JP2003251172A - Device and method for treating easily polymerizable material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for treating an easily polymerizable material capable of preventing a polymer of the easily polymerizable material from growing in a large quantity as excess metal of a weld line or a weld mark as a growth point thereof, manufacturing the easily polymerizable material of a stable quality without containing the polymer and stably operating over an extended time period, and a method for treating the easily polymerizable material. <P>SOLUTION: The device for treating the easily polymerizable material synthesizes, refines, retains or distributes the easily polymerizable material. In the device for treating the easily polymerizable material, a smoothing treatment is applied to a part contacting to the easily polymerizable material in inside of the surface of the device for treating the easily polymerizable material. The smoothing treatment is a treatment to cut away the excess metal of the weld line or the weld mark in the inside surface of the device for treating the easily polymerizable material. The easily polymerizable material is at least one or more kinds selected from (meta)acrylic acid, (meta)acrylic acid esters and (meta)acrolein. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an easily polymerized substance such as (meth) acrylic acid, (meth) acrylic acid ester and (meth) acrolein, which is used for handling such as synthesis, purification, retention or distribution. The present invention relates to an apparatus for handling a polymerizable substance and a method for handling an easily polymerizable substance.

[0002]

2. Description of the Related Art In the production and distribution of easily polymerized substances such as (meth) acrylic acid, (meth) acrylic acid ester, and (meth) acrolein, they are different from substances other than easily polymerized substances. Similarly, various unit operations such as synthesis, distillation, extraction, storage etc. are performed. The easily polymerizable substance is very easily polymerized, and a polymer is easily generated during handling such as production and distribution. Therefore, a polymerization inhibitor is added to the easily polymerizable substance so that the polymerization is suppressed and handled. Further, various devices used when handling the easily polymerizable substance are designed and manufactured on the assumption that a polymerization inhibitor is added to the easily polymerizable substance. In order to make the operation of various devices smooth, during the handling, the easily polymerizable substance does not polymerize at all, or
It is desirable that the production amount of the polymer of the easily polymerizable substance is within the expected range.

[0003]

By the way, towers, tanks, pipes, etc., which constitute various devices for performing unit operations such as synthesis, distillation, extraction, and storage, are usually made of a metal material, and these are manufactured. Welding is used for. When these devices are manufactured by welding, a swell of welding line remains on the inner surface of the device, and welding marks such as slag and metal particles adhere due to unintentionally spattered spatter.
In addition, in various devices that perform unit operations such as synthesis, distillation, extraction, and storage, the easily polymerizable substance is always in contact with the inner surfaces of the tower, tank, pipes and the like that make up this device. Conventionally,
No special removal treatment was required for the surplus weld lines and weld marks on the inner surfaces of these towers, tanks and pipes. Therefore, as in the case of a substance other than the easily polymerizable substance, the device for handling the easily polymerizable substance does not remove the excess weld marks and welding marks on the inner surface of the easily polymerizable substance. Was used for the handling of.

However, when towers, tanks, pipes, etc., whose inner surfaces are not surface-finished as described above, are used for the production of the easily polymerizable substance, the welding line is used during the long-term operation and use of various devices. In some cases, a large amount of a polymer of an easily-polymerizable substance was formed, with the excessive heap and the welding mark as the growth point of the polymerization. This polymer becomes an impurity in the easily polymerizable substance,
When it is present in the easily polymerizable substance of the product, its quality is deteriorated, which is not preferable. Further, this polymer may clog the inside of various devices and pipes, and in some cases, the operation of the device and the stop of the production of the easily polymerizable substance may be forced.

The present invention has been made in view of the above circumstances, and it is possible to prevent a large amount of a polymer of an easily-polymerizable substance from being generated by using a surplus weld wire or a welding mark as a growth point to form a polymer. It is an object of the present invention to provide an easily polymerizable substance handling apparatus and an easily polymerizable substance handling method capable of producing a stable easily polymerizable substance that does not contain quality and capable of stable operation over a long period of time.

[0006]

[Means for Solving the Problems] The above-mentioned problem is an easily polymerizable substance handling device for synthesizing, purifying, retaining or distributing an easily polymerizable substance, wherein the easily polymerizable substance on the inner surface of the easily polymerizable substance handling device is used. It is possible to solve the problem by using a device for easily polymerizing a substance which has been subjected to a smoothing treatment at the point of contact. It is preferable that the smoothing process is a process of scraping off an extra portion or a welding mark of a welding line formed on the inner surface of the easily polymerizable substance handling device. The easily polymerizable substance is (meth) acrylic acid,
At least one selected from (meth) acrylic acid ester and (meth) acrolein is preferable. Further, the above-mentioned problem is a method for handling an easily polymerizable substance using an easily polymerizable substance handling device for synthesizing, purifying, retaining or distributing an easily polymerizable substance, wherein the easy polymerization of the inner surface of the easily polymerizable substance handling device. The problem can be solved by a method of handling an easily polymerizing substance in which a location where a functional substance comes into contact is subjected to a smoothing treatment.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below.
The easily polymerizable substance handling device of the present invention is an easily polymerizable substance handling device for synthesizing, purifying, holding or distributing an easily polymerizable substance, wherein the easily polymerizable substance is contacted on the inner surface of the easily polymerizable substance handling device. A smoothing process is applied to the part to be applied. The easily polymerizable substance handling device of the present invention includes, for example, a distillation device, an extraction device, an absorption device, an evaporation device, a decanter, a compressor, which is used for synthesizing, purifying, holding (storage), and distributing the easily polymerizable substance. Each unit operation device such as a decompressor and a pump is included.

Further, in the apparatus for handling easily polymerizable substances of the present invention, particularly, the handling apparatus as described above is constructed, such as a distillation tower, an extraction tower, an absorption tower, an evaporation tower for synthesizing or purifying easily polymerizable substances. On the inner surface of various towers, the inner surface of storage tanks such as raw material tanks that store easily polymerizable substances, intermediate product tanks, product storage tanks, the inside of piping that distributes easily polymerizable substances, etc. Is preferably smoothed.

The term "smoothing" as used herein means that a grinder finish or a buff finish is applied to the inner surface of the easily polymerized substance handling device so that the welding line formed on the inner surface of the easily polymerized substance handling device at the time of making the device. It is the process of scraping off the excess and welding marks (hereinafter referred to as "welding residue"). In order to finish the inner surface of the easily polymerizable substance handling device into a smoother surface, it is preferable to roughly grind the welding residue using a grinder and then to polish and polish with a buff. Further, in the buffing, an abrasive such as emery powder, pumice powder, diatomaceous earth, or compound may be used to finish the inner surface of the easily polymerizable substance handling device to a smoother surface.

In addition, inert gas arc welding such as TIG welding (TIG) and MIG welding (MIG) can be used for places where the grinder finish or the buff finish cannot be practically applied. Since this inert gas arc welding is a welding method in which the generation of spatter is small and the bead surface of the joint after welding is smooth, it is preferably used for finishing the inner surface of the easily polymerizable substance handling device to be smooth.

The smoothing treatment for the inner surface of the device for handling the easily polymerizable substance is performed not only on the inner surface of the tower, the storage tank, the pipe, etc., which is always in contact with the easily polymerizable substance, but also the easily polymerizable substance. It is preferably applied to all places where there is a possibility of contact. Further, it is preferable to perform a smoothing treatment also on a portion such as an inner surface of the top of a raw material tank, an intermediate product tank, a product storage tank, or the like, which is unlikely to come into contact with the easily polymerizable substance. If the easily-polymerizable substance happens to come into contact with the welding residue existing in such a portion, the easily-polymerizable substance may condense as a growth point and become a seed for polymerization.

As described above, if the portion of the inner surface of the apparatus for handling the easily polymerizable substance contacting the easily polymerizable substance is subjected to the smoothing treatment, the welding residue is used as a growth point to polymerize the easily polymerizable substance. The generation of objects is suppressed.

The easily polymerizable substance handled by the easily polymerizable substance handling device of the present invention is not particularly limited as long as it is a substance that is easily polymerized, and examples thereof include a polymerizable vinyl compound. As the polymerizable vinyl compound, (meth)
Unsaturated carboxylic acids such as acrylic acid, methyl (meth)
Acrylate, normal butyl (meth) acrylate,
Alkyl (meth) acrylates such as isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, stearyl (meth) acrylate, cyclohexyl ( (Meth) acrylate, benzyl (meth) acrylate, isobornyl (meth) acrylate, glycidyl (meth) acrylate, tetrahydrofurfuryl, allyl (meth) acrylate and other alicyclic / aromatic rings / heterocycles and vinyl group-containing (meth) acrylates Hydroxyl such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate Other alkoxyl group-containing (meth)
Acrylates, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, polypropylene glycol di (meth) Acrylate, polyfunctional (meth) acrylates such as trimethylolpropane tri (meth) acrylate, phthalic acid 2-
Carboxylic acid-containing (meth) acrylates such as (meth) acroyloxyethyl, 2- (meth) acroyloxyethyl hexahydrophthalate, dimethylaminoethyl (meth) acrylate, dimethylaminoethyl (meth)
Acrylate methyl chloride salt, dimethylaminoethyl (meth) acrylate benzyl chloride salt, dialkylaminoethyl (meth) acrylates such as diethylaminoethyl (meth) acrylate, trifluoroethyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate, etc. And halogenated alkyl (meth) acrylates and unsaturated aldehydes such as (meth) acrolein. The easily polymerizable substance may be a single substance or a mixture of a plurality of compounds.

To these easily-polymerizable substances, a radical substance such as diphenylpicrylhydrazyl, a phenol derivative, a benzoquinone derivative, a nitro compound or the like is added in an amount of about 0.5 to 10 ppm as a polymerization inhibitor. In the easily polymerizable substance handling device of the present invention, since the inner surface of the device is subjected to the smoothing treatment, the concentration of the polymerization inhibitor as described above should be reduced or the polymerization inhibitor should not be used. Also, it can be handled without polymerizing the easily polymerizable substance. The easily polymerizable substance thus treated can be subjected to polymerization or the like without further purification. The polymer obtained by the polymerization of such an easily polymerizable substance has few impurities.

Further, according to the apparatus for handling an easily polymerizable substance of the present invention, the easily polymerizable substance is polymerized even if water or an organic solvent such as toluene or hexane is mixed as a solvent. Can be handled without Further, in the easily polymerizable substance using the easily polymerizable substance handling device of the present invention, the temperature for handling the easily polymerizable substance is
It is desirable to set the temperature below the temperature at which the polymerization of the easily polymerizable substance starts. By doing so, the concentration of the polymerization inhibitor can be reduced as described above, or the easily polymerizable substance can be stably handled without using the polymerization inhibitor.

As described above, according to the easy-polymerizable substance handling device of the present invention, since the polymer of the easily-polymerizable substance is not generated with the welding residue as a growth point, the quality of the substance does not include the polymer. A stable, easily polymerizable substance can be manufactured, stored, and distributed. Further, in the easily polymerizable substance handling device of the present invention, the polymerized substance of the easily polymerizable substance does not cause clogging of the pipes and the like constituting the device. Therefore,
According to the easily-polymerizable substance handling device of the present invention, the flow rate of the easily-polymerizable substance flowing through the device can be made faster than the flow rate of the easily-polymerizable substance flowing through the conventional device. Also,
This enables stable operation of the device over a long period of time.
Therefore, when the easily polymerizable substance handling device of the present invention is used for synthesizing, purifying, and distributing an easily polymerizable substance, the production line speed can be improved and the frequency of maintenance of the device can be reduced. As a result, the manufacturing cost can be reduced.

[0017]

EXAMPLES The effects of the present invention will be clarified below with reference to specific examples.

Example 1 A methacrylic acid storage tank made of SUS316 having a cylindrical shape with a diameter of 8 m, a height of about 6 m and a capacity of about 280 kl was prepared. In the production of this storage tank, various components were joined by welding. Then, over the entire inner surface of the storage tank, the excess welding wire and the slag attached by the spatter were completely removed by a grinder. It was confirmed that the inner surface of the storage tank was finished smooth by the naked eye and the touch. Next, a hot water coil was installed in the storage tank for heating the methacrylic acid stored therein. Methacrylic acid to which 50 ppm of a polymerization inhibitor (hydroquinone monomethyl ether) was added was placed in this storage tank, stored at a storage temperature of about 40 ° C., and used for shipping methacrylic acid for 5 years. Five years later, when the inside of the storage tank was inspected, it was confirmed that the inside of the storage tank and the surface of the hot water coil were clean, with no generation or adhesion of methacrylic acid polymer.

(Example 2) Diameter 10 m, height 9.5 m,
A storage tank of SUS304 made of methyl methacrylate having a cylindrical shape with a capacity of about 700 kl was prepared. In the production of this storage tank, various components were joined by welding. Then, over the entire inner surface of the storage tank, the excess welding wire and the slag attached by the spatter were completely removed by a grinder. As a result, it was confirmed that the inner surface of the storage tank was finished smooth by the naked eye and the touch. Into this storage tank, methyl methacrylate to which 2.5 ppm of a polymerization inhibitor (2,4-dimethyl-6-tert-butylphenol) was added was placed and stored at a storage temperature of about 15 ° C for shipment of methyl methacrylate. Used for 10 years. After 10 years, when the inside of the storage tank was inspected, it was confirmed that the inside of the storage tank was clean, with no generation or adhesion of polymer of methacrylic acid being observed.

(Example 3) Tower diameter 1800 mm, height about 2
A SUS304 methyl methacrylate purification tower having a cylindrical shape of 0 m was produced. In the production of this purification tower, various constituent members were joined by welding. Then, over the entire inner surface of the purification tower, the surplus welding wire and the slag attached by the spatter were completely removed by a grinder.
It was confirmed that the inner surface of the purification tower was finished smooth by the naked eye and the touch. With this purification tower,
Methyl methacrylate was purified and distilled at a treatment rate of 65,000 tons / year. After the purification, in order to prevent the incorporation of the polymerized product of methyl methacrylate into the product methyl methacrylate, the polymerization inhibitor (N-isopropyl-N ′) was added to the 10th stage from the top of the purification column having 30 stages. -Phenyl-P-phenylenediamine) was added to the purification column-containing solution in an amount of 25 ppm, and the purification column was continuously operated for 1 year. After one year, the inside of the purification tower was inspected, and it was confirmed that the inside of the purification tower was clean, with no generation or adhesion of a polymer of methyl methacrylate being observed.

COMPARATIVE EXAMPLE 1 A methacrylic acid storage tank made of SUS316 having a cylindrical shape with a diameter of 5 m, a height of about 4 m and a capacity of about 70 kl was prepared. In the production of this storage tank, various components were joined by welding. The inner surface of this storage tank was not subjected to a smoothing treatment as in the case of a normal storage tank. Methacrylic acid added with 50 ppm of a polymerization inhibitor (hydroquinone monomethyl ether) was placed in this storage tank and stored at a storage temperature of about 40 ° C.
Used for shipping methacrylic acid for 3 years. Three years later, when the inside of the storage tank was inspected, it was found that the polymer of methacrylic acid was stuck to the extra weld line on the inner surface of the storage tank, and part of it was peeled off and accumulated on the bottom of the storage tank. Was confirmed. In addition, it was confirmed that even during the use period of 3 years, the filter installed in the product shipping line was occasionally clogged with the polymerized product of methacrylic acid, resulting in clogging.

(Comparative Example 2) A storage tank of methyl methacrylate made of SUS304 having a cylindrical shape with a diameter of 8 m, a height of 8.5 m and a capacity of about 400 kl was prepared. In the production of this storage tank, various components were joined by welding. The inner surface of this storage tank was not subjected to a smoothing treatment as in the case of a normal storage tank. Into this storage tank, methyl methacrylate to which 2.5 ppm of a polymerization inhibitor (2,4-dimethyl-6-tert-butylphenol) was added, was stored at a storage temperature of about 15 ° C, and the methyl methacrylate was shipped. Used for 10 years. Ten years later, when the inside of the storage tank was inspected, during use, the inside of the storage tank where methyl methacrylate was always present
It was very clean without the deposition of methyl methacrylate polymer, but the methyl methacrylate polymer was attached to the weld line surplus on the upper part of the inner surface of the storage tank.
It was confirmed that a part of it had peeled off and accumulated on the bottom of the storage tank.

(Comparative Example 3) Tower diameter 1800 mm, height about 1
An 8-m cylindrical column for removing a low boiling point component of methyl methacrylate made of SUS304 was prepared. In the production of this low boiling point component removal tower, various constituent members were joined by welding. No smoothing treatment was applied to the inner surface of the low boiling point component removing tower. This low boiling point component removal tower was continuously used for one year in order to remove the low boiling point component of the annual production of 65,000 tons of methyl methacrylate. During one year of continuous use, a polymerization inhibitor (hydroquinone and N-isopropyl-N′-) corresponding to a distillate amount of 10 ppm was added to the purified methyl methacrylate from the reflux line above the low boiling point component removal tower. Phenyl-P-phenylenediamine) was added. One year later, when the inside of the low boiling point component removal tower was inspected, the polymer adhered to the extra weld line above the inner surface of the low boiling point component removal tower, especially near the observation window of the low boiling point component removal tower. It was confirmed that a large amount of polymer adhered to the welded portion. As a result of analyzing this polymer, it was found that the main component was methyl methacrylate.

From the results of Examples 1 to 3 and Comparative Examples 1 to 3, smoothing treatment was applied to the inner surface of the easily polymerizable substance handling device,
If the weld line swelling and welding marks are completely removed, a polymer of an easily polymerizable substance will not be generated when handling an easily polymerizable substance. The substance can be handled stably for a long period of time.

[0025]

As described above, the easily polymerizable substance handling device of the present invention is an easily polymerizable substance handling device for synthesizing, purifying, holding or distributing an easily polymerizable substance. Since the smoothing treatment is applied to the location on the inner surface of the handling equipment that comes into contact with the easily polymerized substance, no polymerized substance of the easily polymerized substance is generated, and a stable quality of polymer-free substance is obtained. Polymerizable substances can be manufactured, stored and distributed. Further, the polymer of the easily polymerizable substance does not cause clogging of the pipes and the like which compose this apparatus, so that the apparatus can be stably operated for a long period of time. The easily polymerizable substance handling method of the present invention is an easily polymerizable substance handling method using an easily polymerizable substance handling device that synthesizes, purifies, retains or distributes the easily polymerizable substance, A smoothing treatment is applied to the inner surface of the handling device where the easily polymerizable substance comes into contact, so that the polymer does not form during handling of the easily polymerizable substance, and the quality of the product does not contain a stable substance. The easily polymerizable substance can be produced, stored and distributed.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C07C 57/04 C07C 57/04 67/48 67/48 69/54 69/54 Z // B23K 37/08 B23K 37/08 D (72) Inventor Hideyasu Takezawa 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Otake Office F-term (reference) 4G075 AA13 AA51 AA62 BA10 BD16 FC20 4H006 AA05 BD81 BS10 KE00

Claims (4)

[Claims] 1. An easily polymerizable substance handling device for synthesizing, purifying, holding or distributing an easily polymerizable substance, wherein the inner surface of the easily polymerizable substance handling device has a smooth surface on which the easily polymerizable substance comes into contact. An easily polymerizable substance handling device, which is characterized by being subjected to a chemical treatment. 2. The easily polymerizing process according to claim 1, wherein the smoothing process is a process for scraping off a weld line swelling or welding marks formed on the inner surface of the easily polymerizing substance handling device. Material handling equipment. 3. The easily polymerizable substance is at least one selected from (meth) acrylic acid, (meth) acrylic acid ester, and (meth) acrolein, and is characterized in that: Equipment for handling easily polymerizable substances. 4. A method for handling an easily polymerizable substance using an easily polymerizable substance handling device for synthesizing, purifying, holding or distributing an easily polymerizable substance, wherein the easily polymerizable substance on the inner surface of the easily polymerizable substance handling device is used. A method for handling an easily polymerizable substance, characterized in that a smoothing treatment is applied to a place where the substance comes into contact.