Polysiloxanes and formulations incorporating polysiloxanes

Abstract

A polysiloxane comprising an alkyl group having 5 or 6 carbon atoms, an alkyl group having at least 8 carbon atoms, and / or an arylalkyl group having at least 8 carbon atoms. A method for reacting a polymethylhydrosiloxane with a C5 olefin or a C6 olefin, and C... 8‑18 Alkenes or C 8‑20 A method for preparing the polysiloxane by reacting at least one of an aryl olefin in the presence of a catalyst and a solvent. The polysiloxane can be formulated into a grease comprising 50% to 95% of the polysiloxane by weight and 5% to 50% of a filler by weight. This grease composition is suitable for use in dielectric applications, particularly in dielectric applications using silicone-based components under strain or elongation.

Description

Technical Field

[0001] Polysiloxanes, particularly polysiloxanes having alkyl and / or arylalkyl dangling groups, their preparation methods, and their use in the formulation of dielectric greases compatible with silicone elastomers. Background Technology

[0002] Silicone elastomers are used in a wide range of industries, including energy, electronics, automotive and aerospace, medical, apparel, food and beverage, and construction. Silicone elastomers typically exhibit low dielectric constants, stability over a wide temperature range, water resistance, and chemical inertness, making them ideal for a variety of applications. In many of these applications, lubrication and / or sealing of the interface between the silicone elastomer and other surfaces is required. In such cases, it is often desirable to apply a grease exhibiting similar low dielectric properties, temperature resistance, water resistance, and inertness at the interface.

[0003] One of the challenges in formulating greases for use with silicone elastomers is minimizing the diffusion of the grease into the silicone elastomer. This diffusion reduces the grease's usability as a lubricant and / or sealant, and in some cases, may degrade the elastomer's mechanical properties. Silicones possess some of the largest free volumes among polymers. Under strain or elongation, this free volume is even larger, which can occur during the use of silicone elastomers in certain applications. Furthermore, silicone elastomers typically contain fillers (e.g., silica, alumina, carbon black) to enhance mechanical properties and / or impart electrical conductivity. The interaction between the filler and the grease can pose another challenge to suppressing grease diffusion into the silicone elastomer.

[0004] Currently, a wide range of greases with diverse chemical compositions are available on the market. Grease compatibility charts are commonly used to match the composition of a grease with the composition of the surface it is applied to. In the case of silicone elastomers, polyglycol-based greases and perfluoropolyether (PFPE)-based greases are suitable matches for use with silicone elastomers. However, polyglycol-based greases tend to be hydrophilic and may be a less favorable choice in applications where water and / or moisture are harmful. Furthermore, the current regulatory environment is driving the industry to phase out the use of fluorinated organic compounds.

[0005] Polysiloxanes exhibit some of the same physical properties as silicone elastomers (e.g., high thermal stability, low chemical reactivity, and low dielectric constant), suggesting their suitability for applications involving silicone elastomers. However, silicone-based greases, particularly those with viscosity indices of 200-650 based on dimethyl, phenyl, and halogenated greases, are identified as good compatibility matches for many types of polymer substrates, but are less suitable for substrates made from silicone elastomers.

[0006] Therefore, despite the versatility and wide range of applications of polysiloxanes, there is still a need for polysiloxanes with improved properties and performance, especially those used as greases and sealants. Summary of the Invention

[0007] Polysiloxanes can be modified by attaching different dangling groups to silicon atoms in the polymer chain. These dangling groups can affect the properties of polysiloxanes, such as their solubility, flexibility, and compatibility with other materials. For example, alkyl dangling groups, which are carbon atom chains, can make polysiloxanes less likely to diffuse into silicone elastomers by creating steric hindrance and increasing the kinetic and thermodynamic energy barriers to diffusion. On the other hand, if the alkyl substituents become too large, the silicone will no longer be a liquid at the desired operating temperature. Many alkyl-substituted silicone greases marketed for compatibility with silicone elastomers work at zero elastomer elongation but fail at non-zero elongation due to increased diffusion into the elastomer under increased elongation.

[0008] This disclosure relates to polysiloxanes and compositions containing such polysiloxanes, which can be used as lubricants and / or sealants in conjunction with silicone elastomers, particularly in applications where the silicone elastomers are subjected to elongation.

[0009] Therefore, in one aspect, this disclosure provides a polysiloxane comprising a polymer of formula I:

[0010]

[0011] Formula I

[0012] in

[0013] R1 is an alkyl group having 1 to 6 carbon atoms;

[0014] R2 is an alkyl group having 5 or 6 carbon atoms;

[0015] R3 is an alkyl group having at least 8 carbon atoms;

[0016] R4 is an arylalkyl group having at least 8 carbon atoms.

[0017] R5 is selected from hydrogen or hydroxyl.

[0018] w, x, y, and z are integers, and

[0019] x and / or y > 0; and

[0020] in

[0021] The ratio of w / (w+x+y+z) is in the range of 0.01 to 0.30.

[0022] The ratio of x / (w+x+y+z) is in the range of 0 to 0.80.

[0023] The ratio of y / (w+x+y+z) is in the range of 0 to 0.65, and

[0024] The ratio of z / (w+x+y+z) is in the range of 0.1 to 0.25.

[0025] On the other hand, this disclosure provides a method for preparing polysiloxanes, the method comprising reacting at least one of an olefin having at least 8 carbon atoms or an aryl olefin having at least 8 carbon atoms, a polymethylhydrosiloxane, and a C5 olefin or a C6 olefin in the presence of a catalyst and a solvent. In some embodiments, the olefin having at least 8 carbon atoms is C8-C6. 18 An olefin, wherein the aryl olefin having at least 8 carbon atoms is C8-C. 20 Arylolefins.

[0026] In another aspect, this disclosure provides a composition comprising a) 50% to 95% by weight of a polysiloxane and b) 5% to 50% by weight of a filler.

[0027] In another aspect, this disclosure provides an article comprising the composition in contact with a silicone elastomer.

[0028] The above-described invention is not intended to describe every disclosed embodiment or every specific implementation of the invention. The following description illustrates exemplary embodiments in more detail. Detailed Implementation

[0029] Those skilled in the art will understand that variations and modifications may exist in this disclosure in addition to those specifically described. It should be understood that this disclosure includes all such variations and modifications. This disclosure also includes all such steps, features, compositions, and compounds individually or collectively mentioned or indicated in this specification, as well as any and all combinations of any or more of such steps or features.

[0030] As used herein, the term "at least one" is used to mean one or more, and therefore includes both single components and mixtures / combinations.

[0031] As used herein, the term "alkyl" broadly refers to monovalent straight-chain and branched alkyl groups as well as cycloalkyl groups.

[0032] As used herein, the term "olefin" broadly refers to a straight-chain or branched hydrocarbon containing at least one carbon-carbon double bond.

[0033] As used herein, the term "aryl" broadly refers to an aromatic and carbon-cyclic monovalent group. An aryl group has at least one aromatic ring but may contain additional rings (saturated and / or unsaturated).

[0034] As used herein, the term "arylalkyl" broadly refers to a monovalent group in which an aryl group is attached to an alkyl group. For example, an arylalkyl group can be a phenylalkyl group, such as phenylmethyl, phenylethyl, phenylpropyl, etc.

[0035] As used herein, the term "aryl olefin" broadly refers to a straight-chain or branched hydrocarbon containing at least one carbon-carbon double bond and at least one aromatic ring.

[0036] As used herein, terms such as “a,” “an,” and “the (described)” are not intended to refer to a single entity, but rather to include general categories whose specific examples can be used for illustration. The terms “a,” “an,” and “the” are used interchangeably with the term “at least one (kind).”

[0037] As used herein, the term “or” is generally used in its usual sense, including “and / or”, unless the context clearly indicates otherwise.

[0038] As used herein, the term “and / or” means one or all of the listed elements, or any combination of two or more of the listed elements.

[0039] As used herein, the term "comprising" and its variations are not intended to be limiting when they appear in the Detailed Description and the claims. Such terms are to be understood as implying the inclusion of the stated steps or elements or groups of steps or elements, but not excluding any other steps or elements or groups of steps or elements. The phrase "consisting of" means including and limited to what follows the phrase "consisting of". Thus, the phrase "consisting of" indicates that the listed elements are required or mandatory, and that no other elements may be present. The phrase "substantially consisting of" means including any elements listed after this phrase, and is limited to other elements that do not impede or contribute to the activity or function of the listed elements as defined in this disclosure. Thus, the phrase "substantially consisting of" indicates that the listed elements are required or mandatory, but other elements are optional and may or may not be present depending on whether they substantially affect the activity or function of the listed elements.

[0040] As used herein, the term “including (contains)” is used to mean “including (contains) but not limited to”; “including (contains)” and “including (contains) but not limited to” are used interchangeably.

[0041] Furthermore, all figures in this document are assumed to be modified by the term "approximately". As used herein, with respect to the measured quantity, the term "approximately" refers to a deviation in the measured quantity that is commensurate with the target of the measurement and the accuracy of the measuring equipment used, as a technician who would have expected to perform the measurement with a certain degree of care. Additionally, in this document, numerical ranges expressed by endpoints include all numbers contained within that range as well as the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0042] This disclosure provides polysiloxanes of formula I.

[0043]

[0044] Formula I

[0045] In Formula I, R1 is an alkyl group having 1 to 6 carbon atoms. In some embodiments, R1 may be a methyl group or an ethyl group, more particularly a methyl group. R2 is an alkyl group having 5 or 6 carbon atoms; in some embodiments, R2 is a hexyl group, more particularly a 1-hexyl group. R3 is an alkyl group having at least 8 carbon atoms. In some embodiments, R3 is an alkyl group having 8 to 18 carbon atoms, more particularly 9 to 13 carbon atoms. In some embodiments, R3 may be an octyl, decyl, and / or dodecyl group, more particularly a 1-octyl, 1-decyl, or 1-dodecyl group. In some embodiments, R3 is a 1-dodecyl group. R4 is an arylalkyl group having at least 8 carbon atoms, more particularly at least 9 carbon atoms. In some embodiments, R4 is an arylalkyl group having 8 to 20 carbon atoms, more particularly 9 to 20 atoms. In some embodiments, R4 is a 2-phenylpropyl group or a 3-phenylpropyl group. R5 is hydrogen and / or a hydroxyl group. In some embodiments, R5 is hydrogen. In other embodiments, for example, at least some of the hydrogen in R5 has been hydrolyzed into hydroxyl groups.

[0046] In some embodiments, R1, R2, R3, R4, and R5 are each a single group (e.g., all R1s in the polysiloxane are methyl groups, all R2s are 1-hexyl groups, all R3s are 1-octyl groups, all R4s are 2-phenylpropyl groups, and all R5s are hydrogen). In other embodiments, one or more of R1, R2, R3, R4, and R5 contain two or more different groups (e.g., some R2s in the polysiloxane are 1-pentyl groups, and some R2s are 1-hexyl groups).

[0047] In some embodiments, R1 is a methyl group and R2 is a 1-hexyl group. In the same or different embodiments, R3 is a 1-dodecyl group. In the same and / or different embodiments, R4 is a 2-phenylpropyl group or a 3-phenylpropyl group. In some embodiments, R2, R3, R4 and R5 are not phenyl groups or methyl groups.

[0048] The selection of R1, R2, R3, R4, and R5 can be tailored to the desired application of the polysiloxane. For example, alkyl groups R2 and R3, having 5 or 6 carbon atoms and at least 8 carbon atoms respectively, contribute to the hydrophobic properties of the polysiloxane. This hydrophobicity is beneficial in electrical and electronic grease applications because it helps repel water, prevents moisture from affecting electrical properties, and maintains the required low dielectric constant. The arylalkyl group R4, having at least 8 carbon atoms, can also contribute to the hydrophobicity of the polysiloxane.

[0049] In Formula I, the integers w, x, y, and z represent the number of repeating units having R2, R3, R4, and R5 groups, respectively. The ratio of w / (w+x+y+z) is in the range of 0.01 to 0.30; the ratio of x / (w+x+y+z) is in the range of 0 to 0.80; the ratio of y / (w+x+y+z) is in the range of 0 to 0.65; the ratio of z / (w+x+y+z) is in the range of 0.1 to 0.25; and x and / or y > 0. In some embodiments, the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is at least 0.46. In some embodiments, the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is in the range of 0.46 to 0.80.

[0050] The ratios of w, x, y, and z can also be customized for the desired application of the polysiloxane. For example, in some embodiments, the w / (w+x+y+z) ratio can be 0.01. This means that 1% of the total number of units in the polysiloxane has R2 groups, which are alkyl groups having 5 or 6 carbon atoms. This contributes to the overall hydrophobicity and flexibility of the polysiloxane. In some embodiments, the w / (w+x+y+z) ratio is at least 0.01, at least 0.06, at least 0.08, at least 0.09, at least 0.12, or at least 0.19. In some embodiments, the w / (w+x+y+z) ratio is not greater than 0.29, not greater than 0.19, not greater than 0.12, not greater than 0.09, not greater than 0.08, or not greater than 0.06. In some implementations, the ratio of w / (w+x+y+z) is 0.01 to 0.29, and more particularly 0.08 to 0.29.

[0051] In some embodiments, the x / (w+x+y+z) ratio can be 0.80. This means that 80% of the total number of units in the polysiloxane has R3 groups, which are alkyl groups having at least 8 carbon atoms, more particularly 8 to 18 carbon atoms, and even more particularly 9 to 13 carbon atoms. The presence of these larger alkyl groups can enhance the hydrophobicity of the polysiloxane and reduce its dielectric constant, making the polysiloxane more suitable for use in greases for electrical and electronic applications. In some embodiments, the x / (w+x+y+z) ratio is 0, at least 0.08, at least 0.36, at least 0.42, at least 0.46, at least 0.51, at least 0.74, or at least 0.76. In some implementations, the ratio of x / (w+x+y+z) is not greater than 0.80, 0.79, 0.76, 0.74, 0.51, 0.46, 0.42, 0.36, or 0.08. In some implementations, the ratio of x / (w+x+y+z) is between 0 and 0.80, more particularly between 0 and 0.79, or even more particularly between 0 and 0.74.

[0052] In other cases, the y / (w+x+y+z) ratio can be 0.65. This means that 65% of the total number of units in the polysiloxane has an R4 group, which is an arylalkyl group having at least 8 carbon atoms, more particularly having 8 to 20 carbon atoms. The inclusion of these larger arylalkyl groups can further increase the hydrophobicity of the polysiloxane and minimize the diffusion of the polysiloxane into the silicone elastomer (especially the silicone elastomer under stretching). In some embodiments, the y / (w+x+y+z) ratio is 0, at least 0.25, at least 0.28, at least 0.39, at least 0.61, or at least 0.63. In some embodiments, the y / (w+x+y+z) ratio is not greater than 0.65, not greater than 0.63, not greater than 0.61, not greater than 0.39, not greater than 0.28, or not greater than 0.25. In some implementations, the ratio y / (w+x+y+z) is 0 to 0.65, and more particularly 0 to 0.63.

[0053] In other cases, the z / (w+x+y+z) ratio can be 0.10. This means that 10% of the total number of units in the polysiloxane has an R5 group, which is either hydrogen or hydroxyl. In some embodiments, the z / (w+x+y+z) ratio is at least 0.10, at least 0.16, at least 0.17, at least 0.18, or at least 0.24. In some embodiments, the ratio z / (w+x+y+z) is not greater than 0.25, not greater than 0.24, not greater than 0.18, not greater than 0.17, or not greater than 0.16. In some embodiments, the ratio z / (w+x+y+z) is from 0.10 to 0.25, more particularly from 0.16 to 0.25.

[0054] In some embodiments, the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is 0.46. This indicates that 46% of the total number of units in the polysiloxane has R2 and / or R3 groups. In some embodiments, the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is at least 0.46, at least 0.63, at least 0.65, at least 0.69, at least 0.70, at least 0.74, at least 0.75, at least 0.76, at least 0.79, or at least 0.80. In some embodiments, the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is not greater than 0.80, not greater than 0.79, not greater than 0.76, not greater than 0.75, not greater than 0.74, not greater than 0.70, not greater than 0.69, not greater than 0.65, or not greater than 0.63. In some embodiments, the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is 0.46 to 0.80, more particularly 0.46 to 0.79, or even more particularly 0.46 to 0.79. This high proportion of larger alkyl and / or arylalkyl groups contributes to the overall hydrophobicity and low diffusion of the polysiloxane, making it particularly suitable for use in dielectric greases in contact with silicone elastomers under strain or elongation.

[0055] The repeating units (i.e., w, x, y, and z) of the polysiloxane of Formula 1 are usually arranged randomly. However, in some cases, these units may be arranged in a block arrangement.

[0056] A method for preparing the polysiloxanes disclosed herein includes reacting at least one of an olefin having at least eight carbon atoms or an aryl olefin having at least eight carbon atoms, a polymethylhydrosiloxane, and a C5 or C6 olefin (i.e., an olefin having five or six carbon atoms) in the presence of a catalyst and a solvent. In some embodiments, the olefin having at least eight carbon atoms is C8-C6. 18 An olefin, wherein the aryl olefin having at least 8 carbon atoms is C8-C. 20Aryl olefins. In some embodiments, the olefin having at least 8 carbon atoms is 1-decene or 1-dodecene. In the same or other embodiments, the aryl olefin having at least 8 carbon atoms is α-methylstyrene (2-phenylpropene) or allylbenzene. In some embodiments, the C5 or C6 olefin is 1-hexene, and at least one of the olefin having at least 8 carbon atoms or the aryl olefin having at least 8 carbon atoms is 1-dodecene. In some further embodiments, the C5 or C6 olefin is 1-hexene, and at least one of the olefin having at least 8 carbon atoms or the aryl olefin having at least 8 carbon atoms is 1-dodecene and α-methylstyrene.

[0057] The method for preparing this polysiloxane can be carried out at a temperature ranging from 30°C to 200°C. The reaction temperature can be at least 30°C, at least 35°C, at least 40°C, at least 45°C, at least 50°C, at least 55°C, at least 60°C, at least 65°C, at least 70°C, at least 75°C, at least 80°C, at least 85°C, at least 90°C, at least 95°C, at least 100°C, at least 105°C, at least 110°C, at least 115°C, at least 120°C, at least 125°C, at least 130°C, at least 135°C, at least 140°C, at least 145°C, at least 150°C, at least 155°C, at least 160°C, at least 165°C, at least 170°C, at least 175°C, at least 180°C, at least 185°C, at least 190°C, or at least 195°C. In some implementations, the reaction temperature may be no greater than 200°C, no greater than 195°C, no greater than 190°C, no greater than 185°C, no greater than 180°C, no greater than 175°C, no greater than 170°C, no greater than 165°C, no greater than 160°C, no greater than 155°C, no greater than 150°C, no greater than 145°C, no greater than 140°C, no greater than 135°C, no greater than 130°C, no greater than 125°C, no greater than 120°C, no greater than 115°C, no greater than 110°C, no greater than 105°C, no greater than 100°C, no greater than 95°C, no greater than 90°C, no greater than 85°C, no greater than 80°C, no greater than 75°C, no greater than 70°C, no greater than 65°C, no greater than 60°C, no greater than 55°C, no greater than 50°C, no greater than 45°C, no greater than 40°C, or no greater than 35°C. In some cases, the reaction is carried out at 60°C and / or 40°C. The choice of reaction temperature can affect the reaction rate and the properties of the resulting polysiloxane. For example, a higher reaction temperature can increase the reaction rate and produce polysiloxanes with different properties compared to those prepared at lower reaction temperatures. In some cases, the reaction temperature can be specifically selected based on the reactants and catalysts used and the desired properties of the resulting polysiloxane.

[0058] In some embodiments, the polymethylhydrosiloxane has a weight-average molecular weight in the range of 1000 g / mol to 5000 g / mol, more particularly in the range of 1300 g / mol to 2500 g / mol, and even more particularly in the range of 1400 g / mol to 2400 g / mol. In some embodiments, the polymethylhydrosiloxane has a weight-average molecular weight in the range of 1400 g / mol to 1800 g / mol. In other embodiments, the polymethylhydrosiloxane has a weight-average molecular weight in the range of 2100 g / mol to 2400 g / mol. In some embodiments, the polymethylhydrosiloxane is trialkylsilyl-terminated, more particularly trimethylsilyl-terminated.

[0059] Exemplary catalysts include platinum-divinyltetramethyldisiloxane complexes, platinum-cyclovinylmethylsiloxane complexes, platinum-carbonyl-cyclovinylmethylsiloxane complexes, platinum-octaldehyde complexes, tris(dibutyl sulfide)rhodium trichloride, or combinations thereof. In some embodiments, the catalyst is a platinum-divinyltetramethyldisiloxane complex. The choice of catalyst can affect the structure and properties of the resulting polysiloxane. For example, a platinum-divinyltetramethyldisiloxane complex can promote the reaction between a hydrogenated silane-functionalized polysiloxane and an olefin, resulting in the formation of the desired polysiloxane.

[0060] Suitable solvents may include xylene, toluene, benzene, chloroform, dichloromethane, tetrahydrofuran, or combinations thereof. The choice of solvent can affect the reaction conditions and the solubility of reactants and products. For example, xylene, toluene, benzene, chloroform, dichloromethane, and tetrahydrofuran are all suitable solvents that can dissolve reactants and promote the reaction.

[0061] Following the reaction, the solvent can be removed under vacuum to produce a viscous liquid polysiloxane. This step helps purify the polysiloxane and remove any unreacted material or byproducts. The resulting polysiloxane can then be used in the formulation of oils and fats, as further described below.

[0062] The grease composition may comprise 50% to 95% by weight of the polysiloxane disclosed herein and 5% to 50% by weight of filler. In some embodiments, the polysiloxane comprises at least 50%, at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, or at least 90% by weight relative to the total weight of the grease composition. In some embodiments, the polysiloxane comprises no more than 95%, no more than 90%, no more than 85%, no more than 80%, no more than 75%, no more than 70%, no more than 65%, no more than 60%, or no more than 55% by weight relative to the total weight of the grease composition. The polysiloxane in the grease composition can provide the desired hydrophobic properties and low dielectric properties, and this weight percentage can be adjusted to meet the specific application and performance requirements of the grease.

[0063] In some embodiments, the filler may constitute 5% to 50% by weight of the oil composition. In some embodiments, the filler by weight is at least 5%, at least 10%, at least 15%, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, or at least 45% relative to the total weight of the oil composition. In some embodiments, the filler by weight is no more than 50%, no more than 45%, no more than 40%, no more than 35%, no more than 30%, no more than 25%, no more than 20%, no more than 15%, or no more than 10% relative to the total weight of the oil composition. The filler can contribute to the overall consistency and stability of the oil, and the weight percentage of the filler can be adjusted to meet the specific application and performance requirements of the oil.

[0064] The fillers in the grease composition can be selected from a variety of materials, depending on the desired properties of the grease. Exemplary fillers include silica, aluminosilicate clay, alumina, mica, lithium stearate, calcium stearate, carbon black, fluoropolymers, polyurea, or combinations thereof.

[0065] In some embodiments, the filler is silica, more particularly hydrophobic pyrolytic silica. Silica is a commonly used filler in grease compositions due to its excellent thermal stability and ability to increase viscosity. In other embodiments, the filler is aluminosilicate clay. Aluminosilicate clay provides good thermal stability and also enhances the thixotropic properties of the grease, making it more resistant to flow under low shear stress.

[0066] In other embodiments, the filler is alumina. Alumina is a high-temperature resistant material that enhances the thermal stability of greases. In some embodiments, the filler is mica. Mica is a naturally occurring mineral that enhances the lubricity and thermal stability of greases. In other embodiments, the filler is lithium stearate or calcium stearate. These materials are commonly used as thickeners in grease compositions and can enhance the consistency and stability of greases.

[0067] In other embodiments, the filler is carbon black. Carbon black enhances the electrical conductivity of the grease, making it suitable for use in electrical applications. In some embodiments, the filler may be a fluoropolymer. Fluoropolymers are materials with excellent chemical resistance and low abrasion properties, making them suitable for use in harsh environments. In other embodiments, the filler is polyurea. Polyurea is a material that enhances the water resistance and mechanical stability of the grease.

[0068] It should be understood that the specific type of filler used in an oil composition can be selected based on the application and performance requirements of the oil. By changing the type of filler, the properties of the oil can be customized to suit a specific application.

[0069] In some embodiments, the grease composition is formulated from a polysiloxane and hydrophobic pyrolytic silica. The formulation method involves combining the polysiloxane and hydrophobic pyrolytic silica in a high-speed mixer. In some embodiments, the grease composition is formulated from 14 parts by weight of the polysiloxane and 1.5 parts by weight of the hydrophobic pyrolytic silica. The polysiloxane and hydrophobic pyrolytic silica are combined in a high-speed mixer running at 3500 rpm for 1 minute. This formulation method ensures a homogeneous mixture of the polysiloxane and hydrophobic pyrolytic silica, thereby producing a grease composition with the desired properties for use in dielectric applications.

[0070] The hydrophobic pyrolytic silica in this grease composition serves as a filler, contributing to the overall consistency and stability of the grease. The hydrophobic properties of the pyrolytic silica enhance the grease's water-repellent properties, making it suitable for high-voltage applications where moisture resistance is critical. Furthermore, the pyrolytic silica can enhance the thixotropic properties of the grease, making it more resistant to flow under low shear stress, which is beneficial in applications where the grease is subjected to mechanical stress or vibration.

[0071] This disclosure also provides articles comprising the compositions described herein in contact with an elastomer. In some embodiments, the elastomer is silicone rubber or carbon black-filled silicone rubber. The elastomer can be formed into components (e.g., O-rings, gaskets, valves, pipes, membranes, etc.) in, for example, medical devices, safety and respiratory equipment, cooling and cryogenic systems, automotive and aerospace technology, cables and accessories, electronic devices and electronic packaging, food production and processing equipment, pharmaceutical production equipment, industrial and manufacturing equipment, and oil, gas, and mining equipment. In some embodiments, the article may be part of an electrical or electronic construction.

[0072] The compatibility of grease compositions with elastomers can be assessed by measuring the percentage of grease mass absorbed by the elastomer under strain or elongation. The percentage of mass absorption is calculated based on the initial (dry) mass of the elastomer and the mass of the elastomer after immersion in the grease composition for a specified duration and at a specified temperature. A lower percentage of mass absorption indicates lower diffusivity of the grease composition into the elastomer, which is a desirable characteristic for greases used with silicone-based components under strain or elongation.

[0073] The elastomer in the article disclosed herein can exhibit less than 3.0% by weight mass absorption when contacted with a grease composition for a period of more than 14 days at a temperature greater than or equal to 80°C and with an elongation in the range of 50% to about 150% of its original length. In one embodiment, the article comprises a grease composition in contact with a silicone elastomer, which may or may not contain carbon black. In some embodiments, the silicone elastomer exhibits less than 3.0% by weight mass absorption when contacted with a grease composition for 10 days at a temperature of 80°C and with an elongation in the range of about 100% of its original length. In some embodiments, the silicone elastomer exhibits less than 0.5% by weight mass absorption when contacted with a grease composition for 10 days at a temperature of 80°C and with an elongation in the range of about 100% of its original length.

[0074] While specific embodiments have been illustrated, those skilled in the art will understand that various alternatives and / or equivalent embodiments can be used to replace the illustrated and described embodiments without departing from the scope of the invention. This application is intended to cover any modifications or variations of the illustrative embodiments discussed herein.

[0075] Example

[0076] While the purposes and advantages of this disclosure are further illustrated by the following embodiments, the specific materials and quantities listed in these embodiments, as well as other conditions and details, should not be construed as undue limitations on this disclosure.

[0077] Unless otherwise stated, all parts, percentages, ratios, etc., in the embodiments and the remainder of this specification are expressed by weight. Table 1 provides abbreviations and descriptions of the materials used in this section.

[0078] Table 1. Materials used in the examples

[0079]

[0080] Preparation Examples

[0081] Typically, polysiloxanes (P1-P11) are prepared by reacting polymethylhydrosiloxanes with olefins and / or aryl olefins in the presence of a catalyst and a solvent. The catalyst is platinum-divinyltetramethyldisiloxane supplied as a xylene solution. The solvent is toluene.

[0082] Polysiloxane P1

[0083] PMHS 1 (12.83 g, 0.214 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-decene (22.51 g, 0.160 mol), Pt catalyst (1 drop), and toluene (100 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 40 °C, and 1-hexene (4.50 g, 0.053 mol) was added. The mixture was stirred at 40 °C for another 3 days, and the toluene was removed under vacuum to give a viscous liquid product.

[0084] Polysiloxane P2

[0085] PMHS 1 (9.80 g, 0.163 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-dodecene (27.43 g, 0.163 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 40 °C, and 1-hexene (3.45 g, 0.041 mol) was added. The mixture was stirred at 40 °C for another 3 days, and toluene was removed under vacuum to give a viscous liquid product.

[0086] Polysiloxane P3

[0087] PMHS 1 (9.80 g, 0.163 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-dodecene (16.50 g, 0.065 mol), α-methylstyrene (7.68 g, 0.098 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 40 °C, and 1-hexene (3.45 g, 0.041 mol) was added. The mixture was stirred again at 40 °C for 3 days, and toluene was removed under vacuum to obtain a viscous liquid product.

[0088] Polysiloxane P4

[0089] PMHS 2 (15.0 g, 0.25 mol SiH, Mw 2100 g / mol - 2400 g / mol) was added to a solution of 1-dodecene (19.36 g, 0.115 mol), α-methylstyrene (8.86 g, 0.075 mol), Pt catalyst (1 drop), and toluene (150 mL). Toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 40 °C, and 1-hexene (5.05 g, 0.06 mol) was added. The mixture was stirred again at 40 °C for 3 days, and toluene was removed under vacuum to obtain a viscous liquid product.

[0090] Polysiloxane P5

[0091] PMHS 1 (15.0 g, 0.25 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-dodecene (15.15 g, 0.09 mol), α-methylstyrene (13.0 g, 0.11 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 40 °C, and 1-hexene (4.21 g, 0.05 mol) was added. The mixture was stirred again at 40 °C for 3 days, and toluene was removed under vacuum to give a viscous liquid product.

[0092] Polysiloxane P6

[0093] PMHS 1 (15.0 g, 0.25 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-dodecene (3.37 g, 0.02 mol), α-methylstyrene (21.27 g, 0.18 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 40 °C, and 1-hexene (4.21 g, 0.05 mol) was added. The mixture was stirred again at 40 °C for 3 days, and toluene was removed under vacuum to obtain a viscous liquid product.

[0094] Polysiloxane P7

[0095] PMHS 1 (14.67 g, 0.245 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of α-methylstyrene (20.74 g, 0.176 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 40 °C, and 1-hexene (5.76 g, 0.0684 mol) was added. The mixture was stirred at 40 °C for another 3 days, and toluene was removed under vacuum to give a viscous liquid product.

[0096] Polysiloxane P8

[0097] PMHS 1 (15.00 g, 0.250 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-dodecene (25.04 g, 0.125 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 4 days, cooled to 50 °C, and 1-hexene (12.62 g, 0.150 mol) was added. The mixture was stirred at 50 °C for another 3 days, and toluene and excess olefins were removed under vacuum to give a viscous liquid product.

[0098] Polysiloxane P9

[0099] PMHS 1 (8.51 g, 0.142 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-octene (15.91 g, 0.142 mol), Pt catalyst (1 drop), and toluene (100 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 6 days, cooled to 50 °C, and 1-hexene (5.00 g, 0.059 mol) was added. The mixture was stirred at 50 °C for another 2 days, and toluene and excess olefins were removed under vacuum to give a viscous liquid product.

[0100] Polysiloxane P10

[0101] PMHS 1 (9.80 g, 0.163 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of allylcyclopentane (17.96 g, 0.163 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 2 days, cooled to 50 °C, and 1-hexene (5.00 g, 0.059 mol) was added. The mixture was stirred at 50 °C for another 2 days, and toluene and excess olefins were removed under vacuum to give a viscous liquid product.

[0102] Polysiloxane P11

[0103] PMHS 1 (9.80 g, 0.163 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of allylbenzene (19.26 g, 0.163 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 2 days, cooled to 50 °C, and 1-hexene (5.00 g, 0.059 mol) was added. The mixture was stirred at 50 °C for another 2 days, and toluene and excess olefins were removed under vacuum to give a viscous liquid product.

[0104] Comparison of polysiloxane CP1

[0105] PMHS 1 (15.0 g, 0.25 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-hexene (24.2 g, 0.29 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 40 °C for 5 days, and the toluene was removed under vacuum to give a viscous liquid product.

[0106] Comparison of polysiloxane CP2

[0107] PMHS 2 (15.0 g, 0.25 mol SiH, Mw 2100 g / mol - 2400 g / mol) was added to a solution of 1-hexene (24.2 g, 0.29 mol), Pt catalyst (1 drop), and toluene (150 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 40 °C for 5 days, and the toluene was removed under vacuum to give a viscous liquid product.

[0108] Comparison of polysiloxane CP3

[0109] PMHS 1 (9.80 g, 0.163 mol SiH, Mw 1400 g / mol - 1800 g / mol) was added to a solution of 1-hepten (16.00 g, 0.163 mol), Pt catalyst (1 drop), and toluene (100 mL). The toluene was pre-dried using a 4 Å molecular sieve. The reaction mixture was stirred at 60 °C for 3 days, cooled to 50 °C, and 1-hexene (5.00 g, 0.059 mol) was added. The mixture was stirred at 50 °C for another 2 days, and toluene and excess olefins were removed under vacuum to give a viscous liquid product.

[0110] Nuclear magnetic resonance (NMR)

[0111] NMR analysis of the polysiloxanes prepared above was performed using a solution of the polysiloxane in deuterated chloroform. NMR analysis was performed using a Bruker AVANCE III 500MHz NMR spectrometer equipped with a CPBBO gradient cryopreservation probe, a Bruker B-ACS 60 autosampler, and Bruker Topspin 3.04 software. Spectra were analyzed using Advanced Chemistry Development software (Toronto, Canada). For the polysiloxanes, the yield and substitution percentage of the hydrosilylation reaction were determined by integration via the loss of the starting material SiH peak at 4.7 ppm and by the appearance of the product SiCH2 peak at 0.5 ppm. In samples where the polysiloxane contained two or more different dangling groups, the levels of these dangling groups were also determined by integration, for example, by comparing the integration of the alkyl dangling group (terminal CH3, at 0.8 ppm) and the phenylpropyl dangling group (PhCH, at 2.9 ppm). The results are shown in Tables 2 and 3.

[0112] Oil and fat composition G1-G11

[0113] Each of the oil and fat compositions G1-G11 was prepared by mixing 14 parts by weight of the polysiloxane indicated in Table 4 (Column 2) with 1.5 parts by weight of hydrophobic pyrolytic silica in a high-speed mixer at 3500 rpm for 1 minute.

[0114] Comparison of oil and fat compositions CG1-CG10

[0115] Comparative oil compositions CG1-CG4 and CG6-CG8 were each prepared by combining 14 parts by weight of the polysiloxane indicated in Table 4 (Column 2) with 1.5 parts by weight of hydrophobic pyrolytic silica in a high-speed mixer at 3500 rpm for 1 minute. Comparative oil composition CG5 is the polysiloxane indicated in Table 4 (Column 2) used "as is" (i.e., not combined with hydrophobic pyrolytic silica).

[0116] Mass absorption test method

[0117] The performance of each oil composition was evaluated by measuring the mass absorption of the elastomer (ELAS 1 or ELAS 2) immersed in the oil composition over an extended time period. ELAS 1 is a mineral-filled silicone rubber insulator. ELAS 2 is a semi-conductive carbon black-filled silicone rubber.

[0118] The elastomer was molded into tubes with the following dimensions: an inner diameter of 1.91 cm (0.75 inches); a wall thickness of 0.305 cm (0.120 inches); and a length of 20.3 cm (8 inches). The molded tubes were post-cured in an oven at 200°C for 2 hours before being cut into the corresponding test specimens. Ring-shaped test specimens were cut from the molded tubes using a lathe, with the rings cut to 8 mm in length.

[0119] Ring samples of the elastomer were slid onto a stainless steel mandrel or clamp to provide 100% elongation. These rings were then coated with a large amount of the grease composition and placed in an air convection oven at 80°C for 10 days. At the end of the 10 days, the rings were removed from the mandrel, and excess grease was removed from their surfaces using paper towels. The percentage of mass absorption was calculated based on the initial (dry) mass of a given sample. The average values ​​of two or three replicates for each elastomer and grease composition are reported in Table 4.

[0120]

[0121] Table 3. Molar ratios of repeating polysiloxane subunits w, x, y, and z

[0122]

[0123] *CP3 mainly contains 1-heptyl side groups that do not belong to w, x, y or z.

[0124] Table 4. Mass absorption of oils by elastomers

[0125]

[0126] Therefore, this disclosure particularly provides polysiloxanes having alkyl and / or arylalkyl hanging groups, methods for their preparation, and their use in the formulation of greases compatible with silicone elastomers. The following claims set forth various features and advantages of this disclosure.

Claims

1. A polysiloxane comprising a polymer of formula I: Formula I in R1 is an alkyl group having 1 to 6 carbon atoms; R2 is an alkyl group having 5 or 6 carbon atoms; R3 is an alkyl group having at least 8 carbon atoms; R4 is an arylalkyl group having at least 8 carbon atoms. R5 is selected from hydrogen or hydroxyl. w, x, y, and z are integers, and x and / or y > 0; and in The ratio of w / (w+x+y+z) is in the range of 0.01 to 0.

30. The ratio of x / (w+x+y+z) is in the range of 0 to 0.

80. The ratio of y / (w+x+y+z) is in the range of 0 to 0.65, and The ratio of z / (w+x+y+z) is in the range of 0.1 to 0.

25.

2. The polysiloxane according to claim 1, wherein R3 is an alkyl group having 8 to 18 carbon atoms.

3. The polysiloxane according to claim 1 or claim 2, wherein R4 is an arylalkyl group having 8 to 20 carbon atoms.

4. The polysiloxane according to any one of claims 1 to 3, wherein R1 is a methyl group and R2 is a 1-hexyl group.

5. The polysiloxane according to any one of claims 1 to 4, wherein R3 is a 1-dodecyl group.

6. The polysiloxane according to any one of claims 1 to 5, wherein R4 is at least one of 2-phenylpropyl group or 3-phenylpropyl group.

7. The polysiloxane according to any one of claims 1 to 6, wherein the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is at least 0.

46.

8. The polysiloxane according to any one of claims 1 to 7, wherein the sum of the ratios x / (w+x+y+z) and y / (w+x+y+z) is in the range of 0.46 to 0.

80.

9. A method for preparing a polysiloxane according to any one of claims 1 to 8, the method comprising reacting at least one of an olefin having at least 8 carbon atoms or an aryl olefin having at least 8 carbon atoms, a polymethylhydrosiloxane, and a C5 olefin or a C6 olefin in the presence of a catalyst and a solvent.

10. The method of claim 9, wherein the olefin having at least 8 carbon atoms is C8-C. 18 Alkenes, wherein the aryl olefin having at least 8 carbon atoms is C8-C6. 20 Arylolefins.

11. The method according to claim 9 or claim 10, wherein the reaction is carried out at a temperature in the range of 30°C to 200°C.

12. The method according to any one of claims 9 to 11, wherein the catalyst is selected from platinum divinyltetramethyldisiloxane complex, platinum cyclovinylmethylsiloxane complex, platinum carbonyl cyclovinylmethylsiloxane complex, platinum octaldehyde complex, tris(dibutyl sulfide) rhodium trichloride or combinations thereof; and the solvent is selected from xylene, toluene, benzene, chloroform, dichloromethane, tetrahydrofuran or combinations thereof.

13. The method according to any one of claims 9 to 12, the method further comprising removing the solvent in a vacuum to produce the polysiloxane as a viscous liquid.

14. A composition comprising: a) 50% to 95% by weight of the polysiloxane according to any one of claims 1 to 8; and b) 5% to 50% of the filler by weight.

15. The composition of claim 14, wherein the filler is selected from silica, aluminosilicate clay, alumina, mica, lithium stearate, calcium stearate, carbon black, fluoropolymers, polyurea, or combinations thereof.

16. An article comprising the composition according to claim 14 or claim 15 in contact with a silicone elastomer.

17. The article of claim 16, wherein the silicone elastomer further comprises carbon black.

18. The article of claim 16 or claim 17, wherein the silicone elastomer, when contacted with the oil composition for 10 days at a temperature of 80°C and at an elongation of 100% of its original length by strain, exhibits a mass absorption of less than 3.0% by weight, as provided in the mass absorption test method provided herein.

19. The article of claim 16 or claim 17, wherein the silicone elastomer, when contacted with the oil composition for 10 days at a temperature of 80°C and at an elongation of 100% of its original length by strain, exhibits a mass absorption of less than 0.5% by weight, as provided in the mass absorption test method provided herein.

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