A kind of method synthesizing tri trimellitate ester
Technical field
The invention belongs to plasticizer production field, utilize trimellitic anhydride to produce particularly to one
During light component and heavy constituent produce tri trimellitate (2-ethyl hexyl) ester method.
Background technology
Tri trimellitate (2-ethyl hexyl) ester (TOTM) is developed by the U.S. end of the sixties
Kind of trimellitic acid esters, is a kind of electrical property and the most excellent plasticizer of hot property.Its volatilization
Property is low, and resistance to ag(e)ing, resistance to extractable and heat resistance are good, and have good insulating properties, therefore can be used for
105 DEG C of level heat proof cable material and the production of 10kV polyvinyl chloride cable material.In addition, it also can be used
Make pulse and the impregnated material of low voltage power capacitor and synthetic leather plasticizer etc..In the U.S., have
The TOTM of 78% is used for wires and cables industry, accounts for the 13% of electric wire plasticizer total amount, and passes
The dioctyl phthalate (DOP) of system the most only accounts for the 6% of total consumption.China's electric wire row
Industry currently integrates with international standard, supporting in the urgent need to this high-performance plasticizer of TOTM,
And traditional DOP, DBP cannot meet requirement at a lot of aspects.
Abroad, the production and consumption of TOTM increases quickly, and it is to increase in U.S.'s plasticizer
One of fast kind, has many producers all to have TOTM to produce, such as Meng Shan all, BASF, USS
Deng.China only has minimal amount of TOTM and produces, and raw material depends on greatly import, continues to use backward
Sulfation technique, the quality of product and quantity far from can meet user's request.TOTM's
Although the production technology of primary raw material trimellitic anhydride had started to study as far back as the end of the sixties, but extremely
The present reality on producing is almost the most blank.Therefore, develop and produce TOTM and trimellitic acid
Acid anhydride, for Appropriate application petroleum resources, promotes the development of fine chemistry industry, adapts to motor, electric power, moulds
The needs of the industrial departments such as material, aerospace, have huge realistic meaning and far-reaching significance.
Current employing trimellitic anhydride and 2-Ethylhexyl Alcohol direct esterification generate tri trimellitate (2-
Ethyl hexyl) ester, final refining produces.The existing product mode of production ensures inclined benzene due to needs
In three anhydride product, the content of phthalic anhydride is in extremely low level, therefore for removing O-phthalic
When anhydride carries out de-light work, substantial amounts of trimellitic anhydride is carried in light component;And extracting
Because the long-time trimellitic anhydride that extracts can cause material carbon in still under high temperature during trimellitic anhydride
Change so extraction time is limited, still have substantial amounts of trimellitic anhydride to remain in heavy constituent;These
Trimellitic anhydride can not be reasonably utilized, and the process of current weight component is that each is inclined in puzzlement
A difficult problem for benzenetricarboxylic anhydride manufacturing enterprise.Light component exists due to substantial amounts of trimellitic anhydride, it is extremely difficult to
Purify phthalic anhydride therein, be difficult to effectively utilize, the equal conduct of heavy constituent major part enterprise
Solid waste burning processes, and causes substantial amounts of waste, produces simultaneously and add fixed-end forces amount.
Difficulty in treatment for the weight component in current trimellitic anhydride production technology, it is necessary to
A kind of method proposing Appropriate application trimellitic anhydride weight component.And use trimellitic anhydride light
It is a fabulous method that heavy constituent produces tri trimellitate (2-ethyl hexyl) ester.
Summary of the invention
The technical problem to be solved is for the deficiencies in the prior art, it is provided that Yi Zhongli
The method producing tri trimellitate (2-ethyl hexyl) ester by trimellitic anhydride weight component is permissible
Effectively utilize trimellitic anhydride weight component, trimellitic anhydride therein is converted into trimellitic acid
Three (2-ethyl hexyl) ester, the color number of product is extremely low, and content is high, and adjacent benzene content is low.
For solving above-mentioned technical problem, a kind of method synthesizing tri trimellitate ester of the present invention, bag
Include following steps:
S1, esterification reaction of organic acid: by light for trimellitic anhydride component, trimellitic anhydride heavy constituent, first
Alcohol or carbinol mixture and catalyst add anti-with mass ratio 100:100-200:50-500:1-6
Answer still, be warming up to the light component of trimellitic anhydride and trimellitic anhydride heavy constituent is dissolved in methanol, open
Stirring, reacts 1-3h under the conditions of temperature of reaction kettle 60-160 DEG C, reaction pressure 10-25kg,
Close stirring afterwards, open the extraction of still top, steam the water of excessive methanol and generation, the most anti-
Should complete;
S2, closedown still top extraction, continuously add the methanol with S1 moderate or first to reactor
Alcohol mixture, opens stirring, continues to carry out reacting and extraction by S1 condition, repeats this step anti-
Answer 1-8 time;
S3, rectification: under vacuum conditions, be slowly heated tower bottoms, in tower reactor state
185-250 DEG C, 500-6000Pa, tower top state 180-240 DEG C, 150-2500pa, backflow
Ratio carries out rectification under conditions of 1:3-3:1, extract trimethyl trimellitate by rectification;
S4, ester exchange: by trimethyl trimellitate, 2-Ethylhexyl Alcohol and catalyst according to quality
Join in ester interchange vessel than 100:300:0.3, be slowly heated under normal pressure, be heated to from room temperature
220 DEG C, being incubated 3.5h, ester exchange reaction terminates;
S5, desolventizing: under not heated condition, gradually step up ester interchange vessel vacuum to 300Pa,
Temperature solvent removal in time being down to 150 DEG C for 220 DEG C completes;
S6, hydrolysed filtrate catalyst: under normal temperature and pressure, add reactant liquor matter in ester interchange vessel
The distilled water of amount 1%, reacts 3-4h, and hydrolyst terminates, and is evacuated to 300Pa, heating
To dehydration knot when 100 DEG C;
S7, refined: in ester interchange vessel, to add activated carbon and kieselguhr, stir when 40-80 DEG C
Mix 20-60min, filtered while hot, obtain tri trimellitate (2-ethyl hexyl) ester.
Further, S4 also includes the oxygen in ester interchange vessel before ester exchange reaction with nitrogen
Gas displaces, the most again temperature reaction.
Further, in S7, extraction temperature scope is 100 DEG C ± 10 DEG C.
Further, obtained tri trimellitate (2-ethyl hexyl) ester content reaches
95%-99.0%, color 5#-30#, adjacent benzene content is 5-300ppm.
The invention has the beneficial effects as follows:
(1) the light component of lower-cost trimellitic anhydride and inclined benzene three difficult to deal with are used
Anhydride heavy constituent is as the raw materials for production of tri trimellitate (2-ethyl hexyl) ester, to trimellitic acid
Acid anhydride weight component carries out effective recycling, decreases the generation of pollutant simultaneously, add through
Ji benefit, reduces production cost and environmental protection pressure.
(2) the trimethyl trimellitate boiling that trimellitic anhydride and methanol esterification reaction generate is utilized
The advantage that point is relatively low, can pass through rectification by trimethyl trimellitate and other weight composition impurities
Separate, also reduce trimethyl trimellitate color number while improving content, then handed over by ester
Get tri trimellitate (2-ethyl hexyl) ester of low color high-load in return.
Detailed description of the invention
Technical scheme in the embodiment of the present invention will be clearly and completely described below, aobvious
So, described embodiment is only a part of embodiment of the present invention rather than whole enforcement
Example.Based on the embodiment in the present invention, those of ordinary skill in the art are not making creativeness
The every other embodiment obtained on the premise of work, broadly falls into the scope of protection of the invention.
The present invention is a kind of synthesize the method for tri trimellitate ester with trimellitic anhydride weight component and
Methanol is raw material, first passes through trimellitic anhydride weight component and methanol enters under catalyst
Row esterification reaction of organic acid generates trimethyl trimellitate, then obtains the low color number of high-purity by rectification
Trimethyl trimellitate, finally trimethyl trimellitate and 2-Ethylhexyl Alcohol are carried out ester friendship
Change and by being refining to obtain tri trimellitate (2-ethyl hexyl) ester product.
Embodiment 1:
A kind of side producing tri trimellitate (2-ethyl hexyl) ester by trimellitic anhydride weight component
Method, it specifically comprises the following steps that
The first step, by light for trimellitic anhydride component 150g, heavy constituent 150g, methanol 300g and
Catalyst Ti white lead 0.9g successively joins in reactor, and reacting by heating still is warming up to 65 DEG C,
Pressure 12KG, reactant liquor seethes with excitement, and by the water generated and methanol extraction, adds fresh first simultaneously
Alcohol, makes methanol additional amount keep consistent with produced quantity.Response time 3h, obtains trimellitic acid
The conversion ratio more than 95% of trimethyl.
Second step, rectification: esterification reaction of organic acid liquid is squeezed in airtight rectifying still.At vacuum state
Under, it is slowly heated this tower bottoms, in tower reactor state 180~205 DEG C, 500Pa, tower top state
193~195 DEG C, 150pa, carry out rectification under conditions of reflux ratio 1:2~2:1;Pass through rectification
Obtain trimethyl trimellitate intermediate product;
3rd step, ester exchange: by trimethyl trimellitate 390g, 2-Ethylhexyl Alcohol 390g and
Catalyst tetraisopropyl titanate 1.2g joins in ester interchange vessel, displaces still hollow with nitrogen
Gas, is slowly heated under normal pressure, is heated to 220 DEG C from room temperature, is incubated 2.5h, ester exchange reaction
Terminate.
4th step, desolventizing: under not heated condition, gradually step up ester interchange vessel vacuum extremely
500Pa, temperature solvent removal in time being down to 150 DEG C for 220 DEG C completes.
5th step, hydrolyst: under normal temperature and pressure, ester interchange vessel adds 7.5g and steams
Distilled water, stirs 2h, and hydrolyst terminates.It is evacuated to 500Pa, when being heated to 100 DEG C
Dehydration terminates.
6th step, refined: in ester interchange vessel, to add 4g activated carbon and 2g kieselguhr,
Stir 30min, filtered while hot when 50 DEG C ± 5 DEG C, obtain tri trimellitate (2-ethyl hexyl)
Ester product.
In the present embodiment, tri trimellitate (2-ethyl hexyl) ester prepared contains more than 99%, color
Number 12#, can meet the industrial departments such as motor, electric power, plastics, aerospace to tri trimellitate
The use requirement of (2-ethyl hexyl) ester.
Embodiment 2:
The first step, by light for trimellitic anhydride component 150g, heavy constituent 150g, methanol 300g and
Catalyst tetraisopropyl titanate 0.9g successively joins in reactor, and reacting by heating still is warming up to
95 DEG C, pressure 20KG, reactant liquor seethes with excitement, and by the water generated and methanol extraction, adds new simultaneously
Fresh methanol, makes methanol additional amount keep consistent with produced quantity.Response time 5h, obtains inclined benzene
The conversion ratio more than 95% of three acid trimethyls.
Second step, rectification: esterification reaction of organic acid liquid is squeezed in airtight rectifying still.At vacuum state
Under, it is slowly heated this tower bottoms, in tower reactor state 190~215 DEG C, 500Pa, tower top state
200~205 DEG C, 500pa, carry out rectification under conditions of reflux ratio 1:2~2:1;Pass through rectification
Obtain trimethyl trimellitate intermediate product;
3rd step, ester exchange: by trimethyl trimellitate 390g, 2-Ethylhexyl Alcohol 390g and
Catalyst tetraisopropyl titanate 1.2g joins in ester interchange vessel, displaces still hollow with nitrogen
Gas, is slowly heated under normal pressure, is heated to 220 DEG C from room temperature, is incubated 2.5h, ester exchange reaction
Terminate.
4th step, desolventizing: under not heated condition, gradually step up ester interchange vessel vacuum extremely
500Pa, temperature solvent removal in time being down to 150 DEG C for 220 DEG C completes.
5th step, hydrolyst: under normal temperature and pressure, ester interchange vessel adds 7.5g and steams
Distilled water, stirs 2h, and hydrolyst terminates.It is evacuated to 500Pa, when being heated to 100 DEG C
Dehydration terminates.
6th step, refined: in ester interchange vessel, to add 4g activated carbon and 2g kieselguhr,
Stir 30min, filtered while hot when 50 DEG C ± 5 DEG C, obtain tri trimellitate (2-ethyl hexyl) ester
Product.
In the present embodiment, tri trimellitate (2-ethyl hexyl) ester prepared contains more than 99%, color 11#,
The industrial departments such as motor, electric power, plastics, aerospace can be met to tri trimellitate (2-ethyl
Oneself) the use requirement of ester.
Ultimate principle and the principal character of the present invention have more than been shown and described.The technology people of the industry
Member is it should be appreciated that the present invention is not restricted to the described embodiments, in above-described embodiment and description
The principle that the present invention is simply described described, in the premise without departing from spirit and scope of the invention
Under, the present invention also has various changes and modifications, and these changes and improvements both fall within claimed
The scope of the invention in.Claimed scope is by appending claims and equivalence thereof
Thing defines.