DE1720151B2 - Method of treating rubber grist by extraction - Google Patents

Description

_{15 is} carried out. That way you avoid

the difficulties mentioned at the beginning, because after the end of the extraction the in the extraction container

The invention relates to a method for the treatment of imparting amounts of solvent m, t water vapor rubber grist can be driven off by extracting with solution * The gasoline can be

SSS ^{the production of non-marking 2} ^^^^^^^

SL ₁ S ^^^

It is known that to increase the dimensional stability of water in gasoline is so low that the for

"And other properties of the rubber mixture used water without" eiteremi, the

in some cases regenerated material added. The disadvantage is the sewer system can be drained while the ben-

lierbei that mixtures containing regenerate after the, 5 zin immediately again ^z ; ^r can come. Vulcanization rub off if they are not black This idea of the invention is desv, eger, '"bern, -

«Change rubber bodies or paint in constant sight, because every ** f ™ hilft ^h * ™ ^

Lead are coming, gasoline for extraction

To eliminate these difficulties is already well to use, because what has been recognized? the grist swelled by gasoline to a considerable extent before a further 30 This use to subject a pretreatment. In the event of an appearance, a corresponding ve _r . For example, it is known to extract the ground rubber material before the reduced amount of the fill> rn Extrakt.onsbehalter without a regeneration process with non-swelling solvents, but other factors such as acetone, butanone, etc., must be taken into account. The fact that this disadvantage is a not fully exploited advantage of this method is the difficulty that the lumen capacity of the extraction container but solvent residues after the extraction is more than compensated for by the fact that the extraction removes one. Furthermore, the recovery of the essential acceleration experience. The diffusion of the solvent used required a considerable amount of extractable constituents in the rubber ground material over the wall. The profitability of the extraction-swollen solvent is much faster, but depends crucially on the amount of 40 liters than in the non-swollen grist when using solvent losses. If, for example, in the case of acetone or other non-swelling solution extraction using acetone, this is averaged out by heating.

is driven, it still remains in the extraction room. The driving off of the gasoline with water vapor has

still acetone vapor back. Furthermore, the fine sucks the advantage that the extraction material after

Rubber grind the liquid acetone like a sponge 45 discharging and cooling a certain moisture

OTf, so that there is a considerable excess temperature to the extent that the self-ignition and the

expulsion of the acetone is required. electrostatic charge of the very fine, now of

The possibility of removing all antioxidants from the extraction container at the end of the rubber grinding

Blowing hot air through it is a good way to counteract the risk of explosion. In the subsequent regeneration

with himself. In addition, an adsorption system would not be affected by this moisture content

be necessary to remove the acetone from the blown product in general anyway with high

To be able to recover the mixture. pressurized steam is treated directly.

It has also been proposed that the staining is advantageous, furthermore, that it is relatively easy Rubber bodies made from reclaimed rubber are extracted from the gasoline to make rubber mixtures in this way to prevent the 55 from being recovered and possibly in other regenerated material before further processing with peroxides again for the addition in the production or diazonium salts is treated. By using this a rubber compound. That extra treatment either an oxidation occurs or the constituents here can also act as a stabilizing coupling in the case of the discolouring components. Afternoon serve for polyamide. Valuable components of the Part of this, however, is that oxidation products can be obtained from the extract by simple separation processes that still show a delayed discoloration. B. by means of two immiscible solvents can trigger exercise. In addition, they cannot be recovered. For the extraction time is converted peroxides or diazonium salt compounds - the grain fineness of the ground rubber is important, The more finely the rubber is ground, the shorter the times To give reason. Due to peroxides, diazonium salts 65 are required for the extraction, However, bonds are dark not recorded in their negative effects. Finally, have a relatively low solubility in gasoline, if these oxidation or coupling products remain, it may prove useful that the gasoline

Benzene and / or cyclohexane is added. To this In some cases, improved extraction is possible without simply stripping off the extractant from the rubber regrind by means of steam and the subsequent separation made more difficult were.

The extraction can take place in conventional extraction systems, such as those used in the chemical industry, for example in oil mills for the extraction of ground oilseeds or in slaughterhouses for the extraction of ground oil seeds Bone is common. The extraction can be carried out continuously or batchwise in a manner known per se Systems of various construction are carried out. As a starting material, vulcanized Waste from rubber production or old rubber, for example worn tires, conveyor belts or the like. Like., can be used.

In order to be able to carry out the extraction economically, the waste should be sorted according to the type of rubber so that waste from natural rubber, synthetic butadiene-styrene rubber, polychloroprene, Butyl rubber etc. can be processed separately. It should be noted that the gasoline extraction can be used with all types of rubber, but swelling with polychloroprene, for example is small, so that a prolonged extraction time is required. The regeneration of the rubber miniature material can be done by any known method, e.g. B. after aeni superheated steam process, after the Alkali or acid process and also according to the continuous thermo-mechanical process (reclaimator). After regaining the product to meet the highest requirements Light stability still 1 to 5% activated carbon or 1 to 5% methylol compounds of phenols in the kneader or can be added on the roller.

example

500 kg of regrind from old truck tires, with a grain size of approx. The ground material is leached in a batch extraction plant 8 to ten times with hot gasoline boiling range from 80 to 110 ⁰ C. The extractor is then blown through with steam until no more gasoline passes over, ίο The extracted, moist grist is then discharged. A dried sample shows an acetone extract of less than 0.1% compared to 5 to 7% before extraction.

The still moist grist is regenerated in a pressure vessel for 2 hours with direct steam heated to 20 atmospheres and then refined after cooling over fine rollers.

A test mixture is made from the regenerated material obtained in this way made according to the following recipe:

Regenerate 100 parts by weight

Zinc oxide 3 parts by weight

Sulfur 2 parts by weight

Mercaptobenzothiazole ... 1 part by weight

A 2 mm plate is vulcanized from this mixture (30 '/ 143 ^c ). The plate is coated with a white test varnish and air-dried.

If the white lacquered side of the plate is now exposed to an Ultraphil lamp for 30 minutes, it occurs no discoloration of the white paint.

If you regenerate the same truck tire grind

without prior extraction and then performs the described exposure test with a vulcanized If the plate passes through, a strong discoloration of the white lacquer to dark brown occurs.

Claims (1)

also back in the regenerated, although it is due to the partial effect in terms of aging and heat- Patent claims: partial effect ^^ ^ ^ ^^ ν ^ _ 1. Method for treating rubber grinding turns find ^ _g well by extracting with solvents for the 5 genes on Gummiart.kel ^ ε Production of non-marking regenerated material, of diazonium salts! " ode ^ Perox den is therefore not d a d u r c h e k e η η ζ e i c h η e t that the ex- free of remarkable nights traction by means of gasoline of the sieve fraction 60 to the object of the invention is characterized thereby- "S = K SS? Ä ΪΆ ^{Benzo1 and / or cycl} ° - SÄSÄ p ^ added .st. ^^ ^. ^ ^ _{dje extraction miU} els petrol the Boiling fraction 60 to 120 ⁰ C, preferably 80 to 110 C,