JPH04198221A - Polyamideimide resin and its production - Google Patents

Abstract

PURPOSE:To obtain the title high-molecular-weight injection-moldable resin excellent in heat resistance by reacting trimellitic anhydride with hexamethylene 1,6-diisocyanate at a specified temperature in the presence of an alkali metal compound as a catalyst in an aprotic polar solvent. CONSTITUTION:A process for producing a polyamideimide resin of an average molecular weight of 10,000 or above, comprising repeating units of the formula, wherein benzene-1,2,4-tri-carboxylic anhydride is reacted with hexamethylene 1,6-diisocyanate at 150-300 deg.C in the presence of an alkali metal compound (e.g. alkali metal polycarboxylate or alkali metal carbonate) in an aprotic polar solvent (e.g. linear or cyclic amide or sulfone). According to the above process, it is possible to obtain a high-molecular-weight injection-moldable aliphatic aromatic polyamideimide resin having excellent heat resistance in an industrially practical manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel polyamideimide resin and a method for producing the same. More specifically, it has excellent heat resistance,
The present invention also relates to an injection moldable aliphatic, aromatic polyamide-imide resin and a method for producing the same.

[Conventional technology]

Generally, aliphatic polyamide resin (nylon) has excellent moldability but poor heat resistance. Therefore, in an attempt to solve the drawbacks of these resins, aliphatic resins with aromatic rings introduced,
Aromatic polyamide resins have been proposed. For example, JP-A-59-53536 proposes polyamide resins made of aromatic dicarboxylic acids and aliphatic diamines. Furthermore, polyamide resins formed from aromatic carboxylic acids, adipic acids, and aliphatic diamines have also been proposed in JP-A-59-155426. 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 incorporating imide rings have been proposed. For example, U.S. Pat.
No. 39,029 discloses an aliphatic and aromatic polyamide-imide resin produced by synthesizing polyamic acid from anhydrous trimellitic acid chloride and aliphatic diamine and hydrolyzing this. However, in this method of manufacturing resin,
Due to the low reactivity of aliphatic diamines, only low molecular weight products could be obtained, and the molecular weight was not high enough to enable molded products to be obtained only for use as adhesives.

[Problem to be solved by the invention]

An object of the present invention is to provide a novel high molecular weight aliphatic or aromatic polyamide-imide resin that has excellent heat resistance and is injection moldable, and to provide a method for producing the same.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present inventors have conducted extensive research and found that a product obtained by polycondensing benzene-1,2,4-)licarboxylic acid anhydride and hexamethylene-1,6-diisocyanate. The inventors have discovered that an aliphatic, aromatic polyamide-imide copolymer suitable for the above-mentioned purpose has been achieved, and the present invention has been achieved.

That is, the first invention of the present invention is (1) a polyamide-imide resin having a repeating unit of general formula (1) % formula % () and having an average molecular weight of 10,000 or more, and the second invention of the present invention (2) In producing a polyamideimide resin having a repeating unit of general formula (1) % formula %() and having an average molecular weight of 10,000 or more, benzene-1,2
, 4-tricarboxylic anhydride and hexamethylene-1,6
- A method for producing a polyamide-imide resin, characterized in that the reaction is carried out at 150 to 300°C in an aprotic polar solvent in the presence of an alkali metal compound with a diisocyanate as a catalyst. The method for producing a polyamide-imide resin according to claim 2), wherein the polyamide-imide resin is an acid alkali metal salt, an alkali metal carbonate, an alkali metal hydrogen carbonate, an alkali metal hydroxide, or an alkali metal fluoride, (4) , the method for producing a polyamideimide resin according to claim 2), wherein the aprotic polar solvent is a chain or cyclic amide, phosphorylamide, sulfone, sulfoxide, or urea; ), wherein 1 mole of benzene-1,2,4-1-ricarponic acid anhydride is reacted with 0.95 to 1.05 moles of hexamethylene-1,6-diisocyanate. The method for producing the polyamideimide resin described above.

The molar ratio of benzene-1,2,4-)licarboxylic anhydride and hexamethylene-1,6-diisocyanate used in the present invention is 1 mole of benzene-L2,4-tricarboxylic anhydride to hexamethylene- 1,6-diisocyanate The range of 0.95 to 1.05 is preferable, and 0
．． The range of 97 to 1.03 is more preferable. molar ratio is 0
．． If it is less than 95 or more than 1.05, only a low molecular weight polymer will be obtained, and in order to control the molecular weight of the polymer, acid anhydrides such as phthalic anhydride and benzoic acid, monocarboxylic acids, or phenyl isocyanate may be used. Polymerization may be carried out by adding a monoisocyanate such as.

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, sodium salts, potassium salts, rubidium salts of dicarboxylic, tricarboxylic and tetracarboxylic acids. , alkali metal salts of polyhydric carboxylic acids such as cesium salts and furanium salts, lithium carbonate, sodium carbonate, potassium carbonate, rubidium carbonate,
Alkali metal carbonates such as cesium carbonate and francium carbonate; alkali metal hydrogen carbonates such as lithium hydrogen carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, and francium hydrogen carbonate; lithium hydroxide; and sodium hydroxide. , alkali metal hydroxides such as potassium hydroxide, rubidium hydroxide, cesium hydroxide, francium hydroxide, lithium fluoride, sodium fluoride, potassium fluoride, rubidium fluoride, cesium fluoride, francium fluoride, etc. Examples include alkali metal fluorides.

In particular, the above-mentioned alkali metal compounds, preferably sodium salts and potassium salts, may be used alone or in combination of two or more.

Examples of the aprotic polar solvent used in the present invention include N,N-dimethylacetamide and N.

N-dimethylformamide, N-methylpyrrolidone, T
- butyrolactone, hexamethylphosphoric acid triamide, or sulfoxides or sulfones such as dimethyl sulfoxide, diphenyl sulfone, tetramethylene sulfone, N, N'-dimethylethylene; It is a urea such as urea. These solvents need to be used in a substantially anhydrous state.

Other solvents inert to the polymerization reaction, such as benzene, toluene, xylene, etc., can be used in combination.

In the present invention, in order to produce a high molecular weight aliphatic, aromatic polyamideimide having excellent heat resistance and being injection moldable, the benzene-1,2,4-)ricarboxylic anhydride and xamethylene-1,6-diisocyanate at a molar ratio in the range of 0.95 to 1.05 in the presence of an alkali metal compound in an aprotic polar solvent at 150" C to 30
It is necessary to heat the reaction at a temperature of 0°C.

The polycondensation reaction usually requires a temperature of 150°C or higher due to the low reactivity of hexamethylene-1,6-diisocyanate, and a temperature range of 200°C to 260°C is more preferable. This tends to cause problems such as an increase in side reactions.

The reaction time is usually 1 to 20 hours. The point at which the by-product carbon dioxide is substantially no longer observed can be regarded as the completion point of the reaction.

The amount of alkali metal compound added is benzene-1°2.4
-) 0.5 to 20 mol% based on the recarboxylic acid anhydride
The range is preferably 1.0 to 10 mol %, particularly preferably 1.0 to 10 mol %.

Generally, the concentration of benzene-1,2,4-tricarboxylic anhydride hexamethylene-1,6-diisocyanate in the raw material at the start of the polymerization reaction is 50 to 400 g.
/l is preferred, particularly 100 to 300 g/l.

In the present invention, the average molecular weight (weight average molecular weight according to GPC polystyrene standard) of the obtained aliphatic, aromatic polyamideimide resin is 10,000 or more. Particularly preferably, it is 20,000 or more.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to Examples.

Further, the substance values of the polymers obtained in Examples and Comparative Examples were measured by the following method.

Average molecular weight: The polymerization solution was diluted with N-methylpyrrolidone, and the molecular weight right curve was measured using GPC, and the weight average molecular weight was obtained using a polystyrene standard. .

Flow temperature: (manufactured by Ichitsu Seisakusho) Apparent melt viscosity measured using a flow tester is 1
The temperature at which it reaches 0000 Po1se.

Example 1 In a 500d separable flask equipped with a stirrer, thermometer, cooling condenser and addition funnel, benzene-1
,2,4-)licarponic acid anhydride 30.53g (0,
1590 mol), potassium fluoride 0.189 g (0
, 0325 mol), N,N'-dimethylethylene urea (275 d) was charged in a nitrogen atmosphere and dissolved in a dropping funnel, and then hexamethylene-1,6-diisocyanate 27
．． 21 g (0.1618 mol) was weighed out and added into the flask at once. When the internal temperature of this solution was raised to 200°C without stirring, a violent reaction occurred at 130"C and the generation of carbon dioxide was observed. When stirring was continued at 200°C for 1 hour, the color of the solution changed from yellow to reddish brown. The viscosity increased. After further heating for 1 hour and subsequent ripening, the polymer solution was cooled to room temperature and poured into water under high speed stirring to obtain a polymer powder. This polymer powder was further mixed with water. The polymer powder was washed three times with methanol, and then dried under reduced pressure at 150° C. for 8 hours to obtain 46 g of polymer powder. The infrared absorption spectrum of this powder is shown in FIG.

The average molecular weight of the polymer was 22,000. It had excellent heat resistance with a glass transition temperature measured by DSC of 112°C and a 5% decomposition temperature in air of 418°C. Furthermore, it had a flow temperature of 230"C and had heat-melting properties that made injection molding possible.

Examples 2 to 6 Benzene-1,2°4-
Tricarboxylic acid anhydride and hexamethylene-1.6-diisocyanate were similarly polymerized and isolated under the respective conditions, and the physical properties of the resulting polymers are shown in Table 1.

Table 1 TMA: Benzene-1,2,4-)licarboxylic anhydride HDI: Hexamethylene-1,6-diisocyanate T
MA-K: Benzene-1.2.4-) Ricarboxylic acid anhydride potassium salt TMA-Na: Benzene-1.2.
4-) Ricarboxylic acid anhydride sodium salt DMI: N
, N'-dimethylethyleneurea NMP: N-methylpyrrolidone OM^c: N,N-dimethylacetamide Comparative Example 1 Benzene-1,2゜4-
Tricarboxylic anhydride 30.42 g (0,1583
mole), hexamethylene-1,6-diisocyanate 2
6.98g (0,1604 mol), potassium fluoride 0
．． 189g (0,1604 mol), and reaction temperature 130°
Polymerization and isolation were performed in the same manner as in Example 1 except for C.

The average molecular weight of the obtained polymer was 7,300, and the degree of polymerization did not increase due to the low reaction temperature, making it impossible to obtain a high molecular weight polymer.

Comparative Example 2 Benzene-1,2゜4-
Tricarboxylic anhydride 30.59 g (0,1592
mole), hexamethylene-1,6-diisocyanate 2
Polymerization and isolation were carried out in the same manner as in Example 1, except that 7.07 g (0,1609 mol) and no catalyst were added.

The average molecular weight of the obtained polymer was 1500, and since the polymerization was carried out without adding a catalyst, the degree of polymerization did not increase and a high molecular weight polymer could not be obtained.

Comparative Example 3 30.37 g of benzene-1,2,4-tricarboxylic anhydride chloride (0,14
42 mol), potassium fluoride 0.173 g (0,0
0299 mol), N, N'-dimethylethylene urea (180+d) was charged in a nitrogen atmosphere and dissolved in a dropping funnel. 23 m of N, N'-dimethylethylene urea and 16.89 g (0 ，
1453 mol) was dissolved and added into the flask.

Thereafter, polymerization and isolation 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 4 Using the experimental apparatus shown in Example 1, 30.41 g (0,1831 mol) of benzene-1,3-dicarboxylic acid and 30.88 g of hexamethylene-1,6-diisocyanate were prepared.
(0,1836 mol), and potassium fluoride 0.212
Polymerization and isolation were performed in the same manner as in Example 1 except for g (0,00364 mol).

The average molecular weight of the obtained polymer was 320,000, the 5% decomposition temperature was 379'C, and the glass transition temperature was 72°C.
C, and did not have sufficient performance as a heat-resistant resin.

〔Effect of the invention〕

According to the present invention, a high molecular weight aliphatic aromatic polyamideimide resin having excellent heat resistance and capable of being injection molded can be obtained by an industrially practical method, and is an industrially useful invention. .

[Brief explanation of the drawing]

FIG. 1 shows an infrared absorption spectrum of the polyamideimide resin powder obtained in Example 1. Patent applicant Mitsui Toatsu Chemical Co., Ltd.

Claims (5)

[Claims] (1) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc. are available▼(I) A polyamide-imide resin with a repeating unit and an average molecular weight of 10,000 or more. (2) General formula (I) ▲Mathematical formulas, chemical formulas, tables, etc.▼In producing polyamide-imide resin with repeating units of (I) and an average molecular weight of 10,000 or more, benzene-1,2
, 4-tricarboxylic anhydride and hexamethylene-1,6
- A method for producing a polyamide-imide resin, which comprises reacting with a diisocyanate as a catalyst in an aprotic polar solvent at 150 to 300°C in the presence of an alkali metal compound. (3) Claim (2) characterized in that 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 in ). (4) Claim (2) characterized in that the aprotic polar solvent is a chain or cyclic amide, phosphorylamide, sulfone, sulfoxide, or urea.
) The method for producing the polyamideimide resin described in ). (5) Claim (2) characterized in that 1 mole of benzene-1,2,4-tricarboxylic anhydride is reacted with 0.95 to 1.05 mole of hexamethylene-1,6-diisocyanate. The method for producing the polyamideimide resin described above.