KR20040009254A - Manufacturing method of poly(amideimide) with the improved adhesion strength - Google Patents

Abstract

PURPOSE: A method for preparing a poly(amide-imide) and a poly(amide-imide) prepared by the method are provided, to improve the adhesive strength and the viscosity of a polyamideimide for enhancing the durability when used as the heat resistant coating materials of cooking utensils or the insulating coating materials of an electric wire. CONSTITUTION: The method comprises the steps of reacting 1 equivalence of 4-trimellitoyl halide anhydride, 0.9-1.1 equivalence of at least one kind of aromatic diamine and 0.01-0.1 equivalence of acetic anhydride at a temperature of -10 to 120 deg.C for 0.5-12 hours to prepare poly(amide-amic acid); preparing poly(amide-imide) by the imidation of the poly(amide-amic acid); and adding an adhesive strength enhancer having a triazole structure to the obtained poly(amide-imide). Preferably the aromatic diamine is at least one selected from the group consisting of m-phenylene diamine, p,p'-oxybisaniline and p,p'-methylene bisaniline; and the adhesive strength enhancer is at least one selected from the group consisting of 8-azaadenine, benzotriazole and benzotriazole-5-carboxylic acid.

Description

Manufacturing method of poly (amideimide) with the improved adhesion strength}

The present invention relates to a method for producing a highly adhesive polyamideimide, and more particularly, to a rigid plastic material for metal replacement, such as a bearing (bearing), an insulation coating material of a wire wire, a heat-resistant coating material such as a frying pan, a rice cooker, etc. The present invention relates to a method for producing polyamideimide that is used and has excellent adhesion to a metal surface.

The polyamide-imide has a heat deformation temperature of 278 ° C. and a long service temperature of 200 ° C. or more, and has excellent heat resistance and excellent mechanical strength. In addition, it is widely used in parts requiring characteristics such as wear resistance, flame resistance, radiation resistance, creep resistance, and the like.

As such, polyamideimide homopolymers, polyamideimide copolymers, and precursor polymers thereof are used in various applications due to their excellent physical properties.

As an example of a method for producing such polyamideimide, it is disclosed in US Pat. Nos. 4,016,140 and 4,136,085, but it does not disclose a method for improving their adhesion.

Therefore, in the present invention, polyamideimide has various usage ranges, but is used as a heat-resistant adhesive layer for metals as in the case of a frying pan. Therefore, if the adhesive strength is improved without deteriorating existing physical properties, the end product durability is increased. It was determined that this would be, and to develop a method for producing a polyamideimide improved adhesion.

An object of the present invention is to provide a method for producing a polyamideimide with improved adhesion.

A method for producing a polyamideimide of the present invention for achieving the above object is an aromatic of 1: 0.9 to 1.1 equivalent ratio of 4-trimelitoyl anhydride halide, 4- trimellitoyl anhydride halide in an organic solvent A polyamideamic acid was prepared by polymerization at -10 to 120 DEG C for 0.5 to 12 hours using a 1: 0.01 to 0.1 equivalent ratio of acetic anhydride with respect to diamine and 4-trimelitoyl anhydride halide for molecular weight adjustment. First step; A second step of imidating the polyamideamic acid to produce polyamideimide; And a third step of adding an adhesion promoter having a triazole structure.

The present invention will be described in more detail as follows.

The first step of the process for producing the polyamideimide of the present invention is to prepare a polyamideamic acid.

Here, 4-trimelyltoyl anhydride halide and at least one aromatic diamine are used in an equivalent ratio of 1: 0.9 to 1: 1.1, where acetic anhydride is used for 4-trimelyloyl anhydride halide for molecular weight control. It is added in the ratio of 1: 0.01 to 1: 0.1 equivalent.

Diamines used for the polymerization of polyamideimide are generally aromatic diamines, and specific examples thereof include metaphenylenediamine, p, p'-oxybisaniline, p, p'-methylenebisaniline, and the like.

On the other hand, the organic solvent which can be used for superposition | polymerization can generally use N-methylpyrrolidone, N, N'- dimethylacetamide, N, N'- dimethylformamide, etc. which are non-reactive polar solvents containing nitrogen. . In addition, phenols and phenols substituted with alkyl groups may be used. In this case, mixed solvents such as o, m, p-cresol, and xylenol may be used. In addition to the solvents described above, the polymerization viscosity may be lowered by adding a part of a non-solvent at the time of polymerization.

On the other hand, 4-trimellitoyl hydride halide to be polymerized with the diamines are generally used 4- trimellitoyl hydride chloride, in addition to 4- trimellito yl hydride bromide, 4- trimellito yl hydride Ride iodide etc. can also be used.

In the first step, a rapid exothermic reaction of the 4-trimelyltoyl hydride halide and the organic diamine proceeds. The product produced here is polyamideamic acid which is a precursor of polyamideimide.

In the polymerization method, first, the diamine is dissolved in a solvent, and then 4-trimelytoyl anhydride halide is added dropwise.

The addition time of acetic anhydride which is a molecular weight modifier may be added similarly to reaction diamine, or may be added dropwise during the addition of 4-trimelyltoyl hydride halide. Further, 4-trimelyltoyl hydride halide may be added after the dropping is completed.

The production conditions of the first-stage polyamide amic acid were 0.5 to 12 hours of polymerization time and -10 to 120 ° C of polymerization temperature. Preferably, a polymerization time of 2 to 4 hours and a temperature of 20 to 60 ° C are suitable.

In the one-stage reaction, it is also preferable that the moisture content remaining in the solvent is 1000 ppm or less in terms of preventing physical degradation, and more preferably 400 ppm or less.

Next, in the second step, the polyamide-amic acid produced in the above step is imidated to prepare a polyamideimide.

In the second step, the imidation rate should be adjusted to suit the intended use. When used for molding, the imidation rate should be 95 to 100%. It is desirable to maintain the rate of fire.

Imidization is a method of imidating by raising the temperature in the reaction state after the first stage, and is an extension of the reaction conditions of the first stage as a method of imidization in a solution state. This method is insufficient for completely imidating amic acid, but is suitable for the use where polyamideimide-amic acid having excellent solubility partially imidized is used. As for the imidation polymerization temperature of this method, 20-120 degreeC is suitable.

The third step is a process of adding an adhesion promoter to improve the adhesion, which is preferably carried out 0.5 to 2 hours before the end of the two-step reaction. Specific adhesion promoters have a triazole structure, and examples thereof include 8-azadenine, benzotriazole and benzotriazole-5-carboxylic acid. It is preferable that the usage-amount of these adhesion promoters is 0.1-5 weight part with respect to a polymer weight. If the amount of the adhesion promoter is less than 0.1 part by weight based on the weight of the polymer, the adhesion promoting effect is insignificant.

The final step in preparing the polyamideimide of the present invention is to precipitate, neutralize and dry the reaction solution. Precipitation process is a process of precipitating polyamideimide solution in water. It should be possible to grind and stir at the same time as precipitation, so a device such as homomixer should be used. At this time, it is preferable to use ultrapure water having a resistance value of 5 MΩ / cm 3 or more, since metal ions in the water are adsorbed on the precipitate and affect the properties of the final product. The ratio of the solution and water used is a ratio of 1: 3 to 1:10.

The powder thus prepared is filtered and then neutralized using ultrapure water having a resistance of 5 M? / Cm 3 or more. Filtration and rinsing are repeated until the acidity is above 4. The powder thus washed is dried in a vacuum drying oven at 60 ° C. for 12 hours. The intrinsic viscosity of the obtained polyamideimide is 0.2-1.0 dl / g.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples. In the following examples, the evaluation method is as follows.

1) Intrinsic Viscosity: 0.1 g of polyamideimide powder was dissolved in 10 ml of N, N'-dimethylacetamide and measured by a Uberod viscometer in a thermostat maintained at 30 ° C.

2) Solution viscosity: measured with a Bruckner viscometer at 25 ° C.

3) Adhesive strength: 5 × 10 cm stainless steel sheet (SUS 304) was degreased with dichloromethane and dried. Polyamideimide was dissolved in N-methylpyrrolidone at a weight ratio of 20 and coated on a steel sheet. After drying for 2 hours at 200 ℃ polyamideimide film was cut to 5mm × 10cm. Adhesive strength was measured using a 90 ° peel test. After fixing the steel sheet and the film by using a universal testing machine, the polyamideimide film was peeled off the steel sheet at a rate of 5 mm / min and the adhesive strength was measured.

Example 1

4.39 g (0.0406 mol) of metaphenyldiamine, 32.36 g (0.163 mol) of p, p'-oxybisaniline and 0.842 g (0.0061 mol) of acetic anhydride were placed in a 2 liter reactor equipped with a stirrer, a nitrogen purge device, a thermometer and a cooling device. N-methylpyrrolidone with 350 ppm of water as a solvent was added, and 41.5 g (0.197 mol) of N-trimelytoylanhydride chloride was added to the mixture four times over one hour within a range not exceeding 55 ° C. A uniform amount was added. Stirring was continued for 2 hours after the addition of 4- trimellitoylanhydride chloride was complete. After heating up to 55 degreeC over 1 hour, this temperature was hold | maintained for 3 hours and imidation was advanced.

Thereafter, 0.4 g (0.00245 mol) of benzotriazole-5-carboxylic acid was added thereto while maintaining 55 ° C., followed by stirring for 1 hour, and imidization was continued.

A sample was taken after the imidization time ended and the value measured by a Bruckner viscometer at 25 ° C. was 12500 cps.

After completion of the imidization time, the reaction solution was completed with a homomix, and slowly poured into 1000 ml of ultrapure water to obtain a precipitate. After filtering, the precipitate was added to 1000 ml of ultrapure water and stirred for 30 minutes.

Precipitation and stirring were repeated five times, resulting in a pH of 3.9. The neutralized polyamideamic acid was dried in a 60 ° C. drying oven subjected to vacuum with aspirate for 12 hours. The intrinsic viscosity of the dry powder was 0.51 dl / g. Measured physical properties are shown in Table 1 below.

Example 2

The same process as in Example 1 was carried out, except that 1.408 g (0.0102 mol) of acetic anhydride and 40.64 g (0.193 mol) of 4-trimelitoyl-anhydride chloride were added. 0.4 g (0.0029 mol) of 8-azadenine was added as an adhesion promoter, followed by stirring for 1 hour. The value measured by the Bruckner viscometer at 25 degreeC is 9900 cps, and the intrinsic viscosity after aging is 0.47 dl / g. Measured physical properties are shown in Table 1 below.

Comparative Example 1

It was carried out in the same manner as in Example 1, but was carried out in the amount used as shown in Table 1, the adhesion promoter was not used. The value measured with the Bruckner viscometer at 25 degreeC is 14300 cps, and the intrinsic viscosity after aging is 0.55 dl / g. Measured physical properties are shown in Table 1 below.

Comparative Example 2

In the same manner as in Example 1, 0.4 g (0.0024 mol) of benzotriazole-5-carboxylic acid was added to the dried polyamideimide powder in the amount of use as shown in the following Table 1, and then ground in a mortar and pestle. Mixed. The intrinsic viscosity after aging was 14000 cps and the value measured by the Bruckner viscometer at 25 degreeC is 0.53 dl / g. Measured physical properties are shown in Table 1 below.

Example Comparative example One 2 One 2 Input Mole (TMAc: AA: ODA: m-PDA) 0.197: 0.0061: 0.163: 0.0406 0.193: 0.0102: 0.163: 0.0406 0.20: 0.00: 0.1763: 0.044 0.215: 0.00: 0.16: 0.040 Bruckner Viscometer (CPS) 12500 9900 6700 7500 Intrinsic viscosity (dl / g) 0.51 0.47 0.55 0.53 Adhesive strength (N / m) 1300 1530 780 940 TMAc: 4- trimellitoyl anhydride chloride AA: acetic anhydride ODA: p, p'-oxybitm aniline m-PDA: metaphenyldiamine

As described in detail above, according to the present invention, the 4-trimelyltoyl hydride halide, aromatic diamine, and acetic anhydride are polymerized in an equivalent ratio to obtain a polyamideamic acid as an intermediate, which is then imidized and When polyamideimide is prepared by adding adhesion promoters such as azaadenine, benzotriazole, and benzotriazole-5-carboxylic acid, a polyamideimide for coating having high viscosity and excellent adhesive strength can be obtained. When used as a heat-resistant coating material for cooking utensils, such as insulation coating of the wire can be expected to increase the durability.

Claims (6)

4-trimelyltoylanhydride halide and 4-trimelyltoylanhydride halide under an organic solvent, and at least one aromatic diamine in a ratio of 1: 0.9 to 1.1 equivalents and 4-trimelyltoylanhydride for the purpose of molecular weight control A first step of preparing a polyamide-amic acid by polymerization at -10 to 120 DEG C for 0.5 to 12 hours using acetic anhydride so as to be 1: 0.01 to 0.1 equivalent ratio relative to the halide; A second step of imidating the polyamideamic acid to produce polyamideimide; And A method for producing an improved polyamideimide comprising the third step of adding an adhesion promoter having a triazole structure. The polyamideimide having improved adhesion according to claim 1, wherein the aromatic diamine is at least one member selected from the group consisting of metaphenylenediamine, p, p'-oxybisaniline and p, p'-methylenebisaniline. Manufacturing method. The method of claim 1, wherein the adhesion promoter is at least one member selected from the group consisting of 8-azadenine, benzotriazole and benzotriazole-5-carboxylic acid. The method according to claim 1, wherein the imidization of the second step is performed by heating in the reaction state of the solution phase after the first step. The method for producing a polyamide-imide with improved adhesion according to claim 1 or 3, wherein the adhesion promoter is added 0.5 to 2 hours before the end of imidization. Polyamideimide having an intrinsic viscosity of 0.2 to 1.0 dl / g prepared according to the method of claim 1.