Corrosion protective methacrylate adhesives for galvanized steel and other metals
View Patent ↗Compositions for bonding galvanized surfaces are disclosed. The compositions include either (i) a first part that includes at least one (meth)acrylate component in combination with a free radical inhibitor component and a phosphate ester component and a second part that includes at least one accelerator component or (ii) a first part that includes at least one (meth)acrylate component in combination with an accelerator and a phosphate ester component and a second part that includes a carrier component and a free radical initiator component. Methods for preparing and methods for using these compositions also are disclosed, as are processes for inhibiting corrosion on galvanized surfaces.
1. A process for inhibiting corrosion on a galvanized surface comprising the steps of:
1) applying to a galvanized substrate surface a curable composition for bonding galvanized surfaces, and
2) subjecting the composition-applied substrate surface to conditions sufficient to allow the composition to cure, wherein the curable composition comprises:
(a) a first part comprising:
(i) at least one curable (meth)acrylate component;
(ii) a free-radical initiator component;
(iii) a phosphate ester component in an amount sufficient to achieve a tensile strength on a galvanized surface of at least about 1000 psi when measured after humidity aging at 85% relative humidity and 85° C. for 250 hours; and
(iv) methacrylic acid in an amount that is at least about 2% by weight of the total composition; and
(b) a second part comprising one or more of an accelerator component, a carrier component, and a free radical initiator component, wherein at least one of the first part or the second part further comprises a corrosion inhibitor.
2. A process for inhibiting corrosion on a galvanized surface comprising the steps of:
1) applying to a galvanized substrate surface a curable composition for bonding galvanized surfaces, and
2) subjecting the composition-applied substrate surface to conditions sufficient to allow the composition to cure, wherein the curable composition comprises:
(a) a first part comprising:
(i) at least one curable (meth)acrylate component;
(ii) a free-radical initiator component;
(iii) a phosphate ester component; and
(iv) an organic acid component in an amount sufficient to achieve a tensile strength on a galvanized surface of at least about 2500 psi at room temperature; and
(b) a second part comprising one or more of an accelerator component, a carrier component, and a free radical initiator component, wherein the organic acid component is methacrylic acid in an amount that is at least about 2% by weight of the composition.
3. A process for inhibiting corrosion on a galvanized surface comprising the steps of:
1) applying to a galvanized substrate surface a curable composition for bonding galvanized surfaces, and
2) subjecting the composition-applied substrate surface to conditions sufficient to allow the composition to cure, wherein the curable composition comprises:
(a) a first part comprising:
(i) at least one curable (meth)acrylate component;
(ii) a free-radical initiator component;
(iii) a phosphate ester component; and
(iv) an organic acid component in an amount sufficient to achieve a tensile strength on a galvanized surface of at least about 800 psi when measured after humidity aging at 85% relative humidity and 85° C. for 250 hours; and
a second part comprising one or more of an accelerator component, a carrier component, and a free radical initiator component, wherein the organic acid component is methacrylic acid in an amount that is at least about 2% by weight of the composition.