JPH11263842A - Bromine-containing polyamideimide resin, varnish containing same, and production of same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin excellent in film-forming properties and resin properties by reacting a bromine-containing diamine with trimellitic anhydride in the presence of an aprotic solvent, adding a solvent azeotropically distillable with water to the reaction mixture, continuing the reaction at a specified temperature, removing the solvent from the reaction mixture, and reacting the desolvented mixture with an aromatic diisocyanate. SOLUTION: A bromine-containing aromatic diamine represented by formula I is reacted with trimellitic anhydride at 50-90 deg.C in an aprotic solvent such as N-methyl-2-pyrrolidone,0.1-0.5 pt.wt., per pt.wt. aprotic solvent, aromatic hydrocarbon, such as toluene, azeotropically distillable with water is added to the reaction mixture, and the resultant mixture is further reacted at 120-180 deg.C until the theoretical amount of water is distilled out to produce a mixture containing a bromine-containing diimidedicarboxylic acid represented by formula II. Next, this mixture is reacted with an aromatic diisocyanate such as 4,4'- diphenylmethane diisocyanate to obtain a polyamideimide resin. The reaction solution can be used as such as a resin-containing varnish.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a bromine-containing polyamide-imide resin, a varnish containing the same, and a method for producing the same.

[0002]

2. Description of the Related Art Polyamideimide resins are usually synthesized by an isocyanate method by the reaction of trimellitic anhydride and an aromatic diisocyanate, or by an acid chloride method by a reaction of an aromatic diamine and trimellitic acid chloride. ing. In the isocyanate method, the types of aromatic diisocyanates that are industrially manufactured and commercially available are limited to a small extent, so that the polyamideimide resin that can be manufactured is also limited, and it is difficult to provide a wide range of properties. On the other hand, the acid chloride method has a problem that a step of eliminating HCl produced as a by-product is required, a purification cost such as removal of HCl is required, and the cost becomes high. JP-A-3-181511 discloses a polyamideimide resin characterized by a two-step method comprising reacting an aromatic tricarboxylic anhydride with a diamine having an ether bond in an excess of an amine component, and then reacting a diisocyanate. Manufacturing methods have been proposed. Also, Japanese Patent Application Laid-Open No.
No. 66 proposes a method for producing a highly pure diimidedicarboxylic acid by reacting an aromatic diamine and trimellitic anhydride. By reacting diimide dicarboxylic acid produced using this method with diisocyanate,
A variety of aromatic diamines can be used as they are, polyamideimide resins can be easily synthesized without HCl by-product unlike the acid chloride method, and polyamides of sufficient molecular weight with few by-products It is considered that an imide resin can be synthesized.

[0003]

The method proposed in JP-A-3-181511, in which an aromatic tricarboxylic anhydride is reacted with a diamine having an ether bond in an excess state of an amine component and then reacted with a diisocyanate, The first-stage reaction requires a reaction between a carboxylic acid and an amino group in addition to a reaction between an acid anhydride and an amino group, and actually uses a dehydrating agent. Therefore, in the first-stage reaction, oligomerization has already occurred, and in the second-stage reaction with diisocyanate, oligomers having various molecular weights react with diisocyanate. There is a problem that a polyamideimide resin having a characteristically sufficient molecular weight cannot be produced. Further, by reacting the produced diimide dicarboxylic acid and diisocyanate using the method of JP-A-4-182466, it is possible to use many kinds of aromatic diamines industrially produced and commercially available. The resulting polyamideimide resin can also be modified according to the purpose, without generating HCl by-product unlike the acid chloride method.
A polyamideimide resin can be easily synthesized.
However, when a diamine having two or less aromatic rings is used, as described in JP-A-4-182466, the resulting diimidedicarboxylic acid becomes insoluble in the synthesis solvent, and thus the step of diimidedicarboxylic acid becomes insoluble. Therefore, filtration must be performed, and the number of filtration steps and purification steps increases, which is a factor of cost increase. In addition, since the solubility of the purified diimide dicarboxylic acid is low, the molecular weight does not increase even if the diimide dicarboxylic acid is reacted with the aromatic diisocyanate. Inferiority. Further, if bromine can be contained in the resin skeleton, the solvent solubility of the polyamideimide resin is increased, and it can be expected that the polyamideimide resin will be soluble in amide or ether solvents having lower boiling points. The content of bromine not only increases the solubility of the resin, but also in the case of electronic materials, flame retardancy becomes important from the viewpoint of safety. Polyamideimide resin is capable of crosslinking with epoxy resin,
Often mixed with epoxy resin. In order to make it flame-retardant, it is preferable to add bromine to the polyamideimide resin. The present invention relates to a bromine-containing polyamide-imide resin which is soluble in a solvent, has excellent film-forming properties, has few by-products, can provide a simple purification process, and can impart flame retardancy, a method for producing the same, and a varnish containing the same. The challenge was to provide

[0004]

The present inventors have studied to solve the above-mentioned drawbacks, and as a result, use a bromine-containing aromatic diamine represented by the general formula (1) having high solubility in a solvent as a diamine. As a result, it was possible to obtain a bromine-containing polyamide-imide resin having excellent film-forming properties and good flame resistance. The present invention relates to a mixture containing a bromine-containing diimide dicarboxylic acid represented by the general formula (2) obtained by reacting a bromine-containing aromatic diamine represented by the general formula (1) with trimellitic anhydride, A bromine-containing polyamide-imide resin obtained by reacting with an aromatic diisocyanate represented by the following formula (3). Such a bromine-containing polyamide-imide resin is obtained by reacting a bromine-containing diamine represented by the general formula (1) with trimellitic anhydride at 50 to 90 ° C. in the presence of an aprotic polar solvent, and further reacting with water. The azeotropic aromatic hydrocarbon is aprotic polar solvent of 0.1 to
After adding at a 0.5 weight ratio and reacting at 120 to 180 ° C. to produce a bromine-containing diimide dicarboxylic acid, the aromatic hydrocarbon is removed from the solution, and the bromine-containing diimide dicarboxylic acid reacts with the aromatic diisocyanate. This is a method for producing a polyamideimide resin. The reaction solution can be used as it is as a varnish containing a bromine-containing polyamideimide resin.

[0005]

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[0006]

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[0007]

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[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, an aromatic diimide dicarboxylic acid is synthesized by reacting the above-mentioned bromine-containing aromatic diamine with trimellitic anhydride. In producing this aromatic diimide dicarboxylic acid, a mixed solution of an aprotic polar solvent and an aromatic hydrocarbon azeotropic with water is used. After completion of the reaction, the aromatic hydrocarbon is removed by distillation or the like and subsequently reacted with an aromatic diisocyanate to produce a polyamideimide resin.The produced polyamideimide resin is dissolved in the aprotic polar solvent described above, It becomes a product as a varnish.

The bromine-containing aromatic diamine used in the present invention is prepared by reacting tetrabromobisphenol A and p-chloronitrobenzene with N-methyl-2 in the presence of potassium carbonate as described in JP-A-58-8639. After the reaction in pyrrolidone (NMP), it is obtained by reducing the nitro group of the product to an amino group with palladium or the like.

The mixed solvent which can be azeotropically mixed with the aprotic polar solvent and water used in the production method of the present invention is a bromine-containing aromatic diamine and trimellitic anhydride (hereinafter abbreviated as TMA).
It is an organic solvent that does not react with, and the type of mixed solution used and its mixing ratio are important. As the aprotic polar solvent used in the present invention, dimethylacetamide, dimethylformamide, dimethylsulfoxide, N-methyl-2
-Pyrrolidone, 4-butyrolactone, sulfolane, cyclohexanone and the like. N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP), which has a high boiling point because an imidation reaction requires a high temperature, is particularly preferable. The amount of water contained in these mixed solvents is controlled to 0.2% by weight or less because trimellitic acid generated by hydration of TMA does not sufficiently promote the reaction and causes a decrease in the molecular weight of the polymer. Is preferred. Further, the amount of the aprotic polar solvent used in the present invention is not particularly limited. However, if the ratio of the total weight of the bromine-containing aromatic diamine and TMA is large, the solubility of TMA is reduced and sufficient reaction can be performed. Since it disappears and if it is small it will be a factor of cost increase,
It is preferably in the range of 10% to 70% by weight.

The aromatic hydrocarbons azeotropic with water used in the present invention include benzene, xylene, ethylbenzene,
Aromatic hydrocarbons such as toluene can be exemplified. Particularly, toluene having a relatively low boiling point and less harmful to the working environment is preferable, and the amount used is 0.1 to 0.5 of the aprotic polar solvent.
A range of weight ratios is preferred. When the amount of the aromatic hydrocarbon used is less than the above range, the effect of removing water by azeotropic distillation is reduced, and the promotion of the production of bromine-containing diimide dicarboxylic acid is also reduced. When the amount of the aromatic hydrocarbon used exceeds the above range, the bromine-containing amide carboxylic acid and the generated bromine-containing diimide dicarboxylic acid as reaction intermediates may be precipitated. Aromatic hydrocarbons are used to produce by-product azeotropic distillation of aromatic diimide dicarboxylic acid to remove water outside the system. For this reason, water and the solvent may be distilled off at the same time, and the amount of aromatic hydrocarbons in the solvent may be reduced. Therefore, in order to maintain the amount of the aromatic hydrocarbon solvent present in the reaction system at a constant ratio, the solvent flowing out of the system is separated from the water using, for example, a water-quantitative receiver equipped with a cock, and then into the system. It is preferable to perform a method of returning or supplementing.

The reaction conditions in the present invention are as follows. First, the reaction between the bromine-containing aromatic diamine and trimellitic anhydride must be carried out at 50 to 90 ° C. in the presence of an aprotic polar solvent. After this reaction, an aromatic hydrocarbon is charged and reacted at a temperature azeotropic with water. The reaction temperature at this time varies depending on the amount of the aromatic hydrocarbons and the capacity of the moisture meter with a cock.
The reaction is preferably performed at 80 ° C. The reaction is carried out until water is no longer produced as a by-product in the reaction system, and it is particularly preferable to confirm that the theoretical amount of water has been distilled off. The reaction solution may contain an aromatic hydrocarbon, but after the diimide dicarboxylic acid is produced, the temperature is raised to react with the aromatic diisocyanate. Is preferably performed. The obtained bromine-containing aromatic diimide dicarboxylic acid can be reacted with an aromatic diisocyanate to produce a bromine-containing aromatic polyamide-imide resin having a high molecular weight.

As the aromatic diisocyanate used in the present invention, 4,4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, Examples thereof include 2,4-tolylene dimer. These can be used alone or in combination. In particular, MDI is preferred because the isocyanate group is separated in the molecular structure, the concentration of the amide group or imide group in the molecule of the polyamide imide resin is relatively low, and the solubility is improved. When the reaction temperature is low, the reaction time is prolonged.
The reaction is preferably performed at 100 to 200 ° C.

[0014]

Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. (Example 1) 25 ml with a cock connected to a reflux condenser
As a bromine-containing aromatic diamine, brominated BAPP (2,2-bis [4- (4-aminophenoxy) -3,5-) was placed in a 1-liter separable flask equipped with a water determination receiver, a thermometer, and a stirrer. Dibromo-phenyl] propane) 14
5.2 g (0.20 mol) and 76.9 g (0.40 mol) of TMA (trimellitic anhydride) were used as NMP (N-methyl-2-pyrrolidone) as an aprotic polar solvent.
560 g was charged and stirred at 80 ° C. for 30 minutes. And 100 m of toluene as an aromatic hydrocarbon azeotropic with water
After adding 1, the temperature was raised and refluxed at about 160 ° C. for 2 hours. Make sure that about 7.2 ml or more of water has accumulated in the receiver for water content and that no outflow of water has been observed. The temperature was increased to remove the toluene. Thereafter, the solution was returned to room temperature, and 50.1 g (0.20 mol) of MDI (4,4'-diphenylmethane diisocyanate) was added as an aromatic diisocyanate, and 1
The reaction was performed at 90 ° C. for 2 hours. After the completion of the reaction, an NMP solution of a bromine-containing polyamideimide resin was obtained.

Example 2 A brominated BAPP (2,2) as a bromine-containing aromatic diamine was placed in a 1-liter separable flask equipped with a faucet connected to a reflux condenser and having a 25-ml water content receiver, a thermometer and a stirrer. 2-bis [4- (4-
145.2 g (0.20 mol) of aminophenoxy) -3,5-dibromo-phenyl] propane) and 76.9 g (0.40 mol) of TMA (trimellitic anhydride)
As an aprotic polar solvent, NMP (N-methyl-2-
560 g of pyrrolidone) and stirred at 80 ° C. for 30 minutes. Then, 100 ml of toluene was charged as an aromatic hydrocarbon capable of azeotropic distillation with water, and then the temperature was increased and the mixture was refluxed at about 160 ° C. for 2 hours. Make sure that about 7.2 ml or more of water has accumulated in the receiver for water content and that no outflow of water has been observed. The temperature was increased to remove the toluene. Thereafter, the solution was returned to room temperature, and 34.8 g (0.20 mol) of TDI (2,4-tolylene diisocyanate) was added as an aromatic diisocyanate.
The reaction was carried out at 2 ° C. for 2 hours. After the completion of the reaction, an NMP solution of a bromine-containing polyamideimide resin was obtained.

Example 3 A brominated BAPP (2,2) as a bromine-containing aromatic diamine was placed in a 1-liter separable flask equipped with a faucet connected to a reflux condenser and having a 25 ml water content receiver, a thermometer and a stirrer. 2-bis [4- (4-
145.2 g (0.20 mol) of aminophenoxy) -3,5-dibromo-phenyl] propane) and 76.9 g (0.40 mol) of TMA (trimellitic anhydride)
As an aprotic polar solvent, NMP (N-methyl-2-
560 g of pyrrolidone) and stirred at 80 ° C. for 30 minutes. Then, 100 ml of toluene was charged as an aromatic hydrocarbon capable of azeotropic distillation with water, and then the temperature was increased and the mixture was refluxed at about 160 ° C. for 2 hours. Make sure that about 7.2 ml or more of water has accumulated in the receiver for water content and that no outflow of water has been observed. The temperature was increased to remove the toluene. Thereafter, the solution was returned to room temperature, and 25.1 g (0.10 mol) of MDI (4,4'-diphenylmethane diisocyanate) as an aromatic diisocyanate, TD
17.4 g of I (2,4-tolylene diisocyanate)
(0.10 mol), and reacted at 190 ° C. for 2 hours. After the completion of the reaction, the N
An MP solution was obtained.

(Comparative Example 1) BAPP (2,2-bis [] as an aromatic diamine was placed in a 1-liter separable flask equipped with a faucet connected to a reflux condenser and having a 25 ml water content receiver, a thermometer and a stirrer. 4- (4-aminophenoxy) phenyl] propane) 82.1 g (0.20 mo
l), 76.9 g of TMA (trimellitic anhydride) (0.
40 mol) as NMP as an aprotic polar solvent.
560 g of (N-methyl-2-pyrrolidone) was charged, and 8
Stirred at 0 ° C. for 30 minutes. Then, 100 ml of toluene was charged as an aromatic hydrocarbon capable of azeotropic distillation with water, and then the temperature was increased and the mixture was refluxed at about 160 ° C. for 2 hours. Make sure that about 7.2 ml or more of water has accumulated in the receiver for water content and that no outflow of water has been observed. The temperature was increased to remove the toluene. Thereafter, the solution was returned to room temperature, and MDI (4,4'-
50.1 g of diphenylmethane diisocyanate (0.
20 mol) and reacted at 190 ° C. for 2 hours.
After completion of the reaction, an NMP solution of the aromatic polyamideimide resin was obtained.

After the solution varnishes obtained in Examples 1 to 3 and Comparative Example 1 were applied to a glass plate and dried at 150 ° C. for 30 minutes, the film was peeled off from the glass plate and further dried at 180 ° C.
For 1 hour to obtain a polyamide-imide resin film having a thickness of about 60 μm. The glass transition temperature, tensile strength, elongation at break and tensile modulus at room temperature of this film were measured. Further, the molecular weight of the obtained polyamideimide resin was measured, and the results are shown in Table 1. The glass transition temperature was determined by using the obtained film as tan by DVE (wide-range dynamic viscoelasticity measuring device, measuring frequency: 10 Hz).
The value of the maximum value of δ was used. The tensile strength, elongation at break, and tensile modulus at room temperature were measured by cutting the obtained film into strips having a width of 10 mm and using a tensile tester at a crosshead speed of 50 mm / min. Further, the flame retardancy of the obtained film was tested. For the molecular weight of the polyamideimide resin, 50 mg of the obtained varnish was sampled, and dimethylformamide / tetrahydrofuran = 1 /
1 (containing 0.06M phosphoric acid and 0.03M lithium bromide)
5 ml of the solution was added and the solution was measured by GPC, and the value was calculated by converting to standard polystyrene. The results are shown in Table 1. Further, the obtained varnish was reprecipitated in methanol to recover the polyamideimide resin, and the solvent solubility thereof was examined. The results are shown in Table 2.

[0019]

[Table 1] Item Example 1 Example 2 Example 3 Comparative Example 1 Glass transition temperature (° C) 255 235 240 250 Tensile strength (Kg / mm2) 9.1 9.3 9.0 9.5 Elongation at break (%) 1.1 1.8 1.5 1.2 Flame retardant VTM-0 VTM-0 VTM-0 VTM-1 Molecular weight (weight average molecular weight) 72000 76000 75000 75000

[0020]

[Table 2] Solvents Example 1 Example 2 Example 3 Comparative Example 1 N-methylhydrolitone ○ ○ ゛ ゛ methylacetamit ゛ ○ ○ ○ ゛ methylformamide ゛ ○ ○ シ ク ロ Cyclohexanone ○ ○ テ ト ラ Soluble, △: swelling, ×: insoluble

[0021]

The bromine-containing polyamide-imide resin of the present invention, the method for producing the same, and the varnish containing the same can be used for varnishes, adhesives, adhesive films and the like which require flame retardancy and heat resistance. Compared with the conventional production method, bromine-containing diimide dicarboxylic acid and bromine-containing aromatic diimide dicarboxylic acid are soluble in a solvent, and a bromine-containing polyamide-imide resin obtained by reacting it with an aromatic diisocyanate is also soluble in a solvent. This is because Also,
Since there is no by-product, there is no need for a filtration or purification step, and a bromine-containing polyamide-imide resin having a large molecular weight can be produced. As described in the examples, the polyamideimide resin having bromine introduced into the main chain has improved solubility and becomes soluble in a low boiling point solvent such as tetrahydrofuran (THF) as compared with a resin having no bromine. Therefore, molding at a low temperature, which has been impossible in the past, can be made possible.

Claims (4)

[Claims] 1. A mixture containing a bromine-containing diimide dicarboxylic acid represented by the general formula (2) obtained by reacting a bromine-containing diamine represented by the general formula (1) with trimellitic anhydride and a compound represented by the general formula (3): A bromine-containing polyamide-imide resin obtained by reacting an aromatic diisocyanate represented by the formula: Embedded image Embedded image Embedded image 2. An aromatic compound capable of reacting a bromine-containing diamine represented by the general formula (1) with trimellitic anhydride at 50 to 90 ° C. in the presence of an aprotic polar solvent, and further having an azeotrope with water. Group hydrocarbons of aprotic polar solvents 0.1 to
After adding at a 0.5 weight ratio and reacting at 120 to 180 ° C. to produce an aromatic diimide dicarboxylic acid, the aromatic hydrocarbon is removed from the solution, and the reaction with the aromatic diisocyanate is performed. A method for producing a bromine-containing polyamide-imide resin, which is characterized by the following. 3. The method for producing a bromine-containing polyamide-imide resin according to claim 2, wherein the aprotic polar solvent is N-methylpyrrolidone, and the aromatic hydrocarbon azeotropic with water is toluene. 4. A varnish comprising a bromine-containing polyamide-imide resin obtained by the method according to claim 2.