US 12,187,849 B2
Flame-retardant polyimide molding material and molded object
Atsushi Sakai, Kanagawa (JP); Yuuki Sato, Kanagawa (JP); and Naoki Kaneko, Kanagawa (JP)
Assigned to MITSUBISHI GAS CHEMICAL COMPANY, INC., Chiyoda-ku (JP)
Appl. No. 17/435,111
Filed by MITSUBISHI GAS CHEMICAL COMPANY, INC., Chiyoda-ku (JP)
PCT Filed Feb. 25, 2020, PCT No. PCT/JP2020/007359
§ 371(c)(1), (2) Date Aug. 31, 2021,
PCT Pub. No. WO2020/179532, PCT Pub. Date Sep. 10, 2020.
Claims priority of application No. 2019-041766 (JP), filed on Mar. 7, 2019.
Prior Publication US 2022/0135742 A1, May 5, 2022
Int. Cl. C08J 5/10 (2006.01); C08G 73/10 (2006.01); C08J 5/04 (2006.01); C08K 3/34 (2006.01); C09K 21/02 (2006.01)
CPC C08G 73/1082 (2013.01) [C08G 73/1032 (2013.01); C08G 73/1042 (2013.01); C08J 5/042 (2013.01); C08J 5/10 (2013.01); C08K 3/34 (2013.01); C09K 21/02 (2013.01); C08J 2379/08 (2013.01); C08K 2003/343 (2013.01)] 13 Claims
 
1. A flame-retardant polyimide molding material, comprising:
a semi-aromatic polyimide resin (A) having a weight average molecular weight Mw of from 10,000 to 150,000; and
carbon fiber (B) at a content of from 25 mass % to 65 mass %,
wherein the carbon fiber (B) comprises staple fiber having an average fiber length of less than 10 mm, wherein the carbon fiber (B) also has an average fiber diameter of from 3 to 50 μm, number of filaments in the range of from 500 to 100,000, and surface-treated with a surface treatment agent selected from the group consisting of an epoxy-based material, a urethane-based material, an acryl-based material, a polyamide-based material, a polyester-based material, a vinyl ester-based material, a polyolefin-based material, and a polyether-based material,
wherein the semi-aromatic polyimide resin (A) comprises a polyimide resin (A1) comprising a repeating structural unit of the following formula (1) and a repeating structural unit of the following formula (2):

OG Complex Work Unit Chemistry
wherein R1 represents a divalent aliphatic group having from 6 to 22 carbon atoms and comprising an alicyclic hydrocarbon structure,
R2 represents a divalent chain aliphatic group having from 5 to 16 carbon atoms,
X1 and X2 each independently represent a tetravalent aromatic group having from 6 to 22 carbon atoms, and
a content ratio of the repeating structural unit of the formula (1) with respect to a total of the repeating structural unit of the formula (1) and the repeating structural unit of the formula (2) is from 20 to 70 mol %, wherein a 4-mm thick molded article made of the flame-retardant polyimide molding material has flame retardancy corresponding to V-0 in a flame retardant test according to the UL94 standard.