Molybdate-free sterilizing and pasteurizing solutions
View Patent ↗The present invention concerns a composition and method of using non-molybdate corrosion inhibitors in sterilizing and pasteurizing applications. The composition is a blend of one or more components including corrosion inhibitors, surfactants, hydrotropes, polymer dispersants, pH adjusting agents and water. The composition may include two or more of a) alkyl-dicarboxylic acid; b) phosphono-carboxylic acid; c) tri(amino-carboxylic acid); d) anionic polymer dispersant; e) non-ionic surfactant; f) inorganic phosphate; g) phosphonotricarboxylic acid; and h) hydrotrope. Specifically, the composition may comprise sebacic acid, hydroxyphosphonoacetic acid, and 6,6′,6″-(1,3,5-triazine-2,4,6-triyltriimino)tris-hexanoic acid. Optionally, the composition can further comprise a co-polymer of acrylic acid and allyl-2-hydroxy-propyl-sulfonate ether (AA/AHPSE), 2-phosphono-1,2,4-butane-tricarboxylic acid, sodium phosphate monobasic or phosphoric acid, α-decyl-ω-hydroxy-poly(oxy-1,2ethanediyl), and sodium cumenesulfonate. These components are not necessary, and in some embodiments, the composition is utilized without these components. The disclosed composition exhibits comparable or better corrosion protection performance than conventional molybdate containing sterilizing products.
1. A method of sterilizing or pasteurizing a container, comprising contacting the container with a process water solution comprising:
a) an alkyl-dicarboxylic acid,
b) a phosphono-carboxylic acid,
c) tri(amino-carboxylic acid),
d) anionic polymer dispersant,
e) non-ionic surfactant,
f) inorganic phosphate,
g) phosphonotricarboxylic acid, and
h) hydrotope,
wherein said process water solution is at a temperature of about 30-150° C. and
wherein said a) alkyl-dicarboxylic acid is a member selected from the group consisting of succinic acid, adipic acid, sebacic acid, azelaic acid, fumaric acid, maleic acid, citraconic acid, itaconic acid, n-dodecenylsuccinic acid, and n-dodecylsuccinic acid and salts thereof, b) is hydroxyphosphonoacetic acid, c) is 6,6′,6″ (1,3,5-triazine-2,4,6-triyltriimino)tris hexanoic acid, d) is acrylic acid/allyl-2-hydroxy propyl sulfonate ether (AA/AHPSE), e) is α-decyl-ω-hydroxy-poly(oxy-1,2 ethanediyl), f) is monobasic NaPO 4 , and h) is sodium cumene sulfonate.
2. The method as recited in claim 1 wherein a) is sebacic acid.