Modified alkylphenol-aldehyde resins stabilized by a salicylic acid
View Patent ↗The invention relates to a process for improving the stability of a base-modified alkylphenol-aldehyde resin (such as an amine-modified alkylphenol-aldehyde resin). The process comprises the step of reacting a base-modified alkylphenol-aldehyde resin with a salicylic acid to stabilize the base-modified alkylphenol-aldehyde resin. The invention also relates to a modified alkylphenol-aldehyde resin formed from the stabilizing process, and its use in a tackifier composition and rubber composition.
1. A modified alkylphenol-aldehyde resin with improved stability prepared by reacting a salicylic acid with an amine-modified alkylphenol-aldehyde resin of formula (I)
wherein the salicylic acid forms a salt that plasticizes the resin, and
wherein
R 1 is a linear, branched, or cyclic C 1 -C 30 alkyl;
R 2 is —CHR 4 R 5 ;
R 3 is H, R 2 , —CHR 4 OH, or a mixture of H, R 2 , or —CHR 4 OH;
R 4 and R 4′ each are independently H or linear, branched or cyclic C 1 -C 8 alkyl;
R 5 is NR′R″, wherein R′ and R″ are independently H, C 1 -C 6 alkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, aryl, hydroxyl C 1 -C 6 alkyl, carboxy C 1 -C 6 alkyl, or R′ and R″ together form a 5-to 7-membered nitrogenous heterocyclic ring; and
m plus n is at least 1.
2. The modified alkylphenol-aldehyde resin of claim 1 , wherein R 5 is morpholinyl.
3. The modified, hydrocarbylphenol-aldehyde resin of claim 1 , wherein R 1 is a straight or branched C 1 -C 15 alkyl.
4. The modified, hydrocarbylphenol-aldehyde resin of claim 1 , wherein R 1 is tertiary butyl or tertiary octyl.
5. A rubber composition comprising:
the modified alkylphenol-aldehyde resin of claim 1 , and
a natural rubber, a synthetic rubber or a mixture thereof.
6. The rubber composition of claim 5 , wherein R 5 is morpholinyl.
7. The rubber composition of claim 5 , wherein R 1 is a straight or branched C 1 -C 15 alkyl.
8. The rubber composition of claim 7 , wherein R 1 is tertiary butyl or tertiary octyl.
9. The rubber composition of claim 5 , wherein said rubber composition is a natural rubber composition, a natural rubber/polybutadiene rubber blend, a styrene butadiene rubber/butadiene rubber blend or a styrene butadiene rubber/natural rubber blend.
10. A tire comprising the rubber composition of claim 5 .
11. The modified alkylphenol-aldehyde resin of claim 1 , wherein the amine-modified alkylphenol-aldehyde resin is prepared from a high-purity alkylphenol.