(2) background technology
TDE has another name called 1,2-two (penta-bromophenyl) ethane, white powder, fusing point 358-360 ℃, theoretical brominated amount 82.28%.It is the exploitation of U.S.'s ethyl corporation the nineties in last century and commercial a kind of aryl brominated flame retardant (its trade(brand)name Saytex8010).Several respects performances such as its flame retardant resistance, thermostability, uvioresistant ability all are superior to the fire retardant decabromodiphynly oxide, when even more important characteristic is thermolysis again, do not produce the dioxin carcinogenic substance.
TDE adopts the excess bromine method to produce, with Al powder, Fe powder, anhydrous AlCl mostly
3, anhydrous AlBr
3Or FeCl
3Or their compsn is catalyzer, the more sophisticated polyolefins engineering materials that applies to of product, but in the environment such as the PA66 spun glass enhancement techniques of comparatively high temps, utilization is not very desirable.The product of present U.S. Albemarle Corporation (predecessor's ethyl corporation) uses ripe in this respect, but has also adopted portions additive to improve its use properties.
The TDE of aforesaid method production all contains impurity such as free bromine, remainder catalyst and low bromo derivative in various degree, and the product particle diameter is big, and whiteness and thermostability do not have higher breakthrough yet.As everyone knows, have free bromine in the TDE, in plastic working, can equally, also largely influence the colourity of flame retardant plastics the processing units corrosion.Colourity when thermal stability then influences plastics high temperature.For solving the TDE product quality problem, all done purifying research in various degree both at home and abroad.For solid chemical compound, recrystallization is an effective way of removing impurity, purified product.U.S. Pat .5457248 is a solvent with high boiling point aromatic hydrocarbons, 175 ℃ of following recrystallizations.U.S. big lake chemical company uses phenyl ether and ethanol to be the solvent pairs recrystallization.More than invention improves a lot to the TDE quality product, but this class methods cost is high, in suitability for industrialized production, is difficult to implement.
(3) summary of the invention
The objective of the invention is to overcome above-mentioned deficiency, the preparation method of the TDE of a kind of whiteness that under low cost movement, can effectively improve TDE and thermal stability is provided.
The objective of the invention is to realize like this: a kind of preparation method of TDE, adopt diphenylethane and excess bromine under catalyzer, to react and make, it is characterized in that said reaction divides three phases to carry out, said catalyzer adopts Al powder, anhydrous AlCl
3With anhydrous TiCl
4, wherein Al powder and anhydrous AlCl
3Form first catalyzer, add anhydrous TiCl in the fs of reaction
4Form second catalyzer separately, at the subordinate phase adding of reaction, anhydrous AlCl
3Form separately the 3rd catalyzer, add in the phase III of reaction, the quality that always feeds intake of first, second and the 3rd catalyzer accounts for the 0.08-0.15% of finished product TDE theoretical yield; First, second with the molar ratio of the 3rd catalyzer is: (1-3): (1-4): (0.6-0.9), control fs 12-26 ℃, time 2-4 hour; Subordinate phase 26-40 ℃; Time 3-5 hour, phase III temperature of reaction 40-60 ℃, time 4-6 hour; After above three step of reaction are accomplished, continue to improve temperature to 60-65 ℃ of insulation 1~3 hour.
The TDE molecular structural formula:
Reaction equation is:
Do not having in the presence of the catalyzer, phenyl ring and bromine do not react, and the effect of catalyzer is to make bromine become strong electrophilic reagent, promote bromine and phenyl ring generation electrophilic substitution reaction.On catalytic performance, the catalytic activity of Al powder is the strongest, and speed of response is exceedingly fast; Anhydrous AlCl
3Catalytic activity take second place, speed of response is very fast; Anhydrous TiCl
4Flat in the activity, catalyzed reaction speed is steady.
In entire reaction course, ten hydrogen on ten bromine substituted benzene rings are not to carry out faster or slower together.(contain substituent benzene derivative according to orientation effect; When carrying out Reaction of Aromatic Electrophilic Substitution, original substituting group is to the main in-position of the substituting group of new entering; The effect that has certain directive property); Diphenylethane shows the ortho para orientation effect, is actually a speed of reaction problem, and the position reaction slowly between ortho para reacted soon and upward on the bromine.We can be divided into three phases with reaction:
Mainly carry out the ortho para substitution reaction of 1-6 bromine on stage one: two phenyl ring, reaction equation is following:
This reaction occurs in the dropping process of raw material diphenylethane, and this moment, bromine was excessive in a large number, and according to the ortho para orientation effect, mostly the position of bromine substitution reaction is ortho position and contraposition under the effect of catalyzer, and takes place than being easier to.Wayward too soon in order to prevent reaction, the catalyzer that add this moment is Al powder and anhydrous AlCl
3Mixture because Al powder activity is too strong, adds affiliation separately and making the difficult more fast control of reaction, and anhydrous AlCl
3Activity degree then do not reach the speed of reaction requirement, therefore use their mixture first catalyzer, the throwing amount mass ratio of the two is: Al powder: anhydrous AlCl
3=1: (0.7-1.5).In this reaction process, reaction product all is in a liquid state.
Mainly carry out on stage two: two phenyl ring 6-8 bromine between the position substitution reaction, reaction equation is following:
Relatively the fs, the speed of reaction in this stage slows down.In this process, reaction product is changed to C 14 H 4 Br 8 by the hexabromo diphenylethane, is to be solid-state process by liquid transformation.In this process if use Al powder or anhydrous AlCl
3Make catalyzer; Reaction product is being converted into by liquid state in the solid-state process and can a kind of molecule reunion of generation wrapping up phenomenon; Hexabromo diphenylethane to the C 14 H 4 Br 8 that promptly produces is reunited together during for solid-state molecular by liquid transformation, is rolled into globe, and stablely is difficult for disperseing.So; Globe only has skin can continue reaction, and the unreacted that is wrapped completely material be in the middle of the ball, isolated by outer thing; Can not continue to react, cause the finished product to influence whiteness and thermostability because of the impurity that contains incomplete bromination with bromine.And this stage is adopted anhydrous TiCl
4As catalyzer,, can effectively stop the agglomerating phenomenon of molecule in the reaction process because of the stationarity of its highly symmetric positive tetrahedron structure and catalytic activity.Thereby improve the whiteness and the thermostability of the finished product.
Mainly carry out on stage three: two phenyl ring 8-10 bromine between the position substitution reaction, reaction equation is following:
With respect to the stage two, the reaction in this stage is difficulty more.This moment, temperature of reaction raise, and material all is solid-state, has not had agglomerating phenomenon, in order to improve speed of reaction, selects active higher Al Cl
3It is the 3rd catalyzer.
After above three step of reaction are accomplished,, can continue to improve temperature to 60-65 ℃ of insulation 1-3 hour in order to strengthen reaction effect.
The invention has the beneficial effects as follows:
Research shows that the existence of Ti element does not influence the end product quality of TDE, and on the contrary, it can improve the whiteness and the dispersing property of TDE, disperses better effects if when in plastics, using.
Use catalyzer of the present invention and process control method; TDE whiteness >=92 of suitability for industrialized production; Under 250 ℃ of high temperature, continue 2-5 hour thermostability >=88; It is quite successful to strengthen white engineering materials application at high temperature PA66 glass, and its flame retardant properties, material color and luster, PA66 intensity all surpass the use properties of common TDE.
In the above reaction process, material is solid-state by liquid transformation, and material viscosity also changes with each step of reaction, is easy to infer from the variation of viscosity number which stage reaction proceeds to.But because the severe corrosive and the strong and stimulating of bromine are difficult to sampling in the reaction process, also be difficult to use the viscosity measurements appearance or the sensing appearance of any material, so we can not the very clear and definite delta data situation that obtains material viscosity.
As everyone knows, the reaction of the excess bromine method of TDE is under agitation carried out.In step of reaction one, material is in a liquid state, and viscosity is little, stirs load easily; In step of reaction two, to solid state transformation, material viscosity increases reaction product by liquid state, stirs the resistance that receives and increases, and stirs the corresponding increase of load; In step of reaction three, reaction product is converted into solid-state fully, stirs resistance and alleviates to some extent, stirs the also corresponding alleviation of load.For each step of reaction of effective recognition; The opportunity that strict each catalyzer of control adds is according to this phenomenon, under the voltage stabilized source prerequisite; For agitator motor installs frequency-variable controller and reometer additional; The variation of stirring load can intuitively embody through the size of electric current, and here, the use of frequency transformer can be avoided the waste of power resource.Through a large amount of research practices, find that TDE is reflected in the 5000L reaction kettle, voltage of supply 220V, mixing speed is fixed, and installs additional following rule is arranged when carrying out under frequency transformer and the reometer prerequisite:
1, begin from dripping diphenylethane, the agitator motor electric current can continue for some time under the electric current of the 12A left and right sides, be 2-4 hour, and this stage is a step of reaction one;
2, the agitator motor electric current slowly rises to 18A from 12A, and this stage is a step of reaction two, because this moment, reaction product was solid-state by liquid transformation, viscosity increases, and stir and receive the drag loading increase, so electric current can increase to some extent;
3, the agitator motor electric current slowly drops to 15A from 18A, and this stage is a step of reaction three, and this moment, reaction product was converted into solid-stately fully, stirred load and alleviated to some extent, so electric current descends to some extent.
4 and holding stage in the end, electric current slowly drops to 13A from 15A, and end so far reacts completely.
Through putting into practice the particular case that the electric current desired value of finding out can reflect the TDE bromination reaction intuitively; Make operator can get information about level of response; Confirm to add the kind and the opportunity of catalyzer; Control to reaction is more effective, thereby has avoided the generation of impurity, has played very big effect for the quality that improves TDE in the suitability for industrialized production.
(4) embodiment
Instance 1:
Add excess bromine having VFC, fixed rotating speed and add the stirrer of reometer and have in the 5000L glassed steel reaction vessels of heating unit, open and stir, to wherein add first catalyzer altogether 0.55kg (contain Al powder 0.1kg, AlCl
30.45kg), temperature drips diphenylethane 364.5kg altogether at 12-26 ℃, observes the reometer reading.When electric current begins when 12A increases, in reaction kettle, add the anhydrous TiCl of second catalyzer
41.12kg, continue reaction and also observe reometer, when electric current rises to when no longer continuing to raise about 18A, in reaction kettle, add the anhydrous AlCl of the 3rd catalyzer
30.63kg, slowly being warming up to 60 ℃, temperature-rise period continues 1-2 hour, is incubated 3-4 hour, and current value slowly descends in this process.When current value no longer changed in half a hour, reaction finished.Reaction mass is carried out aftertreatment, obtain finished product TDE 1900kg.Whiteness continues whiteness 88.6 after 3 hours for 92.3,250 ℃, and content (liquid chromatography) 99.87%, average diameter of particles are 3.2 μ m.
Instance 2:
Products obtained therefrom is applied to the PA66 glass strengthens white material.Adding proportion is: 11% TDE, 4% Antimony Trioxide: 99.5Min, 55%PA66,30% glass.After a certain amount of PA 66 mixed with high-speed mixer with TDE, Antimony Trioxide: 99.5Min; Add people's twin screw extruder from main opening for feed, and an amount of GF is added from forcing machine the 8th section feeding mouth, the control extruder temperature is 240-260 ℃; Make four kinds of material fusions in forcing machine, plasticizing; Extrudate promptly makes PA 66 glasses and strengthens blend through cooling granulation, and pellet is injection molded into standard test specimen with injection moulding machine behind the dry 24h down at 80 ℃.Flame retardant properties has reached UL94V-0, and its tensile strength is that 268J/m, shock strength 130MPa and flexural strength do not become, and shock strength, modulus in flexure reduce has only 10%.The mechanical property that obviously is better than common market TDE product.
Instance 3:
Add excess bromine having VFC, fixed rotating speed and add the stirrer of reometer and have in the 5000L glassed steel reaction vessels of heating unit, open and stir, to wherein add first catalyzer altogether 0.76kg (contain Al powder 0.13kg, AlCl
30.63kg), temperature drips diphenylethane 500kg altogether at 12-26 ℃, observes the reometer reading.When electric current begins when 12A increases, in reaction kettle, add the anhydrous TiCl of second catalyzer
41.57kg, continue reaction and also observe reometer, when electric current rises to when no longer continuing to raise about 18A, in reaction kettle, add the anhydrous AlCl of the 3rd catalyzer
30.87kg, slowly being warming up to 60 ℃, temperature-rise period continues 1-2 hour, is incubated 3-4 hour, and current value slowly descends in this process.When current value no longer changed in half a hour, reaction finished.Reaction mass is carried out aftertreatment, obtain finished product TDE 2615kg.Whiteness continues whiteness 88.4 after 3 hours for 92.0,250 ℃, and content (liquid chromatography) 99.85%, average diameter of particles are 4.1 μ m.
Instance 3:
Add excess bromine having VFC, fixed rotating speed and add the stirrer of reometer and have in the 5000L glassed steel reaction vessels of heating unit, open and stir, to wherein add first catalyzer altogether 0.85kg (contain Al powder 0.2kg, AlCl
30.65kg), temperature drips diphenylethane 500kg altogether at 12-26 ℃, observes the reometer reading.When electric current begins when 12A increases, in reaction kettle, add the anhydrous TiCl of second catalyzer
41.32kg, continue reaction and also observe reometer, when electric current rises to when no longer continuing to raise about 18A, in reaction kettle, add the anhydrous AlCl of the 3rd catalyzer
30.95kg, slowly being warming up to 60 ℃, temperature-rise period continues 1-2 hour, is incubated 3-4 hour, and current value slowly descends in this process.When current value no longer changed in half a hour, reaction finished.Reaction mass is carried out aftertreatment, obtain finished product TDE 2630kg.Whiteness continues whiteness 88.7 after 3 hours for 92.1,250 ℃, and content (liquid chromatography) 99.88%, average diameter of particles are 3.0 μ m.