BE443485A

BE443485A -

Info

Publication number: BE443485A
Authority: BE
Priority date: 1941-10-27
Also published as: FR876353A; CH225374A

Description

       

  Procédé de fabrication de régénérés de caoutchouc.

  
La fabrication de régénérés de caoutchouc à l'aide de solvants est connue très généralement. On a déjà proposé également l'emploi de solvants à point d'ébullition élevé pour maintenir ainsi le plus bas possible les pertes de solvants. On compte, dans les installations formées d'une façon appropriée pour la récupération et dans le cas de solvants appropriés, sur une consommation de 150 à 200 grammes de solvant par kilogramme de régénéré obtenu. On connaît en outre l'addition dtagents plastifiants au vieux caoutchouc suivie d'un chauffage, par exemple l'emploi d'hydrocarbures de la paraffine et du pétrole.

  
Mais dans les procédés connus on se heurtait à des inconvénients sérieux, car le vieux caoutchouc devait être réduit en petits fragments ou être broyé et la durée du chauffage dans les solvants devait être fort étendue pour obtenir le résultat désiré. En outre, dans les procédés connus jusqutà présent, il était nécessaire de séparer du vieux caoutchouc,

  
à. l'aide de solvants, les matières fibreuses, parce qu'on ne pouvait pas provoquer leur décomposition à. la température relativement basse des solvants employés. 

  
Suivant le procédé objet de la présente invention, tous ces inconvénients sont écartés et d'autres avantages techniques importants sont réalisés grâce à ce qu'on plonge complètement du vieux caoutchouc, découpé en gros morceaux, mais de préférence non broyé, dans un agent chaud qui le mouille facilement, de préférence dans du bitume, de telle façon que, pendant le chauffage, une oxydation du caoutchouc soit évitée. A côté du bitume ou à sa place, on peut, conformément à l'invention, employer aussi des asphaltes, du caoutchouc minéral ou de l'huile à point d'ébullition élevé pour l'immersion du vieux caoutchouc. Suivant l'invention, on chauffe pendant un quart d'heure à une demi-heure le vieux caoutchouc, à l'abri de l'air, dans l'agent précité, à environ 230 à 250[deg.] 'C.

   Dans le procédé objet de l'invention, le vieux caoutchouc ne vient donc en contact ni avec les vapeurs du solvant ni avec l'air. Même lorsqu'on retire le caoutchouc chaud, il est couvert d'une couche mince de l'agent plastifiant en train de se refroidir et il est abrité hermétiquement contre l'action de l'air. Pour ce motif, on peut appliquer des températures plus élevées qu'il n'était possible de le faire jusqu'ici.

  
Par suite de la température de l'agent fondu, dans lequel on plonge le vieux caoutchouc, celui-ci s'ouvre et l'agent plastifiant chaud qui l'entoure pénètre dans les pores du caoutchouc, qui se gonfle, et il mouille une surface devenue plusieurs fois plus grande; en d'autres termes, le vieux caoutchouc se gonfle de part en part dans l'agent plastifiant chaud. De cette façon, on réalise le progrès technique très

  
 <EMI ID=1.1> 

  
teux, du vieux caoutchouc n'est pas nécessaire*



  Manufacturing process for regenerated rubber.

  
The manufacture of rubber regenerates using solvents is very generally known. The use of solvents with a high boiling point has also already been proposed to thus keep the losses of solvents as low as possible. In plants suitably formed for the recovery and in the case of suitable solvents, there is a consumption of 150 to 200 grams of solvent per kilogram of regenerate obtained. Furthermore, the addition of plasticizers to old rubber followed by heating, for example the use of paraffin and petroleum hydrocarbons, is known.

  
However, in the known methods serious drawbacks were encountered, since the old rubber had to be reduced to small fragments or be crushed and the heating time in the solvents had to be very long to obtain the desired result. In addition, in the processes known heretofore, it was necessary to separate old rubber,

  
at. using solvents, fibrous material, because one could not cause their decomposition to. the relatively low temperature of the solvents used.

  
According to the process which is the subject of the present invention, all these drawbacks are eliminated and other important technical advantages are achieved by completely immersing old rubber, cut into large pieces, but preferably not crushed, in a hot agent. which easily wets it, preferably in bitumen, so that, during heating, oxidation of the rubber is avoided. Besides or in place of bitumen, according to the invention, it is also possible to use asphalts, mineral rubber or high-boiling oil for the immersion of old rubber. According to the invention, the old rubber is heated for a quarter of an hour to half an hour, away from air, in the aforementioned agent, at approximately 230 to 250 [deg.] ° C.

   In the process which is the subject of the invention, the old rubber therefore does not come into contact with either the vapors of the solvent or with the air. Even when the hot rubber is removed, it is covered with a thin layer of the cooling plasticizer and is sealed against the action of air. For this reason, higher temperatures can be applied than hitherto possible.

  
As a result of the temperature of the molten agent in which the old rubber is immersed, it opens and the hot plasticizing agent which surrounds it penetrates the pores of the rubber, which swells, and it wets a area that has become several times larger; in other words, the old rubber swells right through in the hot plasticizer. In this way, very technical progress is achieved.

  
 <EMI ID = 1.1>

  
all, old rubber is not necessary *

Claims

As with regard to the case of mechanical particle reduction, the surface of the old rubber which is put into

contact with the anchor is much greater

in the fragment swollen by the action of heat, the duration

heating is also, in the process according to the invention,

reduced to a fraction of what it is in the processes

known. It is necessary, for example, in the processes

known, to heat for about 5 hours between 200 and 2300

rubber reduced to powder by a roller mill, if

we want to obtain a somewhat plastic and sticky regenerated product.

But, according to the process which is the subject of the invention, heating for a quarter of an hour to half an hour is sufficient to obtain the

same effects. This is why the consumption of plasti- <EMI ID = 2.1>

ter according to the present process the old rubber crushed in

a roller mill; but, in this case, the cake formed on heating must be subjected to pressure to express again the major part of the plasticizer which adheres

rubber.

We get rid of their bulges, in which

steel wires, worn tire tires and

cut these bandages into large pieces weighing about 500

grams. These are then immersed in hot bitumen, including

they are kept for a quarter of an hour at. half an hour below the surface of the bitumen heated to between 230 and 2500 approximately. After we have removed and let the

pieces of rubber, these have absorbed bitumen in an amount corresponding to about 10% of their weight. We drive

then these still hot pieces between cylinders of the-

<EMI ID = 5.1> usual way for regenerates. They then immediately form a continuous sheet, because the fibrous material, owing to the high temperature to which it has previously been subjected, crumbles into extremely small particles.

Claims.

-0-0-0-0-0-0-0-0-0-0-0-0-

I / A method of manufacturing rubber regenerates, characterized in that completely immersed old rubber, cut into large pieces, but preferably not crushed, in a pure swelling agent which wets it easily.

smoothness is 90 to 1200 C., and heated in this softening agent to about 230 to 250 [deg.] for about a quarter of an hour to a half hour, away from air .

2 / A method according to claim 1, characterized in that next to the bitumen or in its place, asphalts, mineral rubber or high-boiling oil for the immersion of old, rubber are used. .