JP2001265190A - Cleaning blade - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning blade, which is capable of effectively preventing occurrence of chipping under a high-temperature environment, without impairing the cleanability under a low-temperature environment and is capable of exhibiting the good cleanability in a wide temperature region. SOLUTION: A cured body 1 of a polyurethane composition containing polyisocyanate and polyol of the cleaning blade consisting of the cured body 1 of the polyurethane composition described is formed so as to have the following characteristics (A) to (C), where (A) the tensile strength at 50 deg.C is >=12 MPa, (B) the tan δ peak temperature is <=15 deg.C, and (C) the hardness is <=80 deg..

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 removing toner remaining on the outer peripheral surface of a photosensitive drum of an electrophotographic copying machine or the like.

[0002]

2. Description of the Related Art As an electrophotographic copying machine, an outer peripheral surface of a photosensitive drum is uniformly charged, and then the outer peripheral surface thereof is exposed through a copy image of a copying object, thereby forming an electrostatic latent image on the outer peripheral surface. Generally, an image is formed, a charged toner is attached to the electrostatic latent image to form a toner image, and copying is performed by transferring the toner image to copy paper or the like.

In such an electrophotographic copying machine, since the toner remains on the outer peripheral surface of the photosensitive drum after the transfer of the toner image, the toner is transferred onto the outer peripheral surface of the photosensitive drum by, for example, a plate-like holder 22 as shown in FIG. Cleaning blade 21 supported
, And the residual toner is scraped off with this to remove it.

As the elastic body used for the cleaning blade 21, polyurethane having excellent mechanical properties such as abrasion resistance has been awarded. However, such a cleaning blade 21 made of polyurethane is
If the cleaning blade 21 is used for a long period of time, the edge of the cleaning blade 21 that is in sliding contact with the photosensitive drum is worn, and there is a problem that the residual toner cannot be removed (cleaned) properly.

[0005] Therefore, a method of coating the polyurethane surface with a coating agent or dispersing a lubricant inside the polyurethane has been proposed and put to practical use.

[0006]

However, the above-described method has a problem in cost because a new coating agent and a lubricant are required. In addition, when the solid lubricant is dispersed, there is a problem that the viscosity of the polyurethane composition for molding the cleaning blade becomes high, and the workability is deteriorated. On the other hand, when dispersing the liquid lubricant, the bleed out of the liquid lubricant
Therefore, there is a problem that an image is adversely affected. Therefore, development of a method capable of reducing stress on the cleaning blade without using a coating agent or a lubricant is desired.

[0007] Recently, high speed and high image quality of the electrophotographic copying machine have been strongly demanded, and it is necessary to further enhance reliability in a high temperature environment. That is, even if the photosensitive drum and the cleaning blade slide at high speed, and even if the cleaning blade is subjected to a higher stress than ever before due to the high friction coefficient of the photosensitive drum accompanying the increase in the discharge amount from the charging roller, It is necessary that the edge portion is not chipped and the cleaning can be performed well. In response to such a demand, a method of setting the tan δ peak temperature of the cleaning blade to a high temperature is generally considered. However, this would impair the cleaning performance in a low temperature environment and improve the cleaning performance in a wide temperature range. It doesn't work.

The present invention has been made in view of such circumstances, and it is possible to effectively prevent the occurrence of chipping in a high temperature environment without impairing the cleaning performance in a low temperature environment, and to provide a good cleaning performance in a wide temperature range. It is an object of the present invention to provide a cleaning blade capable of exhibiting the following characteristics.

[0009]

Means for Solving the Problems In order to achieve the above object, a cleaning blade of the present invention is a cleaning blade comprising a cured product of a polyurethane composition containing a polyisocyanate and a polyol. A configuration is provided in which the following characteristics (A) to (C) are provided. (A) The tensile strength at 50 ° C. is 12 MPa or more. (B) The tan δ peak temperature is 15 ° C. or less. (C) The hardness is 80 ° or less.

The inventors of the present invention have developed a cleaning blade capable of effectively preventing the occurrence of chipping in a high-temperature environment without deteriorating the cleaning performance in a low-temperature environment and exhibiting a good cleaning performance in a wide temperature range. , Earnestly studied. In the process, the formulation of the polyurethane composition for cleaning blade molding was changed in various ways, and the characteristics (modulus, elongation, strength, hardness, etc.) of the cured polyurethane composition were repeatedly examined. It has been found that by setting the three properties of tensile strength, tan δ peak temperature, and hardness in specific ranges, cleaning can be performed in a good condition under any of high and low temperature environments. Reached.

[0011]

Next, an embodiment of the present invention will be described.

The cleaning blade of the present invention comprises, for example, a cured polyurethane composition 1 as shown in FIG. 1, and is supported by a plate-like holder 2 for use.

As a material for forming the cured polyurethane composition 1, a polyurethane composition containing a polyisocyanate and a polyol is used.

The above polyisocyanate is not particularly limited. For example, 4,4'-diphenylmethane diisocyanate (MDI), 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate ( 2,6-TDI), 3,3'-bitrylene-
4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 2,4-
Tolylene diisocyanate uretidinedione (2,4-
Dimer of TDI), 1,5-naphthylene diisocyanate, metaphenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,
4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), carbodiimide-modified MDI, orthotoluidine diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, diisocyanate such as lysine diisocyanate methyl ester, triphenylmethane-4,4 ', 4 "-triisocyanate, etc. And the like. These are used alone or in combination of two or more. Among them, MDI is preferable from the viewpoint of abrasion resistance.

And, as the polyisocyanate, M
When DI is used, the mixing ratio of MDI is preferably 30% by weight or more, and particularly preferably in the range of 30 to 40% by weight, based on the entire polyurethane composition.

Examples of the polyol used together with the polyisocyanate include polyester polyols such as polyester diol and polyester triol, and polyether polyols such as polycaprolactone, polycarbonate, polyoxytetramethylene glycol and polyoxypropylene glycol. These may be used alone or in combination of two or more.

As the polyester polyol, a hydroxyl polyester polyol produced from a polybasic organic acid and a polyol and having a hydroxyl group as a terminal group is preferably used. The polybasic organic acid is not particularly limited, and includes oxalic acid, succinic acid, glutaric acid,
Adipic acid, pimelic acid, suberic acid, azelaic acid,
Examples include saturated fatty acids such as sebacic acid and isosebacic acid, unsaturated fatty acids such as maleic acid and fumaric acid, and dicarboxylic acids such as aromatic acids such as phthalic acid, isophthalic acid, and terephthalic acid. Further, acid anhydrides such as maleic anhydride and phthalic anhydride, dialkyl esters such as dimethyl terephthalate, and dimer acids obtained by dimerization of unsaturated fatty acids are also included. The polyol used together with the polybasic organic acid is not particularly limited, and may be ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexylene glycol, or the like. And triols such as trimethylolethane, trimethylolpropane, hexanetriol and glycerin, and hexaols such as sorbitol.

As the above-mentioned polyether polyol, those produced by ring-opening polymerization or copolymerization of a cyclic ether are preferably used. Examples of the cyclic ether include ethylene oxide, propylene oxide, trimethylene oxide, butylene oxide,
α-methyltrimethylene oxide, 3,3′-dimethyltrimethylene oxide, tetrahydrofuran, dioxane, dioxamine and the like.

In the present invention, the polyol used together with the polyisocyanate is preferably polybutylene adipate (PBA), which is excellent in abrasion resistance, among the above series.

Number average molecular weight (Mn) of the above polyol
Is preferably in the range of 1500 to 3000, particularly preferably 2000 to 2600. That is, when the Mn of the polyol is less than 1500, the physical properties of the obtained cleaning blade tend to decrease, and conversely, the Mn
Is more than 3000, the workability tends to deteriorate.

The polyurethane composition used in the present invention contains, in addition to the above polyisocyanate and polyol, a chain extender, a catalyst, a foaming agent, a surfactant, a flame retardant, a colorant,
A filler, a plasticizer, a stabilizer, a release agent and the like may be contained.

As the chain extender, for example, 1,4-
Butanediol (1,4-BD), ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylene glycol, triethylene glycol, trimethylolpropane (TMP), glycerin,
A polyol having a molecular weight of 300 or less, such as pentaerythritol, sorbitol, 1,2,6-hexanetriol;
2,2 ', 3,3'-tetrachloro-4,4'-diaminodiphenylmethane (TCCAM), 3,3'-dichloro-4,4'-diphenylmethane, trimethylene-bis (4-aminobenzoate), 4, 4'-diamino-
And aromatic diamines such as 3,3'-diethyl-5,5'-dimethyldiphenylmethane. These may be used alone or in combination of two or more. Above all, in consideration of adjusting the tensile strength at 50 ° C., the tan δ peak temperature, and the hardness of the cured product to specific ranges, 1,4-B
It is preferable to use D, TMP, TCDAM. In particular, when two kinds of 1,4-BD and TMP are used together, the weight-based mixing ratio of both is 1,4-BD / TMP
= 75/25 to 85/15.

Examples of the catalyst include amine compounds such as tertiary amines, and organometallic compounds such as organotin compounds. Examples of the tertiary amine include a trialkylamine such as triethylamine; a tetraalkyldiamine such as N, N, N ', N'-tetramethyl-1,3-butanediamine; an amino alcohol such as dimethylethanolamine; ethoxyl Amines; ethoxylated diamines;
Ester amines such as bis (diethylethanolamine) adipate; triethylenediamine; cyclohexylamine derivatives such as N, N-dimethylcyclohexylamine; N-methylmorpholine; morpholine derivatives such as N- (2-hydroxypropyl) -dimethylmorpholine;
N, N'-diethyl-2-methylpiperazine, N, N '
And piperazine derivatives such as -bis- (2-hydroxypropyl) -2-methylpiperazine. Examples of the organic tin compound include dialkyltin compounds such as dibutyltin dilaurate and dibutyltin di (2-ethylhexoate), stannous 2-ethylcaproate, stannous oleate, and the like. . Among these catalysts,
Triethylenediamine is preferably used.

The cleaning blade of the present invention can be manufactured according to a conventional method using each of the above materials. Specifically, it can be produced according to a prepolymer method, a semi-one-shot method, or a one-shot method. Among them, the semi-one-shot method is preferably used from the viewpoint of excellent workability.

According to the semi-one-shot method, the cleaning blade of the present invention is manufactured, for example, as follows. That is, first, the above-mentioned polyisocyanate and polyol are prepared, and both are mixed in an appropriate mixing ratio, and reacted under appropriate reaction conditions to prepare a urethane prepolymer (main agent liquid). On the other hand, the above-mentioned polyol and, if necessary, a chain extender, a catalyst and the like are prepared, these are mixed at an appropriate mixing ratio, and mixed under appropriate mixing conditions to prepare a curing agent liquid. Next, the above base liquid and curing agent liquid are mixed and mixed at an appropriate mixing ratio, and the mixed liquid is poured into a cleaning blade molding die holding the plate-like holder 2, and is subjected to reaction curing. Let it. Then, the obtained cured product is taken out of the mold and processed into a predetermined shape. Thus, a cleaning blade integrally formed with the plate-like holder 2 as shown in FIG. 1 can be obtained.

In the thus obtained cleaning blade, the cured product must have a tensile strength (characteristic A) at 50 ° C. of 12 MPa or more. It is preferably in the range of 12 to 20 MPa. That is, if the tensile strength at 50 ° C. is less than 12 MPa, chipping occurs at an edge portion in a high-temperature environment, which is unsuitable as a cleaning blade for an electrophotographic copying machine that meets demands for higher speed and higher image quality. The tensile strength at 50 ° C. is a strength measured in a 50 ° C. atmosphere according to JIS K6251 except for the thickness of the test piece and the tensile speed.

The tan δ peak temperature (characteristic B) of the above-mentioned cured product must be set at 15 ° C. or less. Preferably, it is in the range of 6 to 15 ° C. That is, t
If the an δ peak temperature exceeds 15 ° C., the cleaning property in a low temperature environment deteriorates. Note that ta
The nδ peak temperature is one of the dynamic viscoelastic properties, and is the temperature at which the maximum (peak) of the tan δ (loss tangent) measured by the dynamic viscoelasticity measuring device is reached.

Further, the hardness (characteristic C) of the cured product is
It must be set to 80 ° or less. Preferably 70
In the range of ８０80 °. That is, if the hardness exceeds 80 °, it is too hard, and the cleaning property cannot be sufficiently achieved in both high and low temperature environments. The hardness was measured by Wallace (HWWAL).
LACE) manufactured by JIS
It is a hardness measured according to K6253.

[0029] The cleaning blade of the present invention comprises:
As shown in FIG. 1, it is not always necessary to integrally mold with the plate-like holder 2, and for example, it may be adhered to the surface of the plate-like holder 2 later.

Next, examples will be described together with comparative examples.

[0031]

[Example 1] [Preparation of urethane prepolymer (base liquid)] PBA (N4010, Mn: 2000, manufactured by Nippon Polyurethane Industry Co., Ltd.) previously vacuum degassed at 80 ° C for 1 hour.
To 34 parts by weight (hereinafter abbreviated as “parts”), 66 parts of MDI (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT) was added, and reacted at 80 ° C. for 3 hours under a nitrogen atmosphere to obtain a base liquid. .

[Preparation of a curing agent liquid] First, PBA (N4010, Mn: 2000) manufactured by Nippon Polyurethane Industry Co., Ltd.
To 2 parts, 4 parts of TCDAM was added, and the mixture was heated at 150 ° C. for 1 hour under a nitrogen atmosphere, and TCDAM was added to PBA.
Was dissolved. Then, 1,4-B
10 parts of D, 5 parts of TMP, and triethylenediamine (DABCO, manufactured by Sankyo Air Products Co., Ltd.) as a catalyst so that the concentration in the cured product becomes 100 ppm, and at 80 ° C. under a nitrogen atmosphere. After mixing for 1 hour,
Vacuum defoaming and dehydration were performed at 0 ° C. for 1 hour to prepare a curing agent liquid.

[Preparation of Cleaning Blade] First, a mold for forming a cleaning blade was prepared, and a plate-like holder was arranged at a predetermined position of the mold, and preheated at 140 ° C. Then, the above-mentioned main agent liquid (liquid temperature: 70 ° C.) and a curing agent liquid (liquid temperature: 70 ° C.) were mixed at a weight ratio of 100: 101, and the mixture was mixed for 30 seconds with a stirring blade while defoaming in vacuum. The mixture was poured into a mold, reacted at 140 ° C. for 30 minutes, and cured to obtain a cured product. Thereafter, the mold was removed, and this was formed into a predetermined shape using a knife, thereby obtaining a desired cleaning blade.

[0034]

Example 2 N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. was used as the PBA.
A base solution was prepared in the same manner as in Example 1 except that the MDI was changed to 8 parts and the MDI was changed to 62 parts. Further, N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. is used as PBA.
A curing agent liquid was prepared in the same manner as in Example 1 except that this PBA was changed to 81 parts, 1,4-BD was changed to 11 parts, TMP was changed to 3 parts, and TCDAM was changed to 5 parts. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. In addition,
The compounding ratio of the main component liquid and the curing agent liquid was 100: 100 in terms of weight ratio.

[0035]

Embodiment 3 N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. was used as the PBA.
A base solution was prepared in the same manner as in Example 1 except that the MDI was changed to 5 parts and the MDI was changed to 65 parts. Further, N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. is used as PBA.
The curing agent liquid was prepared in the same manner as in Example 1 except that this PBA was changed to 80 parts, 1,4-BD was changed to 14 parts, TMP was changed to 3 parts, and TCDAM was not used. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. In addition,
The compounding ratio of the main agent liquid and the curing agent liquid was 100: 97 in terms of a weight ratio.

[0036]

Example 4 N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. was used as the PBA.
A base solution was prepared in the same manner as in Example 1 except that the MDI was changed to 8 parts and the MDI was changed to 62 parts. Further, N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. is used as PBA.
The PBA is 81 parts, TMP is 3 parts, TC
A curing agent liquid was prepared in the same manner as in Example 1 except that DAM was changed to 10 parts. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. In addition, the compounding ratio of the main component liquid and the curing agent liquid was 100: 104 in terms of weight ratio.

[0037]

Example 5 N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. was used as the PBA.
A base solution was prepared in the same manner as in Example 1 except that the MDI was changed to 8 parts and the MDI was changed to 62 parts. Further, N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. is used as PBA.
A curing agent liquid was prepared in the same manner as in Example 1 except that this PBA was changed to 81 parts, 1,4-BD was changed to 12 parts, TMP was changed to 3 parts, and TCDAM was changed to 2 parts. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. In addition,
The compounding ratio of the main component liquid and the curing agent liquid was 100: 98 in terms of weight ratio.

[0038]

Example 6 A base solution was prepared in the same manner as in Example 1 except that the MDI was changed to 62 parts and the PBA was changed to 38 parts.
Also, a curing agent liquid was prepared in the same manner as in Example 1 except that PBA was changed to 87 parts. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. The mixing ratio of the main component liquid and the curing agent liquid is expressed by weight, and the main component liquid: the curing agent liquid = 100: 10
It was 6.

[0039]

Comparative Example 1 A curing agent liquid was prepared in the same manner as in Example 1 except that TMP was changed to 3 parts and TCDAM was changed to 10 parts. Then, using this curing agent liquid, a cleaning blade was produced in the same manner as in Example 1. The mixing ratio of the main agent liquid and the curing agent liquid is expressed as a weight ratio.
00: 105.

[0040]

[Comparative Example 2] 1,4-BD in 9 parts, TMP in 3 parts,
A curing agent liquid was prepared in the same manner as in Example 1 except that TCDAM was changed to 15 parts. Then, using this curing agent liquid, a cleaning blade was produced in the same manner as in Example 1. The compounding ratio of the main component liquid and the curing agent liquid was 100: 109 in terms of weight ratio.

[0041]

Comparative Example 3 NBA2727 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. was used as the PBA.
A base solution was prepared in the same manner as in Example 1 except that the MDI was changed to 5 parts and the MDI was changed to 65 parts. Further, N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. is used as PBA.
The curing agent liquid was prepared in the same manner as in Example 1 except that this PBA was changed to 80 parts, 1,4-BD was changed to 12 parts, TMP was changed to 5 parts, and TCDAM was not used. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. In addition,
The compounding ratio of the main agent liquid and the curing agent liquid was 100: 97 in terms of a weight ratio.

[0042]

Comparative Example 4 N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. was used as PBA.
A base solution was prepared in the same manner as in Example 1 except that the MDI was changed to 3 parts and the MDI was changed to 57 parts. Further, N3027 (Mn: 2400) manufactured by Nippon Polyurethane Industry Co., Ltd. is used as PBA.
The curing agent liquid was prepared in the same manner as in Example 1 except that this PBA was changed to 70 parts, 1,4-BD was changed to 7 parts, TMP was changed to 5 parts, and TCDAM was not used. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. In addition,
The compounding ratio of the main agent liquid and the curing agent liquid was 100: 82 in terms of weight ratio.

[0043]

Comparative Example 5 A main solution was prepared in the same manner as in Example 1 except that PBA was changed to 44 parts and MDI to 56 parts.
Also, PBA is 83 parts, 1,4-BD is 8 parts, TM
A curing agent liquid was prepared in the same manner as in Example 1 except that P was changed to 5 parts and TCDAM was not used. Then, a cleaning blade was produced in the same manner as in Example 1 using these base liquid and curing agent liquid. The mixing ratio of the main agent liquid and the curing agent liquid is expressed as a weight ratio.
00:96.

Using the cleaning blades of Examples and Comparative Examples thus obtained, each characteristic was evaluated according to the following criteria. These results are shown in Table 1 below.
~ Shown in Table 3.

[Tensile strength, M100] Tensile strength at room temperature (25 ° C.) and 50 ° C. and 100% at 50 ° C.
The% modulus (M100) was measured based on JIS K6251 except for the thickness and tensile strength of the test piece. That is, first, a sheet having a thickness of 1.0 ± 0.1 mm was cut out from the cured body of the cleaning blade with a slicer, and the sheet was formed into a JIS No. 6 dumbbell shape with a punching blade to obtain a sample. Then, using this sample, at room temperature (25 ° C.) or 50 ° C. atmosphere,
The tensile strength and M100 were measured by pulling at a distance of 20 mm between the marked lines and a tensile speed of 300 mm / min.

[Tan δ peak temperature] First, a cured body of a cleaning blade was prepared as follows: 1.5 mm × 1.5 mm × 30.
A sample was prepared by molding and measuring to 0 mm. Then
This sample was set on a DVE rheospectra manufactured by Rheology Co., Ltd. so that the distance between the chucks of the tension jig was 20.0 mm, and a sine wave strain having a displacement amplitude of ± 10 μm and a frequency of 10 Hz was applied. Tan in the range of ° C
δ (loss tangent) was measured every 1 ° C. at a rate of temperature increase of 3 ° C./min. The temperature at which the value of tan δ becomes maximum (peak) was defined as the tan δ peak temperature.

[Hardness] Wallace (HW WALLA)
CE) using a Wallace micro hardness tester manufactured by JIS K
It was measured based on 6253.

[Low-temperature, low-humidity (L / L) environment] *: Cleaning properties Each cleaning blade is incorporated in a commercially available laser printer (LBP), and is subjected to L / L environment (15 ° C. × 10%).
(RH), 30,000 sheets of image were output in A3 size. Then, there was no problem in the image, fine lines could be clearly imaged, and those which were successfully cleaned were evaluated as ○, and those where a large amount of fogging, white spots, etc. occurred and cleaning was not normally performed were evaluated as ×. Was evaluated. *: Chipping resistance The presence or absence of chipping at the edge of the cleaning blade after the 30,000-sheet image was output was determined using a scanning electron microscope at a magnification of 500.
Observed at times. Then, those with no chipping were evaluated as 、, and those with chipping were evaluated as x.

[High-temperature, high-humidity (H / H) environment] *: Cleaning properties Each cleaning blade is incorporated in a commercially available laser printer (LBP), and is subjected to H / H environment (35 ° C. × 85%).
(RH), 30,000 sheets of image were output in A3 size. Then, there was no problem in the image, fine lines could be clearly imaged, and those which were successfully cleaned were evaluated as ○, and those where a large amount of fogging, white spots, etc. occurred and cleaning was not normally performed were evaluated as ×. Was evaluated. *: Chipping resistance The presence or absence of chipping at the edge of the cleaning blade after the 30,000-sheet image was output was determined using a scanning electron microscope at a magnification of 500.
Observed at times. Then, those with no chipping were evaluated as 、, and those with chipping were evaluated as x.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

From the results shown in Tables 1 to 3, it can be seen that all of the products of Examples have good cleaning properties under the L / L environment and also have excellent chipping resistance under the H / H environment. On the other hand, the product of Comparative Example 1 has a high hardness, and therefore, under any of the L / L and H / H environments,
It turns out that cleaning performance is inferior. Comparative Example 2
It can be seen that the product and the third product are inferior in cleaning properties under the L / L environment because the tan δ peak temperature is high. Further, it can be seen that the products of Comparative Examples 4 and 5 are inferior in chipping resistance under an H / H environment because the tensile strength at 50 ° C. is low.

[0054]

As described above, the cleaning blade of the present invention is made of a cured product in which the tensile strength at 50 ° C., the tan δ peak temperature, and the hardness are set in specific ranges. For this reason, the occurrence of chipping in a high-temperature environment is effectively prevented without impairing the cleaning performance in a low-temperature environment, and good cleaning performance can be exhibited in a wide temperature range. Therefore, when the cleaning blade of the present invention is incorporated into an actual machine (even a high-speed machine), an excellent image can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically showing one example of a cleaning blade of the present invention.

FIG. 2 is a partially broken configuration diagram schematically illustrating an example of a conventional cleaning blade.

[Brief description of reference numerals]

 1 Cured polyurethane composition

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Akihiro Maeda 1-3-1, Higashi 3-chome, Komaki City, Aichi Prefecture (72) Inventor Satoshi Suzuki 1-1-1, Higashi 3-chome, Komaki City, Aichi Prefecture Tokai Rubber Industry Co., Ltd. F term (for reference) 2H034 BF02 BF03 BF05 4J034 BA08 CA01 CA03 CA04 CA05 CB02 CB03 CB04 CB05 CC03 DA01 DC02 DF01 DF02 DF12 DF20 DF21 DF28 DG03 DG04 DG05 HA01 HA06 HA07 HB12 HC12 HC13 HC22 K12

Claims (4)

[Claims] 1. A cleaning blade comprising a cured body of a polyurethane composition containing a polyisocyanate and a polyol, wherein the cured body has the following properties (A) to (C). Cleaning blade. (A) The tensile strength at 50 ° C. is 12 MPa or more. (B) The tan δ peak temperature is 15 ° C. or less. (C) The hardness is 80 ° or less. 2. The cleaning blade according to claim 1, wherein the tensile strength at 50 ° C. of the characteristic (A) is set in a range of 12 to 20 MPa. 3. The cleaning blade according to claim 1, wherein a tan δ peak temperature of the characteristic (B) is set in a range of 6 to 15 ° C. 4. The hardness of the characteristic (C) is 70 to 80 °.
The cleaning blade according to claim 1, wherein the cleaning blade is set in a range of: