DE566206C - Use of mixed esters for the production of cellulose lacquers - Google Patents

Description

Use of mixed esters for the production of cellulose lacquers Cellulose lacquers, which are known to play an increasingly important role in the newer paint technology, are mainly composed of gelulose esters or ethers, resins, elasticizers and solvents together. The main elasticizing agent is here Castor oil, tricresyl phosphate and dibutyl phthalate in use. While the two the latter have good solubility compared to the cellulose compounds, the same does not apply to the same extent for castor oil. On the other hand, however the softening effect of castor oil is an excellent one, which is why it is desirable is to have methods available that allow it to be enriched in the filter, without the usual disadvantages (e.g. exudation) occurring.

It has now been shown that certain tincture derivatives or derivatives from fatty () oils or from similar substances - @ - excellent properties as elasticizing agents for cellulose lacquers, if appropriate combinations are selected will.

Castor oil or fatty oils generally provide known triglycerides of higher Fettäuren represents. Substituting now lukten in such Pro- (one or two fatty acid-resistant by resin acids, one obtains mixed Fettsiure-Har7säure-glycerides, which are now solved as komhinierte ester with cellulose products components Have the ability to dissolve cellulose products in copious amounts, so that they can be used with advantage as elasticizing additives in corresponding paints.

The manufacture of such products takes place, for. B. by heating Glycerin with a mixture of fatty and resin acids, also initially one Mono- or diglyceride of one or the other acid can be prepared, whereupon then the additional esterification is connected to the triglyceride. Furthermore can but you can also free it by heating fatty oils with resin acids while distilling off evolving fatty acids. represent the desired mixed esters. You can also do the same Resin acid and fatty oil first transesterify and then those left in the mixture Esterified fatty acids released separately by Tacher heating with glycerine.

All of these processes can be. by using catalysts or also to a large extent by vacuum. Other fatty acids are here the saturated and unsaturated compounds found in common fatty oils of this type also their derivatives or lower or higher homologues (all corresponding Acids of about C,. . . upwards) into consideration. Instead of glycerin you can also use other polyvalent ones Alcohols or Derivatives of polyhydric alcohols be used, d. H. Glycol, polyglycols, polyglycerols, etc. Resin acids are used z. B. Rosin, Benzoin, Sandarac, Kauri, Manila, Congo, Sierra-Leone, Benguela inter alia: m. in question. The fossil or recent fossil resins can be melted off or they can also be used in their natural state. In the latter case it has the solution expediently by heating with suitable organic acids possibly under Pressure: to be done.

Which mode of operation can be used in detail emerges from the following examples: Example i A mixture of 100 parts of oleic acid and zoo Parts of rosin are mixed with 35 parts of glycerine by prolonged heating at about Esterified 220 ° C in a carbon dioxide atmosphere, with some time at the end is kept under vacuum. The product obtained is diluted with 500 parts of toluene.

To produce a cellulose varnish, 150 parts of the resulting varnish are mixed Solution with a solution of 75 parts of nitrocellulose in i2o parts of butyl acetate and 25o parts of ethyl acetate. This lacquer can also contain pigments, dyes and other resins and known plasticizers are added. In the specified composition the lacquer provides clear and completely homogeneous films of excellent hardness and good Ela-Stizit <it. Example e 150 parts of castor oil fatty acid are mixed with 25 parts Glycol esterified by refluxing, whereupon with 100 parts of Kauri appropriate in Kolilendioxyd''atmosphäre in the presence of small amounts of z. B. tin tetrachloride is further esterified. The mass obtained is dissolved in 500 parts of benzene.

From the solution obtained one takes z. B. 5 parts and mixes them with a solution of 75 parts of acetyl cellulose in 35o parts of acetone, o parts of lactic acid ester, 20 parts of methyl glycol and 15 parts of cyclohexanone. Example 3 100 parts are heated melted Congo chopal with zoo parts of linseed oil for a long time at about 300 ° C; afterward is kept under vacuum for some time, as a result of which volatile fatty acids are distilled off. The class obtained is diluted with 500 parts of xylene.

To produce a varnish one uses z. B. 75 parts of the above Solution made with a solution of 5o parts of ethyl cellulose in 3oo parts of goer benzene and: 2o parts of alcohol are mixed. Example 30 parts of glycerin are used with Zoo Parts of rosin esterified at 25o ° C. while passing a stream of carbon dioxide through. After the reaction has taken place, 100 parts of purified linseed oil fatty acid are added and holds for a few hours at 25o ° C., whereupon it is expedient to keep it under vacuum will.

A solution of 5 parts of this mass in 15 parts of toluene is with .42 parts of a solution of 10 parts of nitro wool in 10 parts of amyl acetate, 2o parts Methyl acetate and 2 parts diamyl phthalate mixed. Example s 50 parts of the Congo Chopal are first heated with 100 parts of oleic acid at 280 ° C (in a carbon dioxide atmosphere) brought into solution. Then 15 parts of glycerine are added and so on heated until the acid number of the mixture has reached a value of about 2. That kind of thing The product obtained in a yield of about 150 parts is an excellent elasticizing agent for cellulose lacquers. B. io parts with 3o parts Toliiol and uses the mixture obtained in this way to elasticize a nitrocellulose lacquer the following composition: 15 parts of nitro wool, low viscosity, 2o parts of lactic acid ester, 10 parts of butyl alcohol, 63 parts of ethyl acetate.

The production of the mixed ester products based on z. B. glycerin cannot be compared to other proposals where only fatty acids play a role will. So is i.a. been recommended to the natural drying glycerides underlying fatty acid mixtures (e.g. the mixture of linseed oil fatty acids) with To esterify polyalcohols of the special character of the mono- or polysaccharides. Such a measure would not even be considered for the purposes of the present invention Come into consideration. Because once it would in no way reduce the ability of the fatty acid esters to dissolve improve compared to cellulose products, but also have disadvantages in other respects to have. When transitioning from triglycerides to z. B. fatty acid esters of polysaccharides but now there are evidently considerable enlargements of the molecules, so the Can only promote drying, but not delay it. For the utility value of a Elasticizing agent is, however, in addition to the corresponding solubility, among other things. even maintaining the original condition for as long as possible from crucial importance. Because a film based on cellulose products is necessary yes, in no way a replica of film-building disperse phases like such at (: elms cannot be dispensed with, but rather, conversely, even through storage more stable hzw. parts that remain fluid are artificially softened, <l. H. elasticized `-ground.

Claims (1)

PATENT CLAIM: Use of mixed esters of polyvalent aliphatic Alcohols, especially glycerine, with high molecular weight fatty acids and resin acids as a plasticizer for the production of oil-free cellulose lacquers.