Document rBDBDOMGQd1KVk1jNQvLkQNrE

BROOKES & MARTIN CHARTERED PATENT AGENTS TRADE MARK AGENTS EUROPEAN PATENT ATTORNEYS RICHARD C. MARTIN, m.A.Can t a*. OAVIO C. WOODCRAFT, b .S*<Ch b m) ERIC E. SARNARD, C.EN<x, M..E.C,,C, Cut>.A.r. GRAHAM F. MATTHEWS, B.A-.C.Rn o . f I.E.E. JOHN F. SYMONDS, LL.S.LOn d ., SOLICITOR JOHN H, BLAKE, HUGH R. WRIGHT, ma o x o n . PETER C. SANDERS. B.Se. H. NICHOLAS MATTHEWS, m.in s t . T.H.A. DONALD J. ATTFIELD, a.S*. C.Ch s m. m.R.S.C. Ornee ma n a o k b - A. J. JELLY Ac c o u n t s -Mr s C.OLSINIA RHCEiVP" JAM 3 0 1990 PATENT FiECC.... CENTER Mr. David J. Gould E.I. DU PONT DE NEMOURS AND COMPANY Legal Department, Patent Records Center 1007 Market Street Wilmington, Delaware 19898 U.S.A. t e l e x 267541 TELEPHONES (Ol) 242 9631 FACSIMILE \Ol) 831 0586 l d x 318 HIGH HOLBORN HOUSE 52/54, HIGH HOLBORN LONDON, WCIV 6SE AIIB BEP DCW/VSW ' RECEIVED FEB 01 1990 DJG 18 January 1990 Dear David, J European Patent Application No. 87 303 681.8 Your reference : CH-1371 Thank you for your letter dated January 8, 1990. I have accordingly filed a supplementary amendment in the EPO and enclose copies, together with copies of added method claims 9 and 10. If you have any comments on the added method claims, please let me know. In the meantime, I enclose our account in this matter. Yours sincerely. <Zl ~A DAVlDX. WOODCRAFT Ends: FILE CHECKED FEB 6 1930 TUNBRIDGE WELLS: l BOYNE PARK, TUNBRIDGE WELLS, KENT. TN4 BEL. TEL.(0892) SIOBUO"--Ttt'w^^o7B-,**f,AC51lMuLe; SI06B BIRMINGHAM: PRUDENTIAL BUILDINGS, B ST. PHILIPS PLACE. BIRMINGHAM. B3 2AK MUNICH: IS ZWEIBRUCKENSTRASSE, 8000 MUNICH 22. TEL. (089) 22 20 IO TEL. (021) 23S GS8Z TELEX 3363B1 FACSIMILE |02l) 2001473 N 30965 ' BROOKES & (WARTIN CHARTERED PATENT AGENTS TRADE MARK AGENTS EUROPEAN PATENT ATTORNEYS RICHARD c. MARTIN, m.a .c an t a*. DAVID C. WOODCRAFT, b .Ss .,{Ch c m) ERIC S.BARNARO. C.eNO,M.l.E.E.,C.0<l.A.F. GRAHAM F. MATTHEWS, b .a , C.En o . r. i.C.C. JOHN F. SrMONOS, LLA-LONO., SOLICITOR j o h n h . s l a k e , b .s c .,(c h c *4> MUCH . WRIGHT, M. A OXO*. p e t e r c, Sa n d e r s , B.se. H. NICHOLAS MATTHEWS, M.in St . f.M.A. DONALD J. ATTFIELD, B.5e. C.Ch e m. M.fl.S.C. O'nce Ma n a o c r - A. J. JELLY ACCOUNTS-MRS C.OLSINIA D-T (fojJ The European Patent Office Erhardstrasse 27 D-8000 Munchen 2 Federal Republic of Germany t e l e x 2675*4} TELEPHONES {Oft 242 963} f a c s imil e (01! 631 0586 LDX 316 HIGH HOLBORN HOUSE 52/54,HIGH HOLBORN LONDON, WCIV 6SE o u r *er DCW/VSW/ CH-1371 18 January 1990 Dear Sirs, J European Patent Application No. 87 303 681.8 E. I. DU PONT DE NEMOURS AND COMPANY I refer to my letter dated 21 December 1989, and now request the opportunity of adding the attached new claims to the above application. The attached new claims are process claims which are supported by page 4, line 25 to page 5, line 16. These claims are patentably distinguished from the prior art cited in the Communication dated 20 September 1989 for the same reasons as given in my letter dated 21 December 1989. Yours faithfully. DAVID C. WOODCRAFT BROOKES & MARTIN Ends: TUNBRIDGE WELLS: I BOYNE PARK, TUNSRIOGE WELLS. KENT, TN4 BEL. TEL. 10698) 510600 TELEX 9S7D78 FACSIMILE IOB92) SJO6G6 BIRMINGHAM oRuOCNTIAL BUILDINGS 5 ST PHILIPS PLACE BIRMINGHAM. B3 2AF. TEL. (021) 236 6262 TELEX 3353BI FACSIMILE iOSIj 200M73 MlMCw IS ZWE'BPUCKENSTRASSE. SOOO MUNICH 22. TEL. 1069} ZZ 20 IO N 30965.01 DUP050449562 9. A method of producing coated TiC^ pigment particles which comprises (a) forming an aqueous slurry containing 200 to 450 grams per litre of Ti02 and having a pH at which cerium ions will remain in solution, (b) adding sufficient cerium salt to provide a cerium ion concentration in the slurry of 0.05 to 2% by weight of TiC>2, (c) adding a sufficient quantity of a source of borate or polyfunctional organic acid anions to provide a concentration of said anions of from 100 to 300% of the cerium ion concentration thereby causing the cerium ions to precipitate onto the surfaces of the TiC>2 particles in association with the said borate or polyfunctional organic acid anions and (d) depositing an alumina or silicaalumina coating on the treated Ti02 particles. 10. A method according to claim 9 wherein in step (d) alumina is precipitated onto the treated Ti02 particles by adding enough sodium aluminate to the slurry to provide a concentration of abut 2 to 8% by weight of the Ti02 and adjusting the pH to within the range of 6 to 9 during the precipitation step. N 30965.02 DUP050449565 *4. C BROOKES 5. MARTIN CHARTERED PATENT AGENTS TRADE MARK AGENTS EUROPEAN PATENT ATTORNEYS "bxs RICHARD C- MARTIN, h .a .o mt a a. OAVIO C. WOOOCRArr. O.9e.,(C<c*0 CRIC E. BARNARO. C-Emo ,, M.l.C.e,C.DP.A.r. GRAHAM r. MATTHEWS, B.A., C.Cmo . F. I.C.C. JOHN r. STMONDS, UL.axoNS., ouidTen JOHN H. BLAKE, B.Sc-(CHtwJ HUGH R. WRIGHT, H.A.Oo n . PETER C. SANDERS, B-s*. H. NICHOLAS MATTHEWS, m.iw s t . t .m.a . DONALD J. ATTPIELO, B,3e. C.Ch c m. M.n.3, a. I. DU PONT OS NEMOURS AND COMPANY ueyal Dept. Patent Records Center 1007 Market Street Wilmington, Delaware 19898 U.S.A. r t c l x 267541 t e l e p h o n e s (01) 242 9631 FACSIMILE (Ol) 831 0586 l o x 318 HIGH HOLBORN HOUSE 52/5-4, HIGH HOLBORN LONDON,WCIV 6SE VAT REG.NO 232 273< 84 DATE & TAX POINT DCW/VSW INVOICE No- ^ >' L C) U 18 January 1990 fc* VAT A# I* % ussssBssssa VAT Total *0* European Patent Application No. 87303681.8 your reference ? CH-T37I_________ _________ 00: Preparing and filing supplementary aoendmen with additional claims in the above application and reporting to you US$ 225 ::SX&K2S2S3SSS5 Trms of Business Payment Is due within 30 days from the date of this account N 30965.03 DUP050449566 BROOKES & MARTIN CHARTERED PATENT AGENTS TRADE MARK AGENTS EUROPEAN PATENT ATTORNEYS RICHARD C. MARTIN, m.a .Ca n t a s . QAVIO C. WOODCRAFT, o .c .,Ic h *k ) ERIC E. BARNARD, C.Cmo , M.l.e.B,C,0.A.r. GRAHAM F. MATTHEWS, l.A, C.En o . f .i.C-C. JOHN F. SVMONDS, LL..Ln d .,SOLiCITO JOHN H. BLAKE, b .S..<Ch c h ) HUGH 9. WRIGHT, h .AOk o n . PETEH C. SANDERS, b .j j o . M, NICHOLAS MATTHEWS, M.In s t , t .m.a . DONALD J. ATTF1ELD, S.Se. C.Cmc m. M.R.S.C. S. 1. Du Pont de Nemours and Company, Legal Depart., Patent Records Center, 1007 Market Street, Wilmington, Delaware,19898, U.S.A. DCW/VSW/CH137lJ TELEX 267541 TELEPHONES (Ofl 242 9631 f a c s imil e (Ol) 831 0586 LDX 318 HIGH HOLBORN HOUSE 52/54, HIGH HOLBORN LONDON, WC1V 6SE VAT REG.NO 232 2734 84 DATE & TAX POINT 21 December 1989 DUP050449568 2 Barnard, U.S. Patent 4,239,548, discloses pigments having inner coatings comprising cerium and phosphate radicals and outer coatings comprising aluminum and phosphate radicals and optionally hydrous alumina. Jacobson, U.S. Patent 4,460,655, describes pigments of Ti02 particles associated with compounds selected from the group consisting of Na7CegF31, K7CegF31, Li7Ce6F31, and(NH,4) 7CegF3j. Jacobson, U.S. Patent 4,461,810, discloses pigments of Ti02 particles, the surfaces of which are associated with cerium cations and sulfate, phosphate, or silicate anions. The particles are also provided with an outer coating of alumina. Newland et al.r U.S. Patent 4,022,632, describes Ti02 pigments treated with carboxylate salts of cobalt, cerium or manganese. Bramekamp, U.S. Patent 3,506,466, discloses Ti02 pigment particles coated with inorganic oxides, where the inorganic oxide bears on its surface an amine salt of an oxycarboxylic acid selected from the group consisting of lactic, citric, malic, tartaric and glycolic acids. GB-A-1580882 describes a method of making a coated inorganic pigment which performs adequately in terms of gloss and dispersibility both organic and aqueous-based paint media. The inorganic pigment particles, which are preferably Ti02 are coated with alumina and then contacted with one or more organic hydroxy acids or salts or with a water-soluble reaction product of one or more di- or polyhydric alcohols and one or more di- or poly-basic organic hydroxy acids. It has now been found that pigments of Ti02 particles treated with cerium cations in association with certain polyfunctional water-soluble acid anions or borate ions, and then topcoated with alumina, exhibit excellent lightfastness, gloss and dispersion characteristics. N 30965.05 DU P050449572 2a SUMMARY OF THE INVENTION The present invention provides a pigment consisting essentially of rutile Ti02 particles bearing coatings of alumina or alumina-silica, the particle surfaces having associated therewith 0.05-2%, by weight of the TiC>2, of cerium cations and an associated DUP050449573