"Selection requirements for non-leafing aluminum paste for paints
(1) Industrial baking paint
Most of these paints are thermosetting, and the resin systems used are generally polymer structures. The most common are thermosetting acrylic and polyester resins, which are characterized by high viscosity, thick construction coating and relatively high acid value. Therefore, this high viscosity is mostly unfavorable for the settlement and drift filling performance of aluminum flakes. Usually, products with a coarse particle size above 30u have better sedimentation and orientation in the paint film. Therefore, the viscosity and leveling of the paint should be adjusted as far as possible during construction. CAB Butyl Acetate Cellulose is an effective raw material to adjust leveling, it can not only promote the orientation of aluminum-phosphorus flakes in the coating, but also improve the brightness, toughness and impact resistance of the paint film. The product is miscible with many resins in any proportion and can be used alone in high-grade paints and coatings. In addition, nitrocellulose is also a good raw material for adjusting the leveling property, but in application, it will reduce the adhesion of the coating and is prone to yellowing, so it must be added in a limited amount.
Due to the relatively high acid value of this type of paint, the active groups in it are easy to erode the surface of the aluminum flakes, resulting in loss of gloss and blackening.
Therefore, it is necessary to choose aluminum paste products with smooth surface of aluminum flakes and high integrity of the auxiliary coating. In order to ensure the smoothness of the paint film and the ideal protection performance. The moisture content must be strictly controlled when applying the butene acid system, and the maximum cannot exceed 1.5%.
Bayer dehydrating agent OF can also be used to remove excess water in the system. It is best to use resin-coated aluminum paste for highly decorative construction processes that require high acid resistance.
(2) Automobile and motorcycle paint
There are many types of resin systems used in this type of paint. Except for the CAB system, they are generally high-solid, high-viscosity, and durable.
High decorative paint with strong friction and strong adhesion, in addition to strict requirements on the particle size distribution of aluminum paste, the selection of types is relatively wide, such as standard sink type, silver white type and flash series products are optional Scope.
(3) Plastic paint
This type of paint is mostly a single-layer paint system, mainly thermoplastic or self-drying, which is characterized by high solid content, high viscosity and viscosity.
Low, high fluidity, moderate acid value, thin coating, generally 14-16, the thickest is not more than 25u, so in the paint making
In the process, aluminum paste products with a particle size of 20μ or more, uniform distribution and smooth aluminum flakes should be selected. Such as: standard sinking type, silver white type, silver dollar type imitation electroplating type, etc. In this way, the surface compactness, smoothness and integrity of the paint film can be ensured, and the phenomenon of silver loss, burr or poor insulation caused by aluminum flakes exposed on the surface of the paint film can be avoided. For coatings that require high resistance to electric shock, it is best to choose resin-coated aluminum paste.
(4) Self-drying paint
There are many types of self-drying paints with different varieties. In order to facilitate the distinction, we divide them into two categories according to the shape of the carrier, namely oil-type self-drying paint and resin-type self-drying paint.
1. Oil-based self-drying paint
Oil-type self-drying paint is mainly oxidative polymerization drying, so it is also called oxidative polymerization drying type. The main ingredient is dry vegetable oil, or a mixture of dry vegetable oil and non-dry vegetable oil. If this kind of paint is not handled properly, it is easy to cause problems such as high acid value and poor drying performance, such as linseed oil type, so it is necessary to choose a smooth and smooth aluminum paste product. It is also prone to sticky surface and orange peel after drying, so try to make the paint film thinner and more uniform when painting. And choose bright and dry season construction.
2. Resin type self-drying paint
Resin type self-drying paint is designed by the volatilization and drying concept of solvent volatilization to fix the coating resin on the surface of the object.
Therefore, it is also called volatile drying type. Its main components are natural resins, synthetic resins, solvents, etc.
This kind of paint is easy to process, and its coating effect and performance are better than oil paint. The selection range of aluminum paste is also relatively wide, and the selection range of aluminum paste can be designed according to the coating grade, application characteristics and cost performance of the paint.