Title of Invention

A POLYMERIC COMPOSITION CONTAINING CHEMICALLY MODIFIED FILLERS

Abstract Described are fillers, e.g., inorganic oxides, that have been modified to have a carbon content of greater than 1 weight percent, a sulfur content of greater than 0.1 weight percent, a Silane Conversion Index of at least 0.3 and a Standard Tensile Stress @ 300% elongation of 7 or more. Polymeric compositions that contain such modified fillers are also described.
Full Text FORM 2
THE PATENTS ACT, 197 0 (39 of 1970)
COMPLETE SPECIFICATION (See Section 10, rule 13)
CHEMICALLY MQDIFIED—FILLERS AND—POLYMERIC—COMPOSITIONS
CONTAINING SAME
A POLYMERIC COMPOSITION CONTAININIG CHEMICALLY
MODIFIED FILLERS
PPG INDUSTRIES OHIO, INC. of 3800 WEST 143RD STREET, CLEVELAND, OH 44111, U.S.A. AMERICAN Company
The following specification particularly describes the nature of the invention and the manner in which it is to be performed : -


FEB-14-2002 13:03

DE WEBB LAW FIRM

412 471 4094 P.0S

CHEMICALLY MODIFIED FILLERS AND POLYMERIC COMPOSITIONS CONTAINING SAME CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S provisional applications Serial No. 60/203,427, filed May 10, 2000, Serial No. 60/172,308, filed December 17, 1939 and Serial No. 60/149,758, filed August 19, 1999,
DESCRIPTION OF THE INVENTION The present invention relates to chemically 10 modified fillers and the use of such fillers in polymeric
compositions. More particularly, this invention relates to particulate or amorphous fillers haying minimum carbon and sulfur contents, a minimum Silane Conversion Index and a minimum Standard Tensile Stress @ 3 00% elongation and 15 polymers, e.g., curable rubber compositions, containing such fillers. Most particularly, this invention relates to a functionaliaed and hydrophobized filler, hereinafter referred to as a modified filler", that improves the efficiency of producing polymeric compositions, such as in rubber 21} compounding, and the performance of polymerized or cured products, e.g., tires.
In the production of polymeric, compositions, it is common to incorporate fillers to improve the physical properties of the polymer. The surfaces of such fillers are . 25 often modified, to increase the reactivity and consequently the two and three dimensional coupling of the filler within the polymeric composition. It is conventional in the rubber, industry to incorporate carbon black and other reinforcing . fillers into natural and synthetic rubber to increase the 30 physical properties of the cured rubber vulcanizate. Fillers used to reinforce such polymeric compositions include natural . and synthetic fillers..


One of the principal non-black fillers used in the rubber industry is amorphous precipitated silica This siliceous filler is used to impart improved tensile strength, tear resistance and abrasion resistance to the rubber 5 vulcanizate. Silica fillers are also used in combination with carbon blacks to obtain maximum mileage in passenger vehicle tires and off the road tires, e.g., tires for mining and logging operations and for road-building equipment. . Such applications have become well established. When used as the
10 sole reinforcing filler, silica fillers that are not well dispersed and/or coupled in the rubber do not provide the overall improved performance obtained by the use of carbon blacks alone This is observed most readily in rubber vulcanizes used for tires, e.g., tire treads.
15 Various coupling agents, e.g., titanates,
zirconattes and silones, have been suggested for use. with fillers when such fillers are incorporated into polymeric compositions,, e.g., rubber, in order to improve the performance of the rubber vulcanizate. Among the various
20 organosilane coupling agents suggested for. such use are the bis (alkoxysilylalkyl)polysulfides, e.g., 3,3"-bis(triethoxy- silylpropyl) tetrasulfide. It has been reported that the use of appropriate amounts of such coupling.agents, particularly 3,3-bis(triethoxysilylpropyl)tetrasulfide, in siliceous
25 filler-reinforced synthetic rubbers provides at least
equivalent performance to carbon black-reinforced synthetic rubbers in several key physical properties such as 300% modulus, tensile strength and abrasion resistance.
The high cost of bis (alkoxysilylalkyl)polysulfides,
30 and the time and energy required to mix them into polymeric compositions have deterred the more general use of siliceous . fillers as the principal reinforcing filler in large volume

WO 01/12734

PCT/US00/22713

applications. U.S. Patent 4,436,847 describes increasing the efficiency of silane coupling agents, e.g., bis(alkoxysilyl-alkyl)polysulfide coupling agents, by using an alkoxysilane in combination with the silane to form a coupling composition.
5 In one specific embodiment described in the 847 patent, the silane coupling composition is formulated with the siliceous filler in a suitable non-reactive liquid that is chemically inert with respect to the coupling composition and siliceous filler to prepare a rubber compounding additive, i.e., a
10 silica-silane concentrate.
U.S. patent 5,116,886 describes a two-step process in which the surface of natural or synthetic, oxide or silicate fillers is modified by using certain organosilicon compounds. In the first step, the organosilicon compound is
15 mixed intensely with the filler at a temperature below G0°C. In the second step, the homogenous mixture is subjected to a temperature of from 60 to 160°C to complete the surface modification of the filler.
U.S. patent 5,908,660 also describes a two-step
20 method for the preparation of hydrophobic silica. In the first step, an aqueous suspension of precipitated silica is contacted with an organosilicon compound in the presence of a catalytic amount of an acid to effect hydrophobizing of the precipitated silica. In the second step, the aqueous
IS suspension of the hydrophobic precipitated silica is contacted with a water-immiscible organic solvent at a solvent to silica weight ratio greater than 5:1 to effect separation of the hydrophobic precipitated silica from the aqueous phase.
It has now been discovered that a modified filler,
30 e.g., a particulate or amorphous inorganic oxide, that is characterized by a carbon content of greater than l weight percent, a sulfur content of greater than 0.1 weight percent,


a Silane Conversion Index (described hereinafter) of at least..
0,3 and a Standard Tensile Stress ® 300% elongation (also
described hereinafter) of 7 or more can be prepared; The
process described in U.s, Patent 5,908,660 may be improved and
used to produce the modified filler of the present invention.
by utilizing a certain combination of functionalizing and .
hydrophobizing agents in an aqueous suspension, of inorganic
oxide having a pH of 2.5 or less and treating the acidic,
aqueous suspension of modified fillers with acid neutralizing
agents to increase the pH of Che suspension to a range of from
3.0 to 10.
As used herein, a functionalizing agent is a
reactive chemical which can cause an inorganic oxide to be covalently bonded to the polymeric composition in which it is used, A hydrophobizing agent is a chemical which can bind to and/or be associated with an inorganic oxide to the extant that it causes a reduction, in the. affinity for water of the inorganic oxide while increasing the inorganic oxide"s affinity for the organic polymeric composition in which it is Used.
The aforementioned Standard Tensile Stress ® 300% elongation (STS®300%) of at least 7 or greater indicates improved reinforcement of the rubber composition. Improved reinforcement translates into an improvement in the mechanical durability of -the product which is evidenced by increasec tear strength, hardness and abrasion resistance. In addition to the improved properties, the modified filler has-the benefit of requiring less time and energy to get incorporated into the polymeric composition.

DETAILED DESCRIPTION OF THE INVENTION
Other than in the operating example, or where otherwise indicated, all numbers expressing quantities., ratios, ranges etc. used herein are to be understood as modified in all instances by the term "about".
The modified filler of the present invention may be produced by any method that results in such a filler, i.e., an inorganic oxids, having a carbon content of greater than 1 weight percent, preferably, at least 1.5 weight percent, and more preferably, at. least 2.0 weight percent, a sulfur content of greater than 0.1 weight percent, preferably, at least 0.3 weight: percent, and more preferably., at least 0.6 weight percent; a Silane Conversion index, of at least.0.3, preferably, at least 0.4, and most preferably, at least 0.5 and a Standard Tensile Stress ® 300% elongation of at least 7.0, preferably, at least 7,5 and more preferably at least 8.0, The modified filler of the present invention may also be characterized by a modified Brunauer-Emmett -Teller (BET) i.e., a single point surface area, of from 20 to 350-m2/g, preferably from 40 to 3 00 m2/g and most preferably of from 100 to 200 m2/g, a pH of from S to 10, preferably from 5.5 to 9.S, more preferably from 6.0 to 9 .0 and most preferably, a pH of from 6.0 to 7.5 or the pH of the product may range between any combination of these values, inclusive of the recited ranges; and a Soxhlet Extractable percent carbon of less than 3 0 percent preferably less than 25 percent and more preferably less than 20 percent, e,g., is percent. The. methods for determining the aforestated characteristics of the modified, inorganic oxide are described in Example 9.
The filler used to prepare the modified filler of the present invention is an inorganic oxide defined herein as any inorganic particulate, or amorphous solid material here


possesses either oxygen (chemisorbed or covalently bonded) or hydroxyl (bound or free) ac its exposed surface. In addition, the inorganic oxide is a material which is suitable for use in the various molding, compounding or coating processes including injection molding, lamination, transfer molding, compression molding, rubber compounding, coating (such as dipping, brushing, knife coating, roller coating, silk screen coating, printing, spray coating and the like), casting, and the like.
The inorganic oxide or mixture of 2 or more inorganic oxides used to produce the modified filler of the present invention may be natural or synthetic Such fillers include oxides of the metals in Periods 2, 3, 4, 5 and 6 of Groups Ib, IIb, IIIa,, IIIb, IVa, IVb (except carbon), Va, VIa, VIIa and VIII of the Periodic Table Of the Elements in
Advanced,. Inorganic Chemistry: A Comprehensive Text by F.
Albert Cotton et al, Fourth Edition, John Wiley and Sons, 1580. Among the natural silicates, kaolines or clays are especially suitable However, kieselguhr or diatomaceous earths can also be used. Aluminum oxide, aluminum hydroxide or aluminum trihydrate and titanium dioxide, which can be obtained from natural deposits, can be named by way of example as Cillers. Especially suitable synthetic fillers are aluminosilicates, silicates, pyrogenic, colloidal and precipitated silicas.
The term "aluminosilicates" can be described as natural or synthetic materials where the silicon atoms of a silicon dioxide are partially replaced, or substituted, either naturally oi synthetically, by aluminum atoms. For example, 5 to 90, alternatively 10 to 80 percent of silicon atoms of a silicon dioxide might be replaced, or substituted, naturally o- sv-ithetically, by aluminum atoms to yield an

aluminosilicats. A suitable process for such preparation might be described, for example,, as by a coprecipitation by pH adjustment of a basic solution, or mixture, of silicate and aluminate of, for example, by a chemical reaction between SiO2, or silanols on the surface of a silicon dioxide, and NaAlO2. For example, in such a coprecipitation process, the. synthetic coprecipitated alurninosilicate. may have"5 to 55 of its; surface composed of silica moieties and, correspondingly, 95 to 5 percent of its surface composed of aluminum moieties.
Examples of natural aluminosilicates include Muscovite, Beryl, Dichroite, Sepiolite and Kaolinire. Examples of synthetic aluminosilicaces include Zeolite and those which might be represented by formulas such as, for example, [(Al2O3)x (Si02)y.(H20) , ]; ((Al2O3),{Si02) yY0] ; wherein Y is magnesium or calcium,
Preferably, the inorganic oxide used to produce the modified filler of the present invention is aluminosilicate, colloidal silica, precipitated silica or mixtures thereof, and most preferably it is a precipitated silica of the type commonly employed for compounding with rubber, various commercially available silicas that may be considered for use . in this invention include silicas commercially available from PFG Industries under the Hi-Sil trademark with designations 210, 243, etc; silicas availably from Rhone-Poulenc, with, for example, designations of Z1165MP and Z165GR and silicas available from Degussa AG with, for example, designations VN2 and VN3, etc.
The precipitated silica used to produce the modified filler of the present invention may be produced, for example, by acidic precipitation from solutions of silicates, e.g., sodium silicate. The method of preparing the recipitated silica is not limiting on the present invention

and will depend upon the desired properties of the silica,
such as surface area and particle size required for a given
application,
The BET surface area of the precipitated silica used in preparing the modified silica of the present invention will generally be within a range of from 50 m2/g to 1000 m2/g, and will preferably be within a range of from 100 m2/g to 500
The precipitated silica used to form the modified silica may be in the form of an aqueous suspension from production stages that precede the drying step, such as a slurry formed during precipitation or as a reliquefied filter cake. The suspension can also be formed by re-dispersing dried silica into an aqueous and/or organic solvent. The concentration of hydrophilic precipitated silica in the aqueous and/or organic suspension is not critical and can. be within a range of about. 1 to 90 weight percent. Preferably, the concentration, of hydrc-philic precipitated silica is. within a range of from 1 to 50 weight percent, and more preferably within a range of from 1 to 20 weight percent.
The silane. Conversion Index is defined by the equation T2/ (TV * T2 + T3) . The values for T1, T2 and T3 are determined by solid.state 29si NMR and represent reacted silane. units. The Silane Conversion Index provides an indication of the degree of reaction or crosslinking of the silanes on adjacent Si atoms and with each other. The higher the index, number, the greater,the amount of crosslinking amongst the Silane, silica surface and adjacent silanes. T1 represents a silane unit chemically bonded at one site to either the ailica surface or another silane. T2 represents a silane unit chemically bonded at two sites to "either a Si atom on the Silica surface and to one adjacent silane, two adjacent
. ■ i -


silanes or to two adjacent: surface Si atoms, i.e., partially crosslink-lug structures. T represents a silane unit chemically bonded at three sites to either a Si atom on Che silica surface and two adjacent silanes. two Si atoms and one silane or three silane units.
It is believed that an organomettalic Rooclant Conversion Index, comparable to .the Silane Conversion Index, can be developed and used by those skilled in the coupling agent art to provide an indication ox the degree of reaction or cross linking of zirconates and/or titanates {alone or in combination with si lanes) with the inorganic cxide and themselves.
The Standard Tensile Stress ® 300% elongation is determined using a Standard Compounding Protocol. The Standard Compounding Protocol described herein does not include the addition of free or unbounded coupling agents to the rubber batch This is an important distinction since others have reported 300% Modulus values greater than 7.0. See U.S. Patent 5,705/137. In this patent, Silane X 50-S, a silica/rubber coupling agent., was added during rubber compounding. Typically, the addition .of. such coupling agents to a. rubber batch requires mare time for mixing by the compounder.
The polymeric compositions, e.g., plastics and/or resin, in which the modified filler can be added include essentially any plastic and/or resin. Included in this definition are rubber compounds, Such polymers are described in Kirk othmer Encyclopedia of chemical Technology; Fourth Edition, 1996, Volume 19, pp aa1-904, which description is herein incorporated by reference. The modified filler may be admixed with the polymer or the polymerizable components thereof while the physical form of the polymer or

polymerizable components is in any liquid or compoundable form such as a solution suspension, latex, dispersion, and the like. The polymeric compositions containing the modified filler may be milled, mixed, molded and cured, toy any manner knovn to the art, to form a polymeric article having dispensed therein 10 to 150 parts per 100 parts polymer of modified filler Suitable polymers include, by way of example, thermoplastic and thermosetting resins, rubber compounds and other polymers having elastomaric properties.
The polymers may be alkyd resins, oil modified, alkyd resins, unsaturated polyesters, natural oils, (e.g., linseed, tung, soybean), epoxides, nylons, thermoplastic polyester (e.g., polyethyleneterephthalate, polybucyleneterephthalate), polycarbonates, i.e., thermoplastic and thermoset, polyethylenes, polybutylenss, polystyrenes, polypropylene, ethylene propylene co and terpolymers, acrylics (homopolymer and copolymers of acrylic acid, acrylates, mathacrylates, acrylamides, their salts, hydrohalides, etc.), phenolic resins, polyoxymethylene (homopolymers and copolymers), polyurethanes, polysulfones, polysulfide rubbers, nitrocelluloses, vinyl butyrates, vinyls (vinyl chloride and/or vinyl acetate containing polymery), ethyl Cellulose che cellulose acetates and butyrates, viscose rayon, shellac, waxes, ethylene copolymers (e.g., ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylaneaerylats copolymers), organic rubbers, silicone greases, resins and rubbers and the. like.
The amount of modified filler that may be. used, in . polymeric composition may range from 5 up to 70 weight percent, based on the total weight of the plastic composition, For example, the typical amount of modified filler used in AES (acrylonitrile-butadiyrena). copolymer is from 3 0 r.o 60
i


weight percent, acrylonitrile styrene acrylate copolymer is 5 to 20 weight percent, aliphatic polyketones is 15 to 30 weight percent, alkyds. resins (for paints and inks) is 30 to. 60 weight percent, thermoplastic olefins is 10 to 30 weight percent, epoxy resins is from 5 to 20 weight percent, ethylene vinylacetate copolymer is up to 60 weight percent, ethylene ethyl acetate copolymer is up to 30 weight percent, liquid crystalline polymers (LCP) is 30 to 70 weight percent, phenolic resins is 30-60 weight percent and in polyethylene the, amount is usually greater than 40 weight percent.
In particular, organic rubber and silicone rubber are preferred. Examples of such rubbers include natural robber; those formed from the homopolymerization of butadiene and its homologues and derivatives such as.; cis-l,4-polyisoprene-, 3,4-polyispprene, cis-1, 4-polybutadiene; trans-1,4-polybutadiene; 1,2-polybutadiene; and those formed from the copolymerization of butadiene and its homolegues and derivatives with one or more copolymerizable monomers containing ethylenic unsaturation such as styrene and its derivatives, vinyl-pyridine and its derivatives, acrylonitrilK, isobutyleue and alkyl-substituted acrylates such as methylmethacrylate, Examples include styrene-butadiene copolyrrter rubber composed of various percentages of styrene and butadiene and employing the various isomers of butadiene as desired (hereinafter "SBR"); terpolymers of styrene, isoprene and butadiene polymers, and their various isomers acrylonitrile-baeed copolymer and terpolymer rubber compositions, and isobutylene-based rubber compositions, or a mixture thereof, as described in, for example United States Patents No. 4,530,959; 4,616,065; 4,748,199; 4,863,131; 4,894,420; 4,925,894"; 5,082,901; and 5,162,409. .



Other suitable organic polymers are copolymers of ethylene with other high alpha olefins such as propylene, butene-1 and pentene-1 and a diene monomer The organic polymers may be block, random, or sequential and may be prepared by emulsion (e.g. e-SBR) or solution polymerization processes (e.g. s-SBR). Additional polymers which may be used include those which are partially or fully functionalised including coupled or star-branched polymers. Additional specific examples of functionalized organic rubbers include polychloroprane, chlorobutyl and bromobutyl rubber as well as brominated isobutylene-co-paramethylstyrene rubber. The preferred organic rubbers are polybutadiene, s-SBR and mixtures thereof,
Examples of silicone rubbers include organic polysiloxane compositions in which the organic polysiloxane is linear or branched, and optionally may contain, in addition to the hydrocarbon groups, certain reactive groups such as for example," hydroxyl hydrolyzable groups, alkenyl groups such as vinyl, hydrogen, fluoro, and phenyl. Further examples are given in United States-Patent No. 5,009,874. at column 5, line 27 through column 6, line 23, the disclosure of which is, in its entirety, incorporated herein ,by. reference.
Preferably, the polymeric composition is a curable rubber. The term "curable rubber" is intended to include both natural rubber and its various raw and reclaim forms as well as various synthetic rubbers. For example, curable ruber could include combinations of SER and butadiene, rubber (BR) , SBR, BR. and natural rubber and any other combination of materials previously described as organic rubber. In the description of this invention, the terms "rubber", "elastomer and rubbery elastomer" may be used interchangeably, unless indicated otherwise. The "rubber composition",


"compounded rubber" and "rubber compound" are used interchangeably to refer to rubber which has been blended or
mixed with various ingredients and materials and such terms are well known to those having skill in the rubber mixing or rubber .compounding- art,
The modified filler of the present invention may be prepared by using step A alone or both steps A and B for preparing hydrophobic silica and fumed silica disclosed in U.S. patent 5,908,660 and 5,519,2.98, respectively, which disclosures are incorporated herein by reference, with the
following changes. The amount of acid used results in a pH of. 2.5.or less in.the aqueous suspension, preferably, a pH of 2.0 or less, and more preferably, a pH of 1.0 or less and most
preferably a pH, of 0.3 or less; the modifying chemical used is a combination of bis (alkoxysilylalkyl)polysulfide. and a non-sulfur containing organometallic compound, which is referred to hereinafter as non-sulfur organometallic compound, in a
weight ratio of the bis(alkaxysilylalkyl)polysulfide to the non-sulfur organometallic compound of at least 0.05:1, preferably.from 0.05;1 to 10:1, more preferably,from o.l;l to 5:1, and most preferably, from 0.2:1 to 2:1, e.g., from 0.5:1 to 1:1, or the weight ratio may range between any combination of these values, inclusive of the recited values; and after the chemical treatment reaction is completed, the acidity (either added or generated in situ by the hydrolysis- of halogenated organometallic compounds) is neutralized, Typically after completing the chemical treatment reaction, the pH of the resulting aqueous suspension is increased to a pH range, of from 3 to 10. The neutralising agents can be of any type typically used to increase the pH of an acidic solution as long a.s the properties of the modifled filler are not adversely effected suitable neutralizing, agents include


sodium hydroxide, potassium hydroxide, ammonium hydroxide and sodium bicarbonate. Neutralization of the modified filler may also be accomplished by adding gaseous ammonia to the aqueous solution during spray drying,
, The acid used in step (A) may be of many types, organic and/or inorganic. The preferred acid catalyst is inorganic Examples of suitable, acid catalysts include hydrochloric acid, hydrobromic acid, hydroiodic acid, sulfuric acid, nitric acid, phosphoric acid., and benzenesulfonic acid. One acid catalyst or a mixture, of two or more acid catalysts may be employed as" desired. When the organometallic reactant . is, for example, a chloresilane, the catalytic amount of the acid may be generated in situ by hydrolysis of the chlorosilane or the reaction of the chlorosilane directly with hydroxyls of the inorganic oxide..
The temperature at which step (A) is conducted is not,critical and is usually within the range of from 20°C to 230°C, although somewhat lesser or somewhat greater . temperatures.may be used when desired. The reaction temperature will depend on the reactants used, e.g., the organometallic.compound(s), the acid and, if used, a co-solvent. Preferably, step (A) is conducted at temperatures in •the range of from 30°C to l50oC, although Step (A) can be conducted at. the. reflux temperature of the- slurry used in step (A) when this is desired.
In the aforedescribed reaction, the modifying chemical or coupling agent may be a combination of functionalizing agent(s) in place of
bis (alkoxysilylalkyl)pclysulfide and hydrophobizing agent(S) in place of a. non-sulfur organomctallic compound. The combination of functionalizing and hydrophobizing agents rosy be used in the same weight ratios specified for the

.combination of bis (alkoxysilylalkyUpolyeulf ide to the non sulfur organometallic compound. Examples of reactive groups that the functionalizing agent may contain include, but are not limited to vinyl, epoxy, glycldoxy and (meth) acryloxy. Sulfide, polysulfide and mercapto groups may also be the reactive groups of the. functionalizing agent provided they are not associated with the reactants represented by chemical formulae I and VII, included herein. As the hydrophobizing Agents, materials include but are not limited to chemicals such as natural or synthetic fats and oils and the non-sulfur organometaliic compounds represented by chemical formulae IT, III, IV, v and mixtures or such hydrophobizing agents..
The initial step of contacting the acidic aqueous
suspension of inorganic oxide with a combination of
bis(alkoxysilylalkyl)polysulfide and non-sulfur organometallic
compound, preferably a non-sulfur organosilicon compound, may
further include adding a water miscible solvent, in amounts
sufficient: to facilitate their reaction with the inorganic
oxide. The solvent acts as a phase transfer, agent speeding up
the interaction of the combination of hydrophobic sulfur and
non-sulfur organometallic compounds with the hydrophilic-
inorganic oxide. When used, the "amount of the water-miscible
organic solvent will typically comprise at least 5 weight
percent of the aqueous suspension, more preferably from 15 to
SO weight percent and most preferably from 20.to 30 weight
percent, of the aqueous suspension or the weight percent may
range between any combination of these values, inclusive, of
the recited values, Suitable water-miscible solvents include,
for example, alcohols such as ethanol, isopropanol and
tetrahydrofuran. Preferably, isopropanol is used as the
water-miscible organic solvent.

A surfactant may also be used in the initial step, either in combination with the water-miscible organic solvent, or in place of the water-miscible organic solvent in an amount sufficient to facilitate the chemical modification of the inorganic oxide toy the bis(alkoxysilylalkyl)polysulfide and non-sulfur organometallic compound. The surfactant may be nonionic, anionic, cationic, amphoteric or a mixture of such surfactants provided that it does not have an adverse effect on the performance of the resulting chemically modified inorganic oxide for its intended use Typically, when used, the surfactant is employed at a level of from 0.05 to 10 weight percent of this aqueous suspension, mors preferably, from 0.x to 5 weight percent, and most preferably from 0.1 to 3 weight percent or the weight percent may range between any combination of these values, inclusive of the recited values
Representative examples of suitable surfactant include alkylphenolpolyglycol ethers, e.g., p-octylphenolpolyethyleneglycol {20 units) ether, p-nonylphenolpolyechyleneglycol (20 units) ether, alkylpolyethyleneglycol ethers, e.g.,
dodecylpolyechyleneglycol [20 units.) ether, polyglycols, .e.g, , polyethyleneglycol 2000, alkyltrimethylammonium salts, e.g.., cetyltrimethylammonium chloride (or bromide) , dialkyldimethylammonium salts, e.g., dilauryldimethylamnium chloride, alkylbenzyltrimethylarmttonium salts; alkylbenzenesulfonates e.g., sodium p-dodecylbenzenesulfonate, sodium p-nonylbenzenesuifonate, alkylhydrogen sulfates, e.g., lauryl hydrogen sulfate,, and alkyl sulfates, e.g., lauryl sulfate. The surfactant may also be, for example,.a polysiloxane polymer or copolymer having an allyl andblooked polyethylene oxide.



Bis (alkoxysilyialkyl)polysulfides used to produce the modified fillers of the present invention are described in U.S. Patents-3,873,489 and 5,580,919." which disclosures are incorporated, herein by reference, and are represented by the following formula 1:
Z-alk-Sn, in which alk is a divalent hydrocarbon radical having from 1 to 18, preferably 1 to 5, and more preferably, 2 to 3, carbon a Corns; n." is a whole number of 2 to 12, preferably 2 to 6 and more preferably "1 to 4; and z is -.

wherein R is an alky 1 group having from 1 to 4. carbon atoms or phenyl, and R is an alkoxy group-having from 1 to ft, pref sraJbly .1 to 4, more- preferably 1 to 2, carbon atoms, a cycloalkoxy group, with from 5 to S carbon atoms, or a straight or branched, chain alkylmercapto group with from 1 to 8 carbon atoms. The R and R" groups can be the same or different. The divalent alk group can be straight or branched chain, a saturated or unsaturated aliphatic hydrocarbon group or a cyclic hydrocarbon group. The high purity"organosilane disulfides disclosed in U.S. Patent 5,580, 519 "require that 80 percent or n" in formula I is 2,
Exemplification of the Ms {alkoxysilylalkyl} -polysulfides include: the bis(2-trialkoxysilylethyl) -polysulfide in which the tiialkoxy group is trimethoxy. triethoxy, tri (mathylethoxy), txipropoKy, tributyl, etc. up


to trioctyloxy and Che polysulfide is the di-, tri-, tetra-, penta-, and hexasulfids. The. corresponding b.is(3-trialkoxysil-ylpropyl) -, bis (3-trialkoxysilylisobutyl)"," -bis (4-trialkoxysilylbunyl)-, etc . up t:o bis (6-trialkoxysilyl-hexyDpolysulfide can also be used. Preferred are the relatively simply construeted organosilanes including the bis(3-trimathcxy-, -triethoxy-, and -tripropoxysilyl-propyDpolysulfide,; namely, the di-, tri- and tetrasulfides.
Specific examples of such bis(alkoxysilylalkyl)-polysulfidas are described in column 6, lines 5-55 of the, aforesaid U.S. Pat. No. 3,873,489. and in column 1.1, lines 1,1-41 of U.S. Patent: No, S, 560,919. Representative examples of such compounds are:
3,3"bis(trimethcxysilylprapyl)disulfide, 3 ,3-bis (triethoxysilylpropyi) tetrasulfide, 3,3"-bis(trimefchoxysilylpropyl)tetrasulfide, 2 ,2 " -bis (triethoxysilylethyl) tetrasulfide; 3,3"-bis(trimethoxysilylpropyl)trisulfide, . 3,3"-bis (triethoxysilylpropyl)trisufide, 3,3" -bis {tributoxytiilylpropyl) disulfide, 3,3"-bis(trimethoxysilylpropyl)hexasulfide and "3 , 3 " -bis (triocfcoxysilylpropyl) tetrasulfide and mixtures thereof. The most preferred compound is 3,3"-bis (triethoxysilylpropyl)tetrasulfide (TE"SPT) .
TESPT is available under the trade name Si- 69 from Detjusss Corp. It is "reported to be a mixture of 3,3"-bis(triethoxysilylpropyl)monosulfide, 3,3"-bis(triethoxysilylpropyl)disulfide, 3; 3"-bis (CriethoxysilylpropyDurijsulfide,
"3,3"-bis(triethoxysilylpropyl)tetrasulfide and higher sulfide homologies having an average sulfide of 3.-5;


The non-sulfur organometallic compounds that may be used to produce the modified, filler of.the present invention may be at least one non-sulfur organomstallic compound or a mixture" of non-sulfur organometallic compounds selected from the-group consisting of organome tail lie compound(s) represented by formula II:

organometallic compound(s) represented by formula III:

organometallic compound(s) represented by the formula IV:

and organometaillic compound(s) represented by formula V:

wherein each. M is. independently silicon, titanium or 2ircon-ium; each .Rl is independently a -hydrocarben group of from, 1 to 18 .carbon atoms; or R1 can be an organofunctioual hydrocarbon group of from a to 12 carbon atoms where, for example the functionality is amino, carboxylic acid, carbinol ester, or amido,- each X it" independently selected from the group consisting of halogen, amino, alkoxy groups of from 1 to 12 carbon atoms and acyloxy groups of from 1 tc 12 carbon atoms, a is the integer 1, 2 or 3,- each R1 is independently halo, hydroxy, or s. hydrocarbon group containing from 1 to is carbon atoms with the proviso that at least 50,mole percent. of

-/■
the R3 substituents are hydrocarbon groups containing from 1 to 18 carbon atoms, c is an integer from 2 to 10,000; each R3 is independently halo, hydroxy, or a hydrocarbon group containing from 1 to 1B carbon atoms and d is an integer from 3 to 20; each R is independently hydrogen or a hydrocarbon group containing from 1 to 18 carbon atoms and k is l or 2; and the halogen or (halo) groups are selected from chloro, bromo, iodo or fluoro In the definition of the substituents shown in formulae II, III, IV and V, like symbols have the same meaning unless stated otherwise.
in formula II each R1 can be a saturated or
unsaturated monovalent hydrocarbon group or a substituted or-" non-substituted monovalent hydrocarbon group, R1 can be, for example, alkyl groups such as methyl, ethyl, propyl, iso-propyl,iso-butyl, t-butyl, n-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and dodecyl; alksnyl groups such as " vinyl,, allyl, and hexenyl; substituted alkyl group such as chloromethyl, 3,3,3-trifluoropropyl, and 6-chlorohexyl; cycloalkyl groups," such as cyclohexyl and cycloootyl, aryl groups.such as phenyl and naphthyl; and substituted aryl groups such as benzyl, tolyl and ethhylphenyl,
When X is a halogen in formula II, it is preferred that the halogen be chloro When X is an alkoxy group, X may be, for example, methoxy, ethoxy, and propoxy. when X is an
acyloxy group, X may be, for example, acetoxy More preferred is when each X is selected from the group consisting of chloro and methoxy.
The viscosity of the aforedescribed organometallic compounds is not limiting and can range from that of a fluid to a gum. Generally, higher molecular weight organometallic compounds should be cleaved by the acidic conditions. of the



chemical modification stop allowing them to react with the hydrophilic inorganic oxide.

the same as the hydrocarbon groups described for R1. For purposes of the present invention, when the organometallic reactant is an organcsilicon reactant, the silicon is considered to be a metal.
Preferably, the non-sulfur orgaiiometallic compound(S) is represented by formulae II, III, IV, v or a mixture of said organometallic compounds wherein each X i.s silicon. More preferably, the non-sulfur organometallic is represented by formula II wherein Rl is C1-C6 alkyl, X is chloro and a is ,2.
Examples of useful organosilicon compounds include, but ara not limited, to compounds and mixtures of compounds selected from the group consisting of diethyldichloros ilane, allylmethyldichlorosilane, methylphenyldichlorosilane, phenylethyldiethoxysilane, 3,3,3- trifluoropropylmethyldichlorasilane .trimethylbutoxysilane sym-diphenyltetramethyldisiloxane, trivinyltrimethyl-cyclotrisiloxaue, octamethylcyclotetrasilaxane, .hexaechyldisiloxane, pentylmsthyldichlorosilane, divlnyidipropoxysilane, vinyldimethylchlorosilane, vinylmethyldichlorosilane, vinyldimethylmethoxysilane, trimethylchlorosilane, Urimethylmethoxysilarie, trimethylechoxysilane, methyltrxchlorosilane, methyltrimethoxysilane, methyltriethoxysilane, hexamethyldisiloxane, hexenylmethyldichlorosilane, hexenyldimethylehlorosilane, dimethylchlorosilane, dimethyldichloros.ilane, dimethyldimethoxysilaixe, dimsthyldiethoxysilane, hexamethyldisilazane, trivinylmethylcyclotrisilaxane, polydimathylfiloxanes

comprising 3 to about 20 dimethylsiloxy units and Crimethylsiloxy or hydxoxydimethylsiloxy endblocked poly(dimethylsiloxane) polymers having an apparent viscosity within the range of from 1 to 1,000 mpa-s at 256C,
Examples" of organotitanium compounds that may be used include, but are not limited to, tetra (C1-C1B) alkoxy titanates, methyl triethoxy titanium (iv), methyl titanium (iv) triisopropoxide, methyl titanium (iv) tributoxide, methyl titanium . (iv) tritoutoxide, isopropyl titanium (iv) tributoxide, butyl titanium (iv) triethoxids, bucyl titanium, (iv) nributoxida, phenyl titanium (iv) triisopropoxide, phenyl titanium (iv) tributoxide, phenyl titanium, (iv) triisobutoxide, . [Ti(CH2fh)3(NC5H10)3 and
[Ti(CH2SiMe3)2(NEt2}2)
Examples of organoairconium compounds that may he. used include, but are not limited to, tetra(C1-c18)alkoxy Zirconates phenyl zirconium (iv) trichloride, methyl zirconium (iv) trichloride, ethyl zirconium (iv) trichloride, propyl zirconium (iv) trichloride, methyl zirconium (iv) tribromide, echyl zirconium (iv) tribromide, propyl zirconium (iv) tribromide, chlorotripentyl zirconium (iv). Zirconium compounds similar to those described above for the-organotitanium compounds and vice-versa are. also contemplated. The amount of bis (alkoxylkoxysilylalkyl)polysulfide and non-sulfur organometallic compound used in the aforeda&cribed" chemical modification process is that amount which is sufficient to produce a modified filler characterized by a carbon content of greater than 1 weight percent, a sulfur content of greater than 0.1 weight percent, .a silane Conversion Index of at least 0.3 and a Standard Tensile Stress ® 300% elongation of at least 7.0. Such an amount is referred to herein as a covlirr amount, i.e.., an amount sufficiant to

bind to the fillar and enable the now modified filler to bind to the polymeric composition.
The weight ratio of bis(alkoxysilylalkyl) polysulfide. to organoraetallic compound will vary from at least
0.05:1, preferably, from 0.05:3. to 10:l more preferably, from 0.l:l to 5:1, ,2nd most preferably, from 0.2:1 to 2:1, e.g., from 0.5:1 to l:l or the weight ratio may range between any combination of these values, inclusive of the recited- ranges. The individual organometallic reactants may be added together or sequentially in any order It is preferred that the — organomatallic reactants be added in an amount that provides an excess of. organometallic units in relation- to the hydroxyl groups available on the, inorganic oxide particles for reaction. The upper limit of the amount of organometallic
reactants added to the process is not critical Excess
bis(alkoxysilyialkyl)polysulfide and organometallic compound . can be removed by filtration, distillation, washing with a solvent, or other known separation techniques.
In, another embodiment, the bis(alkoxysilylalkyl)-polysulfide reactant may be replaced by a combination of a bis{alkoxysilylalkyl)polysulfide and a different sulfur-containing organometallic compound, in a weight ratio of bis(alkoxysilylalkyl)polysulfide to sulfur-containing organometallic compound of from at least greater than 1:1, e.g., l.Ol-.l. The ratio may range from l.0l-.1 to 100:1, preferably from 5;l to 50:1 and more preferably from 10:1 to 30:1 or the weight ratio may range between any combination of these values, inclusive of the recited values Any sulfur-containing organometallic compound (other than the bis (alkocysilylalkyl)polysulfide represented by formula I}, that functions as a coupling agent in the vulcanization of a filler containing rubber, is useful.

Examples of useful sulfur containing organometallic compounds include mercaptoorgaiiometallic reactance that may be represented by the following graphic formula VII:

wherein M is silicon, h is. halogen or -OR7, Q" is hydrogen, C1-C22 alkyl, or halosubstituted C1-C22 alkyl, R6 is C1-C22 alkylene, R1 is C1-C12 alkyl or alkoxyalkyl containing from 2 to 12 carbon atoms, said halogen or (halo) groups being chloro, bromo, iodo or flucro, and a is l, 2 or 3. R* is preferably C3-C3 alkylene e.g. methylene, ethylene, and. propylene., R7 is preferably C1-C4 alkyl, more preferably methyl and ethyl, L is preferably -OR4, and n is; preferably 3 . Mercaptoorganometallic reactanfcs having two mercapto groups may also be used.
Mercaptoorganometallic compounds in which the mercapto group is blocked, i.e., the mercapto hydrogen atom is replaced by another group, may also be used. The blocked mercaptoorganometallic compounds may have an unsaturated hetexoatom Or carbon bound directly to sulfur via a single bond, Examples of specific blocking groups include thiocarboxylace ester, dithiocarbamate ester, thiasuifonate ester, ehiosulfate ester, thiophosphate ester," thiophosphonate ester, ,-thiophosphinate ester, etc.
When reaction of the mixture to couple the filler to the polymer is desired, a deblocking agent is added to tho mixture to deblock the blocked mercaptoorganometallic compound. If water and/or alcohol are present in the mixture, a-catalyst, e.g., tertiary amines, Lewis acids or thiols, may . be used to initiate and promote the loss of the blocking group

by hydrolysis or alcoholysis to liberate the corresponding mercaptoorgahometallic compounds. Procedures for preparing and using such -compounds, e.g., blocked mercaptosilanes, are disclosed in PCT application WO 99/09036. Other procedures for preparing blocked cnercaptosilanes are disclosed in U.S. Patents" 3, 692 ,812 and 3 ,922 , 43G , which patents ara incorporated here in by reference.
Examples of useful mercaptoorganometallic compound(a) include but are not limited to
mercaptonmethyltrimethoxysilane, mercaptoethyltrimethoxysilane-, mercaptopropyltrimethoxysilane, mercaptomethyltriethoxysilane, mercaptomethy1 tripropoxysilane, marcaptopropyltriethoxysilane., (mercaptomethyl)dimethylethoxysiiane,
{mercaptomechyi) methyldiethoxysilane, 3-mercaptopropyl-methyldimsthoxysilane and mixtures thereof. The most preferred compounds, are mereaptopropyltrimethoxysilane, marcaptopropyltriethoxysilane or mixtures thereof.
Examples of useful blocked mercaptosilanes include. but are not limited to 2-triethoxysilyl-i-echyl thioaoetate, 3-trimethoxy-silyl-l-propyl thiocctaate, bis-(3-. triethoysilyl-x-propyl)-methyldithiophosphonate, 3-triechoxysilyl-l-propyldimethylthiophosph-inate, 3-triethoxy"silyl-i-propylmechylthiosulfate, 3-triethoxysilyl~i-propyltoluenath.iosulfo.nace and mixtures thereof.
After the chemical modifying process is completed, the pH of the aqueous suspension of .modified inorganic oxide is increased from the treatment pH of 2.5 or less to a ph.from 3.0 to 10.0. Typically, the pH of the resulting aqueous . suspension is increased to 3 or higher, preferably, 4 or higher, more preferably, 5 or higher and mose preferably, 6 or higher and usually 10 or less, preferably 9 or lees, more preferably-8 or less and more , preferably 7 or less. The pH of
l


the aqueous suspension way range between any combination of these, levels, including the recited levels. This is done, to neutralise the added or generated acidity and produce" a final product (after drying) having a pH of from 5,0 to 10,0.
The modified inorganic oxide is recovered by filtering and drying or by contacting the aqueous suspension of modified inorganic oxide with a water immiscible organic-solvent at a solvent: to inorganic oxide weight ratio greater than 1 to 1, preferably greater than 5 to 1. The modified inorganic oxide recovered in the solvent phase may be used without further treatment or dried. One contemplated embodiment of the present invention is a composition comprising a slurry of the modified tiller in a water-immiscible solvent. The concentration of the. modified filler in the slurry may range from 1 to 90 weight percent based on the total weight of the slurry.
Examples of useful water-immiscible organic solvents include low molecular weight siloxanes, such as hexamethyldisiloxane, octamethylcyclotetrasiloxane, diphenyltetramethyldisiloxane and trimethylsiloxy endblocked polydimethylsiloxane fluids. When a siloxane is employed as a solvent, it may serve both as a solvent and as a reactant with the inorganic oxide. In addition, useful water-immiscible organic solvents include aromatic hydrocarbons, such as toluene and xylene; heptane and other aliphatic hydrocarbon solvents; cyclcaikanes, such as cyclohaxans; ethers,, such as diethylether and dibutylether,- haiohydrocarbon solvents, such as methylene chloride, chloroform, ethylene chloride, and chlorobenzene; and ketones, such as Triethylisobutylketone,
The water-immiscible organic solvent which is used to contact the aqueous suspension of hydrophobic particulate inorganic oxide may or do not contain one or more materials

dissolved therein, as is"desired. Examples of such materials include, but are not limited to, one or more rubbers, oil, coupling agent, antioxidant, and accelerator.
The modified filler of the present invention (as a powder, granule, pellet, slurry, aqueous suspension or solvent suspension) may be combined with base material, i.e., material used in the product to be manufactured, to form a mixture . referred to as a master batch. In the master hatch, the modified filler may be present in a higher concentration than in the final product. . Aliquots of this mixture are typically added to production-size quantities during mixing operations in order to aid in uniformly dispersing very small amounts of such additives to polymeric compositions, e.g., plastics, , rubbers and coating compositions.
The modified filler may be combined with emulsion and/or solution polymers, e.g., organic rubber comprising solution styrene/butadiene rubber (SBR),polybutadiene rubber or a mixture thereof, to form a master batch. One "contemplated embodiment of the present invention, is a. master batch comprising a combination of organic rubber, water-immiscible solvent, modified filler and optionally, processing oil. Such a product may be supplied by a rubber producer to a tire manufacturer. The benefit to the tire manufacturer of using a master batch is that the modified filler is uniformly dispersed in the rubber,which results in minimizing the mixing time to produce the compounded rubber. The master batch may contain from 10 to 150 parts of modified filler per 100 parts of rubber (phr), preferably, from 20 to 130 phr, more preferably, from 30 to 100 phr, and most preferably, from 50 to 80 phr.
In a further embodiment of the present invention, there is contemplated a polymeric are having dispensed

therein from 10 to 150 parts of modified filler per 100 parts of polymer, preferably from 20 to 130, more preferably, from. 30 to 100, and most preferably from 50 to 80 parts of modified, filler per 100 parts of polymer- Alternatively, the amount: of modified filler may range between any combination of these values, inclusive of the recited ranges,. As described herein, the polymer may be selected from the group consisting of thermoplastic resins, thermosetting resins, organic rubber and silicone rubber. Preferably, the polymer is a curable organic rubber.
Curable rubber« principally contemplated for use in combination, with the modified filler of the present invention are well known to the skilled artisan In rubber chemistry and include vulcanizable and sulfur-curable rubbers. Particularly contemplated are those which are typically used for mechanical rubber goods.
The modified filler of the present invention can be mixed with an uncured rubbery elastomer used to prepare the vulcanisable rubber composition by conventional means such as in a. Banbury mixer or on a rubber mill at temperatures between about 100°F". and 300°F (38oC.-150oC,) . A vulcanisable rubber" composition may contain, based on 100 parts of vulcanizable rubber polymer, from 10 to .150 parts of modified filler, preferably, from 2o to 130. phx, more preferably, from 30 to loo phr, and most preferably, from 50 to 80 phr. Other conventional rubber additives present are the .conventional sulfur or peroxide cure systems.
The sulfur-cure system can include 0.5 to 3 parts sulfur, 2 to 5 parts zinc oxide and 0.5 ho 2 parts accelerator. The peroxide-cure system can include 1 to 4 parts of a peroxide such aa dicumyl parotide. Other conventional rubber additives can be used, Such additives

include other fillers, such as carbon black, oils, plastieizers, accelerators, antioxidants, heat stabilizers, light stabilizers, zone stabilizers, organic acids such as for example stearic acid, benzoic acid, or salicylic acid, other activators, extenders and coloring pigments. The particular compounding recipe will vary with the particular vulcanizate prepared; but, such recipes are wall-known to those skilled in the rubber compounding art.
This vulcanilizable rubber composition is vulcanized or cured to a rubber vulcanizate in accordance with customary procedures Known in the rubber industry. Exemplification of industrial rubber vulcanizates (articles.) which, can be produced utilizing the modified filler of the present invention include wire and cable jacketing, hoses, gaskets and seals, industrial and automotive drive-belts, engine mount V-belts, conveyor belts, roller coatings, tires and components -of tirus, such as vehicle tire treads, subtreads, tire carcasses, tire sidewalls, tire belt wedge, tire bead filler, and tire wire skim coat, shoe sole materials, packing rings, damping elements and many others.
The present invention is more particularly described in the following discussion of the Standard Compound Protocol. Examples and Comparative Examples which are intended as illustrative only since numerous; modifications and variations therein will be apparent, to those skilled in the
art.
Standard compounding protocol
The standard Compounding Protocol was used to prepare test samples of formulated rubber composition

containing the silica of the examples and
comparative examples



part-A The following ingredients in amounts of parts per hundred, parts of rubber by weight (phr) were added in the order .described to a polyethylene bag held erect, in a 500-milliliter (mL) plastic cup:

(1) Sundex® 8125 aromatic hydrocarbon processing oil,
obtained commercially from Sun. Company, Inc., Refining . and Marketing Division.
(2) Kadox® surface treated sine oxide, obtained commercially from Zinc Corporation of America.
(3) Wingstay® 100 antipzonant, a mixture of diaryl p-phenylenediamines,, obtained commercially from The Goodyear Tire & Rubber Co.
(4) . Rubber grade stearic acid, obtained commercially from c.
Is.- Hall.
Part,. B A 1.69 liter (D Parrel Banbury mixer (Model"."BR"-.) was used for mixing the various ingredients." Immediately prior to adding the batch ingredients to the mixer, S00 grams (g) of cv-60 grade natural rubber was put through the mixer to clean it of any residue of previous runs and increase the temperature to about 9.3°C. (200°F.).,. After removing the rubber, the mixer was cooled to about 65oC. (150oF.) before adding the ingredients to produce the rubber test sample.



A rubber composition is prepared using the test silica, the following other enumerated ingredients, and the procedure described hereinafter.



(6) (7)
(3) (9)
Solflex® 1.216 solution styrene-butadiene rubber (SBR) obtained commercially from The Goodyaar Tire & Rubber Co. Budene 1207 butadiene rubber (BR) obtained commercially from The Goodyear"Tire & Rubber Co. Santoflex® 13 entiozorant, described as N-(l,3-dimethylbutyl)-N"-phenyl-p-phenylenediamine, obtained commercially from Flesys.
Okerin® 75.40 microctystalline wax/paraffin wax blend obtained-commercially from Astor Corporation, Rubber Makers (PB) sulfur, 100 % active, obtained commercially from Taber, Inc.
(10) N-tert-butyl-2-benzothiazolasulfenamide, obtained commercially from Monsanto.
(11) Diphenylguanidine, obtained commercially from Monsanto.


The first pass was. initiated by adding the rubber, viz., SPR and BR, to the mixer and mixing for 0,5 minute at l16 rpm. The rotor speed was maintained at l16 rpm and 5 7.5 phr of the treated silica sample was added. After a further 1.5 minute, the ram was raised and the chute swept, i.e., the. covering on the entry chute was raised and any material that was found in the chute was swept back into the mixer. After a, further minute, the sample from Part A was added. After another minute, the ram was raised and the chute swept. The contents in the mixer were mixed for. an additional minute to achieve ,a. maximum temperature in the range, of from 14 5 to 150°C. (293-to 302°F.) and to complete the first pass in" the mixer. Depending upon the type of sample, the. rotor speed of the mixer may be increased or decreased after 4 minutes to achieve a temperature in the foregoing range within, the. specified mixing period.
• After completing the first pass, the temperature of
the material was determined with a thermocouple to verify that in did not exceed the maximum temperature of 150oC. The removed material was weighed and sheeted in a Farrel" 12 inch two-roll rubber mill, at 2.032 mm +0,127- mm (0.080 inch + 0.00S inch). The resulting milled stock, was cut into strips in preparation for the second pass in the mixer,
A minimum of one hour wa.s allotted between the completion of the first pass in the mixer and the beginning of the second pass to allow the milled stock to cool. If necessary, the aforedescribed cleaning and warming-up procedure using cv-60 grade natural rubber was completed prior to initiating the second pass. The temperature of the mixer was adjusted to approximately 49oC.(120oF.) , With the cooling water running, the second pass was initiated by adding the strips of first pass stock to the mixer operating at ", ,


and the preweighed combination of Santoflex® 13 antiozonant and Okerin® 7.240 microcryscalline wax/paraffin wax blend. After 0.5 minutes, the second addition of the combination of RM Sulfur, TBBS and DfG was added. Alter a further l.S minutes,, the ram was raised and the chute swept. The second pass was completed by mixing the stock an additional 2.0 minutes while maintaining the temperature at or below 1250C. (2576F.).".
Part _C A Farrel 12 inch two-roll rubber mill was heated to approximately 60°C. (140°F-), The stock from the second pass
of Part B was fed into the"running mill with a nip setting of 2.032 mm ± 0.127 mm (0.080 inch + 0.005 inch) The resulting
sheet was placed on a flat surface until the temperature of the sheet reached room temperature. Typically the sheet
cooled within about 30 minutes. Afterwards, the milled sheet
was fed inco the rubber mill with a. nip setting of 3.81 mm +
0.51 torn (0.l5.inch ± 0.02 inch) . The rolling bank was
adjusted, if necessary, to maintain a uniform thickness. The
resulting material was subjected to 16" side cuts and then. 6
end passes. The rubber mill nip was adjusted to produce a
sheet thickness of 2.032 mm + 0.12*7 rum (O.080 inch + 0.005
inch) . The sheet stock collected off the mill was placed on a
flat clean surface. Using a stencil, a rectangular sample
203.2-mm X.152.4 mm (8 inches x 6 inches) was cut from the
sheet stock.. The sample was conditioned,- i,e., ,stored between
clean"polyethylene sheets and maintained for 15 to 18 hours .at
a temperature of 23o + 2° C, and a relative humidity of, 50% ±
5% .
after conditioning, the sample was placed in a 203.2 nm.x 152.4 mm x 2.296 mm (3 inch x 6 inch x 0.09 inch) standard frame machine steel compression mold having a



polished surface. Tha sample was cured in a 6.1 centimeter x 61 centimeter. (24 inch x. 2.4 inch) K90 kilonewton (100 ton) 4-post electrically heated compression press, for T90, i.e., the time it takes for 90 percent of the cure to occur, in accordance with ASTM D-2084, plus 5 minutes at i50°C. Part_D
. Testing was performed in .accordance with ASTM .D
412-93a - Test Method A. Dumbbell test, specimens were prepared using Die C, An instron model 4204 with an automated contact extensicmeter for measuring elongation was used. The cross-head speed was found to-equal 508 mm/min. All calculations were done using the Series IX Automated Materials Testing software supplied by the manufacturer. The Tensile Stress at 300% elongation (in MPa) for samples prepared using the Standard Compounding Protocol was reported as the Standard Tensile Stress at 300%. elongation (STS © 300%) in Table 3.-.
A precipitated silica was produced by acidifying a sodium silicate solution with sulfuric acid. The majority of the precipitate was formed at a pK above 8.5. Further precipitate was produced by continuing the acid addition until the" solution pK reached a level of about 3.5.
A sample of. the precipitated silica for surface area analysis, as described in Example 5, was prepared t,

filtering and washing a portion of the silica until the rinse water demonstrated a conductivity level of from about 300 to 900 miczomhos. The resulting filter cake, was reliquefied using a high shear agitator to form a solid in liquid suspension, The suspension was dried in a Niro spray drier (inlet temperature about 360oC and the outlet temperature about 1.10°C) . Listed in Table x are the surface areas of the precipitated silicas used to prepare the modified silica of the Examples and comparative Examples.
Approximately 40 kilograms (kg) of a precipitated silica suspension of which about 5,2 kg is silica and about 11.7 kg of isopropy1 alcohol were added to a 30 gallon glass lined vessel having a bottom drain. The vessel was also equipped with a temperature recorder, mechanical stirrer, means for heating and a condenser.
while the contents of the vessel were stirred and heating initiated, Si-69 reinforcing agent, referred to herein as TESfT, was addod over an interval of time (typically, about 10.minutes) that would yield the approximate amounts listed for weight percent of TESPT per silica on a drybasis tor the examples listed in-Table 3. After completion of the TESPT addition, dimethyldichlorosilane (DMPCS) was added in an identical maimer to yield the approximate amounts listed for weight percent of. DMDCS per silica on a dry basis in Table. 3. The weight ratios of TESPT /DMDCS is also listed in Table 3. The resulting pH of the solutions was about O.B.
After completion of the DMDCS addition, the mixture was heated to about 68°C and held at this temperature for about 10 minutes. While cooling, enough toluene (typically 15 kg) adaded to the stirred mixture to effect separation of
i

the hydrophobic precipitated silica from the aqueous phase without forming an. emulsion. The aguecus phase was drained from the vessel. This stirred mixture in the vessel containing the hydrophobic precipitated silica was then washed twice with about 20 kg for Example 1 . and about: 40 kg for Example 2 of water containing about 400 grams for Example I and 500 grams for Example 2 of sodium bicarbonate. The aqueous phase was drained.
After washing was completed, enough additional toluene (about 1.3.9 kg for Example 1 and 23.7 kg for Example 2) was added to the stirred mixture to make a flowable solid-in-liquid suspension that could be. easily discharged from the vessel. The resulting suspension was dried in a rotocone drier under vacuum (minimum 23 inches of mercury) at a minimum of 140eC. Drying was continued until the samples showed a wt.% loss of less than 4.5 % when exposed to 150°C for 3.0 minutes.
EXAMPLE 3-8
Approximately 19 kg of a precipitated silica suspension of which about 1.5 kg is silica was added to a 40 liter glass vessel having a bottom drain. The vessel was also equipped with a temperature recorder, mechanical stirrer, means for heating and a condenser.
While the contents, of the vessel were stirred, about 1 weight percent per silica on a dry basis of the surfactant listed in Table 2 was added. After completion of the surfactant addition, the resulting mixture was stirred for 5 minutes. TESPT was added over a S minute interval to the stirred mixture to yield about 10 weight percent of TESPT per silica on a dry basis. The resulting pH of the solution was about 3.0, After completion of the TESPT addition,


dimethyldichloresiiane (DMDCS) was added in an identical, manner to yield about 13 weight percent of DMDCS per silica on a dry basis.. The resulting pH of the solution ranged from about 0.9 to 1.6. The mixture was heated to from about 61 to 680C and held at this temperature for typically about 20 minutes. The suspensions of Example 3 and B were heated for about 40 and about 16 minutes, respectively. While cooling, enough 50 wt,% NaOH was added to the mixture over an interval oil time (typically 10-15. minutes) to adjust the pH Co about 7.0. 20 L of the stirred mixture containing the hydrophobic precipitated silica was discharged iron the vessel, vacuum filtered, using a Buchner funnel and then washed three times with about 6 kg of water each wash. After washing was completed, enough deionized water and high shear agitation was applied to the filter, cake to make a flowable solid in liquid suspension. The resulting suspension was spray dried in a. Niro spray drier (inlet temperature about 400°C and the outlet temperature about 150°C) to form the treated silica samples of Examples 3-B.
COMPARATIVE EXAMPLE 1-3 17 L of the untreated precipitated silica used in Examples 1-2 containing 820 grans of silica was added to a vessel equipped with a mechanical stirrer. The pH of the slurry before treatment was about 6.5. While the stirrer was mixing the suspension, enough TE"SPT was added to yield the approximate amount listed for weight percent" of TESPT per silica on a dry weight basis for. Comparative Examples"1-3 listed in Table 3. The resulting treated suspensions wera dried in a Niro spray drier (inlet temperature about 360°C and the outlet temperature about 110°C).

The surface area of the treated and untreated test silica samples ot Examples 1-8 and Comparative Examples (CE) 3 was determined using a Horiba 6 200 series* instrument by a dynamic single point surface area technique, ASTM D3037-93, Procedure C (modified) , This procedure simulates the Brunauer-Emmett-Teller (BET) method at p/P = 0,334,using 30% nitrogen-in-helium as the adsorbate gas. The ASTM procedure was modified as follows: a 30% nitrogen-in-helium gas mixture was used; a flow of approximately 40 mL/min was maintained.; samples were dried in the analysis cells under a flow of nitrogen at 18O+5+OC tar one hour; and the adsorbed nitrogen on the sample was desorbed by removing the dewar of liquid nitrogen and allowing the sample to warm to room temperature with no external heat source. Results for the untreated test silica samples are listed in Table 1 and for the treated test silica samples are listed in Table 4.
The percent carbon was determined by CHN analysis using a Carlo Erba model 1106 elemental analyser, A 1 - 2 mq sample in a scaled tin capsule was burned in an oxygen enriched atmosphene at 104 0 °C with a Helium carrier, quantitatively combusted over Cr2o3, then the combustion gases were passed over Cu at 6S0 "C, to eliminate the excess oxygen and reduce, the oxides of nitrogen to nitrogen. The gases were then passed through a chromatographic column, separated and eluted as Na, C02; and H;0, The eluted gases .were measured by a thermal conductivity detector. The instrument was calibrated by combustion of standard compounds. Results are listed in Table 4.
The percent sulfur was determined by x-ray fluorescence spectrometry (XKF) , using a Rigaku.RIx 2000" wavel dispersive spectrometer. Samples were briquetted

into aluminum support cups at 344.75 megapascals (25 cons/in* )
pressure after mixing with SpeccroBland® binder (Chemplex
Industries/Tuckahoe; NY) in a 1:1 weight ratio. NIST- and
WES- "traceable secondary standards (PPG production silicas, or
equivalent) wars used for the empirical XRF calibration,
Detection was via a, gas proportional flow counter using a
germanium crystal monochromator Results are listed in
Table 4,
The Silane Conversion Index reported as SCI in
Table 4 was determined by solid state 29si NMR. This data was
collected at ambient temperature on a Bruker AM-300 NMR with a
narrow bore magnet and a Doty 7 mm standard speed MAS probe.
Samples were packed into 7 nun o,d. .zirconia rotors and Healed
Angle with a speed of about 5.0 kHz. . Cross Polarization
(CP/MAS) data was collected using a 90" 1H pulse, SHOO - 8400
scans per spectrum, a-5 msecond contact time, high power
proton decoupling during data acquisition, and a 3 second
relaxation delay. Hartmann-Hahn conditions were achieved
using a kaolinite sample (J. Rocha and J. Klinowski, J. Magn,.
Res on., 90, 567 (1920)), All chemical shifts were referenced
externally to tetramethylsilane dMS) .
All spectra were analysed using a nonlinear curve
fitting program (LINESIM). on an Aspect 3 000 computer to
determine the relative area % for the Tl (-49 ppm) , T5 (-57
ppm), and T3 (-65 ppm) peaks. Area % values for T1 T3, and T3
were determined by curve fitting over the region of -3 0 ppm
to -80 ppm.
pH determinations were made on the treated silicas of the Examples, and Comparative Examples by the following procedure; add 5.0 g of silica (in powder form) to a 150 mL beaker containing stir bar add 50 mL of


isppropanol and 50 mL of colonized water; and stir vigorously without splashing until the silica is suspended. Place a calibrated pH electrode in the vigorously stirring solution and record the pH reading after one minute (+ S sac), The results are listed in Table 4.
The Soxhlet Extractable percent carbon of the treated silica of Example I was determined by adding 5.44 grams of the material to a 43 mm x 3.33 mm {internal diameter x external length) cellulose extraction thimble which was placed into an appropriately sized Soxhlet extraction tube which was fitted with a condenser. This Soxhlet extractor and Condenser system was attached to a round bottom flask containing 700 mL of toluene. The Hash heated, to the reflux temperature of the toluene. After refluxing for 25 hours, the used toluene was replaced with unused toluene and refluxing was continued for 22.5 hours. The resulting extracted, treated silica was recovered and dried until a sample showed a 1.0 weight percent less when exposed to 160°C for 10 minutes. The percent, carbon of the extracted sample was determined using the procedure described herein. The Soxhlet extractable percent carbon was determined using the. following equation;
(% carbon before extraction )-(% carbon after extraction) x 100 (% carbon before extraction) .
The percent carbon before extraction was 3.50 and the percent carbon after extraction was 3.02 . Therefore, the Soxhlet" Extrractable percent, carbon of the treated silica of Example 1 was 13.7. .



Table .1.
(12) A amphoteric surfactant., reported to be based on cocamldopropyl aminobetaine, available from BASF.
(13) A nonionic surfactant, .reported to be based on ethoxylatad silicone, available from BASF.
(1.4) A nouicaic surfactant, reported to be based on an
alkylchloride end-capped ethylene oxide, available f"
EASF. (15) A nonionic surfactant, reported to be-baaed on glycol
ether, available from BASF. (16)- A nonionic surfactant,, reported, to be "based".on an
polyoxethylene lauryl .ether, available from Aldrich
Chemical Co. (17). A nonionic/cationic, reported to be based on ethoxylat
(50) stearylamlne, available from AKZO Chemical," Inc.





. The results of Table 1 show that that untreated silicas used in the process of producing the. modified silicas of the Examples and Comparative Examples had a surface area that ranged from 18 o tc 196 M2/g.
The results of Table. 4 show that the treated silica samples of the.present invention demonstrated a Standard Tensile Stress @ 300% elongation of at least 7.0, a Carbon weight percent of greater than 1.0, a Sulfur weight percent greater than O.1, and a silane Conversion Index, greater than 0.3.
Comparative Example 1 had a Carbon weight percent lower than the required amount and demonstrated an STS ® 300% of 3.6. Both Comparative Examples 2 and 3 had carbon and sulfur 1evels within the necessary ranges, but both had an STS 300% of leas than 7,0. Comparative Example 3 also had a. SCI value less than the required value.
Although the present invention has been described with references to specific details of certain embodiments" thereof it is not intended that such details should be regarded as limitations upon the scope of the invention except in BO far an they are included in the claims.


WE CLAIM
1. A slurry composition comprising a combination of water immiscible
organic solvent and from 1 to 90 weight percent of amorphous or particulate
inorganic oxide characterized by: (a) a carbon content of greater than 1 weight
percent; (b) a sulfur content of greater than 0.1 weight percent; (c) a Silane
Conversion Index of at least 0.3; and (d) a Standard Tensile Stress at 300
percent elongation of at least 7.
2. The slurry composition as claimed in claim 1 wherein the water immiscible solvent is selected from the group consisting-of aliphatic hydrocarbons, aromatic hydrocarbons, cycloalkanes, halohydrocarbon solvents and ketones.
3. The slurry composition as claimed in claim 1 wherein said inorganic oxide is precipitated silica and is further characterized by a modified BET surface area of 20 to 350 m2/g, a pH of from 5 to 10, and a Soxhlet Extractable percent carbon of less than 30 percent.
4. A master batch composition comprising a combination of organic rubber, water immiscible solvent and from 10 to 150 parts per 100 parts of organic rubber of amorphous or particulate inorganic oxide characterized by:(a) a carbon content of greater than 1 weight percent; (b) a sulfur content of greater than 0.1 weight percent; (c) a Silane Conversion Index of at least 0.3; and (d) a Standard Tensile Stress at 300 percent elongation of at least 7.
5. The master batch composition as claimed in claim 4 wherein the organic rubber comprises solution styrene/butadiene rubber, polybutadiene rubber or mixtures thereof.
6. A polymeric article having dispersed therein from 10 to 150 parts per 100 parts of polymer of amorphous or particulate inorganic oxide characterized by:(a) a carbon content of greater than 1 weight percent; (b) a sulfur content of greater than 0.1 weight percent; (c) a Silane Conversion Index of at least 0.3; and (d) a Standard Tensile Stress at 300 percent elongation of at least 7.
7. The polymeric article as claimed in claim 6 wherein the polymer is selected from the group consisting of thermoplastic resins, thermosetting resins, organic rubber and silicone rubber.
8. The polymeric article as claimed in claim 7 wherein the polymer is a curable organic rubber.
9. The polymeric article as claimed in claim 6 wherein said inorganic oxide is precipitated silica and is further characterized by a modified BET surface area of 20 to 350 m2/g, a pH of from 5 to 10, and a Soxhlet Extractable percent carbon of less than 30 percent.

10. The polymeric article as claimed in claim 9 wherein the polymer is a
curable organic rubber comprising solution styrene/butadiene rubber,
polybutadiene rubber or mixtures thereof.
11. The polymeric article as claimed in claim 10 wherein the article is a tire.
Dated this 15th day of February, 2002.

HIRAL CHANDRAKANT JOSHI AGENT FOR PPG INDUSTRIES OHIO, INC.

Documents:

in-pct-2002-00204-mum-cancelled page-(5-7-2004).pdf

in-pct-2002-00204-mum-claims(granted)-(05-07-2004).doc

in-pct-2002-00204-mum-claims(granted)-(5-7-2004).pdf

in-pct-2002-00204-mum-correspondence(5-7-2004).pdf

in-pct-2002-00204-mum-correspondence(ipo)-(18-5-2005).pdf

in-pct-2002-00204-mum-form 1-(05-07-2004).pdf

in-pct-2002-00204-mum-form 19-(13-10-2003).pdf

in-pct-2002-00204-mum-form 2(granted)-(05-07-2004).doc

in-pct-2002-00204-mum-form 2(granted)-(5-7-2004).pdf

in-pct-2002-00204-mum-form 3-(15-2-2002).pdf

in-pct-2002-00204-mum-form 5-(15-2-2002).pdf

in-pct-2002-00204-mum-form-pct-ipea-409-(15-2-2002).pdf

in-pct-2002-00204-mum-form-pct-isa-210-(15-2-2002).pdf

in-pct-2002-00204-mum-power of attorney-(2-4-2002).pdf


Patent Number 210428
Indian Patent Application Number IN/PCT/2002/00204/MUM
PG Journal Number 44/2007
Publication Date 02-Nov-2007
Grant Date 04-Oct-2007
Date of Filing 15-Feb-2002
Name of Patentee PPG INDUSTRIES OHIO, INC.
Applicant Address 3800 WEST 143RD STREET, CLEVELAND, OH 44111,
Inventors:
# Inventor's Name Inventor's Address
1 OKEL TLMOTHY A; 111 OLD GATE ROAD, TRAFFORD, PA 15083,
PCT International Classification Number C09C1/30
PCT International Application Number PCT/US00/22713
PCT International Filing date 2000-08-17
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/149,758 1999-08-19 U.S.A.
2 60/203,427 2000-05-10 U.S.A.
3 60/172,308 1999-12-17 U.S.A.
4 09/636,711 2000-05-10 U.S.A.