JP4089863B2 - Developer - Google Patents

Description

○：定着が良好である
△：かろうじて定着している
×：定着不良をおこす
環化ブタジエンのみの場合と高融点ポリエステル（１５５℃）のみの場合では、１６０℃以上の温度をかけないと定着せず、他のｔｒａｎｓ 1,4−ポリブタジエンと用いた系では６０〜８０℃定着温度を下げることができた。
【００２９】
上記トナーを用いて保存性テストを行なったところ、表２の結果が得られた。（保存環境４０℃２週間）
【００３０】
【表２】

○印は変化がないことを表わす
【００３１】
帯電量は一成分現像のスリーブ上の帯電量を表わす。
ＯＰＣ地肌汚れは、ＯＰＣ上に付着したトナーを透明な粘着テープでとり、白い紙の上に張り付けてマクベス反射濃度計により濃度ＩＤ１を測定し、更にトナーのついていない透明な粘着テープを白い紙の上に張り付け、その濃度ＩＤ２を測定したものの差であり、数値が小さい程汚れが少ない。
【００３２】
【数１】
ΔＩＤ＝ＩＤ１−ＩＤ２
以上の結果より、環化ブタジエンとｔｒａｎｓ １，４−ポリブタジエンで低融点化を図ったものの保存性や特性に変化がないことが分かる。また、通常の高融点ポリエステルについても保存性に問題はなく、特性についてはやや変化があるものの問題にならないレベルである。しかし、低融点ポリエステルを使用したものは保存テストで完全に固化していまい、特性を測ることすらできない。
【００３３】
トナーのランニング後の経時変化（画像出し２０００枚後）
画像出しは一成分現像で行ない、帯電量はスリーブ上のトナーの帯電量である。
【００３４】
【表３】

表３の結果より、環化ブタジエン単独かあるいは環化ブタジエンとｔｒａｎｓ１，４−ポリブタジエンの組み合わせの場合、帯電量の変化が殆どなく、地肌汚れも殆ど変化していない。環化ブタジエンと高融点ポリエステルの組み合わせでは、僅かに帯電量の変化と地肌汚れの劣化が見られるが、問題とならないレベルである。高融点ポリエステル単独の場合、帯電量の低下と地肌汚れの増加があるが、使えないレベルではない。低融点ポリエステル単独では、大幅な帯電量低下と地肌汚れの劣化が起こり、使えないレベルである。
【００３５】
また、作像系におけるテストを行なった。
トナースペントについては二成分現像、現像ローラフィルミングと現像ブレード固着については一成分現像にてテストを行ない、一成分、二成分現像とも２０００枚の画像を出した後評価した。
【００３６】
【表４】

○：発生なし
△：発生はしているが程度が軽く問題とならない
×：画像品質に大きな影響が出て使えない
【００３７】
環化ブタジエンや環化ブタジエンとｔｒａｎｓ １，４−ポリブタジエンの組み合わせの系では、初期品質と殆ど変化がなかった。
環化ブタジエンと高融点ポリエステルの組み合わせでは、現像ローラフィルミングがわずかに発生しているが、画像上全く問題にならない。高融点ポリエステルのみの場合、二成分現像ではキャリアへのトナースペント、一成分現像では現像ローラフィルミング、現像ブレードへのトナー固着がやや見られるが、問題となるレベルではなく従来からの性能である。低融点ポリエステルの場合、二成分現像におけるトナースペント、一成分現像における現像ローラフィルミング、現像ブレードへのトナー固着など激しいトナーの付着が見られる。このとき、画像上では画像濃度ムラ、転写紙の地肌汚れ、画像の縦白スジなどさまざまな異常画像の発生が見られ、画像品質の上からもこの系は使用できない。
次に、被印刷物の保存性であるが、片面印刷と両面印刷両方の場合に分けてテストした。
【００３８】
【表５】

以上より、比較例２の低融点ポリエステルを使用した場合のみ転写紙の汚染やブロック化が起こり使用できない。
【００３９】
また、トナー化する際の粉砕工程についての評価を行なった。
以下は、一定量のトナーが所望の粒径のトナーとしてでき上がるまでの時間と付着状況の評価である。
【００４０】
【表６】

以上のように実施例１〜８及び比較例１まではほぼ工程上問題ないといえる。また、ワックスを添加したものの方が粉砕時間が非常に短くなることが判る。しかし、比較例２の低融点ポリエステルを使用した系では、粉砕時間が通常の二倍以上かかり、かつ粉砕室内のトナー付着が激しく、粉砕中に粉砕条件が変化してしまう。
従って、低融点ポリエステルの系では、トナー加工上大きな問題があるといえる。
【００４１】
【発明の効果】
以上、詳細かつ具体的な説明から明らかなように、本発明において、環化ブタジエンより融点の低いｔｒａｎｓ １，４−ポリブタジエンで環化ブタジエンが溶解することにより、環化ブタジエンの融点より低い温度で定着が可能となり、省エネルギーが可能となり、また、低融点トナーであっても環化ブタジエン自体の融点は高いので保存性が良好になり、また、環化ブタジエンは硬い樹脂なので、外添剤がトナーにめり込んだり、低分子の樹脂による外添剤の汚染がなく特性変化を最小限に抑えることができ、また、硬く粘着性のない環化ブタジエンを使用することにより、トナースペント、フィルミング、固着等を防止でき、さらにまた、融点の高い樹脂で硬く粘着性のない樹脂なので、被印刷物がブロック化せず、更に、低融点トナーでありながら、使用している環化ブタジエンが柔らか過ぎず適度に硬いので良好に粉砕することができるという極めて優れた効果を奏するものである。
【図面の簡単な説明】
【図１】本発明において環化ブタジエン反応を示した図の一例である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to electrophotography used in copying machines, facsimiles, printers, and the like.
[0002]
[Prior art]
Conventionally, thermal fixing is often used for fixing toner.
As a principle of fixing, in general, in the case of heat fixing, the toner to be fixed must be softened or melted by the heat of the fixing device, and further, the softened or melted toner receives pressure from the fixing device and receives the fiber of the paper. The surface of the toner that has been indented or softened or melted is sticky, and therefore adheres with its adhesive strength.
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.
[0003]
However, in recent years, the demand for energy saving is increasing for the preservation of the global environment, and the energy that can be consumed by the fixing device is being limited. Actually, in order to lower the fixing energy, the temperature of the fixing device must be lowered, and the toner resin corresponding to the fixing device having such a reduced fixing energy inevitably has a low melting point. However, the resin having a lowered melting point tends to be soft, and can be easily blocked after being processed into toner, or because the surface has adhesiveness, the interaction with the external additive in the toner changes over time, Changes in characteristics occur and there are problems in terms of storage stability. Similarly, because the toner is soft and sticky inside the developing machine, 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. Furthermore, there is a problem that the printed paper is likely to be blocked due to environmental changes in the image after printing. In addition, there are problems in the processing of the toner, and if the melting point is lowered with a conventional resin, the resin is too soft, so that the toner is difficult to pulverize in the pulverization process or sticks in the pulverizer. There is also a problem.
[0004]
[Problems to be solved by the invention]
The present invention is to provide a toner that solves the above-described problems.
Accordingly, the object of the present invention is to save energy by lowering the fixing temperature as compared with the prior art, in view of the above prior art, to improve the storage stability compared to the conventional toner using the low melting point resin, and to the external additive The purpose of the present invention is to prevent the interaction with the toner from changing with time, to prevent toner spent, filming, and sticking, to improve the storage stability of the printing material, and to obtain good crushing processability. To do.
[0005]
[Means for Solving the Problems]
The present inventors completed the present invention as a result of intensive studies to improve the above-mentioned drawbacks.
That is, the problem of the present invention, (1) "electrophotographic toner characterized by using the cyclized butadiene main binder", (2) "the cyclization butadiene trans 1,4-polybutadiene characterized in that said dissolving at a temperature higher than the melting point of the trans 1,4-polybutadiene as solvent the (1) the toner for electrophotography according to claim ', (3) "the cyclization butadiene and trans 1,4 by mixing polybutadiene, characterized in that said which enables fixing at a temperature lower than the melting point of the cyclized butadiene first (1) the toner for electrophotography according to claim ', wherein cyclization (4) "binder composition ratio characterized in that said butadiene is at least 10 wt% of the (1) the toner for electrophotography according to claim ', (5) the relative "the cyclization butadiene trans l, 4 - the composition ratio of polybutadiene, 97: 3-5: characterized in that said 95 second (2) or toner for electrophotography according to the (3) ", (6)" the trans 1,4 the melting point of polybutadiene, characterized in that said lower than the melting point of the cyclized butadiene first (2) or the (3) the toner for electrophotography according to claim ', (7) "cyclization of the cyclized butadiene The electrophotographic toner according to item (1), wherein the purity is 50% or more, and (8) “the purity of the trans 1,4-polybutadiene is 60 wt% or more. The toner for electrophotography as described in (2) or (3) above, (9) “Containing as a grinding aid such that wax: resin is 1: 99-50: 50”. The electrophotographic toner described in item (1) above, (10) “Toner for electrophotography according to any one of (1) to (9) above, wherein the penetration of wax used is 0 to 20”. Achieved.
[0006]
The invention of item 10 will be described in detail.
The inventions of the above items (1), (2), and (3) are basic and have a high melting point as a main binder and have good storage stability, resistance to spent, filming, and adhesion resistance. A cyclized butadiene is used, and this is dissolved in trans 1,4-polybutadiene, and solidified to obtain a toner. Therefore, when this is subjected to heat fixing, the cyclized butadiene dissolves in the trans 1,4-polybutadiene at a temperature equal to or higher than the melting point of trans 1,4-polybutadiene, and the cyclized butadiene does not reach the melting point of the cyclized butadiene. Softens or dissolves and develops fixing performance. In addition, since melting | fusing point of cyclized butadiene itself is high, resin is not too soft and favorable crushability is obtained.
[0007]
In the invention described in item (4), when cyclized butadiene is mixed with a conventional resin at a binder composition ratio, the cyclized butadiene content in at least the entire resin is prescribed to be 10 wt% or more. If the amount is less than 10 wt%, the melting point of the toner mixed with the conventional resin cannot be lowered sufficiently, resulting in poor fixing. As a result of intensive studies on the cyclized butadiene content, it is preferably 15 wt% or more, more preferably 20 wt% or more, still more preferably 30 wt% or more, still more preferably 40 wt% or more, and even more preferably 50 wt% or more.
[0008]
In the invention described in item (5), with regard to the composition ratio of trans 1,4-polybutadiene to cyclized butadiene, the greater the amount of trans 1,4-polybutadiene formulated, the lower the dissolution viscosity of cyclized butadiene. However, when the amount of cyclized butadiene is reduced, trans 1,4-polybutadiene does not dissolve other resins and does not mix with the resin, so the resin and trans 1,4-polybutadiene are separated and become toner. Is difficult. When the amount of the cyclized butadiene is large and the amount of trans 1,4-polybutadiene is small, even if the cyclized butadiene is dissolved in the trans 1,4-polybutadiene, the solution viscosity is too high and fixing performance cannot be obtained. As a result of intensive studies, it has been clarified that when the composition ratio of cyclized butadiene and trans 1,4-polybutadiene is 97: 3 to 5:95, performance is obtained. 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 can be considered, and preferably 95: 5 to 20: 80, more preferably 90:10 to 30:70, and even more preferably 80:20 to 40:60 in view of the margin.
[0009]
In the invention described in item (6), unless the melting point of trans 1,4-polybutadiene is lower than the melting point of cyclized butadiene, trans 1,4-polybutadiene does not melt below the melting point of cyclized butadiene. Cyclized butadiene cannot be dissolved with trans 1,4-polybutadiene, 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.
[0010]
In the case of the invention described in item (7), as a result of investigation, it was found that if the degree of cyclization is 50% or more on average, good properties as cyclized butadiene can be exhibited. If the degree of cyclization is low, the cyclized butadiene will exhibit the properties of the original rubber, and the grindability will be significantly reduced and cannot be used in the present invention. In addition, when the degree of cyclization is about 30%, the cyclized butadiene itself becomes soft and the liquid property becomes strong. Therefore, as a result of investigation, a more preferable value is 70% or more.
[0011]
In the case of the invention described in item (8), even if it is a synthetic product, it contains cis 1,4-polybutadiene, isotactic-1,2-polybutadiene, syndiotactic-1,2-polybutadiene, etc. as by-products. As a result of investigation, it was found that the trans 1,4-polybutadiene needs to be 60 wt% or more. Preferably it is 70 wt% or more, more preferably 80 wt% or more, and even more preferably 90 wt% or more.
[0012]
In the case of the invention described in item (9), when the trans 1,4-polybutadiene is too strong and the grindability is inferior, the wax: resin is formulated within the range of 1:99 to 50:50. It can be seen that it is improved, preferably in the range of 5:95 to 30:70.
[0013]
In the case of the invention described in item (10), if the penetration of the wax to be used is high, the cohesiveness of the toner becomes high, the thin layer formation property is lowered, and the toner replenishment performance is remarkably lowered. Penetration waxes in the range of -14, more preferably 0-10, even more preferably 0-5 are preferred.
[0014]
In order to solve the problems of the prior art, the present invention uses a resin having a melting point higher than the minimum fixing temperature and a trans 1,4-polybutadiene having a melting point lower than the minimum fixing temperature, and is higher than the melting point of trans 1,4-polybutadiene. The trans 1,4-polybutadiene functions as a solvent or a plasticizer at the temperature of the resin, so that the resin is dissolved at the molecular level by the trans 1,4-polybutadiene, and the resin is softened or dissolved at a temperature lower than the melting point of the resin. I discovered that it would become a system that could be established. As a result, fixing was possible at a temperature in the vicinity of the melting point of trans 1,4-polybutadiene, which is much lower than the melting point of the actually used resin, and energy saving was achieved. As a result, fixing at a low temperature became possible even when a cyclized butadiene having a high melting point was used.
The melting point of the resin in the present invention refers to the softening point 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.
[0015]
Similar to the present invention, JP-A-7-271100, JP-B-7-15596, JP-B-7-31418, JP-B-7-40146, JP-B-7-62765, Japanese Patent Publication No. 7-82248, Japanese Patent Publication No. 7-104612, Japanese Patent No. 2548091, and Japanese Patent No. 2759482 are all disclosed in Japanese Patent Publication No. 7-82612. It is a so-called capsule forming agent used for the purpose of forming a shell for wrapping a polymerized low softening point resin at the time of forming a polymerized toner for the purpose of preventing blocking or the like.
Therefore, these are completely different inventions that are fundamentally different from the present invention.
[0016]
Cyclized butadiene is formed by a reaction as shown in FIG. An example of a method for producing cyclized butadiene is as follows.
In the Fisher method, 5% of concentrated sulfuric acid is kneaded in rubber and heated at 130 ° C. for 15 hours to obtain cyclized butadiene.
In addition, there are methods using organic sulfonic acid, tin chloride, iron chloride, non-metal halides, halogenated first and second tin acids, etc. as cyclizing agents, and various resinous plastic materials can be produced. As shown in FIG. 1, these substances cause an isomerization phenomenon by the action of an oxidizing chemical, increase the specific gravity, decrease the degree of unsaturation, and obtain substances having completely different properties. Can be created in this way.
[0017]
Examples of the subresin that can be used in the present invention include the following.
Examples of binder resins used for each toner include homopolymers of styrene such as polystyrene, poly p-chlorostyrene, polyvinyltoluene and the like; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers 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-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, Styrene-vinyl methyl ketone copolymer Styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc .; Methyl 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 resins, chlorinated paraffins and the like can be mentioned, and these can be used alone or in combination, but are not particularly limited thereto. In the present invention, carbon black and color pigments may be kneaded and dispersed in these resins as necessary, and naturally a charge control agent can be used in combination.
Further, after powdering, additives such as silica, titanium, and strontium may be added to adjust the fluidity of the toner.
[0018]
In the following, description will be given based on examples.
[Example 1]
Cyclized polybutadiene 60wt%
trans 1,4-polybutadiene 27wt%
Carbon black 12wt%
CCA 1wt%
[0019]
[Example 2]
Cyclized polybutadiene 40wt%
trans 1,4-polybutadiene 20wt%
Magnetic material 39wt%
CCA 1wt%
[0020]
[Example 3]
Cyclized polybutadiene 57wt%
trans 1,4-polybutadiene 24wt%
Carbon black 12wt%
CCA 1wt%
Carnauba 6wt%
[0021]
[Example 4]
Cyclized polybutadiene 57wt%
trans 1,4-polybutadiene 24wt%
Carbon black 5wt%
CCA 1wt%
Candelilla 6wt%
[0022]
[Example 5]
Cyclized polybutadiene 94wt%
Carbon black 5wt%
CCA 1wt%
[0023]
[Example 6]
Cyclized polybutadiene 74wt%
trans 1,4-polybutadiene 20wt%
Cyan 5wt%
CCA 1wt%
[0024]
[Example 7]
Cyclized polybutadiene 72wt%
trans 1,4-polybutadiene 22wt%
Yellow 5wt%
CCA 1wt%
[0025]
[Example 8]
Cyclized polybutadiene 42wt%
High melting point polyester (melting point 155 ° C) 30wt%
trans 1,4-polybutadiene 22wt%
Carbon black 5wt%
CCA 1wt%
[0026]
[Comparative Example 1]
High melting point polyester (melting point 155 ° C) 94wt%
Carbon black 5wt%
CCA 1wt%
[0027]
[Comparative Example 2]
Low melting point polyester (melting point 94 ° C) 94wt%
Carbon black 5wt%
CCA 1wt%
Each of the above examples was kneaded five times with three rolls, cooled and pulverized, and 1 part of silica as an external additive was added to 100 parts of toner and mixed to obtain a final toner.
When these toners were used and the experiment was performed while actually changing the temperature of the fixing device, the results shown in Table 1 were obtained.
In the prescription containing wax, it is not necessary to apply oil to the fixing roller. However, in order to unify the conditions, oil was applied to the roller for all toners.
[0028]
[Table 1]

○: Good fixing Δ: Barely fixed ×: Cyclic butadiene causing poor fixing alone and high melting point polyester (155 ° C.) only, fixing is not performed unless a temperature of 160 ° C. or higher is applied. In the system using other trans 1,4-polybutadiene, the fixing temperature of 60 to 80 ° C. could be lowered.
[0029]
When the storability test was conducted using the toner, the results shown in Table 2 were obtained. (Storage environment 40 ° C for 2 weeks)
[0030]
[Table 2]

A circle indicates that there is no change. [0031]
The charge amount represents the charge amount on the sleeve for one-component development.
For OPC background stains, remove the toner adhering to the OPC with a transparent adhesive tape, paste it onto a white paper, measure the density ID1 with a Macbeth reflection densitometer, and then apply the transparent adhesive tape without toner to the white paper. This is the difference between the measurement results when the density ID2 is pasted on the surface.
[0032]
[Expression 1]
ΔID = ID1-ID2
From the above results, it is understood that there is no change in the storage stability and characteristics of the cyclized butadiene and trans 1,4-polybutadiene which have a low melting point. Moreover, there is no problem in the storage stability of ordinary high-melting polyester, and there is a slight change in characteristics, but it does not become a problem. However, those using low-melting polyesters are completely solidified in the storage test, and the properties cannot be measured.
[0033]
Change with time after running toner (after 2000 images)
Image output is performed 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 cyclized butadiene alone or a combination of cyclized butadiene and trans 1,4-polybutadiene, there is almost no change in the charge amount, and the background dirt is hardly changed. In the combination of cyclized butadiene and high-melting point polyester, a slight change in charge amount and deterioration of background stains are observed, but at a level that does not cause a problem. In the case of the high melting point polyester alone, there is a decrease in charge amount and an increase in background stains, but it is not at an unusable level. The low melting point polyester alone is a level that cannot be used due to a significant decrease in charge amount and deterioration of background stains.
[0035]
In addition, a test in an imaging system was performed.
The toner spent was tested by two-component development, and the developing roller filming and the developing blade fixing were tested by one-component development, and both the one-component and two-component development were evaluated after producing 2000 images.
[0036]
[Table 4]

◯: No occurrence △: Occurred, but the degree is light and no problem ×: Image quality is greatly affected and cannot be used [0037]
There was almost no change from the initial quality in the system of cyclized butadiene or a combination of cyclized butadiene and trans 1,4-polybutadiene.
In the combination of the cyclized butadiene and the high melting point polyester, the developing roller filming is slightly generated, but it does not cause any problem on the image. In the case of high-melting polyester only, two-component development shows toner spent on the carrier, one-component development shows filming on the developing roller and toner adhesion to the developing blade, but this is not a problem level but a conventional performance. . In the case of a low melting point polyester, intense toner adhesion such as toner spent in two-component development, developing roller filming in one-component development, and toner fixing to the developing blade is observed. At this time, various abnormal images such as image density unevenness, transfer paper background stain, vertical white streak of the image are observed on the image, and this system cannot be used from the viewpoint of image quality.
Next, the storability of the substrate was tested separately for both single-sided printing and double-sided printing.
[0038]
[Table 5]

From the above, only when the low melting point polyester of Comparative Example 2 is used, transfer paper is contaminated or blocked, and cannot be used.
[0039]
In addition, the pulverization process when converting to toner was evaluated.
The following is an evaluation of the time taken for a certain amount of toner to be produced as a toner having a desired particle diameter and the state of adhesion.
[0040]
[Table 6]

As described above, it can be said that Examples 1 to 8 and Comparative Example 1 have almost no problem in the process. It can also be seen that the pulverization 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 takes twice or more than usual, and toner adhesion in the pulverization chamber is intense, and the pulverization conditions change during pulverization.
Therefore, it can be said that the low-melting-point polyester system has a large problem in toner processing.
[0041]
【The invention's effect】
As described above, as is clear from the detailed and specific description, in the present invention, the cyclized butadiene is dissolved in trans 1,4-polybutadiene having a melting point lower than that of the cyclized butadiene. Fixing is possible, energy saving is possible, and even with a low melting point toner, the melting point of the cyclized butadiene itself is high, so that the storage stability is good, and since the cyclized butadiene is a hard resin, an external additive is used as the toner. It is possible to minimize changes in properties without being contaminated or contaminated with external additives by low molecular weight resin, and by using hard and non-adhesive cyclized butadiene, toner spent, filming and fixing In addition, since the resin has a high melting point and is hard and non-adhesive, the printed material does not block, and the low melting point toner However, since the cyclized butadiene used is moderately hard without being too soft, an excellent effect that it can be pulverized well is obtained.
[Brief description of the drawings]
FIG. 1 is an example of a diagram showing a cyclized butadiene reaction in the present invention.

Claims (10)

  An electrophotographic toner using cyclized butadiene as a main binder. 2. The electrophotographic toner according to claim 1, wherein the cyclized butadiene is dissolved using trans 1,4-polybutadiene as a solvent at a temperature equal to or higher than the melting point of trans 1,4-polybutadiene. Wherein by mixing the cyclization butadiene and trans 1,4-polybutadiene, toner for electrophotography according to claim 1, characterized in that the fixable at a temperature lower than the melting point of the cyclized butadiene. The electrophotographic toner according to claim 1, wherein the cyclized butadiene is 10 wt% or more based on the constituent ratio of the binder. 4. The electrophotographic toner according to claim 2, wherein a composition ratio of the trans 1,4-polybutadiene to the cyclized butadiene is 97: 3 to 5:95. 5. Melting point of the trans 1,4-polybutadiene is, toner for electrophotography according to claim 2 or 3, characterized in that below the melting point of the cyclized butadiene. 2. The electrophotographic toner according to claim 1, wherein the degree of cyclization of the cyclized butadiene is 50% or more. The electrophotographic toner according to claim 2 or 3 , wherein the purity of the trans 1,4-polybutadiene is 60 wt% or more.   2. The electrophotographic toner according to claim 1, wherein the pulverization aid is contained in a ratio of wax: resin of 1:99 to 50:50. 3.   The toner for electrophotography according to any one of claims 1 to 9, wherein the penetration of the wax used is from 0 to 20.

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