Epoxy floor coating, as an increasingly routine paint commodity, is widely used in infrastructure projects such as industrial plants with its unique beauty and function. The anti-static epoxy floor coating is more and more widely used in electronics and electrical factory workshop, warehouse, computer room, electrical control room, printing factory, textile factory and other places which need anti-static or explosion protection because of its special function of lasting conduction. There are two kinds of Antistatic Epoxy Floor coatings, solvent type and solvent free type. Because of its need for decoration and special anti-static function, it is more difficult to grasp the comparison with other skills. Now it has become the skill center of various epoxy flooring companies. In order to grasp this skill, we must first grasp the selection of different conductive materials for different floor requests. Selection of materials is the first and most important step in the successful use of materials.
Classification of Antistatic Epoxy Floor
Anti-static epoxy flooring can be divided into two categories according to the system: general anti-static epoxy flooring and anti-static epoxy self-leveling flooring. The thickness of general anti-static epoxy floor coating is about 0.1-0.2 mm (two coatings). The cost is relatively low. Solvent is released during coating. The surface flatness and wear-resistant service life of the surface are not as good as that of the self-flow floor coating. In terms of electrical conductivity, the thin film is relatively simple to arrive at. The thickness of self-flowing anti-static epoxy floor is over 0.7 mm, no solvent is released during painting, the construction is convenient, the appearance is flat and beautiful, the anti-static surface wear-resistant life is long, the relative skills are messy, and the cost is slightly higher.
Anti-static floors are divided into dissipative RS106-109_and conductive RS < 106_according to the specifications. Different requests are made according to the occasion. Because of these detailed requests and classifications, it is necessary to select different conductive materials as processing materials according to different situations, and to plan the most reasonable skills and economic formulation system.
Classification of antistatic materials
The common antistatic materials can be roughly divided into the following categories:
1. eigen conductive powder: good conductivity, easy to process, but the color and anti-corrosion defects are significant.
2. coated conductive powder: light color, low price and versatility.
3. conductive agent: ion exchange, which can only conduct short term conduction.
4. conductive fiber: less amount of increase, good electrical conductivity, not easy to lax.
Selection of solvent based anti-static epoxy floor materials
The general anti-static epoxy floor can be prepared by using composite conductive mica powder BC-C. Now the solvent based technology is very sophisticated, and the resistance index can reach 105~109 ohms. Able to get all kinds of anti-static requests, we can plan to increase the amount to arrive at various requests.
The planned conductivity value_corresponds to 109-106 with solid content increasing agent 24%-28%, respectively, because conductive fibers are not easy to disperse and show a brief appearance outcrop for thinner paint film, which has a significant impact on the decorative appearance (its length constraint will also affect the spraying construction); while metal and carbon black powder are also affected by color constraint and electrical corrosion (conductivity). Electric exhaustion) and other factors can not be used, so now it seems that the composite conductive mica powder with beautiful function and operability is the most suitable material for general anti-static floor. It has the most suitable conductivity and appearance and is well recognized by the current floor manufacturers. For example, conductive powder is now used in most of the general anti-static epoxy flooring materials in China, with extensive technical support and customer acceptance.
Digression: there are also conductive conductive materials such as conductive titanium dioxide and conductive sand on the market. However, due to its particle shape is not like mica simple lap, and the conductive function is not easy to reach the best, coupled with the high cost of quotation can not be widely used.
Selection of solvent-free anti-static floor material
For a long time, there has always been some difficulty in selecting conductive materials for self leveling anti-static floor. The main factors are as follows: with the increase of coating thickness, the tendency of resin floating will increase (compared with solvent type) when the paint film is cured, and the sinking factor of conductive data will be added. As a result, the longitudinal dispersion of conductive materials in solvent-free paint film is not continuous uniform, and the mass percentage of conductive materials in the upper layer is significantly lower than the average value. It is precisely because of its characteristics that the production and construction of solvent-free anti-static self-leveling is far from being solvent-based.
The commercial characteristics of graphite powder and metal powder have been discussed before, which restrict their application in floor paint. Moreover, the antistatic agent does not meet the application requirements of floor paint because of its short-term usefulness and long-term usefulness. Therefore, the following discussion focuses on the application of composite conductive mica powder and conductive fibers in solvent-free environment.
To achieve the same effect, the increase of composite conductive mica powder in solvent-free medium is much larger than that in solvent-based medium. Excessive increase of conductive powder will increase the whole viscosity of the system, reduce the leveling property and reduce the film hardness by one order. And it will increase the difficulty of construction (poor thickness control will shake the percentage of conductive data quality in the upper layer, and then the conductive value is unstable), and the cost is relatively high. These factors restrict the use of composite conductive mica powder in solvent free applications.
Conductive fibers have been widely used because of their lax skills. Its advantages are: convenience, bright colors, low cost, good electrical conductivity, etc. But it also has limitations: the self-leveling of anti-static electricity can be made by conductive fibers alone, and the external resistance can only be controlled steadily from the order of 10 to the sixth order of 10_. But it is not easy to make 106-109_stable, and the construction thickness is required high (primer resistance, thickness). Fiber length is also constrained, too long fibers will affect the appearance, too short fibers will affect the conductivity in the anti-static self-current plateau mixed with conductive powder and conductive fibers can be used to deal with the above two limitations. Its principle is to use conductive powder to control the touch resistance, and conductive fibers to deal with the problem of non-uniform longitudinal distribution of conductive data.
The mixture of conductive powder and conductive fiber is prepared by special methods in a reasonable proportion. It has the following characteristics:
The surface resistance can be controlled by conductive primer.
Primers with a conductivity value of 10: 4 times, 10 times 4 times.
规划导电值Ω：106-9，104 -5 ，＜104
Planning electrical conductivity value: 106-9104 -5, < 104
The production operation is simple and has obvious advantages for low construction request and high resistance stability. Completely deal with the problem that the decorative, constructive and functional properties of the floor, which happened before the sole use of conductive fibers or conductive powders, can not reach a unified level.
Conductive function is stable. It is useful to deal with the problems of electrostatic blind spot occurring simply by using conductive fibers, and to deal with the problems of simple sedimentation and large oil absorption by using conductive powders together. The thickness of construction is large enough to be 2MM. once.
This kind of method already has certain application skills in foreign countries. Foreign companies usually finish the stable resistance value of the paint film by adding a variety of matching materials. However, due to the selection of different proportions of conductive materials, the paint film must be thicker, together with a special curing agent to achieve the appropriate curing time, and due to the excessive cost of fillers and color mixing are doubtful, can not reach the promotion. BC-W11 is a stable, reliable and convenient self-leveling conductive material because of its moderate increase and appropriate material proportion.
The original anti-static floor as a functional material, compared with conductive PVC, conductive carpet, etc., has a strong integrity, low cost advantage. And stable electrical conductivity is the center of this commodity and the center of every manufacturer's competition. So the first step is to choose the right information. It has been proved by many practices that the composite conductive powder BC-C and the new concept BC-W11 can meet various requirements of conductive floor, which will undoubtedly greatly promote the progress and development of conductive epoxy floor industry.