JPH0825971B2 - Novel halogenated aromatic diamine and method for producing the same - Google Patents

Description

The present invention relates to a novel halogenated aroma which is useful as a reactive flame retardant or an epoxy resin curing agent and is also useful as a raw material for polyamide, polyimide, bisimide and the like. A group of diamines and their manufacturing methods, and a novel halogenated aromatic diamine as a raw material, which has flexibility and is useful as a resin for fiber-reinforced composite materials, a substrate resin for printed wiring boards, a resin for heat-resistant molding materials, etc. Bisimide compound.

(Prior Art) A compound containing bromine or chlorine is often used as a flame retardant for imparting flame resistance to a polymer compound. In addition, diamines having multiple amino groups include epoxy resin curing agents such as copper-clad laminates and fiber reinforcement, polyamides,
Used as a raw material for polyimide and bisimide. In particular, thermosetting bisimide compounds obtained by imidizing the terminal amino groups of aromatic diamines have excellent mechanical properties, electrical properties, and heat resistance, so fiber-reinforced composite materials, printed wiring boards, heat-resistant molding materials. It is used as a resin.

Conventionally, several kinds of compounds are known as halogenated aromatic diamines containing halogen elements such as bromine and chlorine, and epoxy resin curing agents and polyamides are used to improve flame retardancy, heat resistance and moisture absorption resistance. It is used as a raw material.

As a curing agent for an epoxy resin, an epoxy resin composition disclosed in JP-B-49-23840 or JP-A-62-277435 is used.
There is a diaminodiphenylmethane-type halogenated aromatic diamine such as a curing agent for epoxy resin prepregs disclosed in Japanese Patent Laid-Open Publication No. 2003-242242, but the reactivity is low because the halogen element for nuclear substitution is close to the amino group.

Further, in order to improve the adhesiveness and impact resistance of the cured epoxy resin, a diamine is used which can impart flexibility to the cured product. For example, in the varnish for a flame-retardant epoxy resin copper-clad laminate shown in JP-A-58-8639, as a curing agent that improves both heat resistance and adhesiveness, a compound of formula [III] 2,2-bis [4-having an ether bond represented by
(4-Aminophenoxy) -3,5-dibromophenyl]
There is propane.

Further, in the epoxy resin for fiber reinforced prepreg shown in JP-A-62-36422, as a curing agent that greatly improves impact resistance without significantly impairing heat resistance,
Formula (IV) In addition to the ether bond represented by, there is a halogenated aromatic diamine having an ethylene oxide chain.

As a raw material for the polyamide resin, there is halogenated 2,4-diaminodiphenyl ether of a self-extinguishing aromatic polyamide disclosed in JP-A-49-59898, but bisimide and polyimide resins are heat resistant and flexible. In order to obtain a cured product excellent in both properties, an aromatic diamine having an ether bond in the main chain is used.

For example, a heat-resistant bisimide resin composition shown in JP-B-63-17081, an ether imide compound shown in JP-B-63-37786, shown in JP-A-58-105953. An ether cyanamide compound, a polyether amide imide polymer composition shown in JP-A-63-172766, a polyamide-imide silicone polymer shown in JP-B-63-205322, and the like, Having the above formula [III] as the raw material aromatic diamine
2,2-Bis [4- (4-aminophenoxy) -3,5-dibromophenyl] propane is exemplified. Further, in the case of using a diamine such as diaminodiphenylmethane or diaminodiphenyl ether as a raw material, the bisimide compound has the drawbacks of good heat resistance but poor moldability, and poor flexibility and impact resistance. Therefore, in order to obtain both excellent heat resistance and flexibility and impact resistance, a bisimide compound having an ether bond in the main chain, such as the heat-resistant bisimide composition disclosed in Japanese Examined Patent Publication No. 63-17081 or the Japanese Examined Patent Publication No. 63- The ether imide compounds of 37786 are exemplified.

(Problems to be Solved by the Invention) When 2,2-bis [4- (4-aminophenoxy) -3,5-dibromophenyl] propane represented by the formula [III] is used as an epoxy resin curing agent, Although a little flexibility is imparted to the cured product due to the introduction of an ether bond, it is still insufficient, and there is a problem that satisfactory properties in adhesiveness with the copper foil cannot be obtained.

Further, in the case of a halogenated aromatic diamine having an ethylene oxide chain in addition to an ether bond in the main chain represented by the formula [IV], impact resistance is sufficient, but the terminal aminophenyl group is bonded with an ester bond. Therefore, there is a problem that the heat resistance is lowered.

Similarly, in the case of a raw material of bisimide or polyimide resin, heat resistance can be improved by using 2,2-bis [4- (4-aminophenoxy) -3,5-dibromophenyl] propane represented by the formula [III]. Although it is excellent, there is a problem in that it is still a brittle material having no toughness because its flexibility is still insufficient.

The heat-resistant bisimide-based resin composition of JP-B-63-17081 and the ether-imide-based compound of JP-B-63-37786 provide flexibility by introducing an ether group into the main chain, but are flexible. However, there is a problem in that it is still a brittle material because it is still insufficient.

The present invention provides a novel compound which, when used as a curing agent for epoxy resins or as a raw material for bisimide or polyimide resins, can impart sufficient flexibility to them. Further, the present invention provides a resin having excellent heat resistance, impact resistance and flexibility by using an aromatic diamine having excellent flexibility as a raw material.

(Means for Solving the Problems) The novel halogenated aromatic diamine represented by the present invention has the general formula [I] (In the formula, at least one of X _{1 to} X ₄ represents chlorine or bromine and may be different from each other. R ₁ and R ₂ are hydrogen, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group. And may be the same as or different from each other, and n represents an integer of 1 to 3).

Furthermore, the present invention has the general formula [II] (In the formula, at least one of X _{1 to} X ₄ represents chlorine or bromine and may be different from each other. R ₁ and R ₂ are hydrogen, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group. Which may be the same or different from each other, n is an integer of 1 to 3), and nitrochlorobenzene or nitrofluorobenzene represented by the formula (1) in an aprotic polar solvent. Bis (nitrophenyl ether) of the halogenated aromatic diol can be obtained by reacting with a basic catalyst.
The method for producing a halogenated aromatic diamine represented by the above general formula [I] is characterized by synthesizing a compound and then reducing the nitro group to an amino group. The present invention also provides
The flexible bisimide compound is characterized in that the terminal amino group of the halogenated aromatic diamine represented by the general formula [I] having excellent flexibility is imidized.

The inventors of the present invention convert the halogenated aromatic diol represented by the above general formula [II] into an alcoholate by using a suitable basic catalyst, and easily react with the halogenated benzene compound to obtain the corresponding phenyl ether. They have found that they give compounds, and have invented new halogenated aromatic diamines.

The halogenated aromatic diamine of the present invention has the general formula [I]
In the above, the effect of imparting flexibility increases as the value of n increases, but when it is 4 or more, heat resistance is impaired, which is not preferable.

The aprotic polar solvent in the production method of the present invention,
Although the kind thereof is not particularly limited, it is necessary to stabilize the alcoholate anion to be produced, and in general, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone, hexamethylphosphoric triamide. And tetrahydrofuran and the like are used. Of course, a solvent having a high boiling point is advantageous for shortening the reaction time, and N-methylpyrrolidone and hexamethylphosphoric triamide are preferable.

As the basic catalyst, at least one selected from the group consisting of alkali metal carbonates, alkali metal hydroxides and active copper, or alkali metal hydrides is used. Generally, potassium carbonate, potassium hydroxide and active copper, or sodium hydride is used. Stronger basic catalysts give higher yields of phenyl ethers, with sodium hydride being most preferred from the group above.

The amount of the basic catalyst used is an amount necessary for the corresponding hydroxyl group to become an alcoholate. Ie at least
0.5 molar equivalents of basic catalyst are used, preferably 1.0 molar equivalents or more.

The reduction of the bis (nitrophenyl ether) compound can be easily performed by an ordinary general method. For example, a nitro group can be reduced to an amino group by a reaction between a metal such as Sn, Fe and Zn and hydrogen generated by an acidic substance such as hydrochloric acid or acetic acid.

When the halogenated aromatic diamine of the present invention is used as an epoxy resin curing agent, the kind of the epoxy resin is not limited at all, and conventionally known curing agents such as aromatic diamine or dicyandiamide or tertiary amines or A curing accelerator such as imidazole may be used together.

When the halogenated aromatic diamine of the present invention is used as a raw material for polyamide, polyimide, bisimide, etc., the kind of the carboxylic acid component is not limited at all, and other conventionally known aromatic diamine may be used in combination. .

The flexible bisimide compound of the present invention can be produced by a method of reacting with an acid anhydride or an acid halide in the same manner as ordinary diamines. That is, a suitable solvent obtained by dehydrating the novel halogenated aromatic diamine,
For example, dissolved in acetone, tetrahydrofuran, N, N-dimethylformamide, N-methylpyrrolidone, etc.,
An amic acid is produced by adding an acid anhydride or an acid halide as it is or in a solution at room temperature or in an ice bath. At this time, diamines may be added later to the acid anhydride or acid halide. The formed amic acid may be filtered out if it is precipitated, and then proceed to the next ring-closing step, or, if the amic acid is obtained in the form of a solution, it may be directly advanced to the next step. The ring closure can be performed by so-called chemical ring closure. An acid anhydride such as acetic anhydride is usually used as the ring-closing aid. As a catalyst for the ring-closing reaction, inorganic salts such as nickel acetate, anhydrous potassium acetate and cobalt acetate, and organic amines such as pyridine and triethylamine are used. When a bisimide is produced using a novel halogenated aromatic diamine, the type of carboxylic acid component is not limited at all, and there is no problem even if other conventionally known aromatic diamines are used in combination. .

(Example) An example is shown below and the present invention will be described more specifically.

(Example 1) An example of the method for producing a novel halogenated aromatic diamine provided by the present invention is shown below.

300 mL with stirrer, condenser and thermometer
Into a three-necked flask, 15.8 g of Fireguard FG-3600 (2,2-bis [4-hydroxyethoxy-3,5-dibromophenyl] propane, trade name of Teijin Kasei Co., Ltd.) was charged, and N-methylpyrrolidone 100 mL was added. Was added and dissolved.
Then, with stirring, sodium hydride with a content of about 60% 2.
4 g was added little by little and stirred for 30 minutes.

Next, 9.5 g of p-nitrochlorobenzene was added and completely dissolved, then heating was started in an oil bath, and the reaction was carried out at 175 to 180 ° C. for 3 hours. After cooling, the precipitated sodium chloride was filtered off, transferred to a pear-shaped flask, and N-methylpyrrolidone was distilled off under reduced pressure (58 ° C / 4 mmHg).

The product was then washed with methanol to remove the resin component, filtered and dried to obtain 20 g of a precipitate. The content of di (p-nitrophenyl ether) compound in the precipitate is about 90%
Met.

Next, the nitro group was reduced. To a 1 L three-necked flask equipped with a stirrer, a condenser and a thermometer, 20 g of the bis (p-nitrophenyl ether) compound was charged and dissolved in 500 mL of benzene.

While stirring on a hot water bath, 160 g of iron powder and 40 mL of concentrated hydrochloric acid were added little by little to the active iron over 1 hour, and then reacted at 70 to 75 ° C. for 2 hours. Then add 40 mL of water,
The reaction was continued for 1 hour.

After cooling, the insoluble matter was filtered off, the benzene solution was transferred to a separatory funnel, washed twice with water, dried over anhydrous sodium sulfate for 24 hours, and benzene was volatilized to obtain 14 g of the halogenated aromatic diamine composition of the present invention. It was

The above composition was purified by repeating recrystallization with a mixed solvent of methanol / chloroform to obtain 11 g of crystals having a purity of 99% or more.

 The analytical values of the crystals are as follows.

1) Melting point; 106-107 ℃ (capillary method) 102 ℃ (DSC method, 1 ℃ / min) 2) Elemental analysis value; C: 45.64% (calculated value 45.73%) H: 3.76% (〃 3.72%) N: 3.34% (〃 3.44%) Br: 38.90% (〃 39.25%) 3) Infrared absorption spectrum (KBr); 3456,3374cm ^-1 (pri-NH ₂ ) 2972,2876cm ^-1 (-CH ₃ ) 1238cm ^-1 ( Ar-O-) 1000 to 1100 cm ^-1 (-C ₂ H ₅ O-) 736 cm ^-1 (Ar-Br) 4) ¹ H Nuclear magnetic resonance spectrum (CDCl ₃ ); δ (ppm / TMS) 7.30 (4H, Br ・ AR-H) 6.5 to 6.9 (8H, Ar-H) 4.34 (8H, -CH _2- ) 3.10 (4H, -NH ₂ ) 1.60 (6H, -CH ₃ ) Implemented in Figs. 1 and 2. The infrared absorption spectrum and ¹ H nuclear magnetic resonance spectrum of the diamine compound produced in Example 1 are shown, respectively.

From the above analytical data, the aromatic diamine compound obtained in Example 1 is of the formula [I] which is a novel aromatic diamine of the present invention. Was confirmed to be 2,2-bis [4- (4-aminophenoxyethoxy) -3,5-dibromophenyl] propane.

(Example 2) Since the novel aromatic diamine of the present invention has bromine, it is clear that it is useful as a flame retardant. Therefore, when the halogenated aromatic diamine of the present invention is used as a curing agent, an epoxy resin is obtained. The characteristics of the resin prepreg will be described.

90 g of Epicoat 1001 (bisphenol type epoxy resin, trade name of Shell Chemical Co., Ltd.), 2,2-bis [4- (4-aminophenoxyethoxy) -3,5-dibromophenyl] propane produced according to Example 1 After dissolving 41 g and dicyandiamide 1 g in a mixed solvent of 200 g of methyl ethyl ketone and 20 g of N, N-dimethylformamide, a thickness of 0.18 m
A glass cloth base material of m was impregnated so that the adhesion amount was 40% by weight, and dried at 160 ° C to obtain a prepreg.

Next, eight prepregs were stacked and molded under conditions of 170 ° C. and 50 kg / cm ² for 2 hours to prepare an epoxy resin laminated plate.

From this laminated plate, cut out a test piece with a width of 25 mm and a length of 50 mm,
A bending test was performed at a distance between fulcrums of 25 mm. In addition, a flame resistance test according to the UL method was performed.

Comparative Example 1 In Example 2, 36 g of 2,2-bis [4- (4-aminophenoxy) -3,5-dibromophenyl] propane as a curing agent was used instead of the bromine-containing aromatic diamine of the present invention. Epoxy resin laminates were prepared in the same manner as in Example 2 except that they were used, and a bending test and a UL method flame resistance test were performed.

(Comparative Example 2) An epoxy resin laminate was prepared in the same manner as in Comparative Example 1 except that 10 g of 4,4'-diaminodiphenylmethane was used as a curing agent and 20 g of decabromodiphenyl ether was used as a flame retardant. A sex test was conducted.

Table 1 shows the test results of Example 2 and Comparative Examples 1 and 2.

It is clear from Table 1 that the halogenated aromatic diamine of the present invention is useful as a flame retardant and a curing agent for making a cured epoxy resin flame-retardant, flexible and tough.

(Example 3) Next, characteristics of the bisimide-based polymer when the halogenated aromatic diamine of the present invention is used as a raw material will be described.

50 with stirrer, condenser and gas inlet
To a 0 mL three-necked flask, 10.8 g of maleic anhydride was added and dissolved in 100 mL of acetone. Example 1 under a nitrogen stream on an ice bath
2,2-Bis [4- (4-aminophenoxyethoxy) -3,5-dibromophenyl] propane 43.
200 mL of 7 g of acetone solution was added dropwise over 2 hours. After the completion of dropping, the mixture was stirred at room temperature for 8 hours. The precipitated amic acid was filtered off, washed with acetone to remove excess maleic anhydride, and then dried under reduced pressure.

Next, in a 500 mL three-necked flask equipped with a stirrer, a condenser and a gas introduction tube, the above-mentioned amic acid 52 g, acetic anhydride 14 mL, triethylamine 7.2 mL and nickel acetate (I
I) 1.25 g of tetrahydrate was added and dissolved in 200 mL of acetone.

Then, the mixture was reacted at reflux temperature for 5 hours under a nitrogen stream. After cooling, the reaction mixture was reprecipitated in water, filtered, neutralized with an aqueous sodium hydrogen carbonate solution, and thoroughly washed with water.

After drying under reduced pressure, recrystallization was repeated with a methanol / chloroform mixed solvent for purification to obtain 50 g of the bromaleimidated bromine-containing aromatic diamine of the present invention.

Next, a cured product of this bismaleimide compound was prepared and its mechanical properties were measured.

The above bismaleimide compound (35 g) was put between the stainless steel end plates sandwiching the 2 mm thick Teflon spacer at contact pressure of 170 ° C 3
0 minutes, subsequently cured at 10kg / cm ² 170 ℃ ² hours, 2 mm
After obtaining a cured product of × 100 mm square, after-curing was performed in a dryer at 200 ° C for 1 hour and finally at 280 ° C for 1 hour.

From this cured product, cut out a test piece with a width of 5 mm and a length of 50 mm,
A bending test was conducted at a fulcrum distance of 30 mm.

(Comparative Example 3) In Example 3, instead of the bromine-containing aromatic diamine of the present invention, 2,2-bis [4- (4-aminophenoxy)] was used.
A bismaleimide compound and a cured product thereof were prepared in the same manner as in Example 3 except that -3,5-dibromophenyl] propane was used as a diamine component, and a bending test was conducted.

(Comparative Example 4) As in Comparative Example 3, a bismaleimide compound and a cured product thereof were prepared using 4,4'-diaminodiphenylmethane as a diamine component, and a bending test was conducted.

Table 2 shows the test results of Example 3 and Comparative Examples 3 and 4.

From Table 2, it is clear that the halogenated aromatic diamine of the present invention is useful for making the maleimide-based cured product flexible and tough.

(Effects of the Invention) According to the present invention, a novel halogenated aromatic diamine which is useful as a flame retardant or an epoxy resin curing agent and also as a raw material for polyamide, polyimide, bismaleimide, etc. is provided.

Further, the present invention makes it possible to obtain a useful bisimide compound that is tougher and more flexible than ever before.

[Brief description of drawings]

FIG. 1 is an infrared absorption spectrum of the bromine-containing aromatic diamine of Example 1, which is a novel compound of the present invention, and FIG. 2 is a ¹ H nuclear magnetic resonance spectrum of the same.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C08G 69/00 NRB 73/10 NTF 73/12 NTH // C07B 61/00 300

Claims (9)

[Claims] 1. A general formula [I] (In the formula, at least one of X _{1 to} X ₄ represents chlorine or bromine and may be different from each other. R ₁ and R ₂ are hydrogen, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group. And may be the same as or different from each other, and n is an integer of 1 to 3). 2. The halogenated aroma according to claim 1, wherein the compound represented by the general formula [I] is 2,2-bis [4- (4-aminophenoxyethoxy) -3,5-dibromophenyl] propane. Group diamine. 3. General formula [II] (In the formula, at least one of X _{1 to} X ₄ represents chlorine or bromine and may be different from each other. R ₁ and R ₂ are hydrogen, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group. Which may be the same or different from each other, n is an integer of 1 to 3), and nitrochlorobenzene or nitrofluorobenzene represented by the formula (1) in an aprotic polar solvent. Bis (nitrophenyl ether) of the halogenated aromatic diol can be obtained by reacting with a basic catalyst.
Of the general formula [I], which comprises synthesizing a compound and then reducing the nitro group to an amino group. (In the formula, at least one of X _{1 to} X ₄ represents chlorine or bromine and may be different from each other. R ₁ and R ₂ are hydrogen, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group. And may be the same as or different from each other, n is an integer of 1 to 3). 4. The method for producing a halogenated aromatic diamine according to claim 3, wherein the compound represented by the general formula [II] is 2,2-bis [4-hydroxyethoxy-3,5-dibromophenyl) propane. . 5. The basic catalyst is at least one selected from the group consisting of an alkali metal carbonate, an alkali metal hydroxide and active copper, or an alkali metal hydride. The method for producing a halogenated aromatic diamine according to 1. 6. The basic catalyst is at least one selected from the group consisting of potassium carbonate, potassium hydroxide and active copper, or sodium hydride.
Alternatively, the method for producing a halogenated aromatic diamine according to item 4. 7. A general formula [I] (In the formula, at least one of X _{1 to} X ₄ represents chlorine or bromine and may be different from each other. R ₁ and R ₂ are hydrogen, a methyl group, an ethyl group, a trifluoromethyl group or a trichloromethyl group. And may be the same as or different from each other, n is an integer of 1 to 3), and the terminal amino group of the halogenated aromatic diamine represented by Bisimide compound. 8. The flexible bisimide compound according to claim 7, wherein the bisimide compound is a bismaleimide compound. 9. An aromatic diamine represented by the general formula [I] is
2,2-bis [4- (4-aminophenoxyethoxy)-
The flexible bisimide compound according to claim 7, which is 3,5-dibromophenyl) propane.