JPH0836337A - Cleaning blade for electrophotographic device - Google Patents

Abstract

PURPOSE:To obtain secure adhesive power and to easily assure high positional accuracy by composing a cleaning blade of a blade member consisting of a thermosetting urethane elastomer having water absorptivity, a supporting member and a moisture curing type adhesive layer. CONSTITUTION:This cleaning blade 1 consists of the blade member 3 consisting of the thermosetting urethane elastomer, the supporting member 2 and the adhesive layer 4 for mounting the blade member 3 at the supporting member 2. The thermosetting urethane elastomer is an elastomer having water absorptivity and the adhesive layer 4 consists of the moisture curing type adhesive. The elastomer having the water absorptivity is preferably a polyester urethane elastomer formed by reaction curing of a high-mol.wt. polyester polyol, etc., and polyhydric alcohol, etc., such as short chain diol. The moisture curing type adhesive contains a urethane polymer or hydrolyzable silane compd. and the adhesive layer 4 consists of plural layers. The adhesive in contact with the supporting member 2 is preferably a primer for metals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning blade for an electrophotographic apparatus, which has an excellent adhesive force and can easily secure position accuracy.

[0002]

2. Description of the Related Art An electrophotographic apparatus has a photoconductor provided with a photoconductor layer on a surface thereof. In operation, an outer peripheral surface of the photoconductor is uniformly charged. The electrostatic latent image is formed by exposing the outer peripheral surface of the electrostatic latent image through a copied image, a toner image is formed by attaching toner to the electrostatic latent image, and the toner image is transferred to paper or the like.

After the transfer, a part of the toner remains on the outer periphery of the photoconductor, and it is necessary to remove the residual toner. The removal is performed by a cleaning blade as shown in FIGS. 1 and 2, for example. 1 and 2
Inside, 1 is a cleaning blade, 2 is a supporting member, 3 is a blade member, and 4 is an adhesive layer for attaching the blade member to the supporting member 2.

A method for fixing the blade member 3 to the support member 2 is, for example, Japanese Patent Laid-Open No. 61-13097.
JP-A-63-26 discloses a method using an adhesive tape.
No. 9188 discloses a method using an instant adhesive, Japanese Patent Publication No. 6-
5439 and JP-A-61-145578, a method using a hot melt adhesive, JP-A-1-1292.
In Japanese Patent Publication No. 82, an adhesive containing a mixture of unsaturated polyurethane resins having two or more polymerizable ethylenically unsaturated groups at the ends as a main component is adhered by being cured by irradiation with radiation and / or heat. Method, Actual Kaihei 5-21
No. 71 discloses a method using a moisture-curable reactive hot melt adhesive and the like.

[0005]

However, the method using the above-mentioned adhesive tape can easily perform high-precision initial fixing, but the adhesive force between the supporting member and the blade member is small, and the adhesive strength is lowered especially at high temperature. However, there is a problem in cleaning property. In addition, the method using the instant adhesive is
In addition to the same problems as with adhesive tape, impact resistance,
There are problems such as poor durability. Further, the method using the hot melt adhesive can easily perform adhesive fixing, and the adhesive force is larger than that of the instant adhesive, but the temperature dependency of the adhesive force is large, and further, it is applied at a high temperature (130 to 180 ° C.). Since it is necessary to perform pressure fusion, there is a problem that the blade member may be deformed or deteriorated, and distortion is caused by thermal contraction during cooling. In the case of a method using an adhesive containing a mixture of the above unsaturated polyurethane resins as a main component, since the curing is performed by a radical reaction, the curing rate varies depending on the amount of oxygen present, and thus the performance of the obtained cleaning blade tends to vary. There's a problem.

The method using the moisture-curable reactive hot-melt adhesive can obtain a strong adhesive force, but since the adhesive is a moisture-curable adhesive, it is necessary to take in moisture and completely cure it. 5 days without temperature and humidity adjustment, 30 ° C /
It also requires 3 days under humidity control at 80% RH, and the cleaning blade requires a high degree of positional accuracy. Therefore, it is necessary to fix the cleaning blade with a jig or the like under the above-mentioned moisture-absorption hardening conditions. If this is not done, the position accuracy cannot be obtained, and therefore there is a problem that the electrophotographic device has a defect in the image. In view of the above, it is an object of the present invention to provide a cleaning blade capable of easily securing a strong adhesive force and a high degree of positional accuracy.

[0007]

SUMMARY OF THE INVENTION The gist of the present invention is a cleaning blade for an electrophotographic apparatus comprising a blade member made of a thermosetting urethane elastomer, a supporting member, and an adhesive layer. Is a water-absorbing elastomer, and the adhesive layer is a moisture-curable adhesive.

In the present invention, the thermosetting urethane elastomer constituting the blade member is a water-absorbing elastomer. As the thermosetting urethane elastomer, for example, polyester-based urethane elastomer is preferable. Examples of the polyester-based urethane elastomer include those obtained by reaction-curing a high-molecular-weight polyester polyol, polyisocyanate, etc. and a polyhydric alcohol such as short-chain diol, triol, etc., and then cutting them into a predetermined size. it can.

Examples of the high molecular weight polyester polyols include those having an ester bond in the molecular chain such as polyethylene adipate ester, polybutylene adipate ester, polyethylene butylene adipate ester, polyhexamethylene adipate ester, and polycaprolactone ester. To be

Examples of the polyisocyanate include diphenylmethane diisocyanate (MDI), naphthylene diisocyanate (NDI), tolylene diisocyanate (TDi) and tolidine diisocyanate (TO).
Di) and the like. Examples of the above polyhydric alcohols such as short chain diols and triols include ethylene glycol, butylene glycol, glycerin and trimethylolpropane.

Examples of the above-mentioned supporting member include mounting fittings made of various metals, plastics, ceramics and the like which are generally used for cleaning blades and the like. Among them, a non-treated steel plate, a steel plate that has been subjected to a surface treatment such as zinc phosphate treatment or chromate treatment, and a mounting plate made of a steel plate that has been subjected to a plating treatment are preferable from the viewpoint of temporal change, particularly corrosiveness. .

The adhesive layer is made of a moisture-curable adhesive. As the moisture-curable adhesive, for example, it melts at approximately 65 ° C. or higher and solidifies when cooled to approximately 50 to 60 ° C., but a moisture crosslinking reaction occurs only to such an extent that it is softened again when heated immediately after solidification, It is preferable that the moisture-crosslinking reaction proceeds at about 30 ° C. and exhibits sufficient adhesive strength at room temperature, and the moisture-crosslinking reaction further proceeds to show heat resistance that does not soften even when heated. As the moisture-curable adhesive, for example, one which is liquid at room temperature and which undergoes a crosslinking reaction due to moisture at room temperature and finally does not soften even when heated is preferable.

Examples of the moisture-curable adhesive include
(A) A base polymer (A1) used in a usual hot melt adhesive and a compound (A2) having a moisture-crosslinking reactivity, (B) a base polymer having a moisture-reactive group, (C) Examples thereof include those obtained by introducing a moisture-crosslinkable reactive group into a base polymer having no moisture-reactive group.

As the base polymer (A1) for the reactive hot melt adhesive in the adhesive of the type (A),
For example, ethylene-vinyl acetate-based; low-density polyethylene, polyolefin such as atactic polypropylene, styrene-isoprene-styrene (SIS), styrene-butadiene-styrene (SBS), styrene-ethylene-butadiene-styrene (SEBS), etc. Block copolymer polymer system; butyl rubber system; melting point 50-60
Urethane prepolymer (Hybon 483, which is a reaction product of ester polyol and isocyanate at about ℃)
2, 4830, 4820, 4860, manufactured by Hitachi Chemical Polymer Co., Ltd.); polyurethane based on dimer acid; polyester based (trade name “Vylon” series, manufactured by Toyobo Co., Ltd.); nylon based etc. Resin etc. are mentioned.

The compound (A
As 2), for example, a urethane prepolymer that is crosslinked by moisture, a compound such as a compound obtained by introducing a hydrolyzable silane group into a styrene-ethylene-butadiene-styrene copolymer (SEBS) that is a base polymer having hot-melt property, and the like. Examples thereof include decomposable organosilane compounds.

As the above-mentioned urethane prepolymer which is crosslinked with moisture, for example, a urethane prepolymer which is a reaction product of methylene diisocyanate, hydrogenated methylene diisocyanate, tolylene diisocyanate and the like and their polyols is preferable. A polyester urethane prepolymer containing an ester bond is more preferable. Examples of the hydrolyzable organosilane compound include, for example, -Si (OR) ₃ (R
Represents an alkyl group) and the like.

The moisture-reactive group-containing base polymer (B) is, for example, a hydrolyzable urethane prepolymer having a reactive group such as isocyanate or a polymer obtained by introducing an alkoxysilane into the end of polypropylene glycol. Examples thereof include organic silane compounds. The former is obtained by reacting an isocyanate with a polyol in the same manner as a usual urethane prepolymer, but a polyester-based urethane prepolymer having an ester bond in the polyol is preferable. The latter is obtained by a reaction between polypropylene glycol and an alkoxysilane compound.

Examples of the above-mentioned base polymer having no reactive group (C) in which a crosslinkable reactive group is introduced include, for example, the base polymers mentioned in the above-mentioned reactive hot-melt adhesive base polymer (A1). Examples of the crosslinkable reactive group include a hydrolyzable organic silane compound having an alkoxysilane introduced therein. In order to introduce a group such as the above-mentioned alkoxysilane, for example, a method of graft-polymerizing vinylethoxysilane onto an ethylene-vinyl acetate copolymer or a styrene-ethylene-butadiene-styrene copolymer is used.

The adhesive layer may be a mixture of two or more kinds of adhesives, as long as it does not impair the property of being solidified at room temperature and cured by moisture reaction at the time of bonding the blade member and the supporting member. Alternatively, a plurality of layers may be laminated and adhered. When two or more kinds of adhesives are mixed and used, the above-mentioned adhesive layer is particularly limited as long as at least one kind is an adhesive of any type among (A), (B) and (C) above. However, in the case of laminating two or more layers, the adhesive layer directly applied to the blade member may have the above (A) and (B).
It is necessary to include any one of the three types of adhesives of (1) and (C).

In order to improve the adhesiveness of the adhesive layer, the adhesive in contact with the supporting member may be at least one kind of metal primer. The metal primer is not particularly limited as long as it is usually used for metals, for example,
Examples include urethane-based, polyester-based, silane-based, polyamide-based, and phenol-based resins; silane coupling agents, etc., which are appropriately selected according to the material of the adhesive used for bonding with the blade member. It

In order to bond the blade member and the support member, first, the adhesive is applied to the adhesive surface of the support member by using a roll coater or the like, and then the applied adhesive is applied. Before the agent is cooled and solidified, the blade member is pasted to a prescribed position to cool it, or after the adhesive is applied to the support member, the adhesive is cooled and solidified, and the blade member is pasted and heat-fused again. Then, by cooling and solidifying, it is possible to bond with an initial adhesive strength at room temperature comparable to that of a conventional hot melt adhesive. In the above step, that is, immediately after solidification, the crosslinking reaction proceeds only to such an extent that it is softened again by heating.

The thickness of the adhesive layer is preferably as thick as possible within the specifications of the product from the viewpoint of peel adhesive strength, and is preferably thin from the viewpoint of shear adhesive strength. It is preferably 10 to 100 μm. The bonding of the blade member and the support member is 1
It is preferable to carry out pressure contact with a pressure of 5 kg / cm ² . Examples of the heat fusion means include a hot plate, an ultrasonic wave, a high frequency means, and the like.

When the above-mentioned metal primer is applied, for example, an applicator equipped with a brush, a sponge roller or the like may be used to evenly apply it to a thickness of about 10 to 100 μm and then dried. When the adhesive is solidified after being bonded at the initial adhesive strength and then left to stand in the air at 30 ° C., for example, the adhesive strength at room temperature becomes sufficient. As it progresses, it shows heat resistance that does not soften even if it is heated.

[0024]

[Function] In the case of a blade member other than a water-absorbing elastomer such as polyester urethane elastomer,
Even if the blade member and the supporting member are bonded together by using a moisture-curable adhesive as shown in FIG. 1, since the supply of moisture to the adhesive is extremely small, the curing reaction also becomes very slow. on the other hand,
The cleaning blade for an electrophotographic apparatus of the present invention uses a water-absorbing elastomer such as a polyester-based urethane elastomer as a blade member, and a moisture-curable adhesive is used as an adhesive layer on the blade member to form an adhesive layer from the blade member. Since the moisture migrates to, even if the moisture-reactive adhesive layer is blocked from the outside air after bonding, the curing reaction proceeds faster in a shorter time than before.

[0025]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A fitting made of a phosphate-treated iron plate (manufactured by Nippon Steel Corporation, trade name: Bonte Steel Plate) was washed with trichlorethylene. Moisture-curing reactive hot melt (Hibbon 4832, manufactured by Hitachi Chemical Polymer Co., Ltd.) containing an ester-based urethane prepolymer as a main component as an adhesive layer is heated and melted to 80 ° C. on a bonding surface of a mounting bracket, and a roll coater is used. And the thickness was about 100 μm. Before the adhesive applied next solidifies, a blade member made of polyurethane elastomer and having a thickness of 2 mm is washed with isopropyl alcohol at a predetermined position on the adhesive surface of the metal fitting applied with the above adhesive, and then about 1 kg / cm. Pressed at the pressure of ² , released the pressure after cooling and solidification, 30 ℃ × 60% RH
I left it down. The standing time was 24 hours, 48 hours, and 96 hours, and cleaning blades were obtained.

The blade member has an isocyanate content (NCO%) obtained by reacting polyethylene adipate with diphenylmethane diisocyanate (MDI).
= 6.3% of prepolymer with a mixture of 1,4-butanediol / trimethylolpropane = 60/40,
[NCO] / [OH] = 0.90 were mixed. After molding, the mixed urethane material was left at 120 ° C. for 6 hours for after-curing, then heat-formed at room temperature for 3 days, and then cut into a predetermined size to obtain a blade member made of a polyester-based urethane elastomer.

Example 2 The same mounting brackets and blade members as in Example 1 were used, and a liquid alkoxyl group-containing moisture-curing adhesive (Super X, manufactured by Cemedine) was used as an adhesive layer by a roll coater at room temperature. It was applied to the metal fitting adhesion surface so as to have a thickness of about 100 μm. After that, the above blade members are stuck together, and pressure-bonded at about 1 kg / cm ² for 15 minutes, and after opening, 30 ° C.
The cleaning blades were obtained by leaving them under the same exposure time as in Example 1 under x60% RH.

Comparative Example 1 A cleaning blade was obtained in the same manner as in Example 1 except that polytetramethylene ether glycol was used in place of polyethylene adipate to form a blade member made of a polyether urethane elastomer.

Comparative Example 2 A cleaning blade was obtained in the same manner as in Example 2 except that polytetramethylene ether glycol was used in place of polyethylene adipate and a blade member made of a polyether urethane elastomer was used.

Evaluation of Examples 1 and 2 and Comparative Examples 1 and 2 A 90 ° peeling test was performed on the cleaning blades thus obtained to evaluate the adhesive force at 25 ° C. The results are shown in Table 1.

[0032]

[Table 1]

Example 3 The same procedure as in Example 1 was carried out, and after cooling and solidifying adhesion, 30 ° C. × 60%
The cleaning blade was obtained by leaving it for 24 hours under RH. Then, the adhesive strength was measured at 25 ° C. and 60 ° C., respectively.
The results are shown in Table 2.

Example 4 As an adhesive layer, a moisture-curable reactive hot melt containing a polycarbonate-based urethane prepolymer as a main component (manufactured by Kanebo USC, Bondmaster 70-725)
A cleaning blade was obtained in the same manner as in Example 3 except that 4) was used, and the adhesive strength was measured. The results are shown in Table 2.
It was shown to.

Example 5 Primer (Chemlock # manufactured by Road Far East Co., Ltd.
218) was applied to the metal fitting side in advance using a roll to a thickness of about 30 μm and dried in the same manner as in Example 3 to obtain a cleaning blade and measure the adhesive force. The results are shown in Table 2.

[0036]

[Table 2]

[0037]

The cleaning blade for an electrophotographic apparatus of the present invention comprises a blade member made of a thermosetting urethane elastomer having water absorbency, a supporting member, and an adhesive layer made of a moisture-curable adhesive. It is possible to obtain a cleaning blade having adhesiveness and excellent durability that can easily secure a high degree of positional accuracy.

[Brief description of drawings]

FIG. 1 is a schematic view of a cleaning blade.

FIG. 2 is a side view showing an operating state of a cleaning blade.

[Explanation of symbols]

 1 Cleaning Blade 2 Support Member 3 Blade Member 4 Adhesive Layer 5 Release Agent Adhesion Surface 6 Photoreceptor

Claims (4)

[Claims] 1. A cleaning blade for an electrophotographic apparatus, comprising a blade member made of a thermosetting urethane elastomer, a supporting member, and an adhesive layer, wherein the thermosetting urethane elastomer is a water-absorbing elastomer. A cleaning blade for an electrophotographic apparatus, wherein the adhesive layer comprises a moisture-curable adhesive. 2. The cleaning blade for an electrophotographic apparatus according to claim 1, wherein the water-absorbing elastomer is a polyester urethane elastomer. 3. The cleaning blade for an electrophotographic apparatus according to claim 1, wherein the moisture-curable adhesive contains a urethane prepolymer or a hydrolyzable organic silane compound. 4. The cleaning blade for an electrophotographic apparatus according to claim 1, 2 or 3, wherein the adhesive layer comprises a plurality of layers, and the adhesive in contact with the supporting member is at least one kind of metal primer.