GB2113693A - Method of making liquid suitable as a softener for rubber mixtures or as a furnace fuel oil - Google Patents

Abstract

A method of making liquid product suitable as a softener for rubber mixtures or as a furnace fuel oil comprises the steps of heating a hydrocarbonaceous solvent and introducing there into waste products from vulcanized and/or non-vulcanized rubber under intensive stirring. Then the waste products are thermally decomposition under a pressure from 5.10<2> to 25.10<5> n/m<2>, with the hydrocarbonaceous solvent continuously circulating through the reaction mixture. The end product is distilled from the suspension formed at a temperature of 200 to 560 DEG C and at a pressure of 10 to 2.10<5>n/m<2> in the presence of an inert gaseous agent.

Description

SPECIFICATION Method of making liquid suitable as a softener for rubber mixtures or as a furnace fuel oil The present invention reiates to chemical production procedures and more particularly to methods of making a liquid product useful as a softener for rubber mixtures or as a furnace fuel oil.

The invention consists in a method of making a liquid useful as a softener for rubber mixtures or as a furnace fuel oil, comprising thermal decomposition of a polymeric raw material in a hydrocarbonaceous solvent and subsequent separation of the end product, characterized in that the hydrocarbonaceous solvent is preheated; vulcanized and/or non-vulcanized rubber waste is added thereto with stirring; thermal decomposition of the material is carried out at a pressure from 5.102 to 25.105n/m2 with the hydrocarbonaceous solvent continuously circulating through the reaction mixture; and the end product is separated from the formed suspension by distillation at a temperature from 200 to 560" and at a pressure from 10 to 2.105 n/m2 in the presence of an inert gaseous agent.

The preheating of the hydrocarbonaceous solvent and the circulation of the latter in the reaction mixture, together with observation of the above conditions of thermal decomposition and distillation make it possible to considerably upgrade the quality of the end products and to preclude coking of the raw material. There is an improvement in the properties of the rubber mixtures (vulcanizates) produced with the aid of thus obtained softener. In particular, the method of the present invention makes it possible to reduce the congelation temperature of the rubber mixtures and to improve there viscosity-and-temperature characteristics. It is to be noted that the distinguishing features of the method allow the process to be accomplished more intensively as compared to conventional processes.This is assisted by both the circulation of the heated hydrocarbonaceous solvent and the addition of the inert gaseous agent.

It is advisable that the hydrocarbonaceous solvent be heated up to and used at a temperature of 150 to 600"C. To step up the efficiency of the process, the thermal decomposition of the waste materials from vulcanized and/or non-vulcanized rubber should preferably be carried out over a period from 1 to 300 sec.

The waste materials can be mixed with the hydrocarbonaceous solvent in a ratio of 1:1 to 1:100 parts by weight. The above range is the most suitable for attaining good results, such as a higher quality of the product, a shorter duration time of the process, lower power expenditures etc.

It is preferable that during thermal decomposition the hydrocarbonaceous solvent circulates through the reaction mixture in an amount of 1 to 30 l/hr per kg of waste. This modification of the method provides better conditions for the thermal decomposition of the raw material and thus allows it to be accomplished to a higher extent.

The inert gaseous agent can be nitrogen, steam, stack gases, methane, ethane, propane, hydrocarbonaceous C3-C6 fraction or mixtures thereof. The above gaseous agents are comparatively cheap, widely distributed in anture and easy to produce.

It is advisable that in the course of the distillation the inert gaseous agent is continuously added at a rate of 0.01 to 90 I/hr per kg of the suspension. Such conditions provide for a better removal of sulfur dioxide and at the same time provide a sufficient intensity of the process.

In an embodiment of the method, intended mainly for the production of a furnace fuel the distillation process should preferably be carried out at a temperature of 250 to 560"C and at a pressure of 10 to 1 105 n/m2. Such conditions provide a high quality product in maximum output. In this same modification of the method it is advisable that in the course of the thermal decomposition of waste said hydrocarbonaceous solvent be oil fractions, coke chemical fractions, or a furnace fuel oil obtained from a precious distillation, containing from 0.1 to 100% by mass of aromatic hydrocarbons and resins.

In another form of the method, intended mainly for the production of a softener, it is advisable that the thermal decomposition should be carried out at a temperature of 200 to 400"C and at a pressure of 1.105 to 4.105n/m2, and in the distillation process the temperature should be maintained within the range of 200 to 4000C and at a pressure of 1.103 to 2.105n/m2.

Now the invention will be described with reference to the detailed description of the method as well as of specific examples thereof.

A method of making a softener for rubber mixtures and a furnace fuel oil is carried out in the following way. According to the invention a hydrocarbonaceous solvent is preheated e.g. to a temperature of 150 to 600"C. As the hydrocarbonaceous solvent may be used oil fractions having a boiling temperature of 40 to 120 C,50 to 250"C, 250 to 400"C and 200 to 500"C, and/or a coke-chemical fraction having a boiling temperature of 320 to 535"C, and/or a furnace fuel oil previously produced according to the method of the present invention. The heated hydrocarbonaceous solvent is mixed with the waste from vulcanized and/or non-vulcanized rubbers under intensive stirring.

As raw materials may be used worn tyres, waste from natural rubber products or waste based on butadiene, isoprene, butadinene-styrene, ethylene-propylene, acryl, carboxylated, butadiene-methylstyrene or butadiene-nitrile rubbers.

Such waste from vulcanized and/or non-vulcanized rubbers is mixed with said hydrocarbonaceous solvent usually in a ratio of 1:1 to 1:100 parts by mass.

The obtained mixture is thermally decomposed e.g. at a temperature of 150 to 4850C and at a pressure of 5.102 to 25.105 n/m2 for 1 to 300 sec until the waste is completely disintegrated and a suspension is obtained.

If a softener for rubber mixtures is to be produced, the thermal decomposition process is better carried out at a temperature of 200 to 4000C and at a pressure of 1.205 to 4.105 n/m2.

In the course of thermal decomposition the hydrocarbonaceous solvent continuously circulates through the reaction mixture e.g. in an amount of 1 to 30 l/hr per 1 kg of the waste from vulcanized and non-vulcanized rubbers.

The end product is separated from the suspension formed by distillation at a temperature of 200 to 560"C and at a pressure of 10 to 2.105n/m2 in the presence of an inert gaseous agent.

Example 1 According to the invention a furnace fuel oil was produced from old tyres (materials bsed on ethylene-propylene, butylene rubber). For this purpose a hydrocarbonaceous solvent was preliminarily heated up to a temperature of 362"C. The hydrocarbonaceous solvent (a coke-chemical fraction having a boiling temperature of 335 to 502"C) had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9594 - index of refraction 20 1.5671 - Englerviscosity at a temperature of 50"C, "E 7.6 - content of sulphur, % by mass 1.57 - molecular mass 357 - distillation fractions, "C beginning of boiling 335.5 50% boils away 452 end of boiling 502 - group chemical composition, % by mass:: methano-naphtenic hydrocarbons 12.5 monocyclic aromatic hydrocarbons 10.1 bicyclic aromatic hydrocarbons 32.7 polycyclic aromatic hydrocarbons 42.8 resins 1.9 The heated hydrocarbonaceous solvent was mixed with the above waste. The ratio between the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:10 parts by mass. The thermal decomposition process was carried out for 290 sec at a temperature of 362"C at a pressure of 4.5- 105 n/m2, the hydrocarbonaceous solvent circulating through the reaction mixture at a rate of 7 l/hr per 1 kg of the waste.

From the obtained suspension the furnace fuel oil was separated by distillation at a temperature of 356"C and at a pressure of 5-104 n/m2. In the course of the distillation process the remainder of sulphur dioxide was removed by a gaseous agent, namely steam. The consumption of the steam was 9 l/hr per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperture of 20"C, g/cm3 0.9624 - Englerviscosity at a temperature of 50"C, "E 8.65 - ash content, % by mass 0.05 - content of mechanical admixtures, % by mass 0.03 - flash point (in a closed crucible), "C 98 - heat of combustion (lower value calculated as dry fuel), kcal/kg 9845 The above data prove that the produced furnace fuel oil has such characteristics which are similar to those of mazuts. However, the cost of the produced furnace fuel oil is lower than that of the mazuts.

Example 2 The furnace fuel oil according to the invention was produced substantially as described in Example 1, using the same hydrocarbonaceous solvent. Used as the raw material was waste based on butadienestyrene isoprene rubber.

The conditions of the thermal decomposition were the following: - ratio between the raw material and the hydrocarbo naceous solvent, parts by mass 1:10.2 - tem peratu re, "C 362 - pressure, n/m2 4.5-105 - time, sec 300 The hydrocarbonaceous solvent intensively circulated through the reaction mixture at a rate of 51/hr per 1 kg of the waste.

The distillation process was carried out with the aid of steam used as the hydrocarbonaceous agent at a temperature of 356"C and at a pressure of 5-104 n/m2. The rate of the steam was 9.01/her per 1 kg of the suspension.

The characteristics of the obtained furnace fuel oil were the following: - density at a temperature of 20"C, g/cm3 0.9624 - Engler viscosity at a temperature of 50"C, "E 8.65 - ash content, % by mass 0.05 - content of mechanical admixtures, % by mass 0.03 - content of sulphur, % by mass 1.4 - flash point (in a closed crucible), C 98 - heat of combustion, kcal/kg 9845 Thus, the properties and cost of the obtained furnace fuel oil were similar to those of the furnace fuel oil described in Example 1.

Example 3 The furnace fuel oil according to the invention was produced substantially as described in Example 1 with the difference that the raw material was waste based on isoprene natural rubber, and the hydrocarbonaceous solvent was an oil fraction having a boiling temperature of 400"C. Said hydrocarbonaceous solvent had the following characteristics: - density at a temperature of 20"C g/cm3 0.9007 - index of refraction, nD 1.5204 - Engler viscosity at a temperature of 50"C, "E 1.8 - content of sulphur, % by mass 1.34 - molecular mass 283 - distillation fractions, C beginning of boiling 250 50% boils away 381 end of boiling 400 - group chemical composition, % by mass:: methano-naphtenic hydrocarbons 51.4 monocyclic aromatic hydrocarbons 10.5 bicyclic aromatic hydrocarbons 17.1 polycyclic aromatic hydrocarbons 20.3 resins 0.7 Said hydrocarbonaceous solvent was preliminarily heated to a temperature of 468"C, and the waste was mixed with the heated hydrocarbonaceous solvent in a ratio of 1 :100 parts by mass. The thermal decomposition was carried out for 239 sec at a temperature of 468"C and at a pressure of 12-105 n/m2,the hydrocarbonaceous solvent circulating through the reaction mixture at a rate of 2.3 I/hr per 1 kg of the waste.

The distillation was carried out utilizing ethane as an inert gaseous agent. The consumption of ethane was 6.7 l/hr per 1 kg of the suspension. The distillation was carried out at a temperature of 250"C and at a pressure of 1.5.102 n/m2.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9701 - Engler viscosity at a temperature of 50"C, "E 20.2 - ash content, /O by mass 0.06 - content of mechanical admixtures, % by mass 0.04 - content of sulphur, % by mass 1.5 -flash point (in a closed crucible), "C 139 - heat of combustion, kcal/kg 9968 Thus, the properties and the cost of the obtained furnace fuel oil were similar to those of the furnace fuel oil obtained as described in Example 1.

Example 4 The furnace fuel oil according to the invention was produced substantially as described in Example 1. The raw material was waste based on butadiene-styrene rubber, and the hydrocarbonaceous solvent was an oil fraction described in Example 3.

The hydrocarbonaceous solvent was heated up to a temperature of46100. Then the waste was mixed with the heated hydrocarbonaceous solvent in a ratio of 1:11 parts by mass.

The conditions of the thermal decomposition where the following: - temperature, "C 461 - pressure, n/m2 8.7-105 - time, sec 245 Such being the case, the hydrocarbonaceous solvent intensively circulated through the reaction mixture at a rate of 1.4 l/hr per 1 kg of the waste.

The distillation process was carried out using stack gases as an inert gaseous agent at a temperature of 38300and ata pressure of 6.7-103 n/m2. The consumption ofthestackgaseswas 1.8 l/hr per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20 C, g/cm3 0.9649 - Englerviscosity at a temperature of 50"C, "E - 18.4 - ash content, % by mass 0.02 - content, % by mass: of mechanical admixtures 0.03 of sulphur 1.3 -flash point (in a closed crucible), C 117 - heat of combustion, kcal/kg 10412 Thus, the properties and the cost of the obtained furnace fuel oil where similar to those of the furnace fuel oil obtained as described in Example 1.

Example 5 The furnace fuel oil according to the invention was produced substantially as described in Example 1 with the difference that the raw material was waste based on butadiene-nitrile rubber, and the hydrocarbonaceous solvent was an oil fraction having a boiling temperature of 200 to 500"C. Said hydrocarbonaceous solvent had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9812 - index of refraction, n2g 1.5823 - Englerviscosity at a temperature of 50 C, "E 1.2 - content of sulphur, % by mass 1.37 - molecular mass 265 - distillation fractions, "C beginning of boiling 200 50% boils away 364 end of boiling 500 - group chemical composition, % by mass:: methano-naphtenic hydrocarbons 9.7 monocyclic aromatic hydrocarbons 8.6 bicyclic aromatic hydrocarbons 25.8 polycyclic aromatic hydrocarbons 54.5 resins 1.4 Said hydrocarbonaceous solvent was heated up to a temperature of 453"C, and the waste was mixed with the heated hydrocarbonaceous solvent in a ratio of 1:11.6 parts by mass.

The thermal decomposition was carried out for 250 sec at a temperature of 453"C and at a pressure of 9.2-105 n/m2, the hyerocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 1.8 l/hr per 1 kg of the waste.

The distillation process was carried out with the use of a hydrocarbonaceous C3-C6 fraction as an inert gaseous agent. The consumption of said hydrocarbonaceous C3-C6 fraction was 2.1 I/hr per 1 kg of the suspension. The distillation process was accomplished at a temperature of 432"C and at a pressure of 2.5-103 n/m2.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9657 - Engler viscosity at a temperature of 50"C, "E 17.6 - ash content, % by mass 0.04 - content, in % by mass: of mechanical admixtures 0.02 of sulphur 1.7 -flash point (in a closed crucible), "C 124 - heat of combustion, kcal/kg 9941 Thus, the properties and the cost of the obtained furnace fuel oil were similar to those of the furnace oil obtained as described in Example 1.

Example 6 The furnace fuel oil according to the invention was produced substantially as described in Example 1 with the difference that the raw material was waste based on butadiene-methylstyrene acryl rubber, and the hydrocarbonaceous solvent was a coke-chemical fraction having a boiling temperature of 320 to 535"C. Said hydrocarbonaceous solvent had the following characteristics: - density at a temperature of 20"C, g/cm3 1.1204 - index of refraction, nD 1.6095 - Engler viscosity at a temperature of 50"C, "E 2.3 - content of sulphur, % by mass - 0.38 - molecular mass 275 - distillation fractions, "C beginning of boiling 320 50% boils away 447 end of boiling 535 - group chemical composition, % by mass:: methano-naphtenic hydrocarbons 0 monocyclic aromatic hydrocarbons 13.5 bicyclic aromatic hydrocarbons 31.3 polycyclic aromatic hydrocarbons 50.9 resins 4.3 Said hydrocarbonaceous solvent was heated up to a temperature of 600"C, and the waste was mixed with the heated hydrocarbonaceous solvent in a ratio of 1:11.4 parts by mass.

The thermal decomposition was carried out at a temperature of 600"C and at a pressure of 8.3.105 n/m2, solvent circulation 1 .21/hr/kg Distillation was effected at 56000 and 1.105 n/m2 with the use of stack gases as an inert gaseous agent. The consumption of the stack gases was 90 l/hr per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 1.0017 - Englerviscosity at a temperature of 50"C, "E 40.0 - ash content, % by mass 0.09 content, % by mass: of mechanical admixtures 0.1 of sulphur 0.3 -flash point (in a closed crucible), "C 139 - heat of combustion, kcal/kg 9894 Thus, the properties and the cost of the obtained furnace fuel oil were similar to those of the furnace fuel oil obtained as described in Example 1.

Example 7 The furnace fuel oil according to the invention was produced substantially as described in Example 1 with the difference that the raw material was waste based on ethylene-propylene acryl rubber, and the hydrocarbonaceous solvent was an oil fraction having a boiling temperature of 40 to 120"C. Said hydrocarbonaceous solvent had the following characteristics: - density at a temperature of 20"C, g/cm3 0.6715 - index of refraction, nD 1.3802 - Engler viscosity at a temperature of 50"C, "E 0.1 - content of sulphur, % by mass 0.01 - molecular mass 92 - distillation fractions, "C beginning of boiling 40 50% boils away 89 end of boiling 120 - group chemical composition, % by mass:: methano-naphthenic hydrocarbons 99.9 monocyclic aromatic hydrocarbons 0.1 Said hydrocarbonaceous solvent was heated up to a temperature of 437"C, and the waste was mixed with the heated hydrocarbonaceous solvent in a ratio of 1:11 parts by mass.

The thermal decomposition was carried out for 300 sec at a temperature of 437"C and at a pressure of 25105 n/m2, the hydrocarbonaceous solvent circulating through the reaction mixture at a rate of 1.4 l/hr per 1 kg of the waste.

The distillation process was carried out with the use of methane as an inert gaseous agent at a temperature of 325"C and at a pressure of 7.2-103 n/m2. The consumption of methane was 2.4 I/hr per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9563 - Engler viscosity at a temperature of 50 C, "E 12.7 - ash content, % by mass 0.01 - content, % by mass: of mechanical admixtures o 0.02 of sulphur 1.2 - flash point (in a closed crucible), C 93 - heat of combustion, kcal/kg 10625 Thus, the properties and the cost of the obtained furnace fuel oil were similar to those of the furnace fuel oil obtained as described in Example 1.

Example 8 The furnace fuel oil according to the invention was produced substantially as described in Example 1.

However, the hydrocarbonaceous solvent was the furnace fuel oil of the present invention having the following characteristics: - density at a temperature of 20"C, g/cm3 0.9736 - index of refraction, nD 1.5729 - Englerviscosity at a temperature of 50"C, "E 8.4 - content of sulphur, % by mass 1.25 - molecular mass 342 - distillation fractions, "C: beginning of boiling 293 50% boils away 378 end of boiling 529 - group chemical composition, % by mass:: methano-naphtenic hydrocarbons 41.3 monocyclic aromatic hydrocarbons 12.1 bicyclic aromatic hydrocarbons 13.4 polycyclic aromatic hydrocarbons 30.5 resins 2.7 Said hydrocarbonaceous solvent was heated up to a temperature of 430"C, and the waste was mixed with the heated hydrocarbonaceous solvent in a ratio of 1:11.3 parts by mass.

The thermal decomposition was carried out for 262 sec at a temperature of 430"C and at a pressure of 7-105 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 1.2 l/hr per 1 kg of the waste.

The distillation was carried out at a temperature of 284and at a pressure of 10 n/m2 with the use of propane as an inert gaseous agent. The consumption of propane was 0.01 I/hr per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm23 0.9962 - Engler viscosity at a temperature of 50"C, "E 27.1 - ash content, % by mass 0.03 - content, % by mass: of mechanical admixtures 0.04 of sulphur 1.8 -flash point (in a closed crucible), "C 95 - heat of combustion, kcal/kg 10296 Thus, the properties and the cost of the obtained furnace fuel oil were similar to those of the furnace fuel oil obtained as described in Example 1.

Example 9 The furnace fuel oil according to the invention was produced substantially as described in Example 1 with the only difference that the raw material was waste based on isoprene butadiene-styrene rubber.

The hydrocarbonaceous solvent was heated up to a temperature of 372"C, and the waste was mixed with the heated solvent in a ratio of 1:1 parts by mass. The thermal decomposition was carried out for 95 sec at a temperature of 372"C and at a pressure of 8-104 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 1 I/hr. The distillation process was carried out at a temperature of 410"C and at a pressure of 5-104 n/m2 with the use of nitrogen as an inert gaseous agent. The consumption of nitrogen was 16 l/hr per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9745 - Engler viscosity at a temperature of 50"C, "E 8.9 - ash content, % by mass 0.05 - content of mechanical admixtures, % by mass 0.05 -flash point (in a closed crucible), C 145 - heat of combustion, kcal/kg 9942 Thus, the properties and the cost of the obtained furnace fuel oil were similar to those of the furnace fuel oil obtained as described in Example 1.

Example 70 The furnace fuel oil according to the invention was produced substantially as described in Example 9 using the same raw material and the same hydrocarbonaceous solvent. However, the hydrocarbonaceous solvent was preheated up to a temperature of 1 500. The waste was mixed with the heated solvent in a ratio of 1:5.9 parts by mass. The thermal decomposition was carried out for 300 sec at a temperature of 150"C and a pressure of 5'1 02 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 30 l/hr per 1 kg of the waste.The distillation process was carried out at a temperature of 250"C and at a pressure of 1.102 n/m2 with the use of nitrogen as an inert gaseous agent. The consumption of nitrogen was 0.091/her per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9741 - Engler viscosity at a temperature of 50"C, "E 9.37 - ash content, % by mass 0.08 - content of mechanical admixtures, % by mass 0.05 -flash point (in closed crucible), "C 161 - heat of combustion, kcal/kg 9913 Thus, the properties and the cost of the obtained furnace fuel oil were similar to those of the furnace fuel oil obtained as described in Example 1.

Example ii (negative) Furnace fuel oil was produced substantially as described in Example 1 using the same raw material and the same hydrocarbonaceous solvent. However the hydrocarbonaceous solvent was preheated up to a temperature of 610 C, which is higher than the limit indicated in the claims.

The waste was mixed with the heated solvent in a ratio of 1:11.2 parts by mass. The thermal decomposition was carried out for 129 sec at a temperature of 61000, which is higher than the maximum limit indicated in the claims and at a pressure of 26-105 n/m2, which is also higher than the maximum limit indicated in the claims. This being the case, the hydrocarbonaceous solvent intensively circulated through the reaction mixture at a rate of 1.5 l/hr per 1 kg of the waste.

The distillation process was carried out with the use of nitrogen as an inert gaseous agent. The consumption of nitrogen was 95 l/hr per 1 kg of the suspension, which is higher than the maximum limit indicated in the claims. The distillation process was carried out at a temperature of 570"C which exceeds the maximum limit indicated in the claims and at a pressure of 7.2-104 n/m2.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9505 - Englerviscosity at a temperature of 50"C, "E 18.3 - ash content, % by mass 0.2 - content, % by mass: of mechanical admixtures 1.2 ofsulphur 0.7 -flash point (in a closed crucible), "C 83 - heat of combustion, kcal/kg 9875 Thus, the elevated temperatures of accomplishing the thermal decomposition and distillation cause a partial coking of the reaction mixture, which adversely affects the quality of the furnace fuel oil being produced.

Example 17 (negative) Furnace fuel oil was produced substantially as described in Example 4 using the same raw material and the same hydrocarbonaceous solvent. The hydrocarbonaceous solvent was preliminarily heated up to a temperature of 446"C.

The waste were mixed with the heated hydrocarbonaceous solvent in a ratio of 1:11.5 parts by mass. The thermal decomposition was carried out for 320 sec, which exceeds the maximum limit indicated in the claim, at a temperature of 446"C and at a pressure of 8.6-105 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 2.1 I/hr per 1 kg of the waste. The distillation process was carried out with the use of steam as an inert gaseous agent. The consumption of steam was 0.0051/her per 1 kg of the suspension, which is less than the minimum limit indicated in the claims.The distillation process was carried out at a temperature of 395"C and at a pressure of 5 n/m2, which is also lower than the minimum limit indicated in the claims.

The obtained furnace fuel oil had the following characteristics: - density at a temperature, of 20"C, g/cm3 1.0945 - Engler viscosity at a temperature of 50"C, "E 38.6 - ash content, % by mass 0.1 - content, % by mass: of mechanical admixtures 0.8 of sulphur 1.9 -flash point (in a closed crucible),'0 198 - heat of combustion, kcal/kg 9802 With the above characteristics of the furnace fuel oil the qualities thereof are greatly deteriorated. In addition, it is rather difficult to maintain the above-mentioned value of pressure in the distillation process.

Example 13 (negative) The furnace fuel oil was produced substantially as described in Example 4 with the use of the same raw material and the same hydrocarbonaceous solvent. The hydrocarbonaceous solvent was preliminarily heated up to a temperature of 435"C. The waste was mixed with the heated solvent in a ratio of 1:11 parts by mass. The thermal decomposition was carried out for 0.5 sec, which is lower than the minimum limit indicated in the claims and at a temperature of 435"C and at a pressure of 9.7-105 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 1.8 l/hr per 1 kg of the waste. The distillation process was carried out with the use of steam as an inert gaseous agent. The consumption of the steam was 1.7 I/hr per 1 kg of the suspension.The distillation process was carried out at a temperature of 308"C and at a pressure of 2.5-103 n/nt2.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9813 - Engler viscosity at a temperature of 50"C, "E 15.9 - ash content, % by mass 3.9 - content, % by mass: of mechanical admixtures 2.7 of sulphur 2.1 - flash point (in a closed crucible), "C 79 - heat of combustion, kcal/kg 9897 Thus, because of the insufficient time of thermal decomposition the content of mechanical admixtures in the furnace fuel oil was too high. Also, the ash content was too high, which considerably decreased the quality of the end product.

Example 14 (negative) The furnace fuel oil was produced substantially as described in Example 2 using the same raw material and the same hydrocarbonaceous solvent. The hydrocarbonaceous solvent was preliminarily heated up to a temperature of 272"C. The waste was mixed with the heated solvent in a ratio of 1:0.5 parts by mass, which is lower than the minimum limit indicated in the claims. The thermal decomposition was carried out for 197 sec at a temperature of 272"C and at a pressure of 9-104n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 12 l/hr per 1 kg of the waste. The distillation process was carried out with the use of nitrogen as an inert gaseous agent. the consumption of nitrogen was 1.9 l/hr per 1 kg of the suspension. The distillation process was accomplished at a temperature of 359"C and at a pressure of 1.4-103 n/m2.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9845 - Engler viscosity at a temperature of 50"C, "E 16.8 - ash content, % by mass 4.3 - content of mechanical admixtures, % by mass 3.1 - flash point (in a closed crucible), "C 76 - heat of combustion, kcal/kg 9905 The above ratio between the waste and the hydrocarbonaceous solvent in the obtained furnace fuel oil causes a considerable increase in the content of mechanical admixtures as well as in an ash content, which deteriorates the quality of the end product.

In addition, there occur difficulties in carrying out the production procedure, namely in maintaining the temperature, pressure, and circulation parameters. Also, the labour consumption is rather high.

Example 15 (negative) The furnace fuel oil was produced substantially as described in Example 2 using the same raw material and the same hydrocarbonaceous solvent. The hydrocarbonaceous solvent was preliminarily heated up to a temperature of 264"C. The waste was mixed with the heated solvent in a ratio of :101 parts by mass, which exceeds the maximum limit indicated in the claims. The thermal decomposition was carried out for 204 sec at a temperature of 264"C and at a pressure of 7-104 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 9 l/hr per 1 kg of the waste. The distillation process was carried out using nitrogen as an inert gaseous agent.The consumption of nitrogen was 0.001 I/hr per 1 kg of the suspension, which is lower than the minimum limit indicated in the claims. The distillation process was accomplished at a temperature of 200"C and at pressure of 5-104 n/m2.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9013 - Engler viscosity at a temperature of 50"C, "E 5.4 - ash content, % by mass 0.1 - content of mechanical admixtures, % by mass 0.2 - flash point (in a closed crucible), C 26 - heat of combustion, kcal/kg 9868 With the above production conditions the furnace fuel oil has a low flash point, which decreases the quality of the product. In addition, it is not economically feasible to carry out the production process with the above conditions since the great amount of the hydrocarbonaceous solvent in the reaction mixture involves high heat expenses. Also, the productivity in this case is very low because a low consumption of the raw material.

Example 16 (negative) The furnace fuel oil was produced substantially as described in Example 2 using the same raw material and the same hydrocarbonaceous solvent which was preliminarily heated to a temperature of 140"C, which is lower than the minimum limit indicated in the claims. The waste was mixed with the heated solvent in a ratio of 1:4.3 parts by mass. The thermal decomposition was carried out for 0.5 sec, which is lower than the minumum limit indicated in the claims, at a temperature of 14000,which is also lower than the minimum limit indicated in the claims and at a lower pressure, of102 n/m2. Such being the case, the hydrocarbonaceous solvent intensively circulated through the reaction mixture at a rate of 8 I/hr per 1 kg of the waste.The distillation process was carried out at a temperature of 361and a pressure of 1.5-103 n/m2.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9901 - Engler viscosity at a temperature of 50"C, "E 19.7 - ash content, % by mass 4.1 - content of mechanical admixtures, % by mass 3.9 - flash point (in a closed crucible), "C 78 - heat of combustion, kcal/kg 9912 With the above production conditions the furnace fuel oil contains a comparatively high amount of mechanical admixtures and ash, which impairs its quality.

In addition the raw material has no time to dissolve in the course of the thermal decomposition and should undergo repeated thermal decomposition, which considerably decreases the productivity and increases consumption of energy.

Example 17 (negative) The furnace fuel oil was produced substantially as described in Example 2 using the same raw material and the same hydrocarbonaceous solvent. The hydrocarbonaceous solvent was preliminarily heated up to a temperature of 445"C. The waste was mixed with the hydrocarbonaceous solvent in a ratio of 1:4.7 parts by mass. The thermal destruction was carried out for 125 sec at a temperature of 445"C and at a pressure of 13-105 n/m2. This being the case, the hyrocarbonaceous solvent intensively circulated through the reaction mixture at a rate of 35 l/hr per 1 kg of the waste, which exceeds the maximum limit indicated in the claims.

The distillation process was carried out with the use of stack gases as an inert gaseous agent. The consumption of stack gases was 21 I/hr per 1 kg of the suspension. The process was accomplished at a temperature of 470"C and at a pressure of 2-105 n/m2, which exceeds the maximum limit indicated in the claims.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9712 - Engler viscosity at a temperature of 50"C, "E - 10.3 - ash content, % by mass 3.1 - content of mechanical admixtures, % by mass 2.7 -flash point (in a closed crucible), "C 24 - heat of combustion, kcal/kg 9814 With the above production conditions the furnace fuel oil has a low flash point, an increased content of mechanical admixtures and ash content, which impairs its quality.

In addition, the excessive circulation of the hydrocarbonaceous solvent requires higher consumption of energy.

Example 18 (negative) The furnace fuel oil was produced substantially as described in Example 2 using the same raw material and the same hydrocarbonaceous solvent. The hydrocarbonaceous solvent was preliminarily heated up to a temperature of 293"C. The waste was mixed with the heated solvent in a ratio of 1:5.5 parts by mass. The thermal destruction was carried out for 184 sec at a temperature of 293"C and at a pressure of 4-104 n/m2.

This being the case, the hydrocarbonaceous solvent circulated through the reaction mixture at a rate of 0.5 I/hr per 1 kg of the waste, which is lower than the minimum limit indicated in the claims. The distillation process was carried out at a temperature of 300"C and at a pressure of 5-104 n/m2 with the use of nitrogen as an inert gaseous agent. The consumption of nitrogen was 15 l/hr per 1 kg of the suspension.

The obtained furnace fuel oil had the following characteristics: - density at a temperature of 20"C, g/cm3 0.8794 - Engler viscosity at a temperature of 50"C, "E 10.13 - ash content, % by mass 4.3 - content of mechanical admixtures, % by mass 1.3 -flash point (in a closed crucible), "C 163 - heat of combustion, kcal/kg 9963 With the above production conditions the furnace fuel oil has an increased content of mechanical admixtures and an increased content of ash, which impairs its quality.

In addition, at the above rate of circulation of the hydrocarbonaceous solvent in the course of the thermal decomposition of the raw material there are formed dead spaces, which causes coking of said raw material.

Example 19 The softener for rubber mixtures according to the invention was produced from a waste based on butadiene natural rubber. In doing so, the hydrocarbonaceous solvent described in Example 7 was preheated up to a temperature of 391"C and then mixed with the above waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:11.7 of parts by mass.

The thermal decomposition was carried out for 254 sec at a temperature of 391"C and at a pressure of 3.7-105 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 2.5 l/hr per 1 kg of the waste.

From the obtained suspension the softener was separated by distillation at a temperature of 302"C and at a pressure of 2.4-104 n/m2. In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely ethane. The consumption of ethane was 2.1 l/hr per 1 kg of the suspension.

The obtained softener for rubber mixtures had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9249 - kinematic viscosity at a temperature of 10000 6.5 - viscosity index 183 - distillation fractions, "C: beginning of boiling 312 50% boils away 401 end of boiling 480 - molecular mass 373 - content of sulphur, % by mass 0.35 - congelation temperature, C -46 The viscosity index and the congelation temperature were determined in accordance with the following procedures.

The viscosity index of an oil product (softener for rubber mixtures) characterizes the dependence of the viscosity of the product within the temperature range generally accepted for the measurement of viscosity.

The viscosity index is determined from a nomogram where values of viscosity are plotted at temperatures of 50 and 100 C on the coordinate axis, and the inclined lines correspond to the viscosity index within the range of 40 to 200. The viscosity indexes were determined by drawing perpendiculars to the coordinate axis from the points which correspond to the viscosities of the softener being tested at temperatures of 50 and 10000.

The point of intersection of the perpendiculars with the inclined lines represented the value of the viscosity index.

The procedure of determining the congelation temperature of an oil product (softener for rubber mixtures) was the following. A softener was placed into a test glass and subjected therein to a thermal treatment, i.e.

was heated up to a temperature at which said resinous substances and crystals of paraffin melt or dissolve partially or completely. Then the heated softener was cooled by a cooling mixture down to the hypothetical temperature of congelation. At this temperature the test glass with the softener was installed at an angle of 45"C, and the level of the softener was observed. Irrespective of the fact whether the level of the softener shifted or remained immobile the testing procedure was repeated from the very beginning, including the thermal treatment, whereupon the softener was cooled down to a higher or lower temperature. Thus the highest temperature was found at which the level of the softener in the test glass inclined at an angle of 45" remained immobile for a certain period of time.This temperature was accepted as the congelation temperature of a softener for rubber mixtures.

With the aid of the softener there were produced vulcanizates based on butadiene-nitrile rubber. The amount of the softener per 100 parts by mass of the rubber was 12 parts by mass.

The obtained vulcanizate had the following physical and mechanical properties: - hardness 62 - rebound resilience at a temperature of 20"C, % 36 - tensile strength, kgf/cm2 300 - relative elongation at rupture, % 709 - permanent elongation after rupture, % 15 - heat ageing coefficient after 5 days at a tempe rature of 100 C: - by the tensile strength 1.0 by the relative elongation 0.82 - ripping resistance, kgf/cm 71 - brittleness temperature, C -57 The hardness of the vulcanizate specimens was determined in accordance with the immersion of a standard size needle acted upon by a calibrated spring. The specimens wer 6 mm thick washers which were 50 mm in diameter.The washers were tested at least at three points, and the arithmetic mean of all the results of testing was considered to be the hardness of the specimen.

The rebound resilience was determined by way of an impact of a pendulum heat falling from a certain height against the specimen being tested. The specimens were 50 mm in diameter and 6 mm thick washers.

The specimen was tested at least at three points. The distances among these points as well as the distances from each point to the edge of the washer was not less than 10 mm. The tests were carried out at a temperature of 20"C. To determine the rebound resilience, there was taken the index after the fourth impact of the pendulum head against the specimen at a given point. The rebound resilience was determined by the formula: h1 = hl 100%where W h W = mgh energy spent for deformation of the specimen after the impact by the pendulum head falling from the height h; W1 = mghq returned energy bringing the pendulum head back to the height ht.

The tensile strength was determined by the value of the load at the moment of rupture related to the unit of the initial cross-section of the specimen. The specimens to be tested were 2 mm thick blades. The tensile strength was determined by the formula: f=P where SO f = tensile strength, kgf/cm2; p = load causing the rupture of the specimen, kgf: SO = b0h0 = initial area of the cross-section of the specimen, cm2; b0 = initial width of the specimen, cm; h0 = initial thickness of the specimen, cm; The relative elongation at rupture was determined by the formula: E = 1 100,where o e = relative elongation at rupture, %; t1 = length of the working portion of the specimen at the moment of rupture, mm; = = initial length of the working portion ofthespeicmen, mm.

The permanent elongation after rupture was determined by the formula: H = 2 100, where 0 o = permanent elongation after rupture, %; t2 = length of the working portion of the specimen by the two ruptured specimen portions put together, mm; tO - initial length of the working portion of the specimen, mm; The heat ageing was determined by the change of properties of the vulcanizate specimens prior to and after the ageing. The specimens were tested to determine the tensile strength and the relative elongation at rupture.The specimens were subjected to ageing for 5 days at a temperature of 100 C. The heat ageing coefficient was determined by the formula: O -A K 0-A 100,where 0 K = heat ageing coefficient, %; O = average value of the index characterizing the property of the specimen prior to ageing; A = average value of the index characterizing the property of the specimen after ageing.

The ripping resistance was determined by ripping the vulcanizate specimen. In doing so, the load at which the specimen broke was noted. The specimens to be tested had incisions in the middle of the internal side.

The incisions were made at a right angle to the plane of the specimen. The edges of the specimen were secured in clamps of a ripping machine and the specimen was stretched.

The ripping resistance was determined by the formula: B = Pp/h0where B = ripping resistance, kgf/cm; Pp = maximum force, kgf; ho = initial thickness of the specimen, cm.

To determine the brittleness temperature, there were used 25 mm long, 6.5 mm wide, 2 mm thick specimens in the form of strips. 10-15 similar specimens were subjected to freezing. The highest temperature at which two specimens became brittle, i.e. cracked or broke when subjected to an impact load.

The above data show that the obtained vulcanizate with the use of the softener for rubber mixtures, produced according to the method of the present invention possesses better characteristics than those of conventional vulcanizates and is less costly.

Example 20 The softener for rubber mixtures according to the invention was produced substantially as described in Example 19. The raw material was resin waste based on butadiene-styrene rubber.

The hydrocarbonaceous solvent had such characteristics as those described in Example 7.

Said hydrocarbonaceous solvent was preheated up to a temperature of 200"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:100 parts by mass. The thermal decomposition was carried out for 254 sec at a temperature of 200"C and at a pressure of 11 or n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 2.5 l/hr per 1 kg of the waste. From the obtained suspension the obtained softener was separated by distillation at a temperature of 200"C and at a pressure of 11 103 n/m2.

In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely nitrogen. The consumption of nitrogen was 14 l/hr per 1 kg of the suspension.

The obtained softener has the following characteristics: - density at a temperature of 20"C, g/cm3 0.9526 - kinematic viscosity at a temperature of 10000, cSt 7.9 - viscosity index 145 - distillation fractions, "C: beginning of boiling 350 50% boils away 410 end of boiling 450 - molecular mass 356 - content of sulphur, % by mass 1.3 - congelation temperature, C -40 With the aid of the obtained softener there were produced vulcanizates based on butadiene-nitrile rubber.

The softener was taken in an amount of 5 parts by mass per 100 parts by mass of rubber. The obtained vulcanizate had the following physical and mechanical properties: - hardness 66 - rebound resilience at a temperature of 200C, % 31 - tensile strength, kgf/cm2 302 - relative elongation at rupture, % 551 -permanent elongation after rupture, % 11 - heat ageing coefficient for 5 days at a tempe rature of 100 C: by the tensile strength, % 0.98 by the relative elongation, % 0.66 - ripping resistance, kgf/cm 66 - brittleness temperature, "C -53 The properties and the cost of the obtained vulcanizate were similar to those of the vulcanizate produced as described in Example 19.

Example 21 The softener for rubber mixtures according to the invention was produced substantially as described in Example 19. The raw material was resin waste based on butadiene-styrene rubber. The characteristics, of the hydrocarbonaceous solvent were similar to those described in Example 7. Said hydrocarbonaceous solvent was preheated to a temperature of 400"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:1 parts by mass. The thermal decomposition was carried out for 250 sec at a temperature of 400"C and at a pressure of 4-105n/m2, the hydrocarbonaceous solvent continuously circulating through the reaction mixture at a rate of 3 l/hr per 1 kg of the waste.

From the obtained suspension the softener was separated by distillation at a temperature of 400"C and at a pressure of 2-105 n/m2.

In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely nitrogen. The consumption of nitrogen was 10 l/hr per 1 kg of the suspension.

The obtaines softener had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9545 - kinematic viscosity at a temperature of 1 OO"C,cSt 12.3 - viscosity index 96 - distillation fractions, "C: beginning of boiling 402 50% boils away 436 end of boiling 498 - molecular mass 398 - content of sulphur, % by mass 1.2 - congelation temperature, C -38 With the aid of the obtained softener there were produced vulcanizates based on butadiene-nitrile rubber.

The softener was taken in an amount of 10 parts by mass per 100 parts by mass of rubber. The obtained vulcanizate had the following physical and mechanical properties: - hardness 65 - rebound resilience at a temperature of 20"C, % 33 - tensile strength, kgf/cm2 308 - relative elongation at rupture, % 605 - permanent elongation after rupture, % 13 - heat ageing coefficient after 5 days of ageing at a temperature of 100 C: by the tensile strength, kgf/cm2 0.99 by the relative elongation, % 0.72 - ripping resistance, kgf/cm 67 -brittleness temperature, "C -54 The properties and the cost of the obtained vulcanizate were similar to those of the vulcanizate produced as described in Example 19.

Example 22 The softener for rubber mixtures according to the invention was produced substantially as described in Example 19. The raw material was resin waste based on ethylene-propylene isoprene rubber. The characteristics of the hydrocarbonaceous solvent were similar to those described in Example 8. Said hydrocarbonaceous solvent was preheated up to a temperature of 395"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:11.5 parts by mass. The thermal decomposition was carried out for 225 sec at a temperature of 395 C and at a pressure of 3.5-105 n/m2, the hydrocarbonaceous solvent intensively circulating through the reaction mixture at a rate of 1.3 l/hr per 1 kg of the waste.From the obtained suspension the softener was separated by distillation at a temperature of 306"C and at a pressure of 8.1-104 104 n/m2. In the course of the distillation prpcess the remainder of sulphur dioxide was removed by an inert gaseous agent, namely stack gases. The consumption of stack gases was 2.4 l/hr per 1 kg of the suspension.

The obtained softener had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9318 - kinematic viscosity at a temperature of 10000, cSt 6.7 -viscosity index 176 - distillation fractions, "C: beginning of boiling 323 50% boils away 408 end of boiling 483 - molecular mass 376 - content of sulphur, % by mass 0.43 - congelation temperature, C -45 With the aid of the obtained softener there were produced vulcanizates based on butadiene-nitrile rubber.

The softener was taken in an amount of 12 parts by mass per 100 parts by mass of rubber. The obtained vulcanizate had the following physical and mechanical properties: - hardness 65 - rebound resilience at a temperature of 2000, % 35 -tensile strength, kgf/cm2 304 - relative elongation at rupture, % 702 - permanent elongation after rupture, % 14 - heat ageing coefficient after ageing for 5 days atatemperature of 10000: by the tensile strength, % 1.0 bythe relative elongation, % 0.80 - ripping resistance, kgf/cm c 72 - brittleness temperature, "C -56 The properties and the cost of the obtained vulcanizate were similar to those of the vulcanizate produced as described in Example 19.

Example 23 The softener for rubber mixtures according to the invention was produced substantially as described in Example 19. The raw material was resin waste based on butadiene-stryene rubber. The hydrocarbonaceous solvent had the following characteristics: - density at a temperature of 20"C, g/cm3 0.7663 - index of refraction, nj9) 1.4325 - Englerviscosity at a temperature of 50"C, "E 0.3 - molecular mass 141 - distillation fractions, "C: beginning of boiling 50 50% boils away 165 end of boiling 250 - content of sulphur, % by mass 0.12 - group chemical composition, % by mass:: methano-naphtenic hydrocarbons, % by mass 69.8 monocyclic aromatic hydrocarbons 20.3 bicyclic aromatic hydrocarbons 8.4 polycyclic aromatic hydrocarbons 1.5 Said hydrocarbonaceous solvent was preheated to a temperature of 398"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:12.3 parts by mass.

The thermal decomposition was carried out for 282 sec at a temperature of 398"C and at a pressure of 3.1 105 n/m2, the hydrocarbonaceous solvent continuously circulating through the reaction mixture at a rate of 1.7 l/hr per 1 kg of the waste.

From the obtained suspension the softener was separated by distillation at a temperature of 304"C and at a pressure of 5.7-103 n/m2. In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely steam. The consumption of steam was 1.3 l/hr per 1 kg of the suspension.

The obtained softener had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9506 - kinematic viscosity at a temperature of 100 C, cSt 8.6 -viscosity index 148 - distillation fractions, "C: beginning of boiling 345 50% boils away 412 end of boiling 498 - molecular mass 382 - content of sulphur, % by mass 0.51 - congelation temperature, C -42 With the aid of the obtained softener there were produced vulcanizates based on butadiene-nitrile rubber.

The softener was taken in an amount of 12 parts by mass per 100 parts by mass of rubber. The obtained vulcanizate had the following physical and mechanical properties: - hardness 67 - rebound resilience at a temperature of 20"C, % 34 -tensile strength, kgf/cm2 301 - relative elongation at rupture, % 685 - permanent elongation after rupture, % 12 - heat ageing coefficient after ageing for 5 days at a temperature of 100 C: by the tensile strength, % 0.98 by the relative elongation, % 0.72 - ripping resistance, kgf/cm 73 - brittleness temperature, C -54 The properties and the cost of the obtained vulcanizate were similar to those of the vulcanizate produced as described in Example 19.

Example 24 The softener for rubber mixtures according to the invention was produced substantially as described in Example 19. The raw material was resin waste based on ethylene-propylene acryl rubber. The hydrocarbonaceous solvent had the characteristics described in Example 7.

Said hydrocarbonaceous solvent was preheated to a temperature of 392"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:11.2 parts by mass.

The thermal decomposition process was carried out for 293 sec at a temperature of 392"C and at a pressure of 3.1105n/m2, the hydrocarbonaceous solvent continuously circulating through the reaction mixture at a rate of 1.41/hr per 1 kg of the waste.

From the obtained suspension the softener was separated by distillation at a temperature of 301 C and at a pressure of 5.4-103 n/m2. In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely propane. The consumption of propane was 2.5 l/hr per 1 kg of the suspension.

The obtained softener had the following characteristics: - density at a temperature of 20"C, g/cm3 0.322 - kinematic viscosity at a temperature of 100 C, cSt 6.8 - viscosity index 179 - distillation fractions, "C: beginning of boiling 326 50% boils away 409 end of boiling 485 - molecular mass 374 - content of sulphur, % by mass 0.48 - congelation temperature "C -43 With the aid of the obtained softener there were produced vulcanizates based on butadiene-nitrile rubber.

The softener was taken in an amount of 12 parts by mass per 100 parts by mass of rubber. The obtained vulcanizate had the following physical and mechanical properties: - hardness 64 - rebound resilience at a temperature of 20"C, % 35 -tensile strength, kgf/cm2 310 - relative elongation at rupture, % 694 -permanent elongation after rupture, % 14 - heat ageing coefficient after the ageing of the vulcanizate for 5 days at a temperature of 10000: by the tensile strength, % 0.99 by the relative elongation, % 0.75 - ripping resistance, kgf/cm 70 - brittleness temperature, "C -56 The properties and the cost of the obtained vulcanizate were similar to those of the vulcanizate produced as described in Example 19.

Example 25 The softener for rubber mixtures according to the invention was produced substantially as described in Example 19. The raw material was resin waste based on ethylene-propylene rubber. the hydrocarbonaceous solvent had the characteristics described in Example 23.

Said hydrocarbonaceous solvent was preheated to a temperature of 394"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:11.1 parts by mass. The thermal decomposition process was carried out for 275 sec at a temperature of 394"C and at a pressure of 3.2-105 n/m2, the hydrocarbonaceous solvent continuously circulating through the reaction mixture at a rate of 2.3 l/hr per 1 kg of the waste.

From the obtained suspension the softener was separated by distillation at a temperature of 275"C and at a pressure of 3.1103 n/m2. In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely steam. The consumption of steam was 2.7 l/hr per 1 kg of the suspension.

The obtained softener had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9123 - kinematic viscosity at a temperature of 10000, cSt 4.9 -viscosity index 194 -distillation fractions, "C: beginning of boiling 301 50% boils away 395 end of boiling 463 - molecular mass 369 - congelation temperature, "C -56 With the aid of the obtained softener there were produced vulcanizates based on butadiene-nitrile rubber.

The softener was taken in an amount of 10 parts by mass per 100 parts by mass of rubber. The obtained vulcanizate had the following physical and mechanical properties: - hardness 61 rebound resilience at a temperature of 20 C, % 39 - tensile strength, kgf/cm2 308 - relative elongation at rupture, % 727 - permanent elongation after rupture, % 16 - heat ageing coefficient of the vulcanizate after the ageing of the latter for 5 days at a temperature of 10000: by the tensile strength, % 0.96 by the relative elongation, % 0.84 - ripping resistance, kgf/cm 74 - brittleness temperature, "C -59 The properties and the cost of the obtained vulcanizate were similar to those of the vulcanizate produced in accordance with Example 19.

Example 26 (negative) A softener for rubber mixtures was produced substantially as described in Example 19. The raw material was resin waste based on ethylene-propylene rubber. The hydrocarbonaceous solvent had the characteristics described in Example 23.

Said hydrocarbonaceous solvent was preheated up to a temperature of 410"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:11.2 parts by mass. The thermal decomposition process was carried out for 272 sec at a temperature of 410"C and art a pressure of 4.5-105 n/m2, which exceeds the maximum limits indicated in the claims, the hydrocarbonaceous solvent continuously circulating through the reaction mixture at a rate of 2.5 l/hr per 1 kg of the waste.

From the obtained suspension the softener was separated by distillation at a temperature of 410 C and at a pressure of 2.5-105 n/m2,which also exceeds the maximum limits indicated in the claims. In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely steam.

The consumption of steam was 2.7 l/hr per 1 kg of the suspension.

The obtained softener had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9015 - kinematic viscosity at a temperature of 10000, cSt 0.6 - viscosity index 61 - distillation fractions, "C: beginning of boiling 154 50% boils away 315 end of boiling 407 - molecular mass 265 - content of sulphur, % by mass 0.69 - congelation temperature, "C -57 With the above production conditions the viscosity-and-temperature properties of the softener become worse and the content of sulphur therein higher, which reduces the quality of the same softener for rubber mixtures.

Example 27 (negative) Asoftenerfor rubber mixtures was produced substantially as described in Example 19. The raw material was resin waste based on isoprene rubber. The hydrocarbonaceous solvent had the characteristics described in Example 6.

Said hydrocarbonaceous solvent was preheated up to a temperature of 190"C, whereupon it was mixed with the waste. The ratio of the waste and the hydrocarbonaceous solvent in the reaction mixture was 1:11.3 parts by mass. The thermal decomposition process was carried out for 300 sec at a temperature of 190"C and at a pressure of 0.5-105 n/m2, which is lower than the minimum limits indicated in the claims, the hydrocarbonaceous solvent continuously circulating through the reaction mixture at a rate of 1.9 l/hr per 1 kg of the waste.

From the obtained suspension the softener was separated by distillation at a temperature of 190"C and at a pressure of 0.5-103 n/m2,which is also lower than the minimum limits indicated in the claims. In the course of the distillation process the remainder of sulphur dioxide was removed by an inert gaseous agent, namely steam. The consumption of steam was 3.1 I/hr per 1 kg of the suspension.

The obtained softener had the following characteristics: - density at a temperature of 20"C, g/cm3 0.9982 - kinematic viscosity at a temperature of 100 C, cSt 19.9 -viscosity index 23 - distillation fractions, "C: beginning of boiling 228 50% boils away 495 end of boiling 570 - molecular mass 498 - sulphur content, % by mass 0.93 - congelation temperature, "C +1 With the above production conditions of the softener the viscosity-and-temperature properties thereof are worse, the content of sulphur therein is higher, and the congelation temperature thereof is higher as well.

This reduces the quality of the obtained softener for rubber mixtures.

While particuiar embodiments of the invention have been shown and described, various modifications thereof will be apparent to those skilled in the art and therefore it is not intended that the invention be limited to the disclosed embodiments or to the details thereof and the departures may be made therefrom within the spirit and scope of the invention as defined in the claims.

Claims (10)

1. A method of making a liquid useful for a softener for rubber mixtures or as a furnace fuel oil, comprising thermal decomposition of a polymeric raw material in a hydrocarbonaceous solvent and subsequent separation of the end product, characterized in that the hydrocarbonaceous solvent is preheated; vulcanized and/or non-vulcanized rubber waste is added thereto with stirring; thermal decomposition of the material is carried out at a pressure from 5.102 to 25.105n/m2 with the hydrocarbonaceous solvent continuously circulating through the reaction mixture; and the end product is separated from the formed suspension by distillation at a temperature from 200 to 5600C and at a pressure from 10 to 2.105n/m2 in the presence of an inert gaseous agent.

2. A method as claimed in claim 1, in which the hydrocarbonaceous solvent is heated to and used at a temperature of 150 to 6000C.

3. A method as claimed in claim 1 or 2 in which thermal decomposition of the rubber waste is accomplished over a period from 1 to 300 sec.

4. A method as claimed in claim 1, 2 or 3 in which the weight ratio between the rubber waste and the hydrocarbonaceous solvent is from 1:1 to 1:100.

5. A method as claimed in any one preceding claim in which the hydrocarbonaceous solvent continuously circulates through the reaction mixture at a rate of 1 to 30 litres per hour per kilogram of the waste rubber.

6. A method as claimed in any one preceding claim in which as the inert gaseous agent is used nitrogen, steam, stack gases, methane, ethane, propane, a hydrocarbonaceous C3-C6 fraction or a mixture of the foregoing.

7. A method as claimed in any one preceding claim in which in the course of the distillation the inert gaseous agent is continuously fed at a rate of 0.01 to 90 litres per kilogram of suspension.

8. A method as claimed in any one preceding claim in which distillation is carried out at a temperature from 2500 to 560 and at a pressure from 10 to 1.105n/m2, to produce an oil suitable as a furnace fuel oil.

9. A method as claimed in claim 8 in which the hydrocarbonaceous solvent used is an oil fraction, a coke-chemical fraction or a furnace fuel oil itself obtained from a previous distillation and contains from 0.1 to 100% by weight of aromatic hydrocarbons and resins.

10. A method as claimed in any of claims 1 to 7, in which thermal decomposition of the waste is carried out at a temperature from 200 to 400"C and at a pressure of 1.1 1.105 to 4.105 n/m2, and distillation is carried out at temperatures within the range of 200" to 400"C and pressures within the range from 1.103to 2.103to to 2.105 n/m2.