JPS5984902A - Apparatus for centrifugal thin film polymerization - Google Patents

Abstract

PURPOSE:The titled polymerization apparatus having a sprinkling nozzle for cooling water, etc. and a rotational polymerization vessel with a rising and lowering polymer chopper in a container case having a jacket with a monomer solution feed pipe, capable of polymerizing the monomer in a wide range of concentration, and easily removing the heat of polymerization. CONSTITUTION:A rotary vessel 1 is installed in a container case 2 having a jacket 6 with a monomer soln. feed pipe 4 on the top of the case 2, and a nozzle 3 for sprinkling warm or cooling water on the outer surface of the rotary vessel 1 is provided to the inner surface of a container case 2 to control the temp. of the vessel 1. A monomer solution, e.g. acrylamide, is fed to the apparatus, and the interior of the apparatus is replaced with nitrogen gas fed from a nitrogen gas port 11. Centrifugal thin film polymerization is carried out while rotating the rotary vessel 1 to give the aimed thin film cylindrical polymer 10 on the inner surface of the vessel 1. The resultant polymer 10 is then chopped by rising and lowering a chopper 5, and closing plugs 7 are then opened to take out the polymer 10 from polymer discharging holes 8.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a centrifugal thin film polymerization apparatus that can handle a wide range of monomer concentrations, from so-called low concentrations, usually around 10% (by weight), to high concentrations, that is, monomer concentrations of 20% (by weight) or more. It can be applied to the production of polymers in

- Generally, when polymerizing with a monomer solution containing acrylamide, about 20 cal/mol of polymerization heat is released during the polymerization reaction, but as the polymerization reaction progresses, the viscosity of the polymerization solution increases. Therefore, it becomes difficult to remove the heat of polymerization generated within the polymer in proportion to the concentration of the polymer.

In the so-called low concentration region where the monomer concentration is around 10% (weight), the viscosity is relatively low, so stirring of the polymerization solution is difficult.
However, it is possible to remove polymerization heat by installing a cooling jacket in a general-purpose batch-type polymerization kettle with mixing blades. When monomer 7 has an agricultural content of 15% (weight M) or more, stirring and mixing becomes difficult due to its high viscosity, and the heat of polymerization cannot be removed satisfactorily in the general-purpose batch polymerization kettle. .

When the removal of the heat of polymerization is incomplete, thermal deterioration of quality often occurs. However, from the viewpoint of improving polymerization efficiency and reducing the energy required to dry and remove the polymerization medium from the polymer, it is economically advantageous to adopt 51i or the monomer concentration as high as technically possible. However, due to the difficulty in removing the heat of polymerization, which increases in proportion to the monomer concentration, the polymer is heated to an excessively high temperature, making it difficult to prevent thermal deterioration of quality.

Our goal is to overcome these difficulties and make it possible to easily remove heat from polymers and maintain high quality even in the production of polymers with high monomer concentrations and high viscosity. As a result of intensive research, the present inventors applied the rotation necessary to obtain the necessary centrifugal force to a rotatable metallic container, and while supplying the monomer solution to the rotating metallic container, centrifugal thin film polymerization was carried out. As a result, we discovered a centrifugal thin film polymerization device that can easily remove polymerization heat.

That is, a rotating container is installed in a storage case with a jacket in which a seven-layer solution supply pipe is renumbered in the second part of the storage case, and a nozzle for spraying hot water or cooling water onto the outer surface of the rotating container is stored. To provide a centrifugal thin film polymerization device, characterized in that a shredding machine that can be raised and lowered is provided on the inner surface of a case for shredding a thin cylindrical polymer formed on the inner surface of a rotating container by centrifugal thin film polymerization. This is what we have come to.

With the centrifugal thin film polymerization apparatus of the present invention, the polymerization solution is easily formed into a cylindrical thin film on the inner wall of the rotating container with a completely uniform polymer thickness.

The thickness of the polymer can be arbitrarily set by adjusting the dimensions of the rotating container and the amount of monomer solution supplied. The thickness of the polymer is determined in consideration of the monomer concentration based on the correlation between the amount of removed heat obtained in advance, the thickness of the polymer, and the monomer concentration. It is preferable to supply the monomer solution quantitatively so as to maintain the thickness of the coalescence between 2 mm and 2 onlIll.

The monomer solution includes acrylamide, methacrylamide, acryloni-1-lyl, methacryloni-1-lyl,
or acrylic acid, methacrylic acid, and salts and esters of acrylic acid or methacrylic acid, such as alkyl esters of acrylic acid or methacrylic acid such as methyl, ethyl, and propyl;
Selected from hydroxyalkyl esters such as oral pills, esters such as dimethylaminoethyl, diethylaminoethyl ester, trimethylammonium chloride, triethylammonium chloride, and thorium salt, potassium salt, ammonium salt of acrylic acid or methacrylic acid, etc. A monomer solution consisting of one or more types of monomers can be used, and the concentration of the monomer aqueous solution can be adjusted to 10% to 80% (by weight).

Next, a redox system consisting of persulfate alone or a combination of various reducing agents with persulfate as an oxidizing agent, etc. 1, for example, a redox catalyst of azobis-isobutyroni 1-helyl or persulfate bisulfi 1-type, etc. After the monomer solution is purged with nitrogen by using a commonly-known polymerization initiator, the temperature is raised to about 40°C, and the inside of the solution is then heated through the monomer solution supply pipe (4). A rotating container (1) that is being rotated at the required number of revolutions to form an airtight centrifugal thin film that is being replaced with nitrogen from the nitrogen gas port (11).
Polymerization usually starts in about 10 to 30 minutes.

The heat of polymerization generated at the start of polymerization is instantly and efficiently removed by the cooling water continuously sprayed from the nozzle (3) to the outer surface of the rotating vessel () and by the large heat transfer coefficient generated by the turbulent flow. Due to the centrifugal force of the rotating body, the cooling water that is continuously sprayed on the surface of the rotating container (1) is instantly sprayed onto the storage case (2) attached to the Jacquera 1-(6).
It scatters on the inner surface, is discharged from the drainage nozzle/L/(9), and takes away the heat of polymerization. After polymerization, in the case of a fluid polymer, by stopping the rotation of the container, the polymer peels off from the inner wall of the rotating container and passes through the discharge hole (8), which is closed by gravity during polymerization. It can be easily discharged by opening the stopcock (7). On the other hand, in the case of a rubber-like polymer that has lost fluidity after polymerization, it is impossible to take it out simply by stopping the rotation of the container, unlike the above case.

. Therefore, in the present invention, a shredding machine (5) with a saw-like structure that can be raised and lowered or a fixed knife-like structure that can be raised and lowered is used at 40 rn/min.
A polymer (10
), the polymer is shredded into scales or flakes with a typical diameter of 1 cm to 2 cm, and the shredded polymer is passed through the polymer discharge hole (8), which is closed during polymerization. By opening the cap (7), it is possible to discharge the entire amount without any problem.

In addition, to start polymerization, it is necessary to heat the jacket nozzle by passing steam, hot water, etc., and to remove the polymerization heat generated during polymerization. - Cool by passing cooling water through the nozzle.

In the polymerization apparatus of the present invention, the centrifugal force G value to be applied to the rotating container for forming a thin film of the polymerization solution is 2000 to 100O.
200G to 500G is more preferable from the viewpoint of economy such as power consumption and the fact that the polymer does not separate.

In conventionally proposed typical polymer polymerization devices, heat of polymerization is removed by spraying cooling water from below through the metal surface, and polymerization is carried out while moving horizontally on the metal surface. There are so-called cooling bells 1 (Japanese Patent Application Laid-Open No. 49-9917'8, etc.), which are characterized by the following characteristics, but the centrifugal thin film polymerization apparatus of the present invention has the following advantages compared to these.

(1) Due to the centrifugal effect, it is possible to completely homogenize the liquid film, and it is extremely easy to adjust the thickness of the polymer. can.

In the cooling belt, due to the mechanical structure of the bells 1 to 2,
Free adjustment of polymer thickness beyond on becomes more difficult.

(2) Polymerization reaction and discharge of a fluid polymer is difficult with the cooling bell 1- for reasons described later, but when the objective is to obtain a polymer that still has fluidity, for example, when polymerizing at a low concentration. Furthermore, even in the case of polymerization of polymers with extremely low intrinsic viscosity, the centrifugal thin film polymerization apparatus of the present invention allows both the polymerization reaction and the discharge of the polymer, as in the case of polymers with no fluidity. be.

In cooling bell 1-, in the case of a fluid polymer, the polymerized part and the unpolymerized part are mixed, so it is difficult to select and discharge only the polymerized part, and the reason is that the polymerization reaction itself is difficult. , and u1 output are both impossible.

(3) In the centrifugal thin film polymerization apparatus of the present invention, since cooling water is sprayed onto the container rotating at a relatively high speed, the heat transfer coefficient between the cooling water and the outer surface of the container is large, which can be easily understood from the theory.

In comparison, in the case of the cooling bell 1-, the heat transfer coefficient between the cooling water and the relatively slowly rotating cooling bell 1- is small and relatively wide in terms of the removal rate of polymerization heat.

(4) In the centrifugal thin film polymerization apparatus of the present invention, even if the polymer is highly adhesive, the structure is such that the polymer rotates at a relatively high speed, so even a simple shredder can completely remove the polymer from the inner wall of the container. Not only can the coalescence be peeled off, but it can also be instantly discharged in the form of scales or flakes. On the other hand, in the case of the cooling bell 1-, such active discharge and shredding of highly adhesive polymers is not possible.

(5) The installation area of the centrifugal thin film polymerization apparatus of the present invention is relatively small. Incidentally, the installation area required to obtain the required polymerization area of 3.1a is about 2rrr, but the cooling bell 1- requires a relatively large installation area of about 4m'.

, 6) In the centrifugal thin film polymerization apparatus of the present invention, organic solvents, activators, etc. can also be used, and compared to cooling belts, it is possible to prevent organic solvents, etc. from escaping by forming a tight seal. It's easy.

Production Example I (Note: % and parts are based on weight.) 46.5 parts of a 50% aqueous solution of acrylamide and 52 parts of distilled water
．． After mixing 7 parts with nitrogen gas at room temperature for about 30 minutes to remove dissolved oxygen, ammonium persulfate was mixed with 0.0 parts of monomer.
05%, 1-liethanolamine 0.10% was dissolved in a small amount of distilled water to give a monomer concentration of about 24.0%, and the pH
After adjustment, the temperature of the acrylamide monomer solution was raised to about 40° C. 6 Meanwhile, after purging the inside of a stainless steel rotary container with an inner diameter of 60 cm with nitrogen gas, it was rotated at 1 and 20 Or/m, and a 40° C. While spraying warm water at 40°C,
After supplying the acrylamide monomer solution of C to the inner surface of a rotating rotating container and starting polymerization to form a thin film, approximately 2
After 0 minutes, hot water spraying was stopped, and IO'C cooling water was sprayed, which continued for 20 minutes. The polymer is then discharged,
It was dried and ground to obtain a powder product. The intrinsic viscosity of the powder product is 14.
It was 0.

Production Example 2 Mix 50 parts of distilled water with 8.49 parts of 60% acrylic acid monomer solution, gradually add 3.94 parts of soda carbonate, and adjust the pH.
Neutralize to approximately 7.8.

40 parts of a 50% aqueous solution of acrylamide is mixed with the neutralized solution to obtain a polymerization monomer solution.

The 7mer solution has a concentration of about 25% in terms of acrylamide. An aqueous solution containing 0.125% of 1-heliethanolamine and 0.005% of ammonium persulfate is mixed into the 7-summer solution to complete the adjustment. After this adjustment, nitrogen gas was sent to the seven-layer solution for about 30 minutes to eliminate dissolved oxygen, and then the temperature was raised to about 40°C.

On the other hand, after purging the inside of a stainless steel rotary container with an inner diameter of about 25 cm with nitrogen gas and maintaining the oxygen concentration in the gas phase at 0.5%, 1. ．． While rotating at 950 r/m and spraying hot water at 40°C on the outer surface of the rotating container, the above-mentioned monomani solution was supplied to the inner surface of the rotating container to initiate polymerization and form a thin film. After a minute had elapsed, the hot water spraying was stopped, and 8°C cooling water was sprayed, which continued for 20 minutes. The polymer was discharged, dried, and pulverized to obtain a powder product. The intrinsic viscosity of this powder product was 15.0 or more.

[Brief explanation of drawings]

Figure 1 is a cross-sectional side view of the centrifugal thin film polymerization apparatus of the present invention;
The figure is a sectional view taken along the line A-A in FIG. 1. 1------One rotation container 2------One storage case 3------Nozzle 4---Monomer solution supply pipe 5,---One shredder 6------ ---, Jacket 7 --- Open Plug 8 --- Drain Hole 9 --- Drainage nozzle 10 --- Polymer + 1 --- 1-- Nitrogen gas flow Applicant No. 1 Industrial Pharmaceutical Co., Ltd.

Claims (1)

[Claims] A rotating container is installed in a storage case that has a jacket 1~ equipped with a monomer solution supply pipe at the top of the storage case, and a nozzle for spraying hot water or cooling water onto the outer surface of the rotating container is provided on the inner surface of the storage case. A centrifugal thin film polymerization apparatus, characterized in that it is equipped with a shredding machine that can be raised and lowered to shred a thin cylindrical polymer formed on the inner surface of a rotating container.