JP3209499B2 - Water-based damping paint - Google Patents

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. Regarding paint.

[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 that 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 widely used. However, recently, with the VOC (volatile organic compound) regulations relating 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.

By the way, the vibration-damping paint is a coating in which the coating film undergoes expansion and contraction motion due to the vibration of the object to be coated, and the vibration energy is converted into heat energy by heat generated by internal friction of the coating film to attenuate the vibration. The greater the internal friction of the coating,
High damping performance can be obtained.

The present inventors have found that a method of increasing the amount of filler is effective as one of the methods for increasing the internal friction of the coating film. However, a large amount of filler having a large specific gravity is blended. In this case, there is a problem in the storage stability of the paint, for example, the settling filler solidifies during the storage of the paint.

On the other hand, Japanese Patent Publication No. 29628/1986 discloses a vibration damping paint comprising a viscoelastic resin, an amount of air-crushed slag exceeding the CPVC (critical pigment concentration) and a thixotropic agent. Since this paint contains a large amount of crushed slag, the storage stability of the paint deteriorates due to sedimentation of the slag and the like, and furthermore, there is an environmental problem because it is an organic solvent-based paint.

Japanese Patent Publication No. 62-39628 discloses a water-dispersible acrylic resin having a secondary transition point of 0 ° C. or less.
A paint comprising a powdery filler and an antirust pigment is described.
This paint is used as a pitching-resistant material for sheet metal members outside the vehicle compartment, and has insufficient vibration damping properties as the above-described damping paint for various devices and structures. Further, Japanese Patent Application Laid-Open
Japanese Patent No. 166101 describes a vehicle undercoat paint having a vibration damping property using a styrene-modified acrylic resin emulsion. However, a loss coefficient for evaluating the vibration damping performance of this paint shows only 0.165 at most. It is.

[0008]

SUMMARY OF THE INVENTION In consideration of the above points, the present invention is excellent in stability during storage of paint, and is spray-painted, despite the fact that a large amount of filler is blended to exhibit high vibration damping performance near room temperature. It is an object of the present invention to propose a water-based damping paint excellent in paintability such as brushing.

[0009]

SUMMARY OF THE INVENTION The present inventors have conducted various studies to achieve the above object, and as a result, have a specific glass transition temperature.
Synthetic resin emulsion as a main component a specific synthetic resin, blended in a specific amount of a specific inorganic filler, by blending further a specific <br/> thickener and dispersing agent in the specified amounts, around room temperature It has been found that a water-based vibration-damping paint of the present invention can be obtained which shows high vibration-damping performance and is stable without being solidified over a long period of time during storage of the paint.

That is, the water-based vibration damping paint of the present invention is an emulsion containing an acrylate copolymer having a glass transition temperature of -50 to 5 ° C. in a solid content of 30 to 70% by mass , and a glass transition temperature of -50 to 5 %. With respect to 100 parts by mass of at least one solid content selected from emulsions containing 30 to 70% by mass of an ethylene-vinyl acetate copolymer at 30 ° C in solid content,
250 to 550 parts by mass of an inorganic filler composed of calcium carbonate and / or converter slag powder, a thickener composed of hectorite and / or polycarboxylic acid and / or a polyoxyalkylene And / or a polycarboxylic acid-based dispersant in an amount of 0.1 to 35 parts by mass.

The acrylic which can be used for the water-based vibration damping paint of the present invention
Luic ester copolymer emulsion, ethylene-acetic acid
The vinyl copolymer emulsion is obtained by emulsifying and dispersing these copolymers whose main components have a glass transition temperature of −50 to 5 ° C. in water by a method such as emulsion polymerization.
The content (solid content ) of the copolymer ( resin ) is not particularly limited, but is preferably 30 to 70% by mass.

[0012] Glass transition having a temperature luer acrylic acid ester copolymer and ethylene in the range of the -50~5 ℃ - vinyl acetate copolymer may be used either alone, both These copolymers may be used in combination.
One or both are called “synthetic resins,”
Either or both of the polymer emulsions are synthesized
Resin emulsion ") . These
Synthetic resin is excellent in terms of adhesion, or coating of the chemical resistance and water resistance and vibration damping properties to the substrate.

When the glass transition temperature of the synthetic resin, which is the main component of the synthetic resin emulsion, is lower than -50 ° C., the coating film becomes very soft at normal temperature, so that the strength of the coating film decreases and the surface becomes sticky. At the same time, problems such as an increase in size occur, and at the same time, the vibration damping property near room temperature decreases. On the other hand, when the temperature is higher than 5 ° C., the coating film becomes extremely hard at room temperature, so that not only the coating film becomes brittle, but also when a thick coating is applied, cracks occur upon drying and a good coating film cannot be obtained. A preferred glass transition temperature is -40 to 0C.

Further, the inorganic filler which can be used in the present invention includes:
Damping property, the true specific gravity from the viewpoint of storage stability of the paint Ru include charcoal <br/> calcium and converter slag Powder 2-5. these
Is cost, stability of the paint, preferably in terms of such adhesion of the coating film, may be used alone or in combination of both.

Furthermore, thickeners for use in the present invention, to increase the coating viscosity as it an action of preventing the sedimentation of the inorganic filler, f Kutoraito or polycarboxylic acid and the like, which it may be used alone or in combination of both. F Kutoraito thickener, since it is possible to change the viscosity when added in a small amount, often a small amount of addition, but preferable in cost, the addition amount would only change the viscosity increased slightly changed Therefore, care must be taken in controlling the amount of addition. On the other hand, polycarboxylic acid-based thickeners are most preferable because the viscosity can be easily controlled.

The dispersing agent used in the present invention, which an action to prevent caking due to agglomeration of the filler particles to improve the dispersibility of the inorganic filler particles, Po polycarboxylic acid or <br/> include polyoxyalkylene is, they may be used alone or in combination of both.

The above-mentioned thickener and dispersant may be used in combination, or if only one of them can prevent sedimentation / aggregation of the inorganic filler, only one of them is used. Is fine.

The mixing ratio of the synthetic resin emulsion, the inorganic filler, the thickener, and the dispersant is 250 to 250 parts by mass of the solid content of the synthetic resin emulsion.
550 parts by mass, preferably 290 to 400 parts by mass, and both or one of the thickener and the dispersant is 0.1 to 35 parts by mass, preferably 0.5 to 20 parts by mass.

If the amount of the inorganic filler is too large, the amount of the synthetic resin emulsion will be relatively too small, and the fluidity of the paint will be lost, or the storage stability will be reduced due to sedimentation and condensation of the filler, Not only does the adhesion to the object to be coated decrease, but also the flexibility and strength of the dried coating decreases, and a good coating cannot be obtained. On the other hand, if the amount of the filler is too small, the amount of the synthetic resin emulsion becomes relatively too large, and the vibration damping property is reduced. Also, if the amounts of the thickener and the dispersant are too small, the settling and agglomeration of the filler particles will occur, and the storage stability of the paint will be reduced. If the amount is too large, the viscosity of the paint will be too high, resulting in spray coating and brushing. Coating and the like cannot be performed, and paintability deteriorates.

Therefore, in order to form a good dry coating film, to have excellent storage stability and paintability, and to obtain high vibration damping properties, the amounts of the synthetic resin emulsion, inorganic filler, thickener and dispersant are required. Is important to be within the above range.

The water-based vibration damping paint of the present invention may optionally contain
Other additives, for example, an antifreezing agent, a stabilizer, an anti-skinning agent, a rust inhibitor, a coloring agent, an adhesion improver, and the like can be added, and can be diluted with water or the like as necessary. it can. When a coloring agent is added, the adhesion of the coating film is reduced. Therefore, it is preferable to add an adhesion improver together.

Further, water-based vibration damping paint of the present invention, a well-known method to those skilled in the art, for example, air spray, airless spray, brush coating, spatula coating, can be coated in a conventional manner in the roller coating or the like Especially air spray, air spray
Suitable for spraying . The coating thickness in that case is
If it is too thin, drying of the coating film will be fast, but sufficient vibration damping properties will not be obtained.On the other hand, if it is too thick, the vibration damping properties will improve, but it will take time to dry the coating film, Since a good coating film cannot be obtained, such as occurrence of cracks and the like, about 0.1 to
Suitably 5 mm, preferably about 0.5-3 mm.

As a method for 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.

[0024]

【Example】

Examples 1 to 23, Comparative Examples 1 to 9 <Preparation of paints> The components shown in Tables 1 to 12 were mixed at the mixing ratios shown in Tables 1 to 12 to prepare paints. The results were evaluated in the following manner, and
12 is shown.

<Storage Stability> The storage stability of the paint was evaluated by centrifuging 100 g of each prepared paint.
Observation of the bottom of each paint after 30 minutes of treatment at a rotation speed of 0 rpm, a pass (O) when fluidity was easily restored by stirring, and a fail (X) when fluidity could not be restored.
And

<Spray Coating Property> The spray coating property was evaluated as good (○) 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 evaluated as a loss coefficient measured by the central excitation half width method at 20 ° C. and 1000 Hz.

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

[0033]

[Table 5]

[0034]

[Table 6]

[0035]

[Table 7]

[0036]

[Table 8]

[0037]

[Table 9]

[0038]

[Table 10]

[0039]

[Table 11]

[0040]

[Table 12]

[0041]

According to the present invention, the loss factor at around room temperature to contain the inorganic filler in a large amount is higher damping performance can be obtained as 0.2 or more, yet to contain a large amount of inorganic filler Nevertheless , certain inorganic fillers and certain synthetic resins
Use emulsions and specific thickeners and dispersants.
By using these, storage stability as well as paintability (particularly
A water-based damping paint having excellent spray paintability) can be obtained.

Continued on the front page (72) Inventor Toshihiro Kobori 1134-2, Gondogendo, Satte City, Saitama Prefecture Cosmo Research Institute, Inc. R & D Center (72) Inventor Masahiko Doda 1134-2, Gongendo, Satte City, Saitama Prefecture Cosmo Corporation Within the Research and Development Center, Research Institute (72) Takao Kimura 1134-2, Gongendo, Satte City, Saitama Prefecture Within the Research and Development Center, Cosmo Research Institute, Inc. (56) References JP-A-53-133238 (JP, A) JP-A-2-196848 (JP, A) JP-A-61-89267 (JP, A) JP-A-6-184465 (JP, A) JP-A-53-133238 (JP, A) JP-A-57-105466 (JP JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C09D 131/04 C09D 133/08 C09D 5/00

Claims (2)

(57) [Claims] 1. An acrylic ester copolymer having a glass transition temperature of -50 ° C. to 5 ° C. containing 30 to 70% by mass in solid content.
Free emulsion, the glass transition temperature of -50 ° C. to 5 ° C. Ethylene - 30 to 70 weight vinyl acetate copolymer with solids
% Of an inorganic filler composed of calcium carbonate and / or converter slag powder in an amount of 250 to 550 parts by mass, hectorite-based and polycarboxylic acid-based based on 100 parts by mass of at least one solid content selected from emulsions containing A thickener comprising both or any of the above, and a dispersant comprising a polyoxyalkylene-based and / or a polycarboxylic acid-based dispersant, containing 0.1 to 35 parts by mass of both or either. A water-based damping paint characterized by becoming. 2. The water-based vibration damping paint according to claim 1, which is used for spray coating.