ξ-pentadecalactone) (0-hexadecalactone), (ni-hebutatecalactone) lactone) [A-12) 0 (3-methyloxanecyclo[A-13] (A-14) CA-16] [A-17] [A-18) [A-19) (A-20) [ A-21) [A-2z:+ () 0 0 (,:A-243 In addition, examples of the 1-initiator for forming the linking group R in the general formula [I] include the following compound examples. can be used.

1-1] Water [1-2) Hoci-I2c OH (ethylene glycol) CI-3) I (OCH2CH2OCB2
CH20H (diethylene glycol) (: I-4]
No C1-12CH2C1-L, C on (
butanediol)c I-6] cl(
2onC)1. - C) L, -〇 -CH20HC1chiOH CI -7ml OH→C)12C1-120-kM
-C) 12C Peng (n is 1 to 150) (polyethylene glycol) CI-8)' C(CH20H)4 (pentaerythritol) (7 ether alcohol) [l-1o] H2NCl'l2CH2N)i2 (ethylenediamine) [1: l-12]H2N-〇Cl
-120H, NH force me uniform C pigeon N) -12 (n is 1 to 1
00) CI-13] C(C)12N)'12)4[1-1
4:] H8C)L, Ch2SH(1,1,, ethanedithiol)Cl-15) 80 C)i2C1-i
2N)′i2(ethanolamine)[1-16))io
-fch2CH2C Pigeon C Peng -〇 Series -H (n is 1 to 80
) (Polytetramethylene glycol) The above polylactone ester reacts with polyisocyanate in the presence of a curing agent to give urethane rubber which is the material of the cleaning blade in the present invention. The following can all be considered suitable.

CB-1) Hexamethylene diisocyanate 0 (,
'N (C1-chi)a OCN Commercial product = "Tesmodur H" Manufactured by West German Bayer AG [B-21 Commercial product 2 "Tesmodulpe" Manufactured by West German Bayer AG [B-3] Metaphenylene diincyanate (B −
4)) Lylene diisocyanate commercially available product: "Tesmodur T" manufactured by Bayer AG, West Germany [Hyren TMJ Tejubon 2B-5] 2. '4-'l Reaction product of lylene isocyanate and trimethylol globan (commercial product manufactured by Bayer AG, West Germany) Commercial product = 1 Coronate L' Made by Nippon Horiurethane Awasha [B-7] 3.3'-Dimeterusosenyl 4.4
'-Diisocyanate commercially available product: "Hiren H" manufactured by Dua N7 Co., Ltd. [B-8] diphenylmethane-4,4'-diisocyanate commercially available product 2
Mirio Kyo-), MT j manufactured by Nippon Polyurethane Kogyo Co., Ltd. [B-9] 3.3'-dimethyl-diphenylmethane-4
, 4'-Diincyanate Commercially available product: [Hyren D1vzMj manufactured by DuPont [H-1]
01 Triphenylmethane-triisocyanate commercial product =
"Desmodur R" manufactured by Bayer AG, West Germany (B-113 polymethylene phenyl incyanate, commercial product: [Millione) MRj, manufactured by Nippon Polyurethane Kogyo Co., Ltd. [B-121 naphthalene-1,5-diisocyanate, commercial product: "Desmodur 15", West Germany Specific examples of the hardening agent manufactured by Bayer AG (b-13) dicyclohexylmethane diisocyanate manufactured by Allied Chemicals include the following.

[C-1])10(CH,,)40H(1,4-butanediol)(2,3-butanediol) [C-3] CH20H C2-C-CI(20H C)120H (1,1 ,1-)limeterolpropane)(3,3'-
dichloro-4,4'-diaminodiphenylmethane) [C
-5) N(C)L, -CIIOH).

CH.

(Triisoglobanolamine) [C-6:I HOC)i2C)L, OH (ethylene glycol) (4,4'-diaminodiphenylmethane) (
In order to produce a cleaning fluid made of urethane comb using a polylactone ester (hydroquinone-bis(β-hydroxy7ethyl)ether) or higher, a polyisocyanate, and a curing agent, it is preferable to proceed as follows. Melt. Immediately, the dehydrated polylactone ester and polyisocyanate are mixed and reacted for 10 to 120 minutes at a temperature of 70 to 150°C to form urethane prepolymer 'K.
HM, and for this urethane prepolymer, the number of moles of incyanate groups due to polyisocyanate, hydroxyl groups due to polyester and curing agent, and /=! A curing agent is added in such a proportion that the ratio to the number of moles of amine groups is 100 to 130 to form a dispersed rubber composition 'cl'I:D. The injection is carried out in a centrifugal casting machine maintained at 140°C. Fig. 2 shows an example of a centrifugal casting machine, in which 31 is a heating chamber, 32 is a heating fluid flow path for heating the heating chamber 31, and 33 is a heating fluid flow path for heating the heating chamber 31. A heat insulating material layer, 34 is an opening/closing door, 35 is a cylindrical rotary wheel, 36 is a drive shaft, 37 is a motor, and the rubber composition is rotor 35 rotating at high speed.
Due to the centrifugal force caused by the rotation thereof, it is spread to a uniform thickness on the casting surface formed by the inner circumferential surface of the rotor 35, thereby forming a cylindrical film-like body 38 (indicated by a chain line). This film-like body 38 is solidified as crosslinking by the curing agent progresses,
The solidified urethane rubber layer thus formed is peeled off from the casting surface, and then subjected to heat treatment and aging for several days to form a rubber plate for a blade.This rubber plate meets the specifications of the planned electrophotographic copying machine. A cleaning blade is manufactured by cutting the blade.

In addition to the above-mentioned centrifugal casting method, there are, for example, a method of injecting and solidifying into a mold in the shape of a cleaning blade, a method of pressure molding in such a mold, and the like.

Any of these methods can advantageously produce a cleaning blade made of urethane rubber.

The above-mentioned urethane rubber may contain an anti-aging agent such as monocarbosiimide.

The present invention will be specifically explained below with reference to examples; however, the embodiments of the present invention are not limited to these examples.

EXAMPLE According to Table 1, lactone and a polymerization initiator were measured and mixed, and addition polymerized at a temperature of 150 to 350 C for about 30 to 180 minutes to synthesize a total of 10 types of polylactone esters PLE1 to PLEIO.

Table 1)'LE: Polylactone ester lactone content tt: Content ratio of lactone ester component in PLE Average molecular weight i 2 Average molecular weight of PPG PPG: Polypropylene glycol These tofm'lJt polylactone esters and polyethylene adipate esters According to Table 2, polyinsyanate was added to the mixture, and the temperature was about 7.
A polyurethane prepolymer was synthesized by reacting at 0C for 100 minutes, and the required amount of crosslinking agent was added thereto, and the mixture was heated at 1C.
The rubber composition, which was reacted at 1120C for 2 minutes and was still in a liquid state, was placed in a hot M140 centrifugal casting machine as shown in Fig. 2.
The rotor is injected into the rotor held near tl:', the rotor is rotated at approximately 1000 rpm, and the assimilated rubber layer is formed by continuing to rotate for 20 to 120 minutes, which is peeled off, taken out, and heated. After being heat treated in a heating furnace at about 140C for 180 minutes, it is further aged at room temperature for 6 to 8 days, resulting in an inner diameter of 204u.
A total of 11 types of cylindrical urethane rubber plates URI ~ URI
I got I. These urethane rubber plates, Tl5K630
The hardness according to the 1A scale was within a practically useful range of 62 to 74 degrees.

Table 2 The proportions represent the number of parts based on 100 parts of ester.
: Polyethylene adipate ester 1.4B: 1,4-
Butanediol MODA: 3,3'-dichloro-4,4'-diaminodiphenylmethane When we investigated the sound distribution of the thickness of these polyurethane rubber plates, we found that:
The margin of error was 115 μm11. le 1
These urethane rubber plates obtained with a comb were cut together with the standard VC of an electrophotographic camera [U-B i x 3000 J (manufactured by Konishiroku Photo Industry Co., Ltd.)] and a cleaning blade CBI with a total of 11 glazes was used. CB11*w.

The cleaning blades CBI to CB described above are used as the cleaning blades 19 in the structure shown in FIG.
An electrophotographic camera was constructed using each of I1, and continuous cohesion was performed under conditions of a temperature of 35° C. and a relative humidity of 75%, and the number of cohesions due to dirt generated due to poor cleaning was determined. The cleaning blade 19 is pressed against the holder 20 so that the suppressing force F is 25 g/m when the angle between the tip contact portion and the surface of the photoreceptor drum 11 is 160 degrees with respect to the upstream surface VC. I was forced to hold it. The results are also shown in Table 3. Note that "40,000J" indicates that no cleaning failure occurred even when the number of copies reached 40,000.

As is clear from the results in Table 3, the urethane rubber material is obtained by reacting a polylactone ester containing an ester component of a lactone compound consisting of a multi-membered ring with 8 or more negative rings and a polyincyanate. The electrophotographic copying machine of the present invention equipped with a cleaning blade achieves excellent cleaning of the photoreceptor over a long period of time even in a high temperature and high humidity atmosphere, and forms good copied images, especially when the image is 8 negative or higher. By using a polylactone ester containing 30% by weight or more of a lactone component consisting of a multi-membered ring, or a polylactone ester having an average molecular weight of 1,000 to 4,000, the above-mentioned effects can be significantly and reliably obtained.

[Brief explanation of drawings]

FIG. 1 is an explanatory view of an example of the configuration of an electrophotographic copying machine, and FIG. 2 is an explanatory cross-sectional view of a centrifugal casting machine for manufacturing cleaning blades. 11... Photosensitive drum 12... Charging device 13
...Additional light image exposure mechanism 14...Developer 15
... Feeding roller P... Passage 16...
Transfer electrode 17... - Separation electrode 1B... Exposure mechanism for charge erasure 19... Cleaning blade 20... Holter 21... Toner collection container 31...
... Heating chamber 32 ... Heating fluid flow path 33 ...
・Insulating material layer 34...Opening/closing door 35...Cylindrical rotor 36-...Drive shaft 37...Motor agent Patent attorney Masahiko Ceiling 17 16 Continuation of page 1 ■Inventor Yuko Fujima Konishiroku Photo Industry Co., Ltd., 2970 Ishikawa-cho, Hachioji City ■Applicant: Hokushin Industry Co., Ltd. 2-3-6 Shitte, Tsurumi-ku, Yokohama City

Claims (1)

[Scope of Claims] l) An electrophotographic copying machine comprising a photoreceptor and a cleaning blade that cleans the surface of the photoreceptor by rubbing therewith, the cleaning blade comprising:
1. An electrophotographic copying machine characterized in that the material is urethane rubber obtained by reaction-curing a polylactone ester containing an ester component of a lactone compound consisting of a multi-membered ring or more, and a polyisocyanate. 2) The content ratio of the ester component of the lactone compound composed of a multi-membered ring of 8 or more members in the polylactone ester is 30
The electrophotographic copying machine according to claim 1, wherein the content is at least % by weight. 3) Average molecular weight of polylactone ester is 1000-4
000. The electrophotographic copying machine according to claim 1, which is 000.