KR20010058442A - Manufacturing method of poly(amide-imide) - Google Patents

Abstract

PURPOSE: Provided is a method for preparing a polyamide-imide which has uniform physical properties, and is thus used for heat-proof coating materials of a fry pan, an electric fry pan, insulating coating materials of wire and rigid plastic materials for substituting metals. CONSTITUTION: The method comprises steps of: (i) polymerizing 4-trimellitoyl anhydride chloride and at least one kinds of aromatic diamines in an equivalent ratio of 1:1.01-1.08 in the presence of an organic solvent at a temperature of -10-120 deg.C for 0.5-12 hours to prepare a polyamide amic acid; and (ii) imidizing the polyamide amic acid to prepare a polyamide-imide.

Description

Manufacturing method of poly (amide-imide)

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing polyamideimide useful as a rigid plastic material for replacing metals such as bearings, insulation coating materials for wire wires, heat resistant coating materials for frying plates, electric frying plates, and the like.

The polyamideimide for molding 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 properties such as wear resistance, flame resistance, chemical resistance, radiation resistance, creep resistance, and the like.

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

As an example of a method for preparing such polyamideimide, disclosed in US Pat. Nos. 4,016,140 and 4,136,085, it was possible to obtain polyamideimide having excellent physical properties, but there was a shortage in obtaining uniform physical properties.

Accordingly, it is an object of the present invention to provide a method for producing polyamideimide, which can obtain uniform physical properties.

Method for producing a polyamideimide of the present invention for achieving the above object is obtained by polymerizing the equivalence ratio of 4- trimellitoyl anhydride halide and organic diamine in a ratio of 1: 1.01 ~ 1.08 to obtain a polyamide amic acid, and imidized it It is characterized by that.

The present invention is prepared through the reaction of at least one of four trimellitoyl anhydride chloride and an organic polyamine in an organic solvent, the equivalent ratio of 4-trimelitoyl anhydride chloride and an organic diamine is 1: 1.01 to It is 1.08.

Diamines used for the polymerization of polyamideimide are generally aromatic diamines, and specific examples thereof include metaphenylenediamine, paraphenylenediamine, p, p'-methylenebisaniline, p, p'-sulfonylbisaniline , (p-aminophenyl) sulfone and the like.

On the other hand, the organic solvent used for the polymerization contains nitrogen and non-reactive polar solvents such as N-methylpyrrolidone, N, N'-dimethylacetamide, N, N'-dimethylformamide and the like are generally used. In addition, phenols and phenols substituted with alkyl groups may also be used. In this case, a mixed solvent such as o, m, p-cresol, xylenol is 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 generally use 4- trimellitoyl hydride chloride, in addition to 4- trimellito yl hydride bromide, 4- trimellitoyl silane Hydride iodide etc. can also be used.

The method for producing a polyamideimide using the compound as described above is carried out in two steps. First, the first step proceeds by a rapid exothermic reaction of 4-trimelitoyl anhydride chloride and an organic diamine. The product produced here is polyamideamic acid which is a precursor of polyamideimide.

The production conditions of the first stage polyamideamic acid were 0.5 to 12 hours in polymerization time and -10 to 120 ° C in polymerization temperature. Preferably, the polymerization time of 2-4 hours and the temperature of 20-50 degreeC are suitable.

In the one-step reaction, the water content remaining in the solvent is preferably 1000 ppm or less, and more preferably 400 ppm or less in terms of preventing physical property degradation.

Next, step 2 is to prepare a polyamideimide by imidizing the polyamide amic acid produced in step 1. 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. Two-step imidization is possible in two ways. The first method is to imidize by raising the temperature in the reaction state after the first step, and another method is to precipitate polyamideamic acid dissolved in the organic solvent in the non-solvent and neutralize the remaining hydrogen chloride using pure water. It is then imidized in a hot air oven. This process also increases the molecular weight.

One of two methods of two-step reaction, imidization in solution, is an extension of one-step reaction conditions. This method is insufficient for fully imidating amic acid and is applicable to applications where partial imidation is used. As for the imidation polymerization temperature of this method, 20-120 degreeC is suitable.

In performing the two-step reaction, the method of imidizing the reaction solution by precipitation, neutralization, drying, and aging is as follows; 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 better to use ultrapure water having a resistance value of 5 MΩ / ㎠ or more because the 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.

After filtering the prepared powder, this powder was subjected to resistance of 5 MΩ / ㎠ The ultrapure water is used for the increase. Repeat the filter and pure wash until the acidity is above 3. The powder thus washed is dried in a 60 ° C. drying oven using an aspirator for 12 hours. The dried powder is aged in a hot air oven at 70 to 200 ° C. for 0.5 to 4 hours to finally prepare a polyamideimide.

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 Examples the evaluation method is as follows;

1) intrinsic viscosity

0.1 g of polyamideimide powder is dissolved in 10 ml of N, N'-dimethylacetamide and measured with a Kenon-Penske viscometer in a thermostat maintained at 30 ° C.

2) solution viscosity

Measured with a Bruckner viscometer at 25 ° C.

3) moisture content

Measure with a Karl-Fitness Moisture Meter.

4) Elongation at break, tensile strength

It is measured by ASTM D1708 method.

Example 1

2-liter reactor with stirrer, nitrogen purge, thermometer, and chiller 4.39 g (0.0406 mole) of metaphenylenediamine, 32.36 g (0.1626 mole) of p, p'-oxybisaniline and 350 ppm of water 42.11 g (0.20 mol) of toil anhydride chlorides were added several times over 1 hour, within the range which temperature does not exceed 50 degreeC. Stirring was continued for 3 hours after the addition of 4- trimellitoyl anhydride chloride was complete. The value measured with the Brookner viscometer at 25 degreeC was 12200 cps.

After the reaction was completed, the reaction solution was slowly poured into 1000 ml of ultrapure water while running a homomix 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 polyamide amic acid was dried in a 60 ° C. drying oven under vacuum with an aspirator for 12 hours. The intrinsic viscosity of the dry powder is 0.26 dL / g. The dried powder was aged in a hot air oven at 220 ° C. for 4 hours to obtain a polyamideimide powder having an intrinsic viscosity of 0.55 dL / g. This powder was prepared using a compression molding machine at a temperature of 350 ° C. at a pressure of 10 to 100 tons. The measured physical properties are shown in Table 1 below.

Example 2

In the same manner as in Example 1, 5.623 g (0.052 mol) of metaphenylenediamine and 31.236 g (0.156 mol) of p, p′-oxybisaniline were added thereto. The value measured by the Brookner viscometer at 25 degreeC is 9800 cps, and the intrinsic viscosity after aging is 0.51 dL / g. The measured physical properties are shown in Table 1 below.

Comparative Example 1

In the same manner as in Example 1, 4.758 g (0.044 mol) of metaphenylenediamine and 35.241 g (0.176 mol) of p, p'-oxybisaniline were added thereto. The intrinsic viscosity after aging was 6500 cps and the value measured by the Brookner viscometer at 25 degreeC is 0.41 dL / g. The measured physical properties are shown in Table 1 below.

Comparative Example 2

In the same manner as in Example 1, except that 4.325 g (0.04 mol) of metaphenylenediamine, 32.037 g (0.16 mol) of p, p'-oxybisaniline, and 42.11 g of 4-trimelitoylanhydride chloride (0.215 mol) was added. The value measured with the Brookner viscometer at 25 degreeC is 7700 cps, and the intrinsic viscosity after aging is 0.44 dL / g. The measured physical properties are shown in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Input Mole (TMAc / ODA / m-PDA) 0.20 / 0.1626 / 0.0406 0.20 / 0.156 / 0.052 0.20 / 0.176 / 0.044 0.215 / 0.160 / 0.0040 Brockner Viscosity (cps) 12200 9800 6500 7700 Intrinsic viscosity (dL / g) 0.55 0.51 0.41 0.44 Tensile Strength (kg / ㎠) 1150 1200 520 770 Elongation at Break (%) 9.1 9.9 2.4 4.4

As described above in detail, according to the present invention, when 4-trimelyltoyl hydride chloride and aromatic diamine are polymerized at a constant equivalent ratio, a polyamideamic acid is obtained as an intermediate and then imidized to produce a polyamideimide. It is possible to obtain a molding polyamideimide having high strength and excellent strength, and it can be used as a heat-resistant coating material of a frying plate and an insulating coating material of an electric wire, as well as a rigid plastic material or a metal substitute through compression molding or injection.

Claims (5)

A first process for preparing polyamideamic acid by polymerizing 4-trimelyltoylanhydride chloride and at least one aromatic diamine in an equivalence ratio of 1: 1.01 to 1.08 in the presence of an organic solvent for 0.5 to 12 hours. step; And A method for producing a polyamideimide comprising a second step of imidating the polyamide amic acid to produce a polyamideimide. The method 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. The method for preparing polyamide-imide according to claim 1, wherein the imidization is performed by heating in the reaction state after the first step. 2. The polyimide according to claim 1, wherein the imidization is carried out by precipitating polyamideamic acid dissolved in an organic solvent in a non-solvent, neutralizing residual hydrogen chloride with pure water, and then imidizing it in a hot air oven. Method for producing amideimide. Polyamideimide having an intrinsic viscosity of 0.2 to 1.0 dL / g prepared according to the method of claim 1.