Coating

Nov. 15, 1938.

2,136,557

A. MacLACHLAN

COATING

Filed Dec. 3, 1937

<img file="US2136557A_D0001.tif" />

Patented Nov. 15, 1938

2,136,557

UNITED STATES PATENT OFFICE

2,136,557

COATING

Angus MacLachlan, deceased, late of Metuchen, N. J., by Walter H. Griffin, executor, New York, Νί Ϋ.

Application December 3,1937, Serial No. 177,971 5 Claims. &lt;

This invention relates to an article of fibrous or cellulosic material which is partially or entirely coated or impregnated with a fat to render it waterproof and greaseproof. In a more specific aspect, the invention relates to a container particularly adapted for the packaging of in which the coating material is an edible fat. In another specific. aspect, the invention relates to a container for packaging grease and oils, or oily materials.

Prior to the invention, packages of sheet materials,-and particularly of paper or moulded filirous material have come into very wide use. Where waterproof or moistureprpof qualities are required, such containers have been coated with materials such as paraffin or wax, but the coating materials which have been known prior to the invention have, for the most part, been unsatisfactory as greaseproofing materials and not 20 entirely impervious to vapors, so that moisture may be slowly absorbed through such a package and flavor slowly lost, whereas those which have been adapted for coating the containers in which greasy materials are to be packaged have been so expensive, difficult of application, or unsatisfactory in use as to limit to a considerable extent the use of paper containers.

Accordingly, it is an object of this invention to provide a waterproof, greaseproof, and, if desired, impervious fibrous or cellulosic article which avoids the difficulties and objections to those known materials and which may be uniformly impregnated with or without appreciable surface coating, or may be uniformly surface coated with or without impregnation, and the coating or'impregnating material of which will help to stiffen the fibrous or cellulosic base material, but which may allow substantial flexing thereof without impairment of the greaseproof quality of the maIt is also an object of the present invention to . treatment as just described, is melted provide inexpensive containers (1. e, _a„d preferably maintained at a temperature of5 wrappers, bottles, dishes, and in _ap_Out 250° F. while it is being applied to the designed to hold an article or material or tem- - . . . ---------— « ; porarily to protect it from loss or contamination), which are coated with a material which is unobjectionable from every standpoint, and which furthermore serves to improve on the qualities of the material of which the container is made, and which will satisfactorily resist the action of water, fats, oils and other materials which are present in foods, or other articles or materials, such as are commonly placed in such containers.

It is a further object of the invention to provide a coated container which is not much more (Cl. 91—68) expensive than paraffin-coated containers, but which will be capable of much wider use for the packaging of numerous materials, including milk, crackers, salad dressings, lubricating oils, paints, except that paint thinners may. dissolve the coat- 5 ing, so that paints which contain any large amounts of such thinners should not be packaged in this material, putty, and many other materials.

In the accompanying drawing, are illustrated three types of containers embodying the present , invention. ,. .

In Fig 1 is shown in perspective a cup. type container made from paper which is shaped and pasted and thereafter impregnated m the usual manner with the waterproofing and greaseproofing material hereinafter described.

In Fig. 2, is illustrated a similar type of container made from fibrous pulp deposited upon a mould and subsequently pressed and coated, e. g., by impregnating with a waterproofing and greaseproofing material.

In Fig. 3 is shown a carton lined with a sheet of paper coated with the same material.

A material which has been found to be highly advantageous for this purpose is a hydrogenated fish oil (e. g., menhaden oil) in which the genation has been carried to a point such that the product is a hard material which melts fairly sharply at a temperature near 55 C. (130 F.), and which does not become soft or sticky or greasy much below that temperature. The material as it comes from the hydrogenation process usually has a rather strong, sweetish odor which, if objectionable, may be removed by melting the material in vats at a high temperature and blow- 35 ing with steam under a vacuum as high as is practicable, or by other suitable treatment. After such treatment the .material is substantially odorless and tasteless and it may be used directly for the coating of containers, etc. 40

The hydrogenated oil, preferably^after^tbejieand preferably maintained at a objects to be coated or impregnated. A higher 45 temperature will result in more rapid impregnation, but it has been found that 250° F. produces entirely satisfactory results.

When a container, for example, is immersed in a bath of this material at a temperature of 250° 50 • F or higher, it will at first violently boil exactly as’ a cruller does in hot fat, and when this boiling ’ has ceased, the material will have penetrated the paper sheet and the moisture will have been substantlally entirely driven out from the paper. 55

IS °^{Γ lmpregnatin}? may. however, be ^d°^PeJ“ ^otJher ways well known in the art, as by spraying, brushing or rolling, ^{removlag the} coated paper object from the impregnating bath and cooling to ^atm°s^pheric temperature, it will be found rela^pliabIe’ ^but “Pon standing it will rnndw ^{y h}t^{rden until it; has} assumed its final mi ^^W°ⁿ’ ^{which ls} β¹¹¹*® similar to that of CelSLh⁶·’ ^r.^elatively flexible without cracking, but elastic and hard. The coating may with some «

_ftb™?&lt;^OUgh?^ydrogenated oil as described bove Is preferred, and it has been found that the factory TtTto 2^? ^are Ocularly satS iaotory. it is to be understood that many other ^Wtb^{hin the Scope of the} invention.

The reason for the reason for the advantages of hydrogenated fish oil has not been fully deter mined but the fact that the marine oil?are cJm^{of the Wgher fat}ty acids, R wri ^{ly th}T ^eighteen or more carbon atoms s ver^y Important. It is also quite important that the range in these oils is quite narrow. Thus menhaden oil consists of about 70% of glycerides pfrh¹® ^aCi^dS °^f eighteen and twenty-two of fatty ^{and almost}, ^entlrc^ly of glycerides pLk ^y ?^{ld of} sixteen and twenty-two carbon atoms. This results in a high-melting Product substantially free from any fat that will ^at&lt; ^temPeratures encountered in stornft^^{d shlpplng and gIves} a sharp melting point or very narrow melting range. Other fats, either ydrogenated or not, that contain no appreciable £^OP°f^{tlon of}.^materials which remain liquid In ,^tbe,«^mixtl^® ^{at tem}Peratures below 40° C. may be i Partmularly those materials that melt 40 ^{Ρ ϊ around 55}° C. and contain no apprecipJtat^C°irnrp^tf»^ft^liqUldb^{materlal of lowei-} melting point. Pure fats, such as pure stearin, (glycervl tristearate) are examples of such material . ? ^{so * * * * 55 * * * * * been f}ound that the solid products

4K cnn'f^Iti^{mg f}I°^{m bydrogeil}ation of marine oils which ⁴⁵ h?ffbp^ln °^{f the} hi^er fatty acids with the higher alcohols may be used according to this in°^{1I1S an exain}Ple of such an oil.

Some vegetable oils also give good results but tatsⁿUr^gb^ta^^le °l^{ls and} most Inimaf oils’and ⁵⁰ will be found to contain so much of the bXw 4o« r^{aCld constItaents} which remain liquid tme ^{eVen at ord}mary room temperatreatmpnf ^{CanDOt be used} without special treatment to remove such constituents.

⁵⁵ tb^T? ^iI1Ustrate the essential difference between th??^ °i.^material suitable for use according to

SieraMv^n^d ^tlW ^^{ρε of materi}al which is generally unsuited, menhaden oil may be com.

iTtep u ^iUi .^cocoanut °¹¹· which could be used only fied^bv^Pifi⁰?⁵^^{61115 are sep}arated or solidl„^{d by}_n^{5pe 1 al} treatment and, therefore, may be ^g JL^er^^lly oonsidered to be unsuited. The fattv acids in manhaden oil are given by Allen’s Com , published by Blaklston, Philadelphia, Pa.) as: Per cent

22.7 9.2 1.8

24.9 22.2

20,2 alinitic acid (contains 16 carbon atoms) Myristic acid (contains 14 carbon atoms) __2 Stearic acid (contains 18 carbon atoms) ^Uatoms^{ated aCld containlng 18} carbon

Unsaturated acid containing 20 carbon atoms______________

Unsaturated acid containing 22 carbon atoms_________

9,138,067 inf°f^ya^^ea.ⁿ °¹¹· which also may be used accordlowing composition:

Palmitic acid (contains 16 carbon atoms) Stearic acid (contains 18 carbon atoms) Arachidic acid (contains 20 carbon atoms) Lignoceric acid (contains 24 carbon atoms) Oleic acid (unsaturated) (contains 18 carbon atoms)_______________

Linolic acid (unsaturated) conta’ins’ie’car^ bon atoms)_________________

Other glycerides, acids and impurities in very small proportions.

enSXnr di ^SeTT l^{hat thls 011 c0nsists} almost ¹⁵entirely of oils of fatty acids having more than 14 ^at°“^SJ £“^oanPt.^oi1’^{in c}°ntea_St, contains

Percent ²⁰

20 ²⁵^th' »·« 3» . .. . —-----— moj uc usea accordΐη^ίΐθ has approximately the folPer cent

6.5 £

4.2 0.7 0.1

32.0 It

49.3 « W “&lt;? *«« «S3 .he rohowtag

Commercial Organic Analysis:

p

Caproic acid (containing 6 carbon atoms)

Caprylic acid (containing 8 carbon atoms)

Capric acid (containing 10 carbon atoms) Lauric acid (containing 12 carbon atoms) Myristic acid (containing 14 carbon atoms) __ Palmitic acid (containing 16 carbon atoms) Stearic acid (containing 18 carbon atoms) ” Oleic acid (containing 18 carbon atoms) _ J °^f h^Vf^0WeJ ^{Of these fatty aclds or} their esters have a tendency, as already explained, to give in the hydrogenated products constituents that remain liquid or semi-liquid therein at ordinary temperatures and even a small percentage of such prociucts remaining in liquid condition may give the whole coating a greasy or oily feel and appearance, or even, by being interspersed with the solid material, so divide the particles of solid ma^{Permlt 011 or grease} contained within throu?hth_P°^{r 1}.^mpregnated container to pass through the coating or impregnating material. ., Uli th^e oils which have been found most g ly desirable for use in this invention contain »nd^PAt^rb^C1f ^e(^{am0UIlt of} these lower fatty acids; and other fats and particularly other hydrogenated fats may be used, provided these fats do not contain any appreciable amount of a constituent ti.at remains liquid at temperatures ordiai ^y encountered, that is temperatures up to al around 55° C. or at least up to around 40° C The nr* ^{matenals may} either be originally absent or may be removed or solidified in the preparation of the material, and very small amounts of the lower melting constituents may be present in solid solution in the higher melting fate pu“ steann, laurm, myrlstin, palmitin, etc., or natural the^^{ClaI mlXtUreS} °^{f these}’ ^{may ba} used, S theft ^provided always that in rneir flna! state they contain no appreciable M orH-n^eS °ί ^{materlals th}at will remain fs liquids at ordinary temperatures.

The solid hydrogenated fate used according to 65 the invention, as well as the pure fatty Serials m_at^riⁿi^10ne&lt;L^above’ ^{are in} contrast to greasy materials such as tallow, commercial stearin and the like in that It melts fairly sharply and a? po“nt^eft fed^Srv ?^b5tantia]ly_r ^low its’melting 76 and thPrAfnr ’ h ’ ^{has no Ilquid oU} constituent, ^Pd therefore does not have any tendenev tn ender greasy other materials with which it comes in contact, nor to collect dust

Materials used in the present Invention may be 75 the impregnating and coating material does not affect ordinary printing inks.

It has been found, furthermore, that the invention is applicable to the treatment of nonfibrous materials, such, for example, as flexible cellulosic films used for packaging various materials. The fatty material in this case may be applied as already described, but preferably is incorporated in a surface lacquer, replacing, in the latter case, wax which has been used to ren- . der the permeable cellulosic film impermeable.

The word “coating has been used herein broadly, and to include a coating wholly within the sheet,—thsft is, impregnation as well as surface coating—that is, a substantial layer above the base to which the coating is applied.

The word “fat” has been used to describe the fatty acid glycerides and. mixtures thereof, and it is not intended to include within its meaning derivatives thereof such as oxidation or poly- 20 merization products, the free-fatty acids, and the sulphurization products such as the so-called vulcanized oils. ,

Although a preferred embodiment has been described above and various modifications thereof, 25 it is to be understood that numerous other changes and modifications may be made within the scope of the invention.

Reference is hereby made to the copending application, Serial No. 640,568, filed October 13, 30 1932, by Angus MacLachlan, from which application the claims of the present application are continued.