CN104039835A - Stabilized 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl-containing composition, polymerization inhibitor composition for vinyl compound, and method for inhibiting polymerization of vinyl compound using same - Google Patents

Abstract

The present invention provides a composition containing stabilized 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl, and a stabilized 4-oxo- 2,2,6,6-Tetramethylpiperidin-1-oxyl vinyl compound polymerization inhibitor composition having little reduction in polymerization inhibitory ability even during long-term storage , and a method for inhibiting polymerization of vinyl compounds using the composition. A solution to the problem involves complexing 4-hydroxy-2,2,6,6-tetramethylpiperidine- A composition with 1-oxyl as its stabilizer, a polymerization inhibitor composition for a vinyl compound formed from the composition, and a polymerization inhibition method for a vinyl compound using the composition.

Description

Composition containing stabilized 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl group, polymerization inhibitor composition of vinyl compound, and vinyl compound using same polymerization inhibition method

technical field

The present invention relates to a composition containing stabilized 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl, and a stabilized 4-oxo-2 , the polymerization inhibitor composition of the vinyl compound of 2,6,6-tetramethylpiperidin-1-oxyl groups, and the polymerization inhibition method of the vinyl compound using it, the polymerization inhibitor composition even in the long-term There is also little decline in the ability to inhibit polymerization under long-term preservation and storage.

Background technique

Olefins undergo free radical polymerization under the action of heat, a trace amount of oxygen or peroxide, and metal ions or light to form polymers. It is well known that a polymerization inhibitor is added as a countermeasure in order to prevent the above-mentioned radical polymerization that occurs due to accidents such as the production process, purification process, and storage process. For example, the method of using phenols, hydroxylamines (for example, see Patent Document 1) and further using a polymerization inhibitor such as piperidine-1-oxyls (see Patent Document 2) in the petrochemical ethylene production process has been proposed. methods, especially piperidine-1-oxyls with very excellent polymerization inhibition ability, have been widely used in recent years.

However, it is known that piperidine-1-oxyls themselves are free radical compounds, and if the composition obtained by dissolving piperidine-1-oxyls in a solvent is stored for a long period of time, there will be disappearance of free radicals, inhibition of The above-mentioned tendency is notable especially in 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl group (hereinafter abbreviated as "OXO-TEMPO") as a disadvantage of decreased polymerization ability.

As a method of solving the above-mentioned disadvantages and suppressing the reduction of the polymerization inhibition ability of piperidine-1-oxyl groups over a long period of time, a method of using alcohol as a solvent is disclosed (see Patent Document 3); a method of making the following compounds coexist (See Patent Document 4): piperidine-1-oxyl compound, N-hydroxy-2,2,6,6-tetramethylpiperidine compound and 2,2,6,6-tetramethylpiperidine compound. However, in these methods, the stabilization of OXO-TEMPO is not sufficient, and the degree of decrease in the inhibition ability of OXO-TEMPO is large.

Based on the above situation, 4-hydroxyl-2,2,6,6-tetramethylpiperidin-1-oxyl group (hereinafter abbreviated as "H-TEMPO") which has less ability to inhibit polymerization among piperidine-1-oxyl groups ”) are the most widely used industrially as a polymerization inhibitor.

However, in the manufacture of this H-TEMPO, the following two stages of reaction steps are required: 4-oxo-2,2,6,6-tetramethylpiperidine (also known as triacetoneamine, hereinafter abbreviated as " TAA") was hydrogenated to obtain 4-hydroxyl-2,2,6,6-tetramethylpiperidine as an intermediate (for example, see Patent Document 5), and then further oxidized the intermediate with hydrogen peroxide ( For example, refer to Patent Document 6, Patent Document 7, etc.) to obtain H-TEMPO. In contrast, OXO-TEMPO can be prepared only by a one-stage process of oxidizing TAA. Therefore, compared with H-TEMPO Compared with the advantage that it can be obtained cheaply, the polymerization inhibitor composition containing stabilized OXO-TEMPO, the polymerization inhibitor composition of the vinyl compound formed from it, and the vinyl compound using the composition are required. A method for inhibiting polymerization of a compound, wherein the composition can suppress the decrease of the ability of inhibiting polymerization even in long-term preservation and storage.

Patent Document 1: US Patent No. 4434307

Patent Document 2: Japanese Patent Publication No. 4-26639

Patent Document 3: Japanese Patent Application Laid-Open No. 11-171906

Patent Document 4: Japanese Patent Laid-Open No. 2001-181252

Patent Document 5: Japanese Patent Laid-Open No. 63-303967

Patent Document 6: Japanese Patent Publication No. 44-12142

Patent Document 7: Japanese Patent Application Laid-Open No. 6-247932

Contents of the invention

The problem to be solved by the invention

In view of the above-mentioned actual situation, the present invention takes the following content as a technical problem: provide a stabilized polymerization inhibitory OXO-TEMPO composition, a polymerization inhibitor composition containing a vinyl compound of the composition, and a product using the composition A method for inhibiting polymerization of vinyl compounds, wherein the composition can suppress the decline in the ability to inhibit polymerization even under long-term preservation and storage.

way of solving the problem

The inventors of the present invention have repeatedly conducted intensive studies on the stabilization of OXO-TEMPO, especially the prevention of the decrease in the ability to inhibit polymerization. As a result, it has been found that by adding H-TEMPO to this compound, it can be stabilized, especially in the long term. The decline of the polymerization inhibitory ability of OXO-TEMPO can also be suppressed under the preservation and storage of OXO-TEMPO, thereby completing the present invention.

That is, the first invention of the present invention is a composition containing stabilized OXO-TEMPO, wherein OXO-TEMPO is blended with H-TEMPO as a stabilizer.

The second invention is the composition according to the first claim, wherein 0.01 parts by weight or more of H-TEMPO is blended with respect to 100 parts by weight of OXO-TEMPO.

The third invention is the composition according to the first or second claim, wherein 10 to 500 parts by weight of H-TEMPO is blended with respect to 100 parts by weight of OXO-TEMPO.

The fourth invention is the composition according to any one of the first to third claims, which further contains solvents for OXO-TEMPO and H-TEMPO.

The fifth invention is the composition according to the fourth invention, wherein the solvent is a mixed solvent of water and an alcohol compound.

The sixth invention is a vinyl compound polymerization inhibitor composition comprising 0.01 parts by weight or more of H-TEMPO per 100 parts by weight of OXO-TEMPO.

The seventh invention is the polymerization inhibitor composition of a vinyl compound according to the sixth invention, wherein 10 to 500 parts by weight of H-TEMPO is blended with respect to 100 parts by weight of OXO-TEMPO.

The eighth invention is the vinyl compound inhibitor composition according to the sixth or seventh invention, which further contains solvents for OXO-TEMPO and H-TEMPO.

The ninth invention is the polymerization inhibitor composition of a vinyl compound according to the ninth invention, wherein the solvent is a mixed solvent of water and an alcohol compound.

The tenth invention is a polymerization inhibition method for vinyl compounds, which includes directly adding the polymerization inhibitor described in any one of the sixth to ninth items, or further diluting it in a solvent and then adding it to In fluids containing vinyl compounds.

Invention effect

According to the present invention, by realizing the stabilization of OXO-TEMPO, it is possible to provide a polymerization inhibitor composition of a vinyl compound, which can suppress the decline in the polymerization inhibitory ability even under long-term storage and storage, and is different from the currently widely used H-TEMPO is advantageous in terms of cost.

Detailed ways

The stabilized composition of the present invention contains OXO-TEMPO and H-TEMPO as its stabilizer, but its content ratio, relative to 100 parts by weight of OXO-TEMPO, when H-TEMPO is less than 0.01 parts by weight, there is no In order to suppress the reduction of the polymerization inhibitory ability of OXO-TEMPO under long-term preservation and storage, it is preferable to contain 0.01 weight part or more of H-TEMPO, and it is more preferable to contain 10 weight parts or more. Also, if the content ratio exceeds 500 parts by weight of H-TEMPO relative to 100 parts by weight of OXO-TEMPO, the effect commensurate with the increase in H-TEMPO content cannot be obtained, which is economically disadvantageous.

When it is used as a polymerization inhibitor of vinyl compounds, it contains solvents other than OXO-TEMPO and H-TEMPO. As the solvent, it can be used according to the production equipment, storage equipment, and transportation methods of vinyl compounds to be applied. Conditions Select an appropriate solvent, and aromatic solvents, aliphatic solvents, water, alcohol compounds, process liquids for manufacturing equipment, and the like can also be used. For example, in the butadiene production process, it is particularly undesirable to mix other solvents into the product, and sometimes toluene, which is an aromatic hydrocarbon contained in the process liquid, is selected instead of water or an alcohol compound. In addition, there is no limitation in mixing and using two or more solvents.

Examples of aromatic solvents or aliphatic solvents used in the present invention include benzene, toluene, xylene, ethylbenzene, other aromatic compounds, naphthenic compounds, mineral oil, paraffinic compounds, and the like. In addition, as water, normal industrial water, demineralized water, ion-exchanged water, etc. can be used. Furthermore, examples of alcohol compounds include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 1-pentanol, 3-methyl-1-butanol, 3- Pentanol, n-hexanol, 2-ethylbutanol, n-heptanol, 2-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, n-nonanol, n-decyl alcohol, n-undecyl alcohol , n-dodecyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monophenyl ether , ethylene glycol monobenzyl ether, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, di Triethylene glycol, polyethylene glycol, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, butylene glycol, pentylene glycol, glycerin, cyclohexanol, 2-methylcyclohexanol, benzyl alcohol , phenol, etc.

Considering the solubility and product stability of OXO-TEMPO and H-TEMPO compounded at the same time, the type and compounding amount of the solvent in the polymerization inhibitor composition of the present invention are appropriately selected. From the examples described later, it can be seen that the mixed solvent of water and alcohol compound makes the solubility and product stability of OXO-TEMPO and H-TEMPO excellent, and the effect of inhibiting the polymerization inhibition ability of OXO-TEMPO is also confirmed. These effects are synergistic effects that cannot be obtained with water alone or alcohol alone, and a particularly preferable combination and compounding amount is water:ethylene glycol monobutyl ether=50:1 to 1:50 (weight ratio). In addition, the ability to inhibit polymerization can be exhibited when OXO-TEMPO alone, H-TEMPO alone, and other piperidine-1-oxyl compounds are dissolved in addition to the system using OXO-TEMPO and H-TEMPO in combination. The aforementioned synergistic effect of suppressing the decrease in polymerization inhibition ability by the mixed solvent of water and an alcohol compound.

If the compounding example of a preferable polymerization inhibitor composition is given, it will be 1 weight part of OXO-TEMPO, 1 weight part of H-TEMPO, 2 weight part of water, and 1 weight part of ethylene glycol monobutyl ethers.

The polymerization inhibitor composition of this invention can be manufactured by adding and dissolving H-TEMPO to a solvent at normal temperature, and further adding and dissolving OXO-TEMPO, stirring, and mixing uniformly. The order of dissolving each component is not particularly limited, and the process of changing the order of mixing according to the physical properties of each component is not limited, but in order to prevent the decline in the polymerization inhibition ability of OXO-TEMPO during the manufacture of the composition, it is necessary not to use OXO-TEMPO is heated above the melting point (37°C).

In the polymerization inhibitor composition of the present invention, other known polymerization inhibitors, antioxidants, metal deactivators, dispersants, etc. can be added as needed.

The application of the polymerization inhibitor composition of the present invention is not particularly limited, for example, in petrochemical engineering, the manufacture of various vinyl compounds, refining processes, transportation, storage, in the inhibition of pollution caused by the polymerization of vinyl compounds, the inhibition of pollution caused by When the yield of the vinyl compound decreases due to polymerization, it is preferable to add in the equipment where the polymerization occurs, such as heat exchangers, reboilers, piping, storage tanks, and/or upstream thereof. At this time, the addition amount of the polymerization inhibitor composition of the present invention varies according to the type of vinyl compound and process conditions, so it cannot be determined in general. As the total amount of OXO-TEMPO and H-TEMPO, generally add Make it 0.1-1000ppm with respect to this process fluid.

The method of adding the polymerization inhibitor composition of the present invention is as follows: generally dilute with stock solution or solvent, use a drug injection pump, and add continuously or intermittently according to the type of vinyl compound to be used and the process conditions. The solvent used for dilution can be used without limitation as long as it is a solvent used in the polymerization agent composition or a solvent having an affinity with the solvent, and the process liquid of the target process is usually used for dilution.

In addition, the type of vinyl compound that can be used is not particularly limited, and olefin compounds such as ethylene, propylene, butene, and isobutylene, substituted or unsubstituted ones such as butadiene, isoprene, and chloroprene, etc., are listed. Conjugated diene compounds, aromatic vinyl compounds such as styrene, α-methylstyrene, and divinylbenzene, methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-methacrylate Ethylhexyl, allyl methacrylate, 2-hydroxyethyl methacrylate, 2-(dimethylamino)ethyl methacrylate and other methacrylates and methacrylic compounds, methyl acrylate, Acrylic esters and acrylic compounds such as ethyl acrylate and butyl acrylate, vinyl cyanide compounds such as acrylonitrile and butyronitrile methacrylate, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2- Methoxyethoxy)silane, 2-(5-norbornenyl)ethyl(dimethyl)methoxysilane, 5-hexenylmethyldimethoxysilane, 3-acryloxy Propylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxy Propyltri(trimethylsiloxy)silane, 4-vinylphenyltrimethoxysilane, 2-(4-vinylphenyl)ethyltriethoxysilane, etc. contain ethylenically unsaturated groups Silane and siloxane compounds, vinyl ester compounds such as vinyl acetate, halogenated olefins such as vinyl chloride, vinylidene chloride, vinylidene fluoride, tetrafluoroethylene, hexafluoropropylene, etc.

Example

1. Compounds used in the test

[Piperidine-1-oxyls]

N-1: 4-oxo-2,2,6,6-tetramethylpiperidin-1-oxyl (OXO-TEMPO)

N-2: 4-Hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (H-TEMPO)

N-3: 4-methoxy-2,2,6,6-tetramethylpiperidin-1-oxyl

N-4: 4-carboxy-2,2,6,6-tetramethylpiperidin-1-oxyl

N-5: 2,2,6,6-tetramethylpiperidin-1-oxyl

[solvent]

S-1: Xylene

S-2: Kerosene

S-3: 2-Ethylhexanol

S-4: Ethylene glycol monobutyl ether (hereinafter abbreviated as "EGB")

S-5: Water

W-1: Mixed solvent of water: EGB=1:50 (weight ratio)

W-2: Mixed solvent of water: EGB=1:1 (weight ratio)

W-3: Mixed solvent of water: EGB=2:1 (weight ratio)

W-4: Mixed solvent of water: EGB=50:1 (weight ratio)

2. Test method

The composition obtained by mixing piperidine-1-oxyl groups and various solvents in a specified ratio is placed in a thermostat at 50°C for 10 days, 20 days, and 30 days, and the composition is determined by gas chromatography. The concentration of 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl group (OXO-TEMPO) in the product is compared with the concentration when the composition is made, and the value of OXO-TEMP is calculated. Residual rate (%). The larger the residual ratio is, the smaller the decrease in the polymerization inhibition ability of OXO-TEMPO is (=the larger the inhibitory effect on the polymerization inhibition ability decline is).

From the results shown in Table 1, it was confirmed that OXO-TEMPO had a larger decrease in polymerization inhibition ability than other piperidine-1-oxyl groups.

From the results shown in Table 2, it was confirmed that by making 4-hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (H-TEMPO) coexist in OXO-TEMPO, the Compared with the case where pyridine-1-oxyl groups coexist, it is possible to specifically reduce the decrease in polymerization inhibition ability significantly, and the stabilizing effect of OXO-TEMPO is produced by H-TEMPO.

From the results shown in Table 3, it was confirmed that by coexisting H-TEMPO in an amount of 0.01 parts by weight or more with respect to 100 parts by weight of OXO-TEMPO, it was confirmed that the decrease in the polymerization inhibition ability of OXO-TEMPO can be reduced. The higher the coexistence content of H-TEMPO, the greater the inhibitory effect of OXO-TEMPO on the reduction of the polymerization inhibition ability, and when the content of H-TEMPO exceeds 500 parts by weight, it is difficult to enjoy the corresponding effect. Disadvantageous.

From the results shown in Table 4, it was confirmed that Examples 11 to 14 using a mixed solvent of water and an alcohol compound (W-1 to 4) were different from Example 10 using water (S-5) alone as a solvent, and Example 10 using water alone (S-5) alone. Compared with Examples 8 and 9 in which alcohol compounds (S-3, S-4) were used as solvents, OXO-TEMPO had a greater inhibitory effect on the decrease in the polymerization inhibition ability, and obtained a synergistic effect that cannot be obtained with the solvent of water or alcohol compounds alone. Effect. The preferred mixing ratio of water and alcohol compound is water:EGB=50:1～1:50 (weight ratio), and the particularly preferable mixing ratio is shown as water:EGB=2:1.

[Table 1]

[Table 2]

[table 3]

[Table 4]

Claims (10)

1. one kind contains 4-oxo-2 of having carried out stabilization, and the composition of 2,6,6-tetramethyl piperidine-1-oxygen base wherein, in 4-oxo-2, has coordinated 4-hydroxyl-2 in 2,6,6-tetramethyl piperidine-1-oxygen base, and 2,6,6-tetramethyl piperidine-1-oxygen base is as its stablizer.

2. composition as claimed in claim 1, wherein, with respect to 4-oxo-2 of 100 weight parts, 2,6,6-tetramethyl piperidine-1-oxygen base, coordinates 4-hydroxyl-2 more than 0.01 weight part, 2,6,6-tetramethyl piperidine-1-oxygen base.

3. composition as claimed in claim 1 or 2, wherein, with respect to 4-oxo-2 of 100 weight parts, 2,6,6-tetramethyl piperidine-1-oxygen base, coordinates 4-hydroxyl-2 of 10～500 weight parts, 2,6,6-tetramethyl piperidine-1-oxygen base.

4. the composition as described in any one in claim 1～3, it further contains 4-oxo-2,2,6,6-tetramethyl piperidine-1-oxygen base and 4-hydroxyl-2, the solvent of 2,6,6-tetramethyl piperidine-1-oxygen base.

5. composition as claimed in claim 4, wherein, solvent is the mixed solvent of water and alkylol cpd.

6. a stopper composition for vinyl compound, wherein, with respect to 4-oxo-2 of 100 weight parts, 2,6,6-tetramethyl piperidine-1-oxygen base, coordinates 4-hydroxyl-2 more than 0.01 weight part, 2,6,6-tetramethyl piperidine-1-oxygen base.

7. the stopper composition of vinyl compound as claimed in claim 6, wherein, with respect to 4-oxo-2 of 100 weight parts, 2,6,6-tetramethyl piperidine-1-oxygen base, coordinates 4-hydroxyl-2 of 10～500 weight parts, 2,6,6-tetramethyl piperidine-1-oxygen base.

8. the stopper composition of the vinyl compound as described in claim 6 or 7, it further contains 4-oxo-2,2,6,6-tetramethyl piperidine-1-oxygen base and 4-hydroxyl-2, the solvent of 2,6,6-tetramethyl piperidine-1-oxygen base.

9. the stopper composition of vinyl compound as claimed in claim 8, wherein, solvent is the mixed solvent of water and alkylol cpd.

10. an anti-polymerization method for vinyl compound, it comprises, the stopper composition described in any one in claim 6～9 is directly added or further in solvent, dilute and be added in the fluid that contains vinyl compound again.