KR20020053409A - Vibration-prevent paint with excellent vibration-prevention and formability - Google Patents

Abstract

PURPOSE: A vibration damping paint is provided, to make be sprayed easily, to improve the adhesive power to the metal surface and the formability, to widen the frequency range of vibration damping ability and to minimize the temperature dependence. CONSTITUTION: The vibration damping paint comprises at least one acryl emulsion with a glass transition temperature of -25 to 25 deg.C; a resin; a silane coupling agent; a poly(vinyl alcohol); and 50-55 wt% of an inorganic filler which has a distribution of particle size of 1-100 micrometers and whose void fraction is minimized. Preferably the inorganic filler comprises 30-32 wt% of CaCO3 which has a distribution of particle size of 1-20 micrometers and a mean particle size of 2 micrometers and 5 micrometers; 10-12 wt% of SiO2 which has a distribution of particle size of 1-10 micrometers and a mean particle size of 4 micrometers; 10-12 wt% of mica which has a distribution of particle size of 1-100 micrometers and a mean particle size of 20 micrometers; and 5-10 wt% of aluminum oxide which has a distribution of particle size of 1-100 micrometers and a mean particle size of 15 micrometers.

Description

Vibration-prevent paint with excellent vibration-prevention and formability

The present invention relates to an anti-vibration paint having excellent vibration damping properties and formability, and more particularly, to a vibration damping paint which can convert vibration energy into thermal energy by damping the material and attenuate vibration and reduce the generation of sound. .

In recent years, the precision of machinery and electronics has increased, and people also want to work in a better environment, so techniques for removing noise have developed a lot. When there are many people and many machines in a small area like Korea, it is essential to remove noise. In particular, since metal materials used to increase mechanical strength are causing vibration and noise, it is important to reduce noise of these metal materials.

The method of controlling vibration to reduce noise is to reduce the vibration energy of the element that generates the noise, and to reduce the emission of sound by controlling the speed of vibration or by canceling the energy using wave interference and converting to other energy. Say that.

The material used for this purpose is a vibration damping material, and there are two types of noise reduction methods. First, there is a method of canceling the vibration generated in a solid hard object by increasing the viscoelastic coefficient attached to the surface. The other method is to have two composite structures, which are filled with viscoelastic polymer between steel plates or stainless foils to catch vibrations. This is usually called a sandwich. This sandwich type can be seen that the characteristics that hold the vibration is determined by the viscoelastic properties of the resin filled in the middle. This vibration-catching property is generally the largest around the temperature with the maximum loss factor.

As materials related to the present invention, materials exhibiting a vibration damping effect by surface treatment include a vinyl polymer disclosed in Japanese Patent Application No. 26492/1978, a vibration damper formed of cement, and spherical sand. It is not only good at damping characteristics but also can not be used as a product for a long time, it is known that there are more problems in commercialization.

Japanese Patent Application No. 52545/1978 discloses an anti-vibration agent having excellent vibration damping characteristics in an extremely narrow temperature range of the secondary transition temperature from 0 ° C to 100 ° C in an emulsion type using a water-soluble high molecular weight polymer material. However, this vibration damping agent also has a lot of problems to use when the vibration damping characteristics fall sharply out of the temperature range.

Japanese Patent Application No. 133238/1978 discloses a resin or rubber product using ash, mica, and pieces of organic inorganic fibers in an incinerator as an additive. However, the price of the product can be lowered, but there is a problem that it is not possible to maintain the uniformity of the quality of the product as well as it is not commercialized due to low vibration damping characteristics and moisture resistance.

Japanese Patent Application No. 32538/1979 discloses a product using mica powder and silica sand as a filler. Japanese Patent Application No. 36341/1979 uses a resin that is dispersed in water and sludge produced in a phosphate process. A product using is disclosed. However, all of the products disclosed in these two patent documents have a problem in that the temperature range showing the dustproof property is narrow.

U.S. Patent No. 4,391,857 discloses a product using polyvinyl acetate emulsion, polyethylene powder, and fine inorganic powder as fillers, but the product exhibits vibration damping characteristics over a wide temperature range, but the change in vibration damping properties over time is long and long-term. There was a problem of poor stability in use.

In addition, U.S. Patent No. 5,411,810 discloses a change in the vibration damping characteristics using a water-based resin having a low Tg and a high Tg, but due to the use of ethylene glycol, it is poor in waterproofing properties and is required for drying and curing after application of a damping agent. There was a problem that the time is long.

The present invention was created in view of the above-mentioned problems of the prior art, and was created to solve this problem. The acrylic resin having a glass transition temperature of -25 ° C to 25 ° C is formulated as a basic resin, and the particle size distribution is 1 to It is aimed to provide a vibration damping paint that is filled with more than 50% of inorganic filler having 100㎛ and exhibits vibration damping performance in a wide frequency and temperature range, and has strong adhesiveness, moisture resistance and heat resistance, and is easy to work during molding.

The above object of the present invention is to adjust the total particle size by controlling the average particle size of the polymer emulsion, such as resin, silane coupling agent, polyvinyl alcohol, alone or mixed with each other or the acrylic emulsion having a glass transition temperature of -25 ℃ to 25 ℃ It is achieved by providing an anti-vibration paint having excellent vibration damping properties and moldability, which is prepared by filling an inorganic filler having a distribution of 1 to 100 µm and a minimum porosity of 50 to 55% by weight.

Hereinafter, the configuration of the present invention in more detail.

Vibration phenomena in machine structures usually shorten the life of the machine or often deteriorate its function. Therefore, it is desirable to suppress the vibrations of the machine and to allow the generated vibrations to disappear quickly. In addition, as demands for comfort in the living environment become stronger, interest in vibration damping materials in each field is increasing. The damping paint used as one of these damping materials is applied to trains, automobiles, elevators, etc. to suppress noise caused by vibration.

There are various kinds of vibration damping materials such as paint, sheets, vibration damping plates, and springs, but among them, paints can be effective in a lower cost and in a more convenient way than others. In particular, rubber and asphalt, which are used as materials for sheets and plates, have a disadvantage in that the temperature range that exhibits vibration damping performance is narrow and ages easily due to the external environment. Limited. Therefore, there is an urgent need to develop paints that can increase water resistance and heat resistance and exhibit vibration damping performance over a wide frequency and temperature range. In order to achieve the vibration damping performance of the paint, the glass transition temperature of the resin, the ratio of the resin and the inorganic filler, and the shape and size of the inorganic filler particles should be appropriately designed. The glass transition temperature of the resin determines the temperature range that exhibits vibration damping performance. Therefore, the closer the glass transition temperature of the resin to room temperature, the greater the vibration damping performance at room temperature. However, when the glass transition temperature of the resin is high, at room temperature, the resin is very weak in the glass phase, easily broken due to external impact, and easily broken due to low adhesive strength and high shrinkage rate, while at low glass transition temperature, the adhesive strength is excellent. Very flexible but not satisfactory vibration damping performance. That is, the glass transition temperature of the resin should be high for the damping performance and the glass transition temperature should be low for the moldability. Therefore, there is a need for a resin that can compromise both, that is, a resin having a high glass transition temperature and excellent strength and adhesion and satisfactory moldability. When the ratio of these resins and inorganic fillers is appropriate, the damping performance is maximized.

Inorganic fillers also have a too small particle size (less than 1 micron), which results in poor flowability of the paint and poor moldability (greater than 1 mm) to block nozzle holes during spraying. Therefore, the particle size of the inorganic filler should also be appropriate. In general, the particle shape is known to have a damping effect of the plate-like material, but the disadvantage is that the surface hardness is very low.

The present invention complements the disadvantages of the resin having a high glass transition temperature with a resin having a low glass transition temperature and uses only acrylic styrene resin for compatibility therebetween. A certain amount of a silane coupling agent and a water-soluble high molecular material (polypyrrole, polyvinylacetate, polyvinyl alcohol, polysulfonate, polyimide are optionally added) are added to enhance adhesion and shrinkage of the resin during drying. Prevented. In addition, in order to minimize the porosity of the inorganic fillers in the range of 1 to 100㎛ size, the average particle size of each of the fillers were combined in combination. In addition to the particle size distribution of the fillers, the structural properties of the fillers were limited to the plate shape to improve the sound insulation properties. Therefore, the vibration damping paint exhibits a wide range of vibration suppression performances at room temperature as well as above and below, and completely solves the disadvantages of the resin having a high glass transition temperature in terms of adhesiveness, formability and strength. The damping material used in the present invention exhibits stable properties even with time. In addition, since the porosity of the inorganic filler itself blended at a constant ratio is small, the thickness of the coating film that can exhibit the vibration damping performance is minimized.

In the present invention, a high molecular weight polymer additive is added to satisfy both the vibration damping performance and the moldability. High molecular weight additives should be able to coexist with the emulsion and be able to catch the defects that occur as the resin hardens. Various kinds of additives were used, and the examples described were based on vinyl alcohol based high molecular weight materials. In addition, styrene derivatives were used as water-soluble materials having high molecular weight, copolymers of polyvinylacetate and alcohol, materials synthesized by water solubility as derivatives of polypyrrole, and water-soluble polyimides as additives. One or only one was used alone.

In addition, by controlling the particle size distribution in various ways, the frequency range with vibration damping characteristics is widened. Due to the combination of the particle size distribution, a film with a minimum thickness that can exhibit the vibration damping characteristics can be produced while eliminating the problems of moldability and thin film coating. It is. In the present invention, a particle having a particle size distribution of 1 μm to 100 μm was combined to produce a film capable of exhibiting the above characteristics. In addition, 5 to 10 parts by weight of aluminum oxide having high thermal conductivity was used to rapidly release thermal energy generated by vibration to maximize vibration damping performance and to prevent aging of the coating due to heat. Glass flakes, glass balloons, hollow silica, etc., which have been used in conventional vibration dampening paints, are expensive and do not quickly release heat generated due to their insulation properties. There is a high risk of deterioration. The present invention is characterized in that it does not contain any of these materials, so that the damping effect can be seen at a lower price.

Meanwhile, in order to improve the deterioration of adhesion due to the resin having a high glass transition temperature, a silane coupling agent is used to improve adhesion and induce chemical bonding between inorganic and organic materials, thereby minimizing bonds that may occur during drying. This silane coupling agent can be used individually or in mixture with 2-aminopropyl triethoxysilane (3-aminopropryltrietoxysilane), 3-glycidoxypropyltrimethoxysilane (3-glycidoxypropyltrimethoxysilane). Plasticizers used to control the flowability and drying time of the paint to form a more stable coating film generally gives a free volume to the polymer chain to reduce the glass transition temperature of the resin. Since the glass transition temperature of the plasticizer itself is low, even with a slight plasticizer, the glass transition temperature can be significantly lowered, so the content of the plasticizer should be controlled to within 3%. The plasticizer may be DBP (dibutyl phthalate), DOP (dooctyl phthalate), DEP (diethyl phthalate), DOA (di-2-ethylhexyl adipate) and the like. On the other hand, if the characteristics of the resin changes over time, the compatibility with the product is inferior. Therefore, it is an intended object of the present invention to produce a sample insensitive to such changes over time.

Hereinafter, the present invention will be described in more detail with reference to Examples 1 to 4 and Comparative Examples 1 and 2, but the present invention can be variously modified without being limited by the scope thereof.

Example 1

28 wt% of the acrylic emulsion having a glass transition temperature of -50 ° C. and 55 wt% of the inorganic filler having a particle size distribution were adjusted, and the remaining components were prepared as shown in Table 1 below to prepare vibration damping of the present invention.

Example 2

28 wt% of the acrylic emulsion having a glass transition temperature of -25 ° C., 55 wt% of the inorganic filler having a particle size distribution controlled, and a polymer additive, and the remaining components were prepared as shown in Table 1 to prepare a paint of the present invention.

Example 3

28 wt% of the acrylic emulsion and 55 wt% of the inorganic filler having a glass transition temperature of -25 ° C. were prepared as shown in Table 1 below to prepare the paint of the present invention.

Example 4

5% by weight of an acrylic emulsion having a glass transition temperature of -25 ° C, 15% by weight of an acrylic emulsion having a glass transition temperature of 9 ° C, 10% by weight of an acrylic emulsion having a glass transition temperature of 25 ° C, and 55% by weight of an inorganic filler having a particle size distribution. , A silane coupling agent, and a polymer additive were prepared to prepare a paint of the present invention.

Comparative Example 1

Glass transition temperature is -50 ℃ composed of 43% by weight of the acrylic emulsion and 35% by weight of inorganic filler and the remaining components were prepared as shown in Table 1 to prepare a general paint.

Comparative Example 2

5% by weight of an acrylic emulsion having a glass transition temperature of -25 ° C, 15% by weight of an acrylic emulsion having a glass transition temperature of 9 ° C, 10% by weight of an acrylic emulsion having a glass transition temperature of 25 ° C, and 55% by weight of an inorganic filler having a particle size distribution. The rest of the components were prepared as shown in Table 1 below to prepare a general paint.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 water 20 14 14 14 14 8 Acrylic emulsion 43 (Tg = -50 ° C) 5 (Tg = -25 ° C) 15 (Tg = 9 ° C) 10 (Tg = 25 ° C) 28 (Tg = -50 ° C.) 28 (Tg = -25 ° C) 25 (Tg = -25 ° C) 5 (Tg = -25 ° C) 15 (Tg = 9 ° C) 10 (Tg = 25 ° C) CaCO ₃ (average particle size 2㎛) 25 12 11 11 12 CaCO ₃ (average particle size 5㎛) 10 10 10 10 SiO ₂ (average particle size 4㎛) 10 12 14 14 27 12 Mica (average particle size 20㎛) 11 11 11 32 11 Aluminum oxide (average particle size 15㎛) 10 10 10 10 10 Other additives 2 2 3 3 2 9

The vibration damping performance of each paint prepared according to the composition shown in Table 1 was evaluated using the Modal Method. Cold rolled steel sheets 1mm thick, 30mm wide and 330mm long were washed according to the manufacturing method of steel sheet for paint testing (KSM5000-1111), and each coating was applied with 1mm thickness, and then dried for 48 hours to prepare specimens. The vibration damping performance was measured at 50 ° C and 50 ° C.

T-peel peel strength was measured based on JIS K-6854. At this time, the maximum load measured by the tensile test at 50mm / min was converted to the maximum load per 25mm width of the specimen.

Each test result measured as described above is shown in Table 2 below.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Internal loss factor (400 Hz) 25 ℃ 0.014 0.128 0.025 0.091 0.050 0.134 50 ℃ 0.006 0.112 0.013 0.070 0.041 0.125 Internal loss factor (600 Hz) 25 ℃ 0.016 0.121 0.024 0.082 0.043 0.126 50 ℃ 0.009 0.101 0.008 0.054 0.032 0.108 Internal loss factor (850 Hz) 25 ℃ 0.010 0.105 0.024 0.070 0.041 0.113 50 ℃ 0.004 0.095 0.006 0.043 0.021 0.101 Peel Strength (kg / 25mm) 35.89 13.17 38.24 39.45 36.14 45.98

As can be seen from Table 2, Example 1 in which the content of the inorganic filler was increased, there was an increase in the internal loss coefficient compared to Comparative Example 1 and showed even vibration damping performance in each frequency band. Example 2 using an acrylic emulsion having a glass transition temperature of −25 ° C. and having the same composition as in Example 1 exhibited a damping effect of about three times compared to that of Example 1. In addition, Example 3 in which the mica content in the filler was increased in Example 2, but the performance was decreased, and Example 4 in which the acrylic transition of the glass transition temperature in Example 2 was -25 ° C, 9 ° C, and 25 ° C was mixed. Compared with 2, the damping performance was improved and the variation by temperature was very small.

In the case of peeling strength, Example 4 using the silane coupling agent and the polymer additive together, it can be seen that there was an increase of 3 times or more compared to Comparative Example 2, in which the remaining composition was used in the same manner without using any additives.

On the other hand, after producing the vibration damping paint of the present invention after two months of coating on the surface of the product, the characteristics of the membrane were measured, but the damping properties, waterproofing, mechanical properties, and adsorption properties of the membrane were all equivalent to those immediately after the membrane was manufactured. .

As can be seen from the above description, the anti-vibration paint according to the present invention is a one-component water-based paint composed of an acrylic emulsion, a plate-like filling material capable of satisfying the vibration damping properties and the soundproofing properties at the same time. It is easy to spray, has good adhesion to metal surfaces, exhibits excellent vibration damping capability over a wide frequency range and minimizes temperature dependence.

Claims (2)

Acrylic emulsions having a glass transition temperature in the range of -25 ° C to 25 ° C may be mixed alone or with each other, and polymer additives such as resins, silane coupling agents, polyvinyl alcohols, and the average particle size may be adjusted to 1-100 μm. An anti-vibration coating with excellent vibration damping and formability, which is prepared by filling an inorganic filler with a minimum porosity of 50 to 55% by weight. According to claim 1, wherein the inorganic filler has a particle size distribution of 1 to 20㎛, 30 _~ 32% by weight CaCO ₃ having an average particle size of 2㎛ and 5㎛, a particle size distribution of 1 ~ 10㎛, SiO having an average particle size of 4㎛ ₂ 10 to 12% by weight, 10 to 12% by weight of mica having a particle size distribution of 1 to 100 μm and an average particle size of 20 μm, and 5 to 10% by weight of aluminum oxide having a particle size distribution of 1 to 100 μm and an average particle size of 15 μm An anti-vibration paint with excellent vibration damping and formability, comprising components.