JP2000300978A - Pigment circulating and dispersion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a pigment paste superior in pigment dispersing properties. SOLUTION: The pigment circulating and dispersing device is provided with a pigment dispersing machine B, an agitating and circulating device A for introducing a liquid to be treated into the pigment dispersing machine B, receiving a treated liquid treated in the dispersing machine B and circulating the same and also a pump 15 and a piping 9 for carrying the treated liquid, and the agitating and circulating device A is provided with a washable cylindrical mixing and agitating tank 3 having a treated liquid introduction opening 1 in the upper direction, a treated water discharge outlet 2 in the bottom section direction and rotating shaft 4 suspended to the central section in the agitating tank, and the ratio between the inner diameter of the cylindrical agitating tank 3 and the wing diameter of a bottom section flat paddle wing 6 is 1/0.6-0.9, and the ratio of the height of the bottom flat paddle wing 6 and that of an upper flat paddle wing 7 is in the range of 1/1-4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an apparatus for producing a pigment paste to be blended especially in paints, inks and the like, and a dispersing machine for dispersing aggregates of pigments composed of secondary particles into primary particles. The present invention relates to a device for mixing and stirring a pigment paste to be supplied to the dispersing machine, and a pigment circulating / dispersing device including a pump and a piping required for these devices.

[0002]

2. Description of the Related Art Conventionally, coloring liquids such as paints and inks are
A mixture of a clear resin varnish and a pigment paste is generally used. As the pigment paste, a method is generally used in which a mill base obtained by mixing raw materials such as a pigment, a varnish, and an organic solvent is passed several times through a continuous disperser such as a bead mill disperser to disperse the pigment. In such a method, the untreated pigment paste stored in the supply tank is dispersed by a disperser, and the obtained pigment paste is temporarily stored in a receiving tank, and
After the second pigment dispersing treatment is completed, the pigment paste stored in the receiving tank is dispersed by a dispersing machine, and the pigment paste subjected to the second pigment dispersing treatment is stored in the original supply tank. A method of dispersing a pigment by repeating a plurality of times is generally performed. However, such a method has problems that two tanks, a supply tank and a receiving tank, are required, and a switching operation between these tanks is required. Conventional bead mills that employ dynamic separation require only one tank because of their large processing capacity (flow rate) and the ability to circulate and disperse, and require only one tank to switch between supply and receiving tanks. There is an advantage that it disappears. However, even if the pigment is dispersed and mixed using the above-described bead mill,
If the mixing and stirring in the circulation tank are not sufficient, there is a possibility that the mill base may be short-circuited when flowing in and out through the circulation tank (for example, anchor type, propeller type). If so, there is a disadvantage that the efficiency of pigment dispersion is reduced. Further, a twin-screw mixer equipped with a high-speed stirrer and a low-speed anchor-type stirring blade for scraping off a mill base retained on a tank wall has been developed in order to improve stirring and mixing in the circulation tank. However, since the twin-screw mixer has a high equipment cost and a small distance between the tank wall and the anchor-type stirring blade, it is difficult to wash the mill base by spraying a washing solvent. Has a problem in cleaning properties. Further, in addition to the above-described stirring mixer, for example, a single-shaft mixer disclosed in
Japanese Unexamined Patent Application Publication No. 3-12122 and Japanese Unexamined Patent Application Publication No. 8-252444 are conventionally known. However, these stirring and mixing apparatuses are suitable for simply mixing the processing liquid in the tank uniformly because the circulation flow of the processing liquid in the tank is fast. When used as a circulating dispersion system in which the processing liquid is sent into the tank from the pipe and taken out from the lower part of the tank, and the taken out processing liquid is returned to the return pipe through a disperser, the processing liquid supplied from the return pipe is used in the lower part of the tank. There is a drawback that a short circuit occurs without being mixed in the tank because it is immediately taken out of the tank. Furthermore, since the effect of scraping and mixing and circulating the processing liquid on the wall surface of the circulation tank is weaker than that of the anchor-type stirring blade, the pigment paste having a high structural viscosity tends to stay on the wall surface in the tank, so that the mixing and stirring are inferior. There was a drawback.

[0003]

DISCLOSURE OF THE INVENTION The present invention relates to a pigment circulating method which is excellent in various kinds of processing liquids, fluctuations in the amount of the processing liquids, mixing and dispersibility of processing liquids having different viscosities from low viscosity to high viscosity, cleaning properties, and the like. A dispersing device is provided.

[0004]

Means for Solving the Problems The pigment circulating / dispersing apparatus of the present invention comprises a pigment disperser (B), a treatment liquid fed into a pigment disperser (B), and a treatment liquid treated by the disperser (B). A stirring and circulating device (A) for receiving and circulating, a pump (15) and a pipe (9) for transporting these processing liquids are provided, and the stirring and circulating device (A) supplies the processing liquid upward. A washable cylindrical mixing / stirring tank (3) provided with an opening (1) and a processing liquid outlet (2) in the bottom direction, and a rotating shaft (4) suspended from the center of the stirring tank.
A flat paddle blade (5) held perpendicular to the rotation axis (4), and the flat paddle blade (5) substantially has a central axis of the rotation axis (4). The flat paddle wings (5) are symmetrical to each other, and the flat paddle wings (5) are rectangular in the upper direction at the left and right ends of the bottom flat paddle wing (6) and the bottom flat paddle wing (6), respectively. And the ratio of the inner diameter of the cylindrical stirring tank (3) to the blade diameter of the bottom flat paddle wing (6) is 1 / 0.6.
0.9, a height ratio between the bottom flat paddle wings (6) and the upper flat paddle wings (7) is in the range of 1/1 to 4, In particular, the processing liquid to be mixed and stirred has a liquid viscosity of 0.01 Pa · sec to 100 P
This apparatus is suitable for a · sec, a pigment paste having a Ti value of 1 to 10.

[0005]

Hereinafter, the details will be described with reference to embodiments shown in FIGS. The present invention is not limited to the following examples. In FIG. 1, reference numeral (3) denotes a cylindrical stirring tank, and a rotary shaft (4) is provided in the center of the tank (3). The shaft (4) is provided at one end with a flat paddle blade (5) and at the other end is connected to a drive (8) on the tank top. The flat paddle wing (5) is composed of a bottom flat paddle wing (6) and an upper flat paddle wing (7) having a rectangular shape in the upper direction of both left and right ends of the (6). At the same time as the rotation shaft (4) rotates, the flat paddle blade (5) joined to the rotation shaft (4) passes around the wall surface of the cylindrical stirring tank (3) while rotating in the circumferential direction. The size (horizontal length, width) of the bottom flat paddle blade (6) is determined by the blade diameter of the bottom flat paddle blade (6) with respect to the inner diameter (a) 1 of the cylindrical stirring tank (3). Is in the range of 0.6 to 0.9 (see FIG. 3), preferably 0.6 to 0.8. When the length ratio is less than 0.6, that is, the blade diameter becomes too small, the amount of pigment paste remaining on the tank wall increases. On the other hand, when it exceeds 0.9, that is, the blade diameter becomes too large. This is not good because a short circuit of the pigment paste occurs. The vertical length (height d) of the upper flat paddle wing (7) is equal to the vertical length (height c) 1 of the bottom flat paddle wing (6) (FIG. 2).
See) in the range of 1-4, preferably 1-3. If the height ratio is less than 1, that is, if the height of (d) is too low, the power required for stirring increases, so that the cost of the product increases, and the load on the machine increases the aging. On the other hand, when the value exceeds 4, that is, when the height of (d) is too high, the pigment paste cannot be uniformly mixed in the tank. The vertical length of the flat paddle blade section (5) (the total sum of heights d and c) is 0.8 to 1.1 with respect to the inner diameter (a) 1 of the cylindrical stirring tank (3). 5,
Preferably it is in the range of 1.0 to 1.3. If the height ratio is less than 0.8, that is, if the vertical length of (5) is too short, there is a disadvantage that the pigment paste is likely to be short-circuited, while if it exceeds 1.5, that is, (5) If the vertical length is too long, there is a disadvantage that the pigment paste cannot be uniformly mixed in the tank. The rectangular upper flat paddle wing (7) is a rectangular wing that is long in the longitudinal direction,
Its width (e) (see FIG. 2) may have a length in the range of 5 to 20%, in particular 6 to 15% of the length (b) of the bottom flat paddle wing (6) and the wing diameter. preferable. If the width is less than 5%, the effect of scraping off the pigment paste near the inner surface of the tank decreases, while if it exceeds 20%, short-circuiting of the pigment paste easily occurs, which is not preferable. Flat paddle wings (5)
Is preferably constituted by one sheet as shown in FIG.
Further, the material constituting the blade is not limited, and a material conventionally used in a stirring blade can be used. However, stainless steel is preferably used from the viewpoint of durability and strength. The capacity of the mixing and stirring tank (3) is not particularly limited, but is generally in the range of about 10 liters to about 5000 liters. The treatment liquid supply port (1) is provided above the mixing and stirring tank (3) and is for supplying the pigment paste dispersed from the disperser (B) into the mixing and stirring tank (3). The treatment liquid outlet (2) is provided at the lower part of the mixing and stirring tank (3), and takes out the pigment paste mixed and stirred by the mixing and stirring machine from the mixing and stirring tank (3) and supplies the pigment paste to the dispersing machine (B). It is for. Further, the processing liquid supply port (1) and the processing liquid outlet (2) are connected by a pipe (9) through a pump (15) and a disperser (B). The pump (15) is provided between the disperser (B) and the processing liquid supply port (1).
It can be installed between the disperser (B) and the processing liquid outlet (2) or between both. The disperser (B) is not particularly limited, and a conventionally known pigment disperser can be used. However, it is particularly preferable to use a bead mill disperser or the like which can obtain a large processing flow rate. In the present invention, a washing device (C) capable of washing the inside of the mixing and stirring tank (3) with a washing liquid such as a solvent or water can be provided. The cleaning device (C) includes, for example, a cleaning liquid tank (12), a cleaning liquid outlet (a cleaning nozzle or the like) (13), a pipe (14) for transporting the cleaning liquid, and the like. This cleaning device (C)
After the production of the pigment paste is finished, the pigment paste is discharged from the mixing and stirring tank (3) to the storage tank (11), and then remains in the mixing and stirring tank (3) and the disperser (B). This is a device for washing and removing the pigment paste. The washing liquid is preferably sprayed into a mixing and stirring tank (3) in a shower shape. In the apparatus of the present invention, in particular, the pigment paste has a viscosity of 0.01 Pa · sec to 100 Pa · sec.
It is preferable to treat c, especially in the range of 0.1 Pa · sec to 10 Pa · sec, and Ti value in the range of 1 to 10, especially 1 to 5. The Ti value is an abbreviation for thixotropic index, and is based on JIS K 54004.5.
The value measured by the rotational viscosity method described in 3 (temperature 20 ° C., rotor rotation speed 6 and 60 rpm) was converted into mPa · s, and the apparent viscosity at 6 rpm was mPa · s / 60 rpm.
Is a value calculated by the apparent viscosity mPa · s.

[0006]

The mixing and stirring device according to the present invention provides a rectangular upper flat paddle blade (6) disposed at an optimum position.
Since the flat paddle blades (5) composed of the upper and lower flat paddle blades (7) are used as mixing and stirring blades, the pigment paste is sufficiently stirred in the stirring tank by the upper flat paddle blades (7). Then, the pigment paste flows so that the mixed and stirred pigment paste is pushed out to the bottom outlet by the bottom flat paddle blade section (6), so that it is presumed that the pigment dispersion efficiency is improved as a whole.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing a mixing and stirring apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic sectional view showing the size of a flat paddle wing.

FIG. 3 is a schematic sectional view showing the size of a flat paddle wing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing liquid supply port 2 Processing liquid outlet 3 Mixing and stirring tank 4 Rotating shaft 5 Flat paddle blade 6 Bottom flat paddle blade 7 Upper flat paddle blade 8 Drive 9 Pipe 10 Switching valve 11 Storage tank 12 Washing liquid tank 13 Troll ball 14 Piping 15 Pump A Stirring and circulating device B Pigment disperser C Cleaning device

Claims (2)

[Claims] 1. A pigment disperser (B), a stirring and circulating device (A) for feeding a treatment liquid to the pigment disperser (B) and receiving and circulating the treatment liquid treated by the disperser (B); A pump (15) and a pipe (9) for transporting the processing liquid. The stirring and circulating device (A) is provided with a processing liquid supply port (1) in an upper direction and a processing liquid discharge port (1) in a bottom direction. Washable cylindrical mixing / stirring tank (3) provided with 2) and a rotating shaft (4) suspended from the center of the stirring tank.
A flat paddle blade (5) held perpendicular to the rotation axis (4), and the flat paddle blade (5) substantially has a central axis of the rotation axis (4). The flat paddle wings (5) are symmetrical to each other, and the flat paddle wings (5) are rectangular in the upper direction at the left and right ends of the bottom flat paddle wing (6) and the bottom flat paddle wing (6), respectively. And the ratio of the inner diameter of the cylindrical stirring tank (3) to the blade diameter of the bottom flat paddle wing (6) is 1 / 0.6.
A pigment circulating and dispersing apparatus, wherein the height ratio between the bottom flat paddle wing portion (6) and the upper flat paddle wing portion (7) is in the range of 1/1 to 4. 2. In the above-mentioned pigment circulation / dispersion apparatus, the treatment liquid to be mixed and stirred has a liquid viscosity of 0.01 Pa · sec.
The pigment circulation / dispersion apparatus according to claim 1, wherein the pigment paste has a Pa · sec and a Ti value of 1 to 10.