The domestic primers commonly used in automobile painting mainly include alkyd primers, epoxy primers, nitro-based primers, perchlorethylene primers, and acrylic polyurethane primers. These types of primers are mainly used for the primer and anti-rust of the exterior of the automobile body and the surface of parts. They are often called primers, and the coating construction adopts the spraying method. For the skeleton profiles, plates, and small parts inside the car body, there are mainly two types of phenolic antirust paint and alkyd antirust paint, and the coating construction adopts brush coating or dip coating (dip coating). method. The commonly used domestic primers and antirust paints are briefly introduced as follows.
(1) Alkyd primer
The characteristics of this type of primer are that the surface dries quickly, has good adhesion, is cheap, and is easy to buy. It is mainly used for the first primer on the surface of ordinary cars, such as trucks and passenger cars. The commonly used varieties are C06-1 iron red alkyd primer and C06-17 iron red alkyd primer.
①C06-1 Iron Red Alkyd Primer The paint is mixed with medium-oil or long-oil alkyd resin modified by dry vegetable oil (such as linseed oil, etc.), iron oxide red, lead chrome yellow, and body pigment (talcum powder, etc.) After grinding to a certain fineness, it is prepared by adding drier, No. 200 paint solvent oil (No. 200 gasoline) and xylene. The main feature is that it has good adhesion and anti-rust performance to the metal surface, and has good bonding force with various topcoat coatings such as nitro enamel, polyurethane enamel, alkyd enamel, perchlorethylene enamel, etc., and the price is cheap. durability. However, the weather resistance is poor in humid tropical marine climate and humid areas. It is mainly suitable for priming and rust prevention of ferrous metal surfaces of general automobiles, trains, mechanical equipment, etc. The dosage of spraying construction is 100-120 g/㎡. The coating can be dried or baked at normal temperature, and the drying time at normal temperature is generally 8-12 hours; at 100°C, the drying time is 1 hour, and at 100°C, it is 0.5 hours. When coating with alkyd enamel, it can be done after drying at room temperature. When coating with nitro, polyurethane and other top coats, it is recommended to do it after the coating is baked and dried to prevent the paint film from being fully dry and causing bite. The bottom is wrinkled.
②C06-17 Iron Red Alkyd Primer This paint is mainly made of phenolic modified alkyd resin, mixed with anti-rust pigments and extender pigments, and then added with drier and organic solvent. It is characterized by faster drying than C06-1 iron red alkyd primer, good adhesion and good resistance to nitro paint. It is suitable for anti-rust of ordinary automobiles, small hardware, and mechanical equipment. Other aspects are basically the same as C06-1 iron red alkyd primer.
(2) Phenolic antirust paint
The difference between phenolic antirust paint and alkyd iron red primer is that the paint film has good leveling property and strong rust resistance, but it dries slower than alkyd primer, and because the paint film has better leveling property, It is only suitable for brushing or dipping, not for spraying, otherwise the paint film after spraying will easily flow and hang, which will affect the quality of coating. Commonly used varieties are F53-32 gray phenolic antirust
Paint, F53-33 iron red phenolic antirust paint, F53-36 iron black phenolic antirust paint, F53-41 various colors of boron barium phenolic antirust paint, etc.
① F53-32 gray phenolic antirust paint This paint is made of long oil rosin modified phenolic resin paint, rosin glyceride, antirust pigment, extender pigment, driers No. 200 gasoline or turpentine, etc. mixed. It is characterized by easy painting, good rust resistance and
low price. It is mainly used for anti-rust primer on the surface of general automobiles, such as the skeleton and internal parts of passenger cars. The dosage is 60-80g/㎡, and the drying time is 24 hours at room temperature.
②F53-33 iron red phenolic antirust paint This paint is also called magnetic antirust paint or iron oxide antirust paint. Its main components are the same except that the antirust pigment used is different from F53-32 gray phenolic antirust paint.
③F53-36 Iron Black Phenolic Antirust Paint The raw material composition of this paint is basically the same as that of F53-32 gray phenolic antirust paint, but its antirust performance and brushability are better than those of F53-32 gray phenolic antirust paint. It is suitable for general parts of automobiles. For example, the surface coating of parts that require blackening, such as the engine cover of a passenger car and the fender of a truck, can be used as a primer anti-rust paint or as a top coat, so as to replace the ordinary black top coat to reduce the coating. cost.
④F53-41 Boron-barium phenolic antirust paint of various colors This paint is prepared by mixing rosin-modified phenolic resin, polymerized vegetable oil, barium borate and other pigments, and then adding drier, No. 200 gasoline and other solvents. It is characterized by good rust resistance, strong adhesion to metal, and easy to paint. It is more suitable for the primer coating on the surface of general internal parts of various ordinary automobiles. The dosage is 80g/㎡, it can be diluted with No. 200 gasoline, turpentine or alkyd thinner, and the drying time is 24 hours at room temperature.
(3) Alkyd antirust paint
The surface drying speed of alkyd antirust paint is faster than that of phenolic antirust paint. There are mainly C53-32 zinc gray alkyd antirust paint, iron palm alkyd quick-drying antirust paint and iron black alkyd quick-drying antirust paint which are commonly used in automobile primer.
①C53-32 Zinc Gray Alkyd Antirust Paint This paint is prepared by mixing long oil alkyd resin, antirust pigment and appropriate amount of body pigment, adding appropriate amount of drier, No. 200 gasoline and xylene organic solvent. become. It has the characteristics of fast drying of paint film, good rust resistance and good adhesion. It is mainly used for the antirust of common parts of automobiles or the first primer of automobile interiors.
② Iron brown alkyd quick-drying antirust paint. The paint is made of linseed oil modified medium oil alkyd resin and magnetized iron brown antirust pigment. Made by mixing toluene. The main feature is that it has good rust resistance to steel parts, strong adhesion, and fast drying speed of the paint film. For example, under normal temperature conditions, the paint film can dry on the surface in 20-30 minutes, and it can be completely dry in 8-12 hours. In terms of construction methods, whether it is brushing, dipping or spraying, it is more suitable, and the price is the same as that of ordinary alkyd antirust paint. Therefore, the anti-rust paint is not only suitable for the anti-rust primer on the surface of ordinary automobiles, but also has been widely used in the anti-rust primer on the surface of large iron towers and mechanical equipment.
③Iron black alkyd quick-drying anti-rust paint The composition of this paint is the same as iron brown alkyd quick-drying anti-rust paint except for the anti-rust pigments. In terms of usage, it is more widely used than iron brown alkyd quick-drying anti-rust paint, such as the chassis, chassis, wheels, fuel tanks, and black parts of automobiles.
(4) Epoxy primer
The performance of epoxy primer is better than that of alkyd primer. It not only has strong adhesion, but also has good chemical resistance and is compatible with various topcoats. In terms of drying, it can be dried at room temperature or oven-dried, so this kind of primer is more suitable in the automotive industry, whether it is a car, a bus, or a truck. The varieties mainly include H06-2 iron red, zinc yellow epoxy ester primer and H06-10 epoxy ester zinc-rich primer, etc.
①H06-2 iron red, zinc yellow epoxy ester primer This paint is a more commonly used first primer in automobile painting. It is prepared by esterifying epoxy resin with vegetable oil, then mixing with iron oxide red or zinc chrome yellow and extender pigments, adding appropriate amount of amino resin, drier, xylene and acetone and other organic solvents. It has the characteristics of tough and durable paint film, strong adhesion, and can be dried at room temperature; if it is used together with phosphating primer, it can greatly improve the adhesion, rust resistance, moisture resistance and Anti-salt spray performance. It has a good effect in the anti-rust primer of automobiles in dry areas, cold areas, coastal areas and humid tropical climate areas. Among them, the iron red epoxy primer is suitable for the anti-rust primer of black metal surfaces such as steel plates. Zinc Yellow is mainly used for antirust on the surface of light metals such as aluminum. Drying at room temperature for 812 hours, baking drying at 100°C for 30 minutes, and at 120°C for 20 minutes. The dosage of iron red is 70-90g/㎡, zinc yellow is 80-100g/㎡. Thinning epoxy paint thinner. Nitro lacquer, amino baking varnish, acrylic lacquer and polyurethane lacquer can be used for matching top coat.
② Epoxy ester zinc-rich primer This paint is made of high molecular weight epoxy resin and vegetable oleic acid after high temperature esterification, mixed with metal zinc powder and finely ground, then added appropriate amount of drier and organic solvent to prepare. It is characterized by strong adhesion, tough and durable paint film, good wear resistance, moisture resistance and excellent corrosion resistance, and has cathodic protection. It is mainly suitable for surface rust prevention of automobile chassis. However, this kind of paint has certain toxicity to the human body, and a gas mask should be worn during construction to prevent poisoning.
(5) Nitro-based primer
Nitrogen base primer is composed It is characterized by extremely fast drying. At room temperature, the paint film can be surface-dried in a few minutes, and hard-dried in 30-40 minutes. But the adhesion and anti-rust performance are not as good as other top primers. It is mainly used for the anti-rust of the car's partial touch-up paint, and it is not suitable for the anti-rust of the whole vehicle, otherwise the expected quality effect will not be achieved. Commonly used varieties are Q06-4 nitro-based primers of various colors.
(6) perchlorethylene primer
Perchlorethylene primer is composed of perchlorethylene resin, alkyd resin, plasticizer, antirust pigment, extender pigment, ketones, esters and xylene and other organic solvents. The drying speed is slower than the nitro-based primer, but faster than the alkyd primer, the adhesion and rust resistance are roughly the same as the nitro-based primer, and the three-proof performance (anti-mold, anti-salt spray, anti-humidity) is better. It is suitable for anti-rust primer of ordinary cars in humid tropics. If the paint film is dried at a low temperature of 60-70°C, the adhesion and rust resistance can be improved.
(7) Acrylic polyurethane primer
This type of primer is a high-grade primer. At present, most of the acrylic polyurethane primers used in automobile painting are two-component packaging, that is, the paint and curing agent are packaged in separate tanks or buckets. When using, adjust according to the ratio specified in the product. The characteristics are that the paint film has strong adhesion and is compatible with various topcoats. The solid content in the paint is higher than that of nitro-based primers and perchlorethylene primers, but the drying time is shorter than that of nitro-based primers or perchlorethylene primers. The primer is long, and it takes 15-20 minutes for the surface of the paint film to dry at room temperature, 6-10 hours for solid drying, and 2-2.5 hours for drying at 60-70°C.
The disadvantage is that because it is a two-component paint, it needs to be prepared immediately, and the mixed primer should be used within a few hours after deployment, otherwise it will be easily gelled and scrapped to cause waste, and it is expensive and costly. high. It is mainly used for anti-rust primer of cars and high-end luxury passenger cars.
