JP6966368B2 - Endless belt - Google Patents

Description

The present invention relates to an endless belt.

Conventionally, endless belts have been used in various fields. The endless belt has a tubular base layer, and is usually hung under tension between rollers arranged in the base layer. Examples of this type of endless belt include an intermediate transfer belt installed in an electrophotographic apparatus such as an electrophotographic copying machine, a printer, and a printing machine. As the base layer material of the endless belt, a polycarbonate resin, a polyamide-imide resin, a polyether sulfone resin and the like are known.

The preceding Patent Document 1 comprises a tubular body containing a crystalline resin, carbon black, and a niglocin dye containing 0.5 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the crystalline resin. Intermediate transfer belts are disclosed.

Japanese Unexamined Patent Publication No. 2015-125414

However, the prior art has problems in the following points. That is, when a polycarbonate resin, a polyamide-imide resin, or a polyether sulfone resin having low crystallinity is used as the base layer material of the endless belt, depending on the heating conditions (temperature, temperature rise time, cooling time, etc.) at the time of belt molding, The crystallinity of the molecule may change and crystals may form in the base layer. The crystals in the base layer generated during belt forming behave as defects in the base layer, and thus embrittle the base layer. In addition, hard crystals cause stress concentration and thus reduce bending durability. Further, if the endless belt is left in a high temperature and high humidity environment with tension applied between the rollers, the endless belt is left to bend and deform due to the leaving. The present inventors have found that the crystals generated in the base layer in an environment of high temperature, high humidity and high load are the cause of neglected bending deformation. Further, when carbon black is contained in the base layer, carbon black becomes a nucleus at the time of crystal formation, so that crystals are likely to be formed.

The present invention has been made in view of the above background, and even when a polycarbonate resin, a polyamide-imide resin, or a polyether sulfone resin containing carbon black is used as the base layer material, crystals generated in the base layer can be suppressed. It is intended to provide endless belts.

One aspect of the present invention is an endless belt having at least a cylindrically formed base layer.
The base layer is on an endless belt containing the following components (A) to (C).
(A) At least one selected from the group consisting of polycarbonate resin, polyamide-imide resin, and polyether sulfone resin (B) Carbon black (C) Anthraquinone-based compound, isoquinoline-based compound, and perimidine-based compound. A condensed aromatic compound containing a nitrogen atom and an oxygen atom , which is at least one selected from the group.

The base layer of the endless belt contains the components (A) to (C). That is, in the base layer of the endless belt, the component (C) is added in addition to the component (B) to the component (A). Therefore, in the endless belt, crystals generated in the base layer can be suppressed. It is considered that this is because the condensed aromatic compound containing the nitrogen atom and the oxygen atom of the component (C) enters between the components (A) to prevent crystallization of the molecule. Further, the above-mentioned action and effect can be exhibited even when the component (A) contains (B) carbon black which easily promotes the crystal growth of the molecule. Therefore, the endless belt is advantageous in suppressing the embrittlement of the base layer, improving the bending durability, and suppressing the bending deformation when left unattended.

It is explanatory drawing which shows schematically the endless belt of Example 1. FIG. 2 is a sectional view taken along line II-II of FIG. It is the result of the initial differential scanning calorimetry of the sample 1 and the sample 1C in the experimental example 1. It is an enlargement of a part of FIG. 3 and is an explanatory diagram for explaining a method of measuring an endothermic peak amount.

The endless belt has at least a base layer formed in a cylindrical shape. The base layer contains at least one selected from the group consisting of (A) polycarbonate resin (PC resin), polyamide-imide resin (PAI resin), and polyether sulfone resin (PES resin). The component (A) is a resin component necessary for forming the shape of the base layer. Of the above resins, a polyamide-imide resin is preferable from the viewpoints of amorphousness, handleability at the time of belt molding, cost and the like. The resin may be modified if necessary. In addition, the above resins can be used alone or in combination of two or more.

The base layer has (B) carbon black. Carbon black is a component for imparting conductivity to the base layer. The resin of the above-mentioned component (A), which is the base of the base layer, is generally classified as an amorphous resin having low crystallinity. However, when carbon black is contained in these resins, normally, carbon black becomes the core of crystal formation, so that crystals are likely to be formed. On the other hand, in the endless belt, carbon black can be used by containing the component (C) described later in addition to the carbon black of the component (B) in the resin described above.

The content of the component (B) is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, based on 100 parts by mass of the component (A) from the viewpoint of imparting conductivity to the base layer. More preferably, it can be 3 parts by mass or more. The content of the component (B) is preferably 20 parts by mass or less, more preferably 15 parts by mass or less, still more preferably 15 parts by mass with respect to 100 parts by mass of the component (A) from the viewpoint of suppressing crystals in the base layer. It can be 10 parts by mass or less.

The base layer contains (C) a condensed aromatic compound. Here, the condensed aromatic compound contains a nitrogen atom and an oxygen atom in the molecular structure. When a condensed aromatic compound containing neither nitrogen atom nor oxygen atom is used, crystals are likely to be formed in the base layer during belt molding or when exposed to a high temperature, high humidity and high load environment. Become. As a result, embrittlement of the base layer, deterioration of bending durability, and neglected bending deformation are likely to occur.

(C) a condensed aromatic compound is anthraquinone compounds, isoquinoline compounds, and Ru at least one Der selected from the group consisting of perimidine compounds. According to this configuration, it is possible to ensure the suppression of crystals generated in the base layer. The anthraquinone-based compound can be specifically composed of anthraquinone and its derivative, the isoquinoline-based compound can be specifically composed of isoquinoline and its derivative, and the perimidine-based compound can be specifically composed of perimidine and its derivative. .. The isoquinoline-based compound can contain a chemical structure derived from the perimidine-based compound, and the perimidine-based compound can contain a chemical structure derived from the isoquinoline-based compound. A compound containing a chemical structure derived from an isoquinoline-based compound and a chemical structure derived from a perimidine-based compound is referred to as an isoquinoline / perimidine-based compound.

(C) As the condensed aromatic compound, more specifically, a compound represented by the following formula 1 and a compound containing a chemical structure derived from both the following formula 2 and the following formula 3 compound. Of these, at least one can be exemplified as a suitable one. According to this configuration, it is possible to make the suppression of crystals generated in the base layer more reliable. The chemical structure derived from the compound of the formula 2 and / or the chemical structure derived from the compound of the formula 3 can contain an oxygen atom. Further, in a compound containing a chemical structure derived from both the compounds of the formula 2 and the compound of the formula 3, the portion of the double bond shown in the compound of the formula 2 and the compound of the formula 3 can be changed depending on the bonding state of the molecule. be.

However, in the formula 1, R ₁ is independently a hydrogen atom, a hydrocarbon group having 1 or more and 20 or less carbon atoms (preferably an alkyl group), an aralkyl group, an aryl group, a hydroxyl group, an amino group, an ester group, and the like. a sulfonic acid group, or salts thereof, R ₂ are each independently C 1 to 20 hydrocarbon group carbon atoms, an aralkyl group or an aryl group. In the formula 1, R ₁ is preferably the same from the viewpoint of resin solubility and the like, and preferably all can be hydrogen atoms. In the formula 1, R ₂ is preferably the same from the viewpoint of resin solubility and the like, and preferably all are hydrocarbon groups (preferably alkyl groups), aralkyl groups, or aryl groups. be able to.

(C) The condensed aromatic compound is more specifically selected from the group consisting of the compound represented by the following formula 4, the compound represented by the following formula 5, and the compound represented by the following formula 6. At least one of these can be exemplified as a more suitable one. According to this configuration, it is possible to further ensure the suppression of crystals generated in the base layer. The compound represented by the formula 4 and the compound represented by the formula 5 are anthraquinone-based compounds. Further, since the compound represented by the formula 6 is an isoquinoline-based compound and also a perimidine-based compound, it can be said that it is an isoquinoline / perimidine-based compound. When both the anthraquinone-based compound and the isoquinoline / perimidine-based compound are contained as the component (C), the effect of suppressing the crystal of the base layer is increased, the effect of suppressing the embrittlement of the base layer, the improvement of bending durability, and the effect of suppressing the bending deformation when left unattended. An excellent endless belt can be obtained.

The content of the component (C) is preferably 0.05 part by mass or more, more preferably 0.05 part by mass with respect to 100 parts by mass of the component (A), from the viewpoint of suppressing crystal formation due to addition to the component (A). , 0.1 part by mass or more, more preferably 0.3 part by mass or more, still more preferably 0.5 part by mass or more. The content of the component (C) is preferably 20 parts by mass or less, more preferably 15 parts by mass or less with respect to 100 parts by mass of the component (A) from the viewpoint of solubility in the base layer resin and dispersibility. , More preferably, it can be 10 parts by mass or less.

The base layer may also contain one or more of various additives such as an ion conductive agent, a flame retardant, a cross-linking agent, a leveling agent, a filler, and an antioxidant, if necessary.

The cylinder diameter and thickness of the base layer can be appropriately determined according to the intended use. The cylinder diameter of the base layer can be, for example, about 120 to 1000 mm. The thickness of the base layer can be, for example, 30 to 200 μm, preferably 40 to 130 μm, and more preferably 60 to 100 μm.

The endless belt can be used for electrophotographic equipment. Specific examples of the electrophotographic apparatus include image forming apparatus such as an electrophotographic copying machine using a charged image, a printer, a facsimile, a multifunction device, and an on-demand printing machine.

Specifically, the endless belt can be used as an intermediate transfer belt. The intermediate transfer belt is an electrophotographic apparatus for primary transfer of a toner image carried on a latent image carrier to the surface of the belt and then secondary transfer of the toner image from the surface of the belt to a printing medium such as paper. It is an endless belt built into. According to this configuration, it is possible to obtain an intermediate transfer belt in which crystals are less likely to be formed in the base layer depending on the heating conditions at the time of belt molding, and the embrittlement of the base layer and the deterioration of bending durability due to the crystals are suppressed. Further, according to the above configuration, even when the belt is left in an environment of high temperature, high humidity and high load, there is little bending and deformation when left to stand, and an intermediate transfer belt having excellent transferability after being left to stand can be obtained.

The endless belt may be composed of a single layer or a plurality of layers as long as it has at least the base layer. Specifically, the endless belt is composed of (1) a single layer of a base layer, (2) a structure having a base layer and a rubber elastic layer laminated on the base layer, and (3) laminated on the base layer. It can be configured to have a surface layer formed therein, (4) a configuration having a base layer, a rubber elastic layer laminated on the base layer, and a surface layer laminated on the rubber elastic layer. Known rubber elastic layers and surface layers can be appropriately used.

In addition, each of the above-mentioned configurations can be arbitrarily combined as necessary in order to obtain each of the above-mentioned effects and effects.

Hereinafter, the endless belt of the embodiment will be specifically described with reference to the drawings.

(Example 1)
As shown in FIGS. 1 and 2, the endless belt 1 of this example has at least a base layer 2 formed in a cylindrical shape. The base layer 2 contains the following components (A) to (C).
(A) At least one selected from the group consisting of a polycarbonate resin, a polyamide-imide resin, and a polyether sulfone resin (B) Carbon black (C) A condensed aromatic compound containing a nitrogen atom and an oxygen atom.

In this example, the (C) condensed aromatic compound is an anthraquinone compound and / or an isoquinoline / perimidine compound. The content of the component (C) is 0.05 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the component (A).

Hereinafter, a plurality of samples of endless belts having different configurations were prepared and evaluated. An example of the experiment will be described.

(Experimental example)
<Preparation of additives>
The following additives were prepared as additives to be added to the base layer.
-(B) Carbon black-
・ Carbon black (manufactured by Mitsubishi Chemical Corporation, "MA11")

-(C) Condensation aromatic compound containing nitrogen atom and oxygen atom-
Isoquinoline / perimidine compound (14H-benzo [4,5] isoquino [2,1-a] perimidine-14-one, manufactured by Tokyo Chemical Industry Co., Ltd., "Solvent Red 179")
-Anthraquinone compound (1) (1,4-bis (4-methylphenylamino) -9,10-anthraquinone, manufactured by Tokyo Chemical Industry Co., Ltd., "Solvent Green 3")
-Anthraquinone compound (2) (5,8-bis (p-butylanilino) -1,4-dihydroxyanthraquinone, manufactured by Toyo Science Co., Ltd., "Gream G")
-Anthraquinone compound (3) (1,4-bis (mesitylamino) anthraquinone, manufactured by Toyo Science Co., Ltd., "Blue 2B")
-Anthraquinone compound (4) (1,4-bis (butylamino) -9,10-anthraquinone, manufactured by Wako Pure Chemical Industries, Ltd., "Solvent Blue35")

-Comparison component-
・ Aralkill modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., "KF-410")
Nigrosine dye (1) (manufactured by Tokyo Kasei Kogyo Co., Ltd., "Solvent _Black5", a compound represented by the C ₂₀ H 8 _{N 2)}
-Niglosin dye (2) (manufactured by Tokyo Chemical Industry Co., Ltd., "Solvent Black 7", compound represented by _{C 29} H ₂₄ N ₆₎

<Preparation of coating liquid for base layer>
The following materials were prepared as the coating liquid for the base layer.
-PC-based base layer coating liquid Polycarbonate resin (PC) (manufactured by Mitsubishi Engineering Plastics Co., Ltd., "Iupilon E2000") was dissolved by using NMP with blade stirring so that the solid content was 26%. Next, carbon black and, if necessary, a predetermined additive were added to this PC resin solution at the blending ratio shown in Table 1, mixed at room temperature (25 ° C.) by vane stirring, and then dispersed using a ball mill. I let you. The solid content at the time of dispersion was set to 20% by mass using NMP. Based on the above, the coating liquid for each PC-based base layer was prepared.

22 parts by mass of diphenylmethane diisocyanate (MDI) (manufactured by Nippon Polyurethane Industry Co., Ltd., "Millionate MT") and 29 parts by mass of trizine diisocyanate (TODI) (manufactured by Nippon Soda Co., Ltd., "TODI / R203"). , Trimellitic acid anhydride (TMA) (manufactured by Mitsubishi Gas Chemicals, "TMA") 36 parts by mass, α, ω-polybutadienedicarboxylic acid (manufactured by Nippon Soda, "C-1000") 20 parts by mass, N- 250 parts by mass of methyl-2-pyrrolidone (NMP) was placed in a reaction vessel equipped with a stirrer, a nitrogen introduction tube, a thermometer, and a cooling tube, and the temperature was raised to 130 ° C. over 1 hour while stirring under a nitrogen stream. Then, the reaction was carried out at 130 ° C. for about 5 hours, and then the reaction was stopped. As a result, a PAI resin solution (solid content 26% by mass) was prepared.

Next, carbon black and, if necessary, a predetermined additive were added to this PAI resin solution at the blending ratios shown in Table 2, mixed at room temperature (25 ° C.) by vane stirring, and then dispersed using a ball mill. I let you. The solid content at the time of dispersion was set to 20% by mass using NMP. Based on the above, each PAI-based base layer coating liquid was prepared.

-PES-based coating liquid for base layer Polyester sulfone resin (PES) (manufactured by Sumitomo Chemical Engineering Co., Ltd., "Sumika Excel 3600G") was dissolved by using NMP with blade stirring so that the solid content was 26%. Next, carbon black and, if necessary, a predetermined additive were added to this PES resin solution at the blending ratio shown in Table 3, mixed at room temperature (25 ° C.) with blade stirring, and then dispersed using a ball mill. I let you. The solid content at the time of dispersion was set to 20% by mass using NMP. Based on the above, each PES-based base layer coating liquid was prepared.

<Making endless belts>
After applying the above-prepared PC-based base layer coating liquid, PAI-based base layer coating liquid, or PES-based base layer coating liquid to the outer peripheral surface of the cylindrical mold by the spray coating method, normal temperature (25 ° C.) to Each of the tubular base layers (thickness 80 μm) is formed by heat treatment under the conditions that the temperature is raised to 250 ° C. for 2 hours, the temperature is maintained at 250 ° C. for 1 hour, and the temperature is naturally cooled to room temperature for 1 hour. An endless belt of the sample was formed. The endless belts of each sample are intermediate transfer belts for electrophotographic equipment.

<Measurement of fracture strain>
JIS No. 2 dumbbell type test piece is punched from the endless belt of the prepared sample, and JIS K 7161 "Plastic-How to determine tensile properties", JIS K 7127 "Plastic-Test method for tensile properties-Part 3: Film and sheet" The fracture strain was measured according to the test conditions of.

For the sample using the coating liquid for the PC base layer, the case where the fracture strain was 20% or more was designated as "A", and the case where the fracture strain was less than 20% was designated as "C". For the sample using the PAI-based base layer coating liquid, the case where the fracture strain was 13% or more was designated as "A", and the case where the fracture strain was less than 13% was designated as "C". For the sample using the PES-based base layer coating liquid, the case where the fracture strain was 11% or more was designated as "A", and the case where the fracture strain was less than 11% was designated as "C".

<Bending durability evaluation>
A strip-shaped test piece with a width of 20 mm and a length of 200 mm is punched out from the endless belt of the prepared sample, and the test piece is made in accordance with JIS P8115 "Paper and Paperboard-Folding Strength Test Method-MIT Test Machine Method". The number of breaks before breaking was measured. At this time, in this test, the measurement was performed at a load of 1.0 kgf, a bending angle of 135 °, and a bending speed of 175 cycles / min. Further, the clamp R of the bending endurance jig used was 0.38 mm.

For the sample using the coating liquid for the PC-based base layer, the case where the folding resistance was 500 times or more was designated as "A", and the case where the folding resistance was less than 500 times was designated as "C". For the sample using the PAI-based base layer coating liquid, the case where the folding resistance was 480 times or more was designated as "A", and the case where the folding resistance was less than 480 times was designated as "C". For the sample using the PES-based base layer coating liquid, the case where the folding resistance was 300 times or more was designated as "A", and the case where the folding resistance was less than 300 times was designated as "C".

<Left bending deformation test>
A strip-shaped test piece having a size of 20 mm × 200 mm was punched out from the endless belt of the prepared sample. Next, this test piece was wound in a U shape around a stainless steel round bar having a diameter of 20 mm, and a weight of 500 g was hung on both ends of the wound test piece. Then, the test piece in which the weight was hung was left in a moist heating tank at 60 ° C. × 85% RH for 24 hours. Next, this was taken out from the moist heat tank, and the left bending angle (the side in contact with the round bar) of the bent and deformed portion remaining on the test piece 30 minutes after the weight was unloaded was measured.

For the sample using the coating liquid for the PC-based base layer, the case where the standing bending angle was 80 ° or more was designated as “A”, and the case where the standing bending angle was less than 80 ° was designated as “C”. For the sample using the PAI-based base layer coating liquid, the case where the standing bending angle was 65 ° or more was designated as “A”, and the case where the standing bending angle was less than 65 ° was designated as “C”. For the sample using the PES-based base layer coating liquid, the case where the standing bending angle was 40 ° or more was designated as “A”, and the case where the standing bending angle was less than 40 ° was designated as “C”.

<Initial differential scanning calorimetry (DSC measurement)>
Initial DSC measurement was performed using a DSC measuring device (“DSC-60A” manufactured by Shimadzu Corporation). Specifically, a resin piece cut out from the base layer of the sample by an arbitrary weight (1 to 50 mg) is weighed in an aluminum sample pan, and then the sample pan is covered and crimped to obtain the sample and the sample container. I made it as close as possible to the bottom of the. After that, the first DSC measurement was performed at a heating rate of 40 ° C./min and a measurement temperature range of normal temperature to 400 ° C. under a nitrogen stream, and from the data at this time, a temperature range of 200 ° C. to 330 ° C. The amount of heat absorption peak that appeared inside was read as follows. That is, FIGS. 3 and 4 show DSC measurement results of Sample 1 and Sample 1C as an example. As shown enlarged in FIG. 4, in the temperature range of 200 ° C to 330 ° C, the point where the DSC spectrum falls and the point immediately after the rise are connected, and this is used as the baseline BL, and the arrow A in FIG. 4 is used. The endothermic peak amount (J / g) of the part was read. If no change in endothermic amount (endothermic, heat generation) was observed when the baseline BL was drawn, the endothermic peak amount was not detected. In addition, DSC measurement was performed on some samples.

<DSC measurement after neglected bending deformation test>
For the sample immediately after the above-mentioned neglected bending deformation test, a resin piece was collected from the bending deformation part deformed by a round bar, and other than using this, <initial differential scanning calorimetry (DSC measurement)>
In the same manner as above, the endothermic peak amount (J / g) after the neglected bending deformation test was measured.

The above-mentioned fracture strain measurement and bending durability evaluation are tests for confirming the influence of crystals caused by the heating conditions during belt forming. In addition, the neglected bending deformation test is a test for confirming the influence of crystals that are subsequently generated in the base layer when exposed to an environment of high temperature, high humidity and high load.

Tables 1 to 3 summarize the detailed composition of the base layer and the above test results.

According to Tables 1 to 3, the following can be seen. As shown in Table 1 (base layer resin: PC resin), the base layer of sample 1C does not contain the component (C). Therefore, in Sample 1C, crystals were likely to be generated in the base layer during belt molding or when exposed to a high temperature, high humidity and high load environment. Therefore, the sample 1C has poor fracture strain and bending resistance, and is liable to be bent and deformed when left unattended.

In sample 2C, the base layer contains aralkyl-modified silicone oil, but does not contain the component (C). Similarly, in Samples 3C and 4C, the base layer contains the niglosin dye, but does not contain the component (C). Therefore, the samples 2C to 4C, like the samples 1C, have poor fracture strain and bending resistance, and are liable to be bent and deformed when left unattended. It is considered that this is because the samples 2C to 4C tend to generate crystals in the base layer during belt forming or when exposed to a high temperature, high humidity and high load environment in view of the results of the sample 1C.

On the other hand, in Samples 1 to 5, the base layer contains the above-mentioned components (A), (B) and (C). Therefore, compared to Samples 1C to 4C, Samples 1 to 5 were able to suppress crystals generated in the base layer containing carbon black even when the belt was formed or exposed to a high temperature, high humidity and high load environment. It had good fracture strain and bending resistance, and was less likely to bend and deform when left unattended.

Further, similarly to the above, as shown in Table 2 (base layer resin: PAI resin), the samples 6 to 13 were exposed to the belt forming and the high temperature, high humidity and high load environment as compared with the samples 5C to 8C. As a result of being able to suppress the crystals generated in the base layer containing carbon black, the fracture strain and bending resistance were good, and the bending deformation was less likely to occur. Further, as shown in Table 3 (base layer resin: PES resin), the samples 14 and 15 contain carbon black as compared with the sample 9C even during belt molding or when exposed to a high temperature, high humidity and high load environment. As a result of being able to suppress the crystals generated in the base layer, fracture strain and bending resistance were good, and leaving bending deformation was unlikely to occur.

Although the examples of the present invention have been described in detail above, the present invention is not limited to the above-mentioned examples and experimental examples, and various modifications can be made as long as the gist of the present invention is not impaired.

1 Endless belt 2 Base layer

Claims (5)

An endless belt having at least a tubular base layer.
The base layer is an endless belt containing the following components (A) to (C).
(A) At least one selected from the group consisting of polycarbonate resin, polyamide-imide resin, and polyether sulfone resin (B) Carbon black (C) Anthraquinone-based compound, isoquinoline-based compound, and perimidine-based compound. A condensed aromatic compound containing a nitrogen atom and an oxygen atom , which is at least one selected from the group. The endless belt according to claim 1, wherein the content of the component (C) is 0.05 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the component (A). The condensed aromatic compound is claimed to be at least one of a compound represented by the following formula 1 and a compound having a chemical structure derived from both the compounds of the following formula 2 and the following formula 3. Item 1. The endless belt according to Item 1 or 2.

However, in the formula 1, R ₁ is independently a hydrogen atom, a hydrocarbon group having 1 or more and 20 or less carbon atoms, an aralkyl group, an aryl group, a hydroxyl group, an amino group, an ester group, a sulfonic acid group, or them. salts, R ₂ are each independently C 1 to 20 hydrocarbon group carbon atoms, an aralkyl group, or aryl group

The condensed aromatic compound is at least one selected from the group consisting of the compound represented by the following formula 4, the compound represented by the following formula 5, and the compound represented by the following formula 6. The endless belt according to any one of Items 1 to 3.

The endless belt according to any one of claims 1 to 4 , which is used for an intermediate transfer belt of an electrophotographic apparatus.

Images