Unitika Ltd.

Makoto Nakai

Akira Shigeta

Yumeto Fukubayashi

Munenori Yamada

Mariko Morimoto

Kiwamu Yuki

Atsuko Noda

Mitsuhiro Kawahara

Yuji Kitora

Yusuke Yagi

Yuki Takubo

Takeshi Maruo

Ryosuke Kobayashi

A flexible polyamide including a unit formed from an aliphatic dicarboxylic acid (A1) having 18 or more carbon atoms and/or a unit formed from an aliphatic diamine (B1) having 18 or more carbon atoms, wherein the polyamide has a total content of 10 to 90% by mass of the unit formed from (A1) and the unit formed from (B1) and has a melting point of 240° C. or higher.

Flexible polyamide

The present invention is to provide a polyamide-imide which has a high regularity of molecular structure and few branched structures, does not contain hydrogen halide, is not required to be separated and purified in post processes, and can be suitably used as a film, a varnish, or a molding material; raw material salt of polyamide-imide and production method thereof. The polyamide-imide has a repeating unit represented by the general formula (1): in which R, Rrepresent independently a divalent residue having an aromatic ring, an aliphatic ring or an aliphatic hydrocarbon; R, Rrepresent independently a trivalent residue having an aromatic ring or an aliphatic ring; and an hydrogen atom bonding to the respective rings may be replaced by another atom or an atomic group.

Polyamide-imide, raw material salt of polyamide-imide, and production method thereof

An object of the present invention is to provide an industrially advantageous method for producing a bisimide dicarboxylic acid, which uses substantially no solvent and requires no granulation after completion of the reaction. The above object can be achieved by a method for producing a bisimide dicarboxylic acid with a tricarboxylic acid anhydride and a diamine, including the following processes (i) and (ii):

Method for producing bisimide dicarboxylic acid

The present invention is a method for producing a polyamide resin, wherein a nylon salt obtained from a dicarboxylic acid and a diamine having a boiling point exceeding 100&#xb0; C. is heated to be polymerized under normal pressure while water vapor is being allowed to be present in the polymerization reaction system.

Method for producing polyamide resin

Disclosed is a method for producing a nylon salt powder, wherein in the production of a nylon salt powder by allowing a dicarboxylic acid powder to react, the content of water is regulated to be 5% by mass or less in relation to the total amount of the dicarboxylic acid powder and a diamine, the dicarboxylic acid powder is beforehand heated to a temperature equal to or higher than melting point of the diamine and equal to or lower than the melting point of the dicarboxylic acid, and while this heating temperature is being maintained, the diamine is added to the dicarboxylic acid powder in such a way that the dicarboxylic acid powder maintains the condition of being in powder form.

Method for producing nylon salt powder, and method for producing nylon

At an optional stage in the production step of a biaxially stretched film using a polyamide resin including, as a first component, nylon 6, and as a second component, a polyamide including xylylenediamine and an aliphatic dicarboxylic acid having 4 to 12 carbon atoms, the film is brought into contact with water set at 40&#xb0; C. or higher and lower than 70&#xb0; C. for 1 to 10 minutes and further with water set at 70&#xb0; C. or higher for 1 to 10 minutes. In the film thus obtained, the content of low molecular weight compounds is 0% by mass to 0.2% by mass.

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Kyoto, Japan

Makoto Nakai