KR101950930B1 - Porous catalyst containing zinc oxide and aluminium oxide for hydroxyl group alkylation, preparation method thereof using nonionic surfactant and alkylation method of polyalkylene glycol using the same - Google Patents

Abstract

The present invention relates to a porous catalyst for the alkylation of hydroxyl groups comprising zinc oxide and aluminum oxide, a process for preparing the same using a nonionic surfactant, and a process for alkylating a hydroxyl group of a polyalkylene glycol using the same. The porous catalyst for hydroxyl group alkylation according to the present invention exhibits excellent polyalkylene glycol conversion and methylation conversion, and thus can be used economically and environmentally friendly for the alkylation of polyalkylene glycols.

Description

TECHNICAL FIELD The present invention relates to a porous catalyst for hydroxyl group alkylation including zinc oxide and aluminum oxide, a process for producing the same using the nonionic surfactant, and a process for alkylating a hydroxyl group of a polyalkylene glycol using the same. group alkylation, preparation method thereof using nonionic surfactant and alkylation method of polyalkylene glycol using the same}

The present invention relates to a porous catalyst for the alkylation of hydroxyl groups comprising zinc oxide and aluminum oxide, a process for preparing the same using a nonionic surfactant, and a process for alkylating a hydroxyl group of a polyalkylene glycol using the same. Specifically, it relates to a method for producing a porous catalyst for hydroxyl group alkylation comprising zinc oxide and aluminum oxide having high activity by using a nonionic surfactant, and a method for alkylating polyalkylene glycol in an environmentally friendly and economical manner in the presence of the catalyst will be.

The polyalkylene glycol which is prepared by adding propylene oxide or ethylene oxide with alcohol as a starting material is composed of an alkyl group or a hydroxyl group (-OH) at the terminal. Polyalkylene glycols have long been commercialized as refrigerator oil for automobile air conditioners and are being sold worldwide. However, when the polyalkylene glycol is used as a refrigerant in an air conditioner, the end hydroxyl groups of the polyalkylene glycol are frequently caused to be moisture in the air. To solve this problem, many attempts have been made to alkylate the terminal hydroxyl groups There was an attempt.

A method of preparing a polyalkylene glycol by reacting a hydroxyl group at the terminal of the polyalkylene glycol with an alkylating agent to replace it with a methyl group is disclosed in many documents. US Pat. No. 4,587,365 discloses a process for preparing a polyalkylene glycol by substituting a methyl group with an alkylating agent of methyl halide such as CH ₃ Cl or CH ₃ I. In EP 0302487, methyl sulfate is used as an alkylating agent, Is alkylated with a methyl group. However, these methods using methyl halide are not only slow in reaction itself, but also have various environmental problems, which limits their practical application.

In addition, there is a method of using an acid catalyst. Usually, a liquid acid catalyst is used for the alkylation method using the acid catalyst. Liquid acid catalysts include sulfuric acid and hydrofluoric acid. However, this method has a problem in that there is a high corrosive substance in the material obtained after alkylation due to the strong corrosiveness of sulfuric acid and hydrofluoric acid, and there is an environmental problem that toxic substances such as hydrogen fluoride can be released during the process.

A method of using a solid acid catalyst as the acid catalyst has also been disclosed. U.S. Patent No. 5,986,158 discloses an alkylation process that utilizes an easy regeneration of a zeolite-containing solid acid catalyst, and U.S. Patent No. 8163969 discloses a process for alkylating a zeolite with a solid acid alkylation catalyst comprising rare earths Are known.

However, when the solid acid catalyst is calcined at the time of production, if the catalyst is calcined at a temperature higher than the proper temperature, there is a problem that the surface area of the catalyst is reduced or an undesirable catalyst structure is formed and the catalyst performance is deteriorated.

Accordingly, the present inventors have made efforts to develop a catalyst for alkylation of a hydroxyl group having stable activity, and since the catalyst according to the present invention has excellent conversion and alkylation conversion of polyalkylene glycol, And can be usefully used for hydroxyl group alkylation. The present invention has been completed based on this finding.

It is an object of the present invention to provide a porous catalyst for alkylating a hydroxyl group.

Another object of the present invention is to provide a process for producing the porous catalyst for alkylating the hydroxyl group.

It is still another object of the present invention to provide a method for alkylating a hydroxyl group of a polyalkylene glycol.

In order to achieve the above object,

The present invention relates to a process for the production of zinc oxide and aluminum oxide,

Wherein the catalyst comprises 0.01 to 2 moles of aluminum atom per mole of the zinc atom.

The present invention also relates to a method for producing a micelle comprising dissolving a nonionic surfactant in water to form micelles (step 1);

Mixing the aluminum precursor and the zinc precursor into the micelle-formed solution obtained in the step 1 (step 2);

Adding a precipitant to the solution obtained in step 2 to form zinc-aluminum hydroxide (step 3); And

A step of calcining the zinc-aluminum hydroxide in the step 3 to prepare a porous catalyst for alkylation of a hydroxyl group containing zinc oxide and aluminum oxide (step 4); and to provide.

Further, the present invention provides a method for alkylating a hydroxyl group of a polyalkylene glycol comprising reacting an alkylating agent and a polyalkylene glycol in the presence of the catalyst.

The porous catalyst for hydroxyl group alkylation according to the present invention exhibits excellent polyalkylene glycol conversion and methylation conversion, and thus can be used economically and environmentally friendly for the alkylation of polyalkylene glycols.

1 is an FT-SEM image of a porous catalyst for alkylation of a hydroxyl group containing zinc oxide and aluminum oxide prepared in Example 1 of the present invention.
2 is an FT-SEM image of a porous catalyst for alkylation of a hydroxyl group containing zinc oxide and aluminum oxide prepared in Example 2 of the present invention.

Hereinafter, the present invention will be described in detail.

The present invention relates to a process for the production of zinc oxide and aluminum oxide,

Wherein the catalyst comprises 0.01 to 2 moles of aluminum atom per mole of the zinc atom.

In the porous catalyst for alkylating a hydroxyl group according to the present invention, it is more preferable that the porous catalyst contains 0.1 to 2 moles of aluminum atom per mole of zinc atoms, more preferably 0.5 to 2 moles.

The catalyst according to the present invention may further comprise an acid component. The organic acid may be, but is not limited to, HCl, HBr, HI, HF, H ₂ SO ₄ , H ₃ PO ₄ , HPO ₃ , H ₃ PO ₂ , H ₄ P ₂ O ₇ , HNO ₃ , H ₃ BO ₃ , ₄ , HClO ₃ S, H ₂ FO ₃ P, HPF ₆ , H ₂ SeO ₃ , H ₃ NO ₃ S, H ₂ SO ₃ , HBF ₄ , olophosphoric acid, pyrophosphoric acid, polyphosphoric acid, metaphosphoric acid and ultra phosphoric acid And an acid selected from the group consisting of salts thereof and salts thereof.

The cation for forming the salt is not particularly limited, but may be an alkali metal salt, an alkaline earth metal salt, or ammonium.

In the catalyst according to the present invention, the acid component is preferably contained in an amount of 0.1 to 2 mol, more preferably 0.1 to 1.5 mol, and still more preferably 0.1 to 1 mol, per 1 mol of the zinc atom.

The average pore size of the porous catalyst for hydroxyl group alkylation according to the present invention is preferably 40 to 100 m ² , and the active surface area is preferably 120 to 300 m ² / g.

Further, the porous catalyst for hydroxyl group alkylation according to the present invention is characterized by alkylating a hydroxyl group, and is not limited as long as it is a compound having a hydroxyl group, and can carry out alkylation. In particular, polyalkylene glycol Lt; / RTI > can be alkylated.

The present invention also relates to a method for producing a micelle comprising dissolving a nonionic surfactant in water to form micelles (step 1);

Mixing the aluminum precursor and the zinc precursor into the micelle-formed solution obtained in the step 1 (step 2);

Adding a precipitant to the solution obtained in step 2 to form zinc-aluminum hydroxide (step 3); And

A step of calcining the zinc-aluminum hydroxide in the step 3 to prepare a porous catalyst for alkylation of a hydroxyl group containing zinc oxide and aluminum oxide (step 4); and to provide.

Hereinafter, a method for preparing the porous catalyst for hydroxyl group alkylation according to the present invention will be described in detail.

In the preparation method according to the present invention, the step 1 is a step of dissolving a nonionic surfactant in water to form micelles.

In this case, the nonionic surfactant is not particularly limited as long as it is a nonionic surfactant that is soluble in water and has an alkyl group to which ethylene oxide is added, when the surfactant is dissolved in water.

In the present invention, a surfactant (OA10) having 10 moles of ethylene oxide added to oleyl alcohol is used, but the present invention is not limited thereto.

In the above production method according to the present invention, the step 2 is a step of mixing the aluminum precursor and the zinc precursor into the micelle-formed solution obtained in the step 1.

The aluminum precursor is not particularly limited as long as it is a precursor capable of providing aluminum, and at least one selected from the group consisting of aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum hydroxide, aluminum acetate, sodium aluminate and potassium aluminate Can be used.

The zinc precursor is not particularly limited as long as it is a precursor capable of providing zinc, and is preferably selected from the group consisting of zinc chloride, zinc nitrate, zinc sulfate, zinc hydroxide, zinc acetate, sodium hydroxide and potassium hydroxide May be used.

The aluminum precursor is preferably used in an amount of 0.01 to 2 mol based on 1 mol of the zinc precursor, more preferably 0.1 to 2 mol of the aluminum precursor relative to 1 mol of the zinc precursor, and 0.5 to 2 mol of the aluminum precursor More preferable.

When the aluminum precursor is used in an amount of 0.01 mol or less based on 1 mol of the zinc precursor, not only the catalytic active sites are diluted too much, but also the interactions between the catalysts are too weak to lower the purity of methylation. On the other hand, when the amount of the polyalkylene glycol is more than 2 moles, the polyalkylene glycol is too strongly bound to the finally obtained catalyst, so that the chain of the polyalkylene glycol is broken and the desired alkylated polyalkylene glycol can not be obtained.

Further, in step 2 of the production method according to the present invention, the acid precursor can be further mixed.

The acid precursor include, but are not particularly limited, HCl, HBr, HI, HF , H 2 S0 4, H 3 P0 4, HPO 3, H 3 P0 2, H 4 P 2 O 7, HNO 3, H 3 B0 3 , HClO ₄ , HClO ₃ S, H ₂ FO ₃ P, HPF ₆ , H ₂ SeO ₃ , H ₃ NO ₃ S, H ₂ SO ₃ , HBF ₄ , oleophosphoric acid, pyrophosphoric acid, polyphosphoric acid, And an acid selected from the group consisting of salts thereof and salts thereof.

The cation for forming the salt is not particularly limited, but may be an alkali metal salt, an alkaline earth metal salt, or ammonium.

The acid precursor is preferably used in an amount of 0.1 to 2 moles per 1 mole of the zinc precursor, more preferably 0.1 to 1.5 moles, and still more preferably 0.1 to 1 mole.

In the above production method according to the present invention, step 3 is a step of adding a precipitant to the solution obtained in step 2 to form zinc-aluminum hydroxide.

The precipitant may be a precipitant capable of forming zinc-aluminum hydroxide from a mixed solution of zinc precursor, aluminum precursor and acid precursor in Step 3. Preferably, basic compounds such as ammonia water, sodium hydroxide, potassium hydroxide, sodium carbonate, calcium carbonate and ammonium carbonate can be used, and more preferably, ammonia water or sodium hydroxide can be used.

It is preferable that the precipitating agent is added until the pH of the solution obtained in Step 2 is 8 to 9. When the pH is lower than the above range, a problem that the zinc-aluminum hydroxide is not sufficiently formed occurs, and when the precipitant is added in an excess amount and the pH is increased, the basicity of the catalyst is increased and the reactivity is lowered have.

In the above production method according to the present invention, the step 4 is a step of preparing a porous catalyst for alkylating a hydroxyl group containing zinc oxide and aluminum oxide by burning the zinc-aluminum hydroxide in the step 3.

The firing temperature range is preferably 300 to 900 占 폚, more preferably 400 to 700 占 폚, and still more preferably 500 to 600 占 폚. If the temperature is outside the calcining temperature range, a suitable catalyst form can not be formed, which may cause problems in that the conversion and alkylation conversion of the polyalkylene glycol are low when the catalyst is used.

In the method for producing the catalyst according to the present invention, after the step 3 is carried out, an aging step may be further carried out.

The aging is preferably carried out at room temperature.

Further, the present invention relates to a method for alkylating a hydroxyl group of a polyalkylene glycol comprising reacting an alkylating agent and a polyalkylene glycol in the presence of a porous catalyst for hydroxyl group alkylation comprising zinc oxide and aluminum oxide according to the present invention to provide.

Specifically, the alkylation method comprises reacting an alkylating agent and a polyalkylene glycol in the presence of a porous catalyst for the alkylation of a hydroxyl group, which comprises zinc oxide and aluminum oxide, at a reaction temperature of 110 to 200 ° C in a mass ratio of polyalkylene glycol: to be used in the range 1:20, and polyalkylene glycol-alkylating agent is passed through the mixture in atmospheric pressure to 3 kgf / cm ² pressure with a catalyst can be prepared by alkylating a polyalkylene glycol.

The alkylating agent is not particularly limited, but dialkyl carbonate can be used. It is preferred to use dimethyl carbonate or diethyl carbonate for eco-friendly alkylation where harmful substances are not generated.

The polyalkylene glycol which can be applied to the alkylation method according to the present invention may be any compound having a hydroxyl group at the terminal thereof, and includes polyether polyols, aryl alcohols, alkylene oxide adducts, and the like.

Specifically, the alkylation reaction is carried out in a fixed-bed continuous type while maintaining the pressure at a pressure ranging from atmospheric pressure to 3 kgf / cm ² at 110 to 200 ° C. At this time, if the reaction temperature is less than 110 ° C., The catalyst activity can not be expected. If the temperature is higher than 200 ° C., the stability of the catalyst due to sintering of the catalyst may be lowered, or the polyalkylene glycol as a starting material may be decomposed in the course of the reaction.

In addition, the mass ratio of the polyalkylene glycol to the alkylating agent may be 1: 1 to 1:20, and preferably 1: 2 to 1: 5. When the volume ratio is less than 1: 2, the conversion of the polyalkylene glycol is low. When the volume ratio is more than 1: 5, the amount of the alkylating agent exceeds the amount of the alkylating agent required for the reaction.

Hereinafter, examples and experimental examples of the present invention will be described in detail.

However, the following Examples and Experimental Examples are merely illustrative of the present invention, and the present invention is not limited to the following Examples and Experimental Examples.

< Example  1> zinc oxide and Aluminum oxide  Included Hydroxyl group  Preparation of porous catalyst for alkylation

To 160 g of distilled water, 5.0 g of a nonionic surfactant OA10 (solvent purchased: concentrated solvent, 10 moles of ethylene oxide in oleic alcohol, POLYOXYETHYLENE OLEYL ETHER) was dissolved to sufficiently form micelles. Then, 0.1 mol of AlCl ₃ .6H ₂ O is added to the aqueous solution of the micelles and stirred to prepare an aqueous solution of the first aluminum precursor. Then, 0.05 mol of ZnCl ₂ and 0.01 mol of H ₃ PO ₄ are added and dissolved sufficiently. 28% ammonia water was added to the prepared zinc-aluminum precursor aqueous solution so as to have a pH of 8.0 and stirred to form zinc-aluminum hydroxide. The zinc-aluminum hydroxide thus formed was aged at room temperature for 24 hours, sufficiently washed with distilled water, and then filtered. The filtered zinc-aluminum hydroxide was dried at 110 ° C for 24 hours and then calcined at 500 ° C for 3 hours to prepare a catalyst.

The catalysts were prepared in the same manner as in Example 1 except that only the conditions shown in Table 1 were used.

Example ZnCl ₂
(mole) AlCl ₃
(mole) H ₃ PO ₄
(mole) Firing temperature
(° C) One 0.05 0.1 0.01 500 2 0.05 0.1 0.01 600 3 0.05 0.1 0.01 400 4 0.05 0.1 0.01 700 5 0.05 0.1 0.05 500 6 0.03 0.1 0.05 500 7 0.05 0.1 0.03 500 8 0.05 0.05 0.01 500 9 0.05 0.1 0.005 500 10 0.05 0.1 0.001 500 11 0.03 0.1 0.01 500 12 0.05 0.01 0.01 500

< Experimental Example  1> Zinc oxide and Aluminum oxide  Included Hydroxyl group  Activation experiments of porous catalysts for alkylation

A cylindrical continuous reactor was placed in a cylindrical furnace equipped with a temperature controller, heated to 145 DEG C and held therein. Polypropylene glycol (purchased from Sigma- aldrich, average molecular weight = 2000-5000) and dimethyl carbonate were mixed at a weight ratio of 1: 3 and passed through a catalyst to carry out the reaction. At this time, unreacted dimethyl carbonate, methanol, carbon dioxide and the like were separated by distillation at a maximum temperature of 120 ° C.

The conversion and methylation conversion of the polyalkylene glycol were calculated by the following equations (1) and (2), and the calculation results for each case of Example 1-11 are shown in Table 2 below.

The conversion rate of the reaction was calculated by the formula (1), and the methylation conversion rate was calculated by the formula (2) and shown in Table 1. In this case, the hydroxyl value of the polyalkylene glycol of the formula (1) and the formula (2) was measured through the following blank measurement and calculated by the following equation (3). Specifically, the method of analyzing the hydroxy value of the polyalkylene glycol is as follows .

Blank measurement

Blank measurements were made by placing the magnetic bar in a 250 mL flask, adding 5 mL of imidazole and 25 mL of 1.95 N anhydrous phthalic acid, sealing well and slowly stirring.

In the measurement of the sample, a magnetic bar was placed in a 250 mL flask, and 11.99 g of the sample was added thereto. Then, 5 mL of imidazole and 25 mL of 1.95 N phthalic anhydride were added thereto in the same manner as in the blank measurement method, After stirring for 5 minutes, the blank measurement flask and the sample measurement flask were simultaneously reacted by heating in an oven at 100 DEG C for 50 minutes. After completion of the reaction, the reaction mixture was cooled at room temperature. Thereafter, the liquid on the flask wall was wiped with 25 mL of pyridine in the same manner as in the blank measurement flask and the sample measurement flask, and then 0.5 mL of 1% phenol phthalepyridine solution was added and stirred until the color changed with 0.5 N aqueous NaOH solution And the titration value of the blank and the appropriate value of the sample were measured.

The saponification value of the formula (2) was calculated by the following formula (4), and the specific saponification value acid starting method was as follows.

Experiment for calculating saponification value

A magnetic bar was placed in a 100 mL flask, and 6.0 g of a sample and 25 mL of a 0.5 N KOH aqueous solution were added thereto, and ethanol was added thereto while stirring until the mixture became transparent. The mixture was reduced for 30 minutes using a slurry duck, a reflux condenser and a stirrer, and then cooled at room temperature. After cooling, five drops of a 1% phenol phthalate ethanol solution were added thereto, and the mixture was titrated with 0.5 N HCl aqueous solution while stirring, and the saponification value was calculated by the following formula (4).

Example ZnCl
(mole) AlCl ₃
(mole) H ₃ PO ₄
(mole) Firing temperature
(° C) Conversion Rate
(%) Methylation conversion (%) One 0.05 0.1 0.01 500 98.90 95.20 2 0.05 0.1 0.01 600 99.03 95.11 3 0.05 0.1 0.01 400 95.26 89.51 4 0.05 0.1 0.01 700 97.09 87.33 5 0.05 0.1 0.05 500 96.60 88.55 6 0.03 0.1 0.05 500 95.40 80.71 7 0.05 0.1 0.03 500 97.95 91.28 8 0.05 0.05 0.01 500 99.75 90.34 9 0.05 0.1 0.005 500 96.60 88.55 10 0.05 0.1 0.001 500 93.40 85.62 11 0.03 0.1 0.01 500 93.12 88.11 12 0.05 0.01 0.01 500 93.02 85.12

As shown in Table 2,

The catalyst according to the present invention has a polyalkylene glycol conversion of 93% or more and a methylation conversion of polyalkylene glycol hydroxyl group of 80% or more, indicating excellent alkylation performance.

From the viewpoint of the production conditions of the catalyst,

It can be seen from Example 1-4 that when the sintering temperature is 500 to 600 ° C, it shows an excellent polyalkylene glycol conversion of 98% or more and an excellent methylation conversion rate of 95% or more,

It can be seen that the use of 0.01 to 2 mol of the aluminum precursor relative to 1 mol of the zinc precursor through Examples 1, 6, 8, 11 and 12 shows excellent polyethylene glycol conversion and methylation conversion rate,

It can be seen from Examples 1, 7, 8 and 10 that the acid precursor is used in an amount of 0.1 to 2 mol based on 1 mol of the zinc precursor, which indicates excellent polyethylene glycol conversion and methylation conversion rate.

Accordingly, the porous catalyst for hydroxyl group alkylation, which comprises zinc oxide and aluminum oxide according to the present invention, exhibits excellent polyalkylene glycol conversion and methylation conversion, and in particular, when the firing temperature is 500 to 600 ° C, When the aluminum precursor is used in an amount of 0.01 to 2 mol, and the acid precursor is used in the amount of 0.1 to 2 mol, remarkably excellent polyalkylene glycol conversion and methylation conversion are exhibited.

From the above results, it can be seen that the porous catalyst for alkylation of a hydroxyl group containing zinc oxide and aluminum oxide according to the present invention can be usefully used for the alkylation of polyalkylene glycols.

Claims (13)

Zinc oxide and aluminum oxide,
Wherein the catalyst comprises 0.01 to 2 moles of aluminum atom per mole of the zinc atom.
delete delete delete The method according to claim 1,
Wherein the porous catalyst for hydroxyl group alkylation has an average pore size of 40 to 100 m &lt; ² &gt;.
The method according to claim 1,
Wherein the active surface area of the porous catalyst for hydroxyl group alkylation is 120 to 300 m ² / g.
Dissolving the nonionic surfactant in water to form micelles (step 1);
Mixing the aluminum precursor and the zinc precursor into the micelle-formed solution obtained in the step 1 (step 2);
Adding a precipitant to the solution obtained in step 2 to form zinc-aluminum hydroxide (step 3); And
A process for producing a porous catalyst for hydroxyl group alkylation according to claim 1, comprising the steps of: (a) preparing a porous catalyst for hydroxyl group alkylation comprising zinc oxide and aluminum oxide by firing zinc-aluminum hydroxide in said step (3) Way.
8. The method of claim 7,
Wherein the acid precursor can be further mixed in step 2 above.
8. The method of claim 7,
Wherein the aluminum precursor is at least one selected from the group consisting of aluminum chloride, aluminum nitrate, aluminum sulfate, aluminum hydroxide, aluminum acetate, sodium aluminate, and potassium aluminate.
8. The method of claim 7,
Wherein the zinc precursor is at least one selected from the group consisting of zinc chloride, zinc nitrate, zinc sulfate, zinc hydroxide, zinc acetate, sodium hydroxide and potassium hydroxide.
8. The method of claim 7,
Wherein the aluminum precursor is used in a molar ratio of 0.01 to 2 with respect to 1 mole of the zinc precursor.
A process for alkylating a hydroxyl group of a polyalkylene glycol comprising reacting an alkylating agent and a polyalkylene glycol in the presence of the catalyst of claim 1. 9. The method of claim 8,
Wherein the acid precursor is present in an amount of 0.1 to 2 moles per mole of the zinc precursor.

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