CN110156597A - A kind of preparation method of Di-2-ethylhexyl terephthalate - Google Patents

Abstract

The present invention relates to a kind of preparation methods of Di-2-ethylhexyl terephthalate, comprising: in the presence of a catalyst, by terephthalic acid (TPA) and isooctanol haptoreaction, while except the water of dereaction generation；The catalyst is the bulk phase catalyst of siliceous, tin and oxygen and contains Sn-O-Si key.The conversion ratio and selectivity of the method for the present invention are high, and catalyst is easy to separate with reaction product and can be repeated as many times as required use.

Description

A kind of preparation method of Di-2-ethylhexyl terephthalate

Technical field

The present invention relates to a kind of preparation methods of Di-2-ethylhexyl terephthalate.

Background technique

Plasticizer is in the high molecular materials such as a kind of addition plastics, resin, elastomer, for improve they processability, The auxiliary agent of plasticity, flexibility, draftability.Di-2-ethylhexyl terephthalate (DOTP) is a kind of environment-friendly type plasticising haveing excellent performance Agent, compared with common phthalic acid ester, DOTP is with nontoxic, volatility is lower, electrical isolation and cryogenic property are more preferably excellent Point.

CN101234355A discloses a kind of effective catalyst for synthesizing dioctyl terephthalate, the catalyst Ti metal Compound, tin compound and other metallic compounds composition.CN104610063A discloses the total novel terephthaldehyde in The preparation method of dioctyl phthalate, this method using the tin compound of the titanium metal compound or compounding that compound as catalyst, The tin compound of middle compounding is obtained by mixing by stannous oxide and stannous octoate.

Esterification is one of most important organic reaction, and product is widely used in the every field of chemical industry.Ester Change reaction to generally require using catalyst, catalyst used can be divided into acidic catalyst and non-acidic catalyst.Acidic catalyst Agent is some inorganic acids and organic acid, and major defect is that reaction selectivity is poor, additionally, there may be burn into pollution, catalyst cannot The problems such as recycling is reused, product post-processing is difficult.Non-acidic catalyst is mainly aluminium, titanium, zirconium, tin, zinc, magnesium, antimony, bismuth etc. The compound of metal, these compounds can be used alone, and can also be made composite catalyst, typically no corrosivity, and And the selectivity of reaction is relatively high.Titanate esters are a kind of nonacid homogeneous catalysts, although catalytic activity is higher, need from It is decomposed in reaction product and removes catalyst, cause difficulty to the post-processing of product.The catalytic activity of stannous oxide is high, but aoxidizes sub- For tin when catalytic hydroxy acid esterifying reacts, catalyst is easy refinement and inactivation is very fast, is unfavorable for the long period fortune of continuous esterification technique Capable and batch esterification technique catalyst is reused.

CN1760339A, CN1740277A disclose stannous supported catalyst, and are used for high-acid crude oil or evaporate Divide the esterification decarboxylation of oil.US3520915 also discloses that stannous supported catalyst, catalyst be used to prepare unsaturated lipid Fat nitrile.Wenlei Xie etc. discloses stannic supported catalyst, and catalyst is used for the ester exchange reaction of soybean oil (Silica-Supported Tin Oxides as Heterogeneous Acid Catalysts for Transesterification of Soybean Oil with Methanol, Ind.Eng.Chem.Res.2012,51, 225–231).These catalyst not can be well solved refinement and the deactivation prob of catalyst.Vinicius etc. discloses aluminium With stannous composite oxides, and it is used for the esterification of soya fatty acid, the results showed that " with stannous oxide phase Than the catalytic activity of composite oxides lowers " (Metal oxides as heterogeneous catalysts for Esterification of fatty acids obtained from soybean oil, Fuel Processing Technology, 2011,92,53-57).

Summary of the invention

The present invention provides the preparation methods of Di-2-ethylhexyl terephthalate, and the method use a kind of new catalyzing esterifications Thus agent has higher catalytic activity and selectivity, and the catalyst is easy to separate with reaction product, and can be repeated several times makes With.

Specifically, the invention mainly comprises the following contents:

1. a kind of preparation method of Di-2-ethylhexyl terephthalate, comprising: in the presence of a catalyst, by terephthalic acid (TPA) With isooctanol haptoreaction, while except dereaction generate water；The catalyst is the bulk phase catalyst of siliceous, tin and oxygen and contains There is Sn-O-Si key.

2. according to preparation method described in 1, which is characterized in that while reaction, be passed through inert gas (preferably nitrogen).

3. according to aforementioned any preparation method, which is characterized in that under reflux state, reaction 2h~10h (preferably 3h~ 5h)。

4. according to aforementioned any preparation method, which is characterized in that alcohol and acid molar ratio be 2:1~6:1 (preferably 2.5:1~5:1).

5. according to aforementioned any preparation method, which is characterized in that the dosage of catalyst is the 0.1% of reactant gross mass ~10% (preferably 0.5%~5%).

6. according to aforementioned any preparation method, which is characterized in that further include: after reaction, vacuum distillation removing is light The step of the step of component and decoloration.

7. according to aforementioned any preparation method, which is characterized in that the catalyst is the body phase being made of silicon, tin and oxygen Catalyst.

8. according to aforementioned any preparation method, which is characterized in that in the catalyst, the molar ratio of silicon and tin is 0.8 ~6 (preferably 1.5~5).

9. according to aforementioned any preparation method, which is characterized in that in the catalyst, the mass fraction of tin is 23%~ 65% (preferably 26%~53%).

10. according to aforementioned any preparation method, which is characterized in that in the catalyst, the valence state of tin is divalent or four Valence.

11. according to aforementioned any preparation method, which is characterized in that in the Raman spectrum of the catalyst, in 237cm^-1 Nearby there are a characteristic peaks.

12. according to aforementioned any preparation method, which is characterized in that in the Raman spectrum of the catalyst, in 110cm^-1 Neighbouring and 211cm^-1There is no vibration peak nearby or there are the lesser characteristic peaks of relative intensity.

13. according to aforementioned any preparation method, which is characterized in that in the XRD spectrum of the catalyst, the not no oxygen of tin The characteristic peak of compound crystal.

14. according to aforementioned any preparation method, which is characterized in that the catalyst is unformed solid.

15. according to aforementioned any preparation method, which is characterized in that after reaction, isolate catalyst, and this is urged Agent is recycled and reused for the method.

In the prior art, stannous oxide is preferable nonacid esterification catalyst, but the catalyst has inactivation faster Problem, more seriously, the catalyst are easy gradually to refine in the reaction, cause to be difficult to separate catalyst with reaction product, Very big difficulty is brought to actual production, even if by load or metal composite oxide is made can not ideally solve these and ask Topic.The present inventor has been surprisingly found that in test, is co-precipitated with silicate and pink salt, and active higher, selectivity can be made more Esterification catalyst that is good and not refining；Also unexpectedly, the tetravalence tin catalyst that the method obtains also have well Activity, selectivity and thermal stability.Due to this discovery, the present inventor proposes and completes the present invention.

The invention has the following advantages that being combined more in used catalyst containing new tin species and silicon, tin, between oxygen Securely, to make reaction that there is higher conversion ratio and selectivity；And catalyst is easy to separate with reaction product and can be more Secondary reuse；When stoichiometric ratio of the reactant dosage close to reaction, very high conversion ratio and selectivity still can reach, Recycle stock is seldom, and Atom economy is stronger.In addition, method of the invention does not need to include washing step (alkali cleaning and washing).

Other features and advantages of the present invention will be further described in specific embodiment part.

Detailed description of the invention

Fig. 1 is the XPS photoelectron spectroscopy of stannous oxide and stannic oxide.

Fig. 2 is the photoelectron spectroscopy for preparing the catalyst A in embodiment 1 and the catalyst G in preparation comparative example 1.

Fig. 3 is the Raman light for preparing the catalyst A in embodiment 1, the catalyst G in preparation comparative example 1 and stannous oxide Spectrum.

Fig. 4 is the scanning electron microscope (SEM) photograph of stannous oxide.

Fig. 5 is the scanning electron microscope (SEM) photograph for preparing the catalyst A in embodiment 1.

Fig. 6 is the scanning electron microscope (SEM) photograph for preparing the catalyst G in comparative example 1.

Fig. 7 is the XRD spectrum of stannous oxide.

Fig. 8 is the XRD spectrum for preparing the catalyst J in comparative example 4.

Fig. 9 is the XRD spectrum for preparing the catalyst E in embodiment 5.

Specific embodiment

Below in conjunction with the specific embodiment detailed description present invention, but it should be noted that, protection scope of the present invention is not by these The limitation that specific embodiment and principle are explained, but determined by claims.

In the present invention, other than the content clearly stated, any matters or item that do not mention are directly applicable in ability Without carrying out any change those of known to domain.Moreover, any embodiment described herein can with it is described herein One or more other embodiments freely combine, and the technical solution or technical idea being consequently formed are accordingly to be regarded as the original public affairs of the present invention It opens or a part of original description, and is not considered as the new content for not disclosing or being expected herein, unless this field skill Art personnel think that the combination is obvious unreasonable.

All features disclosed in this invention can in any combination, these combinations should be understood presently disclosed or note The content of load, unless those skilled in the art think that the combination is obviously unreasonable, such as in the present invention, " silicon and tin molar ratio The combination of any range " and " any ranges of Theil indices in catalyst " should all be considered as specifically being disclosed and being remembered by the present invention It carries.Numerical point disclosed in this specification includes not only specifically disclosed numerical point in embodiment, further includes each number in specification It is worth the endpoint of range, the range of these numerical point institute any combination is regarded as the range that the present invention is disclosed or recorded.

Technical and scientific term in the present invention, provide definition be subject to its definition, do not provide definition then by ability The common meaning in domain understands.

In the present invention, " optional " is meant that, including or does not include that for example " optional A " refers to including A or do not include A.

In the present invention, inert gas refers to the gas having no adverse effect to catalyst performance.

In catalyst of the invention, the sum of each component content is 100%.

The present invention provides a kind of preparation methods of Di-2-ethylhexyl terephthalate, comprising: in the presence of a catalyst, will Terephthalic acid (TPA) and isooctanol haptoreaction, while except the water of dereaction generation；The catalyst is the body phase of siliceous, tin and oxygen Catalyst and contain Sn-O-Si key.

According to the present invention, 2h~10h is generally reacted at reflux, preferably reaction 3h~5h.

According to the present invention, the molar ratio of acid and alcohol is (1:2)~(1:6), preferably (1:2.5)~(1:5).

According to the present invention, as a kind of means for adjusting regurgitant volume and/or a kind of measure for protecting reaction system, Ke Yi While reaction, it is passed through inert gas into reactor, for example is passed through nitrogen or argon gas.

According to the present invention, it using isooctanol itself as water entrainer, is not required to that water entrainer additionally is added.

According to the present invention, the dosage of the catalyst be reactant gross mass 0.1%~10%, preferably 0.5%~ 5%.

According to the present invention, the method also includes: after the completion of reaction, isolate catalyst, and the catalyst is repeated For the method.

According to the present invention, the method also includes: after the completion of reaction, by vacuum distillation remove light component the step of and The step of decoloration.In the decolorization process, it is preferred to use the mode of activated carbon adsorption, adsorption temp can be 90 DEG C~120 DEG C, Preferably 100 DEG C~110 DEG C；Adsorption time can be 1h~4h, preferably 2h~3h.

According to the present invention, the catalyst is the bulk phase catalyst of siliceous, tin and oxygen and contains Sn-O-Si key, preferably The bulk phase catalyst that be made of silicon, tin and oxygen and contains Sn-O-Si key.

In the catalyst, as optional component, the other elements other than tin can be contained.The present invention does not have these elements There is special limitation, as long as these elements do not adversely affect to catalyst performance or have other benefits significantly, so that it may These elements are introduced when preparing the catalyst, these elements include but is not limited in aluminium, titanium, zirconium, tin, zinc, magnesium, antimony and bismuth One or more.

In the catalyst, impurity can be contained, as long as its type and content does not significantly reduce catalyst performance.One As for, in catalyst of the invention, in terms of sodium oxide molybdena, the mass fraction of sodium is lower than 0.03%.

Unlike the prior art, the catalyst is bulk phase catalyst.The analysis of XPS the result shows that, body phase is made Catalyst causes new tin species to generate, and hence improves the performance of tin catalyst.Due to not using tradition in bulk phase catalyst Carrier, therefore can break through the load capacity of supported catalyst and the limitation of Active components distribution, there is the catalyst can more Low silicon tin molar ratio, still improves the catalytic activity, selectivity and stability of tin catalyst at this time, and make catalyst be easy with Reaction product separation；The catalyst can also have high silicon tin molar ratio (1~22), and catalyst has more preferably stable at this time Property, and be easier to separate with reaction product.The present invention is not particularly limited the molar ratio of silicon and tin, in the teachings of the present invention Under, those skilled in the art easily choose suitable silicon tin molar ratio.

In the catalyst, the molar ratio of silicon and tin can be 0.5~22, preferably 0.8~6, more preferably 1~5, into One step preferably 1.5~5.

In the catalyst, the mass fraction of tin can be 8%~72%, preferably 23%~65%, more preferably 26%~61%, further preferred 26%~53%.

In the catalyst, the valence state of tin can be divalent and/or tetravalence, preferably divalent.

, according to the invention it is preferred in the XRD spectrum of the catalyst, the not no characteristic peak of the oxide crystal of tin, i.e., There is no the characteristic peak of tin oxide crystal and stannous oxide crystal.The catalyst roasts 3h at 500 DEG C under nitrogen protection Afterwards, in XRD spectrum, there is no sharp crystal characteristic peak between 5 °~70 °；And existing silica gel load tin catalyst, After handling under similarity condition, then occurs sharp crystal characteristic peak within this range.

According to the present invention, by the XRD spectrum of the catalyst it is found that the catalyst is unformed solid.

Under nitrogen protection, after the catalyst roasts 3h at 300 DEG C, in Raman spectrum, in 237cm^-1Nearby deposit In a characteristic peak；And the tin catalyst of existing silica gel load, it is after being handled under similarity condition, then special without this nearby herein Levy peak or there is with 110cm^-1Neighbouring characteristic peak and 211cm^-1The neighbouring characteristic peak feature all small compared to relative intensity Peak.Wherein, the relative intensity of two characteristic peaks is compared with the peak area size of the two, peak area big characteristic peak relative intensity Larger, the relative intensity of the small characteristic peak of peak area is smaller.

, according to the invention it is preferred in the Raman spectrum of the catalyst, in 110cm^-1Neighbouring and 211cm^-1Do not have nearby Characteristic peak.

In a kind of situation, after the catalyst roasts 3h at 300 DEG C under nitrogen protection, in Raman spectrum, 110cm^-1Neighbouring and 211cm^-1Nearby without characteristic peak；And the tin catalyst of existing silica gel load, it is handled under similarity condition Afterwards, then in 110cm^-1Neighbouring and 211cm^-1Nearby respectively there is an apparent characteristic peak.

In another case, after the catalyst roasts 3h at 300 DEG C under nitrogen protection, in Raman spectrum, 110cm^-1Neighbouring and 211cm^-1Nearby there is characteristic peak, but existing characteristic peak and 237cm^-1Neighbouring characteristic peak is compared, phase All small to intensity (such as in 110cm^-1Neighbouring and 211cm^-1Nearby respectively have a characteristic peak, any characteristic peak with 237cm^-11/2) peak area ratio of neighbouring characteristic peak is both less than；And the tin catalyst of existing silica gel load, under similarity condition After processing, if in 237cm^-1Nearby there is characteristic peaks, then in 110cm^-1Neighbouring and 211cm^-1Any feature nearby occurred Peak, relative intensity is all very big by comparison, and the ratio between peak area is much larger than 1.

The present invention provides the preparation methods of the catalyst, including being co-precipitated to the pink salt and silicate that are dissolved in water The step of；In the water, dissolved with or not dissolved with sour (preferably inorganic acid, such as hydrochloric acid, sulfuric acid or nitric acid)；In the water, dissolved with Or not dissolved with other metal salts other than tin.

In the preparation method of the catalyst, the mode of co-precipitation is not particularly limited, existing suitable mode is all It can be used.For example the aqueous solution of pink salt can be both added in aqueous silicate solution, aqueous silicate solution can also be added Into the aqueous solution of pink salt, the two can also directly be mixed or be mixed in a manner of being added dropwise simultaneously, then be allowed to precipitate Entirely.If acid is added, preferable mode is that acid is charged first in tin salt aqueous solution, then again by tin salt aqueous solution and silicate Aqueous solution mixing；If other metal salts are added, preferable mode is also that other metal salts are charged first in tin salt aqueous solution, Then tin salt aqueous solution is mixed with aqueous silicate solution again；If acid and other metal salts are added simultaneously, preferable mode is Acid and other metal salts are all added in tin salt aqueous solution, then use tin salt aqueous solution impregnated carrier again.

In the preparation method of the catalyst, the silicate is generally one or more of sodium metasilicate and potassium silicate.

In the preparation method of the catalyst, the pink salt is generally stannous chloride (including anhydrous stannous chloride or two water Stannous chloride), one or more of tin tetrachloride (including anhydrous stannic chloride or stannic chloride pentahydrate) and stannous sulfate.

In the preparation method of the catalyst, the molar ratio silicon of silicon and tin can be 0.5~22, preferably 0.8~6, more Preferably 1~5, further preferably 1.5~5.

The dosage of the preparation method of the catalyst, silicate and pink salt is respectively with the mole of silicon atom and tin atom Meter, sour dosage preferably satisfy following relationship with the molar amount of releasable proton, the dosage of silicate, pink salt and acid: M_Si- M_Sn=2 × M_Proton。

In the preparation method of the catalyst, the type and dosage of other metal salts are not particularly limited, only Not adversely affect or have other benefits significantly to catalyst performance, so that it may introduce when preparing the catalyst suitable Other metal salts of equivalent.Other described metal salts are preferably selected from aluminium salt, titanium salt, zirconates, pink salt, zinc salt, magnesium salts, antimonic salt and bismuth One or more of salt.

In the preparation method of the catalyst, the temperature of co-precipitation is generally at room temperature (such as 25 DEG C~40 DEG C).

In the preparation method of the catalyst, this method further includes, and after mixing reactant, adjusts the behaviour of aqueous pH values Make.The general pH value for adjusting water phase is 2~12, preferably 4~8, more preferable 4~7.The present invention exchange section aqueous pH values medicament and Mode is not particularly limited, and is adjusted with common aqueous alkali, such as with NaOH aqueous solution, KOH aqueous solution or ammonium hydroxide Solution carrys out the pH value of regulation system.

In the preparation method of the catalyst, after co-precipitation, preferably precipitating is kept a period of time in water, it is general to keep 0.1h~8h can (preferably 0.5h~5h)；The temperature kept in water is generally 25 DEG C~70 DEG C, temperature when preferably precipitating Degree.

In the preparation method of the catalyst, by filtering, easily the precipitating can be separated from water phase.

In the preparation method of the catalyst, the precipitating (is generally washed) preferably through washing, heat treatment, then To catalyst of the invention.

In the preparation method of the catalyst, the temperature of the heat treatment is generally 80 DEG C~600 DEG C, preferably 200 DEG C~ 500 DEG C, more preferable 250 DEG C~350 DEG C.The heat treatment, is preferably handled under inert gas protection, such as in nitrogen Or it is carried out under the protection of argon gas.The time of the heat treatment is generally 2h~5h, preferably 3h~5h.

Embodiment part

The present invention will be described in detail by the following examples, and however, the present invention is not limited to these examples.

In the context of the present specification, all medicaments and raw material both can be commercially available, can also know according to having Know manufacture.In embodiment below and comparative example, unless otherwise specified, used reagent is that analysis is pure.

In the context of the present specification, it is included in embodiment below and comparative example, the oxidation in test and analysis Stannous then passes through the processing of " under nitrogen protection, roasting 3 hours at 200 DEG C " unless otherwise instructed；Oxygen in test and analysis Change tin unless otherwise instructed, then passes through the processing of " under nitrogen protection, roasting 3 hours at 500 DEG C ".

In the context of the present specification, it is included in embodiment below and comparative example, X-ray photoelectron spectroscopic analysis (XPS) using the ESCALab220i-XL type x-ray photoelectron spectroscopy of VG Scientific company production.(test condition: Excitation light source is monochromatization Al K α X-ray, and power 300W, base vacuum is 3 × 10^-9Mbar, electron binding energy simple substance carbon The peak C1s correction.).

In the context of the present specification, it is included in embodiment below and comparative example, X-ray fluorescence spectra analysis (XRF) using the 3271E type Xray fluorescence spectrometer of Rigaku electric machine industry Co., Ltd. production, with scintillation counter and Proportional counter detects the intensity of spectral line, carries out quantitative and semi-quantitative analysis (test condition: powder pressure to constituent content with external standard method Sheetmolding, rhodium palladium, excitation voltage 50kV, excitation current 50mA).

In the context of the present specification, it is included in embodiment below and comparative example, Atomic Emission Spectrometer AES (ICP- AES) (test condition: catalyst is dissolved in using the measurement of 16 type inductively coupled plasma atomic emission of U.S. Atom Scan HCl and HF volume ratio are to be cleared up in the solution of 50:1 using the microwave dissolver of U.S. CE M production.).

In the context of the present specification, it is included in embodiment below and comparative example, Raman spectrum uses France JY Company LAM-800 laser co-focusing Raman spectrometer (test condition: incident light 532nm, resolution ratio 4cm^-1, scanning range For 100~1200cm^-1)。

In the context of the present specification, it is included in embodiment below and comparative example, scanning electron microscope (SEM) Using FEI Co. production Quanta 200F type scanning electron microscope (test condition: sample drying processing after, be evaporated in vacuo metal spraying, To increase electric conductivity and contrast effect, analytic electron microscope accelerating potential 20.0KV, amplification factor is 1~30k).

In the context of the present specification, it is included in embodiment below and comparative example, X-ray powder diffraction (XRD) Using the D5005 type X-ray diffractometer (test condition: Cu target, K α radiation, Ni filter plate, pipe electricity of Siemens production Press 35kV, tube current 45mA, 2 θ=5~70 ° of scanning range).

In the context of the present specification, it is included in embodiment below and comparative example, the calculation method of esterification yield is It is as follows:

The measurement of acid value is using method specified in GB-1668-2008-T in above-mentioned esterification yield calculation method.

In the context of the present specification, it is included in embodiment below and comparative example, esterification selectively uses U.S.'s Agilent 7890A gas chromatograph, chromatographic condition: capillary column (50m × 0.2mm × 0.5 μm), fid detector, inspection 280 DEG C of room temperature are surveyed, column temperature, to 260 DEG C, is gasified 280 DEG C of room temperature, hydrogen flowing quantity 30mL/min by 60 DEG C of temperature programmings, air Flow 400mL/min, nitrogen pressure 10MPa.

Calculation method is as follows:

Prepare embodiment 1

Take 2.26g stannous chloride dihydrate (SnCl₂·2H₂O it) is dissolved in 10ml deionized water, takes Na₂O·SiO₂·9H₂O It is dissolved in deionized water.Two kinds of solution are added in flask simultaneously at 30 DEG C, the Si/Sn ratio that feeds intake is 1, and ammonia spirit is added Adjusting pH value is 6, after precipitating is complete, continues to be kept for 2 hours at 50 DEG C, and filtering, washing are dried at 80 DEG C, then in nitrogen 3 hours are roasted to get tin catalyst of the invention, number A in 300 DEG C under gas shielded.

Through XRF analysis, the Si/Sn molar ratio of catalyst is 0.96.

Through XPS analysis, on catalyst surface, tin atom mass fraction is 5.12%；Through icp analysis, in catalyst, tin Mass fraction is 63.5%.

Prepare embodiment 2

Take 2.26g stannous chloride dihydrate (SnCl₂·2H₂O it) is dissolved in the aqueous hydrochloric acid solution that 80ml concentration is 1mol/L, Take Na₂O·SiO₂·9H₂O is dissolved in deionized water.Two kinds of solution are added in flask simultaneously at 30 DEG C, feed intake Si/Sn Than being 5, it is 7 that ammonia spirit, which is added, and adjusts pH value, after precipitating is complete, continues to be kept for 2 hours at 30 DEG C, be filtered, washed, 80 It is dried at DEG C, then roasts 4 hours in 250 DEG C under nitrogen protection to get tin catalyst of the invention, number B.

Through icp analysis, in catalyst, the mass fraction of tin is 27.2%.

Prepare embodiment 3

It takes 2.15g stannous sulfate to be dissolved in 10ml deionized water, takes Na₂O·SiO₂·9H₂O is dissolved in deionized water. Two kinds of solution are added in flask simultaneously at 30 DEG C, the Si/Sn ratio that feeds intake is 1, and it is 7 that ammonia spirit, which is added, and adjusts pH value, is sunk After forming sediment completely, continues to be kept for 4 hours at 30 DEG C, be filtered, washed, dried at 80 DEG C, then under nitrogen protection in 300 DEG C Roasting 3 hours to get tin catalyst of the invention, number C.

Through XRF analysis, the Si/Sn molar ratio of catalyst is 0.99.

Through icp analysis, in catalyst, the mass fraction of tin is 61.2%.

Prepare embodiment 4

It takes 2.15g stannous sulfate to be dissolved in the aqueous hydrochloric acid solution that 40ml concentration is 1mol/L, takes K₂O·SiO₂It is dissolved in Deionized water.Two kinds of solution are added in flask simultaneously at 30 DEG C, the Si/Sn ratio that feeds intake is 3, and ammonia spirit is added and adjusts pH Value is 7, after precipitating is complete, continues to be kept for 2 hours at 30 DEG C, is filtered, washed, dries at 80 DEG C, then in nitrogen protection Under in 250 DEG C roast 4 hours to get tin catalyst of the invention, number D.

Through XRF analysis, the Si/Sn molar ratio of catalyst is 3.02.

Through icp analysis, in catalyst, the mass fraction of tin is 37.3%.

Prepare embodiment 5

Take 2.26g stannous chloride dihydrate (SnCl₂·2H₂O it) is dissolved in the aqueous hydrochloric acid solution that 80ml concentration is 1mol/L, Take K₂O·SiO₂It is dissolved in deionized water.Two kinds of solution are added in flask simultaneously at 30 DEG C, the Si/Sn ratio that feeds intake is 5, is added Entering ammonia spirit to adjust pH value is 7, after precipitating is complete, continues to be kept for 4 hours at 30 DEG C, is filtered, washed, dries at 80 DEG C It is dry, then 3 hours are roasted to get tin catalyst of the invention, number E in 500 DEG C under nitrogen protection.

Through icp analysis, in catalyst, the mass fraction of tin is 27.1%.

Prepare embodiment 6

Take 3.51g stannic chloride pentahydrate (SnCl₄·5H₂O it) is dissolved in 10ml deionized water, takes Na₂O·SiO₂·9H₂O It is dissolved in deionized water.Two kinds of solution are added in flask simultaneously at 30 DEG C, the Si/Sn ratio that feeds intake is 2, and it is molten that ammonium hydroxide is added Liquid adjusts pH value, after precipitating is complete, continues to be kept for 0.5 hour at 50 DEG C, is filtered, washed, dries at 80 DEG C, then exist 3 hours are roasted to get tin catalyst of the invention, number F in 200 DEG C under nitrogen protection.

Through icp analysis, in catalyst, the mass fraction of tin is 44.0%.

Prepare comparative example 1

Take 5g stannous chloride dihydrate (SnCl₂·2H₂O) it is configured to SnCl₂The aqueous solution that mass fraction is 10%, thereto 10g silica gel is added, stirs 10h, then the ammonia spirit that mass fraction is 20% is added thereto, stirs evenly, washs, filtering, Drying roasts 3 hours tin catalysts to get comparison, number G in 300 DEG C under nitrogen protection.

Through icp analysis, in catalyst, the mass fraction of tin is 20.1%.

Prepare comparative example 2

Catalyst is prepared using method identical with preparation comparative example 1, the difference is that only: stannous chloride dihydrate (SnCl₂·2H₂O dosage) is 4g.Catalyst number is H.

Through icp analysis, in catalyst, the mass fraction of tin is 16.4%.

Prepare comparative example 3

Catalyst is prepared using method identical with preparation comparative example 1, the difference is that only: stannous chloride dihydrate (SnCl₂·2H₂O dosage) is 7g.Catalyst number is I.

Through icp analysis, in catalyst, the mass fraction of tin is 25.3%.

Prepare comparative example 4

Prepare catalyst using with the identical method of preparation comparative example 1, the difference is that only: under nitrogen protection in 500 DEG C roast 3 hours.Catalyst number is J.

Through icp analysis, in catalyst, the mass fraction of tin is 20.1%.

React embodiment 1

This example demonstrates that preparing the effect of Di-2-ethylhexyl terephthalate.

In reaction system, the molar ratio of terephthalic acid (TPA) and isooctanol is 1:2.5, adds reactant gross mass 1% Catalyst.It is passed through nitrogen, is warming up to reflux, reflux water-dividing while reaction is stirred to react 4 hours.After reaction, stop stirring It mixes, stands 10 minutes, sampling, observation upper phase.Separation liquid-phase reaction product and catalyst, liquid-phase reaction product send analysis, Calculate esterification yield and selectivity.

Reaction result is shown in Table 1.

React embodiment 2

The reuse effect of the present embodiment catalyst of the invention for comparative illustration, the catalyst of load and stannous oxide Fruit.

It is carried out according to the method for reaction embodiment 1, unlike: except first set reaction is sub- using catalyst A, G and oxidation Outside tin, the catalyst of later each reaction reuses the catalyst of upper secondary response recycling；Wherein, the campaign of catalyst A The mode for being all made of filtering recycles, the campaign of catalyst G and stannous oxide, due to the original of filtration difficulty and catalyst loss Cause, the mode for being all made of centrifugation recycle catalyst.

Reaction result is shown in Table 2.

React embodiment 3

It is carried out according to the method for reaction embodiment 1, the difference is that only: the molar ratio of terephthalic acid (TPA) and isooctanol is 1:3, catalyst amount are the 3% of reactant gross mass, reaction time 5h.After reaction, separation liquid-phase reaction product and Catalyst, liquid-phase reaction product send analysis.By Analysis result calculation, the esterification yield of reaction is 99.80%, and the selectivity of reaction is 99.50%.

Liquid product removes excessive alcohol by vacuum distillation, then uses active carbon stirring and adsorbing 2 hours at 100 DEG C (decoloration) filters to obtain yellowish transparency liquid product.

React embodiment 4

It is carried out according to the method for reaction embodiment 1, the difference is that only: the molar ratio of terephthalic acid (TPA) and isooctanol is 1:4, catalyst amount are the 5% of reactant gross mass, reaction time 6h.After reaction, separation liquid-phase reaction product and Catalyst, liquid-phase reaction product send analysis.By Analysis result calculation, the esterification yield of reaction is 99.82%, and the selectivity of reaction is 99.25%.

Liquid product removes excessive alcohol by vacuum distillation, then uses active carbon stirring and adsorbing 2 hours at 100 DEG C (decoloration) filters to obtain yellowish transparency liquid product.

Table 1

Table 2

As seen from Figure 1, it is the combination energy of tin in stannous oxide at 486.31ev, is tin in stannic oxide at 486.53ev Combination energy.From Figure 2 it can be seen that for using silica as the combination energy of tin in the supported catalyst of carrier at 487.89ev, It is the combination energy of tin in catalyst of the present invention at 488.31.By Fig. 1 and Fig. 2 it is found that the combination of tin can be most in catalyst of the present invention It is high.

As seen from Figure 3, in 110cm^-1Neighbouring and 211cm^-1Near, supported catalyst and stannous oxide have consistent two Characteristic peak, and the two no characteristic peaks of catalyst of the invention, on the contrary in 237cm^-1Near, there are one for catalyst of the invention A supported catalyst and the no strong characteristic peak of stannous oxide.

From fig. 4, it can be seen that the stannous oxide cuboid particle single for pattern (unprocessed after purchase).As seen from Figure 5, originally The catalyst of invention is the uniform substance of appearance together without clearly profile, cluster.As seen from Figure 6, loaded catalyst In, hence it is evident that visible carrier is the inhomogenous substance of appearance.

By Fig. 7, Fig. 8 and Fig. 9 as it can be seen that existing load tin catalyst (under nitrogen protection, 500 DEG C are roasted 3 hours) and oxygen Changing stannous, there are multiple sharp crystal characteristic peaks between 5 °~70 °, and catalyst of the invention does not have between 5 °~70 ° Sharp crystal characteristic peak.

By Fig. 7, Fig. 8 and Fig. 9 as it can be seen that under nitrogen protection, after being roasted 3 hours at 500 DEG C, supported catalyst and oxidation There are multiple sharp crystal characteristic peaks between 5 °~70 ° for stannous, and catalyst of the invention is no sharp between 5 °~70 ° Sharp crystal characteristic peak.

Claims (15)

1. a kind of preparation method of Di-2-ethylhexyl terephthalate, comprising: in the presence of a catalyst, by terephthalic acid (TPA) with it is different Octanol haptoreaction, while except the water of dereaction generation；The catalyst is the bulk phase catalyst of siliceous, tin and oxygen and contains Sn-O-Si key.

2. preparation method described in accordance with the claim 1, which is characterized in that under reflux state, react 3h~5h.

3. preparation method described in accordance with the claim 1, which is characterized in that the molar ratio of alcohol and acid is 2.5:1~5:1.

4. preparation method described in accordance with the claim 1, which is characterized in that while reaction, be passed through nitrogen.

5. preparation method described in accordance with the claim 1, which is characterized in that the dosage of catalyst is reactant gross mass 0.5%~5%.

6. preparation method described in accordance with the claim 1, which is characterized in that further include: after reaction, vacuum distillation removing is light The step of the step of component and decoloration.

7. preparation method described in accordance with the claim 1, which is characterized in that the catalyst is the body being made of silicon, tin and oxygen Phase catalyst.

8. preparation method described in accordance with the claim 1, which is characterized in that in the catalyst, the molar ratio of silicon and tin is 0.8 ~6 (preferably 1.5~5).

9. preparation method described in accordance with the claim 1, which is characterized in that in the catalyst, the mass fraction of tin is 23% ~65%.

10. preparation method described in accordance with the claim 1, which is characterized in that in the catalyst, the valence state of tin is divalent or four Valence.

11. preparation method described in accordance with the claim 1, which is characterized in that in the Raman spectrum of the catalyst, in 237cm^-1 Nearby there are a characteristic peaks.

12. preparation method described in accordance with the claim 1, which is characterized in that in the Raman spectrum of the catalyst, in 110cm^-1 Neighbouring and 211cm^-1There is no vibration peak nearby or there are the lesser characteristic peaks of relative intensity.

13. preparation method described in accordance with the claim 1, which is characterized in that in the XRD spectrum of the catalyst, not no tin The characteristic peak of oxide crystal.

14. preparation method described in accordance with the claim 1, which is characterized in that the catalyst is unformed solid.

15. preparation method described in accordance with the claim 1, which is characterized in that after reaction, isolate catalyst, and should Catalyst is recycled and reused for the method.