Document 4vNO6dO89z2mJ3bOR2nqD7ndG

PIGMENT COLOR RESEARCH REPORT ENVELOPMENT REPORT Process for G-389-39Q-391-392-D p il e : eanoMiB. aianira HATE:- MS.Y-1935 N36976 vimms mm mmmm. msmt mmummst mmm Fraeeas for {j-58t-$90~m~392-B Copies t* file FlMrt - We* S.B. Barrett #10 Bldg, file Cireolation & R&s&areb. DUP050316589 ww SCTOfB mt(J&bej<h. A&mcmm sr# ..,ik^ nut &ASS* HMT-ltSS This series of greens ms developed to obtain products possessing greater light stability than the Meadows line, G-20T-D to S-210-l> and equal to the Imperial Glen Green line. Formulas for each shad have been standardised and are now giving consistent results in plant operation, The mw greens correspond In depict to the old line mth tfie exception of tbs extra light shads G-38-B which is of the same depth and brightness as G-35-B. The others are less olive in masstone and bluer in drawdown than the standards which they replace, mmmm ffr.m,jmm This process employs lead nitrate liquor install of the tribasie lead acetate. It differs from the Meadows line also in having a high er final pH of strike - about 4*8 instead of 3*0 after addition of the bichromate* The final treated yellow may have a pg of 4,4 to $+0 de pending on the treatment. As a restraining agent, stannous chloride Is used instead of tartaric IQHM^WMSnie acids. Other stabilising agents as sodium sulphide and copper hydroxids are also employed. _____. laboratory development of a green to match Imperial's ea Green A-4002 was begun in June 1933 and continued throughout 1933 and 1934 The product wbidb it was proposed to duplicate #35302, equal in depth to 8-20?- but bluer in drawdown and tint and better in light stability. A formula employing load oxychloride from lead acetate and salt showed some promise in the laboratory but gave unstable results in the Semi works. This formula was a modification of the Oliver Wilkins green in which litharge and hydrochloric acid are used (see Eeports October 1933 to February 1934) * In March 1934, a 'green obtained from the T-309-I> yellow using stannous chloride (as a restraining agent) was found to possess good lightfaatness but was chalky and weak vs. C#35302*. This green was obtained by dry mixing the yellow and blue* Experiments during April were devoted *to increasing the stabil ity of the formula so that yellow and blue could bo slurry mixed and to developing a redder yellow for a more olive green*. The former was accomplished by addition of various materials to the washed yel low and the latter by increasing the ratio of bichromate to sulphate. Work was continued along these lines and in connection with Semi Works development throughout 1934, Semi-Works. The laboratory formula, Exp, 384-??, the modifica tion of"1 discussed above, was given a Semi-Works trial in April 1934. This formula was set up as 0W-T3S9 and & sample was sent to DUP050316590 Panin far durability tests* A detailed study was made is the semi Works covering time rati# of bichromate asd sulphate* type of lead nitrate liquor* amount ? soda ask, is the base and is the treatment of yellow* and numerous other variables reported under Chrome greens - Improved Lightfastness 1934* This formula appeared t be unstable and particularly effected by batch size. Is plant trials it ms necessary to reduce the amount of bichromate considerably before a satisfactory product could be ob tained. inasmuch as plant operation mm Inconsistent* further sealworls study unsuccessful and durability on this product found to be inferior to competition, the problem me returned to the laboratory (September 1934}. An improved formula* Lab* $xp. 411-dSC* was then tried in the semi works with promising results* This formula* CS-7694* differs from the preceding one In several respects* although basically it la of the same type. The chief differences are a higher strike tempera ture* high volume use of sodium sulphide and of aoprie hydroxide* This formula also received a thorough study in the semi Works* the moat promising results being obtained from variation in the treating agents. Serai Works batches were brighter in mss tone and slightly weaker than C#3550S f the Imperial product* Light stability appears to be equal (October 1934)* Plant standardization was 'begun in October 1934 end in December* tentative standards for three shades (XL* H & Die) were set up* These together with another light shade were accepted by Philadelphia and Parlin and coded as g~389~390-391-392-B in order of depth. Plant. Production was begun in the plant in January 1935 and carried on 'intermittently until March at which time a regular schedule for all shades was lined up* Difficulty vmm experienced at first in obtaining brightness of masstonss equal to the standards* and it ms necessary to reduce the alkalinity of the finished yellow by omitting the soda ash from the after treatment. This gave a very definite in crease in brightness of ra&sstone and tint* Attempts were saa&a to elim inate the use of copper hydroxide but because of instability on the dark shade green 0-392-B and because of its effect on light resistance it is advisable to continue its use until complete outdoor exposure tents are available* Stocks and Yfilds - Stocks of all shades have been made up. The estimated product ion and shipments for the first fosse- raonQjs of 1935 are shewn below. Production (approx*) tiHP bMi-p 7w ~mm Shipments 3540 140 2204 753 Disregarding a few batches in which the yields are abnormally low due to losses is pressing or from fire an average yellow yield of 325# per mol Is obtained* DUP050316591 the following mmm%a of blue are used, expressed m pmsantage of the finished green. $ Sia (formula) = *!*- W * * (by analysis) 5. 10*1 25,0 42*8 As a ccmparisin, 13 figures for the Btodows lino are 100 givens *mu > *W* Htt* * {-by analysis) 4**f T.S3 21.3? 34.$ fh higher blue contest of the a-380-3 line is reflects to toe bluer undertone ana higher raw Material east* msuijtmsLm G-302-S 10. 13*44 16*63 G-203-3 6-2$- ~31<M Q*M 11.80 14.8$ mumjgumtm Stond nitrate, if is necessary to use lea nitrate liquor la^sg little 88 copper m ether totals present as imparities, Hum sludge is used to making tfc lionor, toe latter should be purified by circu lating evar sheet mt feathered lead* Soda Ash to base* fertoitons have been mads to the plant tom m to IQ# soda ash per 2 mol ftfcsrg of toad nitrate* With the lowest mmm%9 the soluble lead at to end of bichromate addition to greater while with the highest amount the toad tost is likely to he slight or almost negative* fhe former condition to favorable to brightness provided the resultting acidity to net too great? to the latter ease (high soda ash) dullness and changeabillty my eeevr to the green* An average of 101# soda ash appears to be a satisfactory amount* pa control of the base to .not jo-aetieable as a 10$ change to soda ash in either direction had no effect on the pS reading* Physical Changes, such as batch size and temperature have more influence * Variations la amount of soda ash used ar reflected in different pa readings baton after the strike* fine ash should be dissolved* Bisia?ea*afce of Soda* the amount of bichromate of soda used in the standard formulas is 23# per 2 roe1 charge, sufficient to precipi tate ?8% of the lead* fhe following variations to bichromate and sul phate have been tried to the plant with results noted below* per 2 mol charge Sod. Sis&romats 232 Sod* Sulphate to biehroEsate 22 Sod* Sulphate after bichromate MB . XX 23s? 16 25 XXX 242 11 SB I? 242 m SB * this to toe standard ratio and usually gives a somewhat bluish masston at all depths. DU P050316592 4. XX ~ this gives a slightly olive ms atone sai Is frobably a safe variation to make to obtain this effect. An iatoxmadlali amount should he tried* XU - The higher ratio of bichromate while successful m mmmk plant hatches. even of the dark shades b-Sfl- and -3S-l), apjgrtontos the unstable point and is likely to give off material* IT * Precipitation of the bichromate 1b the presence of the hitt er amount of sodium sulphate gave a bluer mansions than obtained by 1X1. there is as apparent advantage to this combination as compared to 1 and II* Be correction for the iomaai acidity do to the Msfcromate was made In trying the above ratios* leaver, to balance the acidity the following additional amounts of soda ash should to used in making up the base i 1 II XXX If 6 1-1/1 3 3 ' Sulpha*. ah should to sufficient in mmmb to preci pitate tag elicit load excess remaining after the malts precipitation with bichromate-e^aghata* If Insufficient, the yellow is likely to to changeable as the restraining agents arc less effective in the prnmmm of soluble lead* Amount of salt, Shis has not toon decked in tto plant* atpd gemi-vorte results on'a previous formula are ineoBelasiv. fin crystals* SMs material acts as a restraining agent and pre vents change in crystal form and consequent redness in the yellow. Tto msmmt is 33$ higher than m ths earlier formula 03-1559 first tried in the plant. Seduction to the lower amount has not toon re stocked. It is sseecsary to employ it at both points as in the fto mato. The sodium sulphide is also believed to have seme restraining; action* Alum* Addition of alum to the washed yellow preceding tbs tin crystals produces a brighter and more lightfast green* , Use of soda ash to precipitate tbs alum has town discontinued as It was Impossible to obtain clean masstoaea and tlntf * All bat a email amount of alum appease to be preeipitated probably by the basic toad carbonate re maining in the yellow. Copper hydrtnd.de* tbs employment of this reagent, while incon venient In plant operation, appears to be necessary far stability in processing, particularly In the dark shades. In the light shades, emission of copper hydroxide has been Observed to cause flatness of masstens on the dried reboot and lees of glees on exposure in the fadeemter* fto actual ^tokening effect is no greater however. Out door exposures are being made to determine the practical effect of omitting this material, The copper hydroxide should to made up carefully In order to ob tain as stable a product as possible. Sigh temperature, concentrated DUP050316593 s volumes, too great an alkalinity and poor agitation toad to mmfa the precipitate to .torn black quickly. ffes tost oftor adding osmti# soda should 1} slight on Red Litmus. paper* V omBATim fnlvem of strife* The volume of tfee lead nitrate before strife-* ing is relatively high (2400 gallons per 2 mol charge). A lower vol ume (060 gallons) as need on CS-7559 of which the present formal. is a modification. Basalts on GS-75S9 were not successful as to sta bility of color or resistance te light and there is boas evidence that the difference in volume had some effect. However, if necessary* further ooapariaons should bo made. A semi Worfes batch with a &Q% reduction in volume showed little tinctorial difference but did show a Mttls decrease in light stability. Temperature of Strife. Tim temperature of 110 $* is probably the most suitable. It is suggested that at this point the lead chloride is kept in solution to some extent as it is tmmM. muring greater stability as ilia strike proceeds, la the semi Works* 120was ixamtlafaatory due to oliveness and ?5CF was objectionable became of dark mass*tone and somewhat inferior light stability. Time of strike. A one half hour strife has beeu adhered to in practically all of the plant development work. One hatch struck is 12 saturates was equal to & control run. In the Semi Works it was pos sible to strike in 5 minutes without harmful effect provided the agi tation was adequate. Increasing the time of strike to 2 hours re sulted in an olive product. A uniform rate of addition of bichrom in 20 to 30 minutes is probably best adapted to plant equipment. There should be no delay in adding the sulphate and tin crystals following the bichromate* Agitation. Good agitation is required in making this line of greens. Very poor agitation tends to give olive products of inferior light stability. 24 RIM in the 4000 gallon vats in tbs plant and 14 HPM in the 8000 gallons are lowest speeds which should fee used, but 26 BPM and 16 to 20 RPM are recommended for most consistent results* Batch sis, Wo (difference was observed in an increase in batch sis from a 2 mol to I 4 mol charge. Provided agitation is suffi cient , 5 mol charges b&n undoubtedly be made. A possible exception ia the darkest shade, 0-392-P, which has not yet been tried* Washing. Single semi-worfes runs showed & loss in cleanliness of masstone and tint when washing was reduced from 3 to 1 water* and also when the yellow was washed, shaded and pressed out on the same day* Temperature of wash water has not been studied but there is a wide variation in this throughout the year* Drying. Ho precise information was obtained on drying tempera tures, but it is believed that too high a temperature (above 170F) will reduce brightness* On the then? 3band, fairly rapid drying (48 hours) is desired to avoid oliveness* 160? is probably a safe aver age temperature for plant operation. DUP050316594 OMrtvel Tests* The following teats will indicate that the charge is normal but with, the exception of the test for sulphates before flooding and the final pH of the treated yellow, no adjustments are practical. The test for excess sulphates should be observed, particularly as a' deficiency of sodium sulphate can produce change ability in the yellow. The lead test after strike should be observed but chiefly to make sure that no chromate ia present. (1) After bichromate pH * 4.6-4.S averages 4,4 and 5*0 also OK (Bxom&e&mX green indicator) Lead excess ~ slight to positive with 10$ HaSOa (2) struck yellow before flooding pH * 5*8- 8.0 average {Brosaeresol Purple indicator) Sulphate excess - positive test with 10$ Bade (3) Treated Yellow pH * 4*3 without copper hydroxide pH * 4*8-50 with (Browsreeol green indicator ) (4) Copper hydroxide - slightly alkaline on Bed Litmus paper. DUP050316595