Method for manufacturing polyamide resin

Abstract: A polyamide resin having double bonds in its main chain is prepared by reacting a bis-alkenoic amide with an aromatic dihalide. These starting materials are stable, easy to handle and inexpensive.

Description: The present invention relates to a method for manufacturing a polyamide resin which contains double bonds in its main chain. Polyamide resins having double bonds in the main chain have been used as industrial materials because of their excellent photosensitivity. A method for manufacturing the resins has been known in which a diamine and an alkenoic dichloride are made to undergo polycondensation in an organic solvent. The method of the prior art involves problems such that the synthesis is extremely laborious because of the instability of the alkenoic dichloride and the troublesomeness in handling thereof, thus causing disadvantage of difficulty and high cost in manufacturing polyamide resins having double bonds in the main chain. It is the object of the present invention to provide a method for manufacturing a polyamide resin having double bonds in its main chain that starts from materials which are stable, easy to handle, and inexpensive. The aforementioned problems could surprisingly be solved according to the present invention by the use of a bis-alkenoic amide. The present invention relates to a method for manufacturing a polyamide resin having double bonds in its main chain, comprising a repeating unit represented by the formula (I): [-Ar¹-CR¹=CR²-CO-NR³-R⁴-NR³-CO-CR²=CR¹-] (I) wherein Ar¹ is a bivalent aromatic radical, each of R¹, R² and R³ represents independently a hydrogen atom or a univalent aromatic or aliphatic radical, R⁴ is a bivalent aromatic or aliphatic radical, and having a reduced viscosity (ηsp/c) of 0.1 - 5.0 dl/g at a concentration of 0.5 g/dl in N,N-dimethylacetamide at 30°C, characterized in that a bis-alkenoic amide represented by the general formula (II): CHR¹=CR²-CO-NR³-R⁴-NR³-CO-CR²=CHR¹ (II) wherein R¹, R², R³ and R⁴ are defined as above is reacted with an aromatic dihalide represented by the general formula (III): X-Ar¹-X (III) wherein Ar¹ is defined as above and X is a halogen atom, in the presence of a palladium catalyst in an amount ranging from 0.01 to 10% relative to the bis-alkenoic amide and the aromatic dihalide and a base present in an amount ranging from 2 to 5 equiv. to the aromatic dihalide in an organic solvent and within a temperature range of 50 to 250°C. The bis-alkenoic amide represented by the general formula (II) can be prepared easily by linking 2 mols of alkenoic chloride and 1 mol of a diamine. In the formula, each of R¹, R² and R³ represents independently a hydrogen atom, an aryl radical (preferably C₆-C₁₀) such as phenyl, tolyl, anisyl and nitrophenyl, or an aliphatic radical such as C₁-C₈ alkyl. R¹ and R² and/or R¹ and R³ may be linked together to form a ring structure. R⁴ is a bivalent aromatic radical shown below (preferably C₆-C₁₅) or a bivalent aliphatic radical such as C₁-C₁₅ alkylene. The aliphatic radical may be of a branched structure or of an alicyclic ring structure. Bis-alkenoic amides wherein the bridging unit (R⁴) is not a bivalent aromatic radical but a alkenyl radical are disclosed in US-A-4093677. The typical aromatic dihalides represented by the general formula (III) include m-dibromobenzene, p-dibromobenzene, 3,3'-dibromodiphenylmethane, 4,4'-dibromodiphenylmethane, 3,4'-dibromodiphenylmethane, 3,3'-dibromodiphenyl ether, 4,4'-dibromodiphenyl ether, 3,4'-dibromodiphenyl ether, 2,5-dibromothiophene, 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene, m-diiodobenzene, p-diiodobenzene, 3,3'-diiododiphenylmethane, 4,4'-diiododiphenylmethane, 3,4'-diiododiphenylmethane, 3,3'-diiododiphenyl ether, 4,4'-diiododiphenyl ether, 3,4′-diiododiphenyl ether, 2,5-diiodothiophene and 2,5-bis(4-iodophenyl)-3,4-diphenylthiophene. The bases include inorganic bases such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium hydrogencarbonate, potassium hydrogencarbonate, sodium acetate, and potassium acetate, and organic bases such as tributylamine, 4-dimethylaminopyridine, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, and 1,4-diazabicyclo[2,2,2]octane. The organic solvents include amide type solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, tetramethylurea, and hexamethylphosphoramide; aromatic solvents such as benzene, toluene, xylene, nitrobenzene and benzonitrile; and ether type solvents such as dibutyl ether, tetrahydrofuran, dioxane and di(methoxyethyl) ether; and dimethyl sulfoxide and pyridine. The exemplified palladium catalysts include halides, organic acid salts and inorganic acid salts of palladium: specifically, palladium acetate, palladium chloride, palladium bromide, palladium iodide, palladium sulfate, and complexes of the aforementioned palladium compounds with phosphine compounds such as dichloro-bis(triphenylphosphine) palladium, dibromo-bis(triphenylphosphine) palladium, diiodo-bis(triphenylphosphine) palladium, dichloro-bis(tritolylphosphine) palladium, dibromo-bis(tritolylphosphine) palladium, diiodo-bis(tritolylphosphine) palladium, chlorophenyl-bis(triphenylphosphine) palladium, bromophenyl-bis(triphenylphosphine) palladium, tetrakis(triphenylphosphine) palladium, and dichloro-bis(benzonitrile) palladium. The amount of the palladium catalyst employed ranges from 0.01 to 10 %, preferably from 0.1 to 5 % relative to the bis-alkenoic amide and the aromatic dihalide. Addition of triphenylphosphine to the reaction mixture (prior to heat) often gives a more favorable result. The amount of the base employed ranges from 2 to 5 equiv. to the aromatic dihalide, preferably 2.5 to 3 equiv. The reaction temperature is within the range of from 50 to 250°C, preferably from 80 to 200°C. The present invention will be explained in detail by employing working examples. Example 1: 1.055 g (2.5 mmols) of N,N'-bis-acryloyl-3,4-diaminodiphenyl ether, 0.770 g (2.5 mmols) of 4,4'-diiododiphenyl ether, 0.0056 g (0.025 mmol) of palladium acetate, 0.030 g (0.1 mmol) of tritolylphosphine, and 0.533 g (6.5 mmols) of sodium acetate were dissolved in 10 ml of N,N-dimethylformamide, and agitated for 4 hours at 100°C under nitrogen stream. After completion of the reaction, the reaction mixture was poured into 500 ml of methanol to yield the polyamide, and it was dried in vacuo. Yield: 1.185 g (100 %) Reduced viscosity: 0.84 dl/g (at a concentration of 0.5 g/dl in N,N-dimethylacetamide at 30°C) The IR spectrum had a characteristic absorption of amide at 3300 cm⁻¹, absorption of carbonyl at 1660 cm⁻¹, and absorption of carbon-carbon double bonds at 1630 cm⁻¹. Example 2: The polyamide prepared in Example 1 was dissolved in N,N-dimethylacetamide, and was flow-casted on a glass plate to form a film. Approximately half of the area of the film was covered with an aluminum foil, and the whole film was exposed to irradiation from a 400-W high pressure mercury lamp about 20 cm apart therefrom for 30 minutes. The aluminum foil was removed and then the whole film was immersed in N,N-dimethylformamide to find that the portion having been covered with the aluminum foil was soluble in N,N-dimethylformamide, but the portion not having been covered with the aluminum foil was insoluble therein. The present invention has made it possible to manufacture a polyamide resin having double bonds in the main chain by a simpler process at a lower cost with a higher yield than conventional processes.

Claims: A method for manufacturing a polyamide resin having double bonds in its main chain, comprising a repeating unit represented by the formula (I): [-Ar¹-CR¹=CR²-CO-NR³-R⁴-NR³-CO-CR²=CR¹-] (I) wherein Ar¹ is a bivalent aromatic radical, each of R¹, R² and R³ represents independently a hydrogen atom or a univalent aromatic or aliphatic radical, R⁴ is a bivalent aromatic or aliphatic radical, and having a reduced viscosity (ηsp/c) of 0.1 - 5.0 dl/g at a concentration of 0.5 g/dl in N,N-dimethylacetamide at 30°C, characterized in that a bis-alkenoic amide of the general formula (II): CHR¹=CR²-CO-NR³-R⁴-NR³-CO-CR²=CHR¹ (II) wherein R¹, R² and R³ are defined as above is reacted with an aromatic dihalide represented by the general formula (III): X-Ar¹-X (III) wherein Ar¹ is defined as above and X is a halogen atom, in the presence of a palladium catalyst in an amount ranging from 0.01 to 10% relative to the bis-alkenoic amide and the aromatic dihalide and a base present in an amount ranging from 2 to 5 equiv. to the aromatic dihalide in an organic solvent and within a temperature range of 50 to 250°C. A method according to claim 1, wherein the aromatic dihalide is m-dibromobenzene, p-dibromobenzene, 3,3'-dibromodiphenylmethane, 3,4'-dibromodiphenylmethane, 4,4'-dibromodiphenylmethane, 3,4'-dibromodiphenyl ether, 4,4'-dibromodiphenyl ether, 2,5-dibromothiophene or 2,5-bis(4-bromophenyl)-3,4-diphenylthiophene. A method according to claim 1, wherein the organic solvent is an aprotic solvent such as N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide and pyridine. A method according to claim 1, wherein the palladium catalyst is palladium acetate, palladium chloride, dichloro-bis(triphenylphosphine) palladium, tetrakis(triphenylphosphine) palladium, or dichloro-bis(benzonitrile) palladium. A method according to claim 1, wherein said base is a tertiary amine such as 1,4-diazabicyclo[2,2,2]octane, 4-dimethylaminopyridine and 1,8-diazabicyclo[5,4,0]undecene-7.

Inventors: IMAI YOSHIO, KAKIMOTO MASA-AKI, TANAKA MASANORI, YONEYAMA MASARU, IMAI, YOSHIO, KAKIMOTO, MASA-AKI, TANAKA, MASANORI, YONEYAMA, MASARU
Applicants: TOSOH CORP, TOSOH CORPORATION
Application year: 1989
Main classification: C08G69
IPC codes: C08G69, G03F7