Process for production of batch materials comprising renewable raw materials and asphalt for acoustic damping compositions

Abstract

The invention relates to a method by mixing at least one asphalt component B and at least one solid particulate cellulose-containing filler FW at a mixing temperature of 100-180 DEG C for a mixing time of > = 10 min, wherein the weight ratio of the solid particulate cellulose-containing filler FW to asphalt B (FW / B) is from 6: 1 to 1: 1. The mixture has a low possibility of absorbing moisture during storage and the ability to protect the cellulose-containing particles contribute to high loss coefficients in the acoustic damping material. The invention also relates to the use of a mixture in an acoustic damping material for damping vibrations and noise in vehicles or white household appliances, to a vibration and noise damping element comprising a damping layer consisting of an acoustic damping material, to a method for applying a vibration and noise damping element to a noise emitting surface of a substrate, and to a vibration damping system comprising a substrate and a vibration and noise damping element bonded to a noise emitting surface of the substrate.

Description

Technical Field

[0001] The present invention relates to compositions for damping vibrations and noise in mechanical structures for the manufacture of articles. In particular, the present invention relates to the production of compositions comprising renewable raw materials suitable for damping vibrations of components and structures contained in articles of the automotive industry, household appliances and general industry. Background Art

[0002] Acoustic damping materials are widely used in automobiles, household appliances and general industry to reduce unwanted vibrations, structure-borne noise and airborne noise. For example, in a vehicle, it is desirable to prevent the vibrations generated by the engine, pumps, gears and other power generating devices from being transmitted through the vehicle body into the passenger compartment. Structure-borne noise is generated when the vibrations generated by the power generating devices are conducted through a supporting structure (usually a frame or other hollow structure) to a noise emitting surface (e.g., a metal or plastic panel, which converts mechanical vibrations into sound waves). Structure-borne noise and vibrations can generally be effectively reduced by applying vibration damping materials directly to the structure and surfaces of components that are subject to vibration disturbances (e.g., vehicle panels, floor surfaces, and housings of machines, washing machines and drying equipment).

[0003] Acoustic damping materials used for damping vibrations of panels and plates are typically provided in the form of preformed single and multi-layer damping elements or in the form of liquid compositions that are applied directly to the face of a substrate. Damping materials designed for damping vibrations and noise in hollow structures, such as cavities, are typically provided in the form of cavity filling inserts comprising an expandable composition and one or more connecting components that enable the cavity filling insert to be retained at a desired position within the hollow structure.

[0004] Preformed single-layer and multi-layer damping elements include a damping layer, which is in direct contact with the face of the substrate to be damped against vibration disturbances. The damping layer can dissipate the kinetic energy of the vibration surface as heat energy through the extension and compression of the material of the damping layer. Preformed single-layer and multi-layer damping elements often include a layer of an adhesive composition, such as a pressure-sensitive adhesive (PSA) or a hot melt adhesive, so that the damping layer can be bonded to the face of the substrate (e.g., a panel or floor of a vehicle). Liquid-applied damping systems are typically heat-dried, gelled or reactive compositions, which are applied to the face of the substrate in a liquid state, for example, by spraying.

[0005] Acoustic damping materials for damping vibrations of panels and plates can also be provided in the form of constrained layer damping elements, which contain a damping layer and a rigid outer layer, wherein the rigid outer layer "constrains" the damping layer so as to sandwich it between the rigid outer layer and the face of the substrate to be damped. The stiffness of the outer layer is generally ten times the stiffness of the damping material layer. Common materials for the outer top layer include, for example, aluminum and fiberglass fabrics. Constrained layer dampers are generally more effective than single layer damping elements in damping undesirable vibrations, but their production is also more expensive.

[0006] Cavity filling inserts are used for damping of airborne noise within a cavity of a hollow structural assembly and for preventing vibration transmission through the walls of the cavity. Cavity filling inserts are typically comprised of a damping material and at least one connecting component, wherein the connecting component enables the cavity filling insert to be retained at a desired position within the hollow structure. The damping material of the cavity filling insert is typically formulated as an expandable composition which, when activated, for example at an elevated temperature, expands and forms a seal around the inner surface of the wall of the cavity. Expandable damping materials suitable for damping of airborne noise within a cavity are typically referred to as "baffles".

[0007] Materials commonly used in damping layers include highly filled compositions comprising asphalt, elastomers or thermoplastic polymers and varying amounts of additives such as plasticizers, processing aids, rheology modifiers and desiccants. Fillers are added to these compositions to meet different design goals. Some fillers are used to improve the acoustic damping properties, while other fillers are used to reduce the density of the material or to replace more expensive materials in order to reduce the cost of raw materials. Common fillers for acoustic damping materials include, in particular, mineral fillers. Lightweight mineral fillers such as hollow ceramic spheres and hollow glass spheres have been widely used to reduce the density of acoustic damping materials and ultimately reduce the weight of acoustic damping elements. WO 2021 / 105129 describes an acoustic damping material comprising an asphalt component and a solid particulate cellulose-containing filler. The use of cellulose-containing fillers has the advantage of using renewable raw materials that exhibit similar or improved damping properties. The use of solid particulate cellulose-containing fillers in the production method of the acoustic damping material brings the disadvantage of large amounts of dust generation when storing, handling and mixing cellulose-containing fillers. In addition, cellulose-containing fillers tend to absorb moisture during storage and handling, wherein moisture reduces the quality of the acoustic damping material.

[0008] There is therefore a need for a process for producing acoustic damping materials containing solid particulate cellulose-containing fillers wherein the handling of the fillers can be improved without reducing the quality and benefits of the fillers in the final acoustic damping material. Summary of the invention

[0009] It is an object of the present invention to provide an improved process for the production of acoustic damping materials containing solid particulate cellulose-containing fillers.

[0010] The subject of the invention is the mixing method defined in claim 1 .

[0011] It has been surprisingly discovered that mixing solid cellulose-containing particles (eg, wood particles) with asphalt in a specific weight ratio at a specific temperature range significantly reduces the potential for moisture absorption during storage and preserves the ability of the cellulose-containing particles to contribute to a high loss factor in an acoustic damping material.

[0012] Further subjects of the invention are set forth in the other independent claims. Preferred aspects of the invention are set forth in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 5 A vibration and noise damping element (1) is shown in cross section, comprising a damping layer (2) having a first side (3) and a second side (3'), and an adhesive layer (4) covering the first side (3) of the damping layer (2).

[0014] Figure 6 A vibration and noise damping element (1) is shown in cross section, comprising a damping layer (2) having a first side (3) and a second side (3'), an adhesive layer (4) covering the first side (3) of the damping layer (2), and a restricting layer (5) covering the second side (3') of the damping layer (2).

[0015] Figure 7 A cross section of a vibration damping system is shown, comprising a substrate (6) having a noise emitting surface (7) and a vibration and noise damping element (1) comprising a damping layer (2) and an adhesive layer (4), wherein a first side (3) of the damping layer (2) is adhesively bonded to the noise emitting surface (7) via the adhesive layer (4).

[0016] Figure 8 A vibration damping system is shown in cross section, comprising a substrate (6) having a noise emitting surface (7) and a vibration and noise damping element (1) comprising a damping layer (2), an adhesive layer (4) and a limiting layer (5), wherein a first side (3) of the damping layer (2) is adhesively bonded to the noise emitting surface (7) via the adhesive layer (4) and wherein the damping layer (2) is sandwiched between the adhesive layer (4) and the limiting layer (5). DETAILED DESCRIPTION

[0017] The subject of the present invention is a method for mixing:

[0018] - at least one bituminous component B and

[0019] - at least one solid particulate cellulose-containing filler FW,

[0020] The mixing time was ≥ 10 min at a mixing temperature of 100-180°C.

[0021] The weight ratio of the solid particulate cellulose-containing filler FW to the bitumen B (FW / B) is from 6:1 to 1:1, preferably from 5:1 to 3:1.

[0022] The term "bitumen" is defined in this disclosure as a blend of heavy hydrocarbons, having a solid consistency at room temperature. These are typically obtained as vacuum residues from refining processes, which may be distillation (top or vacuum) and / or conversion processes, such as thermal cracking and visbreaking of suitable crude oils. Additionally, the term "bitumen" is also defined as natural and synthetic bitumens and bituminous materials extracted from tar and tar sands.

[0023] Asphalt component B may comprise one or more different types of asphalt materials, such as penetration grade (distillation) asphalt, air-rectified (semi-blown) asphalt and hard grade asphalt.

[0024] The term "peel grade bitumen" here refers to bitumen obtained from the fractionation of crude oil. The heavy fraction consisting of high molecular weight hydrocarbons obtained after removing the gasoline, kerosene and gas oil fractions, also called long boiling residue, is first distilled in a vacuum distillation column to produce more gas oil, distillate and concentrated residual oil.

[0025] The concentrated residual oil is then used as feed for the production of different grades of bitumen, which are graded by their penetration index, which is usually defined by the PEN value, which is the distance a needle penetrates into the bitumen under a standard test method, measured in tenths of a millimeter (dmm). Penetration grade bitumen is characterized by penetration and softening point.

[0026] Preferably, the bitumen component B has a needle penetration of 50-70 (dmm) or 70-100 (dmm), preferably 70-100 (dmm), determined according to DIN EN 1426: 2015. These values ​​have been found to have the best miscibility with the solid particulate cellulose-containing filler FW and to produce the most suitable premix for subsequent use in the sound damping material.

[0027] It is further preferred that the bitumen component B has a softening point of 43-54° C., preferably 43-51° C., determined according to DIN EN 1427:2015. These values ​​have been found to have the best miscibility with the solid particulate cellulose-containing filler FW and to produce premixes that are most suitable for subsequent use in sound damping materials.

[0028] The term "air conditioned asphalt" or "air refined asphalt" in this disclosure refers to asphalt that has been subjected to mild oxidation with the goal of producing asphalt that meets the specifications for paving grade asphalt. The term "hard grade asphalt" in this disclosure refers to asphalt produced from propane precipitated asphalt using extended vacuum distillation with some air conditioning. Hard asphalts generally have low penetration values ​​and high softening points.

[0029] The mixing method uses at least one solid particulate cellulose-containing filler FW. The term "solid particulate filler" is defined in this document as a filler which is present in the sound damping material in the form of solid particles. Preferably, the at least one solid particulate cellulose-containing filler FW consists of particles of a cellulose-containing material.

[0030] The at least one solid particulate cellulose-containing filler FW preferably has a median particle width (X) in the range of 100-1000 μm, preferably 115-850 μm, more preferably 135-750 μm, still more preferably 150-650 μm, yet more preferably 165-550 μm, most preferably 175-450 μm. c,min )D 50 The term "median particle width D" in this disclosure is 50 " refers to a particle width such that 50% of all particles by volume are smaller than the particle width (having a ratio D 50 The term "particle width" in this disclosure refers to the diameter of a particle, which is the largest chord (X C ) of the measurement set (X c,min ). The particle size distribution is preferably measured using a dynamic image analysis method according to ISO 13322-2:2006. For the determination of the particle size distribution, the particles are preferably dispersed in air, preferably using an air pressure dispersion method. The measurement can be performed using any type of dynamic image analysis equipment, such as a Camsizer XT device (trademark of Retsch Technology GmbH).

[0031] According to a preferred embodiment, the at least one solid particulate cellulose-containing filler FW has an aspect ratio of not more than 10, preferably not more than 7.5, more preferably not more than 5. Preferably, the aspect ratio of the particles of the at least one solid particulate cellulose-containing filler FW is in the range of 1-10, preferably 1.25-7.5, more preferably 1.5-7.5, even more preferably 1.5-5, yet more preferably 1.5-4.5.

[0032] The term "aspect ratio" of a particle in the present disclosure refers to the value obtained by dividing the length (L) of the particle by the thickness (T) of the particle. The "length of a particle" in the present disclosure refers to the maximum Feret diameter (X Fe,max ), i.e., the longest Feret diameter in the Feret diameter measurement set. The term "Ferret diameter" in this disclosure refers to the distance between two tangent lines on opposite sides of a particle, the two tangent lines being parallel to a fixed direction and perpendicular to the measurement direction. The "thickness of a particle" in this disclosure refers to the minimum Feret diameter (X Fe,min ), which is the shortest Feret diameter in the Feret diameter measurement set. Therefore, the aspect ratio is calculated as X Fe,maxand X Fe,min ratio.

[0033] The aspect ratio of the particle can be determined by measuring the length and thickness of the particle using any suitable measurement technique (preferably by using dynamic image analysis according to ISO 13322-2:2006 standard), and calculating the aspect ratio from the measured size of the particle as described above. The size of the particle can be measured using a dry dispersion method, wherein the particles are preferably dispersed in air using an air pressure dispersion method. The measurement can be performed using any type of dynamic image analysis equipment, such as a Camsizer XT device (trademark of Retsch Technology GmbH).

[0034] According to one or more embodiments, at least one solid particulate cellulose-containing filler FW has a g / cm 3 , preferably 0.30-1.25g / cm 3 , more preferably 0.35-1.0g / cm 3 , still more preferably 0.40-1.0 g / cm 3 , and more preferably 0.45-0.85g / cm 3 , most preferably 0.50-0.75g / cm 3 The term "true particle density" in this disclosure refers to the actual density of particles that make up the granular material. In contrast, the term "bulk density" refers to the mass of the granular material per unit volume (including the voids between particles).

[0035] According to one or more embodiments, the at least one solid particulate cellulose-containing filler FW contains at least 25 wt.-%, preferably at least 35 wt.-%, more preferably at least 40 wt.-% cellulose.

[0036] Preferably, at least one solid particulate cellulose-containing filler FW consists of wood particles. The term "wood particles" refers to particles consisting of wood fibers. The length dimension of the wood particles is usually oriented parallel to the particle structure of the wood particles, i.e. parallel to the long axis of the main fibers in the wood particles.

[0037] Preferably, the at least one solid particulate cellulose-containing filler FW comprises, for example, all types of softwood and hardwood particles, in particular hardwood particles.

[0038] The term "softwood" refers to wood from the coniferous trees of the order Pinaceae. Softwood production trees include, for example, pine, spruce, cedar, fir, larch, Douglas fir, hemlock, cypress, redwood and yew. In contrast, the term "hardwood" refers to wood from broadleaf or angiosperm trees, such as eucalyptus, maple, birch, beech, poplar, etc. Softwood contains two types of cells, longitudinal wood fibers (or tracheids) and transverse ray cells, while hardwood trees contain pores or vessels. In softwood, water transport within the tree is via tracheids rather than pores in hardwood.

[0039] Preferably, the at least one solid particulate cellulose-containing filler FW comprises or consists of hardwood particles, preferably wood particles selected from the group consisting of eucalyptus, maple, birch, beech and aspen.

[0040] Preferably, the at least one solid particulate cellulose-containing filler FW comprises at least 15% by weight, preferably at least 35% by weight, more preferably at least 50% by weight, still more preferably at least 75% by weight, yet more preferably at least 85% by weight, most preferably at least 95% by weight of hardwood particles, preferably selected from wood particles of eucalyptus, maple, birch, beech and poplar. This is advantageous in terms of obtaining a high loss factor.

[0041] The mixing of the at least one bitumen component B and the at least one solid particulate cellulose-containing filler FW takes place at a mixing temperature of 100 to 180° C. for a mixing time of ≧10 min.

[0042] Mixing times of less than 10 min do not provide adequate impregnation and wetting of the solid particulate cellulose-containing filler FW with the bitumen B. This is seen, for example, in Figure 3 .

[0043] Preferably, the mixing time is 10-45 min, preferably 15-40 min, more preferably 20-35 min. The mixing time is advantageous in providing sufficient impregnation and wetting of the solid particulate cellulose-containing filler FW with the bitumen B and obtaining a high loss factor. This can be seen, for example, in Figure 2 and Figure 4 .

[0044] Mixing temperatures below 100° C. have the disadvantage of insufficient wetting of the solid particulate cellulose-containing filler FW with the bitumen B. Mixing temperatures above 180° C. result in a decrease in the loss factor obtained by the mixture.

[0045] Preferably, the mixing temperature is 130-175° C., 145-175° C., preferably 155-165° C. This temperature range is advantageous with regard to sufficient wetting of the solid particulate cellulose-containing filler FW with the bitumen B and a high loss factor obtained by the mixture.

[0046] A weight ratio of the solid particulate cellulose-containing filler FW to the bitumen B (FW / B) of more than 6:1 does not provide sufficient impregnation and wetting of the solid particulate cellulose-containing filler FW with the bitumen B. This is seen, for example, in Figure 1 .

[0047] A weight ratio of solid particulate cellulose-containing filler FW to bitumen B (FW / B) of less than 1:1 has the disadvantage that not enough particulate cellulose-containing filler FW is contained in bitumen B so that the mixture cannot be used to significantly reduce the loss factor in the sound damping material.

[0048] Preferably, the weight ratio of at least one solid particulate cellulose-containing filler FW to bitumen B (FW / B) is 5:1 to 3:1, preferably 4.5:1 to 3.5:1. This weight ratio is advantageous in terms of sufficient impregnation and wetting of the solid particulate cellulose-containing filler FW with bitumen B and uniform distribution of the solid particulate cellulose-containing filler FW. This is seen, for example, in Figure 1 .

[0049] Any customary type of mixing equipment can be used for the intermixing of the at least one bituminous component B and the at least one solid particulate cellulose-containing filler FW.

[0050] Preferably, the mixing step is carried out in a batch process using a conventional batch mixer, preferably selected from planetary mixers and kneading mixers, preferably a kneading mixer, more preferably a double-arm kneading mixer, also known as a sigma mixer.

[0051] Particular preference is given to mixing using a kneading mixer, preferably a double-arm kneading mixer, at a mixing rate of from 25 to 60 revolutions per minute, preferably from 30 to 50 revolutions per minute.

[0052] The resulting mixture is preferably cooled to a temperature below 35°C, preferably below 30°C, and preferably stored at said temperature, preferably for longer than 1 week.

[0053] The cooled mixed mixture is storage-stable under normal storage conditions. The term "storage-stable" in the present disclosure refers to a material that can be stored under specified storage conditions for a long period of time, such as at least one month, in particular at least 3 months, without any significant changes in the application properties of the material. "Usually storage conditions" refers to a temperature below 35°C, in particular below 30°C.

[0054] Preferably, the mixture contains less than 10% by weight, preferably less than 5% by weight, more preferably less than 2% by weight, based on the total weight of the mixture obtained in the process, of components other than at least one asphalt component B and at least one solid particulate cellulose filler FW and optionally at least one solid particulate mineral filler FM, and more preferably the above-mentioned amounts of components other than at least one asphalt component B and at least one solid particulate cellulose filler FW.

[0055] The resulting mixture is particularly suitable for use as a premix for subsequent use, for example after a storage period, as a component in a composition, preferably an acoustic damping material.

[0056] In a preferred embodiment of the method, after mixing, preferably after an additional storage period after mixing;

[0057] - at least one thermoplastic polymer TP,

[0058] - optionally at least one bituminous component B1,

[0059] - optionally at least one hydrocarbon resin HR,

[0060] - optionally at least one wax W,

[0061] - optionally at least one plasticizer PL, and

[0062] - optionally at least one solid particulate mineral filler FM,

[0063] Addition to a mixture of at least one bituminous component B and at least one solid particulate cellulose-containing filler FW to give a sound damping material.

[0064] Preferably, the amount of the mixture of at least one bituminous component B and at least one solid particulate cellulose-containing filler FW is 1-30% by weight, preferably 3-25% by weight, more preferably 5-20% by weight, based on the total weight of the sound damping material.

[0065] The above-mentioned thermoplastic polymer TP preferably has the following properties:

[0066] - Glass transition temperature (T) determined by dynamic mechanical analysis (DMA) g ), i.e. the peak of the loss modulus (G") curve measured using an applied frequency of 1 Hz and a strain level of 0.1%, which is below 25°C, preferably below 5°C, more preferably below 0°C, and / or

[0067] - Softening point (T) determined by ring and ball measurement according to DIN EN 1238 S), which is higher than 35°C, preferably higher than 45°C, more preferably higher than 55°C, for example in the range of 35-250°C, preferably 45-200°C, more preferably 55-180°C.

[0068] The type of at least one thermoplastic polymer TP is not particularly limited. Various types of thermoplastic polymers, including crystalline, semi-crystalline and amorphous polymers and thermoplastic elastomers, are suitable for use as at least one thermoplastic polymer TP. According to one or more embodiments, at least one thermoplastic polymer TP is selected from polyolefin homopolymers and copolymers, copolymers of ethylene and vinyl acetate, and thermoplastic olefin elastomers (TPE-O).

[0069] The at least one bitumen component B1 preferably has a needle penetration of 10 to 30 (dmm), preferably 10 to 20 (dmm), determined according to DIN EN 1426:2015.

[0070] The at least one hydrocarbon resin HR preferably includes C5 aliphatic resins, mixed C5 / C9 aliphatic / aromatic resins, aromatic modified C5 aliphatic resins, cycloaliphatic resins, mixed C5 aliphatic / cycloaliphatic resins, mixed C9 aromatic / cycloaliphatic resins, mixed C5 aliphatic / cycloaliphatic / C9 aromatic resins, aromatic modified cycloaliphatic resins, C9 aromatic resins, and hydrogenated versions of the aforementioned resins. The notations "C5" and "C9" indicate that the monomers from which the resins are made are mainly hydrocarbons having 4-6 and 8-10 carbon atoms, respectively. The term "hydrogenated" includes fully, substantially and at least partially hydrogenated resins. Partially hydrogenated resins may have, for example, a hydrogenation level of 50%, 70% or 90%.

[0071] The at least one wax W preferably has

[0072] - a softening point in the range of 75-180° C., preferably 80-160° C., more preferably 85-140° C., determined by the ring and ball method as defined in the DIN EN 1238 standard, and / or

[0073] - a melt viscosity at a temperature of 170° C. in the range of 10-10000 mPa·s, preferably 100-5000 mPa·s, more preferably 500-3500 mPa·s, determined according to DIN 53019. The melt viscosity can be determined by using a rotational viscometer at 5 revolutions per minute, for example by using a Brookfield DV-2 Thermosel viscometer with a No. 27 spindle.

[0074] According to one or more embodiments, at least one wax is a polyolefin wax. The term "polyolefin wax" in this document is defined as a low molecular weight polymer of a linear or branched α-olefin having 2 to 30 carbon atoms, having a number average molecular weight (M) in the range of 5000-25000 g / mol. n ). They include both homopolymers and copolymers of the above-mentioned linear or branched alpha-olefins. Polyolefin waxes can be obtained by thermal decomposition of polyolefin plastics, particularly polyethylene plastics, or by direct polymerization of olefins. Suitable polymerization methods include, for example, free radical methods, in which olefins such as ethylene react under high pressure and temperature to provide more or less branched waxes, and methods in which ethylene and / or higher alpha-olefins, particularly propylene, are polymerized using metal organic catalysts (e.g., Ziegler-Natta or metallocene catalysts) to provide unbranched or branched waxes. Polyolefin waxes generally have a structure that is at least partially crystalline.

[0075] Preferably, the above-mentioned at least one plasticizer PL consists of at least one process oil PL1, which is preferably selected from mineral oils, synthetic oils and vegetable oils, and / or the at least one plasticizer PL consists of at least one hydrocarbon resin PL2 which is liquid at 25° C., which is preferably selected from liquid polybutenes and liquid polyisobutylenes (PIB), preferably having a molecular weight (M) of not more than 5000 g / mol, more preferably not more than 3500 g / mol, still more preferably not more than 3000 g / mol. n ) and / or a polydispersity index (Mw / Mn) of not more than 7.5, more preferably not more than 5.0, for example in the range of 0.5-5.0, preferably 1.0-4.5, more preferably 1.0-3.5, still more preferably 1.25-2.5 as determined by gel permeation chromatography (GPC).

[0076] Preferably, the at least one solid particulate mineral filler FM is in the form of solid particles, preferably having a d of not more than 2.5 mm, more preferably not more than 1.5 mm. 90 Particle size. The term "particle size d 90 ” refers to a particle size that is smaller than 90% of all particles by volume (having a ratio d 90 The term "particle size" in this disclosure refers to the area equivalent spherical diameter (X area ). The particle size distribution is preferably measured using dynamic image analysis according to ISO 13322-2:2006. For the determination of the particle size distribution, the particles are preferably dispersed in air, preferably using an air pressure dispersion method. The measurement can be performed using any type of dynamic image analysis equipment, such as the Camsizer XT device (trademark of Retsch Technology GmbH).

[0077] It is also preferred that the at least one solid particulate mineral filler FM is an inert mineral filler and has a water solubility of less than 0.1 g / 100 g water, more preferably less than 0.05 g / 100 g water, still more preferably less than 0.01 g / 100 g water at a temperature of 20°C. The solubility of a compound in water can be measured as the saturation concentration at which the addition of more compound does not increase the concentration of the solution, i.e. at which excess material begins to precipitate. The term "inert mineral filler" in the present disclosure refers to a mineral filler which, unlike a mineral binder, is non-reactive, i.e. does not undergo a hydration reaction in the presence of water.

[0078] According to one or more embodiments, the at least one solid particulate mineral filler FM is chosen from calcium carbonate, magnesium carbonate, talc, kaolin, diatomaceous earth, wollastonite, feldspar, montmorillonite, dolomite, 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.

[0079] A further aspect of the invention is the use of the above-described mixture for producing a sound damping material, preferably for producing a sound damping material for damping vibrations and / or noise in vehicles or white goods.

[0080] A further subject of the invention is a vibration and noise damping element (1) comprising:

[0081] i) a damping layer (2) having a first and a second face (3, 3'), and

[0082] ii) an adhesive layer (4) covering at least a portion of the first side (3) of the damping layer (2), wherein the damping layer (2) comprises or consists of the sound damping material of the present invention.

[0083] A cross section of a vibration and noise damping element according to the invention is shown in Figure 5 middle.

[0084] According to one or more embodiments, the damping layer is a sheet-like element having a first and a second major face, the first and second major faces defining a thickness therebetween, and the length and width of the damping layer are at least 5 times, preferably at least 15 times, more preferably at least 25 times the thickness of the sheet-like element. The term "thickness" refers to the dimension of the sheet-like element measured in a plane substantially 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 faces of the damping layer correspond to the first and second major faces of the sheet-like element.

[0085] The damping layer and the adhesive layer are preferably directly connected to each other on their opposite faces. In the context of the present invention, the expression "direct connection" is understood to mean that there is no additional layer or substance between the two layers and the opposite faces of the layers are directly bonded to each other. According to one or more embodiments, the adhesive layer covers at least 65%, preferably at least 75%, more preferably at least 85%, even more preferably at least 90%, and even more preferably at least 95% of the first face of the damping layer. According to one or more other embodiments, the adhesive layer covers substantially the entire area of ​​the first face of the damping layer. The expression "substantially the entire area" is understood to mean at least 97.5%, preferably at least 98.5%, and more preferably at least 99.5% of the total area.

[0086] The adhesive layer preferably comprises a pressure-sensitive adhesive or a hot-melt adhesive composition. The term "pressure-sensitive adhesive" is understood to also include pressure-sensitive hot-melt adhesives (HM-PSA). According to one or more embodiments, the adhesive layer consists of a pressure-sensitive adhesive or a hot-melt adhesive composition.

[0087] Suitable pressure-sensitive adhesives to be used in the adhesive layer include compositions based on acrylic polymers, styrene block copolymers, amorphous polyolefins (APO), amorphous polyalphaolefins (APAO), vinyl ether polymers or elastomers such as butyl rubber, ethylene vinyl acetate with a high vinyl acetate content, natural rubber, nitrile rubber, silicone rubber and ethylene-propylene-diene rubber. In addition to the above polymers, suitable pressure-sensitive adhesive compositions typically contain one or more additional components, including, for example, tackifying resins, waxes and plasticizers and one or more additives such as UV-light absorbers, UV- and heat stabilizers, optical brighteners, pigments, dyes and dehumidifiers.

[0088] Hot melt adhesive is a solvent-free adhesive, which is solid at room temperature, and is applied to substrates to be combined in the form of a melt. After cooling, the adhesive solidifies and forms a viscous bond with substrates by physical and / or chemical bonding. Suitable hot melt adhesives include, for example, hot melt adhesives based on polyolefins, particularly those based on amorphous polyolefins (APO) and amorphous poly-alpha-olefins (APAO), hot melt adhesives based on thermoplastic copolymers, particularly those comprising copolymer ethylene and vinyl acetate (EVA) or polyamide as main polymer components and hot melt adhesives based on polyurethane. In addition to the above-mentioned polymers, suitable hot melt adhesive compositions generally include one or more additional components, including, for example, resins and waxes and one or more additives such as UV-light absorbers, UV- and heat stabilizers, optical brighteners, pigments, dyes and dehumidifiers. Suitable hot melt adhesives to be used in adhesive layers are disclosed in, for example, WO 2011 / 023768A1, WO 2016 / 139345A1 and WO 2017 / 174522A1.

[0089] According to one or more embodiments, the damping layer has a maximum thickness in the range of 0.5-15 mm, preferably 1-10 mm, more preferably 1.5-7.5 mm, still more preferably 1.5-5 mm and / or a thickness of 0.1-5 g / cm 3 , preferably 0.2-4.5g / cm 3 , more preferably 0.3-3g / cm 3 , still more preferably 0.3-2.5 g / cm 3 Density in the range of 1-5 kg / m 2 , preferably 1-4.5kg / m 2 , more preferably 1.5-4.5kg / m 2 , still more preferably 1.5-3.5kg / m 2 The mass per unit area.

[0090] According to one or more embodiments, the vibration and noise damping element has a loss factor of at least 0.1, preferably at least 0.15, measured at 200 Hz at a temperature of 20° C. using the method defined in the ISO 6721 standard. Such vibration and noise damping elements have been found to be particularly suitable for damping vibrations of components and structures contained in articles for the automotive industry and household appliances.

[0091] According to one or more embodiments, the vibration and noise damping element comprises, in addition to the damping layer and the adhesive layer, a restricting layer covering at least a portion of the second face of the damping layer. The vibration and noise damping element according to these embodiments is generally referred to as a "restricted layer damper". The damping layer and the restricting layer are directly or indirectly connected to each other on their opposite faces, i.e. the damping layer is sandwiched between the adhesive layer and the restricting layer. According to one or more embodiments, the restricting layer covers substantially the entire area of ​​the second face of the damping layer. A cross section of the vibration and noise damping element according to these embodiments is shown in Figure 6 middle.

[0092] According to one or more embodiments, the restricting layer is a metal sheet, preferably an aluminum or steel sheet, or a polymer sheet, preferably a glass fiber reinforced polymer sheet. The thickness of the restricting layer is not particularly limited, but it is generally preferred to use a restricting layer thinner than the damping layer. The preferred thickness also depends on the material of the restricting layer. According to one or more embodiments, the restricting layer has a thickness of 0.05-1.5mm, preferably 0.1-1.25mm, more preferably 0.1-1.0mm. According to one or more embodiments, the restricting layer is a metal sheet with a thickness of 0.05-0.5mm, preferably 0.05-0.4mm. According to one or more other embodiments, the restricting layer is a polymer sheet with a thickness of 0.1-1.2mm, preferably 0.25-1.0mm.

[0093] Preferably, the restricting layer has an elastic modulus greater than that of the damping layer, for example at least 3 times, preferably at least 5 times, more preferably at least 10 times that of the damping layer, wherein the elastic modulus is measured using the method defined in ISO 6892-1:2016 standard (for metal sheets) or in ISO 527-2 standard (for polymer sheets).

[0094] A further subject of the invention is a method for producing the vibration and noise damping element according to the invention, the method comprising the following steps:

[0095] i) providing a damping layer which comprises or consists of the acoustic damping material of the invention and has a first and a second side,

[0096] ii) applying the adhesive composition on the first side of the damping layer. Step i) can be carried out with any conventional technique known to those skilled in the art. For example, the acoustic damping material of the present invention can first be melt-processed in an extruder device 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 by using calendering or hot pressing technology.

[0097] Any conventional technique can be used to apply adhesive composition to the face of the damping layer, and its details depend on the type of adhesive composition.For example, adhesive composition can be applied to the face of the sheet by nozzle extrusion, powder dispersion, hot melt calendering or by spray coating technology.In the case of hot melt adhesive composition or hot melt pressure sensitive adhesive (HM-PSA) composition, first the adhesive composition is heated to a softening point (T ) higher than the adhesive. s ) of an elevated application temperature and then applied to the face of the damping layer.

[0098] A further subject matter of the present invention is a method for applying a vibration and noise damping element according to the invention to a noise emitting surface of a substrate, the method comprising the following steps:

[0099] I) providing a vibration and noise damping element according to the invention,

[0100] II) contacting the outer major surface of the adhesive layer of the vibration and noise damping element with the noise emitting surface and applying sufficient pressure to form an adhesive bond, or

[0101] II′) Heating the adhesive layer and / or the base material of the vibration and noise damping element and bringing the outer main surface of the adhesive layer into contact with the noise emitting surface and forming the adhesive bond by cooling the adhesive layer.

[0102] The term "outer main face" of the adhesive layer refers to the main face of the side of the adhesive layer opposite to the side of the damping layer. The substrate with the noise emitting surface can be any type of shaped article, such as a panel, a sheet or a film, which consists of, for example, metal, plastic or fiber reinforced plastic. The heating of the adhesive layer and / or the substrate in step II') can be carried out using any conventional technique, such as heating in an oven, heating by air flow or heating using infrared (IR) radiation.

[0103] Yet another subject of the invention is a vibration damping system comprising a substrate (6) having a noise emitting surface (7) and a vibration and noise damping element (1) according to the invention, wherein at least a portion of the first surface (3) of the damping layer (2) is adhesively bonded to the noise emitting surface (7) via an adhesive layer (4). A cross section of the vibration damping system is shown in FIG. Figure 7 middle.

[0104] According to one or more embodiments, the vibration and noise damping element (1) is a constrained damping element comprising a constrained layer (5), wherein the damping layer (2) is sandwiched between an adhesive layer (4) and the constrained layer (5). A cross section of the vibration damping system according to these embodiments is shown in Figure 8 middle.

[0105] According to one or more embodiments, the substrate having a noise emitting surface is part of the structure of a vehicle or a white appliance.

[0106] Example

[0107] The products shown below in Table 1 were used in the Examples.

[0108] Table 1

[0109]

[0110] Preparation of mixtures and determination of ideal mixing ratio

[0111] have Figure 1 A damping material composition having a weight ratio of solid particulate cellulose-containing filler FW (the sum of FW1 and FW2) and asphalt B shown in was prepared according to the following procedure.

[0112] In the first step, solid particulate cellulose-containing fillers FW1 and FW2 (the weight ratio of FW1 to FW2 is always 1:1) and bitumen B are mixed in a Figure 1 The weight ratios indicated in are mixed in a laboratory kneading mixer (double Z-blade) at 160° C. and 40 rpm for 30 min. For example, the weight ratios shown in Table 1 with approx. 1.1 g / cm 3The composition of the present invention has a weight ratio of solid particulate cellulose-containing filler FW to bitumen B ((FW1+FW2) / B) of 4:1 and a density of 1.5 and 80 wt.% of the solid particulate cellulose-containing filler FW in an amount of 4:1. The density of the composition is then measured according to DIN EN ISO 1183 standard using an immersion method in deionized water (Archimedes principle) and a precision balance for measuring the mass of the composition.

[0113] from Figure 1 It can be seen that at a ratio of 4:1 to about 4:6, the mixed composition has a viscosity of about 1.1 g / cm 3 This indicates that the solid particulate cellulose-containing filler FW is completely impregnated and wetted by the bitumen B.

[0114] exist Figure 2 The water absorption of the mixed compositions was also tested by weighing the mixed compositions before and after storage at 30°C and 85% relative humidity for 24 hours using a precision balance to determine their water absorption. Figure 1 The measurement results of the density determination are related to

[0115] Preparation of mixtures and determination of ideal mixing time

[0116] In order to determine the ideal mixing time of the solid particulate cellulose-containing filler FW with the bitumen B, a composition with an amount of 80 wt. % solid particulate cellulose-containing filler FW (a mixture of FW1 and FW2 in a 1:1 weight ratio) and a weight ratio of solid particulate cellulose-containing filler FW to bitumen B ((FW1+FW2) / B) of 4:1 was selected and mixed in a laboratory kneader (double Z) at 160° C. and 40 rpm for the time indicated in Table 3, in minutes. Samples of the composition were taken out every 5 min after the start of the mixing process and their density was analyzed as described above. From Figure 3 It can be seen from the data that the mixing reaches about 1.1g / cm after about 20min. 3 The maximum density.

[0117] In parallel, samples of the composition were taken out every 5 min after the start of the mixing process and analyzed for loss factor, such as Figure 4 Each sample was processed by using a conventional calendaring device to have a thickness of about 2 mm and a pressure of about 3 kg / m 2 A sheet with a mass per unit area of ​​1000 Å was prepared. Test specimens of suitable size were obtained by cutting the prepared sheet from the composition. One of the main faces of each test specimen was coated with a layer of an acrylate-based pressure-sensitive adhesive. The adhesive layer had a thickness of 50 μm.

[0118] The loss factor of the test specimen was determined by using the test method defined in ISO 6721. The measurement was performed using a commercially available loss factor tester at a temperature ranging from 20 to 60° C. The value of the loss factor at a frequency of 200 Hz was obtained by mathematically averaging the measured values ​​of the loss factor value.

[0119] from Figure 4 From the data, it can be seen that the acoustic effect decreases significantly after a mixing time greater than 35 minutes.

Claims

1. Methods: Mix at a mixing temperature of 100-180°C - at least one bituminous component B and - at least one solid particulate cellulose-containing filler FW, Mixing time lasting ≥10min, The weight ratio of the solid particulate cellulose-containing filler FW to the asphalt B (FW / B) is 6:1 to 1:1, preferably 5:1 to 3:

1.

2. The method according to claim 1, wherein the weight ratio of at least one solid particulate cellulose-containing filler FW to bitumen B (FW / B) is from 5:1 to 3:1, preferably from 4.5:1 to 3.5:

1.

3. A process according to any preceding claim, wherein the mixing temperature is 130-175°C, preferably 145-175°C, more preferably 155-165°C.

4. A method according to any preceding claim, wherein the mixing time is 10-45 min, preferably 15-40 min, more preferably 20-35 min.

5. A process according to any preceding claim, wherein mixing is carried out in a batch process, preferably using a batch mixer, more preferably selected from a planetary mixer and a kneading mixer, preferably a kneading mixer.

6. The process according to claim 5, wherein the mixing is carried out using a kneading mixer, preferably a double-arm kneading mixer, at a mixing rate of 25 to 60 rpm, preferably 30 to 50 rpm.

7. The method according to any of the preceding claims, wherein the at least one solid particulate cellulose-containing filler FW has an aspect ratio of not more than 7.5, preferably not more than 5.0, wherein the aspect ratio is determined as the ratio of the length (L) and the thickness (T) of the particle.

8. The method according to any of the preceding claims, wherein the at least one solid particulate cellulose-containing filler FW consists of wood particles, preferably comprises at least 75% by weight, more preferably at least 95% by weight, of hardwood particles.

9. The method according to any of the preceding claims, wherein the at least one solid particulate cellulose-containing filler FW has a median particle width D in the range of 100-1000 μm, preferably 115-850 μm, more preferably 150-500 μm. 50 .

10. The method according to any preceding claim, wherein the bitumen component B has a needle penetration of 50-70 or 70-100, preferably 70-100, determined according to DIN EN 1426:2015 and / or a softening point of 43-54°C, preferably 43-51°C, determined according to DIN EN 1427:2015.

11. A process according to any preceding claim, wherein the obtained mixture is cooled to a temperature below 35°C, preferably below 30°C and preferably stored at said temperature, more preferably for longer than 1 week.

12. A method according to any of the preceding claims, wherein the mixture contains less than 10% by weight, preferably less than 5% by weight, more preferably less than 2% by weight, based on the total weight of the mixture obtained in the method, of components other than at least one asphalt component B and at least one solid particulate cellulose filler FW and optionally at least one solid particulate mineral filler FM, more preferably the above-mentioned amounts of components other than at least one asphalt component B and at least one solid particulate cellulose filler FW.

13. A method according to any preceding claim, wherein: After mixing, and preferably after an additional storage period after mixing, - at least one thermoplastic polymer TP, - optionally at least one bituminous component B1, - optionally at least one hydrocarbon resin HR, - optionally at least one wax W, - optionally at least one plasticizer PL, and - optionally at least one solid particulate mineral filler FM, Addition to a mixture of at least one bituminous component B and at least one solid particulate cellulose-containing filler FW to give a sound damping material.

14. The method according to claim 13, wherein the amount of the mixture of at least one bitumen component B and at least one solid particulate cellulose-containing filler FW is 1-30% by weight, preferably 3-25% by weight, more preferably 5-20% by weight, based on the total weight of the sound damping material.

15. Use of the mixture obtained by the process according to any one of claims 1 to 14 for producing a sound damping material, preferably a sound damping material for damping vibrations and / or noise in vehicles or white goods.

16. Vibration and noise damping element (1), comprising: 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 side (3) of the damping layer (2), wherein the damping layer (2) comprises a mixture of at least one bitumen component B obtained according to the method of any one of claims 1 to 14 and at least one solid particulate cellulose-containing filler FW.

17. Method for applying a vibration and noise damping element (1) according to claim 16 to a noise emitting surface (7) of a substrate (6), the method comprising the following steps: 1) providing a vibration and noise damping element (1) according to claim 16, II) contacting the outer major surface of the adhesive layer (4) with the noise emitting surface (7) and applying sufficient pressure to form an adhesive bond or II′) Heating the adhesive layer ( 4 ) and / or the substrate ( 6 ) and bringing the outer main surface of the adhesive layer ( 4 ) into contact with the noise emitting surface ( 7 ) and forming an adhesive bond by cooling the adhesive layer ( 4 ).

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