JP2009241047A - Kneading apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a kneading apparatus providing high dispersion at a low kneading temperature and performing kneading at a high treatment rate. <P>SOLUTION: The kneading apparatus is provided with two rolls for kneading a raw material mixture. A first roll in two rolls has a surface on which wear resistant hardening treatment is applied and the second roll has no surface-treated surface. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a kneading apparatus, and more particularly to a two-roll kneading apparatus capable of kneading a raw material mixture with high dispersibility and a high processing speed.

Semiconductors that are high-concentration pigment dispersions (masterbatches), polymer alloys with high-precision dispersion mixing of multiple types of thermoplastic resins, electrophotographic toners, composite rubber compositions, and epoxy resin molding materials that contain a large amount of silica filler In the production of a sealing insulating material or the like, an advanced dispersion technique is required, and a two-roll mill, which is a kneader that imparts a very high shearing force, is used as the dispersion means.
However, such a two-roll mill is a kneading machine that applies a shearing force to the material to be kneaded while adhering the material to be kneaded on one roll, so that when the pigment concentration or the filler concentration is very high, wax or the like In the case where the release agent is included, when the adhesion of the thermoplastic resin as the dispersion medium is low, advanced adjustment is required for the roll temperature, the gap between the rolls, the supply amount, and the like.
Therefore, the skill of a specific expert is required, or the kneaded material needs to be repeatedly supplied to the roll mill, resulting in a decrease in production speed.
On the other hand, in an open type two-roll mill, it has been proposed to improve the kneading capacity by adjusting the pitch and depth of grooves formed in the roll (for example, Patent Documents 1 and 2). The effect was low, and improvement in productivity at a higher production rate was desired.

JP 2003-29456 A

JP 2003-29457 A

  The present invention has been made under the circumstances as described above, and an object thereof is to provide a kneading apparatus capable of obtaining high dispersion at a low kneading temperature and kneading at a high processing speed.

In order to solve the above-described problems, one aspect of the present invention is a kneading apparatus including two rolls for kneading a raw material mixture, and the first roll of the two rolls has a resistance to the surface. Provided is a kneading apparatus characterized in that a wear hardening treatment is performed and a surface treatment is not performed on the second roll.
In such a kneading apparatus, the raw material mixture does not adhere to the first roll whose surface is subjected to the wear-resistant hardening treatment, and the raw material mixture is not attached to the second roll which has not been subjected to the surface treatment. It will adhere.
In this case, titanium carbide coating, tungsten carbide coating, titanium nitride multilayer coating, triple titanium coating, composite multilayer titanium coating, titanium carbonitride multilayer coating, titanium nitride alumina coating, chromium nitride coating, gas A treatment selected from the group consisting of nitriding, salt bath nitriding, tuftride, and plasma nitriding can be applied to the first roll.

  The kneading apparatus according to one embodiment of the present invention can be a batch type or a continuous type.

  According to the present invention, there is provided a kneading apparatus capable of obtaining high dispersion at a low kneading temperature and kneading at a high processing speed.

Hereinafter, embodiments of the present invention will be described.
A kneading apparatus according to an embodiment of the present invention is a kneading apparatus for kneading a raw material mixture, and includes two rolls. Of the two rolls, the first roll has wear resistance on the surface. A curing process is performed, and the second roll is not subjected to a surface treatment.

  In this way, one of the two rolls is subjected to wear-resistant hardening treatment, and the other roll is not subjected to surface treatment, thereby providing a difference in the adhesion of the material to be kneaded to the roll surface, That is, the processing speed can be greatly improved by reducing the adhesion of the roll that has been subjected to the wear-resistant hardening treatment and maintaining the adhesion of the roll that has not been subjected to the surface treatment.

  For example, as shown in FIG. 1, when a two-roll kneading apparatus comprising a roll 1 subjected to wear-resistant hardening treatment and a roll 2 not subjected to surface treatment is driven, the surface of the roll 2 not subjected to surface treatment is driven. The to-be-kneaded material 3 adheres, but the to-be-kneaded material 3 does not adhere to the surface of the roll 1 subjected to the abrasion-resistant hardening treatment. Thus, by providing a difference in the adhesion of the material to be kneaded 3 between the two rolls, a large shearing force can be applied to the material to be kneaded 3 and the processing speed can be increased.

  If both of the two rolls are subjected to the abrasion-resistant curing treatment, the adhesion of both rolls decreases, and the kneaded material cannot be efficiently and selectively attached to the roll on the side to which the kneaded material is to be attached. Therefore, the kneaded material does not adhere to either roll, and the kneaded material spills as it is, so that it is not possible to apply a shearing force to the kneaded material. On the other hand, if the surface treatment is not applied to both of the two rolls, the kneaded material will also adhere to the roll side that is not desired to adhere, in order to maintain the adhesiveness of both of them. It will cause a decline.

  The wear-resistant hardening treatment includes titanium carbide coating, tungsten carbide coating, titanium nitride multilayer coating, triple titanium coating, composite multilayer titanium coating, titanium carbonitride multilayer coating, titanium nitride alumina coating, chromium nitride coating, gas nitriding method And various treatments such as a salt bath nitriding method, a tuftride method, and a plasma nitriding method.

Specific examples of the roll for a two-roll kneader include an outer layer made of a wear-resistant cast iron material or cemented carbide material, such as a high-speed steel with excellent wear resistance, and an inner layer made of a cast steel material having excellent toughness. The composite roll etc. which are cast and weld-integrated are mentioned.
Examples Hereinafter, examples and comparative examples of the present invention will be shown, and the present invention will be described in more detail.
As a batch type two roll mill, Kodaira Seisakusho Co., Ltd .: Test two roll R2 type (steam heating type) roll size: 63.5φ × 150 Lmm was used. The roll prepared the roll which performed the abrasion-resistant surface treatment by a gas nitriding method, and the roll which does not perform a surface treatment.
As a continuous two-roll mill, Mitsui Mining Co., Ltd. product: open roll continuous kneading granulator: MOS100-500 roll size: 100φ × 500 Lmm was used. As the roll, a roll subjected to wear-resistant surface treatment by a plasma nitriding method and a roll not subjected to surface treatment were prepared.
The materials to be kneaded are a pigment master batch, an electrophotographic toner, and a composite rubber composition having the following composition.
<Pigment master batch>
Mitsubishi Rayon: Polyester resin (Tm: 108 ° C.) 50 parts by mass Magenta pigment Seika First Carmine 1476T-7 (manufactured by Dainichi Seika) 50 parts by mass <Electrophotographic toner>
Kao Co., Ltd .: Polyester resin (Tm: 136 ° C.) 50 parts by mass Magenta pigment Seika First Carmine 1476T-7 (manufactured by Dainichi Seika Co., Ltd.) 5 parts by mass Carnauba wax No. 1 (manufactured by Nippon Wax Co., Ltd.) 5 Part by mass “Bondlon E-84” (manufactured by Orient Chemical Co., Ltd.) 1.5 parts by mass <Composite rubber composition>
Epichlorohydrin rubber (Zeklon G3100, manufactured by Nippon Zeon Co., Ltd.) 100 parts by mass Liquid NBR 27 parts by mass Ketjen Black EC300J (manufactured by Lion Corporation) 25 parts by mass Calcium carbonate 20 parts by mass Zinc oxide 5 parts by mass Surface-treated sulfur 1 part by mass Part Vulcanization accelerator 0.3 part by mass Examples 1-3, Comparative Examples 1-3
The above-described materials to be kneaded were kneaded by a batch type two roll mill.
First, 1.5 kg of a raw material having a predetermined formulation was charged into a Henschel mixer (effective capacity: 10 liters) and mixed for 1 minute at a blade rotation speed of 2500 rpm. Next, manufactured by Moriyama Co., Ltd .: using a tangential (differential) small-capacity pressure type kneader D3-10 mixing capacity: 3 liters, main motor: 10 HP (7.5 kW), the mixing tank temperature is Tg of the binder or more, The temperature was set to Tm or lower, and after pre-kneading until the material was sufficiently uniform, the obtained pre-kneaded product was put into a batch type two-roll mill.

The kneading conditions by the two-roll mill were set at a low temperature so as to give the pre-kneaded material as high a shearing force as possible. Table 1 shows the conditions when the temperature conditions enabling stable production are adjusted.
Examples 4-6, Comparative Examples 4-6
About the above to-be-kneaded thing, the kneading | mixing process by a continuous type 2 roll mill was performed.

  First, 1.5 kg of a raw material having a predetermined formulation was charged into a Henschel mixer (effective capacity: 10 liters) and mixed for 1 minute at a blade rotation speed of 2500 rpm. Next, a twin-screw extruder (L / D = 13) for preliminary kneading and a continuous two-roll mill were arranged as shown in FIG. 2, and continuous feeding was performed in a state where the kneaded material was melted. 2A shows a side view and FIG. 2B shows a front view.

  As shown in FIG. 2A, the biaxial extrusion kneader includes a hopper 11 to which a raw material mixture is supplied, a cylinder 12 divided into a plurality of zones C1 to C8, and a die nozzle 13 from which a molten mixture is discharged. is doing. Each zone C1 to C8 of the cylinder 2 is heated to a predetermined temperature by a heater (not shown), and in the cylinder 12, two are arranged so that their axes are parallel or have a predetermined angle. A cylindrical screw (not shown) is arranged. The screw rotates in the same direction or in the opposite direction.

  The raw material mixture supplied from the hopper 11 is introduced into the cylinder 12 and is melted by the heat from the heated cylinder 12 in the gap between the screws, and is mixed by the compression force and shearing force due to the rotation of the screw. Then, it moves to the side of the die nozzle 13 along the spiral blade of the screw and is discharged from the die nozzle 13.

  The molten mixture discharged from the die nozzle 13 is then fed to a continuous two-roll mill where it is kneaded. As shown in FIGS. 2 (a) and 2 (b), the continuous two-roll mill includes two rolls 22 and 23 arranged in parallel and a discharge unit 24 through which the kneaded material is discharged. .

The molten mixture supplied between the rolls 22, 23 is repeatedly compressed and kneaded by the rotation of the rolls 22, 23 while being wound around one surface of the rolls 22, 23. Moves to the discharge unit 24 side, and the kneaded material is discharged from there.
One of the rolls 22 and 23 is subjected to wear-resistant surface treatment by gas nitriding, and the other roll is not subjected to surface treatment.
The kneading conditions by the two-roll mill were set at a low temperature so as to give the pre-kneaded material as high a cutting force as possible. Tables 2 and 3 below show the conditions when the temperature conditions for stable production are adjusted.

上記表１〜表３に示すように、顔料マスターバッチの混練について、実施例１と比較例１の比較、及び実施例４と比較例４の比較から、以下のことがわかる。即ち、実施例１では比較例１に比べ、ロール設定温度を２０度低く設定することができた。また、実施例４では比較例４に比べ、供給側Ｂロール設定温度を低く設定することができ、処理速度が大きく改善された。
通常、高顔料濃度のマスターバッチの製造のためには、しばしば有機溶剤や水などを添加し、濡れ性を改善するなど独自の手法を行い、高分散性と高生産性を得ようとするが、そうすることにより添加物が残留した場合などの品質トラブルを招く可能性がある。
これに対し、実施例１及び４では、ロールヘの付着性が改善され、上記のような手法をとることなく十分な分散性を得ることができた。顔料の分散性も、下記表４に示すように良好であった。

As shown in Tables 1 to 3, the following can be understood from the comparison between Example 1 and Comparative Example 1 and the comparison between Example 4 and Comparative Example 4 regarding the kneading of the pigment master batch. That is, in Example 1, compared with Comparative Example 1, the roll set temperature could be set 20 degrees lower. Moreover, in Example 4, compared with Comparative Example 4, the supply side B roll set temperature could be set lower, and the processing speed was greatly improved.
Usually, in order to produce a masterbatch with a high pigment concentration, an organic solvent or water is often added to improve the wettability to obtain high dispersibility and high productivity. Doing so may cause quality problems such as when additives remain.
On the other hand, in Examples 1 and 4, adhesion to the roll was improved, and sufficient dispersibility could be obtained without taking the above-described method. The dispersibility of the pigment was also good as shown in Table 4 below.

なお、分散性の評価方法としては、ＪＩＳＫ−５６００（粒度分布法）を用い、アノン：ＴＨＦ＝１：１溶液にマスターパッチを２０質量部溶解させたものを試験した。
また、電子写真用トナーの混練について、実施例２と比較例２の比較、及び実施例５と比較例５の比較から、実施例２及び実施例５では、同様にロール設定温度を低く設定することが可能であった。

In addition, as a dispersibility evaluation method, JISK-5600 (particle size distribution method) was used, and 20 mass parts of a master patch dissolved in anone: THF = 1: 1 solution was tested.
Further, regarding the kneading of the toner for electrophotography, from the comparison between Example 2 and Comparative Example 2 and the comparison between Example 5 and Comparative Example 5, in Example 2 and Example 5, the roll set temperature is similarly set low. It was possible.

  About 200 wax particles in the obtained electrophotographic toner were observed with a transmission electron microscope (2500 times), and the average particle diameter of the wax was calculated to obtain dispersibility (μm). The results are shown in Table 4 below. Since the observed wax shape is elliptical, the average particle size shown in Table 5 below was calculated based on the following equation (1).

ａ：ワックス粒子の長径［μｍ］
ｂ：ワックス粒子の短径［μｍ］
ｎ：ワックス粒子の測定個数

a: Long diameter of the wax particle [μm]
b: Wax particle short diameter [μm]
n: Number of wax particles measured

上記表５から、実施例２及び５では、カルナバワックスの分散性が改善され、耐久性の高いトナーを得ることが可能である。
また、複合ゴム組成物の混練について、以下のように評価した。
得られた複合ゴム組成物を鋼板（材質：ＳＵＳ３０１）上に厚さ２ｍｍで均一に整形し、次いで１５０℃で０．５時間加熱し、加硫させた。その後、研削して鋼板（材質：ＳＵＳ３０１）上に厚さ１ｍｍの導電弾性層を形成した。この導電弾性層について、電気抵抗値を測定した。

From Table 5 above, in Examples 2 and 5, it is possible to improve the dispersibility of carnauba wax and obtain a highly durable toner.
Further, the kneading of the composite rubber composition was evaluated as follows.
The obtained composite rubber composition was uniformly shaped on a steel plate (material: SUS301) with a thickness of 2 mm, and then heated at 150 ° C. for 0.5 hours to be vulcanized. Thereafter, grinding was performed to form a conductive elastic layer having a thickness of 1 mm on a steel plate (material: SUS301). The electrical resistance value of this conductive elastic layer was measured.

  The electrical resistance value was measured by pressing an electrode having a weight of 500 g (φ50 mm) and measuring the electrical resistance value with a steel plate (material: SUS301). The measurement was performed in three normal states (10 ° C./20%, 23 ° C./50%, 38 ° C./80%) at any three points from the center in the length direction and the center, and the average value was taken as the measured value. The results are shown in Table 6 below.

上記表６に示すように、実施例３と比較例３の比較、及び実施例６と比較例６の比較から、実施例３及び６では、導電性カーボンの分散性が向上し、電気抵抗値が低下していることがわかる。
以上、顔料マスターバッチ、電子写真用トナー、及び複合ゴム組成物の混練についての実施例について示したが、本発明は、これらに限らず、（１）フィルムの製造、（２）粉体塗料の製造、（３）プラスチック容器の製造、（４）タイヤの製造、（５）絶縁体の製造、及び（６）廃プラスチックのリサイクルについての混練にも同様に適用することが可能である。

As shown in Table 6 above, from the comparison between Example 3 and Comparative Example 3 and from the comparison between Example 6 and Comparative Example 6, in Examples 3 and 6, the dispersibility of the conductive carbon is improved and the electrical resistance value is increased. It can be seen that is decreasing.
As mentioned above, although the example about the kneading | mixing of a pigment masterbatch, the toner for electrophotography, and a composite rubber composition was shown, this invention is not restricted to these, (1) Manufacture of a film, (2) Powder coating The present invention can be similarly applied to kneading for manufacturing, (3) manufacturing of plastic containers, (4) manufacturing of tires, (5) manufacturing of insulators, and (6) recycling of waste plastics.

  In the above embodiments, the case where the gas nitriding method and the plasma nitriding method are used as the wear-resistant metal surface treatment is shown. However, the present invention is not limited to this, and the titanium carbide coating and the tungsten carbide coating are used. , Titanium nitride multilayer coating, triple titanium coating, composite multilayer titanium coating, titanium carbonitride multilayer coating titanium nitride alumina coating, chromium nitride coating, salt bath nitriding method, tuftride method, etc. can also be used for wear-resistant metal surface treatment is there.

It is a figure explaining operation | movement of the 2 roll kneading apparatus which concerns on one Embodiment of this invention. It is a figure which shows the combination of a twin-screw extruder and a continuous type 2 roll mill.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Roll which gave the abrasion-resistant hardening process, 2 ... Roll which does not surface-treat, 3 ... To-be-kneaded material, 11 ... Hopper, 12 ... Cylinder, 13 ... Die nozzle, 22, 23 ... Roll, 24 ... Discharge part.

Claims (5)

  A kneading apparatus comprising two rolls for kneading a raw material mixture, wherein the first roll of the two rolls is subjected to a wear-resistant hardening treatment on the surface, and the second roll The kneading apparatus is characterized in that no surface treatment is applied.   The raw material mixture does not adhere to the first roll whose surface has been subjected to the wear-resistant hardening treatment, and the raw material mixture adheres to the second roll which has not been subjected to the surface treatment. The kneading apparatus according to claim 1.   The wear-resistant hardening treatment includes titanium carbide coating, tungsten carbide coating, titanium nitride multilayer coating, triple titanium coating, composite multilayer titanium coating, titanium carbonitride multilayer coating, titanium nitride alumina coating, chromium nitride coating, gas nitriding method The kneading apparatus according to claim 1, wherein the kneading apparatus is a treatment selected from the group consisting of a salt bath nitriding method, a tuftride method, and a plasma nitriding method.   The kneading apparatus according to any one of claims 1 to 3, wherein the kneading apparatus is a batch type.   The kneading apparatus according to any one of claims 1 to 3, wherein the kneading apparatus is a continuous type.

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