JP2015196261A - Method of manufacturing resin bottle and method of manufacturing seamless belt for electrophotography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of stably manufacturing a high strength resin bottle having reduced fluctuation of film thickness, and a method of manufacturing a seamless belt for electrophotography.SOLUTION: In a method of manufacturing a seamless belt for electrophotography, which includes a first process of heating a bottom-closed preform 101, a second process of putting the heated preform into a blow mold 103 and expanding the preform while drawing it in the longitudinal direction to obtain a bottle-shaped molded product 112, and a third process of cutting and removing a mouth part and a bottom part to obtain a seamless belt for electrophotography, the first process comprises the steps of inserting a nozzle into the preform 101 and relatively moving the nozzle with respect to the preform 101 while injecting heated air to an inner wall of the preform 101, thereby heating the preform 101.

Description

  The present invention relates to a method for producing a resin bottle and a method for producing an electrophotographic seamless belt.

  As a method for producing a seamless belt for electrophotography such as a resin bottle represented by a PET bottle or a toner bottle or an intermediate transfer belt, stretch blow molding disclosed in Patent Document 1 expands and stretches a heated preform. . For this reason, molecular orientation occurs, and the strength of the bottle and the belt can be greatly improved, and the film thickness variation can be relatively reduced. Therefore, it is preferable as a method for producing a resin bottle or an electrophotographic seamless belt.

On the other hand, with the recent increase in awareness of resource saving, there is an increasing need for weight reduction in resin bottles. Therefore, in order to reduce the film thickness of the resin bottle and maintain the strength, it is required to make the film thickness in the circumferential direction and the axial direction of the bottle as uniform as possible, that is, to further reduce the film thickness variation.
In addition, in addition to the same needs for resin bottles as for seamless belts for electrophotography, it is also necessary to further reduce image color shifts caused by film thickness fluctuations from the viewpoint of high image quality. It has been.

  In order to reduce the film thickness fluctuation of the resin bottle and electrophotographic seamless belt produced by the stretch blow molding, a rod-shaped cartridge heater having a large diameter portion at the end is inserted into the preform, and the preform is A method of heating is disclosed in Patent Document 2.

JP 2006-103260 A JP 62-077919 A

  However, as a result of investigations by the present inventors, it has been found that the method of inserting a rod-shaped cartridge heater having a large diameter portion at the end inside the preform has the following problems.

  As described in Patent Document 2, a rod-shaped cartridge heater having a large-diameter portion at the end tends to increase the intensity of radiant heat at both ends of the heater. And, the phenomenon that the film thickness of the bottle corresponding to the preform part having the same height as the both ends of the heater becomes thinner than the film thickness of the bottle corresponding to the other part of the preform, that is, the end of the bottle body part. There was a phenomenon in which the film thickness fluctuation increased in the area.

  Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a method for stably producing a resin bottle and an electrophotographic seamless belt in which fluctuations in film thickness are sufficiently suppressed.

The method for producing a resin bottle according to the present invention includes:
A first step of heating a preform comprising a thermoplastic resin having a test tube shape with a closed bottom;
The heated preform is placed in a blow mold, stretched in the longitudinal direction of the preform using a stretching rod, and a bottle is formed by inflating the preform by flowing a gas into the preform. A second step of obtaining a molded product,
A method for producing a resin bottle having
The first step is
In the preform,
The body,
A heating element inserted into the enclosure for heating the gas supplied into the enclosure;
A nozzle for ejecting heated gas through the housing;
Inserting a heater comprising:
A step of heating the preform by causing the heater inserted into the preform to move relative to the preform while jetting heated gas from the nozzle toward the inner wall of the preform. It is characterized by including.

The method for producing a seamless belt for electrophotography according to the present invention includes:
A first step of heating a preform comprising a thermoplastic resin having a test tube shape with a closed bottom;
The heated preform is placed in a blow mold, stretched in the longitudinal direction of the preform using a stretching rod, and a bottle is formed by inflating the preform by flowing a gas into the preform. A second step of obtaining a molded product,
A third step of obtaining a seamless belt for electrophotography by cutting and removing the mouth and bottom of the bottle-shaped molded product, and a method for producing a seamless belt for electrophotography,
The first step is
In the preform,
The body,
A heating element inserted into the enclosure for heating the gas supplied into the enclosure;
A nozzle for ejecting heated gas through the housing;
Inserting a heater comprising:
A process of heating the preform by causing the heater inserted into the preform to move relative to the preform while ejecting heated air from the nozzle toward the inner wall of the preform. It is characterized by including.

  ADVANTAGE OF THE INVENTION According to this invention, the high intensity | strength resin bottle with which the film thickness fluctuation | variation was reduced can be provided stably. In addition, according to the present invention, it is possible to stably provide a seamless belt for electrophotography with reduced color shift and excellent image quality.

1 is a schematic cross-sectional view showing an example of a full-color electrophotographic apparatus using an electrophotographic process. It is the schematic which shows an example of the injection molding apparatus used in the Example. It is the schematic which shows an example of the stretch blow molding machine used in the Example. It is the schematic which shows an example of the seamless belt for electrophotography. It is the schematic which shows an example of the preform produced by this invention. It is the schematic which shows an example of the heater used in the Example. It is the schematic which shows an example of the heater used in the Example.

  The present inventor has repeatedly studied a method for suppressing film thickness fluctuations of bottles and belts without using a cartridge heater using radiant heat as in Patent Document 2. As for the deterioration of the heating element, a method other than radiant heat was examined, and the idea was reached that the heated gas was ejected from the nozzle, that is, convection heat was used.

Next, it is clear from Patent Document 2 that it is preferable to make the heat distribution on the inner wall of the preform constant in order to suppress film thickness fluctuation. When convection heat is used, as the distance from the nozzle increases, the temperature of the gas ejected from the nozzle rapidly decreases because of mixing with the surrounding gas. By simply inserting a heater that ejects heated gas from the nozzle into the preform, the temperature of the inner wall of the preform that is close to the nozzle increases. On the other hand, the temperature of the inner wall of the preform, which is far from the nozzle, decreased, and the variation in the heat distribution of the inner wall of the preform increased.
As a result of paying attention to the positional relationship between the position of the nozzle and the inner wall of the preform and as a result of repeated studies, the convection heat can be brought into contact with the inner wall of the preform evenly by moving the heater relative to the preform. The variation in heat distribution could be made very small.

  Hereinafter, preferred embodiments of the present invention will be described in detail.

[Production method of resin bottle]
The method for producing a resin bottle according to the present invention includes:
A first step of heating a preform comprising a thermoplastic resin having a test tube shape with a closed bottom;
The heated preform is placed in a blow mold, stretched in the longitudinal direction of the preform using a stretching rod, and a bottle is formed by inflating the preform by flowing a gas into the preform. A second step of obtaining a molded product,
Have

And the first step is
Insert a heater into the preform,
The heater inserted into the preform is moved relative to the preform while ejecting a gas at a predetermined temperature from the nozzle of the heater toward the inner wall of the preform. Heating.
The heater is
The body,
A heating element inserted into the housing;
A nozzle serving as a gas outlet in the casing heated by the heating element;
It comprises.

[Method for producing seamless belt for electrophotography]
The method for producing a seamless belt for electrophotography according to the present invention includes the first step, the second step, and the following third step:
A third step of obtaining a seamless belt for electrophotography by cutting and removing the mouth and bottom of the bottle-shaped molded product.

In the present invention, a uniform heat distribution can be obtained on the inner wall of the preform in the first step, and a bottle-shaped molded product in which film thickness variation is greatly suppressed by stretch blow molding in the second step. Can be obtained.
Hereinafter, embodiments of the first to third steps will be described in detail. However, the present invention is not limited to these embodiments.

(First step)
In the first step, for example, a test tube-shaped preform is first prepared by an injection molding method or the like using pellets containing a crystalline thermoplastic resin. It is preferable that the pellets used at this time are sufficiently dried before injection molding. This is because by sufficiently drying the pellets, it is possible to suppress a decrease in moldability and mechanical properties due to a decrease in molecular weight during molding. As the dry state, the moisture content is preferably 0.01% by mass or less, and particularly preferably 0.005% by mass or less.

The crystalline thermoplastic resin is not particularly limited as long as the characteristics of the present invention can be satisfied. Examples of the crystalline thermoplastic resin include crystalline thermoplastic resins such as polypropylene (homo, block and random copolymers), polyethylene terephthalate, polyethylene naphthalate, polylactic acid, and polyamide. These resins may be used alone or in combination of two or more. However, it is not limited to the said material.
Among these, preferred crystalline thermoplastic resins include polyethylene terephthalate, polyethylene naphthalate, and “MX nylon” (trade name, crystalline polyamide, manufactured by Mitsubishi Gas Chemical Co., Ltd.), which are crystalline resins having a low crystallization rate. Can be mentioned. By using these resins, a stronger resin bottle and a seamless belt for electrophotography can be produced.
Further, the blending ratio of the crystalline thermoplastic resin contained in the preform is preferably 50% by mass or more as the blending amount capable of forming the preform into a bottle shape. However, it may be less than 50% by mass if a bottle-shaped molded product with molecular orientation can be produced. The pellet may appropriately contain a conductive agent, a colorant, a lubricant, etc. in addition to the crystalline thermoplastic resin.

  As a method of producing a test tube-shaped preform by an injection molding method, for example, there is a method of producing by using an injection molding apparatus shown in FIG. The pellet containing the crystalline thermoplastic resin is put into a hopper 107 and plasticized by being sheared by a screw 113 inside the heating cylinder 108 while being heated to a melting point (Tm) of the crystalline thermoplastic resin or higher by the heating cylinder 108. To do.

  The plasticized preform material is injected from a nozzle at the tip of the heating cylinder 108 into a test tube-shaped mold and cooled to produce the test tube-shaped preform 101. The test tube-shaped mold includes a cavity mold 109, a mounting mold 110, and a core mold 111. The test tube shape is a cylindrical shape having a lower end (hereinafter referred to as an opening) and a closed shape with a U-shape or a flat upper end (hereinafter referred to as a bottom). The size of the preform 101 is appropriately selected depending on the target belt size and strength.

A test tube-shaped preform 101 produced by injection molding or the like is placed in a blow molding apparatus shown in FIG. 3 and heated in the heating furnace 102 to a glass transition temperature (Tg) or higher.
Heating in the heating furnace 102 is performed by, for example, inserting the heater 120 into the rotating preform 101 and blowing the gas at a predetermined temperature from the heater nozzle toward the inner wall of the preform. Move relative to the reform.

FIG. 6 shows an example of the heater. As shown in FIG. 6, the heater 120 includes a casing 601, a heating element 602 inserted into the casing, and a nozzle 603. The gas supplied into the housing 601 is heated by the heating element 602. Then, the gas heated by the heating element through the housing is ejected from the nozzle 603.
Here, the heater may be provided with a temperature sensor 604 between the heating element and the nozzle for ejecting convection heat so that the temperature of the gas heated by the heating element can be measured.
Even if the heating element has deteriorated over time by making the output of the heater variable according to the detected temperature so that the detected temperature detected by the temperature sensor is constant, the temperature of the gas ejected from the nozzle Can be maintained at a constant temperature. As a result, the temperature of the convection heat can be stabilized and the preform can be heated more uniformly.
The nozzle 603 serves as a gas outlet in the housing 601 heated by the heating element 602. The temperature sensor 604 is disposed between the nozzle 603 and the heating element 602. The control unit controls the output of the heating element 602 according to the temperature of the gas detected by the temperature sensor 604 so that the temperature of the gas ejected from the nozzle 603 becomes a predetermined temperature.

While the heated air is ejected from the nozzle and the heater inserted into the preform is moved relative to the preform, the inner wall of the preform is heated to Tg of the crystalline thermoplastic resin or more. Various heat distributions can be formed.
In addition, when the heating of the preform 101 is insufficient with only the heater, an outer wall heater capable of heating the outer wall of the preform 101 may be used in combination. In this case, the outer wall heater is preferably a horizontal type and divided into three or more parts in the vertical direction. By controlling several heaters independently, the heat distribution on the outer wall of the preform 101 can be made uniform. More preferably, the outer wall heater is divided into five or more parts.

Although there is no restriction | limiting in particular regarding the kind of heater, A halogen heater, a far-infrared heater, an IH heater, etc. can be used. The outer wall heater is not suitable for heating the inner wall of the preform because it is difficult to insert the outer wall heater into the inner wall of the preform from the viewpoint of length and size.
The heating temperature of the preform 101 is not particularly limited as long as it is a thermometer, but a non-contact thermometer is preferable so that blow molding can be performed after the measurement, and a radiation thermometer is particularly preferable. However, since the emissivity differs depending on the measurement object, it is necessary to measure the emissivity of the object before measurement.

The heater housing for heating the inner wall of the preform has a built-in heating element for heating the gas and is not particularly limited as long as it is a member that is not easily deteriorated by the heat of the heater. A heat resistant glass such as a metal such as quartz or quartz is preferred.
The nozzle of the heater is not particularly limited as long as it is a member that is not easily deteriorated by the heat of the heater, but heat resistant glass such as quartz is preferable from the viewpoint of design freedom of shape.
The temperature sensor of the heater is composed of a thermocouple made of a thermocouple element such as copper or iron and constantan, chromel and alumel, platinum and platinum rhodium. The position of the temperature sensor needs to be provided between the heating element and the nozzle from the viewpoint of accurately measuring the temperature of the heated gas.
The heating element of the heater is not particularly limited as long as it can heat the gas to a high temperature, but nichrome, tantalum, iron-chromium alloy, platinum alloy and the like are preferable, and from the viewpoint of suppressing crystallization of the preform, It is preferable to eject a large amount of the gas from the nozzle. The temperature of the gas ejected from the nozzle is preferably 300 ° C. or higher, more preferably 500 ° C. or higher. The gas flow rate is preferably 5 L / min or more, and more preferably 10 L / min or more. The type of gas is not particularly limited as long as there is no danger, but air or nitrogen is preferable.

The heater inserted into the preform needs to be moved relative to the preform. When there is no relative movement, the inner wall of the preform near the nozzle is heated more, and the heat distribution of the inner wall of the preform is not uniform. Although the direction of the relative movement is not limited, it is preferable to move in a direction perpendicular to the cross section of the opening of the preform test tube shape from the viewpoint of forming a uniform heat distribution on the inner wall of the preform.
The speed of relative movement is appropriately adjusted so that the heat distribution on the inner wall of the preform is uniform according to the shape of the preform, the shape of the heater, the gas heating temperature and the gas flow rate ejected from the nozzle of the heater, etc. can do.

(Second step)
In the second step, as shown in FIG. 3, the mouth portion of the preform 101 heated to Tg or more is sandwiched between the sealed blow molds 103, and the stretching rod 104 is used in the longitudinal direction of the preform 101. Stretch. At the same time, gas is caused to flow into the preform 101 from the gas inlet 106 which is the mouth portion of the preform 101 and is expanded in the lateral direction. Thereby, the resin bottle or the bottle-shaped molded product 112 is produced. The gas blown into the preform 101 is not limited to air but can be selected from nitrogen, carbon dioxide, argon and the like.

  In the present invention, Tg represents the glass transition temperature of the crystalline thermoplastic resin, and Tm represents the melting point of the crystalline resin constituting the bottle-shaped molded product 112. Tg and Tm are values measured using a differential scanning calorimeter (DSC: trade name “DSC-823”, manufactured by METTLER TOLEDO) for a sample cut out from the bottle-shaped molded product 112.

(Third step)
In the third step, the mouth portion 401 and the bottom portion 402 shown in FIG. 4A of the bottle-shaped molded product 112 heat-treated in the second step are cut and removed to obtain an electrophotographic seamless belt 403 having a desired size. . FIG. 4B is a perspective view of the obtained electrophotographic seamless belt.
The film thickness of the electrophotographic seamless belt thus obtained is preferably in the range of 40 to 300 μm. If it is less than 40 μm, the molding stability is insufficient, film thickness unevenness is likely to occur, the durability is insufficient, and the electrophotographic seamless belt may break or crack. On the other hand, if it exceeds 300 μm, the required materials increase and the cost increases, and the difference in peripheral speed between the inner surface and outer surface of the tension shaft part such as a printer increases, causing problems such as image scattering due to contraction of the outer surface. Cheap. Furthermore, since the bending durability is deteriorated and the rigidity of the electrophotographic seamless belt becomes too high, the driving torque is increased, resulting in a problem that the main body is increased in size and cost.

  The above-described embodiment relates to a single-layer resin bottle or a seamless belt for electrophotography. However, in the case of a resin bottle or a seamless belt for electrophotography composed of a plurality of layers, two or three layers of preforms are used. It is the same except that. As a method for forming a preform with a multilayer structure, a method of forming a second layer or more after performing a one-layer molding called two-color molding in the injection molding is preferable.

  The heater inserted into the preform needs to be relatively moved, but the second direction is performed immediately after completion of the heating of the preform in order to prevent the preform from crystallizing and rupture due to a temperature drop. It is preferable. In addition, after a uniform heat distribution is formed on the inner wall of the preform, an extra thermal history is applied when the heater is pulled out, and the heat distribution on the inner wall of the preform may vary.

From the viewpoint of suppressing crystallization of the preform, preventing rupture, and suppressing variation in heat distribution, it is preferable to pull out the heater immediately after the heating of the preform. Therefore, it is preferable to move the heater from the preform bottom 502 to the opening 501 shown in FIG.
The movement from the bottom of the preform toward the opening may be repeated a plurality of times. Since the preform generally has a bottom surface on the opening side, the movement from the bottom side to the opening side is defined as falling, and the movement from the opening side to the bottom side is defined as rising.

  In the case where the heater is disposed on the bottom side which is a closed shape and the case where the heater is disposed on the opening side, the convection occurs when the gas is disposed around the inner wall of the bottom portion when the heater is disposed on the bottom side. It is easy to heat the entire inner wall of the preform relatively. Therefore, in order to form a more uniform heat distribution, it is preferable that the moving speed of the heater be higher on the opening side than on the bottom side of the preform.

  From the viewpoint of forming a uniform heat distribution on the inner wall of the preform, the gas ejection direction of the heater nozzle should be at least on the bottom side of the preform with respect to the opening cross section of the test tube shape of the preform. This is preferable from the viewpoint of facilitating heat transfer to the inner wall of the bottom of the reform. As for the gas ejection direction, the direction parallel to the opening cross section is defined as 0 °, and the direction perpendicular to the opening cross section is defined as 90 °.

  A plurality of nozzles of the heater may be provided, and according to the shape of the preform, the shape of the nozzle can be appropriately adjusted so that the heat distribution on the inner wall of the preform is uniform.

[Electrophotographic equipment]
The electrophotographic apparatus according to the present invention includes an electrophotographic seamless belt manufactured by the method according to the present invention. The electrophotographic seamless belt produced by the method according to the present invention can be used as an intermediate transfer belt, a transfer material conveying belt, a fixing belt, a photoreceptor belt, or the like in an electrophotographic apparatus.

  An electrophotographic apparatus using the electrophotographic belt according to the present invention will be described with reference to FIG. The electrophotographic apparatus of this embodiment has a so-called tandem configuration in which image forming stations of a plurality of colors are arranged side by side in the rotation direction of the electrophotographic belt of the present invention (hereinafter also referred to as “intermediate transfer belt”). . In the following description, subscripts of Y, M, C, and K are added to the reference numerals for the respective colors of yellow, magenta, cyan, and black, but the subscripts are omitted for similar configurations. There is also a case.

Reference numerals 1Y, 1M, 1C, and 1K in FIG. 1 denote photosensitive drums (photosensitive members or image carriers), and around the photosensitive drum 1, charging devices 2Y, 2M, 2C, and 2K, exposure devices 3Y, 3M, 3C, 3K, developing devices 4Y, 4M, 4C, and 4K, and an intermediate transfer belt (intermediate transfer member) 6 are disposed. The photosensitive drum 1 is rotationally driven in the direction of arrow F at a predetermined peripheral speed (process speed). The charging device 2 charges the peripheral surface of the photosensitive drum 1 to a predetermined polarity and potential (primary charging).
The laser beam scanner as the exposure device 3 outputs a laser beam modulated on / off in accordance with image information input from an external device such as an image scanner (not shown) or a computer, and performs a charging process on the photosensitive drum 1. Scan exposure of the surface. By this scanning exposure, an electrostatic latent image corresponding to target image information is formed on the surface of the photosensitive drum 1.

  The developing devices 4Y, 4M, 4C, and 4K contain toner of each color component of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Then, the developing device 4 to be used is selected based on the image information, and development with a developer (toner) is performed on the surface of the photosensitive drum 1, and the electrostatic latent image is visualized as a toner image. In this embodiment, a reversal development method is used in which toner is attached to the exposed portion of the electrostatic latent image and developed. The charging device, the exposure device, and the developing device constitute an image forming unit.

  Further, the intermediate transfer belt 6 is an endless belt and is disposed so as to be in contact with the surface of the photosensitive drum 1 and is stretched around a plurality of stretching rollers 20, 21, and 22. And it rotates in the direction of arrow G. In this embodiment, the tension roller 20 is a tension roller that controls the tension of the intermediate transfer belt 6 to be constant, the tension roller 22 is a driving roller for the intermediate transfer belt 6, and the tension roller 21 is for secondary transfer. It is a counter roller. Further, primary transfer rollers 5Y, 5M, 5C, and 5K are disposed at primary transfer positions facing the photosensitive drum 1 with the intermediate transfer belt 6 interposed therebetween, respectively.

  Each color unfixed toner image formed on the photosensitive drum 1 is applied to a primary transfer roller 5 by applying a positive primary transfer bias having a polarity opposite to the toner charging polarity by a constant voltage source or a constant current source. Primary transfer is sequentially performed on the intermediate transfer belt 6 in an electrostatic manner. Then, a full color image is obtained in which four color unfixed toner images are superimposed on the intermediate transfer belt 6. The intermediate transfer belt 6 rotates while carrying the toner image transferred from the photosensitive drum 1 in this way. For each rotation of the photosensitive drum 1 after the primary transfer, the surface of the photosensitive drum 1 is cleaned of transfer residual toner by the cleaning device 11 and repeatedly enters an image forming process.

At the secondary transfer position of the intermediate transfer belt 6 facing the conveyance path of the recording material 7, the secondary transfer roller (transfer unit) 9 is brought into contact with the toner image carrying surface side of the intermediate transfer belt 6. Further, a DC bias, which is a counter electrode of the secondary transfer roller 9, can be applied to the back surface side of the intermediate transfer belt 6 at the secondary transfer position, that is, the surface opposite to the toner image carrying surface. The opposing roller 21 is brought into contact.
When the toner image on the intermediate transfer belt 6 is transferred to the recording material 7, a DC bias having the same polarity as the toner is applied to the opposing roller 21 by the transfer bias applying unit 28, for example, −1000 V to −3000 V is applied to −10 μA. A current of -50 μA flows. The transfer voltage at this time is detected by the transfer voltage detection means 29. Further, a cleaning device (belt cleaner) 12 for removing toner remaining on the intermediate transfer belt 6 after the secondary transfer is provided on the downstream side of the secondary transfer position.

  The recording material 7 introduced into the secondary transfer position is nipped and conveyed at the secondary transfer position, and at that time, a constant voltage controlled by the secondary transfer bias applying means 28 to the opposing roller 21 of the secondary transfer roller 9 at a predetermined level. A bias (transfer bias) is applied. A transfer bias having the same polarity as the toner is applied to the opposing roller 21 so that the four-color full-color image (toner image) superimposed on the intermediate transfer belt 6 at the transfer site is collectively transferred to the recording material 7 and recorded. A full color unfixed toner image is formed on the material. The recording material 7 that has received the transfer of the toner image is introduced into a fixing device (not shown) and fixed by heating.

Specific examples according to the present invention are shown below, but the present invention is not limited thereto.
[Evaluation]
The produced preform, resin bottle and electrophotographic seamless belt were evaluated by the following methods.

(Temperature fluctuation amount of inner wall of preform)
After heating the preform, a radiation thermometer was inserted into the preform, and the temperature at each of the following positions A to E was measured. From this, (maximum temperature at each position) − (minimum temperature at each position) was determined, and an average value of N = 10 was defined as the amount of temperature fluctuation. It can be said that the smaller this value is, the more advantageous is the reduction of film thickness variation.

The amount of temperature fluctuation of the inner wall of the preform when the cumulative energization time of the heater used was 10 hours and 1000 hours, respectively, was examined and evaluated according to the following criteria.
○: Difference in temperature fluctuation is less than 1.5 ° C ×: Difference in temperature fluctuation is 1.5 ° C or more If the temperature fluctuation is large, the heater condition must be changed. This is necessary and significantly reduces the production stability.

(Thickness variation of resin bottles and seamless belts for electrophotography)
The center position of the body of the resin bottle and the electrophotographic seamless belt and the film thickness at positions shifted by 100 mm from the center position to the opening side and the bottom side were measured at a pitch of 20 mm in the bottle circumferential direction (total of 108 points). . From the measured value, (maximum film thickness at all measurement points) − (minimum film thickness during all measurements) was calculated, and the average value of N = 10 was defined as the film thickness variation. It can be said that the smaller this value, the more advantageous for the resin bottle drop test or the electrophotographic seamless belt color shift test described below. In addition, what was not able to be shape | molded because the bottle burst was described as x.
The film thickness fluctuation amount of the electrophotographic seamless belt when the cumulative energization time of the heater to be used was 10 hours and 1000 hours was examined and evaluated according to the following criteria.
○: Difference in film thickness variation is less than 1.5 μm ×: Difference in film thickness variation is 1.5 μm or more If the film thickness variation is large, it is necessary to change the heater conditions. Is required, and the production stability is significantly reduced.

(Resin bottle drop test)
The resin bottle is filled and sealed with 2000 mL of water, stored at a temperature of 23 ° C. for one day, and dropped from a height of 3 m on the concrete for evaluation. Ten pieces were evaluated, the number of broken pieces was examined, and evaluated according to the following criteria.

(Color shift test of seamless belt for electrophotography)
The electrophotographic seamless belt was mounted on the full-color electrophotographic apparatus shown in FIG. 1, and a line image was printed on each of 80 g / m ² paper using cyan, magenta, black, and yellow. The amount of deviation of the printed line image was measured, the amount of deviation due to the film thickness of the electrophotographic seamless belt was determined, and evaluated according to the following criteria.

(Example 1)
<Preform production>
PET resin (trade name: “TRF-8550”, manufactured by Teijin Chemicals Limited) 100% by mass

  After the PET resin was dried at a temperature of 140 ° C. for 6 hours, the PET resin was put into the hopper 107 of the injection molding apparatus shown in FIG. 2 and molded at a set temperature of 270 ° C. to produce a test tube-shaped preform 101. . The mold temperature at this time was 15 ° C. Further, the size of the preform 101 was 160 mm for the portion a in FIG. 5 and 45 mm for the portion b.

<Step 1>
The test tube-shaped preform 101 was put into a blow molding apparatus shown in FIG. 3, and the inner wall of the preform was heated. Heating is performed using an air heater (Infridge Industry Co., Ltd., shape of gas ejection part of nozzle: 1 × 26 mm rectangle, number of nozzles: 1, nozzle direction: 90 °) while rotating preform 101 at 100 rpm. went. Air heated to a temperature of 700 ° C. was ejected from the nozzle at 20 L / min.
The nozzle was inserted at a position of 140 mm so as to be perpendicular to the cross section of the preform opening when the position of the opening of the preform was 0 mm. Then, it is lowered to the opening side at a speed of 2 mm / second (first movement speed), and when it is lowered to a position of 100 mm (speed change position), it is changed to a speed of 4 mm / second (second movement speed), and then It was lowered to the opening side. The mixture was heated for a total of 50 seconds and heated to Tg or higher. The average value of N = 10 of the inner wall temperature of the preform 101 confirmed with a radiation thermometer immediately after heating was as follows, and the temperature variation was 1.7 ° C.

<Step 2>
The mouth portion of the preform 101 is sandwiched between sealed blow molds 103, and the stretching rod 10
4 was stretched in the longitudinal direction, and gas was allowed to flow into the preform 101 to swell in the lateral direction. Thus, the bottle-shaped molded product 112 was produced by biaxially stretching vertically and horizontally.
Details of the blow molding conditions are shown below.

得られた樹脂ボトルの評価結果を表６に示す。

Table 6 shows the evaluation results of the obtained resin bottle.

(Examples 2 to 7)
Except that the heater used, the heater insertion position, the first and second moving speeds, the speed changing position, the moving direction, the heating time, the shape and number of nozzles, and the gas ejection direction are as described in Table 6. In the same manner as in No. 1, a resin bottle was molded. Table 6 shows the evaluation results of these resin bottles. FIG. 7 shows the heater used in Example 7. As shown in FIG. 7 and Table 6, the number of nozzles of the heater used in Example 7 is 2, and the gas ejection direction is 45 °.

(Comparative Examples 1-3)
Except that the heater used, the heater insertion position, the first and second moving speeds, the speed changing position, the moving direction, the heating time, the shape and number of the nozzles, and the gas ejection direction are as described in Table 7. In the same manner as in No. 1, a resin bottle was molded. Table 7 shows the evaluation results of these resin bottles.

(Comparative Examples 4-6)
The heater to be used was replaced with a cartridge heater having an iron heater with a length of 140 mm, a diameter of 10 mmφ, and a thickness of 2.5 mm attached to both ends from the air heater, and radiant heat at a temperature of 700 ° C. was generated. In the process of heating the preform by doing in this way, the embodiment is the same except that the heater insertion position, first and second moving speeds, speed changing position, moving direction, and heating time are as described in Table 7. In the same manner as in No. 1, a resin bottle was molded. Table 7 shows the evaluation results of these resin bottles.

(Example 8)
<Preform production>

The PET resin was used as a crystalline thermoplastic resin, and the polyether ester amide resin was used as a conductive agent. The material was melted and kneaded at a temperature of 260 ° C. by a twin-screw extruder to uniformly mix each component, extruded as a strand having a diameter of about 2 mm, cut, and pelletized. This was used as a molding material. Next, the molding raw material is dried at a temperature of 140 ° C. for 6 hours, and then charged into the hopper 107 of the injection molding apparatus shown in FIG. 101 was produced.
The mold temperature at this time was 15 ° C. Further, the size of the preform 101 was 160 mm for the portion a in FIG. 5 and 45 mm for the portion b.

<Step 1>
The test tube-shaped preform 101 was put into a blow molding apparatus shown in FIG. 3, and the inner wall of the preform was heated. Heating is performed using an air heater (Infridge Industry Co., Ltd., shape of gas ejection part of nozzle: 1 × 26 mm rectangle, number of nozzles: 1, nozzle direction: 90 °) while rotating preform 101 at 100 rpm. went. Air heated to a temperature of 700 ° C. was ejected from the nozzle at 20 L / min.
The nozzle was inserted at a position of 140 mm so as to be perpendicular to the cross section of the preform opening when the position of the opening of the preform was 0 mm. Then, it is lowered to the opening side at a speed of 2 mm / second (first movement speed), and when it is lowered to a position of 110 mm (speed change position), it is changed to a speed of 4 mm / second (second movement speed). It was lowered to the opening side. The mixture was heated for a total of 43 seconds and heated to Tg or higher. The average value of N = 10 of the inner wall temperature of the preform 101 confirmed with a radiation thermometer immediately after heating was as follows, and the temperature variation was 1.9 ° C.

<Step 2>
The mouth portion of the preform 101 was sandwiched between sealed blow molds 103 and stretched in the vertical direction using the stretching rod 104, and gas was allowed to flow into the preform 101 to swell in the lateral direction. Thus, the bottle-shaped molded product 112 was produced by biaxially stretching vertically and horizontally.

  Details of the blow molding conditions are shown below.

<Step 3>
Next, as shown in FIG. 4, the opening part and bottom part of the bottle-shaped molded product 112 obtained in the step 2 were cut with an ultrasonic cutter to obtain a seamless belt for electrophotography having a length of 250 mm and a diameter of 225 mm. Table 11 shows the evaluation results of the obtained electrophotographic seamless belt.

(Examples 9 to 14)
Except that the heater used, the heater insertion position, the first and second moving speeds, the speed changing position, the moving direction, the heating time, the shape and number of nozzles, and the gas ejection direction are as described in Table 11. In the same manner as in No. 8, a seamless belt for electrophotography was formed. Table 11 shows the evaluation results of these electrophotographic seamless belts.

(Comparative Examples 7-9)
Except that the heater used, the heater insertion position, the first and second moving speeds, the speed changing position, the moving direction, the heating time, the shape and number of nozzles, and the gas ejection direction are as described in Table 12. In the same manner as in No. 8, a seamless belt for electrophotography was formed. Table 12 shows the evaluation results of these electrophotographic seamless belts.

(Comparative Examples 10-12)
The heater to be used was replaced with a cartridge heater from which an iron heater having a length of 140 mm, a diameter of 10 mmφ, and a thickness of 2.5 mm was attached to both ends. And, in the step of heating the preform by generating radiant heat at a temperature of 700 ° C., the insertion position of the heater, the first and second moving speeds, the speed changing position, the moving direction, and the heating time are as described in Table 12. did. Otherwise, a seamless belt for electrophotography was formed in the same manner as in Example 8. Table 12 shows the evaluation results of these electrophotographic seamless belts.

1Y, 1M, 1C, 1K Photosensitive drum (photosensitive member or image carrier)
2Y, 2M, 2C, 2K Charging device 3Y, 3M, 3C, 3K Exposure device 4Y, 4M, 4C, 4K Development device 5Y, 5M, 5C, 5K Primary transfer roller 6 Intermediate transfer belt 7 Recording material 9 Secondary transfer roller 20, 21, 22 Tension roller 28 Transfer bias applying means 29 Transfer high pressure detecting means 101 Preform 102 Heating furnace 103 Blow mold 104 Drawing rod 106 Gas inlet 107 Hopper 108 Heating cylinder 109 Cavity mold 110 Mounting mold 111 Core mold 112 Bottle-shaped moldings

Claims (10)

A first step of heating a preform comprising a thermoplastic resin having a test tube shape with a closed bottom;
The heated preform is placed in a blow mold, stretched in the longitudinal direction of the preform using a stretching rod, and a bottle is formed by inflating the preform by flowing a gas into the preform. A second step of obtaining a molded product,
A method for producing a resin bottle having
The first step is
In the preform,
The body,
A heating element inserted into the enclosure for heating the gas supplied into the enclosure;
A nozzle for ejecting heated gas through the housing;
Inserting a heater comprising:
A step of heating the preform by causing the heater inserted into the preform to move relative to the preform while jetting heated gas from the nozzle toward the inner wall of the preform. The manufacturing method of the resin bottle characterized by including.   The method for producing a resin bottle according to claim 1, wherein the first step includes a step of moving the heater inserted into the preform from the bottom of the preform toward the opening.   The manufacturing method of the resin bottle of Claim 2 which makes the speed which moves the said heater faster on the opening part side rather than the bottom part side of the said preform.   The resin bottle production according to any one of claims 1 to 3, wherein a gas ejection direction of a nozzle of the heater is at least a bottom side of the preform with respect to an opening section of the test tube shape of the preform. Method.   The method for manufacturing a resin bottle according to claim 1, wherein the heater is provided with a plurality of nozzles. A first step of heating a preform comprising a thermoplastic resin having a test tube shape with a closed bottom;
The heated preform is placed in a blow mold, stretched in the longitudinal direction of the preform using a stretching rod, and a bottle is formed by inflating the preform by flowing a gas into the preform. A second step of obtaining a molded product,
A third step of obtaining a seamless belt for electrophotography by cutting and removing the mouth and bottom of the bottle-shaped molded product, and a method for producing a seamless belt for electrophotography,
The first step is
In the preform,
The body,
A heating element inserted into the enclosure for heating the gas supplied into the enclosure;
A nozzle for ejecting heated gas through the housing;
Inserting a heater comprising:
A process of heating the preform by causing the heater inserted into the preform to move relative to the preform while ejecting heated air from the nozzle toward the inner wall of the preform. A method for producing a seamless belt for electrophotography, comprising:   The method for manufacturing a seamless belt for electrophotography according to claim 6, wherein the first step includes a step of moving the heater inserted into the preform from the bottom of the preform toward the opening.   The method for producing a seamless belt for electrophotography according to claim 7, wherein a speed at which the heater is moved is made faster on the opening side than on the bottom side of the preform.   The seamless for electrophotography according to any one of claims 6 to 8, wherein a gas jet direction of the nozzle of the heater is at least a bottom side of the preform with respect to a cross section of the opening of the test tube shape of the preform. A method for manufacturing a belt. The method for producing a seamless belt for electrophotography according to any one of claims 6 to 9, wherein the heater is provided with a plurality of nozzles.

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