JP5860393B2 - Electrophotographic blade - Google Patents

Description

  The present invention relates to a cleaning blade for removing toner remaining on an image carrier such as a photosensitive drum, a transfer belt, and an intermediate transfer member used in an electrophotographic apparatus. The present invention also relates to a developing blade used in the developing process. Further, the present invention relates to a charging blade for applying an electric charge to the image carrier.

Conventionally, most of the blades used are single-layer blades (single seed materials). In addition, there was a multilayer blade (lamination of flat sheet of multilayer material) using centrifugal molding in part.
These blades have problems of poor cleaning in low-temperature, high-speed printing, spherical toner, etc. in difficult-to-clean environments, and blade stick slip becomes large at high temperatures and high humidity. As a result of this problem, the service life cannot be satisfied, and therefore, measures have been taken to compensate for the problem by machine control or the like.
Conventionally, among the properties of general polyurethane rubbers favorably used for blades, the tan δ peak temperature is −3 to 11 ° C. When the cleaning performance under low temperature and low humidity is regarded as important, the tan δ peak value is −3. It is so favorable that it is ° C (low temperature). On the other hand, the durability under high temperature and high humidity is better as the tan δ peak value is 11 ° C. (high temperature).
Therefore, in the case of a single-layer blade, it was a blade that considered the balance between low-temperature cleaning performance and durability (depending on handling in individual machines). In the two-layer blade, for example, a rubber having excellent high temperature characteristics is used for the edge layer and a rubber having excellent low temperature characteristics is used for the backup layer. However, in the design of the two-layer structure, the function separation as expected is not possible, and the measures to compensate for the problem are taken by the control on the machine side like the single-layer blade.
In other words, there has been no blade that can be cleaned with a low-temperature, high-speed, spherical toner and has durability.
In recent years, OPC (organic photoconductor) coatings tend to have higher hardness for the purpose of improving durability. Further, in the transfer belt or the like, an alternative is studied for the purpose of cost reduction, and as a result, the surface may become rough. For the purpose of high-speed printing, the driving speed of an image carrier such as an OPC drum is also increasing. All of these impose a high load on the blade, and conventional blades (eg, JIS-A hardness of less than 85 degrees) have problems such as blade reversal. In order to solve this problem with a blade, it is effective and desirable to reduce the resistance of the blade itself (low μ).

The present applicant has continuously proposed inventions related to a cleaning blade made of polyurethane for an electrophotographic apparatus comprising a backup layer and a layer having a different polyurethane composition at the edge portion.
In Patent Document 1 (Japanese Patent Application Laid-Open No. 2007-30385), a continuous molding method is used, and a synthetic resin is used as a molding raw material by using a molding drum having a molding groove on the outer periphery and a heating device inside. In the method of continuously forming the raw material of the blade, a method of manufacturing a blade raw material combining different materials by separately casting two or more different liquid synthetic resin raw materials was proposed.
In Patent Document 2 (Japanese Patent Laid-Open No. 2007-163676), a casting method is used, and a liquid synthetic resin that forms a partial layer is cast into a bead shape in one mold of a split mold. Later, a method of manufacturing a blade was proposed in which a mold was assembled, a liquid synthetic resin for forming a base layer was cast, and then heat cured to form a blade material.
In Patent Document 3 (Japanese Patent Laid-Open No. 2009-300551), as a cleaning blade capable of preventing toner from slipping even under low temperature conditions, a polyurethane for an electrophotographic apparatus having an edge portion and a backup layer made of different materials is used. A cleaning blade having a thickness × width of the edge portion of 0.03 to 0.4 × 0.03 to 4 mm was proposed.

JP 2007-30385 A JP 2007-163676 A JP 2009-300551 A

Provided is a blade that satisfies low temperature (10 ° C.) cleaning performance and does not cause blade reversal or blade squealing even when the hardness of the film of the image bearing member is increased or the printing speed is increased.
In addition, we researched the development of blades using ether polyurethane as the edge and nip.

The blade of the present invention is provided with high-hardness polyurethane only on the edge portion that contacts the image carrier and the like, and the backup portion is made of polyurethane with conventional hardness, so that the friction at the contact portion can be lowered and elastic. The behavior is shared by the backup part. And the braid | blade which can be provided for practical use is provided by using the polyurethane from which the specific material described in the claim differs.
1. In polyurethane blades formed from different compositions of edge and backup parts, the polyurethane forming the edge part is harder than the polyurethane forming the backup part, and the JIS-A hardness of the polyurethane forming the backup part 65 to 80, and the polyurethane forming the edge portion has (1) JIS-A hardness of 75 to 100 and tan δ peak temperature of -20 to -1 ° C, or (2) JIS-A hardness of 85. A blade characterized by having a peak temperature of ˜100 and a tan δ peak temperature of −20 to 60 ° C.
2. The polyurethane forming the edge portion is made of an ester polyurethane, and the polyurethane forming the backup portion is an ether polyurethane or an ester polyurethane. The blade described.
3. The polyurethane that forms the edge portion is made of an ether-based polyurethane, and the polyurethane that forms the backup portion is an ether-based polyurethane,
The JIS-A hardness of the polyurethane forming the backup part is 65-80,
The polyurethane forming the edge part is characterized in that (1) JIS-A hardness is 75 to 100 and tan δ peak temperature is -20 to -1 ° C. The blade described.
4). Polyurethane ether to form the edge portion, polytetra main switch glycol as polyether polyol, a saturated fatty acid alkali metal salts and organic tin compounds used, as polyurethane ether polyurethane which forms the backup portion as a curing agent, polyether polyols polytetra main Chi glycol as, 3, characterized by using an amine compound as part of the curing agent. The blade described.
5. 1. Torque is 0.8 kgf / cm or less under the following measurement conditions. ~ 4. The blade according to any one of the above.
Measurement conditions The blade is tangentially penetrated into the OPC drum, and the OPC drum is rotated in a direction opposite to the penetration direction so that the linear velocity is 200 mm / s. When the penetration amount is 1.2 mm, the rotation axis of the OPC drum is rotated. 5. Measured value as load torque A polyurethane having an edge hardness of 80 degrees or more uses a saturated fatty acid alkali metal salt as a curing catalyst. ~ 5. The blade according to any one of the above.
7). The edge portion has a color different from that of the backup layer. ~ 6. The blade according to any one of the above.
8). The thickness x width of the edge portion is 0.03 to 0.4 x 0.03 to 4.0 mm. ~ 7. The blade according to any one of the above.
9. 1. The blade is a cleaning blade, a developing blade or a charging blade. ~ 8. The blade according to any one of the above.
10. In polyurethane blades formed from different compositions of edge and backup parts, the polyurethane forming the edge part is harder than the polyurethane forming the backup part, and the JIS-A hardness of the polyurethane forming the backup part 65 to 80, and the polyurethane forming the edge portion has (1) JIS-A hardness of 75 to 100 and tan δ peak temperature of -20 to -1 ° C, or (2) JIS-A hardness of 85. A method for producing a blade having a peak temperature of -100 and a tan δ peak temperature of -20 to 60 ° C, comprising a molding groove on the outer periphery and a heating device inside, and along the outer periphery of the molding drum The end plate that rotates in synchronization with the rotation of the molding drum while covering the molding groove with the synthetic resin supply means and the molding groove of the molding drum. A method of manufacturing a belt-like blade material having a predetermined width and thickness according to the rotation of a molding drum by using a molding space formed by an endless belt and a molding groove by using a synthetic resin raw material supplied to the molding groove in a sequential manner. A method of manufacturing the blade used is the method in which the polyurethane raw material for forming the edge portion is first poured into a cylindrical mold, cured while rotating the mold, semi-cured, and then the polyurethane raw material for forming the backup portion is prepared. A method for manufacturing a blade, comprising: taking out a belt-shaped blade material by curing while pouring and rotating, cutting the length to a fixed size, and then cutting and molding an edge including an edge portion.
11. The method for manufacturing a blade according to claim 10, wherein the polyurethane forming the edge portion is made of an ester-based polyurethane, and the polyurethane forming the backup portion is an ether-based polyurethane or an ester-based polyurethane.
12 The polyurethane that forms the edge part is made of ether-based polyurethane, the polyurethane that forms the backup part is ether-based polyurethane, and the polyurethane that forms the backup part has a JIS-A hardness of 65 to 80, and forms the edge part. (1) The JIS-A hardness is 75 to 100 and the tan δ peak temperature is −20 to −1 ° C. The manufacturing method of the braid | blade of description.
13. Polyurethane blade in which the edge portion and the backup portion are formed from different compositions, the polyurethane forming the edge portion is harder than the polyurethane forming the backup portion, and the polyurethane forming the edge portion is an ester-based polyurethane The polyurethane forming the backup portion is an ether polyurethane or ester polyurethane, and the polyurethane forming the backup portion has a JIS-A hardness of 65 to 80, and the polyurethane forming the edge portion is (1 ) A blade having a JIS-A hardness of 75 to 100 and a tan δ peak temperature of -20 to -1 ° C, or (2) a blade having a JIS-A hardness of 85 to 100 and a tan δ peak temperature of -20 to 60 ° C is manufactured. A method comprising forming grooves on the outer periphery A molding drum provided with a heating device inside, and rotates around the outer periphery of the molding drum in synchronism with the rotation of the molding drum while covering the molding groove with the synthetic resin supply means and the molding drum. A method of manufacturing a belt-like blade material having a predetermined width and thickness according to the rotation of a molding drum by using a molding space formed from an endless belt and a molding groove by sequentially arranging endless belts and supplying a synthetic resin material supplied to the molding groove. A polyurethane raw material for forming a back-up portion after casting the polyurethane raw material for forming the edge portion into a cylindrical mold, curing it while rotating the mold, and semi-curing it The belt-shaped blade material is taken out by pouring and rotating to remove it, and after cutting the length to a fixed size, the edge including the edge is cut and molded. A method as characterized and.
14 Polyurethane blade in which the edge portion and the backup portion are formed from different compositions, the polyurethane forming the edge portion is harder than the polyurethane forming the backup portion, and the polyurethane forming the edge portion is an ester-based polyurethane The polyurethane that forms the backup portion is an ether polyurethane or ester polyurethane, and the polyurethane that forms the backup portion has a JIS-A hardness of 65 to 80, and the polyurethane that forms the edge portion is (1) JIS-A hardness is 75 to 100 and tan δ peak temperature is -20 to -1 ° C, or (2) a method of manufacturing a blade having a JIS-A hardness of 85 to 100 and tan δ peak temperature of -20 to 60 ° C It is formed by assembling mold members In a blade manufacturing method using a split mold method in which a liquid polyurethane raw material is poured into a cavity to be manufactured, and then demolded after polymerization and curing, a line is placed on the wall surface of one split mold before assembling. Apply the liquid polyurethane raw material to form the edge part in a shape, mold it after semi-curing, inject the polyurethane raw material to form the backup layer, cure and demold to obtain the blade material, A method for manufacturing a blade, comprising cutting an edge and molding an edge portion.
15. Polyurethane blade in which the edge portion and the backup portion are formed from different compositions, the polyurethane forming the edge portion is harder than the polyurethane forming the backup portion, and the polyurethane forming the edge portion is an ester-based polyurethane The polyurethane that forms the backup portion is an ether polyurethane or ester polyurethane, and the polyurethane that forms the backup portion has a JIS-A hardness of 65 to 80, and the polyurethane that forms the edge portion is (1) A blade having a JIS-A hardness of 75 to 100 and a tan δ peak temperature of −20 to −1 ° C. or (2) a JIS-A hardness of 85 to 100 and a tan δ peak temperature of −20 to 60 ° C. is manufactured. A method comprising assembling mold members In a blade manufacturing method using a split mold method in which a liquid polyurethane raw material is cast into a cavity to be formed, and then demolded after polymerization and curing, the side on which the tip of the blade including the edge portion is formed In the state where the mold is inclined from the vertical direction, the liquid polyurethane raw material forming the edge portion is cast, and then the back-up layer is formed in the state of returning to the vertical direction. A method for producing a blade, wherein a polyurethane raw material is injected, cured, and then demolded.
16. 9. The polyurethane raw material forming the edge portion is an ester polyurethane raw material, and the polyurethane raw material forming the backup layer is an ether polyurethane raw material. 11.13. -15. The blade manufacturing method according to any one of the above.
17. 9. A polyurethane colored in a color different from that of the polyurethane forming the backup layer is used as the polyurethane forming the edge portion. -16. The blade manufacturing method according to any one of the above.
18. 9. The blade is a cleaning blade, a developing blade or a charging blade. -17. The blade manufacturing method according to any one of the above.

The blade of the present invention is provided with high-hardness polyurethane only on the edge portion that contacts the image carrier and the like, and the backup portion is made of polyurethane with conventional hardness, so that the friction at the contact portion can be lowered and elastic. The behavior is shared by the backup part. And the blade which can be used for practical use is provided by using the polyurethane from which the specific material described in the claim differs.
The present invention can provide a blade capable of realizing low friction even when contacting at a higher pressure than before. The blade realized by the present invention has a low μ, and as a result, can contribute to the reduction of the power consumption of the apparatus, can extend the life of the image carrier, and can extend the life of the apparatus. .
By using the blade of the present invention, the film hardness of the image carrier is improved, and even when the printing speed is increased, blade reversal and blade squeal do not occur. Further, the cleaning performance of an alternative that is a substitute for an image carrier and has a low surface roughness at a low cost can be satisfied. The reduction in friction can reduce the load applied to the image carrier during driving, leading to a reduction in power consumption and a longer life of the machine.
In particular, by using a saturated fatty acid alkali metal salt as a curing catalyst, a high-hardness polyurethane suitable for the edge portion could be realized. By using this catalyst, a polyurethane having a JIS-A hardness of 80 degrees or more, particularly 100 degrees can be realized.
By forming an edge portion colored differently from the backup portion, the location of the edge portion can be easily detected, and inspection and assembly work can be improved. The range of the preferable edge portion is 0.03 to 0.4 × 0.03 to 4 mm in thickness × width, and if both are transparent, it is difficult to distinguish, but if different colors are used, blade manufacture Not only the process but also the assembly to the electrophotographic apparatus and subsequent confirmation are easy, and the occurrence of mistakes can be suppressed. As the polyurethane, a thermosetting polyurethane is suitable, an ester polyurethane as an edge polyurethane, and an ester polyurethane and an ether polyurethane as a polyurethane forming a backup layer. Especially ether type is suitable. As a blade manufacturing method of the present invention, a continuous molding method using a molding drum and an individual molding method using a casting mold are provided. In addition, when using a casting mold, by injecting the liquid urethane for forming the edge portion in an inclined state, an edge portion having a triangular cross section can be formed, and after being semi-cured, the edge portion is returned to an upright state and backed up. By casting the polyurethane raw material forming the portion, it is possible to provide a molding method using a casting mold that can efficiently form the edge portion.
Furthermore, it was possible to provide a blade using ether-based polyurethane in the edge portion or nip portion. In particular, by using a continuous molding method using a molding drum, it was possible to develop a blade using ether-based polyurethane at an edge portion or a nip portion. Using a molding drum having a molding groove on the outer periphery, the permanent distortion of 0.1 mm or less was achieved in an ether-based polyurethane having a JIS-A hardness of 77 to 78 degrees at the edge.

The figure which shows the cross section of a cleaning blade typically. The figure which shows the example of a cleaning blade apparatus. The figure which shows the example of the apparatus which manufactures a cleaning blade continuously. The figure which shows the hardening process of the polyurethane in a cleaning blade continuous molding method. The figure which shows the example of the partial layer formed in arc shape. Schematic which obtains a blade by dividing a double-width continuous molded sheet into two. Sectional drawing which shows the outline of a split mold structure. The figure which shows the outline which forms the polyurethane resin for partial layers in one side of a split mold in bead shape. Schematic which shows the manufacturing method using slant casting. Edge display matrix display. Blade squeal evaluation test schematic. The figure of the graph which shows the correlation of JIS-A hardness and IRHD hardness. The figure which shows the outline | summary of a permanent set test.

1 Partial layer (edge, nip)
2 Base layer 3 Blade 4 Support member 5 Blade cross section 10 External heating device 11 First casting machine mixing belt 12 Second casting machine mixing belt 13 Molding drum 14 Endless belt 15 Rotating shaft 16 Preheating roll 17 Guide roll 18 Tension roll 19 Cooling roll 20 Cooling conveyor 21 Cooling device 22 Slack detector 23 Feed roll 24 Cutting device 25 Conveyor 26 Upper sensor 27 Lower sensor 101 Strip blade material 103 Standard size blade member 108 Discharge head 110 Mold 110a, 110b Split mold 111 Device for casting into divided mold 112 Slide plate 113 Base plate 114 Side wall 115 Inclined side wall 116 Clamping member 210 Mold 201 Liquid polyurethane resin 202 Liquid polyurethane 204 Support member

  The blade of the present invention is provided with high-hardness polyurethane only on the edge portion that contacts the image carrier and the like, and the backup portion is made of polyurethane with conventional hardness, so that the friction at the contact portion can be lowered and elastic. The behavior is shared by the backup part. And the braid | blade which can be used practically is provided by using the polyurethane from which a specific material differs.

<Blade shape and configuration>
In the case of a conventional blade, for example, a single layer blade, when the hardness is increased, the elasticity is lost. Alternatively, there is a method for increasing the hardness of the edge layer by using a two-layer structure as proposed as a multi-layer blade, but the elasticity of the rubber cannot be sufficiently maintained, and the edge tip necessary as a blade material is required. The part does not have enough stick slip and does not function as a cleaning blade.
However, in the present invention, when only the edge portion is made extremely hard, it is governed by the rubber physical properties of most of the backup portions and can sufficiently maintain the elasticity of the rubber. That is, an appropriate stick-slip can be performed and a sufficient function as a blade can be exhibited.
Furthermore, by making the edge part high in hardness (85 degrees or more in JIS-A), the μ can be reduced by 20% or more by the conventional conventional blade. In this case, the value of the tan δ peak temperature is , Not a constraint. On the other hand, it is effective to increase the elastic modulus of the rubber as another means for reducing μ. When the tan δ peak temperature is in the range of −20 to −1 ° C., the JIS-A hardness is 75. If it is held more than once, the effect can be obtained.
In order to easily produce such high hardness, a fast-curing catalyst (Na acetate) is useful. By using an appropriate amount of Na acetate, a large number of nurate bonds are produced in the manufactured urethane part, and thereby high hardness can be exhibited.

By using a continuous molding method using a molding drum, we have developed a blade that uses ether-based polyurethane at the edge or nip and has low permanent distortion and excellent cleaning properties. In the continuous molding method using a molding drum, it is necessary to proceed the polymerization and curing so that the sheet is taken out within several tens of seconds (for example, about 30 to 60 seconds) after resin casting. It was not easy to manufacture a blade having an ester polyurethane as an edge and having an edge hardness of about 80 and a small permanent distortion by a continuous molding method using a molding drum. On the other hand, ether-based polyurethane has been considered to have low wear resistance and is not suitable for the edge portion, but provided a blade capable of exhibiting excellent printing performance by selecting a curing agent different from the backup portion.
The polyurethane that forms the edge portion is an ether-based polyurethane, the polytetramethylene glycol (PTMG) as the polyether polyol, the saturated fatty acid alkali metal salt and the organotin compound as part of the curing agent, and the polyurethane that forms the backup portion. As the ether polyurethane, it is preferable to use polytetramethylene glycol (PTMG) as the polyether polyol and an amine compound as a part of the curing agent.

In the present invention, the permanent distortion is cut in such a manner that the rubber part is 10 mm after the blade is manufactured to obtain a sample piece. A sample piece is joined to a sheet metal like a blade, this sample piece is set on a dedicated jig for pressure welding storage, and the tip is brought into contact with the jig to obtain an initial value (reference). From here, a 1.4 mm blade is pushed in, the rubber is deformed and left in a storage environment for 3 days. After completion of the storage period, the deformation was released, and after standing at 23 ° C. for 4 hours, data was collected after 1 minute and 4 hours.
In the present invention, this permanent distortion can be suppressed to within 0.1 mm. In particular, by using a molding drum having a molding groove on the outer periphery, an edge portion of ether-based polyurethane having a JIS-A hardness of 77 to 78 degrees achieved this permanent distortion within 0.1 mm.
The outline of the permanent strain test method is shown in FIG.

The blade of the present invention is joined to a metal support member and used as a cleaning blade or the like.
A cross-sectional view of the blade of the present invention is shown in FIG. In order to scrape off the toner, the edge portion and the backup portion serving as the base are formed of different polyurethanes around the edge that is brought into pressure contact with the surface of the image carrier or the like.
The polyurethane forming the edge portion is harder than the polyurethane forming the backup portion. The polyurethane forming the backup part has a JIS-A hardness of 65-80, and the polyurethane forming the edge part is (1) a JIS-A hardness of 75-100 and a tan δ peak temperature of -20 to -1 ° C, Or (2) a blade having a JIS-A hardness of 85 to 100 and a tan δ peak temperature of −20 to 60 ° C.
In the edge part, the polyurethane forming the edge part is an ester-based polyurethane, (1) JIS-A hardness is 75 to 100 and tan δ peak temperature is -20 to -3 ° C, or (2) JIS-A The hardness is 85 to 100 and the tan δ peak temperature is −3 to 60 ° C. The size of the edge portion is preferably 0.03 to 0.4 × 0.03 to 4 mm in thickness × width. Furthermore, it is at least 30 μm or more in the thickness direction and within 0.4 mm, preferably within 0.2 mm, more preferably within 0.1 mm, and at least 30 μm or less in the width direction and within 4 mm. , Preferably within 2 mm, more preferably within 0.5 mm. The edge portion can be identified by coloring it in a color different from that of the backup portion, and trimming, inspection, and assembly work are facilitated. A saturated fatty acid alkali metal salt is effective as a curing catalyst for the formation of high-hardness polyurethane having a JIS-A hardness of 80 degrees or more for the edge portion. In particular, saturated fatty acid alkali metal salts (Na acetate) are suitable. Other catalysts (organotin compounds, tertiary amine compounds) can be used in combination.

  When the polyurethane that forms the edge portion and the backup portion is an ether-based polyurethane, the ether-based polyurethane that forms the edge portion is polytetramethylene glycol (PTMG) as a polyether polyol, and a saturated fatty acid alkali metal as a part of the curing agent. It is suitable to use a salt and an organic tin compound as the polyurethane that forms the backup portion as an ether polyurethane, polytetramethylene glycol (PTMG) as the polyether polyol, and an amine compound as part of the curing agent.

The backup part (base part) is an ether-based polyurethane or an ester-based polyurethane, and the JIS-A hardness of the polyurethane is preferably 65 to 80, regardless of whether the front or back surface is measured. For polyurethane rubber with a JIS-A hardness of up to 80, the catalyst type is not limited regardless of the edge portion or backup portion.
The blade of the present invention can be attached to a support member and used as a cleaning blade, a developing blade, or a charging blade. A cleaning blade for removing toner remaining on an image carrier such as a photosensitive drum, a transfer belt, and an intermediate transfer member used in an electrophotographic apparatus, a developing blade used in a development process, and an electric charge to the image carrier It is a charging blade.
For example, a polyurethane blade 3 comprising a partial layer 1 at the edge portion and a base layer 2 as a backup layer shown in FIG. In the present invention, it is basically preferable to use ester polyurethane for the edge portion and ether polyurethane for the base portion. Alternatively, a special combination of ether-based polyurethanes can be used.

<About hardness>
The JIS-A hardness 65-100 has the following correlation with the IRHD hardness (see FIG. 12).
JIS-A hardness = 0.9052 x (IRHD hardness) + 6.5661

<Types of polyurethane>
The blade used in the present invention is suitably made of a thermosetting polyurethane resin.
As the urethane forming material, a polyurethane composition containing a polyisocyanate and a polyol is used.
As the polyol component, a layer including an edge portion or a nip portion uses an ester-based polyurethane, and a base portion other than the layer including an edge portion or a nip portion uses a combination of an ether-based polyurethane. Alternatively, ether polyurethane can be selectively used for the edge portion or the nip portion and the base portion.
The polyurethane raw material used in the present invention is preferably non-solvent type thermosetting. For example, an ester polyurethane or an ether polyurethane disclosed in Japanese Patent Application No. 2007-18162 filed earlier by the present applicant can be used. If a colorant is added to the edge portion polyurethane resin to give a color different from that of the backup layer, the size of the edge portion can be clearly identified. It becomes easy to trim and form the edge size after the polyurethane is cured.
Alternatively, when the polyurethane forming the edge portion and the backup portion is an ether-based polyurethane, the polyurethane forming the edge portion is an ether-based polyurethane, polytetramethylene glycol (PTMG) as the polyether polyol, and saturated fatty acid alkali as the curing agent. It is suitable to use a metal salt and an organic tin compound as the polyurethane that forms the backup portion as an ether polyurethane, polytetramethylene glycol (PTMG) as the polyether polyol, and an amine compound as part of the curing agent.

(1) Ester polyol
An ester polyurethane is suitable for the edge layer. Polyester polyols such as polyester diol and polyester triol are suitable. (A) JIS-A hardness is 75 to 100 and tan δ peak temperature is −20 to −3 ° C., or (b) JIS-A hardness is 85 to 100 and tan δ peak temperature is −3 to 60 ° C. Although ester polyurethane can be used as a backup layer, it has a lower hardness than the edge layer.
The polyester polyol is produced from a polybasic organic acid and a polyol. Polycaprolactone polyols such as polycaprolactone diol obtained from ring-opening polymerization of ε-caprolactam can also be used.
For polyurethane having an edge hardness of 80 degrees or more, a saturated fatty acid alkali metal salt (Na acetate) is used as a curing catalyst. Also, other catalysts (organotin compounds, tertiary amine compounds) can be used in combination.
Polybasic organic acid is not particularly limited, saturated fatty acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, isosebacic acid, maleic acid, Examples thereof include unsaturated fatty acids such as fumaric acid, and dicarboxylic acids such as aromatic acids such as phthalic acid, isophthalic acid and terephthalic acid. In addition, acid anhydrides such as maleic anhydride and phthalic anhydride, and dialkyl esters such as dimethyl terephthalate can also be used. Furthermore, dimer acid obtained by dimerization of unsaturated fatty acid can also be used. These may be used alone or in combination of two or more.

  The polyol is not particularly limited, and diols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, 1,6-hexylene glycol, trimethylolethane, Examples include triols such as trimethylolpropane, hexanetriol, glycerin, hexaols such as sorbitol, polybutylene adipate (PBA), polyethylene adipate, and the like. These may be used alone or in combination of two or more.

(2) Ether-based polyol When the polyurethane that forms the edge portion and the backup portion is an ether-based polyurethane, the ether-based polyurethane that forms the edge portion is polytetramethylene glycol (PTMG), one of the curing agents. It is suitable to use saturated fatty acid alkali metal salt and organotin compound as part, ether-based polyurethane forming back-up part, polytetramethylene glycol (PTMG) as polyether polyol, and amine compound as part of curing agent ing.

  Examples of the ether-based urethane used as the backup layer include the following. Polyether polyols such as polyoxytetramethylene glycol, polytetramethylene glycol (PTMG), and polypropylene glycol. Examples of the polyether polyol include cyclic ethers such as ethylene oxide, propylene oxide, trimethylene oxide, butylene oxide, α-methyltrimethylene oxide, 3,3′-dimethyltrimethylene oxide, tetrahydrofuran, dioxane, and dioxamine.

(3) Polyisocyanate
The 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′-vitrylene-4,4′-diisocyanate, 3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 2,4-tolylene diisocyanate uretidinedione (2,4-TDI) Dimer), 1,5-naphthylene diisocyanate, metaphenylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate (hydrogenated MDI), carbodiimide-modified MDI, orthotoluidine diisocyanate, xylene diisocyanate Isocyanate, p-phenylene diisocyanate, lysine diisocyanate diisocyanates such as methyl ester, triphenylmethane-4,4 ', 4''- triisocyanate triisocyanates such as polymeric MDI and the like. These may be used alone or in combination of two or more. Of these, MDI is preferred from the viewpoint of wear resistance.

(4) Other materials In addition to the above polyisocyanates and polyols, chain extenders, surfactants, flame retardants, colorants, fillers, plasticizers, stabilizers, catalysts, etc. are usually used in polyurethane compositions. An agent can be blended.

  The chain extender is not particularly limited as long as it is a conventionally known one. 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, pentaerythritol, sorbitol, 1,2,6-hexanetriol, etc. Examples include polyols having a molecular weight of 300 or less. These may be used alone or in combination of two or more.

Examples of the catalyst include amine compounds such as tertiary amines and organometallic compounds such as organotin compounds.
For polyurethane having an edge hardness of 80 degrees or more, a saturated fatty acid alkali metal salt (Na acetate) is used as a curing catalyst.
Examples of the tertiary amine include trialkylamines such as triethylamine, tetraalkyldiamines such as N, N, N ′, N′-tetramethyl-1,3-butanediamine, amino alcohols such as dimethylethanolamine, Ethoxylated amines, ethoxylated diamines, ester amines such as bis (diethylethanolamine) adipate, triethylenediamine, cyclohexylamine derivatives such as N, N-dimethylcyclohexylamine, N-methylmorpholine, N- (2 Morpholine derivatives such as -hydroxypropyl) -dimethylmorpholine, piperazine derivatives such as N, N'-diethyl-2-methylpiperazine, N, N'-bis- (2-hydroxypropyl) -2-methylpiperazine, etc. It is done.
Examples of the organic tin compound include dialkyltin compounds such as dibutyltin dilaurate and dibutyltin di (2-ethylhexoate). Moreover, 2-ethyl caproic acid stannous, oleic acid stannous, etc. are mention | raise | lifted.
About the polyurethane for an edge part or nip part, it is preferable to use it combining a saturated fatty acid alkali metal salt (acetic acid Na) and an organic tin compound for a curing catalyst.

(5) Resin Example The synthetic resin used in the present invention is mainly a thermosetting polyurethane resin. In particular, a non-solvent two-component thermosetting polyurethane is suitable. In the continuous molding method using the outer peripheral molding groove rotating drum, the time from casting to taking out is within one rotation of the forming drum, and it is necessary to be polymerized and solidified so that it can be taken out in about 30 to 60 seconds. Select and design isocyanates and polyols, crosslinking agents, and catalysts that satisfy these conditions. In the step after removal, secondary crosslinking and aging steps can be performed. Even when the split mold is used, it is desirable to shorten the initial curing time of the ester polyurethane used as the edge portion or the nip portion.

Examples of the additive component include a lubricant, a conductivity imparting agent, and abrasive particles.
Examples of the lubricant include silicon compounds such as polytetrafluoroethylene, boron nitride, graphite, molybdenum disulfide, and polydimethylsiloxane.
The conductivity imparting substance is not particularly limited, but carbon black such as ketjen black, acetylene black, furnace black, etc., electron conductive substances such as graphite, metal filler, metal oxide whisker, metal soap, An ion conductive substance such as perchlorate can be used alone or in combination of two or more kinds, and is applied to a developing blade or a charging blade.
The abrasive particles are applied to a blade used for the purpose of refreshing the surface of a mating material that comes into contact with the photosensitive member or the like.

For example, the polyurethane resin previously proposed in Japanese Patent No. 3004586, Japanese Patent No. 2942183, Japanese Patent No. 2645980, Japanese Patent Application Laid-Open No. 2002-214989, Japanese Patent Application Laid-Open No. 2002-214990, and the like is exemplified. be able to.
A bifunctional polyol having a number average molecular weight of 1000 to 3000, a trifunctional polyol having a number average molecular weight of 92 to 980, and a high molecular weight polyol component mixed in at least one of a liquid material of a urethane prepolymer and a liquid material of a crosslinking agent, Is mixed with a polyol having an average functional group number of 2.02 to 2.20 and a diisocyanate compound having an isocyanate group content of 5 to 20% to prepare a prepolymer, and the prepolymer is mixed with an OH group / NCO. A polyurethane liquid (uncured polyurethane composition) is prepared by mixing the cross-linking agent in an amount such that the equivalent ratio of groups is 0.30 to 1.07 at 40 to 70 ° C.

  In this invention, a commercially available thing can be used for the two-component mixing casting machine used for mixing and stirring the liquid material of the urethane prepolymer which is the raw material component of the thermosetting polyurethane and the liquid material of the crosslinking agent. In consideration of the quantitative accuracy, the metering pump preferably uses three or more plunger types, but a gear pump type can also be used. In particular, in the production apparatus of the present invention, it is necessary to use a reaction accelerator in order to obtain a predetermined hardness at the time of demolding, and therefore, a stirring and mixing chamber is disclosed in Japanese Patent Publication No. 6-11389. A small-capacity type that prevents stagnation in the mixing chamber and suppresses heat generation due to reaction heat is preferable.

  The blade resin that can be used in the present invention is preferably a two-component thermosetting polyurethane resin, but is not limited thereto. Either a thermoplastic resin or a thermosetting resin can be used. Since a heated rotating molding drum is used, the non-solvent type containing no solvent is preferable because the thermosetting reaction is started immediately after casting.

  By blending these synthetic resin components, a resin composition to be a partial layer and a resin composition to be a base layer are prepared and used. In general, a synthetic resin serving as a partial layer used for the edge portion is designed to have a high hardness, and a resin used for the base layer is designed to have a lower hardness than the edge layer.

<Blade manufacturing method>
The method of forming the polyurethane layer of the edge part and the polyurethane layer of the base part layer is as follows: (a) a continuous molding method using a rotary molding drum having grooves formed on the outer periphery; A molding method can be used. In the molding method using the split mold, the edge part forming polyurethane raw material is applied in a bead shape to one mold before assembling the mold, and the mold is assembled and inclined after the mold is assembled to the edge forming corner. There is a method of injecting an edge polyurethane raw material.

(1) Method of Continuous Molding Using a Rotating Molding Drum with Grooves on the Perimeter This molding means can use the means disclosed in Japanese Patent Application Laid-Open No. 2007-30385 previously proposed by the present applicant. . Continuously produce a synthetic resin tape having a width that is the same as or slightly larger than the width of the synthetic resin elastic rubber used in the blade, cut the long tape to a fixed size, A technique for joining a side edge of a metal support and finishing it to a developing blade, a cleaning blade or the like is a basic manufacturing method. Alternatively, a means for dividing a wide blade material into two as disclosed in FIG. 5 of Japanese Patent Application Laid-Open No. 2009-51037 can be used.
The basic manufacturing means used in this manufacturing method is to continuously cast a liquid material of polyurethane from the apex to the forming groove while rotating a forming drum having a forming groove on the outer periphery around the horizontal axis. A polyurethane continuous molded product that has been polymerized during the rotation operation and formed into a tape-like shape at a position before the casting site is peeled off, taken out from the molding groove, and supplied to the subsequent process. Since tape-shaped moldings are continuously produced, a series of operations such as cutting to a single standard, cutting with an edge, joining with a metal support, etc. can be performed continuously in the subsequent process, which is wasteful in operation. Productivity is high.

This continuous molding method includes a plurality of casting machines. Synthetic resin blade material with a polyurethane layer that forms an edge part and a polyurethane layer that forms a backup part is manufactured by continuously supplying synthetic resin with different compositions from each casting machine to the molding groove of the molding drum. It is a method to do. Polyurethane that forms a back-up portion cast later on polyurethane that forms the edge portion cast earlier when the casting ports are arranged in front and rear with respect to the molding groove of the continuously rotating molding drum. Is cured to form a layer. The position, width, and thickness of the polyurethane can be controlled by the position and supply amount of the polyurethane to be cast first, the composition and type of the polyurethane, the rotational speed of the molding drum, and the like. The polyurethane to be cast later will supply an amount necessary for filling the whole, and forms a base layer as a backup portion.
When the preceding polyurethane is cast in the corner portion of the molding groove, a blade material in which a different material is provided at the edge portion can be manufactured.
When casting in the middle part, a different material can be provided in the middle of the blade material. For example, as shown in FIG. 6, when a blade material having a double width is continuously formed and an edge portion is formed in the center portion, by dividing at the center, two sheets are formed simultaneously with the formation of the edge portion. A blade can be obtained.

The basic configuration of the continuous molding method is shown in FIG.
As shown in FIG. 3, the blade material manufacturing apparatus, which is an elastic rubber member, includes a molding drum 13 having molding grooves formed on the outer periphery, a first casting machine mixing head 11 that supplies a resin, and a second injection head. It comprises a casting machine mixing head 12, an endless belt 14 having a steel mirror surface, a cooling conveyor 20, a cutting device 24, a carry-out conveyor 25, and the like.
A blade material provided with a different material layer at the edge portion is suitable for a cleaning blade that abuts the edge portion. In addition, by combining different materials, the physical property value of the elastic rubber can be controlled, so that it is possible to improve the temperature change suitability such as the high temperature range and the low temperature range, or wear resistance. Moreover, the continuous molding method of the synthetic resin sheet made of polyurethane using this molding drum can use each of the manufacturing methods and components already proposed by the present applicant.

Synthetic resin (polyurethane) cast in the molding groove is removed from the molding drum in a region covered with a rotating metal endless belt provided in a state where the molding groove is covered on a part of the outer periphery of the molding drum. At a position where the curing polymerization proceeds by heat and the endless belt is separated from the forming drum, it is formed in a sheet shape having a cross-sectional shape of the groove. It is the same as the conventional proposal that a continuous synthetic resin sheet is obtained by pulling out this sheet from the molding groove.
In this method, the resin is removed from the molding groove within several tens of seconds (for example, about 30 to 60 seconds) after resin casting, is not pressurized for molding, and polymerization curing is performed in the lower half of the rotating molding drum. Is the center, and it is possible to reduce the peeling angle from the molding groove, so that the peeling from the bottom of the molding groove is relatively easy, and it is not always necessary to use a release agent. . When the toner is made finer or colored, the release agent may have an adverse effect. In one embodiment of the present invention, such a problem does not occur when the release agent is not used. In addition, since it is not necessary to use a release agent, other surface treatment agents can be allowed to act, and it is also possible to positively utilize the surface treatment agent.

  Further, in order to control the polymerization, an external heating means for heating toward the groove of the molding drum can be provided between the synthetic resin supply position and the endless belt. In the vicinity of the sheet take-out portion, cooling means for blowing cold air or the like from the outside can be provided in order to facilitate peeling. As for the size of the resin sheet obtained in the present invention, both the width and thickness can sufficiently satisfy the range of a developing blade and a cleaning blade that have been conventionally used. For example, a thickness of about 0.40 to 3.00 mm can be sufficiently manufactured.

A schematic diagram of the molding process is shown in FIG.
A molding process from point A of the first casting shown in FIG. 3 to point F covered by the endless belt 14 will be schematically described. In the illustrated example, an example is shown in which the partial layer 1 is formed in a streak shape in the middle of the surface of the elastic rubber member. Further, the cured state of the cast liquid polyurethane resin is indicated by oblique lines, and the uncured portion is marked in white. However, this progress of curing is an image, and curing progresses from the bottom of the heated molding groove and the part in contact with the wall surface, and the endless belt is also heated. It is an image that is promoted.
First, at point A, a polyurethane resin liquid corresponding to the partial layer 1 is cast from the first casting port 11a into the molding groove. In this example, a certain amount that is streaked is continuously supplied. The resin in contact with the bottom surface of the molding groove heated to a temperature suitable for the polymerization shows that the polymerization has started and is semi-cured at point B. At the point C, the resin for forming the base layer 2 is continuously supplied from the second casting port 12a in an amount for filling the remaining molding groove section. At point D, the curing progresses from the bottom part of the forming groove or the part in contact with the high temperature part of the wall surface. At point E just before the endless belt comes into contact, the surface side of the molding groove opening part remains in a fluid state and flows into the downstream side, which indicates a slightly raised state. At the point F, it comes into contact with the mirror surface of the endless belt, and comes into contact with the belt heated to high temperature by preheating. In addition, although the diagonal line has entered in the whole in F point, it does not mean that the polymerization hardening was complete | finished completely.
Polymerization further proceeds from the point F to the take-out position (point G shown in FIG. 3), and the sheet can be drawn out.
In addition, when an external heating device is arranged near the point B or the point D, the polymerization on the surface side can be promoted. Moreover, if a cooling device such as a cold air blower is disposed immediately before point G, the peelability from the forming groove can be improved. Moreover, when supplying a mold release agent, a surface treating agent, etc. continuously, it can arrange | position between G point and A point.
The continuous polyurethane elastic rubber member thus obtained is cut into a fixed length, and further cut and molded to a predetermined width so that the partial layer 1 becomes an edge, thereby providing a desired edge size. Blades can be manufactured. If the edge portion and the base portion are colored in different colors, the cutting position can be easily determined.
FIG. 5 shows a state in which a blade is joined to the support member 4, and the partial layer 1 is formed in an arc shape in cross section, and therefore shows an image for determining the cutting position in consideration of the size of the edge. The illustration shows that cutting is performed with a width of half of the partial layer.

  In the example shown in FIG. 6, the position of the first inlet shown in FIG. 4 is the central portion of the forming groove. It shows that two blades can be obtained by dividing the obtained polyurethane belt from the center in the width direction by setting the groove width to be twice or more the blade width. In other words, the base layer 2 formed by filling the forming groove formed in the circumferential direction of the forming drum 13 and the partial layer (edge part) 1 disposed at the center of the forming groove are covered with the endless belt 14. It is molded by curing polymerization in the state. The blade material manufactured in the form of a continuous sheet is divided into two from the center, and two blades 3A and 3B are manufactured.

(2) Individual molding method using split mold (split mold molding method)
The split mold method combines two mold members that mold a cavity corresponding to the size of a single polyurethane elastic blade, casts a liquid polyurethane material into the cavity, and after polymerization and curing. It is manufactured by demolding. Before forming the mold, apply a liquid ester-based polyurethane raw material that forms a streak-like edge to the wall surface of one of the split molds, and after semi-curing, mold the mold to form an ether-based polyurethane raw material that forms the base It is injected, cured, and demolded to obtain a blade material in which two partial layers are formed.
The method disclosed in Japanese Patent Application Laid-Open No. 2007-163676 filed by the present applicant can be used for the method of forming the partial two layers by the split mold.
That is, it is as follows.
After casting so that the thermosetting resin is applied in a bead shape by moving the head that discharges the liquid polyurethane resin that is the thermosetting resin to the position corresponding to the partial layer, or by moving the mold Then, a split mold is assembled, a thermosetting resin as a base is cast, and is integrally formed in a heating furnace. The integrally formed blade material is disassembled and taken out from the split mold, cut into a predetermined size, and used as a blade. When a mold is assembled, a part of the support is set inside the cavity, and the base-forming resin is cast to integrally bond the support and the blade rubber body.

(A) Bead-shaped partial layer forming mold
FIG. 7 shows a schematic sectional view of the split mold structure.
The mold 110 includes left and right divided molds 110a and 110b. In the middle of the divided molds 110a and 110b, a projecting member is formed for sandwiching the core metal AA serving as a support member. The split molds 110a and 110b are disposed between a base plate 113, a side wall 114 standing on the left and right of the base plate 113, and an inclined side wall 115, and a mold clamping member 116 is pushed in a wedge shape toward the inclined side wall 115. Thus, the mold is clamped and assembled. A blade is molded by casting a synthetic resin serving as a base into a space formed between the two split molds 110a and 110b.
The example shown in FIG. 7 shows an example in which the core metal AA is arranged and the resin heat molding and the core metal are joined at the same time. It is also possible to manufacture a blade by molding a blade material obtained by curing the resin without arranging the core metal AA, and then joining the support member.
FIG. 8 shows a state in which the resin forming the divided layer is discharged from one of the divided molds (110a or 110b) from the discharge head 108 in a longitudinal direction and a bead shape. As the partial layer casting means, for example, a method of moving the ejection head and two methods of moving the split mold can be adopted.

(3) Method of individually molding by mold tilt casting (inclined casting method)
FIG. 9 shows another method of forming an edge portion using a mold.
After tilting the cavity bottom surface of the mold 210 and injecting the liquid polyurethane resin 201 for forming the edge part to be semi-cured, the bottom surface is returned to the horizontal, and the liquid polyurethane 202 for forming the backup part is injected, It is a method of forming a blade by curing and removing the mold.
If the support member 204 is set before casting the liquid polyurethane for forming the backup portion, a blade integrated with the support member can be molded.
In the example shown in the figure, the backup part is cast in an upright state. However, when casting in a state where the mold is sealed, the posture to cast after the formation of the edge part is limited to this. is not.

  An example of a cleaning blade will be described. The manufacturing means used was a method of continuous molding using a rotary molding drum having grooves formed on the outer periphery.

<Cleaning blade>
Elastic rubber member made of polyurethane: thickness 2.0mm, width 12.3mm, length 3
26mm
Edge size: The size shown in Table 2 Metal support: Steel plate with a thickness of 1.2 mm Adhesion treatment: Use of dimer acid-based hot melt adhesive

<Thermosetting polyurethane>
Table 1 shows the blending of ester urethane and ether urethane used for the edge layer or base layer. Table 3 shows urethane combinations and evaluations.

<Printing evaluation test>
Evaluation machine: A commercially available printer is used. Ricoh Co., Ltd. CX9800
Evaluation pattern • 100,000 sheets passed through durability evaluation (23 ° C x 53%) Image pattern printed with 5% area cover
Performed by measuring the occurrence of defective cleaning due to toner slipping, toner fusing, and blade wear depth • Performed with cleaning performance evaluation (10 ° C x 15%) Image pattern is 15 mm wide x 250 mm (x 3 locations) black After 50 belt images are output, the toner that has slipped through the photoconductor is collected with a mending tape, and the width of the slipping through is measured.

<Blade noise evaluation test>
Blade squeal can be evaluated by a stress index applied to the blade. In the evaluation below, the stress index is measured by measuring the torque generated on the roller shaft.
The blade is mounted on a jig that can change the amount of penetration, and the mating material is a commercially available OPC drum.
An outline of the evaluation tester is shown in FIG.
Using a blade having the shape shown in FIG. 10 (a), measurement was performed using a testing machine shown in FIG. 10 (b).
The blade is mounted on a jig that can change the amount of penetration, and is inserted into a commercially available OPC drum (using the Ricoh CX9800 drum) in the tangential direction so that the OPC drum has a linear velocity of 200 mm / s in the direction opposite to the penetration direction. And the torque generated on the shaft of the OPC drum is measured.

As a result of this test, it was confirmed that blade squeal was generated when the torque was 0.8 kgf / cm or more.
In normal use of the cleaning blade, it is necessary that the intrusion amount is 1.0 mm, and the noise is not generated up to +0.1 mm as the margin. That is, it is necessary that no squeal is generated even when the intrusion amount is 1.1 mm, and it can be determined that the performance is better as the intrusion amount margin increases.
From this test result, it is understood that a low torque can be realized when the edge portion has a high hardness. It was found that when the edge hardness was designed to be 85 or more, the torque could be 0.8 kgf / cm or less even when the penetration amount was 1.2 mm or more.

  FIG. 11 shows a matrix display of the results shown in Table 3 as tan δ peak temperature (x axis) and hardness (y axis) for the edge portion.

<Discussion>
In a preliminary test conducted in advance, in a running test using a single-layer sheet, in a high-hardness single layer (85 degrees or more), the rubber is greatly deformed at the bonding portion between the metal fitting and the rubber. For this reason, defective printing occurs during printing over time. (Toner slip-through) In order to suppress this, a low-hardness (compared to the edge portion) that is hard to be permanently deformed is used for backup.
From the results of the torque measurement test, it can be seen that μ tends to decrease as the edge hardness increases. It has been found that squealing occurs in the blade at a torque value of 0.8 kgf / cm or more. When the penetration amount is 1.0 mm, all samples are 0.8 or less, but when the standard penetration amount is 1.1 mm, the hardness of the edge portion is It was found that a torque value of 0.8 kgf / cm or less can be realized when the hardness of the edge portion is 85 or more except for the data of Example 5 when the penetration depth is 0.8 or less at 76 or more and the 1.2 mm penetration amount in view of safety. .
In particular, also in Examples 8 to 11 using ether-based polyurethane in the edge part, it was found that the blade squealed at a torque value of 0.8 kgf / cm or more. The torque value of 0.8 kgf / cm or less could be realized even with a standard penetration amount of 1.2 mm for safety reasons.

The following was found from the results of the printing test.
(1) Focusing on the hardness, good results are shown in the edge hardness 85, 86 or more shown in Examples 5 and 6 and the edge hardness 98 shown in Examples 1 and 2. In Comparative Example 4 having an edge hardness of 84, blade chipping and squeal occurred during the print test, and the print test was 30,000. The tan δ peak temperatures for Examples 1, 2, 5, 6, and 7, which showed good print test results with a hardness of 85 or more, are −14 to 48 ° C. Referring to the fact that edge forming accuracy is poor in Comparative Example 1, it is assumed that the tan δ peak temperature is effective at −20 ° C. or higher and the upper limit value is effective up to about 60 ° C. The hardness of the polyurethane constituting the backup portion is 71. However, it is preferable to select a polyurethane having a lower hardness than the polyurethane hardness of the edge portion. Therefore, the polyurethane hardness of the backup portion is appropriately 65 to 80.
In Examples 8 to 11 where ether-based polyurethane was used for the edge portion, good printing could be performed up to 100,000 sheets. Even in the case of ether-based polyurethane, it is suitable that the edge portion is a polyurethane having a hardness higher than that of the backup portion.
(2) Even if the edge hardness is 85 or less, Examples 3, 4, and 8 with a hardness of 76 show good results. In Comparative Examples 2 and 3 with a hardness of 73, the blades are turned over and squealed. For these boundaries, the edge polyurethane CDKL is a boundary and a slight difference. However, since the hardness is considerably lower than 85 degrees, other test examples ( Polyurethane I (hardness 75), which is slightly harder than the hardness 71), is employed in the backup layer. Among these, if the edge polyurethane has a hardness of 75 ° C. or more, the tan δ peak temperature is low, so it is considered that the increase in μ can be suppressed and low friction can be realized. On the other hand, if it is less than 75 ° C., it is considered that low μ cannot be realized even if the tan δ peak temperature is lowered, and μ becomes high, resulting in blade squealing and turning. As a result, the edge polyurethane has a hardness of 75 or more and a tan δ peak temperature of −20 ° C. to −1 ° C., and the polyurethane of the backup part (base part) preferably has a hardness of 75 or more.
Therefore, considering the whole, the polyurethane forming the edge portion has (1) JIS-A hardness of 75 to 100 and tan δ peak temperature of -20 to -1 ° C, or (2) JIS-A hardness of 85. It is appropriate that the polyurethane forming the backup portion (base portion) has a JIS-A hardness of 65 to 80, and ˜100 and the tan δ peak temperature is −20 to 60 ° C.

Claims (18)

In a polyurethane blade comprising an edge portion made of uniform polyurethane and a backup portion made of uniform polyurethane, and the edge portion and the backup portion are formed from different compositions,
The polyurethane forming the edge part is harder than the polyurethane forming the backup part,
The JIS-A hardness of the polyurethane forming the backup part is 65-80,
The polyurethane forming the edge part has (1) a JIS-A hardness of 75 to 100 and a tan δ peak temperature of −15 to −8 ° C., or (2) a JIS-A hardness of 91 to 100 and a tan δ peak temperature. A blade characterized by a temperature of -15 to 60 ° C.   2. The blade according to claim 1, wherein the polyurethane forming the edge portion is made of an ester-based polyurethane, and the polyurethane forming the backup portion is an ether-based polyurethane or an ester-based polyurethane. The polyurethane that forms the edge portion is made of an ether-based polyurethane, and the polyurethane that forms the backup portion is an ether-based polyurethane,
The JIS-A hardness of the polyurethane forming the backup part is 65-80,
2. The blade according to claim 1, wherein the polyurethane forming the edge part has (1) a JIS-A hardness of 75 to 100 and a tan δ peak temperature of −15 to −8 ° C. 3. The ether-based polyurethane forming the edge portion uses polytetramethylene glycol as the polyether polyol, saturated fatty acid alkali metal salt and organotin compound as the curing agent,
4. The blade according to claim 3, wherein the polyurethane forming the backup portion is an ether-based polyurethane, polytetramethylene glycol is used as a polyether polyol, and an amine compound is used as a part of a curing agent. The blade according to any one of claims 1 to 4, wherein the torque is 0.8 kgf / cm or less under the following measurement conditions.
Measurement conditions Insert the blade tangentially into the OPC drum, rotate the OPC drum in a direction opposite to the penetration direction so that the linear velocity is 200 mm / s, and when the penetration amount is 1.2 mm, the rotation axis of the OPC drum Value measured as load torque Blade according to any one of claims 1 to 5, the edge portion is characterized in that it is a different color from the backup layer. Blade according to any one of claims 1 to 6, thickness × width of the edge portion is characterized by a 0.03~0.4 × 0.03~4.0mm. The blade according to any one of claims 1 to 7 , wherein the blade is a cleaning blade, a developing blade, or a charging blade. In a polyurethane blade comprising an edge portion made of uniform polyurethane and a backup portion made of uniform polyurethane, and the edge portion and the backup portion are formed from different compositions,
The polyurethane forming the edge part is harder than the polyurethane forming the backup part,
The JIS-A hardness of the polyurethane forming the backup part is 65-80,
The polyurethane forming the edge part has (1) a JIS-A hardness of 75 to 100 and a tan δ peak temperature of −15 to −8 ° C., or (2) a JIS-A hardness of 91 to 100 and a tan δ peak temperature. A method for producing a blade at -15 to 60 ° C.,
A molding drum having a molding groove on its outer periphery and a heating device inside. The synthetic drum feeding means and the molding drum rotate while covering the molding groove of the molding drum along the outer periphery of the molding drum. Endless belts that rotate in synchronization are arranged in sequence, and a belt-shaped blade material having a predetermined width and thickness is formed by a molding space formed by the endless belt and the molding grooves from the synthetic resin material supplied to the molding grooves. Blade manufacturing method using a method of manufacturing according to the rotation of,
The polyurethane raw material that forms the edge portion is poured into a cylindrical mold first, and is cured while rotating the mold, and after semi-curing, the polyurethane raw material that forms the backup portion is poured and rotated to be cured and belt-shaped. A method for manufacturing a blade, comprising: taking out the blade material, cutting the length into a fixed size, and then cutting and molding the edge including the edge portion. 10. The blade manufacturing method according to claim 9, wherein the polyurethane forming the edge portion is made of an ester-based polyurethane, and the polyurethane forming the backup portion is an ether-based polyurethane or an ester-based polyurethane. The polyurethane that forms the edge portion is made of an ether-based polyurethane, and the polyurethane that forms the backup portion is an ether-based polyurethane,
The JIS-A hardness of the polyurethane forming the backup part is 65-80,
The method for producing a blade according to claim 9 , wherein the polyurethane forming the edge part has (1) a JIS-A hardness of 75 to 100 and a tan δ peak temperature of -15 to -8 ° C. In polyurethane blades, which are composed of a uniform polyurethane edge part and a uniform polyurethane backup part, and the edge part and the backup part are formed from different compositions, the polyurethane forming the edge part forms the backup part. The polyurethane that has a higher hardness than the polyurethane to be formed and the polyurethane that forms the edge portion is an ester-based polyurethane, and the polyurethane that forms the backup portion is an ether-based polyurethane or an ester-based polyurethane, and the polyurethane that forms the backup portion -A hardness is 65 to 80, and the polyurethane forming the edge is (1) JIS-A hardness is 75 to 100 and tan δ peak temperature is -15 to -8 ° C, or (2) JIS- A hardness is 9 100 and a method of tanδ peak temperature to produce a blade which is -15 to 60 ° C.,
A molding drum having a molding groove on its outer periphery and a heating device inside. The synthetic drum feeding means and the molding drum rotate while covering the molding groove of the molding drum along the outer periphery of the molding drum. Endless belts that rotate in synchronization are arranged in sequence, and a belt-shaped blade material having a predetermined width and thickness is formed by a molding space formed by the endless belt and the molding grooves from the synthetic resin material supplied to the molding grooves. Blade manufacturing method using a method of manufacturing according to the rotation of,
The polyurethane raw material that forms the edge portion is poured into a cylindrical mold first, and is cured while rotating the mold, and after semi-curing, the polyurethane raw material that forms the backup portion is poured and rotated to be cured and belt-shaped. A method for manufacturing a blade, comprising: taking out the blade material, cutting the length into a fixed size, and then cutting and molding the edge including the edge portion. In polyurethane blades, which are composed of a uniform polyurethane edge part and a uniform polyurethane backup part, and the edge part and the backup part are formed from different compositions, the polyurethane forming the edge part forms the backup part. The polyurethane that has a higher hardness than the polyurethane to be formed and the polyurethane that forms the edge portion is an ester-based polyurethane, and the polyurethane that forms the backup portion is an ether-based polyurethane or an ester-based polyurethane, and the polyurethane that forms the backup portion -A hardness is 65 to 80, and the polyurethane forming the edge is (1) JIS-A hardness is 75 to 100 and tan δ peak temperature is -15 to -8 ° C, or (2) JIS-A Hardness is 91 100 and a method of tanδ peak temperature to produce a blade which is -15 to 60 ° C.,
In a blade manufacturing method using a split mold method in which a liquid polyurethane raw material is poured into a cavity formed by assembling a mold member, and then demolded after polymerization and curing,
Before assembling the mold, apply a liquid polyurethane raw material to form the edge part in a streak shape on the wall surface of one split mold,
Molded after semi-curing,
Injecting polyurethane raw material to form a backup layer,
Cured and demolded to obtain blade material,
A method for manufacturing a blade, comprising cutting an edge of the blade material to form an edge portion. In polyurethane blades, which are composed of a uniform polyurethane edge part and a uniform polyurethane backup part, and the edge part and the backup part are formed from different compositions, the polyurethane forming the edge part forms the backup part. The polyurethane that has a higher hardness than the polyurethane to be formed and the polyurethane that forms the edge portion is an ester-based polyurethane, and the polyurethane that forms the backup portion is an ether-based polyurethane or an ester-based polyurethane, and the polyurethane that forms the backup portion -A hardness is 65 to 80, and the polyurethane forming the edge is (1) JIS-A hardness is 75 to 100 and tan δ peak temperature is -15 to -8 ° C, or (2) JIS-A Hardness is 91 100 and a method of tanδ peak temperature to produce a blade which is -15 to 60 ° C.,
In a blade manufacturing method using a split mold method in which a liquid polyurethane raw material is poured into a cavity formed by assembling a mold member, and then demolded after polymerization and curing,
A molding die having a bottom side as a side on which a tip of a blade including the edge portion is formed, and in a state where the molding die is inclined from a vertical direction, a liquid polyurethane raw material for forming the edge portion is cast, and thereafter A method for manufacturing a blade, comprising injecting a polyurethane raw material that forms a backup layer in a state of being returned to a vertical state, curing the polyurethane raw material, and then releasing the mold. The production of a blade according to any one of claims 9 , 10 , and 12 to 14 , wherein the polyurethane raw material forming the edge portion is an ester polyurethane raw material, and the polyurethane raw material forming the backup layer is an ether polyurethane raw material. Method. The blade manufacturing method according to any one of claims 9 to 15, wherein a saturated fatty acid alkali metal salt is used as a curing catalyst for polyurethane having an edge hardness of 80 degrees or more. The method for manufacturing a blade according to any one of claims 9 to 16, wherein a polyurethane colored in a color different from that of the polyurethane forming the backup layer is used as the polyurethane forming the edge portion. The blade manufacturing method according to any one of claims 9 to 17, wherein the blade is a cleaning blade, a developing blade, or a charging blade.

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