JPH0791267B2 - Acrylonitrile solution for transfer or storage of maleimides - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to the transfer or transfer of maleimides useful for handling large amounts of maleimides on an industrial scale.
It relates to an acrylonitrile solution for storage . Maleimides are useful compounds as raw materials for resins, pharmaceuticals, agricultural chemicals, etc., but the present invention is easy to handle on an industrial scale.
The present invention provides an acrylonitrile solution for transferring or storing various maleimides.

[0002]

2. Description of the Related Art Conventionally, maleimides which are solid at room temperature are generally handled in the form of powder, flakes, tablets and the like. However, the maleimides in such a form contain fine powders of maleimides. Especially during the transfer of such solid maleimides,
The powderization of maleimides progresses, and a large amount of fine powder of maleimides is generated.

Maleimides themselves are irritating to the human body, and particularly when inhaling fine powder, they are irritating to the nasal cavity and throat, causing coughing and sneezing, and leaving them attached to the skin cause undesired inflammation. have.
Therefore, when handling maleimides containing such fine powders, it is necessary to be extremely careful to avoid contact with the skin as much as possible.

Therefore, much effort is required to prevent generation of fine powder as much as possible during the transfer of the maleimides, and to remove the fine powder from the transferred maleimides. Further, in many cases, solid substances are transferred by filling paper bags, drums, containers, etc. with solid substances, but in these cases, contact between maleimides and the human body is inevitable, and the maleimides of the human body cannot be avoided. It is inevitable that fine powder adheres.

[0005] In addition, in order to or to close the tube during transport by pipeline solid material is essentially Mutsukashiku pipe transport in order to avoid contact with the human body, in order to transfer these solid materials easily, Strict restrictions are imposed on the shape, size, and specific gravity of solids. Thus, it must be said that the method for transferring maleimides that are solid at room temperature has a number of difficult problems. The same can be said about the storage time.

[0006]

The transfer and storage of maleimides as a solid as described above has many problems, and various disadvantages are caused especially when handled in large quantities industrially. Handling maleimides in liquid form solves problems such as generation of fine powder and blockage in tubes, but maleimides have the property of being polymerized by heating, so maleimides can be used in an industrial state in a molten state by heating. It is virtually impossible to handle a large amount. In order to make maleimides into a liquid form, a method of suspending or dissolving maleimides in a liquid can be considered, but if it is suspended, it is necessary to perform a dissolving operation when using maleimides, which is complicated. Therefore, it is better to dissolve it. However, when dissolved, it becomes bulky for the solvent. Therefore, in the liquid substance for dissolving the maleimides, the maleimides are easily dissolved, the solubility of the maleimides is high, and the solution is stable for a long time (or the liquid substance does not react with the maleimides). Is required. Therefore, an object of the present invention is to transfer
There is no concern about the generation of fine powder, and the piping and tank
Easy transfer and storage without blockage of nozzles, nozzles, etc.
Available at high enough, even at saturated or supersaturated concentrations
The maleimides can be contained in a concentration
No need to worry about precipitation
It is possible to make final resin products with high mid content,
It is to provide a solution of maleimides useful as a raw material .

[0007]

To achieve the above objectives Symbol A resolving means for the ## present inventors have made intensive studies, as a result, maleimides more soluble to acrylonitrile, and, due to its high solubility, easily high concentration Solution of
Unexpectedly, it was discovered that maleimides do not polymerize in acrylonitrile in the presence of a polymerization inhibitor even at a temperature higher than room temperature and are stable. As a result, maleimides temperature 40 ° C above the warm state acrylonitrile solution and without, easily without entirely of a fine powder generated by the <br/> high concentration of more than 50 wt% in this embodiment Toriatsukaieru That is, the present invention has been completed and the present invention has been completed. Therefore, the present invention provides a solution for transporting or storing maleimides on an industrial scale, wherein the maleimides are added in an amount of 50 wt% in acrylonitrile at a temperature of 40 ° C. or higher in the presence of a polymerization inhibitor. Dissolved at a concentration of over%,
It is an acrylonitrile solution for transfer or storage of maleimides. Ma Reimido class is ABS resin, AAS resin, A
It is widely used as a heat resistance improver for S resins and ACS resins, and is often used by copolymerizing it with monomers such as acrylonitrile and styrene.

However, maleimides are not only difficult to dissolve in styrene, but also easily polymerize in styrene in the presence of a polymerization inhibitor even at room temperature. On the other hand, considering the high solubility of maleimides in acrylonitrile, and the stability for the polymerization of maleimides in acrylonitrile, by treating maleimides as a solution of acrylonitrile, without direct contact with the human body, Since it can be handled as a liquid, it can be easily transferred and stored , and no fine powder is generated.
Since acrylonitrile is one type of copolymer composition other than maleimides even during resin synthesis, many advantages such as the fact that an acrylonitrile solution of maleimide can be used as it is in the polymerization reaction can be obtained.

In this way, it must be said that the method of handling as an acrylonitrile solution for transferring maleimides is an ideal method.

Examples of maleimides which can be made into an acrylonitrile solution according to the present invention include N-methylmaleimide, N-ethylmaleimide, N-hexylmaleimide,
N-octyl maleimide, N-dodecyl maleimide, N
-Benzylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, N-nitrophenylmaleimide, N-methoxyphenylmaleimide, N-methylphenylmaleimide, N-carboxyphenylmaleimide, N-hydroxyphenylmaleimide, N-chlorophenylmaleimide, N-dimethylphenylmaleimide,
Examples thereof include, but are not limited to, N-dichlorophenylmaleimide, N-bromophenylmaleimide, N-dibromophenylmaleimide, N-trichlorophenylmaleimide, and N-tribromophenylmaleimide.

Examples of the polymerization inhibitor used in dissolving solid maleimides in acrylonitrile include methoxybenzonoquine, p-methoxyphenol, phenothiazine, hydroquinone, alkylated diphenylamines, methylene blue, tert-butylcatechol. , Tert-butylhydroquinone, zinc dimethyldithiocarbamate, copper dimethyldithiocarbamate, copper dibutyldithiocarbamate, copper salicylate,
Examples thereof include, but are not limited to, thiodipropionic acid esters, mercaptobenzimidazole, triphenylphosphite, alkylphenols and alkylbisphenols. The amount used is 0.000 with respect to the acrylonitrile solution of maleimides.
It is 1 to 0.5% by weight, preferably 0.001 to 0.1% by weight. The type of polymerization inhibitor is selected in consideration of the type of polymer to be produced, the method of polymerization, the initiator used, and the like.

The temperature at which the maleimides are dissolved in acrylonitrile is preferably in the warmed state and is not higher than the boiling point of acrylonitrile. Since acrylonitrile has a high vapor pressure, it is usually dissolved at 40 to 60 ° C. Since the acrylonitrile solution of maleimides of the present invention does not generate fine powder of maleimides and does not cause clogging of pipes, etc., it is possible to use transfer means such as pipelines, tank trucks, trucks, and tank freight cars for railways. Therefore, regardless of the length of the distance, transfer from a monomer manufacturing factory in a chemical complex to a polymerization factory, transfer between complexes, transfer from a monomer manufacturing factory to a monomer user company (polymerization company, etc.) factory That is, they can be transferred within the same company (for example, transferred from a manufacturing plant to a storage container in a monomer manufacturing company), and stored in a storage container after being manufactured or transferred. Moreover, since the acrylonitrile solution of maleimides of the present invention contains maleimides at a high concentration, it can be used in a wide range of applications as a resin raw material, and there are very few restrictions on the applications. Even if the maleimides are contained at a high concentration, they are in a heated state, so that the dissolved maleimides are prevented from precipitating. In particular, a state in which the amount of dissolved maleimides is heated to a temperature at which the solubility becomes saturated or higher is preferable. Although any method can be basically adopted as a dissolution method, acrylonitrile may be added to maleimides, or maleimides may be added to acrylonitrile.
The concentration of the maleimide acrylonitrile solution is determined by the temperature at which the solution is handled, but since the maleimide solution is usually handled at room temperature, a concentration of about 50% by weight is preferably used. However, when a final resin product having a high maleimide content is required, the solution is kept warm and handled as a high-concentration maleimide solution. In such cases, a maleimides concentration of 50-80% by weight is used.

[0013]

EXAMPLES The present invention will be described in more detail below with reference to examples. Example 1 100 g of acrylonitrile and 10 m of p-methoxyphenol were placed in a 500 ml flask equipped with a stirrer and a cooling tube.
g was added. The water bath temperature was adjusted so that the internal temperature was 30 ° C.
Next, 100 g of crystals of N-phenylmaleimide having a purity of 99.5% by weight was added with stirring, and the crystals of N-phenylmaleimide were promptly dissolved, and completely clear yellow acrylonitrile was obtained. In addition, this solution
No precipitation of N-phenylmaleimide was observed even after cooling to 5 ° C., and the solution could be handled in a stable solution state. Next, the internal temperature was raised to 50 ° C. and kept for 30 days. After 30 days, the clarity of the solution remained unchanged, and when acrylonitrile was evaporated from this solution, bright yellow crystals were obtained. When the N-phenylmaleimide content of this product was measured by high performance liquid chromatography, it was 99.5% by weight, and no polymerization was observed.

Example 2 The procedure of Example 1 was repeated except that 50 mg of p-tert-butylcatechol was added in place of 10 mg of p-methoxyphenol to obtain a completely clear yellow acrylonitrile solution. . Next, the internal temperature was raised to 50 ° C. and kept for 30 days. After 30 days, the clearness of the solution did not change at all, and when acrylonitrile was evaporated from this solution, bright yellow crystals were obtained. When the N-phenylmaleimide content of this product was measured by high performance liquid chromatography, it was 99.5% by weight, and no polymerization was observed.

Comparative Example 1 100 g of styrene was placed in the same flask used in Example 1 and the internal temperature was adjusted to 30 ° C. Then, with stirring, crystals of N-phenylmaleimide having a purity of 99.5% by weight 15
When g and 50 mg of p-tert-butylcatechol were added, a completely dissolved yellow styrene solution was obtained. Next, when the internal temperature of this product was kept at 40 ° C., the solution became remarkably white after 3 days. When styrene was distilled off from this solution under reduced pressure, a sticky yellowish white substance was obtained. When the N-phenylmaleimide content of this product was measured by high performance liquid chromatography, it was 75.5% by weight, and it was found that the product was clearly polymerized.

Comparative Example 2 The same operation as in Comparative Example 1 was carried out except that p-methoxyphenol was used in place of p-tert-butylcatechol and the temperature was kept at 20 ° C. in Comparative Example 1. Later the solution became white. When styrene was distilled off from this solution under reduced pressure, a sticky yellowish white substance was obtained. When the N-phenylmaleimide content of this product was measured by high performance liquid chromatography, it was found to be 90% by weight, and it was found that polymerization was apparent.

Example 3 In Example 1, N- (o-methylphenyl) maleimide having a purity of 99.5% by weight was used in place of N-phenylmaleimide, and 2, -p-methoxyphenol was used in place of p-methoxyphenol.
4-Dimethyl-6-tert-butylphenol 100
The same operation was performed except that mg was used to obtain a clear light yellow N- (o-methylphenyl) maleimide solution of 50% by weight in acrylonitrile. The internal temperature of this solution is 50 ° C
And kept for 30 days. After 30 days, the acrylonitrile was evaporated to give bright yellow crystals. Next, the content of N- (o-methylphenyl) maleimide in this product was measured by high performance liquid chromatography to be 99.5% by weight, and no change due to polymerization was observed.

Example 4 The same as Example 1 except that N- (o-chlorophenyl) maleimide having a purity of 99.0% by weight was used in place of N-phenylmaleimide and the amount of p-methoxyphenol was 30 mg. The operation is performed to obtain a clear pale yellow N- (o-
A 50% by weight solution of chlorophenyl) maleimide in acrylonitrile was obtained. Adjust the internal temperature of this solution to 50 ° C
Hold for days. After 30 days, the acrylonitrile was evaporated to give bright pale yellow crystals. Next, the content of N- (o-chlorophenyl) maleimide in this product was measured by high performance liquid chromatography.
It was 9.0% by weight, and no change due to polymerization was observed.

Example 5 60 g of acrylonitrile and 0.6 m of p-methoxyphenol were placed in a 500 ml flask equipped with a stirrer and a cooling tube.
g was added. The water bath temperature was adjusted so that the internal temperature was 50 ° C. Next, 140 g of crystals of N-phenylmaleimide having a purity of 99.5% by weight was added with stirring, and the crystals of N-phenylmaleimide were immediately dissolved, and a completely clear yellow acrylonitrile solution was obtained. Next, the internal temperature of this solution was raised to 70 ° C. and kept for 30 days. Even after 30 days, the clearness of the solution did not change, and when acrylonitrile was evaporated from this solution, bright yellow crystals were obtained. The content of N-phenylmaleimide in this product was measured by high performance liquid chromatography to be 99.5% by weight, and no polymerization was observed at all.

Reference Example 1 The solubility of N-phenylmaleimide in acrylonitrile was measured. The solution curve obtained is shown in FIG.

[0021]

EFFECTS OF THE INVENTION Transfer or storage of maleimides of the present invention
Acrylonitrile solution for use is prohibited from polymerization of maleimides
50 weight in warm acrylonitrile in the presence of agent
Since it is dissolved at a concentration of over%, it is a fine powder when transferred.
There is no concern about the occurrence of pipes, piping valves, tank valves, nozzles, etc.
Can be easily used for transport and storage without causing blockage of
Contain maleimides in a sufficiently high concentration even at a non-saturation concentration
No need to worry about precipitation of maleimides
The maximum content of maleimide is Final resin
It can be made into products and is useful as a resin raw material.

[Brief description of drawings]

FIG. 1 is a solubility curve of N-phenylmaleimide obtained in Reference Example 1 in acrylonitrile.

[Explanation of symbols]

 None

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-59-135210 (JP, A) JP-B-51-40078 (JP, B1) "Acrylonitrile-its chemistry and industry-" Shu Kanbara, 1959 Issued by Gihodo on September 20, pages 41-43 and 107-11

Claims (1)

[Claims] 1. A solution for transfer or storage of maleimides on an industrial scale, wherein the maleimides are added to acrylonitrile at a temperature of 40 ° C. or higher in the presence of a polymerization inhibitor.
An acrylonitrile solution for transferring or storing maleimides, which is dissolved at a concentration of not less than wt%.