Patented Dec. 8, 1942 2,304,304

UNITED STATES PATENT OFFICE 2,304,304 DEFOARMER, James H. Fritz, Bloomfield, N.J., assignor to Na tional Oil Products Company, Harrison, N. J., a corporation of New Jersey No Drawing. Application May 3, 1939, Serial No. 276,555 10 Cairns. (CI. 92-21) this invention relates to defoaming agents, a considerable number of defoaming agents now more particularly to defoaming agents for use in on the market, there is still a great demand in the Inanufacture of pulp and paper. the pulp and paper industries for inexpensive de There are many points in the manufacture of foaming agents having improved defoaming ac pulp by either the sulfite, soda, or kraft processes tion. at which undesirable foaming occurs. For ex It is the object of this invention to provide in ample, when the pulp is screened to remove expensive and highly efficient defoaming agents coarse fibers and dirt therefrom, foaming prac for use in the manufacture of pulp and paper. tically always occurs, whereby the screening effi I have now found that aqueous emulsions of ciency is substantially lowered, and acceptable O mineral waxes upon addition thereof to slurries fibers are caused to go over the screens with the and suspensions of fibrous material produced in tailings. In some plants devices known as rif the manufacture of pulp and paper effectively. flers, which consist of long troughs having a se prevent or abate the formation of foam wher ries of pockets in the bottom thereof, are em ever it tends to develop in the slurries and sus ployed to remove impurities from the pulp slurry 5 pensions and destroy existing foam after it has by passing the slurry through the rifflers, the im formed thereon. These emulsions are preferably purities such as dirt, etc., being heavier than the formed by emulsifying a mineral wax in an aque desired pulp and settling into the pockets. ous medium employing a partial glyceride of a However, foaming is likely to occur in the rif higher fatty acid as an emulsifying agent. The fiers So that the dirt and like material is en 20 term “partial glyceride of a higher fatty acid' is trained in the foam and does not settle into the intended to include mono and di glycerides of pockets; the foam also causes the fibers to float higher fatty acids: in view of the close similarity on the surface of the slurry, thus hindering dirt of the naphthenic acids to the higher fatty acids, removal and destroying the uniform consistency the naphthenic acids are included for the pur of the slurry. When the pulp is washed, a rela 25 poses of this application within the term "higher tively large amount of foam results which lowers fatty acid.' The emulsions of mineral waxes the efficiency of the washers, and the foam may prepared in accordance with my invention have build up to such an extent as to overflow from been found to be extremely effective defoaning the Washers onto the floor. Another point in the agents for use in the manufacture of pulp and manufacture of pulp where foam presents a 30 paper; furthermore, these emulsions are very in problem is at the sewer pipes for disposal of expensive and easy to prepare. waste water where sufficient foam may collect The defoaming agents of my invention may so that it is impossible to dispose of the waste comprise any mineral wax such as paraffin Wax down the sewer. or petrolatum wax. I prefer to employ parafin In the manufacture of paper, foaming tends to 35 wax because of its ready availability and com take place wherever the stock is agitated. The paratively low price; furthermore, emulsions of most serious foaming occurs at the screens and parafin wax are excellent defoaming agents. on the paper machine. As pointed out above, However, it is to be understood other mineral the presence of foam in screening operations low waxes may be employed if desired. ers the Screening efficiency and causes acceptable 40 As pointed out above, the emulsifying agent fibers to be lost in the tailings. With regard to preferably employed in accordance with my in the machines, if a cylinder paper machine is em vention is a partial glyceride of a higher fatty ployed, foam develops in the vats thereof, caus acid; thus, for example, the mono and di glyc ing the formation of an uneven paper product erides of stearic acid, oleic acid, ricinoleic acid, and loss of fibrous material due to the Overflow 45 linoleic acid, palmitic acid, myristic acid, lauric of the foam from the vats. In the Fourdrinier acid, capric acid, naphthenic acid, etc. may be machines foam appears on the pond and this employed. The partial glycerides not only act foam has a tendency to break and go over the to emulsify the mineral Wax in the aqueous ne wire, thereby causing the formation of dirty pa dium, but they also possess inherent defoaming per. 50 properties and thus tend to improve the defoam From the above discussion, it is evident that ing characteristics of the emulsions of my inven efficient and inexpensive agents capable of pre tion. I have found that emulsions of the partial venting or abating foam and of destroying exist glycerides of higher fatty acids containing no ing foam are highly desirable for use in the man mineral wax may be used in the manufacture of ufacture of pulp and paper. While there are 65 pulp and paper to prevent or abate the forma

- --- 2 2,304,304 tion of foam or to destroy existing foam, but more effective defoaning agents are obtained if ployed in the preparation of my products, de mineral Waxes are also included in the emulsions. foaming agents readily available to the trade are The preferred agents of my invention may be obtained. Therefore, my invention constitutes prepared by melting together the non-aqueous an important advance in the art of manufactur 5 ing pulp and paper. constituents of the emulsion, i. e., the Wax and Since certain changes may be made in the the partial glyceride and any other substance it above compositions of matter and different em is desired to include in the emulsion and then bodiments of the invention could be made with adding to the nolten maSS as much Water as de out departing from its Scope, it is intended that Sired with continuous agitation until a Sub 0 all matter contined in the above description shall stantially honogeneous erulsion is obtained. be interpreted as illustrative and not in a lim Preferably, the emulsions added to slurries and iting sense. suspensions of fibrous naterial produced in the Having described my invention, what I claim manufacture of pulp and paper, in accordance as new and desire to Secure by Letters Patent, with my invention, contain between about 0.12% is: and about 1.5% of the mineral Wax, and between about 0.25% and about 2.5% of the partial glyc ... A composition of matter comprising a sus eride, the balance being water. However, it is pension of fibrous material such as is produced to be understood that, if desired, emulsions con in the manufacture of pulp and paper and a de taining a much greater quantity of mineral wax foamer comprising a mineral Wax and a partial and partial glyceride may be prepared and these glyceride of a higher fatty acid, Said defoamer emulsions then diluted before use; it is advan being present in sufficient amount to inhibit the tageous to prepare relatively concentrated emul Suspension.development of foam upon the surface of said Sions if it is desired to transport the emulsions or Store then for any substantial period of time. 2. A composition of matter comprising a sus It is further to be understood that other sub pension of fibrous material such as is produced stances may be mixed with the emulsions of my in the manufacture of pulp and paper and a de invention, which, when properly blended, en foamer comprising paraffin wax and a partial hance the defoaming properties of the agent as a glyceride of Stearic acid, said defoanner being whole. Such substances include animal and veg present in sufficient amount to inhibit the devel etable oils, fats and waxes, such as teaseed oil, opment of foam upon the surface of said suspen olive oil, castor oil, tallow, wool grease, sperm Sion. oil, montain Wax, etc., as well as derivatives of 3. A composition of matter comprising a sus these and other fatty substances, such as fatty pension of fibrous material such as is produced acids, fatty alcohols, fatty amines, fatty amides, in the manufacture of pulp and paper and a de mineral oils and the like. In some cases it may foamer comprising paraffin wax and a partial be advantageous to incorporate sulfonated or glyceride of oleic acid, said defoamer being pres phosphated derivatives of these substances in the ent in Sufficient amount to inhibit the develop emulsions. ment of foam upon the Surface of said Suspen The defoaming agents of my invention may be SOI. employed to destroy foam which has developed 40 4. A composition of matter comprising a sus On the suspensions or slurries produced in the pension of fibrous material Such as is produced manufacture of pulp and paper, and also to pre in the manufacture of pulp and paper and a de Went or abate the formation of foam on these foamer comprising paraffin Wax and a partial slurries and suspensions; the term “defoaming' glyceride of palmitic acid, Said defoamer being is thus intended to include both these actions. present in sufficient amount to inhibit the devel The emulsions of my invention are preferably opment of foam upon the surface of said Sus added to the stock just ahead of the point at pension. - which the foaming has occurred or is likely to 5. A composition of matter comprising a sus OCCur. The term 'stock' is used herein in a pension of fibrous material such as is produced broad sense to mean any water suspension of 0 in the manufacture of pulp and paper and a de fibers produced in the manufacture of pulp and foamer comprising a mineral Wax, a partial glyc paper, thereby including pulp, wholestuff, half eride of a higher fatty acid and a mineral oil, stuff and similar aqueous suspensions of fibrous said defoamer being present in sufficient amount material. The amount of defoaming agent added to inhibit the development of foam upon the depends upon the quantity of foam and the type s 5 Surface of said suspension. of foam that occurs and generally will vary wide 6. A composition of matter comprising a sus ly with the particular conditions of operation; pension of fibrous material such as is produced in however, it is a simple matter for one skilled in the manufacture of pulp and paper and a de the art to adjust the amount of defoaming agent foaner comprising a mineral Wax, a partial glyc added in order to produce the desired results. (5) eride of a higher fatty acid and a sulfonated In every case I have found that the addition of fatty Substance, Said defoanner being present in my novel defoaming agents to slurries and suspen sufficient amount to inhibit the development of Sions of fibrous material produced in the manu foam upon the surface of said suspension. facture of pulp and paper causes substantially 7. In the manufacture of pulp and paper the immediate removal of the foam, if foaming has improvement which comprises incorporating in already taken place, or effectively prevents or the Suspension of fibrous material a relatively abates the formation of foam where there is dan Small amount of a defoaming agent comprising ger of its occurrence. a mineral wax and a partial glyceride of a higher fatty acid, Said defoaming agent being incorpo From the above description it will be evident rated in sufficient quantity to inhibit foaming that my invention provides a new and highly ef upon the Surface of said suspension. fective defoaming agent for use in the manu 8. In the manufacture of pulp and paper the facture of pulp and paper. It will further be improvement which comprises incorporating in evident from the above description that because the Suspension of fibrous material a relatively of the relative cheapness of the materials em Small amount of a defoaming agent comprising

2,304,304 3 affin wax and a partial glyceride of a higher higher fatty acid, the balance being substantially sy acid, said defoaming agent being incorpo all Water. - ed in Sufficient quantity to inhibit foaming 10. A composition for defoaming pulp and pa In the Surface of said Suspension. per stock comprising approximately from 12 to . A composition for defoaming pulp and paper 1.5 percent of paraffin wax and approximately ck comprising approximately from .12 to 1.5 from 25 to 2.5 per cent of a partial glyceride of a Cent of a mineral Wax and approximately higher fatty acid, the balance being substantially in .25 to 2.5 percent of a partial glyceride of a all water. JAMES H. FRITZ.