阅读说明：本技术 商用车底盘漆膜修补用水性环保自喷漆及其制备方法 (Water-based environment-friendly self-spraying paint for repairing commercial vehicle chassis paint film and preparation method thereof ) 是由 黄绍全 杨兴勇 李磊 刘鹏程 黄河 魏林江 于 2020-12-08 设计创作，主要内容包括：本发明公开了一商用车底盘漆膜修补用水性环保自喷漆及其制备方法,包括主漆和抛射剂,其中所述主漆为140-160g,所述抛射剂为120-140g；主漆包括下列质量份配比的原料：35-50份水性改性丙烯酸树脂、7-10份改性树脂、20-35份去离子水、0.8-1.2份分散剂、0.1-0.3份消泡剂、0.1-0.2份防沉剂、0.2-0.4份流变剂、0.2-0.4份的润湿剂、2-3份的缓蚀剂、0.5-0.9份闪锈抑制剂、1-2份密着促进剂、15-25份的颜填料；本发明制备的涂料不含重金属、VOCs低,符合环保大趋势,涂料成膜后在分类底材制成的轻、重卡商用车底盘上具备优秀的附着力和防腐性；另,采用气雾剂形式进行包装,用二甲醚与正丁烷按照6:4复配制成抛射剂,抛射和雾化效果稳定,漆膜外观好,且操作方法简单,使用方便快捷。(The invention discloses a water-based environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis and a preparation method thereof, wherein the water-based environment-friendly self-spraying paint comprises a main paint and a propellant, wherein the main paint is 160g of 140-one-shot paint, and the propellant is 140g of 120-one-shot paint; the main paint comprises the following raw materials in parts by mass: 35-50 parts of water-based modified acrylic resin, 7-10 parts of modified resin, 20-35 parts of deionized water, 0.8-1.2 parts of dispersing agent, 0.1-0.3 part of defoaming agent, 0.1-0.2 part of anti-settling agent, 0.2-0.4 part of rheological agent, 0.2-0.4 part of wetting agent, 2-3 parts of corrosion inhibitor, 0.5-0.9 part of flash rust inhibitor, 1-2 parts of adhesion promoter and 15-25 parts of pigment and filler; the paint prepared by the invention does not contain heavy metal, has low VOCs (volatile organic compounds), accords with the great trend of environmental protection, and has excellent adhesive force and corrosion resistance on the chassis of light and heavy truck commercial vehicles made of classified substrates after film forming; in addition, the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4 by adopting an aerosol form for packaging, the propellant and atomization effect are stable, the paint film appearance is good, the operation method is simple, and the use is convenient and quick.)

1. The utility model provides a commercial car chassis paint film is repaired with aqueous environmental protection from spraying paint, characterized by: comprises a main paint and a propellant, wherein the main paint is 160g of 140-one, and the propellant is 140g of 120-one;

the main paint comprises the following raw materials in parts by mass: 35-50 parts of water-based modified acrylic resin, 7-10 parts of modified resin, 20-35 parts of deionized water, 0.8-1.2 parts of dispersing agent, 0.1-0.3 part of defoaming agent, 0.1-0.2 part of anti-settling agent, 0.2-0.4 part of rheological agent, 0.2-0.4 part of wetting agent, 2-3 parts of corrosion inhibitor, 0.5-0.9 part of flash rust inhibitor, 1-2 parts of adhesion promoter and 15-25 parts of pigment and filler.

2. The aqueous environment-friendly self-spray paint for repairing the paint film of the commercial vehicle chassis as claimed in claim 1, which is characterized in that: the waterborne modified acrylic resin is waterborne epoxy modified acrylic resin and comprises the following components in parts by mass: 5.8 parts of epoxy resin E-44, 1.7 parts of epoxy resin E-20, 2.9 parts of eleostearic acid, 11.5 parts of methyl methacrylate, 11.5 parts of styrene, 6.9 parts of butyl acrylate, 5.8 parts of acrylic acid, 3.5 parts of beta-hydroxypropyl methacrylate, 8.6 parts of propylene glycol methyl ether, 14.4 parts of ethylene glycol monobutyl ether, 0.7 part of benzoyl peroxide, 0.02 part of tetrabutylammonium bromide, 0.5 part of dimethylethanolamine and 26.18 parts of deionized water.

3. The aqueous environmental self-spray paint for repairing the chassis paint film of the commercial vehicle as claimed in claim 1 or 2, which is characterized in that: the preparation method of the waterborne modified acrylic resin comprises the following steps:

step 1) carrying out a first-step reaction, namely carrying out esterification reaction on eleostearic acid, epoxy resin E-44 and epoxy resin E-20 in a reaction kettle;

step 2) in the first step of reaction process, another mixing tank is taken, cleaned to be anhydrous and impurity-free, and monomer premixing in the second step is carried out to prepare mixed monomer of acrylic acid and acrylate;

step 3) after the first-step reaction is finished, adding 0.7 part of benzoyl peroxide as an initiator into a monomer mixed seasoning cylinder for the second-step reaction, and stirring at the speed of 200-300r/min for 5 min;

step 4) adding the mixed monomer prepared in the step 3) into the reaction kettle in the step 1) in a dropwise manner, wherein the dropwise adding time is 60min in total, and after the dropwise adding is finished, keeping the temperature of 120 ℃ for reacting for 180 min; carrying out copolymerization reaction on the product of the esterification reaction obtained in the step 1) and the acrylic acid and the acrylate monomer obtained in the step 2);

step 5) after the reaction in the step 4) is finished, reducing the temperature of the reaction kettle to 100 ℃, continuously keeping the stirring speed of 100-;

and 6) after the step 5), cooling the temperature of the reaction kettle to 80 ℃, adding 26.18 parts of deionized water, continuously stirring for 30-40min at 300r/min under 200-.

4. The aqueous environment-friendly self-spray paint for repairing the paint film of the commercial vehicle chassis as claimed in claim 1, which is characterized in that: the modified resin is water-based polycarbonate polyurethane resin.

5. The aqueous environment-friendly self-spray paint for repairing the paint film of the commercial vehicle chassis as claimed in claim 1, which is characterized in that: the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6: 4.

6. The aqueous environment-friendly self-spray paint for repairing the paint film of the commercial vehicle chassis as claimed in claim 1, which is characterized in that: the color filler is Panzhi steel R-298 titanium dioxide, carbon black C311, permanent red F5RK, permanent yellow G-74, phthalocyanine green 311, modified zinc phosphateSW-111, GB-4 sericite powder and 1250-mesh precipitated barium sulfate.

7. The aqueous environment-friendly self-spray paint for repairing the paint film of the commercial vehicle chassis as claimed in claim 1, which is characterized in that: the dispersant is a modified macromolecular wetting dispersant.

8. The aqueous environment-friendly self-spray paint for repairing the paint film of the commercial vehicle chassis as claimed in claim 1, which is characterized in that: the anti-settling agent is a montmorillonite clay rheological aid.

9. A preparation method of a water-based environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle is characterized by comprising the following steps: the method comprises the following steps:

step 10) selecting sawtooth-shaped stirring equipment with a stirring disc diameter of 35-40cm, adding 10-15 parts of deionized water into a paint mixing cylinder, sequentially adding 0.8-1.2 parts of dispersing agent, 0.1-0.3 part of defoaming agent and 0.1-0.2 part of anti-settling agent under the condition that the stirring speed is 200-450 r/min, keeping the stirring speed for 5min, then adding 15-25 parts of pigment and filler, and increasing the stirring speed to 400-450r/min for stirring for 15min to obtain mixed liquid;

step 20) transferring the mixed material liquid prepared in the step 10) to a grinding process, and grinding the mixed material liquid to the fineness of 15-20 microns by using a horizontal sand mill to prepare slurry for later use;

step 30) cleaning another paint mixing cylinder, adding 35-50 parts of waterborne epoxy modified acrylic resin, 7-10 parts of modified resin and 10-20 parts of deionized water, uniformly stirring at a stirring speed of 200 and 250r/min, adding 2-3 parts of corrosion inhibitor, and stirring for 5min at the stirring speed; adding 0.5-0.9 part of flash rust inhibitor, stirring for 5min at a stirring speed, and adding the slurry prepared in the step 2); then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then reducing the rotation speed to 200-250r/min, keeping the rotation speed, and sequentially adding 1-2 parts of adhesion promoter, 0.1-0.3 part of defoaming agent, 0.2-0.4 part of wetting agent and 0.2-0.4 part of rheological agent into the mixture; finally, the stirring speed is increased to 350r/min at 300-²And/s, the paint preparation is completed.

10. The method for preparing the waterborne environment-friendly spray paint for repairing the chassis paint film of the commercial vehicle as claimed in claim 9, which is characterized in that: step 40) is also included after step 30), and the specific preparation method of step 40) is as follows:

preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-160g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection.

Technical Field

The invention relates to the field of coatings, in particular to an environment-friendly self-spraying paint with low VOCs (volatile organic compounds) for repairing a paint film of a chassis of a commercial vehicle and a preparation method thereof.

Background

The self-spraying paint is also called hand spraying paint or aerosol paint, mainly comprises a pressure-resistant container, paint vehicle, glass beads, a valve and a propellant, is widely applied due to quick and convenient construction, and is mainly applied to the fields of coating repair, industrial machinery, advertisement identification, doodling, constructional steel structures and the like.

At present, the market cardinality of domestic light truck and heavy truck commercial vehicles is huge, and the paint film of the chassis is easy to damage due to the complex running road environment of the vehicle, the chassis accessory substrate loses the protection of the paint film after damage, the chassis can be accelerated to corrode, and then the service life of the chassis spare and accessory parts is greatly shortened. The normal restoration flow need go to the service station and adopt professional equipment to restore, and it is more to take time, therefore the market mostly can select the construction simply, convenient and fast restores the paint film from spraying paint.

The base material of the chassis of the current commercial vehicle relates to cast iron, carbon steel, aluminum alloy, stainless steel, zinc plating and the like, and the coating adopted by the protection and decoration of the original factory relates to various types such as electrophoretic coating, epoxy coating, acrylic coating, powder coating and the like. Due to the diversity of the materials of the base materials of the chassis of the commercial vehicle and the protection of the coating, the repair coating is required to have excellent adhesive force and corrosion resistance on metal base materials such as cast iron, aluminum alloy, stainless steel and the like, and the coating is required to have excellent adhesive force on various types of original coatings such as electrophoresis type, epoxy type, acrylic type, powder and the like, otherwise, the repair coating falls off due to slight external force after being repaired, and the repair effect cannot be achieved. The chassis repairing of the existing light truck and heavy truck commercial vehicles is mostly solvent-based automatic paint spraying, the VOCs content of paint is as high as 400-600g/L, the paint contains solvents such as aromatic hydrocarbon, esters and the like, the paint spraying smell is large, the environment can be greatly influenced, and permanent damage can be caused to the internal organs and nervous systems of the human body; in addition, the partial solvent type automatic spray paint also contains benzene and xylene with carcinogenicity; therefore, if the solvent type automatic paint spraying is adopted to repair the chassis of the commercial vehicle for the light truck and the heavy truck, the chassis is not environment-friendly. In order to solve the environmental protection problem, a technical person in the field develops an environment-friendly water-based self-spray paint, but the application of the environment-friendly water-based self-spray paint to the chassis repair of light and heavy commercial vehicles also has a plurality of problems, which are embodied in the following aspects:

1. most of the existing water-based automatic paint spraying has high requirements on chassis materials, generally has good adhesive force only on a specific substrate, cannot be simultaneously applied to repairing of various chassis materials (such as chassis made of substrates such as cast iron, carbon steel, aluminum alloy, stainless steel, zinc plating and the like), has a limited application range and poor universality;

2. the capability difference of corrosion resistance on base materials such as chassis cast iron, carbon steel, aluminum alloy, stainless steel, galvanized materials and the like is large;

3. the multi-type coating system of the original chassis cannot be compatible at the same time, the bottom biting condition is easy to occur, and the adhesive force difference on different types of original coatings is large;

therefore, the technical personnel in the field are dedicated to develop a water-based environment-friendly self-spraying paint which can be suitable for repairing the chassis paint film of various light truck and heavy truck commercial vehicles.

Disclosure of Invention

In view of the above defects in the prior art, the technical problem to be solved by the invention is to provide a water-based self-spraying paint which can be suitable for repairing the paint film of the chassis of the light truck and heavy truck commercial vehicles, the paint can be firmly attached to the chassis base material and the coatings of various types of light truck and heavy truck commercial vehicles, the spraying requirement is low, and the paint is convenient and quick; the sprayed paint has smooth appearance and no pinholes, can effectively reduce the VOCs content of the paint, meets the requirement of environmental protection, and has excellent universality.

In order to realize the aim, the invention provides an aqueous environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis, which comprises a main paint and a propellant, wherein the main paint is 160g of 140-one and the propellant is 140g of 120-one;

the main paint comprises the following raw materials in parts by mass: 35-50 parts of water-based modified acrylic resin, 7-10 parts of modified resin, 20-35 parts of deionized water, 0.8-1.2 parts of dispersing agent, 0.1-0.3 part of defoaming agent, 0.1-0.2 part of anti-settling agent, 0.2-0.4 part of rheological agent, 0.2-0.4 part of wetting agent, 2-3 parts of corrosion inhibitor, 0.5-0.9 part of flash rust inhibitor, 1-2 parts of adhesion promoter and 15-25 parts of pigment and filler.

Preferably, the waterborne modified acrylic resin is waterborne epoxy modified acrylic resin, and comprises the following components in parts by mass: 5.8 parts of epoxy resin E-44, 1.7 parts of epoxy resin E-20, 2.9 parts of eleostearic acid, 11.5 parts of methyl methacrylate, 11.5 parts of styrene, 6.9 parts of butyl acrylate, 5.8 parts of acrylic acid, 3.5 parts of beta-hydroxypropyl methacrylate, 8.6 parts of propylene glycol methyl ether, 14.4 parts of ethylene glycol monobutyl ether, 0.7 part of benzoyl peroxide, 0.02 part of tetrabutylammonium bromide, 0.5 part of dimethylethanolamine and 26.18 parts of deionized water.

Preferably, the preparation method of the waterborne modified acrylic resin comprises the following steps:

step 1) carrying out a first-step reaction, namely carrying out esterification reaction on eleostearic acid, epoxy resin E-44 and epoxy resin E-20 in a reaction kettle;

step 2) in the first step of reaction process, another mixing tank is taken, cleaned to be anhydrous and impurity-free, and monomer premixing in the second step is carried out to prepare mixed monomer of acrylic acid and acrylate; the step has the function of uniformly mixing the monomers to be subjected to polymerization reaction, and is convenient for subsequent dropwise addition.

And 3) after the first-step reaction is finished, adding 0.7 part of benzoyl peroxide as an initiator into the monomer mixed seasoning cylinder for the second-step reaction, and stirring at the speed of 200-300r/min for 5 min. Under the condition of low temperature, after the initiator is added into the mixed monomer of acrylic acid and acrylic ester, the polymerization reaction can be slowly carried out, so that the mixing time of the initiator and the mixed monomer of acrylic acid and acrylic ester is controlled within 5min, and sufficient time is reserved for the dropwise adding operation of the step 4), so that the esterified epoxy can be subjected to copolymerization reaction with various acrylic monomers when the polymerization reaction process is carried out on the acrylic monomers.

Step 4) adding the mixed monomer prepared in the step 3) into the reaction kettle in the step 1) in a dropwise manner, wherein the dropwise adding time is 60min in total, and after the dropwise adding is finished, continuously preserving the heat (keeping the temperature of 120 ℃) and reacting for 180 min; carrying out copolymerization reaction on the product of the esterification reaction obtained in the step 1) and the acrylic acid and the acrylate monomer obtained in the step 2); after the grafting modification is carried out by the method, the stability of a final product (namely the waterborne modified acrylic resin) is good, a paint film prepared by the method has excellent water resistance and corrosion resistance, and epoxy groups in the paint film can improve the adhesive force of the paint film;

step 5) after the reaction in the step 4) is finished, reducing the temperature of the reaction kettle to 100 ℃, continuously keeping the stirring speed of 100-;

and 6) after the step 5), cooling the temperature of the reaction kettle to 80 ℃, adding 26.18 parts of deionized water, continuously stirring for 30-40min at 300r/min under 200-.

During the polymerization reaction of various acrylic monomers, the esterified epoxy is adopted to carry out copolymerization reaction with the acrylic monomers, then a neutralizing agent is added for neutralization, and water is added for emulsification after neutralization, so that the water-based epoxy modified acrylic resin is obtained. The waterborne epoxy modified acrylic resin prepared by the method has good stability, contains epoxy groups, can improve the adhesive force of a paint film on different substrates in a coating, and simultaneously has the function of improving the water resistance and the corrosion resistance of the paint film.

More preferably, the modified resin is water-based polycarbonate type polyurethane resin, and the compatibility of a water-based epoxy modified acrylic resin system to various substrates can be further improved by adding the water-based polycarbonate type polyurethane resin into a self-spray paint raw material system, and meanwhile, the drying performance, the flexibility and the weather resistance of self-spray paint are improved.

Preferably, the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6: 4. Because the boiling point of dimethyl ether is-24.9 ℃, the vapor pressure at 20 ℃ is about 0.5Mpa, and the solubility of dimethyl ether in water is 35.3 percent (Wt) at 20 ℃ and about 0.49 Mpa; n-butane has a boiling point of-0.5 deg.C, a saturated vapor pressure of about 0.2MPa at 21 deg.C, and a solubility in water of about 3% at 0 deg.C and 0.1 MPa; if dimethyl ether is used as a propellant, the dimethyl ether is dissolved more in the water-based self-spraying paint, and the near-distance spraying paint is easy to foam and has poor appearance in the spraying process. Therefore, dimethyl ether and n-butane are preferably compounded according to the proportion of 6:4, the problem can be well solved, stable throwing and atomizing capability is provided for the self-spraying paint, the problem of easy foaming during spraying is avoided, and the appearance of the paint after spraying is improved.

More preferably, the pigment and filler are Panzhi steel R-298 titanium dioxide, carbon black C311, permanent red F5RK, permanent yellow G-74, phthalocyanine green 311, modified zinc phosphateSW-111, GB-4 sericite powder and 1250-mesh precipitated barium sulfate.

More preferably, the dispersant is a modified polymer wetting dispersant. The modified polymer wetting dispersant which is used for a water-based system and contains pigment affinity groups and is adopted by the dispersant disclosed by the invention can be used for wetting and dispersing the pigment and the filler, so that a paint film has better hydrophobic property after being dried, and the water resistance of the paint film is further improved.

More preferably, the anti-settling agent is a montmorillonite clay rheological aid, so that the anti-settling agent is more suitable for water-based paint.

A preparation method of an aqueous environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle comprises the following steps:

step 10) selecting sawtooth-shaped stirring equipment with a stirring disc diameter of 35-40cm, adding 10-15 parts of deionized water into a paint mixing cylinder, sequentially adding 0.8-1.2 parts of dispersing agent, 0.1-0.3 part of defoaming agent and 0.1-0.2 part of anti-settling agent under the condition that the stirring speed is 200-450 r/min, keeping the stirring speed for 5min, then adding 15-25 parts of pigment and filler, and increasing the stirring speed to 400-450r/min for stirring for 15min to obtain mixed liquid; the step has the function of fully scattering pigment and filler so as to facilitate subsequent material mixing. The purpose of adding the dispersing agent is to keep the stability of the dispersion state of the pigment and the filler, prevent the uncontrolled flocculation and have certain anti-settling effect; more preferably, in order to compensate the anti-settling effect of the dispersing agent, an anti-settling agent is added in the step for further stabilizing the paint liquid, so that the paint liquid can be stably stored for a long time; in addition, because a large amount of bubbles are generated during the stirring, a defoaming agent is also added in the step in order to eliminate the bubbles.

Step 20) transferring the mixed material liquid prepared in the step 10) to a grinding process, and grinding the mixed material liquid to the fineness of 15-20 microns (micrometer, particle size unit) by using a horizontal sand mill to prepare slurry for later use;

the purpose of this step is to further grind and refine the dispersant and pigment filler to reach the qualified particle size required for preparation, so as to prepare slurry. In the first step, because the pigment is limited by stirring shearing force and is not scattered to a very fine state, the pigment filler is further fully refined in a grinding mode, so that the particle size of the pigment filler can approach to the original particle size, and then the pigment filler is wrapped by the dispersing agent to further prevent the pigment filler from flocculating again, so that the anti-settling effect is further improved, and the particle size requirement for preparing slurry is met.

Step 30) cleaning another paint mixing cylinder, adding 7-10 parts by mass of modified resin and 10-20 parts by mass of deionized water into 35-50 parts by mass of waterborne epoxy modified acrylic resin, adding 2-3 parts by mass of corrosion inhibitor at a stirring speed of 200-250r/min, and stirring for 5min at the stirring speed; then adding 0.5-0.9 ofStirring for 5min at a stirring speed for 5min, and adding the slurry prepared in the step 2); then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then reducing the rotation speed to 200-250r/min, keeping the rotation speed, and sequentially adding 1-2 parts of adhesion promoter, 0.1-0.3 part of defoaming agent, 0.2-0.4 part of wetting agent and 0.2-0.4 part of rheological agent into the mixture; finally, the stirring speed is increased to 350r/min at 300-²And/s, the paint preparation is finished;

the effect of this step is to mix the various raw materials thoroughly, wherein the newly added raw materials each have a different effect. Wherein, the corrosion inhibitor is used for assisting the rust prevention pigment to perform rust prevention in the later period; in addition, at the moment that water is contacted with iron, if moisture is slowly volatilized, the water can react with the iron and oxygen to generate iron rust, the process is called flash rust or flash corrosion, and the flash rust has serious influence on the appearance of a paint film and later-stage corrosion prevention, so that the flash rust inhibitor has the function of preventing flash rust generated between water-based paint and steel; the adhesion promoter has the functions of combining with the waterborne epoxy modified acrylic resin on one hand and combining with the organic coating (namely the original coating on the chassis of the light truck or heavy truck commercial vehicle) on the other hand, and can enhance the adhesive force between the paint and the original coating on the chassis of the light truck or heavy truck commercial vehicle when used for repairing the vehicle paint, so that the waterborne paint is more tightly connected with the original coating.

According to the invention, the waterborne epoxy modified acrylic resin is physically modified by the waterborne polycarbonate polyurethane, so that the adhesive force of the self-spraying paint is further improved, and the self-spraying paint can have excellent adhesive force on electrophoretic paint, epoxy paint and acrylic paint; in addition, the paint can be applied to various substrates such as cast iron, carbon steel, aluminum alloy, stainless steel and the like, and has excellent adhesive force and corrosion resistance. Therefore, the paint disclosed by the invention can be compatible with various types of original coating systems and various chassis materials at the same time, and the conditions of bottom biting, no adhesive force and the like during repair on the original coating system are avoided; in addition, the modified self-spraying paint can meet the requirements of repair markets in various aspects such as drying speed, paint film hardness, water resistance, corrosion resistance and the like.

More preferably, step 40) is further included after step 30), and the specific preparation method of step 40) is as follows:

preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-160g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, then filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection. Dimethyl ether is adopted as a propellant in the existing spray paint, but the dimethyl ether has the solubility of 35.3% in water at 20 ℃ and about 0.49MPa, and a large amount of water-based automatic spray paint solvent is water, so that the dimethyl ether content in the water of a paint film is too high in the spray paint process, the paint film generates a large amount of bubbles during short-distance spray paint, and a large amount of pinholes are generated during high-temperature weather repair. Aiming at the problem, the invention selects the n-butane with low water solubility and without influencing other performances to carry out compounding, thereby solving the problem of pinholes caused by a propellant under the condition of quick drying, keeping the paint film with good appearance and providing better protective performance.

According to the invention, epoxy resin is esterified, acrylic acid and acrylate monomers are copolymerized and grafted, polycarbonate type polyurethane is used for physical modification, the low-VOCs environment-friendly film-forming resin is prepared, and a plurality of corrosion inhibiting materials, auxiliaries and pigments and fillers are used, so that the paint has excellent adhesive force and corrosion resistance on substrates such as cast iron, carbon steel, aluminum alloy, stainless steel, zinc plating and the like, and also has excellent adhesive force on various types of original coating systems, the universality of the paint is improved, and the paint can meet the requirements of repairing of chassis paint films of various light-truck and heavy-truck commercial vehicles; in addition, the propellant compounded according to the ratio of dimethyl ether to n-butane of 6:4 ensures the dilution of the paint and the stability of the paint in projection and atomization; the paint has the advantages of excellent appearance, convenience and rapidness in use, simplicity in operation, safety and environmental friendliness under the condition of meeting the requirement of fast drying of paint.

Detailed Description

The present invention is further described below. In the examples, the types and brands of the raw materials were selected as follows:

the waterborne modified acrylic resin is a self-made raw material;

the modified resin is polycarbonate polyurethane produced by European Baodi resin Co;

the cosolvent is one or more of ethanol, isopropanol and dipropylene glycol methyl ether;

dispersant-digao type TEGO Dispers 755W wetting dispersant;

the defoaming agent is German Pasteur aqueous defoaming agent with the typeST2400, the defoamer is a water-based defoamer and is suitable for water-based paint, and compared with the traditional mineral oil defoamer, the defoamer reduces the use amount by 30-50%, has excellent durability, defoams quickly, and is beneficial to reducing the production cost of spray paint;

anti-settling agent-anti-settling agent from Haimines corporation under brand number BENTONE LT;

the rheological agent is a German Mingling auxiliary agent with brand number TAFIGEL PUR 61;

wetting agent-is a digao water-based wetting agent, with a grade TEGO Twin 4000;

the corrosion inhibitor is a corrosion inhibitor of the French LABEMA company, and the product brand is EMARUST CL 7-w;

flash rust inhibitor-Flash rust inhibitor of Haimines company, brand number Halox Flash-x 150;

the adhesion promoter is prepared from Nippon chemical materials of Zhongshan family, and has a product designation of CPS-4306H;

pigment and filler-Pan steel R-298 titanium dioxide, carbon black C311, permanent red F5RK, G-74 permanent yellow, phthalocyanine green 311, modified zinc phosphateSW-111 (beneficial to improving the rust resistance of the paint), GB-4 sericite powder and 1250-mesh precipitated barium sulfate; since the aforementioned substances are extremely readily available on the market, their manufacturers and brand numbers are not further described;

the propellant is a mixture of dimethyl ether and n-butane, and the mixing ratio is dimethyl ether: n-butane is 6: 4; since the propellant raw materials are very readily available on the market, their manufacturer and brand numbers are not further elucidated.

In addition, it should be noted that the self-painting filling machine used in the process of preparing the painting in step 40) is a commercially available self-painting/aerosol paint filling machine, and the self-painting filling machine manufactured by electro-corporation of galleries, inc. The filled paint is shaken and can be sprayed out by pressing.

The working principle of the self-priming paint filling machine and the use of the paint are briefly explained here, so that the person skilled in the art can carry out this step according to the contents of step 40). Before use, the spray paint valve is opened, then the dimethyl ether and n-butane mixture in a liquefied state is pressurized by an automatic spray paint filling machine and is pressed into a spray paint bottle, the pressure in the spray paint bottle generally has a pressure of 0.4-0.6MPa, the dimethyl ether and the n-butane still keep a liquefied state under the pressure, and the valve is automatically closed due to the atmospheric pressure after being loosened. Then a nozzle is arranged on the valve, and the paint liquid, the dimethyl ether and the n-butane mixture are shaken up after shaking. When the dimethyl ether and n-butane paint spraying valve is used, the valve is pressed, then the paint liquid, dimethyl ether and n-butane can be extruded from the valve pipe due to the fact that the internal pressure is high, the paint liquid, dimethyl ether and n-butane mixture is sprayed outwards, the dimethyl ether and n-butane can be gasified and volatilized rapidly under the atmospheric pressure due to the low boiling point, only paint and a small amount of dimethyl ether and n-butane are left to be sprayed to a place needing paint spraying, then the dimethyl ether, n-butane and moisture in the paint liquid are volatilized, and finally a complete paint film is formed.

The embodiment is to test the relevant performance of the spray paint, and the specific test items comprise: 1. the appearance of the paint film; 2. drying time; 3. gloss; 4. hardness; 5. adhesion ratings of different materials; 5. flexibility; 6. impact resistance; 7. water resistance; 8. weather resistance; 8. salt spray resistance of different materials; 9. machine oil resistance; 10. gasoline resistance; 11. diesel resistance; 12. hydraulic resistance; 13. acid resistance; 14. alkali resistance; 15. heavy metal (lead, cadmium, mercury, hexavalent chromium) content; 16. an ejection rate; 17. internal pressure; 18. and (4) carrying out a leakage test.

The detection items and the detection standards/methods are as follows:

paint film appearance, test mode: visual inspection;

drying time, test mode: the drying time test of the paint is carried out according to the national standard GB/T1728-;

gloss, test mode: the glossiness of the paint of the invention after spraying is carried out according to the national standard GB/T9754-2007;

hardness, test mode: the hardness test of the invention is carried out according to the national standard GB/T6739-2006;

adhesion, test mode: the adhesion test of the invention is carried out according to the national standard GB/T9286-1998;

flexibility, test mode: the flexibility test of the invention is carried out by referring to the national standard GB/T1731-1993;

impact resistance, test mode: the impact resistance test of the invention is carried out by referring to the national standard GB/T1732-1993;

water resistance, test mode: the water resistance test of the invention is carried out by referring to the national standard GB/T1733-1993;

weather resistance, test mode: the weather resistance test of the invention is carried out by referring to the national standard GB/T1865-2009;

salt spray resistance, test mode: the salt spray resistance test of the invention is carried out according to the national standard GB/T1771-2007;

machine oil resistance, test mode: the machine oil resistance of the invention is tested by taking the machine oil 5w-30 as a standard and referring to the standard GB/T9274-;

gasoline resistance, test mode: gasoline resistance of the gasoline-free anti-rust paint is tested by taking No. 93 gasoline as a standard and referring to a national standard GB/T1734-93 paint film gasoline resistance testing method;

diesel oil resistance, test mode: the diesel oil resistance of the invention is tested by taking No. 0 diesel oil as a standard and referring to the national standard GB/T9274-;

hydraulic oil resistance, test mode: the hydraulic oil resistance of the invention is tested by taking No. 25 hydraulic oil as a standard and referring to the national standard GB/T9274-;

acid resistance, test mode: the acid resistance test of the invention is carried out by referring to the national standard GB/T1763-79;

alkali resistance, test method: the alkali resistance test of the invention is carried out according to the national standard GB/T1763-79;

heavy metals (lead, cadmium, mercury, hexavalent chromium), test method: the heavy metal detection ejection rate is determined by referring to the determination of the total content of harmful elements in the national standard GB/T30647-2014 coating, and the test method comprises the following steps: testing is carried out according to the specification of 5.3.6 in the national standard GB/T14449-2017;

internal pressure, test mode: performing internal pressure test at 50 ℃ according to the regulation of 5.5.1 in GB/T14449-2007;

leakage test, test mode: leak testing was performed as specified in QB 2549-.

Example 1

An aqueous environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis comprises a main paint and a propellant, wherein the main paint is 140-160g, and the propellant is 120-140 g; the main paint comprises the following raw materials in parts by mass: 38 parts of waterborne modified acrylic resin and 8 parts of waterborne modified acrylic resinU6300 as modified resin, 26 parts of deionized water, 0.8 part of TEGO Dispers 755W as dispersant, 0.2 part ofST2400 as defoamer, 0.2 parts of Bentone LT as anti-settling agent, 0.2 parts of TAFIGEL PUR61 as rheology agent, 0.2 parts of TEGO Twin 4000 as wetting agent, 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor, 0.5 parts of Halox Flash-x 150 as Flash rust inhibitor, 1.9 parts of CPS-4306H as adhesion promoter, and a pigment and filler consisting of 17 parts of titanium dioxide R298, 1 part of GB-4 sericite and 4 parts of modified zinc phosphate SW-111.

A preparation method of an aqueous environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle comprises the following steps:

step 1) selecting a sawtooth-shaped stirring device with a stirring disc diameter of 35-40cm, adding 10 parts of deionized water into a paint mixing cylinder, and stirring at a stirring speed of 200-250.8 part of TEGO Dispers 755W as a dispersant and 0.1 part of TEGO Dispers 755W in sequence at the state of 0r/minST2400 as an antifoaming agent and 0.2 part of Bentone LT as an anti-settling agent, keeping the stirring speed for 5min, adding a pigment filler consisting of 17 parts of titanium dioxide R298, 1 part of GB-4 sericite and 4 parts of modified zinc phosphate SW-111, and stirring for 15min at a stirring speed of 400-450R/min to obtain a mixed feed liquid;

step 2) transferring the mixed material liquid prepared in the step 1) to a grinding process, and grinding the mixed material liquid to the fineness of 15 microns by using a horizontal sand mill to prepare slurry for later use;

step 3) another paint mixing cylinder is taken and cleaned, and then 38 parts of waterborne epoxy modified acrylic resin and 8 parts of waterborne epoxy modified acrylic resin are addedU6300 as modified resin and 16 parts of deionized water, adding 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor at a stirring speed of 200-250r/min, and stirring for 5min while maintaining the stirring speed; then 0.5 part of Halox Flash-x 150 is added as a Flash rust inhibitor, and the slurry prepared in the step 2) is added after the stirring speed is maintained and the stirring is carried out for 5 min; then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then the rotation speed is reduced to 200-ST2400 as defoamer, 0.2 parts TAFIGEL PUR61 as rheology agent and 0.2 parts TEGO Twin 4000 as wetting agent; finally, the stirring speed is increased to 350r/min at 300-²And/s, the paint preparation is finished;

and step 4) preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-140 g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection.

The preparation method of the waterborne modified acrylic resin comprises the following steps:

step 1): the first step of reaction, namely, eleostearic acid, epoxy resin E-44 and epoxy resin E-20 are subjected to esterification reaction; specifically, 5.8 parts of epoxy resin E-44, 1.7 parts of epoxy resin E-20, 11.5 parts of propylene glycol methyl ether and 14.4 parts of ethylene glycol monobutyl ether are added into a reaction kettle, sealed and put into an oil bath magnetic stirrer; raising the temperature of the oil bath to 80 ℃, starting stirring, continuously stirring at the speed of 100-; then, 2.9 parts of eleostearic acid and 0.02 part of tetrabutylammonium bromide are added as catalysts, the temperature is continuously increased to 200 ℃, the temperature is kept for continuous reaction for 120min, the temperature is reduced to 120 ℃ after the reaction is finished, heat is preserved, the mixture is continuously stirred until the reaction is finished, and the temperature is kept constant at 120 ℃;

step 2): in the first step of reaction process, another mixing tank is taken, cleaned to be in an anhydrous and impurity-free state, the second step of reaction is carried out, the second step of monomer premixing is carried out, the mixed monomer of acrylic acid and acrylic ester is prepared, specifically, 8.6 parts of propylene glycol methyl ether, 11.5 parts of methyl methacrylate, 11.5 parts of styrene, 6.9 parts of butyl acrylate, 5.8 parts of acrylic acid and 3.5 parts of methacrylic acid-beta-hydroxypropyl ester are added, stirring is started, and stirring is carried out for 10-15min at 300r/min of 200-materials, so as to obtain the acrylic acid and acrylic ester monomer for later use; the prepared paint film has better compactness, engine oil resistance and diesel oil resistance after being dried due to high glass transition temperature;

step 3): after the first step reaction is finished, 0.7 part of benzoyl peroxide is added into the monomer mixed seasoning cylinder of the second step reaction as an initiator, and the mixture is stirred for 5min at the speed of 200-300 r/min; fully mixing an initiator with acrylic acid and acrylate monomers to promote or catalyze the copolymerization, grafting and modification in the fourth step;

step 4): adding the mixed monomer prepared in the step 3) into the reaction kettle in the step 1) in a dropwise manner, wherein the dropwise adding time is 60min in total, continuously preserving heat after the dropwise adding is finished, keeping the temperature of 120 ℃, and reacting for 180 min; copolymerizing, grafting and modifying the product of the esterification reaction obtained in the step 1) and the acrylic acid and acrylate monomer obtained in the step 2) so as to improve the stability of a final product (namely the water-based modified acrylic resin), wherein a paint film prepared by using the product has excellent water resistance and corrosion resistance, and can be used for improving the adhesive force of the paint film.

Step 5): after the reaction in the step 4) is finished, reducing the temperature of the reaction kettle to 100 ℃, continuously keeping the stirring speed of 100-; the effect of this step is to neutralize the free acidity in the aqueous modified acrylic resin.

Step 6): and 5), cooling the temperature of the reaction kettle to 80 ℃, adding 26.18 parts of deionized water, continuously stirring for 30-40min at 300r/min of 200-.

Example 2

An aqueous environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis comprises a main paint and a propellant, wherein the main paint is 140-160g, and the propellant is 120-140 g; the main paint comprises the following raw materials in parts by mass: 36 parts of waterborne modified acrylic resin and 7.5 parts of waterborne modified acrylic resinU6300 as modified resin, 34.3 parts of deionized water, 1 part of Dispers 755W as dispersant, 0.2 part ofST2400 as defoamer, 0.1 part of Bentone LT as anti-settling agent, 0.2 part of TAFIGEL PUR61 as rheology agent, 0.2 part of TEGO Twin 4000 as wetting agent, 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor, 0.5 part of Halox Flash-x 150 as Flash rust inhibitor, 2 parts of CPS-4306H as adhesion promoter, and a pigment and filler consisting of 2 parts of carbon black C311, 4 parts of modified zinc phosphate SW-111 and 10 parts of 1250-precipitated barium sulfate; and projection with 60 parts of dimethyl ether and 40 parts of n-butaneAnd (3) preparing.

A preparation method of an aqueous environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle comprises the following steps:

step 1) selecting a sawtooth-shaped stirring device with a stirring disc diameter of 35-40cm, adding 14.3 parts of deionized water into a paint mixing cylinder, and sequentially adding 1 part of TEGO Dispers 755W serving as a dispersing agent and 0.1 part of TEGO Dispers 755W in a state that the stirring speed is 200-one-year-at-250 r/minST2400 as a defoaming agent, 0.1 part of Bentone LT as an anti-settling agent, keeping the stirring speed for 5min, then adding pigment filler consisting of 2 parts of carbon black C311, 4 parts of modified zinc phosphate SW-111 and 10 parts of 1250-precipitated barium sulfate, and increasing the stirring speed to 400-450r/min for stirring for 15min to obtain mixed feed liquid;

step 2) transferring the mixed material liquid prepared in the step 1) to a grinding process, and grinding the mixed material liquid to the fineness of 15 microns by using a horizontal sand mill to prepare slurry for later use;

step 3) cleaning another paint mixing cylinder, adding 36 parts of waterborne epoxy modified acrylic resin, 7.5 parts of ALBERDINK U6300 serving as modified resin and 20 parts of deionized water, adding 2 parts of LABEMA EMARUST CL7-w serving as a corrosion inhibitor at the rotating speed of 200 plus 250r/min, and stirring for 5min at the stirring speed; then 0.5 part of Halox Flash-x 150 is added as a Flash rust inhibitor, and the slurry prepared in the step 2) is added after the stirring speed is maintained and the stirring is carried out for 5 min; then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then the rotation speed is reduced to 200-250r/min, the rotation speed is maintained, and 2 parts of CPS-4306H serving as an adhesion promoter and 0.1 part of CPS-4306H serving as an adhesion promoter are sequentially added into the mixtureST2400 as defoamer, 0.2 parts of TEGO Twin 4000 as wetting agent and 0.2 parts of TAFIGEL PUR61 as rheology agent; finally, the stirring speed is increased to 350r/min at 300-;

and step 4) preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-140 g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection.

In this example, the preparation method of the aqueous modified acrylic resin is the same as that in example 1, and is not repeated.

Example 3

An aqueous environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis comprises a main paint and a propellant, wherein the main paint is 140-160g, and the propellant is 120-140 g; the main paint comprises the following raw materials in parts by mass: 37 parts of waterborne modified acrylic resin and 7.8 parts of waterborne modified acrylic resinU6300 as modified resin, 28 parts of deionized water, 1 part of Dispers 755W as dispersant, 0.2 part ofST2400 as defoamer, 0.1 part of Bentone LT as anti-settling agent, 0.2 part of TAFIGEL PUR61 as rheology agent, 0.2 part of TEGO Twin 4000 as wetting agent, 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor, 0.5 part of Halox Flash-x 150 as Flash rust inhibitor, 2 parts of CPS-4306H as adhesion promoter, and a pigment and filler consisting of 5 parts of permanent Red F5RK, 4 parts of modified zinc phosphate SW-111 and 12 parts of 1250-precipitated barium sulfate; and a projectile consisting of 60 parts of dimethyl ether and 40 parts of n-butane.

A preparation method of an aqueous environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle comprises the following steps:

step 1) selecting a sawtooth-shaped stirring device with a stirring disc diameter of 35-40cm, adding 15 parts of deionized water into a paint mixing cylinder, and sequentially taking 1 part of TEGO Dispers 755W as a dispersing agent and 0.1 part of TEGO Dispers 755W under the condition that the stirring speed is 200-one-year-at-250 r/minST2400 as an antifoaming agent, 0.1 part of Bentone LT as an anti-settling agent, keeping the stirring speed for 5min, then adding a pigment filler consisting of 5 parts of permanent red F5RK, 4 parts of modified zinc phosphate SW-111 and 12 parts of 1250-precipitated barium sulfate, and increasing the stirring speed to 400-450r/min for stirring for 15min to obtain a mixed feed liquid;

step 2) transferring the mixed material liquid prepared in the step 1) to a grinding process, and grinding the mixed material liquid to the fineness of 15 microns by using a horizontal sand mill to prepare slurry for later use;

step 3) another paint mixing cylinder is taken and cleaned, and then 37 parts of waterborne epoxy modified acrylic resin and 7.8 parts of waterborne epoxy modified acrylic resin are addedU6300 as modified resin and 13 parts of deionized water, adding 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor at a stirring speed of 200-250r/min, and stirring for 5min while maintaining the stirring speed; then 0.5 part of Halox Flash-x 150 is added as a Flash rust inhibitor, and the slurry prepared in the step 2) is added after the stirring speed is maintained and the stirring is carried out for 5 min; then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then the rotation speed is reduced to 200-250r/min, the rotation speed is maintained, and 2 parts of CPS-4306H serving as an adhesion promoter and 0.1 part of CPS-4306H serving as an adhesion promoter are sequentially added into the mixtureST2400 as defoamer, 0.2 parts of TEGO Twin 4000 as wetting agent and 0.2 parts of TAFIGEL PUR61 as rheology agent; finally, the stirring speed is increased to 350r/min at 300-²And/s, the paint preparation is finished;

and step 4) preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-140 g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection.

In this example, the preparation method of the aqueous modified acrylic resin is the same as that in example 1, and is not repeated.

Example 4

An aqueous environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis comprises a main paint and a propellant, wherein the main paint is 140-160g, and the propellant is 120-140 g; the main paint comprises the following raw materials in parts by mass: 40 parts of waterborne modified acrylic resin and 8.4 parts of waterborne modified acrylic resinU6300 as modified resin, 23.5 parts of deionized water, 0.8 part of Dispers 755W as dispersant, 0.2 part ofST2400 as defoamer, 0.1 part of Bentone LT as anti-settling agent, 0.2 part of TAFIGEL PUR61 as rheology agent, 0.2 part of TEGO Twin 4000 as wetting agent, 3 parts of LABEMA EMARUST CL7-w as corrosion inhibitor, 0.6 part of Halox Flash-x 150 as Flash rust inhibitor, 2 parts of CPS-4306H as adhesion promoter, and a pigment and filler consisting of 5 parts of permanent yellow G-74, 4 parts of modified zinc phosphate SW-111 and 12 parts of 1250-precipitated barium sulfate; and a propellant consisting of 60 parts of dimethyl ether and 40 parts of n-butane.

A preparation method of an aqueous environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle comprises the following steps:

step 1) selecting a sawtooth-shaped stirring device with a stirring disc diameter of 35-40cm, adding 13.5 parts of deionized water into a paint mixing cylinder, and sequentially using 0.8 part of Dispers 755W as a dispersing agent and 0.1 part of Dispers 755W under the condition that the stirring speed is 200-one-year at 250r/minST2400 as an antifoaming agent, 0.1 part of Bentone LT as an anti-settling agent, keeping the stirring speed for 5min, then adding a pigment filler consisting of 5 parts of permanent yellow G-74, 4 parts of modified zinc phosphate SW-111 and 12 parts of 1250-precipitated barium sulfate, and increasing the stirring speed to 400-450r/min for stirring for 15min to obtain a mixed feed liquid;

step 2) transferring the mixed material liquid prepared in the step 1) to a grinding process, and grinding the mixed material liquid to the fineness of 15 microns by using a horizontal sand mill to prepare slurry for later use;

step 3) another paint mixing cylinder is taken and cleaned, and then 40 parts of waterborne epoxy modified acrylic resin and 8.4 parts of waterborne epoxy modified acrylic resin are addedU6300 as modified resin and 20 parts of deionized water, adding 3 parts of LABEMA EMARUST CL7-w as corrosion inhibitor at a stirring speed of 200-250r/min, and stirring for 5min while maintaining the stirring speed; then 0.6 part of Halox Flash-x 150 is added as a Flash rust inhibitor, and the slurry prepared in the step 2) is added after the stirring speed is maintained and the stirring is carried out for 5 min; then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then the rotation speed is reduced to 200-250r/min, the rotation speed is maintained, and 2 parts of CPS-4306H serving as an adhesion promoter and 0.1 part of CPS-4306H serving as an adhesion promoter are sequentially added into the mixtureST2400 as defoamer, 0.2 parts of TEGO Twin 4000 as wetting agent and 0.2 parts of TAFIGEL PUR61 as rheology agent; finally, the stirring speed is increased to 350r/min at 300-²And/s, the paint preparation is finished;

and step 4) preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-140 g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection.

In this example, the preparation method of the aqueous modified acrylic resin is the same as that in example 1, and is not repeated.

Example 5

An aqueous environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis comprises a main paint and a propellant, wherein the main paint is 140-160g, and the propellant is 120-140 g; the main paint comprises the following raw materials in parts by mass: 45 parts of waterborne modified acrylic acidResin, 9.5 partsU6300 as modified resin, 27.2 parts deionized water, 1 part Dispers 755W as dispersant, 0.2 partST2400 as defoamer, 0.1 part of Bentone LT as anti-settling agent, 0.2 part of TAFIGEL PUR61 as rheology agent, 0.2 part of TEGO Twin 4000 as wetting agent, 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor, 0.6 part of Halox Flash-x 150 as Flash rust inhibitor, 2 parts of CPS-4306H as adhesion promoter, and a pigment and filler consisting of 2 parts of phthalocyanine green 311, 5 parts of titanium dioxide R298, 5 parts of 1250-precipitated barium sulfate and 4 parts of modified zinc phosphate SW-111; and a propellant consisting of 60 parts of dimethyl ether and 40 parts of n-butane.

A preparation method of an aqueous environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle comprises the following steps:

step 1) selecting a sawtooth-shaped stirring device with a stirring disc diameter of 35-40cm, adding 13.2 parts of deionized water into a paint mixing cylinder, and sequentially using 1 part of TEGO Dispers 755W as a dispersing agent and 0.1 part of TEGO Dispers 755W under the condition that the stirring speed is 200-one-year-at-250 r/minST2400 as an antifoaming agent, 0.1 part of Bentone LT as an anti-settling agent, keeping the stirring speed for 5min, then adding a pigment filler consisting of 2 parts of phthalocyanine green 311, 5 parts of titanium dioxide R298, 5 parts of 1250 precipitated barium sulfate and 4 parts of modified zinc phosphate SW-111, and increasing the stirring speed to 400-450R/min for stirring for 15min to obtain a mixed feed liquid;

step 2) transferring the mixed material liquid prepared in the step 1) to a grinding process, and grinding the mixed material liquid to the fineness of 15 microns by using a horizontal sand mill to prepare slurry for later use;

step 3) another paint mixing cylinder is taken and cleaned, and then 45 parts of waterborne epoxy modified acrylic resin and 9.5 parts of waterborne epoxy modified acrylic resin are addedU6300 as modified resin and 14 parts of deionized water, adding 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor at a stirring speed of 200-250r/min, and stirring for 5min while maintaining the stirring speed; then 0.6 part of Halox Flash-x 150 is added as a Flash rust inhibitor, and the slurry prepared in the step 2) is added after the stirring speed is maintained and the stirring is carried out for 5 min; then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then the rotation speed is reduced to 200-250r/min, the rotation speed is maintained, and 2 parts of CPS-4306H serving as an adhesion promoter and 0.1 part of CPS-4306H serving as an adhesion promoter are sequentially added into the mixtureST2400 as defoamer, 0.2 parts of TEGO Twin 4000 as wetting agent and 0.2 parts of TAFIGEL PUR61 as rheology agent; finally, the stirring speed is increased to 350r/min at 300-²And/s, the paint preparation is finished;

and step 4) preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-140 g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection.

In this example, the preparation method of the aqueous modified acrylic resin is the same as that in example 1, and is not repeated.

Example 6

An aqueous environment-friendly self-spraying paint for repairing a paint film of a commercial vehicle chassis comprises a main paint and a propellant, wherein the main paint is 140-160g, and the propellant is 120-140 g; the main paint comprises the following raw materials in parts by mass: 43 parts of waterborne modified acrylic resin and 9 parts of waterborne modified acrylic resinU6300 as modified resin, 27.8 parts deionized water, 1 part Dispers 755W as dispersant, 0.2 partST2400 as defoamer, 0.1 part of Bentone LT as anti-settling agent, 0.2 part of TAFIGEL PUR61 as rheology agent, 0.2 part of TEGO Twin 4000 as wetting agent, 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor, 0.5 part of Halox Flash-x 150 as Flash rust inhibitor, 2 parts of CPS-4306H as adhesion promoter, and a pigment and filler consisting of 2 parts of phthalocyanine blue 191, 5 parts of titanium dioxide R298, 7 parts of 1250-precipitated barium sulfate and 4 parts of modified zinc phosphate SW-111; and a propellant consisting of 60 parts of dimethyl ether and 40 parts of n-butane.

A preparation method of an aqueous environment-friendly self-spraying paint for repairing a chassis paint film of a commercial vehicle comprises the following steps:

step 1) selecting a sawtooth-shaped stirring device with a stirring disc diameter of 35-40cm, adding 12.8 parts of deionized water into a paint mixing cylinder, and sequentially using 1 part of TEGO Dispers 755W as a dispersing agent and 0.1 part of TEGO Dispers 755W under the condition that the stirring speed is 200-one-year-at-250 r/minST2400 as a defoaming agent, 0.2 part of Bentone LT as an anti-settling agent, keeping the stirring speed for 5min, then adding a pigment filler consisting of 2 parts of phthalocyanine blue 191, 5 parts of titanium dioxide R298, 7 parts of 1250-precipitated barium sulfate and 4 parts of modified zinc phosphate SW-111, and increasing the stirring speed to 400-450R/min for stirring for 15min to obtain a mixed material liquid;

step 2) transferring the mixed material liquid prepared in the step 1) to a grinding process, and grinding the mixed material liquid to the fineness of 15 microns by using a horizontal sand mill to prepare slurry for later use;

step 3) another paint mixing cylinder is taken and cleaned, and 43 parts of waterborne epoxy modified acrylic resin and 9 parts of waterborne epoxy modified acrylic resin are addedU6300 as modified resin and 15 parts of deionized water, adding 2 parts of LABEMA EMARUST CL7-w as corrosion inhibitor at a stirring speed of 200-250r/min, and stirring for 5min while maintaining the stirring speed; then 0.5 part of Halox Flash-x 150 is added as Flash rust inhibitor and vitamin is addedStirring for 5min at a stirring speed, and adding the slurry prepared in the step 2); then, the stirring speed is increased to 400-450r/min, and the stirring is continued for 15 min; then the rotation speed is reduced to 200-250r/min, the rotation speed is maintained, and 2 parts of CPS-4306H serving as an adhesion promoter and 0.1 part of CPS-4306H serving as an adhesion promoter are sequentially added into the mixtureST2400 as defoamer, 0.2 parts of TEGO Twin 4000 as wetting agent and 0.2 parts of TAFIGEL PUR61 as rheology agent; finally, the stirring speed is increased to 350r/min at 300-²And/s, the paint preparation is finished;

and step 4) preparing an iron aerosol tank with the diameter of 52mm, filling 2 glass beads with the diameter of 14mm, adding 140-140 g of paint, covering a paint spraying valve, pressing the valve tightly by using a self-paint-spraying filling machine, filling 140g of propellant, wherein the propellant is prepared by compounding dimethyl ether and n-butane according to the ratio of 6:4, and installing a nozzle for pressing detection.

In this example, the preparation method of the aqueous modified acrylic resin is the same as that in example 1, and is not repeated.

Table 1 shows a summary of the formulations for preparing the automatic lacquers of examples 1 to 6

The automatic spray paints prepared in examples 1 to 6 were subjected to 18-item performance tests by the aforementioned test standards or test methods, and the test results are shown in table 2 below.

Table 2 shows the performance parameters of the lacquers prepared in examples 1 to 6

By analyzing the above examples 1 to 6 and the performance test results, the paint liquid of the present invention has excellent adhesion, weather resistance, corrosion resistance, protective property and environmental protection property under the condition of satisfying the conventional coating indexes of common paints, such as flexibility, impact resistance, water resistance, etc.

The concrete steps are as follows:

and (3) testing environmental protection: those skilled in the art know that whether a product meets environmental standards depends on the heavy metal content and the content of VOCs (i.e., volatile organic compounds) in the paint liquid. Therefore, in order to prove the environmental protection property of the paint liquid, the content test of VOCs (volatile organic chemicals) and the content test of heavy metals (lead, cadmium, mercury and hexavalent chromium) of the paint liquid are carried out.

The low content of VOCs (volatile organic compounds) refers to the technical requirements of coating products in the national standard GB/T38597-.

TABLE 3 VOC content requirement in Water-borne coatings

TABLE 4 Limit of hazardous substances in Industrial coatings

The upper limit of the content of VOCs in the common water-based paint is 380g/L, while the content of VOCs in the paint liquid is 92g/L to 110g/L, and the content of VOCs in the paint liquid is less than one third of the upper limit of the standard, even if the environmental-protection mandatory standard is referred (the environmental-protection mandatory standard is less than 150g/L), the paint of the invention is far less than the mandatory standard, and the invention has low content of VOCs, better environmental protection and belongs to the environmental-protection paint.

In addition, the content of heavy metals (lead, cadmium, mercury and hexavalent chromium) is tested, and the test result shows that the content of the heavy metals all meets the standard, thereby further proving the environmental protection property of the paint.

And (3) testing the adhesive force: as the adhesion is known to one skilled in the art as one of the most basic properties of the paint, the paint liquid is sprayed on different substrates or coatings, and the paint is proved to have better adhesion on different substrates and coatings. The specific experimental base material or coating is cast iron, carbon steel, aluminum alloy, stainless steel, galvanized sheet, electrophoretic coating, epoxy coating, acrylic coating and powder coating which are used conventionally for chassis of light truck and heavy truck commercial vehicles. From the test results, except that the adhesive force of the powder coating and the electrophoretic coating is grade 1, other materials or coatings are grade 0, and the standard required adhesive force is grade 2 or less, so that the adhesive force of the paint liquid is far better than that of the standard adhesive force, which shows that the paint has better adhesive force on any kind of substrates. In addition, the paint disclosed by the invention has good repairability, and when the primer of the commercial vehicle is collided to cause the damage of a paint film, the paint disclosed by the invention has good adhesive force to a low-layer base material and also has good adhesive force to the paint film on the surface of the outer layer, so that during repairing, the paint can be adhered to the paint film which is intact beside a damaged point, and can also be adhered to the base material of the damaged point, and the aim of repairing is further fulfilled.

Weather resistance and protection test: the accelerated simulation is adopted, the service time of the paint is measured under the conditions of sunshine and rain in natural climate environment, the test result shows that the service time of the paint is 240 hours, and the paint film is proved to have good weather resistance and protection.

And (3) testing the corrosion resistance: the corrosion and protection performance of the paint was verified by the salt spray resistance test. Specifically, the conventional materials of the chassis of the light truck and the heavy truck, such as cast iron, carbon steel, aluminum alloy, stainless steel, cold rolled steel and galvanized sheet, are selected for testing, and the test result shows that the service life of the aluminum alloy and the stainless steel is 480h, the service life of the cast iron, the carbon steel and the cold rolled steel is 240h and the service life of the galvanized sheet is 504 h; the overall corrosion resistance is better, and the salt spray resistance of the galvanized sheet is the best when the galvanized sheet is applied. In addition, in order to further prove the corrosion resistance, the paint is also subjected to an acid and alkali resistance test and an oil resistance test, the test results show that the acid and alkali resistance is 24 hours, the oil resistance test result shows that the time for resisting hydraulic oil and engine oil is 240 hours, the gasoline resistance is 96 hours, and the diesel oil resistance is 48 hours, and the test proves that the corrosion resistance of the paint is excellent.

Therefore, the aqueous environment-friendly spray paint for repairing the paint film of the chassis of the light and heavy truck disclosed by the invention is low in VOCs content, and has high adhesive force, excellent weather resistance and excellent corrosion resistance under the condition of keeping basic appearance; in addition, the paint has certain oil and acid-base chemical resistance and metal part repairing and protecting effects.

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.