JP2002256224A - Gelcoat forming aqueous paint and method of its coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide gelcoat forming aqueous paint stable for washing away by rain right after coating, at a low temperature or raining at a low temperature, and method of its coating. SOLUTION: This method of forming the gelcoat uses an aqueous paint including an emulsion of an anionic synthetic resin including carboxyl group, a polymer including amine functional group, a volatile base and at least a kind of an alkaline imparting agent liquid or solid at normal temperature and comprises (1) a process coating the gelcoat forming aqueous paint in a state free from gel, (2) a process evaporating the volatile base of the gelcoat forming aqueous paint and forming the gelcoat and carrying out a cross linking reaction of the carboxyl group in the synthetic resin emulsion and the amine group in the polymer including amine group, (3) a process concentrating and coagulating components of the aqueous paint caused to evaporation of water in the aqueous paint from the gelcoat, (4) a process forming a dried coated film by carrying out a coagulation of the particles of the synthetic resin emulsion in the aqueous paint component involving other particles.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water-based paint used mainly for finishing an outer wall, a roof or a roof of a structure such as a building. The present invention relates to a film-forming water-based paint.

[0002]

2. Description of the Related Art Conventionally, many water-based paints mainly contain a synthetic resin emulsion. This water-based paint
Since water is used as the dispersion medium, it is easier to handle as a paint than solvent paints and has less influence on the working environment of painting work. . However, since this water-based paint uses water as a dispersion medium, it has a drawback that it takes a long time from completion of coating to obtaining a dried coating film.

For this reason, many quick-drying water-based paints have been proposed. One example is to increase the total solid content of the water-based paint and to reduce water-soluble components such as surfactants and thickeners as much as possible.
A method is known in which a large amount of a low-boiling alcohol such as methanol is contained to speed up drying. However, according to this method, the quick-drying property cannot be sufficiently increased, and the performance such as coating workability and storage stability tends to be impaired. Further, when low-boiling alcohols such as methanol are added in an amount until the quick-drying effect is exhibited, the effect on the working environment of the coating operation, which is a characteristic of the water-based paint, may be large. .

Another example is disclosed in Japanese Patent Application Laid-Open No. 9-3241.
No. 45 or JP-A-11-100552. JP-A-9-324
No. 145 discloses a coating composition comprising an anionic synthetic resin emulsion, a polymer formed from a monomer mixture containing at least 20% by weight of an amine functional group-containing monomer, wherein essentially all of the polyfunctional amine is nonionic. It contains a volatile base, an anionic pigment dispersant neutralized with a volatile base compound and a pigment sufficient to raise the pH of the composition to a point where it is in a state where PVC (pigment volume concentration) is 30%. The total solid concentration is 40 to 80% by weight.

[0005] Further, the coating composition disclosed in Japanese Patent Application Laid-Open No. H11-100552 is an anionic synthetic resin emulsion, which is composed of water 10 which is a monomer other than the anionic monomer among the monomers constituting the emulsion.
A polymer formed from a synthetic resin emulsion having a solubility in 0 g of 0.01 to 1.50 g, a monomer mixture containing at least 20% by weight of an amine functional group-containing monomer, is prepared by adding an amine functional group to a carboxyl equivalent. An equivalent ratio of 5 to 80%, a sufficient amount of a volatile base to raise the pH of the composition to a point where essentially all of the polyfunctional amine is in a nonionic state;
The epoxy resin has an epoxy group number of 5 to 500% with respect to the number obtained by subtracting the equivalent number of the amine functional group contained from the equivalent number of the carboxyl group contained in the above.

[0006] In these disclosed coating compositions, the pH of the coating composition is lowered by evaporation of volatile components of a volatile base containing ammonia or the like as a main component after application, whereby a quick drying property can be obtained. is there. This fast-drying property is that when the pH of the composition drops to the point where the amine function in the coating composition begins to convert from an anion to a cation, the amine function becomes cationic and is stabilized to anionic. This is caused by its action in synthetic resin emulsions.

[0007]

However, since the water-based paint uses water as a dispersion medium, the water evaporates to form a coating film. Therefore, the amount of heat required for the water to evaporate is required. Becomes Further, a quick drying property can be obtained by the coating composition disclosed in JP-A-9-324145 or JP-A-11-100552.
Until a coating film is obtained, a certain amount of heat is required.

[0008] For this reason, rainfall immediately after coating may cause the coating composition to flow because it is not dried. Also, when the temperature of the atmosphere at the time of performing the coating is low, it may take time to obtain the coating film. Of the coating composition may flow.

The present invention has been made by focusing on the problems existing in the prior art as described above. The purpose is to evaporate the volatile base of the water-based paint immediately after coating, form a gelled film, and cause a cross-linking reaction between the carboxyl group of the synthetic resin emulsion and the amine functional group of the amine functional group-containing polymer. An object of the present invention is to provide a gelled film-forming water-based paint which does not flow even when there is rain immediately after painting, low temperature or rain at low temperature by forming a gelled film, and a method of applying the same. .

[0010]

In order to achieve the above object, a water-based coating composition for forming a gelled film according to the present invention according to claim 1 comprises an emulsion of an anionic synthetic resin containing a carboxyl group and a polymer containing an amine functional group. And a volatile base,
A water-based paint containing at least one or more liquid or solid alkali-imparting agents at room temperature, comprising:
Through the step (4), a coating film is formed.
(1) A step of applying a gelled film-forming aqueous paint in an ungelled state to an object to be coated (2) A volatile base of the applied gelled film-forming aqueous paint evaporates to form a gelled film and synthesize Step (3) in which the carboxyl group of the resin emulsion and the amine functional group of the amine functional group-containing polymer undergo a cross-linking reaction.
Step (4) of aggregating the particles of the synthetic resin emulsion blended in the water-based paint component and fusing while involving other particles,
Step of forming a dry coating

The gelled film-forming aqueous coating composition according to the second aspect of the present invention is characterized in that, in the first aspect of the invention, the amount of the amine functional group-containing polymer and / or the amount of the volatile base is increased or decreased to form a gel. The start time is adjusted.

The gelled film-forming aqueous coating composition according to the third aspect of the present invention is characterized in that, in the first aspect, the pH of the aqueous coating composition is changed by increasing or decreasing the alkali-providing agent to start gelation. It adjusts the time.

According to a fourth aspect of the present invention, there is provided a method for coating a gelled film-forming aqueous paint according to any one of the first to third aspects, wherein the gelled film-forming aqueous paint according to any one of the first to third aspects is applied to an object to be coated. After forming the gelatinized film, the above-mentioned gelled film-forming aqueous paint is further applied.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. The gelled film-forming aqueous coating composition contains an anionic synthetic resin emulsion containing a carboxyl group, an amine functional group-containing polymer, a volatile base, and at least one liquid or solid alkali-imparting agent at room temperature.
A water-based paint containing a coating film through the following steps (1) to (4). (1) A step of applying the gelled film-forming aqueous paint in an ungelled state to an object to be coated (2) The volatile base of the applied gelled film-forming aqueous paint evaporates to form a gelled film and to synthesize Step of crosslinking reaction between the carboxyl group of the resin emulsion and the amine functional group of the amine functional group-containing polymer (3) Step of evaporating water in the coating film from the gelled film to concentrate and coagulate water-based paint components (4) Water-based A process in which particles of a synthetic resin emulsion blended in a paint component are fused while entraining other particles to form a dry coating film

First, an anionic synthetic resin emulsion is a main component of a gelled film-forming water-based paint. This synthetic resin emulsion can be produced by a conventional polymerization technique such as emulsion polymerization, and may be a general one containing a carboxyl group in a polymer constituting the synthetic resin, and is anionically stable. . An anionic stable synthetic resin emulsion is necessary for the gelling action of a gelled film-forming aqueous paint.

The carboxyl group undergoes a cross-linking reaction with an amine functional group of an amine functional group-containing polymer described later to improve the strength of the gelled film formed by the gelled film-forming water-based paint, and to further dry the gelled film. It can improve the strength and weather resistance of the coating film.

The synthetic resin emulsion includes an acrylic resin, a silicone resin, a styrene resin, a urethane resin,
Examples include a synthetic resin emulsion manufactured from a resin such as a fluororesin. Among them, an acrylic synthetic resin emulsion and an acrylic styrene synthetic resin emulsion produced from an acrylic resin and a styrene resin are preferable from the viewpoints of paint suitability, physical properties of a coating film, and availability. It can be appropriately selected according to the use and performance of the gelled film-forming aqueous coating material.

It is also possible to use a mixture of an acrylic synthetic resin emulsion or an acrylic styrene synthetic resin emulsion with a synthetic resin emulsion made of a silicone resin, a urethane resin or a fluororesin. The silicone resin, urethane resin or
Fluororesin, acrylic synthetic resin emulsion or
Compared with acrylic styrene synthetic resin emulsion,
Although a coating film having excellent durability such as weather resistance can be obtained, it is costly, may be difficult to obtain, and may not be used in large quantities. Therefore, it can be used by mixing with an acrylic synthetic resin emulsion or an acrylic styrene synthetic resin emulsion.

This makes it possible to easily improve the durability of the acrylic synthetic resin emulsion or the acrylic styrene synthetic resin emulsion such as weather resistance.

The acrylic synthetic resin emulsion includes methyl (meth) acrylate, ethyl (meth) acrylate,
It comprises a (co) polymer produced from monomers such as butyl (meth) acrylate, 2-ethylhexyl acrylate and decyl acrylate. Further, the present invention can be carried out even when the polymer structure of the synthetic resin emulsion has a complicated structure, for example, core-shell particles.

The glass transition temperature of the resin used in the synthetic resin emulsion is preferably in the range of -50 to 70 ° C., but a synthetic resin having a suitable glass transition temperature is selected according to the use of the aqueous coating composition. be able to.

The amine functional group-containing polymer is one of the main components for forming a gelling film together with the anionic synthetic resin emulsion after applying the gelling film forming aqueous paint. In other words, the amine functional group-containing polymer is used. By having the amine functional group contained in the contained polymer as a constituent element, a cross-linking reaction occurs with the carboxyl group contained in the synthetic resin emulsion.

The amine functional group-containing polymer is a polymer formed from a monomer mixture containing 20 to 80% by weight of at least one amine functional group-containing monomer among primary amine, secondary amine and tertiary amine. Yes, as is generally known in the art, it can be obtained by solution polymerization in neutral, alkaline, or acidic aqueous media, depending on the particular polymer sought. As the amine functional group-containing polymer, a water-soluble or water-dispersible polymer is preferably used from the viewpoint of miscibility with a synthetic resin emulsion.

The content of the amine functional group-containing polymer is in the range of 0.1 to 20.0% by weight based on the total weight of the compatible resin emulsion and the amine functional group-containing polymer. If the amount is less than this, the gelling property of the gelled film-forming aqueous coating composition may be reduced, or the crosslinking reaction with the carboxyl group contained in the synthetic resin emulsion may not be sufficient. Conversely, when the amount is large, the stability of the gelled film-forming aqueous coating composition may be impaired or the workability may be reduced.

Further, by adjusting the content of the amine functional group-containing polymer within the above range, the gelling time of the aqueous coating material for forming a gelled film can be adjusted. In other words, if the gelation is to be accelerated, the upper limit of the range is set to a value close to the upper limit or lower, and if the gelation is to be slowed, the setting is set to the lower limit of the range or a value closer to the lower limit or more. It is to be.

The case where the gelation is desired to be accelerated includes a case where the coating atmosphere is low and / or a case where the humidity is high such as when rain is likely to occur. Conversely, when the gelation is desired to be slowed down, The case where the coating atmosphere is high temperature and / or the case where the coating atmosphere is dry and the humidity is low are exemplified. Furthermore, when the amine functional group-containing polymer is not contained in the gelled film-forming aqueous coating, the gelled film-forming aqueous coating can be used as a commonly used aqueous coating.

The volatile base and the alkali imparting agent which is liquid or solid at room temperature can be used to form a gelled film-forming aqueous paint at pH 7.0 to pH 7.0.
By stabilizing in the range of 10.0, the amine functional group of the amine functional group-containing polymer contained in the gelled film-forming aqueous coating material becomes a nonionic or anionic state,
It is capable of stably storing a gelled film-forming aqueous paint.

After the application of the gelled film-forming aqueous coating material, the volatile base of the volatile base starts to evaporate,
It is used to lower the pH of the gelled film-forming aqueous coating material. By this action, the pH of the gelled film-forming aqueous coating material is reduced to a point where the conversion of the nonionic or anionic amine functional group to the cationic state starts to occur. As the amine functionality decreases, the amine functionality becomes cationic. The gelation of the gelled film-forming aqueous paint is initiated by the conversion of such amine functional groups to cationic.

It is necessary that the content of the volatile base is within a range that does not impair the stability due to the action of components such as a synthetic resin emulsion and a dispersant in the gelled film-forming aqueous paint. The content of the volatile base is preferably in the range of 0.01 to 0.50% by weight based on the total weight of the compatible resin emulsion and the amine functional group-containing polymer.

When the amount of the volatile base is too large, the gelation is slowed. On the other hand, when the amount is too small, not only the storage stability is deteriorated but also the gelation is too fast, which affects the workability. give. As described above, since the amount of the volatile base has a large effect on the gelled film-forming water-based paint, the optimum amount is determined by experiments and the like because it varies depending on the other components of the gelled film-formed water-based paint. It is necessary.

Further, by adjusting the content of the volatile base, the gelation time of the gelled film-forming aqueous coating composition can be adjusted. If the gelation is to be performed slowly, the upper limit of the range is set to a value close to the upper limit or lower, and if the gelation is to be performed faster, the lower limit of the range is set to a value close to the lower limit or more. Is to set. That is, when it is desired to perform gelation at a later time, it is necessary to increase the content of the volatile base and to delay lowering the pH of the gelled film-forming water-based paint.

When it is desired to perform gelation at a high speed, it is necessary to lower the pH of the water-based paint for forming a gelled film so as to increase the pH. Thus, the time during which the pH is lowered until the point at which the conversion of the amine function in the nonionic or anionic state to the cationic state begins to occur can be adjusted. Suitable examples of the volatile base include ammonia, methylamine, ethylamine, propylamine, isopropylamine, dimethylamine, trimethylamine, and the like, and have a low boiling point of −33.4 ° C. and fast evaporation of ammonia or ammonia. Those used as components are preferably used.

Further, by using ammonia or a material containing ammonia as a main component, evaporation at a low temperature is possible, so that a gelled film at a low temperature of 5 ° C. or less can be formed. Since ammonia evaporates quickly, the applied gelled film-forming aqueous coating material can quickly lower the pH, but may emit odor with the evaporation.

Therefore, in addition to ammonia or a volatile base containing ammonia as a main component, a liquid or solid alkali-imparting agent is used in combination at room temperature. These alkali imparting agents have less pungent odor and have a higher boiling point than the volatile base. The applied gelled film-forming water-based paint reduces the amount of odor due to evaporation, and can provide a gelled film-forming water-based paint that rapidly gels.

In addition, the gelation start time is adjusted by changing the pH in the water-based paint by increasing or decreasing the amount of the alkali imparting agent. If you want to slow down the gelation,
When it is desired to add a large amount of the alkali imparting agent and to rapidly perform gelation, the gelation can be performed by adding a small amount of the alkali imparting agent. In other words, when it is desired to perform gelation slowly, it is necessary to increase the amount of the alkali-imparting agent added and to delay lowering the pH of the gelled film-forming water-based paint. In other words, the lowering of the pH of the gelled film-forming water-based paint is faster. Thus, the time during which the pH is lowered until the point at which the conversion of the amine function in the nonionic or anionic state to the cationic state begins to occur can be adjusted.

The alkali or liquid alkali at room temperature includes amines and alkali metal salts. For amines, morpholine, 2-dimethylaminoethanol, N
-Methylmorpholine, ethylenediamine, 2-amino-2-methyl-1-propanol and the like, and alkali metal salts such as sodium hydroxide and potassium hydroxide.

Among these alkalis of amines and alkali metal salts, alkalis of amines having excellent water resistance are preferable, and 2-amino-2-methyl-1 is more preferable.
-Propanol is more preferably used. 2-amino-2-methyl-1-propanol makes the dried coating film formed by the gelled film-forming aqueous coating material excellent in water resistance.

[0038] The gelled film-forming aqueous coating composition may contain a pigment. Examples of the pigment include titanium oxide and clay as white pigments, and iron oxide and known organic pigments can be used as coloring pigments. There is no problem in using titanium oxide alone or in combination with other inorganic or organic pigments.

The amount of the pigment to be added is preferably in the range of 5% to 70%, more preferably in the range of 5% to 55%, for the pigment volume concentration (PVC) of the aqueous gelled film-forming paint. The range may be selected according to the use of the gelled film-forming aqueous paint. If it is less than 5%, the opacity of the dried coating film of the gelled film-forming water-based paint will be reduced, and if it is more than 70%, the gloss of the coating film will be easily impaired. When the dried coating film of the gelled film-forming aqueous coating material is glossy, the pigment volume concentration is particularly preferably in the range of 5 to 30%.

The gelled film-forming aqueous coating composition of the present invention comprises, as other components other than the above, a surfactant used as a dispersant or wetting agent for dispersing the pigment, a low-boiling alcohol, a film-forming auxiliary, and an antifreezing agent. Ingredients commonly used in the production of paints, such as high-boiling solvents, thickeners, viscosity modifiers, defoamers, preservatives, fungicides, and alga-proofing agents, which are used as the above, can also be used. In addition, calcium carbonate, silica sand, fibers and the like can be contained as a filler.

Next, the formation of a gelled film and a dried coating film of the gelled film-forming aqueous paint will be described. First, the gelled film-forming water-based paint in an ungelled state is applied to an object to be coated. This application method is not particularly limited, and spray,
The coating can be performed using a general coating device such as a coating roller and a brush.

In the non-gel coating film formed by the applied gelled film forming aqueous coating material in the non-gel state, the volatile base in the non-gel coating film evaporates and a gel film is formed. The gelled film is formed by evaporating the volatile base of the ungelled coating film formed by the gelled film-forming water-based coating, and thus the p
It occurs when H goes down.

The nonionic or anionic stable amine functional groups in the ungelled coating form the aqueous coating composition until the volatile base of the ungelled coating evaporates and the amine functional groups begin to convert to the cationic state. As the pH of the object drops, the amine functionality becomes cationic. The amine functional group that has become cationic electrically attracts the anionic synthetic resin, and the ungelled coating film becomes unstable, forming a gelled film.

In this electrically attracted gelled film, the distance between the polymer of the amine functional group-containing polymer and the polymer of the anionic synthetic resin emulsion is shorter. The carboxyl group of the polymer of the anionic synthetic resin and the amine functional group of the amine functional group-containing polymer containing the amine functional group that has become cationic are ionically bonded to initiate a crosslinking reaction, and the crosslinked gelled coating film is formed. Form.

In the formed crosslinked gelled film, the water in the gelled film evaporates, and the paint components are concentrated and aggregated. Then, the particles of the synthetic resin emulsion in the paint component fuse with other particles to form a dry coating film. When coating with a gel-forming film-forming paint such as this gel-forming film-forming water-based paint, even if the coating film is not completely dried, it can be rained immediately after coating, at low or low temperatures. It does not flow even when there is rainfall or the like, and then gradually forms a dry coating film.

Normally, painting work at 5 ° C. or less is not generally performed. The reason is that after applying the water-based paint, a dried coating film cannot be obtained by the water-based paint, and the undried coating film flows due to rainfall or the like. However, the gelled film-forming water-based paint described in the present invention can form a gelled film without obtaining a dry coating film at a low temperature such as 5 ° C. or lower. But it can do painting work.

It is also possible to apply a gelling film-forming aqueous paint again on the gelling film to form a gelling film. That is, two-layered gelled film is formed and dried at one time. By doing so, the coating interval time can be shortened, and the efficiency of the coating work can be increased.

As described above, according to this embodiment, the following effects are exhibited. A carboxyl group-containing anionic synthetic resin emulsion, an amine functional group-containing polymer, a volatile base,
A water-based paint containing at least one or more liquid or solid alkali-imparting agents at room temperature, comprising:
Through the step (4), a coating film is formed.
(1) A step of applying a gelled film-forming aqueous paint in an ungelled state to an object to be coated (2) A volatile base of the applied gelled film-forming aqueous paint evaporates to form a gelled film and synthesize Step (3) in which the carboxyl group of the resin emulsion and the amine functional group of the amine functional group-containing polymer undergo a cross-linking reaction.
Step (4) of aggregating the particles of the synthetic resin emulsion blended in the water-based paint component and fusing while involving other particles,
Step of forming a dry coating film. As a result, even if there is rain immediately after painting, rain at a low temperature or at a low temperature, the water does not flow.

The gelation start time is adjusted by increasing or decreasing the amount of the amine functional group-containing polymer and / or the amount of the volatile base, so that the coating atmosphere is low and / or rain is likely to occur. If you want to perform gelation quickly, such as when the humidity is high such as when the temperature is high, or if the coating atmosphere is high and / or if the coating atmosphere is dry and the humidity is low, such as when the gelling time is low, you can make adjustments. You can do it.

When the gelation start time is adjusted by changing the pH in the water-based paint by increasing or decreasing the alkali-providing agent, if the gelation is to be performed slowly, If you want to increase the amount of added, delay the lowering of the pH of the gelled film-forming aqueous paint, and perform gelation faster,
Lowering is what makes it faster.

Applying the gelled film-forming aqueous paint to the object to be coated, forming a gelled film, and further applying the gelled film-formed aqueous paint to shorten the coating interval time, This can improve the efficiency of painting work.

When the amine functional group-containing polymer is a water-soluble or water-dispersible polymer, it has good miscibility with a synthetic resin emulsion.

The gelling property is reduced by the content of the amine functional group-containing polymer being in the range of 0.1 to 20.0% by weight based on the total weight of the compatible resin emulsion and the amine functional group-containing polymer. The crosslinking reaction with the carboxyl group is sufficient and the stability of the gelled film-forming aqueous coating composition is not impaired, and the workability is not reduced.

When the content of the volatile base is in the range of 0.01 to 0.50% by weight with respect to the total weight of the compatible resin emulsion and the polymer having an amine functional group, gelation may be delayed. No storage stability and workability.

The volatile base has a low boiling point due to the fact that ammonia or ammonia is the main component,
Because of rapid evaporation, the applied gelled film-forming water-based paint
Since the pH can be rapidly lowered and the evaporation at a low temperature is possible, a gelled film can be formed at a low temperature of 5 ° C. or lower.

When the alkali or liquid imparting agent at room temperature is an amine, the water resistance of the dried coating film formed by the gelled film-forming aqueous coating material becomes excellent. Hereinafter, examples that embody the above embodiment will be described in detail.

[0057]

EXAMPLE In this example, an acrylic synthetic resin emulsion was used as the anionic synthetic resin emulsion containing a carboxyl group. The synthetic resin emulsion had a glass transition temperature of 20 ° C. and a solid content of 50% by weight. A water-dispersible polymer formed from a monomer mixture containing 50% by weight of an amine functional group-containing monomer was used as the amine functional group-containing polymer, and ammonia was used as the volatile base. Further, a 2-amino-2-methyl-1-propanol-based alkali-imparting agent was used as a liquid or solid alkali-imparting agent at room temperature.

Also, titanium oxide was used as a white pigment. Further, a surfactant was used as a dispersant and a wetting agent for dispersing the pigment. Further, a high-boiling solvent, a thickener, and an antifoaming agent used as a film-forming aid and an antifreezing agent were added. Table 1 below shows examples of the gelled film-forming aqueous coating compositions of Examples 1 to 7. Table 2 shows Comparative Examples 1 to 5.
9 shows the formulation of a water-based paint of Comparative Example 4.

Incidentally, dispersants, wetting agents, film-forming auxiliaries, antifreezing agents,
Thickeners and defoamers are collectively shown as other components.

[Table 1]
(Unit: g)

[Table 2]
(Unit: g)

Table 3 shows the coating properties of the aqueous gelled film coatings of Examples 1 to 7 and the aqueous coatings of Comparative Examples 1 to 4.
Shown in However, the water-based paint of Comparative Example 2 gelled during the process of manufacturing the paint and could not be obtained. The pigment volume concentration and solid content were all the same. The unit of viscosity is poise.

[Table 3]

First, a method for testing the gelling properties of the aqueous coating materials for forming gelled films of Examples 1 to 7 and the aqueous coating materials of Comparative Examples 1, 3 and 4 at a low temperature will be described.
0 ° C.
The temperature is kept constant for 24 hours or more in a thermo-hygrostat kept at 85% RH (relative humidity). The instruments used are a glass plate and an applicator for applying paint. This applicator has a coating thickness of 150μ.
m.

When these reached a certain temperature, each paint was applied to a glass plate using an applicator to obtain three test specimens for each paint. Coating thickness is 150μ
m. Immediately after application, the weight of the test specimen is measured. Then, it is left still for a certain period of time in a thermo-hygrostat at 0 ° C. and 85% RH. After standing, the weight of the test specimen is measured and immediately exposed to running water flowing from a tap for one minute to check whether the paint is flowing.

In this test, the fixed time was set to 20 minutes, 40 minutes.
Minutes and 60 minutes were set. In addition, by weighing the weight at the time of preparing the test body and the weight before the start of the test, and calculating the difference between them, the dry state of each paint can be estimated.

Table 4 shows the results of the gelation test. The time is the standing time, and the unit is minutes. Also,
The weight difference is obtained by subtracting the weight before the start of the test from the weight at the time of preparing the test body, and the unit is g. The presence or absence of the coating is that, after exposure to running water, the coating does not flow and the coating is present, and those that have all flowed are x, those that have remained about half, △, all remaining ones are indicated by ○.

[0065]

[Table 4] From the test results in this low temperature state, Examples 1 to 7,
The weight changes of the paints of Comparative Examples 1, 3 and 4 are as follows:
It can be seen that there is almost no water in the paint, and the paint does not form a dried coating film.

As for the gelling property at a low temperature, the water-based paint of Comparative Example 1 did not contain a polymer having an amine functional group, and thus did not form a gelled film. For this reason, the undried or ungelled coating film flows when exposed to running water. In addition, in the water-based paint of Comparative Example 4, the amount of the alkali-imparting agent was large, and the evaporation rate was not fast as in the case of the volatile base. , Has been washed away by running water.

Further, the aqueous gelled film-forming paints of Examples 1 to 7 and Comparative Example 3 did not flow by flowing water because they gelled even at a low temperature of 0 ° C. Furthermore, in a test in a low temperature state, when the standing time is 60 minutes, the coating film does not flow after exposure to running water, and the presence of a gelled coating film is checked at 35 ° C. and 60% RH.
The coating workability was compared using a spray gun at a high temperature (relative humidity).

The aqueous gelling film-forming coating compositions of Examples 1 to 7 had the same workability as those of commercially available aqueous coating compositions, and also had good finishes. However, the gelled film-forming aqueous coating material of Comparative Example 3 had a low content of volatile base and did not contain an alkali-imparting agent, so that the gelation was faster than that of Example. Therefore, the paint sprayed from the spray gun gels before being applied to the object to be coated, and the workability is difficult, and the finish is not good.

From these test results, Examples 1 to 7 were obtained.
The gelled film-forming coating material was well-balanced and excellent in gelling property in a low temperature state and workability in a high temperature state.

Further, from the results in Table 4, it can be seen that by changing the content of the amine functional group-containing polymer, the volatile base, and the alkali-imparting agent, the gelling property of the gelled film-forming aqueous paint can be adjusted. I understand.

Next, the technical ideas that can be grasped from the above embodiment will be described below. The content of the amine functional group-containing polymer is in the range of 0.1 to 20.0% by weight based on the total weight of the compatible resin emulsion and the amine functional group-containing polymer. Item 4. A gelled film-forming aqueous coating according to any one of Items 3. Due to this, there is no decrease in gelling property, the crosslinking reaction with the carboxyl group is sufficient, and the stability of the gelled film-forming water-based paint is not impaired,
The workability is not reduced.

The content of the volatile base is in the range of 0.01 to 0.50% by weight based on the total weight of the compatible resin emulsion and the amine functional group-containing polymer. The gelled film-forming aqueous coating composition according to claim 3. As a result, the gelation is not delayed, and the storage stability and workability are good.

[0073]

The present invention is configured as described above, and has the following effects. According to the gelled film-forming aqueous paint of the invention according to claim 1, rainfall immediately after painting,
It does not flow even when there is low temperature or rain at low temperature.

According to the aqueous gelled film-forming paint of the second aspect of the present invention, in addition to the effects of the first aspect of the present invention, in addition to the effects of the first aspect of the present invention, when the coating atmosphere is low temperature and / or when rainfall is likely to occur, It can be adjusted when gelation is to be performed quickly, such as when the temperature is high, or when the coating atmosphere is high and / or when the coating atmosphere is dry and the humidity is low, such as when the gelation is desired to be performed slowly. .

According to the gelled film-forming aqueous coating composition of the third aspect of the invention, in addition to the effect of the first aspect, the gelation is delayed by adjusting the gelation start time. If it is desired to increase the amount of the alkali-imparting agent added, to delay the lowering of the pH of the gelled film-forming aqueous paint, and to increase the gelation speed, the pH of the gelled film-forming aqueous paint is increased. Lowering is what makes it faster.

According to the method for coating a gelled film-forming water-based coating material of the invention according to the fourth aspect, the coating interval time can be shortened and the efficiency of the coating work can be improved.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 201/02 C09D 201/02 F-term (Reference) 4D075 BB96X CA38 DC02 EB20 EB45 EC07 EC54 4J038 CC021 CD091 CG141 CH031 CH041 CR072 DG031 DL031 HA176 JB03 JB08 JB09 MA13 NA27

Claims (4)

[Claims] 1. An aqueous coating composition comprising a carboxyl group-containing anionic synthetic resin emulsion, an amine functional group-containing polymer, a volatile base, and at least one liquid or solid alkali-imparting agent at room temperature. A gelled film-forming aqueous coating material, which forms a coating film through the following steps (1) to (4). (1) A step of applying the gelled film-forming aqueous paint in an ungelled state to an object to be coated (2) The volatile base of the applied gelled film-forming aqueous paint evaporates to form a gelled film and to synthesize A step of causing a cross-linking reaction between the carboxyl group of the resin emulsion and the amine functional group of the amine functional group-containing polymer (3) a step of evaporating water in the coating film from the gelled film and concentrating and aggregating the aqueous coating component (4) aqueous A process in which particles of a synthetic resin emulsion blended in a paint component are fused while entraining other particles to form a dry coating film 2. The amount of the amine functional group-containing polymer and / or
The gelled film-forming aqueous coating according to claim 1, wherein the gelation start time is adjusted by increasing or decreasing the amount of volatile base. 3. The gelled film-forming aqueous paint according to claim 1, wherein the gelation start time is adjusted by changing the pH in the aqueous paint by increasing or decreasing the alkali-providing agent. 4. After the gelled film-forming aqueous paint according to claim 1 is applied to a substrate to form a gelled film, the gelled film-formed aqueous paint is further applied. A method for applying a water-based paint for forming a gelled film, characterized by applying a paint.