A kind of method for preparing super-fine anhydrous zinc borate
Technical field
The invention belongs to the manufacture method of fire retardant zinc borate, particularly a kind of method for preparing super-fine anhydrous zinc borate.
Background technology
Zinc borate belongs to that to expand be inorganic combustion inhibitor, kind, wherein 2ZnO3B surplus the present known crystal configuration nearly ten
2O
33.5H
2O type (being called for short 2335 types) zinc borate crystal is because of having less crystal water content, and higher mistake crystal water temperature spot, and the representative that is used as the boron flame retardant is widely used.
Many plastics, rubber need high temperature in raw material mixing process, the mistake crystal water temperature of 2335 type zinc borates is about 290 ℃, significantly is better than other commercially available hydration zinc borates.But along with the development of organic polymer materials such as plastics, rubber, resin, some engineering plastics and specialty elastomer goods need be in about 300 ℃~400 ℃ scopes, even higher temperature processing down, and this just need have the zinc borate of higher mistake crystal water temperature.
Report seldom about the research of anhydrous zinc borate that both at home and abroad it is 4ZnOB that U.S. Borax Inc. discloses chemical formula in application U.S. Pat 796289 in 1991
2O
3H
2O type and 4ZnOB
2O
3The preparation method of type, and claim the mistake crystal water temperature spot of this type of zinc borate to be approximately 415 ℃.The said firm has applied for No. 92113403.7, the Chinese patent and the 97102409.X patent of division afterwards November 20 in 1992.Because the restriction of its technical process, the production cycle is long, is unfavorable for applying in actual production.
Summary of the invention
Goal of the invention of the present invention is lower in order to improve present commercially available zinc borate mistake crystal water temperature spot, can not satisfy high molecular polymer needs high processing temperatures such as polysulfones, polymeric amide, polyketone, polyarylate and propose.A kind of anhydrous zinc borate preparation method promptly is provided.
For realizing above purpose, the present invention is achieved through the following technical solutions:
The method that this prepares super-fine anhydrous zinc borate is characterized in that: this method is a main raw material with nano level zinc borate and organic solvent class material, through following steps, and preparation anhydrous zinc borate crystal grain,
1) add the organic solvent class material of 2~4 times of volumes in nano level zinc borate ultrafine powder, mix, described organic solvent class material is an alcoholic solvent,
2) with 1) described in mixture put into vacuum rotary evaporator, be heated to 180~220 ℃, adjust speed of rotation, make the evaporation of organic solvent class material,
3) to 2) in add dehydrated alcohol in the residual pressed powder in evaporation back, stir,
4) pressed powder centrifugal results 3), 80 ℃ of freeze-day with constant temperature promptly get the super-fine anhydrous zinc borate powder.
Wherein: the nano level zinc borate as raw material is meant the amorphous boric acid zinc particle of particle diameter yardstick between 5~90nm; Perhaps the particle diameter yardstick is bordering on amorphous boric acid zinc particle between 5~90nm; Perhaps detect through X-ray crystalline diffraction instrument, its crystalline structure and chemical formula are 2ZnO3B
2O
33.5H
2The zinc borate standard spectrogram of O is consistent, and its grain median size superfine zinc borate between 20~90nm once.Preferred chemical formula is 2ZnO3B
2O
33.5H
2The zinc borate of O, and its once the grain nano level 2335 type zinc borates of median size between 10~60nm as its raw material.If select the zinc borate that disclosed method is made among the disclosed Chinese patent 200710113285.X in early stage for use, effect is more obvious.
Organic solvent class material as raw material is meant alcoholic solvent, particularly: a kind of in propyl alcohol, Virahol, propyl carbinol, isopropylcarbinol, the isoamyl glycol.
Wherein preferred isopropylcarbinol is as raw material.
Useful technique effect of the present invention is: the working method that generates anhydrous zinc borate is easy, is easy to realize in various vacuum reaction stills.The reaction yield height detects through thermal weight loss, and the mistake crystal water warm spot of its product is 498 ℃, can satisfy the needs of high molecular polymer high processing temperature.No coupling product, alcoholic solvent and dehydrated alcohol can reclaim fully, reuse.Compare with the related products of common zinc borate and the described U.S. Borax Inc. of Chinese patent 97102409.X, lose crystal water temperature spot height, technology is simple, can large-scale industrialization manufacture, and has the advantage of significantly applying.
Embodiment
Provide specific embodiment below, method of the present invention is elaborated.
Embodiment 1
Take by weighing nano-scale amorphous zinc borate 100g, add the 300ml isopropylcarbinol, mix.This mixture is placed vacuum rotary evaporator, and heating and maintenance constant temperature are 200 ℃ under the oil bath condition.Be evaporated to the pressed powder complete drying.Reclaim isopropylcarbinol and from vacuum rotary evaporator, take out the exsiccant pressed powder.In this pressed powder, add the 100ml dehydrated alcohol, mix this pressed powder of centrifugal results.The zinc borate powder that absolute ethanol washing is crossed is dry under 80 ℃ of constant temperatures, can obtain the anhydrous zinc borate pressed powder.Yield about 95%.
Embodiment 2
Taking by weighing chemical formula is 2ZnO3B
2O
33.5H
2The nano level 2335 type zinc borate 500g of O add the 1500ml propyl carbinol, mix.This mixture is placed vacuum rotary evaporator, and heating and maintenance constant temperature are 180 ℃ under the oil bath condition.Be evaporated to the pressed powder complete drying.Reclaim propyl carbinol and from vacuum rotary evaporator, take out the exsiccant pressed powder.In this pressed powder, add the 500ml dehydrated alcohol, mix this pressed powder of centrifugal results.The zinc borate powder that absolute ethanol washing is crossed is dry under 80 ℃ of constant temperatures, can obtain the anhydrous zinc borate pressed powder.Yield about 93%.
Embodiment 3
Take by weighing nano level 2335 type zinc borate 500g, add the 1500ml Virahol, mix.This mixture is placed vacuum rotary evaporator, and heating and maintenance constant temperature are 220 ℃ under the oil bath condition.Be evaporated to the pressed powder complete drying.Reclaim Virahol and from vacuum rotary evaporator, take out the exsiccant pressed powder.In this pressed powder, add the 500ml dehydrated alcohol, mix this pressed powder of centrifugal results.The zinc borate powder that absolute ethanol washing is crossed is dry under 80 ℃ of constant temperatures, can obtain the anhydrous zinc borate pressed powder.Yield about 92%.
Embodiment 4
Take by weighing nano level 2335 type zinc borate 500g, add 1500ml isoamyl glycol, mix.This mixture is placed vacuum rotary evaporator, and heating and maintenance constant temperature are 210 ℃ under the oil bath condition.Be evaporated to the pressed powder complete drying.Reclaim the isoamyl glycol and from vacuum rotary evaporator, take out the exsiccant pressed powder.In this pressed powder, add the 500ml dehydrated alcohol, mix this pressed powder of centrifugal results.The zinc borate powder that absolute ethanol washing is crossed is dry under 80 ℃ of constant temperatures, can obtain the anhydrous zinc borate pressed powder.Yield about 90%.
Embodiment 5
Take by weighing nano-scale amorphous zinc borate 100g, add the 300ml propyl alcohol, mix.This mixture is placed vacuum rotary evaporator, and heating and maintenance constant temperature are 190 ℃ under the oil bath condition.Be evaporated to the pressed powder complete drying.Reclaim propyl alcohol and from vacuum rotary evaporator, take out the exsiccant pressed powder.In this pressed powder, add the 100ml dehydrated alcohol, mix this pressed powder of centrifugal results.The zinc borate powder that absolute ethanol washing is crossed is dry under 80 ℃ of constant temperatures, can obtain the anhydrous zinc borate pressed powder.Yield about 88%.
Embodiment 6
Take by weighing nano level 2335 type zinc borate 500g, add the 1500ml isopropylcarbinol, mix.This mixture is placed vacuum rotary evaporator, and heating and maintenance constant temperature are 200 ℃ under the oil bath condition.Be evaporated to the pressed powder complete drying.Reclaim isopropylcarbinol and from vacuum rotary evaporator, take out the exsiccant pressed powder.In this pressed powder, add the 500ml dehydrated alcohol, mix this pressed powder of centrifugal results.The zinc borate powder that absolute ethanol washing is crossed is dry under 80 ℃ of constant temperatures, can obtain the anhydrous zinc borate pressed powder.Yield about 93%.