Document rean2qg2g6JGy552Ggdve2zM7

BROOKES 5* MART N RECEIVEDCHARTERED PATENT AGENTS TELEX 67641 TELEPHONES: (01) 42 9631 FACSIMILE (Ol) S3I 0536 RECEIVEDTRAOE MARK AGENTS EUROPEAN PATENT ATTORNEYS OX 31S 7 ELECTRONIC MAIL 87:CQQI85 DERICK ft. MARTIN, aoucrroR RICHARD C. MARTIN, M.A.CAKTAB. DAVID C. WOODCRAFT, B.So., ERIC E. BARNARD, C.BNO,M.I,E,n.E.,CiP. a .f : JOHN r. SVMONOS. LLA UOHO.,*OUCtTOt* JOHN H. SLAKE, B.Ba,(CHBM) HUGH R.WRIGHT, M.A.OXON. PETER C. SANDERS, B.Se. PAVID M. PRATT, B.Sa. DONALD J. ATTFIELO, b -Bo .C.Ch CW.m.R.b .c . Ornoe Ma n a<ib h -A. J. JELLY Ac c o u n t s -Mr s P. K. DENNIS HIGH HOLBORN HOUSE 53/54, HIGH HOLBORN LONDON, WCIV 6SE DCW/VSW YOUR REP Mr. David J. Gould E. I. Du Pont de Nemours Legal Department, Patent 1007 Market Street Wilmington Delaware 19898 U.S.A. and Company Records Center 12 May 1987 Dear Mr. Gould, New European Patent Application Your ref; CH 1370 - JACOBSON This is to report the filing of the European application requested in your order letter dated March 4, 1987. The application was filed on 27th April 1987, when it received the filing number 87 303 682.6. The filing receipt is enclosed. Prior to filing the application, X reviewed the specification and claims and reduced the number of claims to 14 by making claim 14 appendant to claims 1 to 7 and cancelling the subsequent claims. Two copies of the claims and abstract as filed are enclosed. The following states were designated in the application, namely: Germany, United Kingdom, France, Netherlands, Belgium and Spain. Please check *he list'1 of designated 'countries and Tet me know as soon as possible if you. wish to add"-any further states. . The priority document was filed with the application and we have paid the initial filing fees. The next stage will be the publication of the application or the issue of the search report. In the meantime, I enclose our account covering the cost of filing this application. Yours sincerely, FILE CHECKED Jftssmu ** Enel TUNBRIOGE WELLS: I BOYNE PARK, TUNBRIDGE WELLS. KENT, TN4 BEL. TEL.(0892) 510800 TELEX 957076 FACSIMILE (0896) S0 BIRMINGHAM: PRUDENTIAL BUILDINGS. S ST. PHILIP'S PLACE. BIRMINGHAM. B3 2AF. TEL. (021) 236 6262 TELEX 335381 FACSIMILE (021) 2001473 IMUNICH: IS ZweiBRUCK.EENNSTRASSE, 8 (4UNICH 2. TEL- (089) 22 20 IO . dc. jdUsdLhrfisZ.. , 5'i%! /% n itt:. 1 CLAIMS 1. A pigment consisting essentially of rutile Ti02 particles bearing coatings comprising Si02 and B203* 2. A pigment according to claim 1, wherein the Ti02 5 particles have coatings consisting essentially of from 60- 98 percent by weight Si02 and 0.5-30 percent by weight B2O3, based on coating weight. 3. , A pigment according to claim 2, wherein the Ti02 10 particles have coatings consisting essentially of from 80- 90 percent by weight Si02 and 2-20 percent by weight B203, based on coating weight. 4. A pigment according to claim 3, wherein the Ti02 15 particles have Si02/B203 coatings constituting 2-10% of the total pigment weight. 5. A pigment,according to claim 4, wherein the Ti02 particles have Sio2/B203 coatings constituting 4-8% of the 20 total pigment weight. 6. A pigment according to any one of the preceding claims, wherein the Tio2 particles have outer coatings of alumina constituting 0.5-5% of the total weight of the 25 particles. 7. A pigment according to claim 6, wherein the Ti02 particles have outer coatings of alumina constituting 1-4% of the total weight of the particles. 30 8. A process for preparing Ti02 Pa^ticles bearing coatings of boria-modified silica, comprising: (a) forming an aqueous slurry of rutile Ti02 at 35 a temperature from about 65C to about 90C; N 30933.01 DUP050449416 2 (b) adjusting pH of the slurry to the range 710.5; (a) adding a predetermined quantity of a 5 solution comprising Na2Si03 and B2O3, under conditions which maintain silicate and boria ions in solution; (d) gradually lowering pH of the slurry to 10 about 7.5-8.5 by addition of acid, thereby depositing a coating of silica and boria; and (e) curing the resulting coated pigment at a temperature from about 65C to about 90C for a 15 period of at least 15 minutes. 9. A process according to claim 8, wherein sufficient Na2Si03 and B203 are added in step (c) to provide a coating consisting essentially of from 60-98 20 percent by weight Si02 and 0.5-30 percent by weight B203 based on coating weight. 10. A process according to claim 9, wherein sufficient Na2Sio3 and B203 are added in step (c) to 25 provide a coating consisting essentially of from 80-90 percent by weight Si02 and 2-20 percent by weight B203, based on coating weight. 11. A process according to claim 10, wherein 30 sufficient Na2Si03 and B203 are added in step (c) to provide a Si02/B203 coating constituting 0.5-10% of the total pigment weight. , 12. A process according to claim 11, wherein 35 sufficient Na2Si03 and B203 are added in step (c) to provide a Si02/B2Q3 coating constituting 4-8% of the total pigment weight. 3 13. A process according to any one of claims 8 to 12 comprising the following additional steps (f) adding sufficient NaAlO2 to the slurry, at a temperature from about 50-90C, to provide a 5 concentration of about 2-8% by weight of the TiO2, while adding mineral acid to maintain the pH of the slurry from 6-9. 14. A coating composition comprising a pigment 10 according to any one of claims 1 to 7, a film-forming material, and a liquid carrier. DUP050449418 4 ABSTRACT Titanium Dioxide Pigment Coated with Boria-Modified Silica Pigments are disclosed which consist essentially of rutile Ti02 particles bearing densified coatings comprising SiO 2 and B2O3. DUP050449419 R18055 RX-L.N1 0551 EST 03/13/37 WU10 0001 AA 0132 87-03-18 05s53 AA TOs62921374 EASYLINK 8962447AOO1 13 MARS7 05s51/lS MARS7 05:54 EST FROM: VIA 835420 DUPONTCO WIL 0536 87-03-13 10:52 /k2Ul 9 0 " 5111 o 267541 BRKMAR G ATTENTIONS M.S. TUKE, LEGAL DEPARTMENT NEW EPO APPLICATIONS - YOUR REFS: CH-1370, CH-1371 - JACOBSON RECEIVED. REGARDS, BROOKES + MARTIN 267541 BRKMAR 0 DUPONTCO WIL 267541 BRKMAR G 0550 03/18 PLS REPLY VIA TRT MMMM --- MAR If 1987 FOREIGN PATENTS im 3 O "> 'i ) HI1 ) O 0 3 31 S' $ ) I'ii N 30933.02 DUP050449424