JPH1060311A - Water-base vibration-damping coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration-damping coating material used for reducing the vibration or the noise due to vibration of automobiles, precision machinery, household electrical appliances, construction machines, building structures, and other various machines, structures, etc., and useful for damping these machines and structures particularly at high temperature. SOLUTION: This coating material contains an emulsion comprising mainly at least two synthetic resins each having a glass transition temperature of -10 to 50 deg.C and different in glass transition temperature from each other, and mica having particle diameters in the range from 0.1 to 200μm with a mean particle diameter of 0.5-90μm. The amount of mica is 30-350 parts by mass based on 100 parts by mass of solids of the synthetic resin emulsion.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vibration control device for reducing noise caused by vibrations or vibrations of automobiles, precision instruments, home appliances, construction machines, building structures, and other various devices and structures. The present invention relates to a paint, and more particularly to a damping paint suitable for damping these devices and structures in a high temperature range.

[0002]

2. Description of the Related Art Conventionally, in order to reduce noise caused by vibration or vibration of various devices and structures as described above, asphalt-based damping sheets or damping steel sheets,
Various types of damping materials have been used. Also, a so-called damping paint has been used as a paint type damping material which can be applied to complicated shapes and is easy to construct.

[0003] The vibration damping paint is obtained by dissolving or dispersing a film-forming component such as a resin in an organic solvent or the like, and blending a filler or the like with the solution, and by various means such as spray coating and brush coating. A coating film is formed by applying the coating composition to an object to be dried and drying it, thereby absorbing vibration of the object to be applied and reducing noise. In general, organic solvent-based paints containing an organic solvent as a diluent as described above have been used in many cases, but recently, due to VOC (volatile organic compound) regulations related to environmental issues, organic solvent-based paints have been used. So-called water-based paints in which an organic solvent is replaced with water instead of paints have attracted attention.

In general, the viscoelasticity of a vibration-damping material changes with temperature, so that the vibration-damping performance depends on the temperature and shows a maximum value at a specific temperature. Therefore, even if the damping material shows a large damping performance at a specific temperature, the damping performance is significantly reduced at a lower or higher temperature range, and a sufficient damping effect cannot be obtained. is there.

When the devices to be damped are engines, motors, pumps, etc., the temperature of the main body and the surroundings of these devices is 6
In many cases, the temperature is 0 ° C. or higher or 100 ° C. or higher, and a vibration damping paint that exhibits sufficient vibration damping performance even in these high temperature regions is required.

The water-based damping paint proposed by the present inventors (see the specification of Japanese Patent Application No. Hei 7-274918) exhibits excellent damping performance at around room temperature, and has good storage stability and paintability. Are better. Specifically, at around 20 ° C., the damping performance becomes maximum, the loss coefficient is 0.2 or more, and the damping performance at room temperature is very excellent. However, the damping performance tends to gradually decrease as the temperature increases, and there is a limit to the temperature range in which practical damping performance can be maintained.

[0007] One known damping paint is an automobile undercoat paint using a styrene-modified acrylic resin emulsion disclosed in JP-A-7-166101. However, at 20 ° C.,
Although it exhibits a loss coefficient of about a degree, the vibration damping performance is reduced at room temperature or higher, particularly at 40 ° C. or higher, and there is a problem in use in a high temperature region.

[0008] The temperature at which the damping performance is maximized largely depends on the glass transition temperature of the damping material. If the glass transition temperature is different, the temperature at which the damping performance (loss coefficient) is maximized also differs. come. Therefore, if a material having a glass transition temperature equal to or higher than room temperature is used, it is possible to design a vibration damping material having a maximum vibration damping performance in a high temperature region.

For example, JP-A-8-73648 discloses that mica having an average particle diameter of 90 to 1000 μm is contained in two or more kinds of resin matrices having different peak temperatures of loss coefficients, in other words, having different glass transition temperatures. A vibration damping material having excellent vibration damping properties and sound insulation properties over a wide temperature range from a normal temperature range to a high temperature range by being blended is disclosed. However, this vibration damping material is a molding material formed by a calendering method, an extrusion method, a hot pressing method or the like, and cannot be used as a paint. Moreover, mica having an average particle size of 90 to 1000 μm has a large particle size, which not only reduces the fluidity required as a coating material, but also causes a decrease in storage stability and clogging of nozzles during spray coating. Easy to use for paints.

In the case of using a resin component having a glass transition temperature of room temperature or higher in a water-based vibration damping coating, the coating film becomes harder and less flexible in a temperature range lower than the glass transition temperature. When drying, especially 0.5 ~
When the film is thickly applied to a thickness of 1.0 mm or more, cracks in the coating film easily occur.

[0011]

SUMMARY OF THE INVENTION In view of the above points, the present invention exhibits high vibration damping performance in a wide temperature range from room temperature to high temperature, and is capable of thick coating, and does not crack when dried at room temperature. It is an object of the present invention to propose a water-based vibration damping paint which can obtain a good dried coating film and has excellent storage stability and excellent paintability such as spray coating and brush coating.

[0012]

SUMMARY OF THE INVENTION As a result of repeated studies to achieve the above object, the present inventors have found that a synthetic resin emulsion mainly composed of a synthetic resin having a high glass transition temperature for exhibiting vibration damping properties at high temperatures. And a synthetic resin emulsion composed of a synthetic resin emulsion mainly composed of a synthetic resin having a low glass transition temperature for the purpose of imparting vibration damping properties near room temperature and flexibility for preventing cracking of the coating film. Gained the knowledge that a specific amount of mica should be blended,
The water-based damping paint of the present invention has been developed.

That is, the water-based vibration damping paint of the present invention has an emulsion mainly composed of two or more kinds of synthetic resins having a glass transition temperature in a range of -10 to 50 ° C. and different glass transition temperatures, and a particle size. Mica having a range of 0.1 to 200 μm and an average particle diameter of 0.5 to 80 μm, and the mica is 30 to 350 parts by mass with respect to 100 parts by mass of the solid content of the synthetic resin emulsion. It is characterized by.

The synthetic resin emulsion that can be used in the water-based vibration damping paint of the present invention is obtained by emulsifying and dispersing a synthetic resin as a main component in water by a method such as emulsion polymerization. (Solid content) is not particularly limited, but may be 30
Those having a concentration of about 70% by mass are preferred.

The above-mentioned synthetic resins include acrylic ester copolymer, styrene-acrylic ester copolymer, ethylene-vinyl acetate copolymer, vinyl acetate polymer, acryl-vinyl acetate copolymer, and vinyl chloride polymer. And a vinyl chloride-acryl copolymer, a vinylidene chloride polymer, a butadiene polymer, a styrene-butadiene copolymer, and an acrylonitrile-butadiene copolymer. However, from the viewpoint of the adhesion to the substrate (object to be coated), or the chemical resistance, water resistance and vibration damping properties of the coating film, acrylic ester copolymer, styrene-acrylic ester copolymer, ethylene- A vinyl acetate copolymer is preferred, and a styrene-acrylate copolymer is more preferred.

The glass transition temperature of the above synthetic resin is in the range of -10 to 50 ° C. -10 ° C
If the temperature is lower than the above range, not only does the damping performance at a high temperature of room temperature or higher deteriorate, but also the coating film becomes soft, which causes problems such as a decrease in the strength of the coating film and an increase in surface stickiness. Conversely, if the temperature is higher than 50 ° C., not only does the vibration-damping performance near room temperature deteriorate, but the coating film becomes extremely hard, so that not only the coating film becomes brittle, but when it is thickly applied, cracks occur when drying. , A good coating film cannot be obtained.

Further, the synthetic resin emulsion contains two or more synthetic resins having different glass transition temperatures as main components. Specifically, the glass transition temperature is from −10 ° C. to less than 10 ° C., from 10 ° C. to less than 30 ° C., from 30 ° C. to 50 ° C.
It is preferable to use as a main component at least two types of synthetic resins from the group consisting of the following three types of synthetic resins (particularly, styrene-acrylate copolymers).

In the case of a resin mainly composed of two kinds of synthetic resins (particularly styrene-acrylate copolymer) having a glass transition temperature of -10 ° C. to less than 10 ° C. and 10 ° C. to less than 30 ° C., for example, FIG. 1, which is the result of the example, shows excellent vibration damping properties at around 40 to 60 ° C.
Shows excellent vibration damping properties at a specific temperature. Further, when the main component is a resin having a glass transition temperature of −10 ° C. to less than 10 ° C., 10 ° C. to less than 30 ° C., and 30 ° C. to 50 ° C. (particularly, a styrene-acrylate copolymer), FIG. 3, which is also a result of the later-described embodiment, shows excellent vibration damping properties in a high temperature region.
In FIG. 4, the temperature range showing excellent vibration damping properties extends over a wide range. Therefore, desired vibration damping performance can be obtained by using two or more kinds of synthetic resins having different glass transition temperatures so as to have an optimum glass transition temperature according to the use and the temperature range to be used.

Those having a glass transition temperature of -10 ° C. or more and less than 10 ° C. and those having a glass transition temperature of 10 ° C. or more and 30 ° C. or less contribute to improvement in vibration damping performance near room temperature and impart flexibility to the coating film. This contributes to preventing cracking during drying. Further, the glass transition temperature is 10 ° C. or higher and 3
Those having a temperature of less than 0 ° C. and those having a temperature of 30 ° C. or more and 50 ° C. or less contribute to improvement of vibration damping performance in a high temperature region near room temperature or more.

In this type of paint, the filler is
Inorganic fillers such as calcium carbonate, barium sulfate, clay, talc, mica, diatomaceous earth, alumina, gypsum, cement, converter slag powder, shirasu powder, and glass powder are known, and a large amount of filler is compounded. It is known that a high damping performance can be obtained by this. However, in order to improve the vibration damping performance in a high-temperature region, as described above, in the case of an emulsion mainly composed of a synthetic resin having a glass transition temperature of room temperature or higher, when these fillers are mixed in a large amount, Cracking of the coating film during drying is more likely to occur.

In the present invention, the above-mentioned synthetic resin emulsion is mixed with a specific amount of mica having the above-mentioned specific particle size to prevent cracking of the coating film during drying, and furthermore, a wide temperature range from room temperature to high temperature. High vibration damping performance is exhibited in the region.

The mica used in the present invention has a particle size range of about 0.1 to 200 μm, preferably about 0.5 to 50 μm.
m, more preferably about 1 to 40 μm, the average particle diameter is about 0.5 to 80 μm, preferably about 1 to 20 μm
m, more preferably about 3 to 7 μm. When the particle size is smaller than about 0.1 μm, not only the viscosity of the coating material increases and the fluidity decreases, but also the storage stability of the coating material decreases due to aggregation of the particles. On the other hand, when the particle diameter is larger than about 200 μm, not only the storage stability of the paint is lowered due to the sedimentation of the particles, but also problems such as clogging of nozzles during spray coating occur. Further, if the particle diameter is in the above-mentioned range, it is preferable in terms of vibration damping performance in a high temperature region.

In the present invention, the mixing ratio of the two or more kinds of synthetic resins having different glass transition temperatures is not particularly limited, but when two kinds of synthetic resins are mixed, the synthetic resin having a low glass transition temperature is used. The synthetic resin having a high glass transition temperature is preferably 50 to 200 parts by mass with respect to 100 parts by mass of the resin, and when three kinds of synthetic resins are blended, the glass transition temperature is −10 ° C. or more and less than 10 ° C. The synthetic resin having a temperature of 10 ° C or more and less than 30 ° C and the synthetic resin having a temperature of 30 ° C or more and 50 ° C or less with respect to 100 parts by mass of
Preferably it is 200 parts by mass.

A glass transition temperature of 10 ° C. or more and less than 30 ° C .;
If the mixing ratio of the synthetic resin having a temperature of 30 ° C. or more and 50 ° C. or less is too small, the vibration damping performance in a high-temperature region decreases. Further, if the mixing ratio of the synthetic resin having a glass transition temperature of 30 ° C. or more and 50 ° C. or less is too large, not only does the damping performance near room temperature decrease, but the coating film becomes very hard, so that the coating film becomes brittle. In the case of thick coating, cracks occur during drying, and a good coating film cannot be obtained.

The mixing ratio of the synthetic resin emulsion and the mica is such that the mica is 30 to 350 parts by mass, preferably 50 to 300 parts by mass, based on 100 parts by mass of the solid content of all the synthetic resin emulsions. Is suitable. When the mica is less than 30 parts by mass, the vibration damping performance is reduced. On the contrary, when the mica is more than 350 parts by mass, the fluidity of the paint is lost or the adhesiveness with the base material is reduced, and at the time of drying, Cracks occur and a good coating film cannot be obtained.

The water-based vibration damping paint of the present invention may contain a dispersant, a defoaming agent, a thickener, an adhesion improver, an antifreezing agent, a stabilizer, an anti-skinning agent, a rust inhibitor, if necessary. Additives such as colorants can be added, and if necessary, they can be diluted with water.

The water-based vibration damping paint of the present invention can be applied by a technique known to those skilled in the art, for example, a usual technique such as air spray, airless spray, brush coating, spatula coating, and roller coating. In this case, if the coating thickness is too thin, the drying speed of the coating film is increased, but sufficient vibration damping property is not obtained.If the coating thickness is too thick, on the other hand, the vibration damping property is improved. Not only takes a long time, but also a good coating film such as sagging or cracking is generated.
m, preferably about 0.5 to 3 mm.

As a method of drying the coating film, a usual method, for example, natural drying, hot air drying, electric furnace drying, infrared / far infrared drying and the like can be adopted.

[0029]

【Example】

Examples 1 to 16 and Comparative Examples 1 to 6 <Preparation of paints> The components shown in Tables 1 to 6 were mixed at the mixing ratios shown in Tables 1 to 8 to prepare paints. The results were evaluated in the following manner, and these results were evaluated in Tables 1 to 6,
As shown in FIGS. In addition, in Tables 1-8, glass transition temperature was described as "Tg".

<Storage Stability> The storage stability of the paint was evaluated by centrifuging 100 g of each prepared paint.
Observe the bottom of each paint after processing at 0 rpm for 30 minutes, pass if the fluidity was easily recovered by agitation (o), and fail if it could not be recovered (x)
And

<Spray Coating Properties> The spray coating properties were evaluated as good (O) when the pattern formation was good and a good atomization state was obtained in the spray coating using an electric diaphragm pump. Was bad (x) when no good atomization was obtained.

<State of coating film> The state of the coating film was judged as unacceptable when cracks, peeling, etc., occurred in a dried coating film having a thickness of about 1 mm obtained by drying at room temperature.
The case where these did not occur was regarded as pass (合格).

<Vibration Suppression Performance> The vibration suppression performance was measured according to JIS G0.
According to the method for testing the vibration damping characteristics of a damping steel sheet specified in 602, one side of an electrodeposited stainless steel sheet having a length of 200 mm, a width of 25 mm and a thickness of 0.8 mm has a thickness of about 2 mm after drying. A test piece prepared by applying each paint as described above and drying at room temperature was measured at 20 to 120 ° C. for a loss coefficient by a central excitation half width method, and the measurement result of the loss coefficient of each paint was shown in FIG. -6.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

[Table 4]

[0038]

[Table 5]

[0039]

[Table 6]

[0040]

[Table 7]

[0041]

[Table 8]

[0042]

According to the present invention, it is possible to obtain a good dry coating film which exhibits high vibration damping performance in a wide temperature range from room temperature to high temperature, enables thick coating, and does not crack when dried at room temperature. Thus, a water-based vibration damping paint having excellent storage stability and coatability can be obtained.

[Brief description of the drawings]

FIG. 1 is a view showing a vibration damping performance in one embodiment of the paint of the present invention.

FIG. 2 is a view showing the vibration damping performance of the paint of the present invention in an example different from FIG.

FIG. 3 is a view showing the vibration damping performance of the paint of the present invention in an example different from FIGS.

FIG. 4 is a view showing the vibration damping performance of an embodiment of the paint of the present invention which is different from FIGS.

FIG. 5 is a view showing the vibration damping performance of the paint of the present invention in an example different from those in FIGS.

FIG. 6 is a graph showing the vibration damping performance of a comparative paint.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takao Kimura 1134-2 Gongendo, Satte City, Saitama Pref.

Claims (8)

[Claims] 1. An emulsion having a glass transition temperature in a range of -10 to 50 ° C. and containing two or more synthetic resins having different glass transition temperatures as main components, and a particle size range of 0.1 to 200 μm. And mica having an average particle diameter of 0.5 to 80 µm, wherein the mica is 30 to 350 parts by mass with respect to 100 parts by mass of the solid content of the synthetic resin emulsion. paint. 2. A synthetic resin emulsion comprising a synthetic resin having a glass transition temperature of −10 ° C. or more and less than 10 ° C .;
2. The water-based vibration damping paint according to claim 1, wherein at least two kinds of synthetic resins selected from the group consisting of three kinds of synthetic resins having a temperature of 30 ° C. or more and a temperature of not more than 50 ° C. are mainly used. 3. A synthetic resin emulsion comprising two kinds of synthetic resins having different glass transition temperatures as main components, and 50 to 200 parts by mass of a synthetic resin having a high glass transition temperature per 100 parts by mass of a synthetic resin having a low glass transition temperature. The water-based vibration damping paint according to claim 2, which is a part. 4. A synthetic resin emulsion comprising three kinds of synthetic resins having different glass transition temperatures as main components, and 100 ° C. to less than 30 ° C. with respect to 100 parts by mass of the synthetic resin having a glass transition temperature of −10 ° C. to less than 10 ° C. 3. The water-based vibration damping paint according to claim 2, wherein each of the synthetic resin and the synthetic resin having a temperature of 30 ° C. or more and 50 ° C. or less is 50 to 200 parts by mass. 4. 5. The synthetic resin emulsion has a solid content of 30 to 30.
The water-based vibration damping paint according to claim 1, wherein the amount is 70 parts by mass. 6. The water-based vibration damping paint according to claim 1, wherein the synthetic resin emulsion is an emulsion containing a styrene-acrylate copolymer as a main component. 7. The mica has a particle size range of 0.5 to 50 μm.
The water-based vibration damping paint according to any one of claims 1 to 6, wherein the average particle diameter is 1 to 20 µm. 8. The water-based vibration damping paint according to claim 1, wherein the mica has a particle size range of 1 to 40 μm and an average particle size of 3 to 7 μm.