JP2003005440A - Developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the occurrence of toner spent, filming and sticking, to improve the preservable property of a material to be printed and to obtain good pulverizing processability by making the energy saving by lowering of a fixing temperature to a temperature lower than heretofore possible and making the preservable property better than with toners using the conventional low melting point resins and averting the occurrence of a change of the interaction with external additives with lapse of time. SOLUTION: Electrophotographic toners are prepared by using cyclic butadiene for a main binder.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to electrophotography used in copying machines, facsimiles, printers and the like.

[0002]

2. Description of the Related Art Conventionally, thermal fixing is often used for fixing toner. Generally, in the case of heat fixing, the principle of fixing is that the toner to be fixed must be softened or melted by the heat of the fixing device, and the softened or melted toner receives pressure from the fixing device and becomes a fiber of paper. Since the surface of the toner that has been sunk into the inside or that has been softened or melted has an adhesive property, the toner adheres by its adhesive force. Therefore, the melting point or softening point of the resin used for the toner needs to be lower than the temperature of the fixing device.

However, in recent years, there has been an increasing demand for energy saving in order to preserve the global environment, and the energy that can be consumed by the fixing device is being limited. In fact, in order to lower the fixing energy, the temperature of the fixing device must be lowered, and thus the resin of the toner corresponding to the fixing device with the lower fixing energy inevitably has a low melting point. But,
The resin whose melting point is lowered in this way tends to become soft, and it is easily blocked after being processed into a toner, and because the surface has adhesiveness, the interaction with external additives in the toner changes over time, and the characteristics change. Occurs and there is a problem in terms of storability. Also, the toner is soft and sticky inside the developing machine as well, so that the toner is spent on the carrier, the toner is filmed on the developing roller, or the toner is fixed on the developing blade. There is. Further, there is a problem that the printed papers are apt to cause blocking between the printed papers due to a change in environment even after printing. In addition, there is a problem in toner processing, and if the conventional resin is used to lower the melting point, the resin will be too soft and the toner will not be easily crushed in the crushing process, and it will stick to the crusher. There is also a problem.

[0004]

SUMMARY OF THE INVENTION The present invention is to provide a toner which solves the above problems. Therefore, in view of the above-mentioned conventional technique, an object of the present invention is to save energy by lowering the fixing temperature as compared with the conventional technique, to improve the preservability as compared with a toner using a conventional low melting point resin, and to provide an external additive. The purpose of the present invention is to provide a good smashing processability by preserving the printed material, preventing toner spent, filming, and sticking from occurring in the interaction with aging. To do.

[0005]

The present inventors have completed the present invention as a result of intensive studies to improve the above-mentioned drawbacks. That is, the above-mentioned problems are (1) "a toner for electrophotography characterized by using cyclized butadiene as a main binder" and (2) "transferring cyclized butadiene to the toner of the present invention".
s at a temperature above the melting point of 1,4-polybutadiene, tra
(3) "Electronographic toner characterized by dissolving ns 1,4-polybutadiene as a solvent", (3) "Fixing below the melting point of cyclized butadiene by mixing cyclized butadiene and trans 1,4-polybutadiene" Electrophotographic toner characterized by being possible ”, (4)
"Electrophotographic toner according to item (1), characterized in that cyclized butadiene is 10 wt% or more in terms of binder composition ratio", (5) "tr to cyclized butadiene
The composition ratio of ans 1,4-polybutadiene is 97: 3.
To 5:95, the toner for electrophotography according to any one of the items (1) to (3),
(6) "The electrophotographic toner according to any one of (1) to (3) above, wherein the melting point of trans 1,4-polybutadiene is lower than that of cyclized butadiene" (7) “The degree of cyclization of cyclized butadiene is 50
% Or more, the purity of the trans 1,4-polybutadiene used as a solvent for the cyclized butadiene is 60 wt% or more. The toner for electrophotography according to the item (1), characterized in that the wax: resin is contained as a grinding aid in an amount of 1:99 to 50:50. The toner for electrophotography according to item (1) above, (10) "wherein the penetration of the wax used is 0 to 20. The above items (1) to (9) The electrophotographic toner according to any one of items 1 to 4).

The invention of item 10 will be described in detail. The inventions of the above (1), (2), and (3) are basic, and have a high melting point as a main binder and good storage stability, spent resistance, filming resistance, and sticking resistance. Cyclized butadiene is used and this is trans
What is dissolved in 1,4-polybutadiene is solidified to obtain a toner. Therefore, when this is subjected to heat fixing, tra
The cyclized butadiene dissolves in the trans 1,4-polybutadiene at a temperature equal to or higher than the melting point of the ns 1,4-polybutadiene, and the cyclized butadiene softens or melts even if the temperature does not reach the melting point of the cyclized butadiene, thereby exhibiting fixing performance. To do. Since the melting point of the cyclized butadiene itself is high, the resin is not too soft and good pulverizability can be obtained.

In the invention described in item (4),
When cyclized butadiene is mixed with a conventional resin in a binder composition ratio, at least 10 wt% or more of the cyclized butadiene content in the entire resin must be prescribed. The melting point of the toner mixed with the resin can not be lowered sufficiently, resulting in defective fixing. As a result of diligent studies on the content of cyclized butadiene, it is preferably 15 wt% or more, more preferably 20 wt% or more, and further preferably 30 wt%.
% Or more, more preferably 40 wt% or more, still more preferably 50 wt% or more.

In the invention described in the item (5), as for the composition ratio of trans 1,4-polybutadiene to cyclized butadiene, the higher the prescription amount of trans 1,4-polybutadiene, the higher the solution viscosity of cyclized butadiene. However, when the amount of cyclized butadiene is reduced,
Since the trans 1,4-polybutadiene does not dissolve the other resin and does not mix with the resin,
The rans 1,4-polybutadiene is separated, which makes it difficult to form a toner. The amount of cyclized butadiene is large, and tr
When the amount of ans 1,4-polybutadiene is small, the solubilized viscosity of the cyclized butadiene in the trans 1,4-polybutadiene is too high and the fixing performance cannot be obtained. As a result of diligent studies, it has been clarified that performance is obtained when the composition ratio of cyclized butadiene and trans 1,4-polybutadiene is 97: 3 to 5:95. However, in actual use, it is not limited to fixing in an air-conditioned place such as an office, and various fixing environments such as high temperature, low temperature, high humidity and low humidity are conceivable, and preferably 95: 5 to 20: 80, more preferably 90:10 to 30:70, and even more preferably 80:20 to 40:60 considering the margin.

In the invention described in item (6), tra
Unless the melting point of the ns 1,4-polybutadiene is lower than that of the cyclized butadiene, the trans 1,4-polybutadiene does not melt below the melting point of the cyclized butadiene. It cannot be dissolved and the melting point of the toner cannot be lowered. Therefore, it is naturally desirable to select trans 1,4-polybutadiene as the solvent for the cyclized butadiene.

In the case of the invention described in the item (7), as a result of examination, it was revealed that good properties as cyclized butadiene can be exhibited when the cyclization degree is 50% or more on average. If the degree of cyclization is low, the cyclized butadiene will exhibit its original properties as a rubber, and the pulverizability will be significantly reduced, and it cannot be used in the present invention. When the degree of cyclization is about 30%, the cyclized butadiene itself becomes soft and the liquid property becomes stronger. Therefore, as a result of examination, a more preferable value is 70% or more of the degree of cyclization.

In the case of the invention described in the item (8), cis 1,4-polybutadiene, isotactic-1,2-polybutadiene, syndiotactic-1,2-polybutadiene, etc. are by-products even if they are synthetic products. In some cases, it was found that it is necessary that the content of trans 1,4-polybutadiene is 60 wt% or more. Preferably 70 wt% or more, more preferably 80 wt% or more, even more preferably 90 w
It is preferably t% or more.

In the case of the invention described in item (9), trans
When 1,4-polybutadiene is too tough and poor in pulverizability, it becomes clear that pulverizability is improved by formulating the wax: resin in the range of 1:99 to 50:50, preferably 5 It is preferably within the range of: 95 to 30:70.

In the case of the invention described in the item (10), when the penetration of the wax used is high, the cohesiveness of the toner becomes high,
The thin layer forming property is deteriorated and the replenishment performance of the toner is remarkably deteriorated, and preferably 0-14, more preferably 0-1.
Waxes with a penetration of 0, and even more preferably in the range 0-5 are preferred.

In order to solve the problems of the prior art, the present invention uses a resin having a melting point higher than the lowest temperature for fixing and a trans 1,4-polybutadiene having a melting point lower than the lowest temperature for fixing. When the trans 1,4-polybutadiene functions as a solvent or a plasticizer at a temperature equal to or higher than the melting point of
It has been discovered that the resin is dissolved by trans 1,4-polybutadiene at the molecular level to soften or dissolve the resin, so that the system can be fixed at a temperature lower than the melting point of the resin.
As a result, fixing can be performed at a temperature near the melting point of trans 1,4-polybutadiene, which is much lower than the melting point of the actually used resin, and energy can be saved. This enables fixing at low temperature even when using cyclized butadiene having a high melting point. The melting point of the resin in the present invention refers to the softening point measured by the flow tester method. For example, in the case of cyclized butadiene, an endothermic peak appears between 50 ° C. and 80 ° C. according to the DSC method, but actually it is clearly in a solid state even at about 100 ° C.

Incidentally, one similar to the present invention is disclosed in Japanese Patent Laid-Open No. 7-
271100, Japanese Patent Publication 7-15596, Japanese Patent Publication 7-31418, Japanese Patent Publication 7-40146, Japanese Patent Publication 7-62765, Japanese Patent Publication 7-8224.
No. 8, Japanese Patent Publication No. 7-104612, Japanese Patent No. 25
There are those disclosed in Japanese Patent No. 48091 and Japanese Patent No. 2759482, but all of them are a dispersion stabilizer at the time of preparing a suspension polymerization toner, or are polymerized at the time of formation of a polymerization toner for the purpose of blocking prevention and the like. It is used for the purpose of forming a shell for wrapping the low softening point resin, and is a so-called capsule forming agent. Therefore, these are completely different inventions that are fundamentally different from the present invention.

Cyclized butadiene is formed by the reaction shown in FIG. The following method is an example of the method for producing cyclized butadiene. According to the Fisher method, 5% of concentrated sulfuric acid is kneaded into rubber and heated at 130 ° C. for 15 hours to obtain cyclized butadiene. In addition to this, there is a method of using an organic sulfonic acid, tin chloride, iron chloride, a non-metal halide, and halogenated primary and secondary stannic acids as a cyclizing agent, and various resinous plastic substances can be produced. They are,
As shown in FIG. 1, an isomerization phenomenon is caused by the action of an oxidizing agent, the specific gravity is increased, the degree of unsaturation is decreased, and a substance having completely different properties is obtained. It can be created by any method.

As the sub-resin which can be used in the present invention,
Some examples are as follows. Examples of the binder resin used for each toner include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substitution products thereof; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer. Polymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-
Butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylic acid Methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer Coalesced, styrene-
Styrene-based copolymers such as maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified Rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin,
Aromatic petroleum resin, chlorinated paraffin, etc.
They can be used alone or as a mixture, but are not particularly limited thereto. In the present invention, carbon black or a color pigment may be kneaded and dispersed in these resins, if necessary, and it is of course possible to use a charge control agent together. Further, after pulverization, additives such as silica, titanium, strontium may be added to adjust the fluidity of the toner.

Hereinafter, description will be given based on an embodiment. [Example 1]   Cyclized polybutadiene 60 wt%   trans 1,4-polybutadiene 27 wt%   Carbon black 12wt%   CCA 1wt%

[0019] [Example 2]   Cyclized polybutadiene 40 wt%   20% by weight of trans 1,4-polybutadiene   Magnetic substance 39 wt%   CCA 1wt%

[0020] [Example 3]   Cyclized polybutadiene 57 wt%   trans 1,4-polybutadiene 24 wt%   Carbon black 12wt%   CCA 1wt%   Carnauba 6 wt%

[0021] [Example 4]   Cyclized polybutadiene 57 wt%   trans 1,4-polybutadiene 24 wt%   Carbon black 5wt%   CCA 1wt%   Candelilla 6 wt%

[0022] [Example 5]   Cyclized polybutadiene 94wt%   Carbon black 5wt%   CCA 1wt%

[0023] [Example 6]   Cyclized polybutadiene 74 wt%   20% by weight of trans 1,4-polybutadiene   Cyan 5 wt%   CCA 1wt%

[0024] [Example 7]   Cyclized polybutadiene 72 wt%   trans 1,4-polybutadiene 22 wt%   Yellow 5 wt%   CCA 1wt%

[0025] [Example 8]   42 wt% of cyclized polybutadiene   High melting point polyester (melting point 155 ° C) 30 wt%   trans 1,4-polybutadiene 22 wt%   Carbon black 5wt%   CCA 1wt%

[0026] [Comparative Example 1]   High melting point polyester (melting point 155 ° C) 94wt%   Carbon black 5wt%   CCA 1wt%

Comparative Example 2 Low Melting Point Polyester (Melting Point 94 ° C.) 94 wt% Carbon Black 5 wt% CCA 1 wt% In each of the above examples, three rolls were kneaded 5 times, cooled and pulverized, and silica was added as an external additive. 1 for every 100 parts of toner
Part of the mixture was mixed and used as the final toner. Using these toners, an experiment was conducted by actually changing the temperature of the fixing device, and the results shown in Table 1 were obtained. In addition, it is not necessary to apply oil to the fixing roller for the formulation containing wax,
In order to unify the conditions, oil was applied to the rollers for all toners.

[0028]

[Table 1] ◯: Good fixing Δ: Barely fixing ×: Poor fixing caused only cyclized butadiene and high melting point polyester (15
In the case of only 5 ° C.), fixing was not performed unless a temperature of 160 ° C. or higher was applied, and in the system using other trans 1,4-polybutadiene, the fixing temperature could be lowered to 60 to 80 ° C.

A storability test was conducted using the above toner, and the results shown in Table 2 were obtained. (Storage environment 40 ℃ 2
weekly)

[0030]

[Table 2] ○ indicates that there is no change

The charge amount represents the charge amount on the sleeve for one-component development. For OPC background stains, take the toner attached on the OPC with a transparent adhesive tape, stick it on a white paper, measure the density ID1 with a Macbeth reflection densitometer, and use a transparent adhesive tape without toner on a white paper. This is the difference between the result of sticking on the top and the measurement of the density ID2. The smaller the value, the less the stain.

[0032]

## EQU1 ## ΔID = ID1-ID2 From the above results, cyclized butadiene and trans 1,4
-It can be seen that polybutadiene has a low melting point, but there is no change in storability or characteristics. Further, ordinary high-melting-point polyesters also have no problem in storability, and although the characteristics are slightly changed, they are at a level not causing a problem.
However, the one using low melting point polyester is completely solidified in the storage test, and its properties cannot be measured.

Change with time of toner after running (after 2000 sheets of image output) The image is output by one-component development, and the charge amount is the charge amount of the toner on the sleeve.

[0034]

[Table 3] From the results of Table 3, in the case of using cyclized butadiene alone or the combination of cyclized butadiene and trans1,4-polybutadiene, there is almost no change in the charge amount and the background stain is also hardly changed. With the combination of cyclized butadiene and high-melting point polyester, a slight change in the amount of charge and deterioration of the background stain are observed, but this is not a problem. When high-melting point polyester is used alone, there is a decrease in the amount of charge and an increase in background stain, but this is not at an unusable level. The low-melting point polyester alone is at a level where it cannot be used because the charge amount is significantly reduced and the background stain is deteriorated.

Further, a test in an image forming system was conducted.
The toner spent was tested by two-component development, and the developing roller filming and the development blade fixing were tested by one-component development. Both the one-component and two-component development were evaluated after producing 2000 images.

[0036]

[Table 4] ◯: No occurrence △: Occurrence, but the degree is light and does not pose a problem ×: Image quality is greatly affected and cannot be used

Cyclized butadiene or cyclized butadiene and tra
In the combination system of ns 1,4-polybutadiene,
There was almost no change from the initial quality. With the combination of cyclized butadiene and high melting point polyester, the developing roller filming slightly occurs, but it does not cause any problem on the image. In the case of only the high melting point polyester, toner spent on the carrier in the two-component development, development roller filming in the one-component development, and toner sticking to the development blade are slightly observed, but this is not a problematic level and is conventional performance. . In the case of low melting point polyester, severe toner adhesion such as toner spent in two-component development, developing roller filming in one-component development, and toner sticking to the developing blade is observed. At this time, various abnormal images such as image density unevenness, transfer paper background stain, and vertical white stripes on the image are observed on the image, and this system cannot be used in view of image quality. Next, the storability of the printing material was tested separately for both single-sided printing and double-sided printing.

[0038]

[Table 5] From the above, the transfer paper is contaminated and blocked only when the low melting point polyester of Comparative Example 2 is used, and thus it cannot be used.

Further, the pulverization process in making toner was evaluated. The following is an evaluation of the time and adhesion state until a certain amount of toner is completed as a toner having a desired particle size.

[0040]

[Table 6] As described above, it can be said that there is almost no process problem in Examples 1 to 8 and Comparative Example 1. Also, it can be seen that the crushing time is much shorter when the wax is added. However, in the system using the low-melting point polyester of Comparative Example 2, the pulverization time is twice or more as long as usual, and the toner adheres to the inside of the pulverization chamber so much that the pulverization conditions change during the pulverization. Therefore, it can be said that the low melting point polyester system has a great problem in toner processing.

[0041]

As is apparent from the detailed and specific description above, in the present invention, the cyclized butadiene is dissolved in the trans 1,4-polybutadiene having a lower melting point than the cyclized butadiene, so that Fixing can be performed at a temperature lower than the melting point, energy can be saved, and even a low-melting toner has a high melting point because the cyclized butadiene itself has a high melting point, and the cyclized butadiene is a hard resin. The external additive does not sink into the toner, and the external additive is not contaminated by low-molecular-weight resin to minimize the change in properties, and the hardened and non-adhesive cyclized butadiene allows the toner spent ,
Filming, sticking, etc. can be prevented, and since the resin with a high melting point is hard and non-adhesive, the material to be printed does not block, and even though it is a low melting point toner, the cyclized butadiene used is Since it is not too soft and is moderately hard, it has an extremely excellent effect that it can be crushed well.

[Brief description of drawings]

FIG. 1 is an example of a diagram showing a cyclized butadiene reaction in the present invention.

Claims (10)

[Claims] 1. A toner for electrophotography, wherein cyclized butadiene is used as a main binder. 2. The cyclized butadiene is converted into trans 1,4-
Trans 1,4 at a temperature above the melting point of polybutadiene
An electrophotographic toner characterized by dissolving polybutadiene as a solvent. 3. Cyclized butadiene and trans 1,4-
An electrophotographic toner capable of being fixed at a temperature not higher than the melting point of cyclized butadiene by mixing polybutadiene. 4. The electrophotographic toner according to claim 1, wherein the cyclized butadiene is 10 wt% or more in the binder composition ratio. 5. A trans for cyclized butadiene
The composition ratio of 1,4-polybutadiene is 97: 3 to 5: 9.
5. The electrophotographic toner according to claim 1, wherein the toner is 5. 6. The toner for electrophotography according to claim 1, wherein the melting point of trans 1,4-polybutadiene is lower than the melting point of cyclized butadiene. 7. The toner for electrophotography according to claim 1, wherein the degree of cyclization of the cyclized butadiene is 50% or more. 8. A t used as a solvent for cyclized butadiene.
The purity of trans 1,4-polybutadiene is 60 wt.
The toner for electrophotography according to claim 1, wherein the toner content is at least%. 9. A wax: resin ratio of 1: is used as a grinding aid.
The toner for electrophotography according to claim 1, wherein the toner is contained in an amount of 99 to 50:50. 10. The electrophotographic toner according to claim 1, wherein the wax used has a penetration of 0 to 20.