KR101470600B1 - N-(4-minophenyl)benzoquinone-diimine using anti-aging agent for rubber, and process for preparing thereof - Google Patents

Abstract

The present invention relates to N- (4-aminophenyl) benzoquinone-diimine compounds useful as rubber aging inhibitors and a process for their preparation. The N- (4-aminophenyl) benzoquinone-diimine compound is a novel compound comprising two imine groups and one amine group, and is included as an additive in rubber formulations to provide excellent anti-aging properties, low toxicity and non- Respectively.

Description

(4-aminophenyl) benzoquinone-diimine compound useful as an anti-aging agent for rubber and a process for preparing the same,

The present invention relates to N- (4-aminophenyl) benzoquinone-diimine compounds useful as rubber aging inhibitors and a process for their preparation.

The causes of aging of rubber include oxygen, ozone, heat, ultraviolet rays, and moisture. Ozone antioxidants are used to prevent surface cracking by ozone when exposed to air containing ozone while the rubber product is stretched. do. Such an antioxidant may use one type of antioxidant when used in rubber products, but generally, two or more kinds of antioxidants are selectively used to improve the life of the rubber product due to various aging causes.

Such rubber antioxidants are mainly amine-based antioxidants, but they are often converted to other forms by themselves or by various factors due to their chemical structural properties, which often leads to undesirable colors.

N-phenyl-N '- (1,3-dimethylbutyl) -p-phenylenediamine (hereinafter referred to as 6PPD) represented by the following formula a is the most commonly used amine-based antioxidant. 6PPD has excellent antioxidation properties in a flexed state, but browning phenomenon which is brown when aging occurs easily, and consumers tend to avoid discoloration products irrespective of product performance.

(A)

Further, 4,4'-bis (alkylamino) diphenylamine (hereinafter referred to as BAADA) represented by the following formula (b) is known as an amine-based antioxidant. BAADA is more aggressive than 6PPD, has low toxicity and reduced browning, but tends to discolor to black rather than brown as it ages.

[Formula b]

(Wherein R ₁ and R ₂ are the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a thiol group, a cyano group, a linear or branched C ₁ -C ₁₀ alkyl group, a C ₅ -C ₁₀ cyclo An alkyl group, a C ₂ -C ₁₀ alkenyl group, a C ₁ -C ₁₀ alkoxy group, a C ₅ -C ₁₅ aryl group, a C ₆ -C ₁₅ aralkyl group, a five- to seven-membered heterocycloalkyl group, a heteroaryl group, C ₂ -C ₁₅ alkyl carbonyl, C ₆ -C ₁₅ aryl carbonyl, carbamoyl pushing, a carboxylic acid group, C ₁ -C ₁₀ alkyl ester group, C ₂ -C ₁₀ alkyl ether group, C ₂ It is selected from the group -C ₁₀ ketone, C ₁ -C ₁₀ hydroxyalkyl group, the group consisting of C ₁ -C ₁₀ alkylthio group)

Further, N-phenyl-N'-alkyl-2,5-cyclohexadiene-1,4-diimine (hereinafter referred to as 'N-phenylbenzoquinone-diimine' Weak) is known. N-phenylbenzoquinone-diimine has an effect of improving discoloration and low toxicity, but has a problem of reducing the effect as a rubber aging inhibitor.

(C)

(In the above formula (c), R ₃ is the same as R ₂ defined above)

Meanwhile, in the case of the N-phenylbenzoquinone-diimine compound represented by the above formula (c), the corresponding amine compound is prepared through an imidization reaction. Methods for carrying out the above-mentioned imination reaction in the presence of a catalyst have been reported in several documents. For example, U.S. Patent No. 5,189,218 discloses that manganese, copper, cobalt and nickel are used as catalysts in the oxidation reaction of converting N- (4-hydroxyphenyl) aniline into N-phenylbenzoquinone-diimine. Also, International Patent Publication No. WO98 / 22805 discloses a process for producing N-phenylbenzoquinone-diimine by reacting 6PPD with a Pt / C or Pd / C catalyst in the presence of hydrogen peroxide.

As described above, 6PPD, BAADA, N-phenylbenzoquinone-diimine and the like are known as rubber aging inhibitors, but they can not simultaneously satisfy antioxidation performance, low toxicity and non-discoloring property.

It is an object of the present invention to provide a novel compound of N- (4-aminophenyl) benzoquinone-diimine which is added to rubber compounds to simultaneously satisfy antioxidation performance, low toxicity and non-discoloring property.

The present invention also provides a process for preparing an N- (4-aminophenyl) benzoquinone-diimine compound.

The present invention also provides a use of an N- (4-aminophenyl) benzoquinone-diimine compound as a rubber aging inhibitor.

In order to solve the above problems, the present invention is characterized by an N- (4-aminophenyl) benzoquinone-diimine compound represented by the following formula (1).

[Chemical Formula 1]

(Wherein R ₁ and R ₂ are the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a thiol group, a cyano group, a linear or branched C ₁ -C ₁₀ alkyl group, a C ₅ -C ₁₀ cyclo An alkyl group, a C ₂ -C ₁₀ alkenyl group, a C ₁ -C ₁₀ alkoxy group, a C ₅ -C ₁₅ aryl group, a C ₆ -C ₁₅ aralkyl group, a five- to seven-membered heterocycloalkyl group, a heteroaryl group, C ₂ -C ₁₅ alkyl carbonyl, C ₆ -C ₁₅ aryl carbonyl, carbamoyl pushing, a carboxylic acid group, C ₁ -C ₁₀ alkyl ester group, C ₂ -C ₁₀ alkyl ether group, C ₂ It is selected from the group -C ₁₀ ketone, C ₁ -C ₁₀ hydroxyalkyl group, the group consisting of C ₁ -C ₁₀ alkylthio group)

The present invention also relates to a process for preparing a 4,4'-bis (alkylamino) diphenylamine compound represented by the following formula (2) in the presence of an oxidizing agent to obtain N- (4-aminophenyl) benzoquinone-di And a method for producing an imine compound.

(2)

[Chemical Formula 1]

(In the above formula (1) or (2), R ₁ and R ₂ are as defined above)

Further, the present invention is characterized in that the N- (4-aminophenyl) benzoquinone-diimine compound represented by Formula 1 is a rubber aging inhibitor.

The N- (4-aminophenyl) benzoquinone-diimine compound according to the present invention is used as an anti-aging agent for rubber compounds such as tires and has an effect of extending the service life of the product.

For example, 6PPD, which is a typical amine-based anti-aging agent, easily develops brownish browning phenomenon, and BAADA tends to discolor to black although the degree of color discoloration is weak. However, when the compound represented by the following formula (1) according to the present invention is used as an antioxidant for rubber, it satisfies both excellent antioxidant ability, low toxicity and non-discoloring property.

The present invention relates to N- (4-aminophenyl) benzoquinone-diimine compounds useful as non-fouling amine-based antioxidants.

The N- (4-aminophenyl) benzoquinone-diimine compound according to the present invention comprises two imine (= N-) groups and one amine (-NH-) group. The imine (= N-) group contained in the molecular structure can cause a crosslinking reaction with the double bond of the rubber (NR, HBR, SBR etc.) during vulcanization of the rubber compound to bond firmly to the polymer chain through chemical bonding , Thereby significantly reducing the blooming to the surface of the rubber compound, thereby significantly improving the properties of environmentally friendly and low toxicity. In addition, the amine (-NH-) group contained in the molecular structure can rapidly exhibit the effect of preventing the aging by radicals and ozone binding directly to the polymer chain.

As the anti-aging agent reported so far, 6PPD or BAADA can not be chemically crosslinked with the rubber compound due to the presence of only two amine (-NH-) groups, and N-phenylbenzoquinone-diimine has two imines (= N -) group, the effect as a rubber aging inhibitor was inevitably reduced. On the contrary, the compound represented by the above formula (1) proposed by the present invention has a novel structure which simultaneously contains an amine (-NH-) group and an imine (= N-) group, , And is useful as a non-polluting antioxidant that satisfies even low toxicity and non-discoloration.

Hereinafter, the present invention will be described in detail.

The N- (4-aminophenyl) benzoquinone-diimine compound according to the present invention can be represented by the following general formula (1).

[Chemical Formula 1]

(In Formula 1, R ₁ and R ₂ are each the same or different as in the formula b, R ₁ and R ₂ are the same or different and represents hydrogen atom, a halogen atom, a hydroxyl group, a thiol group, a cyano group, a linear Or a branched C ₁ -C ₁₀ alkyl group, a C ₅ -C ₁₀ cycloalkyl group, a C ₂ -C ₁₀ alkenyl group, a C ₁ -C ₁₀ alkoxy group, a C ₅ -C ₁₅ aryl group, a C ₆ -C ₁₅ aralkyl group, A 5- to 7-membered heterocycloalkyl group, a 5- to 7-membered heteroaryl group, a C ₂ -C ₁₅ alkylcarbonyl group, a C ₆ -C ₁₅ arylcarbonyl group, a carbamoyl group, a carboxylic acid group, a C ₁ -C It is selected from the _10-alkyl ester group, C ₂ -C ₁₀ alkyl ether group, C ₂ -C ₁₀ ketone group, C ₁ -C ₁₀ hydroxyalkyl group, the group consisting of C ₁ -C ₁₀ alkylthio group)

Preferably, in the N- (4-aminophenyl) benzoquinone-diimine compound represented by Formula 1, R ₁ and R ₂ are the same or different from each other and each represents a hydrogen atom, a methyl group, Ethyl, 3-methylpentyl, 1-methylheptyl, cyclobutyl, cyclopentyl, cyclopentyl, cyclohexyl, cyclohexyl, A cyclohexyl group, a cyclohexyl group, a cyclohexyl group, a cyclohexyl group, a cyclohexyl group, a cyclohexyl group, an isopropyl group, a cyclohexyl group, a cyclohexyl group, an isopropyl group, , 2-benzoxazolyl, 2-pyridyl, 2-pyrimidinyl, 2,5-thiadiazolyl, 2-pyrazinyl, adiphenyl, glutaryl, succinyl, malonyl, Acryloyl group, methacryloyl group, caproyl group, 3-mercaptopropionyl group, benzoyl group, phthaloyl group, terephthaloyl group, aminocarbonyl group, Group, a carbonyl group, a formyl group the compound.

More preferably, in the N- (4-aminophenyl) benzoquinone-diimine compound represented by Formula 1, R ₁ and R ₂ are the same or different from each other and each represents a hydrogen atom, a C ₁ -C ₁₀ alkyl group, ₅ are those compounds -C ₁₀ cycloalkyl group, or a phenyl group.

Particularly preferably, in the N- (4-aminophenyl) benzoquinone-diimine compound represented by the above formula (1), R ₁ and R ₂ are simultaneously 1,3-dimethylbutyl groups.

The present invention also relates to a process for preparing an N- (4-aminophenyl) benzoquinone-diimine compound represented by the above formula (1).

According to the production process of the present invention, a 4,4'-bis (alkylamino) diphenylamine compound represented by the following formula 2 is subjected to an imidation reaction to obtain N- (4-aminophenyl) benzoic acid represented by the following formula Quinone-diimine compound.

(2)

[Chemical Formula 1]

(In the above formula (1) or (2), R ₁ and R ₂ are as defined above)

The imidization reaction may be carried out in the presence of an appropriate catalyst and an oxidizing agent.

The catalyst used in the imidization reaction of the present invention is a metal containing the transition metal of periodic table IB, IIB, VB, VIB, VIIB and VIII, and is in the ionic form or metal salt form of the corresponding metal. These metals may be used alone or in combination of two or more metals. More specifically, it is preferable to use a metal such as V, Nb, Ta, Cr, Mo, W, Mn, Tc, Re, Fe, Ru, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Hg can be used. These metals may also be used in the form of supported catalysts such as Pd / C, Pt / C, Ni / Al, Ru / C, Rh / Examples of preferred catalysts include Pt / C, Pd / C, Rh / C, Ru / C, oxidant 2 (II) nickel, carbon cobalt phthalocyanine, and silver oxide (AgO). Examples of particularly preferable catalysts include Pt / C, Pd / C, Rh / C, and Ru / C, but the present invention is not limited thereto. The reaction can be carried out smoothly even if a small amount of the catalyst is added in a catalytic amount. If the amount is limited, the catalyst may be used in an amount of 0.01 to 1 equivalent based on the compound represented by the formula (2).

The oxidizing agent used in the imination reaction of the present invention is selected from the group consisting of hydrogen peroxide, sulfuric acid peroxide, and hydrogen peroxide. The oxidizing agent is used in an amount of 1 to 4 equivalents, preferably 1.5 to 2.5 equivalents, based on the compound represented by the formula (2) used as a starting material. If the amount of the oxidizing agent is less than the above range, the yield of the desired imine compound is low and unreacted starting materials remain in excess. Use of an excessive amount of the oxidizing agent in an amount exceeding the above range is not preferable because it is not economical and may cause side reactions. As the oxidizing agent, hydrogen peroxide is preferably used in a concentration of 5 to 85% by weight, more preferably 10 to 35% by weight.

In the emulsification reaction of the present invention, water, an organic solvent, or a mixed solvent thereof may be used as a reaction solvent. It is preferable to use an organic solvent containing water alone or water. Examples of the organic solvent that can be used for the immobilization reaction of the present invention include alcohols such as methanol, ethanol, propanol, butanol, and cyclohexanol; Ketones such as acetone, cyclohexanone, methyl isobutyl ketone, 5-methyl-2-hexanone and methyl ethyl ketone; Aliphatic and aromatic hydrocarbons such as hexane, heptane, toluene and xylene; Nitriles such as acetonitrile; Halogenated solvents such as chloroform, dichloromethane and carbon tetrachloride; Water-soluble solvents such as dimethyl sulfoxide, N-methyl-2-pyrrolidone, sulfolane, and dimethylformamide; Esters such as ethyl acetate; Ethers such as tetrahydrofuran and 1,4-dioxane; Or a mixed solvent of two or more kinds can be used.

The initial BAADA concentration of the BAADA represented by Formula 2 used as a starting material is maintained in the range of 10 to 80% w / v, preferably 25 to 50% w / v.

The temperature of the emigration reaction of the present invention may vary depending on the solvent used, but it is preferably maintained in the range of 0 ° C to 100 ° C, preferably in the range of 25 ° C to 70 ° C.

The present invention will now be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1. Preparation of N- (4-aminophenyl) benzoquinone-diimine compound

100 g (0.272 mol) of 4,4'-bis (1,3-dimethylbutylamino) diphenylamine (hereinafter abbreviated as BAADA-6C), 1000 ml of methanol, 40 ml of water and 3% Pt / C catalyst 5 g was introduced into the autoclave. The reaction mixture was stirred and the autoclave was purged with oxygen and then charged with 30 psig oxygen at 20-25 [deg.] C. The reaction mixture was heated to 50 < 0 > C and held at 50 < 0 > C until the reaction was complete. As the reaction progressed, the reaction was continued until the oxygen pressure dropped and there was almost no pressure change, and then an additional 1 hour reaction was performed. The total reaction time was completed in about 4 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, the pressure was released, and the catalyst was filtered. The filtered catalyst can be reused for subsequent reactions after washing. The filtrate was concentrated under reduced pressure to obtain 98 g (95%) of a product having a purple color.

The obtained product was analyzed by liquid chromatography (LC), and it was analyzed as 95% of the quinone diimine compound of BAADA-6C and 5% of the unreacted BAADA-6C. Further, analysis using a hydrogen nuclear magnetic resonance analyzer (Bruker, 600 MHz NMR) revealed that NH peaks (隆 2.4 (singlet), 隆 4.6 (singlet)) of the specific peak of BAADA- And a specific peak (δ7.1 (doublet, 1H) corresponding to the double bond of the quinone diimine compound of BAADA-6C is newly generated, whereby BAADA-6C is converted into quadrenedimine of BAADA-6C .

Example 2

200 g of acetonitrile was added to 100 g of BAADA-6C to dissolve in a 1 L reactor equipped with a stirrer. The internal temperature of the reactor was heated to 35 占 폚, 2 g of catalyst 3% Pt / C was added, and 50 g of 30% hydrogen peroxide was added dropwise for 30 minutes. The reaction was stirred for an additional 30 minutes and filtered to remove the catalyst. The filtrate was concentrated under reduced pressure to obtain 97 g (93%) of the product. The obtained product was analyzed by liquid chromatography (LC) and analyzed as 93% of the quinone diimine compound of BAADA-6C and 5% of the unreacted BAADA-6C.

Example 3

In a 1 L reactor equipped with a stirrer, 200 g of N, N-dimethylformamide (DMF) was added to 100 g of BAADA-6C to dissolve it. The internal temperature of the reactor was heated to 35 占 폚, 2 g of catalyst 3% Pt / C was added, and 50 g of 30% hydrogen peroxide was added dropwise for 30 minutes. The reaction was stirred for an additional 30 minutes and filtered to remove the catalyst. The filtrate was concentrated under reduced pressure to obtain 97 g (93%) of the product. The obtained product was analyzed by liquid chromatography (LC) and analyzed as 93% of the quinone diimine compound of BAADA-6C and 5% of the unreacted BAADA-6C.

Example 4

300 g of heptane was dissolved in 100 g of BAADA-6C in a 1 L reactor equipped with a stirrer. The internal temperature of the reactor was heated to 35 占 폚, 2 g of catalyst 3% Pt / C was added, and 50 g of 30% hydrogen peroxide was added dropwise for 30 minutes. The reaction was stirred for an additional 30 minutes and filtered to remove the catalyst. The filtrate was concentrated under reduced pressure to obtain 96 g (91%) of the product. The obtained product was analyzed by liquid chromatography (LC), and it was analyzed as 91% of the quinone diimine compound of BAADA-6C and 7% of unreacted BAADA-6C.

Claims (7)

delete An N- (4-aminophenyl) benzoquinone-diimine compound represented by the following formula (1).
[Chemical Formula 1]

(Wherein R ₁ and R ₂ are the same or different and are a linear or branched C ₁ -C ₁₀ alkyl group or a C ₅ -C ₁₀ cycloalkyl group)
3. The method of claim 2,
Wherein R < ₁ > and R < ₂ > are 1,3-dimethylbutyl groups.
(4-aminophenyl) benzoquinone-diimine compound represented by the following formula (1).
[Chemical Formula 1]

(Wherein R ₁ and R ₂ are the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a thiol group, a cyano group, a linear or branched C ₁ -C ₁₀ alkyl group, a C ₅ -C ₁₀ cyclo An alkyl group, a C ₂ -C ₁₀ alkenyl group, a C ₁ -C ₁₀ alkoxy group, a C ₅ -C ₁₅ aryl group, a C ₆ -C ₁₅ aralkyl group, a five- to seven-membered heterocycloalkyl group, a heteroaryl group, C ₂ -C ₁₅ alkyl carbonyl, C ₆ -C ₁₅ aryl carbonyl, carbamoyl pushing, a carboxylic acid group, C ₁ -C ₁₀ alkyl ester group, C ₂ -C ₁₀ alkyl ether group, C ₂ It is selected from the group -C ₁₀ ketone, C ₁ -C ₁₀ hydroxyalkyl group, the group consisting of C ₁ -C ₁₀ alkylthio group)
(4-aminophenyl) benzoquinone represented by the following general formula (1), which is produced by the imidation reaction of a 4,4'-bis (alkylamino) diphenylamine compound represented by the following general formula Preparation method of diimine compound:
(2)

[Chemical Formula 1]

(Wherein R ₁ and R ₂ are the same or different and each represents a hydrogen atom, a halogen atom, a hydroxyl group, a thiol group, a cyano group, a linear or branched C ₁ -C ₁₀ alkyl group, a C ₅ -C ₁₀ cycloalkyl group, C ₂ -C ₁₀ alkenyl group, C ₁ -C ₁₀ alkoxy, C ₅ -C ₁₅ aryl group, C ₆ -C ₁₅ aralkyl group, 5 heterocycloalkyl group of each square to 7, each of 5 to 7 A C ₂ -C ₁₅ alkylcarbonyl group, a C ₆ -C ₁₅ arylcarbonyl group, a carbamyl group, a carboxylic acid group, a C ₁ -C ₁₀ alkyl ester group, a C ₂ -C ₁₀ alkyl ether group, A C ₂ -C ₁₀ ketone group, a C ₁ -C ₁₀ hydroxyalkyl group, a C ₁ -C ₁₀ thioalkyl group,
6. The method of claim 5,
Wherein the imidization reaction is carried out in the presence of a catalyst selected from the group consisting of Pd / C and Pt / C and an oxidizing agent selected from the group consisting of hydrogen peroxide, sulfuric acid peroxide, and hydrogen peroxide.
6. The method of claim 5,
Wherein the immobilization reaction is carried out using an organic solvent containing water or water.