A method for producing a polyamide excellent in appearance after heating is provided. The method for producing a polyamide contains the heating of a composition including a diamine represented by a formula (1), a dicarboxylic acid and a solvent, removing the solvent during and after the heating of the composition or after the heating of the composition, and adding a basic compound and/or a base generating agent to the composition during the heating of the composition and/or before the heating: wherein X is a hetero atom, and n is an integer of 0 to 5. The ring portion including X represents a cyclic structure including X.

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A method for producing a polyamide excellent in appearance after heating is provided. The method for producing a polyamide contains the heating of a composition including a diamine represented by a formula (1), a dicarboxylic acid and a solvent, removing the solvent during and after the heating of the composition or after the heating of the composition, and adding a basic compound and/or a base generating agent to the composition during the heating of the composition and/or before the heating: wherein X is a hetero atom, and n is an integer of 0 to 5. The ring portion including X represents a cyclic structure including X.

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Provided are a novel polyamide polymer obtained by polymerizing monomers including aromatic diamine substituted with a nitrile group and an amide group and an aromatic dibasic acid compound, a spinning dope comprising the same, and a polyamide molded article. A fiber obtained using the novel polyamide polymer according to the present invention, particularly, a fiber obtained by spinning the polymer according to the present invention may have high strength and high elasticity, such that the fiber may be applied to various industrial fields.

Provided are a novel polyamide polymer obtained by polymerizing monomers including aromatic diamine substituted with a nitrile group and an amide group and an aromatic dibasic acid compound, a spinning dope comprising the same, and a polyamide molded article. A fiber obtained using the novel polyamide polymer according to the present invention, particularly, a fiber obtained by spinning the polymer according to the present invention may have high strength and high elasticity, such that the fiber may be applied to various industrial fields.

Disclosed herein are processes of making furan-based polyamides using solvent-free melt condensation of a diamine and an ester derivative of 2,5-furandicarboxylic acid with a C.sub.2 to C.sub.12 aliphatic diol or a polyol. The processes comprise a) forming a reaction mixture by mixing one or more diamines, a diester comprising an ester derivative of 2,5-furandicarboxylic acid with a C.sub.2 to C.sub.12 aliphatic diol or a polyol, and a catalyst, such that the diamine is present in an excess amount of at least 1 mol % with respect to the diester amount; and b) melt polycondensing the reaction mixture in the absence of a solvent at a temperature in the range of 60° C. to a maximum temperature of 250° C. under an inert atmosphere, while removing alkyl alcohol to form a furan-based polyamide, wherein the one or more diamines comprises an aliphatic diamine, an aromatic diamine, or an alkylaromatic diamine.

The invention relates to a continuous solid-state polymerization process for preparing a polyamide derived from diamine and dicarboxylic acid, wherein the salt is polymerized in a reactor column comprising successive multifunctional zones comprising heating sections and gas-outlet sections, and a residence zone comprising at least one gas-inlet section, wherein the heating sections comprise static heat exchangers. The invention also relates to the reactor column and use thereof in a continuous solid-state polymerization process.

The invention relates to a continuous solid-state polymerization process for preparing a polyamide derived from diamine and dicarboxylic acid, wherein the salt is polymerized in a reactor column comprising successive multifunctional zones comprising heating sections and gas-outlet sections, and a residence zone comprising at least one gas-inlet section, wherein the heating sections comprise static heat exchangers. The invention also relates to the reactor column and use thereof in a continuous solid-state polymerization process.

The invention relates to a process for preparing a semi-aromatic polyamide from diamine and dicarboxylic acid, comprising steps of •(i) dosing a liquid diamine to an agitated powder comprising an aromatic dicarboxylic acid thereby forming a powder comprising a diamine/dicarboxylic acid salt (DD-salt), and •(ii) solid-state polymerizing the DD-salt to obtain the polyamide.

The invention relates to a process for preparing a semi-aromatic polyamide from diamine and dicarboxylic acid, comprising steps of •(i) dosing a liquid diamine to an agitated powder comprising an aromatic dicarboxylic acid thereby forming a powder comprising a diamine/dicarboxylic acid salt (DD-salt), and •(ii) solid-state polymerizing the DD-salt to obtain the polyamide.

The polyamide production method of the present invention comprises the steps of: producing a low-order condensate by effecting a polycondensation reaction between a dicarboxylic acid component containing between about 5 and about 40 mol. % of terephthalic acid, and a diamine component containing between about 70 and about 100 mol. % of a xylylenediamine in which the content of paraxylylenediamine is between about 50 and about 100 mol. %, under conditions of a reaction temperature of at least about 200° C. and less than about 230° C.; discharging and cooling the low-order condensate at a pressure at or below atmospheric pressure, in an inert gas atmosphere; and subjecting the discharged and cooled low-order condensate to solid state polymerization. The production method makes it possible to obtain a polyamide having outstanding mechanical strength, heat resistance, color tone and the like without problems such as gelling.