US1819441A - Paper product and method of making the same - Google Patents

Description

Patented Aug. 18, 1931 I UNITED .s'm'ras PATENT OFFICE HAROLD B. BAIT ON, 01: LAWRENCE, MASSACHUSETTS, ASSIGNOB TO BAFIOLD PROCESS CORPORATION, A CORPORATION OF MASSACHUSETTS PAPER PRODUCT AND METHOD OF MAKING THE BAKE Drawing;

Oneobject'of my invention is to produce a new, useful, and improved sized pa r made with a carbonate filler, and to provlde a simple method for accomplishing this result.

Further objects are the employment of paraflin in manufacturing this paper; the

water insoluble carbonates (normal or basic) of the alkaline earth metals (which expression is herein intended to include magnesium), or-compounds, or double salts, or physically associated mixtures of these with one or more other acid soluble materials of a substantially water insoluble nature, these fillers whether simple or complex as above, being characterized by the fact that, when agitated in bontact with freshly boiled distilled water in concentrated suspension for say an hour, they impart to the water a pH.

value which is on the alkaline side of the neutral point, and also by the fact that they give ofl carbon dioxide gas when brought into contact with an aqueous'mineral acid, e. g. hydrochloric acid. Examples of such fillers are calcium carbonate, of which lime mud from the causticizing process is one form; calcium carbonate magnesium basic carbonate employed in' the paper disclosed inmy U. S. Patent No. 1,595,416 of August 10, 1926; and calcium carbonate magnesium hydroxide, disclosed in my U. S. Patent No. 1,415,391 of May"9.,'1922, and used in the filled paper disclosed in my U. S. Patent No. 1,598,104 of August 31, 1926. Of course these fillers are referred to not only in their chemically pure form, but also in commercial form containing such impurities as may compounding or disintegrating or treating Application filed March 15, 1928. Serial No. 282,031

occur in such commercial products; and also when present with other material, so that they constitute only a part, either major or minor, of the whole, (one special case of which is described more fully in the -following paragraph) Itshould be stated that any given filler of the type referred to is not nec essarily of uniform particle size; nor are the average particle sizes of the fillers neccssarily alike, as some of the fillers of the type referred to have relatively coarse grain particles, whereas other are much more finely divided, and some are so finely divided that they may be said to approachor be in the colloidal condition.

Moreover when I use the expression carbonate filler (or fillers) I mean to include not only the case where it is added as such to the heaters, or other similar or mixing or machine, but also the case where itmay be added wholly or in part incorporated with fibrous material and/or I other material. Such a case would be where aper made with carbonate filler, either a'sa fillmg or coating constituent, or both, is reus'ed'in the papermakingprooess. Such apers may be those known to the trade as old papers or old waste papers or waste pa ers in any form, or returned trimmings or amaged paper or the like, or they may be the broke t at is,

the partially inade, the imperfect, or the waste paper which accompanies the pa ermaking, finishing, storing, packing,'s 1

ping, orthe like operations 1n 9. aper mi 1, and which is reworked either in't e same or some other mill. Such papers are sometimes reworked by themselves and added in broken down or in pulp form in the paper making process, being treated or cooked in some'cases with-or without chemicals and washed if de sired,this reworking meaning .to include the process of deinking if, such is practiced 01 0fbleaching or of-b'oth dcinking and bleaching,or sometimes they; are added directly to the other paper making ingredients in the beateror similar or other mixing or compounding or disintegrat ng or treatlng machine, and broken up directly therein. In

any event they are a source of carbonate filler in the paper to be made, and are included in the term carbonate filler (or fillers) as used herein. a

When I employ the term paraflin herein, I mean paraflin wax, which is solid at ordinary or room temperature. I do not mean to restrict myself only to the paraffin hydrocarbons, but mean to include in this term all the hydrocarbons of a waxy nature substantially unsaponifiable and inert to acidic and alkaline materials under ordinary conditions of temperature and pressure, whether derived from petroleum, shale, lignite, earth wax, or other natural or artifical sources. I do not, however, mean to include in this term material of a pitchy nature.

When I use the word paper herein, I use I it in the broad sense to include products of previously known: e. g., see Loshs manufacture of all types and of all weights and thicknesses, which contain as an essential constituent a considerable amount of prepared fibre and which are capable of being produced on a Fourdrinier, cylinder, or other forming, or felting, or shaping, or molding machine.

The novelty of the present invention does not reside broadly in the production of a sized carbonate filled paper as a new article of manufacture, as such papers have been British Patent No. 2664 of 1859; Cappazas British Patent No. 5776 of 1899; Stathams U. S. Patent No. 1,209,221 of December 19, 1916; and m U. S. Patents No. 1,595,416 of August 10, 1926, and No. 1,598,104 of August 81, 1926.

In some of the examples cited rosin is employed as the sizing agent. My invention,

owever, does not involve the use of rosin size, but on the other hand makes use, in a manner which is set forth fully below, of'

paraflin, preferably in a comminuted form commonly called an emulsion (i. e., a suspension of minute discrete particles of paraffin in a liquid, preferably aqueous or miscible with water), containing an emulsifying agent, (i. e., a material o r materials which tend to prevent the coalescence of the discrete particles of paraflin. Such emulsions are well known and may be satisfactorily produced in a variety of ways, as e. g., in a dispersion machine, such as in one of a variety of coiled mills or homogenizers. An example of such an emulsion is paraflin emulsified in water with a sulphonated oil as emulsifying agent; another example is paraflin emulsified in water with ammonium oleate as emulsifying agent. Others will occur to those skilled in the art. In regard to the paraflin'used, of course, either low or high melting point material can be employed. The so-called fully refined paraflin is entirely satisfactory because it does not impart objectionable color to white sheets. However,

for purposes of economy, it is often desirable to use a less pure material and for instance such material as is known to the trade as semi-refined parafiin scale, containing approximately 1-2% of oil and water as impurities, gives satisfactory results. Such material will perhaps in certain cases have varying melting points, but one particular sample used, for example, had a melting point of approximately F. (46 C.). Other even more impure paraflins may be used, especially if the color (whiteness) requirements of the finished paper are not too exacting,.or if papers, other than white, are to be made.

The use of emulsions of paraffin in paper is known but this use has been directed mainly to the production of parafiined rather than to sized (i. e., resistant in varying degree to ordinary aqueous writing ink) paper, or at least to paper containing a relatively higher percentage of paraffin than that required for sizing in my process. Such papers may have a paraffin finish or be translucent or even transparent, and waterproof, but my paper does not partake of these characteristics, but is similar to, and by mere observation cannot be readily distinguished from, ordinary rosin sized filled papers.

However, to my knowledge, heretofore it has not been proposed to use paraffin emulsions as sizing agents with carbonate fillers,

nor has the specific effect been noted when such employment is made, nor the unique use that can be made of such effect.

In some of the papers referred to above in have been previ which paraflin emulsions ously used, the parafiin is precipitated on the fibre while the fibre is in aqueous pulp condition, usuall by alum, in discrete form so that the indivi ual particles of parafiin are deposited from the emulsion on the fibre and coalesced by fusion on the driers of the paper machine. araflin is normally non-adhesive, in contradistinction to certain pitchy materials which are normally adhesive materials. 'When precepitated in minute discrete particles on the fibre, there is a tendency, however, for some of these particles under the conditions of agitation obtaining in the papermaking process to become detached from the fibre, and such particlesmay be agglomerated by pressure or otherwise so that relatively coarse flakes or lumps of par afiin are formed and exist at the wet end of) ing operations. The use of my method, howcrete particles of paraffin released from the emulsified condition, and is not of such a nature as to adhere to the paper machine or machine clothin L I have not su cient evidence yet to be certain of the exact nature of the action taking lace or of the product thereof and I thereore have named this combination or association of carbonate filler and paraffin, whether physical orchemical or both, a complex.

hen such a complex, prepared by flocculation in dilute suspension from quantities of carbonate filler and paraffin emulsion proportionate for instance to those used in making a filled'sized paper containing say 20% or more carbonate filler, e. g., parts of calcium carbonate magnesium hydroxide and q 3 partsparaffin in emulsified form, and the flocculated mass is separated from the supernatantliquid and then dried say at 100110 C., there is no evidence of melted paraffin, but on the contrary the fiocculent complex dries out to a powdery mass, non-sticky and non-agglomerant'whether hot or cold, and this complex may be seen by floating it on aqueous ink to possess ink resistant qualities. When the dried complex is gently heated in a crucible over a flame a vapor is driven off which has an odor similar to that of volatilized paraffin, and this va orcatches fire if a flame is juxtaposed. oreover if another portion of this same complex before drying is subjected for say several minutes in a beaker in presence of water to a vigorous boiling, and the beak? cooled, no scumof paraflin is found to have separated to the surface, and no evidence of any separation of paraffin is noted. 'I' have also found that if a definite quantity of agiven emulsion be diluted, and

successive quantities of asuspension of carbonate filler be added with agitation until .a all the emulsion has been fiocculated, that there seems to exist a stoichiometrical relation between the amount of paraffin present and the amount of filler required to precipitate it. which is different for different carbonate fillers; e. g., with one emulsion it required approximately 2.4 parts of a certain sample of calcium carbonate magnesium hydroxide to flocculate substantially completely'l part of paraffin in emulsified form, whereas with a certain sample oflime mud only -.6 part was required per 1 part of paraffin. This is not advanced as an argument in favor of the chemical nature of the complex, as it is realized that certain physical conditions might also bring about a similar result.

Furthermore it should be stated that this flocculation does not appear to be the result of the action of the carbonate filler with the emulsifying agent, as for example, although an ammonium oleate stabilized emulsion and calcium carbonate magnesium hydroxide mutually flocculate one another, I have found that this carbonate filler has no noticeable fiocculating effect on this stabilizer in the absence of the emulsified paraffin.

All the above is offered as evidence of the peculiarly stable nature of this novel carbonatefiller-paraffin complex which renders it particularly useful and satisfactory under the conditions under which it is employed.

As an example of the method of practicing my invention I may place the fibrous pulp in the beater, or other similar or compounding or mixing or disintegrating or treating machine, then add the paraffin emulsion,a convenient way being in dilute form,-incorporate this thoroughly with the pulp, then add the carbonate filler, then starch if desired and/or alum (attention in this connection being directed to my copending application Serial No. 202;453, filed June 29, 1927). The above order of addition is not i essential, but a convenient and desirable one for several reasons: 1. It allows thorough incorporation of emulsion with the fibre before'the formation of the carbonate fillerparaffin complex; 2. If the emulsion be one which is cracked or broken by alum, this action will be prevented by the prior formation of the carbonate filler-paraffin complex. Such cracking by alum would produce freei. e., unemulsifiedparaffin in a form tending to agglomerate into specksor lumps, which would cause trouble on the paper machine. a

In the case where broke and/or old papers, containing carbonate filler '(as discussed in detail above) is used as part of the furnish, it is advisable to add this part after the paraffin emulsion has been thoroughly incorporated with the other fibrous ingredients.

It is advisable to use as stable an-emulsion as feasible, this being particularly recom-- mended in cases where hard water is .to be I used and/or where the fibrousconstituents have not been washed sufficiently toremove such soluble materials which have a tendency to crack the emulsion and thus precipitate free paraffin, before the carbonate filler-paraffin complex can be'formed. In such cases it does not suffice to add the carbonate filler to the fibre prior to the emulsion, as there is bound to be at least a partial cracking of the emulsion by the hard water or soluble materials from the fibre with a corresponding pro- ,mp p

duction of undesirable free paraflin. Sometimes in such cases an otherwise less stable emulsion can be protected, as with an alkali, for example ammonia.

It is also desirable in adding the parafiin emulsion to adopt the usual practice in adding liquids in the paper making procedure, namely to pass it through a fine mesh screen before admixture with the other ingredients.

The reaction of the furnish for making my paper will normally be on the alkaline side of the neutral point, that is, will have a pH value higher than 7.

An illustrative furnish which advantageously may be used in practicing my invention, to produce for instance a filled sized book or magazine paper which will give an ink test, (i. e., the time required for an ordinary aqueous writing ink at room temperature to strike through a sample of paper when floated thereon) of from one up to several minutes or more, according to circumstances, is as follows:

Pounds Fibrous furnish (sulphite and soda) 1500 Emulsified paraffin, calculated as lbs. parafiin present (3% on total weight of fibre and filler) Calcium carbonate magnesium hydroxlde 500 Starch Alum 7 5 Of course lesser amounts of paralfin emulsion may be used with lesser sizing effect. The figures (pounds) given above refer to air dry weights in all cases except the filler (calcium carbonate magnesium hydroxide), in which case the figure given refers to bone dry weight.

This furnish may be added to the beater in the ordinary way, and then subjected to the usual paper making procedure on a Fourdrinier, cylinder, or other forming, or felting, or shaping, or molding machine, and the paper finished in the usual manner, using the regular machines normally employed for the various processes or of course special machines may be employed if desired. The resultant paper may be used for such purposes as those to which sized filled papers are normally put, including that as a raw stock for further conversion, as for example for coating. The carbonate filler in my as is the filler in other filled papers, is distributed substantially uniformly throughout.

My paper has the distinct advantage of possessing age resisting qualities in a unique degree. It is well known that acid conditions in papers are very detrimental to permanence: such conditions are rendered impossible by the use of a carbonate filler. It

is also well known that rosin sized apers discolor with age, and some authorities are 0 rosin,

dation. Thus by the combination of a carbonate filler and paraffin in paper, I have avoided in a unique manner the rincipal deteriorating effects which now ten to make paper less permanent and have incorporated in the paper materials which mutually lend their assistance in rendering the paper more 30 permanent and more age resisting.

Such a permanent paper has of course a great advantage for purposes which require preservation of the paper. It also has a decided economic advantage, papers, which inorder to obtain permanency have heretofore'been required to be made with all or a portion of the fibrous furnish consisting of particularly resist-ant cellulose as rag fibre, hanced permanency arising from the carbonate filler-parafiin content, and the absence of be made with a lesser amount of re.- sistant cellulose fibre, or in some cases, in the absence of such resistant fibre. result in economy in the manufacture of such papers, as the resistant celluloses are more exensive than the ordinary fibres substituted therefor.

y ployed I intend to include not only rosin but any compound thereof.

Whereas I have described several illustrative formulae, furnishes, procedures, and methods of o eration, limited therey, as my invention may be practiced in a wide variety of ways, with wide variations of formulae, under a wide variety of conditions, and with a broad variety of raw materials, and various changes may be resorted to in the practice of my invention without departing from the spirit of my invention or the scope of the subjoined claims. Likewise I do not intend to be limited b any theory expressed herein as the scope o my invention is independent thereof.

In the claims, where I use the word compound, I mean one or more compounds of the kind indicated.

Having thus described my invention, I claim:

1. A pa er comprising fibrous material, carbonate ller and paraflin.

2. A pa r comprising fibrous material, carbonate ller distributed substantially uniforml throughout, and parafiin.

3. s a new article of manufacture, a sized paper comprising fibrous material, carbonate filler, and parafiin.

as certain may now, because of the en- 99 This will the term rosin as hereinafter em- I do not intend to be 4. As a new article of manufacture, a sized paper comprising fibrous material, carbonate filler distributed substantially uniformly throughout, and paraffin.

5. As a new article of manufacture, a sized pa er comprising fibrous material, carbonate Her, and paraflin, in the absence of rosin.

6. As a new article of manufacture, a sized paper comprising fibrous material, carbonate filler, paraflin, and an aluminum. compound.

7 As a new article of manufacture, a sized pa er comprising fibrous material, carbonate ller, paraflin, starch, and an aluminum compound.

8. As a new article of manufacture, a sized paper which comprises fibrous material, a filler comprising an alkaline earth metal carbonate, and paraflin.

9. As a new article of manufacture, a sized paper which comprises fibrous material, a filler comprising calcium carbonate, and par- 10. As a new article of manufacture, a sized paper which comprises fibrous material, a filler comprising calcium carbonate and a magnesium compound, and paraffin.

, 11. As a new article of manufacture, a

'sized paper which comprises fibrous material, a filler comprising calcium carbonate magnesium hydroxide, and paraflin.

12. A process of making a sized carbonate filled paper comprising admixing with fibrous material paraflin emulsion and carbonate filler, and forming paper therefrom.

13. A process of making a sized carbonate filled paper comprising admixing with fibrous material carbonate filler and paraflin emulsion in the absence of rosin to effect mutual flocculation of emulsion and filler-to a carbonate filler paraflin complex, and forming paper therefrom.

v 14. A process of making a sized carbonate bonate and magnesium compound paraifin complex, and forming paper therefrom.

17. A process of making a sized carbonate filled paper which comprises admixing with fibrous material parafiin emulsion and a filler comprising calcium carbonate magnesium hydroxide to effect mutual flocculation of emulsion and filler to a calcium carbonate magnesium hydroxide paraflin complex, and forming paper therefrom.

18. Method of manufacturing filled and sized paper, characterized by the employment as a filler of an alkaline compound of an alkaline earth metal in association with emulsified paraffin.

19. Method of manufacturing filled and sized paper, characterized by the employment as a filler of an alkaline compound of an alkaline earth metal associated with emulsified paraflin, and the addition of alum as a final step in the-beater.

20. A method of treating paperpulp involving the use of alum and finely divided calcium carbonate, which comprises incorporating into the ulp such carbonate together with emulsi ed non-pitchy hydrocarbonmaterial of waxy nature substantially unsaponifiable and chemically inert to acidic and alkaline materials under ordinary conditions of temperature and pressure, and adding alum.

In testimony whereof I afiix my signature.

HAROLD R. RAFTON.

filled aper which comprises admixing with fibrous material paraifin emulsion and a filler comprising an alkaline earth metal carbonate to effect mutual flocculation of emulsion and comprising calcium carbonate to effect muv tual flocculation of emulsion and filler to a calcium carbonate paraflin complex, and forming paper therefrom.

16. A process of making a sized carbonate filled paper which comprises admixing with fibrous material parafiin emulsion and a filler which comprises calcium carbonate and a lation of emulsion and filler to a calcium car- Leo