JPS5962537A - Preparation of brominated acenaphthylene condensate - Google Patents

Abstract

PURPOSE:To prepare the titled substance having excellent radiation resistance and flame retardance, with simple operation, by brominating easily available acenaphthene in the presence of a specific catalyst and solvent, condensing the product, brominating the benzyl part with a radical initiator, and dehydrobrominating the product. CONSTITUTION:A brominated acenaphthylene condensate having the unit of formula I or formula II (n and n' are 1-5) as a constituent unit, is prepared by (1) brominating and simultaneously condensing acenaphthene with bromine in a halogenated hydrocarbon in the presence of a Lewis acid catalyst at 10-60 deg.C, (2) removing the Lewis acid catalyst from the system, and brominating the condensate in the presence of a radical initiator (e.g. benzoyl peroxide) at 30-100 deg.C, and (3) dissolving the brominated acenaphthene obtained by the second step in an inert solvent and carrying out dehydrobromination reaction with a base at 30-100 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a brominated acenaphthylene condensate.

In recent years, due to fire prevention measures, polyethylene, polypropylene,
It is widely practiced to make various combustible resins, such as ethylene-propylene rubber, flame-retardant, and one known method is to add various flame retardants to resins to make them flame-retardant. ing.

Recently, it has become essential for electric wires, cables, and various equipment used in nuclear reactors, breeder reactors, ionizing radiation generators, etc. to be flame retardant for safety reasons. Therefore, the electric wires used for these,
Cable insulation materials and various resin compositions are required to have both flame retardancy and radiation resistance.

Brominated acenaphthylene condensate is a compound with excellent flame retardancy and radiation resistance, and since it has a double bond in the molecule, it can be grafted onto resins by subjecting it to free radical generation treatment. Because it is a condensate, it has excellent compatibility with resins, and does not bleed onto the resin surface or volatilize during long-term use, thus maintaining stable flame retardant and radiation-resistant properties over a long period of time. (JP-A-56-122862).

As a method for producing a brominated acenaphthylene condensate,
Using ferric chloride as a catalyst, 6
Bromination method using twice the molar amount at a reaction temperature of 20 to 30°C (Morita, Hagiwara; 30th Polymer Symposium () 3A
14. Tokyo (1981)) and a method of synthesizing brominated acenaphthenes in which bromine is introduced at the aryl and benzylic positions in the presence of a catalyst (Patent Publication No. 122862/1982) have been proposed.

In the former method, a large amount of polybrominated monomers are produced as by-products during bromination, resulting in a low yield.

This poses a problem as an industrial manufacturing method because the waste treatment of these by-products also poses a problem.

In the latter method, catalytic condensation of 1.2.3.5-tetrabromoacenaphthene has been proposed as an example;
The benzylic carbon with bromine is very reactive;
The degree of condensation cannot be controlled because a Friedel-Krach type alkylation reaction easily occurs with a Lewis acid catalyst.

As a result, bromine at the benzyl position is considerably lost, resulting in a disadvantage that the production rate of double bonds decreases during the subsequent HBr removal reaction. In addition, the starting material, brominated acenaphthene with bromine introduced at the aryl and benzylic positions, is used! ) is difficult and yields low when acenaphthene, which is industrially easily available, is used as a starting material.

In order to solve these problems, the present inventors conducted intensive studies on a method for producing a brominated acenaphthylene condensate using acenaphthene as a starting material. When a bromination reaction with bromine is carried out, acenaphthene and condensate in which only the aryl position is brominated are obtained, and it is difficult to obtain a compound in which the benzyl position is brominated. When a bromination reaction with bromine is carried out using bromine, a compound brominated at the benzylic position is obtained, followed by the addition of a Lewis acid catalyst, and then bromine is added again to carry out the bromination reaction and condensation at the aryl position. As a result, it was found that it was difficult to obtain a compound with an extremely high degree of condensation and a compound in which the benzyl position was brominated.

After further investigation, we found that (A) a step in which acenaphthene is brominated and condensed with bromine in the presence of a Lewis acid catalyst in a halogenated hydrocarbon (B) After removing the Lewis acid catalyst, a radical initiator is added, and bromine The present invention was completed based on the discovery that a brominated acenaphthylene condensate can be produced by the step of bromination (c) and the step of dehydrobromation.

The brominated acenaphthylene condensate referred to in the present invention is a compound containing at least one bromine in an aromatic ring, in which brominated acenaphthene formally condenses through a dehydrobromation reaction, with a degree of condensation of 2 or more. This term refers to a product that is subsequently converted into a brominated acenaphthylene condensate through a dehydrobromation reaction.

The condensation mode is an intermolecular bond between the benzylic carbon of acenaphthylene and the aryl carbon of acenaphthylene.

The benzyl position in the present invention means the side chain of the acenaphthene ring, and the aryl position means the naphthalene nucleus of the acenaphthene ring.

The joining points are, for example, 1 (or 2), 3 sen, 1 (or 2), 4'-11 (or 2), and 7/-.

Bonds such as 1 (or 2), s'-, etc. are possible.

If the degree of condensation is 3 or more, any of these bonds K
It has a larger number of constituent units.

The condensate as used in the present invention refers to a condensation product having a degree of condensation of 10 or less and having excellent compatibility with resin.

According to the method of the present invention, in the first step bromination reaction,
By simultaneously performing bromination and condensation at the aryl position and brominating at the benzyl position in the second step, bromination and condensation can be performed in a well-balanced manner, and double bonds can be quantitatively generated. I can do it.

The method of the present invention can be explained using the following reaction formula.

(Here, ni'' is 1 to 6, t is 1 to 2, m is 1 to 10
is within the range of ) Next, the method of the present invention will be specifically explained in each step.

(A) Step Acenaphthene is dissolved in a halogenated hydrocarbon solvent, and simultaneously brominated and condensed with bromine under a Lewis acid catalyst.

The halogenated hydrocarbon solvent used in this step is a solvent inert to the reaction, and examples include carbon tetrachloride, chloroform, methylene chloride, ethylene dichloride, ethylene dipromide, and chlorobenzene. Further, there is no particular limitation on the amount of solvent used. The Lewis acid used as a catalyst is preferably a metal halide, and usually an iron catalyst such as ferric chloride or an aluminum catalyst such as aluminum chloride is used. The amount of catalyst used is 01 to 50 molti per mol of acenaphthene, preferably
It is 1 to 20 molti.

The amount of bromine used in this step is usually 1 to 6 moles per mole of acenaphthene, but Shikei Yoshii2 to
It is 5 moles.

The bromination is suitably carried out at a reaction temperature of between 10 and 60°C.

(B) Step (A) The catalyst is removed from the reaction solution obtained in step (A) by washing with water or the like, a radical initiator is added, and bromine is added to perform bromination.

Although the brominated acenaphthene condensate in the reaction solution obtained in step (A) contains almost no benzyl-position bromide, it is possible to quantitatively obtain the benzyl-position bromide by this step. I can do it.

The radical initiator used in this step is preferably one that decomposes upon heating to generate radicals, and is generally selected from peroxides or azo compounds whose operating temperature range is preferably 30 to 100°C.

For example, benzoyl peroxide, acetyl peroxide.

Examples include lauroyl peroxide and azobisisobutyronitrile.

The amount of bromine used in this step is 1 to 2 moles per mole of acenaphthene.

Bromination is usually carried out at a reaction temperature of 50 to 100°C,
It is preferable to carry out the reaction at a high temperature because the selectivity for bromination at the benzyl position is higher and the reaction proceeds more quickly. During this reaction, almost no condensation occurs.

(C) Step (B) The brominated acenaphthene obtained in step (B) is dissolved in a solvent inert to the reaction, and a base is added to carry out a dehydrobromination reaction.

Examples of the reaction solvent include halogenated hydrocarbons, aliphatic and aromatic hydrocarbons, and ethers, such as carbon tetrachloride, ethylene dichloride, hexane, benzene, toluene, and tetrahydrofuran. Examples of the base include (1) reagents used in ordinary dehydrohalogenation reactions, such as potassium hydroxide-methanol solution, sodium hydroxide-ethanol, and the like.

The reaction is usually carried out at a temperature of 60 to 100°C, but it is preferable to carry out the reaction at a high temperature because the reaction proceeds quickly and quantitatively.

According to the present invention, a brominated acenaphthylene condensate can be produced in good yield by simple operations using raw materials that are easily obtained industrially.

The brominated acenaphthylene condensate produced by the present invention has a quantitative amount of carbon-carbon double bonds at the benzyl position, has a high grafting rate to the resin, and has excellent radiation resistance and flame retardancy. is also excellent.

The present invention will be explained in more detail below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 77 g of acenaphthene and 1 g of ferric chloride a were mixed with 6 carbon tetrachloride
The mixture was added to 90 ml and heated to 60°C. A solution of bromine 2409 and carbon tetrachloride (60 ml) was added dropwise to this solution over 2 hours.

The reaction was carried out under the conditions where the color of the 9 elements disappeared, and after the reaction, the reaction solution was washed with 300 g of 1N aqueous hydrochloric acid solution.

After washing the mixture twice with 500 ml of water, the carbon tetrachloride solution was dried over anhydrous sulfur and magnesium oxide.

Tolyl a2 was added, and a solution of 160 ml of bromine and 40 ml of carbon tetrachloride was added dropwise over 1 hour under reflux at 78°C to react until the color of bromine disappeared.

No precipitation of insoluble matter in carbon tetrachloride was observed in the first and second stage bromination reactions.

After the reaction was completed, the reaction solution was concentrated to dryness, and 550ml of benzene was added.
．． 36 g of potassium hydroxide was dissolved in 150 ml of methanol under heating under reflux, and the resulting solution was added dropwise over 1 hour, and the reaction was continued for another 1 hour. After cooling the reaction solution, the potassium bromide salt was distilled off, the methanol was distilled off, the mixture was washed with water six times, and the benzene solution was condensed by 1' and dropped into acetone for reprecipitation and bromination. Acenaphthylene condensate 152g
I got it. Compositional formula U of the condensate, (Cl2H4,7Brj,
2) Il+, the yield of acenaphthene is 751
Corresponds to

The melting point single element analysis value and the analysis value of the degree of condensation of the obtained condensate were as follows.

Melting point 135-140"C Elemental analysis value (@ G35.6 H1,4Br 62
．． 7 Analysis by high performance liquid chromatography (GPC) 211 bodies 38% 3 Power body 41% 4-octamers 21% The measurement equipment and measurement conditions for high performance liquid chromatography analysis are the same as for manure.

Equipment: High performance liquid chromatograph [Toyo Soda Kogyo (stock system,
"TSK HLC802" trademark] Column: Inner diameter 75mm
x Length 600 mm Filler: TSK GEL G1000H8 (trademark, manufactured by Toyo Soda Kogyo ■) Example 2 Acenaphthene 779 and aluminum chloride 55 were added to carbon tetrachloride 690 and maintained at 60°C.

Add a solution of 620 d of bromine and 80 d of carbon tetrachloride to this solution.
Add dropwise over a period of time and react until the bromine color disappears. After the same treatment as in Example 1, azobisisobutyronitrile a2 was added to the reaction solution, and bromine 80
A solution of g, carbon tetrachloride 20 and f was added dropwise over 0.5 hours, and the reaction was continued until the color of bromine disappeared. Incidentally, no precipitation of insoluble matter was observed in these bromination reactions. Subsequently, the same reaction as in Example 1 was carried out to obtain brominated acenaphthylene condensate 162q. The compositional formula of the condensate determined by elemental analysis is (Cl2H4,7Br3.2)m, and the yield from acenaphthene is 8 (L1 coefficient).

The analytical values of the obtained condensate were as follows.

Melting point 155-160℃ Elemental analysis value (%9 C36,5Hl, 2 Br64
．． 6 Analysis by high performance liquid chromatography (GPO) Dimer 30% 3 (Li integral 32-coupled tetra-octamer 38% Comparative example Acenaphthene 779 and ferric chloride a19 were combined with carbon tetrachloride 7
00 ml and kept at 20°C. Because of this dissolution, a solution of 480 ml of bromine and 120 ml of carbon tetrachloride was added dropwise over 4 hours. After the dropwise addition, the temperature was raised to 55° C., and the reaction was carried out until the color of bromine disappeared.

After 80% of black-brown insoluble matter was formed in the reaction solution, it was allowed to be removed, washed with hydrochloric acid and water, and then deodorized in the same manner as in Example 1 to obtain a brominated acenaphthylene condensate of 140%.
I got it. The compositional formula obtained from elemental analysis is (C'12HM
B'4.2) 11n, corresponding to a yield from acenaphthene of 57.9%. As a result of the analysis, the precipitated insoluble matter was a brominated acenaphthene monomer with a bromine content of 75%, and the obtained brominated acenaphthylene condensate had a bromine content of 69% and a degree of condensation of 2% and 37%. trimer 46%, 4~
It was a compound of 20 octamers.

Patent Applicant Toyo Soda Kogyo Co., Ltd. 1000#7L Supplementary) July 15, 1982! 1 + i old 'I'Jj - Indication of Mr. Kazuo Naganobu Wakasugi 19011 1988 1983 '1 Application No. 169835 2 Name of the invention Process for producing brominated acenaphthylene condensate Name for correction 'I f'l and The relationship between the following: (585) 3 ro 11, +1 5 Sodeichi's object light im 110 [Detailed Description of the Invention 1 Column 6 Amendment Contents 111 as follows: to correct.

Page Line Before correction After correction 15 3 2ii ~ body Dimer or less 14142 Huan body Dike body or less

Claims (1)

[Scope of Claims] A brominated acenaphthylene condensate having a unit represented by the general formula (1) or [■] (where n and nl are integers of 1 to 5) is an example.
(A) In the presence of a Lewis acid catalyst in a halogenated hydrocarbon,
Bromination characterized by comprising the following steps: (B) removing the Lewis acid catalyst, adding a radical initiator and brominating with bromine (C) dehydrobrominating the acenaf f4 Method for producing acenaphthylene condensate.