Lightweight acoustic damping materials

Abstract

The present invention relates to an acoustic damping material comprising at least one liquid rubber LR at 25°C; at least one component CP selected from the group consisting of butyl rubber BR, natural or synthetic polyisoprene PI, and polyisobutylene PIB; at least one solid particle filler FM; and at least one chemical or physical expander BA. The acoustic damping material is suitable for use in damping undesirable vibrations and noises in mechanical structures and components of manufactured articles, is lightweight, and exhibits good heat resistance at 210°C. The present invention also relates to the use of acoustic damping materials for damping vibrations and noises in transport vehicles and white goods, vibration and noise damping elements comprising an adhesive layer made of acoustic damping material, a method for applying vibration and noise damping elements to a noise-generating surface of a substrate, and a vibration damping system comprising a substrate and vibration and noise damping elements bonded to the noise-generating surface of the substrate.

Description

[Technical Field]

[0001] This invention relates to compositions used for damping vibration and noise in the mechanical structure of manufactured articles. In particular, this invention relates to compositions suitable for damping vibrations in components and structures contained in articles of the automotive industry, home appliances, and general industries. [Background technology]

[0002] Acoustic damping materials are widely used in the automotive, home appliance, and general industries to reduce undesirable vibrations, structural noise, and airborne noise. For example, in automobiles, it is desirable to prevent vibrations generated by motors, pumps, gears, and other sources of dynamic force from being transmitted to the passenger compartment through the vehicle body. Vibrations generated by sources of dynamic force are transmitted through support structures, typically frames or other hollow structures, to noise-generating surfaces such as metal or plastic panels, where mechanical vibrations are converted into sound waves, resulting in structural noise. Structural noise and vibration can usually be effectively reduced by directly applying vibration damping materials to the surfaces of vehicle panels, floor surfaces, and the structures and surfaces of components that generate vibrational disturbances, such as the casings of machinery, washing machines, and dryers.

[0003] Acoustic damping materials used to reduce vibrations in panels and plates are generally provided in the form of pre-formed single-layer and multi-layer damping elements, or as liquid compositions applied directly to the surface of a substrate. Damping materials designed to reduce vibrations and noise in hollow structures such as cavities are typically provided in the form of cavity filler inserts containing an expandable composition and one or more mounting elements capable of holding the cavity filler insert in a desired position within the hollow structure.

[0004] Pre-formed single-layer and multi-layer damping elements comprise a damping layer in direct contact with the surface of a substrate from which vibrational disturbances are damped. The damping layer is capable of dissipating the kinetic energy of the vibrating surface into thermal energy through the expansion and contraction of the damping layer material. Materials widely used for the damping layer include bitumen-based and rubber-based compositions containing relatively high content of particle fillers and various amounts of additives, particularly plasticizers, rheology modifiers, and drying agents. Pre-formed single-layer and multi-layer damping elements often include a layer of adhesive composition, such as pressure-sensitive adhesive (PSA) or hot-melt adhesive, enabling the damping layer to adhere to the surface of a substrate, such as an automotive panel or floor. Damping systems applied in liquid form are typically heat-drying, gelling, or reactive compositions, which are applied to the surface of the substrate in a liquid state, for example, by spraying.

[0005] Acoustic damping materials used to dampen vibrations in panels and plates also comprise a damping layer and a rigid outer layer that "restrains" the damping layer, thereby providing a restrained layer damping element in which the damping layer is sandwiched between the rigid outer layer and the surface of the substrate to be damped. The rigidity of the outer layer is generally 10 times higher than the rigidity of the damping material layer. Common materials used for the outer top layer include, for example, aluminum and glass fiber cloth. Restricted layer damping members typically dampen undesirable vibrations more effectively than single-layer damping elements, but they are more expensive to manufacture.

[0006] Cavity filler inserts are used to attenuate noise caused by air in the cavity of a hollow structural component and to prevent the transmission of vibrations through the cavity walls. A cavity filler insert typically consists of a damping material and at least one mounting component capable of holding the cavity filler insert in a desired position within the hollow structure. The damping material of a cavity filler insert is typically formulated as an expandable composition that expands when activated, such as at high temperatures, to form a seal around the inner surface of the cavity walls. Expandable damping materials suitable for attenuating noise caused by air in a cavity are commonly referred to as "acoustic baffles."

[0007] In the automotive and consumer electronics industries, bitumen-based compositions have been widely used as acoustic damping materials due to their high vibration damping properties, reliability, and easily controllable physical properties, all at a low cost. Currently, bitumen-based damping systems hold nearly 100% market share in the consumer electronics market. High-filling bitumen compositions are used to provide soundproofing covers and sound-reducing coatings applied to metal and plastic components in the assembly processes of automotive vehicles and consumer electronics. According to conventional methods, a mixture of bitumen and filler is first extruded and / or rolled to form a film, from which suitable shapes for use as damping elements are prepared by punching or die-cutting. The damping elements are then bonded to the metal or plastic sheet to be damped. The shapes can also be further conformed to the shape of the metal or plastic sheet by heating.

[0008] One of the main application areas for acoustic damping elements is automotive interiors and washing machines in home appliances. In these applications, lightweight components are attracting significant attention due to the growing interest in reducing the weight of vehicles and equipment. Conventional materials used in automotive and home appliance applications weigh at least 2.6 kg / m³. 2It has a relatively high unit area weight, which is a disadvantage as it is not suitable for lightweight structures. However, this material still needs to maintain good adhesion to the substrate on which the acoustic damping elements are placed, especially during firing processes that can reach temperatures of up to 210°C. For example, the automobile manufacturer BMW Group has established standardized tests for this so-called 210°C heat resistance performance.

[0009] Therefore, there is a need for a novel type of acoustic damping material that is lightweight, exhibits good heat resistance at 210°C, and provides vibration and noise damping characteristics similar to or better than those of conventional rubber-based damping materials. [Overview of the project] [Problems that the invention aims to solve]

[0010] The present invention aims to provide a material used for damping undesirable vibrations and noises in mechanical structures and components of manufactured articles, which is lightweight, exhibits good heat resistance at 210°C, and provides vibration and noise damping characteristics similar to or better than those of conventional rubber-based acoustic damping materials. [Means for solving the problem]

[0011] The subject of this invention is the acoustic damping material described in claim 1.

[0012] Surprisingly, the acoustic damping material according to the present invention was found to exhibit vibration and noise damping characteristics similar to, or even better than, commercially available rubber-based acoustic damping materials. In particular, the acoustic damping material of the present invention exhibits high vibration damping performance, defined by the loss coefficient at a temperature of approximately 10 to 20°C, making it particularly suitable for use in damping vibrations and noise related to the structure and components of automobile vehicles.

[0013] Other subject matter of the present invention is presented in other independent claims. Preferred embodiments of the present invention are presented in dependent claims.

Brief Description of the Drawings

[0014] [Figure 1] FIG. 1 shows a cross-section of a vibration and noise attenuation element (1) comprising an attenuation layer (2) having a first face (3) and a second face (3'), and an adhesive layer (4) covering the first face (3) of the attenuation layer (2). [Figure 2] FIG. 2 shows a cross-section of a vibration and noise attenuation element (1) comprising an attenuation layer (2) having a first face (3) and a second face (3'), an adhesive layer (4) covering the first face (3) of the attenuation layer (2), and a restraint layer (5) covering the second face (3') of the attenuation layer (2). [Figure 3] FIG. 3 shows a cross-section of a vibration attenuation system comprising a substrate (6) having a noise generating surface (7) and a vibration and noise attenuation element (1) comprising an attenuation layer (2) and an adhesive layer (4), wherein the first face (3) of the attenuation layer (2) is adhesively bonded to the noise generating surface (7) via the adhesive layer (4). [Figure 4] FIG. 4 shows a cross-section of a vibration attenuation system comprising a substrate (6) having a noise generating surface (7) and a vibration and noise attenuation element (1) comprising an attenuation layer (2), an adhesive layer (4) and a restraint layer (5), wherein the first face (3) of the attenuation layer (2) is adhesively joined to the noise generating surface (7) via the adhesive layer (4) and the attenuation layer (2) is sandwiched between the adhesive layer (4) and the restraint layer (5).

Embodiments for Carrying out the Invention

[0015] The subject of the present invention is: a) at least one liquid rubber LR at 25 °C selected from the group consisting of polybutene liquid at 25 °C and polyisobutylene liquid at 25 °C, preferably polyisobutylene liquid at 25 °C, in an amount of 6 to 25% by weight based on the total weight of the acoustic attenuation material; b) At least one component CP, selected from the group consisting of butyl rubber BR, natural or synthetic polyisoprene PI, and polyisobutylene PIB having a weight-average molecular weight of 250,000 g / mol or more, in an amount of 4 to 15% by weight based on the total weight of the acoustic damping material, preferably selected from the group consisting of butyl rubber BR and natural or synthetic polyisoprene PI, more preferably butyl rubber BR; c) Preferably, 4 to 15% by weight of at least one hydrocarbon resin HR based on the total weight of the acoustic damping material; d) Preferably, 0.75% by weight or more of monomer units derived from 1,3-butadiene, based on the total weight of the acoustic damping material. [ka] At least one polybutadiene PB comprising, wherein the proportion of monomer units of formula (I) in the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, the proportion of units of formula (II) in the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 0 to 10 mole percent, and the proportion of monomer units of formula (III) in the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, wherein the total amount of monomer units (I), (II), and (III) is 100 mole percent, and the polybutadiene preferably has an average molecular weight of 1000 to 4000 g / mol; e) At least one type of solid particle filler FM: f) At least one chemical or physical leavening agent BA It is an acoustic damping material that includes [a specific component].

[0016] Substance names beginning with "poly" indicate substances that formally contain two or more of the functional groups appearing in their name per molecule. For example, polyols refer to compounds having at least two hydroxyl groups. Polyethers refer to compounds having at least two ether groups.

[0017] The term "polymer" refers to a collection of chemically homogeneous macromolecules produced by polymerization reactions (polymerization, polyaddition, polycondensation), where macromolecules differ in their degree of polymerization, molecular weight, and chain length. The term also includes derivatives of such macromolecular collections resulting from polymerization reactions, i.e., compounds obtained by reactions such as the addition or substitution of functional groups in a given macromolecule, and which may be chemically homogeneous or chemically heterogeneous.

[0018] The term "molecular weight" refers to the molar mass (g / mol) of a molecule or a part of a molecule (also called a "structural unit"). The term "average molecular weight" refers to the number-average molecular weight (M) of an oligomer or polymer mixture of molecules or structural units. n ) refers to the molecular weight can preferably be determined by conventional methods, which involve using polystyrene as the standard, styrene-divinylbenzene gel having porosity of 100 angstroms, 1000 angstroms, and 10000 angstroms as the column, and, depending on the molecule, using tetrahydrofuran as the solvent, at a temperature of 35°C, or using 1,2,4-trichlorobenzene as the solvent, by gel permeation chromatography (GPC) performed at 160°C.

[0019] "Glass transition temperature" (T g The term "glass transition temperature (T)" refers to the temperature at which polymer components become soft and flexible above that temperature, and hard and glassy below that temperature. g Preferably, this is measured by dynamic mechanical analysis (DMA) as the peak of the loss modulus (G) curve measured using an applied vibration of 1 Hz and a strain level of 0.1%.

[0020] The term "softening point" refers to the temperature at which a compound softens and becomes rubbery, or the temperature at which the crystalline portion of the compound melts. The softening point can be measured by the ring-spheroid assay method, which is performed in accordance with the DIN EN 1238 standard.

[0021] The term "room temperature" refers to a temperature of 23°C.

[0022] The acoustic damping material of the present invention is particularly suitable for use in damping undesirable vibrations and noise in mechanical structural components of manufactured articles such as products for the automotive, home appliance, or general industrial sectors. In these applications, the acoustic damping material, typically provided in the form of a molded article such as a layer or pad, is applied directly to the surface of a mechanical structure or component subjected to vibrational disturbances. The acoustic damping material can be formed into a suitable molded article by using conventional extrusion and / or rolling or hot pressing techniques. By optimizing the types and quantities of components a) to f) of the acoustic damping material, it is possible to maximize the efficiency of the material in dissipating the kinetic energy of a vibrating surface into thermal energy through the expansion and contraction of the damping material, within the temperature range relevant to the application.

[0023] The acoustic damping material of the present invention is preferably substantially bitumen-free. The expression "substantially free" is understood to mean acoustic damping that may contain only trace amounts of bitumen, such as less than 0.5% by weight, preferably less than 0.25% by weight, more preferably less than 0.1% by weight, and even more preferably less than 0.01% by weight, based on the total weight of the acoustic damping material. The term "bitumen" in this disclosure refers to a blend of heavy hydrocarbons having a solid consistency at room temperature. These are typically obtained as vacuum residues from refining processes, which can be distillation (atmospheric or vacuum distillation) and / or conversion processes such as pyrolysis and bisque breaking of suitable crude oil. Furthermore, the term "bitumen" also refers to natural and synthetic bitumen, as well as bituminous materials obtained from the extraction of tar and bitumen sand.

[0024] Furthermore, it is preferable that the acoustic damping material is substantially free of crosslinking / curing agents such as free radical crosslinking agents, such as peroxides. The phrase "substantially free" is intended to mean that even if a certain amount of crosslinking agent is found in the acoustic damping material, the amount is so negligible that no effect of the crosslinking agent can be obtained. In other words, the amount of crosslinking agent found in the acoustic damping material is not enough to initiate curing of the polymer components, or to initiate only a substantially negligible amount of crosslinking. According to one or more embodiments, the acoustic damping material contains less than 0.15% by weight, preferably less than 0.1% by weight, more preferably less than 0.01% by weight, and even more preferably 0% by weight of the crosslinking / curing agent, based on the total weight of the acoustic damping material.

[0025] The acoustic damping material includes, based on the total weight of the acoustic damping material, at least one liquid rubber LR selected from the group consisting of liquid polybutene and liquid polyisobutylene at 25°C, preferably liquid polyisobutylene at 25°C, in an amount of 6 to 25% by weight.

[0026] At concentrations below 6% by weight, insufficient low-temperature impact performance, as well as low peel strength and loss factor values, are achieved. At concentrations exceeding 25% by weight, low peel strength values ​​are achieved.

[0027] Preferably, the amount of liquid rubber LR at 25°C is 8 to 22.5% by weight, preferably 10 to 20% by weight, and most preferably 13.5 to 18% by weight, based on the total weight of the acoustic damping material. This is advantageous in terms of low-temperature impact performance, peel strength, and loss factor value.

[0028] The term “liquid polybutene at 25°C” preferably in this disclosure refers to an olefin oligomer containing isobutylene and / or 1-butene and / or 2-butene. The ratio of C4-olefin isomers can vary depending on the manufacturer and grade.

[0029] The term "polyisobutylene that is liquid at 25°C" preferably refers in this disclosure to isobutylene polyolefins and olefin oligomers that preferably contain at least 75%, more preferably at least 85%, of isobutylene-derived repeating units.

[0030] Particularly preferred polybutenes and polyisobutylenes that are liquid at 25°C have an average molecular weight of 5,000 g / mol or less, preferably 3,000 g / mol or less, more preferably 2,500 g / mol or less, even more preferably 2,000 g / mol or less, and even more preferably 1,500 g / mol or less.

[0031] Particularly preferred polybutenes and polyisobutylenes that are liquid at 25°C have a polydispersity index (Mw / Mn) measured by gel permeation chromatography (GPC) in the range of 0.5 to 5.0, preferably 1.0 to 4.5, more preferably 1.0 to 3.5, and even more preferably 1.25 to 2.5.

[0032] Liquid polybutene is commercially available under trade names such as Indopol® H- and L- series (manufactured by Ineos Oligomers), Infineum® C- and Parapol® series (manufactured by Infineum), and PB- series (Daelim). Liquid polyisobutylene (PIB) is commercially available under trade names such as Glissopal® V- series (manufactured by BASF) and Dynapak®- series (manufactured by Univar GmbH, Germany).

[0033] The acoustic damping material includes, based on the total weight of the acoustic damping material, at least one component CP selected from the group consisting of butyl rubber BR, natural or synthetic polyisoprene PI, and polyisobutylene PIB having a weight-average molecular weight of 250,000 g / mol or more.

[0034] Preferably, at least one component CP is selected from the group consisting of butyl rubber BR and natural or synthetic polyisoprene PI, and more preferably, at least one component CP is butyl rubber BR.

[0035] At concentrations below 4% by weight, insufficient low-temperature impact performance and low peel strength are achieved. At concentrations exceeding 15% by weight, insufficient low-temperature impact performance and low peel strength are achieved.

[0036] Ref. 1 in Table 3 shows that the absence of at least one component CP results in insufficient high-temperature resistance. This can be seen, for example, in the comparison between Ref. 1 and E1, E5, and E7. Table 3 further shows that the selection of butyl rubber BR and / or natural or synthetic polyisoprene PI results in even better high-temperature resistance compared to polyisobutylene PIB. This can be seen, for example, in the comparison between E1, E5, and E7. Furthermore, butyl rubber BR has the advantage of exhibiting the highest loss coefficient at 20°C and high peel strength. This can be seen, for example, in the comparison between E1, E5, and E7.

[0037] A comparison between E5 and Ref.2 further shows that, based on the total weight of the acoustic damping material, an amount of at least one component CP, particularly butyl rubber BR, exceeding 15% by weight results in insufficient high-temperature resistance.

[0038] Preferably, the acoustic damping material includes at least one component CP in an amount of 6 to 14.5% by weight, preferably 8 to 14% by weight, and more preferably 10 to 13.5% by weight, based on the total weight of the acoustic damping material. This is advantageous in terms of high temperature resistance, a higher loss factor at 20°C, and a higher peel strength. This can be seen, for example, in the comparison between E5 and E8 in Table 3.

[0039] In this document, the term "butyl rubber" refers to a rubber that is predominantly composed of C4-C7 monoolefin monomers, preferably isoolefin monomers, with a small amount of C4-C7 monomers (e.g., 30% by weight or less) being present. 14 The polymer is derived from a monomer mixture containing a multiolefin monomer, preferably a conjugated diolefin. Preferred C4-C7 monoolefin monomers may be selected from the group consisting of isobutylene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, 4-methyl-1-pentene, and mixtures thereof, and is preferably isobutylene.

[0040] Preferred C4~C 14 Multiolefins are C4-C 10 Contains conjugated diolefins. Preferred C4~C 10 The conjugated diolefin may be selected from the group consisting of isoprene, butadiene, 2,4-dimethylbutadiene, piperyline, 3-methyl-1,3-pentadiene, 2,4-hexadiene, 2-neopentyl-1,3-butadiene, 2-methyl-1,5-hexadiene, 2,5-dimethyl-2,4-hexadiene, 2-methyl-1,4-pentadiene, 2-methyl-1,6-heptadiene, cyclopentadiene, methylcyclopentadiene, cyclohexadiene, 1-vinyl-cyclohexadiene, and mixtures thereof, and is preferably isoprene.

[0041] Most preferably, the butyl rubber BR is a polymer derived from isobutylene and isoprene.

[0042] Preferably, at least one butyl rubber BR is selected from the group consisting of butyl rubber and halogenated butyl rubber, preferably butyl rubber, chlorobutyl rubber and bromobutyl rubber, more preferably butyl rubber and bromobutyl rubber, and most preferably bromobutyl rubber.

[0043] Preferred butyl rubber BR has a Mooney viscosity (ML 1+8 at 125°C) of 10-60 MU (Mooney units), preferably 20-50 MU, and preferably 25-40 MU. Preferably, Mooney viscosity refers to the viscosity measurement of the rubber. This is defined as the shear torque resisting the rotation of a cylindrical metal disk (or rotor) embedded in the rubber within a cylindrical cavity. The dimensions of the shear disk viscometer, test temperature, and method for measuring Mooney viscosity are defined in ASTM D1646.

[0044] At least one natural or synthetic polyisoprene PI is preferably natural polyisoprene, most preferably natural rubber.

[0045] Preferably, at least one natural or synthetic polyisoprene PI has an average molecular weight of 100,000 g / mol or more, preferably 100,000 to 2,000,000 g / mol, and more preferably 100,000 to 1,000,000 g / mol.

[0046] Natural rubber is a polymer of isoprene (methylbuta-1,3-diene), but it is distinct from synthetic polyisoprene, which is a product of a metal-catalyzed reaction.

[0047] Preferably, natural or synthetic polyisoprene PI has a Mooney viscosity (ML 1+4) at 100°C of 30 to 120, more preferably 40 to 65. The Mooney viscosity test referred to herein conforms to ASTM D-1646.

[0048] Polyisobutylene PIB has a weight-average molecular weight of 250,000 g / mol or more, preferably 500,000 g / mol or more, more preferably 750,000 g / mol to 3,000,000 g / mol, and most preferably 750,000 g / mol to 1,500,000 g / mol.

[0049] Suitable polyisobutylene PIBs are generally polymers having a polyisobutylene skeleton in the main chain or side chains. Basically, such polyisobutylene polymers can be prepared by polymerizing isobutylene alone or in combination with n-butene, isoprene, or butadiene in the presence of a Lewis acid catalyst such as aluminum chloride or boron trifluoride. Suitable polyisobutylene polymers are commercially available under trade names VISTANEX (Exxon Chemical Co.), HYCAR (Goodrich Corp.), OPPANOL (BASF AG), and JSR BUTYL (Japan Butyl Co., Ltd.).

[0050] Preferably, the acoustic damping material contains at least one hydrocarbon resin HR in an amount of 4 to 15% by weight based on the total weight of the acoustic damping material.

[0051] Preferably, the amount of at least one hydrocarbon resin HR is 5 to 12% by weight, preferably 5.5 to 10% by weight, and most preferably 6.5 to 9.5% by weight, based on the total weight of the acoustic damping material. This is advantageous in terms of good ball drop test performance and a favorable loss factor value in low-temperature performance.

[0052] The term "hydrocarbon resin" preferably, in this document, refers to synthetic resins formed by the polymerization of mixtures of unsaturated monomers obtained from petroleum-based raw materials, such as by-products of cracking liquefied natural gas, diesel fuel, or petroleum naphtha. These types of hydrocarbon resins are also known as "petroleum resins" or "petroleum hydrocarbon resins." Hydrocarbon resins also include pure monomer aromatic resins, which are prepared by polymerizing refined aromatic monomer raw materials to remove contaminants that cause discoloration and to precisely control the composition of the product.

[0053] Examples of suitable hydrocarbon resins HR that should be used as at least one hydrocarbon resin include C5 aliphatic resins, mixed C5 / C9 aliphatic / aromatic resins, aromatic modified C5 aliphatic resins, alicyclic resins, mixed C5 aliphatic / alicyclic resins, mixed C9 aromatic / alicyclic resins, mixed C5 aliphatic / alicyclic / C9 aromatic resins, aromatic modified alicyclic resins, C9 aromatic resins, and hydrides of the aforementioned resins. The notations "C5" and "C9" indicate that the monomers forming the resin are mainly hydrocarbons having 4 to 6 and 8 to 10 carbon atoms, respectively. The term "hydrogenated" includes fully hydrogenated, substantially hydrogenated, and at least partially hydrogenated resins. The partially hydrogenated resin preferably has a hydrogenation level of, for example, 50%, 70% or 90%.

[0054] The type of at least one hydrocarbon resin HR is not particularly limited in the present invention. The selection of the at least one hydrocarbon resin HR depends at least in part on the type of other components contained in the binder matrix of the acoustic attenuation material, particularly the type of the polymer component P.

[0055] Preferably, the at least one hydrocarbon resin HR has: - a softening point measured using the ring and ball method defined in DIN EN 1238 standard of at least 70°C, preferably at least 80°C, more preferably in the range of 70 to 180°C, preferably 80 to 150°C, more preferably 90 to 120°C, and / or, preferably and; - an average molecular weight (M n ) in the range of 250 to 7500 g / mol, preferably 300 to 5000 g / mol.

[0056] Suitable hydrocarbon resins are commercially available under the trade names Wingtack® series, Wingtack® Plus, Wingtack® Extra, and Wingtack® STS (all manufactured by Cray Valley); Escorez® 1000 series, Escorez® 2000 series, and Escorez® 5000 series (all manufactured by Exxon Mobile Chemical); Novares® T series, Novares® TT series, Novares® TD series, Novares® TL series, Novares® TN series, Novares® TK series, and Novares® TV series (all manufactured by RUETGERS Novares GmbH); and Kristalex®, Plastolyn®, Piccotex®, Piccolastic®, and Endex® (all manufactured by Eastman Chemicals).

[0057] The acoustic damping material is preferably monomer units derived from 1,3-butadiene. [ka] The sound-damping material contains at least one polybutadiene PB, comprising 0.75% by weight or more based on the total weight of the sound-damping material, where the proportion of units of formula (I) in the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, preferably 50 to 65 mole percent, and preferably 59 to 62 mole percent, and the proportion of units of formula (II) in the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 0 to 10 mole percent, preferably 1 to 8 mole percent, and preferably 2 to 6 mole percent The polybutadiene is characterized by having a molecular weight of 1,3-butadiene, preferably 1,200-3,500 g / mol, and preferably 1,500-3,000 g / mol.

[0058] In the context of the present invention, the term "polybutadiene" should be understood to mean a product that can be obtained by polymerization of monomer units, each having at least two conjugated double bonds, where, for the sake of preference, at least 80%, preferably at least 85%, preferably at least 90%, preferably at least 95%, preferably at least 98%, preferably at least 99%, most preferably at least 99.9%, monomer units, preferably all of which are 1,3-butadiene. Possible further compounds (impurities) may be, for example, alkanes or alkenes having 3 to 5 carbon atoms, particularly propene, 1-butene, or 1,2-butadiene.

[0059] Preferably, the amount of at least one type of polybutadiene (PB) is 1 to 15% by weight, preferably 1.2 to 10% by weight, preferably 1.3 to 8% by weight, preferably 1.5 to 7% by weight, preferably 1.5 to 5% by weight, and most preferably 1.5 to 3% by weight, based on the total weight of the acoustic damping material. This is advantageous with respect to good ball drop tests in low-temperature performance.

[0060] In monomer units represented by formulas (I), (II), and (III), if the square brackets in the formula expressions selected in this application indicate monomer units (I), (II), and (III) derived from 1,3-butadiene present in polybutadiene, the bond indicated by each square bracket does not terminate with a methyl group; instead, the associated monomer unit is bonded to other monomer units via this bond. In this case, monomer units (I), (II), and (III) may be arranged in the polymer in any desired sequence. A random sequence is preferred.

[0061] Polybutadiene (PB) is preferably heated at 20°C and 2000-8000 mPa. * s, preferably 3000-7000 mPa * It has a viscosity of s. This viscosity (cone plate) is preferably measured using a Rheometer Physica MCR 301 manufactured by ANTON PAAR Germany GmbH, in accordance with DIN 53018.

[0062] It may be advantageous if polybutadiene (PB) has a dispersion degree of 2.1 to 3.0. Dispersion degree is defined as the number-average molar mass (Mn) divided by the weight-average molar mass (Mw).

[0063] The acoustic damping material includes e) at least one solid particle filler FM, preferably at least one solid granular inorganic filler FM.

[0064] Preferably, the acoustic damping material includes at least one solid particle filler FM in an amount of 5 to 75% by weight, preferably 15 to 70% by weight, more preferably 25 to 65% by weight, even more preferably 35 to 65% by weight, and even more preferably 40 to 65% by weight, based on the total weight of the acoustic damping material.

[0065] At least one type of solid particle filler FM has a d size of 2.5 mm or less, more preferably 1.5 mm or less. 90 Preferably, the solid particles have a particle size and are present in the acoustic damping material. 90 In this disclosure, the term "d" means that 90% of all particles, by volume, are d 90 This refers to particle size having a diameter smaller than the value. In this disclosure, the term "particle size" means the area of ​​a particle minus its equivalent spherical diameter (X). 面積 This refers to the particle size distribution. The particle size distribution is preferably measured using a dynamic image analysis method performed in accordance with the ISO 13322-2:2006 standard. For the measurement of the particle size distribution, the particles are preferably dispersed in air using a pneumatic dispersion method. The measurement can be performed using any type of dynamic image analysis device, such as the Camsizer XT device (trademark of Retsch Technology GmbH).

[0066] At least one type of solid particle filler FM is preferably an inert inorganic filler having a water solubility of less than 0.1 g / 100 g of water, more preferably less than 0.05 g / 100 g of water, and even more preferably less than 0.01 g / 100 g of water at a temperature of 20°C. The solubility of the compound in water can be measured as the saturation concentration at which the concentration of the solution does not increase even when a further amount of the compound is added, i.e., at which excess amounts of the substance begin to precipitate. In this disclosure, the term "inert inorganic filler" refers to an inorganic filler that is not reactive, unlike an inorganic binder, i.e., does not undergo a hydration reaction even in the presence of water.

[0067] According to one or more embodiments, at least one type of solid particle filler FM is selected from the group consisting of calcium carbonate, magnesium carbonate, calcium oxide, talc, kaolin, diatomaceous earth, wollastonite, feldspar, montmorillonite, dolomite, silica, preferably fumed silica, cristobalite, iron oxide, iron nickel oxide, strontium ferrite, barium-strontium ferrite, hollow ceramic spheres, hollow glass spheres, hollow organic spheres, glass spheres, mica, barium sulfate, and graphite.

[0068] The acoustic damping material may optionally contain additives that are conventional for acoustic damping materials. Examples of suitable additives include pigments, thixotropes, heat stabilizers, desiccants, and flame retardants. When these additives are used, they are preferably included in an amount of 25% by weight or less, more preferably 15% by weight or less, and even more preferably 10% by weight or less, of the total weight of the acoustic damping material.

[0069] The acoustic damping material contains f) at least one chemical or physical expander BA. A suitable expander may be a chemical or physical expander. A chemical expander is, for example, an organic or inorganic compound that decomposes under the influence of temperature or humidity, and at least one of the decomposition products formed is a gas. A physical expander is, but is not limited to, a compound that vaporizes at a certain temperature. Therefore, both chemical and physical expanders are suitable for expanding the acoustic damping material.

[0070] Preferred chemical leavening agents include, but are not limited to, azo compounds, hydrazides, nitroso compounds, carbamates, and carbazides. Two-component chemical systems, such as acid / base systems, that generate gas during the reaction are also suitable. A preferred example is sodium bicarbonate and citric acid, which, when combined in a suitable medium, produce carbon dioxide.

[0071] Further preferred chemical leavening agents are selected from the list consisting of azodicarbonamide, azoisobutytronitrile, azocyclohexylnitrile, dinitrosopentamethylenetetramine, azodiaminobenzene, benzene-1,3-sulfonyl hydrazide, calcium azide, 4,4'-diphenyldisulfonyl azide, p-toluenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, 4,4'-oxybis(benzenesulfonyl hydrazide), trihydrazinotriadin, and N,N'-dimethyl-N,N'-dinitrosotelephthalamide. The most preferred chemical leavening agent is azodicarbonamide.

[0072] A suitable physical expansion agent is a thermally expandable microsphere (HEM). When these thermally expandable microspheres are heated, the substance they contain expands in volume, and the resin material that makes up the outer shell softens, making it possible to obtain a capsule that has expanded due to internal pressure (an expanded capsule).

[0073] Preferably, the thermally expandable microsphere (HEM) contains a liquid compound inside an outer shell made of a resin material (resin composition).

[0074] The liquid compound that constitutes the thermally expandable microspheres preferably has a boiling point (under atmospheric pressure conditions) that is below the softening temperature of the resin material that constitutes the outer shell of the thermally expandable microspheres.

[0075] Preferably, the liquid compound is selected from a list consisting of n-butane, isopentane, cyclobutane, n-pentane, isopentane, cyclopentane, n-hexane, 2-methylpentane, 2,2-dimethylbutane, cyclohexane, n-heptane, cycloheptane, n-octane, cyclooctane, and hydrocarbons, preferably hydrocarbons, more preferably hydrocarbons having 1 to 5 carbon atoms, and most preferably hydrocarbons having 4 to 5 carbon atoms.

[0076] The liquid compound may be one type or two or more types. The liquid compound is preferably a hydrocarbon, and particularly preferably contains a low-boiling point hydrocarbon having 4 to 5 carbon atoms.

[0077] The resin material constituting the outer shell is preferably thermoplastic. Preferably, the resin material contains structural units derived from the list consisting of acrylonitrile, methacrylonitrile, alkyl acrylate, alkyl methacrylate, vinyl chloride, vinylidene chloride, vinyl acetate, and aromatic vinyl compounds, preferably acrylonitrile. More preferably, the resin material is an acrylonitrile-based copolymer.

[0078] Preferably, the shape of the thermally expandable microsphere (HEM) is spherical or elliptical.

[0079] The thermally expandable microspheres (HEMs) preferably have an average particle size D(0.5) of 10-75 μm, more preferably 20-50 μm, and most preferably 25-45 μm.

[0080] Here, the term "average particle size" preferably refers to the D(0.5) value of the cumulative volume distribution curve, where 50% of the particles have a particle size smaller than this value on a volume basis. The average particle size or D(0.5) value is preferably measured by laser diffraction.

[0081] Expansion start temperature of thermally expandable microspheres HEM (T s The temperature is preferably 95°C to 170°C, preferably 105°C to 155°C, and most preferably 125°C to 145°C.

[0082] Preferably, the maximum expansion temperature (T) of the thermally expandable microsphere HEM. max The optimal temperature is 165°C to 220°C, preferably 175°C to 215°C, and most preferably 185°C to 210°C.

[0083] Preferably, the expansion initiation temperature (T s ) and maximum expansion temperature (T max ) is measured by dynamic mechanical analysis (DMA Q800, TA Instruments), more preferably by the following method: A sample is prepared by placing 0.5 mg of thermally expandable microspheres in an aluminum cup with a depth of 4.8 mm and a diameter of 6.0 mm (inner diameter of 5.65 mm), and covering the cup with an aluminum cap that is 0.1 mm thick and 5.6 mm in diameter.

[0084] A pressure of 0.01 N is applied to the sample using the device's compression unit, and the height of the sample is measured. Then, while applying a pressure of 0.01 N with the compression unit, the sample is heated at a heating rate of 10 °C / min in the temperature range of 20 to 300 °C, and the vertical change in the position of the compression unit is measured. The temperature at which the compression unit begins to change its position in the positive direction is called the expansion onset temperature (T). s The temperature at which the compression unit shows the greatest change is measured as the maximum expansion temperature (T). max ) is measured as follows.

[0085] Thermally expandable microspheres (HEMs) are commercially available, for example, as "Expancel DU Microspheres" (microspheres manufactured by Expansion) or "Matsumoto Microspheres" (manufactured by Matsumoto Oil & Fat Pharmaceutical Co., Ltd.).

[0086] f) It is particularly preferable that at least one chemical or physical leavening agent BA is selected from a list consisting of additives - functionalized chemical leavening agents and physical leavening agents, especially functionalized chemical leavening agents.

[0087] This is advantageous in terms of high-temperature resistance and higher loss coefficients at 20°C. This can be seen, for example, in a comparison between E5 and E9 and E10. Surprisingly, the additive-functionalized chemical leavening agent used in E5 and the physical leavening agent used in E10 were found to exhibit better high-temperature resistance than the non-additive-functionalized leavening agent used in E9. Additive-functionalized chemical leavening agents, especially mineral oil-functionalized leavening agents, exhibit the best high-temperature resistance. It was also surprising that chemical leavening agents, especially additive-functionalized chemical leavening agents, exhibited higher loss coefficients at 20°C compared to physical leavening agents.

[0088] Preferably, the additive-functionalized chemical leavening agent is obtained by spray-drying the chemical leavening agent in the presence of the additive, co-grinding the chemical leavening agent in the presence of the additive, coating the chemical leavening agent with the additive, or extruding the chemical leavening agent in the presence of the additive. The preferred chemical leavening agent used is the preferred chemical leavening agent described above.

[0089] The additive preferably consists of at least one additive selected from the list of polymers, oils, preferably mineral oils, inorganic salts, fats, fatty acids, silanes, and metal siloxylated compounds, preferably polymers and oils, most preferably oils, particularly mineral oils.

[0090] Preferably, the terms “oil” and “mineral oil” are defined as described below in Roempp Chemie Lexikon, online-version, Georg Thieme Verlag, retrieved March 2023, under the terms “Oele” and “Mineraloele” respectively.

[0091] Suitable polymers are selected from the group consisting of polyvinyl alcohol, polyglycol, polysaccharides, poly(meth)acrylic acid, poly(com-maleic acrylate), polyethylenenimine, polyvinylpyrrolidone, N-2(-hydroxypropyl)methacrylamide, and polyoxyalkylene, preferably polyoxyalkylene.

[0092] Suitable inorganic salts are selected from the group consisting of silicates (e.g., sodium silicate), NaCl, KCl, MgCl2, aluminum hydroxide, sodium phosphate, borate, nitrate, nitrite, sulfate, and sulfite.

[0093] Suitable silanes are selected from the group consisting of ester-based silanes, vinyl-based silanes, methacrylateoxysilanes, epoxy-based silanes, sulfur-based silanes, and amino-based silanes.

[0094] The additive-functionalized chemical leavening agent preferably comprises at least 50% by weight and less than 100% by weight of a chemical leavening agent, and at least one of the aforementioned additives in an amount of 50% to 0.02% by weight. More preferably, the additive-functionalized chemical leavening agent comprises at least 65% by weight and less than 100% by weight of a chemical leavening agent, and at least one of the aforementioned additives in an amount of 35% to 0.02% by weight. Even more preferably, the additive-functionalized chemical leavening agent comprises at least 75% by weight and less than 100% by weight of a chemical leavening agent, and at least one of the aforementioned additives in an amount of 25% to 0.02% by weight. Most preferably, the additive-functionalized chemical leavening agent comprises at least 90% by weight and less than 100% by weight of a chemical leavening agent, and at least one of the aforementioned additives in an amount of 10% to 0.02% by weight.

[0095] The expanding agent is preferably included in the acoustic attenuation material in an amount of 0.1 to 5% by weight, preferably 0.5 to 4% by weight, more preferably 1 to 3% by weight, and most preferably 1 to 2% by weight, based on the total weight of the acoustic attenuation material. This is advantageous in terms of a higher loss coefficient at 20°C. This can be seen, for example, in a comparison between E5 and E6.

[0096] Preferred acoustic damping material is - Based on the total weight of the acoustic damping material, preferably 1 to 15% by weight, preferably 1.5 to 3% by weight, of at least one type of polybutadiene PB; - Based on the total weight of the acoustic damping material, 8 to 22.5% by weight, preferably 13.5 to 18% by weight, of at least one liquid rubber LR selected from the group consisting of liquid polybutene and liquid polyisobutylene at 25°C, preferably liquid polyisobutylene at 25°C; - Based on the total weight of the acoustic damping material, at least one component CP selected from the group consisting of butyl rubber BR, natural or synthetic polyisoprene PI, and polyisobutylene PIB having a weight-average molecular weight of 250,000 g / mol or more, preferably selected from the group consisting of butyl rubber BR and natural or synthetic polyisoprene PI, more preferably butyl rubber BR; - Based on the total weight of the acoustic damping material, preferably 5 to 12% by weight, more preferably 6.5 to 9.5% by weight, of at least one hydrocarbon resin HR; and - Based on the total weight of the acoustic damping material, 5 to 75% by weight, preferably 40 to 65% by weight, of at least one type of solid particle filler FM; and - Based on the total weight of the acoustic damping material, 0.1 to 5% by weight, preferably 1 to 2% by weight, of at least one chemical or physical expanding agent BA. Includes.

[0097] Another subject of the present invention is a method for producing an acoustic damping material according to the present invention, the method comprising the step of mixing components a) to f) with each other at a high temperature, preferably in the range of 120 to 200°C, more preferably in the range of 130 to 180°C, until a homogeneous mixture is obtained.

[0098] In this document, the term “homogeneously mixed mixture” refers to a composition in which the individual components are substantially homogeneously distributed within the composition. Furthermore, a homogeneously mixed mixture is preferably a multiphase mixture. In such a mixed composition, regions may be formed in which the concentration of one component is slightly higher than that of other regions, and it will be apparent to those skilled in the art that 100% homogeneous distribution of all components is generally not achievable. However, such mixed compositions with “imperfect” distributions of components are also intended to be included in the term “homogeneously mixed mixture” according to the present invention.

[0099] Any conventional type of mixing apparatus can be used to mix components a) to f). The mixing step can be carried out as a batch process using batch-type mixers such as Brabender mixers, Banbury mixers, and roll mixers, or as a continuous process using continuous-type mixers such as extruders, particularly single-screw or twin-screw extruders.

[0100] The homogeneous mixture obtained in the mixing step can then be cooled to a temperature below 100°C, more preferably below 80°C. If an extruder is used in the mixing step, it is preferable that the homogeneous mixture be extruded through the extruder die before the cooling step. The cooled homogeneous mixture is storage stable under normal storage conditions. The term "storage stability" in this disclosure refers to a material that can be stored under specific storage conditions for a long period of time, such as at least one month, and especially at least three months, without causing any significant change in the material's application properties. "Typical storage conditions" refers to a temperature of 60°C or less, and especially 50°C or less.

[0101] The homogeneously mixed mixture can be further processed into the form of a shaped article, such as a sheet or film, by using any of the conventional techniques, such as extrusion, rolling, and hot pressing. The forming step is preferably carried out before the cooling step. According to one or more embodiments, the homogeneously mixed mixture is extruded through a flat die to form a sheet of film, which is preferably cooled between a pair of rolling cooling rolls. Shaped articles having specific dimensions can be manufactured from the extruded sheet of film, for example, by punching or die-cutting.

[0102] Another subject of the present invention is the use of the acoustic damping material according to the present invention for damping vibration and / or noise in transport vehicles or home appliances.

[0103] Other subjects of this invention include: i) a damping layer (2) having a first surface and a second surface (3,3'), and ii) An adhesive layer (4) covering at least a portion of the first surface (3) of the damping layer (2), which contains or is composed of the acoustic damping material of the present invention. This is a vibration and noise damping element (1) equipped with the following features.

[0104] Figure 1 shows a cross-section of the vibration and noise damping element according to the present invention.

[0105] According to one or more embodiments, the damping layer is a sheet-like element having first and second main surfaces defining a thickness between them, and having a length and width at least 5 times, preferably at least 15 times, and more preferably at least 25 times, the thickness of the sheet-like element. The term "thickness" preferably refers to the dimensions of the sheet-like element measured in a plane perpendicular to the length and width dimensions of the element. In embodiments in which the damping layer is a sheet-like element, the first and second surfaces of the damping layer correspond to the first and second main surfaces of the sheet-like element.

[0106] The damping layer and the adhesive layer are preferably directly bonded to each other at their opposing surfaces. In the context of the present invention, the expression "directly bonded" is understood to mean that there are no further layers or materials between these two layers, and that the opposing surfaces of the layers are directly bonded to each other. According to one or more embodiments, the adhesive layer covers at least 50%, preferably at least 65%, and more preferably at least 75% of the first surface of the damping layer. According to one or more further embodiments, the adhesive layer covers substantially the entire area of ​​the first surface of the damping layer. The expression "substantially the entire area" is understood to mean at least 90%, preferably at least 95%, and more preferably at least 98.5% of the total area.

[0107] The damping layer preferably includes components selected from the list of bitumen components B, thermoplastic polymer components P, and rubber components Ru, preferably rubber components Ru.

[0108] The preferred rubber component Ru is selected from the list of liquid rubber LR, butyl rubber BR, natural or synthetic polyisoprene PI, nitrile rubber NBR, ethylene-propylene copolymer EPDM, ethylene-propylene copolymer EPM, and chloroprene rubber CR, selected from the group consisting of liquid polybutene and liquid polyisobutylene at 25°C. Preferably, it is selected from the list of liquid rubber LR, butyl rubber BR, and natural or synthetic polyisoprene PI, selected from the group consisting of liquid polybutene and liquid polyisobutylene at 25°C.

[0109] Bitumen component B may contain one or more different types of bitumen material, such as penetration-grade (distilled) bitumen, air-rectified (semi-blown) bitumen, and hard-grade bitumen.

[0110] In this disclosure, the term "bitumen" refers to a blend of heavy hydrocarbons having a solid consistency at room temperature. These are typically obtained as vacuum residues from refining processes that may be distillation (atmospheric or vacuum distillation) and / or conversion processes such as pyrolysis and bisque breaking of suitable crude oil. Furthermore, the term "bitumen" also refers to natural and synthetic bitumen, as well as bituminous materials obtained from the extraction of tar and bitumen sand.

[0111] Here, the term “penetration-grade bitumen” refers to bitumen obtained from the fractional distillation of crude oil. After removing gasoline, kerosene, and diesel fractions, the heavy fraction (also known as atmospheric distillation residue), composed of high molecular weight hydrocarbons, is first distilled in a vacuum distillation column to obtain further diesel, distillates, and vacuum distillation residues. The vacuum distillation residues are then used as feedstock to produce different grades of bitumen classified by their penetration index, which is typically defined by the PEN value, which expresses the distance a needle penetrates the bitumen in 0.1 millimeters (dmm) using a standard test method. Penetration-grade bitumen is characterized by its penetration and softening point. The term “air-rectified bitumen” or “air-purified bitumen” in this disclosure refers to bitumen that has been lightly oxidized for the purpose of producing bitumen that conforms to the standards of pavement-grade bitumen. The term “hard-grade bitumen” in this disclosure refers to bitumen produced by extended vacuum distillation using some air rectification from bitumen precipitated with propane. Hard bitumen typically has a low penetration value and a high softening point.

[0112] According to one or more embodiments, bitumen component B preferably comprises at least 75% by weight, preferably at least 85% by weight, and more preferably at least 90% by weight, of at least one penetration-grade bitumen having a penetration value in the range of 15 to 50 dmm, more preferably 20 to 45 dmm and / or a softening point in the range of 40 to 125°C, preferably 50 to 100°C, as measured by a ring-spheroid assay performed in accordance with the DIN EN 1238 standard.

[0113] The preferred thermoplastic polymer component P is selected such that the temperature range over which the vibration damping effect of the acoustic damping material is maximized coincides with the temperature range experienced by the surface of the substrate to be damped during its use. Since the polymer's ability to dissipate vibrations into thermal energy is maximized when the polymer is in a transition state between rigid / glassy and soft / rubber-like states, the preferred thermoplastic polymer P used in acoustic damping materials has a glass transition temperature (T) that falls within the intended application temperature range. g ) has. For example, when an acoustic damping material is used to dampen vibrations and noise in the structure of an automobile vehicle, the applicable temperature is typically in the range of -40°C to 60°C, particularly -35°C to 50°C. On the other hand, a preferred thermoplastic polymer P used in an acoustic damping material has a softening point (T) higher than the maximum applicable temperature of the acoustic damping material. s ) and / or melting temperature (T m ) has.

[0114] According to one or more embodiments, the thermoplastic polymer P is: The glass transition temperature (T) is measured by dynamic mechanical analysis (DMA) as the peak of the loss modulus (G) curve measured using an applied vibration of 1 Hz and a strain level of 0.1% at temperatures below -25°C, preferably below 5°C, and more preferably below 0°C. g ), and / or The softening point (T) is measured by a ring-spheroid assay performed in accordance with the DIN EN 1238 standard, and is above -35°C, preferably above 45°C, more preferably above 55°C, and within the range of 35 to 250°C, preferably 45 to 200°C, more preferably 55 to 180°C. s ) It holds.

[0115] The type of thermoplastic polymer P is not particularly limited. Various types of thermoplastic polymers, including crystalline, semi-crystalline, and amorphous polymers, as well as thermoplastic elastomers, are suitable for use as at least one thermoplastic polymer P. Suitable thermoplastic polymers P include, in particular, polyolefin homopolymers and copolymers, copolymers of ethylene and vinyl acetate, and thermoplastic olefin elastomers (TPE-O).

[0116] More preferably, the damping layer is preferably Based on the total weight of the damping layer, 10 to 18% by weight of at least one liquid rubber LR selected from the group consisting of liquid polybutene and liquid polyisobutylene at 25°C, preferably liquid polyisobutylene at 25°C; 2-5% by weight of at least one type of butyl rubber BR based on the total weight of the damping layer; Based on the total weight of the damping layer, 0.5 to 3% by weight of at least one natural or synthetic polyisoprene PI, preferably natural polyisoprene, most preferably natural rubber; 5-10% by weight of at least one hydrocarbon resin HR based on the total weight of the damping layer; Based on the total weight of the damping layer, 50-80% by weight of at least one type of solid particle filler FM Includes.

[0117] Preferred materials selected from the group consisting of polybutene and polyisobutylene that are liquid at 25°C, such as liquid rubber LR, butyl rubber BR, natural or synthetic polyisoprene PI, hydrocarbon resin HR, and solid particle filler FM, have previously been considered preferred as compositions for acoustic damping materials.

[0118] According to one or more embodiments, the damping layer has a maximum thickness in the range of 0.5 to 10 mm, preferably 0.5 to 7 mm, more preferably 0.5 to 5 mm, and even more preferably 0.5 to 3 mm, and / or 1 to 4 g / cm². 3 Preferably 1-3 g / cm³ 3 More preferably 1-2 g / cm³ 3Densities within the range of 1-5 kg / m³ 2 Preferably 1 to 4.5 kg / m 2 More preferably 1.5 to 4.5 kg / m 2 More preferably 1.5 to 3.5 kg / m 2 It has a mass per unit area.

[0119] The adhesive layer 4 contains the acoustic damping material of the present invention, or preferably is composed of the acoustic damping material of the present invention. Preferred embodiments of the acoustic damping material described above are also applicable to the acoustic damping material in the adhesive layer 4.

[0120] According to one or more embodiments, the adhesive layer has a maximum thickness in the range of 0.5 to 5 mm, preferably 0.5 to 3 mm, more preferably 0.5 to 2 mm, and even more preferably 0.5 to 1 mm, and / or 1 to 4 g / cm². 3 Preferably 1-3 g / cm³ 3 More preferably 1-2 g / cm³ 3 Densities within the range of 0.5-5 kg / m³ 2 Preferably 0.6 to 4 kg / m 2 More preferably 0.7-3 kg / m 2 It has a mass per unit area.

[0121] The vibration and noise damping elements preferably have the following characteristics: - Temperature at which the maximum loss factor is measured (T@LF max The ideal temperature range is 5°C to 25°C, preferably 15°C to 25°C. - Maximum loss factor (LF) max The value of ) is 0.3 or higher, preferably 0.35 or higher, preferably 0.39 or higher, preferably 0.40 or higher, and most preferably 0.41 or higher.

[0122] Preferably, the loss factor is measured using the measurement method specified in the ISO 6721 standard, more preferably using the measurement method described in the experimental section.

[0123] According to one or more embodiments, the vibration and noise damping element further comprises a restraining layer covering at least a portion of the second surface of the damping layer, in addition to the damping layer and the adhesive layer. Vibration and noise damping elements according to these embodiments are generally known as “restraining layer damping members”. The damping layer and the restraining layer are preferably directly joined to each other at their opposing surfaces, and preferably the damping layer is sandwiched between the adhesive layer and the restraining layer. According to one or more embodiments, the restraining layer substantially, preferably completely, covers the entire area of ​​the second surface of the damping layer. A cross-section of a vibration and noise damping element according to these embodiments is shown in Figure 2.

[0124] According to one or more embodiments, the restraining layer is a metal sheet, preferably aluminum or steel plate, or a polymer sheet, preferably a glass fiber reinforced polymer sheet. The thickness of the restraining layer is not particularly limited, but it is generally preferable to use a restraining layer that is thinner than the damping layer. The preferred thickness also depends on the material of the restraining layer. According to one or more embodiments, the restraining layer has a thickness of 0.05 to 1.5 mm, preferably 0.1 to 1.25 mm, and more preferably 0.1 to 1.0 mm. According to one or more embodiments, the restraining layer is a metal sheet having a thickness of 0.05 to 0.5 mm, preferably 0.05 to 0.4 mm. According to one or more further embodiments, the restraining layer is a polymer sheet having a thickness of 0.1 to 1.2 mm, preferably 0.25 to 1.0 mm.

[0125] The restraining layer preferably has an elastic modulus greater than that of the damping layer, at least 3 times, preferably at least 5 times, and more preferably at least 10 times greater, where the elastic modulus is measured using the method specified in ISO 6892-1:2016 standard (for metal sheets) or ISO 527-2 standard (for polymer sheets).

[0126] Another subject of the present invention is a method for manufacturing the vibration and noise damping element of the present invention, which is: i) A step of providing an damping layer having first and second surfaces, ii) Applying an adhesive composition containing the acoustic damping material of the present invention or composed of the acoustic damping material of the present invention to the first surface of the damping layer. Includes.

[0127] Step i) can be carried out by any prior art known to those skilled in the art. For example, the acoustic damping material can first be melted in an extruder and then extruded into the form of a damping layer through an extruder die, preferably a flat die. Alternatively, the acoustic damping material of the present invention can be processed into a damping layer using calendering or hot pressing techniques.

[0128] Step ii) can be carried out by any of the prior art known to those skilled in the art. The adhesive composition can be applied to the surface of the damping layer using any of the prior art. For example, the adhesive composition can be applied to the surface of the sheet by nozzle extrusion, powder dispersion, rolling, or spray lamination, preferably by rolling.

[0129] Another subject of the present invention is a method for applying the vibration and noise damping elements according to the present invention to the noise-generating surface of a substrate, the method being: I) A step of providing a vibration and noise damping element according to the present invention; II) The step of bringing the outer main surface of the adhesive layer of the vibration and noise damping element into contact with the noise generating surface and applying sufficient pressure to form an adhesive bond; or II') Heat the adhesive layer and / or the substrate, bring the outer main surface of the adhesive layer into contact with the noise-generating surface, and form an adhesive bond by cooling the adhesive layer. Includes.

[0130] The term "outer main surface" of the adhesive layer refers to the main surface of the adhesive layer opposite to the damping layer side. The substrate having the noise-generating surface can be any type of shaped article, such as a panel, sheet, or film made of metal, plastic, or fiber-reinforced plastic. Heating of the adhesive layer and / or substrate in step II') can be carried out using any of the conventional techniques, such as heating in an oven, heating by airflow, or heating by infrared (IR).

[0131] Another subject of the present invention is a vibration damping system comprising a substrate (6) having a noise generating surface (7) and a vibration and noise damping element (1) according to the present invention, wherein at least a portion of the first surface (3) of the damping layer (2) is adhesively bonded to the noise generating surface (7) via an adhesive layer (4). A cross-section of the vibration damping system is shown in Figure 3.

[0132] According to one or more embodiments, the vibration and noise damping element (1) is a constrained damping element comprising a constraining layer (5), where the damping layer (2) is sandwiched between an adhesive layer (4) and a constraining layer (5). A cross-section of the vibration damping system according to these embodiments is shown in Figure 4.

[0133] According to one or more embodiments, the substrate having a noise-generating surface is part of the structure of an automobile or a white goods appliance. [Examples]

[0134] The raw materials shown in Table 1 were used for the composition for the adhesive layer shown in Table 3 and the composition for the damping layer shown in Table 2, respectively.

[0135] [Table 1]

[0136] Preparation of composition The acoustic damping materials of the present invention, as shown in Examples E1 to E10 in Table 3, and Reference Examples Ref.1 to Ref.2, used in the adhesive layer, were prepared according to the following method.

[0137] In the first step, the components BR, PI, and HR were mixed in a batch-type mixer. Then, the remaining ingredients, excluding BA, were added continuously over 1 hour and mixed for 20 minutes. Next, the composition was cooled to 80°C and BA was mixed in. The mixed composition was then stored in an unsealed drum and used immediately after mixing.

[0138] In the second step, the components of the damping layer composition were mixed with the following components shown in Table 2.

[0139] [Table 2]

[0140] Half of the BR, PI, HR, and calcite were mixed in a batch-type mixer. The remaining raw materials were then added continuously over 1 hour and mixed for 20 minutes. The mixed damping layer composition was then stored in an unsealed drum and used immediately after mixing.

[0141] For the following tests, test samples (vibration and noise damping elements) were manufactured using 0.6 mm thick adhesive layers made from compositions E1 to E10 and reference examples Ref. 1 to Ref. 2, respectively. A 1.1 mm thick damping layer of the above damping layer composition was added on top of these adhesive layers. A 0.3 mm thick aluminum layer (restraining layer) was added on top of the damping layer. The test results are shown in Table 3.

[0142] Measurement of high temperature resistance ("resistance ht") A heat resistance test at 210°C was conducted in accordance with the BMW group standard, "Adhesives and sealing materials used in the body shop Damping pad, Requirements and testings, GS 97028-16:2012-02 page 4, table 1: Resistance to high temperature ("Waermetest"), AA-0415, edition 2018-10." The test sample had a length / width of 16cm x 7cm.

[0143] Evaluation system: To obtain a Grade 4, there should be no blistering, melting, slipping, or shrinkage. Grade 3 is given when there are no blisters, only slight melting at the corners, no slippage, and no shrinkage. Grade 2 is given when there are no blisters, only slight melting at the corners, slight slippage, and no shrinkage. If the test sample detaches from the substrate or loses contact during the test, the grade is 1.

[0144] Measurement of low-temperature adhesion using a ball drop test at -30°C ("Bdt-30°C") A ball drop test at -30°C was conducted in accordance with the Volkswagen group standard, quality requirements, self-adhesive stiffening pads and sound deadening pads, QP M052 page 12, point 3.7.5 Ball drop test / determination of cold adhesion ("Kugelfall / Bestimmung der Kaeltehaftung"), PV 3971, edition 2020-03. The test sample had a length / width of 7cm x 7cm.

[0145] Evaluation system: Grade 1: No cracking or crushing of the sample, and no chipping from the test sheet. Grade 2: Sample shows cracking or crushing, but no chipping from the test sheet. Grade 3: No chipping from the test sheet; however, slight bending loads may cause the sample to delaminate from the test sheet. Grade 4: Sample cracking or crushing, or chipping from the test sheet in some areas. Grade 5: Sample cracking or crushing, or significant chipping from the test sheet. Grade 6: Complete layer delamination from the test sheet.

[0146] Measurement of adhesive / peel strength ("peel strength") Peel strength tests were conducted in accordance with BMW group standards, "Adhesives and sealing materials used in the body shop Damping pad, Requirements and testing, GS 97028-16:2012-02 page 4, table 1: Adhesion ("Peel-resistance of sound deadening and stiffening materials in the body shop"), AA-0007, edition 2018-10. The test samples had a length / width of 20cm x 3cm.

[0147] Measurement of the loss factor ("loss factor") The loss factor of the test specimen was measured using the measurement method specified in the ISO 6721 standard. The measurement was performed using a commercially available loss factor tester at an anti-resonance point of 200 Hz and a temperature range of 20 to 60°C. The test sample had a length / width of 20 cm × 1 cm.

[0148] It is advantageous when the maximum value of the loss coefficient in Table 3 is measured at 10°C or 20°C, preferably 20°C, because this temperature is the most common operating temperature for vehicles.

[0149] Measurement of expansion ("expansion") The expansion of each test sample was quantified by measuring the density of a square test sample of approximately 10 mm x 10 mm before and after expansion. Density was measured in accordance with DIN EN ISO 1183 using the water displacement method (Archimedes' principle) in deionized water and a precision balance for measuring mass. The test material was expanded at 160°C for 30 minutes or at 210°C for 20 minutes.

[0150] Surprisingly, compositions without the leavening agent BA were found to show significantly inferior results in the "Bdt-30°C" value and "loss factor" measurement. Compositions equivalent to compositions E1 and E5, but without the leavening agent BA, were prepared and tested for the "Bdt-30°C" value (see * in Table 3) and the "loss factor" (see ** in Table 3). The composition corresponding to E1 but without BA1, and the composition corresponding to E5 but without BA1, both showed a value of 4 for "Bdt-30°C" instead of 1 (*, see Table 3). When tested for the "loss factor," the composition corresponding to E1 but without BA1, and the composition corresponding to E5 but without BA1, both showed a 20% lower "loss factor" at 20°C compared to E1 and E5, respectively (**, see Table 3).

[0151] [Table 3]

Claims

1. Acoustic damping material: a) 6 to 25% by weight of liquid rubber LR at 25°C, selected from the group consisting of liquid polybutene and liquid polyisobutylene at 25°C, preferably liquid polyisobutylene at 25°C, based on the total weight of the acoustic damping material; b) At least one component CP, in an amount of 4 to 15% by weight based on the total weight of the sound-damping material, selected from the group consisting of butyl rubber BR, natural or synthetic polyisoprene PI, and polyisobutylene PIB having a weight-average molecular weight of 250,000 g / mol or more, preferably selected from the group consisting of butyl rubber BR and natural or synthetic polyisoprene PI, more preferably butyl rubber BR; c) Preferably, 4 to 15% by weight of at least one hydrocarbon resin HR based on the total weight of the sound-damping material; d) Preferably, 0.75% by weight or more of monomer units derived from 1,3-butadiene based on the total weight of the sound-damping material. 【Chemistry 1】 At least one polybutadiene PB comprising, wherein the proportion of monomer units of formula (I) to the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, the proportion of units of formula (II) to the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 0 to 10 mole percent, and the proportion of monomer units of formula (III) to the total amount of monomer units derived from 1,3-butadiene present in the polybutadiene is 25 to 75 mole percent, wherein the total amounts of monomer units (I), (II), and (III) are 100 mole percent in total, and the polybutadiene preferably has an average molecular weight of 1000 to 4000 g / mol; e) At least one type of solid particle filler FM: f) At least one chemical or physical leavening agent BA Acoustic damping materials, including

2. The amount of liquid rubber LR at 25°C is 8 to 22.5% by weight, preferably 10 to 20% by weight, and most preferably 13.5 to 18% by weight, based on the total weight of the sound-damping material, according to claim 1.

3. The acoustic damping material according to claim 1 or 2, wherein e) at least one leavening agent BA is selected from a list consisting of additives - functionalized chemical leavening agents and physical leavening agents, in particular functionalized chemical leavening agents, and the additive preferably consists of at least one additive selected from a list consisting of polymers, oils, preferably mineral oils, inorganic salts, fats, fatty acids, silanes and metal siloxylated compounds, preferably polymers and oils, most preferably oils, in particular mineral oils.

4. The additive-functionalized chemical leavening agent is obtained by spray-drying the chemical leavening agent in the presence of the additive, co-grinding the chemical leavening agent in the presence of the additive, coating the chemical leavening agent with the additive, or extruding the chemical leavening agent in the presence of the additive, according to any one of claims 1 to 3.

5. The sound attenuating material according to any one of claims 1 to 4, wherein the expanding agent is contained in the sound attenuating material in an amount of 0.1 to 5% by weight, preferably 0.5 to 4% by weight, more preferably 1 to 3% by weight, and most preferably 1 to 2% by weight, based on the total weight of the sound attenuating material.

6. The sound-damping material according to any one of claims 1 to 5, wherein the chemical swelling agent is selected from the list consisting of azodicarbonamide, azoisobutytronitrile, azocyclohexylnitrile, dinitrosopentamethylenetetramine, azodiaminobenzene, benzene-1,3-sulfonyl hydrazide, calcium azide, 4,4'-diphenyldisulfonyl azide, p-toluenesulfonyl hydrazide, p-toluenesulfonyl semicarbazide, 4,4'-oxybis(benzenesulfonyl hydrazide), trihydrazinotriadin, and N,N'-dimethyl-N,N'-dinitrosoterephthalamide, preferably azodicarbonamide.

7. The amount of the at least one component CP is 6 to 14.5% by weight, preferably 8 to 14% by weight, and more preferably 10 to 13.5% by weight, based on the total weight of the sound-damping material, according to any one of claims 1 to 6.

8. The amount of the at least one hydrocarbon resin HR is 5 to 12% by weight, preferably 5.5 to 10% by weight, and most preferably 6.5 to 9.5% by weight, based on the total weight of the sound-damping material, according to any one of claims 1 to 7.

9. The acoustic damping material according to any one of claims 1 to 8, wherein the at least one liquid rubber LR at 25°C has an average molecular weight of 5,000 g / mol or less, preferably 3,000 g / mol or less, more preferably 2,500 g / mol or less, even more preferably 2,000 g / mol or less, and even more preferably 1,500 g / mol or less.

10. The sound-damping material according to any one of claims 1 to 9, wherein the at least one butyl rubber BR preferably has a Mooney viscosity (ML 1 + 8 at 125°C) of 10 to 60 MU (Mooney units), preferably 20 to 50 MU, preferably 25 to 40 MU, in accordance with ASTM D1646.

11. The acoustic damping material according to any one of claims 1 to 10, wherein the at least one natural or synthetic polyisoprene PI has a Mooney viscosity (ML 1+4) of 30 to 120, more preferably 40 to 65, at 100°C, preferably in accordance with ASTM D1646.

12. Use of an acoustic damping material according to any one of claims 1 to 11 for damping vibration and / or noise in a transport vehicle or white goods appliance.

13. Vibration and noise damping element (1): i) a damping layer (2) having a first surface (3) and a second surface (3'), and ii) An adhesive layer (4) covering at least a portion of the first surface (3) of the damping layer (2), comprising the acoustic damping material described in any one of claims 1 to 11, or the adhesive layer (4) being composed of the acoustic damping material described in any one of claims 1 to 11. A vibration and noise damping element (1) comprising:

14. The adhesive layer (4) has a thickness of 0.5 to 5 mm, preferably 0.5 to 3 mm, more preferably 0.5 to 2 mm, and even more preferably 0.5 to 1 mm, and / or 0.5 to 5 kg / m ２ Preferably 0.6 to 4 kg / m ２ , more preferably 0.7 to 3 kg / m ２ The vibration and noise damping element (1) according to claim 13, having a mass per unit area.

15. A method for applying the vibration and noise damping element (1) described in claim 13 or 14 to the noise generating surface (7) of a substrate (6): I) A step of providing a vibration and noise damping element (1) according to claim 13 or 14; II) The step of bringing the outer main surface of the adhesive layer (4) of the vibration and noise damping element (1) into contact with the noise generating surface (7) and applying sufficient pressure to form an adhesive bond; or II') Heat the adhesive layer (4) and / or the substrate (6), bring the outer main surface of the adhesive layer (4) into contact with the noise generating surface (7), and form an adhesive bond by cooling the adhesive layer (4). Methods that include...

16. A vibration damping system comprising a substrate (6) having a noise-generating surface (7) and a vibration and noise damping element (1) according to claim 13 or 14, wherein at least a portion of the first surface (3) of the damping layer (2) is adhesively bonded to the noise-generating surface (7) via the adhesive layer (4), and the substrate (6) having the noise-generating surface (7) is preferably part of the structure of an automobile or a white goods appliance.

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