JPS6048938A - Apparatus for storing thermally polymerizable monomer - Google Patents

Abstract

PURPOSE:To provide the titled storing apparatus for the production of a polymer having excellent quality, by providing the wall at the upper part of the storage tank of the monomer with a heating means to prevent the condensation of a thermally polymerizable monomer on the wall of the tank. CONSTITUTION:A specific amount of a thermally polymerizable monomer is stored in a storage tank 11 composed of the cylindrical side wall 11A and the disc-shaped or conical top plate 11B attached to the top of the wall 11A. The monomer is composed of the liquid phase part 12 and the vapor phase part 13 filling the upper space of the tank keeping the equilibrium with the liquid phase. A cooling means 14 is placed in the liquid part 12. A heating means 19 consisting of an electrical heater 21 wound spirally at a definite spacings is attached to the outer circumference of the vapor phase 13, i.e. the top plate 11B and the upper part of the side wall 11A. The temperature of the vapor phase is maintained at a high level by the heating means 19 to prevent the condensation and the spontaneous polymerization of the monomer vapor. EFFECT:Since there is no formation of a polymer by the spontaneous polymerization, the polymer formed from the liquid phase has high quality, and the cleaning cost of the tank can be saved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a storage device for thermally polymerizable monomers, which are raw materials for producing polymers.

When storing thermopolymerizable materials in a tank, conventionally it has been widely practiced to add a polymerization inhibitor to the monomer liquid or to prevent polymerization by keeping the monomer liquid at a low temperature. Ta. However, when using a monopolymerization inhibitor, it was not possible to prevent the thermopolymerizable 7mer from polymerizing if the thermopolymerizable 7mer evaporated during storage and condensed on the large plates or side walls of the tank. This is because the volatilization f/+ of the polymerization inhibitor is usually lower than that of the thermally polymerizable monomer, so that the condensed liquid contains almost no agent. Furthermore, even if the monomer liquid was kept at a low temperature, the polymerization of the thermopolymerizable monomer condensed on the top plate and side walls of the tank could not be prevented. This is because it is difficult to keep such condensed liquid at a low temperature all the time. In any case, the polymerized polymer dissolves in the thermopolymerizable monomer liquid when it falls naturally or when the liquid surface of the thermopolymerizable monomer is sealed. As a result, the use of these thermopolymerizable polymers has an adverse effect on the polymerization reaction and also deteriorates the quality of the product polymer to be sheared.

For example, styrene monomer is highly thermally polymerizable, so it is usually cooled to lθ to 15°C and added with an anti-IL agent such as para-t-buticatechol to prevent polymerization before being stored in a storage tank. . In spring, autumn, and winter when the outside temperature is lower than the liquid temperature of styrene monomer.

Since the temperature of the tank wall is also lower than the liquid temperature of the styrene monomer, the styrene monomer tends to condense on the top plate and side walls of the gas tank. In particular, styrene monomer condenses significantly on the tank top plate, pools on side walls, corners, etc.

Since para-t-butylcatechol has lower volatility than styrene monomer, the condensed styrene monomer contains almost no para-t-butylcatechol, and the polymerization of the styrene monomer proceeds in the condensate portion.

The polystyrene produced by this polymerization falls and dissolves in the styrene monomer liquid.

If such a styrene monomer liquid is used, the polymer concentration will be too high and the color tone of the product polymer will be poor.

An object of the present invention is to provide a storage device for thermopolymerizable monomers in which even if the thermopolymerizable monomer gas comes into contact with the wall of a storage tank, the 7-mer gas will not condense and produce a polymer. .

Therefore, the present invention provides a heating means at the outer periphery of the container wall in contact with the gas phase, such as the outer periphery of the top plate or the side wall near the top plate, in a storage tank for storing thermopolymerizable liquid. The object of the present invention is to achieve the object (iii) by heating the vessel wall to prevent the thermopolymerizable gas in contact with the vessel wall from condensing.

Hereinafter, an example of unissued Qll will be described based on the drawings.

In FIG. 1, the storage tank 11 has a container wall of, for example, 1'N,
It is composed of 1-shaped sides 1 to t11A, and a large plate 11B in the form of a disc or a hat as a rotary device x (e) provided at one end of the side wall 11A, and the inside contains a styrene monomer liquid, A thermopolymerizable monomer oil body such as α-methylstyrene monomer, acrylonitrile monomer liquid, etc. is stored as a predetermined crystal, and this storage portion is in the liquid phase section 12.
It is said that Further, a portion of this M phase section 12 is filled with thermal polymerization + I monomer gas of styrene monomer gas, α-methylstyrene monomer gas, and acrylonitrile monomer gas cap while maintaining an equilibrium state with the liquid phase section 12. A gas phase portion 13 is a portion filled with 1,000 liters of gas during this thermal polymerization.

A cooling stage 14 is provided at the liquid phase portion 12 of the storage tank 11, or in other words, at the bottom side of the storage tank 11. The cooling means 14 has a cooling pipe 15 laid in the storage tank 11, and a fluorocarbon gas or the like as a cooling heat medium is circulated within the cooling pipe 15. Further, the cooling pipe 15 is taken out to the outside of the storage tank 11, and the cooling heat medium in the cooling pipe 15 is cooled by a cooling heat exchanger 16 such as a fluorocarbon refrigerator, and is circulated by a circulation pump 17. It has become. When the thermopolymerizable hexamer is a styrene monomer, the temperature of the liquid phase portion 12 is normally kept at 15% by the cooling means 14 configured in this manner.
It is designed to be maintained below ℃. In addition, liquid phase part 1
A thermometer 18 is provided at an appropriate position of the thermometer I.
8 allows the operation of the cooling means 14 to be controlled automatically or manually.

The inner peripheral surface of the storage tank 11 on the side of the gas phase section 13 is not provided with any protruding parts, members, etc., that is, the inner peripheral surface is a pool part, a corner part (a part where droplets are likely to occur), etc. It has an extremely flat structure with no ridges. Therefore, the structure is such that the styrene monomer gas "9" constituting the gas phase portion 13 is difficult to condense.

A heating means 19 is provided on the outer periphery of the gas phase section 13 of the storage tank 11 . The heating means 19 includes electric heaters 2 installed on one side of the side wall 11A and on the top plate 11B.
1. This electric heater 2I is connected to the F of the side wall 11A.
As shown in FIG. 2, a number of plates are wound around the outer circumference of the top plate 11B at predetermined intervals, for example, in a spiral manner and arranged on the outer circumferential surface of the top plate 11B. The electric heater 2I configured in this way is connected to the switch 22. It is connected to the electric ID 24 via the fuse 23, so that the heating current is passed to the electric heater 2I. Further, the switch 22 is controlled to open and close by a plurality of surface thermometers 25 or a single surface thermometer 25 provided at a predetermined position in the gas phase section 13 of the storage tank 11, thereby forming the gas phase section 13. When the thermopolymerization monomer is styrene monomer gas, it is always heated to about 25°C, and therefore the temperature of the top plate 11B is lower than the temperature of the liquid phase portion 12 detected by the thermometer 18. Part 1 ■ has been deprecated so that the temperature will be about 10°C higher.

Angle steels 26 as reinforcing members are provided on the outer peripheral surface of the top plate 11B at predetermined intervals along the circumferential direction, for example, at intervals dividing the circumference into 13 equal parts.

Further, the outer peripheral portion of the storage tank 11 is covered with a heat insulating material 27.

According to this embodiment, the outside temperature is low in spring, autumn, and
Even in winter, thermopolymerized gases such as styrene monomer gas can leak into the walls of the storage tank 11 (side wall lIA, top plate 1.1B).
There is no possibility of spontaneous polymerization due to condensation with I-. Therefore, since no naturally polymerized polymer is deposited in the storage tank 11, there is an effect that the storage tank 11 is less prone to sagging and cleaning costs are also reduced.

Furthermore, since spontaneous polymerization does not occur within the gas phase section 13,
The naturally polymerized polymer does not drip into the liquid phase section 12, so the crystallinity of the liquid phase section 12 does not deteriorate, and the polymer produced using the liquid phase section 12 as a raw material has a polymer concentration of -h.
It can be made to have excellent quality without causing W or poor color tone.

History, addition 11. The first means 19 and the surface temperature gauge 25 are all provided on the side where the storage tank 1 is arranged, and there are no protruding parts such as edges or corners in the gas phase section 13. It is extremely li411, which also makes it difficult for the thermally polymerized P1 monomer gas to condense.

FIG. 3 shows the main parts of an embodiment other than the above. In the figure, unlike the heating means 19 which had an inspiratory heater structure, the heating stage 39 has a structure for circulating hot body fluids such as hot water. That is, the heating means 39
It has a cylindrical distribution pipe 41 and a collecting pipe 42 which are arranged concentrically in + and -, and these distribution pipes 41 and collecting pipe 42 are connected to a connecting pipe 43 which is arranged in number along the radial direction of the top plate 11B. are connected to each other. Further, each connecting pipe 43 is provided with a throttle valve 44, and each throttle valve 44 is adjusted to adjust the respective distribution pipes 4], collecting pipes 42, . Also, the flow 111 of hot water or the like flowing through the connecting pipe 473 is made equal.

The distribution pipe 41 includes a feed pipe 4 having a pump 45 in the middle.
A hot water tank 47 is connected to the collecting pipe 42 through a return pipe 48 . A predetermined amount of hot water, etc. is stored in the hot water tank 47, and a heater 51 is provided which is appropriately heated and controlled by a hot water meter 49. As a result, the hot water in the hot water tank 47 is kept at a temperature of 40 degrees at most.
The temperature is maintained at about C. Further, a liquid level gauge 52 is provided in the hot water tank 47, and this liquid level gauge 52
A constant amount of hot water is always stored depending on the liquid level detected by the system.

Although the heating means 39 using such a hot water circulation method is cheaper to construct than the heating means 19 using the electric heating method, it is somewhat difficult to control the temperature. This embodiment has substantially the same functions and effects as those of the embodiment.

In addition, in implementing the heating means 19.39, the thermometer 18
The rI dynamic control may be performed so that the temperature of the liquid phase portion 12 is always approximately 10° C. or more than the temperature detected by the temperature. Also, storage tank i
Although the inner circumferential surface of one example of the gas phase section i is configured to have a very '+' side, the present invention is not limited to this, and for example, a thermometer or the like may protrude inward. However, if it is configured as 1t1, the above-mentioned effects can be obtained.

As described above, according to the present invention, it is possible to provide a storage device for thermally polymerizable monomers in which the thermally polymerizable monomer gas in the gas phase does not condense to produce a polymer through spontaneous polymerization.

[Brief explanation of drawings]

FIG. 1 shows a storage device for thermopolymerizable 1,000 yen according to the present invention.
- A sectional view showing the embodiment; FIG. 2 is a schematic diagram showing the heating means of the embodiment described above; FIG. 3 is a schematic diagram showing the construction of the heating means of the embodiment other than the above. 11...Storage tank, IIA...Side wall as vessel wall, 11
B...Top plate as vessel wall, 12...Liquid phase part, 13
... Gas phase part, 14... Cooling means, 19.39...
Heating means. Agent Patent attorney Sanemasa Kinoshita (and 1 other person) 0

Claims (1)

[Claims] (1) A heating means is provided on the part of the vessel wall in contact with the gas phase portion of the storage tank for storing the thermopolymerizable monomer to prevent condensation of the thermopolymerizable monomer gas in contact with the vessel wall. A storage device for thermally polymerizable monomers.