Патент USA US2406403код для вставки
Aug. 27, 1946. H. G. ROGERS 2,406,403 ‘ POLYHERIZING APPARATUS AND METHOD I8 33 By ' Amd m17( Aug. 27,1946. „,ÀG, ROGERS , A2,406,403 POLYMERIZING APPARATUS AND METHOD `Filed lay 1, 1943 2 Sheets-Sheet 2 . ê â 4 e «o n 2S 3 BY ¿M Patented Aug. 427, 1946l - 2,406,403 ~ UNITED STATES PATENT oFFlcE POLYMERIZING APPARATUS AND METHOD n .Howard G. Rogers, Wellesley Hills, Mass., assign or to Polaroid Corporation, Cambridge, Mass., a corporation of Delaware Application May 1, 1943, Serial No. 485,306 27 claims. (ci. 1s'-1) l 2 , This invention relates to the formation of plas tic elements and more particularly to apparatus and methods for preparing a. polymerizable monomer for molding. only and are not intended as a deñnitlon of the limits of the invention, reference being primarily had for this latter purpose to the appended claims. In the drawings wherein like reference charac ters refer to like parts throughout the several ~ In the fabrication of accurately surfaced and shaped plastic elements, such as lenses and prisms, best results are obtained when the plastic views; , Figure 1 is a. view, partly in elevation and partly in section, of one form of apparatus for carrying out the present invention; ' monomer is partially polymerized before being introduced into the mold for hardening. This minimizes shrinkage and heat of polymerization 10 Fig. 2 is a view, partly in elevation and with ' during hardening and tends to avoid surface de parts broken away, showing another embodiment of the invention whereby a continuous output of formation, non-homogeneltyand internal strains partial polymer may be obtained; and in Itthe is finished accordingly product. one object of the present in Fig. 3 is a. sectional view with parts broken vention to provide a novel method and apparatus_ 15 away, taken substantially along line 3-3 of Fig. 2. whereby a monomer or a partial polymer may The apparatus illustrated in Fig. 1, by way of example, comprises a pair of laterally spaced, have a predetermined proportion of the monomer thereof polymerized to produce a homogeneous parallel piston and cylinder mechanisms nIII and polymer-in-monomer solution, said solution being II suitably mounted on a'support consisting of a sufficiently fluid to be readily introduced into a 20 pair of substantially parallel, vertically spaced plates I2 and I3, said plates being rigidly held in Another object is to provide novel apparatus spaced relation by a plurality of vertical mem mold. of the above type which is adapted to effect or _ bers, such as rods I4. Mechanisms I0 and II are alike and accordingly only one is described in advance the partial polymerization to obtain a Viscous, homogeneous mass. . 25 detail, corresponding numerals designating like parts of said mechanism. ° Still another object is to provide a n_ovel appa ratus of the above character whereby a. continu ous output of partial polymer having a predeter mined concentration of polymer may beobtained. A further object is to provide novel apparatus 30 As shown, mechanism Ill comprises a cylinder I5 having a iianged upper end I6 whereby it is rigidly secured to upper plate I2», for example by screws I 1. A hollow piston I8 is slidably mounted whereby a fluid mass may be subjected to mixing ‘ in said cylinder, and has the lower end thereof and circulation by mechanical kneading. closed and provided with an outwardly extending Still further objects are to' provide novel appa ñange I9 whereby a substantially fiat surface of ratus wherein a plastic mass is adapted to be comparatively large area is provided at the lower partially polymerized and a novel method of 35 end of said piston. Means are provided for re introducing the mass into a mold from said siliently opposing downward movement of plunger apparatus. I8, said means, as shown, consisting of a plurality of coiled springs 20 which are preferably under above character which, when utilized for poly tension and which have the ends thereof secured merizing a monomer, does not inhibit polymer- 40 to flanges I6 and I9. Screws I'I are preferably ization. . utilized to secure the upper end of each of said Further objects are the provision of a simple, springs to ñange I6, and screws 2I may be pro compact, durable and inexpensive device for sub vided for similarly securing the lower end of each jecting different portions of a yielding mass to ' of said springs to flange I9. rpressure and of novel yielding- means for co- 45 To move plungers, I8 downwardly against the operating with said device, said means being resistance of springs 20, fluid under pressure is adapted to contain a quantity of polymerizable introduced into the upper end of each of the cyl material, such as styrene, without contaminating inders I5 of mechanisms I0 and II, and, in the a Still another object is to provide a device of the or exposing the- latter to the atmosphere. form illustrated, the means for accomplishing this The above and other objects and novel features 50 comprise conduits 22 and 23, respectively, each of the invention will morefully appear from the of which communicates at one end with a cylin following detailed description when the same is der end and at the other end is adapted to be read in connection with the accompanying draw connected by suitable valve means 24 to a conduit ings. It is to bev expressly understood, however, y25, the- latter conduit being, in-turn, connected that the drawings are for purposes of illustration 55 to a source of compressed airl as for example a 2,406,403 4 pump (not shown). Valve means 24 acts to alter lution homogeneous and in condition for intro nately admit and exhaust air to and from each of duction into a mold. The introduction into the cylinders I5 and also governs the flow of air so mold may be accomplished either by pouring or that while air is being admitted to one of said by injecting the partial polymer from container cylinders it is being exhausted from the other, 33. A method of readily injecting the polymeric causing plungers I 6 to move in opposite directions. mass into the mold in a novel manner consists Valve means 24 preferably comprises a piston in forming an orifice in the container preferably type slide valve 28 mounted for reciprocation in at one end thereof and thereafter squeezing the a cylinder 21 and actuated by suitable means, material from the container through said orifice such as a crank 28, which is connected by a link 10 into the mold. By means of the above method 29 to valve rod 30. A pair of exhaust ports 3I and apparatus, partial polymers suitable for and 32 are provided in opposite ends of said cyl molding optical elements have been obtained inder and are adapted to cooperate with conduits which have a polymeric concentration between 65 22 and 23, respectively, to permit air to be dis charged from mechanisms I0 and II at predeter mined points in the valve stroke. In operation, reciprocation of valve 26 alternately connects conduit 23 to conduit 25 and to port 32 and also alternately connects conduit 22 to conduit 25 and to port 3I, the connections being such that when conduit 23 communicates with conduit 25, con duit 22 communicates with exhaust port 3l. and when conduit 23 communicates with port 32, con duit 22 is open to conduit 25. Accordingly, for each revolution of crank 28, plungers I8 move and 70 percent. Referring to Figs. 2 and 3, there is shown some through a .complete cycle and in opposite direc- ' ÈÍOIIS. _ 1 In order to polymerize a plastic monomer such what diagrammatlcally another embodiment of the invention whereby a continuous output of partial polymer of predetermined polymer con centration may be obtained. In the form `illus trated, the novel apparatus comprises a platform 35 having mounted thereon a comparatively long, deformable, open ended container or tube 36 which is impervious to air and is internally lined with, or formed from, a material that is inert to the mass which is to be polymerized. It is satis factory, particularly for the polymerization of styrene and cyclohexyl methacrylate, to form said container from laminated polyvinyl alcohol sheet, as styrene, a novel means is provided for co o`r from canvas internally lined with polyvinyl operation with the above described mechanism, 30 alcohol. comprising a- flexible container 33 formed of` or According to the novel method of the present internally lined with a material which is inert invention the mass to be polymerized, for example to said monomer, polyvinyl alcohol constituting styrene monomer, is continuously fed into one a satisfactory material for styrene- Container 33 end of tube 36 as from a tank or other source 31, initially has a cylindrical shape and is open at 35 and is continuously discharged from its other end both ends, one end thereof being thereafter sealed_ into a storage container or directly into molding by overlapping the marginal portions thereof and apparatus such as a prism mold 38. clamping the overlapping portions between two metallic strips 34 which are secured to each other by bolts 35. The container is then partially filled 40 with styrene monomer 36, or other polymerizable ‘ plastic, and the air is exhausted therefromby compressingv the walls `of the container until the monomer level is substantially flush with the open In order to mechanically knead the polymerized mass admitted into tube 36 and simultaneously propel said mass from the input to the discharge end of said tube, a plurality of members, such as rollers 39, are provided which are adapted to en gage successive longitudinal portions of said tube at different times -to press together the Walls of end of said container, the marginal portions of 45 said tube and squeeze the polymerized mass in the latter end being thereafter overlapped and the desired direction. In the form illustrated, sealed in the manner previously described. The rollersv39 are mounted for rotary and limited ra partially filled and sealed container is positioned lengthwise beneath plungers I8 of mechanisms dial movement about axes which are fixed rela opposite the lower ends of said plungers. . When the latter are rendered operative, opposite ends of said container are alternately pressed between said plungers and plate I3, causing the solution in the container to ñow from one end to the other. tudinally so that each extends over a different tive to platform 35 in a plane substantially paral I0 and II' so that portions thereof are disposed 50 lel to said platform, said axes being spaced longi When polymerizing styrene monomer in the above manner, the kneading by mechanisms I0 and II is carried out in an oven or other appa ratus for maintaining container 33 and its con tents at an elevated temperature, as for example between 60 and ’70° C. Crank 28 is preferably ro-tated at approximately from 1 to 10 R. P. M. dur ing the polymerization, although the speed thereof may vary over a wide range without pro ducing unsatisfactory results. It is to be expressly understood that the above apparatus and method may also be used for ad portion of said tube and is substantially perpen dicular to the longitudinal axis of the latter. To this end, each of rollers 39 is mounted on a shaft 40 which has one end thereof slidably mounted in a radial slot 4I provided in a disc 42, said shaft being preferably biased radially outward by suitable means, such as a coil spring 43, carried by said disc. Discs 42 are, in turn, mounted on shafts 44 journalled in bearings 45 (Fi-g. 3) which are fixed relative to platform 35, shafts 44 being driven, for example, from a common drive shaft 46, by means of helical gear drives 4l. In operation, each of discs 42 is rotated at the same speed and preferably in the same direction, i. e., counterclockwise, as viewed in Fig. 2, and rollers 39 are caused to engage the walls of tube vancing the polymerization of a partially poly 36 and press the latter together while moving merized solution. For example, styrene or other from left to right over said tube. By mounting 'A vr"plastic monomer may be initially partially poly 70 said rollers for radial displacement relative to meriz'ed and then the polymer solution may be disc 42, contact between the tube and the rollers introduced into container 33 and the latter sub V may be maintained for almost 120° of each revo jected to the mechanical kneading of apparatus lution of said discs. Each of rollers 39 of suc III, II. The latter operation acts'to increase the cessive discs lags the previous roller, i. e., the polymer concentration while maintaining the so 75 roller to the left thereof, by approximately 120° amarnosy 5 so that the portion of the polymerizable mass propelled forward by one of said rollers is, upon disengagement ofthe latter roller from the tube, acted upon by the next roller and pressed further forward thereby. A sufficient number of rollers 39 is provided to impart to the polymerizable mass which is discharged the desired viscosity and polymer concentration. 2. The method of advancing the polymeriza tion of a fluid mass of polymerizable -plastic ma terial which comprises confining said mass in a deformable container which is inert to said mass, maintaining said container at a tempera . ture adapted to induce polymerization of said plastic, and successively compressing diiïerent To maintain the > mass in container 36 at an elevated temperature, as for example of 60° to 70° C. when styrene is being polymerized, a plurality of heating coils 48 may be embodied in platform 35. , . , portions of said container to cause a circulation and mixing 'of said mass. 10 3. The method of advancing the polymeriza tion of a, lluid mass of polymerizable plastic ma terial which comprises confining said mass in a There is thus provided a novel method whereby deformable container, maintaining said contain-' a plastic monomer may be partially polymerized er at a temperature adapted to induce polymeri or a partially polymerized solution may have th‘e 15 zation of said plastic, and causing circulation- polymer concentration thereof readily increased to produce a homogeneous fluid or viscous mass. Suitable means are provided for carrying out the and mixing of said mass within said container by applying pressure to said container. 4. Th‘e method of- advancing the polymeriza-v partial polymerization in batches and also -for tion of a fluid mass of polymerizable plastic ma carrying out the partial polymerizationl continu 20 terial which comprises confining said mass in a ously. Each apparatus produces the polymer so deformable container, maintaining said contain-. ` lution without inhibiting the polymerization and er at a temperature adapted to induce polymeri- ‘ is capable of subjecting a iluìd to a thorough zation of said plastic, and causing circulation mixture in an atmosphere which' is inert to said and mixing of said mass within said container by fluid. There is also provided a novel means for 25 changing'the shape of said container. containing a polymerizable mass and apparatus 5. The method of advancing the polymeriza for subjecting said means to a mechanical knead tion of a iiuid mass of polymerizable plastic ma ing whereby the mass is alternately and/or con terial which comprises confining said mass in a tinuously circulated from one end of the con deformable container, maintaining said contain tainer to the other. There is additionally pro 80 er at a temperature adapted to induce po'lymeri- ‘ vided a novel method for injecting moldable ma zation of said plastic, and causing circulation terial into a mold from the container of the ap and mixing of said mass within said container by paratus for carrying out the polymerization in continuously changing the shape of said con batches. Although only two embodiments of the inven 35 6. The method of polymerizing styrene mono tainer. _ . tion have been illustrated and described, it is to mer which includes the steps of confining a mass be expressly understood that the same is not lim of said monomer in a polyvinyl alcohol container, ited thereto. For example, it will now be appar maintaining the container at a temperature be ent to those skilled in the art that other types of tween 60 and 70 degrees C., and alternately and valve means maybe substituted for the piston v repeatedly pressing together the side walls adja type valve means 24. It is also to be understood cent opposite ends of said container to reciprocate that rotary rollers mounted as shown in Figs. 2 said mass from one end of said container to the and 3,- may be used 'instead of the plungers of other. ` Fig. l to carry out «the discontinuous method of 7. The method of polymerizing styrene mono polymerization of the latter apparatus, or that 45 mer which includes the steps of coniining a mass a plurality of cylinders and plungers vcould be comprising said monomer in a deformable con substituted for the roller arrangement of Figs. 2 tainer having an internal surface which is inert and 3 to effect lthe continuous polymerization. ' to styrene, exhausting the air from the container, Moreover, one or more of rollers 39 in the ap sealing the container, maintaining the sealed con paratus of Figs. 2 and 3 may be rotated in an 50 tainer at a temperature adapted to induce poly- . opposite direction to the others to augment the merization, and alternately andrepeatedly press mixing effect. Other means for applying pres ing together the side walls adjacent opposite ends sure to a. deformable container so as to mix and of said container to reciprocate said mass from advance the polymerization of a given polymer one end of said container to the other. izable mass, in accordance with the present in 55 v8. The method of polymerizing a monomer vention, may also be employed, as will now be ap which constitutes part or all of a ñuid mass, which parent to those skilled in the art. Various other comprises conñning the mass in a deformable ch'anges may be made in the design and arrange container, and polymerizing said monomer in ment of ‘parts without departing frornthe spirit said- container while kneading said container to and scope of the invention. , 60 induce circulation'and mixing of said mass. It is also to be understood that the following 9. The methodA of advancing the polymeriza claims are intended to cover all the generic and tion of a fluid mass of polymerizable plastic ma specific features of the invention herein de terial which comprises continuously introducing scribed, and all statements ofthe scope of the in said mass into one end of a container of substan vention which, as a matter of language, might be 65 tial length which is inert to said mass, maintain said to fall therebetween. ing said container at a temperature adapted to What is claimed is: . 1. Th'e method of advancing the polymeriza produce polymerization of said plastic, successive ly compressing successive, longitudinal portions tion of a iluid mass of polymerizable plastic ma of said container to mix said mass and cause a terial which comprises confining said mass in a 70 -continuous i‘low of vsaid mass through the con deformable container, maintaining said contain tainer, and discharging the polymerized mass er at a temperature adapted to induce polymeri from the other‘end of said container. zation of said plastic, and successively compress 10. Apparatus of the character described com ing diiferent portions of said container to cause prising, in combination, ,a deformable fluid-tight -a circulation and mixing of said mass. container adapted to be partially ñlled with a 2,406,403 7 8 , mass of polymerizable plastic material, means sealing back endsv of said container, means for supporting said sealed container, and means com a roller eccentrically mounted on said disc for rotary movement therewith and for limited radial movement relatively thereto, and means for ro prising a plurality of reciprocating elements ~ tating said disc whereby said roller is caused to adapted to alternately engage and compress dif ferent portions of said container to induce a re ciprocating circulation of the mass contained engage and compress said container during a sub therein. » ~ » ‘ > 11. In apparatus of the class described, yield , stantial part of the travel of said roller. 17. >Apparatus of the character described com prising, in combination, a deformable container open at both ends thereof, means for admitting able means adapted to contain a fluid mass, a mass of polymerizable material into one end means comprising a plurality of movable mem of said container, a plurality of movable elements adapted to engage and successively compress suc bers for applying pressure to diiîerent portions of said yieldable means at different times whereby cessive portions of said container to propel said polymerizable mass through said container and for heating said fluid mass. » 15 discharge the same at the other end of said con tainer, and means for heating the polymerizable 12. In apparatus for polymerizing alluid mass a circulation'of said mass is obtained, and means material within said container. comprising a quantity of monomer, in combina 18. Apparatus of the character described com tion,y a flexible container adapted to be partially prising, in combination, a. deformable container ñlled with said mass, a plurality of mechanisms, each of -said mechanisms comprising a movable 20 open at both ends thereof, means comprising a support for said container, heating elements in member, means for supporting said container: so said support for heating thev contents of said that a diiîerent portion thereof is disposed adja container, means for admitting a mass of poly cent each said member, and means comprising a merizable material into one end of said container source of compressed air and valve means coop erating therewith for actuating said members so 25 and a plurality of movable elements adapted to engage and successively compress'successive por that each successively engages and compresses the tions of said container to propel lsaidpolymeriz portion of said container thereadjacent. able mass throughsaid container and discharge 13. In apparatus for polymerizing a ñuid mass the same at the other end of said container. comprising a quantity of monomer, in combina 19. Apparatus of the character described com tion, a ñexible container adapted to be partially 30 prising, in combination, a, tubular container of filled with said mass, means for sealing the ends substantial length open at both ends thereof and of said container to render the latter fluid-tight, formed from a flexible material, means compris a plurality of mechanisms, each of said mech ing a support for said container, heating ele anisms comprising a movable member, means for supporting said sealed container so that a differ 35 ments in said support for heating the contents of ent portion thereof is disposed adjacent each said member, and means for actuating said members so that each successively engages and compresses the portion of said container thereadjacent to said container, means for admitting a mass of polymerizable material into one end of said con tainer, said container having the internal surface thereof inert to said polymerizable mass, and a induce reciprocating circulation of said mass, said 40 plurality of movable elementsadapted to engage and successively compress successive portions ofv said container to propel said polymerizable mass through said container and discharge the same at the other end of said container. 20. In apparatus for advancing the polymeriza 14. In apparatus of the class described, sup 45 tion of a mass of polymerizable, plastic material, porting means including a platform, a plurality a flexible container for said material, a plurality of cylinders rigidly supported by said support of mechanisms for compressing diiîerent portions ing means and each having its axis disposed sub of said container to circulate and mix said ma stantially perpendicularly to said platform, a plunger slidably mounted in each said cylinder for 50 terial, each of said mechanisms comprising a disc and a roller eccentrically mounted on said disc. reciprocation toward and away from said plat for rotary movement therewith and for limited ’ form, resilient means normally opposing move radial movement relative thereto, and means for ment of leach said plunger in the direction of Said rotating said discs to bring said rollers successive platform, means communicating with each of said » cylinders, and means including valve means al 55 ly into contact with said container. 21. The method ofadvancing the polymeriza ternately admitting and exhausting compressed tion of a ñuid mass of polymerizable plastic ma air to and from each said cylinder to elïect recip terial, which comprises introducing said mass rocation of said plungers. , ï into one end of a container, maintaining said 15. Apparatus of the character described com prising, in combination, a deformable container 60 container at a temperature adapted to induce polymerization of said plastic, successively com open at both ends thereof, means for admitting pressing diil’erent portions of said container to a mass of polymerizable material into one end‘of mix said mass and to cause said mass to flow said container, a plurality of rotating elements through the container, and discharging the poly adapted to Aengage and successively compress suc cessive portions of said container to propel said 65 merized mass from theother endof said con tainer. polymerizable mass through said container and 22. The method of advancing the polymeriza discharge the same at the other end of said con tion of a ñuid mass of polymerizable plastic ma tainer, and means for heating the polymerizable terial, which comprises introducing said mass material Within said container. i 16. In apparatus for advancing the polymeriza 70 into .one end of a container which is inert to said mass, maintaining said container at a tem tion of a mass of polymerizable plastic material, perature adapted to induce polymerization of said a ñexible container for said material, a plurality of mechanisms for compressing different portions plastic, successively compressing different por of said container to circulate and mix 'said mate tions of said'container to mix said mass and to rial, each of said mechanisms comprising a disc, 75 cause said mass to ñow through the container, actuating means being adapted to apply pressure to any predetermined one of said members simul taneously with the release of pressure from an other of said members. 2,406,403 and discharging the polymerized mass from the other end of said container.. 23. The method of advancing the polymeriza ‘ tion of a fluid mass of polymerizable plastic ma terial,fwhich comprises introducing said mass into one end of a container, maintaining said container at a temperature adapted to induce polymerization of said plastic, causing said mass 10 tion thereof is disposed adjacent each said mem ber, means for actuating said members so that each successively engages and compresses the portion of said container thereadjacent, and means for heating said container and the con tents thereof to a temperature adapted to induce polymerization. 26. Apparatus of the character described com to ñow through said container by applying pres prising, in combination, a deformable container sure to said container, and discharging the poly 10 adapted to be partially ñlled with a mass of poly merized mass from the other _end of said conf merizable plastic material, means for sealing said tainer. container, means for supporting said sealed con _ 24. The method of advancing the polymeriza tainer, and means comprising a plurality of mov tion of a fluid mass of polymerizable plastic ma able elements adapted to engage and compress terial, which comprisesv introducing said mass 15 diiîerent portions of said container to induce into one end of a container, maintaining said reciprocating circulation of the mass contained container at a temperature adapted to induce polymerization of said plastic, causing said mass 27. In apparatus for polymerizing a ñuid mass to flow through said container by changing the comprising a quantity of monomer, in combina~ shape of said container, and discharging the poly 20 tion, a iiexible container adapted to be partially therein. merized mass from the other end of said con tainer. . 25.' In apparatus for advancing the polymeriza Y _ ñlled Iwith said mass, means for sealing said con tainer, a plurality of mechanisms, each of said mechanisms comprising a movable member, tion of a ñuid mass comprising a quantity of means for supporting said container so that a monomer, in combination, a flexible container 25 different portion thereof is disposed adjacent each adapted to be partially ñlled with said mass, a said member, and means for actuating said mem plurality of mechanisms, each of said mecha nisms comprising a movable member, means for supporting said container so that a different por l bers so that each successively engages and com presses a portion of said container thereadjacent. HOWARD G. ROGERS.