US2665206A - Sizing of fibrous materials and compositions useful for sizing and for other purposes - Google Patents

Description

Patented Jan. 5, 1954 Iheodoreli. Bradley, Oakland, -Galif., assignor to hell Development Company, San Francisco, Calif., a corporation of Delaware N 9 Drawing. Application June l5, 1 95l,

Serial No. 33321 1 This -invent ion relates to the sizing of paper, cardboard, textile threads or fabrics, imitation leather and related fibrous materials. It deals with improved methods pf sizing such materials whereby they may be rendered more resistant to water than heretoforeand with new compositions which are not onlvvaluable sizing agents but also have other useful applications.

4 A widevariety of materials have been used for i e fibers 9 t fo e oin tYP Thse i clude, for example, resins of various kinds, both natural and synthetic, paraffin, waxes of difierent -types, bituininous or asphaltic materials, tars, etc., but the most widely used sizing material employed in general commercial practice is rosin or colophony; The usual procedure in paper sizing, for instance, is to add an aqueous dispersion of the sizing agent to the fibers to'be sized :in-the beater or Holland machinewhere the .size is precipitated on the fibers with paper makers alum 'or the like. This is a-very convenient method of sizing :but, particularly in recent years, hasbecomerelaatively expensive due to the increased cost of :rosin. Itfurthermore doesnot provide the :most desirable sizing, especially where a highly waterproof product .is required, as, for example, kraft wrapping paper, cardboard and the like.

An important object of the present invention is to provide alsizing agent which overcomes the ,foregoing disadvantages of conventional sizeszand which will be more economical .to manufacture -and use. Another important .obj ect .is to provide :a paper sizing composition whichrmay be derived entirely from petroleum. A further object is to provide improved articles of manufacture, :parzticularlysized paperand the like, which are-more water-resistant than :prior products .of a similar :type. Still another object is to provide new emulsifiable compositions which are useful not only as sizing agents but also have other imp a -M srs i l be m fully p ted e hereinafter. =Still other objects and advantages ofthe invention will be apparent -fromthefollowing description of the invention in some of its more preferred forms, it being understood that h io :isimi ih r i bi i hroadly a lica l asr eviously pointed o t.

' "Ithas bemfoundthat especiallyadvan ase- 10 Claims. (0].. 22- 3;)

2 pus composition for sizing paper and related fibrous materials comprises a novel mixture of salts of naphthenic acids having acid numbers less than 200 with conventional sizing agents, or preferably with the predominantly cyclic extracts obtainable from mineral oils. For purposes of convenience, the naphthenic acids and naphthenic acid'salts used will be referred to generically hereinafter as naphthenat'es'. The acid numbers of the naphthenic acids as used herein refer to the number of milligrams of potassium hydroxide which will neutralize the acids in a one-gram sample of the naphthenic acids. An especially advantageous source of naphthenates having desirable properties for use in the invention is the n'aphthen'ates produced in the refining of petroleum and its various products, particularly lubricating oil. Methods which are suitable for producing naphthenates which-may be used in the new compositions of the invention, provided suitable starting materials are selected and/or the :naphthenic acids are properly treated to insure that the final product will be naphthenates hjaving acid numbers less than 200, preferably acid numbers ofabout to 175, include, for examplefa'lkali treatment of acid-refined petroleum distillates, or the caustic distillation of mineral oils, particularly oils from Texas and California crudes, to obtain oil-containing naphthenates which may be used as such or maybe partially purified'by acidtreatment or more completely deoiled by dispersion in an aqueous medium followed by de-emulsification in the presence of a solventfor-the oil. The usual commercialnaphthenates do not satisfythisrequirement, but are mixtures from which 'naphthe'nic acids of suitable-acid numbers maybe separated for use according to the invention; "Thus, naphthenic acids having the required acid number 'may b'e separated from their mixtures with undesired naphthenic acids of higher acid number by fractionally distilling off the latter andlusing' only he a ihen a rboil n ab e a ou 200 C- ivrfilmm-ifiep es ereart cu a .suitabl a n t n [a s bo in bet e a u 250 ,Q-andfififl" a z dmm-"fi re sa Petrol um qi wh p boi ab efiqw a 0-5 mm- H pre sure, esnecial yirai n i luhr cati c il o 'the introducing the precipitant.

like boiling between about 250 C. and 350 C. at 0.5 mm. Hg pressure, are preferred sources of the naphthenates used in the new compositions.

The chosen naphthenate or naphthenate mixture corresponding to naphthenic acids having acid numbers less than 200 is preferably used in sizing as an aqueous emulsion with a sizing agent, preferably a sizing agent of the hydrocarbon type, most preferably the aromatic extracts of mineral oils previously referred to. It is a special advantage of these naphthenates that they not only improve the sizing but also are capable of forming stable emulsions of the water-in-oil type with hydrocarbon type sizing agents, particularly the cyclic extracts of petroleum which may be readily inverted to emulsions of the oil-in-water'type which are quite stable, yet are precipitable in the presence of paper fibers by the usual paper makers precipitants. This unusual combination of desirable properties makes it feasible. to prepare very cheaply highly effective sizing compositions as concentrated water-in-oil typeemulsions which can be conveniently shipped"'a't' low cost,

stored until needed, and readily diluted at the paper mill without difficulties from phase separation or loss in sizing power to form emulsions of the oil-in-water type which can be used for sizing although as a rule it is more advantageously introduced when the beating has been substantially completed. The sizing may also be carried out in the Jordan machine or at the screens. A

aecaao 4 solvents may be used for the preparation of such extracts, liquid sulfur dioxide, phenol, cresylic acid, furfural, beta,beta-dichlorethyl ether, nitrobenzene, the sulfolanes and sulfolenes, and the like being typical examples of suitable solvents. There are advantages in reextracting the initial extract with an immiscible solvent to improve the selectivity of the extraction. Thus, extraction of Edeleanu extracts of lubricating oils with gasoline or the like has been found to improve the sizing properties of the compositions produced therefrom in accordance withthe invention. Other extraction methods may be used."

Extracts of heavier petroleum oils such as the lubricating oils and residual stocks are especially useful inthe new sizing compositions of the invention, but other fractions of petroleum or related hydrocarbon products can also be used successfully as sources of the extracts. The ex tracts may be derived, for example, from lubricant distillates-or .bright oils or cylinder stocks which may, for instance, range in gravity from I to 8 API at 60 F. They may be obtained wide range of precipitants may be used for fixing the new sizing compositions on the fibers. Alum, aluminum sulfate, calcium chloride, acids such as sulfuric or hydrochloric acid, and the like are all suitable, but paper makers alum is preferred. The precipitant may be added to the fiber along with the size but generally it is preferred to add it later in the process, thus providing adequate time for uniform distribution of the size before The amount of naphthenate sizewhich it will be most advantageous to employ will dependvon the nature of the fibrous material being treated, the purpose for which it is intended, thetype of naphthenate chosen, and the method of its application. As little as 0.2% based on the dry weight of the paper iseifective but up to 10% or more may be used, the preferred range being usually about 0.5% to about 3%. V

In preparing emulsions of naphthenates of acid numbers less than 200'for use according to the invention, a wide variety of materials may be used as the dispersed phase. Oils or waxes such as, for example, mineral waxes such as paraffin,

ceresin and montan wax, are useful when used either in combination or separately. Hydrocarbons such as lubricating oils, spindle oil, asphalts, bitumens, etc. may thus be used.- However, there are special advantages in using cyclic extracts in preparing emulsions because these not only are highly desirable paper sizing compositions, as

previously pointed out, but also have other advantageous uses.

The cyclic extracts used in the new compositions of the invention are the products of predominantly aromatic and naphthenic nature, obtainable by extracting petroleum or related oils, including hydrogenation products of coal-and the like, with solvents which are selective for nonparaffinic constituents. A wide variety of polar from" any mixed type petroleum oil such as Mid- Continent or Coastal or California crude or, in lower yields, from Pennsylvania type oils. For use in sizing in accordance with the invention, extracts boiling above 300 C. at 760 mm. Hg pressure are preferred, and most preferably extracts boiling from about 125 C. to 300 Cat 1 mm. Hg pressure are used. The more viscous extracts usually give emulsions with the most desirable sizing properties but may be somewhat more difficult to emulsify. For this reason extracts within the viscosity range of about -325 at 210 F., S. U. 8., have advantages, although more viscous extracts, e, g. 400 to 5000 viscosity S. U. S. at 2l0 F., are preferred where it is not disadvantageous to use a colloid mill or other such equipment or prolonged stirring or other methods of promoting emulsification in the preparation of the initial emulsions and/or in their inversion to emulsions of the oil-in-water type. Extracts obtained from narrow fractions may be advantageously ,employed. It is often advantageous to fractionate the initial extract to separate fractions of especially advantageous properties, thus, for instance. ithas been found that the higher boiling 50% .to 7.5% of an Edeleanu extract'of lubricating .oil gives superior sizing judged by permeability to water of sized paper. Theproportion of naphthenate of acid number less than 200 to hydrocarbon used in preparing emulsions of these materials for paper sizing can be varied but as a rule will be such as corresponds to about 3'to about '75, more preferably 5 to 50, per cent by Weight of naphthenate based on the total weight of naphthenate and hydrocarbon. Where desirable, the emulsifying properties of the naphthenate chosen may be supplemented by addition of a small amount, usually about'0.l% to 5% by weight of the naphthenate and hydro.- carbon present, of another emulsifying agent. Soap, higher alkyl sulfate salts, organic sulfonic acid salts, particularly alkyl aryl sulfonates,-sodium rosinate and the like may be usedi-as supplementary emulsifying agents where the naphthenate employed is not itself sufiicient to insure the desired stability in the emulsion, either on account of the acid number of the naphthenic acid used being too high or because an insuflicient amount is used. The mostadvantageous sizing emulsions, however, are those made from naphthenates of acid. number less than 200 without other emulsifying agents.

In order to obtain emulsions of the most desirable particle size for paper sizing, it has been found advantageous to mix together the chosen n'aphthenic acid or naphthenic acid mixture and hydrocarbon, preferably the previously described cyclic extract, with warming necessary to insure uniform distribution of viscous hydrocarbons. and then to add sufficient aqueous base to substantially neutralize the naphthenic acids present. In this way a moderately fine, 'quite uniform emulsion of the wate-in-oil type may be prepared which on further dilution can be converted to an oil-in-water type emulsion of very fine particle size highly advantageous in paper sizing. The transition point for the change in the type of the emulsion is generally about 40% to about50% water in the emulsion.

A wide variety of different alkaline agents may be used in preparing the emulsions. Hydroxides or carbonates of alkali metals or ammonia are suitable; sodium or potassium hydroxides are preferred hydroxides, however, becauseof their relatively low cost. The corresponding, particularly the sodium and potassium, carbonates require higher temperatures and are thus somewhat less preferable. Alkaline earth hydroxides such, for example, as calcium and magnesium hydroxides, etc. may also be used. For certain purposes, neutralization with an organic base such, for example, as aliphatic, alicyclic or aromatic, primary, secondary or tertiary amines or quaternary a1.-- monium bases, is advantageous. Water soluble amines such, for instance, as dimethylamine,-prcpylamine, cyclohexlamine, the ethanolamines, etc. may be used in such cases. The chosen base is preferably employed as an aqueous solution of about 5% to about 30% concentration, most preferably about 5% to concentration. The moststable emulsionsare prepared by the use of slightly less than the stoichiometric amount of base, preferably about 85% to 95% of the amount required for neutralization of the naphthenic acids. A pH of about 8 to 13, preferably 10 to 11.5, is advantageous in the final emulsion. If the initial emulsion is too acid or alkaline it can be brought to the desired pH by adding a weak base or acid.

'As previously indicated the emulsionsizes of the invention made with naphthenates of acid number less than 200 are highly stable compositions which do not coagulate readily in the absence of cellulose fibers. However, these emulsions occasionally show some phase separation on long standing but can be brought backto a homogeneous state by shaking or stirring. Even this separation can be eliminated by adding small amounts of protective colloids such, for instance, as casein and gums.

The invention is, of course, not limited to the method of preparing new emulsion sizes de scribed, asotherprocedures arealso applicable. Thus, for example, it is feasible to produce highly effective sizes by mixing together a cyclic extract of lubricating oil, for instance, and previously neutralized naphthenic acids of acid number less than 200, preferably .the sodium naphthenates, followed by dilution with the required amount of water. The emulsions of sodium naphthenates of :-acid number less than 200'and high boiling hydrocarbons obtainedv as bottoms fromzthe refining of petroleum :oils by distillation in the presence of caustic soda are also very suitable for sizing according to the invention.

'In contrast with sizes usually used in the manufacture of paper and-cardboard :which are generally used in the form of very dilute seminsions, e. .g. of about 0.1% to 0.5% concentration, the products of the invention can often :be used in much more concentrated form. Thus, in the manufacture of paper and cardboard they may be employed as 20% to 50% emulsions o-f theoilin-water type quite successfully.

The new sizes of the invention, as previously pointed out, may be used without any other change in the paper-making process. "They are preferably precipitated on the fiber with paper makers alum and a pH of about 4.5 too, depending on the type of pulp, is desirable during precipitation. If necessary, the pI-I may be controlled by adding diluteacid in the beater. About 25 grams of aluminum sulfate per kilogram of dry stuff in the beater gives satisfactory precipitation. Too much aluminum in the paper should be avoided as it adversely affects the permeability to water.

The sizes of the invention may be used in making papers filled with kaolin and the like as well as in making unfilled papers. The new sizes also do not give any complications with paper dyestuffs. They are not only cheaper than the usual sizes but also have the advantage that the sizing effect obtained is greater than would be expected from sizing with either of the constituent parts of the product alone.

The following examples illustrate typical applications of the sizes of the invention and show their advantages in sizing paper.

Example I To show the superiority of the compositions of the invention to rosin in emulsion sizes using a furfural extract of a lubricatingoil distillate of California petroleum (motor grade lubricating oil having a viscosity of 200 at 210 F'.,.S. U..S:), four emulsions were prepared-byadding suflicient 10% sodium hydroxide solution to mixtures .of the extract and de-oilednaphthenic acid of :acid number 150 or'rosinto-saponify of the acid. The resulting water-in-oil emulsion was mixed with moderate agitation for 15 minutes. The emulsion was then inverted by addition of water to form a 50 oil-in-Water emulsion. Agitation during inversion was afforded by an Eppenbach homo-mixer using as high a rate of shear as possible without incorporation of air.

The size emulsions were diluted to 1% oil-inwater and addedto kraft beaten pulp (2 of size' P t b 'Purgstoty or s y weig weight of naph- Parts by am (if exttheiiicf weight g rac aci o of rosin used l50'acid (mm') (mm'2) number Using a lower boiling fraction" of furfural extract of viscosity 60 at 210 F. instead of that used above, the sizing was not as satisfactory but was still superior in the case of the size containing naphthenate of acid number 150. 5

Similar good results are obtained when sulfite pulp is substituted for the kraft pulp.

Example II The fluorescent size test was carried out as dedescribed by Van den Akker et al. in the Paper Trade Journal, vol. 109, page 33 (1939), and shows clearly the superiority of the naphthenatearomatic extract mixture.

Example IV The superior stability of the emulsion compo-' sitions of the invention is shown by the following results for emulsions of a highly aromatic extract having a viscosity at 210 F. of 2030 obtained from an industrial lubricating oil distillate of California petroleum having a viscosity of 200 at 210 F., S. U. S. All the emulsions were prepared in the same way.

. Size test, sec. Dilution Water TAPPI pH of standard Sizing agent Agitator emul- T 51011 1 5' 3 '7 1 ,0 a Type 0. size size Rosin 31 32 Hydrocarbon-naphthenate mixture. Propeller 31 39 Do do 33 43 Homomixer. 33 41 32 40 34 40 34 38 1 pH adjusted with boric acid.

These results show that under a wide range of conditions the new compositions of the invention are fully equal or slightly superior to the standard rosin size at lower size concentrations and 40 are markedly superior thereto at higher concentrations. Electron micrographs of the sized papers showed that the particles of size on the fibers were much smaller and more uniformly distributed in the case of the mixture of lubrieating oil residue and naphthenates of acid number 150 than with the rosin size.

Example III Comparative tests were made on the use of an aromatic extract of petroleum having a viscosity at 210 F. of 537 'S. U. S. with naphthenic acids of 150 acid number containing about 3% of oil, on the one hand, and an equal amount 55 of rosin, on the other. The emulsions were prepared by mixing 80 parts of the extract with parts of the naphthenic acid or rosin, 1.9 to 2.1 parts of sodium hydroxide and 100 parts of water in a Waring Blendor for minutes at 0., then adding water to form a 50% emulsion and continuing the mixing for 30 minutes. The emulsions were used to size kraft paper, as described in Example I, with the following re- Composition (parts by weight per parts Stabilit water) y Emulsion particle size 95 lub. oil distillate, 5

parts sodium naphthenate (acid number Stable Majority about 0.2

microns.

Emulsion broke Large, several greater over night.

than 20 microns.

Emulsion broke Could not be measured immediately.

because of emulsion instability.

Sizing tests with the above lubricating oil distillate-sodium naphthenate emulsion, using 1.95% size based on the dry weight of kraft pulp, gave the following results:

Dry indicator test (TAP- PI standard proc dure) 41 sees. for penetration Fluorescent size test seconds The other emulsions were too unstable to warrant size testing.

7 Example V The superiority of the emulsions of aromatic extracts with naphthenates of acid numbers less than 200 compared with similar composition prepared with'high acid number naphthenates is shown by the following results for emulsions containing 50% water, 45.5% of an Edeleanu extract of viscosity 79.8 S. U. S. at 210 F. from a lubricating oil distillate of viscosity 60 S. U. S.

Acid Aver: Ml. of upper phase number age separated from of oilmole- Per- 80 m1, of emulfree cular cent 5 i o n a f t e r Form ofnaphthenate naph weight oil in (hours) thenic of crude acid, ifiiphacid mg. emc KOH/g acid 4 8 20-24 44-48 196 Sodium naphthenate. 118 475 3. 2 2 2.

W ile the advanta e of t e ne omp itio 'of the invention in sizing paper and related fibrous materials, particularly cellulose fibers and the like, have been emphasized in the foregoing because of the special importance of this novel application of these products, they have many other advantageous uses. Thus, for example, they are particularly suitable as agricultural sprays where a thin, sticky residual film on the plants is desirable to keep the insecticide or fungicide or the like from being blown off after application. They are also useful in aqueous paint emulsions, particularly when, as is preferred, extracts having drying properties are used in their preparation. Such emulsions are advantageously pigmented by adding a separately prepared slurry of pigment, for example, lithopone, zinc oxide, titanium dioxide, ochre, iron oxide or the like, preferably containing glue, to the emulsion with stirring, in the proportions of about 50 to 700 parts of pigment per 100 parts of emulsified extract and naphthenate.

It will thus be seen that the new compositions of the invention offer many advantages not only as sizing compositions but also in a variety of other uses. It will therefore be understood that the invention is not limited to the applications given as illustrations nor to the details of operation disclosed by way of example.

I claim as my invention:

1. Paper pulp having on the surface thereof a precipitate from an emulsion of a sizing agent comprising cyclic components of a lubricating oil fraction of petroleum soluble in a polar solvent having a preferential solubility for the aromatic and naphthenic components, and having a viscosity of 75 to 5000 S. U. S. at 210 F., together with sodium naphthenate salts derived from naphthenic'acids having an average acid number between 100 and 200, the amount of said naphthenic salts being from about 3% to 75% of the total weight of said salts and said cyclic components.

2. A process of preparing an emulsion of hydrocarbon with water which comprises intimately contacting a liquid cyclic extract of predominantly aromatic and naphthenic nature derived from a mineral oil with 5% to 50% by weight of naphthenic acids having an average acid number between about 100 and 200, reacting the mixture with an aqueous solution of sodium hydroxide of 5% to 15% concentration sufiicient to neutralize 85% to 95% of the naphthenic acid a d. form an muls on o the water n-o t p and diluting said emulsion with'water to bring the total water content of the mixture to 40% to and form an emulsion of said hydrocarboil in water.

3. An emulsion of the water-in-oil type suitable for use as a siz ng agent and for other purposes comprising to parts of a mixture of cyclic components of a lubricating oil fraction of petroleum soluble in a polar solvent having a preferential solubility for the aromatic and naphthenic components, together with a naph thenate salt derived from naphthenic acids having an average acid number between about and 200 in an amount from about 3% to 75% based on the total weight of said cyclic components and said naphthenate salt, and 20 to 40 parts of water.

4. A mixture of a cyclic extract of predominantly aromatic and naphthenic nature obtained by extracting a lubricating oil fraction of petroleum with a polar solvent having a preferential solubility for the aromatic and naphthenic components, together with 3% to 50% of a naphthenate salt derived from naphthenic acids having an average acid number between 100 and 200, said percentage being based on the total weight of said nap-hthenate salt and extract present.

5. Cellulose fibers having the surfaces thereof coated with a precipitate of a cyclic extract of predominantly aromatic and naphthenic nature from a mineral oil, together with from about 3 to 75% of naphthenate salts derived from naphthenic acids having an average acid number of between 100 and 200, said percentage being based on the total weight of naphthenates and extract present.

6. A paper product comprising cellulose fibers having distributed on their surface 0.5% to 5% by weight of the dry fibers of a mixture of a sizing agent made up of a cyclic extract of a mineral oil, which extract is of predominantly aromatic and naphthenic nature, together with a naphthenate salt derived from naphthenic acids having an average acid number between about 100 and 200, said naphthenate salt being present in the amount of 3% to 50% of the total weight of said sizing agent and naphthenate salt.

7. Cellulose fibers having on their surface a sizing agent precipitated thereon from an emulsion of the oil-in-water type essentially comprising at least 40% by weight of Water, a liquid cyclic extract of predominantly aromatic and naphthenic nature derived from petroleum hydrocarbons and having a viscosity of 75 to 5000 S. U. S. at 210 F., together with sodium naphthenate salts derived from naphthenic acids having an average acid number of between about 100 and 200, said sodium naphthenates being present in an amount of 3% to 50% by weight of the total amount of said naphthenate salts and extract.

8. Paper pulp having on the surface thereof a mixture of cyclic components soluble in solvents having a preferential solubility for the arcmatic and naphthenic components extracted, to-

.gether with naphthenate salts derived from total weight of naphthenate salts and said cyclic components,

9. An emulsion of the oil-in-water type essentially comprising at least 40% by Weight of water, a liquid mixture of cyclic components of petroleum having a viscosity of 75 to 5000 S. U. S. at 210 F. which are soluble in a polar solvent having a preferential solubility for the aromatic and naphthenic components, and sodium naphthenate salts derived from naphthenic acids having an average acid number between about 100 and 200, said sodium naphthenates being present in an amount of 3% to 50% by Weight of the total amount of naphthenates and said cyclic components.

10. An emulsifiable composition comprising a mixture of cyclic components extracted from petroleum hydrocarbon having a. viscosity of at least 100 S. U. S. at 210 F., and which are soluble in solvents having a preferential solubility for aromatic and naphthenic components, together with sodium naphthenate salts derived from naphthenic acids having an average acid number between 100 and 175.

THEODORE F. BRADLEY.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Frizell Apr. 27, 1926 Becher July 31, 1928 Novak May 8, 1934 Gay Apr. 7, 1936 Rich et al Sept. 10, 1940 Bradley July 14, 1942 Zimmer et a1. Jan. 25, 1944 Gaver May 2, 1944 Butcher Apr. 30, 1946 Gregg July 1, 1947 Roon July 8, 1947 Kaberg et al Aug. 17, 1948 FOREIGN PATENTS Country Date Switzerland July 1, 1921 Germany Nov. 27, 1922 OTHER REFERENCES Gershzon, Chemical Abstracts, vol. 33, p. 8989. Gershzon, Chemical Abstracts, v01. 34, p. 3119.

Claims (1)

1. 5. CELLULOSE FIBERS HAVING THE SURFACES THEREOF COATED WITH A PRECIPITATE OF A CYCLIC EXTRACT OF PREDOMINANTLY AROMATIC AND NAPHTHENIC NATURE FROM A MINERAL OIL, TOGETHER WITH FROM ABOUT 3 TO 75% OF NAPHTHENATE SALTS DERIVED FROM NAPHTHENIC ACIDS HAVING AN AVERAGE ACID NUMBER OF BETWEEN 100 AND 200, SAID PERCENTAGE BEING BASED ON THE TOTAL WEIGHT OF NAPHTHENATES AND EXTRACT PRESENT.