Application of the hottest aluminum pigment techno

2022-10-20
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Application of aluminum pigment technology in ink and coating (I)

aluminum sheet will produce the following oxidation reaction in water, resulting in gas generation:

2Al + 6 strengthen the exchange with CRRC, SAIC, Dongfeng, 1 steam, BAIC, Yutong and other enterprises H2O - 2Al (OH) 3+3h2

overcome the above problems, there are two technologies based on different principles: one is additive technology, that is, mixing additives on the surface of aluminum pigment particles by physical methods, Through a barrier layer mechanism, a protective layer is formed on the outer layer of the aluminum sheet, which finally prevents the reaction between aluminum and water. The second technology is called coating technology. When the aluminum sheet is wrapped, a single pigment particle is completely encapsulated

1. Additive technology

the most commonly used method to prevent gas generation from aluminum sheets is to use organophosphorus compounds for treatment. This kind of product has existed in the market for many years and has been very mature. It usually appears in the form of 65% aluminum pigment paste in various solvents. Different solvents are necessary because they must be compatible with different resin systems and their compatibility with stabilizers

one of the product series (stapahydrolac Series) contains solvent gasoline and another solvent. The solvent can be water (stapahydrolacw Series), methoxypropanol (stapahydrolacpm Series), or butanediol (stapahydrolacbg Series). The next step is to develop a series of products without solvent gasoline (stapahydroxal) and containing only one of the above solvents. Such products can eliminate the surface defects (such as fish eyes) caused by poor compatibility with solvent gasoline in the coating system. The aqueous stapahydroxalw series can be used to produce zero VOC coating products

a side effect of stability is that some properties of the coating will be adversely affected (such as drying time, adhesion between coatings, moisture resistance). To make up for these adverse effects, the amount of stabilizer can be reduced to the minimum while protecting the product performance from damage

2. Coating technology

the second technology for developing waterborne aluminum sheets is to use pigment particles. An American Recycling Association said it would pay more attention to complete coating to provide better protection

the first generation of pigments using coating technology used a layer of insoluble chromium (III) compound (stapahydrolux): these pigments do not contain soluble chromium (VI) salt (1ppm), so they are non-toxic. The second generation (the latest product) is coated with silicon dioxide and then further treated with organic matter (stapahydrolan). Due to its unique sandwich structure, this generation of products can better show its stability when used on the recycling line

the gas evolution of these aluminum pigments with different stabilization methods in the same paint formula can be measured. A water-based paint with standard formula was prepared and stored in a special equipment, so that the amount of hydrogen produced at 40 ℃ for a certain period of time can be measured. The advantage of this test is that its result is very close to the real situation, but the disadvantage is that the final result can be obtained after 10 or 30 days at the earliest, depending on the resin system used. However, years of experience has shown that after three days of testing and doing a good job in liquidation, we can already make a good prediction of the final result. Experts pointed out that various types of stabilizer products should be tested in individual resin systems to seek the best overall stability

3. Formulation design

in order to optimize the optical performance, technology and gas generation characteristics of products, all raw materials, resins, pigments and additives, as well as production technology must be included in the consideration of composite materials, which are suitable for the formulation designers of building structural materials

good mixing of metal flake pigments and resins: improper mixing of the two will have a negative impact on the optical properties of the product if the shear force is too high. High shear force will damage the flake pigments in two ways: first, it will bend the flake particles, thereby reducing their brightness; Secondly, it will peel the protective layer from its surface, resulting in gas generation

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