(5) Fairclough, R. A., Hinshelwood, C. N., J . Chem. Soc. 1937, p. 538. (6) Flory, P. J., “Principles of Polymer Chemistry,” Sec. IV, Cornell Univ. Press, Ithaca, N.Y., 1953. (7) Gardner, H. A , , “Physical and Chemical Examination of Paints, Varnishes, Lacquers, and Colors,” 11th ed., p. 152, H. A. Gardner Laboratory, Bethesda, Md., 1950. (8) Gowenlock, B. G., Quart. Revs. (London) 14,133 (1960). (9) Mayo, F. R., Reprint booklet ACS Div. of Organic Coatings and Plastics 19, (2), 326 (September 1959). (10) Myers, R. R., Ann. N . Y.h a d . Sci.79, 1 (1959). (11) Myers, R. R., Zettlemoyer, A. C., IND.EX. CHEM.46, 2223 (1954).
(12) Schlick, LV., Farben, Lacke. Anxtrichstofe 3, 303 (1949). (13) Stearns, M. E., 0 8 6 . D i g . Federation Paint @ Varnish Production Clubs 26, 817 (September 1954). (14) Stearns, M. E., Canty, \V. H., Ibid. 30, 58 (January 1958). (15) Von Konow, R., Finrka Kemistsamfundets M e d d 63, 42 (1954). (16) Wheeler, G. K. (to R. T. Vanderbilt Co., Inc.), U. S. Patents 2,526,718 (Oct. 24, 1950); 2,565,897 (Xug. 28, 1951). RECEIVED far review October 27, 1960 ACCEPTED August 10, 1961 Division of Organic Coatings and Plastics Chemistry. 138th Meeting, ACS, New York, N. Y . , September 1960.
PAPER SIZE FROM PINE OLEORESIN H U G H B. S U M M E R S , JR.,
AND G L E N W. H E D R I C K
Naval Stores Laboratory, Southern Utilization Research and Development Division, U. S. Department of Agriculture, Olustee, Fla.
Loeblich and Lawrence in 1958 published results on processing of partially and completely neutralized pine oleoresin and suggested the use of these materials as paper sizes. The current article is a report of a study which has resulted in practical processes for the preparation of sizes, conventional and fortified, from pine oleoresin by partial neutralization of the resin acids in the oleoresin prior to distillation of the terpentine. In making gum rosin sizes, this process obviates the isolation and handling of rosin as such. The elimination of this step should result in a savings in the preparation of gum rosin sizes. To obtain dry sizes, both neutral and acid paste sizes were dried in a ball mill, It is believed that this is the first time this type of equipment has been reported to be used for preparing dry sizes. HE USE of rosin as an agent for sizing paper was discovered Tabout 1807 (2). However, it was about 1900 before rosin was accepted as an ingredient for paper size. The introduction of commercially prepared sizes was some 20 years later. At the start of the century, pine oleoresin was the only source of rosin. More recently, wood- and tall oil-derived rosins have, to a large extent, supplanted gum rosin as a raw material for both conventional and fortified paper sizes ( 3 ) . To make gum naval stores more competitive with wood- and tall oil-derived paper sizes, processes have been developed which obviate the intermediate isolation of rosin and permit the direct processing of pine oleoresin yielding either conventional or fortified paste paper sizes. In these processes, the oleoresin is cleaned as for use in the Olustee rosin process. The resin acids are then partially neutralized, and the turpentine is removed by steam sparging. Since maleic anhydride reacts with the levopimaric acid in the oleoresin at room temperature, treatment with this reagent prior to neutralization produced a fortified size with no other changes in the process. The paste sizes which have been produced in small pilot plant batches have been found to produce satisfactory dry sizes in a small laboratory ball mill which was heated with an oil bath and flushed continuously with a n inert gas, carbon dioxide, to remove water vapor. Both acid sizes and completely neutralized sizes were dried in this manner. The dried products were almost colorless, hygroscopic powders which were readily dispersable in hot, 120’ F., water. A search of the patent literature did not reveal any previous attempts to prepare a dry size by the use of a ball mill. Only such methods as spray drying, drum drying, and drying in vacuo were mentioned.
Experimental
I. Paste Sizes from Crude Pine Oleoresin. Freshly collected crude pine oleoresin, 390 pounds, and freshly distilled turpentine, 280 pounds, were charged to a 100-gallon 56
l & E C P R O D U C T RESEARCH A N D D E V E L O P M E N T
neutralization tank equipped with an agitator for mixing. This yielded on filtration 641 pounds of filtrate, containing 53.9% turpentine and 467, rosin Lvith a resultant resin acid content of 40%. The resin acids were partially neutralized with 91.75 pounds of sodium hydroxide solution (28.1% NaOH, 0.645 moles). To this mixture, 14 pounds of water was added. The batch was agitated until homogeneous. The composition of the mixture is tabulated in Table I. A 154-pound aliquot of the above was charged to the kettle, Figure 1, heated with DoIvtherm a t 260’ F. circulating in the jacket. After about 40 minutes, distillation started. and lvhen the pot temperature reached 215’ F., the steam sparger was turned on and another 95-pound aliquot of the mixture was added over a 60-minute period holding the temperature at 21 5 ’to 21 8 ’F. After 3 hours, the distillate contained less than 1% oils. Steam stripping was continued for another 3 hours to remove volatile oils. The batch was drawn from the kettle. There was 101.5 pounds which contained 77% solids and 19.47, free resin acids on a solid basis. Three batches made by the above procedure were combined in the 100-gallon mixing tank (above), heated to 200” F., and the solids content adjusted to 75% by adding water. 11. Paste Size from Commercially Cleaned Pine Oleoresin. In the conventional process for producing commercial gum rosin and turpentine, pine oleoresin is diluted with about part of turpentine, filtered, and washed with water containing a little oxalic acid. In this experiment, 438 pounds of commercially cleaned pine oleoresin containing 65% rosin with a resin acid content of 87%, 34.2% turpentine, and 1.8Yo water was placed in the neutralization tank and a solution of 24.1 pounds of sodium hydroxide dissolved in 47.5 pounds of water was added. The batch was agitated until uniform composition was obtained. The resultant composition is tabulated in Table I. A 150-pound aliquot of this mixture was charged to the
kettle, Figure 1. heated with Dowtherm a t 250' F. After 20 minutes, the pot temperature had reached 216' F. Steam sparging was started and 50 pounds more of the mixture was added over a period of 80 minutes holding the temperature a t 218-219" F. Most of the turpentine had distilled after an additional 30 minutes of heating. After being stripped for 3 hours, the batch, 152 pounds, was discharged which contained 77y0solids and 22.270 free resin acids o n a solid basis. Three batches were combined and adjusted to 75% solids as described above. I n a series of three batches with a stripping temperature of 215' F., the average solids content was 76.1% while in another series of four batches with a slightly higher temperature, 218' F., the average solids was 797,. 111. Paste Size from Commercially Cleaned Pine Oleoresin. The size preparation in I1 was repeated using a second lot of commercially washed pine oleoresin to test the uniformity in processing and the final product. IV. Fortified Paste Size from Pine Oleoresin. One hundred and twenty-six pounds of commercially cleaned pine gum (65'% rosin, 347, turpentine) was placed in the kettle, Figure 1. .4solution of 3.28 pounds of maleic anhydride and 1.12 pounds of acetone was added and agitated. This was discharged from the kettle and a 110-pound aliquot of the mixture was returned for processing. A solution of 8.13 pounds of sodium hydroxide (0.203 moles) in 24 pounds of water was added during agitation. The composition of the batch a t this point is given in Tablc. I. T h e charge was heated with Dowtherm, at 260' F., in the kettle jacket. After 1 hour, the steam was turned on and the turpentine distilled. This required about 3 hours. The batch was stripped as above. After stripping, tests indicated that the charge contained 67.7% solids. The kettle was heated to distill 12.25 pounds of water. Sinety-eight pounds of paste resulted which contained 76.870 solids and 21.0% free resin acids on a solids basis. V. Dry Neutral Size. Paper size, 500 grams, I1 above, containing 7570 solids and 83 grams resin acid (0.275 moles), 1 6 . 6 7 ~ ,was charged to a ball mill, Figure 2. loaded with 31/2 pounds. 5/8 inch bearing grade steel balls and 7 black iron rods-four. 1 X 2 inch; two, 1 X 3 inch; one, l'/Z X 2 inch. To this \vas added 11.0 grams of sodium hydroxide, 0.27.5 moles) in 22 grams of water. The mill was rotated and heated in a n oil bath maintained a t 260" F. A small stream of carbon dixoide (cylinder) flowed through the mill to remove the water as i t vaporized. After about 3 hours, the water appeared to be removed. The temperature of the bath was raised to 300' F. for about an hour. No ivater distilled at this temperature. Toward the end. movement of the metal rods and balls had stopped because of packing of the dry size. These were broken loose by tapping the side of the mill. T h e oil bath was re-
Figure 1 . Thirty-gallon, nickel-clad kettle used to produce paste sizes Three-bladed propeller agitator, 10 inches in diameter, is driven by a four-speed motor ta provide variable speed agitation. liquid Dowtherm i s circulated in the jacket for heating. Feed inlet, product outlet, vapor outlet to condenser, thermowell, and steam sparger are shown
11
-f
/
E
T
,
n
w I!
.
-
... ......,. ...... ... . ......... .~ _._ ..._ .._ _
Figure 2. Ball mill, 8% inches diameter by 6 inches wide, used to produce dry sizes Table 1.
Composition of Neutralized Pine Oleoresins Used for Making Size
Size
Sodium Resinate,
A70.
%
I I1 IV
28.00
38.25 36.59*
Resin h'eutrals, Acids, 70 7c5
8.24 12.85 11.32
JVonacidic resinous material. modi5ed rosin. a
5.16 6.5 5.86
Turjentine,
Water,
%
70
46.6 29.4
25.38
12.0 13.0 20.85
Sodium salts of resin acids and maleic
Rotary joints are provided for gas inlet and outlet to condenser and water trap. Periodic movement of the plunger keeps the outlet from stopping up with the powdered size
moved and the batch was allowed to cool and grind. Six to 8 hours was required for the whole process. The product was a dry almost colorless, grayish powder with zero acid number containing 4 . 2 7 , water. VI. Dry Acid Size. Paper size I1 above, 500 grams, was dried as above except the oil bath was heated to 300' F. without addition of sodium hydroxide. VOL.
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57
Discussion
Processing. I n 1958, Lawrence and Loeblich (5) described the effect on the r,esin acid composition of resins which were prepared from partially and completely neutralized pine oleoresin. These authors did not describe a process for handling partially neutralized pine oleoresin in order to obtain size compositions in which 60 to 90% of the resin acids had been
Table II. Fotosize Test-TAPPI
Ink Penetration Time" Ink Penetration, Secondsb A. Fortified Paste Sizes Commercial Size A, 70YGSolids 46 Commercial Size B, 70YGSolids 45 Commercial Size C, 70% Solids 39 Commercial Size D, 70% Solids 47 Fortified Size I V 47
B. Unfortified Paste Sizes Pine Gum Size, I Pine Gum Size, I1 Pine Gum Size, I11 Fortified Size, I V
21 29 26 40
C. Dry Size Neutralized Dry Size, V 64 Dry Acid Size, VI 65 Commercial fortified paste Size A above 71 a Fotosize test using standard T a p p i ink p l u s 5% lactic acid. Groups A , B , and C were separate beater runs. Consequently, numerical values i n a group should not be comjared with values outside that group.
Table 111. Estimated Costs for Acid Sizes from Pine Oleoresin, 75% Neutralized, 70% Solids Total Cost w i t h Credit f o r Amount f o r Turpentine, 1000-Lb. Material Size cost, $ 8
CONVENTIONAL SIZE Pine oleoresin (gum) 2.19 bbl. 33.00 per 0.25 per Turpentine credit 27.2 gal. Net cost for gum Sodium hydroxide 57.6 lb. 0 . 0 5 per Processing charge 2 . I 9 bbl. 4.00 per Cost for 1000-lb. size Cost per pound Value of rosin in 2.19 bbl. gum 1 1 . 2 5 per Cost for 1000 lb. size from this rosinb Cost per pound
bbLa gaLa lb. bbl.
77.11 0.077 cwt.=
FORTIFIED SIZE Pine oleoresin (gum) 2.09 bbl. 33.00 per bbLa Turpentine 25.98 gal. 0.25 per gal.a Net cost for gum Maleic anhydride 25.41 lb. 0.24 per lb. Sodium hydroxide 70,52 lb. 0 . 0 5 per lb. Processing charge 2.09 bbl. 4.00 per bbl. Cost per 1000-lb. size Cost per pound Value of rosin in 11.25 per cwt.a 2.09 bbl. gum Cost for 1000 lb. size from this rosinb Cost per pound a Costs August-September 1961. Materials cost only. shipping and size processing charges are not included.
58
72.27 6.80 65.47 2.88 8.76
75.35 78.25 0.078 68.97 6.50 62.47 6.10 3.52 8.36 80.45 0.08
neutralized with a 70 to 75% solids content, a composition similar to that of commercial paste sizes. I n the development of the processes described herein. conditions for distillation were critical. If the batch was overcharged, foaming was excessive. For example, 254 pounds of a n aliquot of neutralized oleoresin like that used in I1 was charged to the kettle. When most of the turpentine had distilled, the rate of distillation had to be drastically reduced to prevent foaming. However, when 44 pounds of the still residue was drawn off, foaming could not be induced by full steam and rapid agitation. This condition was also caused by the addition of too much water. 4 paste from which most of the turpentine was removed and containing 3670 water foamed excessively. When the water content was reduced to 28%, foaming was slight. When the composition contained 23.6%, water foaming could not be induced by any meansvigorous agitation and/or steam sparging. Sizes were prepared with varying degrees of free resin acid content by adjusting the sodium hydroxide used for neutralization. T h e extent of resin acid neutralization ranged from 62 to 90%. A rather long stripping operation was employed to remove as many of the volatiles as possible. By use of -4STM tests ( I ) , the volatile oils were lower than found in gum rosin. Sizing Efficiencies. T h e sizes have been evaluated for sizing efficiencies. In the size tests, lY0 of each size on solids basis and 11/2yoof alum were added to 0.88 brightness pine kraft pulp and the p H adjusted to 4.5. Handsheets, 2.5 grams, were prepared and examined for sizing effect. T h e results are tabulated in Table 11. Part A is a comparison of the fortified size IV with four commercial fortified sizes. Part B is a comparison of a composite of three batches prepared in accordance with I? three batches prepared in accordance with 11: and one batch prepared in accordance with 111. T h e dry sizes used in Part Cwere made in accordance with V and VI. Emulsification properties of the sizes were normal and well within the limits of commercial acceptability. Foaming tests indicate that the sizes were conducive to foam formation on a paper machine. However, the tendency to foam was no greater than that of a conventional. unfortified gum rosin size. T h e results of the sizing tests indicate that the paper sizes prepared from pine oleoresin are effective and compare favorably with commercial materials under the conditions of the tests. A number of industrial concerns, size manufacturers, and paper mills have examined these sizes. T h e results were far from being consistent. Additional study \vi11 be required to prepare materials which will compete in all respects with commercial sizes. Cost Considerations. T h e direct preparation of size from oleoresin should cost less than the current process since the need for handling rosin as such is obviated. Such a size should be cheaper than a conventional gum rosin size. T h e estimated costs for the preparation of size directly from pine oleoresin are tabulated in Table I11 with credit for turpentine at $0.25 per gallon, In the gum naval stores industry, farmers deliver gum to the processor who in turn pays a net, cash price for the oleoresin. T h e processor in figuring this price allows approximately $4.00 per barrel, 435 pounds for plant, processing, and handling charges, which includes operating expenses
71.91 81.53 0,081 T h e rosin
I & E C P R O D U C T RESEARCH A N D D E V E L O P M E N T
Table IV. Current Selling Price, in Cents, for Paper Sizes 10.5 to 11.5 Conventional 70% paste, per pound 15 to 16 Conventional dry size, per pound 13 to 14 Fortified 70% paste, per pound 18 to 20 Fortified dry size, per pound
such as labor, amortization, taxes. and insurance. A charge of $33.00 net per barrel was used as the cost for the oleoresin and $4.00 as a processing charge in the calculations. However, in converting oleoresin to size, processing costs are higher than for preparation of rosin and turpentine because of the additional steam required for the stripping operation and for hold up time in the equipment. If $5.00 per barrel was allowed for processing, the cost of the paste sizes would increase approximately $0.002 per pound. This processing charge is well within the limits obtained from a n engineering study made by another group ( 4 ) . Sizes of these types can be prepared for about $0.08 per pound. Dry sizes can be made or approximately $0.115 per pound. These prices are to be compared with the present selling prices for sizes shown in Table IV. The economic advantages of the process are shown in comparison of the values of the size, the value of the rosin in the size if sold for cash, and value of the size if this rosin were converted to size. For conventional size these values per 1000 pounds are $77.1 1, $75.35, and $78.25, respectively. These same values for fortified size are $80.45, 971.91, and $81.53. The pine gum processors and probably the farmers as well. if this process were used, could net more if the pine oleoresin were converted to paper size rather than gum rosin. Also, savings are evident over the present practice of isolating rosin and con-
verting it to size and amount, to the expense involved in shipping and handling the rosin and size manufacturing. Acknowledgment
T h e authors wish to express their appreciation to A. G. Dreis, formerly with A. G. Dreis and Associates, Chicago, Ill., present address Newport Industries, Division of Heyden Newport Chemical Corp., Pensacola, Fla., for sizing efficiency tests reported and for his encouragement and advice. Literature Cited (1) Am. SOC.Testing Materials, Philadelphia, Pa., “Volatile Oils in Rosin,” D 889-58, Part 8, p. 932, 1958. (2) Baird, P. K., Curran, C. E., T a p p i 23, 5 (1940). ( 3 ) Bump, A. H. (to Monsanto Chemical Co.), U. S. Patent 2,383,933 (Sept. 4, 1945); Wilson, W. S.,Bump, A. H. (to Monsanto Chemical Co.), U. S. Patent 2,628,918 (Feb. 17, 1953); Hastings, R., Dreschel, E. K., Strazdins, E. S. (to .\merican Cyanamid Co.), U. S. Patents 2,771,464 (Nov. 20, 1956) and 2,791,578 (May 7, 1957). (4) Decossas, K. M., Southern Utilization Research and Development Division, New Orleans, La., unpublished results, 1960. (5) Loeblich, V. M., Lawrence, R. V., TND. ENG. CHEM.50, 619 (1958) ; and (to U. S. Government) U. S.Patent 2,846,430 Aug. 5, 1958. RECEIVED for review August 28 1961 ACCEPTEDJanuary 2, 1962
SUBMERGED CITRIC ACID FERMENTATION
OF SUGAR BEET MOLASSES Efect of Ferrocyanide Control D, S
.
C LA R K
,
Division of Applied Biology, National Research Council, Ottawa 2, Canada
The stability of the submerged citric acid fermentation of ferrocyanide-treated beet molasses by Aspergillus niger was improved by precise control of the ferrocyanide treatment. In the improved procedure, the concentration of ferrocyanide in mash after the initial ferrocyanide treatment was accurately adjusted to levels required for optimum acid production. Adjustment was essential since unavoidable variations in ferrocyanide content of mash after treatment were sufficiently large to produce a marked effect on duplication of yield. With adjustment made either before inoculation or during the first stage of fermentation, high yields (above 7570 conversion in 140 hours) were obtained consistently in fermentations carried out in 2.5-liter glass tower fermentors. has been ustd in many citric acid fermentation processes to make crude molasses substrates suitable for fermentation. Its effect has generally been attributed to the precipitation of harmful trace metals ( 3 ) ,but a few studies (7) have indicated that the chemical has a desirable toxic action on the mold itself. Although the amount of ferrocyanide to be added initially to each molasses has been determined by trial and error using mold growth and acid production as criteria, no effort appears to have been made to determine the optimum range of ferrocyanide concentration in the substrate during the different stages of fermentation or to develop methods of controlling the concentration. A study has been niade, therefore, of the optimum ferrocyanide requirement for fermentation of beet molasses by Aspergillus nzger and of the factors that affect fer. rocyanide concentration during substrate preparation. OTASSIUM FERROCYASIDE
Experimental The fermentation procedures, equipment, and methods of analysis used have been described previously ( 7 , 70, 77). Briefly, “standard” pellet-type inoculum ( 7 7) was prepared by adding 106 spores of A . nzger NRC A-1-233 to 1500 ml. of molasses substrate (mash) in 6-liter flasks and incubating the suspensions at 29’ C. for 18 to 24 hours on a rotary shaker. Fermentations were carried out a t 31’ C. in a 2.5-inchdiameter borosilicate glass tower fermentor using 2.5 liters of mash inoculated with 5 X l o 5 pellets. The mash was sparged with air for the first 24 hours of fermentation (growth stage) and with oxygen for the remaining time (acid-producing stage) using a gas flow rate of 700 cc. per minute in all tests. The tests were done in duplicate. Citric acid was determined colorimetrically as anhydrous citric acid by the method of Marier and Boulet ( 5 ) . The sugar content of mash was deVOL. l
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