JP4441473B2 - Masterbatch production equipment and production method - Google Patents

Description

  The present invention relates to a master batch manufacturing apparatus and a manufacturing method, and more particularly to a master batch manufacturing apparatus and a manufacturing method for manufacturing toner used in electrophotography, electrostatic printing, and the like.

Generally, in electrophotography, an electrostatic latent image is formed on a photoconductor, and the latent image is developed using toner to obtain a toner image. Further, a method is known in which a toner image is transferred to a transfer material such as paper and then fixed to obtain a transfer product.
Such a toner is prepared by using a master batch composed of a binder resin and a pigment as a main raw material and adding raw materials such as a charge control agent and an additive. In the conventional toner manufacturing method, the toner manufacturing process includes a master batch manufacturing process, a dilution kneading process of the master batch and other raw materials, a kneaded product pulverizing process, a classifying process, and an external adding process.

In a conventional masterbatch manufacturing process, first, a predetermined amount of each of a binder resin and a pigment is weighed, then both raw materials are mixed, and the raw material mixture is supplied to a vibration feeder and uniformly dispersed.
Subsequently, in order to knead the pigment into the binder resin, the raw material mixture is vibrated by the vibration feeder, adjusted to a desired layer thickness and supply width, and supplied between the two open rolls of the kneader.
In the raw material mixture, the binder resin melts into a highly viscous fluid by the rotation and heating of both open rolls, and the pigment refined by the shearing force of the melted binder resin is kneaded into the binder resin. A master batch is rarely produced. Next, a charge control agent, wax, etc. are appropriately added to the master batch and mixed, and further heated to disperse them uniformly in the binder resin, and then cooled and solidified to prepare a kneaded product ( Dilution kneading step).

Subsequently, the kneaded material is coarsely pulverized as necessary, and further finely pulverized using a jet pulverizer or the like (kneaded material pulverizing step).
Thereafter, there is a step of removing fine particles that cause a decrease in fluidity of the obtained toner and scattering of toner in the copying machine and coarse particles that cause a decrease in image quality, and classifying the particles into a particle size distribution that can exhibit the performance as a toner. It is performed using a wind classifier or the like (classification process).
After the classification step, surface treatment (external addition step), spheroidization treatment, and the like are performed to produce a toner.

By the way, in the manufacturing process of the conventional masterbatch, when the vibration feeder is used, the binder resin and the pigment are always in a vibrating state in the vibration feeder, and the pigment does not adhere around the binder resin. The particle size of the pigment is smaller than the particle size of the binder resin. Therefore, when the binder resin and pigment are vibrated by the vibration feeder, the pigment generates dust and scatters due to the vibration, and the pigment is gradually reduced compared with the measurement, and the master batch binder resin and pigment are blended. There was a problem that the ratio changed, and a problem that the working environment deteriorated because the pigment generated dust and scattered.
Therefore, there is known a technique in which dust generation of the pigment is suppressed by supplying a binder resin and a pigment with a screw feeder instead of the vibration feeder (see, for example, Patent Document 1).
JP 2002-156790 A

  However, since the width of the raw material supplied to the screw feeder is restricted by the screw diameter, the supply width is narrow and the layer thickness is high. In particular, when the supply amount is increased, the mixed raw material deposited on the open roll cannot obtain sufficient heat until the upper layer reaches melting, causing a loss of falling by its own weight due to the rotation of the roll, resulting in productivity. There is a problem that gets worse.

  The present invention has been made in consideration of such circumstances, and produced a master batch in which the mixing ratio of the binder resin and the pigment is appropriate by suppressing the dust generation of the pigment during the production of the master batch. It is possible to provide a masterbatch manufacturing apparatus and a manufacturing method capable of improving the productivity without loss of mixed raw materials while being able to maintain a good working environment.

In other words, the present invention includes a raw material conveyance unit that conveys and discharges a granular raw material to a predetermined position, and a kneading unit that melts and kneads the raw material discharged from the raw material conveyance unit, and the raw material conveyance unit carries the raw material The present invention provides a master batch manufacturing apparatus provided with a belt conveyor for transporting.
The raw material transport unit may include a regulating member that regulates the height of the raw material mounted on the belt conveyor.
The raw material conveyance unit may include an adjustment unit that adjusts the regulated height of the regulating member.
In another aspect of the present invention, from another viewpoint, the master batch production apparatus is used, and a powdery raw material containing a binder resin and a pigment is supplied to a kneading part via a raw material conveying part, and the raw material is melt-kneaded. The masterbatch manufacturing method which consists of is provided.

According to the masterbatch production apparatus of the present invention, it is possible to produce a masterbatch in which the mixing ratio of the binder resin and the pigment is appropriate while suppressing dust generation of the pigment during the production of the masterbatch. The environment can be maintained well.
In addition, if the raw material transport unit includes a regulating member that regulates the height of the raw material mounted on the belt conveyor, at least the supply layer thickness and the supply width of the raw material can be controlled, and the raw material can be stably maintained. Therefore, it is possible to prevent the deterioration of the yield due to the dropping of the raw material caused by the poor winding of the raw material on the open roll.

If the raw material transport unit includes an adjustment unit that adjusts the regulated height of the regulating member, it is possible to easily control the supply layer thickness and the supply width according to the raw material supply amount, and the raw material in a stable state. Therefore, it is possible to prevent the deterioration of the yield due to the dropping of the raw material caused by the poor winding of the raw material on the open roll.
According to the method for producing a masterbatch of the present invention, it is possible to produce a masterbatch in which the mixing ratio of the binder resin and the pigment is appropriate by suppressing the dust generation of the pigment during the production of the masterbatch. The working environment can be maintained well. In addition, since the raw material can be supplied in a stable state with the binder resin and the pigment on the open roll, it is possible to prevent the yield from being deteriorated due to the drop of the raw material caused by the poor winding of the raw material on the open roll.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view of the embodiment, FIG. 2 is a front view of a main part of the embodiment, and FIG. 3 is a top view of the embodiment.
As shown in these drawings, the master batch manufacturing apparatus 11 includes a belt conveyor feeder 12 as a raw material transport unit and an open roll kneader 13 as a kneading unit.
The mixed raw material supply feeder 16 and the belt conveyor feeder 12 are configured to convey the mixed raw material of the binder resin and the pigment previously accommodated in the hopper 17 toward the open roll kneader 13. The open roll kneading machine 13 supplies the raw material supplied from the belt conveyor feeder 12 to the mixed raw material charging part 26 of the pair of open rolls 14a and 14b, and melts and kneads it by rotation of the open rolls 14a and 14b to produce a master batch. To do.

  The belt conveyor feeder 12 is installed between the open roll kneader 13 and the mixed raw material supply feeder 16. The mixed raw material supply feeder 16 may be a general quantitative feeder such as a table feeder or a screw feeder, and is driven by a drive motor 36 and connected to a hopper 17 that stores the raw materials.

  As shown in FIG. 4A, the belt conveyor 18 of the belt conveyor feeder 12 is driven by a drive motor 32 and moves from the mixed raw material receiving unit 19 toward the mixed raw material discharging unit 20. The mixed raw material supplied from the mixed raw material receiving unit 19 is quietly conveyed by the belt conveyor 18 toward the mixed raw material discharge unit 20 without generating dust, and is discharged from the mixed raw material discharge unit 20 to the open roll kneader 13. It has become.

  Further, as shown in FIG. 4B, a cleaning blade 21 is provided at the lower end of the belt conveyor 18 so that the raw material remaining on the belt conveyor 18 is scraped off.

As shown in FIGS. 4A and 4C and FIG. 5, the belt conveyor 18 of the mixed raw material supplied from the mixed raw material supply feeder 16 by the raw material supply regulating member, that is, the regulating blade 22 provided above the belt conveyor 18. The upper uneven supply layer thickness and supply width are adjusted to the desired supply layer thickness and supply width, and the adjusted mixed raw material is supplied to the open roll kneader 13.
As shown in FIG. 5, the regulating blade 22 is L-shaped and supported by two blade support members 33 by bolts 34 and nuts 35 so that the height (supply layer thickness) can be adjusted.

  As shown in FIGS. 2 and 3, the open roll kneader 13 includes an open roll 14a and an open roll 14b, and the open rolls 14a and 14b have a cylindrical shape having spiral grooves 27a and 27b on the surfaces, respectively. The end portions are supported by bearings 37a and 37b as shown in FIG. 6 in a state where they extend in parallel with each other and are provided with a gap at a constant interval between the open rolls 14a and 14b. And it is comprised so that it may mutually rotate in the reverse direction (refer FIG. 1) by the roll drive motors 23a and 23b and the reduction gears 37a and 37b of FIG.

In addition, the open rolls 14a and 14b have circulation channels formed therein, and can supply a heat medium such as steam, hot water and oil, or a coolant such as cooling water to the flow paths, whereby the open rolls 14a and 14b It is comprised so that the surface temperature of 14b can be adjusted arbitrarily.
Moreover, as shown in FIG. 3, the mixed raw material discharge | emission part 20 of the belt conveyor feeder 12 is located in the upper part of the mixed raw material injection | throwing-in site | part 26 in a pair of open rolls 14a and 14b. That is, the mixed raw material conveyed by the belt conveyor 18 is configured to be supplied onto the open roll 14 a via the discharge unit 20.

When the mixed raw material passes through the mixed raw material discharge unit 20 from the belt conveyor 18 and is supplied onto the open roll 14a, the mixed raw material adheres to the open roll 14a without dropping, and the open rolls 14a and 14b are in the directions indicated by the arrows in FIG. , The binder resin and the pigment are melt-kneaded.
That is, the mixed raw material supplied to the open roll 14a is heated by the heat transfer action of the heat medium supplied to the open roll 14a, and the binder resin melts and adheres to the surface of the open roll 14a. , 14b.

  The melted adhering material is kneaded in the gap between the open rolls 14a and 14b by receiving a rapid compressive force and a shearing force of roller rotation, and is further kneaded as a kneaded product discharging unit 28 (FIGS. 2 and 7). ). The cutter 29 is cut out by the cutter 29 and collected by the collection unit 30. The cutter 29 is disk-shaped and rotates in conjunction with the open roller 14a via the gears 24 and 25. Thus, the mixed raw material is melt-kneaded while being repeatedly compressed and sheared continuously between the open rolls 14a and 14b, thereby producing a master batch.

  Next, various raw materials contained in the toner will be described. First, as a binder resin, for example, a polyester resin, polystyrene, a styrene polymer such as styrene-acrylic acid ester copolymer, an acrylic polymer such as polymethyl methacrylate, a polyolefin polymer such as polyethylene, a polyurethane resin, Known materials such as an epoxy resin can be used. These binder resins are used alone or in combination of two or more, and are usually blended in the toner in an amount of 80 to 95% by weight.

  Examples of pigments include red pigments such as quinacridone, brilliant carmine 6B, and permanent red, yellow pigments such as benzimidazolone and dichlorobenzidine, blue pigments such as cobalt blue and copper phthalocyanine, and green colors such as chrome green, chromium oxide, and pigment green B. Examples thereof include black pigments such as pigment, carbon black, and acetylene black. These pigments are used singly or as a mixture of two or more, and are usually blended in the toner in an amount of 3 to 12 wt%.

  Examples of toner raw materials other than the binder resin and pigment include additives such as a charge control agent and wax. The charge control agent is not particularly limited, and a known charge control agent for negatively charged or positively charged toner for black toner or color toner can be used. Examples of the charge control agent for the negatively charged toner include surfactants such as salicylic acid or its derivative chromium, zinc, zirconium complex or salt compound, azo complex dye, and long-chain alkyl carboxylate. Examples of charge control agents for positively charged toners include nigrosine dyes or derivatives thereof, quaternary ammonium salts, and guanidine salts. Examples of the wax include natural waxes such as carnauba wax and synthetic waxes, silicone polymers, higher fatty acids, polyolefin polymers, low molecular weight polymers, and the like.

Next, a master batch and toner manufacturing method using the manufacturing apparatus 11 will be described.
A predetermined amount of the binder resin and the pigment are weighed and mixed, and the mixed raw material is supplied into the mixed raw material hopper 17 of FIG. Thereafter, the manufacturing apparatus 11 is operated to drive the belt conveyor 18 of the belt conveyor feeder 12, and the raw material is supplied from the mixed raw material supply feeder 16 to the mixed raw material receiving unit 19 of the belt conveyor 18, and the mixed raw material is driven by driving the belt conveyor 18. Is conveyed on the belt conveyor 18 from the mixed raw material receiving portion 19 to the mixed raw material charging portion 26 of the open roll 14 a of the open roll kneader 13.
At this time, the raw material gently moves on the belt conveyor 18 without generating dust in the direction of the mixed raw material discharge unit 20, and the raw material is conveyed quantitatively by adjusting the supply layer thickness and the supply width by the regulating blade 22 in the middle. .

Next, a heating medium is supplied into the open roll 14a and heated, and a refrigerant is supplied into the open roll 14b to generate a temperature difference between the open rolls 14a and 14b.
At the same time, both rolls 14a and 14b are rotated so that the rotational speed of the open roll 14a is greater than the rotational speed of the open roll 14b.
And the mixed raw material which consists of binder resin and a pigment passes the mixed raw material discharge part 20 from the belt conveyor 18, and is supplied so that it may fall to the mixed raw material injection | throwing-in part 26 of the open rolls 14a and 14b. Since the mixed raw material is not vibrated unlike the case where the layer thickness and the supply width are controlled by the vibration feeder, dust generation of the binder resin and the pigment is suppressed. Therefore, unlike the case where the binder resin and the pigment are supplied to the open roll kneader 13 using the vibration feeder, the reduction of the pigment during the supply of the raw material is suppressed, and the change in the blending ratio of both raw materials is almost eliminated. Further, since the raw material is supplied to the open roll 14 in a thin uniform layer, the binder resin is uniformly melted and sufficiently adhered to the front roll 24, so that the raw material is hardly dropped.

Subsequently, the mixture supplied to the open roll 14a is heated by the heat transfer action by the heat medium supplied to the mixed raw material charging portion 26 of the open roll 14a, and the binder resin melts and adheres to the surface of the open roll 14a. And it is wound by rotation between the open rolls 14a and 14b.
And by the screw effect of the spiral grooves 27a, 27b provided on the surfaces of the open rolls 14a, 14b shown in FIG. 3, the kneaded product discharge section 28 (FIGS. 2, 7) adheres to the roll. It is transferred, cut out by the cutter 29 (FIG. 28), and collected as a master batch by the collection unit 30 (FIG. 2).
While this molten deposit is being transferred, it is transferred to the kneaded product discharge section 28 as a kneaded product while being kneaded by receiving a rapid compressive force and a shearing force of roller rotation in the gap between the open rolls 14a and 14b. Is done. In this way, a masterbatch is manufactured by melt-kneading while continuously receiving compression and shearing repeatedly between the open rolls 14a and 14b.

  Next, a charge control agent, wax, additives, and the like are added to and mixed with the master batch as appropriate, heated and melt-kneaded to uniformly disperse them in the binder resin, and then cooled and solidified to obtain a kneaded product. Prepare. Subsequently, the mixture is roughly pulverized, finely pulverized and classified, and then a surface treatment is performed to produce a toner. Accordingly, since there is almost no change in the mixing ratio of raw materials, particularly pigments, during the production of the masterbatch, there is almost no change in the mixing ratio of the obtained toner raw materials.

The effects achieved by this embodiment will be described below.
The production apparatus 11 is configured so that the binder resin and the pigment are conveyed from the mixed raw material hopper 17 by the belt conveyor feeder 12 provided in the conveying path and supplied between the pair of open rolls 14a and 14b, and the thickness of the supply layer of the raw material Since the regulating blade 22 having the function of regulating the supply width is provided, the belt conveyor feeder 12 can stably supply the mixed raw material composed of the binder resin and the pigment with uniform supply layer thickness and supply width without generating dust. it can.
Therefore, unlike conventional ones in which the production apparatus is configured to supply the binder resin and the pigment between the pair of open rolls by adjusting the thickness and width of the supply layer by the vibration of the vibration feeder, It is possible to suppress the decrease in pigment. Therefore, it is possible to produce a master batch in which the blending ratio of the binder resin and the pigment is appropriate.
Further, since the dust generation of the pigment is suppressed, the working environment around the manufacturing apparatus 11 can be maintained well.

Further, unlike the conventional apparatus in which the manufacturing apparatus is configured to supply the binder resin and the pigment between the pair of open rolls with a screw feeder, the supply layer thickness and the supply width can be adjusted with the regulation blade 22. Since the mixed raw material is supplied to the open roll 14a in a thin uniform layer, the binder resin is uniformly melted and adhered to the open roll 14a, and the mixed raw material can be prevented from falling.
Since the decrease in pigment is suppressed and there is almost no change in the blending ratio of the binder resin and the pigment, when developing the latent image using the resulting toner, for example, in electrophotography, the tint of the toner image due to the decrease in pigment In addition, it is possible to prevent deterioration in image quality such as freshness.
Since the reduction of the pigment is suppressed and the blending ratio of the binder resin and the pigment is hardly changed, the pigment concentration in the obtained toner can be accurately grasped. In addition, it is not necessary to add the pigment again in order to correct the pigment concentration which is insufficient due to the decrease of the pigment, and it is possible to prevent waste of the pigment and prevent the raw material from falling, so that the yield of the masterbatch is increased. It is possible to prevent the toner production cost from increasing.

  In the belt conveyor 18, the raw material is quietly conveyed by the movement of the belt, so that it does not generate dust. Further, the supply layer thickness and the raw supply width of the mixed raw material can be controlled by the regulating blade 22 provided in the middle, thereby mixing the raw material. It is possible to improve the quantitative quality of the masterbatch and produce it at a high yield by eliminating the problem that the mass of the raw material falls from the discharge unit 20 to the open roll kneader 13 or the pigment is reduced.

Hereinafter, the embodiment will be described more specifically by way of examples.
[Example 1]
(Toner raw material)
Binder resin: Polyester resin (Glass transition point Tg 58 ° C, acid value: 21 mgKOH / g
Aromatic alcohol component: PO-BPA (bisphenol A propylene oxide) and
EO-BPA (Bisphenol A ethylene oxide)
Acid component: Fumaric acid and merit anhydride (70) parts by weight Colorant: Carbon black (MogulL) CABOT (30) parts by weight In addition, the glass transition point is measured by a differential scanning calorimeter (Seiko Electronics Co., Ltd.) When using a DSC 210) and measuring at a heating rate of 10 ° C./min, it shows the maximum slope between the base line extension below the glass transition point and the peak rising portion to the peak apex. The temperature at the intersection with the tangent was taken as the glass transition point.
The acid value of the binder resin was measured as follows. Polyester resin is dissolved in tetrahydrofuran, phenolphthalein is used as an indicator, and 0.1N potassium hydroxide (chemical formula: KOH) ethanol solution is used as a titrant, and an automatic titrator (manufactured by Kyoto Electronics Industry Co., Ltd .: AT-510) A potentiometric titration was performed. In this potentiometric titration, the number of mg of potassium hydroxide used for neutralization was calculated in terms of solid content as the acid value.

The open rolls 14a and 14b of the open roll kneader 13 had a diameter of 138 mm and a length of 800 mm, and the gap between the open rolls 14 a and 14 b was 0.10 mm.
First, 70 parts by weight of the binder resin and 30 parts by weight of the pigment are sufficiently mixed by a super mixer (manufactured by Kawata: SMV-20), supplied to the mixed raw material hopper 17 and bound by the feeder 16 under the condition of 10 kg / h. A mixed raw material made of resin and pigment was supplied to the mixed raw material receiving unit 19.
In addition, the belt conveyor 18 of the belt conveyor feeder 12 was 120 mm in width and 600 mm in length. The belt speed was set to 0.025 m / sec, and the clearance between the regulating blade 22 and the belt was adjusted to 3 mm.
The mixed raw material that has fallen to the mixed raw material receiving unit 19 moves to the mixed raw material discharge unit 20 in a mountain shape with a width of 60 mm and a central height of 15 mm upstream of the belt conveyor 18. The width was regulated, the feed layer thickness was adjusted to 2.5 mm, the feed width was adjusted to 100 mm, and the mixture was supplied from the mixed material discharge unit 20 to the mixed raw material charging portion 26 of the open roll kneader 13 at 10 kg / hr.

The master roll was manufactured by adjusting the temperature of the open roll 14a to 80 ° C. and the temperature of the open roll 14b to 30 ° C., rotating the open roll 14a at 70 rpm and rotating the open roll 14b at 60 rpm, and kneading the raw materials. As a result, since there was almost no dust generation, there was almost no decrease in the pigment, and a master batch with little change in the blending ratio of the binder resin and the pigment could be obtained. Moreover, there was almost no raw material fall at the lower part of the mixed raw material charging site 26, and good productivity was secured.
Subsequently, 40 parts by weight of the masterbatch, 100 parts by weight of the binder resin, negative charge control agent iron azo complex dye (T-77 manufactured by Hodogaya Chemical Co., Ltd.) 1.5 parts by weight, polyethylene wax as an additive { (Melting point: 128 ° C.) Hoechst Wax PE130, manufactured by Hoechst} As a result of diluting and kneading 3 parts by weight, a toner could be produced.

[Other Examples and Comparative Examples]
The same mixed raw material as in Example 1 was used, and Example 2, Example 3, Comparative Example 1, and Comparative Example 2 were carried out using only the method of supplying the mixed raw material to the open rolls 14a and 14b as the conditions in Table 1.
The results are summarized in Table 1.

It is a side view of the masterbatch manufacturing apparatus of this invention. It is a principal part front view of the masterbatch manufacturing apparatus of this invention. It is a top view of the masterbatch manufacturing apparatus of this invention. 4A is a configuration explanatory view of the belt conveyor feeder of the apparatus of FIG. 1, FIG. 4B is a top view of the main part of FIG. 4A, and FIG. 4C is FIG. FIG. It is principal part structure explanatory drawing of the masterbatch manufacturing apparatus of this invention. It is principal part structure explanatory drawing of the masterbatch manufacturing apparatus of this invention. It is the B section enlarged view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Masterbatch manufacturing apparatus 12 Belt conveyor feeder 13 Open roll kneader 14a Open roll 14b Open roll 16 Mixed raw material supply feeder 17 Hopper 18 Belt conveyor 19 Mixed raw material receiving part 20 Mixed raw material discharge part 21 Cleaning blade 22 Regulation blade 23a Roll drive motor 23b Roll drive motor 24 Gear 25 Gear 26 Mixed raw material carry-in part 27a Groove 27b Groove 28 Kneaded material discharge part 29 Cutter 30 Recovery part 32 Drive motor 33 Blade support member 34 Bolt 35 Nut 36 Drive motor 37a Reduction gear 37b Reduction gear

Claims (4)

A belt conveyor that includes a raw material conveyance unit that conveys and discharges granular raw materials to a predetermined position, and a kneading unit that melts and kneads the raw materials discharged from the raw material conveyance unit, and the raw material conveyance unit carries and conveys the raw materials the equipped, master batch, wherein a pair of rotating rolls kneading section for kneading the raw material, the Rukoto a disc-shaped cutter which rotates in conjunction with rotation roll kneaded raw material to cut from the roll apparatus.   The master batch manufacturing apparatus according to claim 1, wherein the raw material transport unit includes a regulating member that regulates a height of the raw material mounted on the belt conveyor.   The master batch manufacturing apparatus according to claim 2, wherein the raw material conveyance unit includes an adjustment unit that adjusts a regulated height of the regulating member.   Using the master batch production apparatus according to any one of claims 1 to 3, a powdery raw material containing a binder resin and a pigment is supplied to a kneading part via a raw material conveyance part, and the raw material is melted. A master batch production method comprising a kneading step.

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