Method for regenerating electrophotographic cleaning blade and method for manufacturing regenerated electrophotographic cleaning blade

Abstract

This method for regenerating an electrophotographic cleaning blade can recover cleaning performance. This method is for regenerating an electrophotographic cleaning blade, and the electrophotographic cleaning blade includes an elastic member and a support member for supporting the elastic member. At least a portion of the tip of the elastic member on the free end side constitutes a contact part with respect to a member to be cleaned. The regenerating method includes: a step for preparing the elastic member to be regenerated; and a cutting step for causing a cutting blade to penetrate the elastic member from a lateral portion of the elastic member at one end A of the elastic member, moving the cutting blade relative to the elastic member toward the other end B of the elastic member, and removing at least a portion of the contact part. When the vibration frequency of a sample sampled from the elastic member is 1×103 Hz, the storage elastic modulus E' is 90.0-500.0 MPa, and the breaking stress is 4.2-30.0 MPa.

Description

Method for regenerating electrophotographic cleaning blade and method for manufacturing regenerated electrophotographic cleaning blade

[0001] The present disclosure relates to a method for recycling an electrophotographic cleaning blade that is disposed in an image forming apparatus utilizing an electrostatic transfer process and has a blade member and a support member for removing residual toner from a photosensitive drum provided in the image forming apparatus. The present disclosure also relates to a method for manufacturing a recycled electrophotographic cleaning blade.

[0002] Image forming devices that utilize an electrostatic transfer process, such as electrophotographic copiers and laser beam printers, adhere toner to an electrostatic latent image formed on a photosensitive drum, and then transfer this to a copier to perform copying or printing. One method for removing residual toner remaining on the photosensitive drum after transfer has been put to practical use, which uses an electrophotographic cleaning blade that is made up of an elastic member made of urethane elastomer and a support member that supports the elastic member.

[0003] The electrophotographic cleaning blade is pressed against the photosensitive drum in a direction counter to the rotation direction, and removes residual toner by contacting the photosensitive drum with a predetermined pressure. With electrophotographic cleaning blades housed in used cartridges, wear occurs at the edge portion that contacts the photosensitive drum over a long period of use, which can lead to poor cleaning performance and other deterioration in wiping performance. Therefore, Patent Document 1 discloses a recycling method for restoring electrophotographic cleaning blades to a good condition, in which the tip portion is cut off and the edge portion is reformed.

[0004] JP 2011-221347 A

[0005] However, according to the studies of the present inventors, when an electrophotographic cleaning blade was regenerated using the regeneration method disclosed in Patent Document 1, the wiping performance of the electrophotographic cleaning blade was not fully satisfactory. At least one aspect of the present disclosure is directed to providing a regeneration method for an electrophotographic cleaning blade that can restore the wiping performance of an electrophotographic cleaning blade whose wiping performance has deteriorated to a better level. Furthermore, at least one aspect of the present disclosure is directed to providing a method for manufacturing a regenerated electrophotographic cleaning blade that exhibits excellent wiping performance similar to that of a new one.

[0006] According to at least one aspect of the present disclosure, there is provided a method for recycling an electrophotographic cleaning blade, wherein the electrophotographic cleaning blade comprises an elastic member and a support member that supports the elastic member, and at least a part of a tip on a free end side of the elastic member constitutes a contact part with a member to be cleaned, the recycling method comprising: a step of preparing the elastic member to be recycled; and a cutting step of inserting a cutting blade into the elastic member from a side part of one end A of the elastic member at the elastic member, and moving the cutting blade relatively to the elastic member toward the other end B of the elastic member to remove at least a part of the contact part, and wherein the vibration frequency measured in an environment at a temperature of 24° C. is 1×10 ３ Hz is 90.0 to 500.0 MPa, and the breaking stress of the sample measured in an environment at a temperature of 24°C is 4.2 to 30.0 MPa.

[0007] According to at least one aspect of the present disclosure, there is provided a method for manufacturing a recycled cleaning blade, the method including a step of obtaining an elastic member recycled by the above-described method for recycling a cleaning blade.

[0008] At least one aspect of the present disclosure can provide a method for regenerating an electrophotographic cleaning blade, which can restore the cleaning performance of an electrophotographic cleaning blade whose wiping performance has deteriorated, and a method for manufacturing a regenerated electrophotographic cleaning blade that exhibits excellent wiping performance similar to that of a new one.

[0009] FIG. 1A is a schematic perspective view of an electrophotographic cleaning blade, and FIG. 1B is a schematic diagram illustrating the cross-sectional state of the cleaning blade when it is in contact with a member to be cleaned. FIGS. 2A to 2C are diagrams illustrating deformation of the tip of an elastic member due to the penetration of the blade. FIGS. 3A to 3C are diagrams illustrating deformation of the tip of a highly hardened elastic member due to the penetration of the blade. FIGS. 4A to 4C are diagrams illustrating an example of a recycling method. FIG. 5 is a schematic diagram illustrating an example of an elastic member recycling device. FIG. 6A is an enlarged view showing the periphery of a cutting unit, and FIG. 6B is a schematic diagram illustrating an example of the entire cutting unit. FIG. 7A is a schematic diagram showing a cross section of the cutting unit and a clamping member, and FIG. 7B is a schematic diagram illustrating the vicinity of the blade of the cutting unit. FIG. 8A is a schematic diagram illustrating elastic deformation of an elastic member, and FIG. 8B is a schematic diagram illustrating an example of a state in which excessive elastic deformation is suppressed by a clamping member. FIG. 9A is a schematic diagram illustrating the curvature of the cut surface, and FIG. 9B is a schematic diagram illustrating an example of a state in which deformation of the cut surface is suppressed by a pressing member. Fig. 10A is a schematic diagram illustrating the curvature of the cut surface, and Fig. 10B is a schematic diagram illustrating an example of a state in which deformation of the cut surface is suppressed by a biasing member. Fig. 11 is a diagram illustrating the macroscopic shape of the elastic member after regeneration of a conventional elastic member. Fig. 12 is a further enlarged schematic diagram illustrating the area around the blade portion and the tip of the elastic member.

[0010] In the present disclosure, expressions such as "XX or more and YY or less" or "XX to YY" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. When a numerical range is described in stages, the upper and lower limits of each numerical range can be combined arbitrarily. Furthermore, in the present disclosure, expressions such as "at least one selected from the group consisting of XX, YY, and ZZ" mean any of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0011] Examples of members to be cleaned by an electrophotographic cleaning blade (hereinafter also simply referred to as a "cleaning blade") include image carriers such as photosensitive members (for example, photosensitive drums), and endless belts such as intermediate transfer belts.

[0012] Hereinafter, specific examples of embodiments for carrying out this disclosure will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in these embodiments may be changed as appropriate depending on the configuration of the components to which the disclosure is applied and various conditions. In other words, the scope of this disclosure is not intended to be limited to the following embodiments. Furthermore, in the following description, components having the same function will be assigned the same numbers in the drawings, and their description may be omitted.

[0013] <Configuration of Cleaning Blade> FIG. 1A 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 3 and a support member 300 that supports the elastic member 3. The end of the elastic member 3 opposite the end supported by the support member 300 is referred to as the free end. For example, in FIG. 1A , the side indicated by arrow A is the free end side. The free end of the elastic member 3 and the adjacent side thereto are also referred to as the free end side. The free end side of the elastic member 3 is also referred to as the tip end of the elastic member or the tip end of the cleaning blade. The end of the elastic member 3 supported by the support member 300 (i.e., the side opposite the free end side of the elastic member 3) is also referred to as the base 100 side. For example, in FIG. 1A , the side indicated by arrow B of the elastic member is the base 100 side.

[0014] 1B is an example that schematically illustrates the cross-sectional state of a cleaning blade in contact with a member to be cleaned. The elastic member 3 has a main surface 4 that faces the member to be cleaned 6 and a tip surface 5 that, together with the main surface 4, forms a tip edge 101 (first edge 101). The tip edge 101 is the contact portion (abutment portion) of the cleaning blade that abuts against the member to be cleaned. A surface 4-2 opposite the main surface 4 may, together with the tip surface 5, form a tip edge 101-2 (second edge 101-2). R indicates the rotation direction of the member to be cleaned.

[0015] 1A and 1B, the elastic member 3 may have, at least on the free end side, a plate-shaped portion 105 having a main surface 4 facing the member to be cleaned 6 and a tip surface 5 that forms a tip edge 101 (first edge 101) together with the main surface 4. A surface 4-2 of the plate-shaped portion 105 opposite the main surface 4 may form a tip edge 101-2 (second edge 101-2) together with the tip surface 5. The elastic member 3 may be entirely plate-shaped.

[0016] At least a portion of the contact portion that is removed by performing a recycling process using the recycling method according to the present disclosure is a portion of the tip of the elastic member 3, and is a portion that includes at least the tip surface 5. It is preferable that at least a portion of the contact portion that is removed includes the tip surface 5, the first edge 101, and the second edge 101-2.

[0017] The present inventors investigated why the wiping performance of a recycled elastic member made of a conventional flexible urethane elastomer recycled by the cleaning blade recycling method disclosed in Patent Document 1 is inferior to that of a new cleaning blade. First, the present inventors closely observed the cut surface of the recycled elastic member. As a result, they found that the cut surface had a wavy, irregular shape (hereinafter, sometimes referred to as a "chatter shape").

[0018] Therefore, the inventors of the present invention conducted detailed observations of the microscopic behavior of the blade and elastic member when a conventional elastic member was regenerated using the regeneration method disclosed in Patent Document 1. First, the regeneration blade was brought into contact with the side surface of one end of the portion to be cut of the elastic member 3 (see FIG. 2A), and then the blade was inserted into the elastic member. As a result, it was found that the pressure of the blade during insertion caused a large elastic deformation of the side surface of the portion to be cut, i.e., the portion where the blade inserted, as shown in FIG. 2B, and that the elastic member then broke and the cutting progressed.

[0019] Furthermore, we found that as the blade advances from one end of the elastic member to the other, the elastic member repeatedly undergoes elastic deformation and breakage, resulting in a chattered cut surface (Figure 2C). This type of cut surface shape is thought to cause uneven contact between the regenerated elastic member and the surface of the member being cleaned, resulting in uneven cleaning of the surface being cleaned.

[0020] Based on these considerations, the inventors have come to the realization that when regenerating an elastic member, it is extremely important to prevent deformation of the elastic member when the blade portion enters, and to prevent repeated deformation and breakage of the elastic member as the blade portion advances, in order to prevent irregularities in the cut surface and obtain a regenerated cleaning blade with excellent cleaning performance.

[0021] The inventors first investigated increasing the hardness of the elastic member 3 to suppress deformation of the elastic member when the blade penetrates ( Figure 3A ). As a result, a high hardness of the elastic member suppressed elastic deformation of the elastic member when the blade penetrated, as shown in Figure 3B . However, they subsequently confirmed that excessive load was applied to the elastic member as the blade advanced until it broke, making the direction of advancement of the blade unstable and resulting in a wave-like, irregular cut shape with a shorter pitch than when the elastic member had a lower hardness ( Figure 3C ). Recycled elastic members with such shapes also contact the surface to be cleaned unevenly, potentially resulting in inconsistent cleaning performance.

[0022] From these analysis results, it was recognized that in order to obtain a recycled cleaning blade that exhibits excellent cleaning performance similar to that of a new one, it is effective to use an elastic member that is resistant to deformation when the blade penetrates and that has physical properties that do not hinder the smooth advancement of the blade after penetration. As a result of further investigation based on this recognition, it was found that setting the storage modulus and breaking stress of the elastic member used for cutting within predetermined ranges contributes to the production of a recycled cleaning blade that has a uniform cut surface and excellent wiping performance similar to that of a new one.

[0023] <Detailed Analysis of the Breaking Phenomenon> The present inventors have discovered that, for example, the elastic member and cleaning blade using the elastic member according to the embodiment described below can suppress the elastic deformation of the elastic member when the blade penetrates for recycling, while also suppressing the load at the time of breakage. As a result, they have found that the occurrence of chattering during cutting is suppressed, and cleaning performance after recycling is restored to the same level as a new member. This makes it possible to reuse the elastic member repeatedly, promoting the effective use of resources.

[0024] When examining the deformability of the blade when it penetrates, the blade collides with the elastic member, causing deformation and breakage of the elastic member due to the blade. Therefore, it was recognized that the deformability against the stress generated in a very short time, such as the collision of the blade, is important, and it was found that this deformability correlates with the elastic modulus when a high-frequency vibration is applied. When evaluating the frequency dependence of the elastic modulus of a general elastic member material, the scale of the vibrating structure tends to become smaller as a high-frequency vibration is applied, and the value tends to be higher. From these results, it was decided that the vibration frequency of the elastic member, 1 x 10, is used as an index showing the deformability of the blade when it penetrates. ３ It was found that deformation of the cutting edge during penetration can be stably suppressed by setting the storage modulus at Hz within a predetermined range.

[0025] Specifically, in an environment with a temperature of 24°C, the vibration frequency is set to 1×10 ３When the storage modulus (hereinafter also referred to as "E'") of a sample sampled from the elastic member at a frequency of 90.0 to 500.0 MPa is taken as Hz, the blade portion can be inserted into the side surface of the elastic member without applying an excessive pressing force to the blade portion, and deformation of the elastic member when the blade portion penetrates can be suppressed. The storage modulus E' is preferably 100.0 to 400.0 MPa, and more preferably 134.0 to 400.0 MPa.

[0026] Furthermore, the inventors conducted detailed observations of the elastic member as the blade advanced through the elastic member during cutting, and confirmed that the elastic member was locally stretched and deformed as the blade advanced, and then the elastic member was broken and cut.

[0027] In other words, it is believed that the repeated elongation and subsequent breakage of the elastic member as the cutting edge advances causes the chattered cut surface. Based on this consideration, the inventors conducted further research and found that adjusting the breaking stress of the elastic member to be recycled within a predetermined range contributes to smooth cutting of the cutting edge.

[0028] Specifically, by setting the breaking stress of the elastic member in the range of 4.2 to 30.0 MPa, stable progression of the blade portion can be achieved. When the breaking stress is 4.2 MPa or more, it is possible to prevent the blade portion from breaking prior to its progression. Furthermore, when the breaking stress is 30.0 MPa or less, it is possible to prevent the direction of progression of the blade portion from becoming unstable due to the increased load on the blade portion as it progresses through the elastic member. The breaking stress of the elastic member is preferably 8.0 to 28.0 MPa, and more preferably 10.0 to 25.0 MPa.

[0029] As described above, in order to prevent the cut surface of the recycled elastic member from becoming chattered and to make the cleaning performance of the recycled elastic member comparable to that of a new elastic member, it is preferable that the elastic member satisfy the following characteristics i) and ii): Characteristic i) A vibration frequency of 1×10 in a 24°C environment of a sample sampled from the elastic member so as to include at least a part of the contact portion is 1×10 ３The storage modulus in Hz is 90.0 to 500.0 MPa. Property ii) The breaking stress of the sample is 4.2 to 30.0 MPa.

[0030] Conventional elastic members, when designed to increase E', tend to have a correspondingly high breaking stress, making it difficult to simultaneously achieve the above-mentioned ranges for E' and breaking stress. In other words, when E' is small, as shown in Figures 2A to 2C, the elastic member deforms when the blade penetrates, causing the shape of the blade penetration site to become distorted. On the other hand, as shown in Figures 3A to 3C, when E' is large, the breaking stress also increases, resulting in excessive load on the blade and unstable blade penetration. As a result, in either case, the cut surface becomes uneven. Therefore, below is a description of specific configurations of elastic members that can achieve both E' and breaking stress, which are the characteristics of the present disclosure, within the above-mentioned ranges.

[0031] <Elastic Member> The material satisfying the above-mentioned specific E' and breaking stress is not particularly limited, but specifically, the elastic member preferably contains polyurethane. The polyurethane is preferably a polyurethane elastomer.

[0032] Polyurethane elastomers are primarily derived from raw materials such as polyols, chain extenders, polyisocyanates, catalysts, and other additives. Polyurethane elastomers consist of hard and soft segments. Hard segments are generally composed of polyisocyanates and chain extenders containing short-chain diols. Examples of these include aggregated crystalline components of urethane bonds, nurate bonds, and components with low molecular mobility near crosslinking points. Meanwhile, soft segments are generally composed of long-chain polyols such as polyester polyols, polyether polyols, and polycarbonate polyols, and polyisocyanates. For example, these segments are located between crosslinking points.

[0033] To achieve the storage modulus E' and breaking stress within the above ranges, it is preferable that the hard and soft segments in the polyurethane are finely and uniformly dispersed. If the hard and soft segments are not uniformly dispersed, some highly mobile components may cause large deformation due to the penetration of the cutting edge, while some less mobile components may cause large loads during the penetration of the cutting edge. As a result, the penetration of the cutting edge becomes unstable, resulting in chattering. Therefore, it is difficult to achieve the storage modulus and breaking stress of the present disclosure within the above ranges.

[0034] Conventional polyurethanes have relatively large hard segments formed by further aggregation of urethane bond aggregates due to interactions. To improve mechanical strength such as storage modulus, it is common to form relatively large hard segment aggregates. However, according to the inventors' investigations, elastic members made using such polyurethanes have not simultaneously satisfied the storage modulus and breaking stress ranges set forth in the present disclosure.

[0035] In addition, the vibration frequency is 1×10 ３ In the high frequency range such as 100 Hz, the hard segments of polyurethane have relatively low molecular mobility and are therefore unable to move sufficiently. Therefore, it is believed that the storage modulus E' in the high frequency range is mainly governed by the movement of the soft segments, which have relatively high molecular mobility. Therefore, in order to obtain a polyurethane with a storage modulus E' within the above range, it is effective to reduce the molecular mobility of the soft segments.

[0036] The molecular mobility of the soft segments can be reduced, for example, by at least one selected from the group consisting of introducing a branched structure (three-dimensional structure) into the molecular structure of the polyurethane and shortening the distance between crosslinking points. Introducing a branched structure and shortening the distance between crosslinking points can reduce the molecular mobility of the soft segments, thereby increasing the storage modulus in the high-frequency range. Furthermore, introducing a branched structure and shortening the distance between crosslinking points can suppress crystallization due to stacking of soft segments and can also prevent aggregation of hard segments. As a result, the formation of large hard segments due to aggregation of hard segments in the polyurethane is suppressed, which also contributes to the fine and uniform dispersion of the hard segments.

[0037] Below, examples of polyurethanes in which hard segments are finely and uniformly dispersed are described. However, the constituent materials of the elastic portion according to the present disclosure are not limited to these polyurethanes. As one example, a cured product of a urethane raw material containing a diisocyanate or a polyfunctional isocyanate having three or more functional groups and a diol or a polyfunctional alcohol having three or more functional groups in an appropriate concentration range has a branched structure in the molecular structure of the polyurethane, and aggregation of the hard segments is suppressed, resulting in a polyurethane in which the hard segments are finely and uniformly dispersed.

[0038] Specifically, for example, it is preferable to use at least one of an alcohol containing a tri- or higher functional alcohol and an isocyanate compound containing a tri- or higher functional isocyanate as the urethane raw material. It is also preferable to use, as the urethane raw material, an alcohol containing at least one selected from a diol and a tri- or higher functional alcohol, and an isocyanate compound containing a tri- or higher functional isocyanate. It is also preferable to use, as the urethane raw material, an alcohol containing a tri- or higher functional alcohol and an isocyanate compound containing a diisocyanate and a tri- or higher functional isocyanate. It is particularly preferable to use a tri- or higher functional isocyanate and a tri- or higher functional alcohol as the urethane raw material.

[0039] For example, the polyurethane elastomer is preferably a reaction product of a polyurethane raw material containing an isocyanate compound containing 4,4'-MDI, a polyester polyol, and a tri- or higher functional alcohol.The polyurethane elastomer is more preferably a reaction product of a polyurethane raw material containing a tri- or higher functional isocyanate, an isocyanate compound containing 4,4'-MDI, a polyester polyol, and a tri- or higher functional alcohol.

[0040] The polyurethane obtained as a reaction product of a tri- or higher functional polyfunctional isocyanate and a tri- or higher functional polyfunctional alcohol has suppressed molecular orientation due to steric hindrance, and thus more reliably suppresses aggregation of hard segments. Furthermore, the molecular mobility of the soft segments is also reduced, making this polyurethane suitable for achieving the storage modulus E' and breaking stress according to the present disclosure.

[0041] Furthermore, when the soft segment portion has, for example, a linear alkylene structure, the soft segments stack together, increasing crystallinity. As a result, the hard segments also become difficult to disperse. Therefore, introducing an alkylene structure having a side chain portion into the soft segment portion is also effective in suppressing the aggregation of the hard segments. Specifically, for example, introducing a partial structure such as those shown in the following structural formulas (i) to (iv) into the soft segment portion between two urethane bonds is effective in miniaturizing the hard segments. -CH ２ -CH(CH ３ )-CH ２ -CH ２ —O— (i) —CH ２ -CH ２ -CH(CH ３ )-CH ２ -O- (ii) -CH ２ -CH(CH ３ )-O- (iii) -CH(CH ３ )-CH ２ —O— (iv)

[0042] The structures of structural formulas (i) and (ii) are structures resulting from ring-opening polymerization of 3-methyltetrahydrofuran and are substantially identical. Furthermore, the structures of structural formulas (iii) and (iv) are structures resulting from ring-opening polymerization of 1,2-propylene oxide and are substantially identical. Urethane resins having these structures between two adjacent urethane bonds can be obtained by reacting a polyether polyol or polyester polyol having these structures with an isocyanate. When a bifunctional alcohol (diol) and a bifunctional isocyanate (diisocyanate) are used as urethane raw materials, it is usually difficult to finely disperse the hard segments. However, by introducing the above partial structure into the soft segment portion, it is possible to finely disperse the hard segments, even when a diol and a diisocyanate are used as urethane raw materials. As a result, a polyurethane can be obtained that provides an elastic member that satisfies the parameters described herein.

[0043] In addition to introducing side chains into the soft segments, another method for suppressing crystallization due to stacking of soft segments and preventing aggregation of hard segments is to use two or more alcohols with different carbon numbers in the linear chain portion as the urethane raw material alcohol. Polyurethanes obtained using two or more alcohols with different carbon numbers in the linear chain portion can suppress crystallization due to stacking of soft segments, even if the soft segments have a linear alkylene structure, due to the different carbon numbers. Furthermore, the different carbon numbers in the soft segments suppress aggregation of urethane bonds, thereby preventing aggregation of hard segments. Therefore, even when diols and diisocyanates having a linear alkylene structure in their molecules are used as urethane raw materials, using multiple diols with different carbon numbers in the linear alkylene structure as the diols can achieve finer hard segments. As a result, polyurethanes that provide elastic materials that satisfy the parameters described herein can be obtained. The maximum difference in the carbon numbers of the linear chain portions of the two or more alcohols is preferably 6 or less, and more preferably 4 or less. It is preferable that the long-chain polyol, such as polyester polyol, polyether polyol, or polycarbonate polyol, contains two or more alcohols having different numbers of carbon atoms in the linear chain portion. More specifically, an example of the multiple diols is a combination of polybutylene adipate polyester polyol and polyhexylene adipate polyester polyol.

[0044] Examples of the alcohol include polyester polyols such as polyethylene adipate polyester polyol, polybutylene adipate polyester polyol, polyhexylene adipate polyester polyol, (polyethylene / polypropylene) adipate polyester polyol, (polyethylene / polybutylene) adipate polyester polyol, and (polyethylene / polyneopentylene) adipate polyester polyol; polycaprolactone polyols obtained by ring-opening polymerization of caprolactone; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol; and polycarbonate diols. These may be used alone or in combination of two or more.

[0045] As described above, it is preferable to use two or more polyols having different numbers of carbon atoms in the linear portion (alkylene chain) as the alcohol, since this suppresses crystallization of the soft segment and allows for the production of a urethane in which aggregation of the hard segment is suppressed. In this case, it is preferable to use at least two selected from the group consisting of polyester polyols such as polyethylene adipate polyester polyol, polybutylene adipate polyester polyol, polyhexylene adipate polyester polyol, (polyethylene / polypropylene) adipate polyester polyol, (polyethylene / polybutylene) adipate polyester polyol, and (polyethylene / polyneopentylene) adipate polyester polyol.

[0046] Among the constituent components of the polyurethane elastomer, the content of tri- or higher functional polyfunctional isocyanate is preferably 8 to 30% by mass, more preferably 12 to 20% by mass. However, it is important to satisfy the storage modulus E' and breaking stress, and tri- or higher functional isocyanate does not necessarily have to be used. Among the constituent components of the polyurethane elastomer, the content of polyol such as polyester polyol is preferably 50 to 80% by mass, more preferably 55 to 70% by mass. Among the constituent components of the polyurethane elastomer, the content of tri- or higher functional alcohol is preferably 1 to 15% by mass, more preferably 2 to 10% by mass.

[0047] As the chain extender, diols capable of extending the polyurethane elastomer chain and tri- or higher-functional polyfunctional alcohols can also be used. Examples of diols include 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. These can be used alone or in combination of two or more. Examples of tri- or higher-functional polyfunctional alcohols include trimethylolpropane (TMP), glycerin, pentaerythritol, and sorbitol. These can be used alone or in combination of two or more.

[0048] One method for improving the storage modulus of a polyurethane elastomer is to introduce a three-dimensional crosslinked structure. The introduction of a three-dimensional crosslinked structure is preferred from the viewpoint of achieving the E' and breaking stress within the above-described ranges according to the present disclosure. As a method for introducing a three-dimensional crosslinked structure, for example, it is preferable to use a trifunctional or higher polyfunctional alcohol as the chain extender. Furthermore, the introduction of a branched structure into polyurethane by using a trifunctional or higher polyfunctional alcohol can suppress the crystallization of the polyurethane and further suppress the aggregation of hard segments. Here, it is preferable to use a trifunctional alcohol as the polyfunctional alcohol from the viewpoint of suppressing an excessive increase in hardness due to an excessively high degree of crosslinking of the polyurethane. Among these, triols, which have a methylene skeleton next to a hydroxyl group and can form a flexible crosslinked structure in terms of molecular structure, are preferred because they have an even greater effect of suppressing the crystallinity of hard segments. Examples of such triols include trimethylolpropane (TMP) and glycerin.

[0049] Examples of the isocyanate compound 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), carbodiimide-modified MDI, triphenylmethane-4,4',4''-triisocyanate (TTI), tris(phenylisocyanate)thiophosphate (TPTI).

[0050] Among these, 4,4'-MDI, in which two isocyanate groups have equivalent reactivity, is preferred from the viewpoint of achieving high mechanical properties. It is also preferred to use a tri- or higher functional polyfunctional isocyanate in combination. The use of a tri- or higher functional polyfunctional isocyanate allows for the introduction of a branched structure into the polyurethane, which is effective in further suppressing aggregation of hard segments. Furthermore, a denser crosslinked structure can be introduced into the polyurethane, resulting in a polyurethane having the storage modulus and breaking stress according to the present disclosure. Among the constituent components of the polyurethane elastomer, the content of isocyanate compounds (diisocyanates) other than tri- or higher functional isocyanates is preferably 5 to 40% by mass, more preferably 10 to 35% by mass.

[0051] The tri- or higher functional polyfunctional isocyanate may be at least one selected from the group consisting of triphenylmethane-4,4',4''-triisocyanate (TTI), tris(phenylisocyanate)thiophosphate (TPTI), and polymeric MDI. Of these, tris(phenylisocyanate)thiophosphate (TPTI) and polymeric MDI are more preferably used. These isocyanates have a methylene group or an ether group between multiple NCO groups, making it possible to maintain an appropriate distance between multiple urethane bonds. This is therefore advantageous in suppressing aggregation of hard segments.

[0052] Here, polymeric MDI is represented by the following chemical formula (1) and chemical formula (1)'. In chemical formula (1)', n is preferably 2 or more and 4 or less. Furthermore, chemical formula (1) is the case where n is 1 in chemical formula (1)'.

[0053] When the polyurethane in the elastic member according to the present disclosure is a cured product of a composition containing an isocyanate compound including a diisocyanate and a tri- or higher functional isocyanate, and an alcohol including a tri- or higher functional alcohol, the elastic member preferably has the following physical properties. Specifically, a sample sampled from the elastic member is heated and vaporized in an ionization chamber, and heated to 1,000°C at a heating rate of 10°C / s using a direct sample introduction mass spectrometer that ionizes the sample molecules. The resulting detected amount of all ions is designated M1, and the integrated intensity of the peak in the extracted ion thermogram corresponding to the range of m / z values ​​derived from the tri- or higher functional isocyanate is designated M2. In this case, the ratio M2 / M1 is preferably 0.0015 to 0.0150, and more preferably 0.0030 to 0.0150. A ratio of 0.0100 to 0.0145 is particularly preferred.

[0054] Furthermore, when the integrated intensity of the peak in the extracted ion thermogram corresponding to the range of m / z values ​​derived from the diisocyanate is M3, M3 / M1 on the tip surface and / or main surface is preferably 0.0200 to 0.1100, more preferably 0.0380 to 0.0760.

[0055] When M2 / M1 and M3 / M1 are within the above ranges, an appropriate amount of a structure derived from a trifunctional or higher functional polyfunctional isocyanate with low crystallinity is introduced into the polyurethane of the elastic member, thereby suppressing aggregation of the hard segments and enabling the hard segments to be more finely and uniformly dispersed. Furthermore, excessive development of crosslinked structures in the polyurethane is suppressed, making it easier to adjust the storage modulus E' to within the range of 90.0 to 500.0 MPa and the stress at break to within the range of 4.2 to 30.0.

[0056] Furthermore, it is preferable that M2 / M3 is 0.0130 or more and 0.3000 or less. M2 / M3 is a parameter that represents the ratio of the structural portion derived from diisocyanate to the structural portion derived from trifunctional or higher polyfunctional isocyanate in the isocyanate-derived structure of the polyurethane. By setting M2 / M3 within the above range, an excessive increase in the elastic modulus of the polyurethane can be suppressed, and aggregation of hard segments in the polyester can be further suppressed.

[0057] Here, when the polyurethane in the elastic member according to one embodiment of the present disclosure is a polyurethane produced using polymeric MDI represented by the above chemical formula (1)′ as a tri- or higher functional polyfunctional isocyanate as one of the raw materials, in the extracted ion thermogram obtained by the above mass spectrometry, M2 may be the sum of the integrated intensities of peaks in the extracted ion thermogram corresponding to the m / z value range of 380.5 to 381.5 resulting from n=1 in the structure represented by chemical formula (1)′, the m / z value range of 511.5 to 512.5 resulting from n=2, the m / z value range of 642.5 to 643.5 resulting from n=3, and the m / z value range of 773.5 to 774.5 resulting from n=4.

[0058] Furthermore, when the polyurethane in the elastic member according to one embodiment of the present disclosure is a polyurethane produced using 4,4'-MDI represented by the following chemical formula (2) as one of the raw materials as a bifunctional isocyanate (diisocyanate), M3 may be the integrated intensity of a peak corresponding to an m / z value in the range of 249.5 to 250.5 derived from the structure represented by chemical formula (2) in the extracted ion thermogram obtained by the above-described mass spectrometry.

[0059] Furthermore, when the polyurethane in the elastic member according to this embodiment is a reaction product of a raw material composition containing an alcohol, including a trifunctional or higher polyfunctional alcohol, particularly when a polyfunctional isocyanate is used in combination so that the M2 / M1 ratio is 0.0010 to 0.0150, the elastic portion preferably has the following physical properties. Specifically, a sample taken from the polyurethane is measured by pyrolysis GCMS (gas chromatography and mass spectrometry). The concentration of the trifunctional or higher polyfunctional alcohol in the polyurethane is preferably 0.04 mmol / g to 0.39 mmol / g, more preferably 0.14 mmol / g to 0.39 mmol / g, and even more preferably 0.18 mmol / g to 0.39 mmol / g. When the concentration of the trifunctional or higher polyfunctional alcohol is 0.04 mmol / g or higher, aggregation of hard segments can be more reliably suppressed. Furthermore, when the concentration of the trifunctional or higher polyfunctional alcohol is 0.39 mmol / g or lower, excessive development of crosslinked structures in the polyurethane can be suppressed, preventing an excessively high storage modulus. The concentration of the tri- or higher functional alcohol in the polyurethane is calculated by the following formula (2).

[0060] Equation (2): Concentration of tri- or higher functional alcohol (mmol / g) = [amount of tri- or higher functional alcohol (g) / molecular weight of tri- or higher functional alcohol × 1000] / [mass of polyurethane (g)]

[0061] Another example of a polyurethane that provides an elastic body satisfying the storage modulus and breaking stress requirements of this embodiment is a cured product of a polyurethane raw material that contains almost no polyfunctional isocyanate, specifically, has an M2 / M1 ratio of less than 0.0015, and contains, as crosslinking components, trimethylolpropane (TMP) and a diisocyanate such as diphenylmethane diisocyanate (MDI).

[0062] Because TMP has a methylene skeleton next to the hydroxyl group, it can provide a polyurethane with a molecularly flexible three-dimensional crosslinked structure. The crosslinked structure derived from TMP is flexible and can form a branched structure through crosslinking. Therefore, by reducing the amount of polyfunctional isocyanate used and using TMP primarily, excessive rigidity can be prevented and crosslinks can be introduced at a higher density. By introducing the three-dimensional crosslinked structure derived from TMP at a high density, the crosslink density is increased and the soft segment portions present between the crosslinked structures are less likely to interact with each other due to the steric hindrance of the crosslinked structure derived from TMP. As a result, the formation of a crystalline structure due to the interaction between soft segments, i.e., the formation of hard segments, can be prevented.

[0063] Furthermore, uniforming the length of soft segments in a state where the crosslink density is increased is effective in preventing aggregation of hard segments derived from urethane bonds. To produce a polyurethane in which the distance between crosslink points is short and the length between crosslink points is uniform, for example, it is preferable to set the number-average molecular weight of the prepolymer used as the polyurethane raw material to a range of 8,000 to 120,000, and to avoid the use of chain extenders such as 1,4-butanediol as much as possible, and it is particularly preferable to avoid the use of 1,4-butanediol at all. It is also preferable not to use 1,4-butanediol because it easily forms a crystalline structure. In this way, polyurethanes that provide elastic bodies satisfying the storage modulus E' and breaking stress according to the present disclosure can be produced without using polyfunctional isocyanates such as Polymec MDI as raw materials. In particular, when it is desired to obtain an elastic member having a lower storage modulus E' within the range (90.0 to 500.0 MPa) according to the present disclosure, it is effective to reduce the amount of polyfunctional isocyanate such as polymeric MDI used, or to use no polyfunctional isocyanate at all, and to use polyurethane into which a three-dimensional crosslinked structure derived from TMP has been introduced.

[0064] In polyurethanes that use little polyfunctional isocyanate as a raw material, specifically polyurethanes that provide elastic bodies that satisfy the storage modulus E' and breaking stress according to the present disclosure when M2 / M1 is less than 0.0015, M2 / M1 is preferably less than 0.0015, and the concentration of components derived from tri- or higher functional alcohols in the polyurethane is preferably 0.30 to 0.70 mmol / g, more preferably 0.40 to 0.61 mmol / g, and even more preferably 0.50 to 0.60 mmol / g.

[0065] Furthermore, in polyurethanes that use little or no polyfunctional isocyanate as a raw material, specifically when M2 / M1 is less than 0.0015, and that provide elastic bodies that satisfy the storage modulus E' and breaking stress according to the present disclosure, M2 / M1 is more preferably 0.0008 or less. The smaller M2 / M1 is, the more preferable, and although there is no particular lower limit, it is preferably 0.0000 or more. With M2 / M1 in the above range, the concentration of components derived from trifunctional or higher polyfunctional alcohols in the polyurethane is preferably 0.30 to 0.70 mmol / g, more preferably 0.40 to 0.61 mmol / g, and preferably 0.50 to 0.60 mmol / g.

[0066] The polyurethane raw material may contain a catalyst for promoting the reaction between the isocyanate compound and the alcohol. As the catalyst, a catalyst commonly used for curing polyurethane elastomers may be used, such as a tertiary amine catalyst or a tertiary amino alcohol. Specific examples include the following:

[0067] 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 compounds, and triazine compounds. Tertiary aminoalcohols include, for example, 2-(dimethylamino)ethanol, 3-(dimethylamino)propanol, 2-(dimethylamino)-1-methylpropanol, 2-{2-(dimethylamino)ethoxy}ethanol, 2-{2-(diethylamino)ethoxy}ethanol, and 2-[{2-(dimethylamino)ethyl}methylamino]ethanol.

[0068] In addition, organic acid salts of metals such as potassium acetate and potassium alkali octylate can also be used. Furthermore, metal catalysts typically used in urethanization, such as dibutyltin dilaurate, can also be used. These can be used alone or in combination of two or more.

[0069] The raw materials constituting the elastic member may contain additives such as pigments, plasticizers, waterproofing agents, antioxidants, ultraviolet absorbers, light stabilizers, and hydrolysis inhibitors, as needed, within the range that does not affect the regeneration of the elastic member.

[0070] 4A to 4C, a case where a cleaning blade including an elastic member is used will be described. However, the elastic member is regenerated by the regeneration process, and cleaning performance is restored to make it reusable, and the regeneration process is not limited to this process.

[0071] In the step of preparing the elastic member to be recycled, a used elastic member is prepared. For example, a cleaning blade provided with a used elastic member may be recycled as is, or the elastic member may be removed from the cleaning blade and recycled.

[0072] As shown in Fig. 4A , a used elastic member may have chips 141 or wear at the contact portion due to friction with the object to be cleaned during the cleaning process. Therefore, a decrease in wiping performance due to chips 141 or wear may be observed. Therefore, as shown in Fig. 4B , the tip portion of the elastic member, including the contact portion, is cut to a predetermined length (dotted line portion 143). In the cutting process, it is preferable to cut the tip of the elastic member 3 so that a cut surface is obtained that is approximately parallel to the tip surface 5.

[0073] Specifically, the recycling method includes a cutting step in which a cutting blade is inserted into the elastic member from a side portion of the elastic member at one end A (e.g., one longitudinal end) of the elastic member, and the cutting blade is moved relative to the elastic member toward the other end B of the elastic member to remove at least a portion of the contact portion. The cutting length may be any length that reliably cuts off chipped or worn portions, and a short cutting length is preferred to allow for multiple recycling. Multiple recycling is preferred because it further promotes effective use of resources. The cutting conditions, including the cutting length, will be described in detail below.

[0074] As shown in Figure 4C, the cutting process removes the tip of the elastic member, which is at least a part of the contact area with the member to be cleaned, and the recycled elastic member has chipped and worn parts removed, restoring the precision of the contact area with the member to be cleaned to the same level as the original. As a result, the used elastic member can be recycled and used as an elastic member with performance equivalent to the original. By repeating the above process, the elastic member can be reused multiple times. If necessary, a cleaning process or other process may be added between the above processes.

[0075] The elastic member recycling process according to the present disclosure is described below. The elastic member recycling process according to the present disclosure preferably includes at least the steps of clamping at least a portion of the elastic member, inserting a cutting blade into the elastic member from a side portion of the tip of the elastic member at one end A of the elastic member, and then relatively moving the cutting blade toward the other end B to cut off the tip of the elastic member.

[0076] The direction in which the cutting blade penetrates and moves into the elastic member 3 is not particularly limited, and may be the longitudinal direction or the lateral direction. In order to achieve the shape precision of the edge portion related to cleaning performance, it is preferable that the blade portion moves in the longitudinal direction, which is perpendicular to the edge portion, to remove the contact portion with the member to be cleaned. In other words, it is preferable that the relative movement is movement in the longitudinal direction of the elastic member. For example, it is preferable that the cutting blade moves so as to cut the first edge 101, the second edge 101-2, and the tip surface 5. In other words, it is preferable that at least a portion of the contact portion to be removed includes the tip surface and tip-side edge of the elastic member.

[0077] The regeneration process of the elastic member according to the present disclosure is preferably carried out with at least a portion of the elastic member clamped. The method of clamping the elastic member is not particularly limited, and there is no problem as long as the stability of the elastic member is maintained against the penetration of the cutting blade. In order to increase the stability of the elastic member when the cutting blade penetrates the elastic member, it is preferable to clamp the portion close to the cutting blade.

[0078] The cutting blade for cutting the tip of the elastic member is not particularly limited, and any known cutting blade can be used. For example, cutting means such as those using a blade, those using an abrasive sheet or grindstone, and those using a laser or water jet can be used. Examples of cutting blades using a blade include a regenerating device or a plane, which will be described later, in which the cutting blade is inserted into the elastic member in the longitudinal direction. Examples of cutting blades in which the blade is inserted into the elastic member in the lateral direction include a cutting machine.

[0079] Among these methods, the method of using a cutting blade to penetrate the elastic member in the longitudinal direction and cut it is preferable because it can form an edge shape that affects cleaning performance with high precision compared to other cutting methods. Furthermore, the recycling device described below is even more preferable because it can form an edge shape with higher precision for the purpose of thinly cutting the tip of a thin elastic member. It is also preferable in terms of reducing equipment costs and enabling high-volume processing.

[0080] The regeneration process of the elastic member according to the present disclosure can be carried out, for example, by using, but not limited to, the following device: That is, the cutting step is preferably a step of removing at least a part of the contact portion using a regeneration device.

[0081] The recycling device comprises a cutting blade that removes at least a portion of the contact portion in the longitudinal direction; a clamping member for the elastic member; a biasing member that contacts end B of the elastic member and biases the elastic member toward end A; and a pressing member that presses the tip of the elastic member, including the contact portion, in the lateral direction of the elastic member, thereby suppressing elastic deformation due to movement of the blade portion.

[0082] The clamping members clamp at least a portion of the elastic member from both sides of the elastic member in a cross-sectional view perpendicular to the longitudinal direction of the elastic member. The clamping members are disposed in positions where they can clamp at least the portion of the elastic member that the blade portions enter, and the position of the clamping members relative to the elastic member is fixed. The pressing member presses the elastic member prior to the relative movement of the blade portions from end A to end B.

[0083] A recycling device that cuts off the tip of an elastic member will be described below. An elastic member recycling device according to one embodiment of the present disclosure will be described using FIGS. 5, 6A, 6B, 7A, and 7B as an example. The recycling device is equipped with a blade portion 31 as a cutting blade. The recycling device cuts off the tip of the elastic member. The recycling device is equipped with a cutting tool in the blade portion and cuts off the contact portion with the member to be cleaned in the longitudinal direction of the elastic member, but the recycling device is not limited to this embodiment.

[0084] Fig. 5 is a schematic diagram showing the appearance of the elastic member recycling device 20. Figs. 6A and 6B are schematic diagrams illustrating the cutting unit 30 equipped with a blade and the cutting motion. Fig. 7A is a cross-sectional view of the cutting unit 30 and the clamping member 21 in the short direction of the elastic member, and Fig. 7B is an enlarged view of the vicinity of the blade 31.

[0085] The elastic member recycling device 20 includes a clamping member 21 as an elastic member fixing member that fixes the elastic member 100. The clamping member 21 clamps the elastic member from the short side direction of the elastic member, thereby fixing the elastic member. The clamping member 21 clamps, for example, the vicinity of the tip of the elastic member. To increase the stability of the elastic member when the blade portion is inserted into the elastic member, it is preferable to clamp a portion close to the blade portion. For example, the clamping member 21 clamps the main surface 4 and the surface 4-2 opposite to the main surface 4 in FIG. 1B. In other words, the clamping member 21 preferably clamps the vicinity of the tip of the elastic member from both sides of the vicinity of the tip of the elastic member in a cross-sectional view perpendicular to the longitudinal direction of the elastic member 3.

[0086] To cut, the blade is brought into contact with the side surface of one end of the elastic member 3 (see FIG. 2A), and then the blade is inserted into the elastic member. At this time, the pressure of the blade during insertion can cause elastic deformation of the side surface of the elastic member, as shown in FIG. 2B. As a result, as shown in FIG. 2C, chattering can occur on the cut surface of the elastic member after cutting. Deformation can be particularly large at the end where the blade first penetrates, resulting in a macroscopically curved surface. Recycled elastic members with such a shape can result in uneven cleaning performance at the end surface.

[0087] In order to prevent the above phenomenon from occurring, it is preferable to optimize the E' and breaking stress of the elastic member as described above, and to clamp the elastic member as follows: In Fig. 5, clamping member 21 is fixed on base 16 by holding member 15, which has an L-shaped cross section in the longitudinal direction of the elastic member.

[0088] As shown in Fig. 7B (enlarged view on the right) and Fig. 8B, the clamping members 21 are arranged in positions where they can clamp at least the portion of the elastic member where the blades 31 enter (end A). In the figures, the clamping members 21 clamp the entire longitudinal area of ​​the elastic member from both sides, including the portion where the blades 31 enter. The position of the clamping members relative to the elastic member is fixed.

[0089] The elastic member recycling device 20 includes a blade portion 31 for cutting the tip of the elastic member, which is at least a part of the contact portion, in the longitudinal direction of the elastic member 3. For example, as shown in Figures 5, 6A, and 6B, the elastic member recycling device 20 includes a cutting unit 30, and the cutting unit 30 may have a blade portion 31 (not shown in Figure 5).

[0090] The cutting unit 30 can move along the elastic member 3. The direction of movement is not important, but movement along the longitudinal direction is preferable because the small area of ​​the elastic member that comes into contact with the blade increases the cutting force and results in a highly accurate cut surface. In FIG. 5, the cutting unit 30 can move along a rail 17 that guides the movement. For example, in FIG. 5, the cutting unit 30 is manually movable using a handle 32, but it may also be driven by an electric cylinder, motor, or the like instead of manually. Note that the cutting unit 30 and the clamping member 21 may not be in contact with each other to facilitate movement of the cutting unit 30.

[0091] 6A and 6B are cross-sectional views from above of the cutting unit 30 in the elastic member recycling apparatus 20. Fig. 6A is an enlarged view of the periphery of the cutting unit 30, and Fig. 6B is an overall view including the clamping member 21. The cutting unit 30, which is equipped with a blade portion 31, moves along the longitudinal direction of the elastic member 3 from end A to end B in the direction of the arrow in the figure.

[0092] Then, the blade portion 31 is inserted into the elastic member 3 from the side of the tip of the elastic member at end A, which is one end in the longitudinal direction of the elastic member, and is moved relatively toward end B, which is the other end in the longitudinal direction, to cut off a part of the tip of the elastic member. By cutting in this manner, worn and deteriorated parts can be removed and a recycled elastic member can be obtained.

[0093] In the illustrated recycling device 20, the blade portion 31 (cutting unit 30) is movable, but it is sufficient that the blade portion 31 is movable relatively from end A to end B. In other words, the cutting unit 30 equipped with the blade portion 31 may be fixed, and the clamping member 21 to which the elastic member 3 is fixed may be movable.

[0094] Furthermore, as shown in Figures 6A and 6B, it is preferable that the playback device 20 is provided with a biasing member 41 that abuts against the side of the tip of the elastic member at end B of the elastic member and biases the elastic member toward end A.

[0095] Even if the blade portion 31 can be advanced to the other end B of the elastic member 3, as shown in FIG. 10A , as the blade portion 31 approaches the side surface of the elastic member on the end B side, the end of the elastic member on the end B side may undergo elastic deformation. This elastic deformation is thought to be particularly likely to occur because the elastic member stretches more at the tip end side than at the support member 300 side. This elastic stretching can also cause the blade portion to shift upward, resulting in burrs on the other end side of the recycled cleaning blade, as shown by the dotted line in FIG. 10A . To prevent burrs, optimizing the E' and breaking stress of the elastic member and including a biasing member 41 are preferred, as they suppress elastic deformation and prevent burrs from occurring.

[0096] The biasing member 41 is, for example, a plate-shaped member, and is inserted into the gap of the clamping member 21. The biasing member 41 presses the end B of the elastic member from the end of the clamping member 21 toward the end A by means of an elastic member 42 such as a spring.

[0097] The recycling device 20 also includes a pressing member that presses the tip of the elastic member, including the contact portion, in the short-side direction of the elastic member to suppress deformation of the elastic member due to movement of the blade portion. More specifically, the pressing member presses the tip of the elastic member, including the contact portion, in the short-side direction of the elastic member and in the thickness direction of the blade portion (a direction perpendicular to the blade length). The pressing member preferably presses the tip surface 5. This makes it easier to suppress elastic deformation due to movement of the blade portion. For example, as shown in Figures 5, 7A, and 7B, the recycling device 20 preferably includes a pressing member 51 that presses the tip of the elastic member toward the support member of the elastic member.

[0098] The blade was inserted from the side of one end (end A) of the elastic member 3 and moved toward the other end in the longitudinal direction of the elastic member to cut the tip of the elastic member. During this process, chattering sometimes occurred on the cut surface. Furthermore, as the blade progressed from one end of the elastic member to the other, the direction of advance of the blade shifted upward, resulting in a macroscopic shape as shown by the dotted line in Figure 9A, resulting in the cleaning blade after cutting becoming shaped as shown by the dotted line in Figure 9A. This deviation in the direction of advance of the blade was more pronounced as the thickness of the elastic member to be cut became thinner. It is believed that the deviation in the direction of advance of the blade is due to the thinness of the elastic member to be cut, which makes it easier for the force applied to the blade to advance the blade to be directed upward.

[0099] In order to prevent deviation of the blade portion's progress, it is preferable to optimize E' and the breaking stress of the elastic member as described above, and also to have a pressing member 51 that presses the tip of the elastic member toward the base 100 (opposite the free end) of the elastic member. Furthermore, it is preferable that the pressing member 51 presses the tip of the elastic member toward the base 100 prior to the relative movement of the blade portion 31 from end A to end B.

[0100] For example, as shown in FIGS. 5 and 7A, the pressing member 51 is provided in the cutting unit 30 and can move in accordance with the movement of the blade portion 31.

[0101] The present inventors believe that the reason why the elastic member recycling device 20 can suppress deformation of the cut surface of the elastic member 3 and obtain a more highly accurate recycled elastic member is as follows.

[0102] The suppression of deformation in the early stages of cutting will now be described. The recycling device 20 is equipped with a clamping member 21 that clamps the elastic member 3. The clamping member 21 is positioned so that it can clamp at least the portion of the elastic member 3 where the blade portion 31 penetrates. It is preferable that the position of the clamping member relative to the elastic member is fixed. That is, in the recycling device 20, it is preferable that the clamping member 21 clamps the elastic member without moving relative to the elastic member even when the blade portion 31 moves.

[0103] In this way, it is thought that clamping the portion of the elastic member 3 where the blade portion 31 enters can suppress elastic deformation of the elastic member due to the pressure when the blade portion 31 enters the elastic member. Therefore, it is possible to suppress the end of the elastic member on the side of the entry portion of the blade portion 31 after cutting from developing a chatter shape and a macroscopically rounded surface.

[0104] For example, without the clamping members 21, as shown in Figure 8A, the elastic deformation of the elastic member may cause the edge of the blade portion 31 on the penetration side to vibrate and become rounded, as indicated by the dashed line, or it may be difficult for the blade portion 31 to penetrate the elastic member depending on the thickness of the cut. On the other hand, clamping the elastic member with the clamping members stabilizes the blade portion's penetration into the elastic member. Furthermore, in a preferred state, when clamping members 21 are present to clamp the elastic member from both sides, as shown in Figure 8B, excessive elastic deformation is suppressed and pressure is applied uniformly to the elastic member. As a result, it is believed that deformation of the cut surface can be suppressed, as indicated by the dashed line.

[0105] In order to suppress deformation of the insertion portion of the blade portion 31, the clamping member 21 only needs to clamp at least the portion where the blade portion 31 is inserted. As shown in Figures 6A and 6B, the clamping member 21 may clamp the elastic member over the entire area of ​​the elastic member in the longitudinal direction.

[0106] Next, we will explain how to suppress elastic deformation caused by chatter during cutting and by the jumping up of cut pieces. The recycling device 20 preferably includes a pressing member 51 that presses the tip of the elastic member toward the base 100 prior to the relative movement of the blade portion 31 from end A to end B. This pressing member 51 can hold the elastic member at a position immediately before the blade portion 31 makes a cut, stabilizing the movement of the blade portion and suppressing elastic deformation of the elastic member caused by the blade portion 31 jumping up of cut pieces. In other words, the pressing member 51 can prevent chatter of the blade portion 31 caused by the movement of the blade portion 31 and shifting of the movement direction toward the tip of the elastic member. As a result, the cutting direction of the blade portion 31 is less likely to change, suppressing deformation of the cut surface.

[0107] For example, without the pressing member 51, as shown in FIG. 9A , the elastic deformation of the elastic member 3 may cause chattering on the cut surface and change the direction of travel of the blade, resulting in a macroscopically curved cut surface as shown by the dashed line. On the other hand, in FIG. 9B , the pressing member 51 moves ahead of the blade 31 in the direction of the arrow, pressing the elastic member 3 together with the blade 31 toward the base 100. That is, the recycling device 20 performs cutting while suppressing elastic deformation caused by the movement of the blade 31 with the pressing member. This makes the elastic member 3 less susceptible to elastic deformation, and is thought to suppress deformation of the cut surface as shown by the dashed line. For example, the pressing member 51 and the blade 31 can be configured to move while maintaining a constant distance between the tip of the blade 31 and the pressing member 51.

[0108] Next, we will explain how deformation at the end portion in the latter half of the cutting process is suppressed. The regenerating device 20 preferably includes a biasing member 41 that abuts against the side of end portion B of the elastic member 3 and biases the elastic member 3 toward end portion A. Such biasing member 41 can suppress elongation due to elastic deformation at the tip side of end portion B of the elastic member, thereby suppressing deformation of the cut surface.

[0109] For example, without the biasing member 41, the elastic deformation at the tip end of the elastic member may become large, causing the cut surface to curve as shown by the broken line in macroscopic terms, as shown in Fig. 10A. On the other hand, with the biasing member 41 as shown in Fig. 10B, the elastic deformation at the end of the elastic member, particularly the stretch at the tip end opposite the base 100, can be suppressed, and it is thought that deformation at the cut surface can be suppressed as shown by the broken line.

[0110] It is believed that the pressing member 51 is effective in preventing elastic deformation of the elastic member 3 caused by the jumping up of the cut pieces, even at the rear end of such a cut portion. However, it is believed that the pressing member 51 alone is insufficient to prevent elastic deformation in the cutting direction (the longitudinal direction of the elastic member). Therefore, in order to sufficiently prevent deformation at the rear end of the cut portion, it is preferable to provide the pressing member 51 and the biasing member 41.

[0111] As described above, the use of specific clamping members, pressing members, and biasing members is preferable because it suppresses elastic deformation of the elastic member from the time the blades enter the elastic member until the cutting is completed, thereby suppressing deformation of the cut surface of the elastic member. This prevents chatter from occurring on the cut surface and the macroscopic shape from becoming an S-shaped curve as shown in Figure 11, allowing the elastic member to be recycled with higher accuracy.

[0112] Each component of the elastic member recycling device 20 will be described in detail below. The recycling device 20 includes a blade unit 31. The blade used for the blade unit 31 may be any blade capable of cutting the elastic member by relative movement. The angle of the blade relative to the short side of the elastic member 3 (blade angle θA) is not particularly limited, and the blade unit 31 may be attached to the recycling device 20 so that the angle is preferably 20 to 70°, more preferably 30 to 60°, and even more preferably 40 to 50°. Figure 6A shows an example in which the blade angle θA is 45°.

[0113] In a longitudinal cross-sectional view of the elastic member of the recycling device 20, the angle θB (not shown) between the longitudinal direction of the elastic member 3 (e.g., the horizontal plane of the device) and a direction perpendicular to the blade length direction and parallel to the blade body is preferably 0 to 10°, more preferably 2 to 8°, and even more preferably 3 to 7°, with the angle being positive when the cutting edge faces the base 100. Having the angle θB within the above range means that the blade is slightly tilted toward the base 100 of the elastic member. This makes it easier for cut pieces to escape in the opposite direction to the blade's traveling direction.

[0114] The blade may be double-edged or single-edged. In the recycling device 20 shown in Figure 5 etc., a double-edged blade is used as the blade portion 31. There are no particular limitations on the blade thickness, and it is preferably 0.05 to 0.50 mm, more preferably 0.10 to 0.30 mm. There are no particular limitations on the blade tip angle (cutting edge angle), and it is preferably 15 to 55 degrees, more preferably 25 to 50 degrees, and even more preferably 35 to 45 degrees. If it is within the above range, it is easy to cut the elastic member appropriately. The illustrated recycling device 20 is an example in which the angle is 45 degrees.

[0115] The blade portion 31 may be fixed to the recycling device 20 (cutting unit 30) with a force that prevents the blade angle from changing during cutting. For example, it may be fastened with a bolt or the like. The blade portion 31 may be fixed on one side as shown in FIG. 6A. For example, the blade portion 31 may be bridged between the left and right cutting units 30 in FIG. 6A, and may be fixed on both sides that straddle the elastic member when the recycling device 20 is viewed from the side of the tip of the elastic member (e.g., from the top of the device). This further improves cutting accuracy.

[0116] The blade feed speed in the recycling device 20 (i.e., the speed of the relative movement) is not particularly limited as long as it is within a range that allows the elastic member 3 to be appropriately cut, and is preferably 500 to 5000 mm / sec, more preferably 800 to 2000 mm / sec, and even more preferably 900 to 1500 mm / sec.

[0117] The width of the slice of the elastic member 3 cut by the blade portion 31 is not particularly limited and depends on the size of the elastic member of the cleaning blade to be used. The material of the blade portion 31 is not particularly limited and any known material may be used depending on the elastic member to be cut. For example, stainless steel or iron may be used.

[0118] The recycling device 20 preferably includes clamping members 21 that clamp at least a portion of the elastic member 3 from both sides of the elastic member 3. The clamping members 21 clamp and fix the elastic member 3, suppressing elastic deformation due to the penetration of the blade portions. The clamping members 21 need only be positioned in a position where they can clamp the portion of the elastic member into which the blade portions 31 penetrate. The portion into which the blade portions penetrate means a portion near the contact point between the blade portions and the elastic member that can be clamped to suppress elastic deformation of the elastic member due to the penetration of the blade portions. For example, this is a portion near the position where the blade portions penetrate, which would elastically deform due to the penetration of the blade portions if the elastic member were not clamped on both sides.

[0119] The clamping member 21 may clamp the entire elastic member. For example, as shown in Figures 6A and 6B, the clamping member 21 can clamp and fix the entire longitudinal area of ​​the elastic member 3 from both sides using a member that is sufficiently longer than the longitudinal length of the elastic member 3. Also, for example, the clamping member 21 clamps the side of the base 100 from the position where the blade portion 31 enters. The material of the clamping member 21 is not particularly limited, and known materials such as steel such as pre-hardened steel, stainless steel, and aluminum can be used.

[0120] The pressure applied when clamping the elastic member with the clamping members 21 to clamp and secure the elastic member is not particularly limited and can be varied as appropriate depending on the material of the elastic member, etc. The clamping force should be sufficient to secure the elastic member and prevent elastic deformation due to the penetration of the blade portion 31. The clamping force should also be sufficient to prevent unnecessary deformation of the elastic member due to clamping. The method of fastening is also not particularly limited, and known methods such as fastening with bolts can be used. For example, the bolt fastening force when clamping the elastic member with the clamping members 21 to clamp the elastic member is preferably 5.0 to 50.0 N / m, 10.0 to 30.0 N / m, or 12.0 to 20.0 N / m. For example, the clamping members 21 preferably clamp the position corresponding to the portion where the blade portion penetrates with the above-mentioned fastening force.

[0121] 12 is a further enlarged view of the periphery of the tip of the elastic member in FIG. 7B, which is a cross-sectional view of the cutting unit 30 and the clamping member 21 in the short direction of the elastic member. The portion of the elastic member 3 clamped by the clamping member 21 is defined as the clamping portion, and the length of the portion of the tip of the elastic member protruding from the clamping portion to the outside of the clamping member 21 is defined as the protruding length A of the elastic member. From the viewpoint of making it easier to suppress elastic deformation of the elastic member 3, A is preferably 0.100 to 1.000 mm, more preferably 0.150 to 0.500 mm, and even more preferably 0.200 to 0.400 mm.

[0122] 12, the length (shortest distance) from the clamping portion of the elastic member by the clamping member 21 to the tip of the blade is defined as length B. From the viewpoint of more easily suppressing elastic deformation of the elastic member, B is preferably 0.200 mm or less, more preferably 0.150 mm or less, and even more preferably 0.130 mm or less. The lower limit is preferably as small as possible, but a length exceeding 0.000 mm is desirable to prevent interference between the blade and the clamping portion. B is preferably greater than 0.000 mm and less than 0.200 mm, greater than 0.000 mm and less than 0.150 mm, or greater than 0.000 mm and less than 0.130 mm.

[0123] Furthermore, from the viewpoint of more easily suppressing elastic deformation of the elastic member 3, the value of B / A is preferably 0.10 to 0.55, more preferably 0.20 to 0.45, and even more preferably 0.30 to 0.40. Furthermore, the thickness of the cut end of the elastic member 3 (the length from the base of the elastic member to the tip of the elastic member) corresponding to A-B in FIG. 12 can be appropriately changed depending on the purpose of recycling, the length of the elastic member before recycling, and the degree of deterioration of the elastic member, and is not particularly limited. From the viewpoint of repeated use through recycling, a thinner cut thickness is preferable because it increases the number of times the elastic member can be recycled. By cutting to a thinner thickness and repeatedly recycling and using the elastic member multiple times, the effective use of resources can be further promoted. The cut thickness is preferably 0.05 to 1.00 mm, more preferably 0.10 to 0.50 mm.

[0124] The pressing member 51 is a member that presses the tip of the elastic member 3 and suppresses elastic deformation due to movement of the blade portion. The recycling device 20 is equipped with the pressing member 51 that presses the tip of the elastic member toward the base 100 prior to the relative movement of the blade portion 31 from end A to end B. There are no particular restrictions on the pressing member 51 as long as it can press the elastic member prior to the relative movement of the blade portion 31. The pressing force may be such that it is sufficient to suppress elastic deformation of the elastic member due to the jumping up of the cut pieces.

[0125] For example, a member having a certain degree of hardness may be provided in a position facing the tip of the elastic member 3 in contact with it. That is, the pressing member 51 preferably moves in contact with the tip of the elastic member 3, and is preferably provided in a position facing the tip of the elastic member. This allows the pressing force to be changed appropriately according to the protruding length A of the elastic member 3. The pressing member 51 may or may not be biased by an elastic member such as a spring in the direction of the base 100 relative to the elastic member 3.

[0126] When the blade portion is moved in the longitudinal direction of the elastic member, as cutting progresses, cut pieces of the elastic member are sent into the spaces above and behind the blade portion. It is preferable that the pressing member 51 weakens or releases the pressure above and behind the tip of the blade portion 31 during the relative movement of the blade portion 31 so that the cut pieces of the elastic member fill the space and the progress of the blade portion is not hindered. One example of the degree of weakening the pressure is to reduce the pressure to a level that does not hinder the progress of the blade portion 31. It is preferable that the pressing member 51 releases the pressure so that the cut pieces can be easily sent behind the blade, from the perspective of more accurately regenerating the elastic member.

[0127] For example, as shown in Fig. 5, the pressing member 51 is preferably a disk-shaped member. The pressing member 51 may be fixed to the cutting unit 30 or may be axially supported, but is preferably axially supported from the viewpoint of facilitating pressing with a constant force. Examples of the pressing member 51 fixed to the cutting unit 30 include a disk-shaped member and a convex member having an R in the elastic member direction. The method of axial support is not particularly limited, and a known method using a bearing or the like may be adopted.

[0128] From the viewpoint of weakening the pressure above and behind the tip of the blade portion 31 or facilitating the release of the pressure, the pressing member 51 is preferably a member that moves in synchronization with (in synchronization with) the movement of the blade portion 31, for example, by being provided together with the blade portion 31 in the cutting unit 30, as shown in FIG. 5 . It is preferable that the pressing member 51 moves while maintaining a constant distance between the tip of the blade portion 31 and the portion pressed by the pressing member 51. In the illustrated embodiment, the pressing member 51 is a disc-shaped roller member that is journaled on the cutting unit 30 and rotates in contact with the clamping member 21 in accordance with the relative movement of the cutting unit 30. This is preferable because the pressing member 51 rotates in contact with the clamping member 21, making it easier to maintain a constant pressing position and pressing force. Furthermore, the pressing force can be controlled by the hardness of the pressing member 51 and the protruding length A of the elastic member.

[0129] 9B , the distance X is defined as the distance in the longitudinal direction of the tip of the elastic member 3 between the position corresponding to the cutting edge of the blade portion 31 and the contact point between the pressing member 51 and the elastic member 3. X is preferably 1 to 30 mm, more preferably 5 to 20 mm, and even more preferably 10 to 18 mm. In other words, it is preferable that the pressing member 51 presses the elastic member a distance X prior to the movement of the blade portion 31. By keeping the distance within the above range, it becomes easier to suppress elastic deformation of the elastic member due to the jumping up of the cut pieces.

[0130] Furthermore, when the pressing member 51 is a disk-shaped member, as shown in Figure 9B, the distance between the center of the disk shape and the horizontal plane of the elastic member 3 is defined as Y. Y is preferably 5.0 to 100.0 mm, more preferably 10.0 to 70.0 mm, and even more preferably 20.0 to 50.0 mm. When X and Y are equal to or less than the above upper limits, it becomes easier to prevent the cut pieces from jumping up. When X and Y are equal to or greater than the above lower limits, it becomes easier to maintain good cutting resistance.

[0131] The value of X / Y is preferably 0.40 to 0.80, more preferably 0.50 to 0.70, and even more preferably 0.55 to 0.65. For example, the elastic member may be pressed so that the value of the radius of the disk-shaped member - Y is preferably 0.01 to 0.2 mm, and more preferably 0.05 to 0.15 mm. The value of the radius of the disk-shaped member - Y indicates the degree of deformation of the pressing member due to pressing.

[0132] The width of the pressing member 51 (the length in the short direction of the elastic member) is not particularly limited as long as it is sufficient to press the elastic member. Preferred examples include 1 to 100 mm, 2 to 50 mm, and 5 to 20 mm. The hardness of the pressing member 51 is not particularly limited as long as it is sufficient to press the elastic member. The Wallace hardness of the pressing member 51 is preferably 70 to 90 degrees, and more preferably 75 to 80 degrees. Within the above range, the pressing member is easily deformed appropriately, the effect of suppressing jumping is further improved, and an excessive increase in cutting resistance can also be suppressed.

[0133] The Wallace hardness can be measured, for example, using a Wallace microhardness tester (manufactured by Wallace Instruments) as a measuring instrument in accordance with Japanese Industrial Standards (JIS) K6253-2:2012.

[0134] The material of the pressing member 51 is not particularly limited, and known materials can be used. Examples include rubber materials such as polyurethane rubber (ester-based polyurethane, ether-based polyurethane, etc.), silicone rubber, fluororubber, and natural rubber; and metals such as aluminum and stainless steel. From the viewpoint of satisfying the Wallace hardness requirement, rubber materials such as ester-based polyurethane are preferred.

[0135] The playback device 20 preferably includes a biasing member 41 that abuts against a side portion of the end B of the elastic member 3 and biases the elastic member toward the end A. The biasing member 41 only needs to bias the end B to an extent that it can suppress longitudinal elastic deformation of the elastic member 3 (particularly elastic deformation at the tip end of the elastic member). For example, the biasing member 41 may be shaped to bias the clamped portion of the clamping member 21 and from the clamped portion to the tip end of the elastic member ( FIG. 10B ), or may be shaped to bias the entire surface of the end B of the elastic member. The biasing member 41 preferably has a shape that can bias the clamped portion and from the clamped portion to the tip end of the elastic member 3.

[0136] The shape of the biasing member 41 is not particularly limited, but may be, for example, a plate-shaped member as shown in FIG. 10B . A plate-shaped member is easy to apply between the clamping members 21. As the plate-shaped member, for example, a shim plate or the like may be used according to the size of the gap between the clamping members 21. The shim plate is not particularly limited, and known metals such as iron, stainless steel, and copper may be used. For example, a cold-rolled steel plate may be used.

[0137] The thickness of the shim plate may be changed as appropriate in consideration of the thickness of the elastic member 3 and the spacing between the clamping members 21. For example, it may be 0.1 to 2.0 mm or 0.2 to 1.0 mm. There are no particular restrictions on the length or height of the shim plate, and it is sufficient to use one that suits the size of the elastic member 3 and the size of the device.

[0138] It is sufficient that the biasing member 41 is able to bias the end portion B to an extent that it can suppress elastic deformation in the longitudinal direction of the elastic member 3. For example, when a spring is used as the biasing member 41 itself or as an elastic member for biasing the biasing member 41, the allowable load of the spring is preferably in the range of 10 to 100 N, more preferably 20 to 60 N. The spring constant is preferably 1.0 to 10.0 N / mm, more preferably 2.0 to 5.0 N / mm.

[0139] Another aspect of the present disclosure relates to a method for producing a recycled elastic member, the method comprising the step of obtaining an elastic member recycled by the above-described recycling method.

[0140] The present invention will be specifically described below using examples. However, the present invention is not limited to the following examples. In the following formulations, parts are by weight unless otherwise specified.

[0141] The compounds used in the examples and comparative examples are also shown below, with the symbols used in the tables showing the formulations described later.

[0142] In the examples and comparative examples, recycled cleaning blades were produced and evaluated. The formulations and evaluation results of the examples and comparative examples are shown in Tables 3 to 5.

[0143] (Example 1) <Support Member> A 1.6 mm thick zinc-plated steel plate was prepared and processed to obtain a support member having an L-shaped cross section as shown in Fig. 1B. A urethane-metal one-layer adhesive (product name: Chemlok 219, manufactured by Lord Corporation) was applied to the area of ​​this support member that would come into contact with the elastic member.

[0144] <Preparation of Raw Material for Elastic Member of Cleaning Blade> The materials and amounts shown in Table 2 were mixed and reacted at a temperature of 80° C. for 3 hours to synthesize a prepolymer.

[0145] Next, the components in Table 3 below were mixed to prepare a curing agent.

[0146] The support member was placed in a cleaning blade mold consisting of an upper mold and a lower mold, with one end coated with adhesive protruding into the cavity. Next, the prepolymer and the curing agent were mixed to obtain a raw material composition. This raw material composition was injected into the cleaning blade mold with the support member attached and cured at 130°C for 2 minutes. The mold was then demolded to obtain an electrophotographic cleaning blade in which the polyurethane-containing elastic member was integrated with the support member. Release agent A was applied to the inside of the mold in advance.

[0147] Release Agent A is a mixture of materials set forth in Table 4 below.

[0148] The tip of the elastic member of the obtained cleaning blade was appropriately cut to obtain elastic member 1 according to Example 1. The edge angle was 90 degrees (the edge angle is the angle between the tip surface 5 and the main surface 4), and the lengths of the elastic member in the short direction, thickness direction, and length direction were 7.5 mm, 1.8 mm, and 240 mm, respectively. The obtained cleaning blade was evaluated by the following method.

[0149] [Method for measuring storage modulus E'] The storage modulus E' was measured by temperature frequency dispersion using a dynamic viscoelasticity device, and a master curve was created and calculated based on the temperature-time conversion rule. The conditions are as follows: Device: Dynamic viscoelasticity measuring device (trade name: DMA EXPLEXOR 500N, manufactured by NETZSCH) Measurement mode: Tensile Static strain: 2% Dynamic strain: 0.5% Measurement temperature: -30°C to 80°C (56 points in 2°C increments) Measurement frequency: 0.1 to 100 Hz (5 points) A master curve was created at a reference temperature of 24°C using the device's software.

[0150] From the obtained master curve, a mathematical approximation was performed based on the generalized Maxwell model, as shown below.

[0151] The above formula can be separated into the storage modulus E' and loss modulus E'' as follows:

[0152] The number of terms in the generalized Maxwell model is increased to the elastic term (E ｅ ) 1 + viscoelastic term (E ｉ ) 20 (i = 1 to 20). τ ｉ is 10 －８ ~10 ５ 20 points were arbitrarily set between these two points. E was calculated by the GRG nonlinear (generalized reduced gradient method) so that the difference between E' and E'' of the Maxwell model and E' and E'' of the master curve was minimized. ｅ , E ｉ was optimized. Specifically, the solver function of Excel was used. From the obtained master curve approximation equation, E' (1 x 10 ３ E' in Hz was obtained.

[0153] The measurement samples were prepared as follows: The samples were prepared so as to include the contact portion of the elastic member with the member to be cleaned. The samples were cut into strips measuring 50 mm in length, 1 mm in width, and 0.7 mm in thickness.

[0154] [Method for measuring breaking stress] Breaking stress was measured using a Tensilon universal testing machine (product name: RTG-1225, manufactured by A&D Co., Ltd.) in accordance with Japanese Industrial Standards (JIS) K6254-1993, with a tensile speed of 500 mm / min, a breaking point measurement sensitivity of 0.01 N, a gauge length of 20 mm, a test temperature of 24°C, and two measurements. The average of the two measurements was taken as the breaking stress. The measurement sample was prepared as follows: A length of approximately 100 mm was cut out in the longitudinal direction from the tip of the cleaning blade, including the contact portion with the member to be cleaned, and the thickness and width of the cut piece were measured to use as a rectangular measurement sample.

[0155] [Method for measuring polyfunctional alcohol species and concentration] Polyfunctional alcohols were detected by pyrolysis GC / MS (gas chromatography and mass spectrometry). The measurement conditions are as follows. Sampling position: A sample sampled at the tip of the elastic member was measured using the method described below. For sampling, a member such as polyurethane was cut using a biocutter. Apparatus: 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 number range m / z 10 to 650 Scan speed 1 second / scan

[0156] The polyfunctional alcohol species were characterized by GC / MS. A calibration curve was created by GC analysis of known concentrations of the characterized polyfunctional alcohol species, and quantification was performed from the GC peak area ratio. The arithmetic mean value of the values ​​obtained from the sample at the tip of the elastic member was taken as the polyfunctional alcohol concentration.

[0157] Measurement of M1, M2, and M3: M1 to M3 were measured using the direct sample introduction method (DI method), in which the sample was introduced directly into the ion source without passing through a gas chromatograph (GC). An ion trap GC / MS (trade name: POLARIS Q, manufactured by Thermo Fisher Scientific) was used as the instrument, and a Direct Exposure Probe (DEP) was used as the direct introduction probe. The sample sampled at the tip of the elastic member was measured using the following method. For sampling, a member such as polyurethane was cut with a biocutter. 0.1 μg of the sample sampled at the tip of the elastic member was fixed to a filament located at the tip of the probe and directly inserted into the ionization chamber. The sample was then rapidly heated from room temperature to 1000°C at a constant temperature increase rate (10°C / s), and the vaporized gas was detected using a mass spectrometer.

[0158] The detected amount M1 of all ions was defined as the sum of the integrated intensities of all peaks in the obtained total ion current thermogram. When the sum of the integrated intensities of the peaks in the extracted ion thermogram of m / z values ​​derived from the tri- or higher functional isocyanate was defined as M2, (M2 / M1) was calculated using the values ​​of M1 and M2. Furthermore, when the sum of the integrated intensities of the peaks in the extracted ion thermogram of m / z values ​​derived from the diisocyanate was defined as M3, (M3 / M1) was calculated using the values ​​of M1 and M3. The arithmetic mean values ​​of the obtained values ​​were defined as the values ​​of (M2 / M1) and (M3 / M1).

[0159] In this example, TTI, which was used as the trifunctional or higher polyfunctional isocyanate, has a structure represented by the following chemical formula (3). In the extracted ion thermogram obtained in this evaluation, a peak derived from a cationized product of TTI was detected, with a peak top at m / z 366.5 to 367.5. Therefore, in this example, the integrated intensity of this peak was designated M2.

[0160] In other examples described later, for an elastic portion made of polyurethane synthesized using polymeric MDI as a tri- or higher functional isocyanate, peaks derived from cationized polymeric MDI were detected in the extracted ion thermogram obtained in this evaluation, with peaks at m / z values ​​in the range of 380.5 to 381.5 indicating n = 1, m / z values ​​in the range of 511.5 to 512.5 indicating n = 2, m / z values ​​in the range of 642.5 to 643.5 indicating n = 3, and m / z values ​​in the range of 773.5 to 774.5 indicating n = 4 in the structure represented by chemical formula (1)'. Therefore, in these examples, the sum of the integrated intensities of these peaks was defined as M2.

[0161] Similarly, in the examples described below, tris(phenylisocyanate)thiophosphate (TPTI) used as a trifunctional or higher polyfunctional isocyanate has the structure shown in chemical formula (4). In the extracted ion thermogram obtained in this evaluation, a peak derived from the cationized product of TPTI was detected, with a peak top at m / z 464.5 to 465.5. Therefore, in these examples, the integrated intensity of this peak was designated M2.

[0162] On the other hand, in the case of the diisocyanate 4,4'-MDI, the structure represented by the above chemical formula (2) derived from 4,4'-MDI was detected as a cationized structure when the m / z value of the structure represented by the above chemical formula (2) was in the range of 249.5 to 250.5. The integrated intensity of the peak in the extracted ion thermogram corresponding to this structure was designated as (M3).

[0163] <Elastic member recycling device> Recycling processing was carried out using a device with the following configuration as the elastic member recycling device 1. (Blade portion 31) The following blade was used and fixed to the cutting unit 30 so as to be at the following angles A and B. Blade type: high-speed steel (SKH material) (product name and material), double-edged, tip angle (cutting edge angle) 45°, polished three times (DLC coated product), blade thickness 0.25 mm Blade angle θA: 45° Blade angle relative to the horizontal plane of the jig (angle θB): 5° Blade clamp: As shown in Figure 7B, the blade was clamped between the cutting unit 30 and both sides of the blade were fastened with bolts.

[0164] (Clamping member 21) The clamping member was as follows, and the elastic member was fixed to the blade portion 31 so as to achieve the following slice width, protrusion length A, and length B. Material of clamping member 21: Free-cutting pre-hardened steel (product number: NAK55) Pressing force: 14.7 N / m (clamped by tightening with an M3 bolt at this fastening force) Slicing width: 2.0 mm Protrusion length A: 0.225 mm Length B (length from clamping portion to tip of blade): 0.125 mm

[0165] (Pressing member 51) The pressing member 51 was a member made by processing a standard urethane sheet made of ester-based polyurethane (product number: UTM, manufactured by Misumi Corporation) into a disk shape with a diameter of 57.0 mm and a width of 10 mm. The pressing member 51 was fixed to the cutting unit 30 at a position where X and Y, as shown in Figure 9B, were the following values. The pressing member 51 was in contact with the elastic member (the radius of the disk - the value of Y = 0.1 mm) and was fixed so that the pressing member 51 could rotate as the cutting unit 30 moved.

[0166] By making contact in this manner, the pressing member 51 can press the tip of the elastic member 3 that protrudes from the clamping member 21 by the protrusion length A. This allows the pressing member 51 to press the elastic member a distance of X prior to the movement of the blade. The disk-shaped pressing member 51 is journaled to the cutting unit 30 by a bearing cam follower (product number: CFUA3-10, manufactured by Misumi Corporation) so that the disk can rotate. Material of pressing member 51: Polyester urethane (product number: UTM, manufactured by Misumi Corporation) Wallace hardness: 80 degrees Distance X: 17 mm Distance Y: 28.4 mm

[0167] (Using member 41) As the urging member 41, a shim plate made of cold-rolled steel plate having a length of 50 mm, a height of 10 mm, and a thickness of 0.6 mm was passed between the clamping members 21 as shown in Figures 5 and 6B, and end B of the elastic member was urged toward end A using a spring 42 and a lid 43. As the spring 42, a spring (model number WL18-35, manufactured by Misumi Corporation) having a spring constant of 2.9 N / mm and an allowable load of 30 to 50 N was used.

[0168] (Recycling process) As described above, in the recycling device A having the above-described configuration in which the elastic member 1 according to Example 1 is fixed, the cutting unit 30 is moved using a Robo Cylinder (product number RCS3-CT8C, manufactured by IAI Corporation) so that the blade feed speed becomes 1000 mm / sec, thereby cutting the elastic member from end A to end B and obtaining a recycled elastic member.

[0169] <Method for Evaluating Cut Surface Accuracy and Chatter Amount After Recycling> The recycled elastic members obtained were evaluated using the following procedure. The cut surfaces of the recycled elastic members were measured using a surface roughness measuring instrument (product name: SE-3500, manufactured by Kosaka Laboratory Co., Ltd.) in accordance with the surface roughness standard of Japanese Industrial Standards (JIS) B0601-1982. Measurements were taken along the length of the cut surface within a 450 μm range from the edge that abuts the member to be cleaned (edge ​​101 in FIG. 1B ) in the transverse direction. The evaluation length was 40 mm, and measurements were repeated to measure the entire length. The maximum height (Rmax), which is the difference between the most convex and most concave portions in each measurement, was calculated, and the maximum value of Rmax in the longitudinal direction was measured as the "chatter amount." Performance was ranked according to the following evaluation criteria. The cutoff value was 8.0 mm, and the feed rate was 1 mm / sec. A: Chatter amount is less than 2 μm. B: The amount of chatter is 2 μm or more and less than 4 μm. C: The amount of chatter is 4 μm or more and less than 8 μm. D: The amount of chatter is 8 μm or more and less than 12 μm. E: The amount of chatter is 12 μm or more.

[0170] <Image evaluation before and after recycling treatment> In this evaluation, the presence or absence of uneven contact between the elastic member of the cleaning blade and the member to be cleaned was confirmed through image evaluation, specifically, the presence or absence of uneven contact due to the occurrence of chattering on the cut surface caused by the recycled cleaning blade. In areas where uneven contact has occurred, if streaky stains remain as residual wiped particles even after cleaning, streaky images are generated, and therefore the uneven contact can be confirmed through the state of the image. The effects of the recycling treatment were confirmed by comparing before and after the recycling treatment.

[0171] <Evaluation of Cleaning Performance> The cleaning blade for an electrophotographic device using the obtained elastic member 1 according to Example 1 was incorporated into the cyan cartridge of a laser beam printer (LBP-672C, manufactured by Canon Inc.) as a cleaning blade for the photosensitive member, which is the member to be cleaned. First, the elastic member 1 according to Example 1 was incorporated into the laser beam printer and left in a low-temperature environment (temperature: 8°C) for 24 hours. Thereafter, one halftone image (an image depicting horizontal lines with a width of 1 dot and intervals of 2 dots perpendicular to the rotation direction of the electrophotographic photosensitive drum) was printed as an evaluation image, and the obtained halftone image was visually evaluated (hereinafter referred to as "initial evaluation"). After the initial evaluation, the printer was recycled according to the procedure described above to obtain a recycled elastic member. Next, the obtained recycled elastic member was incorporated into the laser beam printer and left in a low-temperature environment (temperature: 8°C) for 24 hours. One halftone image was then printed as an evaluation image, and the obtained halftone image was evaluated (hereinafter referred to as "initial evaluation after recycling"). Then, 6,000 images were formed under the same environment. The image formed here was a character image adjusted to a printing rate of 1.0% on A4-sized paper. One halftone image was then output as an evaluation image, and the resulting halftone image was evaluated (hereinafter referred to as "normal evaluation"). Furthermore, a new cyan cartridge was replaced with a recycled elastic member, and 6,000 images were formed again. One halftone image was then output as an evaluation image, and the resulting halftone image was evaluated (hereinafter referred to as "double evaluation"). The halftone images were evaluated according to the following criteria. The results are shown in Table 7. <Evaluation Criteria> Rank A: No streaks due to poor cleaning caused by the cleaning blade were observed in the image. Rank B: Minor streaks (streak length 5 mm or less) due to poor cleaning caused by the cleaning blade were observed. Rank C: Streaks (streak length greater than 5 mm and less than 10 mm) due to poor cleaning caused by the cleaning blade were observed. Rank D: Streaks (streak length greater than 10 mm) due to poor cleaning caused by the cleaning blade were observed.

[0172] (Examples 2 to 16) Elastic members 2 to 13 were produced in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Tables 5-1 and 5-2. Recycled cleaning blades were produced and evaluated in the same manner as in Example 1, except that the produced elastic members and the recycling apparatus shown in Table 6 were used and the recycling process was performed using the combinations shown in Table 7. The evaluation results are shown in Table 7. In the production of elastic members 2, 5, and 9, pentaerythritol (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the polyfunctional alcohol for the curing agent. The storage modulus E' and breaking stress of the obtained elastic members are shown in Table 5-3.

[0173] In producing the elastic member 3, polymeric MDI (trade name: Millionate MR-400, manufactured by Tosoh Corporation) (hereinafter referred to as MR400) was used as the tri- or higher functional isocyanate for the prepolymer.

[0174] In producing the elastic members 4 and 6, polymeric MDI (trade name: Millionate MR-200, manufactured by Tosoh Corporation) (hereinafter referred to as MR200) ​​was used as the tri- or higher functional isocyanate for the prepolymer.

[0175] In the preparation of the elastic members 4 and 8, glycerin (manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the polyfunctional alcohol for the curing agent.

[0176] In producing the elastic member 8, triphenylmethane-4,4',4''-triisocyanate (trade name: Ultite Super CA, manufactured by Toho Chemical Industry Co., Ltd.) (hereinafter referred to as TTI) was used as the tri- or higher functional isocyanate for the prepolymer.

[0177] In preparing the elastic member 7, polymeric MDI (trade name: Cosmonate M-200, manufactured by Mitsui Chemicals, Inc.) (hereinafter referred to as M-200) was used as the tri- or higher functional polyfunctional isocyanate for the prepolymer. Polytetramethylene ether glycol (trade name: PTG-2000SN, manufactured by Hodogaya Chemical Co., Ltd.) (hereinafter referred to as PTG-2000SN) with a number average molecular weight of 2000 was used as the polyol. Furthermore, polytetramethylene ether glycol (trade name: PTG-1000SN, manufactured by Hodogaya Chemical Co., Ltd.) (hereinafter referred to as PTG-1000SN) with a number average molecular weight of 1000 was used as the polyol for the curing agent.

[0178] Comparative Example 1 An elastic member 14 was produced in the same manner as in Example 1, except that the types and amounts of various materials for the prepolymer and the types and amounts of various materials for the curing agent were as shown in Table 5-2. The obtained elastic member 14 was cut by the recycling device D in the same manner as in Example 16 to produce recycled elastic members, which were then evaluated. The evaluation results are shown in Table 7.

[0179]

[0180] The high frequency storage modulus E' is a value measured at a vibration frequency of 1 x 10 ３ is the storage modulus in Hz.

[0181]

[0182]

[0183] The present disclosure is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the present invention. Therefore, the following claims are appended to clarify the scope of the present disclosure. This application claims priority based on Japanese Patent Application No. 2023-131631, filed August 10, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A method for recycling an electrophotographic cleaning blade, the electrophotographic cleaning blade comprising an elastic member and a support member for supporting the elastic member, at least a part of the tip of the elastic member on the free end side forms a contact part with a member to be cleaned, the recycling method comprising the steps of: preparing the elastic member to be recycled; and cutting the elastic member by inserting a cutting blade into the elastic member from a side part of the elastic member at one end A of the elastic member and moving the cutting blade relatively to the elastic member toward the other end B of the elastic member to remove at least a part of the contact part, the method comprising the steps of: preparing the elastic member to be recycled; and cutting the elastic member by inserting a cutting blade into the elastic member from a side part of the elastic member at one end A of the elastic member and moving the cutting blade relatively to the elastic member toward the other end B of the elastic member to remove at least a part of the contact part, the method comprising the steps of: preparing the elastic member to be recycled; ３ Hz is 90.0 to 500.0 MPa, and the breaking stress of the sample measured in an environment at a temperature of 24°C is 4.2 to 30.0 MPa.

2. The method for regenerating an electrophotographic cleaning blade according to claim 1, wherein the elastic member contains polyurethane.

3. The method for regenerating an electrophotographic cleaning blade according to claim 1 or 2, wherein the storage elastic modulus is 100.0 to 400.0 MPa, and the breaking stress is 8.0 to 28.0 MPa.

4. The method for regenerating an electrophotographic cleaning blade according to any one of claims 1 to 3, wherein the relative movement is a movement in the longitudinal direction of the elastic member.

5. The contact portion of the elastic member with the member to be cleaned is formed extending in the longitudinal direction, the cutting step is a step of removing at least a portion of the contact portion using a recycling device, the recycling device comprising: a blade portion as the cutting blade for removing at least a portion of the contact portion in the longitudinal direction, a clamping member for the elastic member, a biasing member that contacts the end B of the elastic member and biases the elastic member in the direction of the end A, and a pressing member that presses the tip of the elastic member including the contact portion in the lateral direction of the elastic member to suppress elastic deformation due to movement of the blade portion, the clamping member clamps at least a portion of the elastic member from both side portions of the elastic member in a cross-sectional view perpendicular to the longitudinal direction of the elastic member, the clamping member is arranged in a position where it can clamp at least a portion of the elastic member into which the blade portion enters, and the position of the clamping member relative to the elastic member is fixed, 5. The method for regenerating an electrophotographic cleaning blade according to claim 1, wherein the pressing member presses the elastic member prior to the relative movement of the blade portion from the end A to the end B.

6. A method for regenerating an electrophotographic cleaning blade according to any one of claims 1 to 5, wherein the elastic member contains polyurethane, and when a sample taken from the tip of the elastic member is measured by pyrolysis GC / MS, the concentration of a component derived from a trifunctional or higher polyfunctional alcohol in the polyurethane is 0.04 mmol / g to 0.70 mmol / g.

7. The method for regenerating an electrophotographic cleaning blade according to any one of claims 1 to 6, wherein the elastic member contains a polyurethane elastomer, the polyurethane elastomer being a reaction product of a polyurethane raw material containing an isocyanate compound containing 4,4'-MDI, a polyester polyol, and a polyfunctional alcohol having three or more functional groups.

8. A method for producing a recycled electrophotographic cleaning blade, comprising a step of obtaining an elastic member recycled by the method for recycling an electrophotographic cleaning blade according to any one of claims 1 to 7.

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