Epoxy and amino trialkoxysilane reaction products

• US 5,336,748 A
• Filed: 07/08/1993
• Issued: 08/09/1994
• Est. Priority Date: 12/21/1990
• Status: Expired due to Fees

• Current Assignee: Northrop Corporation
• Original Assignee: Northrop Corporation
• Inventors: Castellucci, Nicholas T.
• Primary Examiner(s): Sellers, Robert E.
• Application Number:
  US08/089,151
• Time in Patent Office: 397 Days
• Field of Search: 528/38, 523/421, 524/266, 524/588, 525/477
• US Class Current: 528/38
• CPC Class Codes: C08G 77/54 Nitrogen-containing linkages C08G77/485 takes precedence
• CPC Class Codes: C09D 183/14 in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms C09D183/10 takes precedence
• CPC Class Codes: C23C 22/48 not containing phosphates, hexavalent chromium compounds, fluorides or complex fluorides, molybdates, tungstates, vanadates or oxalates
• CPC Class Codes: C23C 2222/20 Use of solutions containing silanes

Abstract

Silane polymer coating compositions which have excellent bonding properties for metallic surfaces and which make such surfaces highly resistant to corrosion. The compositions are formed by anhydrously reacting an epoxy trialkoxy silane with a primary amino trialkoxy silane in a stoichiometric molar ratio which provides one epoxy group for reaction with each primary amino hydrogen site to form the silane polymer coating composition. The composition is applied to the metal surface, and is hydrolyzed and dehydrated in situ to crosslink thereon and bond to the surface to form the corrosion-resistant coating.

Claims

1. A silane polymer coating composition for forming coatings having excellent bonding properties for metallic surfaces and capable of rendering said metallic surfaces resistant to corrosion, said silane polymer coating composition being formed by anhydrously reacting an epoxy trialkoxy silane with a primary amino trialkoxy silane in relative stoichiometric amounts providing one epoxy group for reaction with each primary amino hydrogen site,

said reaction occurring for a period of approximately twenty-four hours at room temperature, and under an inert gas atmosphere,

said silane polymer coating composition being applicable to a metal surface and hydrolyzable thereon to form a silanol polymer capable of being dehydrated and crosslinked thereon, whereby a corrosion-resistant coating strongly bonded to said metal surface is formed.

2. A silane polymer coating composition according to claim 1 in which said epoxy trialkoxy silane has the formula:

##STR9## wherein x is an integer from 1 to 3, y equals three minus x, z is an integer from 1 to 3, and R is an alkyl group having from 1 to 3 carbon atoms.

3. A silane polymer coating composition according to claim 2 in which said epoxy trialkoxy silane comprises 3-glycidoxy propyltrimethoxy silane.

4. A silane polymer coating composition according to claim 1 in which said primary amino trialkoxy silane has the formula:

##STR10## wherein x is an integer from 2 to 3, y is an integer from 1 to 3, z is an integer from 0 to 3, R'"'"' and R" are each alkyl groups having from 1 to 3 carbon atoms, a is an integer from 0 to 1 and b equals 3 minus a.

5. A silane polymer coating composition according to claim 4 in which said primary amino trialkoxy silane comprises N-(2-aminoethyl) 3-aminopropyltrimethoxy silane.

6. A silane polymer coating composition according to claim 1 further comprising a silicone-base wetting agent in a concentration of between about 0.05% and 1.00% by weight.