阅读说明：本技术 制备具有抗降解剂和抗疲劳功效的化合物的方法 (Method for preparing compound with antidegradant and antifatigue effect ) 是由 M.A.布恩 D.L.小菲尔兹 F.伊纳茨-胡佛 于 2018-05-17 设计创作，主要内容包括：本发明公开了一种制备抗降解剂化合物的方法,其中使对应于式IV的对苯二胺与对应于式II的α-羟基羰基化合物反应以由此获得烯二胺,将其还原以由此获得包含对应于式I的抗降解剂化合物的混合物。<Image he="103" wi="215" file="DEST_PATH_IMAGE002.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image><Image he="63" wi="160" file="DEST_PATH_IMAGE004.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image><Image he="135" wi="299" file="DEST_PATH_IMAGE006.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(The present invention discloses a process for the preparation of an antidegradant compound, wherein a p-phenylenediamine corresponding to formula IV is reacted with an α -hydroxycarbonyl compound corresponding to formula II to thereby obtain an enediamine, which is reduced to thereby obtain a mixture comprising an antidegradant compound corresponding to formula I.)

1. A method of making an antidegradant compound, the method comprising:

reacting p-phenylenediamine with an α -hydroxycarbonyl compound to thereby obtain an enediamine;

wherein the p-phenylenediamine corresponds to formula IV:

wherein X is selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen;

the α -hydroxycarbonyl compound corresponds to formula II:

wherein R is¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen,

and wherein R¹And R³Optionally bridged by polymethylene groups; and

reducing the enediamine to thereby obtain a mixture comprising an antidegradant compound according to formula I:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen;

wherein R is¹And R³Each independently selected from alkyl, aryl, alkaryl groups and hydrogen; and is

Wherein R is¹And R³Optionally bridged by polymethylene groups to form cycloalkyl groups.

2. The method of claim 1, wherein the para-phenylenediamine comprises 4-amino-para-phenylenediamine.

3. The method of claim 1, wherein the alpha-hydroxycarbonyl compound comprises one or more of acetoin, acetol, and benzoin.

4. The method of claim 1, wherein the a-hydroxycarbonyl compound comprises acetoin, and wherein the p-phenylenediamine and the a-hydroxycarbonyl compound are reacted in the presence of a solvent and an acid catalyst.

5. The method of claim 4, wherein the acid catalyst comprises one or more of formic acid, acetic acid, propionic acid, p-toluenesulfonic acid, camphorsulfonic acid, hydrochloric acid, sulfuric acid, phosphoric acid, and a solid-supported acidic resin.

6. The process of claim 4, wherein the solvent comprises methyl isobutyl ketone and the mixture comprising the antidegradant compound further comprises N- (1, 3-dimethylbutyl) -N' -phenyl-p-phenylenediamine.

7. The method of claim 4, wherein the solvent comprises acetone and the mixture comprising the antidegradant compound further comprises N-isopropyl-N' -phenyl-p-phenylenediamine.

8. The process of claim 1, wherein the enediamine is reduced by hydrogenation in the presence of: (a) a solvent, (b) a homogeneous or heterogeneous metal catalyst, and (c) one or more of hydrogen, formic acid, or a formate salt.

9. The process according to claim 1, wherein the steps of reacting p-phenylenediamine with an α -hydroxycarbonyl compound and of reducing the enediamine thus obtained are carried out sequentially, optionally with isolation of an intermediate diimine compound.

10. The process of claim 1, wherein the step of reacting p-phenylenediamine with an α -hydroxycarbonyl compound and the step of reducing the enediamine thus obtained are carried out simultaneously in the same reaction mixture.

11. The method of claim 1, wherein the antidegradant compound comprises N, N' - (butane-2, 3-diyl) bis (N-phenyl-benzene-1, 4-diamine).

Technical Field

The present invention generally relates to a process for preparing compounds having antidegradants and anti-fatigue efficacy that are useful as additives to vulcanized rubber articles, vulcanizable elastomeric formulations, lubricants, fuels, fuel additives, and other compositions requiring such efficacy or in compositions that may themselves be used as compositions to impart such efficacy.

Background

Many materials, such as plastics, elastomers, lubricants, cosmetics, and petroleum products (e.g., hydraulic fluids, oils, fuels, and oil/fuel additives for automotive and aerospace applications) are susceptible to degradation upon prolonged exposure to light, heat, oxygen, ozone, repeated mechanical action, and the like. Thus, compounds and compositions that exhibit efficacy as antidegradants are well known in the art. For example, U.S. patent No. 8,987,515 discloses aromatic polyamines that can be used to inhibit oxidative degradation, particularly in lubricant compositions. U.S. patent application publication No. 2014/0316163 discloses antioxidant macromolecules purportedly having improved solubility in many commercially available oils and lubricants.

Antidegradants that can be used to make articles formed from elastomers, plastics, etc., require very specific combinations of qualities that can be difficult to achieve. While antidegradants must have a significant commercially acceptable efficacy, they must also exhibit this efficacy over long periods of time associated with the use of the article, particularly at the exposed surfaces of the article where degradation by environmental factors such as light, oxygen and ozone occurs primarily. Just as it is important to protect surface exposed components, the efficacy of protecting the embedded components of the composite material from oxidative aging and repeated mechanical action is also of critical importance. Antidegradants must achieve these effects without negatively impacting the efficacy or desirable characteristics of other additives in the final article. Furthermore, antidegradants that provide or improve mechanical fatigue life after an article has been put into service, aged by oxidative aging, or aged by exposure to ozone are highly appreciated, as these antidegradants will inherently improve the useful mechanical service life of the article. Thus, elastomeric articles that undergo repeated mechanical bending, stretching, or compression during use would greatly benefit from this discovery.

Articles, particularly tires, formed from general purpose elastomers such as natural rubber are particularly susceptible to degradation by oxygen and ozone. As discussed in U.S. patent No. 2,905,654, the effect of oxygen degradation on rubber is different from the effect of ozone degradation on rubber; however, both of these effects can be detrimental to tire performance, appearance, and life expectancy. Fatigue and crack growth are also of particular concern, particularly for steel belt edge regions and tire sidewalls that are subject to significant stresses and tensile forces when bent, whether inflated, partially inflated, and over the life of the tire. U.S. patent No. 8,833,417 describes an antioxidant system which is said to increase long term resistance to fatigue and crack growth compared to known antioxidants as discussed immediately below.

Materials having efficacy as antidegradants are well known in the art for tire applications and are commercially available. For example, N, N' -disubstituted-p-phenylenediamines (e.g., Santoflex, tradename, available from Eastman Chemical Company)^®Those sold) are generally favored by many tire manufacturers for this purpose. EP patent application publication No. EP 3147321 a1 discloses a rubber composition, a tire, an amine compound and an anti-aging agent, and particularly a rubber composition purportedly suitable for tread rubber or sidewall rubber of a tire. As government regulations, market demands, and consumer expectations drive the rubber industry toward lighter weight tires to improve fuel efficiency and conserve natural resource feedstocks, there remains a continuing need for improved antidegradants, and methods of making the same, that exhibit (i) multiple efficacy against fatigue, crack growth, and various degradation mechanisms; (ii) increased efficacy, especially at lower concentrations; and (a)iii) a longer efficacy period when compared to current commercial materials.

Disclosure of Invention

In one aspect, the present invention relates to methods of making antidegradant compounds, and mixtures containing them, corresponding to formula I shown below and as further described herein. In this aspect, p-phenylenediamine is reacted with an α -hydroxycarbonyl compound to thereby obtain an enediamine;

wherein the p-phenylenediamine corresponds to formula IV:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein each X is independently hydrogen or methyl;

the α -hydroxycarbonyl compound corresponds to formula II:

wherein R is¹And R³Each independently selected from: (a) alkyl, aryl, alkaryl groups and hydrogen; or (b) butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups;

the enediamine corresponds to formula III:

wherein the variables are as described, for example, with respect to formulas IV and II above. In formula III, although the depicted structure indicates a Z conformation, we do not intend to exclude the possibility that a substantial or even major amount of E conformation is present. Thus, the invention relates to the Z conformation, the E conformation and any mixture of these two conformations.

The enediamine corresponding to formula III may then be reduced or hydrogenated to obtain a mixture comprising the antidegradant compound according to formula I:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein each X is independently hydrogen or methyl;

wherein R is¹And R³Each independently selected from: (a) alkyl, aryl, alkaryl groups and hydrogen; or (b) butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups.

In a second aspect, the present invention relates to compositions comprising a compound represented by formula I as shown above, and methods of making the same. In a further aspect, the present invention relates to antidegradant compositions and mixtures comprising the antidegradant compounds of the present invention.

In a further aspect, the present invention relates to antidegradant compositions comprising the compounds of the invention.

In another aspect, the present invention relates to lubricant compositions comprising the compounds of the present invention.

In yet another aspect, the present invention relates to vulcanizable elastomer formulations comprising the compounds of the present invention.

In yet another aspect, the present invention relates to a vulcanized elastomeric rubber article having at least one component formed from the vulcanizable elastomeric formulation of the present invention.

The compounds of the present invention have surprisingly shown efficacy as antidegradants and antifatigue agents and are therefore particularly useful for imparting resistance to crack growth, degradation, and many manifestations thereof in a variety of applications. When used as a component in vulcanizable elastomer formulations forming vulcanized rubber articles, and more particularly in vehicle tires and components thereof, the compounds of the present invention have shown a particularly desirable and surprising combined efficacy against oxidative degradation, ozonated degradation, and resistance against fatigue and crack growth, which is superior to the combinations heretofore achieved by prior art materials. Further advantages and areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the spirit and scope of the present disclosure.

Detailed Description

As used herein, the following terms or phrases are defined as follows:

an "antidegradant" refers to a material that inhibits degradation (caused by, for example, heat, light, oxidation, and/or ozonation) or its manifestation of a composition, formulation, or article to which it is added or applied.

By "anti-fatigue agent" is meant a material that, after being applied in place for a period of time (whereby the composition, formulation or article is subjected to thermal, oxidative, ozone and mechanical degradation forces), improves the flex fatigue resistance of the composition, formulation or article to which it is added or applied.

"antioxidant" refers to a material that inhibits oxidative degradation of a composition, formulation or article to which it is added or applied.

By "antiozonant" is meant a material that inhibits ozone exposure degradation of a composition, formulation or article to which it is added or applied.

"elastomer" means any polymer that can be stretched to at least twice its original length under low stress after vulcanization (or crosslinking) and at room temperature, and will recover under force to about its original length upon immediate release of the stress, including but not limited to rubber.

"vulcanizable elastomer formulation" means a composition that comprises an elastomer and is capable of being vulcanized when subjected to vulcanization conditions.

Non-limiting examples of compounds of the present invention include N, N '- (ethane-1, 2-diyl) bis (N-phenyl-1, 4-diamine) and N, N' - (butane-2, 3-diyl) bis (N-phenyl-1, 4-diamine). These are represented schematically as follows, each with reference to a respective written embodiment(s) of the manufacturing method described below:

preferred examples of compounds according to formula I of the present invention thus include N, N '- (ethane-1, 2-diyl) bis (N-phenyl-1, 4-diamine) and N, N' - (butane-2, 3-diyl) bis (N-phenyl-1, 4-diamine) as depicted above.

In one aspect, the present invention thus relates to a process for preparing antidegradant compounds, corresponding to formula I as shown above and as further described herein, and mixtures containing them. In this aspect, p-phenylenediamine is reacted with an α -hydroxycarbonyl compound to thereby obtain an enediamine;

wherein the p-phenylenediamine corresponds to formula IV:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein each X is independently hydrogen or methyl;

the α -hydroxycarbonyl compound corresponds to formula II:

wherein R is¹And R³Each independently selected from: (a) alkyl, aryl, alkaryl groups and hydrogen; or (b) butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups;

the enediamine corresponds to formula III:

wherein the variables are as described above for formulas IV and II.

The enediamine corresponding to formula III may then be reduced or hydrogenated to obtain a mixture comprising the antidegradant compound according to formula I:

wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; or wherein each X is independently hydrogen or methyl;

wherein R is¹And R³Each independently selected from: (a) alkyl, aryl, alkaryl groups and hydrogen; or (b) butyl, propyl, ethyl, methyl or hydrogen; and wherein R¹And R³Optionally bridged by polymethylene groups.

Suitable p-phenylenediamines corresponding to formula IV useful in accordance with the present invention include those wherein each X is independently selected from the group consisting of alkyl, aryl, alkaryl groups and hydrogen; particularly those in which each X is independently hydrogen or methyl, and particularly 4-amino-p-phenylenediamine.

Suitable alpha-hydroxycarbonyl compounds corresponding to formula II which may be used according to the invention include those wherein R is¹And R³Each independently selected from butyl, propyl, ethyl, methyl or hydrogen; and especially those of methyl or hydrogen. Suitable α -hydroxycarbonyl compounds also include those in which R is¹And R³Those bridged by polymethylene groups to form cycloalkyl groups. Examples of suitable α -hydroxycarbonyl compounds include acetoin, α -hydroxyacetone (acetol), and benzoin. One skilled in the art will readily appreciate that benzoin-type condensation reactions can be used to prepare a series of α -hydroxycarbonyl compounds useful in accordance with the present invention, whether or not the resulting compounds are aromatic.

The thus obtained alkylenediamines of the formula III include in particular those in which each X is independently hydrogen or methyl; and wherein R¹And R³Each selected from ethyl, methyl or hydrogen; and wherein R¹And R³Those bridged by polymethylene groups to form cycloalkyl groups.

The antidegradant compounds of the invention corresponding to formula I as described herein are obtained by reduction or hydrogenation of an enediamine corresponding to formula III, as described hereinafter.

According to the present invention, the enediamine represented by formula III may be prepared by contacting the p-phenylenediamine compound represented by formula I with the α -hydroxycarbonyl compound represented by formula II in the presence of a solvent and an acid catalyst. Preferred p-phenylenediamines include those wherein X corresponds to methyl or hydrogen, and especially hydrogen (i.e., 4-aminodiphenylamine (4-ADPA)). Preferred diols according to formula II include those wherein R¹And R³Each selected from butyl, propyl, ethyl, methyl or hydrogen, and especially those of methyl.

In preparing the enediamines of formula III according to the present invention, suitable solvents include, but are not limited to, methanol, ethanol, isopropanol and n-butanol, cyclohexane, toluene, heptane, glycol ethers, methyl acetate, ethyl acetate, butyl acetate, and mixtures thereof. Examples of acid catalysts that can be used to prepare the enediamine include, but are not limited to, formic acid, acetic acid, propionic acid, p-toluenesulfonic acid, camphorsulfonic acid, HCl, H₂SO₄、H₃PO₄And a solid supported acidic resin. The reaction temperature may be carried out at a temperature of, for example, about 0 ℃ to about 100 ℃, or 5 ℃ to 75 ℃, or 40 ℃ to 60 ℃.

According to the present invention, the antidegradant compound represented by formula I can be synthesized by reducing a precursor enediamine compound represented by formula III as just described. The reduction can be carried out in the presence of a solvent with homogeneous or heterogeneous metal catalysts in the presence of hydrogen or formic acid or formate.

The solvent may be selected from those commonly used in hydrogenation or transfer hydrogenation reactions. Examples of such solvents include, but are not limited to, methanol, ethanol, isopropanol, butanol, cyclohexane, ethylene glycol, t-butyl methyl ether, tetrahydrofuran, formic acid, acetic acid, dimethylformamide, dimethylacetamide,N-methyl pyrrolidone,N-butyl pyrrolidone, methyl acetate, ethyl acetate, butyl acetate, diethylene glycol monobutyl ether, methyl isobutyl ketone. These solvents may be used alone or in combination as a mixture. Of the solvents usedThe amount can be based on the amount of the α -hydroxycarbonyl compound represented by formula II such that the weight% of solvent is from about 1% to about 75%, or from 20% to 40%, based on the amount of α -hydroxycarbonyl compound present.

Examples of metal catalysts that may be used for hydrogenation or reduction include, but are not limited to, palladium on carbon, palladium on alumina, platinum on carbon, platinum sulfide on carbon, platinum on alumina, platinum on silica, platinum oxide, raney nickel, raney cobalt, ruthenium on carbon, ruthenium on alumina, and homogeneous metal catalysts such as tris (triphenylphosphine) rhodium (I) chloride (wilkinson catalyst).

The amount of catalyst used can be based on the amount of alpha-hydroxycarbonyl compound present, such that the weight% of catalyst based on the amount of alpha-hydroxycarbonyl compound present is from about 0.005 weight% to about 20 weight% of active catalyst, excluding water content.

The hydrogen pressure used in the catalytic hydrogenation can be from about atmospheric to about 2,000 psig, or atmospheric to 500psig, or at about atmospheric pressure. Alternatively, formic acid or formate salts can serve as a hydrogen source for the reduction.

The reaction temperature may be ambient up to 250 ℃.

Each of the above parameters can affect reaction kinetics, conversion, and selectivity. It is preferred to select the reaction conditions such that the time required for completion is from 30 minutes to 100 hours.

According to the invention, the process of the invention can also be used to prepare mixtures of antidegradant compounds. Thus, mixtures of the presently disclosed antidegradant product and an alkyl, aryl-p-phenylenediamine, such as 6PPD or IPPD, can be produced by using a ketone (e.g., MIBK or acetone, respectively) as the hydrogenation solvent. Such products may be desirable for producing antidegradant product mixtures with different migration characteristics. The reaction proceeds with hydrogenation of the diimine to form a diamine. At the same time, the ketone solvent will react with any residual 4-ADPA in the diimine starting material, any additional 4-ADPA added, and/or any 4-ADPA from the diimine hydrolysis to form alkyl, aryl, p-phenylene diamines.

It is also possible to use homogeneous or heterogeneous catalystsThe compounds of the present invention are prepared from polyol starting materials by a perhydro self-transfer procedure (for a general description of the mechanism, see, e.g., Guillena et al,Chem. Rev.2010,110, 1611). The compounds of interest can also be prepared from polycarbonyl starting materials using heterogeneous transition metal catalysts in the presence of hydrogen.

Precursors of the compounds of the present invention, the compounds of the present invention and their methods of preparation are illustrated by the following examples, which are not intended to limit the spirit or scope of the invention in any way.