Rubber composition and product thereof

Abstract

A rubber composition and an article thereof. According to one or more purposes of the present disclosure, as implemented and broadly described herein, the present disclosure relates in one aspect to an uncured composition comprising a partially saturated elastomer and pre-silanized silica. In some aspects, an uncured composition includes from about 40 phr to about 200 phr of a pre-silylated silica and at least one partially saturated elastomer including repeating units, where greater than 15% to about 30% of all repeating units of the partially saturated elastomer include double bonds. Also disclosed are vulcanized rubber compositions comprising the uncured composition that has been vulcanized and articles comprising tires and / or tire components, the articles comprising the vulcanized rubber composition.

Description

Background Art

[0001] The need to improve tire performance has led to the development and evaluation of new materials with desired properties such as good stiffness and rolling resistance. In tire elastomer compositions, improving rolling resistance typically comes at the expense of reducing the stiffness of the composition. It is challenging to improve properties such as rolling resistance and tensile strength while maintaining a balance between the trade-offs. There is a need for an elastomer composition for tires that can provide good rolling resistance as well as good tensile strength while maintaining the desired stiffness of the material. Summary of the Invention

[0002] In accordance with one or more objects of the present disclosure, as specifically embodied and broadly described herein, the present disclosure in one aspect relates to an uncured composition comprising a partially saturated elastomer and pre-silanized silica. In some aspects, the uncured composition comprises from about 40 phr to about 200 phr of pre-silanized silica and at least one partially saturated elastomer comprising repeating units, wherein greater than 15% to about 30% of all the repeating units of the partially saturated elastomer comprise double bonds. Also disclosed is a vulcanized rubber composition comprising the vulcanized uncured composition, and an article comprising a tire and / or a tire component made of or comprising the vulcanized rubber composition.

[0003] After studying the following detailed description, other systems, methods, features, and advantages of the present disclosure will be or will become apparent to those skilled in the art. All such additional systems, methods, features, and advantages are intended to be included within this specification, within the scope of the present disclosure, and protected by the appended claims. Furthermore, all optional and preferred features and modifications of the described embodiments can be used in all aspects of the disclosure taught herein. Additionally, the various features of the dependent claims and all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with each other.

[0004] The present invention discloses the following embodiments:

[0005] 1. An uncured composition comprising:

[0006] At least one partially saturated elastomer comprising repeating units, wherein greater than 15% to about 30% of all the repeating units of the partially saturated elastomer comprise double bonds, and

[0007] From about 40 phr to about 200 phr of pre-silanized silica.

[0008] 2. The composition according to embodiment 1, wherein about 16% to about 25% of all the repeating units of the partially saturated elastomer comprise double bonds.

[0009] 3. The composition according to embodiment 1, wherein the partially saturated elastomer comprises repeating units formed from residues of one or more monomers selected from ethylene, propylene, butadiene, isoprene, styrene, and any combination thereof.

[0010] 4. The composition according to embodiment 1, wherein the partially saturated elastomer is a partially hydrogenated styrene-butadiene rubber.

[0011] 5. The composition according to embodiment 4, wherein the partially hydrogenated styrene-butadiene rubber has from about 15% to about 25% of repeating units containing double bonds.

[0012] 6. The composition according to embodiment 4, wherein the styrene content of the partially hydrogenated styrene-butadiene rubber is from about 5% by weight to about 40% by weight of the partially hydrogenated styrene-butadiene rubber, and the butadiene content is from about 60% by weight to about 95% by weight of the partially hydrogenated styrene-butadiene rubber.

[0013] 7. The composition according to embodiment 4, wherein the glass transition temperature of the partially hydrogenated styrene-butadiene rubber is from about -70 °C to about -20 °C.

[0014] 8. The composition according to embodiment 4, wherein the weight average molecular weight of the partially hydrogenated styrene-butadiene rubber is from about 100 kg / mol to about 1500 kg / mol.

[0015] 9. The composition according to embodiment 1, wherein the composition comprises from about 80 phr to about 130 phr of pre-silanized silica.

[0016] 10. The composition according to embodiment 1, wherein the pre-silanized silica has a BET surface area of from about 70 g / m 2 to about 200 g / m 2 of the BET surface area.

[0017] 11. The composition according to embodiment 1, wherein the pre-silanized silica has a CTAB adsorption surface area of from about 120 g / m 2 to about 220 g / m 2 of the CTAB adsorption surface area.

[0018] 12. The composition according to embodiment 1, wherein the pre-silanized silica comprises silica having an alkylsilane, alkoxysilane, organoalkoxysilyl polysulfide, or organomercaptoalkoxysilane bonded thereto.

[0019] 13. The composition according to embodiment 1, wherein the presilylated silica comprises silica having a sulfur-containing silane bonded thereto.

[0020] 14. The composition according to embodiment 13, wherein the sulfur-containing silane comprises bis(3-triethoxysilylpropyl) polysulfide containing on average about 2 - 5 linked sulfur atoms in its polysulfide bridge, or an alkoxy organo mercapto silane.

[0021] 15. The composition according to embodiment 1, wherein the composition further comprises a vulcanizing agent in an amount of 0.4 phr to 15.0 phr.

[0022] 16. The composition according to embodiment 1, wherein the composition further comprises a vulcanization accelerator in an amount of 0.3 phr to 4.0 phr.

[0023] 17. A vulcanized rubber composition comprising the uncured composition of embodiment 1 that has been vulcanized.

[0024] 18. An article comprising the vulcanized rubber composition of embodiment 17.

[0025] 19. The article according to embodiment 18, wherein the article comprises a tire or a component of a tire.

[0026] 20. The article according to embodiment 19, wherein the component of the tire comprises a tread, a base, a sidewall, or any combination thereof. Detailed Description

[0027] Benefiting from the teachings presented in the foregoing specification, many modifications and other embodiments of the disclosed compositions and methods will occur to those skilled in the art to which the disclosed compositions and methods pertain. Accordingly, it is to be understood that the disclosure is not limited to the specific embodiments disclosed, and that modifications and other embodiments are intended to be included within the scope of the appended claims. Those skilled in the art will recognize many variations and adaptations of the aspects described herein. These variations and adaptations are intended to be included in the teachings of this disclosure and covered by the claims herein.

[0028] Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

[0029] As will be apparent to those skilled in the art after reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which can be readily separated from or combined with the features of any of the several other embodiments without departing from the scope or spirit of the disclosure.

[0030] Any of the recited methods may be performed in the order of the recited events or in any other order that is logically possible. That is, unless otherwise expressly stated, no method or aspect set forth herein is ever intended to be construed as requiring that its steps be performed in a particular order. Accordingly, where a method claim does not specifically recite steps in a claim or specification to be limited to a particular order, no inference of order is intended in any respect. This applies to any possible non-explicit basis of interpretation, including logical content regarding arrangements of steps or operational flows, simple meanings derived from grammatical organization or punctuation, or the number or type of aspects described in the specification.

[0031] All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and / or materials related to the cited publications. The publications discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such publications by virtue of prior invention. In addition, the publication dates provided herein may be different from the actual publication dates, which may require independent verification.

[0032] Although aspects of the present disclosure may be described and claimed in a particular statutory class, such as the system statutory class, this is for convenience only and those of ordinary skill in the art will understand that each aspect of the present disclosure may be described and claimed in any statutory class.

[0033] It should also be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the disclosed compositions and methods belong. It will also be understood that terms such as those defined in commonly used dictionaries should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0034] Before describing various aspects of the present disclosure, the following definitions are provided and should be used unless otherwise indicated. Additional terms may be defined elsewhere in the present disclosure.

[0035] Definitions

[0036] As used herein, "comprising" shall be interpreted as specifying the presence of the stated features, integers, steps or components mentioned, but not precluding the presence or addition of one or more features, integers, steps or components or groups thereof. Further, each of the terms "by", "comprising", "comprises", "contains", "include", "includes", "involves", "involved", "involving" and "such as" is used in its open, non-limiting sense and may be used interchangeably. Additionally, the term "comprising" is intended to include the instances and aspects covered by the terms "consisting essentially of" and "consisting of". Similarly, the term "consisting essentially of" is intended to include the instances covered by the term "consisting of".

[0037] As used in the specification and the appended claims, the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "an elastomer", "a pre-silanized silica" or "a vulcanizing agent" includes mixtures or combinations of two or more such elastomers, pre-silanized silicas or vulcanizing agents, etc., without limitation.

[0038] It should be noted that ratios, concentrations, amounts and other numerical data may be expressed herein in range format. It will also be understood that each endpoint of each range is significant relative to the other endpoint and independent of the other endpoint. It should also be understood that many values are disclosed herein, and that each value is also disclosed herein as "about" that particular value in addition to the value itself. For example, if the value "10" is disclosed, then "about 10" is also disclosed. In this document, ranges may be expressed as from "about" one particular value and / or to "about" another particular value. Similarly, when a value is expressed as an approximation by use of the antecedent "about", it will be understood that the particular value forms another aspect. For example, if the value "about 10" is disclosed, then "10" is also disclosed.

[0039] When expressing a range, another aspect includes from one particular value and / or to another particular value. For example, in cases where the range includes one or both of the limiting values, ranges excluding either or both of those included limiting values are also included in this disclosure, e.g., the phrase "x to y" includes the range from "x" to "y" and ranges greater than "x" and less than "y". Ranges may also be expressed as upper limits, e.g., "about x, y, z or less", and should be interpreted as including the specific ranges of "about x", "about y" and "about z" as well as the ranges "less than x", "less than y" and "less than z". Similarly, the phrase "about x, y, z or greater" should be interpreted as including the specific ranges of "about x", "about y" and "about z" as well as the ranges "greater than x", "greater than y" and "greater than z". Additionally, the phrase "about 'x' to 'y'" (where 'x' and 'y' are numerical values) includes "about 'x' to about 'y'".

[0040] It should be understood that the use of this range format is for convenience and brevity, and should therefore be interpreted in a flexible manner to include not only the explicitly recited numerical values that are the limits of the range, but also all individual numerical values or sub-ranges subsumed within that range, as if each numerical value and sub-range were explicitly recited. By way of illustration, a numerical range of "about 0.1% to 5%" should be interpreted to include not only the explicitly recited values of about 0.1% to about 5%, but also individual values (e.g., about 1%, about 2%, about 3%, and about 4%) and sub-ranges within the indicated range (e.g., about 0.5% to about 1.1%; about 5% to about 2.4%; about 0.5% to about 3.2%, and about 0.5% to about 4.4%, and other possible sub-ranges).

[0041] As used herein, the terms "about," "approximate," "at or about," and "substantially" mean that the quantity or value being discussed can be the exact value or a value that provides an equivalent result or effect as recited in the claims or taught herein. That is, it should be understood that quantities, dimensions, formulations, parameters, and other quantities and characteristics are not and need not be exact, but can be approximate and / or larger or smaller as desired, reflecting tolerances, conversion factors, rounding, measurement errors, and other factors known to those of ordinary skill in the art, such that equivalent results or effects are obtained. In some instances, a value that provides an equivalent result or effect cannot be reasonably determined. In such cases, it is generally understood that, as used herein, "about" and "at or about" mean a variation of ±10% of the indicated nominal value, unless otherwise indicated or inferred. Generally, a quantity, dimension, formulation, parameter, or other quantity or characteristic is "about," "approximate," or "at or about," whether or not explicitly stated as such. It should be understood that, unless specifically stated otherwise, when "about," "approximate," or "at or about" is used before a numerical value, the parameter also includes the specific numerical value itself.

[0042] As used herein, the term "optional" or "optionally" means that the subsequent described event or circumstance may or may not occur, and the description includes both the instance where the event or circumstance occurs and the instance where it does not occur.

[0043] As used herein, the term "phr" refers to the parts by weight of each material per 100 parts by weight of rubber or elastomer. Generally, using this convention, an elastomeric composition contains 100 parts by weight of rubber / elastomer. The claimed composition may contain other rubber / elastomers in addition to those explicitly mentioned in the claims, provided that the phr values of the claimed rubber elastomers comply with the claimed phr ranges and the amounts of all rubber / elastomers in the composition result in a total of 100 parts of rubber.

[0044] Unless otherwise specified, the terms "rubber" and "elastomer" are used interchangeably herein.

[0045] As used herein, the "glass transition temperature" or "Tg" of an elastomer or rubber refers to one or more glass transition temperatures of the corresponding elastomer or rubber in its uncured state, or, in the case of an elastomer composition, in some aspects, Tg can be measured in the cured state. g As used herein, the term "uncured composition" refers to a composition that comprises at least one natural or synthetic rubber component and optionally one or more fillers, processing aids, or additional compounds, and that has not been vulcanized. Uncured rubber is sensitive to temperature changes and has a tendency to undergo "cold flow" (slow movement or deformation under stress) over time. In some aspects, the uncured rubber composition is a masterbatch. g As used herein, the term "vulcanized rubber composition" refers to a rubber composition obtained by taking an uncured composition as described herein and curing or vulcanizing it, typically using a sulfur compound and / or other curing additives and in the presence of heat. Vulcanized or cured rubber does not undergo cold flow and is less sensitive to temperature changes relative to uncured rubber. In another aspect, the rubber composition can be cured in a mold to form an article including but not limited to a tire.

[0046] As used herein, the term "repeating unit" as recited in a partially saturated elastomer as described herein is derived from the monomers used to prepare the partially saturated elastomer. For example, polybutadiene has repeating units as provided below.

[0047] In certain aspects, when the partially saturated elastomer is a polymerization product of two different monomers (e.g., A and B), the repeating unit can be represented by -A-B-.

[0048] Unless otherwise specified, pressures mentioned herein are based on atmospheric pressure (i.e., one atmosphere).

[0049]

[0050] It has been found that the combination of a partially saturated elastomer having an increased number of double bonds with a pre-silanized silica results in an unexpected improvement in stiffness and hysteresis. Additionally, the use of the partially saturated elastomers described herein also improves tensile strength.

[0051] Unless otherwise specified, pressures mentioned herein are based on atmospheric pressure (i.e., one atmosphere).

[0052] Rubber composition

[0053] It has been found that the combination of a partially saturated elastomer having an increased number of double bonds with a pre-silanized silica results in an unexpected improvement in stiffness and hysteresis. Additionally, the use of the partially saturated elastomers described herein also improves tensile strength.

[0054] The uncured compositions described herein, such as uncured rubber compositions, comprise a partially saturated elastomer and a presilanized silica. In some aspects, the uncured composition comprises from about 40 phr to about 200 phr of presilanized silica and at least one partially saturated elastomer comprising repeating units, wherein greater than 15% to about 30% of all of the repeating units of the partially saturated elastomer comprise double bonds. Also disclosed herein are vulcanized rubber compositions comprising the uncured compositions, and articles including tires and / or tire components, the articles being made of or comprising the vulcanized rubber compositions. The vulcanized or cured compositions have good rolling resistance and tensile strength, while the stiffness is reduced little to not at all as compared to cured compositions that do not contain presilanized silica.

[0055] In some aspects, the partially saturated elastomer comprises repeating units, wherein greater than 15% to about 30% of all of the repeating units comprise double bonds. In other aspects, the amount of repeating units that include double bonds can be about 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30%, where any value can be the lower and upper endpoints of the range (e.g., 16% to 25%). When calculating double bonds, double bonds in aromatic structures or groups, such as those present in styrene repeating units, are not included in the count. However, styrene units are still counted as repeating units for determining the total number of repeating units in the elastomer.

[0056] In one aspect, the partially saturated elastomer can comprise repeating units formed from residues of monomers selected from one or more of ethylene, propylene, butadiene, isoprene, styrene, and any combination thereof. In a further aspect, the partially saturated elastomer is a hydrogenated styrene-butadiene rubber, in some aspects a hydrogenated solution-polymerized styrene-butadiene rubber (SSBR). The hydrogenated styrene-butadiene rubber can have a styrene content of from about 5 wt% to about 40 wt%, or about 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%, 35 wt%, or 40 wt%, where any value can be the lower and upper endpoints of the range (e.g., 20 wt% to 40 wt%), and a butadiene content of from about 60 wt% to about 95 wt%, or about 60 wt%, 65 wt%, 70 wt%, 75 wt%, 80 wt%, 85 wt%, 90 wt%, or 95 wt%, where any value can be the lower and upper endpoints of the range (e.g., 75 wt% to 90 wt%). In some aspects, when greater than 15% to about 30% of all of the repeating units of the SSBR include double bonds, the SSBR can be referred to as a partially hydrogenated SSBR (HSBR).

[0057] In other aspects, HSBR can be characterized as having about 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or 30% of all repeating units (where any value can be the lower and upper endpoints of a range, e.g., 18% to 23%), including double bonds. HSBR can also be characterized as having a weight average molecular weight (M w ) of about 100 kg / mol to about 4,000 kg / mol, or 100 kg / mol, 200 kg / mol, 300 kg / mol, 400 kg / mol, 500 kg / mol, 600 kg / mol, 700 kg / mol, 800 kg / mol, 900 kg / mol, 1,000 kg / mol, 1,100 kg / mol, 1,200 kg / mol, 1,300 kg / mol, 1,400 kg / mol, 1,500 kg / mol, 2,000 kg / mol, 3,000 kg / mol, or 4,000 kg / mol, where any value can be the lower and upper endpoints of a range (e.g., 600 kg / mol to 900 kg / mol). In a further aspect, HSBR can be characterized as having a polydispersity index (M w / M n , M n being the number average molecular weight) of about 1.05 to about 2.0 or 1.2, 1.4, 1.6, 1.8, or 2.0, where any value can be the lower and upper endpoints of a range (e.g., 1.4 to 1.8). The molecular weight parameters can be determined by gel permeation chromatography using polystyrene calibration standards or equivalents according to ASTM 5296-11. In other aspects, HSBR can have a glass transition temperature of about -70°C to about -20°C, or about -70°C, -60°C, -50°C, -40°C, -30°C, or -20°C, where any value can be the lower and upper endpoints of a range (e.g., -60°C to -40°C).

[0058] Partially saturated elastomers, in some aspects HSBR, can be obtained by hydrogenating elastomers. The hydrogenation method of the elastomer can be carried out by any method known in the art. In one aspect, hydrogenation is carried out by blowing water-containing hydrogen into an elastomer or polymer solution in the presence of a catalyst, such as a heterogeneous catalyst, a homogeneous catalyst, a catalyst using a metallocene such as titanocene, or any combination thereof. Examples of heterogeneous catalysts include noble metal-containing catalysts supported on porous inorganic substances. Examples of homogeneous catalysts include catalysts obtained by reacting soluble salts of nickel, cobalt, etc. with organoaluminum, etc. The degree of hydrogenation in the resulting elastomer can be controlled by changing factors such as the amount of hydrogen added, hydrogen pressure, reaction time, reaction temperature, the amount of catalyst added, polymer solution viscosity, or any combination thereof. In some aspects, the hydrogenation reaction is carried out at a temperature of about 60 °C to 105 °C or about 60 °C, 70 °C, 80 °C, 90 °C, 100 °C, or 105 °C, where any value can be the lower and upper endpoints of the range (e.g., 70 °C to 100 °C). In some aspects, the hydrogenation reaction is carried out by a batch method, a continuous method, or a combination thereof. Other details regarding the production of partially saturated elastomers are described in US Patent Application Publication US2023 / 0138073A1 and European Patent Application Publication EP 4261234 A1, which are incorporated herein by reference.

[0059] In other aspects, the compositions described herein can contain from about 40 phr to about 200 phr of pre-silanized silica. In other aspects, the composition can contain from about 80 phr to about 130 phr of pre-silanized silica or about 40 phr, 60 phr, 80 phr, 100 phr, 130 phr, 160 phr, 190 phr, or 200 phr, where any value can be the lower and upper endpoints of the range (e.g., 100 phr to 160 phr). In some aspects, the pre-silanized silica has a BET surface area of about 70 g / m 2 to about 200 g / m 2 or about 70 g / m 2 、100 g / m 2 、130 g / m 2 、160 g / m 2 or 200 g / m 2 and any value can be the lower and upper endpoints of the range (e.g., 130 g / m 2 to 200 g / m 2 ). In some aspects, the pre-silanized silica has a BET surface area of about 120 g / m 2 to about 220 g / m 2 or about 120 g / m 2 、140 g / m 2 、160 g / m 2, 180 g / m 2 , 200 g / m 2 or 220 g / m 2 of the CTAB absorption surface area, where any value can be the lower and upper endpoints of a range (e.g., 140 g / m 2 to 200 g / m 2 ).

[0060] In one aspect, the pre-silylated silica can include silica having an alkylsilane, alkoxysilane, organoalkoxysilyl polysulfide, or organomercaptoalkoxysilane bonded to the silica. In other aspects, the pre-silylated silica includes silica having a sulfur-containing silane bonded to the silica. In one aspect, the sulfur-containing silane can include an alkoxyorganomercapto silane or bis(3-triethoxysilylpropyl) polysulfide having an average of about 2 to 5 linked sulfur atoms in its polysulfide bridge. Examples of pre-silylated silica suitable for use in the compositions described herein include, but are not limited to 255LD and LP (PPG Industries); silica that has been pretreated with a mercapto silane; 8113 (Degussa); 6508; and 400, 454, and 458 silica from PPG Industries .

[0061] In some aspects, the pre-silylated silica is treated with a silica dispersion aid. Such silica dispersion aids can include diols, such as fatty acids, diethylene glycol, polyethylene glycol, fatty acid esters of hydrogenated or non-hydrogenated C5 or C6 sugars, and polyoxyethylene derivatives of fatty acid esters of hydrogenated or non-hydrogenated C5 or C6 sugars. Exemplary fatty acids include stearic acid, palmitic acid, and oleic acid. Exemplary fatty acid esters of hydrogenated and non-hydrogenated C5 and C6 sugars (e.g., sorbose, mannose, and arabinose) include, but are not limited to, sorbitan oleates (e.g., sorbitan monooleate, sorbitan dioleate, sorbitan trioleate, and sorbitan sesquioleate) and sorbitan esters of lauric fatty acid, palmitic fatty acid, and stearic fatty acid. Exemplary polyoxyethylene derivatives of fatty acid esters of hydrogenated and non-hydrogenated C5 and C6 sugars include, but are not limited to, polysorbates and polyoxyethylene sorbitan esters, which are similar to the above-described fatty acid esters of hydrogenated and non-hydrogenated sugars, except that oxyethylene groups are placed on each hydroxyl group. The silica dispersion aid can be present in an amount of about 0.1 wt% to about 25 wt%, based on the weight of the silica.

[0062] In other aspects, the pre-silylated silica is pre-hydrophobized by treating silica in the form of an aqueous colloidal silica with an organomercaptosilane and an alkylsilane in a weight ratio of 10 / 90 to 90 / 10 (organomercaptosilane to alkylsilane). In some aspects, the alkylsilane is represented by the general formula (I):

[0063] X n -Si-R 1 4-n (I),

[0064] wherein R is an alkyl group having 1 to 18 carbon atoms or 1 to 8 carbon atoms (such as methyl, ethyl, butyl, etc.), n is 1 to 3, and X is a group selected from halogen and alkoxy groups. In some aspects, X is chlorine or bromine. In other aspects, X is an alkoxy group, such as (R 2 O)-, wherein R 2 is an alkyl group having 1 to 3 carbon atoms. In some aspects, the organomercaptosilane is represented by the general formula (II):

[0065] (X) n (R 3 O) 3-n -Si-R 4 -SH (II),

[0066] wherein X is a group selected from halogen and alkyl groups having 1 to 16 carbon atoms, R 3 is an alkyl group having 1 to 16 carbon atoms or 1 to 4 carbon atoms, R 4 is an alkylene group having 1 to 16 carbon atoms or 1 to 4 carbon atoms (such as -(CH2) m -, wherein m is 1 to 16), and n is 0 to 3. In other aspects, X is chlorine or bromine. In other aspects, X is an alkyl group selected from methyl, ethyl, n-propyl, and n-butyl. In other aspects, R 4 is propylene. In some aspects, n is 0.

[0067] Representative alkylsilanes of formula (I) are trichloromethylsilane, dichlorodimethylsilane, chlorotrimethylsilane, trimethoxymethylsilane, dimethoxydimethylsilane, methoxymethylsilane, trimethoxypropylsilane, trimethoxyoctylsilane, trimethoxyhexadecylsilane, dimethoxydipropylsilane, triethoxymethylsilane, triethoxypropylsilane, triethoxyoctylsilane, and diethoxydimethylsilane. Representative organomercaptosilanes of formula (II) are, for example, triethoxymercaptopropylsilane, trimethoxymercaptopropylsilane, methyldimethoxymercaptopropylsilane, methyldiethoxymercaptopropylsilane, dimethylmethoxymercaptopropylsilane, triethoxymercaptoethylsilane, and tripropoxymercaptopropylsilane.

[0068] The uncured rubber composition may further comprise from about 0.4 phr to about 15.0 phr of a vulcanizing agent, or from about 0.4 phr, 3.0 phr, 6.0 phr, 9.0 phr, 12.0 phr, or 15.0 phr of a vulcanizing agent, where any value may be the lower and upper endpoints of the range (e.g., 9.0 phr to 12.0 phr). In some aspects, the vulcanizing agent comprises elemental sulfur, a sulfur-containing silane, or a combination thereof. Additionally, the uncured rubber composition may further contain a vulcanization accelerator. The vulcanization accelerator may preferably but not necessarily be used to control the time and / or temperature required for vulcanization, as well as to improve the properties of the vulcanized composition. The amount of the vulcanization accelerator in the composition may be from about 0.3 phr to about 4.0 phr, or an amount of 0.3 phr, 1.0 phr, 2.0 phr, 3.0 phr, or 4.0 phr, where any value may be the lower and upper endpoints of the range (e.g., 1.0 phr to 2.0 phr).

[0069] In some aspects, the vulcanization accelerator comprises a dithiocarbamate / salt accelerator, a thiuram accelerator, a diphenylguanidine accelerator, a benzothiazole sulfenamide accelerator, or a combination thereof. Potential vulcanization accelerator compounds may include derivatives, e.g., the benzothiazole sulfenamide accelerator includes benzothiazole sulfenamide and may also include derivatives of benzothiazole sulfenamide. In other aspects, the vulcanization accelerator comprises amines, disulfides, guanidines, thioureas, thiazoles, thiurams, sulfenamides, dithiocarbamates / salts, and xanthates / salts. In another aspect, the vulcanization accelerator comprises a combination of a primary accelerator and a secondary accelerator, where the secondary accelerator is used in a smaller amount, e.g., 0.05 phr to 3.00 phr. In some aspects, the secondary accelerator is selected from guanidine, dithiocarbamate / salt, or thiuram. Additionally, a delayed-action accelerator may be used, which is not affected by normal processing temperatures but produces satisfactory curing at ordinary vulcanization temperatures.

[0070] The uncured rubber composition may comprise additional components such as oil. In some aspects, the oil is a processing oil. The processing oil may be included in the composition as an extender oil commonly used for elastomers. The processing oil may also be included in the elastomer composition by directly adding the oil during rubber compounding. The processing oil used may include the extender oil present in the elastomer and the process oil added during compounding. Suitable processing oils include, but are not limited to, various oils known in the art, including aromatic oils, paraffinic oils, naphthenic oils, vegetable oils, and low-PCA oils such as MES, TDAE, SRAE, and heavy naphthenic oils. Suitable low-PCA oils may include those having a polycyclic aromatic content of less than 3 wt% as determined by the IP346 method. The procedure for the IP346 method can be found in the following: Standard Test Methods for Analysis and Testing of Petroleum and Related Products and British Standard 2000 Parts, 2003, 62nd edition, published by the Institute of Petroleum, UK. Suitable TDAE oils may be purchased as Tudalen SX500 from Klaus Dahleke KG, as VivaTec 400 and VivaTec 500 from H&R Group, as Enerthene 1849 from BP, and as Extensoil 1996 from Repsol. The oil may be obtained as a separate oil or together with the elastomer in the form of an extended elastomer. Suitable vegetable oils include, for example, soybean oil, sunflower oil, and low erucic acid rapeseed oil, which are in the form of esters containing a certain degree of unsaturation.

[0071] Vulcanized rubber compositions are described herein, wherein any of the uncured rubber compositions described herein have been vulcanized. In some aspects, the vulcanized rubber composition has improved tensile strength compared to a cured composition that does not include pre-silanized silica. In a further aspect, the tensile strength of the vulcanized composition disclosed herein is about 5% to about 20%, or about 5%, 10%, 15%, 20%, 25%, or 30% higher than the tensile strength of a cured composition that does not include pre-silanized silica (as determined by ASTM D412), where any value may be the lower and upper endpoints of the range (e.g., 10% to 15%).

[0072] In other aspects, compared to a cured composition that does not include presilanized silica, the vulcanized rubber composition can show little to no reduction in stiffness, and in some aspects shows an increase in stiffness. In a further aspect, the vulcanized composition disclosed herein has a stiffness G′ within about 10%, about 15%, or about 5% of a cured composition that does not include presilanized silica, based on ASTM D5289, and wherein the stiffness G′ is measured at 1% strain, 100 °C, and a frequency of 1 Hz. The vulcanized composition can also have a tan δ that is about 10% to about 40% lower, or about 10%, 15%, 20%, 25%, 30%, 35%, or 40% lower, than the tan δ of a cured composition that does not include presilanized silica, where any value can be the lower and upper endpoints of a range based on DIN 53513 (e.g., 10% to 35%), and wherein the tan δ is measured at 6% strain, 30 °C, and a frequency of 7.8 Hz.

[0073] Preparation and use of the rubber composition

[0074] The compositions disclosed herein can be compounded by methods commonly known in the rubber compounding art, such as by mixing: a partially saturated elastomer and presilanized silica with various curable component rubbers and various commonly used additive materials such as sulfur donors; curing aids such as activators and scorch inhibitors; processing additives such as oils, resins (including tackifying resins), and plasticizers; fillers; pigments; fatty acids; zinc oxide; waxes; antioxidants; antiozonants; and peptizers. Zinc oxide can be included in an amount of about 1 phr to about 5 phr. The above additives are selected and typically used in conventional amounts depending on the intended use of the curable and vulcanized materials (rubbers). In some aspects, the tackifying resin is included in an amount of: about 0.5 phr to 10 phr or about 1 phr to 5 phr. In some aspects, the processing additives are included in an amount of about 1 phr to 50 phr. In some aspects, the antioxidant is included in an amount of about 1 phr to 5 phr. Representative antioxidants include, but are not limited to, diphenyl-p-phenylenediamine and others, such as those disclosed in The Vanderbilt Rubber Handbook (1978), pages 344 - 346. In some aspects, the antiozonant is included in an amount of: about 1 phr to 5 phr. Representative antiozonants include, but are not limited to, N-phenyl-N′-(1,3-dimethylbutyl)-p-phenylenediamine (6PPD) and N,N′-bis-xylene-p-phenylenediamine (DTPD). In some aspects, the fatty acid is included in an amount of: about 0.5 phr to 3 phr. Examples of fatty acids used include stearic acid. In some aspects, the wax is included in an amount of about 1 phr to 5 phr. Microcrystalline wax can be used. In some aspects, the peptizer is included in an amount of about 0.1 phr to 1 phr. Typical peptizers include, for example, pentachlorothiophenol and dibenzoyl aminodiphenyl disulfide.

[0075] The compositions disclosed herein can be mixed by methods known in the rubber mixing art. For example, the ingredients can generally be mixed in at least two stages, i.e., at least one non-productive stage, followed by a productive mixing stage. In some aspects, the mixing of the uncured composition includes only a single non-productive stage. The final curing agent, including the vulcanizing agent, can generally be mixed in a final stage, which is typically referred to as the "productive" mixing stage, where the mixing is generally carried out at a temperature or final temperature that is lower than one or more mixing temperatures of the one or more preceding non-productive mixing stages. In one embodiment, the elastomeric composition can be subjected to a thermomechanical mixing step. The thermomechanical mixing step generally includes machining in a mixer or extruder for a period of time, e.g., a time suitable to produce a rubber temperature in the range of about 140 °C to 190 °C. The suitable duration of the thermomechanical machining varies with the operating conditions and the volume and nature of the components. For example, the thermomechanical machining can be for about 1 to 20 minutes.

[0076] The present disclosure also provides articles incorporating any of the vulcanized rubber compositions disclosed herein. In some aspects, the article includes a tire, such as a pneumatic tire, or a component of a tire. The tire can be a racing tire, a passenger tire, an aircraft tire, an agricultural tire, a bulldozer tire, an off-road tire, a truck tire, etc. In one aspect, the tire is a passenger or truck tire. The tire can also be radial or bias. The components of the tire can be a tread, a base, a sidewall, a chafer, a bead filler, a sidewall insert, a wire wrap, a liner, or any combination thereof. In another aspect, the components of the tire incorporating the composition are a tread, a base, a sidewall, or any combination thereof. The vulcanization of the disclosed tires is generally carried out at a conventional temperature of about 100 °C to about 200 °C or about 110 °C to about 180 °C. Such tires can be constructed, shaped, molded, and cured by various methods known and obvious to those skilled in the art.

[0077] Aspects of the present disclosure have now been described. In general, the following examples describe some additional aspects of the present disclosure. While aspects of the present disclosure are described in connection with the following examples and the corresponding text, it is not intended to limit the aspects of the present disclosure to this specification. Instead, it is intended to cover all alternatives, modifications, and equivalents included within the spirit and scope of the present disclosure.

[0078] Aspect

[0079] The present disclosure can be described in terms of the following numbered aspects, which should not be confused with the claims.

[0080] Aspect 1. An uncured composition comprising:

[0081] At least one partially saturated elastomer comprising repeating units, wherein greater than 15% to about 30% of all of the repeating units of the partially saturated elastomer comprise double bonds, and

[0082] from about 40 phr to about 200 phr of a pre-silanized silica.

[0083] Aspect 2. The composition according to Aspect 1, wherein from about 16% to about 25% of all of the repeating units of the partially saturated elastomer comprise double bonds.

[0084] Aspect 3. The composition according to Aspect 1 or 2, wherein the partially saturated elastomer comprises repeating units formed from residues of monomers selected from one or more of ethylene, propylene, butadiene, isoprene, styrene, and any combination thereof.

[0085] Aspect 4. The composition according to Aspect 1 or 2, wherein the partially saturated elastomer is a partially hydrogenated styrene-butadiene rubber.

[0086] Aspect 5. The composition according to Aspect 4, wherein the partially hydrogenated styrene-butadiene rubber has from about 16% to about 25% of repeating units comprising double bonds.

[0087] Aspect 6. The composition according to Aspect 4 or 5, wherein the styrene content of the partially hydrogenated styrene-butadiene rubber is from about 5 wt% to about 40 wt% of the partially hydrogenated styrene-butadiene rubber, and the butadiene content is from about 60 wt% to about 95 wt% of the partially hydrogenated styrene-butadiene rubber.

[0088] Aspect 7. The composition according to any one of Aspects 4-6, wherein the partially hydrogenated styrene-butadiene rubber has a glass transition temperature of from about -70 °C to about -20 °C.

[0089] Aspect 8. The composition according to any one of Aspects 4-7, wherein the hydrogenated styrene-butadiene rubber has a weight average molecular weight of from about 100 kg / mol to about 4000 kg / mol.

[0090] Aspect 9. The composition according to any one of Aspects 4-7, wherein the partially hydrogenated styrene-butadiene rubber has an average molecular weight of from about 100 kg / mol to about 1500 kg / mol.

[0091] Aspect 10. The composition according to any one of Aspects 1-9, wherein the composition comprises from about 80 phr to about 130 phr of pre-silanized silica.

[0092] Aspect 11. The composition according to any one of aspects 1-10, wherein the presilylated silica has a BET surface area of about 70 g / m2 to about 200 g / m 2 2.

[0093] Aspect 12. The composition according to any one of aspects 1-11, wherein the presilylated silica has a CTAB adsorption surface area of about 120 g / m2 to about 220 g / m 2 2.

[0094] Aspect 13. The composition according to any one of aspects 1-12, wherein the presilylated silica comprises silica having an alkylsilane, alkoxysilane, organoalkoxysilyl polysulfide or organomercaptoalkoxysilane bonded to the silica.

[0095] Aspect 14. The composition according to any one of aspects 1-12, wherein the presilylated silica comprises silica having a sulfur-containing silane bonded to the silica.

[0096] Aspect 15. The composition according to aspect 14, wherein the sulfur-containing silane comprises bis(3-triethoxysilylpropyl) polysulfide or an alkoxy organomercapto silane, and the bis(3-triethoxysilylpropyl) polysulfide contains an average of about 2 to 5 linked sulfur atoms in its polysulfide bridge.

[0097] Aspect 16. The composition according to any one of aspects 1-15, wherein the composition further comprises a vulcanizing agent in an amount of 0.4 phr to 15.0 phr.

[0098] Aspect 17. The composition according to aspect 16, wherein the vulcanizing agent comprises elemental sulfur, a sulfur-containing silane or a combination thereof.

[0099] Aspect 18. The composition according to any one of aspects 1-17, wherein the composition further comprises a vulcanization accelerator in an amount of 0.3 phr to 4.0 phr.

[0100] Aspect 19. The composition according to aspect 18, wherein the vulcanization accelerator comprises a dithiocarbamate / salt accelerator, a thiuram accelerator, a diphenylguanidine accelerator, a benzothiazole sulfenamide accelerator or a combination thereof.

[0101] Aspect 20. A vulcanized rubber composition comprising a vulcanized uncured composition according to any one of aspects 1-19.

[0102] Aspect 21. The composition according to aspect 20, wherein the tensile strength of the composition is about 5% to about 20% higher than the tensile strength of a cured composition that does not include pre-silanized silica, as determined by ASTM D412.

[0103] Aspect 22. The composition according to aspect 20 or 21, wherein the stiffness G′ of the composition at 1% strain, 100 °C, and a frequency of 1 Hz, based on ASTM D5289, is within 10% of that of a cured composition that does not include pre-silanized silica.

[0104] Aspect 23. The composition according to any one of aspects 20-22, wherein the composition has a tanδ at 6%, 30 °C, and a frequency of 7.8 Hz, based on DIN53513, which is about 10% to about 40% lower than the tanδ of a cured composition that does not include pre-silanized silica.

[0105] Aspect 24. An article comprising the vulcanized rubber composition of any one of aspects 20-23.

[0106] Aspect 25. The article according to aspect 24, wherein the article comprises a tire or a component of a tire.

[0107] Aspect 26. The article according to aspect 25, wherein the component of the tire comprises a tread, a base, a sidewall, a chafer, a bead wrapper, a sidewall insert, a wire rubber, a liner, or any combination thereof.

[0108] Aspect 27. The article according to aspect 25, wherein the component of the tire comprises a tread, a base, a sidewall, or any combination thereof.

[0109] Examples

[0110] The following examples are presented in order to provide a complete disclosure and description to those of ordinary skill in the art of how to make and evaluate the rubber compounds, compositions, articles, devices, and / or methods claimed herein. These examples are intended as illustrations of the disclosure only and are not intended to limit the scope that the inventors regard as their disclosure. Efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperatures, etc.), but some errors and deviations should be accounted for. Unless otherwise indicated, parts are parts by weight, temperatures are in °C or at ambient temperature, and pressures are atmospheric or near atmospheric.

[0111] Example 1: Rubber Composition

[0112] Table 1 provides two elastomeric compositions containing matrices based on solution-polymerized styrene-butadiene rubber (SSBR). Most of the components of the two compositions are the same. The most significant difference is that SSBR 2 contains presilanized silica, while SSBR 1 contains a comparable amount of conventional silica, i.e., non-presilanized silica.

[0113] The rheological properties of the SSBR 1 and SSBR 2 compositions are listed in Table 2. There is no change in the tensile strength between the two compositions. The tanδ value of the composition containing presilanized silica is reduced by about 14%, which is an improvement compared to the composition containing conventional silica. Since tanδ can be considered an indicator of hysteresis, this reduction also indicates a decrease in the rolling resistance of a tire containing the vulcanized SSBR 2 composition compared to a tire containing the vulcanized SSBR 1 composition. Unfortunately, the stiffness of the SSBR 2 composition is much lower than that of the SSBR 1 composition, and G′ in SSBR 2 is reduced by about 34% compared to SSBR 1. The use of presilanized silica in the elastomeric composition introduces this compromise (improved hysteresis for lower low-strain stiffness) due to improved silica dispersion. Although the reduced hysteresis is a positive result of introducing presilanized silica, the significant reduction in stiffness may be problematic for many performance-oriented tire applications.

[0114] Table 1: SSBR Rubber Compositions

[0115]

[0116]

[0117] 1 Solution-polymerized styrene-butadiene rubber, such as Trinseo's SLR4602

[0118] 2 Polybutadiene rubber, such as Goodyear's Budene TM 1223

[0119] 3 Polyterpene resin, such as Kraton Chemical's Sylvatraxx 4150

[0120] 4 TDAE oil

[0121] 5 Including glycerol monostearate and zinc soap of fatty acid

[0122] 6 Precipitated silica, such as Solvay's Zeosil TM Premium 200MP

[0123] 7 Presiliconized precipitated silica, such as Agilon from PPG Industries TM 400

[0124] 8 Bis - triethoxysilylpropyl disulfide, such as SI266 from Evonik TM

[0125] 9 Based on phenylenediamines

[0126] 10 Diphenyl guanidine (accelerator)

[0127] 11 N - cyclohexyl - 2 - benzothiazole sulfenamide (accelerator)

[0128] 12 50% bis - triethoxysilylpropyl tetrasulfide, on a 50% N330 carbon black carrier, such as X50S from Evonik

[0129] Table 2: Rheological properties

[0130] Property SSBR 1 SSBR 2 <![CDATA[G′(1%), 1Hz [MPa] a > 2.24 1.47 <![CDATA[tanδ(6%), 30℃ b > 0.22 0.19 <![CDATA[Tensile strength [MPa] c > 21.2 21.2

[0131] a G’ was obtained using the RPA 2000 from Alpha Technologies TM Rubber Process Analyzer at 1% strain, 100 °C, and a frequency of 1 Hz based on ASTM D5289

[0132] b tanδ was obtained by Metravib TM instrument at 6% strain and 7.8 Hz based on DIN 53513 or equivalent standards at a temperature of 30 °C

[0133] c Tensile strength was determined by testing S2 dumbbell specimens based on ASTM D412 or equivalent standards, and the tensile strength is the stress at break

[0134] Table 3 provides two elastomer compositions containing matrices based on partially hydrogenated SSBR (HSBR) (about 77% hydrogenated). Most of the components of the two compositions are the same. The most significant difference is that HSBR 2 contains presiliconized silica, while HSBR 1 contains a substantial amount of conventional silica, i.e., non - presiliconized silica.

[0135] The rheological properties of the HSBR 1 and HSBR 2 compositions are listed in Table 4. Similar to SSBR 1 and 2, the tanδ value of the composition containing presilanized silica is reduced compared to the composition containing conventional silica. However, in the HSBR composition, when presilanized silica is used, the reduction of tanδ is more significant (about 29%). In addition, compared with the change in stiffness from SSBR 1 to SSBR 2, the stiffness of the presilanized silica composition HSBR 2 is very close to that of HSBR 1, where the reduction of G′ is less than 10%. Surprisingly, the HSBR 2 composition also shows an increase in tensile strength compared to HSBR 1. It is difficult to improve both the tensile strength and the hysteresis performance at the same time. HSBR 2 has good stiffness, good rolling resistance index and good tensile strength.

[0136] Table 3: Exemplary Rubber Compositions

[0137]

[0138]

[0139] 1 Presilanized precipitated silica, such as Agilon from PPG Industries TM 400

[0140] 2 Precipitated silica, such as Zeosil from Solvay TM Premium 200MP

[0141] 3 Partially hydrogenated SSBR (77% ± 3% butadiene hydrogenation)

[0142] 4 Bis-triethoxysilylpropyl disulfide, such as SI266 from Evonik TM

[0143] 5 Phenylenediamine derivative

[0144] 6 N-cyclohexyl-2-benzothiazole sulfenamide - CBS

[0145] 7 2-mercaptobenzothiazole - MBT

[0146] 8 Diphenylguanidine

[0147] Table 4: Rheological Properties

[0148] Property HSBR1 HSBR2 <![CDATA[G′(1%), 1Hz [MPa] a > 2.33 2.16 <![CDATA[Tanδ (6%), 30 °C b > 0.21 0.15 <![CDATA[Tensile strength [MPa] c > 17.8 19.9

[0149] a G’ is obtained using the RPA 2000 from Alpha Technologies TM Rubber Process Analyzer at 1% strain, 100 °C, and a frequency of 1 Hz, based on ASTM D5289

[0150] b tanδ is obtained by Metravib TM instrument at 6% strain and 7.8 Hz, based on DIN 53513 or equivalent standards, at a temperature of 30 °C

[0151] c The tensile strength is determined by testing S2 dumbbell specimens based on ASTM D412 or equivalent standards, and the tensile strength is the stress at break

[0152] It should be emphasized that the above embodiments of the present disclosure are merely possible examples of embodiments set forth for the purpose of clearly understanding the principles of the present disclosure. Many variations and modifications can be made to the above one or more embodiments without substantially departing from the spirit and principles of the present disclosure. All such modifications and variations are intended to be included within the scope of the present disclosure and be protected by the appended claims.

Claims

1. An uncured composition comprising: At least one partially saturated elastomer comprising repeating units, wherein greater than 15% to about 30% of all of the repeating units of the partially saturated elastomer comprise double bonds, and From about 40 phr to about 200 phr of a presilanized silica.

2. The composition according to claim 1, wherein from about 16% to about 25% of all of the repeating units of the partially saturated elastomer comprise double bonds.

3. The composition according to claim 1, wherein the partially saturated elastomer comprises repeating units formed from residues of one or more monomers selected from ethylene, propylene, butadiene, isoprene, styrene, and any combination thereof.

4. The composition according to claim 1, wherein the partially saturated elastomer is a partially hydrogenated styrene-butadiene rubber.

5. The composition according to claim 4, wherein the partially hydrogenated styrene-butadiene rubber has from about 15% to about 25% of repeating units comprising double bonds.

6. The composition according to claim 4, wherein the styrene content of the partially hydrogenated styrene-butadiene rubber is from about 5 wt% to about 40 wt% of the partially hydrogenated styrene-butadiene rubber, and the butadiene content is from about 60 wt% to about 95 wt% of the partially hydrogenated styrene-butadiene rubber.

7. The composition according to claim 4, wherein the glass transition temperature of the partially hydrogenated styrene-butadiene rubber is from about -70 °C to about -20 °C.

8. The composition according to claim 4, wherein the weight average molecular weight of the partially hydrogenated styrene-butadiene rubber is from about 100 kg / mol to about 1500 kg / mol.

9. A vulcanized rubber composition comprising the uncured composition of claim 1 that has been vulcanized.

10. An article comprising the vulcanized rubber composition of claim 17.

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