Modified amine curing agents, their preparation and use in curable compositions

Patent metadata

Field	Value
Publication number	US-10011679-B2
Application number	US-201514953738-A
Country	US
Kind code	B2
Filing date	Nov 30, 2015
Priority date	Dec 2, 2014
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

A method for producing a modified form of an aromatic amine compound represented by the following structure I:

where A is an amine group —NHR, R is independently selected from hydrogen, linear and branched alkyl groups having 1 to 6 carbon atoms, preferably A is NH 2 ; X is a halogen selected from Cl, Br, F, I, and At, or hydrogen (H). The method includes heating the aromatic amine compound, in its initial crystalline form, to a temperature above its melting point in order to obtain a molten material, then cooling the molten material to a temperature below the melting point of the crystalline compound so as to produce an amorphous, glassy form of the aromatic amine compound. The modified aromatic amine compound is suitable as a curing agent in resin compositions that are used for fabricating fiber-reinforced composites.

First claim

What is claimed is:

1. A method for modifying an aromatic amine compound, comprising:
heating the aromatic amine compound, in its initial crystalline form, to a temperature of 1° C. to 50° C. above its melting point, as determined by Differential Scanning Calorimetry (DSC), in order to obtain a molten material; and
cooling the molten material to a temperature below the melting point of the crystalline form so as to produce an amorphous, glassy form of the aromatic amine compound,
wherein the aromatic amine compound is 9,9-Bis(4-aminophenyl)fluorene, represented by the following structure:

2. A method for fabricating a composite structure comprising:
(a) modifying a single aromatic amine compound in its initial crystalline form so as to produce an amorphous, glassy form of the aromatic amine compound;
(b) combining one or more polyepoxide(s) with the modified aromatic amine compound in amorphous, glassy form to form a curable epoxy-based composition;
(C) infusing a fibrous preform with the curable epoxy-based composition, said fibrous preform comprising an assembly of reinforcement fibers; and
(d) curing the infused preform,
wherein the aromatic amine compound is 9,9-Bis(4-amino-3-chlorophenyl)fluorene represented by the following structure:

wherein 9,9-Bis(4-amino-3-chlorophenyl)fluorene is the only amine compound in amorphous, glassy form in the curable epoxy-based composition.

3. The method of claim 2 , wherein the aromatic amine compound in amorphous, glassy form is prepared by heating a single aromatic amine compound, in its initial crystalline form, to a temperature of 1° C. to 50° C. above its melting point, as determined by Differential Scanning Calorimetry (DSC), in order to obtain a molten material, then cooling the molten material to a temperature of 30° C. or lower so as to produce an amorphous, glassy form of the aromatic amine compound.

4. The method of claim 2 , wherein the curable epoxy-based composition has a viscosity of less than 5 Poise at a temperature in the range of about 80° C. to about 130° C. during infusion.

5. A method for fabricating a composite structure comprising:
(a) modifying an aromatic amine compound in its initial crystalline form so as to produce an amorphous, glassy form of the aromatic amine compound;
(a) forming a curable epoxy-based composition comprising one or more polyepoxide(s) and the modified aromatic amine compound in amorphous, glassy form;
(b) infusing a fibrous preform with the curable epoxy-based composition, said fibrous preform comprising an assembly of reinforcement fibers; and
(c) curing the infused preform,
wherein the aromatic amine compound is 9,9-Bis(4-aminophenyl)fluorene represented by the following structure:

6. The method of claim 5 , wherein the aromatic amine compound in amorphous, glassy form is prepared by heating the aromatic amine compound, in its initial crystalline form, to a temperature of 1° C. to 50° C. above its melting point, as determined by Differential Scanning Calorimetry (DSC), in order to obtain a molten material, then cooling the molten material to a temperature of 30° C. or lower so as to produce an amorphous, glassy form of the aromatic amine compound.

7. The method of claim 5 , wherein the curable epoxy-based composition has a viscosity of less than 5 Poise at a temperature in the range of about 80° C. to about 130° C. during infusion.

Assignees

• Cytec Ind Inc

Inventors

• Meegan Jonathan E

Classifications

• C08G59/5033 Primary

  aromatic · CPC title

• C08K5/18

  with aromatically bound amino groups · CPC title

• C08J5/24

  Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs · CPC title

• C07C211/50

  with at least two amino groups bound to carbon atoms of six-membered aromatic rings of the carbon skeleton · CPC title

• C08J2363/00

  Characterised by the use of epoxy resins; Derivatives of epoxy resins · CPC title