The Development And Experimental Study On The Humidity Control Coating

Humidity is an important environmental parameter, which has close relation with daily life and manufacture work. A proper humidity is very important to human heath, product manufacturing and article conservations. As a passive humidity control method, the humidity control material can control the humidity of the air by its own characteristics without the high power consumption compared with the traditional air conditioner.In this paper, our goal is to make a kind of humidity control coating on the base of traditional humidity control inorganic porous material, which can realize the humidity control in closed space and building environment. Our research begins from the characteristic of the inorganic porous humidity control materials. From the experiment of the equilibrium moisture content, we choose diatomite as a main component to make the coating we need. At the same time, we give it the explanation of absorption with the surface area, pore structure and the microcosmic state.Fist step,we use styrene acrylic latex as the film forming material of the coating as to make latex humidity control coating. By adding different amount of diatomite we gain some different coatings. Data of the adsorption and desorption capacity of these coatings shows that 50%～75% of the diatomite dote is a proper amount.But these organic coatings are not the perfect one, so second step, we add the inorganic material—silica sol to the organic latex. After the interaction of the two materials, the compound humidity control coating is synthesized. By the interaction procedure, the humidity control capacity of organic coating is much improved, and the conventional indexes of the compound coating, for example, adhesion is also reach the national criterion.Third, we add nano TiO2 to the compound coating to improve its mechanics performance. Experimental result indicates that, Comparing to the coating without nano TiO₂, the wet scrub resistance of 2% nano TiO₂ content of the coating increases 1.7 times, pencil hardness increases 2 grades, but the characteristics of its moisture absorption and desorption are not decreased too much.In order to give some guidance to the practical application, we also simulate an office room under Beijing's and Shanghai's climate, we use some criteria of the parameters of the room environment. Calculation shows that, in the winter, Shanghai's humidity is about 4～100%without humidity control coating, but with coating, humidity will change to 10～95%, people will feel more comfortable under this humidity environment.