Патент USA US2070596код для вставки
Feb. 16, 1937. D, w, HANSEN 2,070,596 "MANUFACTURE OF LAMINATED FILMS Filed Dec. 11, 1935 "4 1 [As/LY STQ/PPA BLE HLM - n/ ‘ As Of Caz UL 055 [5 75/? [3/455 _. > % 6" SECOND Hm AS OF P/POLAM/NE BASE C/asr o/v CELL (/1. 05E [5?" 1,4 G i5 5/? f7LM,/l/JH£/2E/vr 7745/95 7'0,A/VD 0 LAss METAL UNITED To 1r AFTER _\57'/?/PP/NG E’ ‘ ‘ h‘ A v SURFACE , I / / J1 I / lg 10 r ' ' fAs/LY STIQIP/JABLE F/LM As 0F CELLULOSE £5 TEE BASE 11/. %'3 14 ~ 11 j ‘ ' F/uv B‘ F/LM A / / 10 v ' ‘ ~ Ewe 72.2‘04 ' ’ 2,070,596 Patented Feb. 16, 1937 UNITED‘ STATES PATENT AOFFICE?‘75.1.15“. 2,070,596 MANUFACTURE OF. LAMINATED FILMS Ill., assignor, by Donald W. Hansen, Decatur, to Prolamine Products , mesne assignments, Incorporated, Dover, vDel., ‘a corporation of . ' Delaware ‘ Application December 11, 1933, Serial No. 70l,865? '1 Claims. (Cl. 18-57)‘ the following description and explanation of ‘the The present'invention relates to the manufac ture of ?lms and has particular reference to the casting of ?lms on smooth surfaces. - invention. ‘ - V ‘ ' 7 In the accomp‘anyingdrawing there is shown diagrammatically a representation of the inven-' I Itls a custom in making ?lms to flow‘ a liquid .5 or viscous mixture onto a smooth surface where tion and the process. ‘ ' ' " » Fig. 1 represents a casting surface of cellulose the mass sets, as for example by the evaporation ' ester ?lm itself cast on and remaining unstripped» of a solvent. Sometimes glass is used, other from a solid smoothsurfaced body. times polished metal, and sometimes mercury. The latter is particularly necessary where the dried or set ?lm is adherent to solid surfaces such as‘ glass or metal. The selection of the solid 1 s second ?lm has been cast thereon, and also shows the united ?lms being stripped from the solid surface material is in part predetermined by the tendency of a particular. ?lm composition to. adhere in the forming process. 15 ' Fig. 2 represents the cast of Fig. 1 after a " Films so formed are ' thereafter frequently coated with a surfacing composition to give to the body.v ‘ h ' Fig. 3 represents the form of Fig. '2 with a third ?lm applied before the stripping operation.v ' In carrying out the invention a smooth sur faced bodyof glass,.povlished metal or stone may be employed as asolid cast. This may be ?at ultimate sheet certain properties which are not ' as a plate for making sheets or curved as a cylin exhibited by the body of the ?lm. As an example of such coating, reference is made to the practice‘ of applying a waterproo?ng nitrocellulose lacquer 20 to a regenerated cellulose to form what is com mercially recognized as “waterproof cellophane”. der for forming continuous sheets, or some suit able form from which a non-adherent ?lm cast‘ 20 thereon'may be stripped without destroying “the continuity of the ?lm. In the drawing a ?at form l0 is'illustrated. Onto the cast“) I form The present invention relates to the formation ' a ?lm of ‘any suitable material, necessarily char; of such a multiplex ?lm, and has‘ particular utility in casting ?lms which have a tendency to adhere to a casting surface, or in other words which do not readily strip from a casting surface. The invention ‘calls for the formation of a ?lm 2 which does strip readily from a casting surface, acterized by ability to strip readily from the 25 cast l0. A very'thin or thick ?lm may be formed, and it may be formed by setting of a mass, or by the evaporation of a solvent from a solution ap plied to the surface ll of cast lit. The ?lmis ‘ designated i2 and its surface is designated IS. 30 30 thus to provide by such ?lm a new'casting sur- - The coated cast I0 thus forms a new cast forthe face onto which another ?lm may be cast. The general object of the invention is the formation of a strippable ?lm on a casting sur face, and the casting on said ?lm of a second ?lm, 35 and stripping the two ?lms together from the second ?lm and a new casting surface l3. _ Onto the new casting surface I3 I form a second ?lm [4 characterized by ability to adhere to the ?lm l2. The new ?lm H may be set from a mass 35 applied, or may be formed by applying a solution to the‘surface l3- and evaporating solventfrom A particular object of the invention is the the solution. In the latter event, the solvent may casting of a ?lm-forming’ composition, which be such as to soften or partially dissolve the ma normally adheres to a casting surface, upon a terial of ?lm l2, but this is not necessary» if ad-_ which is readily ' herence is otherwise obtained or naturally results I 4 O preformed unstripped cast ?lm strippable from its casting surface. ‘from the nature of \ the materials. ' I A further object of the invention is the forma ‘When the new? or second'?lm I4 is dried the tion of a casting surface for ?lms in the form of casting surface.- , i a strippable unstripped ?lm. 45 ‘ Still another object of the invention- is the casting of a prolamine base ?lm onto a strippable unstripped?lm of cellulose ester base. A further object of the invention is the forma tion of a duplex ?lm of which one layer is‘ a 50 prolamine base ?lm. v I ‘ Still another object of ,the invention is the formation of a triplex ?lm of which the inner ' layer is a prolamine base ?lm. 7 Various other and ancillary objects and ad 65 vantages of the invention will be apparent from ‘ two ?lms, whichare now united, may be stripped as one‘?lm from the solid cast Hi. -i The product is a duplex ?lm with layers of differentama terials'on the two-sides.‘ ‘ ; I I I If desired a third layer l5 may be appliedito layér l4 before thestripping operation as shown in Fig. 3. The third layer may bethe sameor 50 different from the ?rst layer l2. It is :pre-‘ ferred to make it the same as the ?rst ?lmso that the‘ resulting triplex product may have a '‘ heavy middle layer as a body, and similar thin‘ coating layers for special surface properties. In 55 V‘ 2,070,596 v the drawing the three layers are designated ?lm used for proo?ng compositions to be applied to p In actually carrying out the invention I have applied it by using as ?lm B a prolarnine base hol, which is a ‘quick solvent for zein, or it will prolamine ?lms already ‘formed and stripped, it is advisable to omit ethyl alcohol or other-alco cause the zein ?lm tostretch and curl, Thus, where'?lm C isto be appliedv to ?lm B, itis and have a- tendency .to adhere to glass, polished, .1 preferred to'apply the composition for ?lm C ?lm,‘ asof zein, hordein or gliadin. .Such ?lms ,may be formed from aqueous alcoholic solution . ’ 5 metal, etc. ' ' ' beforethe stripping operation. . ‘In suchcase the I~ havefound, howeverpthatthe "precaution as to the alcohol need not be so tendency o'fprolamine solutions, to adhere in ?lm formation, is dependent upon’ many’factors, and fully, observed. , 10' The character of 501- 1 " Prolamine ?lm.—For the prolarnine ?lm I may is not easily'predictable. > ' vent,'the concentration, the presencef'of'plastiéi cize'rs,,'the presence of anti-blushing'agents and use zein,ehordein_or .gliadin bases. Using zein, the following composition‘ is suitable. To '75 . of. other modifying agents, the ‘characterof the parts by weight of 12% zein solution in a solvent casting surface, the temperature of drying, ,etc.-,_ ‘consisting: of‘ f 70%' of ' ethyl ‘alcohol and are all. factors affecting this property of ad 30%v of water,“ orv to any equivalent solution/I herence or 'ofstripplng a formed ?lm.” ’ may add a leveling solvent, preferably loeparts'by ‘ v- I, I‘ have also found that ?lm-forming prolarnine ‘weight, suchas ethylene glycol monoethyl ethen' . base solutions which do and which do not‘ strip’ As aplasticizer'I may add 2 parts by weight of easily‘have thepower of adhering to othercast dibutyl‘tartrate._ 'As an anti-blushing agent, I ?lms, particularly to cellulose ester‘ base ?lms. ‘ may add on the basisof zein 2% .to 3%,of ma- , ,Thisis more particularlytruewhen the cellulose terial such‘ as monoethanolamine salt or monopro'e esterebase ?lm contains material, preferably the panolamine salt, such as an acetate or lactate cellulose ester base itself, which-islsoftened by salt. In addition there is added aprotein‘ ?xative 25 "or which‘ is soluble in solvent material v‘used. in " suchas 2.5.parts by weight of 37%Vformaldehyde ] the ?lm-forming prolaminesolutioni. ‘ ,_ ‘ solution, or-a small quantity of glyoxal._f'I'his'~ _ composition may be spread to dry onto’ the ?lm In'practice, therefore, Iiuse a cellulose ester base ‘film as a casting surface for ‘a prolamine . base ?lm“ I prefer a cellulose ester‘?lm‘ which gives valuable surface properties to the resulting product. ‘ “ ' ' '7 ‘ ., \The following formulasare suitable for ?lm A5 ’ ‘ I Formula No.-1fr ‘Y " A._to form ?lm B.. > E .f' ‘ ‘ j In the above description it is to be understood that many variations of the zein solution are per-v 30 mitted, and some of these arefgiven in, full in my copending application Serial No.v 701,863,‘ ?led December 11, 1933; All _ the disclosures for prolamine base compositions.thereinfgiven are Parts by weight “hereby incorporated by reference in“ this appli ' 35 Alcohol soluble cellulose nitrate_i_____v _______ _. 1 cation.- 'Ethyleneglycol monoethyl ether.‘ ____ _'_____‘_ 1,0 Ethyl alcohol ______ _; _____ __'__,____ __~ ____ __v_. 90 ‘ ,r'forma'laNoJ ‘ ‘ ' Parts by weight I’ .7 ; . ' V p agent such as formaldehyde aids in producing a strippable ?lm, yet its use is not to. assure strip pabi1ity.. When ?xing agentfis not usedit is 'vusually impossible to strip a ?lm from the casting ' surface. Therefore, when a prolarnine base ?lm Ethyl lactate ‘____' ________ __j_ B isto be cast onto a strippable ?lm. A, adherence . Acetone . .Le _________ _'_ ____ _;- ____________ __ 90 of .B to A may be increased by reducing‘ the quan 4‘5'These solutions may'bel; applied onto glass, tity of ?xing agent even to the point of omission; polished metal and the like, and ‘will dry in about It'istherefore readily apparent that "film A need 45 5 minutes at 125° F. The examples show quick not contain substance soluble in or. softened'by dryingsolvents such as alcohol and acetone, and solvent used in. the forming composition fora 4.0vCellulose -, a acetate ______ __'__; ___________ _>____ I' .V . In the example above given the-use of, ?xing ~11 ' ‘also slowly volatile high-boiling solvents.¢'Upon prolarnine ?lm B.‘ ‘ = ' . . a - ' , .' lossof the highly volatile solvent‘about, ‘10.%¥of , Theys'olutions used for prolarnine contain‘con the-original solution remains as adry solid. It '. siderable water. ' Since prolamines are not soluble (is set and non-tacky but is not a strong-tenuous in water or in alcohol, but only in aqueous alcohol, - ‘ ?lm. inasmuch as it has only about 10% ester'in ' its, vmake-up. The'rest is .plasticizing solvent 55 whichcan be lost by seasoning or" further ex it is necessary to guard the solvent for prolarnine from dilution to such extent that it becomes a n0n-solvent.- Thus, the'strippable film is first‘ 55 posure. Presence of some of this higher boiling dried to assure that residual solvent contenti solvent assures strippability 'of the ?lm, vbut therein does not alter theeprolamine solvent and not until it is‘ reinforced by the ‘?lm to be cast precipitate prolarnine at theinterface. Another ‘upon it.l- .It-does not matter what composition ‘advantage of dryness for the strippable-?lm lies the ?lm has, because, the essential requirement ‘ in the fact that the dry ?lmis more slowly af 60 isiits strippability. The solution is preferably applied to' form‘ a?lm about “0,00905t9 0.0001 4' ' . ‘inch in thickness. ‘Ifit is too;thin,;.it_mayldissolve' fected or penetrated by solvent of thevprolarnine, ‘ compared to a still-wet strippable ?lm. I'claim': ‘ . ‘ in’the solvents of the applied,p'rolaminecompo-v a 1. The method of forming .aprolaminebase - 65*’ sition. .It‘i‘sto be understood thatthethickness . ?lm with a. surface coat thereon which comprises 65 ofr-the ?lm above speci?ed is given .only by way forming a dry solid strippable ?lm of cellulose of'example, and is not ‘to 'belconsidered. as any ester base’ on a solidv casting body‘ with a surface, : ‘essential limitation. ‘Formula ‘No.7 1, is preferred ifromvwhich the said ?lm may be readily stripped, ‘ forFthe-prolarnine compositions hereinafter given I .70 casting av prolarnine base ?lm'onto said ?rst formed ?lm in ‘adhesive union thereto,'and strip 70 covery system may be employed; _ Proo?ng agents‘ - ping the, united ?lms asa single body from the because both’have‘the samesolvents andgone re may, beadded to the formulas, ‘as by following solid casting body. . ' . ' 2. The ‘method of forming a prolamlne base a’ the general disclosures of the Charch and Prlndle . ' U; S. Patents Nos. 1,826,697’ to"1,826,699. Where ?lm with a surface coat thereon which comprises 75 ‘formulas like those" of Charch and Prindle are... forming‘ a dry solid strippable ?lm of cellulose 3 9,070,598 ester base on a solid casting body with a surface from which the said ?lm may be readily stripped, casting a prolamine base ?lm onto said ?rst taining prolamine solvent, evaporating the solvent from the third ?lm, and stripping the united ?lm as one body from the solid casting body. 5. The method of forming a zein base ?lm with formed ?lm in adhesive union thereto, forming ’ a third, ?lm of cellulose ester base on said a surface coat thereon which comprises forming prolamine base ?lm in adhesive union thereto, a dry solid strippable ?lm of alcohol-soluble and stripping the united ?lms as a single body nitrocellulose base on a solid casting body with a surface from which the said ?lm may be readily from the solid casting body. 3. The method of forming a prolamine base ' stripped, coating an alcoholic solution of zein base ?lm-forming composition onto said nitro 10 ?lm with a surface coat thereon which com prises forming on a surface ‘of a solid casting cellulose ?lm, drying out the volatile solvent of body a dry solid strippable ?lm of cellulose ester said zein composition, and stripping the resulting base which is softened by or soluble in an alcohol solvent, the casting surface of said body being 15 such as to permit stripping said ?lm without de stroying the continuity thereof, casting onto said ?lm a ?lm-forming solution of prolamine base and alcohol solvent which is a softener or solvent for said cellulose ester base, drying out the solvent 20 whereby to form a prolamine base ?lm in ad united ?lms together as one body from the solid o casting body. 6. The method of forming a zein- base ?lm with 15 a surface coat thereon which comprises forming a dry solid strippable ?lm of alcohol-soluble nitroé cellulose base on a solid casting body with a sur face from which the said ?lm may be readily stripped, coating an alcoholic solution of zein 20 base ?hn-forming composition onto said nitro cellulose ?lm, drying out the volatile solvent of said zein composition, casting on the zein ?lm a the solid casting body. ' 4. The method of forming a prolamine base (third ?lm of base composition different from the ?lm with a surface coat thereon which comprises zein base ?lm, and stripping .the resulting united 25' forming on a surface of a solid casting body a‘ ?lms together as one body from the solid casting dry solid strippable ?lm of cellulose ester base hesive union with the cellulose ester base ?lm, and stripping the united ?lm as one'body from which is softened by or soluble in an alcohol solvent, the casting surface of said body being 30 such as to permit stripping said ?lm without de stroying the continuity thereof, casting onto said film a ?lm-forming solution of prolamine base and alcohol solvent which is a softener or solvent for said cellulose ester base, drying out the solvent 35 whereby to form a prolamine base ?lm in ad hesive union with the cellulose ester base ?lm, forming a third ?lm by casting on the prolamine base ?lm a cellulose ester base composition con 7. The method of forming a zein base ?lm with a surface coat thereon which comprises forming a dry solid strippable ?lm_ of cellulose acetate 30 base on a solid casting body with a surface from which the said ?lm may be readily stripped, coat mg a solution of zein base ‘?lm-forming composi- - tion onto said cellulose acetate ?lm, drying out the volatile solvent of said zein composition, and 35 stripping the resulting united ?lms together as one body from the solid casting body. a ' DONALD W. HANSEN.