Heat-curable maleimide resin composition for RTM, fiber-reinforced composite material and radome

Patent metadata

Field	Value
Publication number	US-12516163-B2
Application number	US-202217957378-A
Country	US
Kind code	B2
Filing date	Sep 30, 2022
Priority date	Oct 28, 2021
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

Provided are a heat-curable maleimide resin composition for RTM that is used to produce a fiber-reinforced composite material such as FRP, and is superior in dielectric properties; and a fiber-reinforced composite material using such composition. The composition contains:
(A-1) a maleimide compound having at least one dimer acid skeleton-derived hydrocarbon group per one molecule, and having a viscosity of not higher than 20 Pa·s; (A-2) a maleimide compound having at least one dimer acid skeleton-derived hydrocarbon group per one molecule, having a viscosity of greater than 20 Pa·s, and exhibiting a fluidity at 25° C.; (B) a radical polymerization initiator; and (C) a polymerization inhibitor, wherein the viscosities of the components (A-1) and (A-2) are measured in accordance with a method described in JIS Z8803: 2011, at a measurement temperature of 25° C., and using a Brookfield-type rotary viscometer with a rotation rate of a spindle being set to 5 rpm.

First claim

What is claimed is:

1 . A heat-curable maleimide resin composition for RTM, comprising:
(A-1) a maleimide compound having at least one dimer acid skeleton-derived hydrocarbon group per one molecule, and having a viscosity of not higher than 20 Pa·s; (A-2) a maleimide compound having at least one dimer acid skeleton-derived hydrocarbon group per one molecule, having a viscosity of greater than 20 Pa·s, and exhibiting a fluidity at 25° C.; (B) a radical polymerization initiator; and (C) a polymerization inhibitor, wherein the viscosities of the components (A-1) and (A-2) are measured in accordance with a method described in JIS Z8803:2011, at a measurement temperature of 25° C., and using a Brookfield-type rotary viscometer with a rotation rate of a spindle being set to 5 rpm, wherein the component (A-2) is a maleimide compound represented by the following formula (2):

wherein B independently represents a cyclic structure-containing tetravalent organic group, X independently represents a divalent hydrocarbon group having 6 to 200 carbon atoms, at least one X is a dimer acid skeleton-derived hydrocarbon group, and n is 1 to 100, and wherein B in the formula (2) is any one of the tetravalent organic groups represented by the following structural formulae:

wherein bonds in these structural formulae that are yet unbonded to substituent groups are to be bonded to carbonyl carbons forming cyclic imide structures in the formula (2).

2 . The heat-curable maleimide resin composition for RTM according to claim 1 , wherein the composition has a viscosity of not higher than 3 Pa·s when measured in accordance with the method described in JIS Z8803:2011, at a measurement temperature of 60° C., and using a Brookfield-type rotary viscometer with a rotation rate of a spindle being set to 5 rpm.

3 . The heat-curable maleimide resin composition for RTM according to claim 1 , wherein the component (A-1) is a maleimide compound represented by the following formula (1):

wherein A represents a dimer acid skeleton-derived hydrocarbon group.

4 . The heat-curable maleimide resin composition for RTM according to claim 1 , wherein a ratio between (A-1) and (A-2) on a mass basis is (A-1):(A-2)=95:5 to 40:60.

5 . A fiber-reinforced composite material formed of the heat-curable maleimide resin composition for RTM according to claim 1 and a reinforced fiber.

6 . The fiber-reinforced composite material according to claim 5 , wherein the reinforced fiber is a quartz glass fiber.

7 . A radome having the fiber-reinforced composite material according to claim 6 .

8 . A heat-curable maleimide resin composition for RTM, comprising:
(A-1) a maleimide compound having at least one dimer acid skeleton-derived hydrocarbon group per one molecule, and having a viscosity of not higher than 3 Pa·s; (A-2) a maleimide compound having at least one dimer acid skeleton-derived hydrocarbon group per one molecule, having a viscosity of greater than 20 Pa·s, and exhibiting a fluidity at 25° C.; (B) a radical polymerization initiator; and (C) a polymerization inhibitor, wherein the viscosities of the components (A-1) and (A-2) are measured in accordance with a method described in JIS Z8803:2011, at a measurement temperature of 25° C., and using a Brookfield-type rotary viscometer with a rotation rate of a spindle being set to 5 rpm, wherein the component (A-1) is a maleimide compound represented by the following formula (1):

wherein A represents a dimer acid skeleton-derived hydrocarbon group,
wherein the component (A-2) is a maleimide compound represented by the following formula (2):

wherein B independently represents a cyclic structure-containing tetravalent organic group, X independently represents a divalent hydrocarbon group having 6 to 200 carbon atoms, at least one X is a dimer acid skeleton-derived hydrocarbon group, and n is 1 to 100, and wherein B in the formula (2) is any one of the tetravalent organic groups represented by the following structural formulae:

wherein bonds in these structural formulae that are yet unbonded to substituent groups are to be bonded to carbonyl carbons forming cyclic imide structures in the formula (2),
wherein a ratio between (A-1) and (A-2) on a mass basis is (A-1):(A-2)=95:5 to 40:60.

9 . A fiber-reinforced composite material formed of the heat-curable maleimide resin composition for RTM according to claim 8 and a reinforced fiber.

10 . The fiber-reinforced composite material according to claim 9 , wherein the reinforced fiber is a quartz glass fiber.

11 . A radome having the fiber-reinforced composite material according to claim 10 .

Assignees

• Shinetsu Chemical Co

Inventors

• Tsutsumi Yoshihiro
• Ikeda Tadaharu

Classifications

• C08J2379/08

  Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors · CPC title

• C08F222/404

  substituted imides comprising oxygen other than the carboxy oxygen · CPC title

• C08F290/065

  Polyamides; Polyesteramides; Polyimides · CPC title

• C08K5/13

  Phenols; Phenolates · CPC title

• C08L79/085 Primary

  Unsaturated polyimide precursors · CPC title