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KR-102961972-B1 - Moisture curing Polyurethane vibration Damping material

KR102961972B1KR 102961972 B1KR102961972 B1KR 102961972B1KR-102961972-B1

Abstract

The present invention relates to a vibration-damping steel plate for reducing noise and vibration. More specifically, the invention relates to a vibration-damping steel plate that exhibits vibration damping performance in a laminated form of a metal plate and a vibration-damping layer, which is applied to structures where vibration sources exist, such as automotive body panels, covers for electrical components of electric and hybrid vehicles, and battery housings, and a method for manufacturing the same.

Inventors

  • 김지훈

Assignees

  • 주식회사 디에스피

Dates

Publication Date
20260511
Application Date
20251201

Claims (8)

  1. A first steel plate composed of at least one of aluminum (A3000~6000), CR, GA, GI (mild steel, high-strength steel), and STS; A second steel plate composed of at least one of aluminum (A3000~6000), CR, GA, GI (mild steel, high-strength steel), and STS; A vibration damping layer made of PUR (polyurethane) applied between the first steel plate and the second steel plate; Includes The above vibration damping layer A first region applied to the edge area of the first steel plate and the second steel plate. A second region applied to the central region of the first steel plate and the second steel plate. Includes, The degree of PUR (polyurethane) curing in the first region and the second region is different from each other. The degree of hardening of the second region is lower than the degree of hardening of the first region. The first region is a closed-loop strip-shaped region formed to be continuously wrapped along the outer edges of the first steel plate and the second steel plate, and is formed to have a width of 5 to 50 mm inwardly from the outer edges of the first steel plate and the second steel plate, and The second region comprises a central region 2a in the shape of a disc or polygon arranged in the central part of the first steel plate and the second steel plate, and a plurality of band-shaped regions 2b extending radially from the central region 2a toward the first region. A vibration-damping steel plate utilizing moisture-curing PUR resin, characterized in that the total coating area of the second region is set to have a ratio of 0.5 times or more and 3 times or less with respect to the total coating area of the first region.
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  3. In paragraph 1 In the first region, a plurality of discharge holes are formed penetrating at least one of the first steel plate and the second steel plate and the vibration damping layer so that fine noise and fine vibrations absorbed by the first steel plate and the second steel plate, which are not attenuated by the vibration damping layer, can be released into the atmosphere. A vibration-damping steel plate utilizing moisture-curing PUR resin characterized by being equipped with this.
  4. In paragraph 1 The above vibration damping layer is formed by applying a moisture-curing PUR precursor composition between the first steel plate and the second steel plate, A first step of pre-degassing the above precursor composition for 5 to 60 seconds in a dry atmosphere having a temperature of 10 to 30 degrees and a relative humidity of 20 percent to 40 percent, After the first step above, a second step of initiating curing for 10 minutes to 2 hours while compressing the first steel plate and the second steel plate by a pressure roller applying a linear pressure of 0.1 megapascals to 1.5 megapascals at a relative humidity of 60 percent to 90 percent and a temperature of 30 degrees to 80 degrees, A third step of refining the internal pore structure by applying ultrasonic vibrations of 20 kilohertz to 40 kilohertz for 1 minute to 10 minutes while cycling a vacuum of 10 millibars to 100 millibars and an atmospheric pressure state 5 to 50 times when the curing progress rate of the above vibration damping layer is 30 percent to 70 percent, Vibration-damping steel plate utilizing moisture-curing PUR resin characterized by proceeding as follows.
  5. In paragraph 4 A fourth step, following the third step above, in which the vibration damping layer is rapidly cooled to a temperature of minus 10 to 10 degrees in an inert gas atmosphere, and then reheated to a temperature of 50 to 120 degrees to proceed with the remaining isocyanate reaction. Vibration-damping steel plate utilizing moisture-curing PUR resin characterized by proceeding as follows.
  6. In paragraph 5 A fifth step, following the fourth step above, of adjusting the molecular chain arrangement and loss coefficient by simultaneously irradiating the vibration damping layer with ultraviolet rays or microwaves having a wavelength of 200 nanometers to 400 nanometers in the thickness direction for 30 seconds to 10 minutes and applying an alternating magnetic field of 0.01 Tesla to 0.2 Tesla. Vibration-damping steel plate utilizing moisture-curing PUR resin characterized by proceeding as follows.
  7. In paragraph 1 The moisture-curing PUR precursor composition forming the above vibration damping layer is, 100 parts by weight of a polyol component comprising a polyether polyol and a polyester polyol, wherein the polyol component comprises 60 to 95 parts by weight of a polyether polyol having a number average molecular weight of 1,000 to 3,000 having oxypropylene units as the main component, and 5 to 40 parts by weight of a polyester polyol having a number average molecular weight of 500 to 2,000 derived from adipic acid and ethylene glycol. Based on 100 parts by weight of the above polyol component, 20 to 80 parts by weight of a diisocyanate component comprising a methylene diphenyl diisocyanate-based or hexamethylene diisocyanate-based system; 1 to 20 parts by weight of a chain extender comprising 1,4-butanediol having 2 to 4 hydroxyl groups, ethylene glycol, or trimethylolpropane; 50 to 250 parts by weight of an inorganic filler comprising at least two of calcium carbonate, barium sulfate, silica, and talc; 5 to 50 parts by weight of an ester-based plasticizer comprising a phthalate-free plasticizer; 5 to 80 parts by weight of a tackifying resin comprising at least one of a hydrogenated rosin ester resin or a C5·C9 petroleum resin; 0.01 to 5 parts by weight of a urethane reaction catalyst comprising at least one of a tin-based catalyst and a bismuth-based catalyst; and a carbodiimide-based moisture capture agent or a zeolite-based 0.1 to 10 parts by weight of a moisture capture agent containing a drying agent and 0.1 to 10 parts by weight of a silane coupling agent containing an alkoxysilyl group Vibration-damping steel plate utilizing moisture-curing PUR resin characterized by being made of
  8. In paragraph 1 A vibration-damping steel plate utilizing a moisture-curing PUR resin, characterized in that the second region is formed in a semi-solid (semi-molten) state, the first region improves the bonding strength between the first steel plate and the second steel plate, and the second region can improve vibration damping performance.

Description

Moisture-curing Polyurethane vibration Damping material Moisture-curing Polyurethane vibration Damping material The present invention relates to a vibration-damping steel plate for reducing noise and vibration. More specifically, the invention relates to a vibration-damping steel plate that exhibits vibration damping performance in a laminated form of a metal plate and a vibration-damping layer, which is applied to structures where vibration sources exist, such as automotive body panels, covers for electrical components of electric and hybrid vehicles, and battery housings, and a method for manufacturing the same. The content described in this section merely provides background information regarding the present invention and does not constitute prior art. In conventional automobiles, significant vibration and noise are generated not only in the powertrain system, such as the engine and transmission, but also in various electrical components and auxiliary devices, including electric compressors, inverters, onboard charger covers, integrated charging control unit covers, and oil pans. Such vibrations and noise are transmitted into the vehicle cabin through structures such as subframes, members, and body panels, causing problems that not only degrade ride comfort and quietness but also increase fatigue during long-distance driving and directly lead to a decline in the vehicle's marketability. Accordingly, vibration damping materials and vibration damping steel plates are widely used to effectively absorb vibration energy in body panels or cover parts to reduce noise and vibration. Generally, vibration-damping steel plates for automobiles utilize a structure in which a resin layer is laminated on one or both sides of a single steel plate, or a method of forming a sandwich structure by interposing a resin layer between a first steel plate and a second steel plate. The above resin layer is composed of polymer resins such as polyester, polyolefin, acrylic, and polyurethane types, and is known to reduce noise and vibration by converting vibration energy into thermal energy through shear deformation of the resin layer and interfacial friction between the resin and the steel plate when vibration occurs. These vibration-damping steel plates can exhibit superior vibration damping performance compared to single steel plates of the same thickness, and are recognized as an important means in the automotive industry, which must secure vibration characteristics while pursuing vehicle body weight reduction. Meanwhile, conventionally, a method of attaching viscoelastic damping materials, such as asphalt-based sheets or butyl rubber-based sheets, to panels has been widely used. While these vibration damping materials can exhibit stable damping performance in the relatively low frequency range, they have a problem in that they cause an increase in vehicle weight due to their high specific gravity and thick thickness. In addition, asphalt-based materials are susceptible to sagging in high-temperature environments or performance degradation during long-term use, and they also have limitations in terms of environmental regulations, such as the emission of volatile organic compounds. Accordingly, there has recently been an increasing demand for polymer resin-based vibration-damping steel sheets that are lighter while ensuring uniform vibration damping performance over a wide temperature range and various frequency ranges. Regarding the composition of the resin layer applied to the vibration-damping steel plate, a vibration-damping paste composition has been proposed that is based on an acrylic resin emulsion or a vinyl acetate resin emulsion and contains a plasticizer, a filler, and a phenolic resin adhesive in a predetermined ratio. While the above composition has the advantage of improving adhesion to steel plates and securing a certain level of vibration damping performance, it has been pointed out that there are limitations to vehicle body weight reduction due to the relatively high specific gravity of the composition itself, and that there is still room for improvement in terms of vibration damping characteristics in high-temperature environments or high-frequency regions. In particular, as recent vehicles are equipped with high-output motors and high-voltage electrical components, localized temperature rises occur frequently; however, conventional resin layers exhibit a problem where the loss factor changes significantly under these temperature variations and performance deteriorates rapidly near the glass transition temperature. In addition, in conventional processes for attaching vibration damping materials in roll or sheet form to vehicle body panels, a release liner is often provided on the back of the damping material. In this case, if the release liner is not completely removed or remains partially during the painting process, there is a risk that the final quality will be degraded due to uneven paint film thickness, p