Nonaqueous sol-gel for adhesion enhancement of water-sensitive materials

A sol-gel formulation for an adhesive in contact with a steel substrate, the sol-gel formulation consisting of:

• an organosilane represented by formula (II):
• wherein R is selected from alkyl, cycloalkyl, ether, and aryl;
• 0.2 wt % to 5 wt % of a zirconium alkoxide based on a total weight of the sol-gel formulation;
• 15 wt % to 40 wt % of a corrosion inhibitor based on the total weight of the sol-gel formulation, wherein the corrosion inhibitor is represented by a formula R1—Sn—X—R2 wherein R1 is an organic group, wherein n is an integer greater than or equal to 1, wherein X is a sulfur or a metal atom, wherein R2 is an organic group, wherein one or both of the organic groups of R1 and R2 is a thiol group;
• an acid stabilizer;
• and
• an organic solvent, wherein the sol-gel formulation has a water content of 0 wt % based on the total weight of the sol-gel formulation.

A sol-gel formulation for an adhesive in contact with a steel substrate, the sol-gel formulation consisting of:

• 0.3 wt % to 15 wt % of 3-glycidoxypropyltrimethoxysilane, based on a total weight of the sol-gel formulation;
• 0.2 wt % to 5 wt % of zirconium tetra-n-propoxide based on the total weight of the sol-gel formulation;
• 15 wt % to 40 wt % of a corrosion inhibitor based on the total weight of the sol-gel formulation, the corrosion inhibitor having a formula R1—Sn—X—R2, wherein:
• n is an integer greater than or equal to 1,
• R1 and R2 are organic groups, and
• one or both of the organic groups is a thiol, a polymer, or a combination thereof;
• acetic acid;
• an organic solvent;
• and
• 0 wt % to 0.5 wt % of water based on the total weight of the sol-gel formulation.

A sol-gel formulation for an adhesive in contact with a steel substrate the sol-gel formulation consisting of:

• 0.7 wt % to 5 wt % of an organosilane based on a total weight of the sol-gel formulation, wherein the organosilane is one or more of 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldiisopropylethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane,
• 0.2 wt % to 5 wt % of a zirconium alkoxide based on the total weight of the sol-gel formulation;
• 7 wt % to 40 wt % of a corrosion inhibitor based on the total weight of the sol-gel formulation, the corrosion inhibitor selected from a group consisting of a compound represented by a formula R1—Sn—X—R2 wherein R1 is an organic group, wherein n is an integer greater than or equal to 1, wherein X is a sulfur or a metal atom, wherein R2 is an organic group, wherein one or both of the organic groups of R1 and R2 is a thiol group;
• an acid stabilizer;
• and
• an organic solvent,
• wherein:
• the sol-gel formulation has from 0 wt % to 1 wt % water content based on the total weight of the sol-gel formulation,
• the sol-gel formulation has a pH from 2 to 5, and
• a ratio of the zirconium alkoxide to organosilane is 2:1 to 3:1.