US1552806A - Cellulose-ether composition - Google Patents

Description

Patented Se t. 8, 1925. I

UNITED STATES" 1.5 2.806 PATENT oFmcE'.

30ml I. DONOE'UE, Olff ROCHESTER, NEW YORK, ASSIGIIOB TO EASTMAN KODAK COIYANY, OI ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

ceLLuLosa-E'rnm comosruou.

Io Drawing.

- To all whom it may concern:

Be it known that I, JOHN M. DONOHUE, a

' citizen of the United-States of America, re-

siding at Rochester, in the county of Monroe 6 and State of New York, have invented certain new and useful Improvements in Cellulose-Ether Compositions, of which the following is a full, clear, andexactspecification.

This invention relates to solvents for making strong solutions of cellulose 'ether and also relates to the cellulose ether compositions roduced' by the aid of such solvents. One 0 ject of my invention is to provide a solvent'which Wlll dissolve such large proportions of cellulose ethers that thick or viscous fiowable solutions may be obtained for use in plastic and film making arts.

Another object of my invention is to provide i a cellulose ether solution which may be manufactured into strong, flexible, transpari cut films on the machines and by the methods now in use. Other objects will hereinafter appear. I

In U. S. Patent No. 1,188,376, Lilienfeld, June 20, 1916, there are disclosed a series of alkyl ethers of cellulose. Certain of these are practically insoluble in water, and my invention relates, but is not limited, to the ethers having that property. While cellulose ethers form thin solutions in the formic acid esters of the lower monohydroxy aliphatic alcohols, it has been found that such single solvents by' themselves are inadequate to produce the thick flowable compositions or dopes adapted for use in the manufacture of photographic film base by the customary methods or adapted to the other plastic arts.

I have discovered, however, that the for- 40 mates of the lower monohydroxy aliphatic alcohols have strong latent solventpowers,

these powers being brought out bysuitable common solvents. By lower monohydroxy aliphatic alcohols I include those having less than 6 carbon atoms. Among the common solvents that may be used are benzol, acetone and the lower monohydroxy aliphatic alcohols. In the formation of film methyl alcohol is referred.

While the ingredients may be mixed in widely varying proportions, it is noted, by

. way of example, that a particularly useful composition can be prepared by mixin equal parts by weight of the formate an the common solvent. In the preferred form able do Application filed February 24, 1923. Serial llo. 621,087.

of my invention, I dissolve 1 part by wei ht:

hol. The ingredients by themselves are not sufficiently powerful to make properly flowpes of this strength. Of course, the proportion of mixed solvent or the proportion of theovolatile ingredients may be increased to adapt the composition to the lacquering art, as will be understood by persons'skilled therein.

Other substances which impart additional suppleness, or incombustibility, or other qualitles to the film may also be added to the dope, such, for instance, as triphenyl or tricresyl phosphate, monochlornaphthalene, I

camphor, etc. The ingredients are of the ordinary commercial type and sufficiently purified for the process of film manufacture, so as to give a dope yielding films having the proper relative freedom from color. The

viscous-flowable dope above described can be used in connection with the usual film-form- 111g apparatus without the necessity of expensive alterations in the latter.

In the formation of a film by spreading and drying the hereinabove described composition a considerable amount of the formic acid ester remains behind, because of its relativelylow volatility, the volatility being less in the esters which have the greater number of carbon atoms in the alkyl radical. The esters impart useful plastifying and other properties to. the film, which is normally flexible and transparent. Since the ratio of the weight of alkyl formate to the weight of the cellulose other can be made much greater by the use of my mixed solvent instead of using the formic acid ester alone as a solvent, it follows that 9. correspondingly greater proportion of the formate will be present in the finished film than when the cellulose ethers' are dissolved in the formic acid esters alone.

Having .thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A composition of matter comprising cellulose ether and a formic acid ester of a lower monohydroxy ali hatic alcohol and a common solvent which rings out the latent solvent power of the ester.

2;, composition of matter comprising cellulose ether and methyl foi'mate homogeneously mixed together in unprecipitated '4. A composition of matter comprising cellulose ether dissolved in a mixture of substantially equal parts by weight of a lower monohydroxy aliphatic alcohol and a formic acid ester of a lower monohydroxy aliphatic alcohol.

5. A composition of matter comprising 2 parts by weight of water-insoluble ethyl cellulose, 7 parts of methyl formate and 7 I parts of methyl alcohol.

'6. As an article of manufacture, a film comprising cellulose other and methyl formate.

7. As an article of manufacture, a deosited, transparent, flowable film comprislng cellulose ether and a formic acid ester of a lower monohydroxy aliphatic alcohol,

the proportion of said ester in said film being greater than .the maximum proportion deposit-able in a transparent film from a solution of said cellulose ether in said ester alone. Signed at Rochester,

day of February, 1923.

JOHN M. DONOHUE.

New York, this 16