JPH10333478A - Releasing agent supplying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent fixed image and to make correcting and sticking with respect to a recording material sure by setting the amount of a releasing agent supplied to the surface of a fixing member at a specific value. SOLUTION: In a releasing agent supplying device 2, the quantity and uniformity of oil supplied to a fixing roll 11 are almost decided mainly by the surface roughness of a pickup roll 21. A surface layer 211 is provided on the surface of the pickup roll 21 and set so that the surface roughness Ra of the layer 211 is <=0.23 μm. Therefore, the supplied oil quantity can be kept constant within a desirable range of <=2.5 μl/one surface of the recording material. Further, a metaling blade 23 for controlling the oil with which the pickup roll 21 is coated, to obtain a uniform and proper quantity is compression-bonded in parallel with the pickup roll 21, with a predetermined pressure. By the above- mentioned constitution and operation, the surface of the fixing roll 11 is uniformly coated with the oil in the longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a releasing agent supply device used for a fixing device of an electrophotographic copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, as a fixing device having the above fixing member, as shown in FIG. 8, a fixing roll 50 and a pressure roll 51 are brought into pressure contact with each other, and an unfixed toner image 52 is placed between the two rolls 50, 51. In some cases, the unfixed toner image 52 is fixed on the recording material 53 by passing through the recording material 53 having heat and pressure. At this time, since the surface of the fixing roll 50 contacts the unfixed toner image 52, the toner may be offset to the fixing roll 50 during fixing. Therefore, a release agent such as silicone oil is applied to the surface of the fixing roll 50 by the release agent supply device 54 to prevent the toner from being offset to the surface of the fixing roll 50.

As shown in FIG. 8, the release agent supply device 54 includes an oil pan 56 containing oil 55, a felt 60 for sucking up the oil 55 from the oil pan 56 and applying the oil 55 to a pickup roll 57, and a pickup roll 57. Measuring blade 5 for scraping oil 55 applied to 57
8 and a donor roll 59 for supplying the measured oil 55 to the fixing roll 50. The pickup roll 57 and the donor roll 59
Is rotatably supported, and the pickup roll 5
Reference numeral 7 denotes the donor roll 59, and the donor roll 59 is in contact with the fixing roll 50 with a predetermined pressing force.

Now, when the fixing roll 50 rotates with the copying operation of the copying machine, the donor roll 5 pressing against the fixing roll 50 is pressed.
9, and the pickup roll 57 rotates in the direction of the arrow. After the oil 55 in the oil pan 56 is sucked up by the felt 60 and applied to the pickup roll 57, an oil film having a predetermined thickness is formed on the surface of the pickup roll 57 by the measuring blade 58. The oil film formed on the surface of the pickup roll 57 to a predetermined thickness is transferred to the surface of the donor roll 59 by contacting the donor roll 59, and is further supplied from the surface of the donor roll 59 to the fixing roll 50. .

If the amount of the oil supplied to the surface of the fixing roll 50 is too small, the offset of the toner occurs. If the amount is too large, the oil adheres to the recording material 53 and bleeds the oil. Therefore, the release agent supply device 5
The amount of oil 55 supplied by 4 needs to be an appropriate amount within a predetermined range. If the amount of the oil 55 supplied to the fixing roll 50 is not uniform in the longitudinal direction of the fixing roll 50, an offset may occur in a part of the fixing roll 50. Is required to be uniform over the longitudinal direction of the fixing roll 50.

However, this case has the following problems. That is, in the case of the release agent supply device 54, the blade 58 is simply brought into contact with the surface of the pickup roll 57 to make the amount of the oil 55 applied to the surface of the pickup roll 57 constant. ,
There is a problem that the supply amount of oil varies depending on the edge shape of the tip of the blade 58 and the like. In particular, if the pickup roll 57 or the blade 58 is replaced, there is a problem that an appropriate amount of applied oil and a uniform amount of oil over the longitudinal direction cannot be obtained.

[0007] In order to solve this problem, the present applicant has already proposed a release agent supply device as disclosed in Japanese Patent Application Laid-Open No. H5-119659.

In this release agent supplying apparatus, the surface roughness of the pickup roll 57 shown in FIG.
Ra is set so as to satisfy 5 ≦ Ra ≦ 5 μm, and the surface roughness of the donor roll 59 is adjusted so that the 10-point average roughness Ra is 0.
By configuring so that 2 ≦ Ra ≦ 3 μm,
This makes it possible to surely obtain a uniform supply amount of the release agent along the axial direction of the fixing roll of the fixing device, and to obtain a good fixed image.

[0009]

However, in the case of the above-mentioned device for supplying a release agent, a uniform amount of the release agent can be supplied. However, as a result of further research, a new problem becomes apparent. became. That is, in the above-described release agent supply device, the amount of the release agent supplied to the fixing roll is defined to be 15 to 40 μl / one side of the recording material, but the release agent in this range is supplied and fixed. It became apparent that there was a case that it was difficult to add a recording material using a ballpoint pen or a pencil, or to attach a mending tape or an adhesive / peelable memo paper to the recording material.

Therefore, the present invention has been made to solve the above-mentioned problems of the prior art, and it is an object of the present invention to obtain a good fixed image and to add to a recording material. It is another object of the present invention to provide a release agent supply device capable of reliably obtaining a uniform supply amount of a release agent over the axial direction of a roll to a fixing roll or the like of a fixing device so that bonding can be reliably performed.

[Means for Solving the Problems]

That is, in order to solve the above-mentioned problem, the present invention provides a fixing member for fixing toner on a recording material to a recording material, the fixing member being separated from the toner so that the toner is easily peeled off. In the release agent supply device for supplying the release agent, the supply amount of the release agent to the surface of the fixing member is 2.5
[Μl / one side of recording material]

The inventor of the present invention has found that the amount of the release agent within a range in which writing and adhesion can be reliably performed on a recording material output from an electrophotographic copying machine or the like and the peeling property between the toner and the fixing member is not impaired. As a result of conducting various tests, it was clarified that the above conditions should be satisfied.

Further, the present invention includes at least a first and a second roll whose surfaces rotate in contact with each other, and supplies a release agent to the first roll and is supplied to the first roll. In the release agent supply device that supplies the release agent to the surface of the fixing member via the second roll, a surface layer is provided on the surface of the first roll, and the surface roughness is Ra ≦ 0.
By setting it to be 23 μm and by forming at least the surface of the second roll with an elastic material, the supply amount of the release agent to the surface of the fixing member is set to 2.5 [μl / one side of the recording material] or less. It also does.

In the present invention, the inventor conducted various tests to find out what conditions should be satisfied in order to supply the releasing agent to the fixing roll and the like in the above amount and uniformly. It was clarified that the above conditions should be satisfied.

The first and second rolls include, for example, two rolls of a pick-up roll and a donor roll. However, the present invention is not limited thereto, and three or more rolls may be combined. May be used. Further, the donor roll is disposed so as to be in contact with the surface of the fixing roll. However, the present invention is not limited to this, and the donor roll may be in contact with a pressure roll.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the illustrated embodiment.

FIG. 1 shows a fixing device to which an embodiment of a release agent supply device according to the present invention is applied. In the figure, reference numeral 1 denotes a fixing device. The fixing device 1 includes a heating roll 11, a pressure roll 13 which is in pressure contact with the fixing roll 11 via an endless belt 12 stretched by stretching rolls 15a and 15b, and a pressure pad. 14

The core of the heating roll 11 has an outer diameter of 46 mm.
mm, an aluminum cylinder having an inner diameter of 40 mm. The surface of the core portion is coated with silicone rubber having a thickness of 2 mm and a hardness of 45 °, and the surface is further coated with a 2 μm thick viton rubber (trade name, manufactured by DuPont). The endless belt 12 has a thickness of 75 μm and a width of 300 μm.
mm, polyimide film with a circumference of 188 mm and a thickness of 17
It is coated with 0 μm silicon rubber. This endless belt 12 is made of stainless steel and has a diameter of 23 m.
It is wound with a tension of 49.8 N by a pressure roll of m and tension rolls 15 a and 15 b having diameters of 18 mm and 17 mm, respectively. The pressure roll 13 is pressed against the fixing roll 11 via the endless belt 12 with a force of 35.3 N.

The heating roll 11 and the pressure roll 13
Is heated to a predetermined temperature by heaters 8 and 9 housed therein, and passes the recording material 5 on which the unfixed toner image 6 is formed between the two rolls 11 and 13,
The unfixed toner image 6 is fixed on the recording material 5 by heat and pressure. The fixing device to which the release agent supply device according to the present invention is applied is not limited to a configuration in which such a configuration on the pressing side is configured by an endless belt, but a member having an elastic layer on the surface, for example, FIG. As in the conventional example shown in FIG. 8, fixing may be performed by a heating roll and a pressure roll.

In the vicinity of the fixing roll 2, a release agent supply device 2 for applying a release agent such as silicone oil to the surface thereof is provided.

The release agent supply device 2 includes a pickup roll (first roll) and a donor roll (second roll) whose surfaces rotate in contact with each other, and supplies the release agent to the pickup roll. At the same time, the release agent supplied to the pickup roll is supplied to the surface of the heating roll 11 via the donor roll, and a surface layer 211 is provided on the surface of the pickup roll 21 so that the surface roughness Ra ≦ It is set to be 0.23 μm, and at least the surface of the donor roll 22 is made of an elastic material. In order to uniformly control the amount of oil applied to the pickup roll 21 to an appropriate amount, a metering blade 2 is used.
3 is pressed with a predetermined pressure in parallel with the pickup roll. Furthermore, in order to supply oil as a release agent,
Oil supply pipe 2 parallel to pickup roll 21
A felt 25 is provided in contact with the pickup roll for receiving the oil, and an oil pan 2 provided below the pickup roll 21 and the metering blade 23 for storing excess oil.
Consists of six.

More specifically, the release agent supply device 2
Comprises a pickup roll 21 and a donor roll 22 whose surfaces rotate in contact with each other. The pickup roll 21 is formed by applying a hard chromium plating process as a surface layer 211 on the surface of a stainless steel cylinder, and forming a cylinder having a diameter of 19.5 mm. Having a surface roughness Ra of 0.06 μm
(≦ 0.23). The donor roll 22 is provided with a silicon rubber layer (surface roughness Ra = 1.5 μm) having a hardness of 51 degrees as an elastic layer on a stainless steel cylinder, and has a diameter of 2 mm.
It was a 0 mm cylinder. The donor roll 22 contacts the surface of the pickup roll 21 and also contacts the heating roll 11 of the fixing device 1.

Further, the metering blade 23 for uniformly controlling the oil applied to the pickup roll 21 to an appropriate amount is made of silicone rubber, and the pickup is so pressed as to press the pickup roller 21 with a predetermined pressing force. The roll is disposed over the entire length in the longitudinal direction of the roll. The material of the felt 25 for impregnating the oil supplied from the oil supply pipe 24 is Nomex felt (trade name, manufactured by Chiyoda Integra).
An oil pan 26 for receiving excess oil is provided below the oil supply pipe, the felt 25, and the metering blade 23.

The pickup roll 21 and the donor roll 22 are arranged rotatably.

Then, by rotating the fixing roll 2, the donor roll 22 and the pickup roll 21 that are in contact with the surface of the heating roll 2 are rotated. Then, the oil soaked in the felt 25 is applied to the surface of the pickup roll 21. The oil 13 adhering to the surface of the pick-up roll 21 is measured by a metering blade 23 to a predetermined amount, and becomes a film having a predetermined thickness. Excess oil is returned into the oil pan 26. The oil film formed on the surface of the pickup roll 21 is transferred to the surface of the donor roll 22 that comes into contact with the pickup roll 21, and the oil film transferred to the donor roll 22 is transferred to the heating roll 2 that comes into contact with the donor roll 22. Is applied and supplied to the surface.

In such a release agent supply device 2, the supply amount and uniformity of the oil supplied to the fixing roll (heating roll) 2 are substantially determined mainly by the surface roughness of the pickup roll 21. That is, if the surface roughness of the pickup roll 21 is not within the predetermined range, the amount of oil supplied to the surface of the heating roll 2 becomes too large or too small, or becomes uneven. Also, if the amount of oil supplied to the surface of the fixing roll is large, it becomes difficult to add a recording material after fixing and to adhere a tape.

Therefore, the present inventors first conducted an experiment for confirming the supply amount of oil which does not cause a problem in the rewriting property of the recording material after fixing and the adhesiveness of the tape. Pickup roll 2
Samples with various surface roughnesses of Sample No. 1 were prototyped and tested for oil supply. As a result, the present inventors confirmed the supply amount of the oil which does not cause a problem in the writing property to the recording material after fixing and the adhesiveness of the tape, and confirmed the supply amount (2.5 μm
/ Single-sided recording material) and the surface roughness of the pickup roll 21 that satisfies the uniformity.

Next, the contents of the above experiment will be described.

Experiment 1 (Adhesion Experiment) The present inventor conducted an experiment to confirm the supply amount of oil so as not to cause a problem in the adhesiveness of the tape. FIG. 2 shows the sample at that time. As the adhered paper, A4 copy paper having been fixed is used, an image is formed on one half thereof, and no image is formed on the other half. The reason why the white portion and the image portion are separated in this way is that the toner forming the image absorbs more oil in the image portion and the oil supply amount is larger than that in the white portion. FIG. 2A is a diagram in which a 100 mm square paper is adhered to the adhered paper with a stick-shaped glue with a width of 10 mm. FIG. 2 (b) shows a 100-mm square paper sheet adhered to the member to be adhered with a cellophane tape (trade name, manufactured by Nichiban) having a width of 9 mm and a width of 18 mm. FIG. 2C shows that the width of the bonding portion is 16 mm × 50 mm.
mm (post trade name, manufactured by 3M Company).

In the case of sticky glue or cellophane tape, the square paper is not adhered to the image portion of the adhered paper because these adhesive means cannot peel without affecting the image. This is because, in general, sticking with sticky glue or scotch tape on the image portion is rare. On the other hand, in the case of post-it, the image was not affected even if the adhesive peeling was repeated.

Twenty of these three types of samples were prepared, and as shown in FIG. 3, an external force was applied at an angle of about 45 ° to the paper to be bonded in the direction of the square paper or the post-it bonding portion. The amount of oil for supplying a force required for peeling off the paper to be adhered was measured by variously changing the amount of oil to 20, 2, 4, and 6 [μl / single-sided recording material]. In addition, the spring measurement or the push-pull cage is used for the measurement, and the spring measurement is connected to the punch hole reinforced with the seal provided at the position as shown in FIG. Was done.

FIG. 4 shows the result of the measurement, showing the amount of oil supplied to the paper to be bonded and the force required for peeling off the square paper or post-it at that time.
Further, the force necessary for preventing the bonded portion from peeling off under normal use conditions, that is, the allowable lower limit value of the bonding is 40 [gf].
It is clear from other experiments that Therefore, it was clear from the graph of FIG. 4 that the oil supply amount for obtaining the adhesiveness exceeding the allowable lower limit value of the adhesive was 2.5 [μl / single-sided recording material].

Experiment 2 (Experiment on rewriting properties) The inventor of the present invention determined whether sufficient rewriting properties could be obtained when such an amount of oil was supplied to the recording material.
The following experiment was performed. That is, an image is formed on a copy paper of A3 so as to be divided into a white background portion, a light image portion, and a dark image portion, and characters are written in each portion with a water-based ballpoint pen and an oil-based ballpoint pen. 0, 2, 5, 10
The experiment was performed by changing [μl / one-sided copy paper]. In addition, the evaluation method is to determine whether or not a plurality of subjects can read the characters written on the copy paper, for each of a water-based ballpoint pen and an oil-based ballpoint pen.
The evaluation was performed on a perfect score, and the average of the evaluations of a plurality of subjects was taken.

FIG. 5 shows the result. From the results of this experiment, it was clarified that both the water-based ballpoint pen and the oil-based ballpoint pen can provide satisfactory brushability if the oil supply amount is about 10 [μl / single-sided recording material] or less.

Experiment 3 (Pickup Roll Surface Roughness Experiment) The present inventor further attempted to realize a release agent supply apparatus satisfying an oil supply amount of 2.5 [μl / single-sided recording material] or less. A release agent supply device in which the surface roughness of the pickup roll 21 was variously changed was experimentally manufactured, and the oil supply property was tested. When the surface roughness of the pickup roll 21 is measured along the axial direction and the circumferential direction, a 10-point average roughness Ra
Various types of 0.03, 0.06, 0.23, and 0.45 μm were prepared, and the amount of oil supply when oil was supplied by such a pickup roll 21 was measured. The surface of the pickup roll 21 was cleaned with alcohol.

FIG. 6 shows the results of this experiment. The surface roughness of the pickup roll has a positive correlation with the amount of oil supply to the copy paper, and the pickup roll satisfies the oil supply amount 2.5 [μl / single-sided recording material] or less necessary to maintain the predetermined adhesiveness. 21 was found to have a surface roughness of 0.23 μm or less.

FIG. 7 shows the results of an experiment for confirming the amount of oil supply necessary for maintaining good fixing performance, that is, the lower limit of the amount of oil supply. The surface temperature of the heating roll 11 is set to 120, 130, 140, 1
The peeling property was confirmed by changing the oil supply amount to 2.5, 2.0, 1.5, and 1.1 [μl / A4 single-sided copy paper] while changing the temperature to 50 and 160 ° C. In this experiment, copy paper of thin paper (basis weight 56 to 57 gsm) which is a disadvantageous condition for peeling was used, and a fixed image was formed by superimposing three color toners of yellow, cyan and magenta to TMA 1.5. It was used. "O" in Fig. 7
Indicates that the copy paper was peeled off without any trouble.
“X” indicates that the copy sheet has been wound around a heating roll or the like or a defect has occurred in the image. As a result of this experiment,
It was determined that the lower limit of the oil supply was about 1.0 [μl / single-sided recording material]. It is also clear from the graph of FIG. 6 that even if the surface roughness of the pickup roll is formed smoothly, it does not fall below this lower limit.

Similar results were obtained whether the surface of the pickup roll was provided with a metal layer or a PFA (tetrafluoroethylene perfluoroalkylvinyl copolymer) layer. It has also been found that a predetermined amount of oil can be supplied to the heating roll 11 even if the surface of the donor roll 22 is an elastic body, without specifying the surface roughness.
The method of impregnating the felt 25 with the release agent may be a method supplied from an oil supply pipe as in the embodiment, or the oil stored in the oil pan 26 as shown in FIG. It may be something that sucks up.

In these experiments, the surface temperature of the heating roll 11 and the surface temperature of the pressure roll 13 were both set to 150 ° C. The surface speed of both rolls 11 and 13 was 264 mm / sec. The pickup roll 21 is pressed against the donor roll 22 by a pressing force of 24.5 N.
And press the donor roll 22 to the heating roll 11,
They were pressed with a pressure of 24.5N. The oil used was silicone oil, and its viscosity was 300 cst.

As is apparent from these results, by setting the surface roughness of the pickup roll 21 so that the 10-point average roughness Ra satisfies Ra ≦ 0.23 μm, it is desirable to supply the oil. It was found that the temperature can be kept constant within the range of 5 μl / single-sided recording material. When the surface of the heating roll 11 to which the oil was applied was observed, the oil was applied uniformly along the longitudinal direction of the heating roll 11.

[0041]

According to the present invention, which has the above construction and function, it is possible to obtain a good fixed image, and at the same time, it is possible to reduce the amount of the release agent which can reliably add and adhere to the recording material. It is possible to provide a release agent supply device capable of surely supplying the release agent uniformly to the fixing roll of the fixing device in the axial direction of the roll.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a fixing device to which a release agent supply device according to the present invention is applied.

FIG. 2 shows a sample used in an adhesion test.

FIG. 3 illustrates a measuring method in an adhesion test.

FIG. 4 is a graph showing the upper limit of the amount of oil supply as revealed in an adhesion test.

FIG. 5 is a graph showing the results of a rewriting experiment.

FIG. 6 is a graph showing the results of an experiment for confirming the upper limit of the surface roughness of the pickup roll.

FIG. 7 is a table showing results of an experiment for confirming a lower limit of an oil supply amount.

FIG. 8 is a configuration diagram showing a fixing device to which a conventional release agent supply device is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fixing device, 2 ... Release agent supply device, 21 ... Pickup roll, 211 ... Surface layer, 22 ... Donor roll, 24
... oil supply pipe, 25 ... felt, 26 ... oil pan

Claims (2)

[Claims] 1. A release agent supply device for supplying a release agent to a surface of a fixing member for fixing toner on the recording material to the recording material so that the fixing member and the toner are easily separated from each other. The release agent supply amount S to the fixing member surface is 1.0 [μl
/ One side of recording material] ≦ S ≦ 2.5 [μl / one side of recording material]. 2. The apparatus according to claim 1, further comprising at least a first roll and a second roll whose surfaces rotate in contact with each other, supplying a release agent to the first roll, and supplying a release agent to the first roll. In the releasing agent supply device for supplying the surface of the fixing member via the second roll, a surface layer is provided on the surface of the first roll, and the surface roughness is set so that Ra ≦ 0.23 μm. The release agent supply device according to claim 1, wherein at least a surface of the second roll is formed of an elastic body.