High-solid multifunctional quick-drying intermediate coating composition and purpose thereof

Abstract

The invention discloses a high-solid multifunctional quick-drying intermediate coating composition. The composition comprises the following components in parts by weight: an intermediate coating comprises the following components in parts by weight: 25-40 parts of acrylic resin, 0.3-1 part of a leveling agent, 0.2-2 parts of a dispersing agent, 5-15 parts of a pigment, 35-50 parts of a functionalfiller, 0.2-2 parts of an anti-settling agent, 10-15 parts of a first solvent, 0.2-0.5 parts of a storage stabilizer; and a curing agent comprises the following components in parts by weight: 40 to 60parts of isocyanate, 40 to 60 parts of a second solvent; or the curing agent comprises the following components in parts by weight: 40 to 60 parts of isocyanate, 40 to 60 parts of the second solvent,and 0.01-1 part of a water-removal additive. The invention also discloses a purpose of the high-solid multifunctional quick-drying intermediate coating composition as an automotive paint. The high-solid multifunctional quick-drying intermediate coating composition has good workability and paint film, and has high production efficiency and low VOC.

Description

technical field [0001] The invention relates to the technical field of coatings, in particular to a multifunctional fast-drying intermediate coating composition with high solid content and its application. Background technique [0002] With the rapid development of China's economy, environmental problems have become increasingly prominent, and people's calls for environmental protection are also increasing. To this end, in recent years, local governments have successively issued environmental regulations to regulate the VOC emissions of paints during the coating process. Accordingly, the development direction of automotive refinish paint is high solid content and water-based. According to the experience of foreign developed countries, high solid content is a more reasonable choice for automotive repair primers. According to the current EU standard, the VOC limit of automotive refinish paint is 540g / L, which is also an important reference for local governments in China to f...

AI Technical Summary

Problems solved by technology

[0003] It is difficult to balance the drying speed and construction solid content of traditional automotive refinish paints. Using high molecular weight and high Tg resins can increase the drying speed, but often cannot achieve high construction solid content.

At the same time, due to the materials used, the drying speed of the coating film and the appearance of the paint film cannot achieve a perfect balance. For customers who need higher production efficiency, if the intermediate coating is not polished, the traditional intermediate coating cannot achieve a good paint film appearance.

[0004] Generally, the intermediate coating with high construction solid content needs to meet the high construction solid content, the molecular weight of the resin is small, and the glass transition temperature (Tg) is low, which causes the initial drying speed of the intermediate coating to be slow. According to normal baking conditions or The natural drying time cannot be polished and assembled, which reduces the production efficiency of automobile repair; by changing the main resin type of the coating from acrylic to a special functional resin, a good balance between drying speed and construction solid content can be achieved, and at the same time it brings new problems : Available time is too short

Generally speaking, the intermediate coating of automotive refinish paint needs at least 1 hour of usable time after it is prepared. After the usable time is exceeded, the coating will gel and cannot continue to be used. The usable time of this resin is only 10-30 minutes, unable to meet the actual requirements of production; because of the high solid content requirements and the low gloss of the repair primer, a large amount of functional fillers will be used in the formula, resulting in the PVC of the high solid primer being relatively normal. The coating should be high, which will cause serious problems with the storage stability of the sedimentation agent

At the same time, due to the trend of water-based topcoats, intermediate coatings must have good adhesion with water-based topcoats. Due to the selection of raw materials and formula design of traditional intermediate coatings and general high-solid intermediate coatings, water will not affect the coating film of intermediate coatings. Poor wetting, resulting in poor adhesion when matched with water-based topcoats

[0005] To sum up, automotive refinish paint lacks a multi-functional fast-drying primer with high solid content, that is, VOC<540g / L, fast drying, and non-abrasive process.

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