WO1999038922A1

WO1999038922A1 - Vibration-damping coating material

Info

Publication number: WO1999038922A1
Application number: PCT/JP1998/000445
Authority: WO
Inventors: Masamitsu Muto; Takeshi Hirata
Original assignee: Shishiai-Kabushikigaisha
Priority date: 1998-02-02
Filing date: 1998-02-02
Publication date: 1999-08-05
Also published as: WO1999038922A8

Abstract

A vibration-damping coating material applicable to places where vibration occurs, such as motor vehicles, interior materials, constructional materials, and domestic electrical appliances, in particular, a coating material which is reduced in the deformation, blistering, and cracking caused by baking/drying and in the cracking caused by base resin shrinkage due to cooling after baking/drying. The coating material is characterized by comprising a base resin emulsion, a gelling agent, a nonionic surfactant having a cloud point of 60 °C to 90 °C, a water-soluble polymer, and an ionic cross-linking agent.

Description

TECHNICAL FIELD The present invention relates to a vibration damping paint applied to a place where vibration occurs, such as an automobile, an interior material, a building material, and a household electric appliance. In particular, the present invention relates to a vibration-damping paint which is less susceptible to deformation, swelling, and cracking due to baking and drying, and less occurrence of bright cracks due to shrinkage of a base resin due to cooling after baking and drying. Background Art Conventionally, in places where vibration occurs, such as in automobiles, interior materials, building materials, and home electric appliances, a sheet-shaped vibration-damping sheet has been generally used as a member for absorbing the vibration energy. However, in the case of a damping sheet, it must first be cut into a size and shape corresponding to the application area. In addition, since the damping sheet is attached to the application area using an adhesive or a pressure-sensitive adhesive, most of the attaching work is manual, and there was a problem that the working efficiency was poor. In particular, the damping sheet cannot be pasted on curved surfaces or narrow gaps, or it can be easily occupied by shells, but it can easily be peeled off, or it takes a lot of time to paste. And time was required. In light of these problems, in recent years, based on viscoelastic polymers such as rubber, plastic, and asphalt, these have been dispersed in water to form an emulsion, and a filler such as my scale has been added. So-called damping paints have been proposed. With this damping paint, the damping layer can be easily formed simply by spraying the damping paint to the application area, and the work of cutting and pasting as in the case of the damping sheet is not required. For example, there is an advantage that a vibration damping layer can be easily formed even on a curved surface portion or a narrow gap portion. Further, in the case of this damping paint, since the damping paint is simply sprayed on the applicable portion, the work can be performed using a robot or the like, and there is an advantage that work efficiency can be greatly improved. However, this damping paint is in the form of an emulsion in which the base and fillers are dispersed in water or alcohol. The water inside boils and evaporates at once, forming bubbles, which deform, swell, and crack the coating film, significantly impairing its appearance. In particular, when a coating film with a thickness of 3 mm or 4 mm is formed to enhance the vibration damping performance, the deformation and swelling of the coating film also increase, making it difficult to suppress the occurrence. there were. In addition, in the case of a vibration damping paint based on a plastic, the resulting coating film has poor elasticity as compared with those based on a rubber or asphalt, so that the base resin is cooled by cooling after baking and drying. There was a problem that it shrank and caused a bright crack. DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it has been found that deformation, swelling, and cracks due to baking and drying, and the occurrence of bright cracks due to shrinkage of the base resin due to cooling after baking and drying, are avoided. The object of the present invention is to propose a small amount of damping paint. Hereinafter, the damping paint of the present invention will be described in detail. The vibration damping paint of the present invention The resin emulsion contains a gelling agent, a nonionic surfactant having a cloud point of 60 ° C to 90 ° C, a water-soluble polymer, and an ionic crosslinking agent. It does. Examples of the base resin include unsaturated carboxylic acids such as acrylonitrile, acrylic acid, methacrylic acid, itaconic acid, and fumaric acid, and polymers of the alkyl esters thereof, copolymers with styrene, and the like, or polyvinyl chloride, polyether. Tylene, polypropylene, ethylene-vinyl acetate copolymer, polyurethane, polyvinylidene fluoride, polyisoprene, polystyrene, chlorinated polyethylene and the like can be mentioned. One or more of these are dispersed in water or alcohol and used in the form of emulsion. In addition, as the base resin, the performance is best exhibited in the operating temperature range (120 ° C to 80 ° C) to which the damping coating is applied, such as automobiles, interior materials, building materials, and home appliances. Further, those having a glass transition point (T g) in the operating temperature range are preferable. The gelling agent gels the base resin emulsion. As described above, when the coating is baked and dried after spraying the damping paint to the application area, the water inside the coating film boils and evaporates at once, causing bubbles to be formed, resulting in deformation, swelling, and cracking of the coating. I do. However, if the coating is gelled during baking and drying, water will be entrapped inside the coating, and as a result, the deformation, swelling and cracking of the coating will be suppressed. Known gelling agents having such an action include, for example, calcium acetate, calcium phosphate, calcium nitrate, ferrous sulfate, ferrous nitrate, nickel acetate, nickel sulfate, nickel nitrate, magnesium acetate , Magnesium sulfate, magnesium nitrate, copper sulfate, copper nitrate, zinc acetate, zinc sulfate, zinc nitrate, aluminum acetate, aluminum phosphate, aluminum sulfate, and aluminum nitrate. Among them, calcium nitrate, magnesium nitrate and copper sulfate are performance, It is more preferable from the viewpoint of stability. When the above-mentioned gelling agent is added alone to the base resin emulsion, many of the above-mentioned gelling agents are unstable, so that gelation occurs at room temperature, the viscosity of the paint becomes high, and clogging during spray coating may occur. May occur. Therefore, in the present invention, a nonionic surfactant having a cloud point of 60 ° C. to 90 ° C. is added thereto. Nonionic surfactants with a cloud point of 60 ° C to 90 ° C, for example, when the temperature reaches 60 ° C or 90 ° C, the surface activity that had been acting until then decreases. A surfactant with the property of having When a surfactant having such properties is used in combination, the damping paint is liquid at room temperature due to the action of the surfactant, but the temperature of the coating film is increased by baking and drying. When the surfactant reaches the cloud point temperature of 90 ° C or 90 ° C, the surface activity of the surfactant decreases, and the gelling of the coating film proceeds due to the action of the gelling agent. This leads to the effect of suppressing deformation, swelling and cracking of the coating film. Examples of the nonionic surfactant having a cloud point of 60 ° C. to 90 ° C. include those containing phenol ethoxylate as a main component. The content of the gelling agent and the nonionic surfactant is 0.75 to 3.5% by weight for the gelling agent, and 1.34 to 3.5% by weight for the nonionic surfactant. A range of% is preferred. When the content of the gelling agent is less than 0.75% by weight, gelation is weak, and it is not possible to sufficiently suppress the deformation, swelling, and cracking of the coating film during baking and drying. When the content of the agent exceeds 3.5% by weight, the gelation is too strong, the viscosity of the paint at the time of application becomes high (the effect of the surfactant is not sufficiently exerted), and the spray becomes clogged. May occur. When the content of the nonionic surfactant is less than 1.34, the surface activity is weak, gelation by the gelling agent proceeds, and the viscosity of the paint at the time of application increases. On the other hand, when the content of the nonionic surfactant exceeds 3.5% by weight, The surface activity becomes too strong, and the gelation of the coating film does not proceed sufficiently during baking and drying. The ionic cross-linking agent suppresses the generation of cracks in the coating film during baking and drying of, for example, zinc oxide, and the content thereof is preferably in the range of 0.5 to 2.0% by weight. The water-soluble polymer imparts elasticity to the base resin, so that even if the base resin shrinks due to cooling after baking and drying, the occurrence of bright cracks can be suppressed. The content of the water-soluble polymer is preferably in the range of 0.05 to 0.40% by weight. Further, the vibration damping paint of the present invention has a form in which an active ingredient for increasing the amount of dipole moment in the same base resin is included in the base resin emulsion for the purpose of dramatically improving the vibration damping performance. Can also be taken. First, the relationship between the dipole moment amount and the damping performance will be described. Fig. 1 shows the arrangement of the dipoles 12 inside the base resin 11 constituting the coating film before the vibration energy is transmitted. It can be said that the arrangement state of the dipoles 12 is in a stable state. However, the transmission of vibration energy causes a displacement in the dipoles 12 where the base resin 11 is located, and as shown in FIG. 2, each dipole 12 in the base resin 11 is displaced. It will be in an unstable state, and each dipole 1 2 will try to return to a stable state as shown in Figure 1. At this time, energy is consumed. It is considered that the vibration energy is absorbed (vibration damping performance) through such displacement of the dipole inside the base resin 11 and energy consumption by the restoring action of the dipole. The active ingredient dramatically increases the amount of dipole moment in the base resin. The active ingredient itself has a large amount of dipole moment, or the active ingredient itself has a small amount of dipole moment, but the inclusion of the active ingredient results in a dipole in the base resin. A component that increases the amount of momentum dramatically. For example, the amount of dipole moment generated in the base resin 11 constituting a coating film under a predetermined temperature condition and vibration energy is determined by the fact that the active ingredient is contained in the base resin. As shown in Fig. 3, under the same conditions, the amount will increase by a factor of three or ten. Along with this, the energy consumption due to the dipole restoring action when the vibration energy is transmitted will also increase dramatically, and it is thought that the vibration suppression performance far exceeds the prediction. Examples of active ingredients that induce such effects include N, N-dicyclohexylbenzothiazyl-1-sulfenamide (DCHBSA), 2-mercaptobenzothiazole (MBT), dibenzothiazyl sulfide (MBTS), Cyclohexyl benzothiazyl-1-sulfenamide (CBS), N-tert-butylbenzothiazyl-12-sulfenamide (BBS), N-oxycetylene Lenbenzothiazilyl 2-sulfenamide (OBS), N, N —Compounds containing a mercaptobenzothiazyl group, such as diisopropylbenzothiazirulu-2-sulfenamide (DPBS), and a benzotriazole in which an azole group is bonded to the benzene ring, to which a phenyl group is bonded 2— {2'—Hydroxy-1 3 '— (3,4 ", 5", 6 "tetrahydrophthalimimidemethyl) 1-5'-Methyl Phenyl} -benzotriazole (2HPMMB), 2- {2'-hydroxy-5'-methylphenyl} -benzotriazoyl (2HMPB), 2- {2'-hydroxy-3'-t— Butyl-5'-methylphenyl} -5-chloro benzotriazole (2HBMP CB), 2- {2'-hydroxy-1 3 ', 5'-di-t-butylphenyl} -5-chloro Benzotriazole groups such as benzobenzotriazole (2HDBPCB) A compound containing diphenylacrylate, such as ethyl 2-cyano-3,3-diphenylacrylate, or 2-hydroxy14-methoxybenzophenone (HMBP), 2-hydroxy14 One or more selected from compounds having a benzophenone group, such as —methoxybenzophenone-1-5-sulfonic acid (HMBPS). The content of the above-mentioned active ingredient is preferably from 100 to 100 parts by weight based on 100 parts by weight of the base resin. For example, when the content of the active ingredient is less than 100 parts by weight, the effect of increasing the amount of the dipole moment cannot be obtained, and when the content of the active ingredient exceeds 100 parts by weight, Insufficient compatibility or insufficient film strength may be obtained. In deciding the active ingredient contained in the base resin, it is preferable to take into consideration the easiness of compatibility between the active ingredient and the base resin, that is, the SP value, and select a substance having a similar value. The amount of the dipole moment varies depending on the type of the base resin and the active component described above. And even if the same components are used, the amount of the dipole moment changes depending on the temperature at which the vibrational energy is transmitted. Also, the amount of the dipole moment changes depending on the magnitude of the transmitted vibration energy. For this reason, considering the temperature and the magnitude of vibration energy when applied as a damping paint, the base resin and active component should be selected and used so as to have the largest dipole moment at that time. Is desirable. The above-mentioned active ingredients are not limited to one kind, and two or more kinds can be mixed. Also this In this case, at least two or more types of active components having different glass transition points can be included in the base resin to extend the temperature range in which the vibration damping property is exhibited. As described above, the vibration-damping paint containing the active ingredient in the base resin emulsion significantly increases the amount of the dipole moment in the coating film, thereby exhibiting excellent vibration-damping performance. The amount of this dipole moment is expressed as the difference in dielectric constant (£ ') between A and B shown in Fig. 4. In other words, the larger the difference in dielectric constant (£ ') between A and B shown in Fig. 4, the larger the amount of dipole moment. Now, FIG. 4 is a graph showing the relationship between the dielectric constant ε ′) and the dielectric loss factor (£ 〃). The relationship between the dielectric constant (£ ′) and the dielectric loss factor Has a relationship such as: dielectric loss factor) = dielectric constant (£ ') X dielectric loss tangent (tan (5). The present inventor has studied through the research on vibration damping paints, The higher the £ 〃), the higher the loss factor (r?) And the loss tangent (t anS). That is, the dielectric loss factor (£ 〃), which expresses the electronic properties of a polymer, and the dynamics Based on this finding, there is a correlation between the loss coefficient () and the loss tangent (tancS), which indicate the properties, and based on this finding, the dielectric loss factor (£) in the coating film of the vibration damping paint of the present invention. 〃), when the dielectric loss factor at a frequency of 1 10 Hz is 50 or more, the loss coefficient () and the loss It was found that both of the values of t and were high and that they had excellent damping performance In addition to the active ingredient, the base resin emulsion further improved the damping performance Fillers such as my scales, glass pieces, glass fiber, carbon fiber, calcium carbonate, barite, and precipitated barium sulfate are filled for the purpose. The filling amount of the filler is preferably from 10 to 90% by weight. For example, when the filling amount of the filler is less than 10% by weight, sufficient improvement in vibration damping performance is not observed even when the filler is filled, and conversely, the filling amount of the filler is reduced to 90% by weight. Even if the amount exceeds the above range, adverse effects may be caused if the material cannot be actually filled or if the mechanical strength of the coating film composed of the base resin decreases. In addition, other components such as a dispersing agent, a wetting agent, a thickening agent, a defoaming agent, an antifreezing agent, or a coloring agent may be appropriately added to the damping paint of the present invention as necessary. In addition, this damping paint is obtained by dissolving a base resin, a dispersing medium such as water and alcohol, a filler, and other components containing an active ingredient, a dispersant, and a thickener as necessary, such as a dissolver or a bumper. It is manufactured by dispersing and mixing with a conventionally known mixing and dispersing machine such as a mixer, a planetary mixer, a Glenmill, an open kneader, and a vacuum kneader. When applying the vibration damping paint, a conventionally known application means such as an air spray gun, an air spray gun, or a brush can be used. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing dipoles in a coating film. FIG. 2 is a schematic diagram showing a state of a dipole in a coating film when vibration energy is transmitted. Fig. 3 is a schematic diagram showing the state of the dipole in the coating film when the active ingredient is blended.

Figure 4 shows the relationship between the dielectric constant (<< £ ') and the dielectric loss factor (£ 〃) in the coating film. rough. FIG. 5 is a graph showing the loss coefficient () at each temperature in Examples 1 to 3. BEST MODE FOR CARRYING OUT THE INVENTION

(Hereinafter the margin)

table 1

Was applied to the surface density of the steel plate of the vibration damping paint thickness 0. 8 mm according to Example 1 and Comparative Examples 1 to 4 containing the ingredients shown in Table 1 is 4 kg / m ^2, 16 CTC In 2 The coating was formed on the steel sheet by baking and drying for 0 minutes, and then allowed to cool and then bake and dry again at 160 ° C for 20 minutes. The formed coating film was visually inspected for blisters and cracks, and the results are shown in Table 2 below. The properties of the coating film were evaluated as “X” when the coating film was swollen or cracked, and as “〇” when there was no swelling or cracking. Table 2

The loss coefficient (7?) Of the coating film according to Example 1 was measured. The results are shown in FIG. The loss coefficient (7?) Was measured using an electromagnetic vibration detector (MT-1, A202) manufactured by Denshi Sokki Co., Ltd. In addition, those coated so as to have an areal density of 2 kg / m ² (Example 2) and those coated so as to have an areal density of 3 kg / m ² were used in the same manner as in Example 1. The loss factor (77) was measured and is shown in FIG.

Claims

Scope of word blue

1. Base camphor oil emulsion contains a gelling agent, a nonionic surfactant having a cloud point of 60 ° C to 90 ° C, a water-soluble polymer, and an ionic cross-linking agent Damping paint that is characterized by

2. The above-mentioned gelling agent is 0.75 to 3.5% by weight, the nonionic surfactant is 1.34 to 3.5% by weight, the water-soluble polymer is 0.05 to 0.40% by weight, and ionic cross-linking. The damping paint according to claim 1, wherein the agent is contained in a ratio of 0.5 to 2.0% by weight.

3. The vibration damping paint according to claim 1, wherein the base resin emulsion contains an active ingredient that increases the amount of dipole moment in the base resin.

4. The vibration damping paint according to claim 3, wherein the active ingredient is contained in a ratio of 10 to 100 parts by weight based on 100 parts by weight of the base resin.

5. The vibration damping paint according to claim 3, wherein the active ingredient is one or more selected from compounds containing a mercaptobenzothiazyl group.

6. The vibration damping coating according to claim 3, wherein the active ingredient is one or more selected from compounds having a benzotriazole group.

7. The vibration damping paint according to claim 3, wherein the active ingredient is one or more selected from compounds having a diphenylacrylate group.

8. The vibration damping paint according to claim 3, wherein the active ingredient is at least one selected from compounds having a benzophenone group.

9. The base resin according to claim 3, wherein at least two or more active ingredients having different glass transition points are blended, and a temperature range in which vibration damping is exhibited is extended. 8. The damping paint according to any one of 8.

10. The vibration damping paint according to claim 3, wherein the dielectric loss factor at a frequency of 110 Hz is 50 or more.