WO2009073378A1

WO2009073378A1 - Industrial oil formulations containing macromolecular antioxidants

Info

Publication number: WO2009073378A1
Application number: PCT/US2008/084157
Authority: WO
Inventors: William E. Moehle; Vincent J. Gatto
Original assignee: Albemarle Corporation
Priority date: 2007-11-29
Filing date: 2008-11-20
Publication date: 2009-06-11
Also published as: TW200932897A

Abstract

This invention relates to industrial oil formulations containing at least one amine-based antioxidant and at least one macromoleeular antioxidant product.

Description

INDUSTRIAL OIL FORMULATIONS CONTAINING MACROMOLECULAR ANTIOXIDANTS

FIELD OF THE INVENTION

[0001] This invention relates to industrial oil formulations containing at least one amine-based antioxidant and at least one macromolecular antioxidant product. BACKGROUND OF THE INVENTION

[0002] It is well known that hydrocarbon based products such as industrial oils are susceptible to oxidative degradation in the presence of air or oxygen. Over the years, considerable efforts have been devoted to discovery and development of antioxidants that, when formulated with the hydrocarbon material, are capable of minimizing the degradation of hydrocarbon-based products. These efforts have revealed that the use of a phenolic antioxidant in combination with an aminic antioxidant such as alkylated diphenylamine can provide excellent deposit and varnish control. However, such systems do not always provide satisfactory oil life in the Rotating Pressure Vessel Oxidation Test ("RPVOT"). Further, the use of combinations of phenolic antioxidants and an amine antioxidants such as alkylated phenyl-alpha-naphthylamine ("APANA") can provide for a negative effect in the RPVOT test.

[0003] Figure 1 is a bar graph depicting Phenolic/ AP ANA interactions for several antioxidant combinations.

[0004] Figure 2 is a bar graph depicting RPVOT times for several antioxidants.

[0005] Figure 3 is a bar graph depicting RPVOT times for several two-component antioxidant combinations.

[0006] Figure 4 is a bar graph depicting RPVOT times for several three-component antioxidant combinations.

SUMMA^_OT TJHEjNYENJJON

[0007] The inventors hereof have unexpectedly discovered that the use of macromolecular phenol-aromatic amine reaction products in combination with an amine antioxidant provides for a synergistic effect in the RPVOT test. Thus, in some embodiments, the present invention relates to an industrial oil formulation comprising at least one base oil or base stock, at least one amine- derived antioxidant, preferably alkylated phenyl-alpha-naphthylamine ("APANA"), at least one macromolecular antioxidant product, and optionally at least one other additive commonly used in industrial oil formulations, wherein the macromolecular antioxidant product comprises one or more i) aromatic amines substituted with one 3,5~di-hydrocarbyl-4-hydroxylbenzyl groups; ii) aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; iii) aromatic amines substituted with three 3,5-di-hydrocarby]-4-hydroxylbenzyl groups; iv) aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; v) aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; and vi) aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; and vii) one or more methylene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, wherein the macromolecular antioxidant products are liquid at room temperatures or solids that melt at less than about 100⁰C and are capable of being dissolved in liquid hydrocarbon solvents, and wherein said macromolecular antioxidant product contains in the range of from about 1 to about 10 wt. % of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl.

Unless otherwise specified, "hydrocarbyl" means univalent or multivalent groups formed by removing one or more hydrogen atoms from a hydrocarbon. All the hydrocarbyl groups derived from hydrocarbons may have up to about 1 to about 20 carbon atoms (e.g., C₁-C₂₀ alkyl, C₆-C₂₀ aryl, C₇-C₂₀ alkaryl, C7-C₂₀ aralkyl) or 1 to about 12 carbon atoms (e.g., C₁-Cj₂ alkyl, C₆-Ci₂ aryl, C₇-C₁₂ alkaryl, C₇-C1₂ aralkyl), or 1 to about 8 carbon atoms, or 1 to about 6 carbon atoms. [0008] hi some embodiments, the formulations of the present invention comprise at least one amine derived antioxidant, preferably an alkylated diphenyl amine; more preferably an alkylated phenyl-alpha-naphthylamme ("APANA") and/or phenyl-alpha-naphthylamine; at least one macromolecular antioxidant product; and optionally, at least one other additive commonly used in industrial oil formulations

[0009] In some embodiments, the formulations further comprise the optional at least one additive. In some embodiments, the at least one additive is selected from dispersants, detergents, anti-wear additives, extreme pressure additives, corrosion inhibitors, rust inhibitors, friction modifiers, pour point depressants, viscosity index modifiers, emulsifiers, demulsifiers, air release agents, antistatic agents, seal swell agents, solubilizing agents, antifoam agents, acid scavengers, metal deactivators, and other antioxidants or stabilizers. [0010] Preferred macromolecular phenol-aromatic amine reaction products used in the present invention are liquid at room temperatures (about 23⁰C) or solids that melt at less than about

100⁰C, preferably about 6O⁰C, and that are capable of being dissolved in common organic solvents and especially in liquid hydrocarbon solvents.

DETAILED DESCRIPTION OF THE INVENTION

Industrial Oil

[001 1] "Industrial Oil" or "Industrial Oils" as used herein is used in it broadest sense and is meant to refer to any oil or lubricant. Non-limiting examples of industrial oils include turbine oils, gear oils, circulating oils, compressors oils, hydraulic oils, refrigeration lubes, metalworking fluids and greases, and the like. In a preferred embodiment, the industrial oil is a turbine oil or a hydraulic oil.

Base Oils Or Base Stocks

[0012] The base oils and base stocks suitable for use in producing the industrial oils of the present invention can be selected from any base oil or base stock known. Non-limiting examples of suitable base oils or base stocks include one or more, in some embodiments one, Group I, II,

III, rv and V base stocks, as defined by the API, including dibasic acid esters; polyol esters; poly alkenyl glycols; alkylated aromatics, including alkylated benzenes, alkylated napthalenes, alkylated diphenyl oxides, alkylated diphenyl sulfides and the like; naphthenics; esters; silicones; polyisobutylenes; glycols; mixtures thereof; and bio-lubricants such as, for example, those derived from i) vegetable matter such as corn, rapeseed, cotton seed, coconut, palm, the like, and combinations thereof, ii) modified vegetable oils, e.g. hydrogenated or partially hydrogenated vegetable oils, the like, and combinations thereof, and iii) combinations of bio-lubricants derived from vegetable matter and modified vegetable oils. In formulating industrial oils of the present invention, Group II (hydroprocessed) and III (severely hydroprocessed/isomerized wax) base stocks and gas to liquid base stocks such as those derived by Fischer- Tropsch processes are preferred.

API's April 2008 version of base stocks are:

Group I base stocks contain less than 90 percent saturates and/or greater than 0.03 percent sulfur and have a viscosity index greater than or equal to 80 and less than 120 using the test methods specified in Table 1. b. Group II base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have a viscosity index greater than or equal to 80 and less than 120 using the test methods specified in Table 1 . c. Group III base stocks contain greater than or equal to 90 percent saturates and less than or equal to 0.03 percent sulfur and have a viscosity index greater than or equal to 120 using the test methods specified in Table 1. d. Group IV base stocks are polyalphaolefins (PAO). e. Group V base stocks include all other base stocks not included in Group I, II, III, or TV.

Table 1 — Analytical Methods for Base Stock

Amine-derived Antioxidant

[0013] The industrial oil formulations of the present invention contain at least one, in some embodiments at least two, and in some embodiments two amine-derived antioxidants. The amine-derived antioxidant used herein can be selected from any amine antioxidant known such as aromatic amine antioxidants or hindered amine antioxidants. Non-limiting examples of suitable amine antioxidants include alkylated alpha phenyl napthylamine, diphenylamines, phenyl naphthylamines, phenothiazines, imidodibenzyls and diphenyl phenylene diamines. In some embodiments, the industrial oil formulation contains an alkylated alpha phenyl napthylamine and a diphenyl amine antioxidant, in some embodiments, an alkylated diphenyl amine. The amount of amine-derived antioxidant used in the industrial oil formulations of the present invention is generally in the range of from about 0.01 to about 3.0 weight percent, preferably in the range of from about 0.1 to about 1.0 weight percent, more preferably in the range of from about 0.15 to about 0.5 weight percent, all based on the total weight of the industrial oil formulation. If the industrial oil formulation contains APANA in combination with a diphenyl amine, the amount of APANA used relative to the amount of the diphenyl amine antioxidant is generally a ratio of about 1 part APANA to about between 0.1 to 10 parts diphenyl amine antioxidant, preferably a ratio of about 1 part APANA to about between 1 to 5 parts diphenyl amine antioxidant, more preferably a ratio of about 1 part APANA to about between 2 to 4 parts diphenyl amine antioxidant.

Macromolecular antioxidant products

[0014] The macromolecular antioxidant products used in the present invention are useful as antioxidants; thus, these macromolecular antioxidant products are sometimes referred to herein as antioxidant products, macromolecular antioxidant compositions, or macromolecular oxidation inhibitors. Preferred macromolecular antioxidant products of the present invention are compounds that are liquid at room temperatures (about 23⁰C) or solids that melt at less than about 100⁰C, preferably about 6O⁰C, and that are capable of being dissolved in common organic solvents and especially in liquid hydrocarbon solvents. In addition, in many cases these products have higher solubility in lubricants such as, for example, a base oil consisting of 50% by volume of high viscosity index 100 Neutral and 50% by volume of high viscosity index 250 Neutral such as referred to in U.S. Pat. No. 3,673,091.

[0015] The amount of macromolecular antioxidant product used in the industrial oil formulations of the present invention is generally in the range of from about 0.01 to about 5.0 weight percent, preferably in the range of from about 0.05 to about 1.0 weight percent, more preferably in the range of from about 0.1 to about 0.5 weight percent.

[0016] The macromolecular antioxidant products used in the present invention typically comprise one or more alkylated aromatic amines, and one or more alkylated aromatic amines having one or more methylene bridge(s). The macromolecular antioxidant products typically comprise one or more i) aromatic amines substituted with one 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, sometimes referred to herein as mono-alkylated aromatic amines; ii) aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, sometimes referred to herein as di- alkylated aromatic amines; iii) aromatic amines substituted with three 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, sometimes referred to herein as tri-alkylated aromatic amines; iv) aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, sometimes referred to herein as tetra- alkylated aromatic amines; v) aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, sometimes referred to herein as penta-alkylated aromatic amines; vi) aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, sometimes referred to herein as hexa-alkylated aromatic amines; and vii) one or more methyl ene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups. It is preferred that the macromolecular antioxidant products used in the present invention contain less than about 5wt.% of aromatic amines substituted with one 3,5-di- hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular antioxidant product. In other embodiments the reaction products of the present invention contain 10wt.% or less of aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, on the same basis. In still other embodiments the macromolecular antioxidant products contain 5wt.% or less of aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups and aromatic amines substituted with two 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, on the same basis. In some embodiments, the macromolecular antioxidant products of the present invention comprise greater than 40wt.%, in some embodiments greater than about 45wt.%, in other embodiments, greater than about 50wt.%, of aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, or aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, all based on the total weight of the macromolecular antioxidant product. In the above embodiments, the antioxidant products of the present invention contain in the range of from about 1 to about 20wt.%, preferably in the range of from about 1 to about 15wt,%, and most preferably in the range of about 1 to 10 wt% of one or more methylene-bridged aromatic amines substituted with one or more 3,5-di- hydrocarbyl-4-hydiOxylbenzyl groups, all based on the total weight of the macromolecular antioxidant product.

[0017] hi some embodiments, the macromolecular antioxidant products used herein can be described as comprising i) less than about 5wt.%; preferably less than about lwt.%, more preferably less than about 0.5wt.%, aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, all based on the total weight of the macromolecular antioxidant product; ii) less than about 10wt.%; preferably less than about 5wt.%, more preferably less than about lwt.%, aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, all based on the total weight of the macromolecular antioxidant product; iii) in the range of from about lwt.% to about 35 wt.%, preferably in the range of from about 5wt.% to about 25 wt.%, more preferably in the range of from about 5wt% to about 20wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, on the same basis; iv) in the range of from about 10wt% to about 65 wt.%, preferably in the range of from about 15wt% to about 60wt,%, more preferably in the range of from about 20wt% to about 55wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, on the same basis; v) in the range of from about 5wt% to about 60wt.%, preferably in the range of from about 8wt% to about 50wt.%, more preferably in the range of from about 10wt% to about 40wt.% aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, on the same basis; vi) in the range of from about 1 wt% to about 50 wt.%, preferably in the range of from about 5wt% to about 35wt.%, more preferably in the range of from about 5wt% to about 20wt.% aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, on the same basis; and vii) in the range of from about 1 to about 20 wt.%, preferably in the range of from about 1 to about 15wt.%, more preferably in the range of from about lwt% to about 10wt.% of one or more methylene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups.

[0018] The macromolecular antioxidant products also contain in the range of from about 1 to about 10 wt.%, preferably in the range of from about 1 to about 5 wt.% of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl. hi preferred embodiments, R and R' are H or a straight or branched chain, preferably branched chain, alkyl group . hi a particularly preferred embodiment R and R' are tert-butyl and the compound is 4,4'-methylenebis(2,6-di-tert- butylphenol):

[0019] In some embodiments, the macromolecular antioxidant compositions comprise one or more compounds that can be represented by the following general formula, Formula I:

wherein Ri is H or hydrocarbyl, R₂ is H or hydrocarbyl, R₃ & R₄ are 3,5-dihydrocarbyI-4- hydroxybenzyl, R₅ and R_& are H or hydrocarbyl, n is a whole number in the range of from about 0 to about 1 , p and q are whole numbers and p+q is in the range of from about 1 to about 10, and m is 1 when n=0 and m is a whole number in the range of from about 2 to about 10 whenn=l. It should be noted that in some embodiments, the macromolecular antioxidant compositions of the present invention contain more than one molecule represented by the above-described general formula, hi these embodiments, each of the one or more compounds can have the same or different constituents for R₁, R₂, R₃, R_4, R₅, and R^ and each of the one or more compounds can have the same or different values for p, q, m, and n.

[0020] In some embodiments, the macromolecular antioxidant compositions contain one or more, preferably two or more, compounds represented by the following general formulas: Formula II:

wherein R₁, R₂, R₅, and R₆ of Formula II are independently H or hydrocarbyl, R & R' are independently hydrogen or a branched or straight chain alkyl containing in the range of from about 1 to about 8 carbons, preferably in the range of from about 1 to about 4 carbon atoms, and p and q are independently whole numbers in the range of from about 1 to about 10, wherein p+q is about 10. It should be noted that if the macromolecular antioxidant compositions of the present invention contain more than one compound of Formula II, each of the compounds can have the same or different constituents for R₁, R₂, R₅, and R₆, R and R', and each of the one or more compounds can have the same or different values for p and q; and Formula III:

wherein Ri_; Ro, R₅, R₆, R, R', are the same as described above, and p and q are whole numbers and p+q is in the range of from about 1 to about 12. It should be noted that if the macromolecular antioxidant compositions of the present invention contain more than one compound of Formula III, each of the compounds can have the same or different constituents for R₁, R₂, R₅, and R₆, R and R', and each of the one or more compounds can have the same or different values for p and q.

[0021] It is also obvious to the skilled in the art that the substitution pattern shown in Formulas I, II, and III is for visual representation only and the alkyl and phenolic substitutions may take place on all the available active sites on the amine molecule. [0022] Some non-limiting examples of specific compounds represented by the above-described formulas are:

[0023] The macromolecular antioxidant products used herein preferably have boiling points at atmospheric pressure of at least about 175⁰C.

[0024] In some embodiments, the macromolecular antioxidant products can be, and preferably are, characterized as having one or more, preferably two or more, more preferably all of the following properties:

1. substantially free of unreacted aromatic amine starting material

2. substantially free of phenolic starting material

3. substantially free of aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups

4. have very low levels of aromatic amines substituted with two 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, by very low it is meant within the ranges described above

5. are rich in poly-substituted aromatic amines, by rich it is meant within the ranges described above

6. contain alkylated methylene-bridged amine phenolic macromolecules. "Substantially free" means less than 10000 ppm, or 1000 ppm or 100 ppm or 50 ppm of the material based on the total weight of the macromolecular antioxidant product.

Processes for Forming the Products of the Invention

[0025] The macromolecular reaction products used in the present invention can be formed by, for example, using as reactants:

(A) a sterically hindered 4-alkoxymethyl-2,6-dihydrocarbylphenol, preferably a sterically hindered 4-alkoxymethyl-2,6-dialkylphenol and more preferably, a 4-alkoxymethyl-2,6-di-tert- butylphenol in which the alkoxymethyl group is ethoxymethyl or methoxymethyl, and still more preferably,4-melhoxymethyl-2,6-di-tert-butylphenol; or a sterically hindered 4-hydroxymethyl- 2,6-dihydrocarbylphenol, preferably a sterically hindered 4-hydroxymethyl-2,6-dialkylphenol, and more preferably a 4-hydroxymethyl-2,6-di-tert-butylphenol and

(B) at least one aromatic amine having in the range of 1 to about 4 aromatic rings in the molecule which rings are in the form of fused rings or singly bonded rings, or both, and having at least one primary amino group (-NH₂), secondary amino group (-NHR where R is a hydrocarbyl group containing up to about 18 carbon atoms), or tertiary amino group (NR₂ where each R is π independently a hydrocarbyl group containing up to about 18 carbon atoms), and preferably at least one such primary or secondary amino group; or wherein (B) (a) has at least one replaceable hydrogen atom on a ring thereof, (b) is substituted by one or more branched chain alkyl groups each having in the range of 3 to about 24 carbon atoms and preferably, in the range of 4 to about 12 carbon atoms, and (c) optionally, has one or more additional alkyl side chains each having in the range of 1 to about 3 carbon atoms. [0026] In such processes, reactant (A) is combined with reactant (B) in the presence of (C) an alkylation catalyst, and optionally (D) an organic solvent, thus forming a reaction product that is suitable as, among other things, an antioxidant. Component (A)

[0027] The sterically hindered 4-alkoxymethyl-2,6-dihydrocarbylphenol or 4~hydroxymethyl-2,6- dihydrocarbylphenol, used as a reactant in the processes of this invention can be any of a relatively large group of compounds. The hydrocarbyl groups in the ortho positions relative to the carbon atom carrying the hydroxyl group can be any univalent hydrocarbon group with the proviso that the resultant substitution in the 2- and 6- positions provides steric hindrance to the hydroxyl group. Typically, a total of at least 4 or 5 carbon atoms in the ortho positions is required to achieve steric hindrance. Among suitable hydrocarbyl groups that can be in the ortho positions are alkyl, cyclo alkyl, alkenyl, cycloalkenyl, cycloalkylalkyl, aryl, and aralkyl in which the cyclic moieties, whether saturated or unsaturated, can in turn be alkyl substituted. The alkyl and alkenyl groups can be linear or branched. The individual hydrocarbyl groups in the ortho positions can each contain in the range of 1 to about 12 carbon atoms with the total number of carbon atoms in the ortho positions being in the range of about 4 to about 18 carbon atoms and preferably in the range of 8 to about 16 carbon atoms. 4-Alkoxymethylphenols or A- hydroxymethylphenols in which at least one of the ortho positions is substituted by a tertiaiy alkyl group are preferred. The alkoxy group can be linear or branched and can contain up to about 18 carbon atoms and preferably up to about 6 carbon atoms. Preferred are the 4- alkoxymelhyl hindered phenols in which the alkoxy group is ethoxy, and more preferably where the alkoxy group is methoxy. Branching of alkyl or alkenyl groups can occur anywhere in the alkyl or alkenyl group, including on the alpha-carbon atom of a secondary alkyl group such as isopropyl or sec-butyl, or on more remote positions such as on the beta-position in 2-ethylhexyl. Also, there can be any number of branches in the alkyl or alkenyl group, such as, for example, the four branches in a 1 ,1, 3,3-tetramethylbutyl group.

[0028] Non-limiting examples of suitable sterically hindered 4-alkoxymethyl-2,6- dihydrocarbylphenols include, 4-ethoxymethyl-2,6-diisopropylphenol, 4-methoxymethyl-2-tert- butyl-6-methylphenol, 4-butoxymethyl-2.6-di-tert-butylphenol, 4-hexadecyloxymethyl-2-tert- butyl-6-methylphenol, 4-decyloxymethyl-2-tert-butyl-6-isopropylphenol, 4-hexyloxymethyl-2- cyclohexyl-6-ethylphenol, 4-methoxymethyl-2-tert-butyl-6-phenylphenol, 4-propoxymethyl-2- benzyl-6-isopropylphenol, 4-ethoxymethyl-2,6-di-tert-butylphenol, 4-methoxymethyl-2,6-di-tert- butylphenol, 4-(2-ethylhexyloxymethyl)-2,6-di-tert-butylphenol, and analogous hindered phenolic compounds. A preferred sub-group of sterically hindered 4-alkoxymethyl-2,6-dialkylphenols are those in which one of the ortho alkyl groups is tert-butyl and the other is methyl or, more preferably, tert-butyl and in which the alkoxym ethyl group has a total of 9 carbon atoms. Particularly preferred is 4-methoxymethyl-2-tert-butyl-6-methylphenol. More especially preferred is 4-methoxymethyl-2,6-di-tert-butylphenol.

[0029] Non-limiting examples of suitable sterically hindered 4-hydroxymethyl-2,6- dihydrocarbylphenols include, 4-hydroxymethyl-2,ό-dhsopropylphenol, 4-hydroxymethyl-2-tert- butyl-6-methylphenol, 4-hydroxymethyl-2,6-di-tert-butylphenol, 4-hydroxymethyl-2-tert-butyl-6- methylphenol, 4-hydroxymethyl-2-tert-butyl-6-isopropylphenol, 4-hydroxymethyl-2-cyclohexyl- 6-ethylphenol, 4-hydroxymethyl-2-tert-butyI-6-phenylphenol, 4-hydroxymethyl-2-benzyl-6- isopropylphenol, 4-hydroxymethyl-2,6-di-tert-butylphenol, and analogous hindered phenolic compounds. A preferred sub-group of sterically hindered 4-hydroxymelhyl-2,6-dialkylphenols are those in which one of the ortho alkyl groups is tert-butyl and the other is methyl or, more preferably, tert-butyl. Particularly preferred is 4-hydroxymethyl-2-tert-butyl-6-methylphenol. In one exemplary embodiment, (A) is 4-hydroxymethyl-2,6-di-tert-butylphenol. Component (B)

[0030] In the practice of the present invention, a broad range of aromatic amines are contemplated for use in the present invention. The aryl groups can have one, two or more rings, e.g., they can be phenyl, naphthyl, etc., and can be substituted or unsubstituted. Each aryl group can have in the range of 6 to 36 or more carbon atoms depending upon the nature and degree of substitution although generally they will have from 6 to about 18 carbon atoms. Substituted diphenylamiiies wherein at least one of the rings is substituted by a branched chain alkyl group having in the range of 3 to about 24 and preferably in the range of 4 to about 12 carbon atoms illustrate substitution of this type.

[0031] Non-limiting examples of suitable aromatic amines include diphenylamine, one or a mixture of nonylated diphenyl amines prepared from, for example, propylene trimer and diphenylamine, one or a mixture of octylated diphenylamines prepared from diisobutylene and diphenylamine, one or a mixture of butylated diphenylamines prepared from isobutylene and diphenylamine, one or a mixture of styrenated diphenylamines prepared from styrene and diphenylamine, phenyl-α-naphthylamine, one or a mixture of nonylated phenyl-α-naphthylamines prepared from propylene trimer and phenyl-α-naphthylamine, one or a mixture of octylated phenyl-α-naphthylamines prepared from diisobutylene and phenyl-α-naphthylamine, one or a mixture of butylated phenyl-α-naphthylamines prepared from isobutylene and phenyl-α- naphthylamine, one or a mixture of styrenated phenyl-α-naphthylamines prepared from styrene and phenyl-α-naphthylamine, ortho -phenyl enediamine. para-phenylenediamine, N,N-di-sec- butyl-p-phenylenediamine, aniline, N-methylaniline, N,N-dimethylaniline, toluidine, N-methyl-o- toluidine, N-methyl-p-toluidine, N,N-dimethyl-o-toluidine, N,N-dimethyl-p-toluidine, 2,6- diethylaniline, 2-ethyl-6-methylamline, 2,6-diisopropylaniline, o-tert-butylaniline, triphenylamine, 2-4'-diaminobiphenyl, 4,4^l-diaminobiphenyl, 1-naphthylamine, 2-naphlhylamine, N-methyl- 1-naphthylamine, N,N-dimethyl- 1-naphthylamine, 2-ammobiphenyl, 3-aminobiphenyl, 4-amino-4'-methylbiphenyl and similar alkyl substituted or unsubstituted monoamines or polyamines, and mixtures of any two or more of the foregoing. In some embodiments, (B) is diphenylamine, and in other embodiments, (B) is one or more alkylated diphenylamines. Component (C)

[0032] In the practice of the present invention, an alkylation catalyst is used to promote the reaction between (A) and (B), thus the reaction between (A) and (B) is sometimes referred to as an alkylation reaction herein. The alkylation reaction catalyst used herein can be selected from any alkylation catalyst known to promote the reaction of (A) and (B). hi some embodiments, (C) is preferably an acidic catalyst such as sulfuric acid, an aryl sulfonic acid, an alkyl sulfonic acid, or an aryl alkyl sulfonic acid. Non-limiting examples of other suitable alkylation catalysts include, for example, hydrochloric acid, hydrobromic acid, aluminum chloride, diethyl aluminum chloride, triethylaluminum/hydrogen chloride, ferric chloride, zinc chloride, antimony trichloride, stannic chloride, boron trifluoride, acidic zeolites, acidic clays, and polymeric sulfonic acids such as those sold under the name Amberlyst©. Component (D)

[0033] The processes are carried out in a liquid reaction medium that can result from one of the reactants being a liquid under the conditions of the alkylation reaction, or which can result from use of an inert organic solvent. Non-limiting examples of organic solvents which can be used include, for example, acetic acid, propionic acid, one or more hexane isomers, one or more heptane isomers, one or more octane isomers, one or more decanes, mixtures of one or more of the alkane solvents such as the foregoing, cyclohexane, methylcyclohexane, methylene dichloride, methylene dibromide, bromochloromethane, 1,2-dichloroethane, 1,2-dibromoethane, chloroform, chlorobenzene, mixtures of one or more chlorinated and/or brominated solvents such as the foregoing, and one or a mixture of alkanols such as methyl alcohol, ethyl alcohol, isopropyl alcohol, n-propyl alcohol, n-butyl alcohol, sec-butyl alcohol, isobutyl alcohol, 2- ethylhexyl alcohol, octyl alcohol, and other liquid or low melting homologous alkanols, and one or more ethers like dialkyl ethers, tetrahydrofuran, dioxane or mixtures thereof. In some embodiments, the solvent is a hydrocarbon solvent, hi preferred embodiments, (D) is used in the practice of the present invention.

Process Conditions

[0034] The processes used to product the macromolecular reaction products of the present invention are typically conducted at one or more temperatures in the range of from about 20⁰C to about 160⁰C or higher. In some embodiments, the processes are conducted at one or more temperatures above 4O⁰C, preferably in the range of from 7O⁰C to about 16O⁰C, or higher. The inventors hereof have discovered that reaction temperatures within these ranges are more suitable for producing the reaction products of the present invention. Further, the inventors hereof have discovered that at higher temperatures, i.e. greater than 4O⁰C, the processes proceed more rapidly and thus completion can be reached in shorter periods of time than previously contemplated. For example, when 2.6~di-tert-butyl-4-methoxymethylphenol is used as (A), the reaction tends to initiate relatively rapidly at room temperature, (about 23⁰C) until about one equivalent of the 2,6- di-tert-butyl-4-methoxymethylphenol has been consumed. Thereafter, the reaction tends to proceed more slowly and consequently additional heat energy needs to be applied and/or additional catalyst employed. However, at higher temperatures, i.e. greater than 4O⁰C, this reaction proceeds more rapidly and thus completion can be reached in shorter periods of time. [0035] With lower boiling reactants and/or solvents the reaction may be conducted under pressure, or the reaction may be conducted in the presence of a cooling condenser. In most cases, the reaction results in alkylation on an activated, electron rich ring, hi some cases, alkylalion may occur on a nitrogen atom.

[0036] The inventors hereof have discovered that by varying the relative molar ratio of (A) to (B), one can produce various macromolecular reaction products, as described below, that find use as antioxidants. In some embodiments, (A) and (B) are used in a molar ratio of (B) to (A) in the range of from about 1 :1 to about 1:10, preferably in the range of from about 1 :1 to about 1:7; in some embodiments, in the range of from about 1 :3 to about 1: 10, preferably in the range of from about 1 :3 to about 1 :7. In preferred embodiments, the molar ratio of (B) to (A) can be any of about 1: 1, about 1 :2, about 1 :2.5, about 1 :3, about 1:3.5, about 1 :4, about 1:4.5, about 1 :5, about 1:5.5, about 1 :6, about 1 :6.5, or about 1 :7.

[0037] The above description is directed to several embodiments of the present invention. Those skilled in the art will recognize that other means, which are equally effective, could be devised for carrying out the spirit of this invention. It should also be noted that preferred embodiments of the present invention contemplate that all ranges discussed herein include ranges from any lower amount to any higher amount.

[0038] The following examples will illustrate the present invention, but are not meant to be limiting in any manner.

EXAMPLES EXAMPLE_1

[0039] RPVOT values are an important specification test in many industrial oil applications. We have used a statistical approach to look at the effect of different antioxidants and antioxidant combinations on a typical turbine oil formulation. This turbine oil formulation consists of 0.1 weight percent of a rust inhibitor, 0.05 weight percent of a corrosion inhibitor, 0.45 weight percent of an antioxidant or a combination of antioxidants and 99.4 weight percent of a group II base stock. Using Minitab as the statistical analysis program we have analyzed several three-way antioxidant systems consisting of a phenolic antioxidant or a macromolecular antioxidant product of the present invention with alkylated diphenylamine and APANA. In this analysis we looked at the two-way interaction term between the phenolic macromolecular antioxidant product of the present invention with APANA and we observed that the macromolecular antioxidant product of the present invention, unlike other phenolics, introduces a synergistic rather than an antagonistic interaction term with APANA. The results of this test are shown in Figure 1. EXAMPLE 2

[0040] Using the same formulations and RPVOT data from Example 1, the RPVOT data was analyzed for formulations with one, two or three antioxidants. Figure 2 was generated using this data. As shown in Figure 2, at a treat rate of 0.45 weight percent of a single antioxidant in the formulation, we found that in the RPVOT test that the performance of the macromolecular antioxidant product used in the present invention performs similaraly to conventional phenolic or alkylated diphenylamine antioxidants. It should be noted that in Figure 2 4701, 4702 and 4716 are traditional phenolic antioxidnat compositions available from the Albemarle Corporation® under the Ethanox® line of products, 438L is a nonylated diphenylamine antioxidant available from Chemtura Corporation under the Naugalube®, and AN- 126 IA is a macromolecular antioxidant product suitable for use in the present invention comprising less than about 0.5wt.%, aromatic amines substituted with one 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; about 4wt.% aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; about 22wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; about 45wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, on the same basis; about 17wt.% aromatic amines substituted with five 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, on the same basis; about 1 wt.% aromatic amines substituted with six 3,5- di-hydrocarbyl-4-hydroxylbenzyl groups, on the same basis; about 7 wt.% of one or more methylene-bridged aromatic amines substituted with more than six 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups; and about 1.6wt.% 4-methoxymethyl-2,6-di-tert-butylphenol, wherein all wt.% are based on the total weight of the macromolecular antioxidant product. EXAMPLE 3

[0041] Using the same formulations as Example 1, the RPVOT data for two-component antioxidant systems was analyzed. For the two-component systems containing APANA (at a 0.225 weight percent treat rate) and 0.225 weight percent of one of the other antioxidants (i.e. AN-1261A, 4701, 4702, 4716, or 438L), the RPVOT results are shown in Figure 3. As demonstrated in Figure 3 , AN- 1261 A, a macromolecular antioxidant product suitable for use in the present invention, provides superior performance in a two-component antioxidant system in the RPVOT test when compared to conventional antioxidants, and the performance of the macromolecular antioxidant product behaves like an amine. EXAMPLE 4

[0042] Using the same antioxidants as above, the RPVOT data for three-component antioxidant systems was analyzed. The three-component system contained about 0.15 weight percent APANA, about 0.15 weight percent 438L, and about 0.15 weight percent AN-1261 A or 4701, 4702, 4716, or 438L. This data is contained in Figure 4. As demonstrated in Figure 4, the macromolecular antioxidant product suitable for use in the present invention provides superior performance in a three-component antioxidant system in the RPVOT test when compared to conventional antioxidants.

Claims

WHAT is CLAIMED:

1) An industrial oil formulation comprising: a) at least one base oil or base stock; b) at least one amine-derived antioxidant; c) at least one macromolecular antioxidant product comprising one or more i) aromatic amines substituted with one 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; ii) aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; iii) aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; iv) aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; v) aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; and vi) aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; and vii) one or more methylene-bridged aromatic amines substituted with one or more 3,5-di- hydrocarbyl-4-hydroxylbenzyl groups, wherein the macromolecular antioxidant products are liquid at room temperatures or solids that melt at less than about 100⁰C and are capable of being dissolved in liquid hydrocarbon solvents, and wherein said macromolecular antioxidant product contains in the range of from about 1 to about 10 wt.% of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl; and, optionally, d) at least one other additive commonly used in industrial oil formulations. 2) An industrial oil formulation comprising: a) at least one base oil or base stock; b) at least one amine-dcrived antioxidant; c) at least one macromolecular antioxidant product comprising i) less than about 5 wt.% of one or more aromatic amines substituted with one 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; ii) less than about 10wt.% of one or more aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups; iii) in the range of from about lwt.% to about 35 wt.% of one or more aromatic amines substituted with three 3,5-di-hydrocarbyl- 4-hydroxylbenzyl groups; greater than 40wt.% of at least one of iv) one or more aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups aromatic amines, v) one or more aromatic amines substituted with five 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups; vi) one or more aromatic amines substituted with six 3,5-di- hydrocarbyl-4-hydroxylbenzyl groups; and vii) in the range of from about 1 to about 20wt.% of one or more methylene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, wherein all wt.% are based on the total weight of the macromolecular reaction product, said macromolecular reaction product is liquid at room temperature or solids that melt at less than about 100⁰C, and said macromolecular reaction product contains in the range of from about 1 to about 10 wt.% of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl; and, optionally, d) at least one other additive commonly used in industrial oil formulations.

3) The industrial oil formulation according to claim 2 wherein said at least one base oil or base stock is selected from Group I base stocks, Group II base stocks, Group III base stocks, Group IV base stocks, Group V base stocks, mixtures thereof, and bio-lubricants.

4) The industri al oil formulation according to claim 2 wherein said industrial oil is a turbine oil or a hydraulic oil and said at least one base oil or base stock is selected from Group II base stocks, Group III base stocks, and gas to liquid base stocks.

5) The industrial oil formulation according to claim 2 wherein said at least one amine antioxidant is alkylated phenyl-alpha-naphthylamine ("APANA").

6) The industrial oil formulation according to claim 2 wherein said at least one amine antioxidant is a combination of alkylated phenyl-alpha-naphthylamine ("APANA") and at least one alkylated diphenylamine antioxidant.

7) The industrial oil formulation according to claim 5 wherein the amount of APANA in said industrial oil formulation is in the range of from about 0.01 to about 3.0 wt.%, based on the total weight of the industrial oil formulation.

8) The industrial oil formulation according to claim 6 wherein the amount of APANA relative to the amount of said at least one alkylated diphenylamine antioxidant is in the range of from about 1 part APANA to about between 0.1 to 10 parts diphenyl amine antioxidant.

9) The industrial oil formulation according to claim 2 wherein said macromolecular antioxidant product contains less than about 5wt.% of i) and ii), based on the total weight of the macromolecular reaction product.

10) The industrial oil formulation according to claim 2 wherein said macromolecular antioxidant product is characterized as having one or more of the following properties: a) substantially free of unreacted aromatic amine starting material b) substantially free of the phenolic starting material c) substantially free of aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups.

11) The industrial oil formulation according to claim 2 wherein the macromolecular antioxidant product contains in the range of from about 1 to about 15wt.%, of vii), based on the total weight of the macromolecular reaction product.

12) The industrial oil formulation according to claim 2 wherein said macromolecular antioxidant product comprises one or more compounds represented by the following general formula, Formula I:

wherein Ri is H or hydrocarbyl, R₂ is H or hydrocarbyl, R₃ and R₄ are 3,5-dihydrocarbyl- 4-hydroxybenzyl, R₅ and R₆ are independently H or hydrocarbyl, n is an whole number in the range of from about 0 to about 1 , p and q are whole numbers and p+q is in the range of from about 1 to about 10, m is 1 when n=0 and m is a whole number in the range of from about 2 to about 10 when n=l. 3) The industrial oil formulation according to claim 2 wherein said macromolecular antioxidant product comprise one or more compounds represented by the general formulas: a) Formula II:

b) Formula HI:

wherein each Ri, R₂, R₅, and R₆ of Formulas II and III are independently H or hydrocarbyl, each R and R' are independently hydrogen or a branched or straight chain alkyl containing in the range of from about 1 to about 8 carbons; wherein each p and q of Formula II are independently whole numbers in the range of from about 1 to about 10 and p+q is about 10; each p and q of Formula III are independently whole numbers and p+q is in the range of from about 1 to about 12.

14) The industrial oil formulation according to claim 2 wherein said one or more methylene- bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups are represented by Formula II, Formula III, or Formula II and Formula III.

15) The industrial oil formulation according to claim 2 wherein said macromolecular antioxidant product comprises i) less than about 5wt.% aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl group, based on the total weight of the macromolecular reaction product; ii) less than about 1 Owt.% aromatic amines substituted with two 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; iii) in the range of from about lwt.% to about 35 wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; iv) in the range of from about 10wt% to about 65 wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; v) in the range of from about 5wt% to about 60wt.% aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; vi) in the range of from about lwt% to about 50 wt.% aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; vii)in the range of from about 1 to about 15 wt.% of one or more methyl ene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, wherein said macromolecular reaction product contains in the range of from about 1 to about 5 wt.% of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl; or i) less than about lwt.% aromatic amines substituted with one 3, 5 -di -hydrocarbyl -A- hydroxylbenzyl group, based on the total weight of the macromolecular reaction product; ii) less than about 5wt.% aromatic amines substituted with two 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; iii) in the range of from about 5wt.% to about 25 wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; iv) in the range of from about 15wt% to about 60wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; v) in the range of from about 8wt% to about 50wt.% aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; vi) in the range of from about 5wt% to about 35wt.% aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product; and vi) in the range of from about 1 to about 10wt.% of one or more methylene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of the macromolecular reaction product, wherein said macromolecular reaction product contains in the range of from about 1 to about 5 wt.% of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl;.

16) The industrial oil formulation according to claim 15 wherein said raacromolecular antioxdiant product is characterized as having one or more of the following properties: a) substantially free of unreacted aromatic amine starting material; b) substantially free of phenolic starting material; c) substantially free of aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl group; and

17) The industrial oil formulation according to claim 2, wherein said macromolecular antioxidant product contains one or more of the following compounds: a)

C)

d)

e)

f)

18) The industrial oil formulation according to claim 2 wherein said composition further comprises one or more dispersants, detergents, anti-wear additives, extreme pressure additives, corrosion inhibitors, rust inhibitors, friction modifiers, metal deactivators, pour point depressants, viscosity index modifiers, emulsifiers, demulsifϊers, air release agents, antistatic agents, seal swell agents, solubilizing agents, antifoam agents, other antioxidants or stabilizers, diluents, solvents, carrier fluids, or the like.

19) An industrial oil formulation comprising: a) at least one base oil or base stock is selected from Group I base stocks, Group II base stocks, Group III base stocks, Group IV base stocks, Group V base stocks V, as defined by the API, mixtures thereof, and bio-lubricants; b) alkylated phenyl-alpha-naphthylamine ("APANA"), and/or phenyl-alpha-naphthylamine ("PANA") and at least one alkylated diphenylamine antioxidant; c) a macromolecular antioxidant product selected from i) Antioxidant Product One, containing: less than about 5wt.% aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl group, based on the total weight of Antioxidant Product One; less than about 1 Owt.% aromatic amines substituted with two 3,5-di~hydrocarbyl-4- hydroxylbenzyl groups, based on the total weight of Antioxidant Product One; in the range of from about lwt.% to about 35 wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product One; in the range of from about 10wt% to about 65 wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product One; in the range of from about 5wt% to about 60wt.% aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product One; in the range of from about 1 wt% to about 50 wt.% aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product One; in the range of from about 1 to about 20wt.% of one or more methylene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product One, wherein Antioxidant Product One contains in the range of from about 1 to about 10 wt.% of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl; or ii) Antioxidant Product Two, containing less than about lwt.% aromatic amines substituted with one 3,5~di-hydrocarbyl-4- hydroxylbenzyl group, based on the total weight of Antioxidant Product Two; less than about 5 wt.% aromatic amines substituted with two 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, based on the total weight of Antioxidant Product Two; in the range of from about 5 wt.% to about 25 wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product Two: in the range of from about 15wt% to about 60wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product Two; in the range of from about 8wt% to about 50wt.% aromatic amines substituted with five 3,5~di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product Two; in the range of from about 5wt% to about 35wt.% aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product Two; and in the range of from about 1 to about 20wt.% of one or more methylene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product Two, wherein Antioxidant Product Two contains in the range of from about 1 to about 10 wt. % of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl; and, optionally, d) one or more additive(s) selected from one or more dispersants, detergents, anti-wear additives, extreme pressure additives, corrosion inhibitors, rust inhibitors, friction modifiers, metal deactivators, pour point depressants, viscosity index modifiers, emulsifϊers, demulsifiers, air release agents, antistatic agents, seal swell agents, solubilizing agents, antifoam agents, other antioxidants or stabilizers, diluents, solvents, carrier fluids, or the like.

20) The industrial oil formulation according to claim 19 wherein said macromolecular antioxidant product comprises one or more compounds represented by the following general formula, Formula I:

wherein R[ is H or hydrocarbyl, R₂ is H or hydrocarbyl, R₃ and R₄ are 3,5-dihydrocarbyl-4- hydroxybenzyl, R₅ and R₆ are independently H or hydrocarbyl, n is an whole number in the range of from about 0 to about 1 , p and q are whole numbers and p+q is in the range of from about 1 to about 10, m is 1 when n=0 and m is an whole number in the range of from about 2 to about 10 when n=l .

21) The industrial oil formulation according to claim 20, wherein said macromolecular antioxidant product contains one or more of the following compounds:

d)

0

22) The industrial oil formulation according to claim 19 wherein said macromolecular antioxidant product contains substantially no aromatic amines substituted with one 3,5-di- hydrocarbyl-4-hydroxylbenzyl group or substantially no aromatic amines substituted with one 3,5-di-hydrocarbyl-4-hydroxylbenzyl group and substantially no aromatic amines substituted with two 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups. 23) An industrial oil formulation comprising: a) at least one base oil or base stock; b) alkylated phenyl-alpha-naphthylamine ("APANA"), and/or phenyl-alpha- naphthylamine("PANA") and at least one alkylated diphenylamine antioxidant; c) a macromolecular antioxidant product selected from i) Antioxidant Product One, containing: less than about 5wt.% aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl group, based on the total weight of Antioxidant Product One; less than about 10wt.% aromatic amines substituted with two 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, based on the total weight of Antioxidant Product One; in the range of from about lwt.% to about 35 wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product One; in the range of from about 1 Owt% to about 65 wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product One; in the range of from about 5wt% to about 60wt.% aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product One; in the range of from about 1 wt% to about 50 wt.% aromatic amines substituted with six 3, 5 -di -hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

wherein each R and R' are independently H or a hydrocarbyl; or ii) Antioxidant Product Two, containing less than about lwt.% aromatic amines substituted with one 3,5-di-hydrocarbyl-4- hydroxylbenzyl group, based on the total weight of Antioxidant Product Two; less than about 5wt.% aromatic amines substituted with two 3,5-di-hydrocarbyl-4- hydroxylbenzyl groups, based on the total weight of Antioxidant Product Two; in the range of from about 5wt.% to about 25 wt.% aromatic amines substituted with three 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product Two; in the range of from about 15wt% to about 60wt.% aromatic amines substituted with four 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product Two; in the range of from about 8wt% to about 50wt.% aromatic amines substituted with five 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product Two; in the range of from about 5wt% to about 35wt.% aromatic amines substituted with six 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of

Antioxidant Product Two; and in the range of from about 1 to about 20wt.% of one or more methylene-bridged aromatic amines substituted with one or more 3,5-di-hydrocarbyl-4-hydroxylbenzyl groups, based on the total weight of Antioxidant Product Two, wherein Antioxidant Product Two contains in the range of from about 1 to about 10 wt.% of one or more phenolics represented by the following general formula:

wherein each R and R' are independently H or a hydrocarbyl; and, optionally, one or more additive(s) selected from one or more dispersants, detergents, anti-wear additives, extreme pressure additives, corrosion inhibitors, rust inhibitors, friction modifiers, metal deactivators, pour point depressants, viscosity index modifiers, emulsifiers, demulsifiers, air release agents, antistatic agents, seal swell agents, solubilizing agents, antifoam agents, other antioxidants or stabilizers, diluents, solvents, carrier fluids, or the like, wherein said industrial oil is a turbine oil or a hydraulic oil and said at least one base oil or base stock is selected from Group II base stocks, Group III base stocks, gas to liquid base stocks, and mixtures thereof.