Corrosion-inhibiting microgels and non-chromated primer compositions incorporating the same

Patent metadata

Field	Value
Publication number	US-10240048-B2
Application number	US-201314132547-A
Country	US
Kind code	B2
Filing date	Dec 18, 2013
Priority date	Dec 28, 2012
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

Corrosion-inhibiting microgels that are suitable for use in non-chromated primer compositions. Each discrete microgel is composed of a cross-linked polymer network and organic corrosion-inhibiting compounds entrapped or immobilized within the polymer network.

First claim

What is claimed is:

1. A discrete, corrosion-inhibiting microgel comprising:
a cross-linked polymer network created by emulsion polymerization of monomers selected from: mono-functional or bi-functional acrylic monomers; mono-functional or bi-functional methacrylic monomers; mono-functional vinyl monomers, and combinations thereof; and
organic corrosion-inhibiting compounds entrapped or immobilized within the polymer network,
wherein emulsion polymerization is carried out in the presence of an initiator for free radical polymerization and cross-linking monomers selected from: diacrylates; dimethacrylates; triacrylates; trimethacrylates; dipentaerythritol pentaacrylate; pentaerythritol tetraacrylate; derivatives of methylenebisacrylamide; and combinations thereof,
wherein the corrosion-inhibiting compounds are releasable from the polymer network upon exposure to a corrosion-triggering condition selected from: pH change, moisture exposure, temperature increase, and combination thereof.

2. The microgel of claim 1 , wherein the corrosion-inhibiting compounds are selected from the following:
(a) amino benzothiazole-based compounds having the formula:

wherein R 3 is chosen from H, C n H 2n+1 and OC n H 2n+1 ;
(b) benzotriazole-based compounds having the formula

wherein R 1 is chosen from H, C n H 2n+1 , COOH, and OH;
wherein R 2 is chosen from H and C n H 2n+1 ;
(c) phenylmaleimide-based compounds having the formula:

wherein each R 4 is independently chosen from: S, NH, and O; and
(d) mercaptobenzoimidazole-based compounds having the formula:

wherein R 5 is chosen from: H, C n H 2n+1 , COOH, and OH; and n is an integer.

3. The microgel of claim 1 , wherein the initiator for free radical polymerization is selected from: peroxides; hydroperoxides; persulfates; aliphatic azo compounds; ascorbic acid; formaldehyde sulfoxilate (SFS); tetramethyl ethylene diamine (TMEDA); sodium metabisulfite; and a mixture of disodium salt of 2-hydroxy-2-sulfinatoacetic acid, disodium salt of 2-hydroxy-2-sulfonatoacetic acid and sodium bisulfate.

4. The microgel of claim 1 , wherein some corrosion-inhibiting compounds are covalently bonded to the cross-linked polymer network and some corrosion-inhibiting compounds are physically entrapped or immobilized within the network.

5. A chromate-free, corrosion inhibiting primer composition comprising:
at least one epoxy resin;
a curing agent;
an organosilane comprising a hydrolysable group; and
the corrosion-inhibiting microgel of claim 1 .

6. The primer composition of claim 5 , wherein the curing agent is an amine compound selected from: aromatic amines; substituted amino triazine; modified polyamine; dicyanadiamide (DICY); bis-urea based curing agents; amine-epoxy adducts; diamines, imidazoles; and combinations thereof.

7. The primer composition of claim 6 , wherein the amine curing agent is an aromatic amine selected from: bis(3-aminopropyl)-piperazine (BAPP); 4,4′-diaminodiphenylmethane; 2,2-bis(4-[4-aminophenoxy]phenyl)propane; 3,3′- and 4,4′-diaminodiphenylsulfone; amino and hydroxyl terminated polyarylene oligomers wherein the repeating phenyl groups are separated by one of ether, sulfide, carbonyl, sulfone, and carbonate groups.

8. The primer composition according to claim 6 , wherein the amine curing agent is selected from: 9,10-bis(4-aminophenyl)anthracene; 2,2-bis(4-[3-aminophenoxy]phenyl) sulfone; 2,2-bis(4-[4-aminophenoxy]phenyl) sulfone; 1,4-bis(4-aminophenoxy)biphenyl; bis(4-[4-aminophenoxy)phenyl) ether; 2,2-bis([4-(4-amino-2-trifluorophenoxy)]phenyl) hexafluoropropane; 4,4′-[1,4-phenylene(1-methylethylidene)]-bis(benzeneamine).

9. A method for forming corrosion-inhibiting microgels, said method comprising:
a) forming discrete microgels by emulsion polymerization of monomers selected from: mono-functional or bi-functional acrylic monomers; mono-functional or bi-functional methacrylic monomers; mono-functional vinyl monomers, and combinations thereof;
b) dissolving an organic corrosion inhibitor in an aqueous medium containing an organic solvent and water;
c) mixing the microgels with the aqueous medium, causing the microgels to swell and the organic corrosion inhibitor compounds to become entrapped or immobilized within the polymer networks; and
d) stripping off the solvent to produce a latex emulsion with microgels of smaller particle sizes,
wherein emulsion polymerization at (a) is carried out in the presence of an initiator for free radical polymerization and cross-linking monomers selected from: diacrylates; dimethacrylates; triacrylates; trimethacrylates; dipentaerythritol pentaacrylate; pentaerythritol tetraacrylate; derivatives of methylenebisacrylamide; and combinations thereof.

10. The method of claim 9 , wherein the initiator for free radical polymerization is selected from: peroxides; hydroperoxides; aliphatic azo compounds; persulfates; ascorbic acid; formaldehyde sulfoxilate (SFS); tetramethyl ethylene diamine (TMEDA); sodium metabisulfite; and a mixture of disodium salt of 2-hydroxy-2-sulfinatoacetic acid, disodium salt of 2-hydroxy-2-sulfonatoacetic acid, and sodium bisulfite.

11. The method of claim 9 , wherein the organic corrosion inhibitor used in step (b) is selected from:
(i) amino benzothiazole-based compounds having the formula:

wherein R 3 is chosen from H, C n H 2n+1 and OC n H 2n+1 ;
(ii) benzotriazole-based compounds having the formula

wherein R 1 is chosen from H, C n H 2n+1 , COOH, and OH;
wherein R 2 is chosen from H and C n H 2n+1 ;
(iii) phenylmaleimide-based compounds having the formula:

wherein each R 4 is independently chosen from: S, NH, and O; and
(iv) mercaptobenzoimidazole-based compounds having the formula:

wherein R 5 is chosen from: H n CH 2n+1 , COOH, and OH; and n is an integer.

12. The method of claim 9 , further comprising spraying-drying the latex emulsion resulted from step (d) to produce microgel particles in a powder form.

13. Corrosion-inhibiting particles in powder form produced by the method of claim 12 .

14. The method of claim 9 , further comprising destabilizing and drying the latex emulsion resulted from step (d) to produce microgel particles in a powder form.

15. Corrosion-inhibiting microgels produced by the method of claim 9 .

Assignees

• Cytec Ind Inc

Inventors

• Zhao Yiqiang
• Kohli Dalip
• Ouzineb Keltoum

Classifications

• C09D5/082

  characterised by the anti-corrosive pigment · CPC title

• C08G59/56

  together with other curing agents · CPC title

• C08L33/06

  of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical · CPC title

• C07D235/28

  Sulfur atoms · CPC title

• C08K5/3475

  condensed with carbocyclic rings · CPC title