US1785030A - Manufacture of nitrocellulose - Google Patents

Description

Patented Dec. 16, p i r i umrse sures PATENT DFFICE ARTHUR I-IOUGH, or sumiv'rrr, JOHN ROY nurronn, or ra'rnnson, nn WILLIAM CLELLAND LEONHARD, or PASSAIC, new JERSEY meanness or NITRooELLULosn No brewin Application filed. August 31, 1926. Serial Ne. 132,906.

()ur invention relates to improvements in mum solubility in the selected solvent is nitrated products and also involves the mode required. V i of preparation of a relatively cheap, exceed a This nitration is preferably efiected by ingly stable nitrated product, Very soluble in treating this parchment in a mixture of 5 those solvents commercially employed in the H 50 plus HNO plus H O; the ratio of 5 manufacture of celluloid, lacquers, and klnone acid to the other and to the water condred products. It may also be used in the tent depending upon the degree of nitration preparation of smokeless powders or prodesired as also the degree of solubility looked pellants in the explosive industry wherein for in the selected solvents. For example 3 such nitrated material can be advantageous- 1t nltrated parchment of about 11% Intro (55' 1 em loy d, gen contentis required, with an extremely To carry out the invention, vegetable high solubility of the product in camphorparchment is first made by any of the wellalcohol mixture, then the acid mixture may known methods, such as treatment of cellube close to 6O%VH SO 21% or 22% I-INO lose as such or themore impure type known. and 18% or 19% E 0. The temperature of as wood pulp or preferably alpha fibre pulp the acids during nitration may be about by sulphuric acid'of the desired strength, or 4051 Under these conditions no dextriiiiany suitable parchmentizing reagent. zation can occur. 1 k y The preferred mode of parchmentizing the At a lower temperature, the 'timeof nitrasheets (commonly called waterleaf, which tron is longer, and the solubility of the a is an unsized paper, of any desired thickproduct isso'mewhat less. We do not, howness) is the usual and customary method eveficdnfirie ourselves to this acid mixture which comprises immersing the paper, for o'rtemperature and we may vary them somea short time (a few seconds up to a minute what depending upon the properties desired,

2:: or two) in sulphuric acid of between 5i 1n the finlshed'product. v r

B. and 565 B. (68.6% to 72.4%) and The nitration'having been completed, the preferably between 55 Be. and 555 Be. spent acid,so called, isnow removed and the. (7 0% and 7 0.85%) ,the acid being cold, say product washed with ordinary water till the at below 60 F., and preferably at not above degree of acidity has been reduced to ap- 50" F. The paper is then removed from the proximately .1%. On account of the free 3 acid bath and washed with water, while he dom from loose fibers and dust, the waste niing kept cold. Under these conditions, trating acid which drains off from the niwhich are those always used in commercial trate'd parchment does not carry small bits parclimentizing, no dextrinization of the ofcellulos'ic mater al, hence the usual'd'ifficellulose occurs. cultles attending the regenerating of the nigi The sheets, which are usually of about 23 trating acids from gun cotton and from to 25 lbs, thickness, are sufliciently porous nltrated wood pulp, are avoided. The niso that the parchmentizing acid and the trated parchment is now boiled in excess of nitrating acid readily penetrate the sheets, water for aboutth'ree hours,when the water 4.0 and both the parchmentizing and the mtrat- 1s removed, the product washed free from ing steps are substantially complete. The acid and fresh water added, to wh ch is added parchmentized material is then comminuted sufficlent ammonium hydroxide, or its equivinto pieces of the desired size, and on 210- alent, to render the water ust alkaline count of the fact that the paper is parch- (sllghtly alkaline) to litmus. Heating mentized, there is no loose fibers or dust on should contlnue'for abio'uttwo; or three hours the pieces of parchmentized paper. The or longer.' At thls point 111- Will be seen that co-mminuted parchmentized paper. is then the water 1s colored stronglyyellow, due to soaked in the nitrating acids for sufficient the decompositlon of the nltrated iinpurities time to insure complete nitration and at a 1n the parchment that must be removed to 59 temperature approximating 40 C. if maxlrender the product stable, sln'ce retentlonin the product would make the same unstable. In these subsequent treatments with ammonia, the ammonia must be added cautiously, preferably only enough ammonia to make the water alkaline to phenolphthalein. Any larger excess of ammonia would injure the product. Repeated renewal of water and very slight additions of ammonia hydroxide, or its equivalent, must be made till no more yellow color, or very little develops on heating and the check samples taken from the heater show the required stability test with potassium iodide starch paper, the stability test at 135 C., and the flash point between 170 C., and 180 C.

When this point has been reached, the product may be bleached if desired. In order to preserve the original stability an alkaline bleach must be employed, an acid bleach would impair the stability of the product. A suitable bleaching agent is an alkaline so dium hypochlorite liquor, the quantity of such bleach to be used will depend upon the speed desired in bleaching, and this matter must be left to the discretion or" the operator.

Having described the invention, we claim:

1. A nitrated product prepared from parchmentized paper stabilized by treatment with hot dilute ammonium hydroxide and bleached with an alkaline bleach, substantially as described.

2. A nitrated product prepared from material consisting essentially of vegetable parchment having as the basic substance nitrated parchmentized sheeted wood pulp, substantially free from matter which would dissolve in very dilute boiling ammonia water and which matter when so dissolving in dilute ammonia would produce a strong yellow color, such nitrated parchment also having excellent stability as shown by the usual nitrocellulose tests.

3. The process of making a nitrated prod uct by parchmentizing sheeted wood pulp with sulphuric acid, washing the parchment substantially free from acid, then drying same and nitrating the dry pulp in the form of comminuted parchmentized paper in a nitration mixture, and dissolving out nitrated impurities, substantially as described.

4. The process of making a nitrated prod uct by subjecting sheeted alpha fibre pulp to parchmentizing in sulphuric acid, under parchmentizing but not dextrinizing conditions, washing the parchmentized product substantially free from acid, then drying same and nitrating the parchmentized product in the form of waterleaf in a nitrating acid mixture containing E 80 and HNO washing acid-free, and dissolving out nitration products soluble in very dilute ammonia water, substantially as described.

5. A process of treating wood pulp which comprises treating said pulp in the form of waterleaf with sulphuric acid to parchmentize the pulp, washing the pulp to a substantially acid-free condition, nit-rating the parchmentized water-leaf with a mixture of sulfuric and nitric acids, washing the pulp with water to remove the free acid, and heating the nitrated product with water containing a small percentage only of ammonia so as to remove nitrated products of impurities without altering the pure nitrated waterleaf, and continuing such treatment until the ammoniated wash water remains nearly clear.

6. A process which comprises parchmentizing paper, and thereafter nitrating the parchmentized paper, by treatment with mixed nitric and sulphuric acids.

7. process which comprises parchmentizing paper, thereafter nitrating the parchmentized paper, thereafter washing well with water to remove all free acid, and thereafter boiling the product with water containing a small amount of ammonia.

8. Nitrated paper parchment, in a substantially stable condition.

ARTHUR HOUGII. JOHN ROY DUFFORD. WILLIAM CLELLAND LEONHAR-D.