JP5162911B2 - Endless belt for image forming apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an endless belt (endless belt) for an image forming apparatus capable of high image quality, which has excellent mechanical properties such as bending resistance and surface characteristics, as well as electrical characteristics, and excellent toner transferability and toner cleaning properties. The present invention also relates to an image forming apparatus including the endless belt for the image forming apparatus.

  Conventionally, as an image forming apparatus such as an OA device, an electrophotographic system using a photoconductor and toner, and an image forming apparatus using gel-like ink instead of toner have been devised and put on the market. These devices include conductive belts, intermediate transfer belts, paper transfer belts, transfer separation belts, charging tubes, developing sleeves, fixing belts, toner transfer belts, etc. Endless belts controlled to have various insulating electric resistances are used.

  For example, an intermediate transfer device used in an electrophotographic system is configured to once form a toner image on an intermediate transfer member and then transfer the toner to paper or the like. An endless belt made of a seamless belt is used for charging and discharging the toner on the surface layer of the intermediate transfer member. The seamless belt is set to have different surface electric resistance and electric resistance in the thickness direction (hereinafter referred to as “volume electric resistance”) for each machine model, and is adjusted to be conductive, semiconductive, or insulative.

  In addition, the paper transport transfer device holds the paper once on the transport transfer body, transfers the toner from the photosensitive member onto the paper held on the transport transfer body, and further removes the paper from the transport transfer body by discharging. It is configured. On the surface of the transport transfer body, an endless belt with or without a seam is used for charging or neutralizing paper. The endless belt is set to have different surface electric resistance and volume electric resistance for each machine model, like the intermediate transfer belt.

  FIG. 1 is a side view of a general intermediate transfer apparatus. In the figure, 1 is a photosensitive drum and 6 is a conductive endless belt. 1 is an electrophotographic process unit including a charging device 2, an exposure optical system 3 using a semiconductor laser as a light source, a developing device 4 containing toner, and a cleaner 5 for removing residual toner. Is arranged. The conductive endless belt 6 is wound around the transport rollers 7, 8, and 9 and moves in the direction of the arrow in synchronization with the photosensitive drum rotating in the direction of the arrow.

  Next, the operation will be described. First, the surface of the photosensitive drum 1 rotating in the direction of arrow A is uniformly charged by the charger 2. Next, an electrostatic latent image corresponding to an image obtained by an image reading device (not shown) is formed on the photosensitive drum 1 by the optical system 3. The electrostatic latent image is developed into a toner image by the developing device 4. This toner image is electrostatically transferred to the conductive endless belt 6 by the electrostatic transfer machine 10 and transferred to the recording paper 11 between the conveying roller 9 and the pressing roller 12.

  By the way, in the case of a conductive endless belt used in an image forming apparatus such as an electrophotographic copying machine or a printer, since it is functionally driven with a high tension and a high voltage for a long time by two or more rolls, it is sufficient. Mechanical and electrical durability is required.

  In particular, in the case of an intermediate transfer belt used in an intermediate transfer device or the like, an image is formed with toner on the belt and transferred to paper, so if the belt is loosened, stretched or meandered during driving, the image Due to misalignment, high dimensional accuracy (small circumferential length difference in belt width and uniform thickness), high elastic modulus (high tensile elastic modulus in belt circumferential direction), high bending resistance The thing excellent in (it is hard to break) is desired.

  In recent years, electrophotographic image forming apparatuses such as color laser printers and color LED printers have become more competitive with low-cost inkjet image forming apparatuses. Therefore, the electrophotographic image forming apparatus aims at differentiating from the inkjet system by a high-speed printing technique, and is an image forming apparatus that prints at a high speed by a tandem type paper conveyance transfer in which four photoconductors are arranged and an intermediate transfer system. Has been commercialized. For this reason, further improvement in durability and prevention of image misalignment have become increasingly important for endless belts for image forming apparatuses.

  Conventionally, endless belts have achieved certain results by improving their materials. However, recently, not only high-speed printing but also the demand for improving image quality has been increasing. Especially, high-quality images can be obtained in a wide range of temperature and humidity environments, and only special paper for color printers. However, it is becoming particularly important to obtain high image quality on various types of paper such as high-quality paper, recycled paper, backing paper, and OHP film in order to clarify the features of the ink jet printer.

  For this reason, development of polymerized toners has progressed, and toners with a small particle size of 4 to 6 μm and small variations in particle size have been commercialized, and improvements to surface properties, chemical properties, and electrical properties of transfer belts have been made. The demand is also increasing.

  In particular, in the case of a transfer belt used in an intermediate transfer device or the like, the toner on the photoconductor is directly transferred onto the transfer belt by electrostatic force (primary transfer), and after synthesizing a color image on the transfer belt, the toner is added. In order to transfer to paper with electrostatic force (secondary transfer), not only the electrical resistance characteristics such as the surface electrical resistance and volume electrical resistance characteristics of the transfer belt are important, but also the surface physical characteristics and surface chemical characteristics need to be improved. There is. For example, the surface of an endless belt is required to be smoother in order to improve the cleaning properties for toners having a smaller particle size in recent years. However, if the surface of the endless belt is too smooth, a blade that scrapes off residual toner. The friction of the toner increases, and troubles related to the toner cleaning property are likely to occur.

From the above, the following conditions <1> to <8> are required for the endless belt for an image forming apparatus such as a transfer belt in recent years.
<1> Has predetermined surface electrical resistivity and volume electrical resistivity in the semiconductor region, has little resistance variation, and has excellent toner releasability
<2> Moderately smooth surface and excellent toner cleaning performance
<3> Thin and uniform
<4> Strong mechanical strength (hard to stretch and hard to crack)
<5> Fluctuations in resistance, dimensions, and mechanical strength due to the environment (temperature and humidity) are small.
<6> Low cost
<7> A seamless and perfect circle (small difference in circumference in the belt width direction) belt
<8> High-quality prints on various paper types

  Conventionally, a transfer belt in which a modifier such as a fluororesin or silicone is added to a base polymer such as a thermoplastic resin or a thermosetting resin for the purpose of improving the non-fixing property of the toner transferred onto the transfer belt. Has been proposed.

For example, Patent Document 1 contains a silane coupling agent and an alkylsilane to reduce appearance defects such as thermal decomposition and foaming at the time of melt processing, which is a harmful effect when using carbon black with many surface functional groups. A seamless belt made from an extruded material by an extrusion method has been proposed.
However, in this patent document 1, there is no description from the viewpoint of improving the toner cleaning property, and no consideration is given to the modification of the antioxidant composition, surface roughness, surface tension, folding resistance, and tensile modulus. Absent.

Patent Document 2 discloses a semiconductive resin obtained by an extrusion molding method using a composition in which carbon black, an inorganic filler, and a titanate coupling agent are blended with a thermoplastic resin in order to improve the dispersibility of carbon black. A belt is disclosed.
However, in Patent Document 2, no consideration is given to the blending of an antioxidant for improving the toner cleaning property, the surface roughness, the surface tension, the bending strength, and the improvement of the tensile elastic modulus.

Patent Document 3 discloses an intermediate transfer body obtained by extrusion molding from a material containing a filler that has been surface-treated with silicone oil, a fluorosurfactant or various coupling agents in order to improve the dispersibility of carbon black, and transfer A member is disclosed.
However, in the examples described in Patent Document 3, only a filler subjected to various surface treatments using polypropylene as a matrix polymer is blended, and the blending of antioxidant, surface roughness, surface tension, No consideration is given to the improvement of bending strength and tensile modulus.

Patent Document 4 describes a transfer belt produced by extrusion molding from a material having a silicone content of 0.5 to 10% by weight with respect to a matrix resin. Abrasion reduction and surface filming resistance are improved.
However, this Patent Document 4 only describes that it is good to improve the surface lubricity by including silicone in the matrix resin and using silicone having an average molecular weight of 100,000 or more, preferably 100,000 to 5,000,000. In addition, there is no description regarding the blending of the antioxidant, as well as the optimal balance of surface lubricity, surface roughness, and tensile modulus, and no consideration is given to the problems when blending the antioxidant.

Patent Document 5 describes an intermediate transfer belt made of a resin composition in which at least one of silicone rubber particles or fluorine rubber particles is contained in a raw material resin mainly composed of a thermoplastic resin.
However, in Patent Document 5, silicone rubber particles are blended for the purpose of imparting a certain degree of rubber elasticity and releasability in order to reduce friction in order to increase the dimensional accuracy in the inflation molding method. No consideration is given to the improvement of the formulation of antioxidant, surface roughness, surface tension, bending strength, and tensile modulus from the viewpoint of the above.

  Since belts for image forming apparatuses such as transfer belts are exposed to high temperatures in the production process (during heat-kneading and extrusion molding) and in the usage environment, they are usually oxidized except for special thermoplastic resin materials. It is essential to include an inhibitor. In other words, belts that do not contain an antioxidant have problems that mechanical properties such as bending resistance are easily lost due to oxidative deterioration during heating and kneading and extrusion molding, and cracks are likely to occur. The deterioration over time is remarkable, and practically satisfactory performance cannot be obtained in terms of durability.

On the other hand, as an inexpensive belt manufacturing method, a transfer belt manufacturing method using an extrusion molding method in which an annular die is attached to the tip of an extruder has been proposed.
Japanese Patent Laid-Open No. 2001-305891 Japanese Patent Laid-Open No. 2003-177612 Japanese Patent Application Laid-Open No. 2002-214927 Japanese Patent Laid-Open No. 2005-31040 Japanese Patent Laid-Open No. 2004-70255

  As described above, for the purpose of improving the non-sticking property of the toner transferred onto the transfer belt, it is known to add silicone to the base polymer such as a thermoplastic resin or a thermosetting resin. When a molding material is added by simply adding a toner releasability-imparting component such as silicone resin or silicone rubber to a polymer such as a thermoplastic resin or thermoplastic elastomer, the compatibility between the polymer material and the silicone component In addition to adverse effects such as poor mechanical properties such as bending resistance of the resulting belt, the belt surface roughness is deteriorated and the surface characteristics are also deteriorated. There was a problem of being damaged.

  Even when a filler surface treatment agent such as a silicone component or a silane compound is previously added to a filler such as carbon black, if the interaction effect between the matrix polymer, the surface treatment agent and the filler is not considered, There have been problems such as deterioration in mechanical properties such as flexibility, surface roughness, and toner cleaning failure.

The present invention solves the above-described conventional problems, and provides an endless belt that has a surface roughness that is moderately smooth and that has improved mechanical properties such as bending resistance while moderately reducing the surface tension of the endless belt. The purpose is that.
Furthermore, an endless belt for an image forming apparatus having excellent surface characteristics and electrical characteristics of an endless belt, excellent toner transferability and toner cleaning properties, and an image forming apparatus including the endless belt for an image forming apparatus are provided. The purpose is to do.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have formulated a specific Si compound as an additional component in a specific amount together with an antioxidant and heat-kneaded to thereby form a matrix polymer and an antioxidant. It has been found that the interaction between Si and the Si compound can occur, and that the mechanical strength and the poor cleaning can be simultaneously improved by the interaction between the three components.

  For endless belts, a thermoplastic polymer component with excellent heat resistance is added, especially when endless belts are obtained by heat-kneading at the time of material preparation or by extrusion molding with a relatively long residence time of the molding material. In addition, it is necessary to pay close attention to the addition of additives such as antioxidants to prevent oxidation deterioration reaction in the kneader and oxidation deterioration reaction during heating extrusion molding.

As a result of examining the mechanism of occurrence of defective toner cleaning of the conventional endless belt, the present inventors have found that this antioxidant bleeds to the surface of the endless belt, which can be a main cause of defective cleaning.
That is, the antioxidant that bleeds out on the belt surface adheres to the cleaning blade by rubbing against the cleaning blade during toner cleaning, and the antioxidant accumulates on the edge of the blade, resulting in oxidation. The toner scraping effect is reduced at the blade portion where the inhibitor is deposited, and cleaning failure (toner cleaning blade slipping phenomenon) occurs.
Conventionally used silicone resins, silane coupling agents, and silicone oils can not only prevent the poor cleaning due to bleeding out of this antioxidant, but also improve the smoothness and mechanical strength of the belt surface. I couldn't.

In order to solve this problem, it is conceivable to reduce the amount of the antioxidant which is the main cause of cleaning failure. In this case, the thermoplastic polymer component due to heat applied to the material during kneading or extrusion molding Oxidative degradation (thermal degradation) of the belt causes a problem that the mechanical characteristics of the endless belt are degraded. In addition, even when the amount of the antioxidant is small, when the friction between the belt surface and the blade is large, the antioxidant slightly adhered to the belt surface is scraped off by the blade and fixed to the blade. Eventually, defective cleaning occurs.
Therefore, it is necessary to solve the cleaning failure after blending the antioxidant.

Therefore, as a result of examining the types and amounts of Si compounds that easily reduce the coefficient of friction between the blade and the endless belt surface, and the antioxidant is difficult to adhere to the blade, By blending an antioxidant with a certain amount of thermoplastic polymer, while maintaining the surface smoothness of the belt and lowering the surface tension, the mechanical durability is improved and at the same time the cleaning failure by the antioxidant It was found that it can be made difficult to occur.
That is, this invention makes the following a summary.

[1] An endless belt used in an image forming apparatus, which is an endless belt made of a molding material mainly composed of a thermoplastic polymer component made of a thermoplastic resin and / or a thermoplastic elastomer. An agent component and silicone rubber or silicone oil , and the content of the silicone rubber or silicone oil is 0.1 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the thermoplastic polymer component. image forming apparatus for an endless belt, wherein the ratio of content of less than 200 0.05 over the silicone rubber or silicone oil to the content of inhibitor components.

[2] In [1], the surface roughness (Ra) represented by Ra of the outer surface of the endless belt is 0.02 μm or more and 0.2 μm or less, and the surface wetting tension (E) is 27 dyne / cm or more and 35 dyn / cm. An endless belt for an image forming apparatus, wherein the relationship between the surface roughness (Ra) and the surface wetting tension (E) satisfies the following formula (1):
Ra × 100 <−2 × E + 80 (1)

[3] The endless belt for an image forming apparatus according to [1] or [2], wherein the silicone rubber or the silicone oil is a silicone rubber containing an acrylic component.

[ 4 ] The endless belt for an image forming apparatus according to any one of [1] to [ 3 ], wherein the molding material contains a conductive component.

[5] The image forming apparatus according to [4], wherein the silicone rubber or silicone oil is preliminarily attached to the conductive component before being mixed with a thermoplastic polymer component to form a molding material. Endless belt.

[ 6 ] An endless belt for an image forming apparatus, wherein the conductive component is carbon black in [ 4 ] or [ 5 ].

[7] The endless belt for an image forming apparatus according to [6], wherein the silicone rubber or the silicone oil is a silicone oil and is attached to the carbon black at a ratio of 1% to 20% by weight. .

[8] In any one of [4] to [7], the thermoplastic polymer component and silicone rubber or silicone oil and a conductive component are heated and kneaded to obtain the molding material, and the molding material is heated and extruded. An endless belt for an image forming apparatus obtained by the above method.

[ 9 ] The endless belt for an image forming apparatus according to [ 8 ], wherein the molding material is formed by cooling and solidifying the molten tube obtained by heating and extruding the molding material from an annular die.

[ 10 ] In any one of [1] to [ 9 ], the thermoplastic polymer component is a thermoplastic elastomer / thermoplastic resin = 5/95 to 95/5 in a weight ratio of the thermoplastic elastomer and the thermoplastic resin. An endless belt for an image forming apparatus, comprising:

[ 11 ] The endless belt for an image forming apparatus according to any one of [1] to [ 10 ], wherein the thermoplastic elastomer is a polyester-based thermoplastic elastomer.

[ 12 ] The endless belt for an image forming apparatus according to any one of [1] to [ 11 ], wherein the thermoplastic resin contains polyalkylene terephthalate as a main component.

[ 13 ] The endless belt for an image forming apparatus according to [ 12 ], wherein the polyalkylene terephthalate is polybutylene terephthalate.

[ 14 ] The endless belt for an image forming apparatus according to any one of [1] to [ 13 ], wherein the folding endurance is 2000 times or more and the tensile elastic modulus is 1500 MPa or more and 3500 MPa or less.

[ 15 ] In any one of [1] to [ 14 ], the image forming apparatus is a seamless intermediate transfer belt, conveyance transfer belt, transfer fixing belt, fixing belt, photosensitive belt, or development sleep. Endless belt.

[ 16 ] An image forming apparatus comprising the endless belt for an image forming apparatus according to any one of [1] to [ 15 ].

In an endless belt mainly composed of a thermoplastic polymer component made of a thermoplastic resin and / or a thermoplastic elastomer, an antioxidant component and an Si compound, that is, a silicone component and / or a silane compound, the content of the Si compound However, with respect to 100 parts by weight of the thermoplastic polymer component, 0.1 parts by weight or more and 20 parts by weight or less, and the ratio of the content of the Si compound to the content of the antioxidant component is 0.05 or more and less than 200. By blending,
(1) The friction coefficient between the blade and the endless belt is lowered, the force with which the antioxidant is pressed against the blade is weakened, and the antioxidant is prevented from adhering to the blade edge.
(2) When the Si compound bleeds together with the antioxidant, the antioxidant itself is given a releasability to prevent the deposition of the antioxidant on the blade.
Therefore, the adhesion between the antioxidant and the blade is reduced, and as a result, the chemical and physical properties are excellent in toner transferability and cleaning properties without lowering the mechanical strength and without deteriorating the surface roughness. It is possible to provide an endless belt for an image forming apparatus compatible with high image quality, having excellent physical properties, excellent mechanical properties such as flex resistance and surface properties, excellent toner transferability and toner cleaning properties. Become.

In the present invention, the surface roughness (Ra) represented by Ra on the outer surface of the endless belt is 0.02 μm or more and 0.2 μm or less by blending the antioxidant and the Si compound in the above ratio. Thus, it is preferable that the surface wetting tension (E) is 27 dyne / cm or more and 35 dyn / cm or less, and the relationship between the surface roughness (Ra) and the surface wetting tension (E) satisfies the following formula (1). (Claim 2).
Ra × 100 <−2 × E + 80 (1)

The Si compound used in the present invention is preferably a silicone rubber (Claim 3), and the silicone rubber preferably contains an acrylic component (Claim 4).
That is, for example, it is preferable that the silicone rubber is a copolymer of silicone rubber and acrylic rubber because it is excellent in miscibility with the thermoplastic polymer component and is excellent in the effect of lowering the surface tension. In particular, it is preferable that the silicone-acrylic copolymer is covered with polymethyl methacrylate or a styrene-acrylonitrile copolymer because the dispersibility of the silicone rubber in the thermoplastic polymer component is further improved.

  Further, as the Si compound, silicone oil is also preferable (Claim 5), and the silicone oil is preferably preliminarily attached to carbon black as a conductive component at a ratio of 1% to 20% in terms of weight ( Claim 9).

  In the present invention, the molding material preferably contains a conductive component such as carbon black (Claims 6 and 8), and the Si compound is previously electrically conductive before being mixed with the thermoplastic polymer component to form a molding material. (Seventh aspect) The silicone oil is preferably pre-attached to carbon black.

  That is, the method of blending the Si compound with the thermoplastic polymer component is not particularly limited, and two or more of the thermoplastic polymer component, the Si compound and carbon black are blended in advance, and then from the hopper inlet of the kneader. Examples include a separate feed method in which only Si compounds are fed into a kneader separately from the thermoplastic polymer component and the conductive component, etc. By preliminarily attaching a Si compound such as silicone oil and coating the surface of a conductive component such as carbon black with a thermoplastic polymer component using a kneader to prepare a conductive composition More effective interaction between conductive component such as carbon black and Si compound such as silicone oil and thermoplastic polymer component It is possible to draw a manner.

  The endless belt for an image forming apparatus according to the present invention is preferably formed by heat-kneading a thermoplastic polymer component, an Si compound, and a conductive component to obtain a molding material, and then subjecting the molding material to heat extrusion molding. In particular, it is preferable that the molding material is molded by cooling and solidifying the molten tube obtained by heating and extruding the molding material from an annular die.

  As described above, the endless belt obtained by extruding the tube extruded from the annular die by continuous extrusion in an annular state and taking it out as a cylindrical body, and cutting it into a ring, reduces cost and dimensional stability. Can be achieved at the same time. Further, by providing a plurality of temperature adjusting mechanisms in the circumferential direction of the annular die, an endless belt with little variation in electrical resistivity can be manufactured at low cost.

The endless belt for an image forming apparatus of the present invention includes a thermoplastic elastomer and a thermoplastic resin as a thermoplastic polymer component in a weight ratio of thermoplastic elastomer / thermoplastic resin = 5/95 to 95/5. Polyester terephthalate is preferable as the thermoplastic elastomer, and polyalkylene terephthalate, particularly polybutylene terephthalate, is preferable as the thermoplastic resin (claims 12 to 15).
With such an alloy material of a thermoplastic elastomer and a thermoplastic resin, it is possible to obtain good durability and an appropriate elastic modulus, satisfy the preferred electrical characteristics of the present invention, and good extrusion moldability. Can be obtained.

The endless belt for an image forming apparatus of the present invention preferably has a folding endurance of 2000 times or more and a tensile elastic modulus of 500 MPa to 3500 MPa.
The endless belt for an image forming apparatus of the present invention is particularly suitable for a seamless intermediate transfer belt, a conveyance transfer belt, a transfer fixing belt, a fixing belt, a photosensitive belt, or a development sleep.

  With the image forming apparatus of the present invention including such an endless belt for an image forming apparatus of the present invention, a high-quality image can be formed over a long period of time (claim 18).

  Hereinafter, embodiments of an endless belt for an image forming apparatus and an image forming apparatus according to the present invention will be described in detail.

(1) Endless belt material The endless belt of the present invention comprises a thermoplastic polymer component comprising a thermoplastic elastomer and / or thermoplastic resin, an antioxidant and an Si compound, and more preferably a conductive material, if necessary. It is composed of other added ingredients. The endless belt material according to the present invention only needs to contain a predetermined amount of an antioxidant and an Si compound with respect to the thermoplastic polymer component, and preferably has a surface roughness (Ra) and surface wetting. There are no limitations on the types of thermoplastic polymer components, antioxidants, and other materials, as long as the tension (E), tensile modulus, and bending resistance are satisfied. The endless belt of the present invention can obtain desired conductivity by blending a necessary amount of a substance that exhibits conductivity, such as a conductive filler or an ionic conductive substance.

[Thermoplastic polymer component]
<Thermoplastic resin>
Examples of the thermoplastic resin used in the endless belt of the present invention include polypropylene, polyethylene (high density, medium density, low density, linear low density), propylene ethylene block or random copolymer, rubber or latex component such as ethylene Propylene copolymer rubber, styrene / butadiene rubber, styrene / butadiene / styrene block copolymer or hydrogenated derivatives thereof, polybutadiene, polyisobutylene, polyamide (PA), polyamideimide (PAI), polyacetal (POM), polyarylate ( Par), polycarbonate (PC), polyalkylene terephthalate (PAT), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), polybutylene naphthalate (PBN), polytrimethylene terephthalate (PTT), polymethyl methacrylate (PMMA), polyphenylene oxide (PPE), polyethersulfone (PES), polymethylpentene (TPX), polyoxybenzylene (POB), polyimide ( PI), liquid crystalline polyester, polysulfone (PSF), polyphenylene sulfide (PPS), polybisamide triazole, polyamino bismaleimide, polyether imide (PEI), polyether ether ketone (PEEK), acrylic, polyfluorinated vinylidene (PVDF) ), Polyfluorinated vinyl, chlorotrifluoroethylene, ethylenetetrafluoroethylene copolymer (ETFE), hexafluoropropylene, perfluoroalkyl vinyl ether copolymer An acrylic acid alkyl ester copolymer, a polyester ester copolymer, a polyether ester copolymer, a polyether amide copolymer, a polyurethane copolymer, or the like, or a mixture of two or more thereof can be used. .

  Among the thermoplastic resins used in the endless belt of the present invention, the crystalline resin preferably has at least one of a hydroxyl group, a carboxylic acid group and an ester bond, and has a crystallinity of 20% or more and less than 90%. If it is, there will be no restriction | limiting in particular and a general purpose resin can be used.

  Specifically, among the thermoplastic crystalline resins, PAT (polyalkylene terephthalate) is preferable, and PBT (polybutylene terephthalate), PET (polyethylene terephthalate), and PEN (polyethylene naphthalate) are more preferable, and PBT is crystallized. Since the speed is high, there is little change in crystallinity due to molding conditions, and it is particularly preferable because it is generally stable at about 30%.

  Moreover, a copolymerization component can also be introduce | transduced in the crystalline resin used for this invention in the range which does not impair the effect of this invention remarkably. Specific examples include an ester bond in the main chain and an aliphatic polyester such as polytetramethylene glycol or polycaprolactone or an alicyclic polyester such as polycyclohexadimethylene.

  As the molecular weight of the thermoplastic crystalline resin used in the endless belt of the present invention, a resin having a general molecular weight such as a weight average molecular weight of 10,000 to 100,000 can be used, but mechanical properties such as tensile elongation at break are high. When required, high molecular weight is preferred. Specifically, it is preferably 20,000 or more, more preferably 25,000 or more, and particularly preferably 30,000 or more.

  Among the thermoplastic resins used in the endless belt of the present invention, the amorphous resin preferably has at least one of a hydroxyl group, a carboxylic acid group and an ester bond, and has a crystallinity of 0% or more and 10%. If it is less than this, there will be no restriction | limiting in particular and a general purpose resin can be used.

  Specifically, polyesters such as PC (polycarbonate) and PAr (polyarylate), and resins having ester bonds in the side chains such as PMMA (polymethyl methacrylate) can be given as suitable examples. Of these, polyester is preferable, and PC can be used particularly preferably.

  The amorphous resin used for the endless belt of the present invention can introduce a copolymer component within a range that does not significantly impair the effects of the present invention. Specific examples include ester bonds in the main chain, aliphatic polyesters such as polytetramethylene glycol and polycaprolactone, alicyclic polyesters such as polycyclohexadimethylene, and ester bonds such as polymethylene glycol introduced. Can be mentioned.

  There is no particular limitation on the molecular weight of the amorphous resin used in the endless belt of the present invention. For example, a resin having a general molecular weight such as a weight average molecular weight of 10,000 to 100,000 can be used. When there is a demand for high physical properties, those having a high molecular weight are preferred. Specifically, it is preferably 20,000 or more, more preferably 25,000 or more, and particularly preferably 30,000 or more.

<Thermoplastic elastomer>
As the thermoplastic elastomer used in the present invention, thermoplastic elastomers such as polyester, polyamide, polyether, polyolefin, polyurethane, and vinyl chloride can be used.

  The feature of the thermoplastic elastomer is that the crack resistance of the endless belt can be greatly enhanced and flexibility can be imparted.

<Alloy material of thermoplastic resin and thermoplastic elastomer>
When an alloy material of a thermoplastic resin and a thermoplastic elastomer is used as the thermoplastic polymer component, the thermoplastic elastomer has a common functional group with the thermoplastic resin and has high affinity with the thermoplastic resin. By using an elastomer, the alloy dispersibility of the thermoplastic resin and the thermoplastic elastomer is improved, the crack resistance can be dramatically improved and the tensile elastic modulus can be adjusted. Excellent surface smoothness, carbon black, etc. The conductive material dispersibility is obtained, which is preferable.

  Accordingly, when a polyester such as polybutylene terephthalate or polyethylene terephthalate and / or polycarbonate is used as the thermoplastic resin, it is preferable to use a polyester-based or polyether-based thermoplastic elastomer. In addition, it is preferable to combine a polyamide-based thermoplastic elastomer with an amide-based thermoplastic resin such as nylon.

  The polyester elastomer block is a polyester polyether block copolymer using an aromatic polyester as a hard component, an aliphatic polyether as a soft component, an aromatic polyester as a hard component, and an aliphatic polyester as a soft component. Copolymers can be used.

  More specifically, the following (A) and (B) can be used as the polyester polyether block copolymer and the polyester polyester block copolymer.

(A) Polyester polyether block copolymer The polyester polyether block copolymer comprises (a) an aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, and (b) an aromatic dicarboxylic acid or an alkyl ester thereof. And (c) Polyalkylene ether glycol having a weight average molecular weight of 400 to 6,000 as a raw material, and an oligomer obtained by esterification reaction or transesterification reaction is polycondensed. Examples of the aliphatic and / or alicyclic diol having 2 to 12 carbon atoms include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol. Preferably, 1,4-butanediol and ethylene glycol are the main components, and one or a combination of two or more of these can be used.

  Examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and the like. Preferably, terephthalic acid and 2,6-naphthalenedicarboxylic acid are the main components. A combination of the above may also be used. Examples of the alkyl ester of aromatic dicarboxylic acid include dimethyl esters such as dimethyl terephthalate, dimethyl isophthalate, dimethyl phthalate, and 2,6-dimethyl naphthalate, preferably dimethyl terephthalate and 2,6-dimethyl naphthalate. There may be a combination of two or more of these. In addition to the above, trifunctional diols, other diols and other dicarboxylic acids and esters thereof may be copolymerized in small amounts, and aliphatic dicarboxylic acids such as adipic acid or alicyclic dicarboxylic acids, or What uses alkylester etc. as a copolymerization component is also good.

  As the polyalkylene ether glycol, those having a weight average molecular weight of 400 to 6,000 are used, preferably 500 to 4,000. Here, as polyalkylene ether glycol, polyethylene glycol, poly (1,2 and 1,3-propylene ether) glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, block or random copolymer of ethylene oxide and propylene oxide And a block or random copolymer of ethylene oxide and tetrahydrofuran. Particularly preferred is polytetramethylene ether glycol. The content of the polyalkylene ether glycol is desirably 5 to 95% by weight, preferably 10 to 85% by weight, based on the block copolymer to be produced.

(B) Polyester polyester block copolymer The polyester polyester block copolymer is (d) an aliphatic or alicyclic dicarboxylic acid instead of the above (c) polyalkylene ether glycol having a weight average molecular weight of 400 to 6,000. And a polyester oligomer obtained by condensation of an aliphatic diol, (e) a polyester oligomer synthesized from an aliphatic lactone or an aliphatic monool carboxylic acid, and (a) an aliphatic and / or alicyclic group having 2 to 12 carbon atoms. A diol and (b) an aromatic dicarboxylic acid or an alkyl ester thereof are used as raw materials, and an oligomer obtained by an etherification reaction or a transesterification reaction is polycondensed.

  Examples of the above (d) include 1,4-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, alicyclic dicarboxylic acid such as dicyclohexyl-4,4′-dicarboxylic acid, or succinic acid, oxalic acid, adipic acid And polyester oligomers having a structure in which one or more aliphatic dicarboxylic acids such as sebacic acid and one or more diols such as ethylene glycol, propylene glycol, tetramethylene glycol, and pentamethylene glycol are condensed. Examples of e) include polycaprolactone-based polyester oligomers synthesized from ε-caprolactone, ω-oxycaproic acid and the like.

  Specific examples of thermoplastic elastomers other than polyesters used in the present invention include those based on polystyrene, such as styrene-butadiene-styrene copolymer, styrene-isoprene-styrene copolymer, styrene-ethylene-butylene-styrene copolymer, styrene- There are ethylene-propylene-styrene copolymers, etc., and in the case of polyvinyl chloride, there are cross-linked (three-dimensional) vinyl chloride-linear vinyl chloride polymers, etc., and as olefins, there are polyethylene-EPDM copolymer, polypropylene-EPDM copolymer, polyethylene- There are EPM copolymer polypropylene-EPM copolymer, etc., and PBT (1,4-butadienediol-terephthalic acid condensate) -PTMEGT (polytetramethyleneglycol) (Poly-terephthalic acid condensate) copolymer and the like, and examples of the polyamide system include a copolymer having a basic skeleton of nylon oligomer-dicarboxylic acid-polyether oligomer, and examples of the nylon oligomer include nylon 6 and nylon. 66, nylon 610, nylon 612, nylon 11, nylon 12, and the like. As the polyether oligomer, for example, polyether glycol, polypropylene glycol, polytetramethylene glycol and the like can be used. Examples of the urethane system include a polyurethane-polycarbonate polyol copolymer, a polyurethane-polyether polyol copolymer, a polyurethane-polycaprolactone polyester copolymer, and a polyurethane-adibate polyester copolymer.

(Weight ratio of thermoplastic resin to thermoplastic elastomer)
When an alloy material of a thermoplastic resin and a thermoplastic elastomer is used as the thermoplastic polymer component, the weight ratio of the thermoplastic resin and the thermoplastic elastomer is not particularly limited. However, among thermoplastic resins, crystalline resins are generally excellent in chemical resistance and flex resistance, and amorphous resins are excellent in molding dimensional stability. Therefore, the ratio to thermoplastic elastomer is set according to the purpose of use. Among them, the weight ratio of thermoplastic resin / thermoplastic elastomer is preferably 1/99 to 99/1, more preferably 5/95 to 95/5, and still more preferably 10/90 to 90/10. 70/30 to 30/70 are particularly preferable, and 60/40 to 40/60 are particularly preferable.

(Difference in viscosity between thermoplastic resin and thermoplastic elastomer)
When an alloy material of a thermoplastic resin and a thermoplastic elastomer is used as the thermoplastic polymer component, if the difference in viscosity between the two materials is too large, good dispersion cannot be obtained even if the production conditions are adjusted, Since the functional component and the Si compound are also dispersed in one phase of the thermoplastic resin and the thermoplastic elastomer and are likely to be non-uniformly dispersed, it is preferable that the viscosity difference is small. Specifically, the ratio of the thermoplastic resin and the thermoplastic elastomer measured by MFR under the same conditions is preferably within a range of about 1/20 to 20/1, and should be within a range of 1/10 to 10/1. More preferred.

  In addition, it is preferable to select the conditions close | similar to the processing temperature of a thermoplastic resin composition as measurement temperature conditions based on JISK-7210 as a measuring method of MFR. For example, when PBT and polyester elastomer are selected, it is preferable to set a processing temperature of 240 ° C. as the measurement temperature and compare the difference in viscosity between the two materials. Moreover, it can measure suitably by selecting 2.16 kg, for example as a load.

<Melting point of thermoplastic polymer component>
In the present invention, it is preferable to use a thermoplastic polymer component having a melting point of 130 ° C. or higher and 260 ° C. or lower according to the following DSC measurement.
DSC (Differential Scanning Calorimetry) Measurement Using SSC-5200 (trade name) manufactured by Seiko Denshi Kogyo Co., Ltd., the sample was heated to 400 ° C. at a heating rate of 20 ° C./min, and the melting peak temperature was measured by DSC measurement. The melting point.

  If the melting point of the thermoplastic polymer component is too low, the heat resistance of the endless belt to be obtained is deteriorated, and not only the trace of the roller is easily made but also the creep property is deteriorated. Conversely, if the melting point of the thermoplastic polymer component is too high, the molding temperature at the time of heat-kneading and heat-extrusion is too high, and the appearance of the belt surface may be roughened due to volatilization of the added component. The melting point of the thermoplastic polymer component is more preferably 180 ° C. or higher and 250 ° C. or lower, more preferably 200 ° C. or higher and 240 ° C. or lower.

  In addition, as a thermoplastic polymer component, 1 type (s) or 2 or more types of thermoplastic resins may be used, 1 type or 2 types or more of thermoplastic elastomers may be used, and these may be mixed and used. .

[Antioxidant]
In the present invention, an antioxidant is blended in the molding material in order to prevent oxidative degradation due to thermal decomposition of the molding material in the heat-kneading or thermoforming process and deterioration with time during use. In addition, when blending the polymerization catalyst described later, if the activity of the polymerization catalyst is too high, the depolymerization of the thermoplastic polymer component is promoted, resulting in a decrease in mechanical properties due to a decrease in molecular weight, foaming accompanying the generation of low molecular weight, However, if a chelator having the ability to chelate the metal in the polymerization catalyst is present as an antioxidant, depolymerization can be suppressed. Also in this respect, the addition of an antioxidant is preferable.

  There is no restriction | limiting in particular as a kind of antioxidant, A well-known antioxidant (chelator) can be used.

  Examples include phosphites, phosphates, phosphates, hydrazines, phenolic and sulfur antioxidants, such as Irgafos 168 (manufactured by Ciba Geigy Japan). , PEP36 (Asahi Denka Kogyo Co., Ltd.), Sandstub P-EPQ (Clariant Japan K.K.) phosphorous ester, IRGANOX MD1024 (Nippon Ciba Geigy Co., Ltd.), CDA-6 (Asahi Denka Kogyo Co., Ltd.) Hydrazines, Sumilizer BP101 (manufactured by Sumitomo Chemical Co., Ltd.), Irganox 1010 (manufactured by Nippon Ciba Geigy Co., Ltd.), Adeka Stub AO-80 phenolic, Sumilizer TPS (manufactured by Sumitomo Chemical Co., Ltd.), Yoshinox As sulfur of DMTP (API), Antix S (Nippon Yushi Co., Ltd.) It can be obtained from the market to ease.

  In the present invention, the content of the antioxidant is preferably 0.01 parts by weight or more with respect to 100 parts by weight of the total thermoplastic polymer component, and 0.1% by weight for obtaining a better addition effect. Part or more.

  If the content of the antioxidant is too small, the effect of adding the antioxidant as described above cannot be obtained sufficiently. However, if the content is too large, excessive antioxidant will bleed on the belt surface and oxidize the blade. Insufficient cleaning causes poor cleaning. In addition, since the endless belt having good physical properties may not be obtained due to loss of the activity of the polymerization catalyst, it is preferable not to add too much, preferably 5 parts by weight or less with respect to 100 parts by weight of the pre-thermoplastic polymer component, 3 parts by weight or less is more preferred, and 0.5 parts by weight or less is even more preferred.

[Si compound]
In the present invention, the Si compound blended together with the antioxidant is silicone, that is, silicone rubber, silicone resin (silicone fine particles), silicone oil, and silane compound, and these may be used alone. Two or more kinds may be used in combination.

In addition, each material of Si compound is defined as follows.
Silicone: A high molecular compound with a siloxane bond, silicone oil and silico
Into 2 minutes.
Silicone oil: Of silicone, it is a chain or ring that does not have a cross-linked structure
, Unmodified straight silicone oil and modified silicone oil
Like.
Silicone powder: Of silicone, it has a crosslinked structure,
It is classified into silicone rubber and three-dimensionally crosslinked silicone resin.
Silane compound: A low-molecular compound containing tetravalent Si, and is classified into a silane coupling agent (having two or more functional groups that react with each of an organic resin and an inorganic substance) and an alkylsilane.

Further, as described above, as a method of blending the Si compound into the thermoplastic polymer component, as described above, two or more of the thermoplastic polymer component, the antioxidant, the Si compound, and the conductive component such as carbon black are used. And a separate feed method in which only the Si compound is fed into the kneader separately from the thermoplastic polymer, carbon black, etc. There is no limit to this. Moreover, you may mix | blend Si compound with heat conductive kneading | mixing with electroconductive components, such as carbon black, and antioxidant with respect to a thermoplastic polymer component.
As another method, the Si compound is previously added to a conductive component such as carbon black, and the surface of the conductive component such as carbon black is coated with the Si compound and then kneaded with the thermoplastic polymer component as the base polymer. There is a method of preparing a conductive polymer composition by heating and mixing using a machine, which can more effectively draw out the interaction between a conductive component such as carbon black, a Si compound and a thermoplastic polymer component. It becomes possible.
In this case, it is preferable to use a silicone oil or a silane compound (for example, a silane coupling agent) as the Si compound.

  Known treatment methods for applying a Si compound to the surface of a conductive component, particularly carbon black, include a dry treatment method and a wet treatment method. The dry treatment method is generally a method of spraying silicone dispersed in a solvent on the surface of carbon black, which is advantageous in terms of cost, but it is difficult to adhere completely to the surface of carbon black. There is a drawback that is likely to occur.

  On the other hand, as a wet method, there is a method in which carbon black is placed in a silicone solution dispersed in various solvents, stirred and mixed, and then the solvent is dried and removed. However, there is a drawback that the cost is high. These may be selected as appropriate and are not limited to these processing methods.

  In order to more effectively exert the effect of improving the interaction between Si compound, thermoplastic polymer component and carbon black (the effect of improving the bending resistance by adding an additional component), Si is added to carbon black. In the drying step in which the solvent is removed after the compound is added, it is preferable to cause the baking reaction by heating at 100 ° C. or higher, for example, 100 to 300 ° C. for 1 hour to 24 hours.

  Below, each Si compound is demonstrated.

<Silicone rubber>
(Type of silicone rubber)
The silicone rubber preferred as the Si compound used in the present invention includes a millable type and a liquid type that are in a solid state at room temperature, and a millable type silicone rubber is preferred.

  In addition, a copolymer of silicone rubber and acrylic rubber is particularly preferable because it has the effect of lowering the belt surface tension while improving the miscibility with the resin. Further, the silicone-acrylic copolymer is preferably polymethyl. Covering with methacrylate (PMMA) or styrene-acrylonitrile copolymer (SAN) is more preferable because the dispersibility of the silicone rubber is further improved and the surface smoothness is not impaired.

  In the case of the silicone rubber-acrylic rubber copolymer, the weight ratio of each component is preferably 9/1 to 1/9, more preferably 8/2 to 2 by weight ratio of silicone component / acrylic component. / 8. When the silicone component is extremely large, the surface tension of the belt is lowered, but the dispersibility with the thermoplastic polymer component is inferior, and surface irregularities are generated, which is not preferable. On the other hand, if the acrylic component is extremely large, the acrylic component has excellent miscibility because of its close interfacial tension with thermoplastic polymers such as polyester, but there is an advantage that the belt surface unevenness is difficult to make, but the surface tension decreases. There are also disadvantages that are difficult, which is not preferable.

  Typical silicone rubbers used in the present invention include, for example, trade names Metabrene S-2001, SRK200, SX-006, and SX-005 manufactured by Mitsubishi Rayon Co., Ltd.

(Method of compounding silicone rubber)
As a method of blending the silicone rubber into the thermoplastic polymer, two or more of the thermoplastic polymer component, the silicone rubber, and the conductive component such as carbon black are previously blended, and at once or from the hopper inlet of the kneader. Examples thereof include, but are not limited to, a separate feed method in which the components are separately supplied and heated and kneaded, or only silicone rubber is fed into a kneader separately from the thermoplastic polymer and carbon black. Here, the antioxidant may be added after being pre-blended with the thermoplastic polymer and heated and kneaded, or may be supplied and kneaded with a weight feeder that can be added in a smaller amount in the middle of the heated kneader. It is selected according to the structure, purpose, etc., but is not limited thereto.

<Silicone resin>
(Types of silicone resin)
As a silicone resin preferable as the Si compound used in the present invention, a silicone resin powder and a silicone composite powder obtained by coating a silicone rubber with a silicone resin are used. In general, a silicone resin powder has a structure in which siloxane bonds are cross-linked in a three-dimensional network, so that it is insoluble in an organic solvent and has excellent heat resistance and is not easily melted. Furthermore, since the particles are less likely to aggregate and have good dispersibility, the heat mixing with the thermoplastic polymer component is preferable because there are less restrictions on the heating temperature.

  The preferable particle diameter of the silicone resin is preferably 0.3 μm to 12.0 μm so that an appropriate roughness can be obtained on the endless belt surface when blended, and the particularly preferable average particle diameter is 0.5 μm to 5 μm. It is.

  Typical silicone resins used in the present invention include, for example, Tospearl 103, 105, 108, 120, 130, and 145 manufactured by Toshiba Silicone Co., Ltd.

(Method of blending silicone resin)
As a compounding method of the silicone resin, a method similar to the above-mentioned silicone rubber can be employed.

<Silicone oil>
(Type of silicone oil)
In the present invention, preferable silicone oils as Si compounds are dimethyl silicone, methyl hydrogen silicone, methyl phenyl silicone, amino modified silicone, alkyl modified silicone, fluorine modified silicone, polyether modified silicone, alcohol modified silicone, epoxy modified silicone, alkoxy. Modified silicone, carboxy-modified silicone, and the like, which are preferably oily or gum-like and attached to a filler such as carbon black.

  Moreover, a metal component and another polymer component can also be partially introduced into the silicone oil by graft bonding or block bonding. Specific examples include those having a methacrylic resin as the main chain and graft-bonding polydimethylsiloxane or the like.

<Silane compound>
(Types of silane compounds)
Preferred silane compounds as Si compounds used in the present invention include, for example, tetramethoxysilane, methyltriethoxysilane, hexamethyldisilazane, vinyltrichlorosilane, vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, alkyltriethoxysilane, alkyl, n- Examples include decyltrimethoxysilane, cyclohexylmethyldimethoxysilane, and bis (trimethoxysilyl) hexane.

(Method of blending silane compound)
The compounding method of the silane compound is divided into treatment to an inorganic material (carbon black, etc.) and addition to an organic material, and the treatment to the inorganic material is stirred with a mixer equipped with a stirrer or the like. After spraying or dripping the diluted solution to uniformly disperse and process, or after adding an inorganic material into a solution in which the silane coupling agent is uniformly dispersed to make a slurry, stirring and filtering, drying, etc. There are wet methods for removing the solution. Examples of the addition to the organic material include an integral blend method that is directly added at the time of heat-kneading and a master batch method in which a silane coupling agent is mixed in advance with a small amount of an organic material and heated and kneaded as a master batch. Any method is determined in consideration of the intended physical properties and cost, but is not limited to this in the present invention.

<Amount of Si compound>
In the present invention, the compounding amount of one or more of silicone rubber, silicone resin, silicone oil, and silane compound is the thermoplastic compound as the total compounding amount when these two or more are used. It is 0.1-20 weight part with respect to 100 weight part of polymer components, Preferably it is 0.5-10 weight part, More preferably, it is 1-7 weight part. When the compounding ratio of the Si compound is too large, the miscibility with the thermoplastic polymer component is inferior, so that the surface roughness of the belt is deteriorated and peeling is caused at the interface with the thermoplastic polymer component, and the mechanical properties are extremely lowered. Absent. In particular, silicone rubber is not preferable because the elastic modulus of the endless belt decreases and creep deformation easily occurs. On the other hand, when the Si compounding ratio is too small, friction with the cleaning blade increases, the toner scraping effect by the cleaning blade is reduced, and cleaning failure tends to occur. Further, the lubricant effect of the antioxidant bleed on the belt surface is reduced, and the antioxidant easily adheres to the blade, so that cleaning failure is likely to occur.

  Further, the compounding ratio of the Si compound and the antioxidant is a ratio of the Si compound to the antioxidant, that is, a weight ratio of Si compound / antioxidant of 0.05 or more and less than 200, preferably 0.1 or more and 150 or less. It is. If the compounding amount of the Si compound is too small relative to the antioxidant, the effect of the lubricant bleed on the belt surface will be reduced, and the antioxidant will easily stick to the blade, and cleaning will likely occur. . Conversely, if the amount of the Si compound is too large relative to the antioxidant, it not only acts to hinder the original function of the antioxidant, but also deteriorates the belt surface properties and causes poor cleaning.

<Preferred blending method of Si compound>
In the present invention, it is preferable to use silicone as the Si compound, and add it to carbon as a conductive component in advance and blend it with other components.
Below, the suitable compounding method of this silicone is demonstrated.

(Average molecular weight of silicone)
The average molecular weight of the silicone attached to the carbon black is preferably 100 or more and less than 100,000. When the average molecular weight of silicone is high, the functional group equivalent is relatively increased (the functional group is decreased), so that it is difficult to attach to carbon black, the grafting efficiency is lowered, and bleed out without adhesion is not preferable. Further, if the average molecular weight is a low molecular weight of less than 100, a low molecular weight siloxane gas is likely to be generated, which may cause foaming flaws during heat mixing and heat extrusion. Silicone usually exists in a chain form, but when it becomes low molecular weight, it tends to be cyclic, and when it becomes cyclic, it cannot be attached to carbon black, but it volatilizes and attaches to switch parts of electronic device parts. Since it becomes a switching defect by becoming silica (insulation) with the heat of a switch part, it is not preferred. In particular, an oligomer that volatilizes when used as a product such as a printer is not preferable because it may contaminate the photoreceptor.

  In addition, the average molecular weight of silicone is a weight average molecular weight in terms of polystyrene determined from a peak value in a molecular weight distribution curve measured by gel permeation chromatography.

(Functional group of silicone)
The amount and type of silicone functional groups attached to the carbon black are determined by the type of carbon black to be mixed. For example, in the case of acetylene carbon black, the amount is 0.1 to 10% by weight. The functional group is preferably an amino group, an epoxy group, a carboxyl group, a hydroxyl group, or the like, and a polyether or phenol-modified one or a silanol group or a silazane group is also preferred. Further, the functional group equivalent is preferably 500 or more and 100,000 or less.

  The functional group equivalent is the substance amount of the compound per mole of the functional group, and is expressed in g / mol and is based on the assumed structure at the peak measured by nuclear magnetic resonance spectroscopy (NMR). The ratio of the peak (area) of the functional group and the peak (area) of the silicone is obtained.

  The functional group means a hydroxyl group, amino group, carboxyl group, halogen group, ester group, alkoxy group, imide group, epoxy group, methacryl group, carbodiimide group, carbonyl group, etc. , Refers to those introduced for the purpose of improving the compatibility with the polymer.

  In addition, as a method for synthesizing functionalized silicones, for example, in the case of general amino-modified silicones, equilibration is performed using siloxane oligomers obtained by hydrolysis of aminoalkylmethyldimethoxysilane, cyclic siloxanes and disiloxanes, and basic catalysts. It is obtained by reacting. Moreover, it is obtained by synthesizing using a hydrolyzate of aminoalkylmethyldimethoxysilane, a siloxane having silanol groups at both ends, and a basic catalyst.

The measuring method of the functional group of silicone is as follows.
Using a Varian Inova 500 spectrometer, in order to improve quantitativeness, chromium acetate is added as a relaxation reagent to a final concentration of 50 mM, and Si-NMR is measured. Specifically, 227.3 mg of chromium acetate is weighed and dissolved in 6.5 ml of deuterated chloroform. Further, add 1.5 ml each of the silicone sample and the deuterated chloroform solution to a 10 ml sample bottle, transfer the mixture to an NMR sample tube with an outer diameter of 10 mm, and set 25 ° C., pulse width 30 °, and pulse repetition time to 5 seconds. Then, the dimethylsiloxy main chain signal is measured as 121.00 pm as the standard of chemical shift.
In addition, NMR was measured by the above method using polydimethylsiloxane, which is most commonly used as a silicone having no functional group, and the resulting dimethylsiloxy main chain was compared with the peak attributed to the trimethylsilyl group. Other than the other peaks are assigned as functional group peaks, and the functional group equivalent is determined as silicone per 1 mol of the functional group.

  If the functional group equivalent is too small, it cannot be used for grafting to carbon black, and the unreacted functional group deteriorates the thermoplastic resin during heat mixing, resulting in deterioration of mechanical properties, poor appearance of foam marks due to deteriorated resin, and decrease in melt viscosity. Causes poor electrical properties. Also, if the functional group equivalent is too much, it is not preferred because it is not grafted on carbon black and bleeds.

(Physical properties of carbon black)
In the present invention, carbon black is mixed in consideration of mechanical characteristics, electrical characteristics, dimensional characteristics, and chemical characteristics when used as an endless belt. In order to mix silicone with the powder, it is preferably a powder product or a granular product, and the powder is preferably uniform.
Carbon black to be used by impregnating a silicone, pH 4 or more of the following reasons, DBP oil absorption 50~300cm ³ / 100g, a specific surface area 35~500m ² / g, volatile content 0-20%, average primary particle size 20~50nm It is preferable that the carbon black satisfies the above.

-About pH of carbon black When silicone is added, if the pH of carbon black is low, the silicone is hydrolyzed, the molecular weight of the silicone is lowered, the siloxane bond that is the main chain of the silicone is decomposed, and the silanol groups are increased. For this reason, the thermoplastic polymer component and carbon black are not preferable because they decompose and generate low molecular weight siloxane gas when heated to cause foaming. Further, the silicone is hydrolyzed and bleeds without being attached to the surface of the carbon black, causing surging, and if the bleed silicone has a low molecular weight, foaming may be caused. Also, even if the pH is adjusted to neutrality during heating mixing or extrusion, the silanol groups generated during the dehydration condensation process, so water is generated and becomes steam in the molding machine, which is also the cause of foaming. Therefore, it is not preferable. Accordingly, it is desirable to lower the pH of the carbon black before heating and mixing, and the pH is preferably 12 or less.
In addition, if the pH of the carbon black is 4 or more and 10 or less, hydrolysis of the silicone is suppressed and polycondensation occurs. Therefore, the carbon black is preferably attached to the surface of the silicone.
Further, when the pH of the carbon black is larger than 10, polycondensation is more likely to proceed than the hydrolysis of silicone, but it tends to be hydrolyzed as compared with the case where the pH is 4 or more and 10 or less. It is necessary to consider.
Therefore, the pH of carbon black to which silicone is attached is preferably 4 to 10, particularly 5 to 10.
The pH of the carbon black is, for example, 10 ml of water per 1 g of carbon black in a beaker, and after boiling for 15 minutes to cool to room temperature, the supernatant is removed by a gradient method or a centrifugal method, and then the muddy state. A glass electrode pH meter electrode is inserted into the object and measured according to JIS 28802.

-DBP oil absorption amount of carbon black When silicone is added before heating and mixing, the larger the DBP oil absorption amount of carbon black, the more preferable it is because the silicone can be physically adsorbed. Is undesirably causing deterioration of the resin during heat mixing with the thermoplastic resin. Therefore, DBP oil absorption of the preferred carbon black is 50~300cm ³ / 100g.

-About the particle diameter and specific surface area of carbon black If a specific surface area is too small to attach silicone, the functional group to which it attaches will reduce relatively, and silicone will not be bonded to carbon black but will bleed. On the other hand, if the specific surface area is too large, unattached functional groups are present, which deteriorates the thermoplastic polymer component as the main component and increases the amount of adsorbed moisture, which is not preferable because the drying time before molding becomes long. Accordingly, the average primary particle size of carbon black is preferably 20 to 50 nm, and the specific surface area is 35 to 500 m ² / g.

-About the volatile matter of carbon black The more the volatile matter of carbon black, the better the dispersibility of carbon due to its surface characteristics, but it is disadvantageous in molding because it generates gas during heating and kneading. On the other hand, the smaller the volatile content of carbon black, the less the gas during heating and kneading, so the moldability is good, but the carbon dispersibility tends to deteriorate.
Therefore, the preferable volatile content of carbon black is 0 to 20%, and the particularly preferable volatile content of carbon black is 0 to 10%.

(Method of attaching to carbon black)
In order to attach silicone to carbon black, it is desirable that the surface functional group of carbon black and the functional group of silicone are chemically bonded. Therefore, depending on the type of the functional group, a certain amount of heating was performed. Is easier to combine. Further, as the method of attachment, there are a dry method such as spray coating and mixing with a mixer, and a wet method in which carbon black and silicone are dispersed and mixed in a solution and dried to skip the solution. The dry method is excellent in cost, and the wet method has a merit that it can be uniformly applied.

(Adhesion amount and compounding amount of silicone to be attached to carbon black)
As described above, if either one of the functional groups of silicone and carbon black is too much, the thermoplastic polymer component and the carbon black may be deteriorated and foamed when heated and mixed, which is preferable. Absent.
For this reason, the optimum amount of silicone to be added has a suitable range in terms of the type and amount of carbon black, the surface tension for the desired toner releasability, and the surface roughness, and the silicone is attached to the carbon black. The amount is preferably from 1 to 20% by weight, particularly preferably from 1.5 to 10% by weight, based on the weight of carbon black. In this case, it is preferable to add 0.1 to 10 parts by weight of silicone with respect to 100 parts by weight of the thermoplastic polymer component.

  According to the present invention, particularly preferably, silicone having a functional group of 500 g / mol or more is preliminarily admixed with carbon black before being heated and mixed with other materials to prevent bleeding during or after seamless belt molding. By dispersing carbon black, the silicone is also uniformly dispersed, so that it does not agglomerate on the surface, the surface irregularities are reduced, and the silicone content of the molding material is 0.1 to 10% by weight, the average of silicone By making the molecular weight 100 or more and less than 100,000, the carbon black is efficiently grafted, there is no surface irregularity of the foaming gas trace due to the deterioration action to the thermoplastic polymer component by the unreacted functional group, and the belt toner It is preferable because the releasability is improved.

[Conductive substance]
By adding a conductive substance to the endless belt, the endless belt can be provided with conductivity and the degree of conductivity can be adjusted.

  The conductive material is not particularly limited as long as it satisfies the performance required for the application, and various materials can be used. Specifically, as the conductive filler, carbon black, carbon fiber, graphite, etc. Carbon-based fillers, metal-based conductive fillers, metal-oxide-based conductive fillers, and the like are used. In addition to the conductive fillers, ionic conductive substances such as quaternary ammonium salts are exemplified. Among conductive materials, it is preferable to use carbon black because the humidity dependency of the electrical resistivity tends to be reduced. Carbon black may be used in combination with other conductive materials such as an ion conductive material.

The blending amount of the conductive component varies depending on the type to be used. For example, in the case of carbon black, it is preferably 0.1 to 30 parts by weight with respect to 100 parts by weight of the thermoplastic resin component. If it is less than this range, conductivity will not be manifested, the dispersion state of carbon black will be coarse and the electrical resistivity will be easily dispersed, and the contact resistance will be greatly influenced by the environment. When mounted as a belt, an image abnormality may occur depending on the environment. On the other hand, if the amount is too large, the rigidity of the endless belt is increased, durability is impaired, and moldability is impaired.
It is preferable that the compounding quantity of carbon black shall be 5-20 weight part with respect to 100 weight part of thermoplastic polymer components.

In the present invention, with or without impregnation of silicone, carbon black for the following reasons, DBP oil absorption 50~300cm ³ / 100g, a specific surface area 35~500m ² / g, volatile content 0-20%, average primary particle It is preferable to use carbon black satisfying a diameter of 20 to 50 nm.

1) About the DBP oil absorption amount of carbon black The larger the DBP oil absorption amount of carbon black, the easier it is for carbon to form a bead-like chain (carbon structure), and the advantage that carbon agglomerates are less likely to occur, and the addition amount is small. However, on the other hand, the carbon chain was broken by various shearing forces applied to the resin containing carbon black in the process from compounding to molding, and the electrical resistivity was reduced. However, there is a problem that the fluctuations are not stable.
On the other hand, if the DBP oil absorption amount of carbon black is too small, it is difficult to form a carbon chain, so that the amount of carbon added for expressing conductivity is excessively increased, and there is a problem that the flex resistance of the material is impaired.
Thus preferred DBP oil absorption of carbon black is 50~300cm ³ / 100g.

2) About the particle size and specific surface area of carbon black The larger the specific surface area of carbon black, the more electrically conductive it appears with less added weight, so the mechanical strength is more advantageous in terms of resistance to cracking, but depending on the amount of carbon added. Since the conductivity tends to change abruptly, it is necessary to have a blending accuracy within ± 0.05% in order to control to the semiconductive region, and the resistance variation of the endless belt must be made uniform within ± 1 order. difficult. In addition, since carbon black with a large specific surface area generally has a small particle size, when dispersed in a resin, the carbon black particles are likely to be fooled. As a result, carbon aggregates are mixed in the molded product, and the location of the carbon aggregates Electricity concentrates on the surface, and partial dielectric breakdown is likely to occur. Also, if the specific surface area of carbon black is too small (carbon particles are too large), it is difficult to form carbon aggregates, so the appearance of the molded product is smooth, but the electrical conductivity is easily affected by the contact between the carbon particles. Since the resistivity tends to vary, it is preferable to select an optimized carbon particle size.
Accordingly, the average primary particle size of carbon black is preferably 20 to 50 nm, and the specific surface area is 35 to 500 m ² / g.

3) About the volatile matter of carbon black The more the volatile matter of carbon black, the better the carbon dispersion due to its surface characteristics, but it is more disadvantageous in molding because it generates gas during heating and kneading. Conversely, the smaller the volatile content of carbon black, the less the gas is generated during heating and kneading, so the moldability is better, but the carbon dispersion tends to deteriorate.
Therefore, the preferable volatile content of carbon black is 0 to 20%, and the particularly preferable volatile content of carbon black is 1 to 10%.

There are no particular restrictions on the type of carbon black as long as it satisfies the DBP oil absorption, specific surface area, volatile content, and average primary particle size, and two types of carbon black can be used. It may be above.
However, when silicone is used by being attached to carbon black, it is preferable that the carbon black satisfies the above-mentioned suitable physical properties.

  As the type of carbon black, acetylene black, furnace black, channel black, etc. can be used suitably. Among them, acetylene black, which has few impurities called ash such as potassium, calcium, sodium, etc. and hardly causes poor appearance, is particularly suitable. Can be used. Moreover, there is no problem even if carbon black subjected to a known post-treatment process such as carbon black coated with resin, carbon black subjected to heat treatment, carbon black subjected to graphitization treatment, carbon black subjected to acid treatment, or the like is used. .

  Furthermore, carbon black treated with a coupling agent such as silane, aluminate, titanate, and zirconate may be used for the purpose of improving dispersibility and suppressing gas generation.

In the present invention, the content of carbon black in the endless belt (hereinafter sometimes referred to as “carbon black concentration”) satisfies the following formulas (i) and (ii). This is preferable because the influence on the surface is reduced.
Formula (i): LogY ≧ −X + 20
Formula (ii): LogY ≦ −X + 30
However, X and Y are as follows.
X: Carbon black content (% by weight) in the endless belt
Y: Surface electrical resistivity (Ω) at 100 V applied voltage, 10 seconds for endless belt

  That is, for example, in the case of a belt having a surface electrical resistivity of 1 × 10 6 (Ω), the carbon black concentration is 14 to 24% by weight, and in the case of a belt having a surface electrical resistivity of 1 × 10 10 (Ω), The carbon black concentration is 10 to 20% by weight, and in the case of a belt having a surface electrical resistivity of 1 × 10 14 (Ω), the carbon black concentration is 6 to 16% by weight from high temperature and high humidity to low temperature and low humidity. This is preferable in that the endless belt can be reduced in electric resistance variation with respect to environmental variations.

X and Y are particularly logY ≧ −X + 21
logY ≦ −X + 29
It is preferable that

  If the carbon black concentration is higher than the above range, the appearance of the product deteriorates due to the generation of decomposition gas etc. of the carbon black itself, and the resin is decomposed by the reaction between the carbon black and the resin, and scratches derived from foaming are generated. Therefore, it is not preferable in appearance. Further, the folding resistance is also deteriorated.

  If the carbon black concentration is lower than the above range, the conductivity cannot be expressed, the carbon black dispersion state becomes rough, the electric resistivity tends to vary, and the contact resistance is greatly influenced by the environment. When mounted as an endless belt in an image forming apparatus, an image abnormality may occur depending on the environment.

[Polymerization catalyst]
In the present invention, a known alloying technique such as a simple mixture of a thermoplastic resin and a thermoplastic elastomer, a mixture of these from the polymerization stage, a mixture of these while reacting with a catalyst can be used, What was heat-mixed using the polymerization catalyst is the most preferable from a viewpoint of cost.
The polymerization catalyst is not particularly limited as long as it has the ability to polymerize thermoplastic resins and thermoplastic elastomers.

  Of the polymerization catalysts, Ti-based polymerization catalysts are preferred, and alkyl titanates can be suitably used.

  Among the alkyl titanates, tetrabutyl titanate or tetrakis (2-ethylhexyl) orthotitanate is preferable, and these are easily available as TYZOR TOT (manufactured by DuPont) or TYZOR TBT (manufactured by DuPont).

  In addition, the Ti-based polymerization catalyst is preferably combined with an alkali metal, alkaline earth metal-containing compound or zinc-containing compound because it works more effectively, and it is particularly preferable to have a magnesium-containing compound as the polymerization catalyst.

  The compound containing magnesium is not particularly limited, but an organic acid magnesium salt is particularly preferable, and magnesium acetate is particularly preferable.

  If the content of the polymerization catalyst is too small, it may not work effectively, so it is preferable that the content is high to some extent. Specifically, the mass of the metal in the polymerization catalyst is the total thermoplastic polymer component (thermoplastic resin and heat 1 ppm or more is preferable with respect to the total of the plastic elastomer), more preferably 10 ppm or more, and particularly preferably 20 ppm or more. On the other hand, since ester resins are known to cause depolymerization in the presence of a large amount of heavy metals, it is preferable that they are small to some extent, specifically 10,000 ppm or less, more preferably 1000 ppm or less. 500 ppm or less is particularly preferable. In the following, the weight ratio of Ti and Mg of the polymerization catalyst to the total thermoplastic polymer components may be referred to as “Ti concentration” and “Mg concentration”.

[Killator]
If the activity of the polymerization catalyst is too high, depolymerization of the thermoplastic polymer component may be promoted, resulting in problems such as a decrease in mechanical properties due to a decrease in molecular weight and foaming due to the generation of low molecular weight substances. When a chelator having the ability to chelate is present, depolymerization can be suppressed. Therefore, it is preferable to use a chelator as necessary.

  There is no restriction | limiting in particular as a kind of chelator, A well-known chelator can be used.

  Examples include phosphites, phosphates, phosphates, and hydrazines, such as Irgafos 168 (manufactured by Ciba Geigy Japan), PEP36 (manufactured by Asahi Denka Kogyo Co., Ltd.). Sandstub P-EPQ (manufactured by Clariant Japan Co., Ltd.), phosphite, IRGANOX MD1024 (manufactured by Nippon Ciba-Geigy Co., Ltd.), CDA-6 (manufactured by Asahi Denka Kogyo Co., Ltd.), hydrazines It can be obtained from the market.

  In the present invention, by suppressing the depolymerization and low molecular weight generation by optimizing the molding conditions, it is possible to add no chelator, but when it is necessary to suppress the depolymerization, the addition amount of the chelator is the total heat It is preferable to add 0.001 part by weight or more with respect to 100 parts by weight of the plastic polymer component, and it is preferable to add 0.1 part by weight or more in order to obtain a better effect.

  If the amount of the chelator is too large, the polymerization catalyst loses its activity and an endless belt having good physical properties may not be obtained. Therefore, it is preferable not to add too much, and 10 parts by weight with respect to 100 parts by weight of the total thermoplastic polymer component. The following is preferable, and the amount is further preferably 5 parts by weight or less.

  In general, it is preferable to use a chelator as a small amount of 0.1 parts by weight or less with respect to 100 parts by weight of the total thermoplastic polymer component. As an example of preferred usage, the polymerization catalyst is added in an amount as large as 50 to 500 ppm, and the chelator is also used in an amount of 0.1 to 3 parts by weight, preferably 0.3 to 1 part by weight, higher than common sense. By optimizing the molding conditions (temperature, residence time, etc.) to obtain the endless belt, depolymerization can be suppressed while promoting the formation of chemical bonds and increase in molecular weight between the thermoplastic resin and the thermoplastic elastomer, and unprecedented physical properties. An excellent endless belt can be obtained.

[Thickener]
In the case of alloying a high-viscosity thermoplastic resin and a low-viscosity thermoplastic elastomer, because of the large viscosity difference, the low-viscosity thermoplastic elastomer does not mix well with other components during kneading, and each of the endless belts Ingredients may be poorly dispersed. In order to solve this problem, in the present invention, the viscosity of the entire thermoplastic resin / thermoplastic elastomer / conductive component mixture system is increased so that each component is sufficiently contained even if a considerable amount of low-viscosity thermoplastic elastomer is contained. You may mix | blend a thickener in order to increase to the viscosity which can be disperse | distributed.
In an endless belt using a thermoplastic resin / thermoplastic elastomer / conductive component blending material that is not added at all, the applied voltage dependency on the surface electrical resistivity is very large, and therefore high-accuracy image quality cannot be obtained.

  The thickener is preferably a polymer having an MFR value (190 ° C., 2.16 kgf load) according to JIS K7210 in a range of 0.01 to 10 g / 10 min, more preferably 0.05 to 5 g / 10 min. Particularly preferred is a polymer exhibiting an MFR value of 0.1 to 3 g / 10 min. If the MFR value is less than 0.01 g / 10 minutes, the viscosity becomes too high to be kneaded, and if it exceeds 10 g / 10 minutes, the viscosity of the thickener is too low to provide a sufficient thickening effect. .

  Examples of thickeners used in the present invention include polymers containing epoxy groups such as glycidyl methacrylate groups. Since the epoxy group has high reactivity, a high molecular weight is generated by reaction with a thermoplastic resin or a thermoplastic elastomer at the time of resin kneading, and the thickening effect is very large. Specific examples of the polymer containing an epoxy group include Modiper A4200 in which PMMA is graft-polymerized on an ethylene-glycidyl methacrylate copolymer (EGMA) and Modiper A4400 in which acrylonitrile-styrene copolymer (AS) is graft-polymerized on EGMA (both , Manufactured by Nippon Oils and Fats).

  The addition amount of the thickener is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, more preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the total thermoplastic polymer component. Parts, most preferably 0.1 to 5 parts by weight. If the addition amount of this thickener is less than 0.01 parts by weight, a sufficient thickening effect cannot be obtained, and if it exceeds 20 parts by weight, the viscosity becomes too high to be kneaded.

[Additive ingredients; optional ingredients]
In the endless belt of the present invention, arbitrary blending components can be blended according to various purposes.

  Specifically, phenolic antioxidants such as Irganox 1010, antioxidants such as phosphorous antioxidants such as Irgafos 168 and Sandstub PEPQ, thermal stabilizers, various plasticizers, light stabilizers, ultraviolet absorbers Various additives such as a neutralizing agent, a lubricant, an antifogging agent, an antiblocking agent, a slip agent, a crosslinking agent, a crosslinking aid, a colorant, a flame retardant, a dispersant, and a wax can be added.

  Furthermore, compounding materials such as various thermoplastic resins, various elastomers, thermosetting resins, and fillers can be blended as the second and third components within a range that does not significantly impair the effects of the present invention.

  Thermoplastic resins include polypropylene, polyethylene (high density, medium density, low density, linear low density), propylene ethylene block or random copolymer, rubber or latex components such as ethylene / propylene copolymer rubber, styrene Butadiene rubber, styrene-butadiene-styrene styrene block copolymer or its hydrogenated derivatives, polybutadiene, polyisobutylene, polyamide, polyamideimide, polyacetal, polyarylate, polycarbonate, polyimide, liquid crystalline polyester, polysulfone, polyphenylene sulfide, poly Bisamidotriazole, polyetherimide, polyetheretherketone, acrylic, polyfluorinated vinylidene, polyfluorinated vinyl, chlorotrifluoroethylene, ethylene Lafluoroethylene copolymer, hexafluoropropylene, perfluoroalkyl vinyl ether copolymer, acrylic acid alkyl ester copolymer, polyester ester copolymer, polyether ester copolymer, polyether amide copolymer, polyurethane copolymer What consists of 1 type, such as coalescence, or these mixtures can be used.

  As a thermosetting resin, what consists of 1 type, such as an epoxy resin, a melamine resin, a phenol resin, unsaturated polyester resin, or these mixtures, for example can be used. Examples of various fillers include calcium carbonate (heavy and light), talc, mica, silica, alumina, aluminum hydroxide, zeolite, wollastonite, diatomaceous earth, glass fiber, glass beads, bentonite, asbestos, and hollow. Glass ball, graphite, molybdenum disulfide, titanium oxide, carbon fiber, aluminum fiber, styrene steel fiber, brass fiber, aluminum powder, wood powder, rice husk, graphite, metal powder, conductive metal oxide, organometallic compound, organic In addition to fillers such as metal salts, additives such as antioxidants (phenolic, sulfur, phosphate ester, etc.), lubricants, various organic and inorganic pigments, UV inhibitors, antistatic agents, dispersants, neutralization Agents, foaming agents, plasticizers, copper damage inhibitors, flame retardants, crosslinking agents, flowability improvers, and the like.

(2) Endless belt manufacturing method [heat-kneading and molding]
In the present invention, the thermoplastic polymer component, the antioxidant and the Si compound, more preferably the conductive component, or preferably the conductive component to which the Si compound is added, and other optional components as necessary are heated and kneaded. Then, the endless belt may be formed after forming the thermoplastic resin composition, or the endless belt may be formed as it is by kneading them with heat.

  In the production of an endless belt, a desired surface electrical resistivity can be obtained by either heat-kneading at the stage of obtaining a thermoplastic resin composition or heat-kneading at the stage of molding the resin composition into an endless belt. The appropriate kneading conditions. In any case, since sufficient dispersion is not possible unless it is in a molten state, it is preferable that the heating temperature be higher to some extent. Specifically, the melting point of the crystalline resin should be used as a guide, and the melting point of the crystalline resin should be exceeded. Is preferable, and it is more preferable that it is melting | fusing point +10 degreeC or more. Further, if the heating temperature is too high, thermal decomposition may be caused and physical properties may be deteriorated. Specifically, using the melting point of the crystalline resin as a guide, the melting point of the crystalline resin is preferably + 80 ° C. or lower, more preferably the melting point + 60 ° C. or lower.

  In addition, it is preferable to dry the raw material before drying by heating since the raw material may be dried to obtain an endless belt having better physical properties. In some cases, the mixture may be heat-kneaded to obtain a thermoplastic resin composition, and after heat treatment at a melting point or lower to form an ester bond, it may be formed into an endless belt.

  In the present invention, when a thermoplastic elastomer and a thermoplastic resin are used in combination as the thermoplastic polymer component, a specific dispersion state of the thermoplastic elastomer and the thermoplastic resin is a good dispersion of the conductive material and the surface of the endless belt. It is considered that an endless belt excellent in both toner transferability and releasability can be obtained. Therefore, since the temperature during heat kneading and the time for receiving heat are important, it is desirable to set the heat kneading conditions while grasping the dispersion form of the obtained endless belt. The index of the alloy state at that time is a voltage dependency characteristic of electric resistivity, which will be described later, a variation in electric resistivity, and a ratio between surface electric resistivity and volume electric resistivity.

  There is no particular limitation on the heating and kneading means, and a known technique can be used. For example, if a thermoplastic polymer component, an antioxidant, a conductive component to which an Si compound is added, and other additive components blended as necessary are heat-kneaded to form a resin composition, uniaxial extrusion A machine, a twin-screw kneading extruder, a Banbury mixer, a roll, a Brabender, a plastograph, a kneader, or the like can be used. In particular, a method in which these are mixed by, for example, a biaxial kneading extruder and pelletized to form an endless belt is particularly preferably used.

  The molding method is not particularly limited, and a belt employing a known method such as a continuous melt extrusion molding method, an injection molding method, a blow molding method, an inflation molding method, a centrifugal molding method, or a rubber extrusion method. Particularly desirable is a continuous melt extrusion process. In particular, an extrusion molding method in which a molten tube extruded from an annular die is taken out while being cooled or cooled and solidified is preferable, and an internal cooling mandrel method or a vacuum sizing method of a downward extrusion method capable of controlling the inner diameter of the tube with high accuracy is particularly preferable. In particular, the inner cooling mandrel method is most preferable as a method for forming an endless belt for an image forming apparatus because a seamless endless belt can be easily obtained. In this case, the annular die is preferably provided with a plurality of temperature adjusting mechanisms in the circumferential direction. The melting tube is preferably cooled by bringing a mold whose temperature is adjusted in the range of 30 to 150 ° C. into contact with the inside or the outside, and in this way, the melting tube is taken up while maintaining the cylindrical shape. It is preferable.

  In this case, the molding material preferably has a melt viscosity of 0.1 g / 10 min or more in terms of MFR value (240 ° C., 2.16 kgf load). When the melt viscosity of the molding material is less than 0.1 g / min of MFR, the fluidity during extrusion molding is poor, and in addition to difficulty in extrusion molding, the shear stress applied to the molten resin is increased, making it difficult to adjust resistance. However, when the melt viscosity of the molding material is excessively high, the melt tension is low, and it is difficult to maintain the tube state from the melted state until cooling and solidification, and therefore it is preferably 25 g / 10 min or less. It is preferably 5 to 20 g / 10 minutes. Therefore, it is preferable to adjust the viscosity with a viscous polymer as necessary so that such a melt viscosity can be obtained.

In addition, once a film with creases is produced by the inflation molding method, there is no problem even if it is used as an endless belt in a state in which the creases are not visible in post-processing. It can be an endless belt with seams.
However, as the take-up means, a molding method is preferable in which the endless tube is taken up while being flattened without being flattened.

  Since an endless belt with better physical properties can be obtained by optimizing the molding temperature, residence time, and the like, it is preferable to adjust the conditions according to each formulation.

[Heat treatment]
By heat-treating the endless belt thus obtained, an endless belt with improved physical properties can be obtained. In particular, the number of breaks, the tensile modulus, and the resistance of the rollers are improved.

The heat treatment condition depends on the thermoplastic polymer component used as a raw material, but is usually 50 to 100 ° C., preferably 60 to 90 ° C. for 15 minutes to 5 hours, preferably about 1 to 3 hours. It is.
The heat treatment of the endless belt may be performed by applying heat while driving the belt while being stretched around two or more rollers, or may be performed by attaching an endless belt to a cylindrical mold. Furthermore, the heat treatment may be performed in a cylindrical shape.

(3) Physical properties of endless belt [surface electrical resistivity and volume electrical resistivity]
The endless belt for an image forming apparatus of the present invention is
SR (100 V) is the surface electrical resistivity measured at an applied voltage of 100 V for 10 seconds.
SR (500V), the surface electrical resistivity measured at an applied voltage of 500V for 10 seconds,
The volume resistivity when measured at an applied voltage of 100 V for 10 seconds is VR (100 V),
The volume resistivity when measured at an applied voltage of 250 V for 10 seconds is VR (250 V),
It is preferable that the following expressions (a), (b) and (c) are satisfied.
Formula (a): SR (100 V) / SR (500 V) <VR (100 V) / VR (250 V)
Formula (b): SR (100 V) / SR (500 V) ≦ 30
Formula (c): 8 ≦ VR (100 V) / VR (250 V) ≦ 100

  That is, the rate of change represented by the maximum / minimum value (MAX / MIN) of the surface electrical resistivity measured at an applied voltage of 100 to 500 V (hereinafter sometimes referred to as “surface electrical resistance rate of change”) SR ( 100V) / SR (500V) is 30 times or less and the change rate represented by MAX / MIN of the volume resistivity measured at an applied voltage of 100 to 250V (hereinafter referred to as "volume resistivity change rate"). The relationship between the surface electrical resistance change rate SR (100 V) / SR (500 V) and the volume electrical resistance change rate VR (100 V) / VR (250 V) when VR (100 V) / VR (250 V) is 8 to 100. Is surface electrical resistivity <volume electrical resistivity, that is, SR (100 V) / SR (500 V) <VR (100 V) / VR (250 V).

  The characteristic that the rate of change in surface electrical resistance is small is important in that the toner is uniformly transferred even when the voltage applied by a roller or the like is changed. This is because the charged toner remaining on the belt that has not been subjected to the secondary transfer can be easily cleaned by the self-removing cleaning member, and the toner transfer efficiency on the belt during the secondary transfer can be improved. is there.

  The preferred surface electrical resistance change rate SR (100 V) / SR (500 V) is within 10 times, and the relationship between the volume electrical resistance change rate VR (100 V) / VR (250 V) is twice the surface electrical resistance change rate. It is preferable that the volume electric resistance change rate or less. The lower limit of the surface electrical resistance change rate is not particularly limited, but is usually about 1.5.

  In addition, if the volume electric resistance change rate VR (100 V) / VR (250 V) is too large, there is a problem in that current leaks due to voltage fluctuation. Therefore, the volume electric resistance change rate VR (100 V) / VR (250 V) is It is important that it is within 100 times, preferably within 50 times. In addition, the lower limit of the volume electrical resistance change rate VR (100 V) / VR (250 V) is 8 or more, particularly 10 or more in terms of exhibiting the effect of giving the belt a self-static function.

Therefore, the image forming apparatus belt of the present invention preferably satisfies the following formulas (a ′), (b ′), and (c ′).
Formula (a ′): SR (100 V) / SR (500 V) × 2 ≦ VR (100 V) / VR (250 V)
Formula (b ′): 5 ≦ SR (100 V) / SR (500 V) ≦ 10
Formula (c ′): 10 ≦ VR (100 V) / VR (250 V) ≦ 50

The resistance region of the image forming apparatus belt of the present invention varies depending on the purpose of use, but the surface electrical resistivity 1 × 10 ⁶ to 1 × 10 ¹⁴ Ω or the volume electrical resistivity 1 × 10 ⁶ to 1 × 10 ¹⁴ Ω.・ Selected from the cm range.

Although the more preferable range of the resistance region varies depending on the application, for example, when used as a photoreceptor belt, the surface electrical resistivity 1 × 10 ¹ to 1 × 10 ⁹ so that the charge on the outer surface can escape to the inner surface as necessary. Low resistivity such as Ω or volume electrical resistivity 1 × 10 ¹ to 1 × 10 ⁹ Ω · cm is preferable, and when used as an intermediate transfer belt, surface electrical resistivity 1 × 10 ⁶ to 1 that can be easily charged and transferred. × 10 ¹³ Ω or volume electric resistivity 1 × 10 ⁶ to 1 × 10 ¹³ Ω · cm is preferable, and when used as a transfer transfer belt, it is easily charged and is not easily damaged even at a high voltage. 1 × 10 ¹⁰ to 1 × 10 ¹⁶ A high region such as Ω or volume resistivity 1 × 10 ¹⁰ to 1 × 10 ¹⁶ Ω · cm is preferable.

  Further, it is preferable that the distribution of the surface electrical resistivity in one endless belt is narrow, and in each preferable surface electrical resistivity region, the difference between the maximum value and the minimum value in one belt is within two digits (maximum The value is preferably 100 times or less of the minimum value).

  The surface electrical resistivity and volume electrical resistivity of the endless belt can be easily measured by, for example, “HIRESTA”, “Loresta” manufactured by Dia Instruments Co., Ltd., or “R8340A” manufactured by ADVANTEST Co., Ltd. Can do.

[Tensile modulus]
The tensile elastic modulus of the endless belt of the present invention is preferably 500 MPa or more and 3500 MPa or less. If the tensile elastic modulus of the endless belt is low, for example, when it is used in an image forming apparatus as an intermediate transfer belt, a slight elongation may occur due to the tension, which may cause problems such as color misregistration. If it is too high, a motor load will be applied when driving the belt, so it will be necessary to reduce the thickness setting.If dust gets in between the roller and the belt, or if scratches due to friction with the photosensitive member enter, cracks will occur. Since it is easy to enter and there is a problem in reliability, it is not preferable. Further, in order to improve the transfer efficiency of the toner in the primary transfer, it is necessary to have a tensile elastic modulus that does not allow the belt to stretch and a tensile elastic modulus that does not cause the endless belt to become hard. Therefore, a preferable range of the tensile elastic modulus is 1000 MPa to 3000 MPa, particularly 1200 MPa to 2800 MPa.

  The tensile elastic modulus of the endless belt is adjusted from the viewpoint of improving the transfer efficiency of the toner. As described above, the toner transfer efficiency is improved by the chemical characteristics (contact angle with water) of the belt surface, and the toner transfer by the electrical characteristics. The most appropriate range may be determined in relation to the efficiency improvement effect.

[Surface roughness (Ra)]
The surface roughness (Ra) of the endless belt of the present invention is preferably 0.02 μm or more and 0.2 μm or less. When the surface roughness (Ra) is less than 0.02 μm, the toner primary transfer efficiency is deteriorated. On the other hand, if it exceeds 0.2 μm, the secondary transfer efficiency of the toner deteriorates. The surface roughness (Ra) of the preferred endless belt of the present invention is preferably 0.03 μm or more and 0.15 μm or less, particularly preferably 0.03 μm or more and 0.1 μm or less.

[Surface Wetting Tension (E)]
The surface wetting tension (E) of the endless belt of the present invention is preferably 27 dyne / cm or more and 35 dyne / cm or less because the toner releasability can be improved.
When the surface wetting tension (E) is less than 27 dyne / cm, the friction between the photosensitive member and the belt becomes too short, and the toner primary transfer efficiency is deteriorated. On the other hand, if the surface wetting tension (E) exceeds 35 dyne / cm, the toner releasability deteriorates and the secondary transfer efficiency deteriorates, which is not preferable.
A preferable surface wetting tension (E) is 30 dyne / cm or more and 35 dyne / cm or less, and a particularly preferable surface wetting tension (E) is 31 dyne / cm or more and 34 dyne / cm or less.

[Relationship between surface roughness (Ra) and surface wetting tension (E)]
If the surface is smooth and the surface roughness (Ra) is small, even if the surface wetting tension (E) is relatively large, the toner cleaning property and the toner transfer property are good, in other words, when the surface roughness (Ra) is rough. If the surface wetting tension (E) is reduced, cleaning becomes easier.
The present inventors have found that there is a characteristic between the two, and it is preferable that the relationship between the surface roughness (Ra) and the surface wetting tension (E) satisfies the following general formula (1).
Ra × 100 <−2 × E + 80 (1)
Therefore, it is preferable that the endless belt for an image forming apparatus of the present invention has the surface roughness (Ra) and the surface wetting tension (E) within the above-mentioned ranges and satisfy the above formula (1).

[Fold resistance]
When the endless belt of the present invention is used as an intermediate transfer belt in an image forming apparatus, for example, an endless belt having good bending resistance is preferred because cracks occur and images cannot be obtained if the bending resistance is poor.
The degree of bending resistance can be quantitatively evaluated by following the method for measuring the folding endurance of JIS P-8115, and it is judged that an endless belt with a higher folding endurance is less susceptible to cracking and has superior bending resistance. be able to.
As a specific numerical value, if it exceeds 2000 times, it can be used with an excellent function as an endless belt for the lifetime of the apparatus, but it is practically preferably 8000 times or more and preferably 10,000 times or more. More preferably.

  According to the present invention, depending on the amount of the thermoplastic elastomer added and alloying, the folding endurance of 50,000 times or more, and even 100,000 or more can be obtained. In order to prevent cracks from the end of the endless belt, It is preferable because sufficient crack resistance can be obtained without performing secondary processing such as a commonly used reinforcing tape for preventing cracks.

[Shrinkage factor]
As the shrinkage rate characteristics of the endless belt of the present invention, the shrinkage rate with respect to a temperature of 60 ° C. and a humidity of 90% and a temperature after leaving for 24 hours of 23 ° C. and a humidity of 50% is preferably 0.2% or less. If the shrinkage rate is larger than these condition ranges, it is not preferable because the dimensional change becomes large during transportation and storage of the endless belt and it becomes impossible to use it, and electrical characteristics and mechanical characteristics may also change. More preferred shrinkage characteristics are 0.1% or less, and particularly preferred is 0.05% or less.

[Endless belt thickness]
If the thickness of the endless belt is excessively large, if the curvature with the roller is large, the deformation difference between the outer side and the inner side of the belt is large and the endless belt is easily broken. Further, the toner transferred to the outer side is deformed and scattered, and the image is deformed. On the other hand, if the thickness of the endless belt is excessively small, cracks are likely to occur due to slight scratches between the roller and the belt, or scratches due to contact with the photoreceptor, and the belt is likely to break. Therefore, the thickness of the endless belt of the present invention is preferably 70 to 300 μm, and particularly preferably 100 to 200 μm.

(4) Application of belt for image forming apparatus There is no particular limitation on the application of the belt for image forming apparatus of the present invention, but in the field of OA equipment having particularly strict physical properties such as dimensional accuracy, bending resistance and tensile elastic modulus, Can be preferably used. When this endless belt is formed in a seamless belt shape, there are few problems such as cracking and elongation, which is preferable.

  The endless belt for an image forming apparatus of the present invention can be suitably used for an image forming apparatus such as an electrophotographic copying machine, a laser beam printer, or a facsimile machine, particularly as an intermediate transfer belt, a transfer transfer belt, a photoreceptor belt, or the like. .

  The endless belt of the present invention may be used as it is, or may be wound around a drum or a roll.

  Further, for the purpose of reinforcing the end face, a reinforcing tape such as a heat-resistant tape may be bonded to the outside and / or inside of the endless belt along the side edge as necessary. As the reinforcing tape, a biaxially stretched polyester tape is preferable from the viewpoint of cost and strength, and the tape width is preferably 4 mm or more and 20 mm or less because the apparatus layout is compact. The thickness of the reinforcing tape is preferably 20 μm or more and 200 μm or less from the viewpoint of being able to drive the endless belt with low tension and preventing the occurrence of cracking.

  For the purpose of preventing meandering of the endless belt, a rubber sheet (meandering preventing guide) such as urethane rubber or silicone rubber may be bonded to the side edge of the endless belt with an adhesive. In this case, the preferable sheet width of the rubber sheet to be used is 2 to 10 mm, and 3 to 8 mm is particularly preferable in view of the layout of the apparatus and the adhesive strength. Further, from the viewpoint of preventing meandering, the thickness of the meander-preventing rubber is preferably 0.5 to 3 mm, and more preferably 0.7 to 2 mm from the viewpoint of simplicity of the meandering prevention and meandering preventing effect.

  Furthermore, in combination with the above-mentioned reinforcing tape, it is preferable that the reinforcing tape is bonded to the endless belt and then the meandering prevention guide is bonded to the belt because of the effect of preventing the occurrence of belt cracking and the belt meandering.

  The effects of the present invention will be described below with reference to examples and comparative examples.

<material>
The raw materials were as follows, and the mixing ratio was as shown in Table 1.

(Thermoplastic resin)
・ PBT: “Novaduran 5040ZS” manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Weight average molecular weight = 40,000
PS-converted weight average molecular weight = 122,000
MFR (240 ° C., 2.16 kgf load) = 4 g / 10 min
Ti concentration 84ppm, Mg concentration 43ppm
-PC: "Iupilon E2000" manufactured by Mitsubishi Engineering Plastics Co., Ltd.
Weight average molecular weight = 28,000
PS-converted weight average molecular weight = 64,000
MFR (280 ° C., 2.16 kgf load): 4.8 g / 10 minutes

(Thermoplastic elastomer)
-PEER: Toyobo Co., Ltd. polyester-polyester elastomer "Perp
Len S3001 "
MFR (240 ° C., 2.16 kgf load) = 21 g / 10 min
Crystal melting point = 216 ° C

(Carbon black)
・ Carbon black CB1: "Denka Black" manufactured by Electrochemical Co., Ltd.
DBP oil absorption = 180ml / 100g
Specific surface area = 65 m ² / g
Volatile content = 0%
Average primary particle size = 39 nm
pH = 9

(Polymerization catalyst)
Titanium (IV) butoxide / magnesium acetate

(Antioxidant)
Phosphorylation inhibitor “PEPQ” manufactured by Clariant Japan

(Si compound)
・ Silicone rubber 1: "SX005" manufactured by Mitsubishi Rayon Co., Ltd.
Silicone-based acrylic silicone copolymer Silicone rubber 2: "S2001" manufactured by Mitsubishi Rayon Co., Ltd.
Acrylic silicone copolymer based on acrylic. Silicone rubber 3: "SRK200" manufactured by Mitsubishi Rayon Co., Ltd.
Acrylic-silicone aliquot acrylic silicone copolymer
Silicone oil 4: “KPN-3504” manufactured by Shin-Etsu Chemical Co., Ltd.
Functional group equivalent = 2900 g / mol
Average molecular weight = 2900
Silicone oil 5: “SH200” manufactured by Toray Dow Corning Co., Ltd.
Functional group equivalent = 5000 or more
Average molecular weight = 4400
・ Silicone resin 6: Toshiba Silicone Co., Ltd. “Tospearl 120”
Average particle size = 2μm

  In addition, melting | fusing point calculated | required by DSC measurement about the thermoplastic polymer component was as showing in Table 1.

<Heat kneading>
Each raw material was pelletized using a twin-screw kneading extruder (“PMT32” manufactured by IKG Corporation). The kneading conditions were based on a cylinder temperature of 260 ° C., but were adjusted in the range of 220 ° C. to 270 ° C., except that the cylinder temperature of the kneading part where the temperature of the molten resin rose midway was set from 230 ° C. to 250 ° C. .

<Endless belt molding method>
This material pellet was dried, and the annular die was formed by a 40 mmφ extruder with a six-spiral annular die having a diameter of 190 mm and a die slip width of 1.3 mm (having 16 temperature control mechanisms in the circumferential direction of the annular die). While extruding downward in a molten tube state, the extruded molten tube is cooled and solidified while being in contact with the outer surface (temperature 90 ° C.) of a cooling mandrel having an outer diameter of 184 mm mounted on the same axis as the annular die via a support rod, Next, with a cylindrical core installed in the seamless belt and a 4-point belt type take-up machine installed on the outside, a length of 300 mm is taken while the seamless belt is being held in a cylindrical shape. And cut out to obtain a thickness of 140 μm and a surface electrical resistivity of 1 × 10 ¹⁰ to 1 × 10 ¹¹ Ω. A seamless belt having an inner diameter of 184 mm was prepared while adjusting the feed temperature. Extrusion conditions were such that the cylinder and die temperature were both 260 ° C. as a basic condition.

<Evaluation>
The evaluation was carried out by cutting the endless belt to the required size as required, and the results are shown in Table 1.

-Surface electrical resistivity The product name "Hiresta (UR terminal)" by Dia Instruments Co., Ltd. was used, and the belt circumferential direction was measured at a pitch of 20 mm under conditions of 500 V and 10 seconds.

-Volume resistivity The product name "Hiresta (UR terminal)" manufactured by Dia Instruments Co., Ltd. was used, and the belt circumferential direction was measured at a pitch of 20 mm under conditions of 500 V and 10 seconds.

-Tensile elastic modulus Based on ISO R1184-1970, the test piece was cut into a width of 15 mm and a length of 150 mm, and measured with a tensile speed of 1 mm / min and a distance between grips of 100 mm.

-Folding resistance number In accordance with JIS P-8115, a test piece is cut into a size of 15 mm in width and 100 mm in length, and a bending speed of 175 times / min with a MIT testing machine, a rotation angle of 135 ° left and right, and a tensile load. Under the condition of 0 kgf, the radius of curvature at the tip of the bending jig was set to R = 0.38 mm, and the number of times of bending to breakage was measured.
As a criterion for pass / fail evaluation of folding resistance, 20,000 times or more was evaluated as ◎, 10,000 times or more and less than 20,000 times as ○, 1000 times or more and less than 10,000 times as Δ, and less than 1000 times as ×.

・ Surface wetting tension (E)
The surface wetting tension (E) of the outer surface of the endless belt was measured based on JIS K6768-1995 using a wetting test reagent manufactured by Wako Pure Chemical Industries, Ltd. consisting of a mixture of formamide and ethylene glycol monoethyl ether.
Specifically, various wetting test reagents are applied to the belt surface using a cotton swab (approx. 6 cm 2 for 0.5 seconds), and the belt surface after 2 seconds of application is observed to examine whether it is wet or not wet. The standard solution closest to wetting for 2 seconds was found, and the wetting tension was defined as the surface wetting tension (E) of the belt.
In addition, it shows that the surface energy of a belt is so small that a numerical value is low.

・ Surface roughness (Ra)
The outer surface of the endless belt is cut into a sample of about 50 mm × 50 mm, and measurement of 100 times lens, pitch 0.01 μm, shutter speed AUTO, and gain 835 is performed using the ultra-deep shape measurement microscope trade name “VK8500” manufactured by Keyence Corporation. Under the conditions, the surface roughness of an area of 40 μm × 40 μm was measured at four points, and the average value was taken as the measured value of the surface roughness.

・ Evaluation of cleaning performance Mount the transfer belt on the transfer belt unit of Ricoh's intermediate transfer tandem machine “CX3000”, attach the cleaning blade, and bring the waste toner into contact with the belt surface. Then, after the belt 10 is rotated, the number of toner remaining in a streak shape without being cleaned by the blade is counted. If this is 3 or less, ◎ if 4 or more and 5 or less, ○, if 6 or more and 10 or less. △, and X in the case of 11 or more locations.

<Specifications of Examples and Comparative Examples>
(Example)
Example 1: 2 parts by weight of silicon acrylic rubber “SX005” of Si compound 1 and 0.1% of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component containing 70% by weight of PBT and 30% by weight of PEER. 3 parts by weight and 13.5 parts by weight of carbon black were blended.
Example 2: 5 parts by weight of silicon acrylic rubber “S2001” of Si compound 2 and 0.1 parts of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component blended with 70% by weight of PBT and 30% by weight of PEER. 3 parts by weight and 13.5 parts by weight of carbon black were blended.
Example 3: 5 parts by weight of silicon acrylic rubber “SX005” of Si compound 1 and 0.1 parts of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component containing 70% by weight of PBT and 30% by weight of PEER. 3 parts by weight and 13.5 parts by weight of carbon black were blended.
Example 4: 5 parts by weight of silicon acrylic rubber “SRK200” of Si compound 3 and 0.1 parts of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component blended with 70% by weight of PBT and 30% by weight of PEER. 3 parts by weight and 13.5 parts by weight of carbon black were blended.
Example 5: 10 parts by weight of a silicon acrylic rubber “SX005” of Si compound 1 and 1 part by weight of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component containing 70% by weight of PBT and 30% by weight of PEER. 13.5 parts by weight of carbon black was mixed.
Example 6: 10 parts by weight of a silicon acrylic rubber “S2001” of Si compound 2 and 1 part by weight of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component containing 70% by weight of PBT and 30% by weight of PEER. 13.5 parts by weight of carbon black was mixed.
Example 7: 10 parts by weight of silicon acrylic rubber “SRK200” of Si compound 3 and 1 part by weight of antioxidant with respect to 100 parts by weight of a thermoplastic polymer component blended with 70% by weight of PBT and 30% by weight of PEER 13.5 parts by weight of carbon black was mixed.
Example 8: 5 parts by weight of a silicon acrylic rubber “SX005” of Si compound 1 and 1 part by weight of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component containing 40% by weight of PBT and 60% by weight of PC 13.5 parts by weight of carbon black was mixed.
Example 9: 10 parts by weight of silicon acrylic rubber “S2001” of Si compound 2 and 1 part by weight of antioxidant with respect to 100 parts by weight of thermoplastic polymer component containing 40% by weight of PBT and 60% by weight of PC 13.5 parts by weight of carbon black was mixed.
Example 10: 10 parts by weight of silicon acrylic rubber “SRK200” of Si compound 3 and 1 part by weight of an antioxidant with respect to 100 parts by weight of a thermoplastic polymer component containing 40% by weight of PBT and 60% by weight of PC 13.5 parts by weight of carbon black was blended.
Example 11: Silicone oil “KPN-3504” of Si compound 4 with respect to 100 parts by weight of thermoplastic polymer component blended with 70% by weight of PBT and 30% by weight of PEER is 2.5% by weight with respect to carbon black CB1. %, And dried at room temperature for 24 hours or more, and blended 13.83 parts by weight with respect to 100 parts by weight of the thermoplastic polymer component. The blending amount of silicone oil is 0.33 parts by weight with respect to 100 parts by weight of the thermoplastic polymer component, and the blending amount of carbon black is 13.5 parts by weight with respect to 100 parts by weight of the thermoplastic polymer component.
Example 12: Silicone oil “SH200” of Si compound 5 was treated with 2.5% by weight of carbon black CB1 with respect to 100 parts by weight of the thermoplastic polymer component blended with 70% by weight of PBT and 30% by weight of PEER. And what was dried at room temperature for 24 hours or more was mixed with 13.83 parts by weight with respect to 100 parts by weight of the thermoplastic polymer component. The blending amount of silicone oil is 0.33 parts by weight with respect to 100 parts by weight of the thermoplastic polymer component, and the blending amount of carbon black is 13.5 parts by weight with respect to 100 parts by weight of the thermoplastic polymer component.
Example 13: With respect to 100 parts by weight of a thermoplastic polymer component blended with 70% by weight of PBT and 30% by weight of PEER, 2 parts by weight of silicone resin “Tospearl 120” of Si compound 6 and 0. 3 parts by weight and 13.5 parts by weight of carbon black were blended.

(Comparative example)
Comparative example 1: Except not mix | blending Si compound, it was set as the same mixing | blending as Examples 1-4, and the ratio of Si compound and antioxidant was set to zero.
Comparative Example 2: The composition was the same as in Examples 5 to 7 except that the Si compound was not blended, and the ratio of the Si compound to the antioxidant was 0.
Comparative Example 3 The composition was the same as in Examples 8 to 10 except that the Si compound was not blended, and the ratio of the Si compound to the antioxidant was 0.
Comparative Example 4: Antioxidant was blended extremely small as 0.05 parts by weight, and 10 parts by weight of silicon acrylic rubber “SX005” of Si compound 1 was blended, resulting in a ratio of Si compound to antioxidant of 200. I did it.

From Tables 1 and 2, the following is clear.
The endless belts of any of the examples were at a practical level with no problems in crack resistance and cleaning properties.
Comparing Comparative Example 1 with Examples 1 to 4, it can be seen that the endless belt of any Example has improved crack resistance compared to Comparative Example 1. In other words, it is considered that the entanglement action between the carbon black and the thermoplastic polymer works. Moreover, it is thought that the contribution to the improvement of carbon black dispersibility is small because it shows substantially the same electric resistance value without changing the carbon black blending concentration. Moreover, although the surface roughness became large by the compounding of the Si compound, the cleaning property was improved because the surface wetting tension was lowered.

  Comparing Comparative Example 2 with Examples 5 to 7, it can be seen that the endless belt of any of the examples has improved crack resistance compared to Comparative Example 2. In other words, it is considered that the entanglement action between the carbon black and the thermoplastic polymer works. Moreover, it is thought that the contribution to the improvement of carbon black dispersibility is small because it shows substantially the same electric resistance value without changing the carbon black blending concentration. Moreover, although the surface roughness became large by the compounding of the Si compound, the cleaning property was improved because the surface wetting tension was lowered.

  When Comparative Example 3 is compared with Examples 8 to 10, it can be seen that the endless belt of any of the examples has improved crack resistance compared to Comparative Example 3. In other words, it is considered that the entanglement action between the carbon black and the thermoplastic polymer works. Moreover, it is thought that the contribution to the improvement of carbon black dispersibility is small because it shows substantially the same electric resistance value without changing the carbon black blending concentration. Moreover, although the surface roughness became large by the compounding of the Si compound, the cleaning property was improved because the surface wetting tension was lowered.

Comparing Comparative Example 4 with Examples 1-7 and 11-13, in Comparative Example 4, the surface roughness is increased due to the large amount of Si compound contained in the small amount of antioxidant, and the cleaning property is improved. There was a problem.

  From the above results, by blending the thermoplastic polymer component with a predetermined amount of the Si compound together with the antioxidant, preferably by pre-attaching silicone oil to carbon black or blending silicone rubber. It can be seen that it is possible to provide an endless belt for an image forming apparatus that has good cleaning properties, supports high image quality, and is highly durable.

It is a side view of a general intermediate transfer device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging device 3 Exposure optical system 4 Developer 5 Cleaner 6 Conductive endless belt 7, 8, 9 Conveyance roller

Claims (16)

An endless belt used in an image forming apparatus, which is made of a molding material mainly composed of a thermoplastic polymer component made of a thermoplastic resin and / or a thermoplastic elastomer,
The molding material contains an antioxidant component and silicone rubber or silicone oil ,
The content of the silicone rubber or silicone oil is 0.1 to 20 parts by weight with respect to 100 parts by weight of the thermoplastic polymer component,
Image forming apparatus for an endless belt, wherein the ratio of content of less than 200 0.05 over the silicone rubber or silicone oil to the content of the antioxidant component. In Claim 1, the surface roughness (Ra) represented by Ra of the outer surface of the endless belt is 0.02 μm or more and 0.2 μm or less, and the surface wetting tension (E) is 27 dyne / cm or more and 35 dyn / cm or less. An endless belt for an image forming apparatus, wherein the relationship between the surface roughness (Ra) and the surface wetting tension (E) satisfies the following expression (1).
Ra × 100 <−2 × E + 80 (1) 3. The endless belt for an image forming apparatus according to claim 1, wherein the silicone rubber or the silicone oil is a silicone rubber containing an acrylic component.   The endless belt for an image forming apparatus according to claim 1, wherein the molding material contains a conductive component. 5. The endless belt for an image forming apparatus according to claim 4, wherein the silicone rubber or the silicone oil is previously attached to the conductive component before being mixed with a thermoplastic polymer component to form a molding material. .   6. The endless belt for an image forming apparatus according to claim 4, wherein the conductive component is carbon black. 7. The endless belt for an image forming apparatus according to claim 6, wherein the silicone rubber or the silicone oil is a silicone oil and is attached to the carbon black at a ratio of 1% to 20% by weight. 8. The method according to claim 4, wherein the thermoplastic polymer component and silicone rubber or silicone oil and a conductive component are heat-kneaded to obtain the molding material, and the molding material is heated and extruded. An endless belt for an image forming apparatus.   9. The endless belt for an image forming apparatus according to claim 8, wherein the molding tube is formed by cooling and solidifying the molten tube obtained by heating and extruding the molding material from an annular die.   10. The thermoplastic polymer component according to claim 1, wherein the thermoplastic polymer component is a ratio of thermoplastic elastomer / thermoplastic resin = 5/95 to 95/5 by weight ratio of thermoplastic elastomer and thermoplastic resin. 11. An endless belt for an image forming apparatus.   11. The endless belt for an image forming apparatus according to any one of claims 1 to 10, wherein the thermoplastic elastomer is a polyester-based thermoplastic elastomer.   12. The endless belt for an image forming apparatus according to claim 1, wherein the thermoplastic resin contains polyalkylene terephthalate as a main component.   The endless belt for an image forming apparatus according to claim 12, wherein the polyalkylene terephthalate is polybutylene terephthalate.   14. The endless belt for an image forming apparatus according to claim 1, wherein the folding endurance is 2000 times or more and the tensile elastic modulus is 500 MPa or more and 3500 MPa or less.   15. The endless belt for an image forming apparatus according to claim 1, wherein the endless belt is an seamless intermediate transfer belt, a conveyance transfer belt, a transfer fixing belt, a fixing belt, a photosensitive belt, or a development sleep. .   An image forming apparatus comprising the endless belt for an image forming apparatus according to claim 1.

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