JPH10305537A - Heating member, its manufacture, and primer composition used therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating member having excellent durability with satisfactory adhesive properties of a metal base material to releasable fluororesin layer of a surface without release even under severe conditions such as repeating of heating and cooling and pressurizing at a high temperature. SOLUTION: The heating member is obtained by forming a fluororesin layer on a surface of a metal base material via a primer layer. In this case, the primer layer contains primer composition containing silane coupling agent, fluororesin and heat resistant resin. The primer layer preferably contains a first layer containing the agent as a main agent and a second layer containing fluororesin and heat resistant resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating member such as a heating roller used in a fixing section of an electronic copying machine or a facsimile, and more particularly, to a heating member on a metal substrate even under severe conditions. The present invention relates to a heating member in which a formed surface layer of a fluororesin or the like is hardly peeled off, a method for producing the same, and an adhesive primer composition suitably used for increasing the adhesive strength between a metal substrate and a fluororesin in the heating member. is there.

[0002]

2. Description of the Related Art In an electrostatic electronic copying machine or the like, as a method for fixing a toner image formed on a sheet, a sheet on which a toner image is formed is usually provided with a heating lamp disposed inside, and A method is adopted in which a toner image is fused onto a sheet by passing between a pair of rolls pressed against each other.

FIG. 1 shows a schematic configuration diagram of a fixing device of this electrostatic type electronic copying machine. As shown in FIG. 1, the fixing device includes a metal cylindrical core roll 1 having a lamp 2 therein, a heat roller 10 made of a heat-resistant fluororesin 3 bonded to an outer peripheral surface thereof, and a pressure contact with the heat roller 10. It is configured by a pressure roller 20 arranged, and heat-fixes the sheet by passing a sheet on which an unfixed toner image is formed between the rollers 10 and 20. Thus, the heating roller 10
It has a surface layer made of a fluororesin having a low surface energy.

As the fluororesin used here, a tetrafluoroethylene-perfluoroalkoxyethylene copolymer (hereinafter, appropriately referred to as PFA) is used. Although this fluororesin has good releasability, it has a problem of poor adhesion to a metal substrate.

Further, not only the heating roller but also a heating member used under heating conditions, such as a fixing belt used in a fixing device, a pressure roller opposed to the heating roller, etc. It is important to achieve compatibility with a metal substrate, and various proposals have been made for the purpose of improving the adhesion.

For example, JP-A-57-177067 discloses a polyimide precursor obtained by a reaction between pyromellitic anhydride and diaminodiphenyl ether or diaminodiphenyl ether or diaminodiphenylmethane, and PF.
A method is described in which the cylindrical core roll and the PFA resin layer are adhered to each other via an adhesive primer containing A resin. JP-A-63-112677 discloses a method in which a mixed solvent of a water-soluble organic solvent and water is used. As a main component, an aromatic polyimide precursor obtained by reacting pyromellitic anhydride with 4,4'-diaminodiphenyl sulfone or a product obtained by neutralizing a free carboxylic acid thereof with amines, and a PFA resin. Metallic cylindrical core roll and PF with primer
A method of adhering to the A resin layer has been proposed.

US Pat. No. 4,049,863 discloses grid blasting, flame spraying of metal or metal oxide, and techniques applied to polytetrafluoroethylene (PTFE) which is a fluorine resin material other than PFA. A primer containing, for example, PTFE, colloidal silica, and polyamidoimide (PAI) as a fluoropolymer is coated on a core roll suitably pre-treated or treated with phosphoric acid or chromic acid using a frit coating. Shows, P
A TFE: PAI ratio of 1: 9 and a dry thickness of 2-15 μm has been proposed. Similarly, U.S. Pat. No. 3,801,379 discloses that a poly (arylene sulfide) coating, such as polyphenyl sulfide (PPS), is applied directly to an aluminum substrate after treating the core roll surface with hot water or steam. And preferably 45
A method of processing at 5 ° C. is described, and PPS is 5 to 20.
% PTFE can be included. Also, Canadian Patent No. 887,122 proposes a method of coating with a gradient structure using PAI and PTFE, and British Patent No. 1,512,495 discloses a method of coating with a PAI coating containing PTFE powder. Oh, PTFE: PA
A coating method in which the minimum ratio of I is 1: 7 has been proposed.

[0008]

By the way, when a metal core roll and a fluororesin are bonded to each other using the above-mentioned bonding primers, good results can be obtained in the initial stage, but the above-mentioned bonding primers are used. There has been a problem that the primer is deteriorated with time, and the metallic core roll and the fluororesin are easily peeled off with time, and cannot be used for a long time. That is, the heating member disposed in the fixing device or the like is repeatedly heated and cooled to a high temperature of about 200 ° C. when the device is in operation, and is cooled to room temperature when the device is stopped. Severe conditions, such as pressure rollers being placed in pressure contact and the fluororesin layer constantly being stressed, and a separating claw that constantly prevents the paper from winding around the heating roller is pressed on the outer peripheral surface. Therefore, there has been a problem that the adhesive primer cannot be used for a long period of time due to deterioration with time of the bonding primer and separation of the fluororesin layer on the surface from the metal substrate.

Accordingly, an object of the present invention is to provide a method for forming a releasable fluororesin layer between a metal substrate and a surface under severe conditions such as repeated heating and cooling, pressurization at high temperature, and application of stress. An object of the present invention is to provide a heating member excellent in durability, which has good adhesiveness, does not cause peeling, and maintains the adhesiveness for a long time. Still another object of the present invention is to provide a simple method for producing a heating member having such excellent characteristics and a primer composition used therefor.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a primer used for a heating member in the prior art is a precursor of polyimide, polyimideamide, polyphenylene sulfide or the like. On the other hand, the present inventors have completed the present invention by focusing on a material configuration intended to mainly covalently bond with a hydroxyl group on a metal surface, while being a partially covalent organic bond using is there.

That is, the heating member of the present invention is a heating member in which a fluororesin layer is formed on the surface of a metal substrate via a primer layer, and the primer layer is composed of a silane coupling agent, a fluororesin, and a heat-resistant resin. Characterized by comprising a primer composition containing a conductive resin. This primer layer preferably comprises a first layer mainly containing a silane coupling agent and a second layer containing a fluororesin and a heat-resistant resin.

Further, the method for producing a heating member according to the present invention is characterized in that a primer composition containing a silane coupling agent, a fluororesin and a heat-resistant resin is applied to a surface of a metal substrate and dried to form a primer layer. A fluorine resin layer is formed on the primer layer.

Furthermore, the primer composition of the present invention is used for producing the above-mentioned heating member, and is characterized by containing a silane coupling agent, a fluororesin and a heat-resistant resin. As this silane coupling agent,
Compounds represented by the following general formula (I) are preferred.

[0014]

Embedded image

In the formula (I) (X) _4-n -Si- (OR) _n , R represents a methyl group or an ethyl group, and X represents a vinyl group, an epoxy group, a methacryl group, a mercapto group, or an amino group. Represents a monovalent organic group containing n represents an integer of 2 to 4.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a primer composition used for producing a heating member of the present invention will be described. The primer composition of the present invention contains a silane coupling agent, a fluororesin and a heat-resistant resin, preferably,
This is a two-layer primer composition comprising a first liquid mainly containing a silane coupling agent and a second liquid containing a fluororesin and a heat-resistant resin.

More specifically, this primer layer is made of Si
Silane coupling agent having in the molecule (hereinafter, appropriately,
C. F-silane), a heat-resistant resin or a precursor thereof, and a fluororesin precursor as essential components.

In the heating member of the present invention, the excellent adhesiveness between the metal substrate and the fluororesin layer and the durability thereof are due to the difference in the magnitude of the binding energy. Not by using strong binding energy of perfect covalent bonds. As the substance that brings about this covalent bond, known coupling agents such as Si, Ti, Al, and Zn can be used. However, as in the heating member of the present invention, a fluorine resin layer as an organic material and a metal as an inorganic material are used. A silane coupling agent having Si is most preferable in order to firmly adhere to the substrate made of the material. Therefore, this silane coupling agent is also selected in the present invention.

It is generally known that a silane coupling agent has two or more different reactive groups in a molecule and has a function of chemically bonding an organic material and an inorganic material.
This general one is represented by the following chemical structural formula.

[0020]

Embedded image

Here, X is a reactive group (for example, a vinyl group, an epoxy group, an amino group, a methacryl group, a mercapto group, etc.) chemically bonded to an organic material, and -OR is a chemical group bonded to an inorganic material such as glass or metal. A reactive group to be bonded (eg, a methoxy group, an ethoxy group, etc.).

The mechanism of the two adhesions is explained as follows. That is, the alkoxysilyl group (Si-OR) of the silane coupling agent is hydrolyzed into silanol groups by water or moisture. The silanol group and the inorganic surface form a Si-OM bond by a condensation reaction. Further, the other reactive group X- is bonded or compatible with an organic material, and as a result, both inorganic and organic substances can be chemically bonded.

There are the following two methods for applying the silane coupling agent to the heating member of the present invention. One method is called an integral blending method, in which a silane coupling agent is added and mixed with other primer composition materials at the time of bonding the resin layer and the inorganic material to the surface of the inorganic material. It is easy to incorporate into the manufacturing process and has excellent workability. However, this method is less effective than the direct treatment on the inorganic surface, so that the amount of the silane coupling agent used increases.

Another method is called a pretreatment method, in which the surface of an inorganic material is preliminarily treated with a treatment liquid containing a silane coupling agent as a main component, and the effect of the silane coupling agent is easily obtained. Especially when wet processing
Because of high processing efficiency and uniform processing, it is widely used industrially.

In the case of producing the heating member of the present invention, a wet pretreatment method can be used as a method for obtaining a high effect with a small amount of the primer composition. In this case, the primer composition used is mainly composed of a silane coupling agent. And a second liquid containing a fluororesin and a heat-resistant resin.

When this two-layer primer composition is used, the general addition amount of the silane coupling agent in the first liquid is 1 to 20% by weight, preferably 1 to 20% by weight, based on the solvent.
10% by weight. First containing silane coupling agent
The thickness of the primer layer after drying is 1 to 10 μm, and preferably about 3 to 7 μm. When a silane coupling agent is used in the primer composition, only one kind may be used, or two kinds of silane coupling agents may be used in combination and diluted to 1 to 20% by weight with a solvent. As the solvent at this time, alcohols, toluene, xylene, ethyl acetate, methyl ethyl ketone, acetone,
Alternatively, most organic solvents such as a mixed system of alcohol and water can be used.

The structure of the silane coupling agent used here will be described. In the general formula (I) for the purpose of attaching to the metal side as a functional group, the functional group represented by -OR is a methoxy group. And an ethoxy group, etc., and as the functional group represented by X- which chemically bonds to an organic material, a vinyl group, an epoxy group, an amino group, a methacryl group, a mercapto group, etc. are used, respectively.

Among them, tetramethoxysilane in which four ethoxy groups and methoxy groups are arranged has the highest heat resistance.
It is tetraethoxysilane. It is considered that these compounds do not have organic shame when the coupling reaction is performed, so that the heat resistance is further improved.

As the heat-resistant resin that can be used for the primer composition used in the heating member of the present invention, any heat-resistant resin having a continuous use temperature of 180 ° C. or higher can be used. Aromatic heat-resistant resins such as polyamideimide, polyethersulfone, and polyphenylene sulfide are preferred. Polyimide is generally obtained by reacting tetracarboxylic dihydrate and diamine in an organic polar solvent. In the present invention, the same effect can be obtained even if a precursor thereof is used in place of the heat-resistant resin. Therefore, in the present invention, the term "heat-resistant resin" includes the precursor. For example, for the primer layer constituting the heating member of the present invention, polyimide or a precursor thereof (polyamic acid) can be used as a heat-resistant resin. Polyamide imide is a polymer having a structure containing imide groups and amide groups alternately, and can be usually produced from an aromatic tricarboxylic anhydride and an aromatic diamine. According to the acid chloride method, a precursor polyamic acid is obtained, and when this is dehydrated and ring-closed, it becomes a polyamideimide. According to the isocyanate method or the direct polycondensation method, the polyamideimide is obtained in one step. In the present invention, a polyamideimide or a precursor thereof is used. Polyethersulfone (PES) is a type of aromatic polycondensation polymer generally obtained by a condensation reaction using dichlorodiphenyl sulfone as a main raw material.
Polyphenylene sulfide (PPS) has a melting point of 283
° C, a kind of aromatic polymer having a continuous use temperature of 200 to 220 ° C.

The precursor of the fluorine resin which is the third essential component for forming the primer layer of the heating member of the present invention can also be used. Of this fluororesin,
Preferred examples include the PFA resin described above, which is a fluororesin obtained by copolymerizing 4-fluoroethylene and perfluoroalkoxyethylene, and has heat resistance and an outermost release layer. It is designed so as to form an inclined structure with fluororesin (PFA).

The second liquid of the primer composition applied to the heating member of the present invention comprises a solution prepared by dissolving the above-mentioned heat-resistant resin or precursor in a water-soluble organic solvent such as furfuryl alcohol, butanol, isopropanol, ethanol and the like. It is adjusted by mixing with an aqueous solution in which the resin is uniformly dispersed. This second solution is CF silane (silane coupling agent)
Is coated on the surface treated with the first primer liquid, which is a main component, to form a primer layer for adhesion.

The mixing ratio of the above-mentioned heat-resistant resin or its precursor to the fluororesin in the second primer liquid is 10:90 to 90:10, preferably 3 to 10 by weight.
The range is from 0:70 to 70:30.

In these primer compositions, in addition to the essential components and a solvent for dissolving the components, various additives for improving the properties can be used in combination within a range that does not impair the effects of the present invention. For example, a surfactant such as polyoxyethylene phenyl ether may be added to improve the dispersibility of the fluororesin in the second primer solution.

The thickness of the dried primer layer in the present invention is 1 to 20 μm, preferably 3 to 13 μm.
It is about.

As the metal substrate of the heating member of the present invention, any known members can be used. For example, as a material of the metal core roll constituting the heating roller,
Metals such as aluminum and stainless steel having good thermal conductivity can be used.

In order to improve the affinity between the metal base material and the primer composition when the metal base material and the fluororesin layer as the surface layer are bonded by applying the adhesive primer composition of the present invention. Preferably, the surface of the metal substrate is subjected to a pretreatment such as degreasing, cleaning, or surface roughening, and more preferably to a surface roughening after performing a surface cleaning such as degreasing or cleaning. This surface roughening process is a blast process,
It can be performed by a known method such as a chemical etching treatment.

Next, CF silane (silane coupling agent) is uniformly applied and pre-treated. Apply a top coat primer of a heat-resistant resin and a fluororesin in a dry or lightly wet state. Similarly, under a dry or wet state, a fluororesin powder such as PFA resin or a dispersion is applied thereon, followed by baking, and a heat-resistant resin or a precursor such as a polyimide precursor in the above-mentioned overcoat primer. Is dehydrated and cyclized to form a polyimide, and the PFA resin in the overcoat primer and the applied fluororesin are melted to bond the metal to the fluororesin.

As the fluororesin used for the surface layer having releasability in the heating member of the present invention, in the case of a fixing roller or the like, in order to enable continuous use at a temperature of 200 ° C. or more, heat resistance is particularly low. Excellent ones are preferably selected. Specifically, for example, ethylene tetrafluoride resin (PT
FE), ethylene tetrafluoride-perfluoroalkoxyethylene copolymer (PFA), ethylene tetrafluoride-propylene hexafluoride copolymer (FEP) and the like.

A filler or other resin may be appropriately added to the outermost fluororesin layer as long as the releasability and heat resistance are not impaired. For example, a small amount of SiC
Can be used as long as the releasability required for the fixing roller is not impaired.
Further, the outermost layer made of a fluororesin is formed by a known method, for example, it may be formed by a dispersion method, or may be formed of a PFA tube by a tube insertion method, Further, it may be composed of PFA particles adhered by an electrostatic coating method.

The thickness of the fluororesin layer is 5 to 500 μm,
Preferably it is 20 to 50 μm. If the thickness is too small, the surface layer will be worn over a long period of use, and the primer layer and the substrate surface will be exposed, which is not preferable from the viewpoint of releasability. On the other hand, if it is too thick, the thermal conductivity will be poor, and the warm-up time will be long.

The heating member of the present invention is used under high-temperature conditions, such as a fixing belt and a pressure roller which is in pressure contact with the heating roller, in addition to the above-mentioned heating roller, and is suitable for each member which requires a releasing property on the surface. Can be used for Further, the adhesive primer composition used in the production of this heating member can be widely applied to various heating members used under severe conditions, and has excellent adhesion between the metal substrate and the fluororesin layer in the heating member. It is effective.

[0042]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Examples 1 to 12 and Comparative Example 1 under the following conditions
Were prepared, and the adhesion between these primer layers and the metal substrate was evaluated by the method described below. Evaluation Method of Adhesion A primer layer was formed on a mirror-finished aluminum plate (1 mm thick) as a metal substrate under the following conditions under the following conditions, and the adhesive force between the aluminum plate and the primer layer and its heat resistance were measured by a tape peeling method. Was evaluated by. FIGS. 2A to 2C schematically show the evaluation method. FIG. 2A shows a mirror-finished aluminum plate 30 which is a metal substrate. The aluminum plate 30
The primer layer 32 is formed on the substrate under various conditions. In FIG. 2B, the primer layer 32 has a single-layer structure, but may have a two-layer structure composed of a two-layer primer composition. After forming the primer layer 32 on the base material, the formed primer layer 32
4 and adhere for 48 hours at 400 ° C or 12 hours at 350 ° C.
After storage for 0 hours, the tape was pulled up from one side of the tape at an angle of 90 ° to the attached surface as shown in FIG. 2 (C). At this time, whether or not the primer layer portion was peeled off from the aluminum plate portion was visually evaluated. The evaluation is based on the following criteria.

○: No peeling at all △: Partial peeling ×: Peeling all (Example 1) CF silane (vinyl trimethoxysilane, KBM1003: Shin-Etsu Chemical) as a first primer solution on a degreased mirror-finished aluminum plate A 3% by weight solution was uniformly coated with a brush. Heating at 105 ° C for 5 minutes,
It was dried. The thickness of the first primer layer after drying is 8 μm
Met.

Thereafter, 3% by weight of polyamic acid as a precursor of polyimide, 4% by weight of PFA powder particles and 8% by weight of iron oxide (Bengara) are contained, and water and alcohol are respectively 60% by weight and 25% by weight. Was added with a brush, and heated and dried at 150 ° C. for 5 minutes to obtain a test sample. The thickness of the entire primer layer after drying was 13 μm.

When this test sample was evaluated for the adhesiveness, no peeling was observed under any of the conditions. The details of the primer composition used here and the results of the adhesion test are shown in Table 1 below.

(Example 2) CF as the first primer solution
Silane (vinyltrimethoxysilane, KBM1003:
Epoxy CF silane liquid (γ-
Glycidoxypropyltrimethoxysilane, KBM40
3: Shin-Etsu Chemical Co., Ltd.
A test sample was prepared and an adhesion test was performed in the same manner. As a result, no peeling was observed under any of the conditions. The results are shown in Table 1 below.

Example 3 A test sample was prepared in the same manner as in Example 1 except that a methacrylic CF silane liquid (γ-methacryloxypropyltrimethoxysilane, KBM503: manufactured by Shin-Etsu Chemical) was used as the first primer liquid. It was prepared and subjected to an adhesion test in the same manner. As a result, no peeling was observed under any conditions. The results are shown in Table 1 below.
Shown in

(Examples 4 to 7) Test samples were prepared in the same manner as in Example 1 except that a mercapto CF silane solution (γ-mercaptopropyltrimethoxysilane, KBM803: manufactured by Shin-Etsu Chemical) was used as the first primer solution. Was prepared as Example 4. Thereafter, similarly, in Example 5, an aminoethyl-based CF silane solution [N-β (aminoethyl) γ-
Aminopropyltrimethoxysilane, KBM603: Shin-Etsu Chemical Co., Ltd.], a methyl CF silane solution (methyltrimethoxysilane) in Example 6, and a methoxy CF silane solution (tetramethoxysilane) in Example 7 A test sample was prepared in the same manner as in Example 1. When an adhesion test similar to that of Example 1 was performed on these, no peeling was observed in any of the examples. The results are shown in Table 1 below.

Example 8 An ethoxy group-vinyl CF silane solution (vinyl triethoxysilane, KBE1003: Shin-Etsu Chemical Co., Ltd.) was used as the first primer solution. This is one in which Examples 1 to 7 have an ethoxy group while -OR of the general formula (I) is a methoxy group.
A test sample was prepared in the same manner as in Example 1, and an adhesion test was performed in the same manner. No peeling was observed under any of the conditions. The results are shown in Table 1 below.

Example 9 As the first primer solution, the same vinyltriethoxysilane (KBE100) as in Example 8 was used.
3: Shin-Etsu Chemical Co., Ltd.), and a test sample was prepared in the same manner as in Example 1 except that a polyamic acid as a polyimide amide precursor was used instead of the polyimide precursor in the second primer solution. When an adhesion test was performed, no peeling was observed under any of the conditions. The results are shown in Table 1 below.

Example 10 As a first primer solution,
The same vinyltriethoxysilane (KBE10 as in Example 8)
03: Shin-Etsu Chemical Co., Ltd.) and a test sample was prepared in the same manner as in Example 1 except that polyethersulfone was used instead of the polyimide precursor in the second primer solution. As a result, no peeling was observed under any of the conditions. The results are shown in Table 1 below.

Example 11 As a first primer solution,
The same vinyltriethoxysilane (KBE10 as in Example 8)
03: Shin-Etsu Chemical Co., Ltd.) and a test sample was prepared in the same manner as in Example 1 except that polyphenylene sulfide was used instead of the polyimide precursor in the second primer solution, and an adhesion test was performed in the same manner. However, no peeling was observed under any of the conditions. The results are shown in Table 1 below.

Example 12 The second primer solution used in Example 1 was mixed with a vinyl CF silane solution (vinyl trimethoxysilane, KB) adjusted to a concentration of 5% by weight.
M1003: manufactured by Shin-Etsu Chemical Co., Ltd.) to prepare an integral blend method, that is, a one-part primer composition. This primer composition solution was applied on an aluminum plate with a brush, heated and dried at 150 ° C. for 5 minutes to obtain a test sample. The thickness of the primer layer after drying was 12 μm. When this test sample was prepared and subjected to an adhesion test in the same manner, no peeling was observed at 400 ° C. for 48 hours, and only a part of the film was stored at 350 ° C. for 120 hours. Was observed, but it was judged to be a practically acceptable range. Table 2 shows the results.

Comparative Example 1 As a conventional one-pack type primer composition, 3% by weight of polyamic acid as a polyimide precursor, 4% by weight of PFA powder particles and iron oxide 8 were used as in Example 1. A water-soluble composition containing 5% by weight was prepared, an aluminum solution was applied with a brush, and heated and dried at 150 ° C. for 5 minutes to obtain a test sample. The thickness of the primer layer after drying was 10 μm. When an adhesion test was performed on this test sample in the same manner as in Example 1, peeling was observed under any of the conditions, and it was found that the test sample had no practical adhesive strength. Table 2 shows the evaluation results.

[0056]

[Table 1]

[0057]

[Table 2]

From these evaluation results, it was confirmed that all of the primer compositions of the present invention had sufficient adhesiveness to metal substrates and heat resistance. Examples 1 to 1
From the comparison between Example 1 and Example 12, when the same silane coupling agent was used, the two-layer primer composition had better adhesive strength and heat resistance than the one-pack type. I understand.

Next, examples are shown in which each of the primer compositions shown in the examples was applied to a heating member and developed on an actual machine.

(Example 13) As a metal substrate, an outer diameter of 50 was used.
The surface of an aluminum core roll (pipe shape) of mmφ is roughened by sandblasting, and an ethoxy CF silane solution (tetraethoxysilane, KBE04: Shin-Etsu Chemical) is brushed on the surface as a first primer solution. After coating, it was heated and dried at a temperature of 105 ° C. for 5 minutes. The thickness of the first primer layer after drying was 8 μm.
Then, the polyamic acid and PFA particles used in Example 1,
The second primer solution composed of iron oxide was similarly applied with a brush and dried at 150 ° C. for 5 minutes. The thickness of the entire primer layer after drying was 13 μm. On this primer layer, a powder coating of PFA is applied by an electrostatic coating method to form a coating.
The mixture was heated at 0 ° C. for 30 minutes and melted and fired to form a fluororesin surface layer. The thickness of the fluororesin layer after drying is 30 μm
Met. After firing, the surface was polished with a polishing film to obtain a fixing roller.

(Comparative Example 2) The surface of an aluminum core roll having an outer diameter of 50 mmφ was roughened by sand blasting in the same manner as in Example 13, and the primer single solution used in Comparative Example 1 was applied thereon with a brush. The coating was heated and dried at 5 ° C. for 5 minutes to form a primer layer. The thickness of the primer layer after drying was 5 μm. On this primer layer, a powder coating of PFA was applied by an electrostatic coating method in the same manner as in Example 13, heated at 400 ° C. for 30 minutes, and melted and fired.
A fluororesin surface layer was formed. The thickness of the fluororesin layer after drying was 30 μm. After firing, the surface was polished with a polishing film to obtain a fixing roller.

(Example 14) In the same manner as in Example 12,
A two-layer primer layer was formed. A fixing roller was produced in exactly the same manner as in Example 12, except that a PFA dispersion was applied on the primer layer.

Evaluation Method of Fixing Roller The peel strength between the surface of the metal substrate and the primer layer was measured for the primer layer in each of the fixing rolls obtained in Examples 13 and 14 and Comparative Example 3 by the method shown in FIG. did. The measurement of the peel strength is a peel test method using a load cell as shown in FIG. 3, in which the surface of the fixing roller 31 is cut in a circumferential direction with a knife to a width of 1 cm, and the metal substrate 31 is cut.
The surface and a part of the primer layer 32 are peeled off, and the end of the peeled primer layer 32 is attached to a chuck (not shown) of a peeling tester, and the strength when peeled at 90 ° in the circumferential direction is measured.

Each of the fixing rolls obtained in Examples 13 and 14 and Comparative Example 3 was placed in a fixing section of a copying machine, and a paper passing durability test was performed at a surface temperature of 200 ° C. Table 3 shows the results.
Shown in

[0065]

[Table 3]

As is clear from Table 3, in the peeling test, peeling between the metal substrate and the primer layer did not occur in any of Examples 13 and 14 and Comparative Example 2 initially, and the primer layer was broken. However, it was found that there was a large difference in the peel strength after passing 200,000 sheets.

Further, when a durability test was performed by continuous paper passing in a copying machine incorporating the heating rollers of Examples 13 and 14, no abnormality occurred even for 500,000 sheets.
On the other hand, in the copying machine incorporating the heating roller of Comparative Example 2, delamination occurred between the metal base material and the primer layer after passing 300,000 sheets.

As described above, the heating member of the present invention has a higher adhesive strength between the metal substrate and the surface layer than the conventional product, and has excellent durability even when actually used under heating conditions. I knew it was there.

[0069]

The heating member of the present invention is particularly excellent in the adhesiveness between the metal substrate and the releasable fluororesin layer as compared with the conventional product, and hardly changes with time even under severe conditions.
The metal substrate and the fluororesin do not peel off for a long time. Further, the primer composition used for the heating member has excellent adhesion between the metal substrate and the fluororesin and its durability, and can be widely used for improving the adhesion between the metal substrate of the heating member and the fluororesin.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of an electrostatic electronic copying machine using a fixing roll as an example of a heating member of the present invention.

FIGS. 2A to 2C are schematic views showing steps of a tape peeling test method for evaluating the adhesion between a metal substrate and a primer layer.

FIG. 3 is a schematic view showing an outline of a peeling test method using a load cell for evaluating the adhesion between a cylindrical metal base material and a primer layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal core roll 2 Lamp 3 Fluororesin layer 10 Heating roller 20 Pressure roller

Claims (13)

[Claims] 1. A heating member comprising a substrate and a fluororesin layer formed on a surface of the substrate via a primer layer, wherein the primer layer is formed of a primer composition containing a silane coupling agent, a fluororesin and a heat-resistant resin. A heating member, comprising: 2. The heating member according to claim 1, wherein the primer layer comprises a first layer mainly containing a silane coupling agent and a second layer containing a fluororesin and a heat-resistant resin. 3. The heating member according to claim 1, wherein the fluororesin is a tetrafluoroethylene-perfluoroalkoxyethylene copolymer. 4. The heating member according to claim 1, wherein the silane coupling agent is a compound represented by the following general formula (I). ## STR1 general formula (I) (X) in _4-n -Si- (OR) n Formula, R represents a methyl or ethyl group, X is a vinyl group, an epoxy group, methacryl group, a mercapto group, an amino Represents a monovalent organic group containing a group. n represents an integer of 2 to 4. 5. The heating member according to claim 1, wherein the heat-resistant resin is at least one selected from the group consisting of polyimide, polyamide imide, polyether sulfone, and polyphenylene sulfide. 6. The heating member according to claim 1, wherein the heating member has a base made of a metal member. 7. The heating member according to claim 1, wherein the heating member has a hollow cylindrical member as a base. 8. The heating member according to claim 1, wherein the heating member is a heating roller having a metal hollow cylindrical core roll as a base. 9. A method of applying a primer composition containing a silane coupling agent, a fluororesin and a heat-resistant resin on the surface of a substrate, forming a primer layer by drying, and forming a fluororesin layer on the primer layer. A method for producing a heating member, characterized in that: 10. A primer first solution containing a silane coupling agent is applied to the surface of the substrate and dried to form a first primer layer. Thereafter, a fluororesin and a heat-resistant resin are formed on the first primer layer. A primer second solution containing is applied and dried to form a primer second layer, and further, a fluororesin layer is formed on the primer second layer, the heating member according to claim 9, Production method. 11. The method according to claim 9, wherein the fluororesin layer is formed by any one of an electrostatic coating method, a dispersion method, and a tube insertion method. . 12. A primer composition comprising a silane coupling agent, a fluororesin, and a heat-resistant resin, which is used for forming a primer layer of a heating member according to any one of claims 1 to 8. 13. A heating element according to claim 1, comprising a first liquid containing a silane coupling agent as a main component and a second liquid containing a fluororesin and a heat-resistant resin. A two-layer primer composition comprising: