US1357876A - Nitrocellulose composition - Google Patents

Description

v "UNITED STATES PATENT OFFICE.

JOHANNES M. KESSLER, OF WEST ORANGE, NEW JERSEY, ASSIGNOIR TO I. Di: PON'I m: NEMOURS & COMPANY, OF WILMINGTON, DELAWARE, A CORPORATION OF DELA.

Patented Nov. 2, 1920:

WARE. NITROGELLULOSE COMPOSITION.

1,357,876. ,Specification of Letters Patent, No Drawing. Application filed December 6, 1919. Serial No. 348,047.

To all whom it may concern:

Be it known'that I, JOHANNES M. Knssnnn,

. a citizen of the United States, and a resident of West Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Nitrocellulose Compositions,

of'which the following is a specification.

This invention relates to nitrocellulose compositions containing as a softening facture of pyroxylin plastics is the substance used as the softening or conditioning agent for the cellulose ester. Although the patent literature discloses a very large number of substances as substitutes for camphor, only a small number have found practical .application. Only a few of these substances show any superiority over c'amphor, and in these cases the difference is usually insufficient to make up for their much higher cost. About the only one at present avail-' able in this country is triphenylphosphate which is employed to a limited extent in the nitrocellulose plastic industry, and then only in connection with camphor.

The scarcity and high cost of camphor has led me to investigate the suitability of various substances as camphor substitutes which have not heretofore been suggested for this purpose; as a result of this investigation I have discovered that cellulose ester sheets and films having excellent physical and chemical properties from the standpoint of their use in the arts may be obtained by using as a softener any one of several classes of substances which may be produced from available raw materials at a reasonably low cost. I

One of these classes of substances which I have found to be suitable as camphor substitutes, and to which in combination with nitrocellulose, the present application is directed, comprises the esters of acyloxy dealkyl or aryl esters.

rivatives of aliphatic acids, and especially of monobasic aliphatic acids containing more than three carbon atoms. The acyl group is preferably either an aliphatic group with a small number of carbon atoms such as formyl, acetyl, and propionyl, or a carbocyclic acyl such as benzoyl. As esters there may be used the glycerid of the acyloxy fatty acids or the corresponding prefer those which are readily obtainable such as methyl, ethyl, butyl, etc.; and for aryl radicals; phenyl and alphaor betanap hthyl.

he acyloxy derivatives of the lower aliphatic acid esters are not suitable as camphor substitutes or softeners on account of their relative low boiling point, which in the case of eth .l acetylglycollate (3H CO.OCH CO.OC is 179 (1., and in the case of ethyl acetyllactate (GH CO.OCH (CH ).C();()C H is 177 C. at 733 millimeters of mercury pressure.

The esters which I have found to be particularly suitable as softeners'are the esters of acyloxy derivatives of the higher fatty acids. Examples of such substances are the alkyl esters of mono-, di-, or triacetyloxystearic acid, and thealkyl esters of acetyloxy-oleic acid (that is alkyl acetylric'inoleates). The methyl and ethyl esters are preferred, although the glyceryl esters have the advantage that they can be obtained di- For alkyl radicals l rectly from the corresponding glycerids xyste'arin, ricinolein. etc.) by acetylation of these oils with acetic anhy rid.

The properties which the new softeners impart to pyroxylin are very remarkable.

\Vithout the use of any camphor the methyl and ethyl acetylricinoleates form with nitrocellulose a pyroxylin plastic having an exceedingly great flexibility and pliability. v

For example I have found that this plastic material has a Schopper number (resistance to cracking on repeated folding) of 170 as compared with 20 for regular transparent pyralin or celluloid. I My invention may be illustrated by the following example: parts (by weight) of dry nitrocellulose are kneaded with 32 f parts of methyl acetylridinoleate and from 60 to 70 parts of denatured alcohol at a temperature preferably between 40 and 55 C. until the nitrocellulose is properly c01- loided, after which it is put on rolls and through the different operations such as rolling, cake pressing, sheeting. and seasoning which are well known in the manufacture of pyroxylin plastics such as pyralin, cellu loid, etc. Suitable amounts of stabilizer, for example urea, and of pigments and colors may be mcorporated either during the mix- 7 I ing or the rolling operation.

he proportions of the ingredients may be varied considerably Without departing from my invention;v thus, from 28 to 35 parts of the alkyl acetylricinoleate may be combined with 100 parts of the cellulose ester with good results, although I prefer to have the ratio of nitrocellulose to softener equal about 3 to 1. A part of the alkylacyloxy aliphatic acid ester may be replaced by camphor or other camphor substitute such as triphenyl' phosphate;

For producing very flexible films such as are required in the artificial leather industry, a nitrocellulose solution may be prepared in accordance with my invention having the following composition:

' Nitro'cellulose (preferably dry) l0 parts Ethyl acetylricinoleate- 10 to 15 parts Ethyl acetate "10 parts Benzene- 60 parts The proportions of the volatile solvents in the above formula may be made greater or less depending upon the viscosity desired,

I and part of the ethyl acetate may with ad- Vantage be replaced by a higher alkyl acenitrocellulose and a softener comprising an ester of an acyloxy derivative of a monobasic aliphatic acid having more than three carbonatoms'. J

.2. A composition consisting essentially of nitrocellulose and an alkyl ester of an A composition consisting essentially of acyloxy derivative of a monobasic aliphatic acid havingmore than three carbon atoms.

naensrc nitrocellulose and a softener comprising an ester of an acetyloxy derivative of a mono basic aliphatic acid having more than three carbon atoms.

,4. A composition comprising a cellulose ester and an alkyl esterof an acyloxy derivative of a higher fatty acid.

5. A composition comprising nitrocellulose and an alkyl ester of an acyloXy derivative of a higher fatty acid. I

6. A composition comprising nitrocellulose and a methyl ester of an acyloXy derivative of a higher fatty acid.

7. A composition comprising nitrocellulose, an ester of an acyloxy derivative of a higher fatty acid, and a solvent therefor.

8 A composition comprising nitrocellulose, an ester of an acyloxy derivative of a higher fatty acid, and a solvent therefor comprising an alkyl acetate and benzene.

9. A composition comprising nitrocellulose, an alkyl acetylricinoleate, and a solvent for said substances comprising an alkyl acetate and benzene.

10. A compositioncomprising 3 parts of nitrocellulose and at least about 1 part of.

a softener comprising an alkyl ester of an acetyloxy derivative of a higher fatty acid.

11. A composition comprising-3 parts of nitrocellulose and at least about'l part of ethyl acetylricinoleate. I

12. composition comprising nitrocelluloseand an alkyl ester, of an acyloxy derivative of a fatty. acid having 18 carbon atoms.

13. A composition comprising nitrocellulose and an acid.

lose and ethyl acetylricinoleate.

15. A composition consisting essentially of nitrocellulose and a softener comprising camphor and an alkyl ester of an acyloxy derivative of a higher fatty acid.

16. A flexible sheet of material comprising nitrocellulose and an alkyl ester ofan acetyloxy derivative of a higher fatty'acid.

117. A flexible sheet of material comprising nitrocellulose and an alkyl ester of acetylricinoleic acid.

alkyl ester of an acyloxyoleic I i 14:. A composition comprising nitrocellu- 18. A flexible material comprisingnitrocellulose and a softener therefor comprising an alkyl acylricinoleate. I I

lln testimony whereof I affix my signature.

QJOHANNES M. nnssrnn.