阅读说明：本技术 用于充气轮胎的橡胶组合物 (Rubber composition for pneumatic tire ) 是由 艾琳·希普沃什 于 2020-04-26 设计创作，主要内容包括：本发明提供一种可硫化橡胶组合物,该可硫化橡胶组合物包含：(i)橡胶组分,该橡胶组分包含聚异戊二烯弹性体；(ii)硫基固化剂；(iii)氧化锌；和(iv)共熔组合物。(The present invention provides a vulcanizable rubber composition comprising: (i) a rubber component comprising a polyisoprene elastomer; (ii) a sulfur-based curing agent; (iii) zinc oxide; and (iv) a eutectic composition.)

1. A vulcanizable rubber composition, comprising:

(i) a rubber component comprising a polyisoprene elastomer;

(ii) a sulfur-based curing agent;

(iii) zinc oxide; and

(iv) a eutectic composition.

2. The vulcanizable composition of any one of the preceding claims, wherein the rubber component comprises greater than 60 wt.% of the polyisoprene elastomer.

3. The vulcanizable composition of any one of the preceding claims, wherein the rubber component comprises greater than 70 wt.% of the polyisoprene elastomer.

4. The vulcanizable composition of any one of the preceding claims, wherein the rubber component comprises greater than 80 wt.% of the polyisoprene elastomer.

5. The vulcanizable composition of any one of the preceding claims, wherein the rubber component comprises greater than 90 wt.% of the polyisoprene elastomer.

6. The vulcanizable composition of any one of the preceding claims, wherein the polyisoprene elastomer is natural rubber.

7. The vulcanizable composition of any one of the preceding claims, wherein the eutectic composition is represented by the formula Cat⁺X^-zY is defined wherein Cat⁺Is a cation, X^-Is a counter anion (e.g., lewis base), and z refers to the number of Y molecules that interact with the counter anion (e.g., lewis base).

8. The vulcanizable composition of any one of the preceding claims, wherein Cat⁺Is an ammonium, phosphonium or sulfonium cation, and X^-Is a halide ion.

9. The vulcanizable composition of any one of the preceding claims, wherein the eutectic composition is selected from the group consisting of type I, type II, type III, and type IV eutectic compositions.

10. The vulcanizable composition of any one of the preceding claims, wherein the eutectic composition is formed by mixing an ammonium compound with a metal halide, a metal halide hydrate, or a hydrogen bond donor.

11. The vulcanizable composition of any one of the preceding claims, wherein the ammonium compound an ammonium compound may be defined by formula II:

(R₁)(R₂)(R₃)(R₄)—N⁺—Φ^–

wherein each R₁、R₂、R₃And R₄Independently hydrogen or a monovalent organic group, or alternatively, R₁、R₂、R₃And R₄Are joined to form a divalent organic group, and Φ^–Are counter anions.

12. The vulcanizable composition according to any of the preceding claims, wherein the ammonium compound is selected from the group consisting of N-ethyl-2-hydroxy-N, N-dimethylethylammonium chloride, 2-hydroxy-N, N, N-trimethylethylammonium chloride (which is also known as choline chloride), and N-benzyl-2-hydroxy-N, N-dimethylethylammonium chloride.

13. The vulcanizable composition according to any of the preceding claims, wherein the ammonium compound is selected from 2-chloro-N, N, N-trimethylethanaminium (which is also known as chlorocholine chloride) and 2- (chlorocarbonyloxy) -N, N, N-trimethylethanaminium chloride.

14. The vulcanizable composition according to any one of the preceding claims, wherein the hydrogen bond donor is selected from the group consisting of amines, amides, carboxylic acids and alcohols.

15. The vulcanizable composition of any one of the preceding claims, wherein the hydrogen bond donor is selected from the group consisting of aliphatic amines, ethylene diamine, diethylene triamine, aminoethylpiperazine, triethylene tetramine, tris (2-aminoethyl) amine, N' -bis- (2 aminoethyl) piperazine, piperazineethylethylene diamine and tetraethylenepentamine, propylene diamine, aniline, substituted anilines, and combinations thereof.

16. The vulcanizable composition of any one of the preceding claims, wherein the hydrogen bond donor is selected from the group consisting of urea, 1-methylurea, 1-dimethylurea, 1, 3-dimethylurea, thiourea, urea, benzamide, acetamide, and combinations thereof.

17. The vulcanizable composition of any one of the preceding claims, wherein the hydrogen bond donor is selected from the group consisting of phenylpropionic acid, phenylacetic acid, benzoic acid, oxalic acid, malonic acid, adipic acid, succinic acid, citric acid, tricarballylic acid, and combinations thereof.

18. The vulcanizable composition of any one of the preceding claims, wherein the hydrogen bond donor is selected from the group consisting of aliphatic alcohols, phenols, substituted phenols, ethylene glycol, propylene glycol, resorcinol, substituted resorcinols, glycerol, benzenetriols, and mixtures thereof.

19. The vulcanizable composition of any one of the preceding claims, wherein the metal halide is selected from the group consisting of aluminum chloride, aluminum bromide, aluminum iodide, zinc chloride, zinc bromide, zinc iodide, tin chloride, tin bromide, tin iodide, ferric chloride, ferric bromide, ferric iodide, and combinations thereof.

20. The vulcanizable composition of matter of any one of the preceding claims, wherein the vulcanizable composition comprises greater than 1.5pbw zinc oxide per 100pbw rubber.

21. The vulcanizable composition of matter of any one of the preceding claims, wherein the vulcanizable composition comprises greater than 2.0pbw zinc oxide per 100pbw rubber.

22. The vulcanizable composition of matter of any one of the preceding claims, wherein the vulcanizable composition comprises from about 0.005pbw to about 3pbw of the eutectic composition per 100pbw rubber.

23. The vulcanizable composition of matter of any one of the preceding claims, wherein the vulcanizable composition comprises from about 0.01 to about 1pbw of the eutectic composition per 100pbw of rubber.

24. The vulcanizable composition of any one of the preceding claims, wherein the vulcanizable composition further comprises a reinforcing filler, a resin, and a wax.

25. The vulcanizable composition of any one of the preceding claims, wherein the vulcanizable composition comprises less than 25pbw oil per 100pbw rubber.

26. The vulcanizable composition of any one of the preceding claims, wherein the vulcanizable composition comprises less than 15pbw oil per 100pbw rubber.

27. The vulcanizable composition of any one of the preceding claims, wherein the vulcanizable composition is free of oil.

28. The vulcanizable composition of any one of the preceding claims, wherein the sulfur-based curing agent is sulfur.

29. The vulcanizable composition of any one of the preceding claims, wherein in phr, the vulcanizable composition comprises from about 0.8pbw to about 2.5pbw sulfur.

30. A vulcanized rubber prepared from the vulcanizable composition of matter of any one of the preceding claims.

31. The vulcanizate of any of the preceding claims, where the vulcanizate is a component of a heavy vehicle tire.

32. The vulcanizate of any of the preceding claims, where the vulcanizate is a tread or undertread of a heavy vehicle tire.

33. The vulcanizate of any of the preceding claims, wherein the heavy vehicle tire is an off-road tire.

34. The vulcanizate of any of the preceding claims, wherein the heavy vehicle tire is an aircraft tire.

35. The vulcanizate of any of the preceding claims, where the vulcanizate is characterized by a percent reversion of less than 20%.

36. The vulcanizate of any of the preceding claims, where the vulcanizate is characterized by a percent reversion of less than 18%.

Technical Field

Embodiments of the present invention relate to rubber compositions for pneumatic tires, particularly polyisoprene-based rubber formations.

Background

Polyisoprene rubber (such as natural rubber) is commonly used in the manufacture of components for pneumatic tires. Natural rubber is advantageously used at relatively significant levels in tire components of heavy vehicles, such as, for example, truck tires, bus tires, subway train tires, tractor trailer tires, aircraft tires, agricultural tires, bulldozer tires, and other off-the-road (OTR) tires, due to strain-induced crystallization of natural rubber.

However, natural rubber is susceptible to a relatively high degree of rubber reversion, a phenomenon generally understood to result in a loss of desirable properties such as mechanical strength and dynamic modulus. Reversion is believed to be caused by the breaking of sulfur crosslinks within the sulfur vulcanized rubber system.

Disclosure of Invention

One or more embodiments of the present invention provide a vulcanizable rubber composition comprising: (i) a rubber component comprising a polyisoprene elastomer; (ii) a sulfur-based curing agent; (iii) zinc oxide; and (iv) a eutectic composition.

Drawings

The figure is a graph of rubber reversion as a function of eutectic solvent loading for various experimental samples.

Detailed Description

Embodiments of the present invention are based, at least in part, on the discovery of polyisoprene vulcanizates, which are characterized by an advantageous balance of properties. According to an embodiment of the invention, the vulcanized rubber is prepared from a vulcanizable composition comprising a eutectic composition. It has been unexpectedly found that by including a eutectic composition in a polyisoprene-based vulcanizable composition, one or more advantageous properties, such as increased reversion resistance and increased toughness, can be achieved.

Polyisoprenyl vulcanizable compositions

As noted above, the vulcanizates of this invention are prepared from polyisoprene-based vulcanizable compositions. According to one or more embodiments, the polyisoprene-based vulcanizable composition comprises: a vulcanizable rubber component comprising a threshold amount of polyisoprene elastomer; a eutectic composition; a filler; a sulfur-based curing agent; stearic acid; and metal compounds such as zinc oxide or zinc oxide derivatives. Other optional ingredients may also be included such as, but not limited to, processing and/or extender oils, resins, waxes, cure accelerators, scorch inhibitors, antidegradants, antioxidants, and other rubber compounding additives known in the art.

Vulcanizable rubber component

In one or more embodiments, the vulcanizable rubber component includes a polyisoprene polymer (which may also be referred to as a polyisoprene elastomer), and optionally one or more additional vulcanizable polymers (which may be referred to as elastomers other than polyisoprene polymers or complementary polymers). Polyisoprene polymers include synthetic polyisoprene and natural rubber.

In one or more embodiments, other optional additional vulcanizable polymers may include those polymers that can be vulcanized to form compositions having rubber or elastomeric properties. These elastomers may include synthetic rubbers. Useful synthetic rubbers may be derived from the polymerization of conjugated diene monomer (e.g., 1.3-butadiene), the copolymerization of conjugated diene monomer with other monomers such as vinyl-substituted aromatic monomers, or the copolymerization of ethylene with one or more alpha-olefins and optionally one or more diene monomers. These additional vulcanizable polymers include synthetic isoprene-based polymers, which include copolymers of isoprene and monomers copolymerizable therewith. Exemplary isoprene-based polymers include, for example, poly (styrene-co-isoprene), poly (styrene-co-isoprene-co-butadiene), polyisobutylene-co-isoprene and poly (isobutylene-co-isoprene), synthetic isoprene-based polymers.

Exemplary elastomers that may be included in the rubber component with the polyisoprene polymer include polybutadiene, neoprene, poly (ethylene-co-propylene), poly (styrene-co-butadiene), poly (ethylene-co-propylene-co-diene), polysulfide rubber, acrylic rubber, polyurethane rubber, silicone rubber, epichlorohydrin rubber, and mixtures thereof. These elastomers may have a wide variety of macromolecular structures including linear structures, branched structures, and star structures. These elastomers may also contain one or more functional units, which typically include heteroatoms.

As noted above, the rubber component comprises at least a threshold amount of polyisoprene polymer. Threshold amounts include those amounts that have a significant impact on the practice of the invention. In one or more embodiments, the rubber component of the vulcanizable compositions of the invention includes greater than 50, in other embodiments greater than 55, in other embodiments greater than 60, in other embodiments greater than 65, in other embodiments greater than 70, in other embodiments greater than 75, in other embodiments greater than 80, in other embodiments greater than 85, in other embodiments greater than 90, in other embodiments greater than 95, in other embodiments greater than 97, and in other embodiments greater than 99 weight percent polyisoprene elastomer based on the total weight of the rubber component. In particular embodiments, the rubber component is free or substantially free of vulcanizable rubber other than polyisoprene polymer. In particular embodiments, the rubber component is free or substantially free of vulcanizable rubber other than natural rubber.

Eutectic mixture

In one or more embodiments, eutectic compositions include those formed by mixing two or more compounds that provide a resulting combination having a melting point that is lower than the respective compounds being mixed. For purposes of this specification, a eutectic composition may be referred to as a eutectic mixture, eutectic composition, or eutectic pair. Each of the mixed compounds may be referred to as a eutectic composition, a eutectic component, a eutectic member, or a compound used to form a eutectic composition (e.g., a first compound and a second compound), respectively. Depending on the relative amounts of the respective eutectic components and the temperature at which the observation is made, the eutectic composition may be in the form of a liquid, which may be referred to as a eutectic liquid or a eutectic solvent. Where the relative amounts of the respective ingredients are at or near the lowest melting point of the eutectic mixture for a given composition, then the composition may be referred to as a deep eutectic solvent, which may be referred to as DES.

Without wishing to be bound by any particular theory, it is believed that the eutectic components mix, or otherwise react or interact to form a complex. Thus, any reference to a eutectic mixture or eutectic combination, pair or compound will include the combination and reaction product or compound between the components being mixed and result in a composition having a lower melting point than the corresponding component. For example, in one or more embodiments, useful eutectic compositions may be defined by formula I:

Cat⁺X^-zY

wherein Cat⁺Is a cation, X^-Is a counter anion (e.g., lewis base), and z refers to the number of Y molecules that interact with the counter anion (e.g., lewis base). For example, Cat⁺Ammonium, phosphonium or sulfonium cations may be included. X^-May include, for example, halide ions. In one or more embodiments, z is the amount of solvent that achieves deep eutectic, or in other embodiments, the amount of compound that otherwise achieves a melting point lower than the corresponding eutectic component.

In one or more embodiments, useful eutectic compositions include a combination of acids and bases, where the acids and bases may include lewis acids and lewis bases or bronsted acids and bronsted bases. In one or more embodiments, useful eutectic compositions include a combination of a quaternary ammonium salt and a metal halide (which is referred to as a type I eutectic composition), a combination of a quaternary ammonium salt and a metal halide hydrate (which is referred to as a type II eutectic composition), a combination of a quaternary ammonium salt and a hydrogen bond donor (which is referred to as a type III eutectic composition), or a combination of a metal halide hydrate and a hydrogen bond donor (which is referred to as a type IV eutectic composition). Similar combinations of sulfonium or phosphonium salts in place of ammonium compounds can also be employed and are readily envisioned by those skilled in the art.

Quaternary ammonium salts

In one or more embodiments, the quaternary ammonium salt is a solid at 20 ℃. In these or other embodiments, the metal halide and hydrogen bond donor are solid at 20 ℃.

In one or more embodiments, useful quaternary ammonium salts (also referred to as ammonium compounds) may be defined by formula II:

(R₁)(R₂)(R₃)(R₄)—N⁺—Φ^–

wherein each R₁、R₂、R₃And R₄Independently hydrogen or a monovalent organic group, or alternatively, R₁、R₂、R₃And R₄Are joined to form a divalent organic group, and Φ^–Are counter anions. In one or more embodiments, R₁、R₂、R₃And R₄At least one, in other embodiments at least two, and in other embodiments at least three are not hydrogen.

In one or more embodiments, the counter anion (e.g., Φ)^–) Selected from the group consisting of halides (X)^-) Nitrate radical (NO)₃ ^-) Tetrafluoroborate (BF)₄ ^-) Perchlorate (ClO)₄ ^-) Triflate (SO)₃CF₃ ^-) Trifluoroacetic acid (COOCF)₃ ^-). In one or more embodiments, Φ^–Are halide ions, and in certain embodiments are chloride ions.

In one or more embodiments, the monovalent organic group comprises a hydrocarbyl group, and the divalent organic group comprises a hydrocarbylene group. In one or more embodiments, monovalent and divalent organic groups include heteroatoms, such as, but not limited to, oxygen and nitrogen, and/or halogen atoms. Thus, monovalent organic groups may include alkoxy groups, siloxy groups, ether groups, and ester groups, as well as carbonyl or acetyl substituents. In one or more embodiments, the hydrocarbyl and hydrocarbylene groups include from 1 (or a suitable minimum number) to about 18 carbon atoms, in other embodiments from 1 to about 12 carbon atoms, and in other embodiments from 1 to about 6 carbon atoms. The hydrocarbyl and hydrocarbylene groups may be branched, cyclic or linear. Exemplary types of hydrocarbyl groups include alkyl, cycloalkyl, aryl, and alkaryl groups. Exemplary types of alkylene groups include alkylene, cycloalkylene, arylene, and alkylarylene groups. In particular embodiments, the hydrocarbyl group is selected from methyl, ethyl, octadecyl, phenyl, and benzyl groups. In certain embodiments, the hydrocarbyl group is a methyl group and the alkylene group is an ethylene or propylene group.

Useful types of ammonium compounds include secondary ammonium compounds, tertiary ammonium compounds, and quaternary ammonium compounds. In these or other embodiments, the ammonium compound includes an ammonium halide, such as, but not limited to, ammonium chloride. In a particular embodiment, the ammonium compound is a quaternary ammonium chloride. In certain embodiments, R₁、R₂、R₃And R₄Is hydrogen and the ammonium compound is ammonium chloride. In one or more embodiments, the ammonium compound is asymmetric.

In one or more embodiments, the ammonium compound comprises an alkoxy group and may be defined by formula III:

(R₁)(R₂)(R₃)—N⁺—(R₄—OH)Φ^–

wherein each R₁、R₂And R₃Independently hydrogen or a monovalent organic group, or alternatively, R₁、R₂And R₃Are joined to form a divalent organic group, R₄Is a divalent organic radical and Φ^–Are counter anions. In one or more embodiments, R₁、R₂、R₃At least one, in other embodiments at least two, and in other embodiments at least three are not hydrogen.

Examples of ammonium compounds defined by formula III include, but are not limited to, N-ethyl-2-hydroxy-N, N-dimethylethyl ammonium chloride, 2-hydroxy-N, N-trimethylethanyl ammonium chloride (which is also known as choline chloride), and N-benzyl-2-hydroxy-N, N-dimethylethyl ammonium chloride.

In one or more embodiments, the ammonium compound includes halogen-containing substituents and may be defined by formula IV:

Φ^–—(R₁)(R₂)(R₃)—N⁺—R₄X

wherein each R₁、R₂And R₃Independently hydrogen or a monovalent organic group, or alternatively, R₁、R₂And R₃Are joined to form a divalent organic group, R₄Is a divalent organic group, X is a halogen atom, and Φ^–Are counter anions. In one or more embodiments, R₁、R₂And R₃At least one, in other embodiments at least two, and in other embodiments at least three are not hydrogen. In one or more embodiments, X is chlorine.

Examples of ammonium compounds defined by formula III include, but are not limited to, 2-chloro-N, N-trimethylethanaminium (which is also known as chlorocholine chloride) and 2- (chlorocarbonyloxy) -N, N-trimethylethanaminium chloride.

Hydrogen bond donor compounds

In one or more embodiments, hydrogen bond donor compounds (which may also be referred to as HBD compounds) include, but are not limited to, amines, amides, carboxylic acids, and alcohols. In one or more embodiments, the hydrogen bond donor compound comprises a hydrocarbon chain component. The hydrocarbon chain component may include a carbon chain length of at least 2 carbon atoms, in other embodiments at least 3 carbon atoms, and in other embodiments at least 5 carbon atoms. In these or other embodiments, the hydrocarbon chain component has a carbon chain length of less than 30 carbon atoms, in other embodiments less than 20 carbon atoms, and in other embodiments less than 10 carbon atoms.

In one or more embodiments, useful amines include those compounds defined by the formula:

R₁—(CH₂)_x—R₂

wherein R is₁And R₂is-NH₂、—NHR₃or-NR₃R₄And x is an integer of at least 2. In one or more embodiments, x is from 2 to about 10, in other embodiments from about 2 to about 8, and in other embodiments from about 2 to about 6.

Specific examples of useful amines include, but are not limited to, aliphatic amines, ethylene diamine, diethylene triamine, aminoethylpiperazine, triethylene tetramine, tris (2-aminoethyl) amine, N' -bis- (2 aminoethyl) piperazine, piperazineethylethylene diamine and tetraethylenepentamine, propylene diamine, aniline, substituted anilines, and combinations thereof.

In one or more embodiments, useful amines include those compounds defined by the formula:

R—CO—NH₂

wherein R is H, NH₂、CH₃Or CF₃。

Specific examples of useful amines include, but are not limited to, urea, 1-methylurea, 1-dimethylurea, 1, 3-dimethylurea, thiourea, urea, benzamide, acetamide, and combinations thereof.

In one or more embodiments, useful carboxylic acids include monofunctional, difunctional, and trifunctional organic acids. These organic acids may include alkyl acids, aryl acids, and mixed alkyl-aryl acids.

Specific examples of useful monofunctional carboxylic acids include, but are not limited to, aliphatic acids, phenylpropionic acid, phenylacetic acid, benzoic acid, and combinations thereof. Specific examples of difunctional carboxylic acids include, but are not limited to, oxalic acid, malonic acid, adipic acid, succinic acid, and combinations thereof. Specific examples of trifunctional carboxylic acids include citric acid, tricarballylic acid, and combinations thereof.

Types of alcohols include, but are not limited to, monohydric alcohols, dihydric alcohols, and trihydric alcohols. Specific examples of monohydric alcohols include aliphatic alcohols, phenols, substituted phenols, and mixtures thereof. Specific examples of diols include ethylene glycol, propylene glycol, resorcinol, substituted resorcinols, and mixtures thereof. Specific examples of triols include, but are not limited to, glycerol, benzene triol, and mixtures thereof.

Metal halides

Types of metal halides include, but are not limited to, chloride, bromide, iodide, and fluoride. In one or more embodiments, these metal halides include, but are not limited to, transition metal halides. The skilled person can easily imagine the corresponding metal halide hydrate.

Specific examples of useful metal halides include, but are not limited to, aluminum chloride, aluminum bromide, aluminum iodide, zinc chloride, zinc bromide, zinc iodide, tin chloride, tin bromide, tin iodide, ferric chloride, ferric bromide, ferric iodide, and combinations thereof. The skilled person can easily imagine the corresponding metal halide hydrate. For example, aluminum chloride hexahydrate and copper chloride dihydrate correspond to the above halides.

Eutectic compound formation

The skilled artisan can select the appropriate eutectic members in the appropriate molar ratios to provide the desired eutectic composition. The skilled artisan understands that the molar ratio of the first compound of the pair (e.g., lewis base) to the second compound of the pair (e.g., lewis acid) will vary based on the compound selected. As the skilled person will also appreciate, the melting point depression of the eutectic solvent includes the eutectic point, which is the molar ratio of the first compound to the second compound that yields the maximum melting point depression (i.e. the deep eutectic solvent). However, the molar ratio of the first compound to the second compound can be varied to produce a melting point depression of the eutectic solvent relative to the individual melting points of the first compound and the second compound that is not a minimum melting point (i.e., not a maximum depression point). Thus, operation of one or more embodiments of the present invention includes forming the eutectic solvent at a molar ratio other than the eutectic point.

In one or more embodiments, the compounds of the eutectic pair, and the molar ratio of the first compound to the second compound of the pair, are selected to produce a mixture having a melting point of less than 130 ℃, in other embodiments less than 110 ℃, in other embodiments less than 100 ℃, in other embodiments less than 80 ℃, in other embodiments less than 60 ℃, in other embodiments less than 40 ℃, and in other embodiments less than 30 ℃. In these or other embodiments, the compounds of the eutectic pair and the molar ratios of the compounds are selected to produce a mixture having a melting point above 0 ℃, in other embodiments above 10 ℃, in other embodiments above 20 ℃, in other embodiments above 30 ℃, and in other embodiments above 40 ℃.

In one or more embodiments, the compounds of the eutectic pair and the molar ratio of the first compound to the second compound of the pair are selected to produce a eutectic solvent having the ability or capacity to dissolve the desired metal compound, which may be referred to as solubility or solvency. As the skilled person will appreciate, when preparing a saturated solution, the solubility may be quantified based on the weight of metal compound dissolved in a given weight of eutectic solvent at a specified temperature and pressure over a specified time. In one or more embodiments, the eutectic solvent of the present invention is selected to achieve a solubility of zinc oxide of greater than 100ppm, in other embodiments greater than 500ppm, in other embodiments greater than 1000ppm, in other embodiments greater than 1200ppm, in other embodiments greater than 1400ppm, and in other embodiments greater than 1600ppm, as measured by weight of solute versus weight of solvent, within 24 hours at 50 ℃ and atmospheric pressure.

In one or more embodiments, the eutectic solvent (i.e., the liquid composition at the desired temperature) is formed by mixing the first compound and the second compound in an appropriate molar ratio to provide a solvent composition. The mixture may be mechanically agitated by using a variety of techniques including, but not limited to, solid state mixing or blending techniques. Generally, the mixture is mixed or otherwise agitated until a visually homogeneous liquid is formed. Additionally, the mixture may be formed at elevated temperatures. For example, the eutectic solvent may be formed by heating the mixture to a temperature greater than 50 ℃, in other embodiments greater than 70 ℃, and in other embodiments greater than 90 ℃. Mixing may continue during heating of the mixture. Once the desired mixture is formed, the eutectic solvent may be cooled to room temperature. In one or more embodiments, the cooling of the eutectic solvent may be performed at a controlled rate, such as at a rate of less than 1 ℃/min.

In one or more embodiments, useful eutectic compositions are commercially available. For example, the deep eutectic solvent is commercially available from Scionix under the trade name Ionic Liquids. Useful eutectic compositions are also generally known, as described in U.S. publication nos. 2004/0097755 a1 and 2011/0207633 a1, which are incorporated herein by reference.

Filler material

As noted above, the vulcanizable compositions of the invention may include one or more fillers. These filler materials may include reinforcing and non-reinforcing fillers. Exemplary fillers include carbon black, silica, and various inorganic fillers.

Useful carbon blacks include furnace blacks, channel blacks, and lamp blacks. More specific examples of the carbon black include super abrasion furnace black, medium super abrasion furnace black, high abrasion furnace black, fast extrusion furnace black, fine furnace black, semi-reinforcing furnace black, medium processing channel black, difficult processing channel black, conducting channel black, and acetylene black.

In one or more embodiments, the carbon black may have a surface area of greater than 60g/kg, in other embodiments greater than 70g/kg, in other embodiments greater than 80g/kg, and in other embodiments greater than 90g/kg, as defined by the iodine adsorption number determined according to ASTM D1510. In these or other embodiments, the carbon black may have a surface area, such as by Brunauer, Emmet, and Teller ("BET)") method (described in journal of the american chemical society (j.am. chem. soc.), volume 60, p. 309), which is about 70 to 200m²A/g, in other embodiments from about 100 to about 180m²A/g, and in other embodiments from about 110 to about 160m²(ii) in terms of/g. The carbon black may be in particulate form or non-particulate flocculent form. The preferred form of carbon black may depend on the type of mixing equipment used to mix the rubber compound.

In one or more embodiments, useful carbon blacks may be characterized as carbon blacks of the N-300 series or lower according to ASTM D1765. These carbon blacks may include, for example, the N-100 series, N-200 series, and N-300 series carbon blacks. Exemplary N-100 series carbon blacks include N-100, N-115, N-120, N-121, N-125, N-134, and N-135 carbon blacks. Exemplary N-200 series carbon blacks may include N-220, N-231, N-294, and N-299. Exemplary N-300 series carbon blacks may include N-326, N-330, N-335, N-343, N-347, N-351, N-356, N-358, and N-375.

Examples of suitable silica fillers include precipitated amorphous silica, wet silica (hydrated silicic acid), dry silica (anhydrous silicic acid), fumed silica, calcium silicate, aluminum silicate, magnesium silicate, and the like.

In one or more embodiments, the silica may be characterized by its surface area, which gives a measure of its reinforcing properties. Brunauer, Emmet and Teller ("BET") methods (described in journal of the american chemical society (j.am. chem. soc.), volume 60, page 309, et seq.) are accepted methods for determining surface area. The BET surface area of the silica is generally less than 450m²(ii) in terms of/g. Useful ranges for surface area include about 32 to about 400m²Per g, from about 100 to about 250mm²(ii) g and from about 150 to about 220m²/g。

Where one or more silicas are employed, the pH of the silica is typically from about 5 to about 7 or slightly above 7, or in other embodiments from about 5.5 to about 6.8.

In one or more embodiments, when silica is employed as a filler (alone or in combination with other fillers), a coupling agent and/or a masking agent may be added to the rubber composition during mixing in order to enhance the interaction of the silica with the elastomer. Useful coupling and masking agents are disclosed in U.S. Pat. Nos. 3,842,111, 3,873,489, 3,978,103, 3,997,581, 4,002,594, 5,580,919, 5,583,245, 5,663,396, 5,674,932, 5,684,171, 5,684,172, 5,696,197, 6,608,145, 6,667,362, 6,579,949, 6,590,017, 6,525,118, 6,342,552, and 6,683,135, which are incorporated herein by reference. Examples of the sulfur-containing silica coupling agent include bis (trialkoxysilylorgano) polysulfide or mercaptoorganoalkoxysilane. Types of bis (trialkoxysilylorgano) polysulfides include bis (trialkoxysilylorgano) disulfide and bis (trialkoxysilylorgano) tetrasulfide.

Other useful filler materials include various inorganic and organic fillers. Examples of organic fillers include starch. Examples of the inorganic filler include silica, aluminum hydroxide, magnesium hydroxide, titanium oxide, boron nitride, iron oxide, mica, talc (hydrous magnesium silicate), and clay (hydrous aluminum silicate).

Resin composition

In one or more embodiments, the vulcanizable compositions of the invention may include one or more resins. As understood by the skilled person, the resin may comprise a plasticizing resin and a hardening or thermosetting resin. Useful plasticizing resins include hydrocarbon resins such as cycloaliphatic resins, aliphatic resins, aromatic resins, terpene resins, and combinations thereof. Useful resins are commercially available from a variety of companies under various trade names, including, for example, Chemfax, Dow Chemical Company, Eastman Chemical Company, Idemitsu, Neville Chemical Company, Nippon, Polysat inc., Resinall corp., Pinova inc., Yasuhara Chemical co., ltd., Arizona Chemical and SI Group inc., and Zeon.

In one or more embodiments, useful hydrocarbon resins may be characterized by a glass transition temperature (Tg) of from about 30 ℃ to about 160 ℃, in other embodiments from about 35 ℃ to about 60 ℃, and in other embodiments from about 70 ℃ to about 110 ℃. In one or more embodiments, useful hydrocarbon resins may also be characterized by having a softening point above its Tg. In certain embodiments, useful hydrocarbon resins have a softening point of from about 70 ℃ to about 160 ℃, in other embodiments from about 75 ℃ to about 120 ℃, and in other embodiments from about 120 ℃ to about 160 ℃.

In certain embodiments, one or more cycloaliphatic resins are used in combination with one or more of aliphatic resins, aromatic resins, and terpene resins. In one or more embodiments, one or more cycloaliphatic resins are used as the major weight component (e.g., greater than 50 weight percent) relative to the total loading of the resin. For example, the resin employed comprises at least 55%, in other embodiments at least 80%, and in other embodiments at least 99% by weight of one or more cycloaliphatic resins.

In one or more embodiments, cycloaliphatic resins include both cycloaliphatic homopolymer resins and cycloaliphatic copolymer resins, including those derived from cycloaliphatic monomers, optionally in combination with one or more other (non-cycloaliphatic) monomers, wherein a majority by weight of all monomers are cycloaliphatic. Non-limiting examples of useful cycloaliphatic resins suitably include cyclopentadiene ("CPD") homopolymer or copolymer resins, dicyclopentadiene ("DCPD") homopolymer or copolymer resins, and combinations thereof. Non-limiting examples of the alicyclic copolymer resin include CPD/vinyl aromatic copolymer resin, DCPD/vinyl aromatic copolymer resin, CPD/terpene copolymer resin, DCPD/terpene copolymer resin, CPD/aliphatic copolymer resin (e.g., CPD/C5 fraction copolymer resin), DCPD/aliphatic copolymer resin (e.g., DCPD/C5 fraction copolymer resin), CPD/aromatic copolymer resin (e.g., CPD/C9 fraction copolymer resin), DCPD/aromatic copolymer resin (e.g., DCPD/C9 fraction copolymer resin), CPD/aromatic-aliphatic copolymer resin (e.g., CPD/C5 and C9 fraction copolymer resin), DCPD/aromatic-aliphatic copolymer resin (e.g., DCPD/C5 and C9 fraction copolymer resin), and the like, CPD/vinyl aromatic copolymer resins (e.g., CPD/styrene copolymer resins), DCPD/vinyl aromatic copolymer resins (e.g., DCPD/styrene copolymer resins), CPD/terpene copolymer resins (e.g., limonene/CPD copolymer resins), and DCPD/terpene copolymer resins (e.g., limonene/DCPD copolymer resins). In certain embodiments, the cycloaliphatic resin may comprise a hydrogenated version of one of the cycloaliphatic resins described above (i.e., a hydrogenated cycloaliphatic resin). In other embodiments, the cycloaliphatic resin does not include any hydrogenated cycloaliphatic resin; in other words, the cycloaliphatic resin is not hydrogenated.

In certain embodiments, one or more aromatic resins are used in combination with one or more of aliphatic resins, cycloaliphatic resins, and terpene resins. In one or more embodiments, one or more aromatic resins are used as the major weight component (e.g., greater than 50 weight percent) relative to the total loading of the resin. For example, the resin employed comprises at least 55 weight percent, in other embodiments at least 80 weight percent, and in other embodiments at least 99 weight percent of one or more aromatic resins.

In one or more embodiments, aromatic resins include both aromatic homopolymer resins and aromatic copolymer resins, including those derived from the combination of one or more aromatic monomers with one or more other (non-aromatic) monomers, with the largest amount of any type of monomer being aromatic. Non-limiting examples of useful aromatic resins include coumarone-indene resins and alkyl-phenol resins, as well as vinyl aromatic homopolymer or copolymer resins, such as those derived from one or more of the following monomers: alpha-methylstyrene, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, vinyltoluenes, p- (tert-butyl) styrene, methoxystyrenes, chlorostyrenes, hydroxystyrenes, vinylmesitylenes, divinylbenzene, vinylnaphthalene or any vinylaromatic monomer obtained from a C9 fraction or a C8-C10 fraction. Non-limiting examples of the vinyl aromatic copolymer resin include vinyl aromatic/terpene copolymer resins (e.g., limonene/styrene copolymer resins), vinyl aromatic/C5 fraction resins (e.g., C5 fraction/styrene copolymer resins), vinyl aromatic/aliphatic copolymer resins (e.g., CPD/styrene copolymer resins and DCPD/styrene copolymer resins). Non-limiting examples of alkyl-phenol resins include alkylphenol-acetylene resins such as p-tert-butylphenol-acetylene resins, alkylphenol-formaldehyde resins (such as those having a low degree of polymerization). In certain embodiments, the aromatic resin may comprise a hydrogenated version of one of the aromatic resins described above (i.e., a hydrogenated aromatic resin). In other embodiments, the aromatic resin does not include any hydrogenated aromatic resin; in other words, the aromatic resin is not hydrogenated.

In certain embodiments, one or more aliphatic resins are used in combination with one or more of cycloaliphatic resins, aromatic resins, and terpene resins. In one or more embodiments, one or more aliphatic resins are used as the major weight component (e.g., greater than 50 weight percent) relative to the total loading of the resin. For example, the resin employed comprises at least 55%, in other embodiments at least 80%, and in other embodiments at least 99% by weight of one or more aliphatic resins.

In one or more embodiments, aliphatic resins include both aliphatic homopolymer resins and aliphatic copolymer resins, including those resins derived from the combination of one or more aliphatic monomers with one or more other (non-aliphatic) monomers, with the largest amount of any type of monomer being aliphatic. Non-limiting examples of useful aliphatic resins include C5 fraction homopolymer or copolymer resins, C5 fraction/C9 fraction copolymer resins, C5 fraction/vinyl aromatic copolymer resins (e.g., C5 fraction/styrene copolymer resins), C5 fraction/cycloaliphatic copolymer resins, C5 fraction/C9 fraction/cycloaliphatic copolymer resins, and combinations thereof. Non-limiting examples of cycloaliphatic monomers include, but are not limited to, cyclopentadiene ("CPD") and dicyclopentadiene ("DCPD"). In certain embodiments, the aliphatic resin may comprise a hydrogenated version of one of the above aliphatic resins (i.e., a hydrogenated aliphatic resin). In other embodiments, the aliphatic resin does not include any hydrogenated aliphatic resin; in other words, in such embodiments, the aliphatic resin is not hydrogenated.

In one or more embodiments, terpene resins include both terpene homopolymer resins and terpene copolymer resins, including those resins derived from the combination of one or more terpene monomers with one or more other (non-terpene) monomers, with the largest amount of any type of monomer being a terpene. Non-limiting examples of useful terpene resins include alpha-pinene resins, beta-pinene resins, limonene resins (e.g., L-limonene, D-limonene, dipentene that is a racemic mixture of the L-isomer and the D-isomer), beta-phellandrene, delta-3-carene, delta-2-carene, pinene-limonene copolymer resins, terpene-phenol resins, aromatic modified terpene resins, and combinations thereof. In certain embodiments, the terpene resin may comprise a hydrogenated version of one of the terpene resins described above (i.e., a hydrogenated terpene resin). In other embodiments, the terpene resin does not include any hydrogenated terpene resin; in other words, in such embodiments, the terpene resin is not hydrogenated.

Processing oil

In one or more embodiments, the vulcanizable compositions of the present invention include a processing oil, which may also be referred to as an extender oil. In one or more embodiments, the vulcanizable composition is free or substantially free of processing oil.

In particular embodiments, the oils employed include those commonly used as extender oils. Useful oils or extenders that can be employed include, but are not limited to, aromatic oils, paraffinic oils, naphthenic oils, vegetable oils other than castor oil, low PCA oils (including MES, TDAE, and SRAE), and heavy naphthenic oils. Suitable low PCA oils also include oils of various vegetable origin, such as those harvestable from vegetables, nuts, and seeds. Non-limiting examples include, but are not limited to, soybean or soybean oil, sunflower oil, safflower oil, corn oil, linseed oil, cottonseed oil, rapeseed oil, cashew oil, sesame oil, camellia oil, jojoba oil, macadamia nut oil, coconut oil, and palm oil. As is generally understood in the art, oil refers to those compounds that have a relative viscosity as compared to other components of the vulcanizable composition (such as resins).

In one or more embodiments, the oil includes those hydrocarbon compounds having greater than 15, in other embodiments greater than 20, in other embodiments greater than 25, in other embodiments greater than 30, in other embodiments greater than 35, and in other embodiments greater than 40 carbon atoms per molecule. In these or other embodiments, the oil includes those hydrocarbon compounds having less than 250, in other embodiments less than 200, in other embodiments less than 150, in other embodiments less than 120, in other embodiments less than 100, in other embodiments less than 90, in other embodiments less than 80, in other embodiments less than 70, in other embodiments less than 60, and in other embodiments less than 50 carbon atoms per molecule. In one or more embodiments, the oil includes those hydrocarbon compounds having from about 15 to about 250, in other embodiments from about 20 to about 200, in other embodiments from about 25 to about 100, in other embodiments from about 25 to about 70, in other embodiments from about 25 to about 60, and in other embodiments from about 25 to about 40 carbon atoms per molecule.

In one or more embodiments, the oils include those compounds having a dynamic viscosity of greater than 5 mPas, in other embodiments greater than 10 mPas, in other embodiments greater than 15 mPas, in other embodiments greater than 20 mPas, in other embodiments greater than 25 mPas, and in other embodiments greater than 30 mPas, in other embodiments greater than 35 mPas, and in other embodiments greater than 40 mPas at 25 ℃. In these or other embodiments, the oils include those compounds having a dynamic viscosity of less than 3000 mPas, in other embodiments less than 2500 mPas, in other embodiments less than 2000 mPas, in other embodiments less than 1500 mPas, in other embodiments less than 1000 mPas, in other embodiments less than 750 mPas, in other embodiments less than 500 mPas, in other embodiments less than 250 mPas, in other embodiments less than 100 mPas, and in other embodiments less than 75 mPas at 25 ℃. In one or more embodiments, the oils include those compounds having a dynamic viscosity at 25 ℃ of from about 5 to 3000 mPa-s, in other embodiments from about 15 to about 2000 mPa-s, in other embodiments from about 20 to about 1500 mPa-s, in other embodiments from about 25 to about 1000 mPa-s, in other embodiments from about 30 to about 750 mPa-s, in other embodiments from about 35 to about 500 mPa-s, and in other embodiments from about 50 to about 250 mPa-s.

Curing agent

As noted above, the vulcanizable compositions of the invention include a cure system. The cure system includes a curative, which may also be referred to as a rubber curative or vulcanizing agent. Curing agents are described in the following documents: Kirk-Othmer, encyclopedia of chemical technology, Vol.20, pp.365-468, 3 rd edition 1982 (Kirk-Othmer, E)_{NCYCLOPEDIA OF} C_HEMICAL T_ECHNOLOGY,Vol.20,pgs.365-468,(3^rdEd.1982)), in particular in "vulcanizing Agents and Auxiliary Materials (Vulcanization Agents and Autoxiliary Materials)", p.390-402, and A.Y.Coran, second edition 1989 of encyclopedia of Vulcanization of Polymer science and engineering (V)_{ULCANIZATION,}E_{NCYCLOPEDIA OF} P_OLYMER S_{CIENCE AND} E_NGINEERING(2nd Ed.1989)), which are incorporated herein by reference. In one or more embodiments, useful curing systems include sulfur or sulfur-based curing agents. Examples of suitable sulfur-based vulcanizing agents include soluble sulfur of "rubber articles"; sulfur donating vulcanizing agents such as a disulfide amine, a polymeric polysulfide or a sulfur olefin adduct; and insoluble polymeric sulfur. The vulcanizing agents may be used alone or in combination. The skilled person will be able to readily select the amount of vulcanizing agent to achieve the desired level of cure.

In one or more embodiments, the curing agent is employed in combination with a cure accelerator. In one or more embodiments, accelerators are used to control the time and/or temperature required for vulcanization and to improve the properties of the vulcanizate. Examples of accelerators include thiazole vulcanization accelerators such as 2-mercaptobenzothiazole, dibenzothiazyl disulfide, N-cyclohexyl-2-benzothiazole sulfenamide (CBS), and the like; and guanidine vulcanization accelerators such as Diphenylguanidine (DPG) and the like. The skilled person will be able to readily select the amount of cure accelerator to achieve the desired level of cure.

Metal activator and organic acid

As noted above, the vulcanizable compositions of the invention comprise a metal compound. In one or more embodiments, the metal compound is an activator (i.e., aids in the vulcanization or curing of the rubber). In other embodiments, the metal activator is a metal oxide. In particular embodiments, the metal activator is a zinc species formed in situ by a reaction or interaction between zinc oxide and an organic acid (e.g., stearic acid). In other embodiments, the metal compound is a magnesium compound, such as magnesium hydroxide. In other embodiments, the metal compound is an iron compound, such as iron oxide. In other embodiments, the metal compound is a cobalt compound, such as a cobalt carboxylate.

In one or more embodiments, the zinc oxide is unfunctionalized zinc oxide characterized by a BET surface area of less than 10m²(ii) a,/g, in other embodiments less than 9m²A,/g, and in other embodiments less than 8m²(ii) in terms of/g. In other embodiments, nano-zinc oxide is employed, including those characterized by a BET surface area greater than 10m²Those zinc oxide particles per gram.

In one or more embodiments, the organic acid is a carboxylic acid. In particular embodiments, the carboxylic acid is a fatty acid including saturated and unsaturated fatty acids. In particular embodiments, saturated fatty acids, such as stearic acid, are employed. Other useful acids include, but are not limited to, palmitic acid, arachidic acid, oleic acid, linoleic acid, and arachidonic acid.

Other ingredients

Other ingredients commonly used in rubber compounding can also be added to the rubber composition. These ingredients include accelerators, accelerator activators, additional plasticizers, waxes, scorch inhibiting agents, processing aids, zinc oxide, tackifying resins, reinforcing resins, fatty acids (such as stearic acid), peptizers, and antidegradants (such as antioxidants and antiozonants).

Amount of ingredients

Rubber composition

In one or more embodiments, the vulcanizable composition includes greater than 20 wt.%, in other embodiments greater than 30 wt.%, and in other embodiments greater than 40 wt.% of rubber component, based on the total weight of the composition. In these or other embodiments, the vulcanizable composition includes less than 90, in other embodiments less than 70, and in other embodiments less than 60 percent by weight of rubber component, based on the total weight of the composition. In one or more embodiments, the vulcanizable composition includes from about 20 to about 90, in other embodiments from about 30 to about 70, and in other embodiments from about 40 to about 60 percent by weight of the rubber component, based on the total weight of the composition.

Eutectic composition

In one or more embodiments, the vulcanizable composition includes greater than 0.005 parts by weight (pbw) of the eutectic composition per 100 parts by weight rubber (phr), in other embodiments greater than 0.01pbw of the eutectic composition, and in other embodiments greater than 0.02pbw of the eutectic composition. In these or other embodiments, the vulcanizable composition includes less than 3pbw, in other embodiments less than 1pbw, and in other embodiments less than 0.1pbw of the eutectic composition per 100 parts by weight rubber (phr). In one or more embodiments, the vulcanizable composition includes from about 0.005 to about 3, in other embodiments from about 0.01 to about 1, and in other embodiments from about 0.02 to about 0.1 parts by weight of the eutectic composition per 100 parts by weight of rubber (phr).

In one or more embodiments, the amount of eutectic solvent may be described with reference to the loading of a metal activator (such as zinc oxide). In one or more embodiments, the vulcanizable composition includes greater than 2 wt.%, in other embodiments greater than 3 wt.%, and in other embodiments greater than 5 wt.% eutectic solvent, based on the total weight of eutectic solvent and metal activator (e.g., zinc oxide) present in the vulcanizable composition. In these or other embodiments, the vulcanizable composition includes less than 15 wt.%, in other embodiments less than 12 wt.%, and in other embodiments less than 10 wt.% of the eutectic solvent, based on the total weight of the eutectic solvent and the metal activator (e.g., zinc oxide) present in the vulcanizable composition. In one or more embodiments, the vulcanizable composition includes from about 2 to about 15, in other embodiments from about 3 to about 12, and in other embodiments from about 5 to about 10 weight percent of the eutectic solvent, based on the total weight of the eutectic solvent and the metal activator (e.g., zinc oxide) present in the vulcanizable composition.

Metal compound

In one or more embodiments, the vulcanizable composition includes greater than 1.5 parts by weight (pbw), in other embodiments greater than 2.0pbw, and in other embodiments greater than 2.5pbw, of a metal activator (e.g., zinc oxide) per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes less than 8.0pbw, in other embodiments less than 7.0pbw, and in other embodiments less than 6.0pbw, of metal activator (e.g., zinc oxide) in phr. In one or more embodiments, the vulcanizable composition includes, in phr, from about 1.5pbw to about 8.0pbw, in other embodiments from about 2.0pbw to about 7.0pbw, and in other embodiments from about 2.5pbw to about 6.0pbw of a metal activator (e.g., zinc oxide).

Organic acids

In one or more embodiments, the vulcanizable composition includes, per 100 parts by weight of rubber (phr), greater than 0.5 parts by weight (pbw) of organic acid (e.g., stearic acid), in other embodiments greater than 0.7pbw of organic acid (e.g., stearic acid), and in other embodiments greater than 1.0pbw of organic acid (e.g., stearic acid). In these or other embodiments, the vulcanizable composition includes less than 5pbw, in other embodiments less than 3pbw, and in other embodiments less than 2pbw, of organic acid (e.g., stearic acid) per 100 parts by weight rubber (phr). In one or more embodiments, the vulcanizable composition includes from about 0.5 to about 5, in other embodiments from about 0.7 to about 3, and in other embodiments from about 1.0 to about 2 parts by weight of organic acid (e.g., stearic acid) per 100 parts by weight of rubber (phr).

Filler material

In one or more embodiments, the vulcanizable composition includes, per 100 parts by weight of rubber (phr), greater than 0 parts by weight (pbw), in other embodiments greater than 10pbw, in other embodiments greater than 25pbw, in other embodiments greater than 35pbw, in other embodiments greater than 45pbw, in other embodiments greater than 55pbw, and in other embodiments greater than 65pbw of filler. In these or other embodiments, the vulcanizable composition includes, in phr, less than 200pbw, in other embodiments less than 150pbw, in other embodiments less than 120pbw, in other embodiments less than 100pbw, and in other embodiments less than 80pbw of filler. In one or more embodiments, the vulcanizable composition includes, in phr, from about 0pbw to about 200pbw, in other embodiments from about 35pbw to about 120pbw, and in other embodiments, from about 45pbw to about 100pbw filler.

Carbon black

In one or more embodiments, the vulcanizable composition includes, per 100 parts by weight of rubber (phr), greater than 0 parts by weight (pbw), in other embodiments greater than 10pbw, in other embodiments greater than 25pbw, in other embodiments greater than 45pbw, in other embodiments greater than 55pbw, in other embodiments greater than 60pbw, in other embodiments greater than 65pbw, and in other embodiments greater than 75pbw of carbon black. In these or other embodiments, the vulcanizable composition includes, in phr, less than 200pbw, in other embodiments less than 150pbw, and in other embodiments less than 100pbw of carbon black. In one or more embodiments, the vulcanizable composition includes, in phr, from about 10pbw to about 200pbw, in other embodiments from about 40pbw to about 150pbw, and in other embodiments, from about 50pbw to about 100pbw carbon black.

Silicon dioxide

In one or more embodiments, the vulcanizable composition includes greater than 0.1 parts by weight (pbw), in other embodiments greater than 2.5pbw, and in other embodiments greater than 5.0pbw silica per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition contains, in phr, less than 50pbw, in other embodiments less than 30pbw, in other embodiments less than 25pbw, in other embodiments less than 20pbw, in other embodiments less than 18pbw, and in other embodiments less than 15pbw silica. In one or more embodiments, the vulcanizable composition includes, in phr, from about 0.1pbw to about 50pbw, in other embodiments from about 2.5pbw to about 30pbw, and in other embodiments, from about 3pbw to about 20pbw of silica. In one or more embodiments, the vulcanizable composition is free or substantially free of silica.

Filler ratio

In one or more embodiments, the vulcanizable composition may be characterized by a ratio of carbon black to other filler compounds such as silica. In one or more embodiments, carbon black is used in excess relative to other fillers such as silica. In one or more embodiments, the ratio of the amount of carbon black to silica is greater than 2:1, in other embodiments greater than 3:1, in other embodiments greater than 5:1, in other embodiments greater than 7:1, in other embodiments greater than 10:1, in other embodiments greater than 15:1, and in other embodiments greater than 20:1, on a weight to weight basis.

Silica coupling agent

In one or more embodiments, the vulcanizable composition includes greater than 1 part by weight (pbw), in other embodiments greater than 2pbw, and in other embodiments greater than 5pbw, of the silica coupling agent per 100pbw of silica. In these or other embodiments, the vulcanizable composition includes less than 20pbw, in other embodiments less than 15pbw, and in other embodiments less than 10pbw, of silica coupling agent per 100 parts by weight silica. In one or more embodiments, the vulcanizable composition includes from about 1 to about 20, in other embodiments from about 2 to about 15, and in other embodiments from about 5 to about 10pbw of silica coupling agent per 100 parts by weight silica. In one or more embodiments, the vulcanizable composition is free or substantially free of silica coupling agents.

Plasticizing resin

In one or more embodiments, the vulcanizable composition includes, per 100 parts by weight of rubber (phr), greater than 0.1 parts by weight (pbw), in other embodiments greater than 0.5pbw, in other embodiments greater than 1.0pbw, in other embodiments greater than 1.5pbw, in other embodiments greater than 15pbw, and in other embodiments greater than 25pbw of the plasticizing resin (e.g., hydrocarbon resin). In these or other embodiments, the vulcanizable composition contains, in phr, less than 150pbw, in other embodiments less than 120pbw, in other embodiments less than 90pbw, in other embodiments less than 80pbw, in other embodiments less than 60pbw, in other embodiments less than 45pbw, in other embodiments less than 15pbw, in other embodiments less than 10pbw, and in other embodiments less than 3.0pbw of plasticizing resin (e.g., hydrocarbon resin). In one or more embodiments, the vulcanizable composition includes, in phr, from about 1pbw to about 150pbw, in other embodiments from about 0.5pbw to about 15pbw, in other embodiments from about 1pbw to about 10pbw, in other embodiments from about 1.5pbw to about 3pbw, in other embodiments from about 15pbw to about 100pbw, and in other embodiments from about 25pbw to about 80pbw of the plasticizing resin (e.g., hydrocarbon resin). In one or more embodiments, the vulcanizable composition is free or substantially free of plasticizing resin.

Process/extender oils

In one or more embodiments, the vulcanizable composition includes, per 100 parts by weight rubber (phr), greater than 0.1 parts by weight (pbw), in other embodiments greater than 0.5pbw, in other embodiments greater than 1pbw, in other embodiments greater than 1.5pbw, and in other embodiments greater than 2pbw of processing oil (e.g., naphthenic oil). In these or other embodiments, the vulcanizable composition contains, in phr, less than 20pbw, in other embodiments less than 18pbw, in other embodiments less than 15pbw, in other embodiments less than 12pbw, in other embodiments less than 10pbw, and in other embodiments less than 8pbw, in other embodiments less than 5pbw, and in other embodiments less than 3pbw of processing oil. In one or more embodiments, the vulcanizable composition includes, in phr, from about 0.1pbw to about 20pbw, in other embodiments from about 0.5pbw to about 18pbw, in other embodiments from about 0.5pbw to about 15pbw, in other embodiments from about 1pbw to about 10pbw, in other embodiments from about 0.5pbw to about 18pbw, in other embodiments from about 1.5pbw to about 3.0pbw, and in other embodiments from about 2pbw to about 12pbw oil. In one or more embodiments, the vulcanizable composition is free or substantially free of oil.

Plasticizing additive

In one or more embodiments, the plasticizing resin and the processing oil may be collectively referred to as a plasticizing additive, a plasticizing component, or a plasticizing system. In one or more embodiments, the vulcanizable compositions of the invention include greater than 0.5 parts by weight (pbw), in other embodiments greater than 1pbw, and in other embodiments greater than 1.5pbw plasticizing additive per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes, in phr, less than 15pbw, in other embodiments less than 12pbw, in other embodiments less than 10pbw, in other embodiments less than 5pbw, and in other embodiments less than 3pbw plasticizing additives. In one or more embodiments, the vulcanizable composition includes, in phr, from about 0.5pbw to about 15pbw, in other embodiments from about 1pbw to about 10pbw, and in other embodiments from about 1.5pbw to about 3pbw plasticizing additive.

Hardening resin

In one or more embodiments, the vulcanizable composition includes, in phr, less than 2pbw, in other embodiments less than 1pbw, and in other embodiments less than 0.5pbw of the curative resin. In one or more embodiments, the vulcanizable composition includes, in phr, from about 0.1pbw to about 8pbw, in other embodiments from about 0.5pbw to about 6pbw, and in other embodiments from about 2pbw to about 4pbw of the hardening resin. In one or more embodiments, the vulcanizable composition is free or substantially free of hardening resins.

Sulfur

In one or more embodiments, the vulcanizable composition includes sulfur as a curing agent. In one or more embodiments, the vulcanizable composition includes greater than 0.1 parts by weight (pbw), in other embodiments greater than 0.3pbw, and in other embodiments greater than 0.9pbw sulfur per 100 parts by weight rubber (phr). In these or other embodiments, the vulcanizable composition includes, in phr, less than 6pbw, in other embodiments less than 4pbw, in other embodiments less than 3.0pbw, and in other embodiments less than 2.0pbw sulfur. In one or more embodiments, the vulcanizable composition includes, in phr, from about 0.1pbw to about 5.0pbw, in other embodiments from about 0.8pbw to about 2.5pbw, in other embodiments from about 1pbw to about 2.0pbw, and in other embodiments from about 1.0pbw to about 1.8pbw sulfur.

Overview of the method

In one or more embodiments, the vulcanizable composition is prepared by mixing the vulcanizable rubber with a eutectic solvent to form a masterbatch, followed by adding the curative to the masterbatch. The preparation of the masterbatch may be carried out using one or more sub-mixing steps, wherein one or more of the ingredients may be added sequentially to the composition, for example, after the initial mixture is prepared by mixing two or more ingredients. In addition, additional ingredients such as, but not limited to, carbon black, additional fillers, chemically treated inorganic oxides, silica coupling agents, silica dispersants, processing oils, processing aids such as zinc oxide and fatty acids, and antidegradants such as antioxidants or antiozonants may be added in the preparation of the vulcanizable composition using conventional techniques.

In one or more embodiments, the eutectic composition is prepared prior to its introduction into the vulcanizable rubber. In other words, the first component of the mixture is premixed with the second component of the mixture prior to introducing the mixture into the vulcanizable composition. In one or more embodiments, the combined components of the mixture are mixed until a homogeneous liquid composition is observed.

In one or more embodiments, the eutectic composition is pre-mixed with one or more ingredients of the rubber formulation prior to introducing the eutectic mixture into the vulcanizable composition. In other words, in one or more embodiments, the components of the vulcanizable composition (e.g., a metal compound such as zinc oxide) are mixed with the eutectic mixture to form a pre-mix or masterbatch prior to introducing the pre-mix into the mixer in which the rubber is mixed. For example, zinc oxide can be dissolved in a eutectic solvent prior to its introduction into the rubber in the mixer. In other embodiments, the eutectic composition is a minor component of the pre-mix, so the components pre-mixed with the eutectic composition act as a carrier for the eutectic composition. For example, the eutectic composition may be mixed with a larger volume of zinc oxide, and the zinc oxide will act as a carrier for the delivery of the combination of zinc oxide and eutectic composition in solid form into the rubber within the mixer. In other embodiments, one of the members of the eutectic pair acts as a solid carrier for the eutectic composition, and thus the combination of the first and second components of the eutectic composition form a pre-mix that may be added in solid form to the rubber within the mixer. The skilled person will appreciate that mixtures of this nature may be formed by mixing an excess of the first or second eutectic member relative to the other eutectic members to maintain the solid composition at the desired temperature.

In one or more embodiments, the eutectic solvent is introduced into the vulcanizable rubber as an initial ingredient in the formation of the rubber masterbatch. Thus, the eutectic solvent is mixed with the rubber at high shear and high temperature. In one or more embodiments, the eutectic solvent is mixed with the rubber at a minimum temperature in excess of 110 ℃, in other embodiments at a minimum temperature in excess of 130 ℃, and in other embodiments at a minimum temperature in excess of 150 ℃. In one or more embodiments, the high shear, high temperature mixing is conducted at a temperature of from about 110 ℃ to about 170 ℃.

In other embodiments, the eutectic solvent and the sulfur-based curative are introduced into the vulcanizable rubber sequentially or simultaneously. Thus, the eutectic solvent is mixed with the vulcanizable rubber at a maximum temperature of less than 110 ℃, in other embodiments at a maximum temperature of less than 105 ℃, and in other embodiments at a maximum temperature of less than 100 ℃. In one or more embodiments, the mixing with the curing agent is conducted at a temperature of from about 70 ℃ to about 110 ℃.

As with the eutectic solvent, zinc oxide and stearic acid may be added as initial ingredients to the rubber masterbatch, and thus these ingredients will undergo high temperature, high shear mixing. Alternatively, zinc oxide and stearic acid may be added along with the sulfur-based curing agent, so that only low temperature mixing is performed.

In one or more embodiments, the zinc oxide and the eutectic solvent are each separately introduced into the vulcanizable rubber. In other embodiments, the zinc oxide and the eutectic solvent are pre-mixed to form a zinc oxide masterbatch, which may include a solution of zinc oxide dissolved or otherwise dispersed in the eutectic solvent. The zinc oxide masterbatch can then be introduced into the vulcanizable rubber.

In one or more embodiments, the polyisoprene rubber (e.g., natural rubber) is first masticated to achieve the desired viscosity and processability characteristics. After mixing the polyisoprene rubber, other ingredients such as eutectic solvents are introduced into the pre-processed polyisoprene rubber according to one or more embodiments of the present invention.

Mixing conditions

In one or more embodiments, the vulcanizable composition is prepared by first mixing the vulcanizable rubber with the cosolvent at a temperature of from about 140 ℃ to about 180 ℃, or in other embodiments from about 150 ℃ to about 170 ℃. In certain embodiments, after initial mixing, the composition (i.e., masterbatch) is cooled to a temperature of less than 100 ℃, or in other embodiments, to a temperature of less than 80 ℃, and the curing agent is added. In certain embodiments, mixing is continued at a temperature of from about 90 ℃ to about 110 ℃, or in other embodiments, from about 95 ℃ to about 105 ℃, to produce the final vulcanizable composition.

In one or more embodiments, the masterbatch mixing step or one or more sub-steps of the masterbatch mixing step can be characterized by the peak temperature attained by the composition during mixing. This peak temperature may also be referred to as the drop out temperature. In one or more embodiments, the peak temperature of the composition during the masterbatch mixing step may be at least 140 ℃, in other embodiments at least 150 ℃, and in other embodiments at least 160 ℃. In these or other embodiments, the peak temperature of the composition during the masterbatch mixing step may be from about 140 ℃ to about 200 ℃, in other embodiments from about 150 ℃ to about 190 ℃, and in other embodiments from about 160 ℃ to about 180 ℃.

Final mixing step

After the masterbatch mixing step, the curative or curative system is introduced into the composition and mixing is continued to ultimately form the vulcanizable composition of matter. This mixing step may be referred to as a final mixing step, a curable mixing step, or a productive mixing step. The product resulting from this mixing step may be referred to as a vulcanizable composition.

In one or more embodiments, the final mixing step can be characterized by the peak temperature obtained from the composition during final mixing. The skilled person will recognize that this temperature may also be referred to as the final drop temperature. In one or more embodiments, the peak temperature of the composition during final mixing may be at most 130 ℃, in other embodiments at most 110 ℃, and in other embodiments at most 100 ℃. In these or other embodiments, the peak temperature of the composition during final mixing may be from about 80 ℃ to about 130 ℃, in other embodiments from about 90 ℃ to about 115 ℃, and in other embodiments from about 95 ℃ to about 105 ℃.

Mixing apparatus

All of the ingredients of the vulcanizable composition can be mixed using standard mixing equipment such as internal mixers (e.g., banbury mixers or Brabender mixers), extruders, kneaders, and two-roll mills. The mixing can be carried out separately or in tandem. As noted above, the ingredients may be mixed in a single stage, or in other embodiments in two or more stages. For example, in the first stage (i.e., the mixing stage), a masterbatch is prepared, which typically comprises a rubber component and a filler. Once the masterbatch is prepared, the vulcanizing agents may be introduced and mixed into the masterbatch in a final mixing stage, which is typically conducted at a relatively low temperature, in order to reduce the chance of premature vulcanization. Additional mixing stages, sometimes referred to as remills, may be employed between the masterbatch mixing stage and the final mixing stage.

Preparation of tires

The vulcanizable composition can be processed into tire components according to common tire manufacturing techniques, including standard rubber shaping, molding and curing techniques. Typically, vulcanization is achieved by heating the vulcanizable composition in a mold; for example, it may be heated to about 140 ℃ to about 180 ℃. Cured or crosslinked rubber compositions may be referred to as vulcanizates, which generally contain a thermoset three-dimensional polymer network. Other ingredients (such as fillers and processing aids) may be uniformly dispersed throughout the crosslinked network. Pneumatic tires can be prepared as discussed in U.S. Pat. nos. 5,866,171, 5,876,527, 5,931,211, and 5,971,046, which are incorporated herein by reference.

Characteristics of vulcanized rubber

According to aspects of the present invention, a tire component (which may also be referred to as a vulcanizate) is characterized by favorable cure characteristics while containing relatively low levels of metal activators, such as zinc species.

In one or more embodiments, the vulcanizates are characterized by less than 2pbw, in other embodiments less than 1phr, and in other embodiments less than 0.7pbw zinc per 100pbw rubber.

In one or more embodiments, the tire component is a tire tread. While only containing a limited content of metal activator, such as a zinc species, as outlined in this specification, the tread is characterized by a 300% modulus of greater than 3MPa, in other embodiments greater than 5MPa, and in other embodiments greater than 7MPa, as determined by ASTM D-412 at room temperature.

INDUSTRIAL APPLICABILITY

As noted above, the vulcanizable compositions of the invention can be cured to prepare a variety of tire components. These tire components include, but are not limited to, tire treads, tire sidewalls, belts, innerliners, plies, and apexes. These tire components may be included in a variety of vehicle tires, including passenger tires.

In particular embodiments, the vulcanizates of this invention comprise one or more components of a heavy vehicle tire, such as the tread or undertread of a heavy vehicle tire. As understood by those skilled in the art, heavy vehicle tires include, for example, truck tires, bus tires, TBR (truck and bus tires), subway train tires, tractor tires, trailer tires, aircraft tires, agricultural tires, bulldozer tires, and other off-the-road (OTR) tires. In one or more embodiments, the heavy vehicle tires can be new tires as well as those that have been re-treaded. Heavy vehicle tires can sometimes be classified according to their use. For example, truck tires can be classified as drive tires (those powered by the truck engine) and steering tires (those used to steer the truck). The tires on tractor trailers are also individually sorted.

In particular embodiments, the heavy vehicle tire is a relatively large tire. In one or more embodiments, the heavy vehicle tire has an overall diameter (tread to tread) of greater than 17.5 inches, in other embodiments greater than 20 inches, in other embodiments greater than 25 inches, in other embodiments greater than 30 inches, in other embodiments greater than 40 inches, and in other embodiments greater than 55 inches. In these or other embodiments, the heavy vehicle tire has a section width greater than 10 inches, in other embodiments greater than 11 inches, in other embodiments greater than 12 inches, and in other embodiments greater than 14 inches.

In certain embodiments, the heavy vehicle tire is further characterized by its cure time (i.e., the amount of time required to achieve t 90). In one or more embodiments, the green (i.e., uncured) heavy vehicle tire requires a cure time of greater than 30 minutes, in other embodiments greater than 1 hour, in other embodiments greater than 5 hours, in other embodiments greater than 10 hours, and in other embodiments greater than 16 hours.

Experiment of

To demonstrate the operation of the present invention, several vulcanizable compositions were prepared in the following experiments. The vulcanizable compositions were prepared by using the ingredients and mixing sequence provided in the table below. All amounts are expressed as parts by weight per 100 parts by weight of rubber, unless otherwise indicated. The following table also provides the results of some analytical tests performed on the compositions and/or vulcanizates thus produced.

In a first set of experiments, vulcanizable compositions were prepared using the rubber formulations and mixing sequences provided in Table I. The rubber formulation indicates a rubber formulation that may be used to manufacture a tire tread for a heavy vehicle tire. As shown in table I, the mixing procedure was a two-step mixing procedure, which included a masterbatch mixing step and a final mixing step. The individual mixing steps were carried out in a Banbury mixer. During masterbatch preparation, the mixer was operated at 75rpm and a peak composition temperature of 160 ℃ was obtained. At this point, the composition was dripped from the mixer and allowed to cool to below about 85 ℃. At this point in time, the composition is reintroduced into the mixer along with the ingredients identified for the "final mixing stage". Mixing was continued at 40rpm with a peak composition temperature of about 100 ℃. The composition was then dropped from the mixer and a sample was obtained from the composition for the purpose of analytical testing.

TABLE I

Percent reversion was assessed by MDR at 160 ℃ for 60 minutes. MDR evaluation was performed using MDR 2000. The data obtained for each analysis are listed in table II, and the relevant data are plotted in the figure. The amounts of natural rubber, butadiene rubber, zinc oxide and eutectic solvent are provided for each sample as shown in table II.

TABLE II

As shown by the data in table II, the addition of the eutectic solvent increased the reversion by 2% -4%, with the greatest improvement observed in those formulations containing the exclusive polymer of natural rubber as the rubber component (i.e., samples 5-8).

The dynamic rheological properties (e.g., tan δ) of the vulcanizates were obtained from temperature sweep studies conducted in the range of about-100 ℃ to about 100 ℃ and 10 Hz.

TABLE III

The dynamic behavior shows that the change in tan delta is small after addition of eutectic solvent and that G' at 30 ℃ increases slightly, probably due to the slightly higher crosslink density observed from the MH-ML values in the MDR data (table III).

The tensile mechanical properties (maximum stress, modulus, elongation and toughness) of the vulcanizates were measured by using the standard procedure described in ASTM-D412.

TABLE IV

For compounds containing DES, the room temperature tension was relatively constant. However, at 100 ℃, the toughness of the DES-containing compounds was improved by up to 12% compared to the control compounds without DES, especially for 100phr of NR compound (compounds 5-8).

Various modifications and alterations that do not depart from the scope and spirit of this invention will become apparent to those skilled in the art. The present invention should not be unduly limited to the illustrative embodiments set forth herein.