JPH07173092A - Method for producing high melting point crystal of 2,3-dibromopropyl compound - Google Patents

Abstract

PURPOSE:To economically and industrially obtain the subject high melting point crystal useful as a flame retardant for synthetic resins and excellent in dispersibility and aggregation resistance by distilling off an organic solvent from the mixture solution of the organic solvent solution of a specific compound with a specified aqueous solution. CONSTITUTION:An organic solvent is distilled off from the mixture solution of an organic solvent solution with the aqueous solution of a water-soluble polymer such as PVA to obtain the objective high melting point crystal. The organic solvent solution is produced by dissolving a compound of formula I [A is C(CH3)2, CH2), SO2, S, O] or tris(2,3-dibromopropyl)isocyanurate of formula II in an organic solvent such as methylene chloride.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing high melting point crystals of a 2,3-dibromopropyl compound useful as a flame retardant for synthetic resins.

[0002]

PRIOR ART Bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl] sulfone, isopropylidenebis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl ], Tris (2,3
2,3-dibromopropyl) isocyanurate, etc.
Dibromopropyl compounds are useful as flame retardants for synthetic resins, and are used in various resins represented by olefin resins and styrene resins. Resins containing these flame retardants are electrical and electronic materials that require flame retardancy. It is used for various purposes mainly in the field.

However, it has been difficult to obtain high melting point crystals of these compounds in the past, and usually only an amorphous solid having a low melting point was obtained. This low-melting point amorphous solid is likely to be fused and solidified in the summer when the temperature is high, so that handling during transportation, storage, use and the like becomes very complicated, which is a practical problem. Further, because of its low melting point, it may be melted during crushing, mixing, and kneading, failing to attain the purpose.

Various proposals have been made to solve such problems. For example, JP-B-57-289 discloses that a good solvent such as methylene chloride is used in order to obtain a high melting point product of isopropylidene bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl]. A method has been proposed in which a poor solvent such as methanol is added to the solution and the mixture is stirred with a large shearing force. However, although a high melting point product can be obtained by this method, it is not easy to collect and use because both solvents used are mixed, and the product is dissolved in the solvent, so the yield is lowered and the economy is very poor. There is a problem of becoming.

Further, JP-A-2-286645 discloses that bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl] sulfone or isopropylidenebis [4- (2,2) in a molten state. 3-dibromopropyloxy) -3,5-dibromophenyl], and the crystals of the compound are added and mixed at a temperature not higher than the melting point to obtain 50 to 100.
A method of keeping the temperature at ℃ has been proposed. However, this method needs to be kept warm in an oven for 8 hours, which is poor in workability and economical efficiency as a manufacturing method, and has many problems as an industrial manufacturing method. As described above, various methods for obtaining crystals of the 2,3-dibromopropyl compound have been proposed, but in reality, they are not satisfied in practice.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a method for producing a high melting point crystal of a 2,3-dibromopropyl compound useful as a flame retardant for synthetic resins. .

[0007]

[Means for Solving the Problems] As a result of intensive studies, the inventors of the present invention have found that an organic solvent is distilled from a mixed solution of an organic solvent solution of a 2,3-dibromopropyl compound and a water-soluble polymer aqueous solution. By removing, it was found that high melting point crystals of the 2,3-dibromopropyl compound can be obtained,
The present invention has been reached.

That is, according to the present invention, the organic solvent is distilled off from a mixed solution of a solution of the 2,3-dibromopropyl compound represented by the general formula (I) or the general formula (II) in an organic solvent and a water-soluble polymer aqueous solution. And a method for producing a high-melting point crystal of a 2,3-dibromopropyl compound.

[0009]

[Chemical 3]

[In the formula, A is --C (CH ₃ ) _2- , --CH ₂
-, - SO ₂ -, - representing the S- or -O-]

[0011]

[Chemical 4]

The present invention will be described in detail below. The 2,3-dibromopropyl compound used for producing the high melting point crystal of the present invention is represented by the above general formula (I) or general formula (II). The compound can be synthesized by a general method. For example, it can be obtained by brominating the corresponding allyl ether or ester in a solvent such as a halogenated hydrocarbon. Further, the corresponding allyl ether or ester can be obtained by allylating bisphenols or isocyanuric acid with an allylating agent such as allyl chloride.

As the water-soluble polymer used in the present invention,
Synthetic polymers such as polyvinyl alcohol, polyethylene oxide, polyacrylamide, styrene-maleic anhydride copolymer resin; ionic polymers such as polystyrene sulfonate sodium, polyacrylate sodium, sulfonic acid modified polyvinyl alcohol; gelatin, gum arabic, Natural polymers such as guar gum, locust bean gum and sodium alginate; semi-synthetic polymers such as carboxymethyl cellulose, methyl cellulose, hydroxyethyl cellulose and the like can be mentioned.

The organic solvent used in the present invention is a general organic solvent, and it is desirable that the 2,3-dibromopropyl compound of the present invention can be dissolved at room temperature or upon heating. Typical organic solvents include methylene chloride, ethane dichloride,
Examples thereof include halogenated hydrocarbons such as methylene bromide; aromatic hydrocarbons such as toluene and benzene; esters such as ethyl acetate.

The method for producing a high melting point crystal of the present invention is 2, 3
-By vigorously stirring a mixed solution of an organic solvent solution of a dibromopropyl compound and an aqueous solution of a water-soluble polymer, by distilling off the organic solvent under normal pressure or reduced pressure in the temperature range of room temperature to 100 ° C, water The method is to disperse the crystals of the 2,3-dibromopropyl compound in water, and the crystals dispersed in water can be separated, washed, and dried to obtain a powdery 2,3-dibromopropyl compound. .
When the water-soluble polymer is not added, the 2,3-dibromopropyl compound is suitable for water in the method of distilling off the organic solvent from the mixed solution of the organic solvent solution of the 2,3-dibromopropyl compound and water. It does not disperse into a lump and becomes a lump, and a high melting point crystal cannot be obtained.

The amount of the water-soluble polymer of the present invention added is 2, 3
-0.
A range of 2 to 15 parts by weight is preferred.

The high melting point crystal of the 2,3-dibromopropyl compound obtained by the method of the present invention can be blended as a flame retardant with various synthetic resins such as thermoplastic resins, thermosetting resins and thermoplastic elastomers. . Among them, polyolefins typified by polyethylene and polypropylene; vinyl resins such as vinyl acetate resin and vinyl chloride resin; polystyrene, high-impact polystyrene, AB
It is effective for styrene resins represented by S (acrylonitrile-butadiene-styrene copolymer) and the like.

[0018]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 Methylene chloride 390 was placed in a 1 liter glass reactor equipped with a stirrer, condenser, thermometer and dropping funnel.
g and isopropylidene bis (4-allyloxy-3,
274 g of 5-dibromophenyl) was added, and 156 g of bromine was added dropwise over 1 hour at a reaction temperature of 10 to 20 ° C. with stirring to cause a bromination reaction. After completion of dropping, the mixture was aged at 10 to 20 ° C for 1 hour. After completion of the aging, excess bromine was reduced, washed with water and neutralized to obtain 800 g of a solution of isopropylidene bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl] in methylene chloride. On the other hand, in a 1 liter glass reactor equipped with a stirrer, concentrator and thermometer,
While stirring 400 g of water, 13 g of sodium polystyrene sulfonate (Polynas PS-5, manufactured by Tosoh Corporation) was added and dissolved, and the methylene chloride solution obtained above was added thereto, and the internal temperature was increased while heating in a water bath. The temperature was gradually raised, and methylene chloride was concentrated and distilled off. The internal temperature reached 80 ° C., and the temperature was kept stirring for 1 hour while maintaining the temperature. After cooling to room temperature, the crystals became dispersed in water. The state of dispersion at this time was observed. The crystals were separated by filtration, washed with water and dried, and then 410 g of crystals of isopropylidene bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl].
Got The crystals obtained were subjected to bromine content, melting point measurement and consolidation test. The analysis was performed according to the evaluation method described below, and the analysis results and the dispersed state of the crystals are shown in Table 1.

Evaluation method (1) The bromine content was measured by a method according to JIS K 7299 (flask combustion method). (2) The melting point was measured with a Mettler melting point measuring instrument (Mettler FP61) after the sample was finely ground in a mortar and filled in a capillary. The temperature rising rate was 10 ° C./min, and the temperature at the end of melting was the melting point. (3) For the consolidation test, 10 g of the sample was placed in an aluminum cup (No. 6 manufactured by Inouchi Sakaeido Co., Ltd.) and stored in a blow dryer at 40 ° C., and a weight of 200 g was applied on the sample. 7 when stored in a dryer at 40 ° C
The state of caking after the day was observed and evaluated according to the following four grades. ◎: No solidification ○: Almost no solidification △: Partially solidified ×: Severe solidification

[0021]

[Table 1]

Example 2 Except that 274 g of bis (4-allyloxy-3,5-dibromophenyl) sulfone was used instead of 274 g of isopropylidene bis (4-allyloxy-3,5-dibromophenyl) in Example 1. Bromination was performed in the same manner as in Example 1 to obtain 805 g of a methylene chloride solution of bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl] sulfone. In addition, crystallization was performed in the same manner as in Example 1 except that polyvinyl alcohol (PVA-235, manufactured by Kuraray Co., Ltd.) was used instead of the polystyrene sulfonate soda of Example 1, and bis [4- (2,2 3-dibromopropyloxy) -3,5-
419 g of crystals of dibromophenyl] sulfone were obtained. The crystals obtained were subjected to bromine content, melting point measurement and consolidation test. Table 1 shows the analysis results and the dispersed state of the crystals.

Example 3 In Example 1, 167 g of triallyl isocyanurate was used instead of 274 g of isopropylidene bis (4-allyloxy-3,5-dibromophenyl), and 620 g of ethane dichloride was used instead of 390 g of methylene chloride. 1
Example 1 except that 332 g of the same was used instead of 56 g.
In the same manner as in (1), 1,090 g of a solution of tris (2,3-dibromopropyl) isocyanurate in ethane dichloride was obtained. Crystallization was performed in the same manner as in Example 1 except that gum arabic was used in place of the sodium polystyrenesulfonate in Example 1 to obtain 471 g of tris (2,3-dibromopropyl) isocyanurate crystal. . The crystals obtained were subjected to bromine content, melting point measurement and consolidation test. Table 1 shows the analysis results and the dispersed state of the crystals.

Comparative Example 1 Methylene chloride was concentrated and distilled off in the same manner as in Example 1 except that sodium polystyrene sulfonate was not used. The product became lumpy and did not disperse well. Therefore, it was difficult to take it out of the reactor. A part of the taken out mass was post-treated in the same manner as in Example 1 to obtain a mass of isopropylidene bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl]. The obtained lump was crushed in a mortar, and the bromine content, melting point and solidification test were carried out. Table 1 shows the analysis results and the dispersed state of the crystals.

Comparative Example 2 Methylene chloride was concentrated and distilled off in the same manner as in Example 2 except that polyvinyl alcohol was not used. The product became lumpy and did not disperse well. Therefore, it was difficult to take it out of the reactor.
A part of the taken out mass is post-treated in the same manner as in Example 1,
Bis [4- (2,3-dibromopropyloxy) -3,
A mass of 5-dibromophenyl] sulfone was obtained. The obtained lump was crushed in a mortar, and the bromine content, melting point and solidification test were carried out. Table 1 shows the analysis results and the dispersed state of the crystals.

Comparative Example 3 In Example 3, ethane dichloride was concentrated and distilled off in the same manner as in Example 3 except that gum arabic was not used. The product became lumpy and did not disperse well. Therefore, it was difficult to take it out of the reactor. A part of the taken out mass was post-treated in the same manner as in Example 1 to obtain a mass of tris (2,3-dibromopropyl) isocyanurate. The obtained lump was crushed in a mortar, and the bromine content, melting point and solidification test were carried out. Table 1 shows the analysis results and the dispersed state of the crystals.

Comparative Example 4 The isopropylidene bis [4] obtained in Example 1 was used.
A methylene chloride solution of-(2,3-dibromopropyloxy) -3,5-dibromophenyl] was heated and concentrated under normal pressure with stirring as it was, and methylene chloride was distilled off to an internal temperature of 120 ° C. Further, after concentration under reduced pressure at 120 ° C., the melt was taken out in an enamel vat and cooled to room temperature to solidify to obtain 412 g of glass. The obtained glassy material was crushed in a mortar, and the bromine content, melting point and solidification test were carried out. The analysis results are shown in Table 1.

Comparative Example 5 A methylene chloride solution of bis [4- (2,3-dibromopropyloxy) -3,5-dibromophenyl] sulfone obtained in Example 2 was concentrated as it was in Comparative Example 1. Then, 420 g of a glassy material was obtained. The obtained glassy material was crushed in a mortar, and the bromine content, melting point and solidification test were carried out. The analysis results are shown in Table 1.

Comparative Example 6 The ethane dichloride solution of tris (2,3-dibromopropyl) isocyanurate obtained in Example 3 was concentrated as it was in Comparative Example 1 to obtain 470 g of glass. The obtained glassy material was crushed in a mortar, and the bromine content, melting point and solidification test were carried out. The analysis results are shown in Table 1.

[0030]

As described above, according to the present invention,
The method for producing a high melting point crystal of a dibromopropyl compound is easy to industrialize and excellent in economical efficiency. Further, the high-melting point 2,3-dibromopropyl compound obtained by the method of the present invention is easy to handle because it is hard to congeal, and is useful as a flame retardant for synthetic resins.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C07C 317/22 319/28 323/19 C07D 251/34 A C08K 5/06 KAP 5/3492 KBN / / C09K 21/08 21/10 (72) Inventor Keizo Tsukamoto 92 Minohokicho, Fukuyama City, Hiroshima Prefecture Manac Co., Ltd. Minohoki Factory

Claims (1)

[Claims] 1. An organic solvent is distilled off from a mixed solution of an organic solvent solution of a 2,3-dibromopropyl compound represented by the general formula (I) or the general formula (II) and an aqueous solution of a water-soluble polymer. And a method for producing a high melting point crystal of a 2,3-dibromopropyl compound. [Chemical 1] In the formulas, A is _{-C (CH 3) 2 -,} - CH 2 -, - SO 2
Represents-, -S- or -O-]