Conductive coating before electrostatic spraying of thermosensitive base material and preparation method and device for conductive coating

Abstract

The invention discloses a conductive coating before electrostatic spraying of a thermosensitive base material and a preparation method and device for the conductive coating. The conductive coating isformed in the mode that the surface of the thermosensitive base material is composed of solid conductive particles with the particle size being micro-nanometer grade, and the thickness of the conductive coating is 5-25 [mu]m. The conductive coating enables the non-conductive or poor-conductivity thermosensitive base material to obtain even sheet resistance, and the adverse effect on subsequent electrostatic spraying is avoided. The conductive coating can be prepared through a pressure spin coating method and / or a pressure spin coater, simpleness and the easy-to-do effects are achieved, the efficiency is high, the using amount of a conductive material is less, the obtained conductive coating is even, the sheet resistance is 10<4> omega to 10<6> omega, the conductive coating is suitable forelectrostatic spraying, scattered conductive particles can be recycled, the cost is low, a solvent is not adopted, and environmental protection is achieved.

Description

technical field [0001] The invention relates to the field of powder coatings and coatings, in particular to a conductive coating before electrostatic spraying of a heat-sensitive substrate and its preparation and device. Background technique [0002] Under the background of vigorously advocating energy conservation and environmental protection in the country, powder coatings have become a rapidly developing popular coating material due to their advantages such as low volatile organic compound (VOC) emissions, high film quality, and convenient recycling. For a long time, traditional powder coatings have been aimed at metal substrates, which are easy to conduct electricity. Through electrostatic attraction with oppositely charged powder particles, adsorption accumulation, and high-temperature melting-curing (180°C-200°C) film formation. With the rapid development of powder coatings, the curing of powder coatings presents a trend of low-temperature and rapid response. Researche...

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Problems solved by technology

[0004] (1) Preheating treatment: bake the board at a temperature range of 70°C-80°C for 15min-20min, so that the internal moisture and other solvents evaporate to the surface, in order to reduce the surface resistance and control the evaporation of water, but the above method is practical The process is difficult to control, and pinholes, bubbling and difficulty in powdering will still occur locally, which cannot meet the actual production needs;

[0005] (2) Brushing conductive liquid: spray or paint the solid conductive polymer dispersed in water or organic solvents to the wood surface, dry naturally or bake at 70°C-80°C to remove water and organic solvents, the above method can Reduce the surface resistance to 10 4 Ω and evenly distributed, but the adhesion between the conductive substance and the substrate is poor, and the subsequent film layer is easy to fall off. If the introduced water and organic solvent are not completely removed, pinholes and bubbling will also appear; in addition, the conductive substance is chemically active , may react with subsequent powder coating components and affect the coating film performance;

[0006] (3) Pre-coated liquid epoxy resin: For example, Chinese patent ZL201210537047.2 discloses a method for preparing a non-conductive substrate powder coating, which uses a non-conductive substrate plate in a low-viscosity bisphenol A type epoxy resin Take it out after soaking for a period of time, and use the viscosity of the liquid resin to absorb the powder coating. The process is complicated and difficult to control;

[0007] (4) Pre-spray conductive powder coating: For example, Chinese patent application CN201711086303.X discloses a graphene conductive powder coating before wood product coating and its preparation and application. Conductive powder (composed of raw materials: epoxy resin, graphene, dispersant, filler, silane coupling agent, phthalate coupling agent, leveling agent, curing agent and defoaming agent) is used for conductive treatment of wood, but The spraying of conductive powder still encounters the same problem of poor electrical conductivity of the substrate, and it is still necessary to pre-treat the wood, and then spray the conductive powder, which increases the process and cost

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