US1863867A - Paper size and process of making same - Google Patents

Description

m niscus 21,- 1932 r .Um -so 'sr'A ras PATENT OFFICE new I. ma. oil-omen, new assrenon, a! muslin Assres, 'ro

mean GHEIICAL COKPANY; OF IONTGLAIB, NEW JERSEY, A CORPORATION OF miwnnalr runnsrzamr Oil KAKINGSAKE Io Drawing, Original application fled December 30, 1925, Serial Ho. 78,829. Divided and this application fled April 10, 1928.

This invention relates to an improved pasoaps, rosin and waxes. Particular difficulty seems to have been encountered in roducing such a size as will make a paper 0 proper transparency or of proper waterproofness,

. and which will at the same time take rint well, that is, absorb printing inks uni ormly over the entire surface. Another fault of the present type of size is that of producing a too brittle paper.

My invention comprises the preparation of such new and improved sizes as will largely overcome the difliculties heretofore encountered and in drder to do this I pre are a size by emulsifying a wax such as, or example, pa'rafin wax, japan wax, carnauba, ceresine, Montam'beeswax, etc., with an 011 and water. I prefer to use a petroleum hydrocarbon oil of extremely li ht color boiling substantially over 200 and having a specific gravity of approximately 0.850 at 17 0., although various other hydrocarbon and slow dryin vegetable oils may in some cases be used. t is also possible to utilize partially, or completely hydrogenated vegeQ table or marine oils, in which case, some or all of the wax may be eliminated. The use of a pure white, practically medicinal grade of petroleum hydrocarbon oil, such as is generally known in the trade as Marcol and fNuJol in combination with a wax, especially parafin wax, is of particular value in the manufacture of paper or paper products intended to come into contact with food products, such as milk. bottle discs, ice cream containers, oyster pails, etc. The comparative physiological inertness of paraflin and such pure water-white petroleum oils renders them of particular value and use thereof confers the needed pliability or flexibility, whereb the paper is more readily drawn throng dies, or subjected to other mechanical operations.

The use of these oils is the primary feature Serial Io. 101,1.

of my invention, for by utilizin'j these oils I render the paper impregnated with these sizes much more exible than would otherwise be the case and at the same time the surface texture is improved to such an extent that the printing ink is absorbed more uniformly than would otherwise be the case. Considerable variation in these roperties may be toduced by variations in the proportions 0 oil and wax, and in some cases, it is advisable to introduce a small amount of some soluble soap in the emulsion, although not essentially necessary, particularly if a colloid mill be used to prepare the emulsion. Such a composition as sodium or ammonium stearate, almitate, resinates and the like, are suitable or the purpose.

In preparing these emulsions, it is usually advisable to previously dissolve the soaps, when used, in water. he wax is preferabl dissolved in hot oil and then admixed wit the water, or aqueous soap solutions. The use of a colloid mill to accomplish the proper dispersion and emulsification of the wax and oil is advisable, althou h I may utilize special stirring devices, or 0 er suitable means to produce this emulsification. In some cases, the addition of small amounts of alkaline salts, such as sodium phosphate, soda ash, or

of an alkali suchas caustic soda, or potash may be emplo ed to promote the emulsification, the useo such 'argillaceous materials as bentonite also bein somewhat advantageous for this purpose. entonite when used with a wax dispersion appears to exert a softening influence and helps to increase the pliability.

It is objectionable to use such substances as rubber, gutta-percha, sulphurized oils, etc., in these emulsions and articularly for the production of papers which are intended for use in contact with food products, for all objectionable odors and flavor inducing substances must be avoided and it is also of great importance to utilize-very pale colored, nondarkening, chemically inert materials.

In the preparation of wax emulsions for paper sizing, according to my invention, it is of importance to use veer; little, if any, soaps or foam forming ingr ients as are present stability with only of 1 per cent of a water soluble soap, and in some cases, no soap at all need be used.

In the practice of my invention it is of real: importance to utilize paer pulps containing a substantial amount of ydrocellulose, since Y the h drocellulose causes a greater and more rapi absorption of the wax dispersions or waxes and produces a product of better texture and increased water resistance. In order to insure the presence or suficient hydrocellulose l find it necessary to either subject the pulp to an unusually long treatment in the eater engine, that is, over forty-eight hours, or else to pretreat the paper pul chemically to form a substantial amount 0 hydrocellulose. It is understood that paper which has been Well-worked in the'beatercontains a. certain amount of hydrocellulose in dispersed form and this colloidal agent coming in contact with the dispersion of the substantially homogenized wax, or other waterproofing agent, through certain absorptive phenomena,

causes its occlusive union with a part of the fibre. The action is quite a different one from that which occurs when a sheet of paper is passed through a bath of, for example, molten parallin. Under these conditionsthere is no colloidal occlusion.

The formation of an increased amount of hydrocellulose may be accomplished in many ways, but particularly by an acid hydrolysis with sulphuric or otheracids such as for example, h drochloric, hosphoric, oxalic; acid salts sue as, zinc ch oride, sodium or potassium bisulphate; salts such as, potassium iodide, or'calcium thiocyanate, and other substances may be used in lieu of the sulphuric acid. When sulphuric acid is to be used, I preferably employ an acid having a specific gravity of approximately 1.52 to 1.54 and allow the pulp to soak in an excess of this acid for three to four hours, or more, then neutralize and wash. The beating operation, namely; the incorporation of my improved waxoil dispersions may then be started and will require much less time than if no acid hydrolysis was used.

Since various papers will require difi'erent amounts of hydrocellulose for best results, I do not wish to limit myself to any particular stage of hydration of the cellulose in carry! ing out my invention. As indicated, the preferred form contemplates a substantial degree of hydration, suflicient to engender a notable afiinit towards the dispersions of waxes involve herein. Furthermore, mixtures of the hydrated cellulose and unhydrated cellulose may be employed in preparin the paper stock, for example, dry pulp which has been thorou hlydried, or dr paper stock from any ot er source which is relatively dificult of hydration'in the beater engine, may be admixed with fresh wet ulp which has not been dried and which by rates rely and mixture of these two types of pa er stock duy subjected to treatment in the eater.

he rocess may be better understood from the fol owing example, to which, however, the invention is not limited. 1

Two tenths parts by weight of ammonium stearate is dissolved in approximately 10 parts by weight of water.

Four partsby weight of parafin wax are dissolved in 0 parts by weight of petroleum hydrocarbon oil having a specific gravity of 0.850 at 170 (1., boiling substantially over 200 (6., and practically water-white in color, and known generally as Marcol, said oil being Suficiently heated to readily dissolve the parafin. The two liquids may then be fed simultaneousl to a colloid mill in order to produce an emu sion. Various other soaps may be employed, or may in some cases be entirely onutted, especially when emulsification is produced by a colloid mill. The soaps, however, in general act as stabilizingagents, and their use is recommended. It is sometimes advisable to use a fatty acid as such and add an alkali in order to form a soap in the mix-. ture, while in other cases the soap is formed separately and then added to the mixture.

In place of paraflin wax, I may utilize various other waxes, such as ceresin, carnauba, japan, beeswax, etc. Rosin or rosin soaps may be added if desired.

Variations in the method of mixing the various ingredients may readily be made, as for example, the soap may be added to the wax and oil solutions and then introduced to the water, and while I have indicated a special procedure in the foregoing example, it is not absolutely necessary to follow just this procedure, and many variations in the' method of mixing may be introduced. Wheresaponifiable oils are used in place of the petroleum oils, they may, in some cases, be partially saponified by the slight addition of alkaline materials, in which case. no soaps need to be added under any conditions.

Having prepared the emulsion I finally introduce said emulsion into a heater with the wood pulp. I find it highly desirable to add the emulsion before the pulp has been thoroughly disintegrated and hydrated and is ready tobe removed from the beater. The emulsion is rapidly absorbed by the fibres (the speed of absorption depending to some extent on the proportion of hydrocellulose Eresent). On dr 'ng the paper, the emulsied material is eft occluded in and upon the fibres. On passing the sheets through calender rolls, the latter preferably hot, t e occluded material is forced under high pressure even more thoroughly throughout the sheet, and such uniform distribution renders sheets of thin paper unusually transparent. For the preparation of opaque and cheap wate roof papers, such as pressboard, and the li e, I may introduce into the beater a certain proportion of ground wood flour and similar materials. Various other rocedures of introducing the size into the u p to form paper may readily be used and t e foregoin 1S merely given as an example of one suc method.

The present application is a division of my prior application, Serial No. 78,329, filed December 30. 1925, nowPatent No. 1,607,552.

What I claim is 1. In the process of making water-resistant I paper, the step which comprises adding to a r 111 in a beater, an aqueous dispersion f p ar fiir i wax and an oil, said wax and oil being of substantially non-odorous and nonfiavor inducing character; said dispersion havin the progprty of substantial freedom from oaming w en incorporated in the beater engine. a v

2. n the process of makm paper, the step which comprises adding to t e pulp containing a substantial amount of hydrocellulose, in the beater engine, an aqueous dispersion of araflin wax and a water-white substantial y medicinal grade of a troleum hydrocarbon oil; said dispersion aving the property of substantial freedom from foaming when incorporated in the beater engine.

3. In the process of making paper, the step which comprises adding to the pulp in the beater engine, substantially at the beginning 5. In the process of making water-resistantpaper, the step which comprises incorporatmg with the paper pulp, a dispersion comprising paraflinwax; said dispersion contaming a minimum amount of appetizing agent,

whereby foaming of the pulp when agitated is substantially avoided.

6. A paper size consisting of an aqueous dispersion containing wax and an oil in proportions o yield a size, said size having the property of substantial freedom from foaming when incorporated in the beater engine.

7. A paper size consisting of an aqueous dispersion containing paraflin wax and a hydrocarbon oil in proportions to yield a size, said size having the property of substantial freedom from foaming when incorporated in the beater engine.

8. A paper size consisti of an aqueous diSAJBISlOII containing para n wax an oil, an a small amount of a water soluble soap, in proportions to a yield a size having the properly of substantial freedom from foammg when incorporated in the beater en 'ne.

9. In theprocess of making paper t e step which comprises adding to pulp m t e beater engine, a dispersion of wax and oil, said disgerslon containing particles comparable in egree to those resulting from colloid mill. treatment, said dispersion having the property of substantial freedom from foaming when incorporated in the beater engine.

I 10. In the process of makin paper, the step wh 1ch comprises adding to 51a pulp contaming a substantial amount of hydrocellulose 1n the beater engine, an a ueous dispersion of paraflin wax and hydrocarbon oil, said dis ersion containing particles comparahis in egree tothose resulting from colloid mill treatment, said dispersion havin the property of substantial freedom from 0ammg when incorporated in the beater engine.-

11. In the process of making paper, the step of incorporatin with paper pulp, an aqueous dispersion o wax and oil.

12. In the process of making paper, the step which comprises incorporating with paper pulp, a non-foaming, soap containing aqueous dlspersion of wax and oil.

13. In the process of making paper, the ste which comprises incorporating with pa p containing a substantial amount of hydrocellulose, an aqueous dispersion of wax and oil.

14. In the process of making paper, the step which comprises incorporating with pulp containing hydrocellulose, a non-foammg soap containing aqueous dispersion of wax and oil.

15. A paper product produced from a paper pulp incorporated with an aqueous dispersion of wax and oil.

16. A paper product produced from paper pulp incorporated with a non-foaming soap containing aqueous dispersion of wax and oil.

. 17 A paper product produced from a paper pulp containing hydrocellulose incorporated with an aqueous dispersion of wax and oil.

18. A paper product produced from a paper pulp containing hydrocellulose, incorporated with a non-foaming soap containing aqueous dispersion of wax and oil.

19. A paper product produced from a paper pulp incorporated with a dispersion of wax and oil, which dispersion contains particles comparable in degree to those resulting from colloid mill treatment. I g 20. A paper product produced from a pa r pulp containing a substantial amount of ydrocellulose and incor orated with an aqueous dis rsion of para wax and hydrocarbon oi which dispersion contains particles comparable in degree to those resulting from 10 colloid mill treatment, and which dispersion possesses the property of substantial freedom from foaming when incorporated in the beater engine. 7 W V AUGUSTUS E. MAZE. l5