JP2008026576A - Roll cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roll cover which is excellent in productivity of the roll cover, can be bonded to a roll main body with a sufficient bonding strength without performing chemical inner surface treatment of the roll cover which is dangerous and troublesome and is made of a fluorocarbon polymer excellent in bonding stability with elapse of time. <P>SOLUTION: The roll cover 40 has at least a first layer 41 and a second layer 42, wherein the first layer 41 is formed of a thermoplastic fluorocarbon polymer and the second layer 42 is formed of a thermoplastic fluorocarbon polymer containing dicarboxylic acid anhydride group. Thereby, the outer circumference surface (the first layer 41) of the roll cover 40 has non-tackiness and the inner circumference surface (the second layer 42) of the roll cover 40 can be bonded to a roll main body 20 without performing the chemical inner surface treatment. As the result, the chemical inner surface treatment is made unnecessary in a manufacturing process of the roll cover 40 and the productivity of the roll cover 40 can be extremely enhanced. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a roll cover that constitutes a part of a roll used as, for example, a heat fixing roll or a pressure roll in a copying machine or a printer.

  Copiers, printers, and the like are provided with a heat roll type fixing device that heats and fixes toner. Examples of the fixing device include a heat fixing roll and a pressure roll that is pressed against the heat fixing roll ( Hereinafter, a “roll” is provided. Such a roll is composed of a round bar-shaped roll body and a tubular roll cover covering the outer peripheral surface thereof, and the roll cover is bonded to the outer peripheral surface of the roll main body.

  Since the outer surface of the roll (roll cover) is required to be non-adhesive with a recording medium such as toner or paper, a fluoropolymer having characteristics such as heat resistance and non-adhesiveness is suitable as the material of the roll cover. A tubular body (tube) made of a fluoropolymer is generally used as a roll cover. On the other hand, since the fluoropolymer has non-adhesive properties, in order to bond the tube body (roll cover) made of the fluoropolymer to the roll body, first, the inner peripheral surface of the tubular roll cover (inner surface of the tube body) After surface-treating, it was necessary to adhere to the roll body using an adhesive.

  The inner surface treatment of a tube made of such a fluoropolymer is described in, for example, Patent Document 1, and a solution in which a complex of sodium (alkali metal) and naphthalene is dissolved in an organic solvent or sodium (alkali metal) is used. After the liquid ammonia solution dissolved in liquid ammonia is sealed inside the tube and subjected to a chemical inner surface treatment, a very troublesome treatment of washing the inside of the tube with alcohol, water, and acetone has been conventionally performed. It was.

Japanese Patent Laid-Open No. 10-60139

  In the conventional roll cover made of a fluoropolymer, as described above, an inner surface treatment of the roll cover is necessary to bond the roll cover to the roll body. Since the inner surface treatment uses metallic sodium, it is dangerous and requires a cleaning step with alcohol, water, and acetone. Thus, the productivity of the roll cover has been significantly reduced by the very troublesome inner surface treatment step.

  Further, in Patent Document 1, continuous processing is possible, excellent in productivity and workability, no deterioration of processing liquid and processing spots occur, and the processing effect is great. Describes a continuous inner surface treatment method of a fluororesin tube that can be treated with a liquid ammonia solution of an alkali metal that could not be used. However, since the continuous inner surface treatment method using a liquid ammonia solution needs to perform the inner surface treatment at a low temperature, a large facility is required.

  In addition, a method using a solution in which an alkali metal and naphthalene complex is dissolved in an organic solvent can be easily carried out as compared with a method using a liquid ammonia solution of an alkali metal. As a result, the activity of the treated surface deteriorates with time, and as a result, the adhesiveness to the roll body is lowered.

  Furthermore, when used in a place where the temperature becomes high (about 200 ° C.) such as a heat fixing roll, the adhesive strength with the roll body decreases with time, and it peels off from the roll body and has a difficulty in adhesion stability. .

  Furthermore, after the chemical inner surface treatment, it is necessary to sequentially wash the inside of the tube with alcohol, water, and acetone, which not only significantly reduces the productivity of the roll cover, but also when performing the chemical inner surface treatment. For example, when the tube body is sandwiched between pinch rollers, the surface of the tube may be damaged, creased, or wrinkled, and the print quality may deteriorate as a roll cover.

  The present invention has been made in view of the above-described circumstances, and the object of the present invention is excellent in productivity of the roll cover, and sufficient adhesion to the roll body without performing chemical inner surface treatment of the dangerous and troublesome roll cover. An object of the present invention is to provide a roll cover made of a fluoropolymer that can be bonded with strength and has excellent adhesion stability over time.

  In order to achieve the above object, the roll cover of the present invention covers a round rod-shaped roll body, and is a tubular roll cover formed of a thermoplastic fluoropolymer. The roll cover includes at least a first layer and a second layer. The first layer is formed of a thermoplastic fluoropolymer and constitutes the outer peripheral surface of the roll cover, and the second layer has a dicarboxylic anhydride group and is polymerizable unsaturated in the ring. An inner peripheral surface of the roll cover formed of a thermoplastic fluoropolymer containing a repeating unit based on a cyclic hydrocarbon monomer having a group (hereinafter also referred to as a thermoplastic fluoropolymer containing a dicarboxylic anhydride group). It is characterized by comprising.

  Thereby, since the first layer constituting the outer peripheral surface is formed of the thermoplastic fluoropolymer, the outer peripheral surface of the roll cover has non-adhesiveness, and on the other hand, the first peripheral surface constituting the inner peripheral surface in contact with the roll body. Since the second layer is formed from a thermoplastic fluoropolymer containing dicarboxylic anhydride groups, the roll main body and the inner surface of the roll can be formed without chemical inner treatment with an organic solvent or alkali metal liquid ammonia solution in which an alkali metal complex is dissolved. It is possible to adhere. As a result, in the manufacturing process of the roll, a dangerous and troublesome process of chemical inner surface treatment with an organic solvent in which an alkali metal complex is dissolved or an alkali metal liquid ammonia solution is unnecessary, and the productivity of the roll cover is significantly improved and It becomes possible to reduce the production cost of the roll.

  Furthermore, since no chemical inner surface treatment is performed, the problem of peeling of the roll cover from the roll main body can be solved without causing a temporal deterioration of the adhesive stability at a high temperature.

  In the roll cover of the present invention, the first layer is formed of a perfluoroalkoxyalkane polymer (PFA), the second layer has a dicarboxylic anhydride group, and a polymerizable unsaturated group in the ring. It is formed by the copolymer of the cyclic hydrocarbon monomer which has these, tetrafluoroethylene, and perfluoroalkyl vinyl ether. Since the first layer and the second layer are melted and integrated by, for example, two-layer extrusion molding, the first layer and the second layer are firmly bonded, and further excellent in durability and heat resistance. A roll cover can be provided.

According to the present invention, the roll cover is excellent in productivity, and can be bonded to the roll body with sufficient adhesive strength without carrying out the chemical inner surface treatment of the dangerous and troublesome roll cover. It is possible to provide a roll cover made of a fluoropolymer characterized by being excellent. And since the process of a chemical inner surface process becomes unnecessary in the manufacturing process of a roll, it becomes possible to improve the productivity of a roll remarkably, and also to reduce the production cost of a roll.
In addition, according to the present invention, it is possible to bond the roll cover and the roll body with sufficient adhesive strength without performing chemical inner surface treatment, so that no chemical inner surface treatment is required in the roll manufacturing process. In addition to significantly improving the productivity of the roll, it is also possible to improve the adhesion stability over time. This makes it possible to reduce the production cost of the rolls and to extend the life without peeling off the roll cover from the roll body when used at high temperatures. It is also possible to provide equipment.

  Hereinafter, an embodiment of a roll cover according to the present invention will be described. The embodiments described below do not limit the invention according to the claims, and all the combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. Absent.

  First, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing a part of a roll 100 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line XX of FIG.

  A roll 100 whose outline is shown in FIG. 1 is, for example, a roll used as a heat fixing roll of a copying machine, a printer or the like (hereinafter referred to as “recording apparatus”) or a pressure roll pressed against the heat fixing roll. As shown in FIG. 1, it is substantially constituted by a core metal 10, a roll body 20, and a roll cover 40.

  The cored bar 10 is a hollow or solid round bar made of a material such as metal, and is preferably formed of aluminum, but may be any type as long as it is a core part that supports the roll 100. There may be.

  The roll body 20 is a cylindrical elastic body formed by being fixed to the outer peripheral surface of the cored bar 10, and is preferably formed of silicon resin. However, the roll body 20 is not limited to an elastic body, and may be formed of metal or the like. Moreover, in embodiment shown in FIG. 1, FIG. 2, although the roll main body 20 and the metal core 10 are each comprised, it is the form of the roll 100 which utilizes the metal core 10 as mentioned later as the roll main body 20. Also good.

  As shown in FIGS. 1 and 2, the roll cover 40 is around the roll body 20 (in the case of the roll 100 using the core metal 10 as the roll body 20, the core metal 10 becomes the roll body 20. The same applies hereinafter). The tube is formed of a first layer 41 constituting the outer layer of the roll cover 40 and a second layer 42 constituting the inner layer of the roll cover 40. The second layer 42 is bonded to the outer peripheral surface of the roll body 20 via the adhesive layer 30 or a primer. The second layer 42 can be directly bonded to the outer peripheral surface of the roll body 20 without using the adhesive layer 30 or the primer. As a result, the core metal 10, the roll main body 20, and the roll cover 40 are combined, and if the core metal 10 is rotated with respect to the axial direction, the roll cover 40 also rotates integrally with the core metal 10 and the roll main body 20.

  As described above, the roll cover 40 of the present embodiment includes the first layer 41 that forms the outer layer and the second layer 42 that forms the inner layer, and the first layer 41 is formed of a thermoplastic fluoropolymer, Further, the second layer 42 is a thermoplastic fluoropolymer (hereinafter referred to as dicarboxylic anhydride) having a repeating unit based on a cyclic hydrocarbon monomer having a dicarboxylic anhydride group and having a polymerizable unsaturated group in the ring. In other words, the inner surface treatment of the conventional roll cover can be omitted from the process of manufacturing the roll 100. Below, the characteristic part of the roll cover 40 which concerns on this invention is demonstrated.

  The inventor of the present invention, as a result of earnestly researching and developing a roll cover made of a thermoplastic fluoropolymer containing a dicarboxylic acid anhydride group, results in a roll made of a thermoplastic fluoropolymer containing a dicarboxylic acid anhydride group. It has been found that the cover can be bonded to the roll body 20 via the adhesive layer 30 or primer or directly without the aforementioned surface treatment.

  Therefore, the present inventor forms the first layer 41 on the outer peripheral surface side of the roll cover 40 that comes into contact with the recording medium with a thermoplastic fluoropolymer, and adheres the roll body 20 to the adhesive layer 30 or a primer. The adhesive layer 30 or the second layer 42 bonded without using a primer was formed of a thermoplastic fluoropolymer containing dicarboxylic anhydride groups. Note that the thermoplastic fluoropolymer retains non-adhesive properties.

  Further, the inventor of the present invention provides a roll cover 40 composed of a first layer 41 formed from a thermoplastic fluoropolymer and a second layer 42 formed from a thermoplastic fluoropolymer containing a dicarboxylic anhydride group. It has been found that it can be produced by a layer extrusion method or the like, and that the first layer 41 and the second layer 42 are fused and bonded together.

  Next, the example of the preferable form of the roll cover 40 which concerns on this invention is demonstrated. First, the thermoplastic fluoropolymer applicable to the first layer 41 constituting the outer layer of the roll cover 40 is perfluoroalkoxyalkane polymer (PFA), perfluoroethylenepropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer ( ETFE) and polyvinylidene fluoride (PVdF). Among these, perfluoroalkoxyalkane polymer (PFA) or ethylene-tetrafluoroethylene copolymer (ETFE) is preferable from the viewpoint of durability, and perfluoroalkoxyalkane polymer (PFA) is the most preferable from the viewpoint of non-adhesiveness and heat resistance. Is preferred. The thermoplastic fluoropolymer that forms the first layer 41 may be mixed with a carbon-based filler in order to impart conductivity.

  Next, the diameter of the tube used as the roll cover 40 can be arbitrarily adjusted according to the size of the roll body 20. Moreover, although the thickness of the roll cover 40 can be arbitrarily selected according to the kind of roll 100 and its usage, it is generally preferably 10 to 300 μm, more preferably 20 to 150 μm. Further, the thickness of the roll cover 40 is preferably one third or more of the thickness of the roll cover 40 from the viewpoint of durability and wear resistance. The thickness of the second layer 42 is preferably 0.01 μm or more in order to ensure sufficient adhesive strength with the roll body 20.

  Further, the roll cover 40 may be a type that contracts in the radial direction or the axial direction by heat or a type that does not contract. The shrinkable type of the roll cover 40 can be arbitrarily selected depending on the type of the roll 100 and its usage.

  The thermoplastic fluoropolymer containing the dicarboxylic acid anhydride group of the second layer 42 of the roll cover 40 is a cyclic hydrocarbon monomer having a dicarboxylic acid anhydride group and having a polymerizable unsaturated group in the ring. It can be obtained by copolymerization of (monomer) and fluorine-containing monomer (monomer). Examples of cyclic hydrocarbon monomers having a dicarboxylic anhydride group and having a polymerizable unsaturated group in the ring are described below.

  In the present invention, “a cyclic hydrocarbon monomer having a dicarboxylic anhydride group and having a polymerizable unsaturated group in the ring” (hereinafter sometimes abbreviated as “cyclic hydrocarbon monomer”). Means a polymerizable compound which is a cyclic hydrocarbon composed of one or more 5-membered or 6-membered rings, and which further has a dicarboxylic acid anhydride group and an intra-ring polymerizable unsaturated group. The cyclic hydrocarbon is preferably a cyclic hydrocarbon having one or more bridged polycyclic hydrocarbons. That is, a cyclic hydrocarbon composed of a bridged polycyclic hydrocarbon, a cyclic hydrocarbon condensed with two or more of the bridged polycyclic hydrocarbon, or a cyclic hydrocarbon condensed with a bridged polycyclic hydrocarbon and another cyclic hydrocarbon. Preferably there is. Further, this cyclic hydrocarbon monomer has one or more endocyclic polymerizable unsaturated groups, that is, one or more polymerizable unsaturated groups existing between carbon atoms constituting the hydrocarbon ring. This cyclic hydrocarbon monomer further has a dicarboxylic anhydride group (—CO—O—CO—), and the dicarboxylic anhydride group may be bonded to two carbon atoms constituting the hydrocarbon ring. , May be bonded to two carbon atoms outside the ring. Preferably, the dicarboxylic anhydride group is a carbon atom constituting the ring of the cyclic hydrocarbon and bonded to two adjacent carbon atoms. Furthermore, a halogen atom, an alkyl group, a halogenated alkyl group, or other substituents may be bonded to the carbon atom constituting the ring of the cyclic hydrocarbon instead of the hydrogen atom.

Specific examples thereof are those represented by Chemical Formulas 1 to 8. Here, R in Chemical Formula 2, Chemical Formula 5 to Chemical Formula 8 is a lower alkyl group having 1 to 6 carbon atoms, a halogen atom selected from a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, in the lower alkyl group. A halogenated alkyl group in which a hydrogen atom is substituted with a halogen atom.

  The cyclic hydrocarbon monomer is preferably 5-norbornene-2,3-dicarboxylic acid anhydride (hereinafter referred to as NAH) represented by Chemical Formula 1, and Chemical Formula 2 and Chemical Formula 5 to Chemical Formula 8. , A cyclic hydrocarbon monomer in which the substituent R is a methyl group. Most preferred is NAH. Further, as the above-mentioned fluorine-containing monomer (monomer), one is selected from tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoroalkyl vinyl ether, chlorotrifluoroethylene, vinylidene fluoride, and the like. Or a combination of two or more of these can be selected and used. Furthermore, it is also possible to combine one or more of these with other monomers such as ethylene and propylene. Preferably, a combination of tetrafluoroethylene and perfluoroalkyl vinyl ether is superior from the viewpoint of heat resistance.

The ratio of the above-mentioned cyclic hydrocarbon monomer and fluorine-containing monomer (monomer) is preferably 0.01 to 3 mol% of the cyclic hydrocarbon monomer with respect to the total monomers, More preferably, it is 2 mol%.
There is no restriction | limiting in particular in the manufacturing method of the thermoplastic fluorine polymer containing the dicarboxylic anhydride group used for this invention, A general radical polymerization method is used. Examples of the polymerization method include bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization.

  Next, a method for manufacturing the roll cover 40 according to the present invention will be described. The roll cover 40 according to the present invention can be manufactured by a normal two-layer extrusion method. For example, two extruders each having a screw in a cylinder equipped with a heater are mounted in a commonly used two-layer mold so that each material can be poured from each extruder. Then, the material of the first layer 41 and the material of the second layer 42 are extruded from each extruder into a two-layer mold and distributed into two layers in the two-layer mold. The object to be molded distributed into the two layers is shaped into a desired dimensional shape using a sizing die or the like. As a method for shaping into a desired dimensional shape, a method such as a vacuum sizing method or an inside mandrel method can also be used.

  Next, the manufacturing method of the roll 100 which concerns on this invention is demonstrated. The method for manufacturing the roll 100 is an application of a conventional method for manufacturing a roll. As a conventional roll manufacturing method, for example, the following three manufacturing methods are generally implemented.

  The first manufacturing method is, for example, after forming a roll body 20 made of an elastic layer of silicone rubber, silicone foam, urethane rubber, fluorine rubber or the like having a certain thickness on the outer periphery of the metal core 10 at the center. In this method, the adhesive layer 30 is provided on the surface, and then the roll body 40 is covered with the roll cover 40.

  The second manufacturing method is, for example, a method in which a layer of the adhesive layer 30 is directly provided on the central metal core 10 and the core cover 10 is covered with the roll cover 40. That is, this method uses the cored bar 10 as the roll body 20 without forming the roll body 20, and is a method of directly covering the roll cover 40 on the cored bar 10.

  In the third manufacturing method, for example, the roll cover 40 is disposed so as to have a predetermined interval on the central metal core 10, and the material of the roll body 20, for example, unvulcanized silicone rubber is poured between them, and then In this method, the roll body 20 is formed by vulcanization.

  In the first to third manufacturing methods, a primer may be used when the roll body 20 (or the core metal 10) and the roll cover 40 are bonded.

Next, examples of the present invention will be described.

[Example 1] Roll cover A
PFA (Fluon (registered trademark) P-802UP, MFR = 2.0, manufactured by Asahi Glass Co., Ltd.) is used as the first layer material, and a thermoplastic fluoropolymer (TFE / TFE / 2) containing a dicarboxylic anhydride group as the second layer material. CF ₂ = CFO (CF ₂ ) ₃ F / NAH = 96.7 / 3.2 / 0.1 mol%) and using a two-layer extruder, the outer diameter is 29 mm and the thickness of the first layer A roll cover A having a two-layer structure of 45 μm and a second layer thickness of 5 μm was obtained.

[Example 2] Roll cover B
The first layer material is PFA (Teflon (registered trademark) 445HPJ, MFR = 4.8, manufactured by Mitsui DuPont Fluorochemical Co., Ltd.), and the second layer material is a thermoplastic fluoropolymer (TFE) containing dicarboxylic anhydride groups. / CF ₂ = CFO (CF ₂ ) ₃ F / NAH = 96.7 / 3.0 / 0.3 mol%) and using a two-layer extruder, the outer diameter is 50 mm, the thickness of the first layer A roll cover B having a two-layer structure with a thickness of 50 μm and a second layer thickness of 20 μm was obtained.
[Example 3] Roll cover C
In Example 1, a second layer using a thermoplastic fluoropolymer containing dicarboxylic anhydride groups _{(TFE / CF 2 = CFO (} CF 2) 3 F / NAH = 96.2 / 3.0 / 0.5 mole %) Was changed in the same manner as in Example 1 except that the mol% was changed.

[Comparative Example] Roll cover D
Using PFA (Fullon (registered trademark) P-802UP manufactured by Asahi Glass Co., Ltd., MFR = 2.0), a roll cover D having a one-layer structure with an outer diameter of 29 mm and a thickness of 50 μm was obtained. Next, after surface treatment of only the inner peripheral surface of the roll cover D for 10 seconds using a fluoropolymer surface treatment agent (tetraetch (registered trademark) manufactured by Junko Co., Ltd., a liquid obtained by dissolving a sodium naphthalene complex in a solvent), methanol, Water and acetone were washed in this order and dried.

[Production of rolls]
An aluminum metal core is placed in the center of the cylindrical mold, and the inner surface of the roll cover as a covering is treated with a primer for additional silicone rubber (GE Toshiba Silicone XP81-A6361 (A) (B)). An unvulcanized addition-type silicone in which a catalyst and a reinforcing agent are mixed between a metal core and a cover after the two types of coated bodies and two types of non-primer coated bodies are arranged concentrically on the metal core. Rubber was injected, primary vulcanization at 130 ° C. for 30 minutes, and secondary vulcanization at 150 ° C. for 4 hours to produce a roll.

[Evaluation Test] A roll immediately after creating a roll main body and a roll cover and a heat test and a roll left in a thermostatic bath at 230 ° C. for 1000 hours are cut out with a width of 10 mm and a length of 100 mm. After partly peeling, each end was sandwiched between chucks of a tensile tester, and the adhesive strength was measured at a tensile strength of 50 mm / min.

[Test results]
Table 1 shows the test results of the roll covers of Example 1, Example 2, Example 3, and Comparative Example.

  As described above, the embodiments and examples of the present invention have been described. According to the present invention, as can be seen from Table 1, the chemical inner surface treatment of the roll cover is excellent, which is excellent in productivity of the roll cover and is dangerous and troublesome. It is possible to provide a roll cover 40 made of a fluoropolymer characterized in that it can be bonded to the roll body with sufficient adhesive strength. Furthermore, since it is not necessary to carry out chemical inner surface treatment, there is no fear of deterioration in adhesion stability over time at high temperatures, and it is possible to extend the life. And since the process of a chemical inner surface process becomes unnecessary in the manufacturing process of the roll cover 40, it becomes possible to improve the productivity of the roll cover 40 remarkably, and also to reduce the production cost of the roll cover 40. It becomes. In addition, it is possible to provide manufacturing equipment excellent in environmental measures. Furthermore, in the manufacturing process of the roll 100, the primer treatment process is not required, so that the productivity of the roll 100 can be improved.

  The scope of the present invention is not limited to the above-described embodiments and examples, and can be applied to various other embodiments as long as they do not contradict the description of the claims. For example, in the embodiment of the present invention, the roll cover 40 has a two-layer structure including the first layer 41 and the second layer 42. However, the roll cover 40 is not limited to the two-layer structure, In the case of a multilayer structure having at least a first layer and a second layer, for example, the first layer is made of a thermoplastic fluoropolymer, the intermediate layer is made of a thermoplastic fluoropolymer containing a carbon-based filler, and the second layer The layer may be a three-layered thermoplastic fluoropolymer containing a dicarboxylic anhydride group or a layer structure of more than that.

  In this embodiment, the roll 100 has the roll main body 20 and the core metal 10. However, the roll 100 uses the core metal 10 as the roll main body 20, and the core metal 10 is the roll main body. The structure which functions as 20 may be sufficient.

  Further, the present invention can be carried out by using a thermoplastic fluoropolymer containing a dicarboxylic anhydride group and a thermoplastic fluoropolymer, but the thermoplastic fluoropolymer containing the dicarboxylic anhydride group and / or the The thermoplastic fluoropolymer is not limited to the thermoplastic fluoropolymer exemplified in the present specification, and may be any thermoplastic fluoropolymer applicable to the present invention.

  The roll cover according to the present invention and the roll including the roll cover can be applied to roll products made of fluoropolymers used in various fields, in addition to being used in heating and pressure fixing units of copying machines and printers. It is. Moreover, the manufacturing method of the roll which concerns on this invention is applicable to manufacture of these roll products.

It is a perspective view which shows a part of roll 100 which concerns on one Embodiment of this invention. FIG. 2 is a cross-sectional view taken along the line XX of FIG.

Explanation of symbols

10 cored bar, 20 roll body, 30 adhesive layer, 40 roll cover, 41 first layer, 42 second layer

Claims (4)

A tubular roll cover that covers a round rod-shaped roll body and is formed of a thermoplastic fluoropolymer, wherein the roll cover has at least a first layer and a second layer, and the first layer is thermoplastic. A repeating unit based on a cyclic hydrocarbon monomer formed of a fluoropolymer and constituting the outer peripheral surface of the roll cover, wherein the second layer has a dicarboxylic anhydride group and a polymerizable unsaturated group in the ring A roll cover characterized by comprising an inner peripheral surface of the roll cover formed of a thermoplastic fluoropolymer containing The first layer is formed of a perfluoroalkoxyalkane polymer (PFA), and the second layer is a cyclic hydrocarbon monomer having a dicarboxylic anhydride group and a polymerizable unsaturated group in the ring. 2. The roll cover according to claim 1, wherein the roll cover is formed of a copolymer of tetrafluoroethylene and perfluoroalkyl vinyl ether. The roll cover according to claim 1 or 2, wherein the cyclic hydrocarbon monomer is 5-norbornene 2,3-dicarboxylic acid anhydride. The roll cover according to any one of claims 1 to 3, wherein the cyclic hydrocarbon monomer is 0.01 to 3 mol% with respect to all monomers.

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