Low-temperature curing compositions for rubber-based adhesives and sealants

Abstract

The present invention relates to a rubber composition that can be thermocured at low temperatures while maintaining performance over a wide curing temperature range, comprising at least one solid rubber, at least one diene polymer or copolymer containing an olefinic double bond and / or an aromatically substituted olefin, and existing as a quinone dioxime, peroxide, and any polyfunctional acrylate, preferably in the absence of elemental sulfur, in a curing system. The cured composition exhibits improved resistance to reversion and adhesive strength to aluminum.

Description

[Technical Field]

[0001] The present invention relates to thermosetting rubber compositions useful as adhesives and / or sealants, cured products thereof, and methods for producing and using the same. [Background technology]

[0002] With the advent of low-temperature curing electrodeposition (E-coat) coatings, there is a need for adhesives and sealants that co-cure with these coatings and perform under the same conditions. While the typical curing temperature range for automotive adhesives and sealants is 160°C to 200°C, new electrodeposition coatings aim for curing at a low temperature of 140°C.

[0003] Attempts have been made to manufacture adhesives and sealants with lower curing temperatures for co-curing with paints in various manufacturing applications, but success has been limited. Rubber-based compositions have shown potential for curing at low temperatures of 120°C by extending the curing time to 150 minutes (2.5 hours). However, this extended curing time is not applicable to most line assembly processes, including E-coating, where painted parts are passed through a baking oven in approximately 10-20 minutes. Therefore, there is a need for low-temperature curing rubber-based adhesives and sealant compositions that cure at temperatures below approximately 140°C and achieve curing times ranging from 5 to approximately 25 minutes.

[0004] While accelerated curing systems can cure at temperatures below 160°C, they have been shown to have poor storage stability and limited shelf life. They are also susceptible to overbaking during line stoppages, and significant degradation occurs at temperatures exceeding 200°C. One-component systems rely on encapsulation methods to maintain shelf life, leading to increased manufacturing costs and complexity. Other conventional low-temperature compositions are two-component systems, which are inconvenient to use and pose risks of premature curing, poor wet-out, or contamination of the open bead surface during storage. Therefore, there is a need for low-temperature curing rubber-based adhesives and sealant compositions with excellent storage stability.

[0005] Thermosetting rubber compositions are typically heated and cured in an oven at temperatures ranging from approximately 160 to 180°C. However, the temperature inside the oven can rise to high temperatures (e.g., 190°C or higher), leading to a so-called overbaking condition. Therefore, the object of the present invention is to provide a thermosetting composition that exhibits excellent adhesion to metal substrates, particularly aluminum, substantially uniform curing characteristics at oven temperatures of 130°C to 200°C, and shows little reduction in strength even when heated at temperatures above 190°C (hereinafter referred to as "rebound resistance").

[0006] In vehicle manufacturing, one application of thermosetting rubber adhesives and sealant compositions is the application of so-called underlays between the white body of the vehicle and corresponding structural materials such as roof arches, rocker panels, security elements, and reinforcing elements. Underlays can strengthen the vehicle structure and provide bonding, sound insulation, and / or sealing functions.

[0007] The growth of the electric vehicle (EV) market has presented new challenges to the conventional curing conditions of adhesives and sealants. In particular, many electric vehicles have a significant amount of added reinforcement to the lower rocker panel to protect the battery system. This added mass increases the temperature of the mass, requiring more thermal energy to form a heat sink, which prevents the white body from reaching a uniform curing temperature for the adhesive and sealant during the E-coat curing process. This uneven body temperature leads to under-baking of large masses and / or over-baking of thin structures such as the roof. Therefore, there is a need for low-temperature curing rubber-based compositions that maintain strength even when curing at temperatures of approximately 190-230°C.

[0008] The objective of the present invention is to solve one or more of the above-mentioned drawbacks. [Overview of the project] [Means for solving the problem]

[0009] The present invention relates to a thermosetting rubber composition that can be cured at a low temperature of about 130°C to 140°C; a curing composition that adheres to a metal surface; an adhesive, sealant or acoustic damping product thereof that exhibits one or more improved rebound resistance, such as reduced strength reduction after high-temperature heating, and excellent adhesion to aluminum; and a product, component or assembly manufactured with or containing the composition, as well as a method for manufacturing and using the composition.

[0010] The present invention cures at an extremely low temperature of approximately 130°C to 140°C with a curing time of approximately 10 to 20 minutes, while also exhibiting substantial resistance to reverting even at high curing temperatures of approximately 190°C to 230°C. Due to these characteristics, the composition can be used in white body parts that become hot during curing (e.g., roofs) and parts that become cold (e.g., heavy parts such as reinforced body sections).

[0011] The thermosetting composition includes a low-temperature curing system, preferably one that is sulfur-free or substantially sulfur-free, and comprises two or more polyfunctional co-reactants such as quinone dioximes, peroxides, and (meth)acrylate monomers, oligomers, or polyols. Conventional accelerators such as organic accelerators and / or metal oxides, which are different from the peroxides and unsaturated co-reactants disclosed herein, may also be included, but their amount is preferably kept to a minimum, and they are not included in some embodiments. Examples include dithiocarbamates (in the form of ammonium salts or metal salts), xanthogenic salts, thiuram compounds (monosulfide and disulfide), thiazole compounds, aldehyde / amine accelerators (such as hexamethylenetetramine), dibenzothiazyl disulfide (MBTS), 2-mercaptobenzothiazole (MBT), its zinc salt (ZMBT), zinc dibenzyl dithiocarbamate (ZBEC), and N-cyclohexylbenzodithiazylsulfenamide (CBS).

[0012] In one aspect of the present invention, the composition may consist of natural rubber and synthetic rubber containing olefinic unsaturated rubber, suitable for curing in a system comprising at least two of a quinone dioxime, a peroxide, and a polyfunctional co-reactant containing a plurality of α,β-unsaturated carbonyl functional groups.

[0013] The composition may further contain a process oil / plasticizer and a filler for improving the pumpability and / or sag resistance of the uncured composition, as well as an antioxidant, a colorant or a dye, an adhesion promoter, a hydrocarbon resin different from the diene component, and a rheology modifier.

[0014] Various aspects of the present invention can be summarized as follows.

[0015] Aspect 1: (a1) Solid rubber, (a2) An olefinically unsaturated bond-containing polymer that is liquid or pasty at 22°C, (a3) Process oil, and (a4) Liquid polydiene, Component (a) containing the above, and (b1) Quinone dioxime, (b2) Organic peroxide, and (b3) A polyfunctional co-reactant containing a plurality of α,β-unsaturated carbonyl functional groups, Component (b) curing system containing two or more of the above, A thermosetting composition containing the above.

[0016] Aspect 2: (c1) A physical blowing agent in an amount of 0 to 3% by weight based on the total weight of the composition, (c2) A chemical blowing agent in an amount of 0 to 4.0% by weight based on the total weight of the composition, and (c3) A urea-based blowing agent accelerator in an amount of 0 to 1% by weight, The thermosetting composition according to Aspect 1, further containing Component (c) containing the above.

[0017] Aspect 3: The curing system (b) is (b2) An organic peroxide present in an amount of 0.2 to 2.0% based on the total weight of the composition, and (b3) A polyfunctional co-reactant present in an amount of 0.3 to 7% by weight based on the total weight of the composition, and is the thermosetting composition according to any one of the preceding aspects.

[0018] Aspect 4: The thermosetting composition according to any one of the preceding aspects, wherein the amounts of (c1), (c2), and (c3) are 0% by weight based on the total weight of the composition.

[0019] Aspect 5: The thermosetting composition according to any one of the preceding aspects, wherein the olefinically unsaturated bond-containing polymer (a2) contains polybutadiene grafted with maleic anhydride and has a weight average molecular weight of 750 to 10,000 Daltons.

[0020] Aspect 6: The thermosetting composition according to any one of the preceding aspects, wherein the polybutadiene (a2) grafted with maleic anhydride contains 4 to 20 parts by weight of maleic anhydride moiety.

[0021] Aspect 7: The thermosetting composition according to any one of the preceding aspects, wherein the process oil (a3) contains paraffin oil in an amount of 5% to 30% by weight based on the total mass of the composition.

[0022] Aspect 8: The thermosetting composition according to any one of the preceding aspects, wherein the liquid polybutadiene (a4) different from (a1) to (a3) is a polybutadiene polymer having a weight average molecular weight of 1000 to 50,000 g / mol.

[0023] Aspect 9: The thermosetting composition according to any one of the preceding aspects, wherein the polyfunctional co-reactant (b3) containing the monomer, oligomer or polymer having a plurality of α,β-unsaturated carbonyl functional groups includes at least one trifunctional (meth)acrylate.

[0024] Aspect 10: The solid rubber (a1) is present in an amount of about 8 to 20% by weight based on the total weight of the composition, The olefinically unsaturated bond-containing polymer (a2) that is liquid or pasty at 22°C is present in an amount of about 5 to 15% by weight based on the total weight of the composition, The process oil (a3) ​​is present in an amount of approximately 5-30% by weight based on the total weight of the composition. A liquid polydiene (a4) different from (a1) to (a3) ​​is present in an amount of approximately 3 to 20% by weight based on the total weight of the composition. The quinone dioxime (b1) is present in an amount of 0.1 to 5% by weight based on the total weight of the composition. The organic curing agent (b2) is an organic peroxide present in an amount of 0.05 to 5.0% based on the total weight of the composition. The polyfunctional co-reactant (b3) is present in an amount of 0.1 to 10% by weight based on the total weight of the composition. The thermosetting composition includes, as an additional component, Calcium oxide present in an amount of 0.1 to 6% by weight, and It further contains fillers present in a total amount of 10-50% by weight, All weight percentages are based on the total mass of the composition. A thermosetting composition according to any of the preceding embodiments, wherein the components are selected such that the thermosetting composition has a viscosity that allows it to be pumped using a pump at a temperature in the range of 15 to 60°C.

[0025] Appearance 11: A thermosetting composition according to any of the preceding embodiments, further comprising a filler (d) in an amount of 10% to 45% by weight based on the total weight of the composition.

[0026] Appearance 12: A product comprising a component including a metal surface, preferably an aluminum surface, wherein a composition according to any of the preceding embodiments is bonded to the metal surface, and the product is cured at a temperature in the range of 120 to 140°C for a time in the range of 10 to 20 minutes to form an adhesive bond between two parts of the product and / or between the sealing surfaces of the product, and is a product that is a component of a vehicle, device, tool, or aircraft.

[0027] Appearance 13: A method for applying an adhesive or sealant to a metal substrate having at least one aluminum metal surface, A step of delivering the composition described in any of the preceding embodiments to the application site at a temperature in the range of 15 to 60°C, preferably by a pump; A step of depositing the composition in a liquid or paste form onto a selected area of ​​the first aluminum metal surface of the substrate; Optionally, a step of bringing a second metal substrate into contact with the selected region having the composition; and Subsequently, the composition is heated at a temperature in the range of 130 to 220°C for a sufficient time to form a cured composition adhered to the aluminum metal surface; Includes, A method wherein the overlap shear strength and adhesive strength of the composition cured at 220°C is preferably at least 80%, 85%, or 90% of the adhesive strength of the composition cured at 130°C.

[0028] Appearance 14: The method according to embodiment 13, further comprising the step of heating the composition to a temperature in the range of 120 to 140°C, maintaining that temperature range for 10 to 60 minutes to heat-cur it, and optionally causing it to foam.

[0029] For various reasons, it is preferable that the composition according to the present invention, whether a single-component composition (1K) or a multi-component composition (for example, in which parts A and B as defined above are packaged separately), substantially does not contain many of the components used in compositions for similar purposes in the prior art. Specifically, independently of each of the preferably minimized components listed below, the adhesive composition of the present invention, when in direct contact with metal in the method of the present invention, is increasingly preferably containing each of the following components in an amount of 1.0, 0.5, 0.35, 0.10, 0.08, 0.04, 0.02, 0.01, 0.001, or 0.0002% or less, more preferably in grams per liter, and even more preferably in ppm, in the order listed: epoxy resin or polymer, organic filler, thickener, chromium, nitrite ion, formaldehyde, formamide, hydroxylamine, ammonia; rare earth metals; elemental sulfur and / or its compounds; permanganate; chlorite and perchlorate; boron, e.g., borax, borate; strontium; and / or free chloride. Furthermore, independently of each of the preferably minimized components described below, the curing adhesive according to the present invention is increasingly preferably to contain each of the following components in a value expressed in parts per thousand (ppt) of 1.0, 0.5, 0.35, 0.10, 0.08, 0.04, 0.02, 0.01, 0.001, or 0.0002% or less, more preferably in parts per thousand (ppt), in the order listed: organic fillers, thickeners, chromium, nitrite ions, formaldehyde, formamide, hydroxylamine, ammonia; rare earth metals; elemental sulfur and / or its compounds; permanganates; chlorites and perchlorates; boron, e.g., borax, borate; strontium; and / or free chlorides.

[0030] "Copolymer" refers to any polymer composed of two or more different monomers. The composition of comonomers present in a copolymer is not particularly limited unless otherwise specified. Copolymers may be block copolymers, random copolymers, end-cap copolymers, or telechelic copolymers.

[0031] As used herein, the term “paint” encompasses all similar materials that may be referred to by more specialized terms, such as lacquer, enamel, varnish, shellac, and topcoat, unless explicitly stated or necessarily implied by the context. The terms “metal” or “metallic” mean, to those skilled in the art, a material (article or surface) composed of atoms of a metallic element, such as aluminum, where the amount of the metallic element is preferably at least 55, 65, 75, 85, or 95 atomic percent in that order; for example, the term “aluminum” encompasses pure aluminum, its alloys containing preferably at least 55, 65, 75, 85, or 95 atomic percent of aluminum atoms in that order, and aluminum surfaces. A bare metal surface is understood to mean a metal surface without any coating layer other than metal oxides produced from the metal surface by aging in air and / or water.

[0032] Except as in the examples or unless otherwise stated, all numerical values ​​defining the amounts, reaction conditions, or component parameters of components used herein shall be understood in all cases to be modified by the term “approximately.” Throughout the specification, unless otherwise specified, percentages, parts, and ratios are based on weight or mass. Where, in relation to the present invention, a group or class of materials is described as suitable or preferred for a particular purpose, it means that a mixture of any two or more members of that group or class is equally suitable or preferred. Chemical descriptions of components refer to components at the time they are added to a combination specified in the specification, or components produced in situ in the composition by a chemical reaction between one or more components newly added at the time other components are added and one or more components already present in the composition. Molecular weight (MW) is the weight-average molecular weight Mw unless otherwise specified. The term “mole” means “gram mole,” and this term itself and all its grammatical variations may be used for any chemical species defined by all the types and number of atoms contained therein, regardless of whether the chemical species is ionic, neutral, unstable, virtual, or a stable neutral substance having a clearly defined molecule. The terms “storage stability” or “shelf stability” are understood to encompass an uncured composition in which the viscosity increase is 10% or less, preferably less than 10%, over an observation period of at least 100, 1000, 1500, 2000, or 2500 hours, for example, preferably 30, 60, or 90 days, during which the material is not mechanically disturbed and the temperature of the material is maintained at ambient room temperature in the range of approximately 15°C to 40°C (approximately 60°F to 104°F). Preferably, after storage under the above conditions, the overlap shear test performance described herein is equivalent to the initial test performance. Viscosity may be measured by means known to those skilled in the art, e.g., Mooney test apparatus, Brookfield viscometer, or parallel plate rheology. [Brief explanation of the drawing]

[0033] [Figure 1] Figure 1 shows a cross-sectional view of the shear test specimen used to measure the overlapping shear strength and the strength reduction rate due to high-temperature heating in the example. [Figure 2] Figure 2 is a front view of the shear test specimen used to measure the overlapping shear strength and the rate of strength reduction due to high-temperature heating in the example. The arrow indicates the direction of the tensile test. [Modes for carrying out the invention]

[0034] A thermosetting composition according to one embodiment of the present invention includes: Ingredients (a) include the following: (a1) At least one solid rubber present in an amount of about 8 to 20% by weight based on the total weight of the composition; preferably a solid rubber based on styrene and butadiene monomers; (a2) at least one olefinic double bond-containing polymer that is liquid or paste-like at 22°C, present in an amount of about 4 to 20% by weight based on the total weight of the composition; and (a3) Process oil present in an amount of about 5 to 30% by weight based on the total weight of the composition; for example, petroleum-based base oil or natural or synthetic equivalent, preferably paraffin oil; (a4) Liquid polydienes different from (a1) to (a3) ​​that are present in an amount of about 1 to 20% by weight based on the total weight of the composition; and Ingredients (b) include the following: (b1) Quinone dioxime in an amount of 0.1 to 5.0% by weight, preferably 0.3 to 2.0%, more preferably 0.1 to 1.0%, and most preferably 0.15 to 0.5% by weight, based on the total weight of the composition; (b2) an organic curing agent, preferably an organic peroxide, in an amount of 0.05 to 5.0%, preferably 2.0 to 4.5% by weight, based on the total weight of the composition; and (b3) A polyfunctional co-reactant comprising a plurality of unsaturated reactive sites, for example, a monomer, oligomer, or polymer having a plurality of α,β-unsaturated carbonyl functional groups, wherein the polyfunctional co-reactant is present in an amount of 0.1 to 10% by weight, preferably 0.3 to 7% by weight, based on the total weight of the composition.

[0035] The thermosetting composition of the present invention can be cured in a wide temperature range of approximately 130°C to approximately 200°C to obtain a cured adhesive, sealant, or sound-dampening product, and the reduction in strength due to low or high temperature curing is reduced compared to similar compositions that require 160°C to 200°C for curing. In this specification, the cured product is also referred to as the "cured material." In this specification, the "cured material" means that the composition has been crosslinked to a considerable extent and has become a solid, no longer fluid, and has adhesive properties such as good sealant properties and / or adhesive strength (lap shear test performance) for joining substrates.

[0036] In this specification, "thermosetting composition" may be simply referred to as "composition." Furthermore, in this specification, amounts expressed in "%" represent weight percentages based on the total weight of the composition, unless otherwise specified. In this specification, "average molecular weight" represents the weight-average molecular weight of the polymer, unless otherwise specified, and is specifically obtained by converting it to molecular weight using a calibration curve with monodisperse polystyrene as the standard substance, using gel permeation chromatography (GPC).

[0037] The following describes in detail the thermosetting composition according to the present invention, its components, its cured products, their uses, and their manufacturing methods.

[0038] Ingredients (a): Resin components (a1) Solid rubber Examples of solid rubber (a1) (including thermoplastic polymers that exhibit elastomer elasticity at room temperature (22°C)) include solid rubbers based on polybutadiene, styrene-butadiene rubber (styrene / butadiene / styrene copolymer (SBS)), butadiene / acrylonitrile rubber, styrene / isoprene rubber (styrene / isoprene / styrene copolymer (SIS)), styrene-ethylene / propylene-styrene copolymer (SEPS), and styrene-ethylene / ethylene / propylene-styrene copolymer (SEEPS), and optionally some of the styrene may contain a second unsaturated functional group. The amount of styrene in the copolymer, if present, is 10% by weight or more, more preferably 15% by weight or more, and most preferably 20% by weight or more, and the styrene content is preferably 50% by weight or less, more preferably 40% by weight or less, and most preferably 30% by weight or less. Other examples of solid rubber include synthetic or natural isoprene rubber, polyoctenomer, butyl rubber, and polyurethane rubber. The solid rubber (a1) may include one or more of the solid rubbers described herein. Preferably, when using two or more solid rubbers, different polymers and copolymers (which may be based on the same monomer or different monomers) may be selected.

[0039] The molecular weight and other properties of the solid rubber are not particularly limited, as long as the solid rubber exhibits elastomer elasticity at room temperature (22°C). For example, the Mooney viscosity (ML1+4 (100°C)) of the solid rubber is not particularly limited, but is preferably in the range of 20 to 60, more preferably 30 to 50. The Mooney viscosity can be measured according to ASTM D1646.

[0040] Examples of "solid rubber based on polybutadiene" include butadiene homopolymers and copolymers containing small amounts (e.g., 10 mol% or less) of monomer units other than butadiene monomer (1,3-butadiene). Examples of monomer units other than butadiene monomer include conjugated dienes such as isoprene, 1,3-pentadiene, 2-ethyl-1,3-butadiene, 4-methylpentadiene, and 2,4-hexadiene; acyclic monoolefins such as ethylene, propylene, butene, and pentene; cyclic monoolefins such as cyclopentene, cyclohexene, and norbornene; and non-conjugated diolefins such as dicyclopentadiene and 1,5-hexadiene. Furthermore, solid rubber based on polybutadiene preferably has a high cis content, with a cis-1,4-double bond content of 80% or more, preferably 85% or more, and most preferably 95% or more.

[0041] In the present invention, the solid rubber (a1) is present in an amount of at least about 8.0, 8.5, 9.0, 9.5, 10.0, 10.25, 10.5, 10.75, 11.0, 11.25, 11.50, 11.75, 12.0, 12.25, 12.50, 12.75, 13.0, 13.25, 13.50, or 14.0% by weight, based on the total amount of the composition. A balance between strength and flexibility can be ensured if the solid rubber content is 8.0% by weight or more. Furthermore, the solid rubber content is preferably 20% by weight or less, and in order of preference, it is about 19.5% or less, 19.0% or less, 18.5% or less, 18.0% or less, 17.5% or less, 17.0% or less, 16.5% or less, 16.0% or less, 15.5% or less, or 15.0% by weight or less. When the solid rubber content is 20% by weight or less, the viscosity of the uncured material allows for pumping without increasing the amount of plasticizer added. High concentrations of plasticizer may reduce adhesive strength and / or tend to leach from the compound or cured adhesive. In embodiments where the composition is applied at high temperatures (temperatures higher than room temperature), it may be desirable to increase the solid rubber / solid polymer content to 17-25% by weight, and even up to 30% by weight. On the other hand, in embodiments where the composition is applied at ambient temperature or below, it is effective to keep the solid rubber content low, to 9.0-12.0% by weight.

[0042] (a2) Olefin double bond-containing polymer in liquid or paste form at 22°C Unlike (a1), olefinic double-bond-containing polymers that are liquid or paste-like at 22°C may be selected to control the viscosity of the composition, as well as the tensile strength, elongation, and adhesion to aluminum of the cured product. In this specification, “olefinic double-bond-containing polymer (a2) that is liquid or paste-like at 22°C” is also referred to as “olefinic double-bond-containing polymer (a2)”. The olefinic double-bond-containing polymer may be a single polymer or a mixture of two, three, four or more olefinic double-bond-containing polymers.

[0043] The olefinic double-bond-containing polymer (a2) preferably has a glass transition temperature (Tg) below room temperature (about 20-30°C). Specifically, the glass transition temperature may generally be about -110°C, -100°C, -95°C, -90°C, -80°C, -70°C, -60°C, -50°C, -40°C, -30°C, -20°C, -10°C, or 0°C, and preferably less than 20°C or less than 15°C. Here, "liquid" means a state in which the polymer can be poured from a container under the influence of gravity, and "paste-like" means a state in which the polymer can be spread into a flat and uniform layer. In this specification, the glass transition temperature means a value measured using "differential scanning calorimetry (DSC)" in accordance with ASTM-D3418. The polymer may be a homopolymer or a copolymer. A mixture of two or more olefinic double-bond-containing polymers generally exhibits a Tg similar to that described above; however, the Tg of individual polymers in the mixture may be lower or higher than that of the mixture. For example, if the mixture is liquid or paste-like at room temperature (22°C), the Tg may be as low as -100°C or higher than the ambient temperature.

[0044] In one embodiment, the olefinic double bond-containing polymer (a2) is preferably a polymer of a diene and / or aromatically substituted olefin, and may be a copolymer of styrene and a diene from the viewpoint of improving the vibration damping properties of the cured product. The diene polymer may be a polydiene such as polybutadiene or polyisoprene, or a mixture of polydienes, and optionally a diene copolymer.

[0045] In one embodiment, a polydiene having functional groups in the main chain and / or side chains is also effective. Examples of functional groups include carboxyl groups, hydroxyl groups, and amine groups, and the polydiene may contain a combination of two or more functional groups. From the viewpoint of adhesion to a metal substrate, it is preferable that the liquid polydiene contains carboxyl groups. The functional groups only need to be present in at least one of the main chain and / or side chains, and may be located at any position such as the chain ends or within the chain, but it is preferable that they be present at least at the chain ends.

[0046] If present, the copolymer of styrene and diene preferably has a styrene content of 10% by weight or more, more preferably 15% by weight or more, and preferably 50% by weight or less, and more preferably 30% by weight or less. Having a styrene content within the above range provides excellent dissipative vibration damping characteristics (i.e., the ability to convert mechanical vibration energy into heat).

[0047] In one embodiment, the olefinic double bond-containing polymer may be composed of a combination of two or more diene polymers. The diene polymers may be homopolymers or copolymers of butadiene, isoprene, etc. The diene polymers may be cis-type, trans-type, or mixtures thereof, and may have active functional groups such as carboxyl groups. Preferably, one or more of the diene polymers have a large proportion of cis bonds. In a preferred embodiment, one of the olefinic double bond-containing polymers is or contains a polybutadiene maleic anhydride adduct, and preferably has an average molecular weight Mw of less than 10,000, 5,000, 4,500, or 3,000 daltons, and at least 750, 775, 800, 850, or 900 daltons. Independently and preferably, the polybutadiene maleic anhydride adduct contains maleic anhydride units in the following order of preference, based on the total weight of maleic anhydride grafted polybutadiene: at least 4% by weight, 4.5% by weight, 5% by weight, 5.5% by weight, 6% by weight, 6.5% by weight, 7% by weight, and preferably 20% by weight, 18% by weight, 16% by weight, 14% by weight, 12% by weight, and 10% by weight or less.

[0048] In another embodiment of the present invention, the olefinic double bond-containing polymer (a2) is preferably selected from unfunctionalized liquid polybutadiene that contributes to viscosity and tensile properties; liquid polybutadiene having active carboxyl groups that contribute to adhesion to aluminum; and liquid polyisoprene that contributes to elongation and tensile properties; and preferably a combination of two or more of the above polydienes.

[0049] The position of the olefinic double bond formed in the polymer chain by the polymerization of the diene is not particularly limited, but from the viewpoint of curing properties and acoustic damping performance, in one embodiment, the olefinic double bond-containing polymer (a2) is formed to include an unsaturated diene moiety. The proportion of the vinyl moiety in this diene moiety (i.e., the proportion of 1,2-vinyl bonds to the total olefinic double bonds) is not particularly limited. In some embodiments, the vinyl moiety may be in the range of 1 mol% to 50 mol%, preferably 1 mol% to 16 mol%, but in some embodiments it may be as high as 70 to 80 mol%.

[0050] The weight-average molecular weight of the olefinic double-bond-containing polymer (a2) is not particularly limited, but is preferably 1,000 or more, more preferably 2,000 or more, even more preferably 5,000 or more, preferably 75,000 or less, more preferably 65,000 or less, and even more preferably 55,000 or less. The weight-average molecular weight of the olefinic double-bond-containing polymer (a2) is particularly preferably in the range of 5,000 to 55,000. The olefinic double-bond-containing polymer (a2) preferably has the above structure and the above weight-average molecular weight. The olefinic double-bond-containing polymer (a2) may be used alone, or it may be used in combination with two or more polymers that differ in monomer type and amount, functional groups, viscosity, molecular weight, glass transition temperature (Tg), and stereochemistry (cis / trans content).

[0051] To obtain sufficient elongation and tensile properties, as well as adhesion to metals, particularly aluminum, the content of the olefinic double bond-containing polymer (a2) is preferably at least 5% by weight, and more preferably 7% by weight, based on the total weight of the composition. Furthermore, to maintain strength, the content of the olefinic double bond-containing polymer (a2) is preferably 15% by weight or less, and more preferably 12% by weight or less, based on the total weight of the composition. Based on the total weight of the composition, it is at least about 5.0% by weight, 5.5% by weight, 6.0% by weight, 6.5% by weight, 7.0% by weight, 7.25% by weight, 7.5% by weight, 7.75% by weight, 8.0% by weight, 8.25% by weight, 8.50% by weight, 8.75% by weight, 9.0% by weight, 9.25% by weight, 9.50% by weight, 9.75% by weight, 10.0% by weight, 10.25% by weight, 10.50% by weight, or 11.0% by weight. If the content of the olefinic double bond-containing polymer is at least 5.0% by weight, sufficient crosslinking can be obtained and high strength can be maintained. Preferably, the content of the olefinic double bond-containing polymer is 18% by weight or less, and in order of preference, it is about 16.5% by weight, 16.0% by weight, 15.5% by weight, 15.0% by weight, 14.5% by weight, 14.0% by weight, 13.5% by weight, 13.0% by weight, 12.5% ​​by weight, or 12.0% by weight or less. If the content of the olefinic double bond-containing polymer is 18% by weight or less, the uncured adhesive maintains a viscosity suitable for pumping at ambient temperature. In embodiments in which the composition is applied at high temperatures (temperatures higher than room temperature), the olefinic double bond-containing polymer / solid polymer content can be increased to 19-25% by weight, and even up to 30% by weight.

[0052] (a3) Petroleum-based base oil or natural or synthetic equivalent The compositions of the present invention may further contain (a3) ​​a petroleum-based base oil or a natural or synthetic equivalent, preferably a paraffin-based oil. (a3) ​​may act as a processing lubricant, a diluent for other components or compositions, and / or a plasticizer. When the composition contains (a3), it can improve the processability of the composition and improve the mechanical properties of the cured product. The content of the base oil (a3) ​​is not particularly limited, but is generally 40% by weight or less, preferably 30% by weight or less, more preferably 25% by weight or less, and also preferably 2% by weight or more, more preferably 5% by weight or more, for example, 15 to 20% by weight, based on the total amount of the composition.

[0053] Examples of materials useful as (a3) ​​include hydrocarbon oils, e.g., white oil; natural oils that are liquid at 22°C (e.g., fatty acid glycerol esters such as so-called triglycerides, e.g., rapeseed oil, soybean oil, walnut oil, linseed oil, sunflower oil, and olive oil) or phthalate esters. In one embodiment, a low viscosity process oil is used. Naphthenic oils and / or paraffinic oils may be used. Paraffinic oil is preferred because, compared to other process oils, it has the lowest viscosity of the composition at the same weight % content. Due to its low viscosity, the ratio of rubber to plasticizer can be increased, contributing to improved performance in low-temperature curing. Depending on the viscosity of the selected additive (a3), the relative amounts of solid rubber and liquid rubber may be adjusted. For example, phthalate esters may be used in compositions with less solid rubber and more liquid rubber.

[0054] (a4) Liquid polydiene The compositions of the present invention may use a low-viscosity liquid polydiene (a4) different from (a1) to (a3). Examples of polydiene diene monomers include ethylene propylene diene, butadiene, isoprene, and chloroprene, and examples of polydiene oligomers or polymers include homopolymers or copolymers of these diene monomers (optionally partially hydrogenated), and hydroxylated derivatives of these oligomers and polymers. Among these, preferred liquid polydienes (a4) include polybutadiene and polyisoprene, with polybutadiene being particularly preferred.

[0055] In some embodiments, the liquid polydiene, such as polybutadiene, may preferably have a high cis bond content in the polymer. In one embodiment, the liquid polydiene comprises polybutadiene with a cis-1,4-double bond content of about 50% or more. In another embodiment, the liquid polydiene preferably has a cis-1,4-double bond content of 85% or more, most preferably 80% or more. The liquid polydiene compound preferably has a weight-average molecular weight Mw such that the polydiene is liquid at room temperature (22°C). For example, the MW of the polydiene is in the range of 500 to 50,000 daltons, more preferably in the range of 1,000 to 10,000. Furthermore, the liquid polydiene preferably has a glass transition temperature of less than -50°C, preferably less than -60°C, and most preferably less than -90°C.

[0056] The liquid polydiene (a4) content is preferably 3% by weight or more, more preferably 5% by weight or more, based on the total amount of the composition. Furthermore, the liquid polydiene content is preferably 20% by weight or less, more preferably 10% by weight or less, relative to the total amount of the composition. Including liquid polydiene (a4) at an amount of approximately 3% to 20% by weight relative to the total amount of the composition tends to improve the vibration damping and adhesion properties of the cured product obtained from the composition.

[0057] In another embodiment, the solid rubber (a1) is present in an amount of less than 8%, preferably 1-7%, most preferably less than 1%, and in a particularly preferred embodiment, the solid rubber (a1) is absent. In this embodiment, the polymer is selected to be a low-viscosity or high-viscosity liquid (a suitable viscosity is typically less than 1200 Pa·sec at 38°C), and contains a larger amount of (a4) at least one olefinic double-bond-containing polymer. Generally, the (a4) polymer in this embodiment may have a low molecular weight (1700-55,000 Daltons) and may be a liquid rubber, such as polybutadiene, natural rubber, isoprene rubber, or SBR.

[0058] Any hydrocarbon resin Any hydrocarbon resin can be added as a diluent, plasticizer, or tackifier. The hydrocarbon resin content is preferably 0 to 15% by weight based on the total weight of the composition, with a lower limit of preferably 1% by weight or more, more preferably 5% by weight or more, and an upper limit of preferably 12% by weight or less, and more preferably 10% by weight or less. When the composition contains hydrocarbon resin, the cured product exhibits vibration damping properties as described above, and when the content is 15% by weight or less, the decrease in strength of the cured product when the composition is heated to a high temperature can be suppressed. In particular, by including the above-mentioned plasticizer and hydrocarbon resin in the composition, the acoustic attenuation characteristics in the temperature range of -5°C to 40°C can be improved.

[0059] Hydrocarbon resins can be all-aliphatic or all-aromatic, or they can have both aliphatic and aromatic structures. Furthermore, they can be aromatically modified aliphatic resins. In any case, it is particularly preferable that the hydrocarbon resin is compatible with other polymer components. Examples of hydrocarbon resins include natural hydrocarbon resins such as terpene resins (e.g., terpene resins, hydrogenated terpene resins, and aromatically modified terpene resins) and rosin resins (e.g., rosin and modified rosin such as hydrogenated rosin, disproportionated rosin, and polymerized rosin); and synthetic hydrocarbon resins such as petroleum-based hydrocarbon resins, coumarone-indene resins, xylene resins, and styrene resins, among which petroleum-based hydrocarbon resins are preferred.

[0060] Preferably, petroleum-based hydrocarbon resins are those obtained by polymerizing fractions containing unsaturated hydrocarbon monomers produced as by-products of the thermal decomposition of petroleum naphtha, etc. Specifically, examples include C5 aliphatic petroleum resins, C9 aromatic petroleum resins, C5 / C9 petroleum resins, hydrogenated petroleum resins obtained by hydrogenating C9 or C5 / C9 petroleum resins, and alicyclic petroleum resins such as dicyclopentadiene petroleum resins. These may be used individually or in combination of two or more types.

[0061] Component (b): Curing component (b1) Quinone dioxime The composition according to the present invention comprises the following components as a curing system: (b1) 0.1 to 5.0% by weight of quinone dioxime based on the total weight of the composition; (b2) 0.1 to 5.0% by weight of an organic curing agent, preferably an organic peroxide, based on the total weight of the composition; and (b3) 0 to 10% by weight, preferably 0.1 to 9% by weight of a polyfunctional, preferably at least one trifunctional (meth)acrylate monomer, oligomer, or polyol, based on the total weight of the composition. By increasing the amounts of (b2) and (b3), the amount of quinone dioxime may be reduced or eliminated entirely.

[0062] Quinone dioxime (b1) is a crosslinking agent and adhesion promoter for rubber. Quinone dioxime forms crosslinks that are resistant to reversal even at high temperatures (190-210°C). Automotive roofs often reach such high temperatures during E-coat curing, which can cause crosslinks based on other curing agents such as sulfur to break.

[0063] In some embodiments, quinone dioxime (b1) may be incorporated into the composition as a mixture of the active ingredient (i.e., a compound having a curing effect, i.e., a crosslinking effect) and compounds other than the active ingredient. In this invention, "quinone dioxime content" means the content of the active ingredient only. When the content of each curing component in the composition is within the above range, the cured product has sufficient adhesive strength and shows little decrease in strength even when cured by high-temperature heating.

[0064] The compositions according to the present invention preferably do not contain elemental sulfur. Trace amounts of sulfur may be present, for example, in preferred order, less than 1.0% by weight, less than 0.5% by weight, less than 0.25% by weight, less than 0.1% by weight, less than 0.05% by weight, less than 0.025% by weight, or less than 0.001% by weight, and these amounts are 1 / 1000th of elemental sulfur, most preferably 1 / 1,000,000th. Advantages of having little or no elemental sulfur include a longer shelf life for single-packet adhesives ("1K adhesives") and compatibility with certain electrodeposition coatings (often referred to in the art as "E-coat" coatings) that are sensitive to sulfur-containing adhesives or undergo undesirable reactions with sulfur-containing adhesives.

[0065] (b2) Organic peroxide curing agent In various embodiments, the curing system is a peroxide-based curing system. In corresponding embodiments, at least one peroxide compound contained in the composition according to the present invention is preferably a dibenzoyl peroxide, tert-butylperoxybenzoate, particularly 1,1-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane, butyl 4,4-di-(tert-butylperoxy)valerate, dicumyl peroxide, di-(2-tert-butylperoxyisopropyl)benzene, tert-butylcumyl peroxide, 2,5-dimethyl-2,5-di-(te The following are selected from the group consisting of rt-butylperoxy)hexane, di-tert-butylperoxide, 3,3,5,7,7-pentamethyl-1,2,4-trioxepane, tert-butylperoxy-2-ethylhexyl carbonate, di(4-methylbenzoyl)peroxide, di(2,4-dichlorobenzoyl)peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and di-tert-butyl-1,1,4,4-tetramethylbuta-2-yin-1,4-ylenediperoxide.

[0066] In some embodiments, the amount of peroxide compound is preferably about 0.1% by weight to about 7% by weight based on the total weight of the composition, for example, about 0.1% by weight, 0.2% by weight, 0.3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1.0% by weight, 1.5% by weight, 2.0% by weight, 2.5% by weight, 3.0% by weight, 3.5% by weight, 4.0% by weight, 4.5% by weight, 5.0% by weight, 5.5% by weight, 6.0% by weight, 6.5% by weight, or 7.0% by weight. Or, approximately 0.1% by weight to approximately 5% by weight, for example, approximately 0.15% by weight, 0.25% by weight, 0.35% by weight, 0.45% by weight, 0.55% by weight, 0.65% by weight, 0.75% by weight, 0.85% by weight, 0.95% by weight, 1.05% by weight, 1.1% by weight, 1.2% by weight, 1.4% by weight, 1.7% by weight, 1.9% by weight, 2.1% by weight, 2.4% by weight, 2.6% by weight, 2.8% by weight, 3.3% by weight, 3.7% by weight, 4.1% by weight, 4.6% by weight, 4.9% by weight, or 5.0% by weight.

[0067] In various embodiments, the curing system is a peroxide-based curing system, and the composition of the present invention contains at least one peroxide compound in an amount of about 0.1% to about 7% by weight, preferably about 0.1% to about 5% by weight, based on the total weight of the composition. In other embodiments, the organic peroxide may be present in an amount ranging from 2.0% to 4.5% by weight.

[0068] The inventors have found that when the sulfur and sulfur accelerator described herein are not present in the curing system, and the thermosetting composition contains more than 0.1% by weight of quinone dioxime, for example, 0.2 to 0.6% by weight, in the presence of an organic peroxide, the components of the curing system synergistically improve the adhesion LSS results when cured on aluminum at 140°C and suppress the decrease in strength of the cured product subjected to high-temperature thermal curing. In particular, it was observed that when the composition of the present invention does not contain sulfur and sulfur accelerators conventionally used in thermosetting compositions, the decrease in strength of the cured product due to high-temperature heating (overbake) is within an acceptable range.

[0069] Examples of organic curing agents include curing systems other than those mentioned above, as long as they do not significantly hinder the objective of the present invention. Other curing systems include quinones, nitrosobenzenes, and dinitrosobenzenes (especially p-dinitrosobenzenes). In some embodiments, it is preferable to use dioximquinone in combination with an organic peroxide.

[0070] (b3) Polyfunctional co-reactants A polyfunctional co-reactant (b3) comprising monomers, oligomers, or polymers having multiple α,β-unsaturated carbonyl functional groups may be included in the composition in an amount of 0.1 to 10% by weight based on the total weight of the composition. The polyfunctional co-reactant preferably contains multiple reactive unsaturated sites, but these sites are not particularly limited. In some embodiments, the unsaturated sites include two, three, or more α,β-unsaturated carbonyl functional groups, such as multiple (meth)acrylate-terminated functional groups, preferably polyfunctional acrylates and methacrylate esters. The polyfunctional (meth)acrylate may be disubstituted, trisubstituted, or more substituted, meaning that the molecule has two, three, or more ethylenically unsaturated sites. In one embodiment, (b3) includes trimethacrylate, triacrylate, diacrylate, dimethacrylate, or a combination of two or more of these co-reactants. In some embodiments, the (meth)acrylate terminal functional group is separated by a linear or branched C2-C12 alkyl group, or one or more EO or PO groups.

[0071] The polyfunctional (meth)acrylate monomer, oligomer, or polymer (b3) is not particularly limited, as long as it does not adversely affect low-temperature curability, storage stability, reversion resistance, or other purposes of the present invention. Examples of materials (b3) include monomers such as trimethylolpropane triacrylate (TMPTA), trimethylolpropane trimethacrylate (TMPTMA), ethylene dimethacrylate (EDMA), diethylene glycol dimethacrylate (EGDMA), ethylene glycol dimethacrylate (DEGDMA), pentaerythritol tri(meth)acrylate (PETRA, PETRMA), and pentaerythritol tetraacrylate (PETTA); 1,1,1-tris[4-(2'-hydroxy-3'-methacryloyloxypropoxy)phenyl]ethane (THMPE) and 1,1,1-tris[4-(2'-hydroxy-3'-methacryloyloxypropoxy)phenyl]methane (THMPM); and hydroxy-functional monomers such as 3-(acryloyloxy)-2-hydroxypropyl methacrylate. Polyfunctional (meth)acrylate oligomers and polymers such as alkoxylated trimethylolalkane tri(meth)acrylates, for example, ethoxylated (3) trimethylolpropane triacrylate (EO3) and propoxylated (3) trimethylolpropane triacrylate (PO3), may also be used. Preferably, di- and tri-(meth)acrylates are used, understood to belong to the group of di- and tri-acrylates and di- and tri-methacrylates, and it is desirable that the molecular weight is at least about 198 daltons and at most about 500 daltons. Trimethylolpropane triacrylate (TMPTA), ethoxylated (3) trimethylolpropane triacrylate (EO3), propoxylated (3) trimethylolpropane triacrylate (PO3), ethylene dimethacrylate (EDMA), and ethylene glycol dimethacrylate (EGDMA) are commonly used.

[0072] In certain embodiments of the compositions of the present invention, the thermosetting composition and its cured product may contain one or more additives such as a foaming agent (optional), a filler, a flame retardant, a colorant (e.g., carbon black), a hygroscopic agent, an antioxidant, and a plasticizer, which may be used in combination with the above components.

[0073] Ingredients (c): Foaming agent In one embodiment of the present invention, the composition may contain a blowing agent to irreversibly expand (foam) before or during thermal curing, preferably comprising (c1) 0 to 3% by weight of a physical blowing agent based on the total weight of the composition and (c2) 0 to 4% by weight of a chemical blowing agent based on the total weight of the composition. The irreversible expansion of the blowing agent causes an irreversible volume increase, thereby allowing cavities or intermediate spaces to be more completely filled with the cured compound. For highly expandable materials, a chemical blowing agent having an expansion rate of 100% or more is preferred.

[0074] The content of (c1) physical blowing agent in the composition is not particularly limited, but is preferably 0 to 3% by weight, more preferably 0.1% to 2.5% by weight, and even more preferably 0.2% to 2.0% by weight, based on the total weight of the composition.

[0075] As a "physical blowing agent," a resin blowing agent that expands with heat (thermally expandable resin blowing agent) is preferred, and a foaming plastic hollow microsphere that expands with heat is more preferred. A physical blowing agent useful in the present invention may consist of a thermoplastic polymer shell containing a low-boiling point liquid hydrocarbon and a thermoplastic microsphere. When heated, the shell softens and the hydrocarbon contained inside expands to form microballoons. Examples of thermoplastic resin blowing agents include those based on polyvinylidene chloride copolymer or acrylonitrile / (meth)acrylate copolymer, which are commercially available, for example, under the name "Dualite®" from Pierce & Stevens and "Expancel®" from Casco Nobel.

[0076] (c2) Examples of "chemical blowing agents" include those that release gas upon decomposition, typically referred to as exothermic blowing agents and endothermic blowing agents. Examples of exothermic blowing agents include azobisisobutyronitrile, azodicarbonamide, dinitrosopentamethylenetetramine, 4,4'-oxybis(benzenesulfonyl hydrazide), diphenyl sulfone-3,3'-disulfohydrazide, benzene-1,3-disulfohydrazide, and p-toluenesulfonyl semicarbazide.

[0077] Endothermic chemical blowing agents are often bicarbonates, solid, optionally functionalized polycarboxylic acids and their salts, and mixtures thereof. Suitable bicarbonates are those represented by the formula XHCO3. In the formula, X is any cation, especially an alkali metal ion, preferably Na + or K + and Na + is particularly preferred. Other suitable cations X + are NH4 + , 1 / 2Zn 2+ , 1 / 2Mg 2+ , 1 / 2Ca 2+ and mixtures thereof may be selected. Particularly preferred is the use of sodium bicarbonate and / or potassium carbonate, especially sodium bicarbonate. Suitable polycarboxylic acids include, but are not limited to, solid organic dicarboxylic acids, tricarboxylic acids, or tetracarboxylic acids, especially hydroxy-functionalized or unsaturated dicarboxylic acids, tricarboxylic acids, tetracarboxylic acids, or polycarboxylic acids such as citric acid, tartaric acid, malic acid, fumaric acid, and maleic acid. Particularly preferred is the use of citric acid. One advantage of citric acid is that it is an environmentally friendly blowing agent.

[0078] Also, salts of the acids and mixtures of two or more of the compounds are also suitable. In the case of salts of polycarboxylic acids, the counterion is preferably Na + , K + , NH 4+ , 1 / 2Zn 2+ , 1 / 2Mg 2+ , 1 / 2Ca 2+ and mixtures thereof, and Na+ and K + , especially Na + This is preferable. In particular, salts of polycarboxylic acids shift the decomposition temperature to the higher temperature side, so by mixing them, the decomposition temperature range can be broadly adjusted. When polycarboxylic acids are used, carbonates can also be used in combination. Preferably, bicarbonates and mixtures of carbonates and polycarboxylic acids are used, which specifically allows for different activation stages and decomposition reactions to be set.

[0079] Particularly preferred blowing agents are sodium bicarbonate and / or citric acid / citrate, and most preferably, the blowing agent is a mixture of sodium bicarbonate and citric acid. Such mixtures have a low onset temperature of only 120-140°C compared to conventional exothermic blowing agents such as ADCA or OBSH. The onset temperature of OBSH is 140-160°C, and ADCA is activated by zinc salts at an onset temperature of 160-170°C.

[0080] To lower the decomposition temperature of ADCA or OBSH, these blowing agents may contain approximately 0.1 to 0.5% by weight of urea. It has been reported that the decomposition temperature (°C) of ADCA can be reduced to the range of 148°C to 152°C, and the decomposition temperature (°C) of OBSH can be reduced to the range of 127°C to 129°C.

[0081] The endothermic foaming agent is a mixture of polycarboxylic acid and inorganic carbonate, and both the polycarboxylic acid and inorganic carbonate are surface-treated with components that prevent moisture absorption.

[0082] The content of the chemical blowing agent (c2) in the composition is preferably 0 to 0.2% by weight, more preferably less than 0 to 0.2% by weight, based on the total weight of the composition, and even more preferably does not contain the exothermic chemical blowing agent (c2) (i.e., 0% by weight). The inventors have found that when the content of the chemical blowing agent, which is commonly used as a blowing agent in thermosetting compositions, is preferably 0.2% by weight or less, more preferably less than 0.2% by weight, and even more preferably does not contain the chemical blowing agent, the decrease in strength of the composition due to high-temperature curing can be suppressed. Therefore, when the composition of the present invention contains a blowing agent, it is particularly preferable that the composition contains a physical blowing agent and does not contain a chemical blowing agent. Furthermore, it is preferable that the composition contains less than 0.05% by weight of an exothermic chemical blowing agent, particularly azodicarbonamide or 4,4'-oxybis(benzenesulfonyl hydrazide).

[0083] In this embodiment, the use or non-use of a foaming agent can be appropriately selected depending on the intended use of the composition. For example, in vehicle manufacturing applications, foaming of the composition during the firing and hardening process is effective in reducing distortion of the outer shell, so it is desirable to add a foaming agent within an appropriate range.

[0084] Component (d): Filler The composition of the present invention may contain a filler (d). The amount of filler is not particularly limited, but based on the total amount of the composition, the lower limit is preferably 10% by weight or more, more preferably 15% by weight or more, and even more preferably 25% by weight or more, and the upper limit is preferably 50% by weight or less, more preferably 45% by weight or less, even more preferably 40% by weight or less, and still more preferably 36% by weight or less.

[0085] The filler can be selected from a variety of materials, including, for example, fumed silica, chalk, natural, precipitated or pulverized calcium carbonate, calcium magnesium carbonate, silica, talc, mica, and barite. In one embodiment, at least a portion of the filler may be surface-treated. For example, to reduce the absorption of moisture into the hardened material and to reduce the hygroscopicity of the hardened material, the filler is preferably coated with stearic acid, such as calcium carbonate or chalk coated with stearic acid. In one embodiment, a filler with a high aspect ratio, such as a flake-shaped filler with a thickness small compared to the size of the flake surface, may be used. As a flake-shaped filler, from the viewpoint of providing good acoustic attenuation characteristics, a filler with an aspect ratio of 10 or more (i.e., the thickness in the direction perpendicular to the flake surface is 1 / 10 or less of the minimum area of ​​the flake surface), such as layered silicates (preferably mica, talc), graphite, etc., is preferred. It is also possible to use general inorganic lightweight aggregates (glass balloons, ceramic balloons, etc.) to adjust the specific gravity.

[0086] In addition to the filler, the composition of the present invention may further contain 0 to 10% by weight, preferably 1 to 6% by weight, and more preferably 1.5 to 5.5% by weight of calcium oxide based on the total amount of the composition, in order to bind moisture.

[0087] Furthermore, the composition of the present invention may contain carbon black. The carbon black content is preferably 0.1% by weight or more, more preferably 0.3% by weight or more, preferably 3% by weight or less, and more preferably 2% by weight or less, based on the total weight of the composition.

[0088] The composition of the present invention may optionally further contain fibrous reinforcing fillers, preferably organic short fibers in the form of pulp fibers or staple fibers, glass fibers, or carbon fibers. The fiber content in the composition is not particularly limited, but is preferably 0.5 to 10% by weight based on the total amount of the composition.

[0089] The composition of the present invention comprises the above components (a) and (b), and more preferably comprises at least one selected from the group consisting of (c) a foaming agent, (d) a filler, and a plasticizer / process oil. In some embodiments, the composition does not contain any foaming agent or fibrous filler. In other embodiments, the composition contains all of (c) a foaming agent, (d) a filler, and a plasticizer / process oil.

[0090] Table 1 shows examples of the components constituting the thermosetting composition of the present invention, but the present invention is not limited to these.

[0091] [Table 1]

[0092] The compositions of the present invention are not limited to those listed in Table 1 above, and the amounts of each component can be changed. In addition to the exemplary components listed above, or in place of any of the exemplary components listed above, the compositions may also contain fibers, other typical curing accelerators and / or crosslinking agents, other antioxidants, coactivators, catalysts, oils, resins, anti-aging agents, rheological aids, adhesion promoters, pigments, thermoplastic polymers, and the like.

[0093] The composition of the present invention can be produced, for example, by putting each of the above components into a mixer such as a bead mill, pulverizer, pot mill, three-roll mill, rotary mixer, or twin-screw mixer and mixing them at a temperature below the curing start temperature.

[0094] The composition of the present invention is a mixture of multiple components that are liquid or solid at 22°C, and an advantage is that the mixing ratio of the components can be appropriately adjusted without impairing the effects of the present invention. Therefore, in one embodiment of the present invention, the ratio of the components can be adjusted so that mechanical coating (e.g., by robot) or manual coating is possible at temperatures of 60°C or lower using standard coating equipment for adhesives and sealants in the manufacturing industry. For this purpose, the acoustic damping resin is preferably liquid or paste-like at 22°C, and as detailed above, the solid rubber, acoustic damping resin, hydrocarbon resin, and liquid polydiene are blended in preferred proportions. Therefore, the composition according to a preferred embodiment of the present invention has a viscosity that can be pumped by a pump (rotary pump, gear pump, or lift piston pump) in a temperature range of 15 to 60°C. According to this embodiment, there is an advantage that there is no need to use special extrusion molding technology and there is no need to manufacture injection molded products in advance.

[0095] Another aspect of the present invention relates to a method for coating with the composition of the present invention. Accordingly, the present invention relates to a method for applying the composition of the present invention, comprising injecting the composition of the present invention into the application site at a temperature in the range of 15 to 60°C using a pump (for example, the aforementioned pump), and applying the liquid or paste-like composition onto a lubricated substrate, an untreated substrate, or a clean substrate.

[0096] After application, the composition of the present invention can be heat-cured using a baking oven commonly used in the vehicle manufacturing and equipment manufacturing industries. The activation temperature for heat curing and any foaming is preferably in the range of 130 to 220°C. This temperature is preferably maintained for 10 to 30 minutes.

[0097] In addition to being used in pump applications, the molded articles, which are cured products of the composition of the present invention, can also be used as retrofit parts in trim shops (outfitting processes) and the aftermarket (repair market).

[0098] Another aspect of the present invention relates to a cured product (cured material) obtained by curing the composition of the present invention. The cured material of this embodiment has excellent vibration damping properties (acoustic attenuation characteristics) and exhibits little reduction in strength due to high-temperature heating.

[0099] In this embodiment, the glass transition temperature of the cured product is preferably in the range of -20 to 40°C, more preferably -15 to 30°C. Having the glass transition temperature within this range allows for good vibration damping characteristics (acoustic damping behavior) over a wide temperature range. The glass transition temperature of the cured product can be defined as the temperature at which the loss coefficient (tanδ) is maximized.

[0100] The cured product of this embodiment can be manufactured by heating the composition of the present invention, for example, at a temperature range of 130 to 220°C for 10 to 30 minutes. In this case, the composition may be applied directly to the part of use before curing, or it may be processed into a fired and cured product and used as an add-on part.

[0101] Another aspect of the present invention relates to the use of compositions and cured products thereof according to the present invention. The compositions of the present invention can be suitably used, in particular, as base materials and adhesives / sealants for structural members (e.g., doors, engine hoods, trunk lids, roofs, fronts, chassis parts), as well as in the interiors of vehicles (automobiles, buses, etc.) and in the manufacture of railway vehicles. Furthermore, the compositions of the present invention can be suitably used in the manufacture of equipment that needs to dampen acoustic vibrations (generally vibrations generated by rotating machinery) originating from motors, gears, or pumps. Accordingly, the present invention relates to the use of the compositions of the present invention as acoustic damping materials, adhesives and / or sealants in the manufacture of vehicles and equipment. [Examples]

[0102] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0103] Examples 1-6 The compositions of Examples 1 to 6 were prepared by mixing each component in the amounts shown in Table 2. The lap shear strength of each prepared composition was tested as described.

[0104] [Table 2]

[0105] Stacked shear strength test The compositions of Examples 1 to 6 were tested on X621 aluminum as follows.

[0106] As shown in Figures 1 and 2, X621 aluminum plates with a thickness of 0.8 mm and dimensions of 100 mm x 25 mm were cleaned, rust-preventive oil was applied, and a 3 mm thick layer of the composition was applied to a 25 mm x 25 mm area on one plate, and the composition was applied to a second plate. Figure 1 is a cross-sectional view of the shear test specimen, and Figure 2 is a front view of the shear test specimen used. For Examples 1 to 5, separate shear test specimens were prepared at each curing temperature as shown in Table 3, and cured by holding each specimen for 20 minutes at each curing temperature. For Example 6, four separate shear test specimens were prepared for each curing temperature. Each of the four specimens in Example 6 was baked for 20 minutes under the curing conditions shown in Table 3, and cured at 170°C, 190°C, or 290°C. The panels in Example 6 were overbaked to test whether high-temperature curing reduced adhesive strength or cohesive strength. Each shear test specimen was cooled to ambient temperature. Subsequently, the overlapping shear strength until adhesive failure was evaluated using a general-purpose tensile testing machine. A controlled force was applied to each shear specimen at a controlled speed until the adhesive broke, and the maximum force was recorded. The clamp movement speed was 50 mm / min. For Examples 1-6, the failure mode was visually evaluated qualitatively based on the amount of adhesive remaining on the aluminum substrate after adhesive failure (higher adhesive strength indicates less cohesive failure and better performance). The LSS results are shown in kilopascals (kPa).

[0107] [Table 3]

[0108] The above test results tend to indicate that some of the compositions of the present invention cured at temperatures of 130°C to 150°C, lower than the standard oven curing temperature of 160°C to 200°C, showed performance of A or B and good LSS test results. At curing at 140°C, Example 6 performed better than Examples 1 to 4, showing an LSS of 270 kPa·s. A slight decrease in the LSS score was observed in the panels of Example 6 that were overbaked on aluminum in the range of 170°C, 190°C, or 290°C. The overbaked panels showed significantly better LSS than Examples 3 and 4 across the entire overbaking temperature window. Low-temperature bake-cured compositions that exhibit overbaking resistance are highly desirable in line production where line downtime can lead to overbaked conditions.

[0109] Examples 6-12 In this series of examples, the effects of increasing the amount of organic peroxides and polyfunctional (meth)acrylate monomers added, and decreasing the amount of quinone dioxime added, were investigated. Compositions 6 to 12 were prepared by mixing each component in the amounts shown in Table 4.

[0110] [Table 4]

[0111] [Table 5]

[0112] Lap Shear Strength Test (LSS) The compositions of Examples 6-12 were tested on 6111 aluminum plates as follows: A 0.8 mm thick, 100 mm x 25 mm 6111 aluminum plate was cleaned, coated with rust-preventive oil, and then the composition was applied to a 25 mm x 25 mm area to a thickness of 3 mm. As shown in Figures 1 and 2 above, a second plate was applied to this composition. Each shear test specimen was fired for 20 minutes under the curing conditions shown in Table 4. Using the composition of Example 6, shear test specimens were prepared, each cured at three different temperatures. Each shear test specimen was cooled to ambient temperature. Then, using a general tensile testing machine, a load was applied to each shear test specimen at a controlled speed, and the maximum load was recorded until the joint fractured. The clamp travel speed was 50 mm / min. The LSS results are shown in megapascals.

[0113] The present invention fully cures at an oven temperature of 130-150°C, with a curing time of approximately 10-30 minutes, preferably up to 20 minutes, and is applicable to all industrial fields requiring adhesives and sealants with minimal strength reduction due to high-temperature curing (curing temperature of 190-210°C). The compositions of the present invention are particularly effective in the vehicle and equipment manufacturing industries.

Claims

1. (a1) Solid rubber, (a2) An olefinic double bond-containing polymer that is liquid or paste-like at 22°C, (a3) Process oils, and (a4) A liquid polydiene different from (a1) to (a3), Component (a) including, and (b1) Quinone dioxime, (b2) Organic peroxides, and (b3) A polyfunctional co-reactant comprising a monomer, oligomer, or polymer having multiple α,β-unsaturated carbonyl functional groups, (b) curing system containing two or more of the following components, A thermosetting composition containing [a specific substance].

2. (c1) A physical blowing agent in an amount of 0 to 3% by weight based on the total weight of the composition. (c2) A chemical blowing agent in an amount of 0 to 4.0% by weight based on the total weight of the composition, and (c3) 0 to 1% by weight of a urea-based foaming agent accelerator, The thermosetting composition according to claim 1, further comprising component (c) containing the above.

3. The curing system (b) is (b) Organic peroxides present in an amount of 0.2 to 2.0% based on the total weight of the composition, (b3) The thermosetting composition according to claim 1, wherein the polyfunctional co-reactant is present in an amount of 0.3 to 7% by weight based on the total weight of the composition.

4. The thermosetting composition according to claim 2, wherein the amounts of (c1), (c2), and (c3) are 0% by weight based on the total weight of the composition.

5. The thermosetting composition according to claim 1, wherein the olefinic double bond-containing polymer (a2) comprises polybutadiene grafted with maleic anhydride and has a weight-average molecular weight of 750 to 10,000 daltons.

6. The thermosetting composition according to claim 5, wherein the polybutadiene (a2) grafted with maleic anhydride contains 4 to 20 parts by weight of maleic anhydride.

7. The thermosetting composition according to claim 1, wherein the process oil (a3) ​​contains paraffin oil in an amount of 5% to 30% by weight based on the total mass of the composition.

8. The thermosetting composition according to claim 1, wherein the liquid polydiene (a4) different from (a1) to (a3) ​​is a polybutadiene polymer having a weight-average molecular weight of 1,000 to 50,000 g / mol.

9. The thermosetting composition according to claim 1, wherein the polyfunctional co-reactant (b3) comprising a plurality of monomers, oligomers, or polymers having α,β-unsaturated carbonyl functional groups comprises at least one trifunctional (meth)acrylate.

10. The solid rubber (a1) is present in an amount of about 8 to 20% by weight based on the total weight of the composition. The aforementioned olefinic double-bond-containing polymer (a2), which is liquid or paste-like at 22°C, is present in an amount of about 5 to 15% by weight based on the total weight of the composition. The process oil (a3) ​​is present in an amount of about 5 to 30% by weight based on the total weight of the composition. A liquid polydiene (a4) different from (a1) to (a3) ​​is present in an amount of about 3 to 20% by weight based on the total weight of the composition. The quinone dioxime (b1) is present in an amount of 0.1 to 5% by weight based on the total weight of the composition. The organic curing agent (b2) is an organic peroxide present in an amount of 0.05 to 5.0% based on the total weight of the composition. The polyfunctional co-reactant (b3) is present in an amount of 0.1 to 10% by weight based on the total weight of the composition. The thermosetting composition includes, as an additional component, Calcium oxide present in an amount of 0.1 to 6% by weight, and It further contains fillers present in a total amount of 10-50% by weight, All weight percentages are based on the total mass of the composition. The thermosetting composition according to claim 1, wherein the components are selected such that the thermosetting composition has a viscosity that allows it to be pumped using a pump at a temperature in the range of 15 to 60°C.

11. The thermosetting composition according to claim 1, further comprising a filler (d) in an amount of 10% to 45% by weight based on the total weight of the composition.

13. A product comprising a component including a metal surface, preferably an aluminum surface, wherein the composition described in claim 1 is bonded to the metal surface, and the product is cured at a temperature in the range of 120 to 140°C for a time in the range of 10 to 20 minutes to form an adhesive bond between two parts of the product and / or between the sealing surfaces of the product, and is a component of a vehicle, device, tool, or aircraft.

14. A method for applying an adhesive or sealant to a metal substrate having at least one aluminum metal surface, A step of delivering the composition according to claim 1 to the application point at a temperature in the range of 15 to 60°C, preferably by a pump; A step of depositing the composition in a liquid or paste-like state onto a selected area of ​​the first aluminum metal surface of the substrate; Optionally, a step of bringing a second metal substrate into contact with the selected region having the composition; and Subsequently, the composition is heated at a temperature in the range of 130 to 220°C for a sufficient time to form a cured composition adhered to the aluminum metal surface; Includes, A method wherein the overlap shear strength and adhesive strength of the composition cured at 220°C are preferably at least 30%, 40%, 50%, 60%, 70%, 80%, and 90% of the adhesive strength of the composition cured at 130°C.

15. The method according to claim 14, further comprising the step of heating the composition to a temperature in the range of 120 to 140°C, maintaining that temperature range for 10 to 60 minutes to thermally cure it, and optionally foaming it.

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