Studies On Chemical Modification And Application Performance Of Ultramarine Pigment

Ultramarine Blue occupies a unique location in blue pigment chromatograpHy, it has a wide range of uses. It can not be replaced by Other pigments and get its hue by mixed methods. Ultramarine Blue has excellent alkali resistance, light resistance, heat resistance, weather resistance; at 200℃for long periods without discoloration; it has good hydropHilic; but it has poor acid resistance, even weakly acidic atmospHere will make it fade to gray, and can not play its unique distinctive tone, which has affected its use results. Ultramarine pigments are currently modified with SiO2, although the acid resistance improved to a certain extent, but the shade will decrease. Since SiO2 is inorganic, its coating layer is not compactness enough, and its adhesion with pigments is poor, easy to get off from pigments. In addition, because the compatibility between inorganic and resin of organic coating is poor, leading to pigments in the paint easily agglomerate, difficult to disperse evenly, resulting in the coating has decreased gloss, poor film, and poor flexibility.This research uses three silane coupling agent to modify ultramarine pigment respectively, which areγ-aminopropyl triethoxysilane (APTES), tetraethoxysilane (TEOS), octyl trimethoxysilane (OTMOS). Firstly analysis the effect of temperature, molar ratio of water and silicon, catalyst concentration and time on the loading rate of hydrolysis and condensation product of APTES on the surface of ultramarine pigment. And get the optimal modification conditions of APTES to Ultramarine blue pigment. Then preparing modified ultramarine pigment with different load rates, print with the modified pigments, compare the dry and wet rubbing fastness of the printed fabrics and test the acid resistance of modified pigments, and get the optimum load rate. Finally, at the optimal modification conditions and the best load rate conditions, use OTMOS and TEOS modify ultramarine pigment respectively, comparing the modification effect of the three different silane coupling agent on the ultramarine pigment by dry and wet rubbing fastness and acid resistance of printed fabric. In this paper, we use our laboratory stirring ball mill to study the effect of milling time, ball to powder weight ratio, colorant concentration, dispersant dosage, ball size and gradation to particle size and distribution of ultramarine pigment. Then use APTES modify different particle size of ultramarine pigments, compare the application properties of the modified ultramarine blue pigments, and obtain the optimum particle size range of ultramarine blue pigment.The study showed that the best conditions of the ultramarine pigment modified with APTES are:at the condition of the amount of the ultramarine is 0.5g, the modified temperature is 70℃, water/Si molar ratio is 15:1, ammonia 0.4mL, reaction time 3h. The acid resistance of modified ultramarine pigments be enhanced with the increase of the products of hydrolysis and condensation of APTES on the surface of ultramarine pigment. When the load rate of APTES hydrolysis condensation product on ultramarine pigment surface get to 50%, a best acid resistance effect can be obtained. Put printed fabrics containing modified ultramarine pigments into 0.1% hydrochloric acid in 2min, the discoloration fastness gets from the original 1 to 4-5. The dry rubbing fastness of the printed fabrics of different modified ultramarine pigments changed little and wet rubbing fastness gradually increased with the more the products of hydrolysis and condensation of APTES on the surface of ultramarine pigment, when the load rate is 90%, the wet rubbing fastness increased to 4 from original 2.By comparing pigment dispersion stability, acid resistance and dry and wet rubbing fastness of the modified ultramarin with APTES, TEOS, OTMOS,at the load rate 50%, We can draw the best of the ultramarine pigment modifier is APTES..In the milling process of ultramarine pigment, the pigment particle size decreases with milling time increases; with the increase of ball to powder weight ratio, colorant concentration and dispersant dosage, the pigment particle size increases firstly and then decreases; ball size and gradation has little effect to the pigment particle size. After different particle size of ultramarine pigments modification, their acid resistance has increased significantly, but the smaller of the particle size is, the lower of the acid resistance will be; with ultramarine pigment particle size decrease, dry rubbing fastness of the printed fabrics tendency to increase and wet rubbing fastness to decline. Take thought of the application performance of ultramarine pigment comprehensively, the most appropriate ultramarine pigment is about 800nm in diameter.