MX2011006741A - Method for producing sprayable mixture containing protected crosslinkable groups. - Google Patents

Abstract

The present disclosure relates to a method for producing a sprayable mixture containing protected crosslinkable groups. The sprayable mixture has a substantially consistent viscosity and can produce a crosslinked coating composition having a good appearance useful in the painting industry.

Description

METHOD TO PRODUCE AN ATOMIZABLE MIXTURE THAT CONTAINS PROTECTED RETICULABLE GROUPS FIELD OF THE INVENTION This invention relates to a painting operation and a method for controlling the viscosity of a coating composition, wherein the coating composition is a sprayable mixture containing protected crosslinkable groups. This spray-applied mixture subsequently forms a layer of the coating composition which is possible to dry and cure to form a durable protective coating on a substrate.

BACKGROUND OF THE INVENTION Automotive coatings typically comprise a crosslinked polymer network comprised of multiple reactive components. Typically, the coatings are sprayed onto a substrate, such as the body or body parts of a motor vehicle by the use of an atomizing device, and then cured to form a coating layer having the crosslinked polymer network.

In currently used atomization technologies, multiple reactive components of a coating composition are mixed to form a reaction mixture before atomization and placed in a cup-shaped container or container that is attached to a spray device, Ref .: 220313 such as a spray gun. Due to the reactive nature of the multiple reactive components, the pot mixture will begin to react as soon as the components mix with each other, which will cause a continuous increase in the viscosity in the pot mixture. When the viscosity reaches a certain point, the mixture of the pot becomes a practically non-atomisable mixture. The possibility that the spray gun itself may become clogged with the crosslinked polymeric materials is, furthermore, a disadvantage. The time it takes the viscosity to increase to the point where the atomization becomes ineffective, generally an increase of up to twice the viscosity, is called "shelf life".

It is possible to produce coating mixtures with extended shelf life through the use of protected crosslinkable groups. The protected crosslinkable groups do not react to form the crosslinked network until after going through a deprotection reaction. The protected crosslinkable groups can form pot mixtures containing the crosslinkable groups, the crosslinking components and the crosslinking catalysts with a long shelf life. When these pot mixtures are applied to a substrate by atomization, the humidity of the air may be sufficient to cause the hydrolysis reaction to take place and form a crosslinked network. However, there is a relatively narrow range of ambient humidity that allows this coating composition to crosslink to a useful speed. With too much moisture the appearance may be unacceptable and, with very low humidity, the applied layer of coating composition would cure very slowly.

Another way to extend the "shelf life" is to add a larger amount of solvent known, moreover, as a diluting agent, to the pot mixture. However, the diluting agent, such as an organic solvent, contributes to increasing the volatile organic compound (VOC) emissions and also increases the curing time.

Other attempts to extend the "shelf life" of a pot mixture of a coating composition have been concentrated in "chemical-based" solutions. For example, it has been suggested to include modifications of one or more of the reactive components or certain additives that retard the polymerization reaction of the multiple components in the pot mixture. The modifications or additives should be such that the curing speed is not adversely affected after applying the coating to the surface of a substrate.

Another method is to mix one or more key components, such as a catalyst, together with other components of the coating composition immediately before atomization. An example is described in U.S. Pat. no. 7,201,289 in which a catalyst solution is stored in a separate dispenser and dosed and mixed with a liquid coating formulation before atomizing the coating formulation.

Yet another method is to separately atomize two components, such as a catalyst and a resin, of a coating composition and mix the two atomized components after atomization. One such example is described in U.S. Pat. no. 4,824,017. However, this approach requires the atomization of two components separately through the use of pumps and independent injection means for each of the two components.

BRIEF DESCRIPTION OF THE INVENTION The following description relates to a painting operation and a method for controlling the viscosity of a coating composition, wherein the coating composition is a sprayable mixture, the method comprising the steps of: (A) producing a first atomized stream of a first coating component of the coating composition through an orifice of the atomizing gun with a stream of a p-textured carrier, wherein the first coating component is stored in a first container of storage and is transported through a first inlet of the atomizing gun to the orifice and wherein the viscosity of the first coating component remains substantially constant before be transported through the first entrance; (B) producing a second atomized stream of a second coating component of the coating composition, wherein the second atomized stream is produced by siphoning the second coating component with a siphoning current selected from the first atomized stream of the first coating component, the pressurized carrier stream, or a combination thereof, from at least one supply outlet coupled to a second storage vessel containing the second coating component, and the supply outlet is located in the hole; (C) optionally, regulating the supply of the second coating component to the supply outlet when coupling a regulating device to the supply outlet; (D) intermixing the first atomized stream and the second atomized stream to form a coating mixture; Y (E) applying the coating mixture on the substrate to form the layer of the coating composition on the substrate; Y wherein the coating composition comprises protected crosslinkable functional groups.

This description also describes a method comprising the steps of: (A) producing a first atomized stream of a first coating component of the coating composition through an orifice of the atomizing gun with a stream of a pressurized carrier, wherein the first coating component is stored in a first container of storage and transported through a first inlet of the atomizing gun to the orifice, and wherein the viscosity of the first coating component remains substantially constant before being transported through the first inlet; (B) producing a second atomized stream of a second coating component of the coating composition, wherein the second atomized stream is produced by siphoning the coating component with a siphoning current selected from the first atomized stream of the first component of coating, the pressurized carrier stream, or a combination thereof, from at least a first supply outlet of a supply device coupled to a second storage vessel containing the second component, and the first supply outlet is located in the hole; (C) optionally, regulating the supply of the second coating component to the first supply outlet when coupling a first regulating device to the first outlet of supply; (D) producing a subsequent atomized stream of a subsequent coating component of the coating composition, wherein the subsequent atomized stream is produced by siphoning the subsequent coating component with the siphoning stream of at least one supply outlet the rear one coupled to a rear storage container containing the rear component, and the subsequent supply outlet is located in the hole; (E) optionally, regulating the supply of the aftercoating component to the subsequent supply outlet when coupling a subsequent regulating device at the subsequent supply outlet; (F) intermixing the first atomized stream, the second atomized stream and the rear atomized stream to form a coating mixture; Y (G) applying the coating mixture on the substrate to form a layer of the coating composition thereon; Y wherein the coating composition comprises protected crosslinkable functional groups.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows a spray gun attached to an example of a delivery device representative of this invention.

Figures 2A-2D shows front views of the delivery device seen from the direction 2A indicated in Figure 1. (2A) A schematic presentation of a representative example of the 2D delivery device constructed as an additional device. (2B) A schematic presentation of a representative example of the delivery device 2 'having a supply outlet constructed in the air cap of the spray gun. (2C) A schematic presentation of a representative example of the supply device 2"having two supply outlets constructed in the air cap of the atomizing gun. (2D) A schematic presentation of a representative example of the delivery device 2" ' which has three supply outlets (14) constructed in the air cap of the spray gun.

Figure 3 shows an enlarged front view, in a schematic presentation, of a representative example of the 2D supply device constructed as an additional device that can be attached to the air cap of a spray gun. A single air intake coupling (8) is shown.

Figure 4 shows an enlarged front view, in a schematic presentation, of another representative example of the 2D delivery device 'constructed as an additional device that can be attached to the air cap of a gun atomizer. Two air intake couplings (8) are shown.

Figure 5 shows an enlarged front view of the details of the delivery device and the relative position of the delivery device and the orifice of the spray gun. Two supply outlets (14), two connection paths (11) and one hole (13) are shown. The arrows 6 indicate the direction of a cross-sectional view used in Figures 6, 7 and 8.

Figure 6 shows an enlarged side cross-sectional view of the details of an example of the delivery device and the relative position of the delivery device and the orifice of the spray gun. The orifice (13) can be located in three different regions indicated with a, b and c, respectively.

Figures 7A-7B show schematic presentations of examples of the formation of a coating mixture. (7A) An example of a first coating component that is sprayed into an orifice of a spray gun without the introduction of a second coating component. (7B) An example of the coating mixture formed by a first atomized coating component and a second atomized coating component.

Figures 8A-8B show schematic presentations of another example of the formation of a coating mixture. (8A) A first coating component atomized in a orifice of a spray gun without the introduction of a second coating component. (8B) A coating mixture formed by a first atomized coating component and a second atomized coating component.

Figures 9A-9B show other examples of the delivery device of this invention constructed as an additional device. (9A) An example of the delivery device having a configuration of two air intake couplings (8) and two supply outlets (14). (9B) An example of the supply device having a configuration of two air intake couplings (8) and a common supply outlet (14). The hole (13) is shown in the figure to indicate the relative position of the delivery device when it is attached to the air cap. The hole (13) is part of the spray gun.

Figures 10A-10H show schematic presentations of various configurations of the delivery device of this invention. (10A) An example of a delivery device having an air intake coupling that is coupled to a storage container. (10B) An example of a delivery device having an air intake coupling that is coupled to two individual storage containers. (10C) An example of a supply device that has two air intake couplings that are coupled to two storage containers. (10D) An example of a supply device having three air intake couplings, where the three are coupled to a single storage container. (10E) An example of a delivery device having three air intake couplings, wherein one of them is coupled to an individual storage container at the same time that the other two are coupled to a single storage container. (10F) Another example of a supply device having three air intake couplings, wherein only one of them is coupled to a single storage container. (10G) Another example of a supply device having three air intake couplings, two of which are coupled to a single storage container. (10H) Another example of a supply device having three air intake couplings, wherein each of the first and second couplings is coupled to an individual storage container, while the third is not coupled to any container. The schematic representations are given for illustrative purposes only, and the elements in the presentations may not be in scale. The hole (13) is part of the atomizing gun.

Figure 11 shows an example of another representative configuration.

DETAILED DESCRIPTION OF THE INVENTION Persons of ordinary skill in the art will more readily understand the features and advantages of the present invention upon reading the following detailed description. It should be understood that certain features of the invention which, for clarity, have been described above and will be described below in the context of separate embodiments may also be provided in a single embodiment. On the other hand, the various features of the invention, which, for the purpose of being brief, are described in the context of a single embodiment may also be provided separately or in any secondary combination. In addition, references in the singular may also include the plural (for example, "one" and "he / she" may refer to ones and / or) unless the context indicates specifically in any other way.

Unless expressly indicated otherwise, the numerical values used in the various ranges specified in this application are expressed as approximations, as if the minimum and maximum values within the indicated ranges were preceded by the term "approximately" in both cases. In this way you can use slight variations by. above and below the intervals stated in order to obtain essentially the same results of the values within the interval. In addition, the description of these intervals is intended to constitute a continuous interval, including all values between the minimum and maximum values.

As used in the present description: The phrase "coating composition" means a liquid composition transported by solvent or water that can be applied to a substrate through a spray gun. The coating composition comprises a crosslinkable component and a crosslinking component. Other additives that are used to produce a coating composition, as is known in the art and, generally, are not described in the present disclosure. These additives may include organic solvents, aqueous solvents, pigments, rheology control agents, light stabilizers and leveling agents. In one embodiment the coating composition comprises crosslinkable and crosslinking components which it is possible to mix together to form a pot mixture prior to spray application by use of the method described in the present disclosure. In another embodiment, the coating composition comprises crosslinkable and crosslinking components as separate components that can be applied as separate components by use of the method described in the present disclosure.

The phrase "pot mix" means a mixture comprising a crosslinked component and a crosslinking component that is formed prior to spray application. The pot mixture can be added to the first storage container (3).

"Low VOC coating composition" means a coating composition that includes less than 0.6 kilograms per liter (5 pounds per gallon), preferably less than 0.52 kilograms per liter (4.3 pounds per gallon), and, more preferably, less than 0.42 kilograms per liter (3.5 pounds per gallon), of volatile organic component, such as certain organic solvents. In the present description reference is made to the phrase "volatile organic compound" as "VOC". The VOC level is determined according to the procedure provided in ASTM D3960.

The phrase "viscosity of a component remains substantially constant" means that the viscosity of the component shows, in one embodiment, an increase of less than 40% over a period of 8 hours. In another embodiment, the increase in viscosity is less than 25% over a period of 12 hours and, in a third embodiment, the increase in viscosity is less than 10% over a period of 16 hours. To measure the viscosity change over time, the viscosity of a component is measured when the component is prepared at first; the component is stored in a covered container at room temperature for 8, 12 or 16 hours; The viscosity of the component is measured again by using the same technique. The difference between the two viscosity measurements must not exceed the percentages listed above. There are several methods available to measure the viscosity of a liquid. In one embodiment, the Zahn viscosity is measured (in seconds).

"Productive paint" describes a coating composition wherein an applied layer of the coating composition, 10 to 150 micrometers thick, can be dried and cured, in one embodiment, in less than 20 minutes at 60 ° C or less 90 minutes at room temperature. In another embodiment, the productive paint layer of 10 to 150 micrometers in thickness can be dried and cured in less than 10 minutes at 60 ° C or in less than 45 minutes at room temperature. In a third embodiment, the productive paint layer of 10 to 150 micrometers in thickness can be dried and cured in less than 5 minutes at 60 ° C or in less than 20 minutes at room temperature. The ambient temperature is defined as a temperature within the range of 21 ° C to 24 ° C.

By "drying and curing" it is meant that the coating composition is crosslinked to the point where the handling of the substrate does not ruin the surface, the substrate is dry to the touch and neither the dust nor the dirt is removed. 1S stick to the surface. Although some reticulation has occurred, over time the additional crosslinking can continue, which will allow sanding and / or polishing of the applied layer, if necessary. Preferably, the sanding and / or polishing operations can occur within the hour following the drying and curing and, more preferably, within the following half hour.

The phrase "constant appearance" means that a measured appearance value of a dry and cured coating composition layer applied at the time the painting operation begins does not vary by a given percentage above the measured appearance value of a layer of the same dry and cured productive paint applied at a time that occurs 8 hours after the painting operation started. The measured appearance values can be one or more of the image sharpness (DOI), the long and short wavescan measurements of an applied coating. For the measurement of DOI, the percentage change can be less than 10 percent and, for long and short wavescan measurements, the change must be less than 20 percent. For example, a layer of a coating composition is applied to a first substrate by use of the method described in the present disclosure. The applied layer of coating composition is dried and cured and the DOI and the long and / or short wavescan measurements of the coating are obtained. After not less than 8 hours, it is coated a second substrate prepared in a similar manner by using the same method and with the same coating composition that was used to coat the first substrate. This second substrate is dried and cured by using the same conditions used to dry and cure the first substrate. The measured appearance values should not vary by more than the percentages listed.

The sharpness of the image and the long and short wavescan measurements can be measured by the use of wavelenometers or wavescan instruments available from Byk-Gardner USA, Columbia, Maryland.

The phrase "good appearance" means that multiple dry and cured layers of a coating composition applied by use of the method described in the present description have a short wavescan measure of less than 40. Preferably, the short wavescan is less than 30. With maximum preference, the short wavescan is less than 20. It is also possible to measure the long wavescan and, to be considered as having good appearance, the long wavescan measurement must be less than 15. To determine the wavescan measurement, at least one of the applied layers of primer, basecoat or, »gloss coat must be applied in accordance with this method. In one embodiment at least the gloss layer composition is applied according to the method described, and in a second embodiment, at least the compositions of the primer and the Gloss coat are applied according to the method described. In a third embodiment, a layer of primer, base coat and gloss coatings are applied through the use of the described method.

As used in the present description, "crosslinkable component" includes a compound, oligomer or polymer having protected crosslinkable functional groups positioned on each molecule of the compound, the oligomer, the polymer backbone, suspended from the polymer backbone, positioned at the terminal end of the main chain of the polymer, or a combination of these. The term "protected" means that the crosslinkable functional groups are not immediately available for curing with the crosslinking groups, but must previously be subjected to a reaction to produce crosslinkable functional groups. Suitable protected crosslinkable components with protected crosslinkable groups include, for example, acetalamine, orthocarbonate, orthoacetate, orthoformate, spiro orthoester, orthosilicate, oxazolidine or combinations thereof.

The protected crosslinkable groups are generally not crosslinkable without further chemical transformation. The chemical transformation for these groups can be a hydrolysis reaction that deprotects the group to form a crosslinkable group that can be reacted with the crosslinking component to produce a crosslinked network. Each of these protected groups forms, after the deprotection reaction, at least one crosslinkable group. For example, after hydrolysis, an acetalamide can form an amide diol or one of two amino alcohols. Another example would be the hydrolysis of an orthoacetate which can form a hydroxy group.

While the intention is that the embodiments described in the present disclosure contain protected crosslinkable groups, a portion of the crosslinkable component may contain compounds, oligomers and / or polymers having crosslinkable functional groups that do not need to be subjected to a chemical reaction to produce the group crosslinkable These crosslinkable groups are known in the art and include, for example, hydroxyl, acetoacetoxy, thiol, carboxyl, primary amine, securary amine, epoxy, anhydride, imino, ketimino, aldimino, silane, aspartate or a suitable combination thereof.

The "crosslinking component" is a component that includes a compound, oligomer or polymer having crosslinking functional groups positioned in each molecule of the compound, the oligomer, the polymer backbone, suspended from the polymer backbone, positioned in the terminal part of the polymer backbone, or a combination thereof, wherein these functional groups they are capable of reacting with the unprotected crosslinkable functional groups of the crosslinkable component (during the curing step) to produce a coating in the form of crosslinked structures. The crosslinking component can have, on average, from 2 to 25, preferably, 2 to 15, more preferably from 2 to 7 and, even more preferably, from 3 to 5 crosslinking groups per molecule. Typical crosslinking components can be selected from a compound, an oligomer or a polymer having crosslinking functional groups selected from the group consisting of isocyanate, amine, ketimine, melamine, epoxy, carboxylic acid, anhydride and a combination thereof.

A coating composition may further comprise a catalyst, an initiator, an activator or a combination thereof.

A catalyst can initiate or promote the reaction between reactants, such as between the deprotected crosslinkable functional groups of a crosslinkable component and crosslinking functional groups of a crosslinking component of a coating composition. The amount of the catalyst will depend on the reactivity of the functional groups. Generally, it is used within the range of from about 0.001 percent to about 5 percent, preferably, within the range of 0.01 percent to 2 percent, more preferably, within the range from 0.02 percent to 1 percent, all in percent by weight based on the total weight of the crosslinkable solid components, of the catalyst. It is possible to use a wide range of catalysts, for example, organotin compounds such as tin catalysts, dibutyltin dilaurate, tin octane (II); 1, 4-diazabicyclo [2.2.2] octane, zinc octoate, triphenyl phosphamine, quaternary ammonium compounds, strong bases, aluminum halides, aluminum alkyl halides or tertiary amines such as triethylenediamine, depending on the crosslinkable and crosslinking functional groups unprotected. These catalysts can be used alone or in combination with carboxylic acids, such as acetic acid. An example of commercially available catalysts is dibutyltin dilaurate such as the FASCAT® series sold by Arkema, Bristol, Pennsylvania, under the respective trademark.

In one embodiment, it is possible to use an activator to deprotect the protected crosslinkable groups. Suitable activators include, for example, water, water and acid, organic acids or a combination thereof. In one embodiment it is possible to use water or a combination of water and acid as an activator to deprotect the crosslinkable component. For example, water or acid water may be an activator for a coating described in PCT publication no. WO2005 / 092934, published on 6 October 2005, where the water activates the hydroxyl groups of the ortho-form groups that block the reaction of the hydroxyl groups with cross-linking functional groups.

In another embodiment an activator can be a compound, oligomer or polymer containing crosslinkable functional groups that react very rapidly with the functional groups of the crosslinking group, or the activator can be polymers with high concentration of crosslinkable groups, for example, dispersion polymers non-aqueous or hyperbranched polymers. These quick-reacting components, oligomers or polymers can be added as one of the components described in the present disclosure to help build the network of the applied layer of the coating composition. Examples of crosslinkable functional groups which react rapidly with a crosslinking component comprising isocyanate groups include amines and / or aspartates.

An initiator can initiate one or more reactions. Examples may include photoinitiators and / or sensitizers that cause polymerization or curing of a radiation curable coating composition, such as a UV curable coating composition when performing radiation, such as UV irradiation. Several are photoinitiators known to those skilled in the art, and may be suitable for this invention. Examples of photoinitiators can include, but are not limited to, benzophenone, benzoin, benzoin methyl ether, benzoin n-butyl ether, benzoin isobutyl ether, propiophenone, acetophenone, 1-hydroxycyclohexyl phenyl ketone, 2,2-diethoxyacetophenone, ethylphenylpiloxylate, diphenyl oxide (2,4,6-trimethylbenzoyl) phosphine, phosphine oxide, phenyl bis (2,4,6-trimethyl benzoyl), phenanthraquinone, and a combination thereof. Other commercial photoinitiator products exist, or combinations thereof include, for example, DAROCURE® and IRGACURE® available from Ciba Specialty Chemicals Corporation, New York.

In the practice of conventional coating through the use of protected crosslinkable functional groups, the crosslinkable components and the crosslinking components can be mixed with the crosslinking catalyst and / or the activators immediately before atomization. These catalyzed pot mixtures can have a useful life of the order of a few minutes to several hours, after which time the viscosity has increased to the point where the application by atomization of the compound can be difficult. The shelf life may depend on the ambient humidity, the amount of water that has been added to protect the protected crosslinkable groups and other factors. Too much water or too little water available from ambient humidity or added water as an activator can have an impact not only on shelf life but also on curing speed and appearance of the dry and cured coating composition. This disclosure provides a method for controlling the viscosity of a coating composition so that it is possible to increase the service life in relation to the conventional coating practice and that the appearance of the dry and cured coating composition has a constant appearance throughout the period of application. A layer of dry and cured coating composition according to the described method can also look good.

One embodiment of the disclosure relates to a painting operation and a method for controlling the viscosity of a coating composition, wherein the coating composition is a sprayable mixture comprising a protected crosslinkable functional group. The coating composition comprises two or more coating components. The method may comprise the following steps: (A) producing a first atomized stream of a first coating component of the coating composition through an orifice of the atomizing gun with a stream of a pressurized carrier, wherein the first coating component is stored in a first container of storage and is transported through a first inlet of the atomizing gun to the orifice, and wherein the viscosity of the first coating composition remains substantially constant before be transported through the first entrance; (B) producing a second atomized stream of a second coating component of the coating composition, wherein the second atomized stream is produced by siphoning the second coating component with a siphoning current selected from the first atomized stream of the first coating component, the pressurized carrier stream, or a combination thereof, from at least one supply outlet of a supply device coupled to a second storage vessel containing the second component, and the supply outlet is located at the hole; (C) optionally, regulating the supply of the second coating component at the supply outlet by coupling a regulating device to the supply outlet, - (D) intermixing the first atomized stream and the second atomized stream to form a coating mixture; Y (E) applying the coating mixture on the substrate to form the coating composition layer on the substrate, wherein the coating composition comprises protected crosslinkable functional groups.

Another embodiment of the method for controlling the viscosity of a coating composition, wherein the coating composition is a sprayable mixture comprising a protected crosslinkable functional group, which may comprise the steps of: (A) producing a first atomized stream of a first coating component of the coating composition through an orifice of the atomizing gun with a stream of a pressurized carrier, wherein the first coating component is stored in a first container of storage and transported through a first inlet of the atomizing gun to the orifice, and wherein the viscosity of the first coating composition remains substantially constant before being transported through the first inlet; (B) producing a second atomized stream of a second coating component of the coating composition, wherein the second atomized stream is produced by siphoning the coating component with a siphoning current selected from the first atomized stream of the first component of coating, the pressurized carrier stream, or a combination thereof, from at least a first supply outlet of a supply device coupled to a second storage vessel containing the second component, and the first supply outlet is located in the hole; (C) optionally, regulating the supply of the second coating component to the supply outlet when coupling a first regulating device to the first supply outlet; (D) producing a subsequent atomized stream of a subsequent component of the coating composition, wherein the subsequent atomized stream is produced by siphoning the subsequent coating component with the siphoning stream of at least one subsequent supply outlet of the supply device coupled to a rear storage container containing the rear component, and the rear delivery outlet is located in the hole; (E) optionally, regulating the supply of the aftercoating component to the subsequent supply outlet when coupling a subsequent regulating device at the subsequent supply outlet; (F) intermixing the first atomized stream, the second atomized stream and the rear atomized stream to form a coating mixture; Y (G) applying the coating mixture on the substrate to form the layer of the coating composition on it, wherein the coating composition comprises protected crosslinkable functional groups.

Any atomizing gun that can produce a stream of atomized coating composition may be suitable for this invention. A spray atomizing spray gun is preferred. Even more preferred is a spray gun powered by gravity using a pressurized carrier as a spray carrier. The pressurized carrier can be selected from compressed air, compressed gas, compressed gas mixture, or a combination thereof. Typically, the pressurized carrier can be compressed air. Typically, a spray gun comprises a spray gun body (1), a nozzle unit (2) including an orifice (13) and an air cap (24), a carrier coupling (12) for coupling to a source of a pressurized carrier, such as compressed air, an air regulating unit (25) for regulating the flow rate and pressure of the carrier, a flow regulator of the coating (21) for regulating the flow of the first coating component that is stored in a main receptacle, further known as a first storage container (3), and a first inlet (10) that couples the atomizing gun (1) to the first storage container (3). Typically, the spray gun also includes additional controls, such as a trigger (22) and an atomizing fan regulator (20) to regulate the compressed air. Typically, in a typical spray gun powered by the action of gravity, the first coating component is not pressurized and is stored in the first storage vessel (3), which is at atmospheric pressure. The first coating component can be transported to the orifice by gravity, siphoning, or a combination of the action of gravity and siphoning.

The pressurized carrier can be selected from compressed air, compressed gas, compressed gas mixture, or a combination thereof. Typically, the pressurized carrier is compressed air. In addition, compressed gases, such as compressed nitrogen, compressed carbon dioxide, compressed fluorocarbon, or a mixture thereof, may be used. The compressed carrier may also include gases produced from compressed liquids, solids or liquids and solids reactions.

The coating composition may be a primer, a base coat, a pigmented base coat or a gloss composition. The coating layer formed with these may be a primer layer, a base coat, a pigmented base coat, or a gloss coat, respectively.

In one embodiment of this method, the first coating component can be a pot mixture comprising one mixing crosslinkable and crosslinking components of a coating composition, and the second coating component can include one or more materials selected from a catalyst, an initiator, an activator or a combination thereof.

In some embodiments, it is also possible to use mixtures of protected crosslinkable functional groups and crosslinkable functional groups that are not protected. For example, the crosslinkable component can be a mixture of compounds, oligomers or polymers containing both hydroxy functional groups and acetal amide functional groups. In another example the crosslinkable component can be a mixture of compounds, oligomers and polymers containing hydroxy functional groups and compounds, oligomers and polymers containing orthoacetate functional groups.

In another embodiment the crosslinkable component can be the first coating component, the crosslinking component can be the second coating component and a subsequent coating component can be added which can be a catalyst, activator and / or initiator. In another embodiment the crosslinking component can be the first coating component, the crosslinkable component can be the second coating component and a subsequent coating component can be added which can be a catalyst, activator and / or initiator. "| In another embodiment the first coating component may comprise a mixture of protected crosslinkable functional groups and crosslinking components and the second coating component may comprise water and / or acid to deprotect the protected crosslinkable groups and it is possible to add subsequent coating components which include one or more of a catalyst, an activator and / or an initiator.

In a further embodiment, the first coating component may comprise the protected crosslinkable groups, the second coating component may comprise the crosslinking groups, and the subsequent coating components may include water and / or acid; catalysts; activators and / or initiators.

The crosslinking reactions used to form the crosslinked network can be addition reactions of the polymerization of unsaturated double bonds through the use of any of the described initiators, condensation reactions resulting from the condensation of, for example, a crosslinkable functional group unprotected and an isocyanate group, or a combination of addition and condensation reactions can form the crosslinked network.

Table 1 lists examples of protected crosslinkable groups and crosslinkable groups that occur after being deprotected. The groups The crosslinkable groups achieved after deprotection can determine the crosslinking groups which may be suitable for use with each protected crosslinkable group. Table 1 This method relates to a painting operation and helps to control the viscosity of a coating composition, wherein the coating composition is a sprayable mixture. Controlling the viscosity of the coating composition prior to application to the substrate contributes to maintaining a constant appearance of the subsequently dried and cured coating composition during the entire period of application.

The method described for controlling the viscosity of a coating composition can result in a dry and cured coating composition layer having a constant appearance. The described method can use a productive paint and provide a layer of dry and cured coating composition that has a constant appearance. The period of time it takes to apply the coating composition according to this method is not particularly critical and, generally, can vary within the range of several minutes to 8 or more hours. While the method can be used in any painting operation, it may be suitable for use in automotive refinishing, original equipment manufacturers (OEMs) for aviation industries, heavy duty trucks and marine.

The method, as described in the present description, can be applicable to many commercial painting industries. In the fleet and automobile auction markets, a quick curing coating is desirable to maximize output output. Generally, fast curing compositions are produced by increasing the amount of catalyst that is added to the pot mixture, which results in a short shelf life. With this method, the viscosity of the pot mixture is kept substantially constant during the application, since the catalyst is not added until the atomization step. In the industries of coatings for aviation, heavy duty trucks and marine applications, the substrates are sometimes very large. To coat such large surfaces, a composition with a long shelf life is needed. In the Currently, pot mixes with low levels of catalysts provide the necessary shelf life. However, a low level of catalyst results in a long cure period, which is not desired. The method as described in the present description can provide the desired long useful life, in addition to a relatively fast cure. In many other industrial coating operations, a VOC coating is desired due to the expensive solvent / air separation techniques necessary to comply with environmental regulations. These low VOC coatings generally have a short shelf life. This method can provide low VOC compositions and extended shelf life. In the priming / inner layer industry, large amounts of pigments and / or fillers are needed to give the coatings the desired properties and the pigments and / or fillers may affect the activity of the catalyst over time as a result of the absorption of the catalyst to the surface of the pigment / filler. This can result in a non-constant cure and shelf life problems. Adding the catalyst in the atomization stage reduces the absorption of the catalyst to the surface of the pigment / filler, which can contribute to eliminate the problems of curing and useful life. It is also known that catalysts and other ingredients that are typically added to coating compositions Inside can cause discoloration of uncured compositions before application. The discoloration is often perceived as the yellowish color of the inner layer compositions in storage. This method can be used to add the catalysts and other ingredients during the spraying operation so that color development does not occur before application of the composition.

In the above embodiments one or more of the components of the second coating component can be siphoned off separately, such as in the configurations shown in Figures 9A, 10C, 10E or 10H. One or more of the subcomponents of the second coating component can be siphoned off together, such as in the configurations shown in Figure 10B.

The second coating component can be siphoned from at least one supply outlet (14) with a siphoning current selected from the first atomized stream of the first coating component, the pressurized carrier stream, or a combination thereof. The supply outlet is coupled to a second storage container containing the second component, and the supply outlet is located in the orifice. The supply outlet and the hole can be placed at any relative angle or relative positions so that the siphoning can occur effectively. Without intending to be limited by any particular theory, it is thought that "siphoning" occurs when the siphoning current moves at high speed at the supply outlet and causes negative air pressure around the supply outlet. It is believed that the negative air pressure causes the second coating component to be transported to the supply outlet. It is believed that the high velocity of the pressurized carrier stream and the sudden change in air pressure associated with the negative air pressure at the supply outlet cause the second coating component to be atomized and intermixed in the siphoning stream and the first atomized stream of the first coating component. In this invention the first and second coating components can be mixed at a predetermined mixing ratio to form a coating mixture. The second coating component can also be transported to the delivery outlet by gravity or by a combination of gravity and siphonage in certain configurations described in the present description.

Both the first and the second coating component can be stored in the respective storage vessels at atmospheric pressure.

Depending on the relative position between the hole (13) and the supply outlet (14), the second component of Siding can be siphoned off. with different siphoning currents. When the orifice is located in the position illustrated by region 13a and 13b of Figure 6, the second coating component can be siphoned off mainly by movement of the pressurized vehicle, at high speed, in the direction shown by the arrow (32). ). Figures 7A-7B show examples of a delivery device having two supply outlets. Figures 8A-8B show examples of a delivery device having a delivery outlet. Then, the pressurized carrier continues to produce the first atomized coating component in the orifice (13). The first and second atomized coating components can be intermixed to form the coating mixture (16) (Figures 7B and 8B). When the hole is located in the position illustrated by the region 13c of Figure 6, the second coating component can be siphoned off mainly by a combination of the movement of the pressurized vehicle, at high speed, in the direction shown by the arrow (32). ) and the first atomized stream of the first coating component. If the second coating component is not supplied to the supply outlet, for example, if a regulating device (32) is closed, then only the first coating component (15) is atomized (Figures 7A and 8A). The flow of the first component of Coating is indicated by the arrow (31). The flow of the second coating component is indicated by the arrows (30).

The coating mixture can be applied on a substrate. Typically, a painter can hold the spray gun at a certain distance from the substrate and move it in the desired directions so that the coating mixture can be atomized onto the substrate and form a layer of the coating composition. This invention may further comprise the step of curing the layer of the coating composition on the substrate to form a coating on the substrate. This curing step may depend on the coating composition employed. The layer can be cured at ambient temperatures or at elevated temperatures, such as up to 180 ° C. Curing can also be done by exposing the coating layer to radiation, such as UV light or electron beam, when the coating composition can be cured by radiation.

The substrate may include wood, plastic, leather, paper, woven and non-woven fabrics, metal, gypsum, cementitious and asphalt substrates, and substrates having one or more existing layers of coating thereon. The substrate can be a vehicle, the body of a vehicle or parts of the body of a vehicle.

In another modality, the method to control the The viscosity of a coating composition may comprise the steps of: (A) producing a first atomized stream of a first coating component of the coating composition through an orifice of the atomizing gun with a stream of a pressurized carrier, wherein the first coating component is stored in a first container of storage and transported through a first inlet of the atomizing gun to the orifice, and wherein the viscosity of the first coating composition remains substantially constant before being transported through the first inlet; (B) producing a second atomized stream of a second coating component of the coating composition, wherein the second atomized stream is produced by siphoning the coating component with a siphoning current selected from the first atomized stream of the first component of coating, the pressurized carrier stream, or a combination thereof, from at least a first supply outlet of a supply device coupled to a second storage vessel containing the second component, and the first supply outlet is located in the hole; (C) optionally, regulate the supply of second coating component in the supply outlet when coupling a first regulating device to the first supply outlet; (D) producing a subsequent atomized stream of a subsequent component of the coating composition, wherein the subsequent atomized stream is produced by siphoning the subsequent coating component with the siphoning stream of at least one subsequent supply outlet of the supply device coupled to a rear storage container containing the rear component, and the rear delivery outlet is located in the hole; (E) optionally, regulating the supply of the aftercoating component to the subsequent supply outlet when coupling a subsequent regulating device at the subsequent supply outlet; (F) intermixing the first atomized stream, the second atomized stream and the rear atomized stream to form a coating mixture; Y (G) applying the coating mixture on the substrate to form the layer of the coating composition on it, wherein the coating composition comprises protected crosslinkable functional groups.

The first supply outlet and the supply outlet Subsequent outputs can be separate supply outputs or combined in a single supply outlet. Figures 2C, 2D, 4, 5, 6, 7, 9A show some examples of separate supply outlets. Figure 9B shows an example where the two supply outlets can be combined into a single supply outlet. In accordance with the description of the present invention, those skilled in the art will be able to configure more supply outlets and / or different locations and placement of supply outlets without departing from the scope and spirit of this invention.

All components, including the first and second coating components, and any subsequent components, can be stored in the respective storage vessels at atmospheric pressure.

An advantage of this invention is that the first atomized coating component, the second atomized coating component and any subsequent coating component, if present, can be mixed at a predetermined mixing ratio to form the coating mixture, without the need to perform complex controls, such as those described in US Pat. UU no. 4,824,017. The predetermined mixing ratio can be determined by modulating or selecting the size of the supply outlet (14), the size of the connection path (11), or by providing a regulating device, such as a flow rate controller functionally coupled to the delivery device, or a combination of these. It can be configured that a regulating device can regulate the flow velocity of one or more supply outlets. The mixing ratio can also be controlled by modulating the viscosity of the first, the second, or both, the first and second coating components. In one example, the viscosity of the second coating component can be increased to reduce the amount that is siphoned out in the coating mixture. In another example, the viscosity of the second coating component can be reduced to increase the amount that is siphoned out in the coating mixture. Similarly, the viscosity of the first coating component can be increased or reduced, as necessary, to obtain a desired mixing ratio.

Unexpectedly, applicants discovered that by using the method of this invention the mixing ratio can be constant within a wide range of pressurized carrier pressures, ranging from 137.9-551.6 kPa (20 -80 pounds per square inch gauge). ). In one example the pressure of the pressurized vehicle can be in a range of 172.4 to 482.6 kPa (25 to 70 psig). In another example the pressure of the pressurized carrier may be in a range of 193.1 to 448.2 kPa (28 to 65 psig). In yet another example the pressure of the pressurized carrier may be in a range from 206.8 to 413.7 kPa (30 to 60 psig).

In one example, the mixing ratio can be determined by selecting different sizes of the diameter of the delivery outlet. The coating mixtures formed by using different sizes of the outlets can be sprayed onto suitable substrates. The properties of the coating layers formed on the substrates can be measured. Depending on the measurement of the properties, a suitable size or an appropriate range of sizes of the supply outputs can be selected. In another example, the mixing ratio can be determined by selecting different sizes of connection path diameters.

The regulating device can be selected from a mechanical flow restrictive, an electrical flow restrictive, a pressure controlled flow restrictor, a pneumatically driven flow restrictive, or a combination thereof. Examples of a mechanical flow restrictive may include a tube with a predetermined flow passage diameter that is coupled to the delivery outlet, or a mechanical valve that can control the flow passage. Examples of an electronic flow restrictor may include electric valves or an electric valve actuator. A pressure controlled flow restrictor can be any mechanical or electrical controller that can control flow as a function of pressure.

A flow rate controller, such as a valve or commercial in-line flow controller, may be coupled to the supply outlet to regulate the flow of the second coating component and thereby affect the mixing ratio. A flow rate controller may also be a small accessory that is placed within a connection path or a pipe connected to a connection path that is coupled to the supply outlet. Such an accessory can effectively reduce the size of the connecting path or the pipe and thereby reduce the flow of the second coating component.

The size selection and the use of the flow rate controller can be combined. For example, a size may be selected within a suitable range of the delivery outlet, and a valve may be coupled to the delivery outlet for a better adjustment of the mixing ratio. Any flow rate controller that can be coupled to the delivery outlet may be suitable for this invention.

A regulating device can be coupled to a supply outlet in any of the places that can effectively regulate the flow to that supply outlet. The regulating device can be coupled to an air intake coupling or it can be placed in a connection path that connects to that specific supply outlet. The device The regulator may also be placed anywhere along a pipe that supplies the second coating component or the subsequent coating component from its storage container to the air intake coupling of the supply device.

Another advantage of this invention is rapid curing while maintaining the extended pot life. In a conventional process the short life in the pot is a challenge when formulating a coating composition for quick cure, since all the components are mixed together in a pot mixture and the curing reaction begins immediately after mixing. In this invention the coating composition can extend its pot life before being atomized, since one or more components for curing, such as a catalyst, do not mix with each other. Then, the coating composition can be cured quickly after atomization since the second coating component, such as a catalyst, is mixed after atomization during spraying.

Yet another advantage of this invention is that some aspects of the atomization or coating property can be modified on demand. For example, the curing time of a coating composition can be modulated by modifying the amount of catalyst that is mixed in the coating composition during the atomization. This can be done by adjusting the regulating device during atomization.

This description also relates to a system for controlling the viscosity of a coating composition. The system can include: (A) a spray gun comprising a spray gun body (1), one or more inlets, a nozzle unit (2) including an orifice (13) and an air cap (24); Y (B) a delivery device comprising: (i) at least one supply outlet (14), wherein the supply outlet is located in the orifice (13); (ii) at least one air intake coupling (8); Y (iii) at least one connection path (11) connecting the air intake coupling (8) and the supply outlet (14), wherein the delivery outlet is coupled through the connection path and the coupling air intake to a storage container (4) containing a second coating component; (C) optionally, a regulating device (32) coupled to the supply outlet that regulates the supply of the second coating component at the supply outlet; wherein a first atomized stream of a first coating component of the coating composition is produced through the orifice (13) with a stream of a pressurized carrier, wherein the first coating component is stored in a first storage container and it is transported through a first inlet of the atomizing gun to the orifice and wherein the viscosity of the first coating component remains substantially constant before being transported through the first inlet; wherein a second atomized stream of a second coating component of the coating composition is produced by siphoning the second coating component with a siphoning current selected from the first atomized stream of the first coating component, the pressurized carrier stream , or a combination thereof, from the supply outlet (14) coupled to a second storage container containing the second component, and wherein the coating composition comprises protected crosslinkable functional groups.

The supply outlet (14), the air intake coupling (8) and the connection path (11) can be constructed as an additional device fixed to the air cap of the spray gun or they can be incorporated in the air cap of the spray gun. the atomizing gun. Representative examples of the additional device may include those shown in Figures 2A, 3, 4, 9A and 9B. The additional device can be fixed to the air cap by the use of conventional means, such as one or more threads, staples, jaws, adhesives, pins, or a combination thereof. Examples of the delivery device with the elements incorporated in the air cap may include. shown in Figures 2B, 2C and 2D. The delivery device may comprise a delivery outlet, such as those shown in Figures 2A, 2B and 3. The delivery device may further comprise two or more delivery outlets, such as those shown in Figures 2C. , 2D, 4 and 9A. Two or more supply outlets may be combined in a single supply outlet, such as the one shown in Figure 9B.

The representative configurations of the additional device (2D) are shown in Figures 2A, 3, 4, 9A and 9B. The system may have a single supply outlet (14), as shown in Figures 2A, 3 and 9B; or two or more supply outlets (14), as shown in Figures 4 and 9A. Depending on the descriptions described in the present description, those skilled in the art will be able to make modifications and reconfigurations so that the additional device can be used with other spray guns, nozzle units, air caps, or a combination of these.

Figure 5 shows an enlarged front view of the hole (13) and two of the supply outlets (14). Figure 6 shows a cross-sectional side view of the delivery device indicating the relative positions of two of the supply outlets (14) and the orifice (13), wherein each delivery outlet (14) is located in the orifice (13) As described above, depending on the relative position between the orifice (13) and the supply outlet (14), the second coating component (or a subsequent coating component) can be siphoned off with different siphoning current. Although a relative perpendicular position is shown in the figures and examples of this description, the supply outlet and the orifice can be placed in any relative position so that the siphoning can be efficiently produced.

The system described in the present description can be configured to siphon a third component or a later component. A delivery device of this invention can be configured to have multiple couplings of air intakes (8), multiple connection paths (11) or multiple supply outlets (14), as shown in the representative examples of Figures 2C, 2D, 4, 9A and 9B. Other examples of configurations are shown in Figures 10A to 10H. In another representative configuration, two or more Connection paths may be combined at a point so that the connection paths are connected to a single supply outlet (14), which may be located in the hole (13). An example is shown in Figure 9B.

One or more of the air intake couplings (8) may be configured to be coupled with one or more individual storage containers (4) through a direct coupling, such as a threaded or plug type coupling, or via connection means, such as fixed or flexible pipes. In addition, additional metal parts may be used, such as one or more "Y" shaped connectors. Examples of suitable configurations are shown in Figures 10A-10H: (10A) a delivery device having only one supply outlet / air intake coupling that engages a single container; (10B) a supply device having a single air intake coupling which is coupled to two individual containers; (10C) a supply device having two outlets / couplings of air intakes which couple to two individual containers (shown) or to a single container (not shown); (10D) - (10H) a supply device having multiple outlets and couplings of air intakes in which only some of them are coupled to one or more containers, where the other one (s) take (s) of air can (n) be closed (s). When a supply device has two or more air intake couplings and only one of them is coupled to a container, it is preferred to close the air intake couplings that are not coupled via conventional means, such as a lid, a stopper or a valve. Optionally, one or more regulating devices (32) that control the flow rate, such as a valve, an accessory, a clamp, or a commercial in-line flow controller, may be positioned and configured to control the flow velocity of one. or more components in one or more positions. The regulating device may be selected from a mechanical flow restrictive, an electrical flow restrictive, a pressure controlled flow restrictive or a combination of these. Those skilled in the art will be able to design or modify configurations according to the descriptions set forth herein without departing from the spirit and scope of this invention.

Figure 11 shows an example of another representative configuration. In this example the container (4) can be connected to the upper part of the air intake coupling (8) by means of conventional connections, such as a threaded connection or a plug-type connection. A regulating device (32), such as a valve, can be placed in the path connecting the container (4) and the air intake coupling (8). In one example, the regulating device (32) is a valve having two coupling ends: one coupled to the air intake coupling (8) and the other coupled to the container (4). In another example, the regulating device (32) is a valve incorporated in the container that can be coupled to the air intake coupling (8). In yet another example, the regulating device (32) is a valve incorporated in the air intake coupling (8) that can be coupled to the container (4). The regulating device (32) can be opened or closed manually or by connecting the trigger (22) mechanically or electronically. It is preferred that the regulating device (32) be closed when the atomizing gun is not performing the atomization to prevent leakage of the contents in the container (4) and can be opened to allow the contents of the container (4) to flow towards the supply outlet (14) The storage container (4) containing the second coating component or a subsequent component can be a flexible container, such as a plastic bag; a fixed shaped container, such as a canister made of hard metal or plastic; or a flexible inner container within a fixed forming container, such as a flexible plastic bag placed within a fixed shaped metal container. A flexible container that can be easily disassembled is preferred. He The flexible container can be a removable liner that can be sealed and used directly or placed inside a fixed forming container. The storage container can be transparent or have a transparent window so that the level of contents of the container can be easily seen. The storage container may have an indicator to indicate the level of content in the container. The storage container may be disposable or reusable. The storage container can be coupled to an air intake coupling (8) which is connected to the supply outlet (14) via a connection path (11). The storage container can be coupled to the air intake coupling (8) by conventional means, such as a staple, a clamp, a set of matched screw bearings or a plug-type connector. In one example, the storage container comprises a tube that can be connected to the air intake coupling (8). In another example, the storage container is threaded onto the air intake coupling (8) by means of matched screw bearings. In yet another example, the storage container is connected to the air intake coupling (8) and secured with an additional securing means. The storage container may also have a unidirectional flow restrictor (26) to eliminate the reflux, wherein the unidirectional flow restrictor may allow the content to flow only in one direction, such as only from the container to the delivery outlet. Any reflux can be stopped with the directional flow limiter to avoid potential contamination. For a fixed shaping vessel, ventilation may be provided so that the contents of the vessel are maintained at atmospheric pressure.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (23)

CLAIMS Having described the invention as above, the content of the following claims is claimed as property:

1. In a painting operation, a method for controlling the viscosity of a coating composition, characterized in that the coating composition is a sprayable mixture, the method comprises the steps of: (A) producing a first atomized stream of a first coating component of the coating composition through an orifice of the atomizing gun with a stream of a pressurized carrier, wherein the first coating component is stored in a first container of storage and transported through a first inlet of the atomizing gun to the orifice, and wherein the viscosity of the first coating component remains substantially constant before being transported through the first inlet; (B) producing a second atomized stream of a second coating component of the coating composition, wherein the second atomized stream is produced by siphoning the second coating component with a siphoning current selected from the first atomized stream of the first component of coating, the pressurized carrier stream, or a combination thereof, from at least one supply outlet coupled to a second storage vessel containing the second coating component, and the supply outlet is located in the orifice; (C) optionally, regulating the supply of the second coating component to the supply outlet when coupling a regulating device to the supply outlet; (D) intermixing the first atomized stream and the second atomized stream to form a coating mixture; Y (E) applying the coating mixture on the substrate to form the coating composition layer on the substrate; Y wherein the coating composition comprises protected crosslinkable functional groups.

2. The method according to claim 1, characterized in that in addition the first coating component is a mixture of a crosslinkable component and a crosslinking component.

3. The method according to claim 1, characterized in that in addition the crosslinkable functional groups are selected from the group consisting of amine acetal, orthocarbonate, orthoester, spiro orthoester, orthosilicate, oxazolidine and combinations of these.

4. The method according to claim 3, characterized in that in addition the first coating component comprises crosslinkable components selected from a compound, an oligomer or a polymer with crosslinking functional groups and wherein the crosslinking functional groups are selected from the group consisting of isocyanate, amine, ketiminium, melamine, epoxy, carboxylic acid, anhydride, and a combination of these.

5. The method in accordance with the claim 1, characterized in that in addition the applied coating mixture can be dried and cured in less than 20 minutes at 60 ° C or in less than 90 minutes at room temperature.

6. The method according to claim 1, characterized in that in addition a layer of the coating composition applied over a period of 8 hours provides a dry and cured layer of a coating composition having a constant appearance.

7. The method according to claim 6, characterized in that in addition the dry and cured coating composition layer has short wavescan measurements of less than 40.

8. The method according to claim 1, characterized in that the layer is also a primer layer, a base layer, a pigmented base layer or a gloss layer.

9. The method according to claim 1, characterized in that in addition the second coating component comprises one or more materials selected from a catalyst, an initiator, an activator or a combination thereof.

10. The method according to claim 1, characterized in that in addition the second coating component comprises water or water with acid.

11. The method according to claim 1, characterized in that in addition the second atomized stream is produced by siphoning the second coating component with the first atomized stream.

12. The method according to claim 1, characterized in that in addition the second atomized stream is produced by siphoning the second coating component with the current of the pressurized carrier.

13. The method according to claim 1, characterized in that in addition the second atomized stream is produced by siphoning the second coating component with a combination of the first atomized stream and the pressurized carrier stream.

14. The method according to claim 1, characterized in that the substrate is also a vehicle, the body of a vehicle or parts of the body of a vehicle. .

15. The method according to claim 1, characterized in that in addition the regulating device is selected from a mechanical flow restrictive, an electric flow restrictor, a pressure controlled flow restrictor or a combination of these.

16. The method according to claim 1, characterized in that it further comprises the step of curing the layer of the coating composition on the substrate to form a coating on the substrate.

17. A coating layer characterized in that it is produced by the method according to claim 1.

18. A coated substrate characterized in that produced by the method according to claim 1.

19. In a painting operation, a method for controlling the viscosity of a coating composition, characterized in that the coating composition is a sprayable mixture, the method comprises the steps of: (A) producing a first atomized stream of a first coating component of the coating composition through an orifice of the atomizing gun with a stream of a pressurized carrier, wherein the first coating component is stored in a first container of storage and is transported through of a first inlet of the atomizing gun to the orifice and wherein the viscosity of the first coating component remains substantially constant before being transported through the first inlet; (B) producing a second atomized stream of a second coating component of the coating composition, wherein the second atomized stream is produced by siphoning the coating component with a siphoning current selected from the first atomized stream of the first component of coating, the pressurized carrier stream, or a combination thereof, from at least a first supply outlet of a supply device coupled to a second storage vessel containing the second component, and the first supply outlet is located in the hole; (C) optionally, regulating the supply of the second coating component to the first supply outlet when coupling a first regulating device to the first supply outlet; (D) producing a subsequent atomized stream of a subsequent component of the coating composition, wherein the subsequent atomized stream is produced by siphoning the subsequent coating component with the siphoning current from at least one subsequent supply outlet coupled to a container of subsequent storage containing the rear component, and the subsequent supply outlet is located in the hole; (E) optionally, regulating the supply of the aftercoating component to the subsequent supply outlet when coupling a subsequent regulating device at the subsequent supply outlet; (F) intermixing the first atomized stream, the second atomized stream and the rear atomized stream to form a coating mixture; Y (G) applying the coating mixture on the substrate to form a layer of the coating composition thereon; Y wherein the coating composition comprises protected crosslinkable functional groups.

20. The method in accordance with the claim 19, characterized in that in addition the first coating component is a mixture of a crosslinkable component and a crosslinking component.

21. The method in accordance with the claim 19, characterized in that in addition the crosslinkable functional groups are selected from the group consisting of acetalamine, orthocarbonate, orthoester, spiro orthoester, orthosilicate, oxazolidine and combinations thereof.

22. The method in accordance with the claim 19, characterized in that in addition the second coating component comprises one or more materials selected from a catalyst, an initiator, an activator or a combination thereof.

23. The method in accordance with the claim 19, characterized in that in addition the subsequent coating component comprises water or water with acid.