JPS6131087B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to polybrominated aryldihalocyclopropane derivatives, particularly novel polybrominated aryldihalocyclopropane derivatives,
The present invention relates to its manufacturing method and its uses. Aryldihalocyclopropanes in which the aryl group is substituted with one halogen or aryldihalocyclopropanes in which the aryl group is substituted with two halogens are known. for example,

【formula】

[Formula] (X: Cl or Br), etc. are from J.Chem.
Soc.) [Perkin, 2060
(1973)], [B1024 (1969)] and [B1499
(1971)]. Also,

The formula is described in US Pat. No. 3,012,079 and has use as a fungicide. The present inventors took advantage of the relatively high halogen content of these compounds to study their use as flame retardants for synthetic resins and the like. As a result, they discovered that this compound could be further brominated to increase the bromine content and be used as a flame retardant. That is, by bonding three or more bromines to an aryl group, a polybrominated aryldihalocyclopropane that can be used as a flame retardant is obtained. The present invention relates to this polybrominated aryldihalocyclopropane, which is a novel compound represented by the following general formula. X: Cl or Br R: H or CH ₃ Since the higher the bromine content, the higher the flame retardance, it is preferable that X is Br and R is H. Also,
In normal bromination, three bromines are introduced into the benzene nucleus, and their positions are thought to be the 2, 4, and 5 positions. Representative examples of specific compounds of the present invention are as follows.

【formula】

【formula】

【formula】

[Formula] The halogen content of these compounds is 50% or more,
In particular, compounds with a bromine content of 50% or more are effective as flame retardants. There are two main methods for producing the compounds of the present invention. One is a method in which a dihalocyclopropane ring is formed and then a benzene nucleus is brominated, and the other is a method in which bromine is introduced into a benzene ring and then a dihalocyclopropane ring is formed. The latter method is
Although a nuclear bromine-substituted compound having an unsaturated group in the side chain is used as a starting material, the former method is particularly used because such a starting material is difficult to produce. A dihalocyclopropane ring is formed by adding a dihalocarbene to an α/β unsaturated group. Various methods are known for forming dihalocarbenes (;CX ₂ ). For example, methods of reacting haloform with alkali metal alcoholates, thermal decomposition of trihaloacetates, cleavage reactions of trichloroacetic alkyl esters, etc., reactions of BrCCl ₃ with alkali metal hydrocarbons, decomposition of φHgCX ₃ , etc. are known. Although these methods are possible on a laboratory scale, they are difficult to use on an industrial scale. Currently, dihalocarbenes, which can be used on an industrial scale, are formed by reacting haloform with aqueous alkali metal hydroxide in the presence of a catalyst. That is, a dihalocarbene is formed by reacting haloform with a concentrated alkali metal hydroxide in the presence of a phase transfer catalyst, particularly a quaternary ammonium salt, and at this time, a compound containing an α/β-unsaturated group is formed in the system. A dihalocyclopropane ring is formed by the presence of . Haloform is chloroform or bromoform. Preferred alkali metal hydroxides are sodium hydroxide or potassium hydroxide, with sodium hydroxide being most suitable on an industrial scale. A phase transfer catalyst is a catalyst that can move between an aqueous phase and an organic phase, and quaternary ammonium salts, quaternary phosphonium salts, and the like are known, but quaternary ammonium salts are preferred. Specific examples of quaternary ammonium salts include triethylbenzylammonium chloride, trimethylcetylammonium bromide, methyltricaprylylammonium chloride, tetrabutylammonium bromide, dodecyltrimethylammonium chloride, tetrabutylammonium bromide, dodecyltrimethylammonium chloride, and trimethylammonium bromide. Examples of the quaternary phosphonium salts include hexylmethylammonium chloride and n-hexadecyltributylammonium chloride, and examples of quaternary phosphonium salts include n-hexadecyltributylphosphonium bromide. Starting materials in the present invention include styrene, α-methylstyrene, and the like. A catalyst is added to a mixture of these starting materials and haloform to form an organic phase, and an alkali metal hydroxide is added to the mixture and reacted to produce aryldihalocyclopropane. By brominating this aryldihalocyclopropane by a conventional method, the polybrominated aryldihalocyclopropane derivative of the present invention can be obtained. As described above, in addition to this method, the compound of the present invention can be obtained by forming a dihalocyclopropane ring using previously nuclear brominated styrene or α-methylstyrene as a starting material. The reaction will be further explained in detail. A catalyst is added to a mixture of styrene or its derivatives as a starting material and haloform, and an aqueous alkali metal hydroxide solution is added thereto. At this time, the concentration of the alkali metal hydroxide aqueous solution is 10% by weight or more, especially 20 to 70% by weight.
is appropriate. The reaction temperature is not particularly limited, but
A temperature of 10 to 90°C is suitable, and a temperature of 20 to 60°C is particularly preferred. The mixing ratio of styrene or its derivatives and haloform is not particularly limited, but since both form an organic phase, it is common to use an excess of one or both. Since it is particularly appropriate to use haloform as a solvent, it is preferable to use haloform in excess. Theoretically, 1 mol of dihalocarbenes is generated per 1 mol of alkali metal hydroxide, and 1 mol of dihalocarbenes is thought to react with 1 mol of styrene or its derivatives, but in reality, the generation of dihalocarbenes is less than the theoretical amount. , the alkali metal hydroxide is usually used in excess. Since the product is dissolved in the organic phase, the organic phase can be separated and the product isolated by distillation or other means. This isolated aryldihalocyclopropane is then brominated. For bromination, a conventionally known method is used. for example,
Bromination is carried out with a brominating agent such as bromine or bromine chloride in the presence of a Friedel-Crafts catalyst (eg iron halide) in a solvent such as a halogenated hydrocarbon. Alternatively, bromination in a heterogeneous solvent system of water and an organic solvent, bromination in the absence of a catalyst, etc. can be used. Polybrominated aryl dihalocyclopropane derivatives can be used as flame retardants for synthetic resins, synthetic fibers, or other flammable materials. Therefore, the present invention also relates to a flame retardant comprising a polybrominated aryldihalocyclopropane derivative represented by the following general formula. X: Cl or Br R: H or CH ₃ The higher the halogen content, or the more halogen
Since Br has a higher flame retardant effect than Cl,
is Br and R is preferably H. The flame retardant of the present invention can be used alone or in combination with a flame retardant aid or other flame retardants. There are various flame retardant aids such as antimony compounds, tin compounds, and boron compounds, but antimony compounds such as antimony trioxide are preferred. Other flame retardants include halogen-containing compound flame retardants, phosphorus-containing compound flame retardants,
Although there are nitrogen-containing compound flame retardants, flame retardants containing halogen, phosphorus, or both are particularly preferred. A particularly effective system is a combination of the flame retardant of the invention and antimony trioxide. The flame retardant of the present invention is effective in making various combustible materials flame retardant, such as synthetic resins, synthetic fibers, paper, and wood. It is particularly effective as an additive flame retardant for synthetic resins or synthetic fibers. Synthetic resins that can be made flame retardant by adding the flame retardant of the present invention include thermoplastic synthetic resins and thermosetting synthetic resins. Thermoplastic resins include polyolefin resins such as polyethylene, polypropylene, and polybutylene, polystyrene resins such as polystyrene, ABS, and AS, polyester resins such as polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate, nylon 66, nylon 6, etc. Polyamide resins, polymethyl methacrylate, acrylic resins such as polymethyl acrylate, polyvinyl chloride,
Examples include polyvinyl chloride resins such as vinyl chloride-ethylene copolymers, polycarbonate resins, cellulose resins such as cellulose acetate, polyurethane resins, and other various thermoplastics.
In particular, thermoplastic resins that can be effectively made flame retardant by the addition of the flame retardant of the present invention are polyolefin resins, polystyrene resins, polyester resins, polyamide resins, and polycarbonate resins. In addition, thermosetting resins for which the flame retardant of the present invention is effective include phenolic resins, unsaturated polyester resins, epoxy resins, vinyl ester resins,
There are allyl resins and other thermosetting resins. Furthermore, as synthetic fibers that can be effectively made flame retardant, fibers of the above-mentioned synthetic resins are effective, and in addition to synthetic fibers, natural fibers such as cellulose are also effective. Various additives below the flame retardant of the present invention may be added to the synthetic resin or other materials to be flame retardant. Additives include plasticizers, fillers, stabilizers,
These include coloring agents, reinforcing agents, lubricants, hardening agents, foaming agents, flame retardant aids, and flame retardants other than those of the present invention. The amount of the flame retardant of the present invention added to the material to be flame retardant is not particularly limited, but usually 5 to 40% by weight based on the material to be flame retardant (including additives) is appropriate. If a flame retardant less than the flame retardant is used in combination, the amount may be further reduced. The method of adding the flame retardant of the present invention to the material to be flame retardant is not particularly limited, and various methods such as screw kneading or other kneading, impregnation, coating, and dissolving in a solution of the material to be flame retardant can be used. Since the flame retardant of the present invention has a high bromine content and a high flame retardant effect, an excellent flame retardant material can be obtained even when used in a relatively small amount. Moreover, the physical and chemical properties of the material containing the flame retardant of the present invention are less likely to deteriorate, making it particularly suitable for flammability of synthetic resin molding materials. For example, thermoplastic resins containing the flame retardant of the present invention exhibit little decrease in strength, and almost never suffer from lead-up or deterioration in weather resistance. Furthermore, the flame retardant of the present invention has good affinity or solubility with these resins and can be easily mixed and kneaded, and is particularly suitable for making foamed resins flame retardant. EXAMPLES The present invention will be specifically explained below using Examples, but the present invention is not limited to these Examples. Example 1 3.27 parts of trimethylcetylammonium bromide was added to a solution consisting of 93.7 parts of styrene (parts by weight, same hereinafter) and 337.5 parts of chloroform, and 50 to 53 parts of trimethylcetylammonium bromide was added.
While stirring at °C, an aqueous solution of 276 parts of sodium hydroxide dissolved in 500 parts of water was gradually added. After the addition was completed, stirring was continued at 50 to 60°C for a total of 3 hours. After the reaction was completed, the reaction mixture was poured into 1000 parts of water, the lower organic phase was separated and fractionally distilled under reduced pressure to obtain 138.3 parts of 1-phenyl-2,2-dichlorocyclopropane (yield 82%). ) was obtained. 130.9 parts of this 1-phenyl-2,2-dichlorocyclopropane was dissolved in 750 parts of dichloromethane,
Add 6.0 parts of iron powder and heat to 0°C while stirring to remove bromine 347.9
The solution was added dropwise over a period of 2 hours. Furthermore, at room temperature 2
After continuing to stir for a period of time, unreacted bromine was reduced with sodium sulfite, and then the dichloromethane phase was separated and dichloromethane was removed to obtain 293 parts of white powder. This was considered to be 1-(2,4,5-tribromophenyl)-2,2-dichloropropane, and its properties were as follows. Melting point: 94.6℃ IR: Figure 1 NMR: Figure 2 C ₉ H ₅ Br ₃ Cl ₂ (423.8) Calculated value: C25.51% H1.19% Br56.57%
Cl 16.73% Actual value: C25.39% H1.39% Br56.59%
Cl 16.48% Example 2 Add triethylbenzylammonium chloride to a solution of 123.9 parts of styrene and 300.8 parts of bromoform.
Add 2.38 parts to 50% by weight while stirring at 35-40℃
900 parts of an aqueous NaOH solution was added. After reacting at 43-45°C for 4 hours, the reaction mixture was poured into 1200 parts of water. The lower layer was separated and subjected to fractional distillation under reduced pressure to obtain 199 parts of 1-phenyl-2,2-dibromocyclopropane (yield 61%). Dissolve 165.6 parts of 1-phenyl-2,2-dibromocyclopropane in 780 parts of dichloromethane, and dissolve iron powder.
5.03 parts of bromine was added thereto, and while stirring, 296.5 parts of bromine was added dropwise at 0° C. over 80 minutes. Furthermore, after continuing the reaction at room temperature for 3 hours, unreacted bromine was reduced with an aqueous sodium sulfite solution. White powder 304 is obtained by separating the dichloromethane layer and distilling off the dichloromethane.
I got the department. This was considered to be 1-(2.4.5-tribromophenyl)-2.2-dibromocyclopropane, and its properties were as follows. Melting point: 110.3℃ IR: Figure 3 NMR: Figure 4 C ₉ H ₅ Br ₅ (512.7) Calculated value: C21.09% H0.98% Br77.93% Actual value: C20.92% H1.02% Br78 .05% Example 3 1-(2.4.5-tribromophenyl)-2.2 prepared in Example 1 above was added to commercially available polystyrene.
- dichlorocyclopropane and antimony trioxide were added to the total composition, respectively 1-(2.4.
5-Tribromophenyl)2,2-dichlorocyclopropane (13.6% by weight) and antimony trioxide (4% by weight) were mixed. This composition was manufactured into test pieces using an extruder and an injection molding machine, and JIS
Its flame retardant effect was measured according to K7201. As a result, it was found that the limiting oxygen index was 27.0 and that it was self-extinguishing. For comparison, a test piece made of resin alone was similarly tested, and as a result, the limiting oxygen index was 19.0. The table below shows the results of a similar test in which the above flame retardant was added to other thermoplastic resins.

[Table] Example 4 1-(2.4.5-tribromophenyl)-2.2 produced in Example 2 above was added to commercially available polystyrene.
- Add dibromocyclopropane and triphenyl phosphate, each adding 1-
(2,4,5-tribromophenyl)-2,2-dibromocyclopropane was mixed in an amount of 4.7% by weight and triphenyl phosphate in an amount of 5% by weight. A test piece was produced from this composition using an extruder and an injection molding machine, and the flame retardant effect was measured according to JIS K7201. As a result, it was found that the limiting oxygen index was 26.2 and that it was self-extinguishing. For comparison, a test piece made of resin alone was tested in the same manner, and the limiting oxygen index was 19.0. The table below shows the results of a similar test in which the above flame retardant was added to other thermoplastic resins.

[Table] Example 5 7.5 parts of 1-(2,4,5-tribromophenyl)-2,2-dibromocyclopropane produced in Example 2 and amine were added to 100 parts of a commercially available epoxy resin (Epicote 828). Add 7 parts of hardening agent to 20~
Mixed at 40°C. The composition was cured at 100°C for 1 hour and then at 150°C for 24 hours. After cooling, a test piece was cut out and its flame retardant effect was measured according to JIS K-7201. As a result, it was found that the limiting oxygen index was 32.2 and that it was self-extinguishing. For comparison, a test piece made of resin alone was tested in the same manner, and the limiting oxygen index was 24.0.

[Brief explanation of the drawing]

Figure 1 shows 1-(2, 4, 5) produced in Example 1.
Fig. 2 is a diagram showing the IR of -tribromophenyl)-2,2-dichlorocyclopropane;
It is a figure showing NMR. In addition, FIG. 3 shows Example 2.
FIG. 4 is a diagram showing the IR of 1-(2,4,5-tribromophenyl)-2,2-dibromocyclopropane produced in Example 1, and FIG. 4 is a diagram showing its NMR.

Claims (1)

[Scope of Claims] 1. A polybrominated aryldihalocyclopropane derivative represented by the following general formula. Claim 1: X: Cl or Br R: H or CH ₃ 2 X is Br and R is H
Polybrominated aryldihalocyclopropane derivatives of. 3 In the coexistence of [Formula] (R is below) and haloform, a reaction is carried out by adding an aqueous alkali hydroxide solution in the presence of a phase transfer catalyst. Production of a polybrominated aryldihalocyclopropane derivative represented by the following general formula, characterized by producing an aryldihalocyclopropane derivative represented by (X is below) and then brominating the derivative. Method. X: Cl or Br R: H or CH ₃ 4 A flame retardant consisting of a polybrominated aryl dihalocyclopropane derivative represented by the following general formula. Claim 4: X: Cl or Br R: H or CH ₃ 5 X is Br and R is H
flame retardant. 6. The flame retardant according to claim 4, wherein the flame retardant is a flame retardant for synthetic resins.