Document bOeGdO04nza5oXe0kGNa6xz6

PP-.'s^Er. E.-iCif!CATION one cc~y to l;:.*ary United States Patent -?wic Runachandrmn . \ vjV tm 4,183,814 (45] Jan. 15,1980 [54] ASBESTOS COMPOSITION HAVING ORGANO-SILANE COATING [75] Inventor Sondaraaaa Ramachaadraa, North Tonawanda, N.Y. [73] Assignee: Union Carbide Corporation, New York, N.Y. pi] Appl. No.: 8*ft525 [22] Filed: Jaa.3,1978 [51] lat a* .......................C07F 7/10; C09K 7/DO [52] UJS. a _____________ 232/8.5 Q 2*0/441.2 E; 260/441.2 N [58] Field of South ____ 2*0/448.2 N; 260/448.2 E; 252/8.5 C [56] Rafmneea CHad U.S. PATENT DOCUMENTS 3,471.438 10/1969 Chwasiak---------------------- 260/40 X979.276 9/1976 Scraia--------------- 260/448.2 N UX FOREIGN PATENT DOCUMENTS 2540061 10/1973 Fed. Rep. of Oermany . OTHER PUBLICATIONS -J. Appl. Chem.", 2ft pp. 76-79, Mar. 1970. Primary Examiner--Paul F. Shaver Attorney, Agent, or Firm--J. Hart Evans [57] ABSTRACT A chrysotile asbestos base material having a precipita tion deposited siliceous layer and an organo-silane coat ing bonded to and overlying said siliceous layer. 6 Palms, No Drawings & '- ; a^ 'Z /t.,e r 0 yy/-L PLAINTIFFS EXHIBIT UC-206 1 ASBESTOS COMPOSITION HAVING ORGANO-SILANE COATING 4.183,,814 2 (l*Opencd ponicuUir Hfaoua rrfcn to punicuUu mbaun ta wtuck Ike aaturaUy occumn{fiber bundles have been puniad into ihcsr uhimulr Mmdial fibers to tbs esmt that ami of the consmucsl parados art fa the forsr of individual fibrils Following the precipitation coating of the aabestoa as This invention relates to an asbestos base composi- 3 above described, the slurry is adjusted to the extent tion. More particularly, this invention relates to a chrys necessary to provide a pH in the range of about 6 to 9.0, olite asbestos base material which can be used to en preferably 7 to t, and an organo-silane is added to the hance the rheological properties of fluids such as oil slurry in an amount of about 0.5 to 10 percent by weight drilling muds and also in reinforcing polyolefins, thick of the asbestos base material in the slurry. The thus ening polyester resins, vinyls and rubbers. 10 treated solids are recovered and dried by conventional Chrysolite asbestos, as it naturally occurs, may be techniques. The resulting asbestos material has a coat generally defined as a hydrous magnesium hydroxide. ing of organo-silane over-lying the siliceous layer of the In contact with polar liquids, asbestos exhibits a strong asbestos base material. positive charge and thereby attracts anions and thus can The properties of the organo-silane coated material of be used in removal of detergents from liquids; asbestos, 13 the present invention are influenced by the particular in the natural state, is also highly effective as a flocculat ing agent for minerals such as titanium dioxide and clays. It has been proposed in German Patent Publica tion No. 2,346,061 to provide asbestos, and other miner als, with an organo-silane coating by first acid leaching 20 organo-silane employed. For example, octyl thietboxy silane provides an oleophilic coating which has a poaitive interaction with oil base fluids, such as drilling muds, and improves the rheological properties of these the mineral to remove the outer octahedral layer, under fluids as hereafter described. The organo-silanes used in controlled conditions, and thereafter react the leached the practice of the present invention are substantially as mineral with an organo-silane. The organo-silane described in the abovenoted German Patent Publication coated material is described as being desirable as an and are characterized by one of the two following additive in oil well drilling muds and as a gelling agent 23 structures: and reinforcing agent in resins. However, the controlled acid leaching technique described in the German Patent Structure 1 Publication must be carefully practiced in order to avoid excessive removal of asbestos material and pres ent industrial needs require further improvement in the 30 rheological properties of fluids such as oil base drilling I O--Si--Y rI muds. Accordingly, it is an object of the present invention where G is a hydroxyl group or a group bydroxyzable to provide an asbestos base material for enhancing the to hydroxyl such as, for example, alkoxy or halogen; Y rheological properties of fluids. 33 is an alkyl group containing from 1 to 20 carbon atoms, Other objects will be apparent from the following a phenyl group, an alkyl substituted phenyl group description and claims. where the alkyl groups can contain a total of from I to An asbestos base material in accordance with the 12 carbon atoms or a polyoxyalkylene radical having tip present invention comprises opened chrysotile asbestos to 25 carbon atoms bonded to the silicon atom by a having a precipitation deposited siliceous layer and an 40 silicon to carbon bond, R and R' are selected from the organo-silane coating bonded to and over-lying the siliceous layer. group described by G and Y or hydrogen; or The asbestos base material of the present invention is produced by providing in an aqueous media, opened Structure H chrysotile asbestos having a precipitation deposited 43 siliceous outer layer and providing in the aqueous media an organo-silane to provide an organo-silane coating chemically bonded on the siliceous layer. I C--Si--z rI In the practice of the present invention, the siliceous layer on the chrysotile asbestos can be provided by the 30 where G is a hydroxyl group or a group bydroxyzable method of U S. Pat. No. 3,471,438--Chwastiak, the to a hydroxyl such as, for example, alkoxyl or halogen: disclosure of which is incorporated herein by reference. Z is an alkyl group containing from 1 to 20 carbon In a particular embodiment of the method of this patent, atoms bearing a functional group such as, for example, opened (l> particulate chrysotile asbestos is provided, amino, oxirane, mercapto or acryloxy; R and R' are such as that available commercially as High Purity 33 selected from the groups described by G and Z, hydro Grade Asbestos from Union Carbide Corporation. This gen, an alkyl group containing from 1 to 20 carbon asbestos is slurried with water, the slurry conveniently atoms, phenyl, or alkyl substituted phenyl where the containing from about 0.5% to 4% by weight asbestos alkyl groups can contain a total of from 1 to 12 carbon and more suitably about 1-2% asbestos by weight. A atoms. predetermined amount of concentrated sodium silicate 60 The following examples will further illustrate the solution, suitably an amount which provides about 12 present invention. parts by weight of SiOj per 100 parts of asbestos, is added to the slurry followed by neutralization to pro EXAMPLE I vide in the slurry a pH of about 9.5 or less. Acetic acid Short fiber chrysotile asbestos from the Coalinga, is preferably used as the neutralizing agent. Under these 63 Calif, deposit, obtained from Union Carbide Corpora circumstances, i.e., a pH of about 9.5 or less, a siliceous tion under the designation High Purity Grade and hav gel is precipitated and this gel adheres to and coats the ing the properties shown in Table A was added to wa slurried asbestos and provides a siliceous layer thereon. ter, at 31* C. in an amount of about 1.4% by weight. A C7:3 4.183.814 34 _______________ TABLE A_______________ < Specific surface area WL*/gm 40-10 Magnetite coolant pnrcrai 0.04-0.5 Reflectance do____________ 72-71 312.5 ail of No. 2 Duel Oil 17.) ml of Water The actual amounts of the additions were 2, 4 and 7 Specific surface area is calculated from adsorption gm. data using the BET (Brunauer, Emmet. Teller) method The testing procedure for viscosity evaluation of the as described in Brunauer, The Adsorption of Gases drilling mud was as follows: and Vapors," Princeton University Press (1943). 10 The oil and water were mixed at high speed in a Magnetite content is measured by permeametric de Waring blender (Model No. 91-264) for 2 minutes prior vice patterned after ASTM standard method D-l US- to the addition of the prepared asbestos base material of 37. However, because the lower limit ofdetection of the ASTM device is only about 0.20% magnetite, the Example I. Following the addition, stirring was contin ued in the blender, also at high speed, for 10 minutes, ASTM method has been improved with respect to sen 13 after which time, the sample was removed to a Fann sitivity to measure a limit of detection of 0.003% mag Viscometer (Model No. 35A), cooled to 113* F. (46* C.) netite, and the range extended to measure 0.10% mag and the viscosity and gel strengths determined using netite in the mid-scale of the instrument. In order to standard procedures.* The results are shown in Table I. obtain this greater range and improved sensitivity, the *A> described in American Petroleum Institute Publication No. API IIP I1B. fourth edition, November 1972. ASTM method has been modified to detect the phase 20 changes of the current generated when magnetic mate TABLE I rials are placed in a transformer core rather than the voltage changes generated. Reflectance is measured on a sample prepared ac cording to TAPP1 (Technical Association of the Pulp 25 and Paper Industry) standard T-432-m-38 and reported as percent of ultimate reflectance based on magnesium oxide as 100% reflectance. The water-asbestos mixture (33 grams of asbestos in 2.3 liters of water) was introduced into a large Waring 30 Effect of Aibotoa Baae Material of ibm Invention on Mud Proemes Fans Vneontv Results Additive y.p. Ocl Suenflh Loading A.V. P.V. (is (m P/100 ft1 No. (Ib/bbl) Cm epa) (m epa) #/l00ft2) Initial 1' 2 24 )7 S4 17.5 70.0 16 s 23 tos 3 39 BlendoH2* and the blendor was run at its highest speed for about 3 minutes. Following this treatment, sodium EXAMPLE II silicate (1 M solution) in the amount of 70 milliliters was Fifty grams of high purity asbestos (the same starting gradually added to the asbestoswater slurry while 33 material used in Example I) were acid leached prior to slowly stirring the slurry with a mechanical stirrer. This silane treatment following the procedure outlined in the provided in the slurry the equivalent of about 4.2 grams above cited German Patent Publication No. 2,546,061 of SiOj. This mixture was then treated by slowly adding as follows: Fifty grams of the high purity asbestos was acetic acid (1 M) to neutralize the solution and obtain a slurried in 600 ml of water and 18 gm of 98% sulfuric pH of about 9.3. At this pH, precipitation of siliceous 40 acid were added and the slurry was stirred using a me material occurred which was substantially all adsorbed chanical stirrer for 3 hours. Subsequently, 10.8 gm. of a by the slurried asbestos particles and such particles 30% sodium hydroxide solution was added to the slurry when added to water exhibit a negative charge as can be to increase the pH to 6.5. This was followed by adding demonstrated by standard electrophoresis techniques. to the slurry 3 grams of octyl triethoxy silane mixed in On the other hand, untreated asbestos exhibits a strong 45 20 ml of methanol and mixing was continued for 16 positive charge under the same circumstances. hours. After this step, the slurry was filtered and the wiModel No. CBS solids were dried at 110* C. for 3 hours. The product After this step, additional acetic acid (1 M) was added was then opened in a Waring blender (Model No. to bring the pH to about 7.6 and the slurry was slowly 91-264) for 30 seconds at high speed. stirred by a mechanical mixer for about 3 minutes. The jq The above acid leached, silane treated sample was total amount of acetic acid used was about 40 milliliters. used as an additive and tested in a standard drilling mud 2.1 grams of octyl triethoxy silane was added to the composition as described in connection with the mate slurry which was mixed further for about 5 minutes. rial of Example I. The results are given in Table II. The solids were removed by filtration and dried at about 110' C. for about 3 hours. The resulting product 35 TABLE II had an oleophilic organo-silane coating overlying and chemically bonded to the siliceous layer on the opened chrysotile asbestos. A particular embodiment of the present invention is Effect of Acid Leeched. Silane Treated Asbestos on Oil Mud Properties Fann Viscosity Results Additive Ocl Strength the use of the material of the present invention as an 60 Loadins A.V P.V. Y.P. (in #/l00 ft2 additive to conventional and well known drilling fluids No. (Ib/bbl) (in cpi) (in cpi) (in t/100 ft2' Initial used as drilling muds in oil and gas well drilling opera tions. In connection with this embodiment material 1 7 21.5 10.0 2 14 0.0 11.0 37 124 21 64 prepared as in Example I was opened in a Waring blender (Model 91-264) at high speed for about 30 sec- 65 A comparison of the results of Table I and Table II onds. It was then employed, in the proportions shown in reveals that the material of this invention (Table I of Table I, as an additive in a standard oil base fluid (dril Example I) has superior thickening properties as com ling mud) having the following composition: pared to the material of Example 11. For example, as can * * o O 7 \ 4 4,183,814 be seen by comparing the results shows is Tables 1 and siliceous layer and an organo-silane coating bonded to II an apparent viscosity of 70 cpt is achieved through the practice of the present invention using additive is and over-lying said siliceous layer. 1A drilling fluid for use in oil and gas drilling opera proportions of about 7 lbs. per bbl while almost twice as tions containing from about 0.10 to 7% by weight of the much additive of Example II materia! wu required to 3 material of claim S. achieve similar results. Further, the gel strength pro X A method for producing organo-silane coated as vided by the present invention for as addition of 7 lbs per bbl provides about double the gel strength achieved bestos base materia] which comprises: (1) providing opened chrysotile asbestos material hav with the material of Example II. The improved proper ties enable superior performance of oil base drilling 10 seeds. The material of the present invention can be ing a precipitation deposited siliceous outer layer in an aqueous media at a pH of sbout 6 to 9 (ii) contacting said material with organo-silane to added to the oil base fluid in an amount of about O.lOto 7% by weight, with the preferred amount being from about 0.S to 2%. As previously mentioned, the asbestos provide an organo-silane coating on said siliceous layer (iii) recovering the organo-silane coated asbestos base bate materia] of the present invention can be used as an 1* material from the slurry. addition to polyolefins, polyester resins, vinyls, rubbers 4. A method for coating chrysotile asbestos with an and the like. organo-silane which comprises: Drilling fluids to which material of the present inven (i) providing an aqueous slurry of opened chrysotile tion can be added are oil base fluids, usually diesel oil, asbestos and water base fluids such as described in "Fluid Con- 20 (ii) providing in mixture with the slurry a solution of trol" 12th Ed. Subcommittee of API published by Pe a material capable of precipitating s silica gel troleum Extension Service. University of Texas at Aus (iii) treating the mixture of slurry and solution with a tin (1969) and 37 Composition and Properties of Oil neutralizing agent to obtain a pH of about 9.5 or u,ell Drilling Fluids" W. F. Rogers. 3rd Ed (1963)-- less in the slurry-solution mixture to thereby cause Gulf Publishing Co., Houston, Texas. For water base precipitation of siliceous material onto the asbestos fluids a hydrophillic organo-silane coating is provided in the slurry and provide a siliceous layer thereon on the additive material, e.g., using a polyoxyalkylene (iv) further treating the slurry with a neutralizing substituted hydrolyzable silane such as agent to the extent necessary to provide a pH in the range of about 6 to 9. CHjO(CiH,Ob.sCjH*Si(OCHi)>- 30 (v) adding organo-silane to the slurry of step (iv) to thereby provide an organo-silane coaling on said In the practice of the present invention, the siliceous siliceous layer layer on the opened chrysolite asbestos is less than 23% (vi) recovering organo-silane coated chrysotile asbes by weight of the asbestos and preferably about 10 to tos from the slurry. 13% by weight and the organosilane coating is prefers- 33 5. A material in accordance with claim 1 wherein the bly about 5 to 7% by weight of the asbestos. organo-silane is octyl triethoxy silane. What is claimed is: 6. A method in accordance with claim 3 wherein the 1. An asbestos base material comprising opened chrysotile asbestos having a precipitation deposited organo-silane is octyl triethoxy silane. 43 30 33 60 63