A Study On The Modification Of Paraffin Wax And Its Application For Crayons

This paper conducts a systematic study on the method of preparation and the emulsification process of oxidized wax, and its application for crayons.The melting of paraffin wax, as the main raw materials can be enhanced via adding a certain quality of microcrystalline wax. In the effect of catalysts, the crude wax was oxidized with pure oxygen. This paper focuses on the study of factors such as species and amount of catalysts and additives, reaction time, reaction temperature, flow rate of oxygen, which affect the properties of oxidized wax. Experimental results show that the best conditions for the preparation of oxidized wax are 0.52% manganese sulfate as catalyst and 6% stearic acid as auxiliary in the condition of flow rate of 80 milliliters per minute for oxygen and 150℃ for four hours. Under such conditions, oxidized wax with acid value of 23.44mgKOH·g-1 and saponification value of 49.13mgKOH·g-1 can be obtained. The oxidized wax with light color, less smell and drop melting point of 63.0℃, has a high acid value and saponification value. IR spectrum shows there are polar groups such as carbonyl group and alcoholic hydroxyl group in oxidized wax. The spectrum of SEM shows that irregular folding structures exist on the surface of oxidized wax.Oxidized waxes, as the target of emulsification, was emulsified by a variety of emulsifiers, and Span-60 and Tween-60 were determined finally. Experimental analysis show that the best conditions for preparation of emulsifying waxes are 0.9g Span-60,2.1g Tween-60,5g oxidized wax,70mL water in the condition of 1500 revolutions per minute for emulsification rate and 85℃ for forty minutes. Under such conditions, the diameter of particles for emulsified wax is 106.5nm with 39mPa s for viscosity. The product is a dispersion of level one, and breaks up after 120 days.Oxidized wax and paraffin wax, as the main raw materials, were used for the preparation of crayons. The effect of various components on the physical properties of crayons was studied. The crayons in accordance with the industry standard QB1336-2000 were prepared by adjusting the proportions of each component. Through experimental analysis, the formula of crayon is determined as below:17.5g oxidized wax,3.5g paraffin wax,3.0g stearic acid,12.0g calcium compound,1.9g hydrogenated castor oil, and the right amount of pigment and others. The 1# crayon made of oxidized wax is drew thickly on paper with bright color, less shavings, and natural blending. Experiments show that compared with the performance of 2# crayons made of imported wax, the performance of 1# crayons made of oxidized wax is close to that of 2# crayons.It is proved that instead of imported wax, oxidized wax is used for crayons, and the same effect can be achieved.