US1236579A - Acetyl-cellulose process and product. - Google Patents

Description

l @TATE% PATENT @FFIfiE.

WILLIAM G. LINDSAY, OF NEWARK, NEW JERSEY. ASSIGNOR TO THE CELLULOID COMPANY, A CORPORATION OF NEW JERSEY,

ACETYL-CELLULOSE PROCESS AND PRODUCT.

No Drawing.

To all whom it may concern.

Be it known that-I, WILLIAM G. LINDSAY, a citizen of the United States, residing at Newark, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Acetyl-Cellulose Pr'ocesses and Products, of which the following is a full, clear, and exact specification.

This invention relates to acetyl-cellulose and a process of making the'same. Its objectis to accomplish acetylation of the cellulose in fibrous form, without solution of the cellulose, and withoutzthe use of sulfuric acid, sulfo-acids, or other constituents tending to induce decomposition.

' In practice I proceed as follows:

Cellulose, preferably high grade bleached cotton rovings, is given 'a preliminary treatment with acetic acid and zinc chlorid. For best results the cellulose should contain a normal amount of moisture, generally from 2% to 4%. I prefer about 3:}%. The

acetic acid should be about 90% strength,

and the zinc chlorid should be pure, free from iron and substantially anhydrous. A good example of proportions is cellulose 100 parts, acetic acid 200 parts and zinc chlorid parts. The zinc chlorid is dissolved in the acetic acid at ordinary room temperature byagitation and the solution thus produced is poured on to the cellulose contained in a suitable stoneware receptacle and allowed to penetrate. The position of the cellulose is changed from time to time and the reaction is allowed to proceed for forty-eight hours at a room temperature of from 60 to 70 F.

After the foregoing preliminary treatment, the impregnated cellulose is subjected to the acetylating bath, which -consists of acetic anhydrid and benzene. For best results the acetic 'anhydrid should be of the highest commercial purity obtainableabout 925%. The benzene is of the so-called commercial chemically pure variety. A good example of proportions, consistent with the forgoing proportions for preliminary treatment, is acetic anhydrid 4.50 parts, benzene 1650 parts. The acetic anhydrid and benzene are mixed and the mixture warmedin a suitable vessel, such as an enameled steel kettle, to a temperature of about 150 F. The preliminarily treated Specification of Letters Patent.

Patented Aug. 141., 1917.

Application fi1ed July 11, 1914. Serial No. 850,432.

an hour, and then slowly and gradually drops until the temperature of the water bath (150 F.) is reached. This ordinarily takes place in about twelve hours. lVhen this temperature has been reached the productmay be removed from the bath, or the reaction may be continued, depending upon the nature of the product desired. In many cases the product resulting from the reaction of twenty-four hours is desirable.

In the preliminary treatment, the bath of acetic acid, water and zinc chlorid may be composed of any suitable equivalents for its ingredients, for example the water may be substituted by any other suitable hydroxyl containing substance which, like water, is neutral with respect to the cellulose and miscible with the acetylizing bath but will act to induce acetylization; in place ofacetic acid other suitable diluent may be employed, and in place of zinc chlorid as a condensing agent other suitable inorganic salts may be employed.

At the end of the reaction period the product is freed from the spent acetylating liquor by any suitable means; for example, by whizzing or by pressing. After the bulk of the spent acetylating liquor has been separated from the acetyl-cellulose, the balance is then removed by washing the acetyl-cellulose in hot water, or, if preferred, by means of'a suitable vacuum machine.

The product thus obtained exhibits a physical form identical with the raw cotton, and is soluble in acetylene tetrachlorid, and with difliculty in chloroform.

Having thus described my invention, I

declare that what I claim as new and desire to secure by Letters Patent 1s I 1. The process of acetyliznigcellulose which consists in treating cellulose with a agent, acetic acid and water,

acid condensing agent and is miscible with the acetylizing bath and which does not alter the cellulose as such and acts to induce later acetylization, and then subjecting the.

treated cellulose to theaction of a non-solvent acetylating bath containing no additional condensing agent. 5. The process of acetylizing cellulose which consists in preliminary bath containin jzinc chlorid and an agent which acts to Induce acetylation without altering the cellulose as such and is miscible with the acetylizing bath, and then subjecting the impregnated cellulose to the action of a non-solvent acetylating bath. i

6. The process of acetylizing cellulose which consists in treating approximately '100 parts of cellulose with 200 parts of 90% acetic acid and 50 parts'of zinc chlorid, and

subjecting the impregnated cellulose to the action of anon-solvent acetylizing bath.

' 7. The process of acetylizing cellulose which consists in treating approximately 100 parts of cellulose with 200 parts of 90% acetic acid and 50 parts of zinc chlorid, and subjecting the impregnated cellulose to an acetylating bath of 450 parts acetic anhydrid and 1650 parts benzene. 1 i

- 8. The process of acetylizing cellulose which consists in treating cellulose with a hydroxvl containing substance which acts to induce acetyla-tion without altering the cellulose as ,such and is miscible with the acetylizing bath, a diluent therefor and a non-acid condensing agent, and then subjecting the impregnated cellulose tothe ac.- tion of a non-solvent acetylating bath.

9. The process of acetylizing. cellulose which consists in treating cellulose with a hydroXyl-containing substance which acts to induce acetylation without altering the cellulose as such and is miscible with the acetylizlng bath, a diluent therefor and a concellulose first with a non-acid condensing densing agent consisting of an inorganic salt, and then subjecting the impregnated cellulose to the action of a non-solvent acet ylating bath.

'10. The process of acetylizing cellulose to induce acetylation without altering the .drid and benzene.

treating cellulose with a i which ing cellulose as such and is miscible with the acetylizing bath, non-acid condensing agent, and then subjecting the impregnated cellulose to the action of an acetylating bath of acetic anhyof acetylizing cellulose, which consists in first impregnating the cellulose with a preliminary bathicomprismg a condensing agent and an ingredient that will facilitate later acetyllzation and 11. The process 'then subjecting the treated cellulose to a second bath comprising an acetylating agent without any additional condensing agent.

12. The process which consists in treating cellulose with zinc chlorid and a diluent which does not, react wlth the cellulose, and

a diluent therefor and a then subjecting the'treated cellulose to an acetylating bath.

13. The process which consists in treating cellulose with zinc chlorid and hydrous acetic acid, and then subjecting the treated cellulose to an acetylating bath.

14. The process which consists in treating cellulose with zinc chlorid and a diluent does not react with the cellulose, and then subjecting the treated cellulose to a diluent of said agent inwhich the cellulose is insoluble. I

-15. The process which consists in treat cellulose with zinc chlorid and a diluent which does not react with thecellulose, and then subjecting the'trea-ted cellulose to a reactive bath of acetic anhydrid and benzene.

Y 16. The rocess which consists in treating i cellulose with a non-acid condensing agent and a hydroxyl containing substance which acts to induce acetylation without alterin the cellulose as such and is miscible wit reactive bath of an acetylating agent and a the acetylizing bath, both of which are diluted with a diluent which does not react upon the cellulose, and then subjecting the treated cellulose to an acetylating bath.

17 The rocess which consists in treating cellulose with a non-acid condensing a cut, and a h droxyl'containing substance w ich acts to, induce acetylation without altering the cellulose as such and is miscible'with the acetylizin bath, both of which are diluted with a di uent which does not react upon the cellulose, and then subjecting the treated cellulose to a reactive bath containing an acetylating agent and a diluent of' said agent in which the cellulose is insoluble.

18. The process which comprises treating cellulose with an inorganic salt which acts as 3 a condensing agent and then with 5.11

acetylizing agent, and a diluent of said'130 acetylizing agent in which the cellulose is in- 7 soluble.

acetylizing agent in which the cellulose is insoluble.

21. The-process of acetylizing cellulose which comprises treating the cellulose with zincchlorid and thereafter with an acetylizing agent and benzene.

22. The. process of acetylizing cellulose which consists in treating-cellulose with a hyd'roxyl .containing substance which acts to induce acetylation without altering the cellulose as such and is miscible with the acetylizing bath, a diluent therefor and a non-acid condensing agent, .and then subjecting the same to the action of an acetylizing bath of acetic anhydridand a diluent therefor in which the cellulose is insoluble.

23. The product which comprises "acetyl cellulose obtained by treating cellulose with a non-acid condensing agent and a hydroxyl containing substance which acts to induce acetylation without altering the cellulose as such and is miscible with the acetylizing bath, both of which are diluted with a di1 uent which does not react upon the cellulose, and then subjecting the treated cellulose to an acetylating bath.

24. The product which comprises acetyl .cellulose obtained by treating cellulose with a non-acid condensing agent and a hydroxyl containing substance which acts to induce ac'etylation without altering the cellulose as such and is miscible with the acetylizing bath, both of which are diluted with a diluent which does not react upon the cellulose,

- and then subjecting'the treated cellulose to a reactive bath of an acetylizing agent and a diluentof said agent in which the cellulose is insoluble.

25. The product which comprises acetyl cellulose obtained by treating cellulose'with a non-acid condensing agent and a hydroXyl containing substance which acts to induce acetylation without altering the cellulose as such and is miscible with the acetylizing bath, both of which are diluted with a diluent which does not react upon the cellulose, and then subjecting the treated cellulose to a reactive bath of acetic anhydrid andbenzene.

26. A product ofthe hereinbefore described process comprising an acetyl cellulose, the original fibrous structure of the cellulose being substantially unaltered, the

product being obtained without hydrolysis of the cellulose and being ditiicultly but nevertheless soluble in chloroform.

27. The product which comprises acetyl cellulose obtained without hydrolysis of the cellulose by treating it with a condensing agent and a substance that acts to facilitate later acetylization and then with an acetylizing bath.

28. The product which comprises acetyl cellulose obtained by treating cellulose with a non-acid condensing agent and a substance which acts to facilitate later acetylization and is miscible with the later acetylizing bath and which does .not perceptibly alter the chemical composition of the cellulose and thereafter subjecting the treated cellulose to an acetylizing bath.

In testimony whereof I aflix my signature, in presence of two witnesses.

WVILLIAM G. LINDSAl lVitnesses C. V. EDWARDS, C. GALvIoN.