JP2015049269A - Fixing film and fixing device provided with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fixing film which has stable folding endurance through endurance use with blended resin of crystalline resin and amorphous resin.SOLUTION: A fixing film has blended resin containing crystalline polyarylketone resin which has thermal resistance and amorphous resin which has a glass transition temperature higher than a glass transition temperature of the crystalline resin. The blended resin has two or more glass transition temperatures measured by a differential scanning calorimetry.

Description

  The present invention relates to a fixing film suitable for use in a fixing device mounted on an image forming apparatus such as an electrophotographic copying machine or an electrophotographic printer.

A film heating type is known as a fixing device (fixing device) mounted on an electrophotographic copying machine or printer. This type of fixing device has a heater having a resistance heating element on a ceramic substrate, a fixing film that moves while in contact with the heater, and a pressure roller that forms a nip portion with the heater via the fixing film. doing. The recording material carrying the unfixed toner image is heated while being nipped and conveyed by the nip portion of the fixing device, whereby the toner image on the recording material is fixed to the recording material.
Materials used for the fixing film include heat-resistant resins such as polyimide (PI), polyetheretherketone (PEEK), polyetherimide (PEI), polyphenylsulfone (PPSU), and polyethersulfone (PES). Proposed. Among these, PI (polyimide) having particularly high heat resistance and mechanical strength is adopted as a fixing film in many image forming apparatuses. PI (polyimide) is a thermosetting resin and has excellent heat resistance and mechanical performance, but has a drawback that the manufacturing method is complicated and the material unit price is high. On the other hand, thermoplastic resins such as PEEK, PEI, PPSU, and PES can be extruded and are advantageous in terms of manufacturing tact and material unit price, but disadvantages include crack resistance, heat resistance, mechanical strength, etc. May have a problem.
As a supplement for such a drawback of the thermoplastic resin, a blend resin of PEEK which is excellent in crack resistance among thermoplastic resins and PEI which is excellent in mechanical strength at high temperature has been proposed (Patent Documents 1 and 2). . These materials are very compatible, have compatibility at the molecular level, and have been proposed as suitable materials under high temperature use.

JP 59-187054 A JP-T 61-500023 Publication

The present inventors made a cylindrical fixing film by extrusion molding using a blended resin of PEEK and PEI showing good compatibility, and attempted durability evaluation using a film heating type fixing device. As a result, it became clear that the folding resistance of the fixing film was lowered after the endurance. It is a new issue that has not been recognized so far that the film made of a blended resin of PEEK and PEI, which has good compatibility, will endure when used at high temperatures. The present inventors have recognized that this is a problem to be solved.
That is, an object of the present invention is to provide a fixing film that uses a blend resin of a crystalline resin and an amorphous resin and has stable folding resistance through durable use.

In order to solve the above-mentioned problems, the fixing film for electrophotography of the present invention is
In a fixing film having a blend resin layer comprising a crystalline polyaryl ketone resin and an amorphous resin having a glass transition temperature higher than the glass transition temperature of the crystalline resin,
The blend resin has two or more glass transition temperatures measured by differential scanning calorimetry.

  It is possible to provide a fixing film that ensures high film-forming ability and does not deteriorate in folding resistance due to progress of crystallization due to use at a high temperature.

Schematic of an image forming apparatus according to an example of the present invention Schematic of a fixing device according to an example of the present invention Layer structure of fixing film according to an example of the present invention Results of MIT test of fixing film according to examples of the present invention Results of DSC of fixing film according to examples of the present invention Schematic of fixing device according to Embodiment 3

[Example 1]
The image forming apparatus according to Embodiment 1 will be described, but the image forming apparatus to which the fixing film of the present invention can be applied is not limited to this. The fixing film of the present invention can be applied to any image forming apparatus as long as it uses a fixing device to which the fixing film can be applied. Preferably, as described below, a fixing rotating member, a backup member that contacts the fixing rotating member to form a nip portion, a heating element that heats at least one of the fixing rotating member and the backup member, And a fixing device that heats and fixes the toner image on the recording material while nipping and conveying the recording material carrying the toner image at the nip portion.

(1) Schematic Description of Image Forming Apparatus FIG. 1 is a sectional view showing a schematic configuration of an image forming apparatus in which a fixing device according to the present invention can be mounted. This image forming apparatus is a full-color printer using an electrophotographic recording technique. An image forming unit that forms a toner image on the recording material P includes four image forming stations Pa, Pb, Pc, and Pd. Each image forming station includes a photoreceptor 117, a charging member 119, a laser scanner 118, a developing device 120, a transfer member 124, and a cleaner 122 for cleaning the photoreceptor. The image forming unit further includes a belt 123 that conveys the toner image while being carried, and a secondary transfer roller 121 that transfers the toner image from the belt to the recording material P. Since the operation of the image forming unit is well known, detailed description thereof is omitted. The recording material P is fed out one by one from the cassette 102 by the rotation of the roller 105, and this recording material is conveyed to the secondary transfer nip formed by the belt 123 and the secondary transfer roller 121 by the rotation of the roller 106. The recording material P onto which the unfixed toner image has been transferred at the secondary transfer nip is sent to the fixing unit 109, and the toner image is heated and fixed to the recording material at the fixing unit. The recording material P exiting the fixing unit 109 is discharged onto the tray 112 by the rotation of the roller 111.

(2) Fixing unit (fixing device)
A fixing device constituting the fixing unit 109 will be described. FIG. 2 is a cross-sectional view illustrating a schematic configuration of the fixing device 109 according to the present exemplary embodiment. The fixing device 109 includes a heating unit 10 and a pressure roller 30 as a pressure member. The heating unit 10 includes a cylindrical film (fixing film) 16, a film guide 19 as a support member (a backup member that forms a nip portion in contact with the fixing film as a fixing rotating member), and a nip portion forming member. Ceramic heater (heat source / heating element) 15 and the like. The fixing film 16, the film guide 19, the ceramic heater (hereinafter referred to as a heater) 15, and the pressure roller 30 are all indicated in a direction (hereinafter referred to as a longitudinal direction) orthogonal to the recording material conveyance direction (see FIG. 2). ) Is a long member.

A heater 15 is supported on the film guide 19, and a fixing film 16 is loosely fitted on the film guide. By sandwiching the fixing film 16 between the heater 15 and the pressure roller 30, a nip portion N is formed by the film and the pressure roller. Hereinafter, each member will be described in more detail. The pressure roller 30 has a round shaft-shaped metal core (shaft portion) 30A made of a metal material such as iron, SUS, or aluminum. An elastic layer 30B mainly composed of silicone rubber or the like is formed in a roller shape on the outer peripheral surface of the core metal 30A. Further, a release layer 30C mainly composed of polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoroethylene propene copolymer (FEP) or the like is formed on the outer peripheral surface of the elastic layer 30B.
The film guide 19 is formed in a substantially concave shape in cross section using a predetermined heat resistant material. On the flat surface of the film guide 19 on the pressure roller 30 side, a groove 19A is formed along the longitudinal direction, and the heater 15 is supported by this groove. The heater 15 has a thin plate-like heater substrate 15A mainly composed of ceramic such as alumina or aluminum nitride. On the film sliding surface of the heater substrate 15 on the fixing film 16 side, an energization heating resistor mainly composed of silver, palladium or the like is printed in a pattern along the longitudinal direction of the heater substrate. A conductive portion for energizing the energization heating resistor and an electrode portion for supplying power to the energization heating resistor via the conductive portion are pattern printed on the sliding surface of the film. Further, a protective layer mainly composed of a heat-resistant resin such as glass or fluororesin or polyimide is provided on the film sliding surface so as to cover the energization heating resistor.

The fixing film 16 is loosely fitted on the film guide without tension (the layer configuration and material of the fixing film 16 will be described later). The fixing film 16 externally fitted to the film guide 19 is arranged in parallel with the pressure roller 30, and both end portions in the longitudinal direction of the film guide are horizontal with a pressure spring (not shown) perpendicular to the generatrix direction of the pressure roller 30. It is biased in the direction. The heater 15 supported by the film guide 19 brings the fixing film 16 into contact with the outer peripheral surface (surface) of the pressure roller 30 in a pressurized state by the pressure of the pressure spring. Thereby, the elastic layer 30 </ b> B of the pressure roller 30 is crushed and elastically deformed, and a nip portion N having a predetermined width is formed between the pressure roller surface and the outer peripheral surface (surface) of the fixing film 16. In FIG. 2, reference numeral 43 denotes a guide for guiding the recording material P to the nip portion N. Reference numeral 44 denotes a guide for guiding the recording material P discharged from the nip portion N.
Next, the heat fixing process operation of the fixing device 109 will be described. The driving force of a motor (not shown) provided in the image forming apparatus is transmitted to a gear (not shown) provided at the longitudinal end of the core metal 30A of the pressure roller 30, whereby the pressure roller 30 moves in the direction of the arrow. Rotate. The fixing film 16 rotates in the direction of the arrow following the rotation of the pressure roller while the inner peripheral surface (inner surface) of the film slides on the protective layer of the heater 15. The energization heating resistor of the heater 15 is energized from a commercial power source via a triac (not shown), whereby the energization heating resistor generates heat and the heater is heated. The triac is controlled by a control unit 101 including a CPU and a memory such as a RAM and a ROM so that the detection temperature of the temperature detection element 201 that monitors the temperature of the non-sliding surface of the heater substrate 15 maintains the fixing temperature (target temperature). Be controlled.
The recording material P carrying the unfixed toner image T is guided to the nip portion N by the guide 43. While the recording material P is nipped and conveyed at the nip portion N, the heat of the heater 15 and the pressure of the nip portion are applied to the unfixed toner image, whereby the toner image is heated and fixed on the recording material. The recording material P that has exited the nip portion N is guided by the guide 44 and fed to the roller 111.

(3) Description of Fixing Film of Invention Example 1 The fixing film 16 of Invention Example 1 has a two-layer structure (see FIG. 3), and the base layer 16A is a crystalline polyaryl ketone resin PEEK (Victrex 381G, Tg 143). ℃
) And sulfonated PEI (Sabic Ultem XH6050, Tg 247 ° C.), which is an amorphous resin, and a PFA tube (DuPont 450HP) (thickness 30 μm) was used for the surface layer 16B. The fixing film was produced as follows. The base layer 16A made of a blend of PEEK and PEI was manufactured by molding into a cylindrical shape by extrusion using pellets dry blended at a predetermined ratio using a biaxial kneader. As the surface layer 16B, a PFA pellet was molded into a cylindrical shape by an extrusion molding machine, and fitted into the base layer 16A to produce a fixing film 16 having a two-layer structure.
As in Invention Example 1, the fixing film of the present invention may have a two-layer structure in which a blend resin is laminated on the surface layer as a base layer. The material used for the surface layer 16B is not particularly limited, but a resin is preferable, and examples of the resin include those selected from perfluoroalkoxyalkane (PFA), perfluoroethylenepropene copolymer (FEP), and the like.

  The blend ratio of the blend resin of the base layer 16A in Invention Example 1 was 70 parts by mass of PEEK and 30 parts by mass of sulfonated PEI in the example of the present invention. In the blend resin used in the present invention, the blend ratio of the crystalline polyaryl ketone resin and the amorphous resin (crystalline polyaryl ketone resin: amorphous resin) is 50:50 to 99: 1 in parts by mass. It is preferable that it is 70: 30-99: 1. If the mass part of the crystalline polyaryl ketone resin is reduced, there is a concern about folding resistance due to the brittleness of the amorphous resin, so it is desirable to make the mass part of the crystalline polyaryl ketone resin larger than 50 parts by mass. .

  In the examples of the present invention, PEEK was used as the crystalline polyaryl ketone resin, but various types of crystalline polyaryl ketone resins such as polyether ketone (PEK), polyether ether ketone (PEEK), and polyether ketone ether were used. Ketone ketone (PEKEKK), polyether ketone ketone (PEKK), polyaryl ether ketone ether ketone ketone (PAEKEKK), polyallyl ether ketone (PAEK), polyallyl ether ether ketone (PAEEK), polyether ether ketone ketone (PEEKK) , Polyaryl ether ketone ketone (PAEKK), and one or more selected from the group consisting of polyaryl ether ether ketone ketone (PAEEKK) may be used.

When there is a concern that the base layer 16A is charged up during image formation due to the configuration of the fixing device, or when mechanical strength needs to be improved, a conductive filler may be added. Examples of the conductive filler to be added include carbon black, graphite powder, metal powder, and metal oxide whisker.
Among these, conductive carbon black is particularly preferable from the viewpoint of mechanical properties and the like. Examples of the conductive carbon black include acetylene black, oil furnace black, thermal black, and channel black. These conductive carbon blacks may be used alone or in combination of two or more. The ratio of the conductive filler in the resin composition is preferably 1 part by mass or more and 40 parts by mass or less, and more preferably 3 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin (blend resin) used for the base layer 16A. Or less. When the proportion of the conductive filler is too large, the brittleness of the fixing film increases, and the mechanical properties may be deteriorated. If the proportion of the conductive filler is too small, the volume resistivity of the fixing film may be too high.

The average value of the total thickness of the fixing film of Invention Example 1 was 150 μm. The average value of the total thickness of the fixing film 16 of the present invention is preferably in the range of 50 to 400 μm, more preferably in the range of 50 to 250 μm, and still more preferably in the range of 70 to 200 μm. If the fixing film is too thin, it tends to be difficult to make the thickness uniform. On the other hand, when the thickness of the fixing film is too thick, the plastic deformation of the film bending portion tends to deteriorate.
The fixing film 16 was subjected to annealing treatment to remove residual stress at the time of molding, and subjected to crystallization treatment in order to obtain necessary initial strength and heat resistance.
When the fixing film has a two-layer structure, the thickness of the base layer 16A is preferably in the range of 50 to 200 μm, and more preferably in the range of 50 to 140 μm. The thickness of the surface layer 16B is preferably in the range of 10 to 60 μm, and more preferably in the range of 10 to 30 μm.
The fixing film 16 is heated from about 80 ° C. to about 240 ° C. during image formation, depending on the thickness and size of the recording material P used. Further, as described above, since the fixing film 16 is in contact with the outer peripheral surface (surface) of the pressure roller 30 in a pressurized state, the fixing film 16 is rotated in a state of being deformed in the elastic deformation region. For the above reasons, it is important for the fixing film 16 to maintain a wide range of heat resistance and folding resistance within the elastic deformation region within the product lifetime.

(4) Description of Difference between Comparative Example and Invention Example In the method for producing the fixing film of Invention Example 1, the composition of the blend resin used for the base layer 16A was changed to the composition shown in Table 1, and In the same manner, fixing films of Invention Example 2 and Comparative Examples 1 to 3 were produced.
Table 1 shows the results of performance confirmation of Comparative Examples 1 to 3 (fixing films prepared using the materials disclosed in the prior art) and Invention Examples 1 and 2 (fixing film 16 of this example). Show.

The fixing film prepared by PEEK shown in Comparative Example 1 has low heat resistance, and the fixing film may be damaged or deformed during image formation. This is because PEEK (Victrex 381G) has a glass transition temperature (Tg) of 143 ° C., which is lower than the operating range temperature. Although the glass transition temperature of the sulfonated PEI (Sabic Ultem XH6050) shown in Comparative Example 2 is as high as 247 ° C., it is an amorphous resin and has poor folding resistance, so there is a possibility that the fixing film will crack. is there.
Comparative Example 3 is a blend resin of PEEK (Victrex 381G) and PEI (Ultem # 1000) with good compatibility disclosed in Patent Document 1. When the fixing film made of the blend resin disclosed in Comparative Example 3 is new, there is no problem in both heat resistance and folding resistance, but the durability was confirmed using the image forming apparatus shown in the present invention example. In addition, a decrease in folding resistance was observed after the endurance.
On the other hand, in Invention Example 1, both heat resistance and folding resistance were less deteriorated throughout the life of the image forming apparatus, and no problematic defect was observed. Invention Example 2 is obtained by adding 10 parts of the conductive filler to Invention Example 1 with respect to 100 parts by mass of the blended resin. In both cases, good performance was obtained without any problems.

It can be said that the difference between Comparative Example 3 and Inventive Examples 1 and 2 is the fatigue strength of the film folding resistance. This will be described using the results of the MIT test (folding resistance test method) defined in JIS P 8115.
The test conditions were such that the bending radius of the bending surface of the bending clamp was 0.38 mm, the width of the test piece was 10 ± 0.1, the load was 9.8 N, and the bending angle was 135 ± 2 °. The number of times until the test piece was broken was defined as the number of folding times.
FIG. 4 shows the MIT test results when new and Comparative Example 3, Invention Example 1 and Invention Example 2 and the MIT test results after performing life durability using the image forming apparatus. In the case of the combination of materials of Comparative Example 3, the number of MITs was significantly reduced after durability. On the other hand, it can be seen that the fixing films of the materials of Invention Example 1 and Invention Example 2 have a small decrease in MIT before and after endurance, and the folding resistance is stable throughout life.

The present inventors consider that the difference in durability between Comparative Example 3 and Invention Examples 1 and 2 is due to the compatibility state of the blend resin. The estimation mechanism is described below.
When a material composed of a blend resin is used for the fixing film, the compatibility between the resins constituting the blend resin is important. If the resin is incompatible, when trying to form as a thin film, the film forming ability is low and it can not be formed into a film, or even if it can form a film apparently, it will break easily if pulled by hand, It cannot be used as a fixing film. On the other hand, in the case of a blend resin that is completely compatible as in Comparative Example 3, these resins are compatible at the molecular level, and a film can be formed without problems.
However, when a completely compatible blend resin is used as a fixing film in an image forming apparatus, it is presumed that folding resistance deteriorates during the crystallization growth process. PEEK promotes crystallization when exposed to high temperatures, but the progress of PEEK crystallization in a blend resin that is completely compatible at the molecular level is caused by crystallization with PEI having good compatibility in the crystal nucleus of PEEK. It is thought that progress will be made. That is, the present inventors consider that the comparative example deteriorates in folding resistance because the crystal nucleus grows in a state where PEI having poor folding resistance is incorporated in the crystal nucleus of PEEK.
On the other hand, in the example of the present invention, PEEK and sulfonated PEI form a mildly compatible state. Since the grain boundary forming the incompatible part exists in units sufficiently fine with respect to the thickness of the film, the film forming ability is high and the film has sufficient mechanical strength. When the blend resin in such a mildly compatible state is used as a fixing film in an image forming apparatus, the crystallization of PEEK is formed without involving sulfonated PEI in the crystal nucleus of PEEK. The present inventors believe that there is no decrease.

(5) Results of Differential Scanning Calorimetry (DSC) of Comparative Example 3 and Invention Example Differences between Comparative Example 3 and the inventive example will be described as follows using differential scanning calorimetry (DSC).
First, the measuring method of the glass transition temperature (Tg) in this invention is demonstrated.
The sample to be measured is precisely weighed 5 to 20 mg, preferably 10 mg. This was put in an aluminum pan, and an empty aluminum pan was used as a reference, and measurement was performed at a temperature increase rate of 10 ° C./min within a measurement temperature range of 80 to 380 ° C. In addition, the apparatus used for the measurement used DSC823 of METTLER TOLEDO Co., Ltd.
A: PEEK 100 parts by mass B: PEEK 70 parts by mass / PEI 30 parts by mass (Comparative Example 3)
C: PEEK 70 parts by mass / sulfonated PEI 30 parts by mass (Invention Example 1)

As shown in B in FIG. 5, although Comparative Example 3 is a blend resin of two types of resins, PEEK (Tg 143 ° C.) and PEI (Tg 217 ° C.), the observed glass transition temperature is One (B _PEEK ) and its temperature was 159 ° C. That is, the result that the glass transition temperature of PEEK in the comparative example 3 was higher than the glass transition temperature (A _PEEK = 143 ° C.) of 100 parts by mass of PEEK (pure PEEK) was obtained.
It is generally known that the glass transition temperature when a resin that is completely compatible and has a glass transition temperature different from Tg, 1 and Tg, 2 is in accordance with the FOX formula represented by formula (1) is known. In Comparative Example 3, the observed glass transition temperature (159 ° C.) almost conforms to the glass transition temperature (159.4 ° C.) obtained from the FOX equation, so that the blend resin of Comparative Example 3 is completely PEEK and PEI. It can be said that they are in a compatible state.

On the other hand, in the case of Invention Example 1 indicated by C in FIG. 5, the observed glass transition temperatures were two derived from PEEK (C _PEEK ) and sulfonated PEI (C _S-PEI ). The glass transition temperature (C _PEEK ) derived from PEEK observed in Invention Example 1 was 145 ° C., which was substantially the same as the glass transition temperature (A _PEEK ) of 100 parts by mass of PEEK (pure PEEK). On the other hand, the glass transition temperature (C _S-PEI ) derived from sulfonated PEI was around 230 ° C., and it was confirmed that the glass transition temperature shifts to a lower temperature side than 247 ° C., which is the glass transition temperature of pure sulfonated PEI. The present inventors believe that this is because sulfonated PEI and PEEK are not completely incompatible but form a mildly compatible state.
As described above, it is considered that a mildly compatible state is formed when the glass transition temperature of the blend resin is 2 or more. Therefore, the blend resin used in the present invention has two or more glass transition temperatures measured in the differential scanning calorimetry. Moreover, it is preferable that the glass transition temperature derived from the amorphous resin measured by the differential scanning calorimetry of the blend resin is lower than the glass transition temperature of the amorphous resin measured by the differential scanning calorimetry.

Moreover, it can be said also from the result of the tensile elastic modulus measurement in the film state that the material of the example of the present invention is not completely incompatible but forms a loose compatible state. Table 1 shows the results of measuring the tensile modulus using a film having a thickness of 100 μm in a 160 ° C. environment.
In the present invention, the measurement of the tensile elastic modulus using a film having a thickness of 100 μm in a 160 ° C. environment was carried out by a method based on JIS7127.
In Comparative Example 1, which is pure PEEK, when the glass transition temperature was exceeded, a decrease in elastic modulus was observed, and the tensile elastic modulus in an environment of 160 ° C. was 0.76 GPa. The sulfonated PEI of Comparative Example 2 was below the glass transition temperature in a 160 ° C. environment and had a high elastic modulus of 1.41 GPa. Comparative Example 3 which is a highly compatible blend resin has a viscosity of 1.08 GPa, and the elastic modulus is improved by adding PEI. This is because Comparative Example 3 has high compatibility between resins and excellent film-forming ability, and thus a reinforcing effect was obtained by adding PEI even in the film state. On the other hand, also in Invention Example 1, the tensile elastic modulus was 1.04 GPa, and the elastic modulus was improved by adding sulfonated PEI. In addition, in Example 2, since the filler is added, the elastic modulus is further improved. From this, it can be said that Examples 1 and 2 of the present invention have excellent film forming ability and are in a moderately compatible state. In addition, the same tendency was seen in this tendency when the film thickness is in the range of 50 to 150 μm.
As described above, in the present invention, it is preferable that the blended resin has a higher tensile elastic modulus than the crystalline polyaryl ketone resin in a film sample having a thickness of 100 μm in an environment of 160 ° C.

Although the details are unknown as to the mechanism by which the blended resin of sulfonated PEI and PEEK shown in Invention Example 1 is not completely compatible but forms a mildly compatible state, the present inventor Think as follows.
The structure of the sulfonated PEI has a sulfonyl group having a large polarity in the main chain of the PEI as shown in the following structural formula (1). Although PEEK and PEI are very highly compatible with each other, there is a sulfonyl group that contains S and is highly polarized. Therefore, the interaction between molecules is affected by the electrostatic force due to polarization. It is speculated that the compatibility is partially incompatible. As described above, the amorphous resin used in the blend resin according to the present invention is preferably a resin having a group having a large polarity such as a sulfonyl group in the main chain.
The amorphous resin used in the present invention is preferably one or more selected from sulfonated polyetherimide (PEI), polyethersulfone (PES), polyphenylsulfone (PPSU), polysulfone (PSf), and the like. It can be illustrated.

  As described above, the crystalline polyaryl ketone resin and the amorphous resin ensure a high film-forming ability by being in a moderately compatible state, and crystallization progresses when used under high temperature conditions. It is possible to provide a fixing film that does not deteriorate the folding resistance.

[Example 2]
The manufacturing method of the fixing film of the present invention example is different from that of Example 1 only in the material of the fixing film used, and the rest is the same, so only the difference will be described.
(6) Description of Difference between Comparative Example and Example of Invention Related to Example 2 Also in the example of the present invention, the fixing film 16 has a two-layer structure. Inventive Example 3 (see Table 2) is based on PEEK (Victrex 3) whose base layer 16A is a crystalline polyaryl ketone resin.
81G, Tg 143 ° C.) and PPSU which is an amorphous resin (Solvay Advanced Polymers Corp. Radel R R-5000, Tg 220 ° C.) (thickness 90 μm),
The surface layer 16B is made of a PFA tube (DuPont 450HP) (thickness 30 μm).
Invention Example 4 includes PEEK (Victrex 381G, Tg 143 ° C.) whose base layer 16A is a crystalline polyaryl ketone resin and PES (Solvay Advanced Polymers Radel polyether sulfone, Tg 220 ° C.) which is an amorphous resin. Blend resin (thickness 90 μm), surface layer 16B is PFA tube (DuPont 450HP) (thickness 30
μm).
In both Invention Examples 3 and 4, the average value of the total thickness of the fixing film 16 was 120 μm.

Table 2 shows a list of the results of confirming the performance of the fixing film 16 of this example using the above-described image forming apparatus in comparison with the conventional example 3. In Invention Example 3, both heat resistance and folding resistance were less deteriorated throughout the life of the image forming apparatus, and no problematic defect was observed. Inventive Example 4 was also made by using PPSU as the amorphous resin, but no deterioration due to durability was observed. Moreover, the tensile elasticity modulus in the film state of 100 micrometers thickness was also equivalent to the comparative example 3 which is completely compatible (refer Table 2).
The Tg of the blend resin in the fixing film of Invention Example 3 is 150 ° C. and 210 ° C. (derived from the amorphous resin), and the Tg of the blend resin in the fixing film of Invention Example 4 is 152 ° C. and 208 ° C. Derived from a crystalline resin).

From the above, even in the inventive examples, although the inventive examples 3 and 4 are not completely compatible with each other, they are in a dispersed state in very fine units, so that sufficient mechanical strength can be obtained. In addition, since PEEK is not completely compatible with the amorphous resin, the PEEK crystal mass grows by removing the amorphous resin when PEEK is crystallized, so that the deterioration due to durability is slight. It is thought that it becomes.
The structural formulas of PPSU and PES are shown below. All have a structure having a sulfonyl group in the main chain. As described above, the sulfonyl group includes S and has a large polarity. It is presumed that the compatibility with PEEK is partially incompatible by the influence of electrostatic force due to the polarization of the sulfonyl group on the intermolecular interaction with PEEK.

  As described above, the crystalline polyaryl ketone resin and PPSU blend resin, and the crystalline polyaryl ketone resin and PES blend resin are in a moderately compatible state to ensure high film-forming ability, In addition, it is possible to provide a fixing film with little deterioration in folding resistance due to the progress of crystallization under high temperature use.

[Example 3]
In this embodiment, the fixing device used is different. The configuration will be described below with reference to FIG. A fixing roll 41 having a heating source 42 such as a halogen lamp inside, a fixing film 16 that rolls with the fixing roll 41 and sandwiches and conveys paper, and an inner peripheral surface side of the cylindrical fixing film 16 are arranged in contact with each other. A fixing pad 46 for forming a fixing nip N is provided between the fixing roll 41 and the fixing film 16. The fixing pad 46 in the present embodiment includes a pressing pad 46a as a low pressure pad portion disposed on the upstream side, and a fixed pad as a high pressure pad portion having a higher pressing force than the pressing pad 46a disposed on the downstream side. The fixing nip width is the same from the center portion of the fixing pad 46 to both end portions. The pressing pad 46a and the fixing pad 46b are supported by a rigid support 47 having a recess for supporting these (46a and 46b), and the fixing film 16 is attached to the fixing roll 41 from the back side of the fixing film 16. Pressed against the surface. Further, a belt travel guide 45 made of, for example, a rigid and low thermal conductive resin is provided below the rigid support 47 to smoothly rotate the fixing film 16.

A temperature sensor 49 for measuring the surface temperature of the fixing roll 41 is disposed around the fixing roll 41, and the temperature sensor 49 allows the surface temperature of the fixing roll 41 to reach a predetermined temperature. Temperature control is performed. The temperature sensor 49 is not particularly limited as long as it can measure the surface temperature of the fixing roll 41. For example, a temperature sensitive element such as a thermistor or a posistor can be used.
The fixing roll 41 in this embodiment includes a cylindrical core 41a made of metal such as aluminum having excellent mechanical strength and good thermal conductivity, and an elastic layer such as silicone rubber formed on the surface of the core 41a. 41b and a release layer 41c that covers the surface of the elastic layer 41b and is provided to prevent the offset of the unfixed toner image on the paper.
Here, the material of the core 41a is not particularly limited as long as it has mechanical strength and good thermal conductivity, and may be a metal or an alloy such as stainless steel, steel, or brass. Further, the elastic layer 41b is not limited to silicone rubber, and may be, for example, fluorine rubber as long as it has heat resistance. The method of forming the elastic layer 41b on the surface of the core 41a is not particularly limited, An injection molding method or a coating method can be employed. Further, the release layer 41c may be any material that has heat resistance and appropriate release properties for the toner. For example, fluorine rubber or fluorine resin is used. The heating source 42 in the fixing roll 41 is not particularly limited as long as it has a shape and structure that can be accommodated in the core 41a, and may be appropriately selected according to the purpose.

(7) Description of Fixing Film 16 According to this Example The fixing film of Invention Example 5 is PEEK (Victrex 381G, Tg 143 ° C.) which is a crystalline polyaryl ketone resin and PSf (Solvay Advanced) which is an amorphous resin. A polymer resin Udel P-1700 (Tg 189 ° C.) blended resin (thickness 120 μm) and a PFA tube (DuPont 450 HP) (thickness 30 μm) as the surface layer 16B were used in the same manner as in Invention Example 1. The blend ratio of the base layer 16A in Invention Example 5 was 70 parts by mass of PEEK and 30 parts by mass of PSf with respect to 100 parts by mass of the resin. The average value of the total thickness of the fixing film 16 was 100 μm. The Tg of the blend resin in the fixing film of Invention Example 5 was 148 ° C. and 180 ° C. (derived from an amorphous resin). Moreover, the tensile elastic modulus (100 micrometers in thickness) in 160 degreeC environment was GPa.
In the fixing device of the present invention, a fixing roll 41 having a three-layer structure and a recording material are present between the fixing film 16 and the heating source 42. For this reason, the heat from the heating source 42 is characterized by the fact that the fixing film 16 is unlikely to reach a high temperature due to the influence of the thermal resistance of the member.

Also in the above-described invention examples, the blend resin can form a mildly compatible state, and there is no problem in heat resistance and folding resistance, and a fixing film with little deterioration throughout the life of the image forming apparatus is provided. Is possible.
The structural formula of PSf is shown below. PSf also has a structure having a sulfonyl group in the main chain. As described above, the sulfonyl group includes S and has a large polarity. It is presumed that the compatibility with PEEK is partially incompatible by the influence of electrostatic force due to the polarization of the sulfonyl group on the intermolecular interaction with PEEK.

  As described above, the blended resin of crystalline polyarylketone resin and PSf is in a mildly compatible state to ensure high film forming ability and to be crystallized by use at high temperatures. Therefore, it is possible to provide a fixing film with less deterioration of folding resistance.

10 Heating unit 15 Ceramic heater (heat source)
15A Heater substrate 16 Fixing film 16A Base layer 16B Surface layer 19 Film guide 19A Groove 30 Pressure roller 30A Round shaft core (shaft part)
30B Elastic layer 30C Release layer 43, 44 Guide 41 Fixing roll 41a Core 41b Elastic layer 41c Release layer 42 Heat source 45 Belt running guide 46 Fixing pad 46a Press pad 46b Fixed pad 47 Rigid support 49 Temperature sensor 101 Control unit 102 Cassette 105, 106 Roller 109 Fixing unit 109 Fixing device 111 Roller 112 Tray 117 Photoconductor 118 Laser scanner 119 Charging member 120 Developer 121 Secondary transfer roller 122 Cleaner 123 Belt 124 Transfer member 201 Temperature detection element

Claims (9)

In a fixing film having a blend resin layer containing a crystalline polyaryl ketone resin and an amorphous resin having a glass transition temperature higher than that of the crystalline polyaryl ketone resin,
The fixing resin, wherein the blend resin has two or more glass transition temperatures measured by differential scanning calorimetry.   The glass transition temperature derived from the amorphous resin measured by differential scanning calorimetry of the blend resin is lower than the glass transition temperature of the amorphous resin measured by differential scanning calorimetry. Item 4. The fixing film according to Item 1.   3. The fixing film according to claim 1, wherein the blended resin has a higher tensile elastic modulus in a film-like sample having a thickness of 100 μm in a 160 ° C. environment than in the crystalline polyaryl ketone resin. .   The fixing film according to claim 1, wherein the amorphous resin is a resin having a sulfonyl group.   The fixing film according to claim 4, wherein the amorphous resin is a sulfonated polyetherimide.   The fixing film according to claim 4, wherein the amorphous resin is one or more selected from the group consisting of PES, PPSU, and PSf.   The crystalline polyaryl ketone resin may be polyether ether ketone (PEEK), polyether ketone (PEK), polyether ketone ether ketone ketone (PEKEKK), polyether ketone ketone (PEKK), polyaryl ether ketone ether ketone ketone ( One or more selected from the group consisting of PAEEKKK), polyallyl ether ketone (PAEK), polyallyl ether ether ketone (PAEEK), polyether ether ketone ketone (PEEKK), and polyaryl ether ketone ketone (PAEKK) The fixing film according to any one of claims 1 to 6.   The fixing film according to claim 1, wherein the blend resin includes a conductive filler in an amount of 1 part by weight to 40 parts by weight with respect to 100 parts by weight of the blend resin. A fixing rotation member; a backup member that forms a nip portion in contact with the fixing rotation member; and a heating element that heats at least one of the fixing rotation member and the backup member. A fixing device that heats and fixes a toner image on a recording material while sandwiching and conveying the recording material carrying the toner image at
The fixing device according to claim 1, wherein the fixing rotation member is the fixing film according to claim 1.

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