Method for producing a vehicle body perceram and paint composition

Abstract

The invention relates to a method for reducing the amount of particles ejected, in which the particles are more easily trapped while changing the reaction kinetics such that the paint cannot polymerize at low temperatures and is easy to clean if deposited. The method is achieved by electrostatic painting with a bell mouth, where the electrostatic painting is influenced by the size of paint droplets and the amount of charge that can be generated on these droplets, where the composition of the paint comprises melamine and the presence of a closed acid catalyst.

Description

Technical Field

[0001] The object of the present invention, as stated in the title, is to provide a method for producing a vehicle body enamel paint which avoids the problem of paint particles being deposited on the vehicle body due to particles sprayed in the vicinity of the automobile plant, in particular in the vehicle painting area.

[0002] Another object of the invention is a paint composition for use in a process for producing a vehicle body enamel.

[0003] The particles that are sprayed out can aggregate when they settle, and especially in the summer, the bodies of vehicles parked near the plant can reach very high temperatures.

[0004] The present invention is characterized in that the steps and the sprayed paint composition are specially designed and configured so that the sprayed paint has fewer particles, a lower degree of aggregation, and is easier to clean.

[0005] Therefore, the present invention is limited to the field of vehicle painting. Background Art

[0006] In car manufacturing plants, especially in areas where vehicles are painted, a series of particles are sprayed, which melt and begin to polymerize when deposited on hot surfaces. After several hours at high temperatures, the deposited paint polymerizes and can only be removed by polishing or using strong solvents that alter the original paint.

[0007] This phenomenon occurs on cars parked in the sun near car factories, especially in areas where the cars are painted.

[0008] Vehicles exposed to the sun (especially black vehicles) can reach very high temperatures and polymerization effects have been observed on the vehicle's windows, windshield rubber or black plastic parts.

[0009] It was therefore an object of the present invention to develop a process and a paint composition which reduce the amount of particles sprayed, wherein the particles are more easily trapped, while at the same time changing the reaction kinetics so that the paint cannot polymerize at low temperatures and is easier to clean if deposited. Summary of the invention

[0010] The object of the present invention is to provide a method for applying a vehicle body enamel paint which seeks to function in the following aspects:

[0011] - Improves paint transfer during the painting process, thereby reducing the amount of sprayed particles.

[0012] - Particles are more easily trapped in the water curtain of the paint spray booth

[0013] - Change the reaction kinetics so that the paint cannot polymerize at low temperatures, but starts to polymerize at higher temperatures (above 100°C), which cannot be reached under normal ambient conditions.

[0014] -The paint is easily cleaned by a variety of solvents.

[0015] To achieve these goals, the following technical work has been carried out:

[0016] - Use low paint flow rate and low air pressure, for this the following must be done:

[0017] A. Higher dry extracts than conventional reference paints,

[0018] B. The paint meets all required specifications at the smallest possible thickness.

[0019] - Use some materials that are soluble in both solvents and water in the composition, so that the paint denatures and partially loses its polymerization ability when it comes into contact with water.

[0020] -Using materials that are less reactive than conventional materials, and then using a blocked catalyst with a deblocking temperature of over 90°C to accelerate the reaction at high temperatures.

[0021] - As the paint does not polymerize at temperatures of 80°C for hours or days and contains some water-soluble components, it can be cleaned with mild solvents, alcohol or a mixture of alcohol and water (in a ratio of 30 / 70).

[0022] The method of producing the body enamel is achieved by electrostatic spray painting with a flared nozzle and is influenced by the size of the paint droplets and the amount of charge that can be generated on these droplets, wherein the paint composition includes melamine and the presence of a blocked acid catalyst.

[0023] Unless otherwise specified, all technical and scientific elements used herein have the meaning commonly understood by those skilled in the art to which the invention belongs. In the practice of the present invention, methods and materials similar or equivalent to those described herein can be used.

[0024] Throughout the specification and claims, the word "comprise" and its variants do not exclude other technical features, additives, ingredients or steps. For those skilled in the art, other purposes, advantages and features of the present invention are partly derived from the specification and partly from the practice of the present invention. DETAILED DESCRIPTION

[0025] The method of applying the paint has the following characteristics:

[0026] -Electrostatic spray painting with horn. During the electrostatic spray painting process, the paint is transferred by the electrostatic attraction between the charged paint particles and the car body, and the car body is grounded and acts as a discharge electrode.

[0027] Electrostatic painting is affected by the size of the paint droplets and the amount of charge that can be generated on those droplets. At the same voltage, the lower the paint flow rate, the better the effect of both.

[0028] In a possible implementation, the parameter values ​​affecting electrostatic painting are + 10% range:

[0029] -Paint flow rate 280cm 3

[0030] -Guided air 200NL / min

[0031] - Voltage 60kv

[0032] -Paint conductivity 500+ / -50kΩ

[0033] Another aspect that influences paint deposition is the composition of the paint, where there are some water-soluble ingredients, such as a melamine, which are partially hydrophilic rather than hydrophobic when in contact with water and are therefore more easily entrapped.

[0034] Melamine is not very reactive and requires the presence of an acid catalyst to react under the usual curing conditions of the car body.

[0035] A blocked acid catalyst was selected as the acid catalyst, the deblocking temperature of which is higher than 80° C., which is the temperature that a vehicle body, especially a black or red vehicle body, can reach in the sun.

[0036] In one possible, but non-limiting, embodiment, the composition of the paint, in addition to melamine and the catalyst, is:

[0037] - Pigment dispersant 3-6%

[0038] - Hydroxylated resin 25-40%

[0039] - Rheological additives 2-5%

[0040] -Titanium dioxide 1-40%

[0041] -Supplementary pigments 1-20%

[0042] - Melamine resin 5-15%

[0043] -Surfactant 0.5-5%

[0044] -Toughening polyol 3-20%

[0045] - Catalyst 1-3%

[0046] -Solvent 5-25%

[0047] Having fully described the nature and embodiments of the present invention, it should be noted that, within the essential scope of the present invention, the present invention may also be implemented in other embodiments that differ in details from the exemplary embodiments as long as the basic principles of the present invention are not changed, altered or modified, and the protection claimed by the present invention will also apply to these embodiments.

Claims

1. A method for producing a vehicle body enamel, characterized in that: The method is carried out by electrostatic spray painting with a flared nozzle and is influenced by the size of the paint droplets and the amount of charge that can be generated on these droplets, wherein the paint composition includes melamine and the presence of a blocked acid catalyst.

2. The method for producing a vehicle body enamel paint according to claim 1, characterized in that: The parameter values ​​used in electrostatic spray painting are + 10% range: -Paint flow rate 280cm 3 -Guided air 200NL / min - Voltage 60kv -Paint conductivity 500+ / -50kΩ.

3. A paint composition for use in a method for producing a vehicle body enamel paint according to any one of the preceding claims, characterized in that The paint composition is: - Pigment dispersant 3-6% - Hydroxylated resin 25-40% - Rheological additives 2-5% -Titanium dioxide 1-40% -Supplementary pigments 1-20% - Melamine resin 5-15% -Surfactant 0.5-5% -Toughening polyol 3-20% - Catalyst 1-3% -Solvent 5-25%.