Preparation And Performance Of Inorganic-organic Composite Pigments

Considering the poor performances of hiding power, water resistance, solvent resistance, oil resistance, plasticizer resistance, weather resistance and heat resistance , the composite pigments are synthesized with the use of colorless and lightless Mengxi clay materials as inorganic "core", organic pigment as "shell", citric acid as a modifier,γ-methyl acrylyl trimethoxysilane (Kh570) as the fixing agent, and MMA as coated material to increase the performances of organic pigments.Mengxi clay is used as a pigment core taking advantage of its high specific surface area and methylamine Red(P. R. 3), lightfast yellow 10G(P. Y. 3), blue AR were adsorbed on the surface Mengxi clay, and then forms the composite pements, i.e. Yellow, blue ,yellow, were synthesized with polymethyl methacrylate ,which processes transparent property. Because of Fe₂O₃ and organics in Mengxi clay, Mengxi clay must be treated by hydrochloric acid and sodium sulfite. The white clay ,the white degree 76.8%, was prepared when Mengxi clay 20.00 g, hydrochloric acid 50 ml, temperature 85℃, reaction time 2.0 h. The appropriate condition increasing the white degree was attained when white clay 20.00 g,M2 sodium sulfite 0.80 g, citric acid 0.50 g,temperature 75℃, reaction time 45 mins, and then a result products are attainable: surface area 187.20 m2/g, average particle size 1092nm, the whiteness 87.6%.The appropriate preparation conditions of the composite pigment blue and the composite pigment red are acquired when bleaching clay dosage of 3.00g, citric acid 0.80g, modified temperature 70⁸0℃, the modified time 2.0h. The appropriate preparing conditions of the composite color blue: bleaching clay 3.00g, the citric acid 0.60g, modified temperature 65⁷5℃, the modified time 2.0h. The appropriate conditions of coated fixing: silane coupling agent dosage of 0.25g, the amount of methyl methacrylate 0.60g, initiator dosage 0.0040g, reaction time 2.0h, 95% alcohol 10mL, drying time and temperature 0.5 h and 120℃.The appropriate preparation conditions of the composite pigment yellow was acquired by the orthogonal experiment: white clay 3.00 g, citric acid 0.60 g, the modification temperature 60℃, modification time 2.0 h, silane couping agent 0.20 g, 95% alcohol 10mL, drying temperature and time 120℃and 0.5 h. Four parallel experiments shows that the preparation conditions owned good reproducibility.When organic pigments utilization ratio measured by the spectrophotometer of three composite pigments are 98.4%, 93.0%, 88.0%, color retention ratio of composite pigments in water rates are 99.15%, 98.7% and 99.6%The application emperiment shows that the ability of adsorbing oil of compound pements are low relatively, and the capacity of anti-acid and anti-alkali, light, oil, friction, oxidation were increased to an extenment, because of special core-shell structure,the goal of reducing cost of the compound pements and increasing the application capacity is available.The analytic result of IR, XRD, BET, particle size analysis and characterization shows that organic pigment molecule does not enter the lattice core, but by the adsorption and package between inorganic core and organic shell core organic pigment can be fixed on the surface of inorganic core. The inorganic pigments "core" is coated by organic "shell",and forms the inorganic-organic composite pigment .Most of the composite pigment particles own only one inorganic pigment core, and composite pigments and inorganic pigments are well dispersed during the preparation of the kernel without aggregation.