JP2012233155A - Coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition superior in heat retentivity or thermal insulation ability, and easy to coat thick.SOLUTION: The coating composition comprises: beads of inorganic microballoons; an emulsion structure-retaining material to the beads; and a thickening agent. In this coating composition, the beads' content is 1.5-3.5 in mass ratio based on the emulsion structure-retaining material. This coating composition, because of stably bonding/holding the beads of inorganic microballoons by the emulsion structure-retaining material and the thickening agent, can form a thick coating film, and the thus formed coating film can exhibit excellent heat retentivity or thermal insulation ability inherent in the beads of inorganic microballoons as well.

Description

  The present invention relates to a coating composition that is excellent in heat retaining properties and heat insulation properties and is easy to apply with a large film thickness.

  2. Description of the Related Art Conventionally, in order to efficiently control temperature changes inside buildings and various pipes, it has been widely practiced to cover an object with a heat insulating material or a heat insulating material. In recent years, the development of coating materials with heat insulation and heat insulation has progressed, and instead of regular heat insulation materials or heat insulation materials, these heat insulation materials and insulation materials can be applied to heat insulation or insulation objects. Has been done.

  In order to give heat insulation and heat insulation properties to the coating material, it is necessary to lower the thermal conductivity of the entire coating material to be applied. One method is to include a material with low thermal conductivity in it. Can be mentioned.

  Since gas has a low molecular density, it can function as a material having low thermal conductivity. However, since it causes convection, it functions as a medium for transferring heat as it is. Therefore, resin emulsions in which hollow particles (hereinafter also referred to as “beads”) are kneaded are used in coating materials in order to lower the thermal conductivity and increase the heat retaining property and heat insulating property.

  For example, the following Patent Document 1 discloses a transparent or semi-transparent silicon boride ceramic bubble and a bubble having a small particle size in a gap between the bubble having a large particle size that expresses structural viscosity and has a large viscosity. A solvent-based heat-shielding coating material used for reflecting and radiating the thermal energy of sunlight, comprising a structure-retaining agent that is densely layered and arranged so as to enter, and a film-forming material. 1 to 3% by weight of any one or more of oxidized polyethylene wax and organic bentonite, and 1 to 3% by weight of silica particles having a particle size of 0.5 to 100 μm to the whole paint As a component, the bubble has a particle size of 5 to 150 μm and has a wide range of large and small particle sizes, and the bubble content is 30 to 6 in volume ratio to the entire coating film. A thermal barrier coating having a value of 0% is disclosed.

  Patent Document 2 listed below is a heat insulating coating material containing a resin emulsion (A), hollow beads (B) having an average particle diameter of 1 to 300 μm, and a thickener (C), which are hollow beads (B). The blending amount is 20 to 98% by volume in the heat insulating coating material solid content, the blending amount of the thickener (C) is 0.01 to 5% by weight in the heat insulating coating material solid content, and the viscosity is 2 to 100 Pa · s. An insulating coating material is disclosed.

Japanese Patent No. 3794824 International Publication WO2002 / 83326 Pamphlet

  However, when these beads are blended in water, a solvent or a paint solution, they may float on the surface rapidly due to their buoyancy and fall into a separated state. In such a state, in order to re-disperse the beads in water, solvent or paint solution, it is necessary to stir again to disperse the beads. In addition, when a large amount of beads are dispersed in the coating solution, there is a tendency that cracks are likely to occur after the coating solution is cured.

  Further, in order to improve the heat insulating property or heat retaining property of the paint, it is effective to increase the content of beads in the paint. However, when the bead content in the coating solution increases, it becomes difficult to uniformly disperse the beads, and it is difficult to simply increase the concentration of the beads in the coating solution. In order to improve the heat retaining property or heat insulation of the entire coating surface, it is effective to increase the coating thickness of the coating. However, it is difficult to apply the conventional coating solution thickly. Even if it can be applied thickly, it is difficult to ensure the desired heat retaining properties or heat insulation properties due to separation of beads on the surface side during drying and a state called a hard cake or cracks. Met.

  In particular, beads made of inorganic hollow particles such as ceramics have a low thermal conductivity, so that it is widely known that a paint excellent in heat retention or heat insulation can be obtained by kneading into a paint solution. However, a coating solution containing a high concentration of beads made of inorganic hollow particles is very susceptible to hard cake when thickly applied, and it cannot achieve heat retention or heat insulation depending on the coating thickness. There were challenges.

  The inventors of the present invention have made extensive studies in order to obtain a coating composition containing a high concentration of beads composed of inorganic hollow particles such as ceramics. As a result, it is not a system in which beads made of inorganic hollow particles as a dispersoid are dispersed in an emulsion as a dispersion medium like conventional coating solutions, but beads made of inorganic hollow particles are joined by emulsion. The present inventors have found that the problem can be solved by using a retained system, and have completed the present invention.

  That is, an object of the present invention is to provide a coating composition that is excellent in heat retaining properties and heat insulating properties and that hardly cracks even when applied thickly.

  In order to achieve the above object, the coating composition of the present invention is a coating composition containing beads composed of inorganic hollow particles, an emulsion structure holding material for the beads, and a thickener, which contains the beads. The amount is 1.5 to 3.5 in terms of mass ratio with respect to the emulsion structure holding material.

  According to the coating composition of the present invention, the emulsion structure-holding material and the thickener can be bonded and held in a stable state to the beads composed of inorganic hollow particles, so that a thick coating film can be formed. Can exhibit the excellent heat retaining property or heat insulating property of beads made of inorganic hollow particles.

  The coating composition of the present invention has a very high content of beads comprising inorganic hollow particles relative to the emulsion structure-retaining material and the thickener, and from the inorganic hollow particles as the dispersoid in the emulsion as the dispersion medium. Unlike the system in which the beads are dispersed, the beads composed of inorganic hollow particles are joined and held by the emulsion. Therefore, in the coating composition of the present invention, hard cake does not easily occur after coating, and since the emulsion structure holding material and the thickener penetrate between the beads made of inorganic hollow particles, the emulsion structure holding material is cured. The occurrence of cracks due to the expansion and contraction of the later emulsion structure holding material itself is suppressed, and the thick coating workability is also improved.

  In the coating composition of the present invention, the dispersoid in the emulsion as a dispersion medium is obtained by setting the content of beads comprising inorganic hollow particles to a mass ratio of 1.5 or more with respect to the emulsion structure holding material. Thus, a coating composition can be clearly distinguished from the system in which beads comprising inorganic hollow particles are dispersed, and hard cake does not easily occur after coating. That is, when the content of beads consisting of inorganic hollow particles in the coating composition is less than 1.5 by mass ratio with respect to the emulsion structure holding material, the inorganic hollow shape as a dispersoid in the emulsion as a dispersion medium. Since the system is a system in which beads made of particles are dispersed, the beads are separated on the surface side after coating, and a hard cake is likely to occur, and thick coating is difficult to perform. In addition, content of the bead which consists of a more preferable inorganic hollow particle is 2.0 or more by mass ratio with respect to an emulsion structure holding material.

  In addition, when the content of beads made of inorganic hollow particles exceeds 3.5 by mass ratio with respect to the emulsion structure holding material, the beads that are made of inorganic hollow particles are not bonded or held by the emulsion. Comes to occur. In such a state, the beads made of the inorganic hollow particles easily peel off from the surface of the coating film, and the bonding strength between the beads is reduced, so that the strength of the coating film is also reduced. Therefore, in the coating composition of the present invention, the content of beads made of inorganic hollow particles is preferably 1.5 or more and 3.5 or less by mass ratio with respect to the emulsion structure holding material.

  In addition, as beads composed of inorganic hollow particles used in the present invention, commercially available shirasu balloons, fly ash balloons, alumina balloons, glass balloons, zirconia balloons and the like can be appropriately selected and used. In addition, beads made by pulverizing foam glass can also be used. In this case, there are many beads whose cavities are opened / exposed on the outer surface (hereinafter referred to as “open cavities”). If there are many beads with such open cavities, the emulsion structure retaining material will penetrate into the cavities and the heat insulation effect or thermal insulation effect will decrease, so the beads with open cavities will be removed by sieving. It is preferable to use one having many closed-cavity beads.

  In addition, most of the beads made of commercially available inorganic hollow particles are classified, but they are not necessarily classified. In addition, the beads composed of inorganic hollow particles that can be used in the present invention are most preferably spherical when considering the dispersibility in the coating and the strength of the coating. A paint having properties or heat insulating properties can be obtained. In addition, the beads made of these inorganic hollow particles may not necessarily all have closed cavities, but if the cavities are many open and exposed on the outer surface as a result of foaming, the emulsion structure holding material is hollow. Since the heat insulation effect or the heat retention effect is reduced by permeating into the liquid, it is preferable to use a sieve having a closed cavity.

  In addition, as a thickener which can be added to the coating composition of this invention, a well-known thing can be suitably selected and used as a thickener of a coating material. By using such a thickener, it is possible to improve the viscosity of the coating composition, and to further increase the viscosity of the coating composition such as beads composed of inorganic hollow particles by imparting thickening, anti-sagging and anti-settling properties. Sediment separation can be suppressed, and thick coatability is imparted during coating. In the coating composition of the present invention, as other additives, a surfactant, an antifoaming agent, a pH adjuster and the like that are commonly used in coating compositions may be kneaded.

  In addition, when forming a coating film using the coating composition of this invention, it is preferable to apply | coat so that the thickness of a coating film may be 3 mm thru | or 20 mm, and when it is set to 5 mm thru | or 10 mm, since it is convenient, it is more preferable. Moreover, in order to maintain heat retaining properties or heat insulation properties, it is preferable that the surface of the coating film is substantially free of irregularities and is flat. Furthermore, the thicker the coating film, the better the heat retention or heat insulation. However, when the thickness exceeds 10 mm, not only the coating workability is lowered but also it is difficult to maintain a uniform thickness. The difference in effect from the heat retaining or heat insulating paint is not so much.

  In the present invention, examples of the emulsion structure holding material include acrylic resins, vinyl acetate resins, vinyl chloride resins, styrene / butadiene resins, epoxy resins, alkyd resins, polyester resins, and silicon resins. , Fluorine resin, polyurethane resin, acrylic urethane resin, and the like. However, urethane-based materials are rich in elasticity but have low heat resistance, and silicon-based materials are excellent in heat resistance, but the tensile strength may not be sufficient. .

  When an acrylic resin emulsion is employed as the emulsion structure holding material, the bonding / holding strength between the beads made of glass-based hollow particles is particularly strong. Acrylic resin emulsion (for example, solvent-type acrylic resin emulsion, modified acrylic resin emulsion, acrylic-styrene resin emulsion, acrylic-silicone resin emulsion, acrylic-urethane resin emulsion, etc.) should be used as the emulsion structure retaining material. Is preferred. When an acrylic resin emulsion is used as the emulsion structure holding material, the content of beads made of inorganic hollow particles can be increased, so the content of beads made of inorganic hollow particles can be reduced relative to the emulsion structure holding material. The mass ratio may be 2.0 or more and 3.5 or less. An acrylic-styrene resin emulsion can be used to obtain a coating film having excellent rigidity and impact resistance as the acrylic resin emulsion.

  In addition, the corresponding temperature range (recommended use temperature range) of the coating composition of the present invention is substantially determined by the temperature characteristics of the emulsion structure holding material, but the heat resistance is increased when the content ratio of beads made of inorganic hollow particles increases. It becomes good. For example, when an acrylic resin emulsion is used as the emulsion structure holding material, the corresponding temperature range is −10 ° C. when the content of beads made of inorganic hollow particles is 0.5 by mass with respect to the emulsion structure holding material. -80 ° C, but if the content of beads made of inorganic hollow particles is 2.5 to 3.5 by mass ratio to the emulsion structure retaining material, the corresponding temperature range is -10 ° C to 250 ° C. , Heat resistance is improved.

  In the coating composition of the present invention, the beads are made of borosilicate glass hollow particles, and the content of the beads is 2.5 to 3.0 by mass ratio with respect to the emulsion structure holding material. It is preferable to do. Many borosilicate glass beads are produced industrially, and have the property that alkali is not easily eluted with high strength. Moreover, borosilicate glass beads can be used in large quantities because of their good wettability with the emulsion structure retaining material, but if they are too much, the heat insulating effect or the heat retaining effect is saturated, and the borosilicate glass beads on the surface fall off. It becomes easy to do. Therefore, from the viewpoint of heat resistance and coating strength, the content of the borosilicate glass beads is preferably 2.5 to 3.0 in terms of mass ratio with respect to the emulsion structure holding material.

Moreover, in the coating composition of this invention, it is preferable that the average particle diameter of the bead which consists of inorganic hollow particles is 40-70 micrometers. If the average particle size of the beads is less than 40 μm, the heat retention effect may be reduced. If the average particle size exceeds 70 μm, the coating workability is deteriorated and the particles are easily broken, resulting in irregularities on the coating surface. There is a risk of damage. The “average particle diameter” in the present specification means the particle diameter (D ₅₀ ) at an integrated value of 50% in the particle size distribution obtained by a commercially available laser diffraction particle size analyzer. Furthermore, it can be easily obtained by classifying the hollow beads as the raw material that the average particle diameter of the beads comprising inorganic hollow particles is 40 to 70 μm.

  Moreover, in the coating composition of this invention, it is preferable to contain a light-shielding material. As the light-shielding material, materials known as pigments, such as titanium dioxide, zinc white, precipitated barium sulfate, and carbon black can be used. Thus, when a pigment is added to the coating composition of the present invention, deterioration of the coating film against ultraviolet rays and visible light is suppressed, weather resistance is increased, and the life of the coating film is extended.

1A to 1E are laser micrographs of each part of a coating film obtained from the coating composition of Example 1, respectively. 2A to 2E are laser micrographs of each part of the coating film of the coating composition of Comparative Example 1, respectively. It is a graph which shows the relationship between the amount of hollow glass beads mixed in the coating composition and the surface temperature. It is a graph which shows the relationship between the time after heating of the sample which formed the coating film by the coating composition of Example 1, 2 and Comparative Example 1, 2, and temperature. It is a graph which shows the relationship between the time after heating of the sample which changed the thickness of the coating film by the coating composition of Example 1, and temperature.

  Hereinafter, the form for implementing this invention is demonstrated in detail by an Example and a comparative example. However, the following examples illustrate coating compositions for embodying the technical idea of the present invention, and are not intended to limit the present invention to these examples. The present invention can be equally applied to various modifications without departing from the technical idea shown in the claims.

[Experimental Example 1]
First, the compositions of the coating compositions of Examples 1 to 3 and Comparative Examples 1 and 2 will be described. In common with Examples 1-3 and Comparative Examples 1 and 2, a commercially available acrylic-styrene resin emulsion (CG-8490: trade name, manufactured by DIC Corporation) was used as the emulsion structure-retaining agent. In addition, a commercially available hydroxyethyl cellulose thickener is used as the thickener, a commercially available film forming aid for acrylic resin emulsion is used as the film forming aid, and is further commercially available for the purpose of improving the light resistance of the coating composition. The rutile type titanium dioxide pigment was added.

  In all of Examples 1 to 3 and Comparative Examples 1 and 2, 100 parts by mass of the acrylic-styrene resin emulsion as the emulsion structure-retaining agent, 140 parts by mass of the thickener, 100 parts by mass of the pigment, and film formation aid. A coating solution was prepared by kneading the agent to 50 parts by mass and water to 200 parts by mass. In addition, a small amount of a surfactant, an antifoaming material, a pH adjusting material and the like that are commonly used in coating compositions are added to the coating solution. Next, the inorganic particles corresponding to each of Examples 1 to 3 and Comparative Examples 1 and 2 were added to the coating solution, and a predetermined amount was added and kneaded, whereby Examples 1 to 3 and Comparative Examples 1 and 2 were used. A paint composition corresponding to

The inorganic particles used were commercially available hollow borosilicate glass (average particle diameter (D ₅₀ ) = 60 μm) in Example 1, Example 2 and Comparative Example 1, and the amount added in each case was: With respect to 100 parts by mass of the emulsion structure-retaining agent, it was 280 parts by mass in Example 1, 200 parts by mass in Example 2, and 50 parts by mass in Comparative Example 1. In Example 3, after pulverizing foamed glass made of commercially available borosilicate glass, it was sieved to use a standard sieve passage of 212 μm, and the addition amount was 280 parts by mass with respect to 100 parts by mass of the emulsion structure-retaining agent. It was. In Comparative Example 2, commercially available borosilicate glass powder (average particle size (D ₅₀ ) = 60 μm) was used, and the addition amount was 280 parts by mass with respect to 100 parts by mass of the emulsion structure-retaining agent.

Using each coating composition of Examples 1 to 3 and Comparative Examples 1 and 2 prepared as described above, the iron plate wall surface of the temperature-controlled room is 5 mm thick and the coating area is 1 m ² with a trowel. Application samples corresponding to Examples 1 to 3 and Comparative Examples 1 and 2 were prepared by coating. At that time, the workability, the work time, and the results of comprehensive determination on the dispersibility of the inorganic particles after drying were evaluated as workability. With regard to workability and work time, in particular, it has the same level of coatability as ordinary mortar, so-called dripping hardly occurred. Spilled during coating, but the dripping part could be corrected by applying a trowel several times, and the original shape could not be recovered even after applying spilling several times. Differentiated.

  Moreover, about the dispersibility of an inorganic particle, the coating film obtained after drying was cut | disconnected and peeled, and the sample corresponding to each of Examples 1-3 and Comparative Examples 1 and 2 was obtained. With respect to these samples, the states of the top surface, the back surface, the upper portion of the cut surface, the middle portion, and the lower portion were examined by a laser microscope (VK-9510 manufactured by KEYENCE Co., Ltd.). The measurement result of the sample corresponding to Example 1 is shown in FIG. 1, and the measurement result of the sample corresponding to Comparative Example 1 is shown in FIG. The measurement results of Examples 2 and 3 and Comparative Example 2 were determined by distinguishing the measurement result corresponding to Example 1 as the best and the measurement result of the sample corresponding to Comparative Example 1 as the worst.

Then, after adjusting the temperature of the wall of the temperature-controlled room to be 200 ° C., it is allowed to elapse for 1 hour, and the state of the coating composition according to each of the examples and comparative examples is observed, and the heat retaining property, heat insulating property, cracking Was judged. Judgment criteria are as follows.
Thermal insulation and heat insulation: The surface temperature of the coating composition is measured, ◎ when the temperature is 120 ° C. or lower, ○ when the temperature is 140 ° C. or lower and over 120 ° C., Δ when the temperature is 160 ° C. or lower and over 140 ° C. The case where it exceeded was judged as x.
Cracks: Judgment by the judge's subjectivity to determine whether the cracker has been observed visually from a distance of 1 m, and when the crack was not found ◎, when it was slightly seen locally ○, a case where a partial crack was observed was evaluated as Δ, and a case where a partial crack was observed was determined as X.

  Then, about heat retention and heat insulation, the accelerated exposure process equivalent to 3 months was performed using the sunshine weather meter as an acceleration test, and heat retention and heat insulation were determined similarly to the above-mentioned case after that. Table 1 summarizes the results of the workability, heat retention / heat insulation properties, and cracks determined as described above.

  According to the measurement results shown in FIG. 2 corresponding to Comparative Example 1, it is clear that A to C in FIG. 2 are compared, and the beads made of hollow borosilicate glass gather on the surface side of the paint, and the lower surface side. The number is very low, and it is in a hard cake state. Accordingly, as is apparent from the comparison of D and E in FIG. 2, the surface side shows irregularities due to the presence of beads made of hollow borosilicate glass, but these beads are hardly exposed, On the back side, the existence of beads made of substantially hollow borosilicate glass is not observed.

  Further, according to the measurement results shown in FIG. 1 corresponding to Example 1, it is clear from comparison between A to C in FIG. It can be seen that it exists. Accordingly, it is recognized that beads made of hollow borosilicate glass are exposed on both the front surface side and the back surface side, as is clear when D and E in FIG. 1 are compared.

  This is because, in the coating composition of Comparative Example 1, as in the case of the conventional coating composition, since the amount of the emulsion structure-retaining agent is larger than that of beads made of hollow borosilicate glass, it becomes a solution. Therefore, when thickly coated, it means that these beads are lifted to the surface side by buoyancy and become a hard cake state before a coating film is formed. On the other hand, in the coating composition of Example 1, since the amount of the emulsion structure-retaining agent is smaller than that of beads made of hollow borosilicate glass, these beads are dispersed in the emulsion structure-retaining agent. However, since these beads are in a state where they are bound together by an emulsion structure-retaining agent, that is, in a paste state, a coating film is formed while maintaining the initial painted state even when thickly coated. Means. Therefore, it was confirmed that the coating composition of Example 1 was suitable for thick coating as compared with the coating composition of Comparative Example 1.

  Moreover, the following can be understood from the results shown in Table 1. In Examples 1 to 3 including glass hollow particles by pulverizing and sieving glass hollow particles or foamed glass, practically sufficient heat retention and heat insulation, cracking characteristics, workability And it had heat insulation and heat insulation after 3 months. However, in Comparative Example 1, since the addition ratio is small while using glass hollow particles, the heat retaining property, heat insulating property, and cracking properties were practically sufficient, but there was much dripping and workability was poor. Moreover, the heat retention and heat insulation after 3 months were inferior in heat retention and heat insulation due to the large deterioration of the resin component.

  Moreover, in the case of the comparative example 2 which used glass powder as an inorganic particle, even if the content rate of glass powder is made into the same amount as the case of Example 1 and 3, gas (bubble) is not contained in the coating film. Therefore, heat insulation and heat insulation were inferior, and there were most cracks. However, although the coating composition of Comparative Example 2 was less fluid than the coating composition of Comparative Example 1 and the coating property was practically sufficient, it was easier to work than the coating compositions of Examples 1 to 3. Was bad. Also, the heat retention and heat insulation after 3 months were the worst.

[Experiment 2]
As Experimental Example 2, the same three types as in the coating composition of Example 1 except that the content of the hollow spherical borosilicate glass in the acrylic-styrene resin emulsion was changed to 1.0, 1.5, and 3.5. A coating composition was prepared and three types of coated samples were prepared in the same manner as described above. And after adjusting so that the temperature of the wall surface of a temperature-controlled room might be 200 degreeC, it was made to pass for 1 hour, and the surface temperature of the coating composition was measured about each case. The obtained results are shown together with the measurement results of Examples 1 and 2 and Comparative Example 1 (the contents of hollow spherical borosilicate glass corresponding to acrylic-styrene resin emulsions correspond to 0.5, 2.0 and 2.8, respectively). This is shown in FIG.

  FIG. 3 shows the following. That is, when the mass ratio of the hollow sphere borosilicate glass to the acrylic-styrene resin emulsion exceeds 1.0 or less than 3.0, the degree of decrease in the surface temperature accompanying the increase in the amount of hollow sphere borosilicate glass mixed (ie, The degree of improvement in heat retention effect is relatively small. On the other hand, in the case of 1.0 or more, particularly 1.5 or more and 2.5 or less, the surface temperature is greatly reduced.

  Therefore, in the present invention, if the mixing ratio of beads made of hollow spherical borosilicate glass to the acrylic-styrene resin emulsion is 1.5 or more in mass ratio, a good effect is obtained, but 2.0 or more. In particular, it can be seen that it is preferably 2.5 or more. Further, even if the amount of the beads mixed becomes too large, the heat retaining effect or the heat insulating effect starts to saturate, and when 4.0 is reached, beads not bonded to the acrylic-styrene resin emulsion are generated. Therefore, the mixing amount of beads made of hollow spherical borosilicate glass with respect to the acrylic-styrene resin emulsion is preferably about 3.5 in terms of mass ratio.

[Experiment 3]
Using each of the coating compositions of Examples 1 and 3 and Comparative Examples 1 and 2, a coating film was formed on an iron plate having a width of 5 cm, a length of 10 cm and a thickness of 2 mm so as to have a thickness of 5 mm. A coated sample was prepared. A thermocouple was attached to the surface of each of these four types of coating films, and a thermocouple was attached as a reference sample on an iron plate having a width of 5 cm, a length of 10 cm, and a thickness of 2 mm. These four types of coated samples and one type of reference sample were placed on a heating plate. And the preset temperature of a heating plate was set so that the temperature of a reference sample might be 200 degreeC, and each detection temperature with progress of the incident after starting electricity supply to a heating plate was measured simultaneously. The results are summarized in FIG.

  From the results shown in FIG. 4, the following can be understood. That is, since the beads made of hollow spherical glass have the ability to block radiant heat transfer, when the coating composition of Example 1 having the largest content of beads made of hollow spherical glass is used, It has a good heat insulation and heat insulation effect. Moreover, since the coating composition of Example 3 uses the inorganic particle produced from the foam glass, since all are not hollow balloons, it seems that the result was inferior to Example 1. It is.

  On the other hand, the coating composition of Comparative Example 1 contains beads made of hollow spherical glass, but its content is small, so that the heat retaining and heat insulating effect is similar to that in Example 3. It was. Moreover, in the coating composition of the comparative example 2, since the glass powder was used, since the gas (bubble) was not included in the inside, the result with the inferior heat insulation and heat insulation effect was obtained.

  Using the coating composition of Example 1, a coating film was formed on an iron plate having a width of 5 cm, a length of 10 cm, and a thickness of 2 mm so as to have a thickness of 6 mm, 13 mm, and 20 mm, thereby preparing three types of coated samples. . A thermocouple was attached to the surface of each of these three types of coating films, and a thermocouple was attached to an iron plate having a width of 5 cm, a length of 10 cm, and a thickness of 2 mm as a reference sample. These four types of coated samples and one type of reference sample were placed on a heating plate. And the preset temperature of a heating plate was set so that the temperature of a reference sample might be 200 degreeC, and each detection temperature accompanying progress of the incident after starting electricity supply to a heating plate was measured simultaneously with room temperature. The results are summarized in FIG.

  The following can be understood from the results shown in FIG. That is, the temperature of the iron plate is stable at about 200 ° C., the sample with a thickness of 6 mm is stable at about 130 ° C., the sample with a thickness of 13 mm is 90 ° C., and the sample with a thickness of 20 mm is stable at about 75 ° C. Was almost constant. This proves that the coating composition of the present invention has a good heat-retaining and heat-insulating effect, and as the thickness of the coating composition of the present invention increases, the heat-retaining and heat-insulating effect increases. It shows that it becomes good.

  In Examples 1 to 3, an example in which rutile titanium dioxide was used as a pigment in the coating composition was shown. However, the pigment is not necessarily a necessary component, and may be appropriately selected according to the application, use environment, and the like. That's fine. In particular, in the coating composition for indoor use, the pigment may not be used. In each of the above experimental examples, the emulsion structure retention agent is 100 parts by mass, the thickener is 140 parts by mass, the pigment is 100 parts by mass, the film forming aid is 50 parts by mass, and the water is 200 parts by mass. Although the coating solution is used, the present invention is not limited to this composition and may be appropriately changed according to the required physical properties of the coating film.

  The coating composition of the present invention can be used not only on the walls of ordinary buildings (houses and warehouses), but also on structures such as the outer walls of heat insulation cabinets and the exteriors of pipes and pipes that want to maintain a heat insulation effect. In addition, it is possible to improve transportability and workability by tiling using such a coating composition, and when it is processed into a sheet, it is suitable for wrapping around structures such as piping and valves. Become.

Claims (6)

A coating composition containing beads comprising inorganic hollow particles, an emulsion structure holding material for the beads, and a thickener,
Content of the said bead is 1.5 or more and 3.5 or less by mass ratio with respect to the said emulsion structure holding material, The coating composition characterized by the above-mentioned.   The emulsion structure-holding material is an acrylic resin emulsion, and the content of the beads is 2.0 or more and 3.5 or less in a mass ratio with respect to the emulsion structure-holding material. Paint composition.   The coating composition according to claim 2, wherein the emulsion structure holding material is an acrylic-styrene resin emulsion.   The said bead is a borosilicate glass hollow particle, and content of the said bead is 2.5 or more and 3.0 or less by mass ratio with respect to the said emulsion structure holding | maintenance material. A coating composition according to claim 1.   The coating composition according to any one of claims 1 to 4, wherein the beads have an average particle size of 40 to 70 µm.   Furthermore, the coating composition in any one of Claims 1-5 containing a light-shielding material.