US1583704A

US1583704A - Electrodeposition of rubber under gas-removing conditions

Info

Publication number: US1583704A
Application number: US35612A
Authority: US
Inventors: Samuel E Sheppard; Leon W Eberlin
Original assignee: Eastman Kodak Co
Current assignee: Eastman Kodak Co
Priority date: 1925-06-08
Filing date: 1925-06-08
Publication date: 1926-05-04
Anticipated expiration: 1943-05-04
Also published as: FR616461A; GB253091A

Description

May 4,1926. 1,583,704 v s. E. SHEPPARD ET AL msc'rnonsr'osrrxou or RUBBER UNDER GAS azuovme scum-nous I Filed June s, 1925 FIQL. v .10

an 1 Folk "rpm in um A I mwz zvrox Samuel/ E. Sheppard ($139011 WEberZiw,

I ATTO EY.

Patented Mays, I

UNITED ST TES smear. a. snar'raan Ann LEON w. anrmm, ohL-aooaasrnaimw YORK, aa-

SIGNOBS TO EASTMAN KODAK COMPANY, OF BQOHESTEIF, NEW YORK, A COB- .ronarron '0! NEW roux.

' nnnc'raonnrosrrxon or Brianna UNDER oAs-annovmo connrrrons.

Application filed June 8, 1925. Serial No. 85,812.

To all whom it may mom:

ram) and LEON W. EBERLIN, subject of the King of Great Britain, and a citizen of the United States of America, respectivelhresiding at Rochester, in thecounty of. on-

roe and State of New York, have invented ing i's a full, clear, and exact specification.

his invention relates to processes and apparatus for electrodepositing organic materi'al, such as rubber for example, under such conditions that evolved gas is removed from the anode.

One object of the invention is to prov1de 'a process of electrodepositing such material in a way that will remove gases evolved at the anode from the zone of electrode osition before they produce deleterious e ects. Another object of the invention is to provide such a process in which the gases, generated at the anode surface, are removed rearwardly from the zone of electrodeposition so as not to interfere with the movement of the material to the zone of electrodeposition.

the invention is to provide such a process in I which the evolved gases may be removed mechanically, either with or without the assistance of chemical gas-removing expedients. Still a further object of the invention is to provide. an a paratus in which such gas-removal is readily effected. Still another object is to provide a porous anode through which the gases may be drawn away from the active anode surface. Other objects will hereinafter appear.

In the accompanying drawing, Fig. 1 is a diagrammatic cross section upon an exaggerated scale of an apparatus embod ing certain features of our invention an in which our process may be conveniently carried out. I

' Fig. 2 is a diagrammatic-cross section I upon an exaggerated scale of adifierent apparatus embodying our .invention and by means of which our process may be carried paratus illustrated in our prior Patent 0.

Arsu'r lorries.

V a d an'outgrowth'of the process and a i Be it known that we, SAMUEL E. Sara 1,476,374, December 4, 1923, for electrodepoatively high current densities. nder such circumstances gas, like oxygen, may be libsition of rubber coatings. When rubber or equivalent organic material is depositedv from an electroconducting aqueous emulsion thereof upon an unattackable anode, the dep-.v ositlon may be speeded by em loying relthis evolved gas may be wholl or substanthis removal is rearward from the anode surface, that is, the gas passes-away from the anode surface on the side of the-latter opposite to that from which the rubber partlcles come. The result is especially useful when theelectrodeposited rubber is to be stripped from the anode surface as a smooth sheet of suitable continuity and uniformity.

We have found that a vacuum is the best means for removing. the gas mechanically and we prefer to carry outthis removal by means of a porous anode, to the rear side of which a vacuum isapplied. Stated differently, the porous'anode is connected at'its rearwith a chamber, the-pressure in which is kept materially below the pressure in. the

active electrolyte.

The porosity of the electroconducting anodes may obviously be-varied considerably to suit different conditions, and such anodes may be formed of different materials. We have found .that wire cloth or rated sheet metal may be used, but in the preferred form of our-invention we emplo' porous carbon. Of course, we do not wis to be limited to these examples, except as indicated in the appended claims, since the principles of our invention may be applied in many different. ways. A Where metallic wire cloth is used we can employ one of a erfoliitl highly resistant metal having'a'mesh of ,4, to inch thickness, there being 5 pore. space therein; but we, of course, do

not, wish to be limited to these characteristics,- since the porosity and thickness-may vary widely without interfering with the the action of the vacuum tends not only to effectiveness of our invention.

Referring to Fig. 1 of thedrawing, 1 represents a container in which is located an electroconducting aqueous emulsion 2 and a cathode 3. I 4 represents the porous anode of the type describedabove. Ob- 25 viously the anodes may have any suitable -shape,"straight, 'curvedor irregular. In

Fi 1 it is shown as slightly curved sothat a fibric 7 drawn-across 1t Wlll move smoothly and yet make good contact therewith. The anode 4 is located in one end of *chamber .5 of any suitable or referred re sist-ant gas-tight material. hamber 5, is connected by pipe iii with any suitable vac uum source, such"=as a pump or asp rator (not shown).

The electrodeposition' may be made directlyupon the anode 4, or a fabr1c'7 may be drawn through the-electrolyte over the I surface of anode. 4 andin

good contact

8, 9 and 10, the latter being preferably driven. 'Of course,-. the movement may be continuous or intermittent. When the rubber is deposited u on the anode 4 directly, it may be strippe therefrom, as a coherent uniform sheet afterwashing and drying as indicated in our prior patent. .When the Q cloth is drawn slowly across the surface, the rubber is electrodepositcd in the meshes of; the fibers the'cloth in intimate relation to so as to impregnate it. u

' The degree of vacuum can be'- varied greatl', without interfering with the'prac- I portion'to'the gas evolution. The gases move in Fig.1 from "the outer surfaceof an'odefi-through thefpores in the anode.

\ -"Qinto chamber 5 aridtheiie through [pipe 6' tothe'evacuatin'g apparatus. If some liquid.

.Iiis draw through-the the mode 4 into E'the chamber 5 .ifianay be removed i by draining awayunder 'vacuum'or anyj sides. 7 suitable type, preferably above the level of therewith, sayover suitable rolls, such as" tice 0 our invention. In fact, it is preferother suitable expedient. Usually there is no trouble from such liquid. The current densities and voltages are preferably of the order of magnitude of those indicated in our'prior patent cited above. The nature of the current (continuous, pulsating, etc.) may also be varied so long as it is eflectively unidirectional,even an unbalanced A. C.

current may be useful.

Where the electrodeposition of rubber takes place into the fabric 7 the action of the kind described in our above cited prior patent where non-conducting objects were rendered suitable for receiving the deposition by impregnating them with solutions of electrolytes. The emulsion with which the fabric is wetted or saturated performs this function. It will be noted that remove the gases rearwardly from the anode zone but likewise may tend to some extent to maintain the sheet 7 in contact with the anode 4. r

In Fig. 2 a difl'erent form is shown. The

vessel 1 contains one or more cathodes 3 preferably surrounding the anode on all In a stationary bearing 11 of any the emulsion 1, is located rotatable anode 12,-say in the form of a hollow cylinder having a collar 13 at the'top which bears upon the bearing 11. This collar may be provided with means for actuating it, such as a pulley surface 14 operated through belt '15. In the top of the anode 12 is "a closure 16 through which enters a pipe 17 by means of a stuffing box 18. The pipe 17 can remain stationary, while the anode 12 and I closure '16 rotate, yet stufing box 18 main tains a sufficiently gas-tight connectionpermittingvacuum to be maintained in the hollow'anode 12. The pipe 17 is connected with any suitable evacuating apparatus.

Electric cont-act with the anode 12 is maintained by any suitablemeans, such as a metallic conductin ring 19 mounted thereon, against 'Whic bears a brush 20 mounted on the lower face of bearing 11.

The emulsion 4, such as one of those described in our above cited patent, or a natural or modified latex, is located around the anode to the-desired level. The current is then'started, the vacuum being created in the anode'12-at about the same time that the electrodeposition starts, or even before it. The plating practice preferably follows that described in our above cited patent. WVhen 'a de osit of rubber 21. has formed to a suita le thickness, it may be treated in the usual manner, such as by stripping it off and vulcanizin'g it or vulcanizing in situ and then removing it.

Obviouslya fabric, to be impregnatedwith rubber, may be drawn acrossthe rotating anodein'timed relationto its movement, this operation being similar to that described '--and illustrated in connection with Flg. 1,

suitable rolls being, used.

The removal of the gas mechanically may be supplemented by the use of chemical deoxidizing materials in the electrolyte. Thus we mayv add to the rubber emulsion sodium or ammonium sulfite or thiosulfate.-

Sodium hydrosulfite is also very useful. The concentration of these bodies will vary in accordance with the difliculty in combating the evolved gas. It is a'simple'adjustment for any workman, to supply sufficient reducing agents for each particular case. These reducing agents, which are preferably sulfo-bodies, form on electrolytic oxidation, polythionates which assist in maintaining dispersion of colloidal sulfur and may assist in the vulcanization process itself.

Having thus described our in ention, what we claim as new and desire to secure by Letters Patent is: v

1. The process of depositing organic material on a gas-permeable anode surface,

which comprises bringing said surface into contact with an electroconductmg aqueous suspenslon'of said matenahJpassing a depositing electric current through said surface and suspension,the-current-density beingsuch that gas is evolved-adjacent said surface, and removing said gas rearwardly from said surface." I I Y 2. The process of'depositmg rubber on'a gas-permeable anode surface which comprises bringing said surface into contact with an electroconducting aqueous emulsion of said material, passing a depositing electric current throughsaid surface. and. emulsion, the current density being such that gas is evolved at the anode, and removing "said gas rearwardly from said surface.

3. The process of depositing organic material on a gas-permeable anode surface,-

which comprises moving said surfacewhile in contact with an'electroconducting aqueous emulsion of said material, relative to said emulsion, passing a depositing electric our ing said movement, the current density being such that gas is evolved'adjacent said surface, and removing said gas rearwardly from said surface during said movement. I 4. The process of de ositin'g organic material in a fabric whic comprises locating said fabric on a gas-permeable anode in contact with aqueous electroconductingemulsion of said material, passin a depositin electric current through sai 'sl'irface an f'ment. rent through said surface and emulsion duremulsiomand removing gas liberated at the anode rearwardly fronfsaid surface away from said fabric.

5. The process of depositing rubber in a fabric which comprises moving saidfabric across a gas-permeable anode in contact with 'ing electric current through said surface and emulsion, and removing any as evolved at said surface which is not acts upon by said -educing agent, rearwardly from said surace.

7. In an electrodeposition' apparatus for use with an electro-conducting aqueous .sus-

pension of organic material a gas-permeable anode, and'means for w1th rawmg gas rearwardly from the surface of sa1d anode.

Bill

.8. In an electrodeposition apparatus for e use withan aqueous electroconductingemuL sion of rubber particles movable toward the anode, a porousanode, and-a vacuum chamber connected to the rear of said anode.

9,. In an electrodeposition "a paratus for fuse with an aqueous electrocon ucting emulsion' of organic material, a gas-permeable anode, means for removing as rearwardly from the active face of sand anode, and

means for holding a fabric adjacent said .anode. In an electrode osition apparatus for 10. use with an aqueous e 'ectroconducting emul- S1011 of organic material, a gas-permeable ,anode, means for moving said anode during electrode ositionj,"-a'nd means for withdrawmg gas rom said anode during said move- 7 '11. In anelectrodeposition apparatus, a

gas-permeable anode, said anode including a cylindrical-portion rotatable about its axis,

and-means for withdrawing gas from the interior of said cylindrical portion during rotation of the latter.

Signed at Rochester, New York, this 2nd day of June, 1925.

SAMUEL. E. SHEPPARD. LEON w. EB RLIN;

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