Patented Nov. 26, ‘1946 2,411,580 "UNITED "STATES PATENT);oF-nce1_ Willard. 0. Manor, Monroe, . Mich., assignor to 1 Consolidated Paper Company, Monroe, Mich., a I _ corporation of Michigan . , No Drawing. Application'S'eptember 30, . . I 7 Serial No. 504,383 ‘1943, - 2 for the purposeasought.h This invention relates to shielding, protecting and coating walls, more particularly of ?ber-‘like , y . In thisibuildéup'for the M Thisinvention.hasutility when incorporated in solids of the starch and ?lm-forming plastic, such may be 7# each with say 200# of water. ‘This’ thin gruel direct Water solution, desirably as a methods of compounding, and applying, and also in ingredients of compositions and their associ trait or softness characteristic imparted thereto ation, especially with‘referenceto ?ber typesfof ‘ containers with an undercoating for a barrier. by some 20# of glycerine. The pliancy or soft-. ness in achieving this nondrying factor for this containers. ‘ . v batch, may have a ‘tempering, or water-holding tough characteristic may be attained for the plasg between the contents and the wall. The primary course herein is laying of athin?lm, desirably 10 ticvof the coating composition by the use, in lieu ofqglycerine, of, di-ethylene glycol, tri-ethylene of elastic or stretchable properties having tough glycol, or sulphonated oil, say of the castor type, This proportion of the tempering agent, when in the "region of 20# in the 214# proportion sug The skin andundercoating mayserve as a re sponsive severing means to effect isolation be 15 gested, is of commercial economy. However, as there may be longer storage period or other fac-' tween the wall and- contents. The container tors, suchxas the character of the calendering or proper may be, in itsuuse, not primarily for re?ll facing for the ?ber, variation may be adopted. service. In such latter instances the material In fact, as much as 40# of tempering agent or; may be ?ber developed from rag, paper, grass, ,-; I _ straw, or wood pulp, and compositions therewith, '20 plasticizer has been used. . , This composition of starch, plastic and-“tem in the general class of ?ber board, paper board, ‘ ness in maintaining askinfupon ,a container wall or undercoating. ’ , '. box board, and the like. __ ' " h ‘ . ' pering agent, has .but slight absorption proper v . As tothe coatings‘ or coating. materials, special value has been developed in features oftoughnessv ties as to ‘penetration of the ?ber board or wall 7 to be coated. It has non-crumbling properties of .' containers. In this blanking, there may be‘scor ing and marking or cutting. Under this inven—. hbruslnidipping o'r'roll coating, may be only just orelasticity. . In this type of compressible ?ber 25 viscosity as well as retained elasticity e?ective as‘ the tempering is a property thereof. In vpractice, board stock, such . is frequently-blanked out and it seems to extend as a very thin ?lm or skin. sent in knocked-down shape to be built up into The extent thereof in applying, whetherby spray, tion the coating may be applied at or before the 3.0 sufficient to'e?ect the continuity for. such coating‘.v blanking operation and be eilicient in the, assem blyv of the blank into a container even as to the corners where‘ there has beenvscoring or folding, .. This ?lm coating continuity is an isolating ' agent effecting dissipating of attack upon the well due to the ‘contents. . In'the instance of._sev ering from the contents, ‘iwhenl'of a non-tacky The purpose of the coating is to isolate the charged contents ormaterial from attackingthe 35 nature, altho molten or at a'high temperature as ?lled into the container, thev coating may t'oa container. The contents may be hygroscopic, a major extent go with the wall, insteadIof adhering solvent, vapongrease or oil. ‘ . > Additional problems arise in the handling of - with or becoming a part of the contents. In the instance that the contents are edible,‘ these‘ are hot substances. The substance to be placed in the containermay have seemingly no a?inity for 40 matters tobe givenattention,» However, due to the, very thin character of this ?lm, it is of such the container, or be ‘readily fracturable there incredibly minor proportion "as 'to be not in the from, asparaf?ne wax. Again, it may be a sub- . realm for consideration as an adulterant or con stance having tacky or adhesive traits as asphalt. " tamination of. the (container contents " when, in The contents of the container as reposing or so removal,’ this film be'associated with such conev lidifying may .or may not tend to hold the. con ' tainer to shape. ‘ Should such contents normally tents. '. >> " .. ' ~ . . ~ ?lm on an undercoating.‘ The unde'rcoating co its container walls ‘as to be effective for such hold ins 1.30 Shape- K -. El?icient isolation between the container and its contents is achieved by locating this'stretchable tendnotto hold to shape, the containeradopted hereunder maybe} offsuch‘vphysical strength in 50 With 50% starch, as Casava, there may be an equal‘quantity, or 50% of a ?lm-forming chemi cal. “These areinthe ?elds of resins, or resin- ‘ like. materials, vandinvthe‘ cellulose group from operatesv as'a dam oribarrier comprising aV-dis persion of a powder-like material, preferably very ?ne andto have it effective in continuity. ~ How ever, .ef?cient results in the non-food ?eld have been obtained with ?ne clays or silicates, such as . _. polyvinyl alcohol and’ including methyl cellulose. 55 kaolin. This under-coating is wiped, laid, sprayed In this-compounding,referredto asequal quan tities,‘ there 'may. ‘be ayariation in the starchy or rolled, say in association with Water'or a glue agent, and thereby anchored through theaction substancespf as-much as one1-half,5and-;up1to 100%. of the ?lm, forming. material without starch. The'jtraits to be‘ considered fare'those :of economy. of this ?lm-carrying overcoating. » . Instead of elementally handling engender coating as merelythe kaolin and thev glue- and.‘ 2,411,580 3 4 water vehicle therefor, supplemental traits of ad vantage may be achieved in e?icient dispersion thru the medium of a low grade karaya gum of When an additional or undercoating be desired, such may be Kaolin 265# high viscosity. This gum has been used in quan titles and range from 5%# to 7#. In fact, in stead of this karaya gum, gum arabic or gum tragacanth may answer; but commercially there has been advantage in the karaya type. This ad vantage arises from its great rate of water solu bility. With a charge or quantity of gum, there 10 may be mixed therewith a carbonate. For this solution there may be 150# of water. The carbonate, when an ammonium bicarbonate, seems among the carbonates to contribute to a greater 7 extent in smoothing out the mix and holding such for a maintained high degree of ?uidity. ‘This proportion for the carbonate may be taken as 13%#. At times there are variations in the gum, and this quantity of the carbonate has been increased and decreased as much as 50%. With this ‘under-coating of viscosity or water carrying traits established in a degree of sta bility for smoothness, further advantage arises from incorporating an adhesive therewith. For commercial purposes, a low grade animal glue may be taken, and its proportion may be 13%#, that is, in the quantity adopted for the am monium bicarbonate. The glue, dissolved in the Water _______________________________ __ 90# Gum, as karaya ______________________ __ 5%# Carbonate, as ammonium _____________ __ 13%# Glue _______ _l _______________________ __ 13%# and may have Glycerine ____________________________ __ 511/2# Sodium nitrate _______________________ __ 51/2# Pigment, as carbon black _____________ __ 8# Sodium benzoate _____________________ __ 1% Tetra-sodium~pyro-phosphate ________ __ 1. 3# thinned with water to the consistency desired for applying. , The clay powder or under-coating in its nature is porous, as distinguished from the ?lm-form ing 'overcoatin-g being impervious. Furthermore, the ?lm-forming overcoating has a property of adherence. The interposition of the powder ma terial undercoating thereby provides a support for the ?lm-forming overcoating and hereunder is desirably sufficient in the proportions to isolate the ?lm-forming overcoating from the wall, due to the continuity of the undercoating. An instance of ‘practical range for coverage, water, may have its lplasticizing traits or proper may betaken as to a container for asphalt. The ties increased hereunder by the inclusion of say 30 area for one side, say of a ream of ?ber board 51/2# of sodium nitrate therewith. While these 24” x 36”—a total of 2880 sq. ft.—may have proportions for the adhesive, sodium nitrate, glue the clay add to the weight of the board as much and water are suggested as 13%# of the glue In practice this runs around 184%. as to like quantity for the ammonium bicar The ?ber board itself varies over quite a range, bonate, such may vary with or away from the 35 according to the volume of asphalt. For l0# carbonate. ' of asphalt, the container Wall may run .020" to .040", or say from 2201? to 440# per ream. When Furthermore, in this primary or undercoating, there ‘may be adopted retaining .traits against the container is to carry 400# of asphalt, the ready fracture. This tempering or water-carry ?ber board thickness may run .050" to .100", or ing or retaining quality, which may even go to the 40 weigh from 560# to 1120# per ream. The clay extent of increasing the Water-carrying or mix undercoating for one side would thus run say 18# ing values, is attained'thru glycerine, which may to'the ream, whether for the thin or heavier ?ber be in the quantity of 511/2#. For such tempering ‘ board._ The ?lm-forming overcoating would run agent, sulphonated oils, of which sulphonated l# to '2# per ream. castor oil may be preferred, may be adopted with 45 The functioning in all instances is to the end that there is ‘non-adherence and non-contami nation between the material of the container and the quantity in the range of 45#. There may even be variation ‘up and down of 5% or more, as well as with the glycerine. With this gum dispersed thru the carbonate and nitrate treated adhesive as a vehicle or carrier including the glycerine or tempering agent, there may be introduced the clay or kaolin, 265#, even with an additional 90# of water. The purpose had with this clay is that such may be the ?ller or body and be of ?ne particle size or texture. The quantity of water may have its variation for the desired degree of spreadability and be suf ?cient in the viscosity range for the ingredients, as for dip, spraying, brush painting or roll coat the container walls. In the practice hereunder, even from heat of the contents, the container wall is immune from or resistant to attack by the contents. The water dispersed clay has such clay run in solids, say from 40% to 60%, in the suspension mixture, with ingredients in solution to provide adhesive properties in body and effectiveness, rel atively minor as to the clay, but with the adhe sive traits at least just sufficient to establish a bonding mounting for the clay. This is in real ity only a temporary characteristic for the bond ing. ' (K) ing or holding action and is possessed as the coat Upon pouring a charge of hot material into the ing is at ?rst applied. For speed advantage in container coated with the barrier or dam and manufacture, it’ has been found that this single having thereon for the ?lm substance a resin, undercoating has its continuity better established in two applications. These may be in relatively non-adhesive or di?ering from the traits of as phalt, the severance may result in approximately close succession to range for the total clay some all of each of the coatings or residue thereof go 5# per 1000‘ sq. ft. of surface. Immediately thereafter, and while this under ing with the container. Example of ?lm coating: coating is still alive in its adherent property; that is, before any crumbling away has occurred; Starch material _______________________ __ 70 an overcoating is, applied. This overcoating skin Plastic ?lm-forming material __________ __ 7# or ?lm, in some practice may be complete for the Water ________________________________ __ 200# job. However, more efficient results are achieved in association with the major volume undercoat and may have ing. The traits of this ?lm are continuity against Tempering agent __________________ _l___‘__ 20# 75 rupture. "Commercial advantages as developed , 2,411,580 5 6 hereunder extend not only to polyvinyl alcohol, asphalt fOr'SllCll gauge of ?berboard. In such but to celluloses or" methyl ‘cellulose type, pro teins of casein and mazein types. In getting away instance the clay may run from 51;‘: to '7# per 60% methyl cellulose. The proportion has been I as gum arabic and gum tragacanth, the skin-de veloping body in the starch association brings therewith physical problems. A de?nite com parison is the fact that with methyl cellulose such may be used in su?icient quantity at 1A.;# per 1000 sq. ft. of surface. For comparable results as to I the tough ?lm and continuity, the experience is for up to 2# of the proteins and 5# and more . , . 1000 sq. ft. and the starch-methyl cellulose ll/iyt-t per 1000 sq. ft. in which the latter ?lm coat is from the celluloses by the proteins toward gums, of the gum. , used successfully with 5# of clay per 1000 sq. ft. for‘the undercoating and 1/2# starch-methyl cel m inert- clay body as the ‘barrier. In this embodi ment, the absence of a moisture- or water vapor Y The ?lm or thin skin overcoating has physical ing of the wall for inside or outside corner, as well as scoring. This holding trait and elasticity, not only are e?ective against its rupture in nor ?lm and adhesives of the character of gum or. .glue, there remains the undercoating relatively y strength for continuity and distortion by fold lulose for 1000 sq. ft. for the overcoating. With the'hot asp-halt acting to vaporize or destroy the barrier, e?lciently permits a sort of vapor breath 15 ing to‘ avoid any entrapment .01" void cluster regions. The coatings as applied are of ?uidity tov be ready flowing mixtures or solutions, with entire absence of tacky or jelling characteristics. v mal carton handling practice, but the undercoat From the foregoing, the subject-matter disclosed ing is anchored against crumbling away from the 20 herein relates to a container wall'comprising an wall. The overcoating su?iciently seals that its film strength allows of collapsed carton storage, outer layer of ?brous material and an inner dual coating layer impermeable to asphaltum, bonded even for months, and with evaporation as to - to but severable from said ?brous layer, said inner dual coating layer comprising a ?rst major the undercoating limited to thruthe wall body, even when such wall be ?ber, it is very material ly retarded, and may be further slowed down by 25 body undercoating of water-dispersed clay and su?icient adhesive that this ?rst undercoating a waterproo?ng coating on the converse or outer ‘ may isolate the second coating from the Wall, side of a ?berboard wall. The characteristic of and said second continuous lesser-body-carrying ?uidity in applying the undercoating due to am—' coating agent thereon of organic resin-like mate monium carbonate, may be in some measure taken 30 rial, independent of emulsion with water, possess-J care of by other carbonate, especially of the al ing a, characteristic for thin ?lm spreading in di— kali type as sodium or potassium. In the selection of ingredients or materials, costs, as to ef?ciency, are factors controlling. ' The course adopted by applicant has shown advantages in compensating for, or rather per mitting volatilizatiom or some vapor escape. In those instances where the container is to‘ take rect water solution over the less thin ?rst under coating and with such cohesive consistency to maintain the clay as a dam effectually spacing the 35 ?lm from the ?brous body thruout the extent of the wall during hot charging thereon of as phaltum, 'for wall severability thereafter from the solidi?ed asphaltum. Importance resides in water solubility characteristics of methyl cellu a charge as hot ?lled; that is, above the boiling point of water, as say hot asphalt at 300° F., en 40 lose in its use with starch in providing the or-' training or trapping, of the vapors would tend to ‘ ganic resin-like material of the second lesser produce blisters at or in the wall and foaming ' body-carrying coating. or voids in the contents. Herein, the starch and It is to be noted that'the coatings as e?ective methyl cellulose or other solution of the‘over to retain asphalt and the like, have oil proof and coating ?lm or skin, tends to pass off at the high 45 grease proof resistant qualities. However, due temperature. This it is freeto. do thru the por to the use of water suspensions and solutions for I ous clay body of the undercoating. The under carrier or spreadability traits in applying, there is coating adhesive is of such minor proportion as some slight moisture present. The ?lm and wall not to ?ll or seal the pores of the ?berboard. Ac tend to slow up drying out. Somewhat di?erent cordingly, the vapors generated by the hot as 50 rate is developed when hot charge of contents be phalt do not come back into the asphalt, but introduced into the container. This speeded up thru and from the clay body pass into, thru and drying out is a sort of exhaling from the container from the ?berboard outer side, at a rate to avoid bubbling or foaming of the asphalt, and still This application is a continuation-in-part of so distributed in the ?neness of exit ways as not 55 myPatent 2,333,023 for Container wall. to weaken the container wall. Flow of the as What is claimed and it is vdesired to secure by ‘ phalt is not to contact the wall inner side, for Letters Patent is: there is the inert clay barrier or wall. A container wall comprising an outer layer of With the container charged with the congeal ?brous material and an inner dual coating layer ing asphalt, there is the physical strength of the 60 impermeable to asphaltum, bonded to but sever ?berboard wall suf?cient, at least at this setting able from said ?brous layer, said inner dual coat stage ‘for the contents, to hold the clay as a ing layer comprising a ?rst major body under sort of partition or barrier between the asphalt coating of water-dispersed clay and suf?cient ad and the ?berboard, even should the ?lm have ' hesive that this ?rst undercoating may isolate disintegrated. ' The body of the clay is su?icient, 65 thesecond coating from the wall, and said second wall. in this inter-asphalt-and-?berboard compart ment as to constitute a dam against attack of ' . continuous lesser-body-carrying coating agent thereon of organic resin-like material of methyl the ?berboard by the asphalt. As the asphalt cellulose and starch, possessing a characteristic congeals, the hardness of its solid state is suf for thin ?lm spreading in direct water solution ?cient reinforcement .05" to .10" thickthat as 70 when applied over the less thin ?rst undercoating. a drum it may have a capacity of up to 400# of , . WILLARD O. MANOR.