US1958202A - Method of making sizing material - Google Patents

Description

Patented May 8, 1934 PATENT OFFICE METHOD OF MAKING SIZING MATERIAL Izador J. Novak, Bridgeport, Conn., assignor to Raybestos-Manhattan, Inc., Bridgeport, Conn, a corporation of New Jersey No Drawing. Application December 19, 1931, Serial No. 582,183

1 Claim. (Cl. 9221) An object of this invention is to produce a sizing material for use in treating fibrous material for use in paper, comprising a water insoluble, fatty acid soap.

5 I am aware of the fact that soluble fatty acid soaps, such as sodium oleate, have been introduced with paper fiber, such as kraft, sulfite, et cetera, into a paper beater, and later precipitated on the fiber as, for example, aluminum l0 oleate.

Previous methods, however, have been extremely difiicult to control because of excessive foaming of the soap emulsion causing the beater mix to swell enormously, making it diificult to completely acidify and precipitate the soap, which later manifested itself by severe foaming in the paper machine in which the beater mix was formed into a sheet. Also, the sizing and waterproofing qualities are reduced because of the presence of unreacted soap, which is water soluble.

The present invention reduces foaming in the heater and in the paper machine to a minimum and produces a highly waterproof soap substantially completely reacted to insoluble condition. The invention is capable of easy commercial use in large quantities and the soap may be used in large proportions in the stock without manufac-' turing difficulty.

The concept involved comprises the use of an emulsion of the fatty acid itself, wherein the emulsifier consists of a minimum quantity of the same fatty acid saponified with a limited amount of alkali. Thus, the quantity of soluble soap (i. e. saponified fatty acid) is kept at a minimum, and the attendant difficulties of foaming and loss of waterproofing are minimized. During the reaction with aluminum sulfate or other precipitating agent the small proportion of water soluble alkali soap reacts with the precipitating agent in the usual manner to form aluminum soap, for example,ialuminum oleate, and the large proportion of unsaponified fatty acid which is present in emulsified form reacts directly with the aluminum sulfate to form the same aluminum soap so that the resultant precipitate, which is the final waterproofing agent, is the same by this method as by the method where the fatty acid was completely or largely saponified.

The production of the emulsion comprises the use of a minor fractional part of the alkali necessary for complete saponification of the soap in combination with large dilution with water so as to reduce the saponification reaction to a point where complete emulsification is obtained with a minimum of saponification.

One method of preparing this sizing material is to heat about 300 pounds of water to about 125 F., dissolve completely therein about three pounds of technical caustic soda, making a solution of less than 1% alkali, and slowly add,

with stirring, about 30 pounds of oleic acid. This is then thoroughly agitated, preferably with live steam, and the temperature is increased until it has risen to about 175 F. The product is a thin cream-colored liquid equivalent to about 10% oleic acid concentration.

The invention, of course, is not limited to agitation with steam, as mechanical agitation produces substantially the same result.

As a test, if one part of this liquid is diluted with, say ten parts of water by volume, the result is a cloudy liquid free from any visible particles. The fact that the diluted mix is cloudy instead of clear is an evidence that the fatty acid oil is emulsified rather than saponified, as a soap solution of equal concentration would be comparatively clear. Also, the above diluted mix shows very little tendency to foam when agitated, indicating again that the proportion of true soap is very low.

When introduced into the beater engine, the above size mixes smoothly with fiber without excessive foaming and may be precipitated with alum without difliculty. It is especially satisfactory as a Waterproofing agent for asbestos fibers, and as much as 20% by weight of aluminum oleate has been added to asbestos fiber by this method without difficulty in preparation in the beater or in running on the paper machine. Both wet machines and continuous paper machines have been found satisfactory for running asbestos sized with high percentages of aluminum oleate in this way. The ordinary paper fibers such as kraft, sulfite, wood pulp, asbestos, etc., are effectively sized by this method.

I have shown oleic acid as an example, but I may also use any equivalent fatty acids such as palmitic, stearic, linoleic, oleostearic, or mixtures of fatty acids which are liquid below the boiling point of water and produce sizing com positions having the specific characteristics of these fatty acids and later their insoluble metallic soaps by employing the method described above.

I have also used technical caustic soda as an example, but it is to be understood that caustic I claim as my invention:

In the sizing of fibrous material, the method which comprises precipitating on the fibrous material during heating thereof an insoluble size from an emulsion of a saponifiable free fatty acid dispersed with an emulsifier consisting of a relatively minor proportion of the same fatty acid saponified with an alkali.

IZADOR J. NOVAK.