Polyalkyl p-phenylenediamine anti-degradants and intermediates and preparation method thereof
A polyalkyl p-phenylenediamine antidegradant having a structure represented by Formula I, its intermediates and a preparation method thereof are provided. The polyalkyl p-phenylenediamine antidegradant provides good thermal oxidative aging resistance and UV aging resistance.
1 . A compound of Formula I:
wherein each R 1 is independently a C1-C18 chain hydrocarbon group or a C3-C18 alicyclic hydrocarbon group, a is an integer of 1 to 5, at least one of the one or more R 1 is a methyl, and when a is 1, R 1 is at para-position to —NH group, and when a is 2 to 5, one of the R 1 is at the para-position to —NH group;
R 2 , R 3 , R 4 , and R 5 are each independently H, a C1-C18 chain hydrocarbon group, or a C3-C18 alicyclic hydrocarbon group, and at least one of the R 2 , R 3 , R 4 , and R 5 is not H; and
R 6 and R 7 are each independently a C1-C18 chain hydrocarbon group or a C3-C18 alicyclic hydrocarbon group, or R 6 forms a C3-C18 aliphatic ring with R 7 .
2 . The compound according to claim 1 , wherein each R 1 is independently a C1-C8 alkyl, a is 1 or 2;
R 2 , R 3 , R 4 , and R 5 are each independently H or a C1-C8 alkyl, and two to three of R 2 , R 3 , R 4 , and R 5 are H;
R 6 and R 7 are each independently a C1-C8 alkyl or a C3-C8 cycloalkyl, or R 6 forms a C3-C8 aliphatic ring with R 7 .
3 . A method for preparing the compound of claim 1 , comprising:
(1) reacting a compound of Formula A and a compound of Formula B in a condensation reaction in presence of a first catalyst to obtain a condensate comprising a compound of Formula C, a compound of Formula C′, or both, and reducing the condensate in presence of H 2 and a second catalyst to obtain a compound of Formula II:
(2) reacting the compound of Formula II with a compound of Formula D in reductive alkylation in presence of H 2 and a third catalyst to obtain the compound of Formula I:
4 . The method according to claim 3 , wherein the first catalyst is an alkali metal hydroxide, an alkali metal alkoxide, a quaternary ammonium base, a combination of an alkali metal hydroxide and a halide of tetraalkyl ammonium, or a combination thereof.
5 . The method according to claim 3 , wherein the second catalyst is a porous metal catalyst or a supported metal catalyst.
6 . The method according to claim 5 , wherein the porous metal catalyst is Raney nickel, Raney cobalt, Raney copper, or a combination thereof.
7 . The method according to claim 5 , wherein the metal in the supported metal catalyst is nickel, cobalt, copper, platinum, palladium, ruthenium, rhodium, or a combination thereof, and
the support in the supported metal catalyst is carbon, alumina, silica gel, molecular sieve, or a combination thereof.
8 . The method according to claim 3 , wherein the third catalyst is a supported metal catalyst.
9 . The method according to claim 8 , wherein the metal in the supported metal catalyst is nickel, cobalt, copper, platinum, palladium, ruthenium, rhodium, or a combination thereof, and
the support in the supported metal catalyst is carbon, alumina, silica gel, molecular sieve, or a combination thereof.
10 . The method according to claim 3 , wherein in step (1), a molar ratio of the compound of Formula A to the compound of Formula B is 2:1 to 15:1.
11 . The method according to claim 3 , wherein in step (1), vacuum degree is −0.09 to −0.99 MPa.
12 . The method according to claim 3 , wherein in step (2), a molar ratio of the compound of Formula D to the compound of Formula II is 1:1 to 15:1.
13 . A rubber composition, comprising the compound of claim 1 .
14 . A rubber product, comprising the rubber composition of claim 13 .
15 . The rubber product according to claim 14 , wherein the rubber product is a tire.
16 . A method for improving thermal oxidative aging resistance and/or UV aging resistance of rubber or a rubber product according to claim 1 , comprising adding the compound of claim 1 to the rubber or rubber product.
17 . The compound according to claim 1 ,
wherein R 2 , R 3 , R 4 , and R 5 are each independently H, a C1-C18 chain hydrocarbon group, or a C3-C18 alicyclic hydrocarbon group, one of the R 2 , R 3 , R 4 , and R 5 is H, and other three groups of the R 2 , R 3 , R 4 , and R 5 are not H.