JPH04225030A - Production of polyamide-imide resin - Google Patents

Abstract

PURPOSE:To obtain the title resin with high heat resistance by condensation between a benzenetricarboxylic anhydride and aliphatic diisocyanate followed by polycondensation of another aliphatic diisocyanate. CONSTITUTION:A reaction is made between (A) 1mol of benzene-1,2,4- tricarboxylic anhydride and (B) 0.475-0.525mol of a diisocyanate of formula I [R1 is (CH2)x; (x) is 4-12] such as hexamethylene-1,6-diisocyanate in the presence of (C) as catalyst, pref. an alkali metal compound such as polycarboxylic alkali metal salt in (D) an aprotic polar solvent at 100 250 deg.C. Then, (E) 0.475-0.525mol of a second diisocyanate of formula II [R2 is (CH2)y; (y) is 4-12] is added to the resulting reaction product followed by polycondensation at >=150 deg.C to effect molecular arrangement control, thus obtaining the objective resin having recurring unit of formula III capable of molding by injection molding.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel method for producing polyamideimide resin. More specifically, the present invention relates to aliphatic and aromatic polyamide-imide resins that have excellent heat resistance and controlled molecular arrangement that can be injection molded, and methods for producing the same.

0002

BACKGROUND OF THE INVENTION Aliphatic polyamide resins (nylon) generally have excellent moldability but poor heat resistance. Therefore,
In an attempt to solve the drawbacks of these resins, aliphatic and aromatic polyamide resins into which aromatic rings have been introduced have been proposed. For example, JP-A-59-53536 proposes a polyamide resin made of an aromatic dicarboxylic acid and an aliphatic diamine. Furthermore, JP-A-59-155426
Publications have also proposed polyamide resins formed from aromatic carboxylic acids, adipic acids, and aliphatic diamines. Although these resins can be melt-molded, they are not satisfactory in terms of heat resistance and the like.

On the other hand, as a method for improving the heat resistance, mechanical properties, etc. of polyamide resins, polyamide-imide resins into which imide rings have been introduced have been proposed. For example, US Pat. No. 3,939,029 discloses aliphatic and aromatic polyamide-imide resins produced by synthesizing polyamic acids from anhydrous trimellitic acid chloride and aliphatic diamines and dehydrating them by heating. However, with this method of producing resin, only low molecular weight products can be obtained because the reactivity of aliphatic diamine is lower than that of anhydrous trimellitic acid chloride, and molded products can only be obtained for use as adhesives. It did not have a high enough molecular weight to be able to be used. In order to solve these problems, the present inventors proposed in a previous application a high molecular weight, randomly arranged aliphatic, aromatic polyamide-imide resin that has heat resistance and is injection moldable. There is. Although this randomly arranged polyamide resin has excellent heat resistance, it is difficult to achieve its performance in applications where higher heat resistance is required.

0004

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel aliphatic or aromatic polyamide-imide resin with controlled molecular arrangement that has excellent heat resistance and can be injection molded, and to produce the same. It is a provision of law.

[0005]

[Means for Solving the Problems] In order to solve the above problems, the present inventors have conducted intensive research and have found that benzene-
Diimide dicarboxylic acid obtained by condensing 1,2,4-tricarboxylic anhydride and aliphatic diisocyanate,
Furthermore, it has been discovered that an aliphatic and aromatic polyamide-imide copolymer with controlled molecular arrangement obtained by polycondensing aliphatic diisocyanate can be suitable for the above purpose,
We have arrived at the present invention.

That is, in producing a polyamide-imide resin having the repeating unit of the above general formula (I) (Chemical formula 1), the present invention provides the 0.4 of diisocyanate of 2
The reaction is carried out at 100 to 250°C in an aprotic polar solvent in the presence of an alkali metal compound using 75 to 0.525 mol of the catalyst, and further 0.475 to 0.
The present invention provides a method for producing a polyamide-imide resin, which comprises adding 525 mol of the polyamide resin and polycondensing the resin at 150° C. or higher to control the molecular arrangement. Controlling the molecular arrangement in this case means that the diimide units that face each other produced in the first-stage imidization are arranged regularly through the amide bonds produced in the second-stage amidation reaction. It means.

The alkali metal compound is preferably an alkali metal salt of a polyhydric carboxylic acid, an alkali metal carbonate, an alkali metal hydrogen carbonate, an alkali metal hydroxide, or an alkali metal fluoride. The aprotic polar solvent is preferably a linear or cyclic amide, phosphorylamide, sulfone, sulfoxide or urea.

Benzene-1,2 used in the present invention
, 4-tricarboxylic anhydride and the diisocyanate of Chemical Formula 2 is 0.475 to 0.475 to 0.475 to 0.47 to 1 mole of benzene-1,2,4-tricarboxylic anhydride.
The range of 525 is preferable, and the range of 0.49 to 0.51 is more preferable. The molar ratio is less than 0.475, or 0.
If it exceeds 525, the amount of diimide dicarboxylic acid produced as an intermediate product decreases, which is not preferable.

Furthermore, the molar ratio of the diisocyanate of formula 3 to be added next is 0.00 to 1 mole of benzene-1,2,4-torcarboxylic anhydride.
The range is preferably from 475 to 0.525, and from 0.49 to 0.475.
A range of 51 is more preferred. If the molar ratio is less than 0.475 or more than 0.525, only a low molecular weight polymer will be obtained. Further, in order to control the molecular weight of the polymer, an acid anhydride such as phthalic anhydride or benzoic acid, a monocarboxylic acid, or a monoisocyanate such as phenyl isocyanate may be added and reacted.

Examples of alkali metal compounds used as catalysts in the process of the invention are mono- and/or di- and/or tri- and/or tetralithium salts of dicarboxylic, tricarboxylic and tetracarboxylic acids;
Alkali metal salts of polycarboxylic acids such as sodium salts, potassium salts, rubidium salts, cesium salts, and francium salts; alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate, cesium carbonate, and francium carbonate; and carbonic acid. Alkali metal hydrogen carbonates such as lithium hydrogen, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, francium hydrogen carbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, Alkali metal hydroxides such as francium hydroxide, lithium fluoride,
Examples include alkali metal fluorides such as sodium fluoride, potassium fluoride, rubidium fluoride, cesium fluoride, and francium fluoride. Particularly preferred are sodium salts and potassium salts. The above alkali metal compounds may be used alone or in combination.
You may use a mixture of more than one species.

Examples of the aprotic polar solvent used in the present invention include N,N-dimethylacetamide, N
, N-dimethylformamide, N-methylpyrrolidone,
γ-Butyrolactone, linear or cyclic amides or phosphorylamides such as hexamethylphosphoric triamide, sulfoxides or sulfones such as dimethyl sulfoxide, diphenyl sulfone, tetramethylene sulfone, tetramethyl urea, N,N'-dimethyl It is a urea such as ethylene urea. These solvents need to be used in a substantially anhydrous state. Other solvents inert to the reaction, such as benzene, toluene, xylene, etc., can be used in combination.

In the present invention, in order to produce an aliphatic or aromatic polyamideimide having a controlled molecular arrangement that has excellent heat resistance and can be injection molded, the benzene-1,2,4
- Tricarboxylic anhydride and hexamethylene-1,6-diisocyanate are reacted by heating at a temperature of 100 to 250°C in an aprotic polar solvent in the presence of an alkali metal compound at a molar ratio of 0.475 to 0.525. After imidization, hexamethylene-1,6-diisocyanate was added at a molar ratio of 0.475 to 0.525 to benzene-1,2,4-tricarboxylic anhydride at 150°C.
It is necessary to perform the amidation by heating the reaction at a temperature above.

As a result of investigating the reactivity of the anhydride ring and carboxyl group of benzene-1,2,4-tricarboxylic anhydride toward isocyanate using phthalic anhydride, benzoic acid, etc. as model compounds, we found that the reaction of the anhydride ring (imide It has been found that there is a large difference in the rate of imidization and amidation in the temperature range of 100 to 250° C. in the reaction between carboxyl groups (amidation) and carboxyl groups (amidation). The first stage imidization reaction, in which benzene-1,2,4-tricarboxylic anhydride and diisocyanate are condensed, requires a temperature of 100 to 250°C, and
A temperature range of 0 to 180°C is more preferred. If it is less than 100°C, the reactivity between the anhydride ring and the isocyanate will decrease, which is undesirable, and if it exceeds 250°C, the rate of amidation will increase, making it impossible to obtain a polymer with controlled molecular arrangement, which is not preferred. Further, in the second stage amidation reaction, since the reactivity of diisocyanate is low, a temperature of 150°C or higher is usually required, and a temperature range of 200 to 260°C is more preferable. In this case, the intermediate product diimide dicarboxylic acid is not isolated and undergoes a polycondensation reaction (amidation) with the diisocyanate, but even if the produced diimide carboxylic acid is isolated and the polycondensation reaction (amidation) is performed. There is nothing wrong with that.

The reaction time is usually 1 to 20 hours for both imidization and amidation reactions. The point at which by-product water and carbon dioxide are substantially no longer observed can be considered as the completion point of the reaction. The amount of the alkali metal compound added is preferably in the range of 0.5 to 20 mol%, particularly 1.
．． 0 to 10 mol% is preferred. Generally, the raw material monomer (
The concentration of benzene-1,2,4-tricarboxylic anhydride + hexamethylene-1,6-diisocyanate) is 50~
A range of 400 g/l is preferred, especially 100-300 g
/l is preferred. In the present invention, the average molecular weight (weight average molecular weight according to GPC polystyrene standard) of the obtained aliphatic, aromatic polyamideimide resin with controlled molecular arrangement is preferably 10,000 or more, particularly preferably 20,000 or more. That's all.

[0015]

[Examples] The present invention will be explained in detail below with reference to Examples. Further, the physical property values of the polymers obtained in Examples and Comparative Examples were measured by the following method. Average molecular weight: Dilute the polymerization solution with N-methylpyrrolidone,
The molecular weight distribution curve was measured using GPC, and the weight average molecular weight was obtained using polystyrene as a standard. Flow temperature: Temperature at which the apparent melt viscosity measured using a flow tester (manufactured by Shimadzu Corporation) becomes 10,000 Poise.

(Example 1) 20.33 g (0.1058 mol) of benzene-1,2,4-tricarboxylic anhydride was placed in a 500 ml separable flask equipped with a stirrer, thermometer, cooling condenser, and dropping funnel. ), potassium fluoride 0.129g (0.00222mol), N,N'-
220 ml of dimethylethylene urea was charged and dissolved in a nitrogen atmosphere, and the internal temperature was raised to 140°C while stirring. 8.92 g (0.05301 mol) of hexamethylene-1,6-diisocyanate was measured into a dropping funnel, added to the flask at once, and reacted at 140° C. for 4 hours. Furthermore, 8.88 g (0.05280 mol) of hexamethylene-1,6-diisocyanate was measured into the dropping funnel and added to the flask at once. Immediately add this solution to
When the temperature was raised to 0°C, a violent reaction occurred at 150°C, and the generation of carbon dioxide was observed. When stirring was continued at 220° C. for 1 hour, the color of the solution changed from yellow to reddish brown and the viscosity increased. After continuing to heat for another 1 hour to age, the mixture was cooled to room temperature, and the polymerization liquid was poured into water under high speed stirring to obtain a polymer powder. This polymer powder was further washed three times with water, and finally with methanol, and then dried under reduced pressure at 150° C. for 8 hours to obtain 31 g of polymer powder. The average molecular weight of the polymer was 45,000. It had excellent heat resistance, with a glass transition temperature measured by DSC of 116°C and a 5% decomposition temperature in air of 428°C. Furthermore, the flow temperature is 236℃
It had heat-melting properties that made injection molding possible.

(Examples 2 to 5) Using the experimental apparatus shown in Example 1, benzene-1,2,4-tricarboxylic anhydride and hexamethylene-1,6-diisocyanate were treated under the same conditions. Table 1 shows the physical property values of the polymers obtained.

(Example 6) Benzene-1,2,4-tricarboxylic anhydride and hexamethylene-1,6-diisocyanate were reacted under similar conditions in the experimental apparatus shown in Example 1, and the obtained After cooling the reaction solution, it was placed in an aqueous hydrochloric acid solution adjusted to pH 2, and bis-[(4-carboxy)
Phthalimide]-1,6-hexamethylene was isolated. The melting point measured by DSC was 320°C. Next, hexamethylene-1,6-diisocyanate was added to this compound to perform polycondensation, and the physical properties of the obtained polymer are shown in Table 1.

[Table 1] TMA: benzene-1,2,4-tricarboxylic anhydride HDI 1: initially added hexamethylene-1,6-
Diisocyanate HDI 2 : Hexamethylene-1,6-diisocyanate added later TMA-K : Benzene-1,2,4-tricarboxylic acid anhydride potassium salt TMA-Na: Benzene-1,2,4-tricarboxylic acid anhydride sodium Salt DMI: N,N'-dimethylethylene urea NMP: N
-Methylpyrrolidone DMAc: N,N-dimethylacetamide

001
9] (Reference example) Potassium fluoride 0.0174 was placed in a four-necked flask equipped with a stirrer, thermometer, and cooling condenser.
g (0.0003 mol), benzoic acid 7.4713 g (0
．． 0612 mol) and 109.84 g of N,N'-dimethylethyleneurea were charged into a nitrogen atmosphere and dissolved. After keeping the temperature constant, 4.9489 g (0.029 mol) of hexamethylene-1,6-diisocyanate was charged at once, and the amount of hexamethylene-1,6-diisocyanate lost at each time was determined by liquid chromatography. The reaction rate constant k of amidation was determined at each temperature using the integral method. In addition, the reaction rate constant at each imidization temperature was similarly determined using phthalic anhydride. Table 2 shows the reaction rate constants obtained at each temperature.

[Table 2] Values in parentheses are calculated values obtained using Arrhenius plot.

(Comparative Example 1) 30% of benzene-1,2,4-tricarboxylic anhydride was added to the experimental apparatus shown in Example 1.
23g (0.1573mol), potassium fluoride 0.20
54 g (0.00354 mol) and 285 ml of N,N'-dimethylethylene urea were introduced into a nitrogen atmosphere and dissolved. Weigh 27.21 g (0.1618 mol) of hexamethylene-1,6-diisocyanate into a dropping funnel,
Added all at once into the flask. When the internal temperature of this solution was raised to 200° C. while stirring, a violent reaction occurred at 130° C. and the generation of carbon dioxide was observed. When stirring was continued for 1 hour at 200℃, the color of the solution changed from yellow to reddish brown.
Viscosity increased. After continuing to heat for another hour and aging,
It was cooled to room temperature and post-treated in the same manner as in Example 1. The average molecular weight of the polymer was 22,000. Although it had heat resistance with a glass transition temperature measured by DSC of 112°C and a 5% decomposition temperature in air of 418°C, there was a difference in heat resistance compared to the polymer obtained in Example 1.

(Comparative Example 2) Benzene-1,2,4-tricarboxylic anhydride 30.
42g (0.1583mol), hexamethylene-1,6
-Diisocyanate 26.98g (0.1604mol)
, potassium fluoride 0.189g (0.00326mol)
Polymerization and post-treatment were carried out in the same manner as in Example 1, except that the reaction temperature was 130°C. The average molecular weight of the obtained polymer was 7
300, the degree of polymerization did not increase due to the low reaction temperature, and a high molecular weight polymer could not be obtained.

(Comparative Example 3) Benzene-1,2,4-tricarboxylic anhydride 30.
59g (0.1592mol), hexamethylene-1,6
-Diisocyanate 27.07g (0.1609mol)
Polymerization and post-treatment were carried out in the same manner as in Example 1, except that no catalyst was added. The average molecular weight of the obtained polymer was 150
0, the degree of polymerization did not increase because it was carried out without adding a catalyst,
It was not possible to obtain a high molecular weight polymer.

(Comparative Example 4) 30.3% of benzene-1,2,4-tricarboxylic anhydride was added to the experimental apparatus shown in Example 1.
7g (0.1442 mol), potassium fluoride 0.173
g (0.00299 mol) and 180 ml of N,N'-dimethylethylene urea were introduced into a nitrogen atmosphere and dissolved. Add 23 m of N,N'-dimethylethylene urea to the dropping funnel.
16.89 g of hexamethylene-1,6-diamine (
0.1453 mol) was dissolved and added into the flask. Thereafter, polymerization and post-treatment were performed in the same manner as in Example 1. The average molecular weight of the obtained polymer was 4,300, and a high molecular weight polymer could not be obtained.

(Comparative Example 5) 30.41 g of benzene-1,3-dicarboxylic acid (0.1
Polymerization and post-treatment were carried out in the same manner as in Example 1, except for 30.88 g (0.1836 mol) of hexamethylene-1,6-diisocyanate and 0.212 g (0.00364 mol) of potassium fluoride. Ta. The average molecular weight of the obtained polymer was 32,000, and the 5% decomposition temperature was 379°C, but the glass transition temperature was as low as 72°C, and it did not have sufficient performance as a heat-resistant resin.

[0025]

[Effect of the invention] According to the present invention, it has excellent heat resistance,
This is an industrially useful invention, since it is possible to obtain an aliphatic or aromatic polyamideimide resin with a controlled molecular arrangement that can be injection molded by an industrially practical method.

Claims (4)

[Claims] Claim 1: A polyamide-imide resin having a repeating unit of general formula (I) (Chemical formula 1) [Chemical formula 1] (where x is an integer of 4 to 12, and y is an integer of 4 to 12) In the method for producing 1 mol of benzene-1,2,4-tricarboxylic anhydride, a compound of the formula [Image Omitted] (wherein, R1 is -(CH2) x, and x has the same meaning as above). ) diisocyanate 0.47
5 to 0.525 mol is reacted at 100 to 250°C in an aprotic polar solvent in the presence of an alkali metal compound as a catalyst, and further reacted with the formula [Chemical formula 3] (wherein R2 is -(CH2) y) , y has the same meaning as above) diisocyanate 0.47
A manufacturing method characterized by adding 5 to 0.525 mol and performing polycondensation at 150°C or higher to control molecular arrangement. [Claim 2] In producing a polyamideimide resin having a repeating unit of formula (II) (chemical formula 4), hexamethylene- 1,6-diisocyanate in the presence of an alkali metal compound as a catalyst in an aprotic polar solvent.
The reaction was carried out at 250°C, and 0.475 to 0.525 mol of hexamethylene-1,6-diisocyanate was added, and 1
A method for producing a polyamide-imide resin, which comprises controlling the molecular arrangement by polycondensing at 50° C. or higher. 3. Claim 1, wherein the alkali metal compound is an alkali metal salt of a polyvalent carboxylic acid, an alkali metal carbonate, an alkali metal hydrogen carbonate, an alkali metal hydroxide, or an alkali metal fluoride. The method for producing the polyamideimide resin described above. 4. The method for producing a polyamideimide resin according to claim 1, wherein the aprotic polar solvent is a chain or cyclic amide, phosphorylamide, sulfone, sulfoxide, or urea. .