Polyene for a curable liquid rubber-based composition

Abstract

A curable liquid rubber composition comprising at least one liquid polyene component and at least one heat-activated crosslinker. The liquid polyene component may be a single polyene or a mixture of polyenes. In one embodiment, the liquid polyene component may contain, on a molar basis, at least one monomer providing at least 45 mole percent C2 to C13 pendant groups. In another embodiment, the liquid polyene component may contain, on a molar basis, at least one monomer providing at least 20 mole percent C2 to C5 pendant groups and at least one monomer providing at least 7 mole percent C6 to C13 pendant groups. After curing, the liquid rubber composition may have a loss factor greater than 0.51, a maximum loss factor temperature greater than -10°C, and a swelling ratio in toluene of 40% to 170% by weight.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application is related to and claims the benefit of priority of U.S. Patent Application No. 16 / 376,375 (Title of Invention: POLYENES FOR CURABLE LIQUID RUBBER - BASED COMPOSITIONS, filed on April 5, 2019).

[0002] Technical Field Aspects of the present invention relate to curable liquid rubber compositions, and in particular to curable liquid rubber compositions containing a liquid polyene component that is a liquid polyene or a mixture of liquid polyenes, wherein the liquid polyene component can contain at least 45 mol% of C2 - C13 aliphatic pendant groups or aromatic pendant groups along the main chain of the polyene or mixture of polyenes on a molar basis. Alternatively, the liquid polyene component can contain at least 20 mol percent of C2 - C5 aliphatic pendant groups and at least 7 mol percent of C6 - C13 aliphatic pendant groups or aromatic pendant groups along the main chain of the polyene or mixture of polyenes.

Background Art

[0003] Liquid rubber compositions are commonly used as adhesives, sealants, and / or sound or vibration damping materials. Such compositions are liquid at room temperature (25°C) but contain one or more polymers that can be cured by a cross - linking reaction to provide a solid elastomer composition, and thus are called "liquid rubber compositions". Generally, it is necessary to balance the damping properties and hardness after curing. In many cases, the solution is to incorporate a solid rubber to impart hardness to a relatively low - molecular - weight liquid rubber. However, these low - molecular - weight liquid rubbers may have a slow cross - linking rate, and at the same time, the addition of the solid rubber increases the viscosity of the curable rubber composition at room temperature to an unacceptable level, even when using a liquid rubber with a slightly higher molecular weight.

[0004] The hardness of the crosslinking material can be measured according to the standard protocol (ASTM D2240-15) given as the Shore A hardness value at room temperature. This measurement is used to compare the hardness of several formulations at one temperature. However, hardness does not provide insight into the crosslink density of various compositions, and thus, the hardness value alone is not sufficient to compare compositions based on different liquid rubbers and / or solid rubbers. This is because the crosslink density also affects the damping characteristics, which are usually measured as the loss factor value (tanδ).

[0005] Manufacturers of damping materials based on liquid polyenes having an Mn of less than 3000 g / mol blend them with solid rubber(s) to optimize some important properties of their formulations, such as the loss factor and hardness. The incorporation of solid rubber significantly increases the viscosity of the formulation at room temperature and also increases the temperature for applying the formulation.

[0006] Therefore, there is a great desire for an improved liquid rubber composition that is liquid at ambient temperature and yet retains excellent damping characteristics. SUMMARY OF THE INVENTION

[0007] Aspects of the present invention relate to a curable liquid rubber composition comprising a liquid polyene component. The liquid polyene component may each be a liquid polyene having a polyene backbone or may be a mixture of liquid polyenes each having a polyene backbone. In particular, the liquid polyene component may have at least 45 mol percent C2-C13 pendant groups along the polyene backbone on a molar basis. Alternatively or in addition, the liquid polyene component may have at least 20 mol percent C2-C5 pendant groups and at least 7 mol percent C6-C13 pendant groups along the polyene backbone or the main chain on a molar basis. The curable composition also includes at least one heat-activated crosslinking agent. After curing, the cured rubber composition has the following properties: · A loss factor (tanδ) greater than 0.51 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10°C to 45°C; · A maximum loss factor temperature above -10°C, and · A swelling ratio of 40 wt% to 170 wt%, measured by the equilibrium weight gain in toluene at 25 °C

[0008] In addition to the large amount of pendant groups, the liquid polyene component may have a weight average molecular weight of 2000 g / mol or more. The polyene component can have a weight average molecular weight higher than 2500 g / mol. The curable liquid rubber composition may contain 0 wt% to 1 wt% of a solid rubber or a solid thermoplastic substance.

[0009] Due to the high content of pendant groups and the weight average molecular weight of the polyene component being higher than 2000 g / mol, the cured composition disclosed herein can have a higher maximum loss factor (tanδ) compared to cured rubbers obtained from liquid rubber-based formulations that do not contain polyenes having these attributes. The improved damping is seen in the temperature range of -10 °C to +45 °C, as described in the examples for systems cured with either sulfur or organic peroxide. This improvement in damping performance is achieved for swelling ratios in the range of 40% to 170% without adversely affecting the hardness of the cured formulation.

[0010] Furthermore, the present invention relates to a cured rubber composition produced by heating a curable liquid rubber composition to 100°C to 240°C and maintaining the temperature for at least 5 minutes and up to 10 hours. The curable liquid rubber composition that is heated to produce the cured rubber composition contains a liquid polyene component. The liquid polyene component can be a liquid polyene containing a polyene main chain or a mixture of liquid polyenes each containing a polyene main chain. The liquid polyene component can include at least one monomer that, on a total molar basis, as a polymerization unit, provides at least 45 mole percent of C2 - C13 pendant groups along the polyene main chain. The liquid polyene can further or alternatively include, on a total molar basis, as a polymerization unit, at least one monomer that provides at least 20 mole percent of C2 - C5 pendant groups along the main chain of the polyene and at least one monomer that provides at least 7 mole percent of C6 - C13 pendant groups along the main chain of the polyene. The curable liquid rubber composition that is heated to produce the cured rubber composition also contains at least one heat - activated cross - linking agent.

[0011] The properties of the cured rubber formulation, when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of 10°C to 45°C, are a loss factor (tanδ) exceeding 0.51; a maximum loss factor temperature exceeding - 10°C; and a swelling ratio of 40 wt% to 170 wt% when measured by the equilibrium weight gain in toluene at 25°C. Due to their specific microstructure and macrostructure, it is possible to increase the amount of a specific liquid polyene component in the formulation and decrease the content of the high Mw polymer. Thus, materials that reduce vibration, noise, and harshness containing the liquid polyene component described herein result in compositions with lower viscosities, which are more easily applied to substrates under ambient conditions. Detailed Description of the Invention

[0012] Aspects of the present invention relate to liquid rubber compositions having a peroxide-based or sulfur-curable liquid polyene component. The liquid polyene component is a liquid polyene or a mixture of liquid polyenes. The curable liquid rubber composition is well-suited for use as an adhesive, a sealant, and / or for vibration or acoustic damping applications. By using aspects of the present invention, a curable rubber composition can be obtained that is liquid at ambient temperature (e.g., 20 °C to 40 °C), and that, when cured, has a loss factor (tan δ) greater than 0.51 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of 10 °C to 45 °C, a maximum loss factor temperature above -10 °C, and a swelling ratio of 40% to 170% by weight as measured by equilibrium weight gain in toluene at 25 °C. For example, a liquid rubber polyene composition in which the liquid polyene component has a weight average molecular weight greater than 4000 g / mol as disclosed herein can have a swelling ratio in toluene of 150% to 155% and a Shore A hardness value of 60 at 25 °C after curing.

[0013] A curable rubber composition as disclosed herein comprises the disclosed liquid polyene component to 10 to 80 weight percent including can be obtained. The disclosed curable rubber composition can comprise 15 to 55 weight percent of the liquid polyene component disclosed herein. Another suitable range is 20 to 50 weight percent of the liquid polyene component disclosed herein.

[0014] Liquid polyene component: As used herein, the term "liquid" means that a polyene or mixture of polyenes containing the liquid polyene component can be pumped or poured without additional additives at a temperature below 100 °C prior to curing.

[0015] As used herein, the term "liquid polyene component" means either a single liquid polyene or a mixture of liquid polyenes. Thus, the properties of the liquid polyene component refer to a single polyene when only one polyene is used. When a mixture of liquid polyenes is used, the properties refer to the entire mixture. For example, the weight average molecular weight refers to not only a single polyene in the mixture but also the entire mixture. Similarly, the molar percentage of monomers containing liquid polyenes in the mixture refers to the mixture as a whole rather than each individual liquid polyene in the mixture.

[0016] Monomer: The structure of the liquid polyene component is important for the performance and physical properties of the curable liquid rubber composition disclosed herein, both before and after crosslinking or curing. As described above, the liquid polyene polymer component may be either a single liquid polyene or a mixture of liquid polyene polymers. Prior to curing, the liquid polyene polymer component desirably has a weight average molecular weight of greater than 2000 g / mol and a minimum molar amount of pendant groups overall. This minimum molar amount of pendant groups is described in detail below.

[0017] A polymer containing a polymer or polyene component has a polyene backbone, which means that the backbone of the polymer chain contains a plurality of carbon-carbon double bonds in at least a part of the polymer backbone. There are pendant groups (i.e., groups other than hydrogen atoms that are pendant to the polymer backbone) along this backbone, which can include aliphatic groups, aromatic groups, or mixtures thereof. The polyene or mixture of polyenes as a whole must contain at least 45 mole percent of C2 - C13 pendant groups along the polyene backbone, or alternatively, must contain at least 20 mole percent of C2 - C5 pendant groups and at least 7 mole percent of C6 - C13 pendant groups along the polyene backbone. In practice, the polyene in the polyene or mixture of polyenes, as a polymerization unit, means including monomers or comonomers that bring the listed molar amounts of the listed pendant groups to the entire single polyene or such a mixture of polyenes. Further, the polyene or polyenes can be optionally terminated with a hydroxyl group or a functional derivative thereof as known in the art. Non-limiting examples of such functional groups include, in addition to the -OH group, esters, carboxylic acids, epoxides, amides, amines, anhydrides, acrylates, methacrylates, and silanes.

[0018] To avoid doubt, the mole percent of pendant groups in the liquid polyene component does not necessarily correspond to the mole percent of monomers polymerized together to form the polyene. As is well known in the art, especially in the case of diene monomers such as butadiene, when not only one but both double bonds in the diene molecule are incorporated into the polyene backbone, there are no pendant groups resulting from that diene molecule. Thus, as detailed herein, it is important to utilize analytical techniques (e.g., NMR) to measure the amount of pendant groups in the polyene, especially for polyenes incorporating butadiene as a monomer or comonomer. Further explanation of how the mole % of pendant groups in the liquid polyene component can be determined is described in the Examples section below.

[0019] When polymerized alone, it produces C2 - C13 pendant groups and monomers present in the polyene as polymerization units at a level sufficient to produce at least 45 mole percent of C2 - C13 pendant groups along the main chain of the liquid polyene component:

[0020] Examples of such monomers or comonomers include, but are not limited to, C4 - C15 dienes, C6 - C15 trienes, C8 - C15 tetraenes, vinyl aromatic compounds containing 15 or fewer carbon atoms (i.e., vinyl aromatic compounds containing 8 - 15 carbon atoms), and mixtures thereof. Specific non - limiting examples of suitable vinyl aromatic - containing monomers that can be used in the practice of the present invention are styrene, alpha - methylstyrene, 2 - methylstyrene, 3 - methylstyrene, 4 - methylstyrene, 4 - propylstyrene, 4 - t - butylstyrene, 4 - cyclohexylstyrene, 2,4 - dimethylstyrene, 2,4 - diisopropylstyrene, 2,4,6 - trimethylstyrene, 1 - vinylnaphthalene, 2 - vinylnaphthalene, N,N - diethyl - 4 - aminoethylstyrene, vinylpyridine, 4 - methoxystyrene, monochlorostyrene, dichlorostyrene, divinylbenzene, and mixtures thereof. Suitable non - limiting examples of C4 - C15 dienes that result in C2 - C13 pendant groups along the main chain of the polymer are butadiene; isoprene; 2,3 - dimethylbutadiene; 2 - phenylbutadiene; 1,3 - pentadiene; 2 - methyl - 1,3 - pentadiene; 1,3 - hexadiene; 1,3 - octadiene; 1,3 - cyclohexadiene; 2 - methyl - 1,3 - octadiene; bergamotene; limonene; and mixtures thereof. Non - limiting examples of C6 - C15 trienes are 1,3,7 - octatriene; zingiberene; bisabolene; sesquiphellandrene; ocimene; myrcene; and mixtures thereof. A suitable non - limiting example of a C8 - C15 tetraene is farnesene.

[0021] The monomers as listed above can be present in the liquid polyene component in polymerized form in an amount that provides at least 45 mole percent of C2 - C13 pendant groups along the polymer main chain. Also, C2 - C13 pendant groups along the polyene component main chain up to at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, at least 95 or 100 mole percent are suitable.

[0022] Monomers that, when homopolymerized, provide C2 - C5 pendant groups and are present as polymerization units in the polyene at a level sufficient to produce at least 20 mole percent of C2 - C5 pendant groups along the polyene component main chain:

[0023] Examples of such monomers or comonomers include, but are not limited to, C4 - C7 dienes and mixtures thereof. Non - limiting specific examples include butadiene; isoprene; 2,3 - dimethylbutadiene; 1,3 - pentadiene; 2 - methyl - 1,3 - pentadiene; 1,3 - hexadiene; 1,3 - cyclohexadiene; and mixtures thereof. These monomers can be present in the liquid polyene in polymerized form in an amount that provides at least 20 mole percent of C2 - C5 pendant groups along the polymer main chain. Also, C2 - C5 pendant groups along the main chain of the polyene(s) up to at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, at least 80, at least 85, at least 90, or 93 mole percent are suitable.

[0024] Monomers that, when homopolymerized, can produce C6 - C13 pendant groups and are present as polymerization units in the polyene at a level sufficient to produce at least 7 mole percent of C6 - C13 pendant groups along the liquid polyene component main chain:

[0025] Examples of such monomers or comonomers include, but are not limited to, C8-C15 dienes, trienes and tetraenes, vinyl aromatic monomers containing 8-15 carbon atoms, and mixtures thereof. Non-limiting specific examples of such monomers or comonomers include myrcene; styrene; α-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 4-propylstyrene; 4-t-butylstyrene; 4-cyclohexylstyrene, 2,4-dimethylstyrene; 2,4-diisopropylstyrene; 2,4,6-trimethylstyrene; 1-vinylnaphthalene; 2-vinylnaphthalene; N,N-diethyl-4-aminoethylstyrene; vinylpyridine; 4-methoxystyrene; monochlorostyrene; dichlorostyrene; divinylbenzene; farnesene; 1,3,7-octatriene, 1,3-octadiene, 2-methyl-1,3-octadiene, bergamotene, limonene; zingiberene, bisabolene, sesquiphellandrene, ocimene; farnesene; and mixtures thereof. These monomers may be present in polymerized form in the liquid polyene component in an amount that provides at least 7 mole percent C6-C13 pendant groups along the polyene component backbone. Also, C6-C13 pendant groups along the polyene component backbone up to at least 10, at least 15, at least 20, at least 25, at least 30, at least 35, at least 40, at least 45, at least 50, at least 55, at least 60, at least 65, at least 70, at least 75, or 80 mole percent are suitable.

[0026] Weight average molecular weight: The weight average molecular weight (Mw) of the liquid polyene described in this specification can be a weight average molecular weight exceeding 2000 g / mol. The polyene may have an Mw exceeding 2100 g / mol, exceeding 2200 g / mol, exceeding 2300 g / mol, exceeding 2400 g / mol, exceeding 2500 g / mol, exceeding 2600 g / mol, exceeding 2700 g / mol, exceeding 2800 g / mol, exceeding 2900 g / mol, exceeding 3000 g / mol, exceeding 3250 g / mol, exceeding 3500 g / mol, exceeding 3750 g / mol, exceeding 4000 g / mol, exceeding 4250 g / mol, exceeding 4500 g / mol, exceeding 4750 g / mol, exceeding 5000 g / mol, exceeding 5250 g / mol, exceeding 5500 g / mol, exceeding 5750 g / mol, exceeding 6000 g / mol, exceeding 7000 g / mol, exceeding 8000 g / mol, exceeding 9000 g / mol, exceeding 10,000 g / mol, exceeding 12,000 g / mol, exceeding 14,000 g / mol, exceeding 16,000 g / mol, exceeding 18,000 g / mol, exceeding 20,000 g / mol, exceeding 22,500 g / mol, or exceeding 25,000 g / mol. The weight average molecular weight can be measured by the method described in the Examples section below. Also, as described above, the weight average molecular weight refers to the liquid polyene component as a whole. That is, when the liquid polyene component is a mixture of liquid polyenes, the weight average molecular weight refers to the weight average molecular weight of the entire mixture.

[0027] Loss coefficient (tanδ): The loss coefficient tanδ is typically measured over a temperature range using dynamic mechanical analysis (DMA). tanδ is a measure of the ability of a material to dissipate energy, and thus, higher tanδ values are associated with higher damping performance. Since the tanδ value varies with temperature, the temperature at which the maximum tanδ is measured is reported as the maximum loss rate temperature. tanδ is measured over a temperature range from -10°C to 45°C at a frequency of 50 Hz and an amplitude of 3 μm.

[0028] After curing (crosslinking), the thermosetting liquid rubber compositions disclosed herein may have a tan δ of 0.51 or greater. The maximum tan δ is higher than 0.525, higher than 0.550, higher than 0.575, higher than 0.600, higher than 0.625, higher than 0.650, higher than 0.675, higher than 0.700, higher than 0.725, higher than 0.750, or higher than 0.775. After curing, the thermosetting liquid rubber compositions disclosed herein may have a maximum loss factor temperature above -10 °C, above -5 °C, above 0 °C, above 5 °C, above 10 °C, above 15 °C, above 20 °C, above 25 °C, above 30 °C, above 35 °C, or above 40 °C.

[0029] Shore A hardness: The Shore A hardness described herein is measured in accordance with ASTM D2240-15. The cured thermosetting liquid rubber polyene composition can have a Shore A hardness above 30, above 35, above 40, above 45, above 50, above 55, above 60, above 65, above 66, above 67, above 68, above 69, above 70, above 71, above 72, above 73, above 74, or above 75. The Shore A hardness of the cured thermosetting liquid rubber polyene composition as disclosed herein can be 30 - 90, 40 - 85, or 60 - 80.

[0030] Swelling ratio: The swelling ratio is related to the crosslink density of the cured rubber composition and is measured by determining how much solvent the crosslinked (cured) sample of the thermosetting liquid rubber composition absorbs at a constant temperature. Generally, a lower swelling ratio is associated with a higher crosslink density. As described herein, the crosslink density is reported as the equilibrium weight percent increase in toluene at 25 °C. The swelling ratio of the crosslinked liquid rubber composition can be 40 wt% - 150 wt%, 40 wt% - 125 wt%, 50 wt% - 110 wt%, or 60 wt% - 100 wt%. The swelling ratio is measured according to the procedure described in the examples.

[0031] Viscosity: The viscosity described in this specification is the viscosity of the liquid polyene component alone. To avoid doubt, it is not the viscosity of a thermosetting composition liquid rubber composition containing the liquid polyene component. The viscosity here is reported as the Brookfield viscosity measured at 25 °C using an S spindle. The viscosity of the liquid rubber polyene may be from 500 to 700,000 mPa·sec at 25 °C. When a mixture of different liquid rubber polyenes is used as the liquid polyene component, the viscosity of the mixture can be measured.

[0032] Solid rubber or thermoplastic resin: The thermosetting liquid rubber composition can contain less than 1 wt%, i.e., 0 - 1 wt% of solid rubber or thermoplastic resin. Solid rubber is defined as rubber that cannot be pumped or poured at temperatures below 100 °C without additives and has a weight average molecular weight exceeding 100,000 g / mol before curing.

[0033] Thermally activated crosslinking agent: The terms "crosslinking" and "curing" are interchangeable as used herein and are understood to mean that chemical bonds are formed between adjacent chains of individual polyene molecules. Examples of suitable crosslinking agents or curing agents that can be used in the curable liquid rubber composition are sulfur and peroxides. Any of these types of crosslinking agents can be used at appropriate levels together with suitable auxiliaries, accelerators or activators known in the art and used to increase the rate and completeness of crosslinking. The curing agent can be selected based on the desired curing temperature of the liquid rubber polyene composition. Typically, the curing temperature is from 100 °C to 190 °C.

[0034] The term "phr" as used herein means parts by weight per 100 parts by weight of resin or liquid rubber, where the resin is the liquid polyene component, i.e., the liquid polyene or combination of liquid polyenes in the curable liquid rubber composition.

[0035] Organic peroxide: The polyenes of the present invention can be cured using organic peroxides. Suitable organic peroxides include those commonly used in the art to crosslink polymers containing rubber. Suitable peroxides include, but are not limited to: dicumyl peroxide; allyl peroxide or diallyl peroxide; diacetyl peroxide; benzoyl peroxide; dibenzoyl peroxide; di-tert-butyl peroxide; tert-butyl-cumyl peroxide; 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane; cumyl peroxyde; 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexene-3; p-bis[2-(2-t-butylperoxy)propyl]benzene; 2,5-dimethyl-2,5-di-tert-butylperoxyhexane; tert-butyl peroxide; tert-butyl perbenzoate; tert-butyl peroxyisopropylate, di-(2-tert-butylperoxy-isopropyl)benzene; butyl 4,4-di-(tert-butylperoxy)valerate; 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane; and mixtures thereof.

[0036] Non-limiting examples of other suitable peroxides are peroxyketals (e.g., 1,1'-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane or di(tert-butylperoxy)-cyclohexane); diacyl peroxides (e.g., dibenzoyl peroxide or dilauroyl peroxide) and peroxy esters (e.g., tert-butylperoxyisobutyrate or tert-amylperoxy-2-ethylhexyl carbonate). In another embodiment, the peroxide can be selected from the group consisting of peroxyketals (e.g., 1,1'-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane or di(tert-butylperoxy)-cyclohexane, etc.); diacyl peroxides (e.g., dibenzoyl peroxide, etc.) and peroxy esters.

[0037] The curable liquid rubber composition can contain two or more organic peroxides as heat-activated crosslinking agents. For example, the curable liquid rubber composition can contain at least two peroxides selected from the group consisting of peroxyketals (e.g., 1,1'-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane or di(tert-butylperoxy)-cyclohexane); diacyl peroxides (e.g., dibenzoyl peroxide or dilauroyl peroxide) and peroxy esters (e.g., tert-butyl peroxyisobutyrate or tert-amyl peroxy-2-ethylhexyl carbonate). "Half-life" is a convenient means of representing the decomposition rate of an organic peroxide at a specific temperature. Measure the time required for half of the originally present organic peroxide to decompose at a specific temperature.

[0038] Organic peroxides having a 10-hour half-life temperature of 47°C to 127°C are preferred. The amount of peroxide present in the curable liquid rubber composition varies depending on the type of peroxide used, the reactivity of the polyene, the type and reactivity of the accelerator or activator (if present), as well as the desired curing profile and target cured rubber properties, and other factors. However, typically, the curable liquid rubber composition will contain one or more peroxides in an amount of 1 to 30 phr (parts per 100 parts by weight of the liquid polyene component), or 1.5 to 20 phr. In addition to the peroxide, suitable accelerators, auxiliaries or activators can be used. Each of the accelerator or auxiliary or activator (if present) is typically present in an amount of 0.1 to 30 phr. The accelerator or auxiliary or activator (if present) can be present between 0.2 and 25 phr or 0.2 and 20 phr.

[0039] Sulfur: As the heat-activated crosslinking agent, sulfur can be used. Typically, sulfur is added in an amount of 1 to 30 phr, or 1.5 to 20 phr (parts per 100 parts by weight of the liquid polyene component). It should be understood that this amount refers to sulfur added only in elemental form. Sulfur donors can also be used. Each of the accelerator or coagent or activator (if present) is typically present between 0.1 and 30 phr. The accelerator or coagent or activator (if present) can be present between 0.2 and 25 phr or 0.2 and 20 phr. In addition to sulfur, suitable accelerators, coagents or activators can be used. Each of the accelerator or coagent or activator (if present) is typically present between 0.1 and 30 phr. The accelerator or coagent or activator (if present) can be present between 0.2 and 25 phr or 0.2 and 20 phr.

[0040] The sulfur donor can also be used together with sulfur to reduce the sulfur content incorporated into the formulation. Non-limiting examples of sulfur donors are thiuram tetrasulfide and morpholine derivatives such as tetramethylthiuram disulfide; 4,4'-dithiomorpholine; dipentamethylenethiuram tetrasulfide; and thiocarbamyl sulfenamide.

[0041] Accelerator: Examples of accelerators that can be used together with sulfur as a primary curing agent include sulfenamides, thiazoles, dithiocarbamates, thiuram compounds of N-cyclohexyl-2-benzothiazole sulfenamide (CBS); N-tert-butyl-2-benzothiazyl sulfenamide (TBBS); zinc dimethyldithiocarbamate (ZDMC), zinc dibenzyldithiocarbamate (ZBEC); 2-mercaptobenzothiazole (MBT); benzothiazyl disulfide (MBTS), but are not limited thereto. Some primary accelerators such as thiazole (MBT or MBTS) or dithiocarbamate (ZDMC or ZBEC) can be used in a mixture with sulfenamides or instead of sulfenamides. Other non-limiting examples of accelerators are thiurams (e.g., tetramethylthiuram disulfide (TMTD) or tetrabenzylthiuram disulfide (TBzTD)). The above dithiocarbamates or xanthates, such as zinc isopropylxanthate (ZIX) or sodium isopropylxanthate (NaIX) can also be used.

[0042] Activator: Examples of suitable activators that can be used together with organic peroxides or sulfur as a primary crosslinking agent include metal oxides, fatty acid metal salts (e.g., metal stearates), fatty acids, and mixtures thereof, but are not limited thereto. Non-limiting specific examples include zinc oxide, calcium oxide, magnesium oxide, zinc stearate, or stearic acid.

[0043] Auxiliary agent: The curable liquid rubber composition may also contain at least one auxiliary agent compatible with crosslinking with organic peroxides and / or sulfur. The auxiliary agent may contain one or more ethylenically unsaturated sites (carbon-carbon double bonds) per molecule and may be selected from the group consisting of acrylates, methacrylates, bismaleimides, vinyl esters, allyl compounds, and their derivatives. In a preferred embodiment of the present invention, the curable liquid polyene composition contains a total of 0 phr to 30 phr of the auxiliary agent. In other embodiments, the liquid rubber composition can contain 0.5 to 15% by weight of the auxiliary agent. Non-limiting examples of suitable auxiliary agents include metal acrylates, metal methacrylates, metal acrylate salts, and metal methacryl salts. In particular, zinc acrylate, zinc methacrylate, zinc acrylate salt, and zinc methacrylate salt can be mentioned.

[0044] Also, when crosslinking these liquid polyene-based compositions with an organic peroxide, sulfur can be introduced as an auxiliary agent. The sulfur content should be low, i.e., 0.5% by weight or less of sulfur, when used as an auxiliary agent with the peroxide.

[0045] Non-solid rubber·non-thermoplastic filler: The curable liquid rubber composition can contain at least one filler that is not the aforementioned solid rubber or thermoplastic substance. In particular, the filler can contain at least one inorganic filler. Suitable fillers include any of the fillers known in the art related to curable liquid rubber compositions, including, for example, calcium carbonate, silica, carbon black, clay, talc, mica, calcium oxide, alumina, magnesium carbonate, and the like. The aforementioned fillers can be treated with heat treatment or with silanes, resins, or cationic species to prevent or reduce the decomposition of some peroxides. The curable liquid rubber composition can contain 15 to 70 weight percent of the filler or 25 to 60 weight percent of the filler.

[0046] Other additives: Optionally, one or more additional components can be included in the thermosetting liquid rubber composition to achieve desired final properties for a particular end use (such as adhesive and sealant applications). A non-exhaustive list of such optional additional components is as follows: - tackifiers and / or coupling agents; - adhesion promoters such as functionalized liquid rubber resins (e.g., maleated liquid polybutadiene resin); - plasticizers or extender oils, such as paraffinic oils, and / or - stabilizers against heat, thermo-oxidation, or ozone degradation.

[0047] Typical uses: The thermosetting liquid rubber composition of the present invention is particularly useful for the manufacture of materials intended for vibration and / or acoustic noise reduction, such as in automotive and other vehicle applications. The cured state of the curable liquid rubber composition has acoustic attenuation properties. To manufacture articles made of cured rubber obtained from the curable liquid rubber composition of the present invention, any known or conventional coating, molding, shaping, forming, or impregnation method known in the art can be used. For example, the curable liquid rubber composition of the present invention can be utilized in the manufacture of acoustic attenuation components, belts, hoses, rubber rollers, industrial products, vibration mounts, tires, O-rings, gaskets, wire and cable coatings, expansion joints, etc., including elastomeric products or composite products generally containing an elastomeric component. Use of the curable liquid rubber composition of the present invention as adhesives, sealants, and coatings is also contemplated. In one embodiment, the curable liquid rubber composition is applied to a substrate surface (such as a metal sheet, panel, or other such component) using any suitable technique such as spraying, dipping, roller coating, etc., and then heated to a temperature effective to cure the curable liquid rubber composition. Accordingly, the curable liquid rubber composition can be formulated to have a viscosity that can be applied by pumping and / or spraying. For example, the curable liquid rubber composition may be pumpable and / or sprayable with the aid of an automated application system such as a robotic system.

[0048] According to a further aspect of the present invention, a cured rubber composition is provided. The cured rubber composition may be obtained by curing a curable liquid rubber composition as disclosed herein by heating a curable low-sulfur liquid rubber composition. The curable low-sulfur liquid rubber composition is advantageously curable by heating the curable liquid rubber composition to a temperature of about 100°C to about 240°C or a temperature of about 100°C to about 190°C. To effect curing, the curable composition is held at that temperature for 5 minutes to 10 hours. As a result of such curing, the curable liquid rubber composition is converted into a solid elastomeric (rubbery) composition (e.g., by a crosslinking reaction). Typically, curing of the curable liquid rubber composition is achieved by heating to a temperature effective to initiate a desired crosslinking reaction that includes at least a polymer component. Typically, the time to achieve proper curing is 5 minutes to 10 hours.

[0049] Curing conditions: Typically, curing is achieved by heating the curable liquid rubber composition to a temperature effective to initiate a desired crosslinking reaction. The curing temperature depends on the crosslinking system used and the reactivity of the other components of the curable liquid rubber composition, but generally speaking, a temperature in the range of about 100°C to about 240°C is suitable (a temperature of about 100°C to about 190°C is typically preferred). The heating can be carried out for a time effective to achieve the desired state of cure. Such curing time is variable depending on many factors, but is typically about 5 minutes to about 10 hours.

[0050] Various exemplary aspects of the present invention can be summarized as follows:

[0051] Aspect 1. A thermosetting liquid rubber composition, a. A liquid polyene containing a polyene backbone or a mixture of liquid polyenes each containing a polyene backbone, on an all-mole basis as polymerized units, i. At least one monomer that provides at least 45 mole percent of C2-13 pendant groups along the polyene backbone, ii. At least one monomer that provides at least 20 mol percent of C2-5 pendant groups along the main chain of the polyene, and at least one monomer that provides at least 7 mol percent of C6-13 pendant groups along the main chain of the polyene, a liquid polyene component comprising, and b. at least one heat-activated crosslinking agent, and; and After curing, the thermosetting rubber composition has a loss factor (tan δ) greater than 0.51 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10 °C to 45 °C; a maximum loss factor temperature above -10 °C; and a swelling ratio of 40 wt% to 170 wt%, measured by equilibrium weight gain in toluene at 25 °C, to produce a cured rubber composition having a thermosetting liquid rubber composition.

[0052] Aspect 2: The liquid polyene component has a weight average molecular weight greater than 2000 g / mol and a Brookfield S spindle viscosity of 500 to 700,000 mPa·sec at 25 °C, of the thermosetting liquid rubber composition according to Aspect 1.

[0053] Aspect 3: The thermosetting liquid rubber composition contains a total of 0 wt% to 1 wt% of solid rubber or solid thermoplastic plastic, of the thermosetting liquid rubber composition according to Aspect 1 or Aspect 2.

[0054] Aspect 4: At least one liquid polyene in the liquid polyene or the mixture of the liquid polyenes is terminated with a hydroxyl group or a functional derivative thereof, of the thermosetting liquid rubber polyene composition according to any one of Aspects 1 to 3.

[0055] Aspect 5: After curing, the cured rubber composition has a Shore A hardness greater than 55 when measured according to ASTM standard D2240-15, of the thermosetting liquid rubber composition according to any one of Aspects 1 to 4.

[0056] Aspect 6: The at least one monomer that provides the C2-C13 pendant group is selected from the group consisting of C4-C15 dienes, C6-C15 trienes, C8-C15 tetraenes, vinyl aromatic compounds containing 15 or fewer carbon atoms, and mixtures thereof, and is the thermosetting liquid rubber composition according to any one of Aspects 1 to 5.

[0057] Aspect 7: The at least one monomer that provides the C2-C13 pendant group includes at least one vinyl aromatic compound selected from the group consisting of styrene; alpha-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 4-propylstyrene; 4-t-butylstyrene; 4-cyclohexylstyrene; 2,4-dimethylstyrene; 2,4-diisopropylstyrene; 2,4,6-trimethylstyrene; 1-vinylnaphthalene; 2-vinylnaphthalene; N,N-diethyl-4-aminoethylstyrene; vinylpyridine; 4-methoxystyrene; monochlorostyrene; dichlorostyrene; divinylbenzene; and mixtures thereof, and is the thermosetting liquid rubber composition according to any one of Aspects 1 to 6.

[0058] Aspect 8: The at least one monomer that provides the C2-C13 pendant group includes: a) a C4-C14 diene selected from the group consisting of butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, and mixtures thereof; b) a C6-C15 triene selected from the group consisting of 1,3,7-octatriene, myrcene, and mixtures thereof; or c) at least one of farnesene, and is the thermosetting liquid rubber composition according to any one of Aspects 1 to 7.

[0059] Aspect 9: The at least one monomer that provides the C2-C13 pendant group is selected from the group consisting of butadiene, isoprene, alpha-methylstyrene, styrene, myrcene, farnesene, and mixtures thereof, and is the thermosetting liquid rubber composition according to any one of Aspects 1-8.

[0060] Aspect 10: The at least one monomer that provides the C2-C5 pendant group is selected from the group consisting of C4-C7 dienes, C6-C7 trienes, and mixtures thereof, and is the thermosetting liquid rubber composition according to any one of Aspects 1-9.

[0061] Aspect 11: The at least one monomer that provides the C6-C13 pendant group is selected from the group consisting of C8-C15 dienes, C8-C15 trienes, C8-C15 tetraenes, vinyl aromatic monomers containing 8-15 carbon atoms, and mixtures thereof, and is the thermosetting liquid rubber composition according to any one of Aspects 1-10.

[0062] Aspect 12: The at least one monomer that provides the C2-C5 pendant group is selected from the group consisting of butadiene; isoprene; 2,3-dimethylbutadiene; 1,3-pentadiene; 2-methyl-1,3-pentadiene; 1,3-hexadiene; 1,3-cyclohexadiene; and mixtures thereof; and the at least one monomer that provides the C6-C13 pendant group is selected from the group consisting of 1,3-octadiene; 2-methyl-1,3-octadiene; 1,3,7-octatriene; myrcene; styrene; alpha-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 4-propylstyrene; 4-t-butylstyrene; 4-cyclohexylstyrene; 2,4-dimethylstyrene; 2,4-diisopropylstyrene; 2,4,6-trimethylstyrene; 1-vinylnaphthalene; 2-vinylnaphthalene; N,N-diethyl-4-aminoethylstyrene; vinylpyridine; 4-methoxystyrene; monochlorostyrene; dichlorostyrene; divinylbenzene; farnesene; and mixtures thereof, and is the thermosetting liquid rubber composition according to any one of Aspects 1-11.

[0063] Aspect 13: The thermally activatable crosslinking agent contains sulfur, and the thermosetting liquid rubber composition further contains at least one accelerator and at least one activator, the thermosetting liquid rubber composition according to any one of Aspects 1 to 12.

[0064] Aspect 14: The at least one accelerator is selected from the group consisting of sulfenamides, thiazoles, dithiocarbamates, thiuram compounds, and mixtures thereof; and the at least one activator is selected from the group consisting of metal oxides, fatty acid metal salts, fatty acids, and mixtures thereof, the thermosetting liquid rubber composition according to Aspect 13.

[0065] Aspect 15: The at least one accelerator is selected from the group consisting of N-cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazyl sulfenamide (TBBS), and mixtures thereof, and the at least one activator is selected from the group consisting of zinc oxide, calcium oxide, magnesium oxide, zinc stearate, and mixtures thereof, the thermosetting composition according to Aspect 13 or 14.

[0066] Aspect 16: The thermally activatable crosslinking agent contains an organic peroxide having a 10-hour half-life temperature of 47°C to 127°C, the thermosetting liquid rubber composition according to any one of Aspects 1 to 12.

[0067] Aspect 17: The thermosetting liquid rubber composition further contains a metal oxide, a fatty acid, and at least one auxiliary agent, and the at least one auxiliary agent is selected from the group consisting of metal acrylates, metal methacrylates, and mixtures thereof, the thermosetting liquid rubber composition according to Aspect 16.

[0068] Aspect 18: The liquid polyene component has a weight average molecular weight exceeding 2500 g / mol, the thermosetting liquid rubber composition according to any one of Aspects 1 to 17.

[0069] Aspect 19: A thermosetting liquid rubber composition according to any one of Aspects 1 to 18, comprising a liquid polyene component of 10 to 80% by weight.

[0070] Aspect 20: A thermosetting liquid rubber composition according to any one of Aspects 1 to 19, comprising a liquid polyene component of 15 to 55% by weight.

[0071] Aspect 21: A thermosetting liquid rubber composition according to any one of Aspects 1 to 20, further comprising at least one filler.

[0072] Aspect 22: The thermosetting liquid rubber composition according to Aspect 21, wherein the at least one filler is selected from the group consisting of calcium carbonate, silica, carbon black, clay, talc, mica, calcium oxide, alumina, magnesium carbonate, and mixtures thereof.

[0073] Aspect 23: A thermosetting liquid rubber composition according to any one of Aspects 1 to 22, comprising 15 to 70% by weight of the at least one filler.

[0074] Aspect 24: A thermosetting liquid rubber composition according to any one of Aspects 21 to 23, comprising 25 to 60% by weight of the at least one filler.

[0075] Aspect 25: The thermosetting liquid rubber composition according to any one of Aspects 1 to 24, which can be cured between 100°C and 190°C.

[0076] Aspect 26: An adhesive composition comprising a thermosetting liquid rubber composition according to any one of Aspects 1 to 25, at least one filler, and at least one adhesion promoter.

[0077] Aspect 27: A sealant composition comprising a thermosetting liquid rubber composition according to any one of Aspects 1 to 25, and at least one filler.

[0078] Aspect 28: A vibration damping composition comprising the thermosetting liquid rubber composition according to any one of Aspects 1 to 25, wherein the loss factor (tan δ) is greater than 0.53 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10°C to +35°C.

[0079] Aspect 29: A cured rubber composition which is a cured reaction product of the thermosetting liquid rubber composition according to Aspects 1 to 28, After curing at a temperature between 100°C and 240°C for 5 minutes to 10 hours, the thermosetting liquid rubber composition provides a cured rubber composition having the following: i) A loss factor (tan δ) greater than 0.51 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10°C to 45°C; ii) A maximum loss factor temperature above -10°C; and iii) A swelling ratio of 40 wt% to 170 wt% as measured by the equilibrium weight gain in toluene at 25°C.

[0080] Although the embodiments have been described in a way that enables a clear and concise specification, it is intended and will be understood that the embodiments may be variously combined or separated without departing from the invention. For example, it will be understood that all the preferred features described herein are applicable to all aspects of the invention described herein.

[0081] In some embodiments, the invention herein can be construed to exclude any element or process step that does not substantially affect the basic and novel features of the curable liquid rubber composition, the process using the curable liquid rubber composition, or the article made using the curable liquid rubber composition. Further, in some embodiments, the invention herein can be construed to exclude any element or process step not specified herein.

[0082] The present invention is illustrated and described herein with reference to specific embodiments, but the present invention is not intended to be limited to the details shown. Rather, various modifications can be made in detail within the equivalent scope and range of the claims without departing from the present invention.

Example

[0083] The following non-limiting examples are provided for the purpose of explaining the advantages obtained from aspects of the present invention.

[0084]

Table 1

[0085] Method for defining the microstructure of a liquid rubber resin and definition of pendant groups Using the 1H nuclear magnetic resonance (NMR) method, the microstructure of liquid rubber resins (especially those listed in the following table) was determined using a Bruker Avance III 400 MHz analyzer with CDCl3 as the solvent. The analysis protocol is defined in Iranian Polymer Journal 12(6), 2003, p515 - 521 and Polymer Engineering and Science, 2007, p87 - 94; as well as in the Proceedings of conference presented at the ACS Cleveland, OH, Fall 190th Technical Meeting of Rubber Division on October 11 - 13, 2016.

[0086] Content of pendant groups: In Table 1 above, a new criterion called the pendant group content is defined to characterize the liquid polyene component. This corresponds to the molar amount of pendant groups present in the microstructure of the liquid rubber polyene component and is calculated by adding three values: · The vinyl percentage of the molar percentage of butadiene comonomer in the polyene component · Mole percent of styrene comonomer in the polyene component · Mole percent of farnesene comonomer in the polyene component

[0087] Since the butadiene component can have various amounts of groups, the total molar amount of pendant groups along the polyene backbone contributed by the butadiene comonomer is the vinyl % times the mole percent of butadiene in the liquid polyene.

[0088] Calculation example of the mole percent of pendant groups in the polyene component: As detailed in Table 1, the composition "SB copolymer 1" contains 72 mole percent of butadiene comonomer, 30 percent of which is present as vinyl pendant groups. "SB copolymer 1" also has 28 mole percent of styrene comonomer, 100 percent of which is present as pendant groups. Therefore, the total mole percent of pendant groups in "SB copolymer 1" is calculated as follows: (0.30 x 72) = 21 mole percent of pendant groups from butadiene PLUS (1.0 x 28) = 28 mole percent of pendant groups from styrene 21% + 28% = 49 mole percent of pendant groups in SB copolymer 1

[0089] To avoid doubt, considering 100 monomer units in the polyene component, according to the above explanation, 21 monomer units have vinyl pendant groups, 28 monomer units have phenyl pendant groups, and thus a total of 49 out of 100 monomer units have pendant groups.

[0090] For polyene components containing a mixture of two or more polyenes, the mole percent of pendant groups is based on the mixture as a whole. For example, referring to the following examples, Comparative Examples 1 and 2 (Tables 1 and 2 below) contain a polyene component that is 70 weight percent "LPB1" and 30 weight percent "LPB2". Referring to Table 1 above, LPB1 has a Mw = 4800 g / mol and a pendant group content of 15 mol%. LBP2 has a Mw = 9500 g / mol and 28 mol% pendant groups. Thus, it can be calculated that this polyene component contains 82 mol% LPB1 and 18 mol% LPB2. Therefore, the polyene component as a whole has a pendant group content of (0.82×15)+(0.18×28)=17.3 mol%.

[0091] To avoid doubt, considering 100 monomer units in the polyene component, according to the above explanation, 17.28 of the monomer units in the mixture containing the polyene component have vinyl pendant groups.

[0092] Method for measuring the weight average molecular weight of liquid rubber resin: Using standard size exclusion chromatography (SEC), the average molecular weight of the liquid rubber sample is determined with a degassing device, an isocratic pump, and an Agilent 1260 Infinity II setup using an RID (refractive index) detector.

[0093] The SEC analysis is performed in THF (tetrahydrofuran) using one Styragel HR4E column and refractive index detection. For the SEC analysis, 15 mg of the liquid rubber sample was dissolved in a 15 ml THF (purity: ≧99.5% - stabilized Normapur or equivalent) solution containing 1 drop of toluene (internal standard). The conditions for the SEC analysis were as follows: 20 μl for the injection volume; 1.0 ml / min for the flow rate, and 35 °C for the temperature.

[0094] The weight average molecular weight (Mw) values of the low molecular weight butadiene-based homopolymers and butadiene-(β-)farnesene copolymers were determined by calibration using in-house poly(butadiene) calibration. The Mw values of the low molecular weight butadiene-styrene copolymers and poly(trans-β-farnesene) were calculated using poly(styrene) calibration standards.

[0095] Viscosity of the liquid rubber resin: The viscosity values of the liquid rubber resins were measured at 25 °C with a Brookfield DV-II viscometer using an “S” serial spindle. To perform the measurements at a stable temperature, the Brookfield viscometer chamber was connected to a LAUDA L100 bath with a temperature set point of 25 °C.

[0096] Preparation of the thermosetting liquid rubber-based compositions and measurement of the properties of the cured compositions: The liquid rubber-based compositions were prepared at room temperature using a speed mixer (capable of mixing the components at at least 3000 rpm). An exemplary procedure was as follows: Step 1: Add the liquid rubber, crosslinking agent, metal oxide, antioxidant and other chemicals contained in the formulation and then mix them at 3000 rpm for 60 seconds; Step 2: Add half of the amount of the filler to the composition and then mix it at 3000 rpm for 60 seconds; Step 3: Add the remaining amount of the filler to the composition and then mix it at 3000 rpm for 60 seconds; Step 4: Perform a visual control of the formulation (to check the uniformity of the formulation) for 180 seconds at 3000 rpm before starting the final mixing step.

[0097] After the mixing process, all the compositions were cured in the temperature range of 100 °C to 190 °C. The curing step was carried out in a mold to obtain a sheet having the following size: 75 mm × 75 mm × 3.7 mm.

[0098] Swelling test: Two test pieces with the following dimensions: 25 mm × 7 mm × 3.7 mm were cut from the hardened sheet and weighed (initial weight - approximately 0.7 g to 1.0 g). Each sample was completely immersed in pure toluene in a sealed glass bottle at room temperature (25 °C) until equilibrium swelling occurred. The swelling test took approximately 24 hours. Once this process was completed, the swollen samples were removed from the bottles. Excess toluene was wiped from the surface of each sample, and the weight of the swollen sample (swollen weight) was measured immediately.

[0099] From the initial weight of the sample and the weight at the end of the swelling test, the swelling ratio can be calculated: Swelling ratio (%) = 100 × [(swollen weight - initial weight) / initial weight]

[0100] Shore A hardness: The hardness of the cured sheet of each composition was measured using a Shore A hardness device. The sheet thickness was 3.7 mm at room temperature (23 °C ± 2 °C). The Shore A hardness was recorded after a measurement period of at least 20 seconds. The Shore A hardness was measured in accordance with ASTM D2240-15.

[0101] Maximum loss factor and maximum loss factor temperature: To determine the maximum loss factor and the temperature of the maximum loss factor, the compositions were tested using a Q800 DMA (Dynamic Mechanical Analyzer) device (manufactured by TA Instruments) operated with a Shear Sandwich clamp. Test pieces with dimensions of 10 mm × 10 mm × 3.7 mm were cut from the cured sheets of each composition and analyzed using the DMA device according to the following conditions: - Amplitude: 3 μm - Frequency: 50 Hz - Temperature range: -80 °C to +80 °C

[0102] The maximum loss factor at 50 Hz corresponds to the maximum tanδ value observed on the tanδ curve of the composition, recorded during the DMA analysis.

[0103] Sulfur-cured formulations: As described above, thermosetting liquid rubber composition formulations based on liquid polyenes are crosslinked in a system generally containing sulfur and accelerators and have pendant groups. Some compositions based on low vinyl polybutadiene (as the main liquid rubber resin) were prepared (see the compositions of Comparative Examples 1 and 2 in Table 2). Their damping performance is considered to be the "standard". Their maximum loss factor is at a temperature below -8°C. All amounts of the components are shown as percentages of liquid rubber (phr) in the following table.

[0104]

Table 2

[0105] By substituting polybutadiene with a low vinyl content with a butadiene-based homopolymer or farnesene homopolymer having a pendant group content of more than 45% and an Mw of 2000 g / mol or more, the maximum loss factor value of the composition increases by about 7.5% with a swelling ratio that is the same as or less than that of the "comparison" composition. Further, the three compositions having the criteria "Examples" in Table 2 above have a maximum loss factor in the temperature range of -10°C to +45°C.

[0106]

Table 3

[0107] In sulfur-cured formulations, instead of liquid polybutadiene that does not meet these criteria, incorporating a butadiene copolymer having a molecular weight of 2000 g / mol or more and a pendant group content exceeding 45% results in at least an 8% improvement in the damping performance of the liquid polyene composition in the temperature range of -10°C to +45°C. It is also clear that the viscosity of the liquid rubber-based composition decreases significantly due to the incorporation of the farnesene-based homopolymer and / or the butadiene-farnesene copolymer. (See Table 1 above.)

[0108] Formulations cured with organic peroxides To establish whether a liquid polyene component having a pendant group content exceeding 45% and an Mw exceeding 2000 g / mol can improve the damping performance of formulations containing liquid rubber, several peroxide-cured formulations were prepared. All amounts of the components are shown in the following table as percentages (phr) of the liquid polyene.

[0109]

Table 4

[0110] By incorporating a liquid polybutadiene having an Mw>2500 g / mol and a vinyl content higher than 45%, it is possible to increase the maximum loss factor value of the composition by about 10% at a temperature range of -10 °C to +40 °C with a lower or similar swelling ratio compared to the "comparison" composition.

[0111]

Table 5

[0112] By replacing a low Mw butadiene homopolymer having a pendant group content exceeding 45 mol% and an Mw exceeding 2000 g / mol with a butadiene-styrene or butadiene-farnesene copolymer, it is observed that the maximum loss factor (tanδ) value of the formulation increases by at least 20% over a wide temperature range with a similar crosslink density compared to the reference formulation.

[0113] Polyfarnesene diol can be crosslinked by an organic peroxide. The composition based on polyfarnesene diol is characterized by a higher maximum loss factor value (about 15% higher) than the comparison composition specified in Table 5 above. This disclosure further includes the following aspects: "Aspect 1" A thermosetting liquid rubber composition comprising: a. A liquid polyene containing a polyene main chain or a mixture of liquid polyenes each containing a polyene main chain, wherein, on a total molar basis as polymerized units: i. At least one monomer that provides at least 45 mol% of C2-13 pendant groups along the polyene main chain; ii. At least one monomer that provides at least 20 mol% of C2-5 pendant groups along the main chain of the polyene and at least one monomer that provides at least 7 mol% of C6-13 pendant groups along the main chain of the polyene, including a liquid polyene component, and b. At least one heat-activated crosslinking agent; and After curing, the thermosetting rubber composition has: (i) A loss factor (tanδ) greater than 0.51 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10°C to 45°C; (ii) A maximum loss factor temperature above -10°C; and (iii) A swelling ratio of 40 wt% to 170 wt%, measured by equilibrium weight gain in toluene at 25°C, producing a cured rubber composition, a thermosetting liquid rubber composition. "Aspect 2" The thermosetting liquid rubber composition according to Aspect 1, wherein the liquid polyene component has a weight average molecular weight exceeding 2000 g / mol and a Brookfield S spindle viscosity of 500 to 700,000 mPa·sec at 25°C. "Aspect 3" The thermosetting liquid rubber composition according to Aspect 1, wherein the thermosetting liquid rubber composition contains a total of 0 wt% to 1 wt% of solid rubber or solid thermoplastic plastic. "Aspect 4" The thermosetting liquid rubber polyene composition according to Aspect 1, wherein at least one liquid polyene in the liquid polyene or the mixture of liquid polyenes is terminated with a hydroxyl group or a functional derivative thereof. "Aspect 5" The thermosetting liquid rubber composition according to Aspect 1, wherein after curing, the cured rubber composition has a Shore A hardness greater than 55 when measured according to ASTM standard D2240-15. "Aspect 6" [[ ​ The thermosetting liquid rubber composition according to Embodiment 1, wherein at least one monomer that provides the C2-C13 pendant group is selected from the group consisting of C4-C15 dienes, C6-C15 trienes, C8-C15 tetraenes, vinyl aromatic compounds containing 15 or fewer carbon atoms, and mixtures thereof. 《Embodiment 7》 The thermosetting liquid rubber composition according to Embodiment 6, wherein at least one monomer that provides the C2-C13 pendant group contains at least one vinyl aromatic compound selected from the group consisting of styrene; alpha-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 4-propylstyrene; 4-t-butylstyrene; 4-cyclohexylstyrene; 2,4-dimethylstyrene; 2,4-diisopropylstyrene; 2,4,6-trimethylstyrene; 1-vinylnaphthalene; 2-vinylnaphthalene; N,N-diethyl-4-aminoethylstyrene; vinylpyridine; 4-methoxystyrene; monochlorostyrene; dichlorostyrene; divinylbenzene; and mixtures thereof. 《Embodiment 8》 The thermosetting liquid rubber composition according to Embodiment 6, wherein at least one monomer that provides the C2-C13 pendant group contains at least one of the following: a) C4-C14 dienes selected from the group consisting of butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, and mixtures thereof; b) C6-C15 trienes selected from the group consisting of 1,3,7-octatriene, myrcene, and mixtures thereof; or c) farnesene. 《Embodiment 9》 The thermosetting liquid rubber composition according to Embodiment 1, wherein at least one monomer that provides the C2-C13 pendant group is selected from the group consisting of butadiene, isoprene, alpha-methylstyrene, styrene, myrcene, farnesene, and mixtures thereof. 《Embodiment 10》 The thermosetting liquid rubber composition according to Embodiment 1, wherein at least one monomer that provides the C2-C5 pendant group is selected from the group consisting of C4-C7 dienes, C6-C7 trienes, and mixtures thereof. 《Embodiment 11》 The at least one monomer that provides the C6-C13 pendant group is selected from the group consisting of C8-C15 dienes, C8-C15 trienes, C8-C15 tetraenes, vinyl aromatic monomers containing 8-15 carbon atoms, and mixtures thereof, the thermosetting liquid rubber composition according to Embodiment 1. <<Embodiment 12>> The at least one monomer that provides the C2-C5 pendant group is selected from the group consisting of butadiene; isoprene; 2,3-dimethylbutadiene; 1,3-pentadiene; 2-methyl-1,3-pentadiene; 1,3-hexadiene; 1,3-cyclohexadiene; and mixtures thereof; and the at least one monomer that provides the C6-C13 pendant group is selected from the group consisting of 1,3-octadiene; 2-methyl-1,3-octadiene; 1,3,7-octatriene; myrcene; styrene; alpha-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 4-propylstyrene; 4-t-butylstyrene; 4-cyclohexylstyrene; 2,4-dimethylstyrene; 2,4-diisopropylstyrene; 2,4,6-trimethylstyrene; 1-vinylnaphthalene; 2-vinylnaphthalene; N,N-diethyl-4-aminoethylstyrene; vinylpyridine; 4-methoxystyrene; monochlorostyrene; dichlorostyrene; divinylbenzene; farnesene; and mixtures thereof, the thermosetting liquid rubber composition according to Embodiment 1. <<Embodiment 13>> The thermosetting liquid rubber composition according to Embodiment 1, wherein the thermally activated crosslinking agent contains sulfur, and the thermosetting liquid rubber composition further contains at least one accelerator and at least one activator. <<Embodiment 14>> The at least one accelerator is selected from the group consisting of sulfenamides, thiazoles, dithiocarbamates, thiuram compounds, and mixtures thereof; and the at least one activator is selected from the group consisting of metal oxides, metal fatty acid salts, fatty acids, and mixtures thereof, the thermosetting liquid rubber composition according to Embodiment 13. <<Embodiment 15>> The at least one accelerator is selected from the group consisting of N-cyclohexyl-2-benzothiazolesulfenamide (CBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and mixtures thereof, and the at least one activator is selected from the group consisting of zinc oxide, calcium oxide, magnesium oxide, zinc stearate, and mixtures thereof, the thermosetting composition according to embodiment 14. 《Embodiment 16》 The thermally activated crosslinking agent comprises an organic peroxide having a 10-hour half-life temperature of 47 °C to 127 °C, the thermosetting liquid rubber composition according to embodiment 1. 《Embodiment 17》 The thermosetting liquid rubber composition further comprises a metal oxide, a fatty acid, and at least one auxiliary agent, and the at least one auxiliary agent is selected from the group consisting of metal acrylates, metal methacrylates, and mixtures thereof, the thermosetting liquid rubber composition according to embodiment 16. 《Embodiment 18》 The liquid polyene component has a weight average molecular weight of more than 2500 g / mol, the thermosetting liquid rubber composition according to embodiment 1. 《Embodiment 19》 The thermosetting liquid rubber composition according to embodiment 1, comprising 10 to 80 weight percent of a liquid polyene component. 《Embodiment 20》 The thermosetting liquid rubber composition according to embodiment 1, comprising 15 to 55 weight percent of a liquid polyene component. 《Embodiment 21》 The thermosetting liquid rubber composition according to embodiment 1, further comprising at least one filler. 《Embodiment 22》 The at least one filler is selected from the group consisting of calcium carbonate, silica, carbon black, clay, talc, mica, calcium oxide, alumina, magnesium carbonate, and mixtures thereof, the thermosetting liquid rubber composition according to embodiment 21. 《Embodiment 23》 The thermosetting liquid rubber composition according to embodiment 21, comprising 15 to 70 weight percent of the at least one filler. 《Embodiment 24》 The thermosetting liquid rubber composition according to embodiment 21, comprising 25 to 60 weight percent of the at least one filler. 《Embodiment 25》 The composition is curable between 100 °C and 190 °C, the thermosetting liquid rubber composition according to embodiment 1. 《Embodiment 26》 An adhesive composition comprising the thermosetting liquid rubber composition according to embodiment 1, at least one filler, and at least one adhesion promoter. 《Embodiment 27》 A sealant composition comprising the thermosetting liquid rubber composition according to embodiment 1 and at least one filler. 《Embodiment 28》 A vibration damping composition comprising the thermosetting liquid rubber composition according to Embodiment 1, wherein the loss factor (tan δ) is greater than 0.53 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10°C to +35°C.

Claims

1. A thermosetting liquid rubber composition comprising: a. A liquid polyene containing a polyene main chain or a mixture of liquid polyenes each containing a polyene main chain, wherein, on a total molar basis as polymerized units, i. At least one monomer that provides at least 45 mol% of C2-13 pendant groups along the polyene main chain, or ii. At least one monomer that provides at least 20 mol% of C2-5 pendant groups along the main chain of the polyene and at least one monomer that provides at least 7 mol% of C6-13 pendant groups along the main chain of the polyene, comprising a liquid polyene component; b. At least one heat-activated crosslinking agent, and c. At least one filler and; after curing, the thermosetting liquid rubber composition (i) Has a loss factor (tan δ) greater than 0.51 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10°C to 45°C; (ii) A maximum loss factor temperature above -10°C; and (iii) A swelling ratio of 40 wt% to 170 wt%, measured by equilibrium weight gain in toluene at 25°C, to produce a cured rubber composition having, the liquid polyene component has a weight average molecular weight greater than 2000 g / mol and a Brookfield S spindle viscosity of 500 to 700,000 mPa·sec at 25°C, contains 15 to 70 weight percent of said at least one filler, said at least one heat-activated crosslinking agent is selected from sulfur and peroxides in an amount of 1 to 30 phr based on the liquid polyene component, a thermosetting liquid rubber composition.

2. The thermosetting liquid rubber composition according to claim 1, containing a total of 0 wt% to 1 wt% of solid rubber or solid thermoplastic.

3. At least one liquid polyene in said liquid polyene or said mixture of liquid polyenes is end-capped with a hydroxyl group, ester, carboxylic acid, epoxide, amide, amine, anhydride, acrylate, methacrylate, or silane, the thermosetting liquid rubber polyene composition according to claim 1.

4. After curing, the cured rubber composition has a Shore A hardness greater than 55 when measured according to ASTM standard D2240-15, the thermosetting liquid rubber composition according to claim 1.

5. ​ ​ The thermosetting liquid rubber composition according to claim 1, wherein at least one monomer that provides the C2-C13 pendant group is selected from the group consisting of C4-C15 dienes, C6-C15 trienes, C8-C15 tetraenes, vinyl aromatic compounds containing 15 or fewer carbon atoms, and mixtures thereof.

6. The thermosetting liquid rubber composition according to claim 5, wherein at least one monomer that provides the C2-C13 pendant group contains at least one vinyl aromatic compound selected from the group consisting of styrene; alpha-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 4-propylstyrene; 4-t-butylstyrene; 4-cyclohexylstyrene; 2,4-dimethylstyrene; 2,4-diisopropylstyrene; 2,4,6-trimethylstyrene; 1-vinylnaphthalene; 2-vinylnaphthalene; N,N-diethyl-4-aminoethylstyrene; vinylpyridine; 4-methoxystyrene; monochlorostyrene; dichlorostyrene; divinylbenzene; and mixtures thereof.

7. The thermosetting liquid rubber composition according to claim 5, wherein at least one monomer that provides the C2-C13 pendant group is: a) a C4-C14 diene selected from the group consisting of butadiene, isoprene, 2,3-dimethylbutadiene, 2-phenylbutadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 1,3-octadiene, 1,3-cyclohexadiene, 2-methyl-1,3-octadiene, and mixtures thereof; b) a C6-C15 triene selected from the group consisting of 1,3,7-octatriene, myrcene, and mixtures thereof; or c) at least one of farnesene.

8. The thermosetting liquid rubber composition according to claim 1, wherein at least one monomer that provides the C2-C13 pendant group is selected from the group consisting of butadiene, isoprene, alpha-methylstyrene, styrene, myrcene, farnesene, and mixtures thereof.

9. The thermosetting liquid rubber composition according to claim 1, wherein at least one monomer that provides the C2-C5 pendant group is selected from the group consisting of C4-C7 dienes, C6-C7 trienes, and mixtures thereof.

10. The at least one monomer that provides the C6-C13 pendant group is selected from the group consisting of C8-C15 dienes, C8-C15 trienes, C8-C15 tetraenes, vinyl aromatic monomers containing 8 to 15 carbon atoms, and mixtures thereof, the thermosetting liquid rubber composition according to claim 1.

11. The at least one monomer that provides the C2-C5 pendant group is selected from the group consisting of butadiene; isoprene; 2,3-dimethylbutadiene; 1,3-pentadiene; 2-methyl-1,3-pentadiene; 1,3-hexadiene; 1,3-cyclohexadiene; and mixtures thereof; and the at least one monomer that provides the C6-C13 pendant group is 1,3-octadiene; 2-methyl-1,3-octadiene; 1,3,7-octatriene; myrcene ； styrene; alpha-methylstyrene; 2-methylstyrene; 3-methylstyrene; 4-methylstyrene; 4-propylstyrene; 4-t-butylstyrene; 4-cyclohexylstyrene; 2,4-dimethylstyrene; 2,4-diisopropylstyrene; 2,4,6-trimethylstyrene; 1-vinylnaphthalene; 2-vinylnaphthalene; N,N-diethyl-4-aminoethylstyrene; vinylpyridine; 4-methoxystyrene; monochlorostyrene; dichlorostyrene; divinylbenzene; farnesene; and mixtures thereof, the thermosetting liquid rubber composition according to claim 1.

12. The thermally activated crosslinking agent contains sulfur, and the thermosetting liquid rubber composition further contains at least one accelerator and at least one activator, The at least one accelerator and the at least one activator are used to increase the rate and completeness of crosslinking by the thermally activated crosslinking agent, the thermosetting liquid rubber composition according to claim 1.

13. The at least one accelerator is selected from the group consisting of sulfenamides, thiazoles, dithiocarbamates, thiuram compounds, and mixtures thereof; and the at least one activator is selected from the group consisting of metal oxides, fatty acid metal salts, fatty acids, and mixtures thereof, the thermosetting liquid rubber composition according to claim 12.

14. The at least one accelerator is selected from the group consisting of N-cyclohexyl-2-benzothiazolesulfenamide (CBS), N-tert-butyl-2-benzothiazylsulfenamide (TBBS), and mixtures thereof, and the at least one activator is selected from the group consisting of zinc oxide, calcium oxide, magnesium oxide, zinc stearate, and mixtures thereof. The thermosetting composition according to claim 13.

15. The thermally activatable crosslinking agent contains an organic peroxide having a 10-hour half-life temperature of 47°C to 127°C. The thermosetting liquid rubber composition according to claim 1.

16. The thermosetting liquid rubber composition further contains a metal oxide, a fatty acid, and at least one auxiliary agent. The at least one auxiliary agent is selected from the group consisting of metal acrylates, metal methacrylates, and mixtures thereof. The thermosetting liquid rubber composition according to claim 15.

17. The liquid polyene component has a weight average molecular weight exceeding 2500 g / mol. The thermosetting liquid rubber composition according to claim 1.

18. The thermosetting liquid rubber composition according to claim 1, containing 10 to 80 weight percent of a liquid polyene component based on the total weight of the thermosetting liquid rubber composition.

19. The thermosetting liquid rubber composition according to claim 1, containing 15 to 55 weight percent of a liquid polyene component based on the total weight of the thermosetting liquid rubber composition.

20. The at least one filler is selected from the group consisting of calcium carbonate, silica, carbon black, clay, talc, mica, calcium oxide, alumina, magnesium carbonate, and mixtures thereof. The thermosetting liquid rubber composition according to claim 19.

21. The thermosetting liquid rubber composition according to claim 1, containing 25 to 60 weight percent of the at least one filler based on the total weight of the thermosetting liquid rubber composition.

22. The composition is curable between 100°C and 190°C. The thermosetting liquid rubber composition according to claim 1.

23. An adhesive composition comprising the thermosetting liquid rubber composition according to claim 1 and at least one adhesion promoter.

24. A sealant composition comprising the thermosetting liquid rubber composition according to claim 1.

25. A vibration damping composition comprising the thermosetting liquid rubber composition according to claim 1, wherein the loss factor (tan δ) is greater than 0.53 when measured at a frequency of 50 Hz, an amplitude of 3 μm, and a temperature of -10°C to +35°C.

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