Synthesis Of Zinc Borate And Improvement Of Its Shape

Zinc Borate is one of the inorganic flame retardant, it poses the advantage of stability, fine particle and innocuity.Three synthesis methods of zinc borate, method of zinc hydroxide and boric acid, method of zinc salt and borax, method of zinc oxide and boric acid, were explored, borax was determined as experimental by comparing the three methods and the raw material was improved.It was found the product synthesized in this experimental condition was a sort of zinc borate with new type component. Thereinto, the content of boric oxide was lower than traditional zinc borate of 2335 type. Data of experiment were analyzed synthetically and the composition of obtained product was identified by TG-DTG and XRD. The reaction equation was: 3.5Zn(NO₃)₂+3.5Na₂B₄O₇+0.5ZnO+10H₂O→4ZnO·5B₂O₃·10H₂O+7NaNO₃+4H₃BO₃Synthesis parameters were sought by single factor experimentation, orthogonal factors and the levels of orthogonal experiment were selected, the effect of reaction temperature, feed compositions, ratio of liquid to solid and reaction time on the synthesis of zinc borate was researched. The optimal reaction conditions synthesizing ZB4510 were temperature 65℃, materials ratio 1∶1, liquid-solid ratio 6∶1, reaction time 7h.Under the best condition, the shape of zinc borate was long columniation, length was about fifty to eighty micron, diameter was about ten micron.In order to make the granule of zinc borate much more fine, distribution of crystal shape much more uniform,changing reaction equipment and reaction solvent,adding surfactant and crystal ameliorant were researched in this paper.The results proved that the grain of zinc borate synthesized in the constant temperature shaking trough was fine and uniformity. The shape of zinc borate synthesized in this condition,adding chlorination aluminum , was fine,with better roundness, which diameter was about one micron; When Sodium dodecyl benzene sulfonate was chosen, the shape of zinc borate was uneven slice, thickness was about 0.1 micron, surface was about 1 square micron. The effect of improvement was preferable.The flame retarding properties of zinc borate were tested. The rate of charring forming which the poplar wood treated by homemade fine ZB4510 after burring test was 39.6%, the rate of charring forming which the poplar wood treated by market ZB2335 only was 30.4% in the same condition. The rate of charring forming of homemade zinc borate was higher 30.26% than the market zinc borate. It was indicated the flame retarding property of homemade zinc borate was more excellent than the market zinc borate.Innovation of this paper was the product synthesized in this experimental condition was a sort of zinc borate with new type component, the grain was thinner, and the flame retarding was more excellent. This product has not been reported in literature so far.