JP7621752B2 - Electrophotographic cleaning blade, process cartridge, and electrophotographic image forming apparatus - Google Patents

Description

The present invention relates to a cleaning blade, a process cartridge, and an electrophotographic image forming apparatus for use in an electrophotographic device.

Electrophotographic devices are equipped with cleaning members to remove toner remaining on the surfaces of image carriers and intermediate transfer bodies after a toner image is transferred from the image carriers and intermediate transfer bodies, such as photoconductors, to a transferee. (Hereinafter, the image carriers and intermediate transfer bodies are also referred to as the members to be cleaned.) One of these cleaning members is a cleaning blade.

Patent Literature 1 discloses a cleaning blade made of a polyurethane member that contains a polyurethane material containing a hard segment and a soft segment, and in which the cross-sectional area occupied by hard segment aggregates having a diameter in the range of 0.3 μm to 0.7 μm is 2% to 10%. It also discloses that this cleaning blade is capable of achieving both chipping resistance and abrasion resistance.
According to the inventors' investigations, there is still room for improvement in terms of chipping resistance of the cleaning blade disclosed in Patent Document 1. Specifically, for example, chipping may occur when the cleaning blade is used for a long period of time in a low-temperature, low-humidity environment, such as a temperature of 15° C. and a relative humidity of 10%.

JP 2016-14740 A

One aspect of the present invention is directed to providing an electrophotographic cleaning blade that is highly resistant to chipping and can stably exhibit excellent cleaning performance. Another aspect of the present invention is directed to providing a process cartridge that contributes to the stable formation of high-quality electrophotographic images. Still another aspect of the present invention is directed to providing an electrophotographic image forming apparatus that can stably form high-quality electrophotographic images.

According to one aspect of the present invention,
1. An electrophotographic cleaning blade comprising an elastic member containing polyurethane and a support member supporting the elastic member, the cleaning blade cleaning a surface of a moving member to be cleaned by bringing a part of the elastic member into contact with the surface of the member to be cleaned,
When the side of the cleaning blade that contacts the surface of the member to be cleaned is defined as the tip side of the cleaning blade,
the elastic member has a plate shape having a main surface facing the member to be cleaned at least at the tip side and a tip surface forming a tip edge together with the main surface,
Assuming that a first line segment is drawn on the tip surface in parallel to the tip edge with a distance of 10 μm from the tip edge , the length of the first line segment is L, and points 1/8L, 1/2L, and 7/8L from one end side on the first line segment are P0, P1, and P2, respectively,
an average value of the elastic modulus of the elastic member measured using an SPM at 70 points at a pitch of 1 μm on the first line segment, each of which is centered on P0, P1, and P2 on the first line segment , is 15 MPa or more and 470 MPa or less ;
The coefficient of variation of the elastic modulus is 6.0% or less,
The Martens hardness of the elastic member measured at the position P1 is defined as HM1 , and assuming that a bisector of an angle between the main surface and the tip surface is drawn on a cross section of the elastic member that includes P1 and is perpendicular to the tip surface and the tip edge, the Martens hardness of the elastic member measured at a position on the bisector that is 500 μm away from the tip edge is defined as HM2.
The absolute value of the difference between HM1 and HM2 is 0.10 N/mm2 or ^less ;
the ratio [(S2/S1)×100] of the number of hard segments (S2) having a circle equivalent diameter of 40 nm or less to the total number of hard segments (S1) in each of three square observation regions on the tip surface, each of which has a center of gravity at P0, P1, and P2, a side length of 1 μm, and a side parallel to the first line segment, is 92% or more;
The S1 is 300 or more and 1500 or less,
and,
Assume that a third line segment is drawn on the tip surface in parallel to the tip edge with a distance of 0.5 mm from the tip edge, the length of the third line segment is L', and points 1/8L', 1/2L', and 7/8L' from one end side on the third line segment are P0', P1', and P2', respectively;
The samples sampled at P0', P1' and P2' are heated and vaporized in an ionization chamber, and a direct sample introduction type mass spectrometer is used to ionize the sample molecules. The samples are heated to 1000°C at a heating rate of 10°C/s, and the amount of all ions detected is taken as M1, the integral intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 380.5 to 381.5 derived from the polymeric MDI is taken as M2, the integral intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 249.5 to 250.5 derived from 4,4'-MDI is taken as M3, and the integral intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 749.5 to 750.5 derived from the isocyanurate of 4,4'-MDI is taken as M4.
M2/M1 is 0.001 to 0.015,
M3/M1 is 0.04 to 0.10,
M4/M1 is 0.001 or less,
The concentration of the trifunctional alcohol in the polyurethane is 0.22 to 0.39 mmol/g;
In a DSC chart obtained by differential scanning calorimetry of a sample sampled at each of the P0', the P1', and the P2',
The peak top temperature of the only endothermic peak is 200° C. or higher;
The melting onset temperature of the endothermic peak is 175° C. or higher;
The electrophotographic cleaning blade has a difference between the melting initiation temperature and the peak top temperature of 15° C. or more .

According to another aspect of the present invention, a process cartridge having the electrophotographic cleaning blade is provided. According to another aspect of the present invention, an electrophotographic image forming apparatus having the electrophotographic cleaning blade is provided.

According to one aspect of the present invention, a cleaning blade that is highly resistant to chipping and can stably exhibit excellent cleaning performance can be obtained. According to another aspect of the present invention, a process cartridge that contributes to the formation of high-quality electrophotographic images can be obtained. According to yet another aspect of the present invention, an electrophotographic image forming apparatus that can stably form high-quality electrophotographic images can be obtained.

1 is a schematic perspective view of an electrophotographic cleaning blade according to one embodiment of the present invention. 13 is a diagram showing a state in which the edge of the cleaning blade abuts against a member to be cleaned when the process cartridge is stationary. FIG. FIG. 13 is a diagram showing a line segment on the tip surface, parallel to the tip edge and at a distance of 10 μm from the tip edge, for measuring the elastic modulus by SPM. FIG. 1 is a diagram showing the cut-out position of a sample for SPM measurement. FIG. 1 is a diagram showing positions for measuring SPM and Martens hardness HM1. FIG. 4 is a diagram showing positions at which Martens hardness HM2 is measured. FIG. 1 shows the locations at which the size and number of hard segments are measured. FIG. 1 is a diagram showing the position at which measurement is performed by a direct sample introduction method (DI method). FIG. 13 is a diagram showing a method for measuring edge chipping. FIG. 2 is a DSC chart obtained by differential scanning calorimetry for the elastic member of the electrophotographic cleaning blade according to one embodiment of the present invention. FIG. 11(a) is a diagram showing a binary image obtained from the elastic member of Example 1, and FIG. 11(b) is a diagram showing a binary image obtained from the elastic member of Comparative Example 1.

In the present invention, the expressions "XX or more and YY or less" and "XX to YY" representing a numerical range mean a numerical range including the endpoints, that is, the lower limit and the upper limit, unless otherwise specified.
When numerical ranges are stated in stages, the upper and lower limits of each numerical range can be combined in any way.
Examples of members to be cleaned to which the electrophotographic cleaning blade according to one aspect of the present invention (hereinafter also simply referred to as "cleaning blade") is applied include image carriers such as photoreceptors, endless belts such as intermediate transfer belts, etc. Hereinafter, an embodiment of the cleaning blade according to one aspect of the present invention will be described in detail, taking an image carrier as an example of the member to be cleaned, but is not limited thereto.

<Configuration of cleaning blade>
1 is a schematic perspective view of a cleaning blade 1 according to one embodiment of the present invention. The cleaning blade 1 includes an elastic member 2 and a support member 3 that supports the elastic member 2.

Figure 2 is a schematic example of a cross-sectional state of a cleaning blade according to one embodiment of the present invention in contact with a member to be cleaned. The side of the cleaning blade that comes into contact with the surface of the member to be cleaned is defined as the tip side of the cleaning blade. The elastic member 2 has a plate shape with a main surface 4 that faces the member to be cleaned 6 and a tip surface 5 that forms a tip edge together with the main surface 4. R indicates the direction of rotation of the member to be cleaned. Then, a part of the elastic member is brought into contact with the surface of the moving member to be cleaned, thereby cleaning the surface of the member to be cleaned.

The inventors have found that, for example, the cleaning blade of the embodiment described below has excellent chipping resistance and can exhibit excellent cleaning performance.

When it is assumed that a first line segment is drawn on a tip surface of an elastic member containing polyurethane, parallel to the tip edge and at a distance of 10 μm from the tip edge,
The length of the first line segment is L, and points 1/8L, 1/2L, and 7/8L from one end on the first line segment are designated as P0, P1, and P2, respectively (see Figs. 3, 4, and 5). The average value of the elastic modulus of the elastic member measured using an SPM at 70 points on the first line segment at a pitch of 1 µm, centered on each of P0, P1, and P2 on the first line segment, is 15 MPa or more and 470 MPa or less.
If the average elastic modulus is 15 MPa or more, the contact pressure required for cleaning can be obtained, and if it is 470 MPa or less, it is not too hard and has good conformability to the image carrier, thereby preventing the occurrence of cleaning defects.
When the number of sheets used increases, the surface of the image carrier such as the photoconductor is rubbed against the contact member in the presence of toner containing fine particles, causing stripe-like unevenness in the circumferential direction. Therefore, poor conformability makes cleaning defects more likely to occur, but if the average elastic modulus is 470 MPa or less, the surface of the image carrier such as the photoconductor will conform even when stripe-like unevenness is present, and the occurrence of cleaning defects can be suppressed.
The average elastic modulus is preferably 15 MPa or more and 60 MPa or less.

The elastic member has a coefficient of variation of elastic modulus of 6.0% or less, and preferably has a coefficient of variation of 3.4% or less.
The coefficient of variation is calculated by the following formula (1).
Equation (1) Coefficient of variation (%) = standard deviation / average value of elastic modulus × 100

Polyurethane (specifically polyurethane elastomer) is composed of hard segments and soft segments, and it is known that by changing the amount of hard segments, which have a reinforcing effect, polyurethane (polyurethane elastomer) with different mechanical properties can be obtained. However, when aggregation of the hard segments is promoted, the hard segments become larger, and as a result, the contact area with the soft segments increases. Therefore, when used under stress such as the edge of a cleaning blade, the hard segments are more likely to chip from the soft segment, and this chipping can lead to edge chipping. In order to respond to the trend toward smaller diameter and more spherical toners in response to demands for higher image quality, it is preferable to suppress edge chipping to less than 3 μm, and more preferably less than 1 μm.

As the aggregation of the hard segments progresses, separation of the hard and soft segments also progresses. When the elastic modulus of a cleaning blade in this state is measured at 70 points at 1 μm pitch using the SPM described below, the coefficient of variation of the elastic modulus will be large even if the average value of the elastic modulus falls within the above range. In other words, a coefficient of variation greater than 6.0% indicates the presence of hard segments with advanced aggregation that may cause edge chipping.

On the other hand, in the cleaning blade of the present disclosure, the aggregation of the hard segments is suppressed, the hard segments are finely dispersed, and the dispersion is uniform without bias, so that when the elastic modulus is measured using the SPM described later, the variation between the measured values is small, and the coefficient of variation of the elastic modulus is small.
Therefore, even if the average value of the elastic modulus is set to 15 MPa or more and 470 MPa or less at a specific point on the line segment, the coefficient of variation of the elastic modulus can be 6.0% or less. As described above, the hard segments are finely dispersed throughout the entire elastic member, and the dispersion is uniform without bias, so that edge chipping due to loss of hard segments is unlikely to occur. In addition, in a low-temperature environment, the viscosity increases due to the temperature characteristics of the urethane elastomer, and the contact pressure is likely to be insufficient, so that even if the edge chipping is small, it is likely to cause cleaning defects. The cleaning blade of the present disclosure can suppress edge chipping, so that the occurrence of cleaning defects can be suppressed even in a low-temperature environment.

When the amount of hard segments is reduced, the soft segment portion increases, which may result in the coefficient of variation falling below 6.0%, but the average value of the elastic modulus will be less than 15 MPa, and the contact pressure will be insufficient, causing the toner to slip through and resulting in streaky image defects.

By introducing a structure with low regularity or low crystallinity into the hard segments, it is possible to suppress the aggregation of the hard segments. In addition, if the soft segments also become highly crystalline, they tend to gather together, making it difficult for the hard segments to disperse. For this reason, by introducing a structure with low crystallinity into the soft segments, it is possible to suppress the aggregation of the hard segments.

Furthermore, assuming that a line segment is drawn on the tip surface of the elastic member parallel to the edge and at a distance of 10 μm from the edge, the length of the line segment is L, and the Martens hardness of a point P1 that is 1/2L from one end side of the line segment is HM1.
Also, assuming that a bisector of the angle between the main surface and the tip surface is drawn on a cross section orthogonal to the tip surface and the tip edge including P1, the Martens hardness of the elastic member measured at a position on the bisector that is 500 μm away from the tip edge is defined as HM2 (see FIG. 6). In the elastic member of the present invention, the absolute value of the difference between Martens hardness HM1 and Martens hardness HM2 is 0.10 N/mm2 or ^less . Also, it is preferable that the absolute value of the difference between Martens hardness HM1 and Martens hardness HM2 is 0.05 N/mm2 or ^less .

In order to increase the contact pressure, a method of increasing the hardness of the blade surface by surface treatment is used, but in this case, the hardness differs between the treated layer and the inside of the blade, making it prone to chipping at the boundary between hardness. If the absolute value of the difference between HM1 and HM2 is 0.10 N/mm2 or ^less , the difference in hardness between the inside and the surface is small, and edge chipping that is likely to occur at the hardness boundary region when the contact pressure is increased in a low-temperature environment can be suppressed.

Assuming that a line segment is drawn on the tip surface of the polyurethane-containing elastic member parallel to the tip edge at a distance of 10 μm from the tip edge, the length of the line segment is L, and points 1/8L, 1/2L, and 7/8L from one end on the line segment are P0, P1, and P2, respectively. The observation area is a square on the tip surface with a side length of 1 μm and one side parallel to the line segment, with each of the points P0, P1, and P2 as its center of gravity. In each observation area, the ratio ((S2/S1) x 100) of the number of hard segments with a circle equivalent diameter of 40 nm or less to the total number of hard segments (S1) is 92% or more, and S1 is 300 to 1500 (see Figure 7).

If the total number S1 of hard segments per ¹ μm2 is 300 or more and the ratio (S2) of hard segments with a circle equivalent diameter of 40 nm or less is 92% or more [(S2/S1)×100], the aggregation of the hard segments is suppressed and the segments are finely dispersed. Therefore, the hard segments are less likely to fall off from the soft segment, and edge chipping of the cleaning blade can be suppressed. If the total number S1 of hard segments is 1500 or less, the hard segments are not too hard and have good conformability to the image carrier, so that the occurrence of cleaning defects can be suppressed.
The ratio [(S2/S1)×100] is preferably 95% or more and 100% or less.
The S1 is preferably 630 or more and 1,380 or less.

Assuming that a line segment is drawn on the tip surface of the polyurethane-containing elastic member parallel to the tip edge at a distance of 0.5 mm from the tip edge, the length of the line segment is L', and points 1/8L', 1/2L', and 7/8L' from one end on the line segment are P0', P1', and P2', respectively. At each of P0', P1', and P2', the sample to be sampled is heated and vaporized in an ionization chamber, and heated to 1000°C at a heating rate of 10°C/s using a direct sample introduction type mass spectrometer that ionizes the sample molecules,
The amount of all ions detected is M1,
The integrated intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 380.5 to 381.5 derived from the polymeric MDI was designated as M2.
The integrated intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 249.5 to 250.5 derived from 4,4'-MDI was designated as M3.
When the integral intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 749.5 to 750.5 derived from the isocyanurate of 4,4'-MDI is defined as M4,
M2/M1 is 0.001 to 0.015,
M3/M1 is 0.04 to 0.10,
M4/M1 is 0.001 or less.

The polyurethane preferably contains a reaction product of a composition containing an isocyanate compound including a diisocyanate and a polyfunctional isocyanate having three or more functional groups, and an alcohol including a polyfunctional alcohol having three or more functional groups.
For example, the polyurethane preferably contains a crosslinked reaction product (allophanate reaction product) between a polymer of a composition containing polymeric MDI represented by the following chemical formula (1) and 4,4'-MDI represented by the following chemical formula (2) and a trifunctional alcohol.
In addition, an alcohol that has three hydroxyl groups in one molecule is called a trifunctional alcohol.

Polymeric MDI is represented by the following chemical formula (1) and chemical formula (1)'.
In the chemical formula (1)′, n is preferably 1 or more and 4 or less.
Chemical formula (1) corresponds to the case where n is 1 in chemical formula (1)′.

4,4'-MDI is represented by the following chemical formula (2).

The isocyanurate form of 4,4'-MDI is shown in the following chemical formula (3).

If M2/M1 is 0.001 or more, a structure derived from, for example, polymeric MDI, which has low crystallinity, is introduced into the polyisocyanate forming the hard segment, suppressing aggregation of the hard segment and allowing fine dispersion. Therefore, the hard segment is prevented from being chipped from the soft segment portion, and edge chipping caused by the chipping of the hard segment can be suppressed. If M2/M1 is 0.015 or less, the crosslinking amount derived from polymeric MDI is in a moderate range, so that the hard segment does not become too hard, and therefore the conformability to the image carrier is good, and the occurrence of cleaning defects can be suppressed.
The ratio M2/M1 is preferably 0.003 to 0.014.

Compared with trifunctional or higher functional polyisocyanates, difunctional polyisocyanates have a structure that is more easily chain extended, and therefore are more likely to be increased in molecular weight and have improved abrasion resistance. Among difunctional polyisocyanates, 4,4'-MDI is preferred because the reactivity of the two isocyanate groups is equivalent and it is easier to increase the molecular weight.
A compound having one isocyanate group in one molecule is referred to as a monofunctional isocyanate, and a compound having n isocyanate groups in one molecule is referred to as an n-functional isocyanate.

When M3 is the integrated intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 249.5 to 250.5 derived from 4,4'-MDI, if M3/M1 is 0.04 or more, the polymer is easily increased in the curing reaction, and the abrasion resistance can be improved. Since 4,4'-MDI has a highly symmetric structure, if the amount of 4,4'-MDI is large, the hard segments are easily aggregated. Therefore, by setting M3/M1 to 0.10 or less, aggregation of the hard segments can be suppressed, and edge chipping caused by loss of the hard segments can be suppressed.
The ratio M3/M1 is preferably 0.04 to 0.08.

By introducing an isocyanurate structure of 4,4'-MDI, it is possible to suppress the aggregation of hard segments consisting only of 4,4'-MDI, and to suppress edge chipping caused by loss of hard segments. However, if there is too much isocyanurate structure of 4,4'-MDI, stress relaxation increases, resulting in a decrease in contact pressure and a decrease in cleaning performance. By setting M4/M1 to 0.001 or less, this decrease in cleaning performance can be suppressed.

Assuming that a line segment is drawn on the tip surface of the elastic member containing polyurethane in parallel to the tip edge at a distance of 0.5 mm from the tip edge, the length of the line segment is L', and points 1/8L', 1/2L', and 7/8L' from one end on the line segment are P0', P1', and P2', respectively, and in a DSC chart obtained by differential scanning calorimetry of samples sampled at each of P0', P1', and P2',
The peak top temperature of the only endothermic peak is 200° C. or higher;
The melting onset temperature of the endothermic peak is 175° C. or higher, and
The difference between the melting initiation temperature and the peak top temperature is 15° C. or more.

The polyurethane preferably contains a crosslinked reaction product (allophanate reaction product) between a polymer of a composition containing polymeric MDI represented by the above chemical formula (1) and 4,4'-MDI represented by the above chemical formula (2) and a trifunctional alcohol.

As described above, promotion of aggregation of the hard segments leads to chipping of edges, but in a DSC chart obtained by differential scanning calorimetry, the presence of an endothermic peak below 200° C. indicates the phenomenon of melting of the aggregation of the hard segments. In other words, in a state in which the aggregation of the hard segments is suppressed, the melting phenomenon does not become apparent, and therefore no endothermic peak below 200° C. is generated.
In order to prevent edge chipping due to loss of hard segments, the hard segments must be finely dispersed. The molecular motion of the finely dispersed hard segments is present as a broad endothermic peak derived from hydrogen bonds in the polyurethane structure. The broad endothermic peak has an endothermic peak melting onset temperature of 175° C. or higher, and the peak top temperature of the only endothermic peak is 200° C. or higher. In the broad peak, the difference between the melting onset temperature and the peak top temperature is 15° C. or higher.

In differential scanning calorimetry of polyurethane, first, an annealing step is performed at 80° C. for 4 hours, which makes it possible to remove peaks due to aggregation of the soft segments and accurately measure endothermic peaks due to the hard segments.
The peak top temperature of the sole endothermic peak is preferably 210° C. or higher, and more preferably 213° C. or lower.
The melting onset temperature of the endothermic peak is preferably 182° C. or higher, and more preferably 190° C. or lower.
The difference between the melting onset temperature and the peak top temperature is preferably 22° C. or more, and more preferably 28° C. or less.

[Support member]
The material constituting the support member of the cleaning blade of the present invention is not particularly limited, and examples thereof include the following materials: metal materials such as steel plate, stainless steel plate, zinc-plated steel plate, and chrome-free steel plate, and resin materials such as 6-nylon and 6,6-nylon. The structure of the support member is also not particularly limited. One end of the elastic member of the cleaning blade is supported by the support member, as shown in FIG. 2 etc.

[Elastic member]
The polyurethane elastomer constituting the elastic member is obtained mainly from raw materials such as polyol, chain extender, polyisocyanate, catalyst, other additives, etc. These raw materials will be described in detail below.

Examples of the polyols include the following: polyester polyols such as polyethylene adipate polyol, polybutylene adipate polyol, polyhexylene adipate polyol, (polyethylene/polypropylene) adipate polyol, (polyethylene/polybutylene) adipate polyol, and (polyethylene/polyneopentylene) adipate polyol; polycaprolactone-based polyols obtained by ring-opening polymerization of caprolactone; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; and polycarbonate diols. These may be used alone or in combination of two or more. Among the above polyols, polyester polyols using adipate are preferred because they give polyurethane elastomers with excellent mechanical properties.

In particular, those using glycols with 4 or more carbon atoms, such as polybutylene adipate polyol and polyhexylene adipate polyol, are more preferable. It is also preferable to use polyols with different glycol carbon numbers, such as polybutylene adipate polyol and polyhexylene adipate polyol. The presence of different types of polyols can suppress crystallization of the soft segment, thereby suppressing aggregation of the hard segment.

As the chain extender, glycols and polyhydric alcohols capable of extending the polyurethane elastomer chain can also be used. Examples of glycols include the following: ethylene glycol (EG), diethylene glycol (DEG), propylene glycol (PG), dipropylene glycol (DPG), 1,4-butanediol (1,4-BD), 1,6-hexanediol (1,6-HD), 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, xylylene glycol (terephthalyl alcohol), and triethylene glycol. Examples of trihydric or higher polyhydric alcohols include trimethylolpropane, glycerin, pentaerythritol, and sorbitol. These can be used alone or in combination of two or more.

One method for improving the elastic modulus of polyurethane elastomers is to introduce crosslinks. A preferred method for introducing crosslinks is to use a polyhydric alcohol as the chain extender.

In addition, if there are too many branches, it becomes difficult to react all the hydroxyl groups and to obtain the intended degree of crosslinking, so it is more preferable to use trifunctional alcohols among polyhydric alcohols. Among them, trimethylolpropane (TMP) is more preferable because it has a methylene skeleton next to the hydroxyl group, which allows for a flexible crosslinking structure in terms of molecular structure and also has the effect of suppressing the crystallinity of the hard segment.

The concentration of the trifunctional alcohol calculated by the following formula (2) is preferably 0.22 to 0.39 mmol/g. If it is 0.22 mmol/g or more, it is very effective in suppressing hard segment aggregation, and edge chipping of the cleaning blade can be further suppressed.
If the molecular weight is 0.39 mmol/g or less, the elastic modulus due to the introduction of crosslinks does not become too high, so that the conformability to the image bearing member is very good, and the occurrence of cleaning defects can be further suppressed.

Equation (2): Concentration of trifunctional alcohol (mmol/g)=
[amount of trifunctional alcohol (g)/molecular weight of trifunctional alcohol×1000]/[mass of polyurethane (g)]

Examples of the polyisocyanate include the following: 4,4'-diphenylmethane diisocyanate (4,4'-MDI), polymeric MDI, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), xylene diisocyanate (XDI), 1,5-naphthylene diisocyanate (1,5-NDI), p-phenylene diisocyanate (PPDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), tetramethylxylene diisocyanate (TMXDI), and carbodiimide-modified MDI. Of these, 4,4'-MDI is preferred because the two isocyanate groups have equal reactivity and provide high mechanical properties. In addition, since the polyisocyanate that forms the hard segment itself has a branched structure, it is more preferable to use a polyfunctional isocyanate with three or more functional groups, such as polymeric MDI, which has a very high effect of suppressing the aggregation of the hard segment.

As the catalyst, a catalyst generally used for curing polyurethane elastomers can be used, for example, a tertiary amine catalyst, specifically, the following can be mentioned. Aminoalcohols such as dimethylethanolamine, N,N,N'-trimethylaminopropylethanolamine, and N,N'-dimethylhexanolamine; trialkylamines such as triethylamine; tetraalkyldiamines such as N,N,N'N'-tetramethyl-1,3-butanediamine; triethylenediamine, piperazine-based compounds, and triazine-based compounds. In addition, organic acid salts of metals such as potassium acetate and potassium alkali octylate can also be used. Furthermore, metal catalysts generally used for urethane formation, such as dibutyltin dilaurate, can also be used. These can be used alone or in combination of two or more.

The raw materials that make up the elastic member can contain additives such as pigments, plasticizers, waterproofing agents, antioxidants, UV absorbers, and light stabilizers, as necessary.

<Manufacturing Method of Cleaning Blade>
The method for producing the cleaning blade according to the present invention is not particularly limited, and an appropriate method may be selected from known methods. For example, after placing a support member in a mold for a cleaning blade, the polyurethane raw material composition is injected into the cavity and heated to harden, thereby obtaining a cleaning blade in which a plate-shaped blade member and a support member are integrated. Alternatively, a polyurethane elastomer sheet is separately molded from the polyurethane raw material composition, and cut into strips to prepare an elastic member, and the adhesive portion of the elastic member is superimposed on a support member to which an adhesive has been applied or attached, and the adhesive is bonded by heating and pressurizing.

By carrying out the surface treatment, the elastic modulus measured by SPM at the tip surface of the cleaning blade can be increased. The light source used in the surface treatment process generates ultraviolet light. In particular, it is preferable that the wavelength of the maximum emission peak is in the vicinity of 254 nm, for example, in the range of 254±1 nm. This is because ultraviolet light in the above wavelength range or with the above wavelength can efficiently generate active oxygen that modifies the polyurethane surface.
When there are multiple ultraviolet emission peaks, it is preferable that one of them is near 254 nm.

The intensity of the light emitted from the light source is not particularly limited, and may be measured using a spectroradiometer (USR-40V/D, manufactured by Ushio Inc.), an ultraviolet ray integrating light meter (UIT-150-A, UVD-S254, VUV-S172, VUV-S365, manufactured by Ushio Inc.), or the like. The integrated amount of ultraviolet light irradiated to the polyurethane in the surface treatment step may be appropriately selected depending on the effect of the surface treatment to be obtained. This can be determined by the irradiation time of light from the light source, the output of the light source, the distance from the light source, and the like, and may be determined so as to obtain a desired integrated amount of light, such as 10,000 mJ/ ^cm2 .
The integrated amount of ultraviolet light irradiated onto the conductive member can be calculated by the following method.
UV integrated light quantity (mJ/cm ² )=UV intensity (mW/cm ² )×irradiation time (sec)
As a light source that emits ultraviolet light, for example, a high pressure mercury lamp or a low pressure mercury lamp can be suitably used. These light sources are preferable because they can stably emit ultraviolet light of a suitable wavelength that is less attenuated depending on the irradiation distance, and can easily irradiate the entire surface uniformly.

<Process cartridge and electrophotographic image forming apparatus>
The cleaning blade can be incorporated into a process cartridge that is detachably attached to an electrophotographic image forming apparatus and used. Specifically, for example, in a process cartridge that includes an image carrier as a member to be cleaned and a cleaning blade that is arranged to be able to clean the surface of the image carrier, the cleaning blade according to the present embodiment can be used as the cleaning blade. Such a process cartridge contributes to the stable formation of high-quality electrophotographs.
An electrophotographic image forming apparatus according to one aspect of the present invention includes an image carrier such as a photoreceptor, and a cleaning blade arranged to be capable of cleaning the surface of the image carrier, the cleaning blade being the cleaning blade according to this aspect. Such an electrophotographic image forming apparatus can stably form high-quality electrophotographic images.

The present invention will be explained below with reference to the following manufacturing examples, examples, and comparative examples, but the present invention is not limited to these examples. Raw materials other than those shown in the examples and comparative examples were reagents or industrial chemicals.

In this example, an integrally molded cleaning blade as shown in Figure 1 was manufactured and evaluated. The formulations and evaluation results for each example are shown in Tables 1 to 4.

Example 1
[Support member]
A galvanized steel plate having a thickness of 1.6 mm was prepared and processed to obtain a support member having an L-shaped cross section, as shown by reference numeral 3 in FIG.
A single layer urethane-metal adhesive (trade name: Chemlock 219, manufactured by Lord Corporation) was applied to the portions of the support member that would come into contact with the elastic member.

[Preparation of raw material for elastic member]
As an isocyanate, 353.6 g of 4,4'-diphenylmethane diisocyanate (product name: Millionate MT, manufactured by Tosoh Corporation) (hereinafter referred to as 4,4'-MDI)
Polymeric MDI (product name: Millionate MR-400, manufactured by Tosoh Corporation) (hereinafter referred to as MR400) 10.0 g,
As the polyol, 636.4 g of butylene adipate polyester polyol having a number average molecular weight of 2500 (product name: Nipporan 3027, manufactured by Tosoh Corporation) (hereinafter referred to as PBA2500) was used.
The reaction was carried out at 80° C. for 3 hours to obtain a prepolymer having an NCO content of 10.0% by mass.

Next, 7.1 g of 1,4-butanediol (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter referred to as 1,4-BD) was used as a curing agent.
Glycerin (Tokyo Chemical Industry Co., Ltd.) 27.1 g,
250.9 g of hexylene adipate polyester polyol having a number average molecular weight of 1000 (product name: Nipporan 164, manufactured by Tosoh Corporation) (hereinafter referred to as PHA1000),
Polycat 46 (product name, manufactured by Air Products Japan Co., Ltd.) 0.13 g,
0.55 g of N,N'-dimethylhexanolamine (trade name Kao Raiser No. 25, manufactured by Kao Corporation) (hereinafter referred to as No. 25) was mixed therein to prepare a curing agent.

This mixture (curing agent) was added to the above prepolymer and mixed to obtain a polyurethane elastomer composition.
The adhesive application portion of the support member was positioned so as to protrude into the cavity of a mold for forming a cleaning blade. The polyurethane elastomer composition was then injected into the mold for forming a cleaning blade, cured at 130° C. for 2 minutes, and then demolded to obtain an integrally molded body of polyurethane and the support member.

The mold used was one that had been coated with release agent A before the polyurethane elastomer composition was poured into it. The release agent A was a mixture of 5.06 g of ELEMENT14 PDMS 1000-JC (trade name, manufactured by Momentive Performance Materials), 6.19 g of ELEMENT14 PDMS 10K-JC (trade name, manufactured by Momentive Performance Materials), 3.75 g of SR1000 (trade name, manufactured by Momentive Performance Materials), and 85 g of EXXSOL DSP145/160.
This integrally molded body was appropriately cut to an edge angle of 90 degrees, and the lengths in the short direction, thickness direction and length direction of the polyurethane were 7.5 mm, 1.8 mm and 240 mm, respectively. The obtained cleaning blade was evaluated by the following method.

[Method of measuring elastic modulus]
The elastic modulus by SPM was measured by the following method.
The scanning probe microscope (SPM) used was an MFP-3D-Origin (Oxford Instruments Ltd.).
The measurement sample was prepared as follows.
Assuming that a first line segment of length L was drawn on the tip surface of the obtained cleaning blade parallel to the tip edge and with a distance from the tip edge of 10 μm, three square measurement samples of 2 mm squares with one side parallel to the first line segment were cut out with points P0, P1, and P2 of 1/8L, 1/2L, and 7/8L from one end side of the line segment as the center of gravity. Next, from each measurement sample, a polyurethane thin piece of 100 μm square and 1 μm thick with one side parallel to the first line segment and with P0, P1, and P2 as the center of gravity was cut out at -50 ° C. using a cryomicrotome (UC-6 (product name), manufactured by Leica Microsystems). In this way, three measurement samples were prepared. Each of the obtained measurement samples was placed on a smooth silicon wafer and left in an environment of room temperature of 25 ° C. and humidity of 50% for 24 hours.

Next, the silicon wafer with the measurement sample placed on it was set on the SPM stage and observed with the SPM. The spring constant and proportional constant (Invols constant) of the silicon cantilever (product name: OMCL-AC160, manufactured by Olympus Corporation, tip curvature radius: 8 nm) were previously confirmed to be as follows in the thermal noise method installed in this SPM device (spring constant: 30.
22 nN/nm, proportionality constant (Invols constant): 82.59 nm/V).
Furthermore, the cantilever was tuned in advance to determine the resonance frequency of the cantilever (285 KHz (first order) and 1.60 MHz (higher order)).
The measurement mode of the SPM was AM-FM mode, the free amplitude of the cantilever was 3 V (primary) and 25 mV (higher order), the set point amplitude was 2 V (primary), and a phase image was obtained by scanning in a square field of view of 70 μm×70 μm at a scan speed of 1 Hz and a number of scan points of 256 vertically and 256 horizontally. The field of view was selected so that P0, P1, and P2 of each measurement sample were in the center of the field of view and one side was parallel to the first line segment.
From the obtained phase image, the locations of the measurement sample where the elastic modulus was measured by force curve measurement were specified. That is, 70 points were specified at 1 μm pitch (interval) on the first line segment, centered on each of P0, P1, and P2 on the first line segment.
Then, the force curve was measured once at each point in contact mode under the following conditions:
In force curve measurements, the piezoelectric element that drives the cantilever is controlled so that the tip of the cantilever touches the sample surface and the deflection reaches a certain value, at which point the cantilever turns back. The turning point at this time is called the trigger value, and it indicates how much the voltage must increase from the deflection voltage at the start of the force curve before the cantilever turns back.
In this measurement, the force curve was measured with the trigger value set to 0.2 V. Other conditions for the force curve measurement were a distance of 500 nm from the tip position of the cantilever in a standby state to the point where the cantilever turns back at the trigger value, and a scan speed of 1 Hz (the speed at which the probe makes one round trip).
Thereafter, fitting based on the Hertz theory was performed for each of the obtained force curves to calculate the elastic modulus.
The elastic modulus (Young's modulus) according to the Hertz theory is calculated by the following formula (*1).

Calculation formula (*1)
F=(4/3)E ^* R ^1/2 d ^3/2
where F is the force applied to the sample by the cantilever at the time when the cantilever is folded back, E ^* is the complex elastic modulus, R is the radius of curvature of the tip of the cantilever (8 nm), and d is the deformation of the sample at the time when the cantilever is folded back.

And, d is calculated from the following formula (*2).
Calculation formula (*2)
Calculate d = Δz - D.
Δz is the displacement of the piezoelectric element from when the tip of the cantilever comes into contact with the sample until it is turned back, and D is the amount of warping of the cantilever at the time when it is turned back.
Then, D is calculated using the following formula (*3).

Calculation formula (*3)
D = α・ΔV _deflection
In the calculation formula (*3), α is the proportional constant (Invols constant) of the cantilever, and ΔV _deflection represents the amount of change in the deflection voltage from when the cantilever starts to contact the sample to the point of turning back.

Furthermore, F is calculated using the following formula (*4).
Calculation formula (*4)
F = κ D
κ is the spring constant of the cantilever.
Since ΔV _deflection and Δz are actual measured values, E ^* in formula (*1) can be calculated from formulas (*1) to (*4). Furthermore, the desired elastic modulus (Young's modulus) Es can be calculated from the following formula (*5).

Calculation formula (*5)
1/E ^* = [(1-Vs ² )/Es] - [(1-Vi ² )/Ei]
Vs: Poisson's ratio of the sample (fixed at 0.33 in this embodiment)
Vi: Poisson's ratio of the cantilever tip (in this embodiment, the value for silicon is used)
Ei: Young's modulus of the cantilever tip (in this embodiment, the value of silicon is used)

The elastic modulus was determined as the average of the elastic modulus values calculated from the force curve at 70 points and 3 locations, totaling 210 points. The coefficient of variation was also calculated from the average elastic modulus values at 210 points and the standard deviation. The calculated values are shown in Table 1.

[Method of measuring size and number of hard segments]
A measurement sample was prepared in the same manner as described in the above-mentioned method for measuring the elastic modulus. In addition, three phase images (256-level grayscale images) were obtained in the same manner as described in the above-mentioned method for measuring the elastic modulus, except that the size of the field of view was set to 1 μm × 1 μm.
Each of the obtained phase images was binarized using an image processing analysis system (product name: Luzex-AP, manufactured by Nireco Corporation). Specifically, the phase images were binarized using the binarization setting function of the image processing analysis system. The threshold value in the binarization setting function was set to 85 (the 85th of 256 gradations). This operation resulted in a binarized image in which the soft segments were displayed in black and the hard segments were displayed in white. One of the binarized images obtained from the elastic member of Example 1 is shown in FIG. 11(a).

Next, the number and size of the hard segments in the obtained binarized image were measured using the above-mentioned image processing analysis system. The number of hard segments was measured using the "particle number" parameter, and the size of the hard segments was measured using the "circle equivalent diameter" parameter.
The ratio [(S2/S1) x 100] of the number of hard segments (S2) having an equivalent circle diameter of 40 nm or less to the total number of hard segments (S1) was calculated for each of three square observation regions on the tip surface, each of which has a center of gravity at P0, P1, and P2, with one side being 1 μm long and parallel to the line segment. The values are shown in Table 1.

[Method of measuring Martens hardness]
The Martens hardness can be measured by the following method.
Assuming that a line segment is drawn on the tip surface of the elastic member parallel to the edge and at a distance of 10 μm from the edge, the length of the line segment is L, and the Martens hardness of a point P1 that is 1/2L from one end of the line segment is HM1.
Furthermore, assuming that a bisector of the angle between the main surface and the tip surface is drawn on a cross section orthogonal to the tip surface and the tip edge, including P1, the Martens hardness of the elastic member measured at a position on the bisector that is 500 μm away from the tip edge is defined as HM2 (see FIG. 6 ).
The values of |HM1-HM2| are shown in Table 1.
Microhardness tester: Shimadzu Corporation, model: DUH-211S
Measurement environment: 23±5℃
Measuring indenter: triangular pyramid indenter 115° (ridge angle 115°)
Measurement mode: Depth setting test Depth setting: 2 μm
Load speed: 0.03mN/s
Holding time: 5 s
Calculation formula: Martens hardness = 1000F/ ^26.43h2 [N/ ^mm2 ]
F: test force (mN), h: indentation depth (μm)

[Method of measuring polymeric MDI, 4,4'-MDI, and isocyanurate of 4,4'-MDI]
The direct sample introduction method (DI method) was used, in which the sample was directly introduced into the ion source without passing through a gas chromatograph (GC).
The apparatus used was POLARIS Q manufactured by Thermo Fisher Scientific Inc., and a Direct Exposure Probe (DEP) was used.
Assuming that a line segment is drawn on the tip surface parallel to the tip edge at a distance of 0.5 mm from the tip edge, the length of the line segment is L'. The polyurethane is scraped off with a biocutter from points 1/8L', 1/2L', and 7/8L' from one end of the line segment (called P0', P1', and P2', respectively).
Approximately 0.1 μg of the sample to be sampled at each of the P0′, P1′, and P2′ was fixed to a filament located at the tip of the probe and directly inserted into the ionization chamber, which was then rapidly heated from room temperature to 1000° C. at a constant heating rate (10° C./s), and the vaporized gas was detected by a mass spectrometer.

The amount M1 of all ions detected is the sum of the integrated intensities of all peaks in the total ion current thermogram obtained,
The integrated intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 380.5 to 381.5 derived from the polymeric MDI was designated as M2.
The integrated intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 249.5 to 250.5 derived from 4,4'-MDI was designated as M3.
The integrated intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 749.5 to 750.5 derived from the isocyanurate of 4,4'-MDI was designated as M4, and M2/M1, M3/M1 and M4/M1 were calculated. The arithmetic average values of the values obtained for each of P0', P1' and P2' were designated as the values of M2/M1, M3/M1 and M4/M1 in the present disclosure.

[Method of measuring trifunctional alcohol species and concentration]
The trifunctional alcohol was detected by pyrolysis GC/MS. The measurement conditions are as follows: Sampling position: Assuming that a line segment is drawn on the tip surface parallel to the tip edge at a distance of 0.5 mm from the tip edge, the length of the line segment is L', and the polyurethane is cut out with a biocutter from points 1/8L', 1/2L', and 7/8L' from one end of the line segment (referred to as P0', P1', and P2', respectively).
The samples sampled at each of the P0', P1', and P2' were measured by the following method. The arithmetic mean values obtained for the samples at each of the P0', P1', and P2' were regarded as the measured values in this disclosure.
Device:
Pyrolysis apparatus: Product name: EGA/PY-3030D, manufactured by Frontier Labs Gas chromatography apparatus: TRACE1310 gas chromatograph, manufactured by Thermo Fisher Scientific Mass spectrometer: ISQLT, manufactured by Thermo Fisher Scientific Pyrolysis temperature: 500°C
GC column: 0.25 mm inner diameter x 30 m stainless steel capillary column
Stationary phase: 5% phenyl polydimethylsiloxane Heating conditions: Hold at 50°C for 3 minutes, then heat to 300°C at 8°C/min MS conditions: Mass range m/z 10-650
Scan speed: 1 second/scan

The types of trifunctional alcohols were identified using GC/MS. A calibration curve was created using GC analysis of known concentrations of the identified trifunctional alcohol species, and quantification was performed from the GC peak area ratio.

<DSC Measurement>
DSC measurement was carried out using a differential scanning calorimeter (product name: TGA/DSC3+, manufactured by Mettler) according to the Japanese Industrial Standards (JIS) K7121 method for measuring transition temperatures of plastics.
In this case, 5.0 mg of the sample was weighed out and placed in an aluminum pan, and the sample was heated from room temperature to 80°C at a heating rate of 10°C/min, annealed for 4 hours, cooled to 10°C at 5°C/min, and then heated from 10°C to 250°C at a heating rate of 10°C/min.
The DSC curve was differentiated to obtain a differential curve, from which the peak top temperature of the endothermic peak was calculated. The melting onset temperature was calculated as the temperature at the intersection of a straight line extending the baseline on the low-temperature side of the endothermic peak to the high-temperature side and a tangent drawn at the point where the slope of the curve on the low-temperature side of the endothermic peak is maximum.
Assuming that a line segment is drawn on the distal end surface parallel to the distal end edge at a distance of 0.5 mm from the distal end edge, the length of the line segment is L', and points 1/8L', 1/2L', and 7/8L' from one end on the line segment are P0', P1', and P2', respectively, and samples were used at P0', P1', and P2'. The arithmetic average values of the values obtained for each sample at P0', P1', and P2' were used as the measured values in this disclosure.

<Method of Manufacturing Toner 1>
In the following, "parts" are all by mass unless otherwise specified.
(Preparation process of aqueous medium 1)
Into a reaction vessel equipped with a stirrer, a thermometer, and a reflux condenser, 650.0 parts of ion-exchanged water and 14.0 parts of sodium phosphate (12-hydrate, manufactured by Rasa Kogyo Co., Ltd.) were added, and the mixture was kept at 65° C. for 1.0 hour while purging with nitrogen.
Using T.K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), while stirring at 15000 rpm, add calcium chloride aqueous solution in which 9.2 parts of calcium chloride (dihydrate) is dissolved in 10.0 parts of ion-exchanged water at once to prepare an aqueous medium containing a dispersion stabilizer.Furthermore, add 10% by mass hydrochloric acid to the aqueous medium, adjust pH to 5.0, and obtain aqueous medium 1.
(Preparation of polymerizable monomer composition)
Styrene: 60.0 parts C.I. Pigment Blue 15:3: 6.5 parts The above materials were put into an attritor (manufactured by Mitsui Miike Chemical Engineering Co., Ltd.), and further dispersed for 5.0 hours at 220 rpm using zirconia particles having a diameter of 1.7 mm to prepare a pigment dispersion. The following materials were added to the pigment dispersion.
Styrene: 20.0 parts n-Butyl acrylate: 20.0 parts Crosslinking agent (divinylbenzene): 0.3 parts Saturated polyester resin: 5.0 parts (polycondensate of propylene oxide modified bisphenol A (2 mole adduct) and terephthalic acid (molar ratio 10:12), glass transition temperature Tg = 68 ° C, weight average molecular weight Mw = 10,000, molecular weight distribution Mw / Mn = 5.12)
Fischer-Tropsch wax (melting point 78° C.): 7.0 parts This was kept at 65° C. and uniformly dissolved and dispersed at 500 rpm using a T. K. Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) to prepare a polymerizable monomer composition.

(Granulation process)
While maintaining the temperature of the aqueous medium 1 at 70° C. and the rotation speed of the T.K. homomixer at 15,000 rpm, the polymerizable monomer composition was charged into the aqueous medium 1, and 10.0 parts of t-butyl peroxypivalate as a polymerization initiator was added. Granulation was continued for 10 minutes while maintaining the stirring speed at 15,000 rpm with the stirring device.
(Polymerization and distillation process)
After the granulation step, the agitator was replaced with a propeller agitator blade, and polymerization was carried out for 5.0 hours while stirring at 150 rpm and maintaining the temperature at 70° C., and then the temperature was raised to 85° C. and heated for 2.0 hours to carry out the polymerization reaction.
Thereafter, the reflux tube of the reaction vessel was replaced with a cooling tube, and the slurry was heated to 100° C. to perform distillation for 6 hours to distill off the unreacted polymerizable monomer, thereby obtaining a toner base particle dispersion liquid.

(Polymerization of Organosilicon Compounds)
60.0 parts of ion-exchanged water was weighed into a reaction vessel equipped with a stirrer and a thermometer, and the pH was adjusted to 4.0 with 10% by mass of hydrochloric acid. This was heated with stirring until the temperature reached 40°C.
Then, 40.0 parts of methyltriethoxysilane, an organosilicon compound, was added and stirred for 2 hours or more to carry out hydrolysis. The end point of hydrolysis was confirmed by visual inspection when the oil and water were not separated and became one layer, and the mixture was cooled to obtain a hydrolyzed liquid of the organosilicon compound.
The temperature of the obtained toner mother particle dispersion liquid was cooled to 55° C., and then 25.0 parts of the hydrolyzed liquid of the organosilicon compound was added to initiate polymerization of the organosilicon compound. After maintaining the mixture for 15 minutes, the pH was adjusted to 5.5 with a 3.0% by mass aqueous solution of sodium bicarbonate. After maintaining the mixture for 60 minutes while continuing stirring at 55° C., the pH was adjusted to 9.5 with a 3.0% by mass aqueous solution of sodium bicarbonate, and the mixture was maintained for a further 240 minutes to obtain a toner particle dispersion liquid.

(Washing and drying process)
After the polymerization process was completed, the toner particle dispersion was cooled, and hydrochloric acid was added to the toner particle dispersion to adjust the pH to 1.5 or less, and the dispersion was left to stand with stirring for 1 hour, and then the toner cake was subjected to solid-liquid separation using a pressure filter. This was reslurried in ion-exchanged water to make a dispersion again, and then the solid-liquid separation was performed using the above-mentioned filter to obtain a toner cake.
The obtained toner cake was dried in a thermostatic chamber at 40° C. for 72 hours and classified to obtain Toner 1.

<Evaluation of cleaning performance>
The cleaning blade 1 was incorporated into a cyan cartridge of a color laser beam printer (product name: HP LaserJet Enterprise Color M553dn, manufactured by Hewlett-Packard Company) as a cleaning blade for a photosensitive drum, which is a member to be cleaned.
Further, the toner in the developing machine of the cyan cartridge was entirely replaced with the above-mentioned toner 1.
Next, after leaving it for 24 hours in a low temperature and low humidity environment (temperature 15° C., relative humidity 10%), image formation was performed on 12,500 sheets, which is the maximum number of sheets that can be printed, in the same environment (hereinafter referred to as "normal evaluation").
Furthermore, the used developing machine was replaced with a new developing machine of a cyan cartridge in which the toner was entirely replaced with toner 1, and image formation was again performed on 12,500 sheets, which is the maximum number of printable sheets (hereinafter referred to as "2x evaluation").
In addition, the evaluation was performed while the waste toner was periodically sucked out through a hole made in the rear surface of the cartridge. The obtained images were ranked according to the following evaluation criteria.
A: No image defects (streaks on the image) caused by the cleaning blade occurred in either the normal evaluation or the double evaluation.
B: Image defects (streaks on the image) caused by the cleaning blade did not occur in the normal evaluation, but occurred very slightly in the 2x evaluation (streaks length 5 mm or less).
C: Image defects (streaks on the image) caused by the cleaning blade did not occur in the normal evaluation, but slightly occurred in the 2x evaluation (streaks longer than 5 mm but 10 mm or less).
D: Image defects (streaks on the image) caused by the cleaning blade did not occur in the normal evaluation, but did occur in the 2x evaluation (exceeding 10 mm).
E: Image defects (streaks on the image) caused by the cleaning blade occur in both the normal evaluation and the double evaluation.

<Evaluation of cleaning blade edge chipping>
After the cleaning performance evaluation was completed (evaluation at 2x magnification), the cleaning blade was removed from the cartridge and observed at 1000x magnification using a digital microscope (product name: main body VHX-5000, lens VH-ZST, manufactured by Keyence Corporation).
The tip of the main surface of the elastic member of the cleaning blade was used as the observation surface, and the cleaning blade was placed in a position tilted at 45° so that the support member was on top and the tip of the elastic member was on the bottom as shown in Figure 9, and the entire area in the longitudinal direction was observed. As shown in the partially enlarged view of Figure 9, the maximum value of the distance in the short direction of the edge chipping was measured as the "amount of edge chipping," and the performance was ranked according to the following evaluation criteria.
A ⁺ : No edge chipping occurs.
A: The amount of edge chipping is less than 0.5 μm.
B: The amount of edge chipping is 0.5 μm or more and less than 1 μm.
C: The amount of edge chipping is 1 μm or more and less than 3 μm.
D: The amount of edge chipping is 3 μm or more.

<Overall evaluation>
Based on the rank of the image evaluation of the cleaning performance and the rank of the evaluation result of edge chipping of the cleaning blade, a comprehensive evaluation was made as follows.
A: The evaluation results are combinations of A/A ⁺ , A/A, A/B, B/A, and B/A ⁺ . There are no problems in practical use.
B: The evaluation results are combinations of A/C, C/A, C/A ⁺ , B/B, B/C, and C/B. There are no problems in practical use.
C: The evaluation result is a combination of C/C.
D: There are no E's in the evaluation results, but there is one or more D's.
E: There is one or more E's in the evaluation results.

Example 2
The isocyanate used was 345.5 g of 4,4'-MDI, 20.0 g of MR400, the polyol used was 634.5 g of PBA2500, and the curing agents used were 10.7 g of 1,4-BD, 26.9 g of glycerin, and 275.7 g of PHA1000. The cleaning performance was evaluated using a normal toner from an existing developing machine, but the same procedure as in Example 1 was repeated.

Example 3
The same procedure as in Example 1 was repeated except that the isocyanate was 345.5 g of 4,4'-MDI, 20.0 g of MR400, the polyol was 634.5 g of PBA2500, and the curing agents were 7.0 g of 1,4-BD, 42.2 g of glycerin, and 302.7 g of PHA1000.

Example 4
As isocyanates, 334.6 g of 4,4'-MDI and 40.0 g of MR400, as polyols, 625.4 g of PBA2500, NCO content 10.2 mass%, as curing agents, 10.9 g of 1,4-BD, 27.5 g of glycerin, and 281.0 g of PHA1000.
The same procedure as in Example 1 was carried out, except that the amount was 2 g.

Example 5
The same procedure as in Example 4 was repeated except that the isocyanate was 301.9 g of 4,4'-MDI, 80.0 g of MR400, the polyol was 618.1 g of PBA2500, and the curing agents were 11.6 g of 1,4-BD, 29.4 g of glycerin, and 301.3 g of PHA1000.

Example 6
The same procedure as in Example 5 was repeated, except that the curing agents were 10.9 g of 1,4-BD, 27.5 g of glycerin, and 281.2 g of PHA1000.

Example 7
The same procedure as in Example 4 was repeated except that the isocyanate was 269.2 g of 4,4'-MDI, 120.0 g of MR400, the polyol was 610.8 g of PBA2500, and the curing agents were 13.8 g of 1,4-BD, 27.7 g of glycerin, and 304.4 g of PHA1000.

Example 8
The same procedure as in Example 7 was repeated, except that the curing agents were 4.1 g of 1,4-BD, 45.6 g of glycerin, and 364.5 g of PHA1000.

<Example 9>
The same procedure as in Example 7 was repeated, except that the curing agents were 10.9 g of 1,4-BD, 27.5 g of glycerin, and 281.2 g of PHA1000.

Example 10
The same procedure as in Example 7 was repeated, except that 1,4-BD was not used as the curing agent, and 35.9 g of glycerin and 263.5 g of PHA1000 were used.

Example 11
The same procedure as in Example 10 was repeated, except that the curing agents were 30.8 g of glycerin and 225.9 g of PHA1000.

Example 12
The same procedure as in Example 10 was repeated, except that, instead of using glycerin as the curing agent, 50.3 g of trimethylolpropane (manufactured by Tokyo Chemical Industry Co., Ltd.) (hereinafter referred to as TMP) and 285.0 g of PHA1000 were used.

<Example 13>
The same procedure as in Example 12 was repeated except that the isocyanate used was 241.4 g of 4,4'-MDI, 150.0 g of polymeric MDI (product name: Millionate MR-200, manufactured by Tosoh Corporation) (hereinafter referred to as MR200), the polyol used was 608.6 g of PBA2500, and the curing agents used were 50.3 g of TMP and 285.0 g of PHA1000.

<Example 14>
The same procedure as in Example 12 was repeated except that the isocyanate was 220.2 g of 4,4'-MDI and 180.0 g of MR400, the polyol was 599.8 g of PBA2500, and the curing agents were 50.3 g of TMP and 285.0 g of PHA1000.

Example 15
The same procedure as in Example 14 was repeated except that 57.5 g of TMP and 325.7 g of PHA1000 were used as the curing agents.

<Example 16>
The same procedure as in Example 14 was repeated, except that 61.1 g of TMP and 346.1 g of PHA1000 were used as the curing agents.

<Example 17>
The same procedure as in Example 16 was repeated, except that as the curing agent, a butylene adipate polyester polyol having a number average molecular weight of 1000 (product name: Nipporan 4009, manufactured by Tosoh Corporation) (hereinafter referred to as PBA1000) was used instead of PHA1000.

<Example 18>
The same procedure as in Example 16 was repeated, except that the isocyanate was 217.5 g of 4,4'-MDI and 180.0 g of MR400, and the polyol was 602.5 g of hexylene adipate polyester polyol (trade name: Nipponran 136, manufactured by Tosoh Corporation) having a number average molecular weight of 2600 (sometimes referred to as PHA2600) instead of PBA2500.

<Example 19>
The same procedure as in Example 18 was repeated, except that the curing agent was changed from PHA1000 to PBA1000.

<Example 20>
The same procedure as in Example 16 was repeated except that the isocyanate was 236.5 g of 4,4'-MDI and 180.0 g of MR400, the polyol was 583.5 g of PBA2500 with an NCO content of 10.8 mass %, and the curing agent was 64.7 g of TMP and 366.4 g of PHA1000.

<Example 21>
The same procedure as in Example 16 was repeated except that the isocyanate was 191.1 g of 4,4'-MDI and 210.0 g of MR200, the polyol was 598.9 g of PBA2500, and the curing agent was 61.1 g of TMP and 346.1 g of PHA1000.

<Example 22>
The same procedure as in Example 16 was repeated except that the isocyanate was 187.5 g of 4,4'-MDI and 220.0 g of MR400, the polyol was 592.5 g of PBA2500, and the curing agents were 57.5 g of TMP and 325.7 g of PHA1000.

<Example 23>
The same procedure as in Example 22 was repeated except that the isocyanate was 163.0 g of 4,4'-MDI, 250.0 g of MR400, and the polyol was 587.0 g of PBA2500.

<Example 24>
The same procedure as in Example 22 was repeated except that 50.3 g of TMP and 285.0 g of PHA1000 were used as the curing agents.

<Example 25>
The same procedure as in Example 24 was repeated except that 63.8 g of TMP and 255.3 g of PHA1000 were used as the curing agents.

<Example 26>
The same procedure was carried out as in Example 4, except that the adhesive used was a one-liquid adhesive for casting urethane resin and metal (product name: Metalock UA, manufactured by Toyo Kagaku Kenkyusho).

<Example 27>
The same procedure was carried out as in Example 4, except that the release agent was changed to release agent B. Release agent B was a mixture of 4.05 g of ELEMENT14 PDMS 1000-JC (trade name, manufactured by Momentive Performance Materials), 4.95 g of ELEMENT14 PDMS 10K-JC (trade name, manufactured by Momentive Performance Materials), 6.00 g of SR1000 (trade name, manufactured by Momentive Performance Materials), and 85 g of EXXSOL DSP145/160.

<Example 28>
The same procedure was carried out as in Example 27, except that the adhesive used was a one-component adhesive for casting urethane resin and metal (product name: Metalock UA, manufactured by Toyo Kagaku Kenkyusho).

<Example 29>
The same procedure as in Example 4 was carried out, except that the release agent was changed to release agent C. Release agent C was a fluororesin-containing metal release agent (product name: Fluorosurf FG-5093F130-0.5, manufactured by Fluoro Technology Co., Ltd.). It was applied to the mold before the urethane composition was poured therein and dried at 130°C.

<Example 30>
The same procedure was carried out as in Example 29, except that the adhesive used was a one-liquid adhesive for casting urethane resin and metal (product name: Metalock UA, manufactured by Toyo Kagaku Kenkyusho).

<Example 31>
The cleaning blade obtained in Example 3 was irradiated with ultraviolet rays for 15 seconds using an ultraviolet ray irradiation treatment device with an ultraviolet ray intensity of 32.8 mW/ ^cm2 , and a surface treatment was performed with an ultraviolet ray integrated light quantity of 492 mJ/ ^cm2 . The same procedure as in Example 3 was performed, except that the surface treatment was performed.
The light source of the ultraviolet irradiation treatment device was a low-pressure mercury ozone-less lamp (manufactured by Toshiba Lighting & Technology Corporation) using titanium oxide-containing quartz glass with a maximum emission peak at 254 nm.

<Example 32>
The cleaning blade obtained in Example 7 was irradiated with ultraviolet rays for 60 seconds using an ultraviolet ray irradiation treatment device with an ultraviolet ray intensity of 32.8 mW/ ^cm2 , and a surface treatment was performed with an ultraviolet ray integrated light quantity of 1968 mJ/ ^cm2 . The same procedure was carried out as in Example 31.

<Example 33>
The cleaning blade obtained in Example 25 was irradiated with ultraviolet rays for 120 seconds using an ultraviolet irradiation treatment device with an ultraviolet intensity of 32.8 mW/ ^cm2 , and a surface treatment was performed with an ultraviolet integrated light quantity of 3936 mJ/ ^cm2 . The same procedure was carried out as in Example 31.

<Comparative Example 1>
Except for using 334.7 g of 4,4'-MDI as the isocyanate, 665.3 g of PBA2500 as the polyol, and 19.4 g of 1,4-BD, 15.5 g of glycerin, and 159.0 g of PBA1000 as the curing agent, the same procedure as in Example 1 was carried out. The binarized image obtained from the elastic member according to Comparative Example 1 is shown in Fig. 11(b).

<Comparative Example 2>
The cleaning blade obtained in Comparative Example 1 was subjected to ultraviolet irradiation for 150 seconds using an ultraviolet irradiation treatment device with an ultraviolet intensity of 32.8 mW/ ^cm2 , and surface treatment was performed with an ultraviolet integrated light quantity of 4920 mJ/ ^cm2 . The same procedures as in Comparative Example 1 were carried out.

<Comparative Example 3>
The cleaning blade obtained in the same manner as in Example 1 was subjected to secondary curing at 130° C. for 60 minutes, after which 2 mm of the tip of the elastic member was immersed in 4,4′-MDI dissolved at 80° C. for 3 minutes, and then the 4,4′-MDI attached to the blade surface was washed off with butyl acetate. The blade was then aged for 24 hours to obtain a surface-treated cleaning blade. The obtained cleaning blade was evaluated in the same manner as in Example 1.

<Comparative Example 4>
The same procedure as in Example 1 was carried out except that 296.6 g of 4,4'-MDI was used as the isocyanate, 703.4 g of PBA2000 was used as the polyol, 26.5 g of 1,4-BD and 39.7 g of glycerin were used as the curing agent, Polycat46 was not added as the catalyst, and 0.23 g of No. 25 was used. After demolding, secondary curing was carried out at 130°C for 60 minutes.

1: cleaning blade, 2: elastic member, 3: support member, 4: main surface facing the member to be cleaned, 5: tip surface forming the tip edge together with the main surface, 6: member to be cleaned, R: rotation direction of the member to be cleaned

Claims (4)

1. An electrophotographic cleaning blade comprising an elastic member containing polyurethane and a support member supporting the elastic member, the cleaning blade cleaning a surface of a moving member to be cleaned by bringing a part of the elastic member into contact with the surface of the member to be cleaned,
When the side of the cleaning blade that contacts the surface of the member to be cleaned is defined as the tip side of the cleaning blade,
the elastic member has a plate shape having a main surface facing the member to be cleaned at least at the tip side and a tip surface forming a tip edge together with the main surface,
Assuming that a first line segment is drawn on the tip surface in parallel to the tip edge with a distance of 10 μm from the tip edge , the length of the first line segment is L, and points 1/8L, 1/2L, and 7/8L from one end side on the first line segment are P0, P1, and P2, respectively,
an average value of the elastic modulus of the elastic member measured using an SPM at 70 points on the first line segment at a pitch of 1 μm and centered on each of the points P0, P1, and P2 on the first line segment is 15 MPa or more and 470 MPa or less ;
The coefficient of variation of the elastic modulus is 6.0% or less,
The Martens hardness of the elastic member measured at the position P1 is defined as HM1 , and assuming that a bisector of an angle between the main surface and the tip surface is drawn on a cross section of the elastic member that includes P1 and is perpendicular to the tip surface and the tip edge, the Martens hardness of the elastic member measured at a position on the bisector that is 500 μm away from the tip edge is defined as HM2.
The absolute value of the difference between HM1 and HM2 is 0.10 N/mm2 or ^less ;
the ratio [(S2/S1)×100] of the number of hard segments (S2) having a circle equivalent diameter of 40 nm or less to the total number of hard segments (S1) in each of three square observation regions on the tip surface, each of which has a center of gravity at P0, P1, and P2, a side length of 1 μm, and a side parallel to the first line segment, is 92% or more;
The S1 is 300 or more and 1500 or less,
and,
Assume that a third line segment is drawn on the tip surface in parallel to the tip edge with a distance of 0.5 mm from the tip edge, the length of the third line segment is L', and points 1/8L', 1/2L', and 7/8L' from one end side on the third line segment are P0', P1', and P2', respectively;
A direct sample introduction type mass spectrometer is used in which the samples sampled at each of P0', P1', and P2' are heated and vaporized in an ionization chamber, and the sample molecules are ionized.
When the amount of all ions detected when the sample is heated to 1000° C. at a heating rate of 10° C./s is M1, the integral intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 380.5 to 381.5 derived from the polymeric MDI is M2, the integral intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 249.5 to 250.5 derived from 4,4'-MDI is M3, and the integral intensity of the peak in the extracted ion thermogram corresponding to the m/z value in the range of 749.5 to 750.5 derived from the isocyanurate of 4,4'-MDI is M4,
M2/M1 is 0.001 to 0.015,
M3/M1 is 0.04 to 0.10,
M4/M1 is 0.001 or less,
The concentration of the trifunctional alcohol in the polyurethane is 0.22 to 0.39 mmol/g;
In a DSC chart obtained by differential scanning calorimetry of a sample sampled at each of the P0', the P1', and the P2',
The peak top temperature of the only endothermic peak is 200° C. or higher;
The melting onset temperature of the endothermic peak is 175° C. or higher;
a difference between the melting initiation temperature and the peak top temperature being 15° C. or more ; 2. The electrophotographic cleaning blade according to claim 1 , wherein the trifunctional alcohol is trimethylolpropane. 3. A process cartridge comprising the electrophotographic cleaning blade according to claim 1. 3. An electrophotographic image forming apparatus comprising the electrophotographic cleaning blade according to claim 1 or 2 .

Images