Corrosion-indicating materials and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-11236195-B2
Application number	US-202016799137-A
Country	US
Kind code	B2
Filing date	Feb 24, 2020
Priority date	Feb 24, 2020
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A corrosion-indicating material and methods of producing and using the corrosion-indicating material are provided. The corrosion-indicating material comprises a cured product of reacting a bisphenol A diglycidyl ether epoxy (DGEBA) resin with a curing agent, the curing agent comprising a 1,10-phenanthroline derivative having formula (I):where: R1 and R2 are independently selected from —NH2; —NH(CH2)aNH2, where a is 1, 2, or 3; —OC(═O)(CH2)bNH2, where b is 1, 2, or 3; and —H; R3 and R4 are either: non-joined monovalent radicals each independently chosen from —H, —NH2, and (C1-C20)heterohydrocarbyls comprising at least one primary amine or at least one secondary amine; or joined as a single divalent radical, the single divalent radical being a (C1-C40)heterohydrocarbyl comprising at least one primary amine or at least one secondary amine; and at least one of R1, R2, R3, and R4 is not —H.

First claim

What is claimed is:

1. A corrosion-indicating material that indicates corrosion of a metal substrate underlying the corrosion-indicating material, the corrosion-indicating material comprising a cured product of reacting a bisphenol A diglycidyl ether (DGEBA) epoxy resin with a curing agent, the curing agent comprising a 1,10-phenanthroline derivative having formula (I):

where:
R 1 and R 2 are independently selected from —NH 2 ; —NH(CH 2 ) a NH 2 , where a is 1, 2, or 3; —OC(═O)(CH 2 ) b NH 2 , where b is 1, 2, or 3; and —H;
R 3 and R 4 are either:
non-joined monovalent radicals each independently chosen from —H, —NH 2 , and (C 1 -C 20 )heterohydrocarbyls comprising at least one primary amine or at least one secondary amine; or
joined as a single divalent radical, the single divalent radical being a (C 1 -C 40 )heterohydrocarbylene comprising at least one primary amine or at least one secondary amine;

at least one of R 1 , R 2 , R 3 , and R 4 is not —H; and
provided at least one of (i), (ii), (iii), (iv), (v), or (vi) is true:
(i) R 1 and R 2 are independently selected from the group consisting of —NH 2 and —H and:
both R 1 and R 2 are —H, or
both R 1 and R 2 are —NH 2 ; or

(ii) R 1 , R 2 , R 3 , and R 4 are independently —NH 2 or —H, provided at least one of R 1 , R 2 , R 3 , and R 4 is —NH 2 and:
R 1 and R 2 are —H and R 3 and R 4 are —NH 2 , or
R 1 and R 2 are —NH 2 and R 3 and R 4 are —H; or

(iii) both R 3 and R 4 are —NH 2 ; or
(iv) R 3 and R 4 are identical non-joined monovalent radicals selected from the group consisting of —CH 2 NH 2 , —CH 2 N(CH 2 CH 2 NH 2 ) 2 , —CH 2 N(H)(cyclohexyl), —CH 2 N(H)[(CH 2 ) d CH 3 ] where d is 1, 2, or 3, —CH 2 N(H)[CH 2 ) 2 N(H)(phenyl)], and —CH 2 N(H)[CH 2 )(2-pyridyl)]; or
(v) R 3 and R 4 are joined as a single divalent radical having the formula —CH 2 —NH—[(CH 2 ) x N(H)—] n CH 2 —, where x is 2 or 3 and n is 2, 3, 4, or 5; or
(vi) R 3 and R 4 are joined as a single divalent radical having the formula —CH═N—(CH 2 ) 2 {—N[CH 2 ) 2 NH 2 ]—(CH 2 ) 2 } y —N═CH—, where y is 1 or 2.

2. The corrosion-indicating material of claim 1 , in which at least (i) is true and:
the non-joined monovalent radicals are selected from the group consisting of —NH 2 , —CH 2 NH 2 , —CH 2 N(CH 2 CH 2 NH 2 ) 2 , —CH 2 N(H)(cyclohexyl), —CH 2 N(H)[(CH 2 ) d CH 3 ], where d is 1, 2, or 3, —CH 2 N(H)[(CH 2 ) 2 N(H)(phenyl)], —CH 2 N(H)[CH 2 )(2-pyridyl)], and —H; or
the single divalent radical is selected from the group consisting of —CH 2 —NH—[(CH 2 ) x N(H)—] n CH 2 —, where x is 2 or 3 and n is 2, 3, 4, or 5; and —CH═N—(CH 2 ) 2 {—N[(CH 2 ) 2 NH 2 ]—(CH 2 ) 2 } y —N═CH—, where y is 1 or 2.

3. The corrosion-indicating material of claim 1 , in which at least one of (iii) through (vi) is true and one of R 1 and R 2 is —NH 2 and the other of R 1 and R 2 is —H.

4. The corrosion-indicating material of claim 1 , in which at least (i) is true and R 3 and R 4 are identical non-joined monovalent radicals.

5. An article comprising a metal substrate and a layer of the corrosion-indicating material according to claim 1 overlying a surface of the metal substrate.

6. The article of claim 5 , in which:
the metal substrate comprises an oxidizable metal that is converted to metal ions when the metal substrate corrodes;
the metal ions form complexes with the 1,10-phenanthroline derivative present in the corrosion-indicating material;
the complexes impart a color change to the corrosion-indicating material in the presence of moisture from an initial color before corrosion to a corrosion-indicative color different from the initial color.

7. The article of claim 6 , in which the oxidizable metal is selected from iron, vanadium, chromium, manganese, cobalt, nickel, copper, and combinations of any of the foregoing.

8. The article of claim 5 , in which the metal substrate is selected from iron, iron alloys, and iron-based steels.

9. A coating composition comprising a corrosion-indicating resin according to claim 1 and a solvent.

10. The coating composition of claim 9 , in which the solvent comprises tetrahydrofuran (THF), chloroform, acetone, isopropanol, or combinations thereof.

Assignees

• Saudi Arabian Oil Co

Inventors

• Alamri Haleema
• Fihri Aziz
• Bouhrara Mohamed
• Bovero Enrico
• Mishari Bashayer

Classifications

• C08G59/5053

  containing only nitrogen as a heteroatom · CPC title

• C08G59/245

  aromatic · CPC title

• C09D5/00 Primary

  Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced {(electrically insulating plastics, resins or waxes H01B3/30)}; Filling pastes · CPC title

• C09D163/00

  Coating compositions based on epoxy resins; Coating compositions based on derivatives of epoxy resins · CPC title

• G01N31/22

  using chemical indicators (G01N31/02 takes precedence) · CPC title