Showing papers on "Precipitated silica published in 1996"

Rubber composition suitable for treads containing aluminium doped precipitated silica

Abstract: A rubber compsn. vulcanisable by sulphur based on dienic polymer contains: (i) a reinforcement filling of a pptd. silica contg. an Al content of 0.35-3%, relative to silica. Also claimed is a rubber tube or belt, made from the new material.

Use of Nonblack Fillers in Tire Compounds

Abstract: A variety of nonblack fillers are used in the rubber components of tires. Calcium carbonate, clay, precipitated silica, talc and titanium dioxide are used in white sidewall compounds to impart desired physical properties and appearance. Precipitated silica can be used in black sidewall compounds, including nonstaining EPDM black sidewalls, to significantly improve tear strength, cut-growth resistance and resistance to ozone aging. Precipitated silica is used extensively in wire coat compounds in conjunction with resorcinol and methylene donating resins, and can be used with organocobalt salts to improve adhesive properties, tear strength and cut-growth resistance. Calcium carbonate, clay, mica and talc are found in innerliner compounds, and precipitated silica can be used. Precipitated silica is used in the treads of off-the-road tires such as earthmover tires, in order to improve tear strength and cut-growth resistance. Clay and talc can be used in tire treads. Precipitated silica is also used i...

Process for the preparation of precipitated silica, new precipitated silicas containing zinc and their use for the reinforcement of elastomers

Abstract: The invention relates to a new process for the preparation of precipitated silica which has a good dispersibility and very satisfactory reinforcing properties. It also relates to new precipitated silicas which are in the form of powder, of substantially spherical beads or of granules, these silicas being characterized by the fact that they have a CTAB specific surface of between 90 and 250 m 2 /g, a DOP oil uptake lower than 300 ml/100 g, a pore distribution such that the pore volume consisting of the pores whose diameter is between 175 and 275 Å represents less than 50% of the pore volume consisting of the pores of diameters smaller than or equal to 400 Å, a zinc content of between 1 and 5% by weight and by the fact that the number N of molecules of stearic acid consumed per nm 2 of silica surface, when stearic acid is reacted with the said silica in xylene for 2 hours at 120° C., is at least 1. The invention also relates to the use of the said silicas as reinforcing fillers for elastomers especially for improving their rheological properties.

Diatomaceous earth insecticidal composition

Abstract: An insecticidal dust composition comprising an effective amount of diatomaceous earth (DE) in combination with an effective amount of silica selected from the group consisting of precipitated silica and aerogel silica, the DE and silica mixed in different proportions by weight depending on the type of DE, and may preferably be about 95% to 65% DE to about 5% to 35% silica.

Novel method for preparing precipitated silica, novel aluminium-containing precipitated silicas, and use thereof for reinforcing elastomers

Abstract: A novel method for preparing precipitated silica having a good dispersibility and highly satisfactory reinforcing properties is disclosed. Novel precipitated silicas in the form of a powder, substantially spherical beads or granules are also disclosed. Said silicas are characterised in that they have a CTAB specific surface area of 90-250 m2/g, a BET specific surface area of 90-250 m2/g, a DOP oil absorption of less than 300 ml/100 g, and a zinc content of 1-5 wt %, and in that the number N of stearic acid molecules consumed per nm2 of the silica surface, when stearic acid is reacted with said silica in xylene for 2 hours at 120 °C, is at least 1. Furthermore, the use of said silicas as reinforcing fillers for elastomers, in particular for enhancing the rheological properties thereof, is disclosed.

Polar copolymer–surface-modified precipitated silica

Abstract: To improve the performance of rubber compounds using precipitated silica as a reinforcing filler, the silica surface was directly modified by (1) adsorption of a surfactant onto the surface, (2) adsolubilization of an organic monomer, (3) in situ polymerization of the monomer in the surfactant bilayer, and (4) partial surfactant removal. Silica was thus modified using copolymers of isoprene or 1,3-butadiene with vinyl acetate, acrylonitrile, 4-methoxystyrene, 4-chlorostyrene, and methyl methacrylate on the silica surface. 4-Methoxystyrene/butadiene modification afforded the most promising candidate based on evaluation in a silica-filled, natural/styrene-butadiene rubber shoe sole compound that also has been used as a model tire compound. Physical testing showed that cure times were decreased, and break strength, tear energy, elongation to break, and cut growth resistance were increased. Thus, surface modification of silica by the in situ polymerization of organic monomers has been shown to be a flexible process capable of producing unique materials useful in improving rubber cure properties and the cured compound physical properties.

Interaction between Carboxylated Nitrile Rubber and Precipitated Silica: Role of (3-Aminopropyl)Triethoxysilane

Abstract: On the basis of measurements of bound rubber and physical properties and the results of Monsanto rheometer, dynamic mechanical and infrared spectroscopic studies, it is observed that strong rubber-filler interaction occurs between XNBR and precipitated silica filler. During molding, XNBR was found to be crosslinked by the filler surface through the formation of primary bonds. The coupling agent, namely (3-aminopropyl)triethoxysilane facilitates the formation of rubber-filler bonds at the expense of filler-filler networks, leading to improved dispersion and enhanced degree of crosslinking.

Tire with cap/base construction tread

Abstract: PROBLEM TO BE SOLVED: To obtain a pneumatic tire usable under a relatively heavy load which shows reduced heat generation during running, excellent abrasion resistance of a tread and the like by using a specific compound for a tread cap. SOLUTION: A pneumatic tire having a TRA rated maximum load limit of at least 1,220 kg at an inflation pressure in a range of 723 to 792 KPa and a bead diameter of at least 48 cm is provided with a rubber tread of cap/base construction wherein the tread cap comprises 20-50 phr of a natural rubber, 25-80 phr of an emulsion polymerization-prepared or solution polymerization prepared styrene/butadiene copolymer, 0-50 phr of a cis-1,4-polybutadiene elastomer and 40-80 phr of a reinforcing silica and a carbon black comprising 5-60 phr of a precipitated silica and a silane coupler having a group reactive with the surface of the silica and a group interactive with the elastomer, said silica being characterized by a combination of BET surface area of 160-200, an average V (Hg) value in a range of 1.7-1.95 and an average PSD in a range of 10-45. COPYRIGHT: (C)1996,JPO

Highly effective vanadia-silica catalyst for propane oxidative dehydrogenation

Abstract: A vanadia on precipitated silica catalyst exhibits high yield, productivity and stability along with high propene concentration in the outlet stream in the oxidative dehydrogenation of propane.

Sorbent precipitated silica particulates

Abstract: Novel precipitated silica particulates, well suited for conditioning/sorbing a wide variety of liquid active agents thereon, e.g., the vitamins, have (i) a BET surface area of at least 170 m2 /g; (ii) an oil absorption (DOP) ranging from 220 to 300 ml/g; (iii) a fill density in the packed state of at least 0.29; (iv) a mean particle diameter ranging from 80 to 150 μm; and (v) a maximum grain size distribution index of 0.70.

Compositions comprising hydrophilic silica particulates

Abstract: The present invention relates to structured surfactant compositions comprising a detergent surfactant and hydrophilic silica particulates to be used in granular detergent compositions. The preferred silica particulate is hydrophilic precipitated silica. The process for making a structured surfactant composition comprising a detergent surfactant and hydrophilic silica particulates is also included. The present invention encompasses a structured surfactant composition consisting essentially of: (a) from about 35 % to about 60 % of a detergent surfactant; (b) from about 1 % to about 20 % of hydrophylic, finely-divided silica particulate; and (c) from about 15 % to about 25 % moisture.

Conductive material for oxygen ion and its production

Abstract: PURPOSE: To obtain a conductive material for oxygen ion having a small activation energy and high oxygen ion conductivity at low temp. by using specified compd. as the main component and forming a hexagonal crystal structure as the main structural phase of a sintered compact. CONSTITUTION: This conductive material for oxygen ion is obtd. by mixing La2 O3 , Ce2 O3 , Pr2 O3 , Nd2 O3 , Sm2 O3 , Eu2 O3 , Gd2 O3 , Tb2 O3 , Dy2 O3 as the source material of rare earth elements and precipitated silica, silica gel, crystalline silica, or the like as the source material of SiO2 in a specified proportion, kneading the mixture in an alcohol by using a ball mill, drying, calcining at 1000 deg.C, pulverizing the calcined material, and then sintering at 1300-1700 deg.C. The conductive material for oxygen ion consists essentially of Lnx Si6 O(3x/2)+12 , wherein Ln is tervalent rare earth element such as La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy and x ranges 6

Aqueous suspension of silica and of aluminium sulphate or of alum, processes for the preparation and uses of the said suspension

Abstract: The invention relates to aqueous suspensions of precipitated silica and of aluminum sulphate which have a pH lower than 4 and a solids content of between 10 and 50% by weight and which, after a period at rest of 48 hours, are in the form of a gel. The gel is reversible under low shear. The invention also relates to processes for the preparation of these suspensions and to their uses, especially in the field of cement mixes, mortars and concretes.

Silica reinforced rubber composition and its use in tire

Abstract: PROBLEM TO BE SOLVED: To obtain the rubber compsn. reinforced by a combination with a silica-bonding agent by mixing an elastomer, silica, a particulate filler, an organosilane polysulfide, a sulfur source, a vulcanization accelerator, and additional ingredients. SOLUTION: 100 pts.wt. sulfur-vulcanizable elastomer selected for among a conjugated diene homo- or copolymer and a conjugated diene-arom. vinyl compd. copolymer is mixed with 15-100 phr. at least one particulate filler selected from among precipitated silica, alumina, an aluminosilicate, and a carbon black, an organosilane polysulfide of formula: Z-R 1 -S n -R 1 -Z [wherein n is 2-8; and Z is a group represented by formula I (wherein R 2 is 1-4C alkyl or phenyl; and R 3 is 1-4C alkyl, phenyl, 1-8C alkoxy, or 5-8C cycloalkoxy)] in an amt. of 0.05-20 pts.wt. based on 1 pt.wt. particulate filler, a sulfur source (e.g. an elemental sulfur or a polysulfide) in an amt. of 0.05-2 phr (in terms of free sulfur), 0.1-0.5 phr vulcanization accelerator, and additional ingredients. COPYRIGHT: (C)1996,JPO

The Change in Wettability and Structure of Silica Powder Surfaces Modified with Hexamethyldisilazane

Abstract: The wettability and surface structure of precipitated silica surface loaded trimethylsilyl groups were investigated. By measuring water and nitrogen adsorptions, it was found that the non-treated sample had micro pores. The pores of diameter less than 0.8nm were not modified, while the pores of diameter from 0.8 to 0.9nm were modified by trimethylsillyl groups and closed by them. From these results, it was assumed that the former pores would become sites for water vapor as surface silanol groups after modification, and the latter pores would be independent of water adsorption. The character of the bare silica surface disappeared above a surface conversion rate of 33%. These results are deduced from a neopentane adsorption experiment. Furthermore, the water a adsorption capacity near the saturated pressure, as an index of micro-wettability, did not reach theoretical monolayer capacity above the same conversion rate (33%). It was also indicated that the preferential dispersion property as an index of macro-wettability drastically changed at a conversion rate of about 33%. From these results, it was demonstrated that the wettability is closely related to the surface structure interfering with the adsorption of water.

Mechanism by Which Precipitated Silica Improves Brass-Coated Wire-To-Natural Rubber Adhesion

Abstract: Quantitative determination of elements in the interfacial growth layer formed on brass-coated wire when reacted in sualene suspensions containing carbon black and curatives, with and without precipitated silica and an organocobalt adhesive, was accomplished by using direct surface characterisation techniques: Sacnning Electron Microscopy with Energy Dispersive Analysis of X-rays(SEM-EDX), Auger Electron Spectroscopy(AES), X-ray photoelectron Spectroscopy(XPS) and Proton induced X-ray Emission(PIXE) spectroscopy. The effects on elemental changes in the interfacial growth layer upon addition of silica and/or cobalt neodecanoate to the squalene suspensions were statistically analysed. Since the mechanism for silica improvement of brass-coated wire-to-rubber adhesion was previously shown not to be a simple effect of improving rubber physical properties, a chemical mechanism is proposed involving silica to reduce the thickness of the interfacial growth layer and to change the relative concentration of compounds formed in the interfacial growth layer

Tire of sedimented silica base having improved rolling resistance

Abstract: PROBLEM TO BE SOLVED: To substantially decrease rolling resistance of a radial carcass tire without significantly impairing other characteristics such as adhesiveness, wear resistance and resistance to fatigue of a crown reinforcement portion. SOLUTION: A precipitated silica having a CTAB specific area /g and a BET specific area /g is used as a reinforcing filler for a diene elastomer composition used as a crown reinforcement rubber of a radial carcass tire.

Partially hydrophobic precipitated silicic acid

Abstract: PURPOSE: To obtain partially hydrophobic precipitated silicic acid improved in workability in milling with an organic rubber, having high reinforcing properties and giving a rubber compound markedly reduced in Mooney viscosity by surface-treating precipitated silica with an organosilicon compound to form a product having a specified BET specific surface area and a specified di-n- butylamine absorption. CONSTITUTION: It is desirable that the organosilicon compound (e.g. trimethylsilanol, hexamethyldisilazane or trimethylmonochlorosilazane) has two or less reactive functional groups. A high-speed mixer such as a Henschel mixer is desirable to obtain partially hydrophobic precipitated silicic acid because the treatment can be performed uniformly. The process is however not limited to this process. The obtained compound should have a BET specific surface area in the range of 100-200m/g, a di-n-butylamine adsorption of 100-180 mmol/kg, a pH of 5-11, a bulk density of 200-350g/L, a mean particle diameter of 0.1-10nm, and a particle hardness of 10-30gf.

Rubber composition based on aluminum dope precipitated silica and used for production of tire

Abstract: A rubber compsn vulcanisable by sulphur based on dienic polymer contains: (i) a reinforcement filling of a pptd silica contg an Al content of 035-3%, relative to silica Also claimed is a rubber tube or belt, made from the new material

Tire with tread having silica reinforcement

Abstract: The invention relates to a tire with a tread which is reinforced with carbon black and precipitated silica where the tread rubbers are of a blend comprised of at least one diene-based elastomer and a styrene/alphamethylstyrene resin, as hereinafter described

Calcium silicate mass for storing acetylene gas

Abstract: A hardened asbestos-free, porous, calcium silicate filler material (50) for an acetylene storage vessel (10) is made by mixing quicklime with water to form a first mixture. Then ground quartz silica is added to form a second mixture. A fibrous reinforcing material is blended in to form a third mixture. A precipitated silica (or synthetic silica) is added and homogenized to form a fourth mixture. The fourth mixture is transferred into a cylinder (10) to be filled and is cured under saturated steam pressure. Thereafter, the cylinder (10) is dried. A gas storage cylinder (10) so formed has a monolithic dry mass (50) filling a metal shell (20). The mass (50) has a porosity of about 88 to 92 %, a density in the range of 250 g/l to 350 g/l, and a crush strength of 250 to 550 psig.

Aqueous suspensions of silica or silicoaluminate

Abstract: Aqueous suspension of precipitated silica or precipitated silicoaluminate is used as anti-segregation agent in concrete compositions containing mineral binder. Also claimed are uses for concrete compositions and method of treatment of sweated or segregated concrete by said suspension.

Polypropylene compatible grease compositions for optical fiber cable

Abstract: For use as a cable filler grease composition, the grease composition contains from about 25 to 75 parts by weight of castor oil or ricinoleate polyol, from about 13 to 71 parts by weight of polymerized castor oil, or polyisocyanate compounds with castor oil or ricinoleate polyhydroxy-terminated polymeric reaction product of a hydroxy compound constituting, from about 4 to 12 parts by weight of colloidal particles such as fumed silica, precipitated silica, clays, or their mixture. Optionally, it may also be added to impart antioxidant properties to a high temperature component, to impart leaching resistance, generally of rubber loss inhibitor, reducing the water permeability of the superabsorbent component may be added micro ball to reduce the weight of the formulation, and / or conventional additives such as bactericides, biocides and the like. The present invention further relates to a method of manufacturing such items such as a cable, said cable having an optical fiber in which a number of surrounding the armor, and one in which a grease composition of the present invention.

Processing method for precipitated silica filler

Abstract: A process for treating fillers, preferably precipitated silica, to improve the physical property profile of heat curable and room temperature vulcanizable silicone rubbers and a composition for room temperature vulcanizable rubbers comprising the silica filler treated by the process of the invention.

Vulcanisable rubber compositions for the production of vehicle tyres

Abstract: Vulcanisable rubber compositions consisting of styrene-butadiene copolymers, vinyl polybutadiene and finely divided, precipitated silica or mixtures of finely divided, precipitated silica and carbon black, are outstandingly suitable for the production of tyres, in particular tyre treads.

Precipitated silica prepn.

Abstract: Pptd. silica is prepared by reacting an alkali metal silicate with an acidifying agent, then adding further alkali metal silicate to give a suspension, separating and drying. An initial starter is formed in which the silicate concn., based on SiO2, is below 20 g/l, the amount of acidifying agent added is such that \-5% of the amt. of M2O in the initial starter is neutralised, and the remaining metal silicate is added simultaneously such that the ratio of silicate added, based on SiO2, to the silicate in the initial starter is 4-100. Also claimed are: (i) pptd. silica (I) having a specific ctab surface Sctab of 140-240 m /g, a median dia., after disaggregation by ultra-sound, of below 2.5 mu and a disaggregation factor after ultra-sound of more than 11 ml; and (ii) pptd. silica (II) having a specific CTAB surface (SCTAB) of 140-240 m /, a median dia., after disaggregation by ultra-sound, of below 5 mu , a disaggregation factor after ultra-sound of more than 5.5 ml as well as a porous distribution such that the proportion of pores of dia. 175-275 A is less than 50% of the porous vol. of pores of dia. at most 400 A.