JP2894918B2 - Manufacturing method of toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner containing a high molecular weight polymer component and a low molecular weight polymer component.

[0002]

2. Description of the Related Art Toners containing a high molecular weight polymer component and a low molecular weight polymer component are used for electronic copying and have required properties such as offset resistance, fixing property and blocking resistance. In order to sufficiently exhibit the above, both polymer components must be sufficiently compatible.

For this reason, a conventional binder resin for a toner is prepared by (1) a method in which both polymer components are mixed and dissolved in an organic solvent, and (2) a method in which a high molecular weight polymer component is dissolved in an organic solvent.
A method of dissolving a monomer which gives a low molecular weight polymer component and polymerizing the monomer, (3) polymerizing a part or all of the monomer to form a high molecular weight polymer component, Is dissolved in an organic solvent, and a monomer that gives a low molecular weight polymer component is polymerized therein.

In each of the above-mentioned conventional methods, a resin solution in which both polymer components are dissolved in an organic solvent is obtained at the final stage of the production, and finally, by heating and reducing the pressure,
The final resin is obtained by distilling the organic solvent. Then, after the binder resin thus obtained is pulverized and atomized, the colorant, the charge control agent, and the additives such as wax are supplied to a kneading machine such as an extruder to form the binder resin and the additives. To obtain the desired toner.

[0005]

However, in the above-mentioned conventional method, since the organic solvent is used, the residual concentration of the organic solvent in the binder resin for the toner may be higher than a predetermined concentration depending on the conditions. This may cause a problem that the performance required of the toner, particularly the effect of blocking resistance, cannot be sufficiently exhibited. In particular, when the content of the high molecular weight polymer component in the binder resin composition for toner is large, the organic solvent in the resin is often contained at a predetermined concentration or more. Further, in the conventional method, since batch mixing is performed, there is a problem that productivity is poor when the mixing ratio of the high molecular weight polymer component and the low molecular weight polymer component is changed.

Further, in the conventional production method, it is necessary to pulverize and pulverize the binder resin, knead the additives such as the coloring agent again with a kneading machine such as an extruder, and pulverize this again. Many were not efficient manufacturing methods.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem and to provide a method for continuously producing a toner having a low residual concentration of an organic solvent in a resin and excellent blocking resistance with good productivity. To provide.

[0008]

According to the method for producing a toner according to the present invention, a high molecular weight polymer component is supplied from a first raw material supply section of a kneading extruder into a cylinder, and an organic solvent is distilled off after solution polymerization. The discharged low molecular weight polymer component is supplied into the cylinder from a second raw material supply section of the kneading extruder, and an additive containing at least a colorant is added to the first raw material supply section and the second raw material supply section. Is supplied into the cylinder from at least one of the above, and the high molecular weight polymer component and the low molecular weight polymer component melted in the cylinder are kneaded with the additive.

The high molecular weight polymer component and the low molecular weight polymer component used in the present invention are not particularly limited, but include styrene polymers and (meth) acrylate monomer polymers. , Styrene monomer and (meth)
A copolymer with an acrylate monomer is preferably used.

In the present specification, the (meth) acrylate monomer means an acrylate monomer and a methacrylate monomer. When a copolymer of a styrene monomer and a (meth) acrylate monomer is used, the content of the styrene monomer component is 50 to 95% by weight, and (meth) acrylic acid is used. The content of the ester monomer is preferably 5 to 50% by weight. When the content of the styrene-based monomer component is less than 50% by weight, the pulverizability of the toner is deteriorated, and when it is more than 95% by weight, the fixability of the toner is sometimes deteriorated.
In addition, the content of the (meth) acrylate monomer is 5%.
If the content is less than 5% by weight, the fixing property of the toner deteriorates,
If the amount is more than 0% by weight, the pulverizability of the toner deteriorates.

The weight average molecular weight of the high molecular weight polymer component is 200,000 to 2,000,000, and that of the low molecular weight polymer component is 0.5 to 10,000,000.
10,000 is preferred. In the present invention, as the organic solvent used to produce the low molecular weight polymer component, hexane,
Heptane, toluene, xylene and the like can be mentioned. Among them, toluene and xylene are preferable.

In the present invention, the additive contains at least a colorant, and in addition to the colorant, a charge control agent, a magnetic material, a carrier powder, and, if necessary, a lubricant, an abrasive, a fluidity-imparting agent. Etc. may be included.

Examples of the charge control agent include nigrosine, an azine dye having an alkyl group having 2 to 16 carbon atoms, a chlorinated dye, a metal complex salt of a monoazo dye, nitroamic acid and a salt thereof. Examples of the coloring agent include carbon black, aniline black, and acetylene black as pigments. Examples of the magnetic material include magnetite and hematite, and examples of the carrier powder include iron powder, ferrite powder, and nickel powder.

In the present invention, the number of supply ports of the first raw material supply section and the second raw material supply section is not limited to one, and may be supplied from two or more supply ports. If there are a plurality of mouths, they may be located apart.

[0015]

According to the present invention, a high molecular weight polymer component is supplied from a first raw material supply section of a kneading extruder, and a low molecular weight polymer component is supplied from a second raw material supply section. The additive is supplied from at least one of the supply section and the second raw material supply section, whereby the high molecular weight polymer component and the low molecular weight polymer component melted in the cylinder are mixed with the additive by kneading. ing. Since no organic solvent is used when mixing both polymer components and additives,
The organic solvent in the low molecular weight polymer component can be easily distilled off, and the solvent removing ability can be sufficiently exhibited.
Therefore, the concentration of the organic solvent in the polymer can be reduced as compared with the conventional case, and the blocking resistance of the toner can be improved.

Further, in the present invention, in a kneading extruder for kneading a high molecular weight polymer component and a low molecular weight polymer component, these and an additive are simultaneously kneaded and mixed. Therefore, a kneading step only for mixing with an additive as in the related art is not required, and the toner can be efficiently manufactured.

[0017]

FIG. 1 is a schematic diagram showing a toner manufacturing apparatus according to an embodiment of the present invention. The low molecular weight polymer component is polymerized by a usual solution polymerization method. After the polymerization is completed, the concentration of the residual organic solvent in the resin is distilled out to a predetermined concentration or less by heating and pressure reduction, and then the mixture is kneaded and extruded via a gear pump 3. It is supplied from the second raw material supply section 6 of the machine 10. The second raw material supply unit 6 is provided at a position halfway from the upstream to the downstream of the kneading extruder 10.

The high molecular weight polymer component can be produced by a method similar to the conventional method, and after being charged into the supply hopper 8, is supplied from the first raw material supply section 5 into the kneading extruder 10. . An additive containing a colorant is charged into a supply hopper 9 and a kneading extruder 1 is also supplied from the first raw material supply unit 5.
It is supplied within 0. The first raw material supply unit 5 is provided on the upstream side of the kneading extruder 10.

The high molecular weight polymer component and the additives supplied from the first raw material supply unit 5 into the kneading extruder 10 are melted by heating with a barrel heater and shearing the screw 4.
Distributed. The low molecular weight polymer component supplied from the second raw material supply unit 6 is added to the mixture of the high molecular weight polymer component and the additive thus melted, and the high molecular weight polymer component, the low molecular weight polymer component, And the mixture of the additives are uniformly mixed and dispersed by the kneading action of the kneading extruder 10. The mixed resin extruded from the kneading extruder 10 is cooled and solidified and formed into an appropriate shape capable of being pulverized, and becomes a target toner.

A degassing unit 7 is provided near the downstream end of the kneading extruder 10, and a minute amount of residual monomer and solvent are removed from the degassing unit 7 using a vacuum pump. I have. In addition, in order to prevent thermal decomposition of the resin, an inert gas such as N ₂ may be purged in the vicinity of the first raw material supply unit 5 for the purpose of avoiding air from being mixed.

Hereinafter, Examples and Comparative Examples for producing a toner composition using the apparatus shown in FIG. 1 will be described. Example 1 25 kg / weight of a high molecular weight polymer component having a weight average molecular weight of 600,000 (a copolymer composed of 75% by weight of styrene, 20% by weight of n-butyl acrylate, and 5% by weight of methyl methacrylate)
Supply hopper (weight control feeder) with supply amount of H 8
From the first raw material supply section 5 of the kneading extruder 10. At the same time, 100 parts by weight of a resin mixture of a high molecular weight polymer component and a low molecular weight polymer component are mixed with 10 parts of carbon black (Diablack MA-100: manufactured by Mitsubishi Kasei Corporation).
Parts by weight, 1 part by weight of a charge control agent (Spiron Black THR: manufactured by Hodogaya Chemical Co., Ltd.), wax (Viscol 660P:
The first extruder 10 of the kneading extruder 10 is supplied from a supply hopper (weight control feeder) 9 using 5 parts by weight of an additive (manufactured by Sanyo Chemical Industries, Ltd.) as an additive.
From the raw material supply unit 5.

Separately, 600 parts by weight of toluene were used as an organic solvent, 350 parts by weight of styrene, 75 parts by weight of n-butyl acrylate, 75 parts by weight of methyl methacrylate, and azobisisobutyronitrile as a polymerization initiator. Solution polymerization was carried out using 30 parts by weight. Thereafter, the solution of the low molecular weight polymer component is heated and depressurized to distill toluene, and the low molecular weight polymer component is supplied at 105 kg / H from the second raw material supply unit 6 of the kneading extruder 10 via the gear pump 3. Supplied in quantities. As the kneading extruder 10, a biaxial co-rotating type (diameter Dφ65mm, L / D = 42) was used.

The polymer extruded from the kneading extruder 10 is
After being cooled and solidified to obtain a crushable shape, it was crushed. Further, the mixture is finely pulverized by a jet mill to an average particle size of 11 μm, and 3 parts by weight of hydrophobic silica fine powder is mixed with 100 parts by weight of the toner pulverized product, and 1500 parts by weight of carrier iron powder is mixed with 100 parts by weight of the mixture. did.

Example 2 A toner was produced in the same manner as in Example 1. However, the supply amount of the high molecular weight polymer component supplied to the kneading extruder 10 is 60
kg / H, supply amount of low molecular weight polymer component is 90 kg / H
And

Comparative Example 1 (1) Production of Resin According to the conventional production method, solution polymerization of 350 parts by weight of the same high molecular weight polymer component as in Example 1 and low molecular weight polymer component obtained in the same manner as in Example 1 Was mixed with 1130 parts by weight of the solution after the above, and the mixture was stirred. Thereafter, the polymer solution was heated and reduced in pressure to distill toluene, and then the polymer was cooled, solidified and pulverized.

(2) Production of toner To 100 parts by weight of the resin obtained as described above, 10 parts by weight of carbon black, 1 part by weight of a charge control agent and 5 parts by weight of wax were mixed as in Example 1. Then 16
Roll kneading at 0 ° C. for 5 minutes, cooling and coarse pulverization, further fine pulverization with a jet mill to an average particle size of 11 μm, 3 parts by weight of hydrophobic silica fine powder per 100 parts by weight of the pulverized product, 100 parts by weight of this mixture Was mixed with 1500 parts by weight of carrier iron powder to prepare a toner.

Comparative Example 2 The amount of the high molecular weight polymer component used was changed from 350 parts by weight to 200 parts by weight.
A toner was prepared in the same manner as in Comparative Example 1, except that the amount was changed to parts by weight.

The residual solvent amounts of the resins of Examples 1 and 2 and Comparative Examples 1 and 2 obtained as described above were measured, and the obtained toners were evaluated for blocking resistance. 1 is shown. In addition, the evaluation of blocking resistance was performed by placing 10 g of the toner in a 100 cc
Was left in a thermostat for 16 hours, and the presence or absence of coalescence of the particles was visually determined.

[0029]

[Table 1]

As is clear from Table 1, both Examples 1 and 2 according to the present invention have a residual solvent content of 0.1%.
Also, the blocking resistance was good. On the other hand, the residual solvent amount of the resin of Comparative Example 1 was as high as 0.4% to 0.5%, and the blocking resistance was poor. Comparative Example 2 was produced by a conventional method with a lower blending ratio of the high molecular weight polymer component, and had a relatively small residual solvent amount of 0.2% and good blocking resistance. This is because the amount of the high-molecular-weight polymer component is reduced. If the amount of the high-molecular-weight polymer component is reduced, the offset resistance and the like are slightly lowered, which is not preferable.

As is evident from the above results, by producing a toner composition according to the present invention, a toner composition having excellent blocking resistance can be obtained, and a conventional composition for adding an additive such as a colorant can be obtained. The kneading process is unnecessary,
The toner composition can be manufactured efficiently, and the productivity can be improved.

[0032]

According to the present invention, since a high molecular weight polymer component and a low molecular weight polymer component are mixed using a kneading extruder, both polymers are mixed with an organic solvent as in the prior art. There is no need to mix the components. For this reason, the residual concentration of the organic solvent can be significantly reduced, and a toner composition having excellent blocking resistance can be obtained. Further, according to the present invention, since the high molecular weight polymer component and the low molecular weight polymer component are melted and kneaded and mixed in a kneading extruder, any high molecular weight polymer component / low molecular weight polymer component Also in the composition ratio, a toner composition having excellent blocking resistance can be obtained.

Also, in the present invention, the high molecular weight polymer component and the low molecular weight polymer component and the additive are kneaded and mixed by using a kneading extruder, so that only the conventional additive mixing is performed. The kneading step is not required, and the toner composition can be manufactured more efficiently than before, and the productivity can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a manufacturing apparatus according to one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 3 ... Gear pump 4 ... Screw 5 ... 1st raw material supply part 6 ... 2nd raw material supply part 7 ... Deaeration part 8 ... Supply hopper (weight control type feeder) of high molecular weight polymer 9 ... Supply hopper of additive Weight control type feeder) 10. Kneading extruder

Claims (1)

(57) [Claims] 1. A first extruder for kneading and extruding a high molecular weight polymer component.
And the low molecular weight polymer component from which the organic solvent was distilled off after the solution polymerization was supplied into the cylinder from the second raw material supply section of the kneading extruder, and at least a colorant was supplied. Is supplied into the cylinder from at least one of the first raw material supply section and the second raw material supply section, and the high molecular weight polymer component and the low molecular weight polymer component melted in the cylinder are added. A method for producing a toner, comprising kneading an agent with the toner.