Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/40—Compounds of aluminium
  • C09C1/405—Compounds of aluminium containing combined silica, e.g. mica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K9/00—Use of pretreated ingredients
  • C08K9/04—Ingredients treated with organic substances
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/40—Compounds of aluminium
  • C09C1/42—Clays
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/06—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of zinc, cadmium or mercury
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
  • B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
  • B01J37/0027—Powdering
  • B01J37/0036—Grinding
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
  • C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/22—Rheological behaviour as dispersion, e.g. viscosity, sedimentation stability

Definitions

• the present invention generally relates to the field of zinc carboxylate clays and zinc carboxylate clays intercalated with quaternary ammonium salts (e.g., zinc carboxylate organoclays), methods for making zinc carboxylate clays and zinc carboxylate organoclays, and various applications of such zinc carboxylate clays and zinc carboxylate organoclays, including applications in products made from rubber, plastic, other polymer materials and the like, in which the zinc carboxylate clays and organoclays function, e.g., as one or more of an anti-reversion agent, a vulcanization activator and/or accelerator, a rheology modifying agent, a filler and/or a reinforcing agent (especially in rubber tires).
• quaternary ammonium salts e.g., zinc carboxylate organoclays
• methods for making zinc carboxylate clays and zinc carboxylate organoclays e.g., zinc carboxylate organoclays
• Zinc compounds, zinc clays and other additives can be used in rubber compounding (e.g., in the manufacture of tires) to obtain desired properties in a finished rubber product.
• zinc montmorillonite clay to replace zinc oxide in rubber compounding to reduce the amount of zinc oxide used in such rubber compounds for both environmental and economic reasons.
• Such zinc montmorillonite clays are usually made by mixing sodium montmorillonite with zinc chloride to exchange zinc ions with sodium ions in the clay (e.g., as described in PCT/NL2003/000880, the relevant portions of which are incorporated herein by reference).
• Organoclays may also used in rubber and plastic compositions as fillers. These organoclay fillers are usually made from smectic clays such as calcium montmorillonite, sodium montmorillonite, saponites, nontronites, beidellites, hecorites, etc. These minerals in turn are dominant parts of bentonite rock. Such clays may be treated with acid, then washed free of the acid and other soluble matter, then converted to their corresponding sodium salts by treatment with soda ash or caustic soda.
• a sodium montmorillonite clay is then reacted with quaternary ammonium chloride salts (e.g., dimethyl bis-(hydrogenated tallowalkyl) ammonium chloride) or amines (e.g., laurylamine or tallowalkyl amine) and their salts to form an organoclay.
• quaternary ammonium salt intercalates between platelets and/or layers of the clay, helping to expand the interlayer distance in the clay to about 20 angstroms or more. Such intercalation into the clay platelets results in easier exfoliation of the clay during rubber compounding or plastic processing.
• the exfoliation aids in dispersion of the nanoscale platelets from the clay into various compositions, and imparts various properties like higher hardness, modulus, heat resistance, etc. to products containing such intercalated clays.
• a zinc soap of a carboxylic acid dry milled with a layered material of nanoscale thickness
• This patent publication uses mostly montmorillonite clay material.
• a zinc clay as described in US Pat. Appl. No. 12/577,370 as a starting material, the performance of the layered material can be further improved, especially as a filler for rubber compounds and formulations.
• a zinc ammonia carbonate complex solution as described in US Pat. Appl. No. 12/577,370 is also an excellent starting material for making the zinc soap layered clay material.
• the layers of those clay materials are usually from a few angstroms to about 15 angstroms apart in their natural form. In that form, the layers are difficult to break apart. It is known that if the layers can be intercalated to 20 angstroms or more, it is easier to break apart the clay layers.
• the D 001 parameter is usually used to indicate the largest gap of the platy layers. If it is 20 angstroms or more, the clay layers are more easily broken apart.
• Stearic acid and its various metal salts are widely used in the rubber and plastic industries.
• Embodiments of the present invention relate to zinc carboxylate clays and organoclays, methods of making zinc carboxylate clays and zinc carboxylate organoclays, and various applications of such zinc carboxylate clays and organoclays, including applications in rubber and other polymer materials and the like, in which the zinc clay functions, e.g., as one or more of an anti-reversion agent, a vulcanization activator and/or accelerator, a rheology modifying agent, a filler and/or a reinforcing agent for rubber or plastics (especially in tires).
• an anti-reversion agent e.g., a vulcanization activator and/or accelerator, a rheology modifying agent, a filler and/or a reinforcing agent for rubber or plastics (especially in tires).
• the present invention provides methods for making a zinc carboxylate clay, comprising mixing (i) a carboxylic acid or an ammonium salt of the organic acid (e.g., in the presence of ammonia or an ammonia-containing solution) with (ii) a zinc- containing clay (e.g., a cation-exchangeable clay containing chemically-bound zinc ions) to form a clay slurry; attrition milling and/or heating the clay slurry to incorporate the organic acid into the zinc-containing clay and form the zinc carboxylate clay, and optionally, heating to remove substantially all ammonia in the clay slurry; and filtering and drying the zinc carboxylate clay.
• a carboxylic acid or an ammonium salt of the organic acid e.g., in the presence of ammonia or an ammonia-containing solution
• a zinc- containing clay e.g., a cation-exchangeable clay containing chemically-bound zinc ions
• the method comprises mixing a zinc clay derived from a cation exchangeable clay with the carboxylic acid or an ammonium salt of the carboxylic acid to form the zinc carboxylate clay.
• the carboxylic acid is selected from the group consisting of C 5 to C 24 aliphatic and/or aromatic carboxylic acids.
• This aspect of the present invention also provides a method for preparing a zinc carboxylate organoclay (i.e., a zinc- and organoamine-containing clay), comprising performing the method for making a zinc carboxylate clay, and mixing an organic amine or an organic ammonium salt with the zinc carboxylate clay under conditions sufficient to intercalate the amine or ammonium salt into the zinc carboxylate clay and form the zinc carboxylate organoclay.
• a zinc carboxylate organoclay i.e., a zinc- and organoamine-containing clay
• the present invention provides a method for preparing a zinc organoclay, comprising mixing (i) a carboxylic acid an ammonium salt of the carboxylic acid with (ii) a zinc-containing cation exchangeable clay under conditions sufficient to intercalate the organic acid into the zinc-containing cation exchangeable clay and form a zinc carboxylate clay; and isolating the zinc carboxylate clay.
• mixing the carboxylic acid or ammonium salt thereof with the zinc-containing clay comprises heating the zinc-containing clay and the carboxylic acid or the ammonium salt thereof at a temperature sufficient to facilitate the incorporation of the carboxylic acid or ammonium salt into zinc-containing clay.
• the method further comprises preparing the zinc-containing clay by a process comprising mixing (i) a solution of zinc ammonia carbonate or a zinc salt with (ii) a cation-exchangeable clay under conditions sufficient to chemically bind at least a portion of the zinc to the cation-exchangeable clay and form a zinc- containing clay; and isolating the zinc-containing clay.
• the carboxylic acid or ammonium salt thereof can be mixed with the zinc-containing clay by mixing the zinc-containing clay with a solution of the ammonium salt of the carboxylic acid, the solution optionally further containing dissolved carbon dioxide; mixing a slurry of the zinc-containing clay with the carboxylic acid; or spraying a solution of the ammonium salt of the carboxylic acid onto the zinc-containing clay.
• a zinc carboxylate organoclay can be made by performing the method for making a zinc carboxylate clay, and mixing an amine or an ammonium salt with the zinc carboxylate clay under conditions sufficient to intercalate the amine or ammonium salt into the zinc carboxylate clay.
• the present invention provides a method for preparing a zinc carboxylate clay, comprising mixing (i) a carboxylic acid with (ii) a zinc ammonia complex solution to form a zinc carboxylate salt; combining the zinc carboxylate salt with a slurry or suspension of a cation-exchangeable and/or layered clay under conditions sufficient to increase the spacing of layers of the cation-exchangeable clay and form the zinc carboxylate clay; and isolating the zinc carboxylate clay.
• the zinc ammonia complex solution comprises a solution of a zinc ammonia carbonate complex.
• the method further comprises mixing an amine or an ammonium salt with the zinc carboxylate clay under conditions sufficient to intercalate the amine or ammonium salt into the zinc carboxylate clay.
• a zinc carboxylate clay comprising a cation-exchangeable clay; zinc ions, at least a portion of which are chemically bound to the cation-exchangeable clay; and a carboxylic acid, intercalated into the cation- exchangeable clay.
• the zinc carboxylate clay contains from about 1 wt% to about 20 wt% of zinc ions, and the zinc ions are substantially insoluble in an aqueous solution of ammonia and carbon dioxide water.
• the zinc carboxylate clay further comprises an ammonium salt intercalated into the cation-exchangeable clay (thereby forming a zinc carboxylate organoclay).
• the composition may be part of a tire, a roller, a shoe sole, a rubber support, a belt, a roller, a ball, a hose, an automobile part or another rubber or plastic product.
• the invention also relates to a method of making a rubber or plastic product, comprising mixing (i) the present zinc carboxylate clay and/or zinc carboxylate organoclay (a“zinc carboxylate (organo)clay”) with (ii) one or more rubber or plastic materials to form a zinc carboxylate (organo)clay-containing mixture; and forming the rubber or plastic product from the zinc carboxylate (organo)clay-containing mixture.
• the present invention enables the zinc carboxylate (organo)clay to have a zinc ion content from about 1 wt% to about 20 wt%.
• Zinc carboxylate (organo)clays according to the present invention are generally easier to mill or to break up into fine powder relative to zinc clays produced by conventional methods. Furthermore, zinc carboxylate (organo)clays of the present invention may have a zinc ion content (e.g., a content of zinc ions chemically bound to the clay and substantially insoluble in an aqueous solution comprising ammonia and carbon dioxide, or aqueous ammonium carbonate) that is higher than conventional zinc clays.
• the present invention provides zinc carboxylate organoclays comprising one or more organic ammonium salt(s) and methods of making zinc carboxylate organoclays comprising one or more organic ammonium salt(s).
• compositions comprising a rubber and a zinc carboxylate (organo)clay according to the present invention generally provide improved performance and/or impart special properties to rubber products equal to or better than conventional additives (e.g., precipitated silica or carbon black) for certain rubber products.
• conventional additives e.g., precipitated silica or carbon black
• FIG. 1 is an XRD analysis of the quaternary ammonium chloride-treated zinc stearate clay of Example 5, compared to a similar type of quaternary ammonium chloride- treated zinc clay (Sample RAA of Example 1).
• FIG. 2 is an XRD analysis of the zinc stearate clay of Example 4, with the zinc stearate clay of Example 7, which is made according to the method of US Pat. Appl. Publ. No. 2009/0199945A1.
• a cation exchangeable clay is mixed with a zinc ion source (such as a zinc ammonia carbonate complex solution) and a carboxylic acid (or salt thereof) to form a zinc clay suspension.
• a zinc ion source such as a zinc ammonia carbonate complex solution
• a carboxylic acid or salt thereof
• Zinc ammonia carbonate complex solution is prepared from water, ammonia, carbon dioxide, and a zinc material, which includes zinc oxide, zinc carbonate, etc.
• the solution typically has 5 to 15% ammonia, 2 to 10% carbon dioxide, and 2 to 11% zinc.
• this solution can be mixed with a layered clay with good cation exchange capacity to make zinc clay.
• the cation exchange capacity of the clay is usually about 50 to 150 meq of Zn/100 grams of clay.
• the zinc may be present in the zinc-containing clay in an amount of from 1% to 20% by weight.
• the clay is mixed with water to form a slurry prior to mixing with a zinc solution.
• the clay may be ground prior to mixing with water to form the slurry.
• the slurry may subsequently be degritted by, for example, filtering through a mesh screen or by passing through a hydrocyclone with an appropriate cone size to remove undesired coarse components of the clay before mixing with the zinc ammonia complex solution.
• the mesh of the screen may be essentially any mesh size that removes undesired coarse components of the clay.
• the screen is a 325 mesh screen.
• the ratio of clay to water in the slurry may be, for example, 1:100 to 1:10 wt:vol, preferably 1:20 to 1:14 wt:vol.
• the ratio of clay to water is not limited, and essentially any suitable ratio may be employed in the preparation of the slurry.
• the clay to water ratio is 1:15 wt:vol.
• the zinc ammonia carbonate complex solution may be prepared as described in U.S. Pat. No. 7,635,729 and/or co-pending U.S. Pat. Appl. No. 12/346,535 (filed December 30, 2008, Atty. Docket No. GLO-003), the relevant portions of each of which are incorporated herein by reference.
• the zinc ammonia carbonate complex solution can optionally be replaced with a solution of another zinc ammonia complex, such as a zinc ammine salt, like zinc ammine chloride, zinc ammine sulfate, etc., or a mixture thereof.
• X F, Cl, Br, I, NO 3 , CN, OCN, CNO, NCO , or CO 2 CH 3
• n 1, X is SO 4 , HPO 4 , or CO 3 .
• other monovalent and/or divalent anions compatible with the present methods are also suitable.
• the native clay or a slurry thereof may then be combined with the zinc ammonia carbonate complex solution to form a zinc clay suspension.
• the zinc ammonia carbonate complex solution is added to the clay slurry.
• dry clay may be combined with the zinc ammonia carbonate complex or zinc ammine salt solution.
• the suspension is mixed and maintained under heavy mixing or agitation for a length of time sufficient to allow for absorption of zinc ions by the clay. In a typical embodiment, the suspension is mixed for 1 hour or more, depending on the reactivity of the clay (e.g., 2 hours).
• the mixing and/or agitation time is not particularly limited, and may be carried out for a length of time sufficient to effect a desired zinc ion content of the product zinc clay up to its maximum cation exchange capacity.
• the mixture may optionally be heated after the absorption of zinc ion. Heating is preferably conducted at a temperature of from about 50 oC to about 150 oC. If desired, the mixture may then be cooled to a temperature of from about 15 oC to about 30 oC.
• the zinc clay suspension may then optionally be milled with a suitable wet milling device such as an attritor for a length of time sufficient to provide a particular particle size and/or homogeneity of the suspension and help to incorporate the zinc ion into the clay. Milling may also be performed with a plugmill or a Manton-Gaulin homogenizer (as mentioned in U.S. Pat. No. 5,110,501, the relevant portions of which are incorporated herein by reference).
• the zinc clay is mixed together with a carboxylic acid source (such as a fatty acid or a derivative thereof, such as an alkali metal salt of the fatty acid) to make a zinc carboxylate clay.
• a carboxylic acid source such as a fatty acid or a derivative thereof, such as an alkali metal salt of the fatty acid
• a solution of a zinc salt is mixed with the cation-exchangeable clay.
• the zinc salt may comprise zinc chloride and/or zinc sulfate.
• the carboxylic acid and the zinc-containing clay can be mixed in a ratio of from 0.05:1 to 0.5:1 by weight.
• the zinc ammonia complex solution can be mixed with a carboxylic or fatty acid first, before it is mixed with the layered clay (e.g., to coagulate and precipitate a zinc carboxylate clay suspension).
• the layered clay Before precipitation, the layered clay can be first dissolved or suspended in water and degritted with a wire mesh (as described above), or it can be added dry to the zinc ammonia complex solution/carboxylic acid mixture.
• the cation-exchangeable clay is preferably a layered clay with good cation ion exchange capacity, and typically a clay having a suitable cation exchange capacity for binding of zinc ions.
• the clay may have a cation exchange capacity of from about 50 to about 150 meq/100 gram of clay for binding of zinc or other metal ions.
• the cation-exchangeable clay may be selected from smectic clays, calcium montmorillonite, sodium montmorillonite, synthetic montmorillonite, bentonite, bentonite-derived clays, zeolites, saponites, nontronites, beidellites, hecorites, vermiculites, swellable micas and mixtures thereof.
• the clay may be ground or milled prior to mixing with the zinc ammonia complex solution or zinc salt solution to form the zinc clay suspension.
• the clay may also be graded or screened after grinding or milling and prior to mixing to remove coarse components.
• the carboxylic acids generally include, but are not limited to, carboxylic acids of 3 to 25 carbon atoms, including propionic acid, capric acid, caprylic acid, caproic acid, lauric acid, palmitic acid, stearic acid, other fatty acids (e.g., myristic acid, arachidic acid), etc., and mixtures thereof.
• Other suitable organic acids include aliphatic C 5 to C 24 aliphatic and/or aromatic carboxylic acids, such as oleic acid, palmitoleic acid, linoleic acid, benzoic acid, 2-methylbenzoic acid, phenylacetic acid, phthalic acid, 1- or 2-naphthoic acid, naphthalic acid, etc.
• the zinc- and carboxylic acid-intercalated clay suspension can then be filtered, dried and milled.
• the zinc carboxylate clay suspension can be filtered, for example, by vacuum filtration.
• the retained filter cake may then be dried directly and milled, leaving excess zinc (if any) as zinc oxide and/or zinc carbonate in the zinc carboxylate clay powder.
• the filter cake is washed to remove excess zinc.
• the washing fluid may comprise deionized water, and optionally, ammonia and/or carbon dioxide.
• the concentration of ammonia and/or carbon dioxide in the washing solution is not particularly limited. Essentially any concentrations of ammonia and/or carbon dioxide may be selected that are effective in removing excess zinc from the filter cake.
• Washing may be conducted until essentially all ammonium carbonate solution-soluble zinc in the filter cake has been extracted or removed (e.g., until a zinc content in the filtrate reaches a desired level, such as less than 0.5%, less than 0.2% or 0.1 %,, etc.).
• the filtrate comprising ammonia, carbon dioxide and/or recovered zinc may be reused and/or recycled to make zinc ammonia carbonate complex solution.
• zinc and/or ammonia may be recovered from the filtrate by boiling and distillation as described in co-pending U.S. Pat. Appl. No. 11/519,949 (filed September 11, 2006, Atty. Docket No. GLO-002).
• the filter cake may then be further washed with deionized water and/or dried, preferably at a temperature of from about 50 oC to about 200 oC. Drying may be conducted for a length of time sufficient to reduce a moisture content of the zinc carboxylate clay to a desired level, such at less than 1%, less than 0.5% or lower.
• the filter cake is then calcined at a temperature of 200 °C, 250 °C or greater, for a length of time sufficient to effect complete drying of the zinc carboxylate clay.
• the zinc carboxylate clay product may then be milled to a powder (e.g., as described herein).
• the milled powder may be further refined by e.g., screening with a mesh screen of suitable gauge to achieve a desired maximum particle size in the milled zinc carboxylate clay. Thereafter, the zinc carboxylate clay is ready to be used in rubber or plastic polymer formulations.
• the method may further comprise milling the clay suspension and/or the zinc carboxylate clay.
• the zinc- and fatty acid-intercalated clay can be further intercalated with one or more quaternary ammonium salts to make a zinc-fatty acid- amine organoclay (e.g., a zinc carboxylate organoclay).
• a zinc-fatty acid- amine organoclay e.g., a zinc carboxylate organoclay.
• One method of applying the quaternary ammonium salt to the zinc carboxylate clay is by spraying it with or without solvent into the dry zinc carboxylate clay, then evaporating the solvent, if necessary, and optionally milling the dry materials.
• Another method is to add the quaternary ammonium salt, with or without solvent, directly to the freshly precipitated zinc carboxylate clay before the drying and milling steps.
• zinc clay prepared according to the methods described above may be reslurried in water before addition of the ammonium salt (which may be added directly or in an aqueous and/or alcoholic solution).
• the relative ratio of clay to water in the slurry is not particularly limited.
• the mixture of the ammonium salts and the zinc clay may then mixed (e.g., in an attritor) for a length of time sufficient to homogenize the mixture.
• the quaternary ammonium salts may include ester quaternary ammonium salts, alkoxy alkyl quaternary ammonium salts, trialkyl monomethyl quaternary ammonium salts, dialkyl dimethyl quaternary ammonium salts, etc.
• the ammonium salt may therefore comprise one or more compounds of the formula R 4 NX, where each instance of R is independently hydrogen, tallow (e.g., a mixture of saturated, monounsaturated and polyunsaturated C 12 -C 24 carboxylic acid moieties, in the form of C x H y (CO)- groups, where x is from 11 to 23 and y is from 2x-5 to 2x+1), alkyl, C 2 -C 24 alkenyl, C 6 -C 20 aryl, C 7 -C 20 aralkyl, mono- or dialkyaminoalkylene, C 2 -C 24 hydroxyalkyl, (CO)R 2 , or (CO)OR 2 , where R 2 is C 1 -C 24 alkyl, C 2 -C 24 alkenyl, C 6 -C 20 aryl, or C 7 -C 20 aralkyl, and X is a halide, alkylsulfate, nitrate,
• no more than one R is H (preferably no R group is H), and generally, at least one R group (preferably two R groups) are tallow, C 8 -C 20 alkyl, C 8 -C 20 alkenyl, or C 8 -C 20 hydroxyalkyl.
• the ammonium salt may be selected from the group consisting of methyl tallow bis-(2-hydroxyethyl) ammonium halides, methyl tallow bis-(2- hydroxyethyl) ammonium alkylsulfates, methyl tallow bis-(2-hydroxyethyl) ammonium nitrate, methyl tallow bis-(2-hydroxyethyl) ammonium hydroxide, dimethyl hydrogenated- tallow (2-ethylhexyl) ammonium halides, dimethyl hydrogenated-tallow (2-ethylhexyl) ammonium alkylsulfates, dimethyl hydrogenated-tallow (2-ethylhexyl) ammonium nitrate, dimethyl hydrogenated-tallow (2-ethylhexyl) ammonium hydroxide, dimethyl (dehydrogenated-tallow) ammonium halides, dimethyl (dehydrogenated-tallow) ammonium alkylsulfates,
• exemplary salts include (but are not limited to) dimethyl bis- (hydrogenated tallow) ammonium chloride, (hydrogenated tallow alkyl) (2-ethylhexyl) dimethyl ammonium methylsulfate, di-C 8 -C 18 -alkyl dimethyl ammonium chloride, and bis- (hydrogenated tallow) dimethyl ammonium chloride.
• the quaternary ammonium salts can be generated in situ by adding one or more amines (or a solution thereof) to the reslurried zinc carboxylate clay, then converting the amine(s) to the corresponding ammonium salt(s) by treating the zinc carboxylate clay-amine mixture with an acid (or solution thereof).
• Suitable acids include mineral acids like hydrochloric or sulfuric acid.
• Suitable amines include primary, secondary or tertiary amines. Suitable amines may comprise one or more compounds of the formula R 3 N, where each instance of R is as described above.
• Exemplary amines include (but are not limited to) laurylamine, butylamine, diethylamine, dipropylamine, methylbutylamine, dialkylaminoalkyl-amines, ethylene diamine, stearylamine, tallow amine, bis(tallow)amines, dimethyl or diethyl tallow amine, and methyl or ethyl bis(tallow)amines.
• the ammonium salt-containing mixture may then be mixed, washed, dried, filtered and/or milled as previously described.
• the zinc ion concentration in the present zinc carboxylate (organo)clay may be from about 2 wt% to about 20 wt%.
• Zinc ions in the present zinc carboxylate (organo)clays are at least partially chemically bound to the clay, and are substantially insoluble in an aqueous solution of ammonia and carbon dioxide (or ammonium carbonate).
• the zinc ion concentration in a zinc carboxylate (organo)clay washed with aqueous ammonia/carbon dioxide and/or deionized water may be from 5 to 12 wt% or higher.
• Zinc carboxylate (organo)clays produced according to embodiments where the zinc carboxylate (organo)clay is not washed, leaving excess zinc thereon (e.g., as zinc oxide and/or zinc carbonate) may have a zinc concentration from about 4 wt% to about 50 wt% of the product zinc clay.
• Zinc carboxylate (organo)clays according to the present invention may have a milled powder bulk density of from about 0.2 to about 0.8 g/cm 3 (e.g., from about 0.3 to about 0.65 g/cm 3 ) and/or a D 001 interlayer spacing of from about 20 to about 60 Angstroms or more (e.g., from about 30, 40 or 45 Angstroms to about 60 Angstroms).
• Zinc carboxylate (organo)clays may contain smectic or bentonite clays, as previously described.
• Zinc carboxylate (organo)clays generally contain one or more carboxylic acids as previously described, and optionally one or more quaternary ammonium salts, intercalated between the clay platelets.
• the amounts of carboxylic acid(s) and optional ammonium salt(s) present are not particularly limited, and may be selected to provide a desired degree of intercalation and/or D 001 interlayer spacing based on a target application and/or target properties of the product zinc carboxylate (organo)clay.
• the ammonium salt(s) are present in amounts of from 0.1 wt% to 50 wt% (or any value therein) of the zinc carboxylate organoclay.
• Zinc carboxylate (organo)clays according to the methods described above can be further processed into compositions such as master batches for rubber and plastic products and parts.
• Such compositions comprising 5 to 70 wt% zinc carboxylate clay or zinc carboxylate organoclay, with or without added ammonium salts.
• the rubber compositions may comprise natural or synthetic rubber, processing aids, fillers, etc.
• the plastic compositions may comprise one or more polymers, such as polyethylene, polypropylene, polystyrene, polycarbonates, polyesters, polyacrylates, polymethacrylates, copolymers thereof, etc., plus optional processing aids, fillers, etc.
• the relative amounts and/or types of additives and fillers may be selected according to the desired characteristics of the compositions.
• compositions may be prepared by mixing the zinc carboxylate (organo)clay, rubber, and other additives to impart special properties and/or other desired characteristics to the composition (where applicable) in a Banbury-type mixer at a shear force and for a length of time sufficient to exfoliate the zinc carboxylate (organo)clay and provide a sufficient degree of mixing.
• the present compositions as described may be used to make finished products like tires, belts, shoe soles, rubber sections, rubber or plastic parts (e.g., rubber supports, hoses, automobile parts, etc.), balls, rollers, and other rubber products.
• the present invention therefore further concerns a method of making a rubber or plastic product, comprising mixing (i) the present zinc carboxylate (organo)clay with (ii) one or more rubber or plastic materials to form a zinc carboxylate (organo)clay-containing mixture; and forming the rubber or plastic product from the zinc carboxylate (organo)clay-containing mixture.
• a method of making a rubber or plastic product comprising mixing (i) the present zinc carboxylate (organo)clay with (ii) one or more rubber or plastic materials to form a zinc carboxylate (organo)clay-containing mixture; and forming the rubber or plastic product from the zinc carboxylate (organo)clay-containing mixture.
• Testing methods and equipment include:
• Zinc ammonia carbonate complex solution (12,000 grams) was prepared, having 8.94% zinc (using technical grade zinc oxide), 10.10% ammonia, and 6.03% carbon dioxide.
• bentonite Pc7 10,000 grams was added into 100 liters of water with good agitation, and the mixture was stirred for two hours. The resulting solution was de-gritted with a 325 mesh screen. Then the zinc ammonia carbonate complex solution was added slowly into the solution-like bentonite slurry while continue to agitate. The resulting zinc clay slurry was attrition milled for two hours and then boiled to eliminate substantially all of the ammonia and most of the carbon dioxide. The zinc clay was filtered, then dried at 170 °C.
• the dried cake was attrition milled and sieved through a 200 mesh screen.
• the zinc clay has the following properties: No. Bulk Density Zinc % D 001 Spacing, Angstroms RA 0.83 10.29 12.3** [0044] A quaternary ammonium chloride is added to the above zinc clay to make a zinc organoclay according to the procedure of U.S. Pat. Appl. No. 12/577,370 to obtain zinc organoclay RAA: No. Bulk Density Zinc % D001 Spacing, Angstroms RAA 0.43 7.29 45.12** [0045] D 001 spacing is measured with a X-ray diffractometer (TTRAX III) from Rigaku, Japan.
• TTRAX III X-ray diffractometer
• An ammonium stearate solution was prepared by mixing 113.5 grams of stearic acid with 567 grams of ammonia/carbon dioxide solution containing 12% of ammonia and 10% of carbon dioxide. The solution was sprayed onto 756 grams of zinc clay R591, then the mixture was mixed well and heated to 60 °C. The resulting powder was heated at 110 °C for 18 hours. The dried powder was attrition milled again and then sieved with a 140 mesh sieve. The product was jet milled with the Nissen jet mill (see Example 2) to produce zinc stearate clay RC. There is some loss of material through dusting at the various milling processes. Its properties are listed below: No. Bulk Density Zinc % D 001 Spacing, Angstroms
• Zinc ammonia carbonate complex solution (3,640 g) was prepared, having 8.67% zinc, 10.54% ammonia and 5.84% carbon dioxide.
• Stearic acid 450 grams was then added into the solution with good agitation.
• the solution was heated to 100 °C, at which point the solution gels slightly.
• bentonite clay (3 kg) was added to 40 liters of water.
• the solution-like slurry was agitated well and degritted with a 325 mesh screen.
• the zinc stearate solution was then added slowly into the bentonite slurry with good agitation.
• the bentonite coagulates and precipitates out from the solution-like slurry.
• the resulting slurry was attrition milled for two hours.
• the slurry was filtered, and the filter cake dried at 110 °C for 72 hours.
• the dried powder was attrition milled again, and the product sieved with a 140 mesh sieve.
• the resulting product was jet milled with the Nissen jet mill (see Example 2) to produce zinc stearate clay RD. There is some loss of material through dusting at the various milling processes. Its properties are listed below:
• FIG. 2 shows an XRD analysis of the zinc stearate clay of Example 4, as compared with the zinc stearate clay of Example 7, which is made according to the method of US Pat. Appl. Publ. No. 2009/0199945A1.
• the zinc ammonia carbonate stearate mixture of Example 4 greatly facilitates the coagulation and precipitation of the bentonite.
• the stoichiometrically excess zinc (as compared with the amount of stearic acid) in the zinc ammonia carbonate stearate mixture may also facilitate the precipitation of bentonite and bring benefit to a rubber formulation containing the zinc stearate clay prepared from a zinc ammonia carbonate stearate mixture.
• Example 5 Treating zinc stearate clay with a quaternary ammonium chloride
• Dehydrogenated tallow dimethyl ammonium chloride 400 grams from Evonik Industries, USA was mixed with 400 grams of isopropanol, then the resulting mixture was mixed well with 1,000 g of the zinc stearate clay RD. The mixture was dried at 80 °C for 48 hours. The dry powder was attrition milled for two hours and sieved through a 140 mesh screen. The screened powder was jet milled to obtain an amine chloride-treated zinc stearate clay RE having the following properties:
• FIG. 1 is an XRD analysis of the quaternary ammonium chloride-treated zinc stearate clay of Example 5, compared to a quaternary ammonium chloride-treated zinc clay (e.g., Sample RAA made with zinc clay and dehydrogenated tallow dimethyl ammonium chloride, without stearic acid).
• a quaternary ammonium chloride-treated zinc clay e.g., Sample RAA made with zinc clay and dehydrogenated tallow dimethyl ammonium chloride, without stearic acid.
• the present method produces a zinc organoclay with much better intercalation.
• the degree of intercalation of the quaternary ammonium chloride-treated zinc stearate clay is greatly enhanced.
• the level of intercalation of zinc stearate clays of Examples 2, 3, 4 and 5 are in ascending order, with that from Example 5 being the best of the four Examples.
• the zinc stearate also helps the dispersion of the fine clay into a rubber molding mixture and greatly reduces the chance and/or extent of “white spot,” which is associated with coagulation of very fine particles of organic clay in the rubber mixture. This is especially evident when laurylammonium chloride is used as the intercalation agent.
• Example 6 Preparation of zinc stearate clay from zinc clay made from zinc sulfate
• a zinc clay was prepared by adding 2.5 kg of bentonite Pc7 into 40 liters of water and agitating well. The solution/suspension was degritted by passing it through a 325 mesh screen. Then, a solution of 633 grams of zinc sulfate heptahydrate in 2000 ml of water was added to the clay slurry, and the mixture was attrition milled for two hours. The filter cake was washed, filtered, and dried. The dry powder was attrition milled and then sieved and jet milled with a Nissen jet mill (see Example 2). The resulting zinc clay has 5.26% zinc and a D 001 spacing of 15.34.
• Example 7 Preparation of zinc stearate clay according to US Pat. Appl. Publ. No.
• FIG. 2 compares the zinc stearate clay of Example 4 with the zinc stearate clay of Example 7 by XRD analysis. Both zinc organoclays include zinc stearate, but the degree of intercalation of Sample RD in Example 4 (exemplifying the present invention) is much better than the zinc organoclay of Example 7, as shown in the wide angle X-ray diffraction patterns shown in FIG. 2.
• Example 8 Preparation of zinc clay with lower molecular weight fatty acids
• a caprylic/capric acid blend (containing a mixture of 40-50% caprylic acid and 38-45% capric acid, 227 grams) from Imperial Industrial Chemical Co. Ltd in Thailand was mixed with 500 gram of the zinc clay from Example 1 (RA).
• the procedure of Example 2 was followed and a zinc carboxylate clay RH intercalated with a blend of caprylic and capric acids was obtained.
• the resulting zinc carboxylate clay has the following properties:
• An ammonium stearate solution was prepared with 6.5 liters of water, 19.5 grams of ammonia, 13.6 grams of carbon dioxide and 137.5 grams of stearic acid. The solution was heated to 60 °C and agitated well. Medical grade calcium montmorillonite (550 grams, from R & L Chemical Industry, Inner Mongolia, China) was added to the solution with good agitation. The montmorillonite coagulated and precipitated out. The slurry was heated to at 80 °C for 1 hour to get rid of the remaining ammonia, and then the slurry was attrition milled for two hours. The slurry was filtered, and the filter cake was dried at 110 °C for 18 hours.
• Medical grade calcium montmorillonite 550 grams, from R & L Chemical Industry, Inner Mongolia, China
• Tire tread formulations were mixed in two stages. The first stage consisted of ingredients as shown below:
• zinc stearate clay can replace silica in a conventional rubber formulation, providing slightly better hardness, modulus, and reversion resistance than a comparative rubber formulation without such a clay.
• Zinc stearate clay can further reduce tan delta and heat build-up of rubber compounds, which means cooler running tires with lower rolling resistance and greater energy savings.
• zinc stearate and stearic acid have been widely used in rubber and plastic formulation for many years, they are believed to be more compatible with rubber formulations than quaternary ammonium salts.
• zinc carboxylate (organo)clays are as good as some of the organoclays for rubber and for plastic.
• the invention concerns zinc carboxylate clays and zinc carboxylate organoclays, methods of making zinc carboxylate (organo)clays, and various applications of such zinc clays, including applications in rubber and other polymer materials and the like, in which the zinc carboxylate (organo)clays function, e.g., as one or more of an anti-reversion agent, a vulcanization activator and/or accelerator, a rheology modifying agent, a filler and/or a reinforcing agent for rubber or plastics (especially in tires).
• the zinc carboxylate (organo)clays of the present invention may afford a higher zinc content in zinc clays relative those produced by conventional methods.

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