Document 3JQErjMRzq1JB8gbegj7qRmXJ

K N -7 1 -4 CUROMATE-MOLiB DATE SO LID SOLUTION E. I. DU PONT DE NEMOURS & COMPANY 256 VANDERPOOL STREET NEWARK, NEW JERSEY Serial No. KN 71-4 Copy No. 13 NEWARK PLANT PIGMENT COLOR RESEARCH REPORT CHROMATE-MOLYBDATE SOLID SOLUTION PIGMENTS Period Covered JUNE 1969 - JANUARY 1969 FILE 210 DATE* 2 /10/71 NJ 18179 DUP050082581 m 71-4 Copy 13 1* Numerical File 2. Research Office File - 210 3. Newark Library File - 210 4. M.Hunt/E.Gonick, Pigments, Wilmington 5 . W.S.Struve/J.Jackson/A.R.Hanke 6. R.H.Wetzel, Newport (Circ. and File) 7. E.E.Jaffe/E.F.Klenke/B.H.Perkins/Library 8. P.J.Monahan, Newark (Vital Records) 9. N.G.Fisher, Central Research Dept., Wilmington 10. Newark Library - for Central Report Index 11. Newark Library - for Central Report Index 12. fttrinrn 13 Extra 14. Extra 15. Extra 16. Extra 17. Extra NEWARK PLANT PIGMENT COLOR RESEARCH REPORT SUBJECT; CHROMATE-MOLYBDATE SOLID SOLUTION PIGMENTS PERIOD COVERED; JUNE 1968 - JANUARY 1969 SUBMITTED BY; APPROVED BY; < ' J || J. F. HIGGINS C . 'j ft E. F. KLENKE, JR. Date Submitted: 1/18/71 Date Released: 2/10/71 ABSTRACT: Solid solutions of Ba, Sr, Ca,. Cu and Zn chromates with molybdate and tungstate ion plus a little sulfate ion were explored. While all had moderate to good activity as primers, none equalled zinc chromate (Y-539-D) No unique color properties were found. The superiority of the solid solutions over mixtures in primer capability was demonstrated. DUP050082582 HCTRODUCTIOH Because of the unique color of molybdate orange# the three component solid solution of lead chromate-molybdate and sulfate, it was decided to explore other metal combinations to determine whether other unexpected colors or properties might be obtainable in the barium, strontium, calcium, zinc and copper series, using essentially similar preparation techniques. The lighter metal chromates alone have a variety of uses: calcium for example in ship-bottom paints, corrosion inhibition defoliation in soybeans and cotton, cement hardening, and as a fungicide; barium as a primer, explosive delay and a craze-inhibitor in plastic sheets; strontium as a primer and explosive delay; zinc as a primer and in tomato blight control; and copper as a tarnish inhibitor, in termite control and as a catalyst. The corresponding molybdates have less utility except for copper molybdate, utilized as a fungicide, wood preservative and to protect against marine borers, and zinc molybdate as a primer pigment. In order to round out the series it was also planned to substitute tungstate ion for molybdate ion. SUMMARY AND CONCLUSIONS The systems indicated in Tables I and II were delineated. Generally speaking solid solution formation occurred, as indicated by x-ray patterns, with relatively small amounts of the larger molybdate and tungstate ions going into the respective chromate lattices and larger amounts of the chromate ion going into the molybdate or tungstate lattices The fifteen areas of composition indicated by the letters A to 0 are the solid solution compositions determined. Usually the x-ray pattern of the solid solution was that of the chromate or molybdate or tungstate but two unique patterns, composition K and Kf were found. Color shifts took place about where the solid solution formation was found. Except for the copper series the shifts were not too great. Since a small amount of sulfate was in the commercial sodium chromate used these are all actually ternary solid solutions as indicated in Table III. Table IV lists the compositions by groups according to decreasing chromate ion content and is a further breakdown of the data in Table I. Table V indicates the results of NC 68-31 (a salt chamber exposure series). None were the equivalent of zinc chromate primer, on close examination. Because of higher solubility the copper series was more effective at lower loading. Table VI contains the results of experiments which showed the superiority of solid solutions over mixtures. Table VII shows the color changes and lightfastness achieved. DUP050082583 -2- A1though P and P expressed interest in the Strontium and Calcium series the testing program was cancelled at an early stage* Coil coating primers in a baked system (which we have not tested) was the area of interest for P and F. Additionally the copper series was of interest for marine primer bottom coats Areas which could be explored are the ternary solid solutions having a higher sulfate or other third ion content* A patent proposal has been submitted primarily to protect us if sampling outside the company is begun* A typical preparation is as follows * Solution I Strontium nitrate (anhydrous) 78*29 grams was dissolved in 2000 cc* of water and the pH adjusted 6.9 -- 7*0* It was then heated to 180P. Solution 11 20.74 grams of Ha2Cr04 and 43*01 grams of Na2Mo04 was dissolved in 2000 cc. of water and the pH adjusted 9.8 - 9.9. It was then heated to 180P. Solution II was introduced through a high speed jet for rapid mixing as follows: Volume of Minutes Solution II 0 500 3 500 6 500 9 500 12 Str period Sixty grams of NaCl in 250 cc. H20 was then added and the mixture stirred for ten minutes at 180 ^P. whereupon the pH was adjusted 6*0 with Na2C03 and stirred five minutes. Then 7.2 g. of Ka2SiOa (19%) in 70 cc. of water was added. After a five minute stir 8.9 grams of Ala(S04)3H20(16-18) in 75 cc. of water was added and after- a five minute stir, 3.4 grams Of Na2C0s was added and then a mixture of 1.8 grams of sulfonated petroleum oils and sulfated castor oil was added. This paragraph describes coatings normally added to molybdate orange pigments for lightfast ness and wettability and need not be added to these compositions. DUP050082584 --3-- The process for calcium compounds was essentially that of U.S* 2,745,764 and U*S* 2,745,765 wherein nuclei of sodium aluminosilicate are formed to aid the precipitation and the volumes were concentrated for insolubility purposes* Experiments are recorded in N.B* 1899* DUP050082585 N.B. 1899 Ex p * 3 System BaCr04-Mo04-S04 BaCr04 -Wo04-S04 TABLE I Per Cent Chromate X-Ray Si Lattice A) >85 SaCr04 B)>85 BaCr04 5 S rCr04-Mo04~S04 Mixture .> SO Srcro4-Wo04-S04 Mixture >"55 - Per Cent Chromate .........Sp C) <.25 D) <.55 X-Ray Lattice BaMop4 BaWo04 E) <- 60 F) <55 SrMo04 SrWo04 9 Cacr04-Mo Q4-SO4 6) >85 CaCr04 K) C 40 CaMoOt CaCr04 -Wo04 --S Q4 Mixture >55 X) < 55 CaWo04 10 CuCr04-Mo04-S04 J)> 85 CuCr04 K) S3 <25 Unique CuCr04-Wo04-S 04 Mixture * L) Ss t 55 CuMo04 M) < 40 CuWo04 11 ZnCr04-Mo04~S04 N) 70-85 Unique 0) < 55 ZnMo04 ZnCr04-Wo04-S04 Too Amorphous to read x-ray Too' Amorphous to read x-ray Too Amorph 3US to read x-ray - DUP050082586 TABLE II 1. System BaCrCXt - BaWCU - Bs SOa As a two-coraponent system# it may be represented as follows. CrC>4 W04 Sx >85 100 0 Sx + Ss 55 Ss i 0 WO4 100 Si has the lattice of barium chromate while sa has the lattice of barium tungstate* System BaCrO* - Ba MoO,i - BaSCL. A ladder series indicates solid solutions at both ends of the range with t 15% BaMo04 dissolving in BaCr04 and t 25% BaCr04 dissolving in Ba M0O4. The system, ignoring the very small amounts of sulfate (2.5 - 0.3 mole percent) may be represented as a two component system as follows. Si + Ss $3 85 25 Cr04 M0O4 100 0 Cr04 0 M0O4 100 Color value decreases with increased molybdate content going essentially colorless with greatly improved texture. The Si lattice is 8a chromate while the Ss is that of barium molybdate. 2. System SrCrpA - SrHOQ* - SrSO* This system shows a marked intensification of color from the weak, greenish yellow of pure SrCrC>4 to a redder shade, approximating the light chrome yellow range. As a two-component system, it may be represented as follows. | SrCrQ4 i_________Sj_________________ SO CrC>4 100 M0O4 0 Sx Cr04 0 M0O4 100 Srcr04 + Si cr04 100 WO4 0 55 Jo. Cr04 0 W04 100 DUP050082587 t a b l e II (Cont'd) 3. System CaCr04~caMo04/W04-CaSQ4 The ladder series for calcium. x-rays indicate the following, reduced to a two component system. i Sj. ...1,,_...,sa.,j-..,sa......_\_____Sp,___________i 85 40 Cr04 100 Cr04 0 Mo04 0 Mo)4 100 1 CaCrpA + Si t ............ 55 Cr04 100 WO4 _________ 1 Cr04 0 W04 100 4. System CuCrO*-Mo Oa /WOa -Cu SOa This system has produced a series of greenish yellow colors. The x-ray patterns in the molybdate ladder are especially interesting in that a unique pattern is found for S3 which is unlike either CuCr04 or CuMo04. Ml Mi 85 sp Sp 4* Sa 35 Ml Cr04 100 M0O4 Cr04 0 M0O4 100 In this series S* has the pattern of CuCr04, S2 of copper molybdate and S3 has a peak not common to either. This does not occur in the series when tungstate is used. I CuCr04 + Sj. | Si -----------------------------------gfr----------------------------- Cr04 100 W04 0 Cr04 0 W04 100 The pattern of Si is that of copper tungstate. 5* System Zn C:r04/Mo Oa AJOa - ZnS04 The zinc chromate/Mo04 series by x-ray indicates the following. 1 zn Cro4 .. 1 Si,; ) Si + sa, j sa j 85 70 cro4 100 55 M004 100 DUP050082588 TABLE IV Svs:tein Composition % Chromate Ba - Cr04 W0O4 - SO4 Ba cr04-M0O4-SO4 > 85 Cr04 Ca - Cr04 -M0O4-SO4 2.5 SO4 Cu - Cr04 ~Mo 04-SO4 Lattice Metal Chromate Zn Cr04 M0O4-SO4 Cu Cr04 M0O4--SO4 70 - 85 55 t 5 Unique Metal Molybdate Ba Cr04 W0O4-SO4 Sr Cr04 W0O4-SO4 Ca Cr4 W0O4-SO4 Zn Cr04 M0O4-SO4 <55 Metal Tungstate Metal Tungstate Metal Tungstate Metal Molybdate Sr Cr04 M0O4-SO4 <60 Metal Molybdate Ca Cr04 M0O4-SO4 Cu Cr04 W0O4-SO4 < 40 Metal Molybdate Metal Tungstate Ba Cr04 M0O4-SO4 Cu CrOi Mo Oa -SO*. <25 Metal Molybdate Unioue DUP050082590 Ja b l b Data From NC-68-31 combined With Data of Table I SW tot NO,a 00026 00027 BaCr04/Mo04 II II 85/15 25/75 00030 " /Wo04 25/75 00034 II II 95/5 00035 Sr Cr04/Uo0* 55/45 00039 * /W0O4 60/40 00041 /M0O4 25/75 00042 " /W0O4 10/90 00044 Cacr04/Mo)4 25/75 00045 CaCro4/Wo04 40/60 00046 CaCr04/Wo04 10/90 00050 CuCr04/M004 55/45 00051 CuCr()4/Mo04 85/15 00052 CuCr04/Mo04 95/5 00053 CuCr04/Mo04 25/75 00055 ZnCr04/Mo04 25/75 00056 znCro4/Mo04 70/30 00057 ZnCr04/Vo04 85/15 00053 ZnCr04/Wo04 55/45 Zinc Yellow Control TableTM! . Comp . A c D B E Mixt E F H I I t J : G K 0 N mm - Hours to Failure 25% 100% Active> Active 148 124 148 179 148 179 148 124 148 148 179 179 148 179 124 179 179 179 179 179 179 50 50 179 46 72 179 179 124 46 179 179 179 179 179 50 179 50 179 DUP050082591 SW Lot WO- TABLE VI (From NC -69-13 10/14/69) Active Composition Rating (10 - 0) Table I 179 hours. Comp 0 Wo Chancre 00077 00049 25% 25% CuCr04/Mo04 85/15 CuMo04(Cr Molyb) j - 4 2 00078 25% CuCr04/Mo04 95/5 j 4 00076 25% CuCr04 -1 Mixt 85 25% 85% CuCr04 + 15% CuMolyb -1 Mixt 95 25% 95% CuCr04 * 15% CuMolyb -1 S DUP050082592 TABLE VII Series Ctt Sr Ba Zn Ca Color Chance in Solid Solution Formation Brown --light brown - green L.F. None Very green yellow___red shade yellow improved Green shade yellow to red shade Unproved To darker greener masstones Little change Lighter more intense yellow MT Little change DUP050082593