Naphthylmethylquinone compounds, and preparation method and application thereof

Abstract

The present application relates to naphthyl methylene quinone compounds, and preparation method and application thereof, the naphthyl methylene quinone compound has the structural formula of formula I, wherein R1 and R2 are each independently H, C 1‑18 Alkyl or C 1‑18 Cycloalkyl; R3 is H, C 1‑3 Alkyl, C 1‑3 Alkoxy, hydroxyl, nitro or carboxyl.The naphthyl methylene quinone compound of the present application has extended electronic delocalization, which is beneficial to disperse free radicals, makes the structure stable, and plays a role in the termination of free radical reaction chain.The polymerization inhibitor composition containing the naphthyl methylene quinone compound provided by the present application has excellent polymerization inhibition performance, and can be used in the industrial device for inhibiting the polymerization of double bond polymerization monomers.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of synthesis and application of organic compounds, and particularly relates to a naphthyl methylene quinone compound for styrene polymerization inhibition, and a preparation method and application thereof. BACKGROUND

[0002] Styrene is an important chemical raw material, which is used to produce a variety of chemical products closely related to the national economy and people's livelihood, such as polystyrene, styrene-acrylonitrile copolymer resin, styrene-butadiene rubber, styrene block copolymer and unsaturated resin, etc. At present, the main production processes of styrene are ethylbenzene dehydrogenation process, ethylbenzene co-oxidation process, and styrene extraction process of ethylene cracking gasoline. Styrene contains a living double bond, which can slowly self-polymerize at room temperature, and the self-polymerization rate rapidly increases with temperature. In various process of styrene production, the temperature in the separation tower can be as high as about 140℃, and the self-polymerization is serious, which not only consumes raw materials, but also blocks the device, seriously affecting production and safety.

[0003] In order to prevent the self-polymerization of unsaturated hydrocarbons such as styrene, inhibitors or retarders are added to prevent or slow down the polymerization of unsaturated hydrocarbons. The retarder is divided into inhibitor and retarder, and the currently used retarder contains nitro group, such as 2-sec-butyl-4,6-dinitrophenol (DNBP), which has high toxicity and serious environmental pollution. In the case of increasing attention to environmental problems, quinone methyl retarders are favored because they only contain C, H and O, and methylene quinone is an important type thereof.

[0004] US20120316369A1 discloses the use of a methylene quinone compound, which has the structure of 2,6-dialkyl-7-substituted quinone methyl compound (QM), and when QM is used in combination with inhibitor diimide, the polymerization inhibition effect on styrene monomer is obvious at an experimental temperature of 130℃.

[0005] The retarder for styrene polymerization inhibition needs to have certain thermal stability, which can reduce unnecessary loss in industrial application. The compound with unsubstituted methylene group as a styrene polymerization inhibitor has obvious thermal instability in practical application. SUMMARY

[0006] The purpose of the present application is to provide a stable naphthyl methylene quinone compound, which has low toxicity, is friendly to the environment, and has high thermal stability, and to provide a combination of such compounds, which is used in combination with stable free radical compounds to reduce or inhibit the thermal initiation self-polymerization of styrene monomers and reduce the generation of polymers.

[0007] The present application provides a naphthyl methylene quinone compound, which has the structural formula of formula I,

[0008]

[0009] wherein R1and R2are each independently H, C 1-18 alkyl or C 1-18 cycloalkyl; R3is H, C 1-3 alkyl, C 1-3 alkoxy, hydroxyl, nitro, or carboxyl.

[0010] In one embodiment, R1and R2are each independently t-butyl.

[0011] The present application also provides a method for preparing a naphthyl methylene quinone compound having a structural formula of Formula I,

[0012]

[0013] wherein R1and R2are each independently H, C 1-18 alkyl or C 1-18 cycloalkyl; R3is H, C 1-3 alkyl, C 1-3 alkoxy, hydroxyl, nitro, or carboxyl.

[0014] The method comprises:

[0015] reacting a 2,6-disubstituted phenol and a substituted 2-naphthaldehyde with an organic secondary amine to form a Mannich base having a structural formula of Formula II:

[0016]

[0017] wherein R4and R5are C 1-5 alkyl;

[0018] deaminating the Mannich base to obtain the naphthyl methylene quinone compound.

[0019] In one embodiment, the reacting a 2,6-disubstituted phenol and a substituted 2-naphthaldehyde with an organic secondary amine is performed in an organic solvent.

[0020] In one embodiment, the organic solvent is selected from the group consisting of benzene, toluene, xylene, butanol, and combinations thereof, preferably toluene.

[0021] In one embodiment, the deaminating the Mannich base is performed under the condition of reduced pressure distillation or in the presence of an acid solution.

[0022] The present application also provides the use of the above-mentioned naphthyl methylene quinone compound as a polymerization inhibitor.

[0023] The application also provides a polymerization inhibitor composition comprising the naphthyl methylene quinone compound of the application.

[0024] In one embodiment, the polymerization inhibitor composition further comprises an inhibitor component selected from a stable free radical type compound.

[0025] In one embodiment, the stable free radical type compound is selected from at least one of 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-carbonyl-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-acetylamino-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-amino-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-methoxy-2,2,6,6-tetramethylpiperidinyloxy free radical, diethylhydroxylamine, diisopropylhydroxylamine.

[0026] In one embodiment, the polymerization inhibitor composition further comprises a solvent component.

[0027] In one embodiment, the polymerization inhibitor composition comprises:

[0028] the naphthyl methylene quinone compound,

[0029] the optional inhibitor component,

[0030] the solvent component,

[0031] wherein the mass percentage of the naphthyl methylene quinone compound is 20-40%, the mass percentage of the inhibitor component is 0-15%, and the mass percentage of the solvent component is 55-80%, based on the total mass of the polymerization inhibitor composition.

[0032] The naphthyl methylene quinone compound of the application has an extended electronic delocalization, which is conducive to dispersing free radicals, stabilizing the structure, and playing a role in terminating the free radical reaction chain. The polymerization inhibitor composition containing the naphthyl methylene quinone compound provided by the application has excellent polymerization inhibition performance and can be used in industrial devices for inhibiting the polymerization of double bond monomers. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A chromatogram showing the solution after the QM-naphth synthesis reaction of Example 1

[0034] Figure 2 A chromatogram showing the solution after the QM-Ph synthesis reaction of Comparative Example 1 DETAILED DESCRIPTION

[0035] The application will be further described in detail below by means of examples. Through these descriptions, the features and advantages of the application will become more apparent.

[0036] The term "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0037] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as there is no conflict.

[0038] In one aspect, the present application provides a naphthyl methylene quinone compound having a structural formula of Formula I,

[0039]

[0040] wherein R1 and R2 are each independently H, C 1-18 alkyl or C 1-18 cycloalkyl; R3 is H, C 1-3 alkyl, C 1-3 alkoxy, hydroxyl, nitro or carboxyl.

[0041] In one embodiment, R1 and R2 are each independently t-butyl. In one embodiment, R3 is at the 6-position of the naphthyl group.

[0042] The naphthyl methylene quinone compound has an extended electron delocalization, which is beneficial for dispersing free radicals, stabilizing the structure, and playing a role in terminating the free radical reaction chain.

[0043] The present application also provides a method for preparing a naphthyl methylene quinone compound having a structural formula of Formula I,

[0044]

[0045] wherein R1 and R2 are each independently H, C 1-18 alkyl or C 1-18 cycloalkyl; R3 is H, C 1-3 alkyl, C 1-3 alkoxy, hydroxyl, nitro or carboxyl.

[0046] The method comprises:

[0047] reacting 2,6-disubstituted phenol and substituted 2-naphthaldehyde with an organic secondary amine to form a Mannich base having a structural formula of Formula II:

[0048]

[0049] wherein R4 and R5 are C 1-5 alkyl;

[0050] deaminating the Mannich base to obtain the naphthyl methylene quinone compound.

[0051] Specifically, the 2,6-disubstituted phenol can have the following formula

[0052]

[0053] wherein R1and R2are each independently H, C 1-18 alkyl, or C 1-18 cycloalkyl; specifically, t-butyl. Specific examples of the 2,6-disubstituted phenol include, but are not limited to, 2,6-di-t-butylphenol, 2,6-dimethylphenol, and the like.

[0054] The substituted 2-naphthaldehyde can have the following formula

[0055]

[0056] wherein R3is H, C 1-3 alkyl, C 1-3 alkoxy, hydroxyl, nitro, or carboxyl. In one embodiment, R3is at the 6-position of the naphthyl group. Examples of the substituted 2-naphthaldehyde include, but are not limited to, 2-naphthaldehyde, 6-hydroxy-2-naphthaldehyde, 6-nitro-2-naphthaldehyde, and the like.

[0057] The organic secondary amine can have the formula HNR4R5, wherein R4and R5are C 1-5 alkyl. In one embodiment, the organic secondary amine can be selected from di-n-methylamine, di-n-ethylamine, di-n-propylamine, methylethylamine, and the like.

[0058] In the reaction of the 2,6-disubstituted phenol and the substituted 2-naphthaldehyde with the organic secondary amine, the molar ratio of the 2,6-disubstituted phenol to the substituted 2-naphthaldehyde can be 1 : 0.8-1.2, and the molar ratio of the 2,6-disubstituted phenol to the organic secondary amine can be 1 : 1.0-1.4.

[0059] The reaction of the 2,6-disubstituted phenol and the substituted 2-naphthaldehyde with the organic secondary amine can be represented by the following equation:

[0060]

[0061] In one embodiment, the reaction of the 2,6-disubstituted phenol and the substituted 2-naphthaldehyde with the organic secondary amine is carried out in an organic solvent. In one embodiment, the organic solvent can be selected from benzene, toluene, xylene, butanol, and combinations thereof, preferably toluene.

[0062] In one embodiment, the reaction temperature for the reaction of the 2,6-disubstituted phenol and the substituted 2-naphthaldehyde with the organic secondary amine can be 100-140°C.

[0063] After the above reaction, the Mannich base is deaminated to obtain the naphthyl methylene quinone compound.

[0064] The deamination can be carried out under the condition of reduced pressure distillation: the reaction solution of the above reaction is subjected to reduced pressure distillation, and the deamination can be carried out to obtain the crude product of the naphthyl methylene quinone compound. Then, recrystallization is carried out, and the product of the naphthyl methylene quinone compound can be obtained.

[0065] The deamination can be carried out in the presence of an acid solution: an acid solution is added to the reaction solution of the above reaction, and the deamination can be carried out after incubation for a period of time to obtain the crude product of the naphthyl methylene quinone compound. Then, recrystallization is carried out, and the product of the naphthyl methylene quinone compound can be obtained. The acid can be various inorganic acids, such as sulfuric acid, hydrochloric acid, etc.

[0066] The reaction formula of the deamination of the Mannich base is as follows:

[0067]

[0068] The present application also relates to the use of the naphthyl methylene quinone compound as a polymerization inhibitor.

[0069] The present application also relates to a polymerization inhibitor composition comprising the naphthyl methylene quinone compound of the present application.

[0070] In an embodiment, the polymerization inhibitor composition further comprises an inhibitor component selected from a stable free radical type compound.

[0071] In an embodiment, the stable free radical type compound can be selected from at least one of 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-carbonyl-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-acetylamino-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-amino-2,2,6,6-tetramethylpiperidinyloxy free radical, 4-methoxy-2,2,6,6-tetramethylpiperidinyloxy free radical, diethylhydroxylamine, diisopropylhydroxylamine.

[0072] In an embodiment, the polymerization inhibitor composition further comprises a solvent component. The solvent component can be one or more of benzene, toluene, ethylbenzene, xylene, styrene, heavy aromatic hydrocarbon.

[0073] In an embodiment, the polymerization inhibitor composition comprises:

[0074] the naphthyl methylene quinone compound,

[0075] the optional inhibitor component,

[0076] the solvent component,

[0077] wherein the naphthylmethylidene quinone compound is present in an amount of 20 to 40% by mass, the inhibitor component is present in an amount of 0 to 15% by mass, and the solvent component is present in an amount of 55 to 80% by mass, based on the total mass of the polymerization inhibitor composition.

[0078] In one embodiment, the inhibitor component is present in an amount of 0 to 15% by mass, or 5 to 15% by mass, based on the total mass of the polymerization inhibitor composition.

[0079] In one embodiment, the naphthylmethylidene quinone compound is present in an amount of 20 to 40% by mass, or 20 to 30% by mass, based on the total mass of the polymerization inhibitor composition.

[0080] The present application is further illustrated by way of the following examples.

[0081] Example 1: Synthesis of 4-naphthylmethylidene-2,6-di-tert-butyl-2,5-cyclohexadiene-1- one (QM-naphth)

[0082] The synthesis of 4-naphthylmethylidene-2,6-di-tert-butyl-2,5-cyclohexadiene-1-one (QM-naphth) comprises the following steps:

[0083] To a three-necked flask equipped with a thermometer, a constant pressure dropping funnel and a condenser-accumulator, 2,6-di-tert-butylphenol 20.63 g (0.1 mol), 2-naphthaldehyde 18.74 g (0.12 mol), di-n-propylamine 5.05 g (0.04 mol) and 100 mL of toluene were added, and the mixture was heated to 120°C to reflux under stirring, and maintained at this temperature for 1 hour. Di-n-propylamine 10.12 g (0.10 mol) was added dropwise over a period of 2 hours, and the reaction was continued for 10 hours. The cooled solution was analyzed by chromatography, which showed that a chromatographic peak with a retention time of 43 minutes was present, indicating the formation of the β-di-n-propylamino Mannich base. Figure 1

[0084] The cooled reaction solution was transferred to a single-necked flask, and subjected to vacuum distillation at a distillation temperature of 120°C and a pressure of 200 mbar. After 3 hours, a red-brown solid was obtained.

[0085] The red-brown solid was dissolved in 20 mL of hot ethanol, and recrystallized at a temperature of -20°C. The product was obtained by filtration, and analyzed by mass spectrometry.

[0086] Example 2: Synthesis of 6-hydroxynaphthylmethylidene-2,6-di-tert-butyl-2,5-cyclohexadiene-1- one (QM-naphth-OH)

[0087] ​To 2,6-di-tert-butylphenol 20.63 g (0.1 mol), 6-hydroxy-2-naphthaldehyde 20.66 g (0.12 mol), di-n-propylamine 5.05 g (0.04 mol) and 100 mL of toluene, contained in a three-necked flask equipped with a thermometer, a constant pressure dropping funnel and a condenser- trap, was added, under stirring, heating to 120°C to reflux, maintaining the temperature constant for 1 hour, dropwise addition of di-n-propylamine 10.12 g (0.10 mol), dropwise addition time 2 hours, reaction continued for 10 hours.

[0088] The cooled reaction liquid was transferred into a single-necked flask and subjected to distillation under reduced pressure at a temperature of 120°C and a pressure of 200 mbar, obtaining a red-brown solid after 3 hours.

[0089] The red-brown solid was dissolved in 20 mL of hot ethanol and recrystallized at a temperature of -20°C, obtaining the QM-naphth-OH product after filtration. The product was analyzed by mass spectrometry.

[0090] Example 3: Formulation of QM-naphth / 701 / ethylbenzene retarder

[0091] The retarder was formulated in the following proportions by mass percentage:

[0092] QM-naphth: 30%

[0093] 4-hydroxy-2,2,6,6-tetramethylpiperidinooxy free radical (701): 10%

[0094] Ethylbenzene: 60%

[0095] To 30 g of analytical purity styrene and 0.009 g of the above retarder, contained in a clean 200 mL stainless steel autoclave, the autoclave was sealed and placed in a 120°C preheated oven, maintaining the temperature constant for 2 hours, then it was removed and cooled to room temperature. To 10 g of the cooled styrene solution, contained in a viscometer, the viscosity of the solution was measured at 40°C, as shown in Table 1.

[0096] Example 4: Formulation of QM-naphth / ethylbenzene retarder

[0097] The retarder was formulated in the following proportions by mass percentage:

[0098] QM-naphth: 30%

[0099] 4-hydroxy-2,2,6,6-tetramethylpiperidinooxy free radical (701): 0%

[0100] Ethylbenzene: 70%

[0101] Into a clean 200 mL stainless steel autoclave, 30 g of analytical grade styrene and 0.009 g of the above inhibitor were added. The autoclave was sealed and placed in a 120 °C preheated oven and kept at constant temperature for 2 hours. The autoclave was removed and allowed to cool to room temperature. 10 g of the cooled styrene solution was injected into a viscometer and the viscosity of the solution was measured at 40 °C. The results are shown in Table 1.

[0102] Example 5: Formulation of QM-anphth / 701 / ethylbenzene inhibitor

[0103] The inhibitor was formulated in the following proportions by mass percentage:

[0104] QM-naphth: 20%

[0105] 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy free radical (701): 10%

[0106] Ethylbenzene: 70%

[0107] Into a clean 200 mL stainless steel autoclave, 30 g of analytical grade styrene and 0.009 g of the above inhibitor were added. The autoclave was sealed and placed in a 120 °C preheated oven and kept at constant temperature for 2 hours. The autoclave was removed and allowed to cool to room temperature. 10 g of the cooled styrene solution was injected into a viscometer and the viscosity of the solution was measured at 40 °C. The results are shown in Table 1.

[0108] Example 6: Formulation of QM-naphth-OH / 701 / ethylbenzene inhibitor

[0109] The inhibitor was formulated in the following proportions by mass percentage:

[0110] QM-naphth-OH: 30%

[0111] 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy free radical (701): 10%

[0112] Ethylbenzene: 60%

[0113] Into a clean 200 mL stainless steel autoclave, 30 g of analytical grade styrene and 0.009 g of the above inhibitor were added. The autoclave was sealed and placed in a 120 °C preheated oven and kept at constant temperature for 2 hours. The autoclave was removed and allowed to cool to room temperature. 10 g of the cooled styrene solution was injected into a viscometer and the viscosity of the solution was measured at 40 °C. The results are shown in Table 1.

[0114] Comparative Example 1: Synthesis of 4-benzylidene-2,6-di-tert-butyl-2,5- cyclohexadiene-1-one (QM-Ph)

[0115] Take 2,6-di-tert-butylphenol 20.63 g (0.1 mol), benzaldehyde 12.73 g (0.12 mol), di-n-propylamine 5.05 g (0.04 mol) and 100 mL of toluene, add to a three-necked flask equipped with a thermometer, constant pressure dropping funnel and condenser water separator, slowly heated to 120°C to reflux under stirring conditions, maintain constant temperature for 1 hour, drop di-n-propylamine 10.12 g (0.10 mol), drop time 2 hours, continue reaction for 10 hours, then cool, take the cooled solution for chromatographic analysis, as shown in Figure 2 .

[0116] The cooled reaction solution is transferred to a single-necked flask, and vacuum distillation is carried out at a distillation temperature of 120°C and a pressure of 200 mbar, and a red-brown solid is obtained after 3 hours.

[0117] The above red-brown solid is dissolved in 20 mL of hot ethanol, and then recrystallized at a temperature of -20°C, and the QM-Ph product is obtained after filtration, and the product is analyzed by mass spectrometry.

[0118] As can be seen from the comparison of Example 1 and Comparative Example 1, both QM-naphth and QM-Ph have good polymerization inhibition effect. In the chromatogram of Figure 1 , the peak with a retention time of 43 minutes is the main product of the reaction, and the peaks before it are the solvent and the unreacted raw material peaks, and it can be seen that there is no side reaction in the reaction; in the chromatogram of Figure 2 , the peak with a retention time of 36 minutes is the main product of the reaction, and the peaks before it are the solvent and the unreacted raw material peaks, and there is a series of side product peaks after 36 minutes. It can be seen that the synthesis of QM-naphth has higher yield and purity than QM-Ph, which may be due to the fact that the steric hindrance is more conducive to the synthesis of QM-naphth, which is unexpected for those skilled in the art, because steric hindrance is generally not conducive to chemical synthesis.

[0119] Comparative Example 2

[0120] The polymerization inhibitors of the comparative examples are prepared according to the following mass percentage proportions:

[0121] 2-sec-butyl-4,6-dinitrophenol (DNBP): 30%

[0122] 4-hydroxy-2,2,6,6-tetramethylpiperidinooxy free radical (701): 0%

[0123] Ethylbenzene: 70%

[0124] Take 30g of pure styrene and 0.009g of the above polymerization inhibitor into a clean 200mL stainless steel autoclave, seal the autoclave and put it into a 120℃ preheated oven, keep the temperature constant for 2 hours, take out and cool to room temperature. Take 10g of the cooled styrene solution into a viscometer, measure the viscosity of the solution at 40℃, as shown in Table 1.

[0125] Comparative Example 3: Evaluation of the polymerization inhibition performance of QM-Ph

[0126] The polymerization inhibitor is prepared according to the following mass percentage ratio:

[0127] QM-Ph: 30%

[0128] 4-hydroxy-2,2,6,6-tetramethylpiperidinooxy free radical (701): 10%

[0129] Ethylbenzene: 60%

[0130] Take 30g of pure styrene and 0.009g of the above polymerization inhibitor into a clean 200mL stainless steel autoclave, seal the autoclave and put it into a 120℃ preheated oven, keep the temperature constant for 2 hours, take out and cool to room temperature. Take 10g of the cooled styrene solution into a viscometer, measure the viscosity of the solution at 40℃, as shown in Table 1.

[0131] Table 1

[0132] Example Polymerization Inhibitor viscosity mm 2 / s]]> Example 1 QM-anphth / 701 / ethylbenzene 0.71 Example 2 QM-anphth / ethylbenzene 0.85 Example 3 QM-anphth / 701 / ethylbenzene 0.76 Example 4 QM-anphth-OH / 701 / ethylbenzene 0.82 Comparative Example 2 DNBP / ethylbenzene 0.92 Comparative Example 3 QM-Ph / 701 / ethylbenzene 0.72

[0133] As can be seen from the data in Table 1, the naphthyl methylene quinone compound of the present application has good retardation effect on styrene, and its polymerization inhibition performance is better than that of DNBP, and it can completely replace DNBP with higher toxicity and be used as a polymerization inhibitor for double bond polymerization monomers. The polymerization inhibitor formula provided in the present application has excellent polymerization inhibition performance and can be used in industrial devices for double bond polymerization monomer polymerization inhibition.

[0134] The above describes the present application in combination with preferred embodiments, but these embodiments are only exemplary and serve only to illustrate. On this basis, various substitutions and improvements can be made to the present application, and these all fall within the protection scope of the present application.

Claims

1. A process for preparing a naphthyl methylene quinone compound having a structural formula of Formula I, ###0001### Formula I wherein R1 and R2 are each independently H or t-butyl; R3 is hydroxyl, and is at the 6-position of the naphthyl group; the process comprising: reacting a 2,6-disubstituted phenol and a substituted 2-naphthaldehyde with an organic secondary amine at 100-120°C to form a Mannich base having a structural formula of Formula II: ###0002### Formula II; deaminating the Mannich base to obtain the naphthyl methylene quinone compound. Formula I wherein 2. The process of claim 1, wherein the molar ratio of the 2,6-disubstituted phenol to the substituted 2-naphthaldehyde is 1:0.8-1.2, and the molar ratio of the 2,6-disubstituted phenol to the organic secondary amine is 1:1.0-1.

4.

3. The process of claim 1, wherein the reacting of the 2,6-disubstituted phenol and the substituted 2-naphthaldehyde with the organic secondary amine is carried out in an organic solvent, and the organic solvent is selected from the group consisting of benzene, toluene, xylene, butanol, and combinations thereof.

4. The process of claim 1, wherein the organic solvent is toluene. Formula II wherein R4and R5are C 1-5 alkyl; 5. The process of claim 1, wherein the deaminating of the Mannich base is carried out under the condition of reduced pressure distillation or in the presence of an acid solution. wherein the organic secondary amine has the formula HNR4R5, wherein R4and R5are C 1-5 alkyl; and 6. Use of a polymerization inhibitor composition as a polymerization inhibitor, the polymerization inhibitor composition comprising the naphthyl methylene quinone compound prepared by the process of any one of claims 1 to 5.

2. The method of claim 1, wherein, 7. The use of claim 6, wherein the polymerization inhibitor composition further comprises an inhibitor component selected from the group consisting of stable free radical type compounds.

3. The method of claim 2, wherein, 8. The use of claim 7, wherein the stable free radical type compound is selected from at least one of 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy, 4-carbonyl-2,2,6,6- tetramethylpiperidinyloxy, 4-acetylamino-2,2,6,6-tetramethylpiperidinyloxy, 4- amino-2,2,6,6-tetramethylpiperidinyloxy, 4-methoxy-2,2,6,6-tetramethylpiperidinyloxy, diethylhydroxylamine, and diisopropylhydroxylamine.

4. The method of claim 1, wherein, 9. The use of claim 6, wherein the polymerization inhibitor composition further comprises a solvent component.

10. The use of claim 9, wherein the polymerization inhibitor composition comprises: the naphthyl methylene quinone compound, an optional inhibitor component, and a solvent component.

6. Use according to claim 5, wherein, 11. The use of claim 10, wherein the naphthyl methylene quinone compound is present in an amount of 20-40% by mass, the optional inhibitor component is present in an amount of 0-15% by mass, and the solvent component is present in an amount of 55-80% by mass, based on the total mass of the polymerization inhibitor composition.

7. Use according to claim 6, wherein, ​ 8. The use according to claim 5, wherein, ​ 9. The use according to claim 5, wherein, ​ ​ ​ ​ ​

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