US 3190262 A
Description (OCR text may contain errors)
li 22, 1955 R. BAKISH srm. 3,190,262
VAPOR nnrosu'xou Filed Oct. 20. 1961 ,44 v AUXILLIARY GAS l 3s 56 42 50 as 22 32 54 52 24 AUXILUARY GAS COOLING e0 AUXILLIARY FEZT U rr 58 GAS 5| DEcogn PgsAsLE I 78 COOLING I 80 I, 74 68 UNIT I RESIDUAL AND "Ki EAUXILLIARY GAS 72 70' s4 62 F|G.l
, INVENTORS ROBERT BAKISH IWAN MARINOW BY CHARLES A. GELLAR ATTORNE Y S United. States Patent Ice Patented June. 22,1965
The present invention relates to the deposition of metal on sheet material and, more particularly, to the deposition of metal from a gaseous compound of which the metal is a component. Although the device of the present invention is applicable to a variety of organic and inorganic sheet materials, it is particularly useful for coating paper. In the coating of paper, many of a variety of requirements mustbe met. Thus, in the production of metal coated decorative paper, deposition must be effected rapidly and inexpensively. And in the production of metal coated capacitor paper, deposition must be precisely controlled to meet specific characteristics. In all cases, temperature, pressure and time must be selected carefully in order to avoid scorching and outgasing of the paper and to ensure adherence and uniformity of the metal coat. r j The primary object of the present invention is to provide a novel device by which a metal is deposited. The heat decomposable metal compound may be normally solid or liquid but must be vaporizable without undue decomposition. The device is characterized by an elongated convex surface in contact with which the elongated sheet is tensioned and which defines, in conjunction with an associated elongated concave surface, a curved chamber for subjecting the elongated sheet to the metal bearing vapor in a novel manner. The process involves the steps of heating the elongated sheet, which specifically is composed of paper, and depositing on one of its faces a metal from its vapor in a predetermined sequence that results in an adherent coat of high quality. The system and process eflect the decomposition substantially at, atmospheric pressure. j H
Other objects of the present invention will in part be obvious and will in part appear hereinafter.
The invention accordingly comprises the apparatusinvolving the several steps and components and the relation and order of one or more such components with respect to each of the others, which are exemplified in the following disclosure, and the scope of which will be indicated in the appended claims. 7 T i For a fuller understanding of the nature and objects of the present invention, reference should be had to the following detailed 'descriptiom taken in connection with the accompanying drawings, wherein:
FIGQlis an exaggerated cross-sectional diagrammatic 'view, partly broken away, of a device for performinga 1 and 2 involves the steps of advancingan elongated sheet of paper from a supply spool through a curved path to a take-up spool, the path being defined by a heated convex surface against which the sheet is tensioned and a cooled concave surface which is slightly spaced from the sheet. The sheet is tensioned against the convex surface to prevent the back of the paper as well as the convex surface from being affected by the deposition process. The sheet is spaced from the concave surface and the concave surface is cooled to provide a region within which the metal bearing gas may flow in contact with the surface of the sheet to be coated and to prevent deposition from occurring on the concave surface in such a Way as to constrict this region. The metal bearing'vapor is flowed through an entrance port into a deposition zone of the region and through an exit port from the deposition zoneQ Auxiliary gas is flowed into zones on opposite sides of the deposition zone in order to isolate the metal hearing vapor and its residue from the extremities of the region into which and from which the sheet advances. In this system, the metal bearing compound is an organometallic, a metal hydride, a metal carbonyl or a metal halide, which may be heated in the presence of a suitable auxiliary gas, to an elevated temperature at which decomposition of the vapor and deposition of the metal occurs. 7 'It is known that useful rates of metal deposition from such gaseous metal bearing compounds occur generally within the range of from 200 to l000 F. It has been found that paper can Withstand, without appreciable physical-chemical change, temperatures within the range from 1 to seconds, a typical paper being able to withstand without appreciable chemical change a temperature of approximately 500 F. for approximately 30 seconds. In the illustrated process, successive increments of a paper sheet are heated and subjected to a metal bearing gas to cause metal to be reduced thereupon from a metal bearing gas. The auxiliary gas may be an activematerial such as hydrogen or an inert material such as argon (or other noble gas) or nitrogen. The overall pressure in evaporation chamber 64 preferably ranges from .1 to 15 psi. above atmospheric pressure in order to concentrate the heat decomposable gas prior to its entrance into decomposition zone 34. Also, this pressure prevents the outgassed vapors from the paper from entering the decomposition zone, I
Particularly good papers for the purpose of the present invention arecalendered papers having at least a glossy surface at which the sheet is denser than it is in its interior. v I
The metal bearing compounds to be vaporized prefen ably are selected from carbonylssuch as iron carbonyl, molybdenum carbonyl, nickel carbonyl, chromium carbonyL'tungstencarbonyl and cobalt carbonyhalkyls such as aluminum diisobutylhydride, aluminum triisobutyl, aluminum triethyl and molybdenum ditoluene; aryls such as chromium dibenzene, molybdenum dibenzene, vanadium' dibenzene and vanadium 'dimesitylene di-iodide;
sandwich compounds such as bis-cyclopentadienyls of num hydride, :and tin hydride; and Q combinations -and mixtures thereof such' as alkyl and. aryl carbonyls including benzene chromium tricarbonyl, phenanthrene chromium tricarbonyl, naphthalene chromium tricarbonyl,
o-xylene chromium tricarbonyl, benzene molybdenum tricarbonyl, cyclo-octadiene molybdenum tricarbonyl; bis-f cyclopentadienyl chlorides, bromides and diodides'of titanium, zirconium, hafnium, vanadium, molybdenum, tungsten and tantalum, cyclopentadienyl carbonyls such as cyclopentadienyl manganese tricarbonyl, bis-cyclopentadienyl carbonyls of molybdenum, tungsten or iron,
carbonyl'halogens such as sodium carbonyl bromide, ru-,
thenium carbonyl chloride, and organo hydride compounds such as triethyl amine-aluminum hydride and trimethyl amine-aluminum hydride. 1 I The device illustrated in FIGS. land 2' for performing the, process of the present invention is shown generally as comprising an inwardly concave wall 20 and an outwardly concave Wall 22 which define therebetween a curved.
chamber 24, the profile of which constitutes what may be termed a relatively minor segment of a closed curve. Preferably-the distance between the adjacent surfaces of walls 20. and 22 ranges between and 574, of an inch and preferably is approximately 43 of an inch. 7 Side walls (notshown) complete curved chamber 24 except for its ends. The open ends of chamber-24am adjacent, respectively, to a supply spool 26 and a take-up spool 28 for a substrate 30 to be advanced through chamber 24.
Chamber 24, includes a preheat zone 32," a decomposition zone 34 and a dwell zone 36. Substrate 30 advances" through preheat zone 32, decomposition zone 34 and dwell zone 36,;in sequence, while constrained against wall 22 throughout its length. Wall 22 includesrsections 38, 40
and 42, which respectively incorporate separate heating 1 elements, extending throughouttheir'lengths, that are energized by a-suitable electrical source 44.
Gaskets 46,48 and 50 respectively, partially seal zone 32 from its exterior, zones 32 and 34 from'each other and zone 36 from its exterior. A'mixture of auxiliary and heat decomposable gas is introduced-at the junction of zones 36 and 34 through a series of small holes in a vent component 51, one hole of which is shown in FIG. 1 at 52. Additionally, auxiliary gas is introduced at the outer extremities 54 and56 of zones 36 and 32. Residual and auxiliary gas is exhausted from zones 34 and 36 at the junction 58 between zone 34 and zone'32, Auxiliary .gas is exhausted from zone 32 at its inner extremity 70rfor distributing heat throughout the exterior'of vessel.
64, and a heating unit 72 for water jacket 70; In the illustration, the heat decomposable gas is supplied in liquid form as successive drops 74 and is vaporized by a series'of jets 76. It willbe noted also that the concave surface ,of zone 34 is cooled as at 78 in order to prevent .depositionthereupon and that the gas exhausted at .the
junction of zones 32 and 34 is cooled asat 80 in order to increase the exhaust elfect. In general, the temperatures generated in preheating zone 32 and dwell'zone 36 are below the decomposition temperature of-the decomposable gas and the temperature generated in decomposition zone 34 is above the decomposition temperature; of the decomposable gas.
- EXAMPLE I A paper substrate wasadvanced throughchamber 24 of FIG. 1 at 15 ft./mm'. Heating section 38 was at160 C.,
heating section 40 was at 235 C. and heating sectioni42 V was at 190 C. The spacing between the adjacent curvedsurfaces of chamber 34 was 4; inch. Water jacket 70 was at 85 C. I Thepartial vapor pressure of iron pentaearbonyl was 100 mml-lg, the totalvapor pressure within nitrogen was introduced at slightly greater than atmospheric pressure in order to ensure outward flow through. the extremities of chamber 24. The flow of gas through decomposition chamber 34 is at the rate of 5 cu. ft./hr. a coat, 5000 A. thick, composed of 98.5% iron and 1.9%
carbon resulted. v
' EXAMPLE II The process of Example I Was repeated except that. the substrate was paper coated with casein. A ferromagnetic stratum was deposited on the casein coating.
EXAMPLE Ill The process of Example I was repeated :except that the substrate was Mylar. deposited.
. EXAMPLE IV iron, 24% cobalt, 14% nickel and 3% 'carbonf j EXAMPLE V a partial pressure of copper hydride and aluminum triisobutyl in'2 to 1 ratio with respect to each other andin amount approximately equal to the vapor pressure of the nickel is introduced. The resulting product is composed of approximately 49% iron, 24% coba t, 14% nickel, 8% aluminum, 3% copper and 1% carbon.
IPreferredferromagnetic strata of the above described. character are produced in the system of EIG..1- where;
the heat decomposable gas is an iron carbonyl, preferably iron pentacarbonyl, which is liquid under usual conditions; alternatively the iron carbonyl may be iro'ndodeca carbonyl; the auxiliary gas issan inert gas such as, nitro- 0 gen; the temperature of heating section 38 ranges from 140180 C.; the temperature of heating section ranges from 16(5-250 .C.; the partial pressure of the heat decomposable gas ranges from '75 to 1 25 .mm. Hg; the auxiliary. gas issupplied in such a way as to produce a flow through decomposition chamber 34 ranging from 1 to 10 cu. ft./hr.; and substrate 30 is advanced ata rate Accordingly, the present invention providesnovelsys.
tems for producing thin metallic coats 'of high quality.
Since certain changes may be made in'the foregoing de+;
scription and the accompanying drawing without depart+ ing from the scope of the invention herein involved, it
is intended that all matter discloscd'herewith be interpreted in an illustrative and not in ,a limiting sense.
5 .What is claimed is: i .An apparatus for depositing metal on an elongated sheet material, said apparatus comprising first means pro-' viding an outer concave surface and secondmeans pro- 'viding an inner concave surface, said outer concave su r-; face and said inner concave surfacebeing spaced, aparta distance ranging fl'Qm' /gg to inch and defining a concave path said path providing in sequence a preheatzone, a decomposition zone and a dwell zone, means for ad-:- vancing an elongated sheetmaterial through said concave path and .tensioned against said inner concave surface, means for heating said inner concave surface substan- ;tially continuously throughout said decompositionzone; means for cooling said outer concave surface substantially continuously throughout said decomposition zone, '70 means defining an entrance port and ,a first, exit portatm opposite extremities. of said decomposition zone, means for directing a heatdecomposable metal bearing .gas through saidentrance port, said decomposition zone and said first exit port, means for directing an auxiliary gas; into said preheat zone and said dwell zone in order to A ferromagnetic stratum was.
The process of Example IV is repeated 'except that 5 shield the outer extremities of said preheat zone and said dwell zone from said heat decomposable gas, a first gasket at the outer extremity of said preheat zone, a second gasket at the junction between said preheat zone and said decomposition zone and a third gasket at the outer extremity of said dwell zone, means defining a second exit port in said preheat zone, said first exit port and said 7 second exit port being contiguously located on opposite sides of said second gasket, and means for exhausting said first exit port and said second exit port, the profile of said concave path being such that it constitutes a relatively minor segment of a closed curve.
References Cited by the Examiner UNITED STATES PATENTS Pawlyk 117107.1 Schladitz 117107.1 Vodonik 117-107.1 X Homer et a1 117107.1 X Marvin 117-107.1 X Toulmin 1171 07.1 X
RICHARD D. NEVIUS, Primary Examiner.