Document 5bQv6yxpJXBYL8vYEdx2NvdN0

KH-'i,o -4 aq o s g u b w m . m s s] t o q a. w it h c o h t r o l Bys I Return to: R. Return to: CDTOept. Jackson Laboratory R. & D, File Room CDP Dept. Jll Jackson Laboratory R. & D. File Room u .. Return to: CDP Dept. Jackson Laboratory R. & D. File Room > Return to: CDP Dept. Jackson Laboratory R. & D. File Room Return to: CDP Dept. Jackson Laboratory R. & D. File Room Return to: MU-1780 (Rev. 3/78) CDP Dept. Jackson Laboratory R. & D. File Room DUP050081922 E. I. DU PONT DE NEMOURS & COMPANY 256 VANDERPOOL STREET NEWARK, NEW JERSEY Serial Ne. KN-70-4 Copy No. 15 ^teases return k> MCK5QN LABORATORY Fll L-S NEWARK PLANT PIGMENT COLOR RESEARCH REPORT AQUEOUS OXIDATION OF DQA TO QA WITH PHASE CONTROL Period Covered January, 1968 - January, 1969 (Part time) | FHE= 22 3.91 | | DATE: 2/17/70 NJ 14071 DUP050081923 KN -70-4 X* numerical File 2. Research Office File, Newark 3. Newark Library File 4. M.Bunt/E.Gonick, Pigts,, Wilm. 5. W.S.Struve, Newark 6. F.F.Ehrich/E.F.Klenke/B.H.Perkins/Newark Library 7. A.R.Hanke/E.E.Jaffe/Newark Library 8* P.J.Monahan, Newark (Vital Records) 9* R.H.Wetzel, J.F.Maurer, J.W.Minnich, W.A.West 10. M.C.Crossan, Newport Research File 11. N.G.Fiaher, Central Research, Wilm. 12. J.Jackson 13. Extra 14. Extra 15. Extra 16. Extra 17. Extra NEWARK PLANT PIGMENT COLOR RESEARCH REPORT FINAL REPORT SUBJECT: AQUEOUS OXIDATION OF DQA TO QA WITH PHASE CONTROL PERIOD COVERED: JANUARY, 168 - JANUARY, 1969 - Part Time SUBMITTED BYi^ULIUS JTCKSON DDAATTEE SSUUBBMMIITTTTEEDD:: 1/15/70 APPROVED BY: DATE RELEASED: feasibility of oxidizing 6,13-dihydroquinacridone to a or 8 phase QA in an aqueous system, not involving additional organic solvents, has been demonstrated. A novel system of regenerative catalysts involving Fe`f+/Fe+++ ion and the sodium salt of 2-anthraquinone sulfonic acid was developed. In the event a shortage of oxidation capacity arises, this system should be considered be cause of its lower ingredient costs and higher kettle capacity. RETURN TO JACKSON LABORATORY FILE ROOM DUP050081924 TABLE OF CONTENTS I. INTRODUCTION II. SUMMARY AND CONCLUSIONS III. PATENT STUDIES IV. EXPERIMENTAL DETAIL V. REFERENCES Page 1 1 2 2 12 DUP050081925 I. INTRODUCTION The knowledge that DQA can be oxidized to QA utilizing air as the oxidant has been available for some time. Various workers have demonstrated the feasibility of this operation using suspensions high in organic solvents. 1. Klein and Cooper, Ref. 5, demonstrated the feasibility of air oxidation of DQA to QA using a polycyclic aromatic quinone/air/ tetramethyl sulfone system. This work has led to the issuance of U.S. 3,475,436. 2. Griswold, Ref. 6, demonstrated the use of 2-anthraquinone sulfonic acid as a catalyst for the oxidation of DQA to QA with air or hydrogen peroxide in a mixture of NaOH/HsO/methanol. 3. Kolski, Ref. 7, studied the dry oxidation of DQA to QA by heating in air or oxygen. This work is being extended by others. 4. West, Ref. 8, demonstrated the oxidation of DQA to QA using 2-chloroanthraquinone as a catalyst with air in a NaOH/fejsO/ methanol system and attempted to oxidize DQA to QA, utilizing a KOH/HaO system and the sodium salt of 2-anthraquinone sulfonic acid. None of these workers demonstrated air oxidation with control of phase in a strictly aqueous system with less than stoichiometric quantities of the anthraquinone. For further details concerning the prior art see CP-92, Air Oxidation of DQA, Ref. 9. Initial work in this report was directed at making QA of any phase, since it was thought that current HT acid drowning studies would make it possible to convert to either 8QA or yOA in a sub sequent size reduction and drowning operation. After the initiation of the work, it was found possible to direct the operations to yield either f3QA or y QA by seeding opera tions, which could be of interest in the manufacture of QA by our standard processes. II* SUMMARY AND CONCLUSIONS 1. Methods of oxidizing 6,13-dihydroquinacridone to QA in an aqueous solution were successfully developed on a laboratory scale. 2. The manufacture of yQA or PQA phases can be made at will. 3. Semi-Works development of the 3 process was satisfactory. More work would be required on the Semi-Works yQA process. 4. The methods are more economic than our presently used Sitol oxidation. 5. Exterior exposure of fi phase pigment made by dispersion milling of air-oxidized f3 crude are being obtained in Series 68450. At six months exposure, the products were satisfactory. DUP050081926 -2 - 6. Substituted DQA's exhibiting high solubility in NaOH or KOH can probably be oxidized by these techniques. 7. The work was discontinued in view of the presently large oxidation kettle capacity at Newport and the progress shown by studies on the direct dry air oxidation of DQA to QA. III. PATENT STUDIES The basic processes developed in the body of this report are believed to be new and novel. A patent memorandum CP-92 (11/14/68) has been written and is awaiting action by the Patent Group. IV. EXPERIMENTAL DETAIL Typical Processes Type I - Preparation of 3QA in Absence of Fe+* Catalyst Ref. 1803-34B 90 grs. a-DQA (.285 moles) made as per U.S. 2,821,529 into 200 cc H20 containing 2 cc Dowanol EB (1) 1.5 cc Surfynol 485 (2) 1.0 cc Emcol P10-59 (3) stir 5 min. add under reflux - good agitation 50% NaOH 214 cc (107 gr. NaOH =2.67 moles) wash in with 15 cc H20. Heat to 105-110. Hold at 105-110 for 30 minutes. Add 2.5 gr. p-sodium anthraquinone monosulfonate (AQS) or "silver" salt. turn on air hold at 105-110 under reflux for 5 hrs. wash down walls of flask with 40 cc H20 every hour. Dilute to 6 1 Ha0 heat to boil filter wash negative to BY dry. Yield 88 grs. Infrared - Nujol Rub - No absorption 6.6; 14.37 microns - no DQA. Crystal phase - beta % QA 96.3 - sulfuric acid (1) Dow chemical Co. (2) Airco Chemical Co. (3) Witco Chemical Ethylene glycol butyl ether Ethoxylated acetylenic glycol iacpropj-lamine salt^ dodecyl benzene sulfonic acid DUP050081927 3 Comments - Type I Role of Surfactants Since a-DQA is not readily wet by water, it was ound benefi cial to include surface active agents to assist in this operation. Dowanol EB and Surfynol 4B5 are a highly effective combination and did not interfere with the oxidation mechanism. The low solubility and extremely poor wetting characteristics of the QA generated by aeration mechanism created the formation of a thick, extremely stable difficultly stirrable foam. The addition of Emcol 10-59 overcame this problem and aided in the lowering of viscosity of the system. Alkali Use Lesser amounts tend to give lower levels of oxidation. Large excess over the theoretical equivalent to form Na2DQA has been used. KOH may be substituted for NaOH, KOH use tends to slow rate of oxidation and results in formation of some quinacridoneguinone. Study of DOA Purity Several samples of DQA were worked with. Lots # 5230 9623-3 9622 Feb. 68 shipment Fluorescence Value 91 92 106 124 A marked increase in difficulty of oxidation has been observed with purer DQA (despite the fact that such DQA particles appear to be smaller). Influences on the ease of formation of Na2DQA may be a factor although this could not be substantiated by microscopic examination. Reaction Mechanisms The following reaction mechanisms were examined and are commented on. 1. ctDQA + H20 + NaOH + Air + AQS* aQA (very slow rate) 2. PDQA + H20 + NaOH + Air + AQS* ^-t -y QA (slow rate) 3. Na2DQA + H20 + NaOH + Air 4. Na2DQA + Air -------r- PQA (v slow rate) A' -----^ Na2QA (v slow rate) 5. Na2DQA in solution. + AQS* in solution (3QA + Na2anthrahydro- ' quinone(very fast rate) DUP050081 928 -4- At this point in the study, the optimum mechanism seemed to involve the formation of the Na2DQA salt - its solution and oxidation. 1. ODQA + H20 + 2NaOH Na2DQA solid Na2DQA (solution) 2. Na2DQA (solution + AQS* (solution) ------0QA + Na2anthrahydroquinone (solution) 3. Na2anthrahydroquinone-sulfonate + H20 + Air anthraquinone sulfonate + NaOH *AQS - P sodium salt anthraquinone monosulfonic acid. Ingredient Ratios Since rapid oxidation (which always seems accompanied by formation of the purest |3QA) is essential, a study of the DQA/HsO/ NaOH ratio was undertaken, on the basis of finding the point of (1) maximum solubility of Na2DQA coupled with sufficiently high alkalinity to prevent hydrolysis. This is complicated by the extremely low solubility of the sodium salt of sulfonic acidanthraquinone in strongly alkaline solutions. Disulfonic acid salts are even less desirable from this point of view. Other anthraquinones have been found less desirable than the mono acid salt. Temperature High temperatures seem essential to accomplished the oxidation (possibly because of maximizing the solubility of Na2DQA and AQS). This, of course, lowers the solubility of 02 in the reaction mass. This high temperature tends to promote recrystallization of the Na2DQA and particle size growth as the reaction progresses. Studies involving the addition of water after partial oxidation to increase the solubility of the Ha2DQA component, and better dispersion of the air bubbles were made to increase the rate of the reaction and minimize recrystallization effects. Attempts to lower the tempera ture to prevent hydrolysis of Na2DQA prior to oxidation resulted in very low oxidation rates. Cost Reduction This study was then continued in an attempt to determines 1. Minimum amounts of AQS. 2. Most suitable oxidant. 3. Optimum conditions for scale up. 1. Despite the theoretical possibility of the anthraquinone to be reduced by interaction with the DQA and reoxidized by air, a significant quantity is needed by this reaction. We have studied the range .03 moles per mole DQA to 0.18 moles/mole. Secondary reactions leading to the formation of such compounds as anthrone and anthranol its enol form, and oxanthrone from the anthrahydroquinone probably account for the need to use more than trace quanti ties of anthraquinone sulfonic acid. salt. DUP050081929 ~5- The most reproducible process at this period was achieved with higher levels of AQS, but intermediate levels of .034 moles/mole DQA seemed feasible. The high cost of this compound necessitates a minimum use. 2, This reaction seems to involve three basic requirements in addition to economics. a. Oxidation potential of the quinone hydroquinone system. b. Solubility and chemical stability in the aqueous al kali solution of the quinone. c. Ease of oxidation of the reduced hydroquinone by Os. We have studied anthraquinone, P-carboxylanthraquinonehydroquinone, 2,5-ctihydroxy-p-benzoquinone, 2NH2, 1 Cl, anthrax quinone, 1,5-disulfonate (Na) anthraquinone,none of which are as effective as $ monosodium sulfonate of anthraquinone. At this stage of the study, we felt that the dehydrogenation of the DQA is caused by two factors: 1. Direct oxidation with the oxidized quinone form. 2. Secondary oxidation caused by B2O2 resulting from regeneration of the hydroquinone. We have found that H202 will oxidize DQA to QA in the alkaline system we are using, but at an inefficient rate unless AQS is present* Study of the Use of 02~ Catalyst System _ The speculation that a secondary source of oxidation caused by 02~ resulting from regen eration of the hydroquinone by air (Ref. 1803-41) led to the concept of introducing into the system an Os* generator. This was done by studying the effect of the addition of 'Fe to the system utilising the reaction. 4*4* 4*4,4* ^ 2 Pe + QS -------p>2 Fe + 02 We have demonstrated that the addition of FeSd* to the re action mass along with the anthraquinone sulfonic acid salt results in a process which is more rapidly oxidized and permits the use of less of the quinone. we have not been able to see a quantity of Pe+2/Pe+3 (OH)3 in the suspension (by microscopic examination) to ^ DUP050081930 -6 make us believe that the iron is in hydrated oxide form. The existence of FeQ4~ may explain this observation. This compound is, of course, a powerful oxidizing agent and can be formed by reactions between Fe(OH)3 and Na202 (Ref. 1803-40,45). In addition, we have determined that DQA plus our standard ingredients (H20/c h ~/a q s ) will react with Fe(0H)3 to give signifi cant quantities of 0A, indicating that production of Fe+++ may also be involved (Ref. 1803-47). By this approach, we can reduce the quantity of AQS from .034 moles/mole DQA to .009 mole/mole DQA at a significant cost savings. This work led to the development of the process called Type II. { "{ 'I' Type II - Preparation of gQA in Presence of Fe Catalyst 90 g ccDQA (U.S. 2,821.529) into 200 cc HaO1 2 cc Dowano1 e p 1.5 cc Surfynol #485 1.0 cc Emcol P10-59 stir 5 min. add under reflux 50% NaOH 214 cc2 Wash in 15 cc h 20 Heat to 105-110c. Hold at 105-110G. 30min. add 1.33 g P sodiumanthraguinone monosulfonate 18.5 g PeSO.i . 7H2O/30 cc H2Q4 Turn on air Hold at 105-110C . fur 2-1/2 hrs.5 Wash down at 1,2 hrs , - 60 cc H20 Discharge into 6 1 H20 106 cc 98% H2S04 pH 11,5 Adjusted to pH 1.6 with cone. HCl Heated to 95*C. Held 45 min. Filtered, washed S04~-free. Dried Yield 93.5 g Infrared - Nujol Rub - No d q a 6.6, 14.37 microns (6) X-ray - Pure |3QA[3 (AQS)3 Comments iUp to 450 cc seems OK - lower limit governed by viscosity (1803-62), a25% reduction gave poorer degree of oxidation (1803-48A). 3Note lowered amount required decreasing cost vs. Type I. Reduction to .83 g OK (1803-48B), reduction to .5 g. NG (1803-45B), reduction to 13.9 g OK (1803-49)? %ote shortness of cycle vs. Type I, decreasing cost. The development c seeding techniques (see attached Type III). PQA process gave rise to additional ingredient savings in that the amount of AQS could be substantially reduced at a good oxidation rate. DUP050081931 7 Type Ill-Preparation of 8QA in Presence of Fe++ Catalyst and PQA Seed Ref. 1900-18 90 g a-DQA (U.S. 2,821,529) ^'4.5 g RT-795-D (Disp.Milled small particle size PQA) Ex. V U.S. 3,030,370 into 200 cc H2O*1 2 cc Dowanol EB 1.5 cc Surfynoi #485 1.0 cc Etacol PI0-59 stir 5 min. add under reflux - good agitation 50% HaOH 214 cc wash in with 15 cc H20 heat to 105-110c hold 30 min. at 110 under reflux add .5 g p sodium anthraquinone2 monosulfonate (AQS) 13.9 g Peso.: .7--;o 30 cc Ha0 Turn on air Hold at 105-110C. for total 5 hrs. Sampled at 3 hrs.,15 min. and 5 hrs. Wash down at hourly intervals. 50 cc HaO isolation route - 1. filtered washed neg. to BY paper 2. h 2S04 acid extracted. Yield 96 g. Infrared-Nujol rub completely oxidized at 3 hr.15 rain.3 No'absorption 6,6, 14.37 microns X-ray - P phase Comments J.300 cc OK. 2Note lower requirement for AQS. aNote good oxidation cycle. Process for Manufacture of ^QA Crude It was decided at this stage of the study that the economics of this operation could be made more attractive by: 1. utilizing the pQA-type crude in HP milling operations* 2, Development of methods to manufacture yQA crude since the economics of yQA pigment manufacture via dispersion milling are quite attractive and little incentive exists to develop an HT-tube drowning method. Dispersion milling requires yQA crude feed. The successful routes are attached hereto. Type IV shows the manufacture of yQA via oxidation of PDQA in an Fe+vFe+++ quinona catalyzed system. DUP050081932 -8 - mmTYPE IV Preparation of yQA ex Reference 1900-2B Make pDQA ex aDQA1 (u.s. 2,821,529) 90 g aDQA into 105 cc H20 400 cc methanol add 56.2 g 50% NaOH Stir 20 minutes. Add 2 cc Dowanol EB 1.5 cc Surfynol #485 1.0 cc Emcol P10-59 Heat to reflux. Hold 10 min, at reflux. Distill off methanol until 98C. reached. Add water 110 cc 50% NaOH 159 cc. Add 1,5 g fi sodium anthraquinone monosulfonate 13.9 g PeS04.7H20 in 30 cc HaO Aerate at 105-110 under reflux. Add 50 cc H20 at 5 hrs. Stop aeration at 8 hrs. isolate via acid extraction. Infrared - Nujol rub - No b q & at 6.6, 14.37 microns X-ray yQA Comments i Alternatively d q a ex cyclxzation of a dialkyl 2, 5-dianiiino-3,6dihydroterephthalate in a high boiling inert medium may be utilised i.e., Britisl 1,093,692 or (3DQA made by solvent contact with aDQA U.S. 3,007,930. Table V shows the development of a successful method of oxida tion to yQA by means of y seeding. TYPE V - Preparation of yQA ex aDQA via *vQA Seeding Ref. 1900--10B 10 gr, yQA crude1 ex U.S. 2,821,529 90 gr D.QA into 200 cc H20 2 cc Dowanol EB 1.5 cc Surfynol 485 1.0 cc Emcol P10-59 Stir 5 rain. Add under reflux - good aaitation 50% NaOH 214 cc Wash in 15 cc H20 Heat to 105-110c. Hold at 105-110C. 30 min. DUP050081933 -9- Add .5 g P-anthraquinone monosulfonate (2) 13.9 g FeS04.7H20/30 cc HaO Aerate 5 hrs. Wash down hourly 50 cc H2o Acid extract Filter Wash Dry Yield 101.6 g. Infrared - Nujol Rub-No. detectable aDQA 6.6, 14.37 microns X-ray - pure gamma phase. Comments 1 ... a - 4.5-710 g satisfactory b - A suspension of air oxidized slurry can be utilized as seed, c - y pigment RT-796-D (US 2,030,370) also works 1.5 -v*!.5 g. This work is detailed in n b -1900. Elucidation of Mechanism Hydrolysis of NaPDQA - 3 Oxidations These processes involve as the first step the formation of a saturated solution of Ka2DQA and is conducted at 110s with a 30 minute hold period. Isolation of the grayish white compound showed the probable existence of Na2DQA and some (3DQA after this period (Ref. 1803-38). Role of B Monosulfonate Anthraquinone In addition to its role as an oxygen carrier, the presence of this compound seems to be essential in controlling phase direction, perhaps by inhibiting the hydrolysis of NaaDQA. Oxidation in the presence in sufficient quantity to insure completeness of oxidation always gives (3 phase. Decreased quantities result in incompletely oxidized yQA and flDQA (the latter perhaps inside the particles of yQA). This could result from the hydrolysis of the NasDQA. A study of the d q a /a q s ratio in the presence of yQA seed showed that larger amounts of AQS could be used with resultant more complete and rapid oxidations (18 03 -45,' 1300-19). Role of Surfactants In addition to controlling viscosity and foaming, the surfactants (Dowanol EB, Surfynol #485, Emcol P10-59) are assisting degree of oxidation achieved with 02 or H20a (Ref. 1803-45). Mechanism of yQA Seeding An attempt was made to determine the mechanism of the y seeding. The Na2DQA formation was accomplished in the presence of and in the absence of yQA. x-ray examination of these products, as filtered, without washing, showed the presence of similar peaks which are not identified as being any "known DQA or QA types, or Na2QA or NaGR. DUP050081934 - 10 - We must assume then that they are NasDQA and that y seeding does not work by alteration of the sodium salt of DQA or by a 0DQA mechanism. The latter point is also supported by the lack of UV fluorescence of this salt. aDQA fluoresces yellow and 0DQA fluoresces as a redder yellow or orange shade. Unknown 20 values were 8.5, 9.8, 11.4, 12.6, 25.6. (Ref. 1900~13D,E) The addition of yQh seed after the formation of NagDQA resulted in a yQA type oxidation. This supports the premise that phase direction results from a seeding mechanism (Ref. 1900-16)* 0 phase seeding was also studied and led to more rapid oxidation at lower levels of AQS. Ref. 1900-18. Miscellaneous Experiments - &QA Oxidations 1803-9,10 Size reduction of DQA prior to air oxidation had little influence on result. 1803-11 Fusion of d q a /n 4o h /s odium salt 2 anthraquinone sul fonic acid gave rise to low level of QA, DQA, and no QAQ. 1803-9,12,13, 14,15 Attempts to substitute K0H for NaQH in early work had little influence on course of oxidation. The object was to obtain greater solubility of K salt. 1803-151 Attempts to utilize H2O2 in place of air did not give rise to greater levels of oxidation although oxidation does fate place. 1803-23 Deereasing total alkalinity (to maximize solubility of Na2DQA and AQS)was not beneficial. 1803-24,26 Topping of reaction mass with AQS or Sitol did not benefit degree of oxidation. 1803--19A,B Attempts to utilize the following in the system were unsuccessful. 1. 2., 5 dihydr oxy-p-benzoquinone. 2. 2-arnino/chloro anthraquinone, 3. 2-chloroanthragainona. 1803-19C Complete oxidation of NaaDQA with equimolar quantities of AQS can be accomplished in the absence Of 0. 1803-39B The use of ::oA/NaOH/2-pyrrolidone/air as in British 1,080,850 was briefly studied. Incomplete oxidation resulted. 1803-390 The use of hydroquinone-air, and hydroquinone-NaClOa in the system otherwise similar to our standard opera tion old not give evidence of'Oxidized QA. DUP050081935 - 11 - 1803-46 The use of anthraquinone and 8 anthraquinone carboxy lic acid was not satisfactory. 1803-50,56 Presence of QAAF during air oxidation to 8QA reduced particle size obtained, but the products were not pigmentary. 1803-59,62 Study of DQA/j^o/NaOH ratio shows wide variations possible. 1900-11,12,20 Attempts to oxidize 2,9-diraethyldihydroquinacridone in a manner similar to that used for DQA failed. Attempts to increase solubility by means of KOH were not successful. 1900-16 C0SO4 found to act similarly to PeS04 as an Oa carrier. 1900-20,22 Attempts to oxidize 2,9-difluoroDQA and 4,11-dimethyiDQA showed the presence of considerable levels of oxidation. Analytical Procedures Surfynol #475 and also sodium salt of 2-anthraquinone sulfonic acid solutions in sulfuric show similar absorption to OQA. Inade quate washing gives rise to apparently low QA results. SEMI-WORKS STUDIES (For details see DNS-68-1) 8QA air oxidations were successfully scaled up in the Semi-Works and converted to pigments via dispersion millings. (Ref. DSN 68-1, SW-00333,4,5,8,00342), The pertinent, findings are; 1. Air oxidation scaledup easily, 2. Crudes presented no filtration problems, 3. Can be directly converted to 8-phase pigments (without prior acid extraction). 4. Gave dispersion-milled products which were close in masstone, darker and bluer in tint versus standard 0-phase crude controls. vQA Air Oxidation Semi-Works studies on the air oxidation of yQA were not totally successful. Lower levels of conversion to yQA resulted that achieved in the laboratory. The y-QA crude was dispersionHnilied to convert to pigmentary form and presence of DQA further confirmed. (Ref. SDN 68-1, SW-C0365, 00388, 00390). This phase of the work was not completed for reasons previously stated. DUP050081936 - 12 REFERENCES 1* NB 1803 2. SB 1900 3. DSN 68-1 . 4. Miscellaneous Product Improvement Studies 2/12/68 5. Klein KN-64-11 oxidation of Dihydroquinacridone in Tetra- methylene Sulfone 6. Griswold NB 5077-83,91,98,124* 7. Kolski, Exp. Station Request WPES167-8, 9/14/67 8. W.A.West, NB 5108-16, 5108-34B 9. CP-92, Air Oxidation DQA, J.Jackson 11/14/68 10, Vansant WPP 69-9, Air Oxidation of DQA - Economic Evaluation 11. Exposure Series 68450 dc DUP050081937 o (J a g^4 p i | GO * *^-4 oO o cu r K-' 4 CCOl. ^ 3 a<y BS5 *> jo O 0) 00 w cq f CD ,<y Pu a) 3 DUP050081938