A kind of preparation method of pentaerythritol tetraoctyl stearate
Technical field
The invention belongs to chemosynthesis technical field, the preparation method being specifically related to a kind of pentaerythritol tetraoctyl stearate.
Background technology
Pentaerythritol tetraoctyl stearate is a kind of liquid fat with bigger relative molecular mass, basic odorlessness, has the combination of 4 ester bonds, forms stereochemical structure, belongs to the ester that is obstructed;There is higher heat stability, there is film forming, water resistant, skin moistening function, be the emollient of performance brilliance.Pentaerythritol tetraoctyl stearate is mainly used in the products such as protective skin cream, sunscreen product, color make-up, shampoo hair conditioner.
The conventional esterification methods of pentaerythritol tetraoctyl stearate is that tetramethylolmethane and isostearic acid high temperature generation esterification form under the effects such as acidic catalyst such as p-methyl benzenesulfonic acid.The method adopting alkali cleaning is needed the catalyst in product and excessive isostearic acid to be removed after its flaw response, owing to pentaerythritol tetraoctyl stearate is a kind of high viscosity ester coming from chain saturated fatty acids, emulsifying is very easily there is when alkali cleaning and washing, layering difficulty, it is difficult to normal hierarchical operations, even if being layered reluctantly, acid number reduces also inconspicuous, and the yield of product can substantially reduce, simultaneously need to alkali cleaning, the operations such as washing, produce a large amount of waste water, contaminated environment, this mode of production has not met the requirement of current environmental protection policy and Green Chemistry.
Simultaneously because tetramethylolmethane has four hydroxyls, steric effect is big, esterification difficulty, so the reaction time of esterification length (8~24h) of polyhydric alcohol and fatty acid, reaction temperature high (160~240 DEG C).Therefore, many scholars are devoted to research and develop a kind of new synthesis technique or catalyst to optimize its preparation condition both at home and abroad, improve productivity.
Metal-oxide such as zinc oxide, aluminium oxide, Tin monoxide etc. can some esterifications of catalysis, as Chinese patent application CN101293828A uses the synthesis of zinc oxide or Ferric Chloride pentaerythritol isostearic acid ester, but it yet suffers from reaction temperature height, the problem that product quality is poor.Metal composite oxide has the crystal structure of uniqueness, electromagnetic property and higher catalysis activity due to it, obtaining paying attention to widely and application in raw catelyst material, preparation method conventional at present has freeze-drying, high temperature and high pressure synthesis, infusion process, coprecipitation, hydro-thermal method, sol-gel process, microwave liquid method etc..
To sum up, it is necessary to the preparation method researching and developing a kind of pentaerythritol tetraoctyl stearate, to reduce reaction temperature, shorten the response time, and improve productivity and the quality of pentaerythritol tetraoctyl stearate.
Summary of the invention
In order to solve problems of the prior art (reaction temperature is high, the response time is long, and productivity is on the low side), the preparation method that the invention provides a kind of pentaerythritol tetraoctyl stearate, the method reaction temperature is low, and the response time is short, and productivity is high.
The preparation method that the present invention provides a kind of pentaerythritol tetraoctyl stearate, comprises the following steps:
S1, tetramethylolmethane and isostearic acid put in reactor according to mol ratio 1: 4.0~4.2 feeding, open stirring;
S2, addition metal composite oxide, 4~5h is reacted at 140~150 DEG C, reaction terminates, separate metal composite oxide, obtain pentaerythritol tetraoctyl stearate crude product, crude product is decompressed to 0.05 negative~0.1Mpa at 100~130 DEG C, and organic solvent and water are distilled off, and namely obtains pentaerythritol tetraoctyl stearate product after filtration.
Preferably, described step S2 carries out under nitrogen protection.
Preferably, the addition of described metal composite oxide is the 0.2~1% of isostearic acid weight.
Preferably, the preparation method of described metal composite oxide is as follows: weigh ZnCl2·2H2O and FeCl2·4H2O is made into mixed-salt aqueous solution, separately weighs NaOH and Na2CO3It is made into mixed base aqueous solution;Two kinds of solution is simultaneously introduced in rotating liquid-film reactor fast nucleation according to volume ratio 1: 1, and circulates 2min;Then microwave treatment 1~2h under 700~800w, crystallization 12h, filtration at normal temperatures, obtains much filtrate subsequently;Then through 60 DEG C of dry 12h after washing much filtrate, finally move into roasting 2~3h in 500~600 DEG C of muffle furnaces, obtain Zn-Fe metal composite oxide.
It is furthermore preferred that c (Zn in described mixed-salt aqueous solution2+) concentration be 0.2~0.4mol L-1, c (Fe2+) concentration be 0.6~0.8mol L-1。
It is furthermore preferred that c (OH in described mixed base aqueous solution-) concentration be 0.6~0.8mol L-1, c (CO3 2-) concentration be 0.9~1.2mol L-1。
nullIn the preparation of pentaerythritol tetraoctyl stearate,Owing to tetramethylolmethane has four hydroxyls,Steric effect is big,Esterification difficulty,In order to reduce esterification difficulty,Shorten the response time and reduce reaction temperature,Inventor tentatively adopts coprecipitation to prepare Zn-Fe metal composite oxide,It is surprised to find that the synthesis of tetramethylolmethane and isostearic acid is had catalytic action by this Zn-Fe metal composite oxide,And by substantial amounts of experimentation,The preparation method that inventor finally determines this Zn-Fe metal composite oxide,Wherein strictly control the material ratio of zinc ion and iron ion,The kind of precipitant and consumption,And the temperature and time of roasting,The synthesis to pentaerythritol tetraoctyl stearate can be prepared and have the catalyst of notable catalytic action,Apply this catalyst and can reduce reaction temperature to 140~150 DEG C,At least 10 DEG C are reduced than prior art;Shortening response time 4~5h, reduce at least 1h than prior art, productivity may be up to 99%, but coloured product is relatively deep, and purity is not high.Accidental operation, the solution after co-precipitation is placed under microwave and processes by inventor, subsequently again crystallization, roasting, it has been found that the Zn-Fe metal composite oxide crystal obtained is bigger, it is easier to separate with product, simultaneously can improve the problem that coloured product is deep, purity is low.
Therefore, compared with prior art, present invention have an advantage that and effectively reduce reaction temperature by the catalyst that the invention provides during a kind of new Zn-Fe metal composite oxide is prepared as pentaerythritol tetraoctyl stearate, shorten the response time, improve production efficiency, reduce production cost, and the inventive method is simple, reliable and stable, can industrialized production, pentaerythritol tetraoctyl stearate product colour is shallow, and acid number is low, and purity is high.
Detailed description of the invention
Further describe the present invention below by way of detailed description of the invention, but the present invention is not limited only to following example.Within the scope of the invention or without departing from, in present disclosure, spirit and scope, the present invention being suitably modified, replaces the component that effect is identical, apparent to those skilled in the art, they are considered as being included in the scope of the present invention.
Embodiment 1, pentaerythritol tetraoctyl stearate of the present invention preparation method
S1,27.2kg tetramethylolmethane and 227.6kg isostearic acid are put in reactor, open stirring;
S2, add isostearic acid weight 0.2% metal composite oxide; under nitrogen protection, reacting 5h at 140 DEG C, reaction terminates; separate metal composite oxide; obtaining pentaerythritol tetraoctyl stearate crude product, crude product is decompressed to negative 0.1Mpa at 100 DEG C, and organic solvent and water are distilled off; namely pentaerythritol tetraoctyl stearate product is obtained after filtration; productivity is 97.4%, product colourity (Gardner's method)≤1, and acid number is 0.20.
The preparation method of described metal composite oxide is as follows: weigh ZnCl2·2H2O and FeCl2·4H2O is made into mixed-salt aqueous solution, separately weighs NaOH and Na2CO3It is made into mixed base aqueous solution;Two kinds of solution is simultaneously introduced in rotating liquid-film reactor fast nucleation according to volume ratio 1: 1, and circulates 2min;Then microwave treatment 2h under 700w, crystallization 12h, filtration at normal temperatures, obtains much filtrate subsequently;Then through 60 DEG C of dry 12h after washing much filtrate, finally move into roasting 2h in 600 DEG C of muffle furnaces, obtain Zn-Fe metal composite oxide.
Wherein c (Zn in mixed-salt aqueous solution2+) concentration be 0.2mol L-1, c (Fe2+) concentration be 0.8mol L-1;In mixed base aqueous solution, the concentration of c (OH-) is 0.6mol L-1, c (CO3 2-) concentration be 1.2mol L-1。
Embodiment 2, pentaerythritol tetraoctyl stearate of the present invention preparation method
S1,27.2kg tetramethylolmethane and 239.0kg isostearic acid are put in reactor, open stirring;
S2, add isostearic acid weight 1% metal composite oxide; under nitrogen protection, reacting 4h at 150 DEG C, reaction terminates; separate metal composite oxide; obtaining pentaerythritol tetraoctyl stearate crude product, crude product is decompressed to negative 0.05Mpa at 130 DEG C, and organic solvent and water are distilled off; namely pentaerythritol tetraoctyl stearate product is obtained after filtration; productivity is 98.0%, product colourity (Gardner's method)≤1, and acid number is 0.18.
The preparation method of described metal composite oxide is as follows: weigh ZnCl2·2H2O and FeCl2·4H2O is made into mixed-salt aqueous solution, separately weighs NaOH and Na2CO3It is made into mixed base aqueous solution;Two kinds of solution is simultaneously introduced in rotating liquid-film reactor fast nucleation according to volume ratio 1: 1, and circulates 2min;Then microwave treatment 1h under 800w, crystallization 12h, filtration at normal temperatures, obtains much filtrate subsequently;Then through 60 DEG C of dry 12h after washing much filtrate, finally move into roasting 3h in 500 DEG C of muffle furnaces, obtain Zn-Fe metal composite oxide.
Wherein c (Zn in mixed-salt aqueous solution2+) concentration be 0.4mol L-1, c (Fe2+) concentration be 0.6mol L-1;C (OH in mixed base aqueous solution-) concentration be 0.8mol L-1, c (CO3 2-) concentration be 0.9mol L-1。
Embodiment 3, pentaerythritol tetraoctyl stearate of the present invention preparation method
S1,27.2kg tetramethylolmethane and 233.3kg isostearic acid are put in reactor, open stirring;
S2, add isostearic acid weight 0.6% metal composite oxide; under nitrogen protection, reacting 4.5h at 140 DEG C, reaction terminates; separate metal composite oxide; obtaining pentaerythritol tetraoctyl stearate crude product, crude product is decompressed to negative 0.05Mpa at 120 DEG C, and organic solvent and water are distilled off; namely pentaerythritol tetraoctyl stearate product is obtained after filtration; productivity is 99.2%, product colourity (Gardner's method)≤1, and acid number is 0.10.
The preparation method of described metal composite oxide is as follows: weigh ZnCl2·2H2O and FeCl2·4H2O is made into mixed-salt aqueous solution, separately weighs NaOH and Na2CO3It is made into mixed base aqueous solution;Two kinds of solution is simultaneously introduced in rotating liquid-film reactor fast nucleation according to volume ratio 1: 1, and circulates 2min;Then microwave treatment 1.5h under 700w, crystallization 12h, filtration at normal temperatures, obtains much filtrate subsequently;Then through 60 DEG C of dry 12h after washing much filtrate, finally move into roasting 3h in 500 DEG C of muffle furnaces, obtain Zn-Fe metal composite oxide.
Wherein c (Zn in mixed-salt aqueous solution2+) concentration be 0.3mol L-1, c (Fe2+) concentration be 0.7mol L-1;C (OH in mixed base aqueous solution-) concentration be 0.7mol L-1, c (CO3 2-) concentration be 1.0mol L-1。
Comparative example one,
S1,27.2kg tetramethylolmethane and 233.3kg isostearic acid are put in reactor, open stirring;
S2, add isostearic acid weight 0.6% metal composite oxide; under nitrogen protection, reacting 4.5h at 140 DEG C, reaction terminates; separate metal composite oxide; obtaining pentaerythritol tetraoctyl stearate crude product, crude product is decompressed to negative 0.05Mpa at 120 DEG C, and organic solvent and water are distilled off; namely pentaerythritol tetraoctyl stearate product is obtained after filtration; productivity 95.3%, product colourity (Gardner's method)=6, acid number 5.7.
The preparation method of described metal composite oxide is as follows: weigh ZnCl2·2H2O and FeCl2·4H2O is made into mixed-salt aqueous solution, separately weighs NaOH and Na2CO3It is made into mixed base aqueous solution;Two kinds of solution is simultaneously introduced in rotating liquid-film reactor fast nucleation according to volume ratio 1: 1, and circulates 2min;Crystallization 12h, filtration at normal temperatures, obtains much filtrate subsequently;Then through 60 DEG C of dry 12h after washing much filtrate, finally move into roasting 3h in 500 DEG C of muffle furnaces, obtain Zn-Fe metal composite oxide.
Wherein c (Zn in mixed-salt aqueous solution2+) concentration be 0.3mol L-1, c (Fe2+) concentration be 0.7mol L-1;C (OH in mixed base aqueous solution-) concentration be 0.7mol L-1, c (CO3 2-) concentration be 1.0mol L-1。
This comparative example is compared with embodiment 3, the preparation of Zn-Fe metal composite oxide does not adopt microwave treatment, the structure of this catalyst of result is looser than microwaved, and the pentaerythritol tetraoctyl stearate product colour prepared under this catalyst is deep, and purity is low, and inventor speculates that this is possibly due to microwave treatment and can change the crystal structure of Zn-Fe metal composite oxide, make its rugged construction, crystal formation is bigger, and suppresses side reaction better, improves product purity.
Comparative example two,
This comparative example and embodiment 3 are distinctive in that: c (Zn in mixed-salt aqueous solution in the preparation method of metal composite oxide2+) concentration be 0.5mol L-1, c (Fe2+) concentration be 0.5mol L-1.Other operations and parameter are with embodiment 3.
The productivity of this comparative example is 87.1%, product colourity (Gardner's method)=2, and acid number is 2.34.
Comparative example three,
This comparative example and embodiment 3 are distinctive in that: use 2.0mol L in the preparation method of metal composite oxide-1NaOH solution replace NaOH and Na2CO3Mixed base aqueous solution.Other operations and parameter are with embodiment 3.
The productivity of this comparative example is 82.5%, product colourity (Gardner's method)=2, and acid number is 1.73.
Comparative example four,
This comparative example and embodiment 3 are distinctive in that: then through 60 DEG C of dry 12h after much filtrate, finally move into roasting 3h in 400 DEG C of muffle furnaces, obtain metal composite oxide.Other operations and parameter are with embodiment 3.
The productivity of this comparative example is 84.8%, product colourity (Gardner's method)=3, and acid number is 3.84.
From comparative example two~tetra-it can be seen that the ratio of material, kind the preparation of Zn-Fe metal composite oxide, Zn-Fe metal composite oxide all can be produced impact by sintering temperature etc., thus causing that catalytic effect is not good.
Below being only the preferred embodiment of the present invention, it is noted that above-mentioned preferred implementation is not construed as limitation of the present invention, protection scope of the present invention should be as the criterion with claim limited range.For those skilled in the art, without departing from the spirit and scope of the present invention, it is also possible to make some improvements and modifications, these improvements and modifications also should be regarded as protection scope of the present invention.