US2892877A

US2892877A - Process for the conversion of paraffin into rubber-like products

Info

Publication number: US2892877A
Application number: US525376A
Authority: US
Inventors: Kolling Helmut; Noeske Heinz; Rappen Friedrich
Original assignee: Ruhrchemie AG
Current assignee: Ruhrchemie AG
Priority date: 1954-08-05
Filing date: 1955-07-29
Publication date: 1959-06-30
Anticipated expiration: 1976-06-30

Description

i'RocEss FOR THE CONVERSION OF PARAFFIN INTO RUBBER-LIKE PRODUCTS Helmut Kolling, Duisburg-Hamborn, and Heinz Noeske and Friedrich Rappen, Oberhausen-Sterkrade, Germany, assignors to Ruhrchemie Aktiengesellschaft, Oberhausen-Holten, Germany, a corporation of Germany No Drawing. Application July 29, 1955 Serial No. 525,376

Claims priority, application Germany August 5, 1954 6 Claims. (Cl. 260-677) This invention relates to conversion of paraflins into rubber-like products.

It is known that paraflin, which is solid at normal temperature, may be converted into hydrocarbons containing olefinic bonds by chlorination and subsequent dehydrochlorination. In this known product less than 1 gram atom of chlorine is generally added per mol of hydro carbon in order to obtain as high as possible a yield of mono-olefinic products.

It has also been suggested to convert hard parafiin from the Fischer-Tropsch synthesis or fractions obtained from hard paraffin into flexible waxes having properties which correspond to microcrystalline petroleum waxes. This conversion is etfected by the addition of more than 1 gram atom, as, for example, 2-4 gram atoms of chlorine per mole of hydrocarbon to the hard parafiin or fraction, and by thereafter subjecting the chlorinated products to a dehydrochlorination.

In accordance with the invention it has now been discovered that paraffin having more than 20 carbon atoms in the molecule may be readily converted into rubber (caoutchouc) -like products by adding more than 4 gram atoms of chlorine, and preferably -610 gram atoms of chlorine per mole of parafiin, and subsequently subjecting the reaction products obtained to a dehydrochlorination.

The quantity of chlorine to be added is dependent upon the average number of carbon atoms in the initial paraffin. About 6 gram atoms of chlorine per mole should be added to hard paraifin from the Fischer-Tropsch synthesis, having, for example, a boiling range of above about 460 C. and an average number of carbon atoms of about 45. Paraflins having a lower number of carbon atoms such as slab paratfins require 7-8 gram atoms of chlorine per mole, while about 10 gram atoms of chlorine per mole must be added to paraffin having a still lower number of carbon atoms, such as soft paraflins.

The chlorination in accordance with the invention is efiected in the conventional manner by introducing gaseous chlorine into the melted hard parafiin at a temperature ranging slightly above the melting point of the paraffin. The chlorination may be effected at normal atmospheric pressure or at slightly elevated pressure. The dehydrochlorination is elfected by heating the chlorinated products for several hours at a temperature of between about 250 and 320 C. During the dehydrochlorination is it preferable to introduce a small amount of nitrogen and to admix several percent by weight of activated carbon.

The dehydrochlorination is most preferably effected at 2,892,877 Patented June 30, .1959

ICC

. 2 a partial vacuum. or at. normal atmospheric pressure. It is also possible, however, to dehydrochlorinate at a slight superatmospheric pressure up to about '5 kg./ sq. cm.

Suitable starting products for the process of the invention are all of the paratfins having more than 20 carbon atoms in the molecule, viz. synthetic parafiins as well as paraflins derived from the processing of petroleum.

The following examples are given by way of illustration and not limitation:

Example 1 A hard parafiin from the catalytic hydrogenation of carbon monoxide, containing the hydrocarbons boiling above 460 C. and having a setting point of 98 C. and an average number of carbon atoms of 48 was chlorinated at 120 C., while irradiating and stirring until 6 gram atoms of chlorine had been taken up per mole. The product obtained was then heated to 300 C. while passing through a stream of nitrogen. After heating for 5 hours, the content of the flask solidified. The product formed was insoluble in most solvents and could not be melted below a temperature of about 200 C. It showed elasticity to compression and was of caoutchouc-like character.

Example 2 Slab parafiin derived from petroleum, having a setting point of 52 C. and an average number of carbon atoms of 28 was treated with chlorine at C. while stirring until 8 gram atoms of chlorine had been taken up per mole of hydrocarbon. The chlorinated product was heated to 300 C. while passing through a stream of nitrogen. After 8 hours the mass solidified. There was formed a product which would only melt with decomposition.

Example 3 C hydrocarbons from the catalytic hydrogenation of carbon monoxide, the unsaturated portions of which had previously been hydrogenated were chlorinated at 60 C. while stirring until 10 gram atoms of chlorine had been taken up per mole. The chlorinated product was heated to 300 C. while passing through small amounts of nitrogen. After 8 hours, a product was obtained which melted at temperatures of above 200 C. with decomposition.

We claim:

-1. Process for the production of rubber-like products from paraffin which comprises chlorinating a parafiin having more than 20 carbon atoms in the molecule with an amount of chlorine corresponding to at least 10 gram atoms of chlorine per mol of parafiin having about 22 carbon atoms in its molecule, at least 8 gram atoms of chlorine per mol of parafiin having about 28 carbon atoms in its molecule and at least 6 gram atoms of chlorine per mol of parafiin having about 48 carbon atoms in its molecule, thereafter dehydrochlorinating the chlorinated reaction product by heating to a temperature between about 250-320 C. for at least several hours and recovering the rubber-like product formed.

2. Process according to claim 1 in which said chlorination is effected in the presence of nitrogen.

3. A rubber-like paraflin product obtained by dehydrochlorinating a chlorinated paraflin having more than 20 carbon atoms in the molecule and 6-10 gram atoms of chlorine per mol according to the process of claim 1.

4. A rubber-like paraflin product obtained by dehydrochlorinating a chlorinated paraifin having about 22. carbon atoms in the molecule and 10 gram atoms of chlorine per mol according to the process of claim 1.

5. A rubber-like paraffin product obtained by dehydrochlorinating a chlorinated parafin having about 28 carbon atoms in the molecule and 8 gram atoms of chlorine per mol according to the process of claim 1.

6. A rubber-like parafi'ln product obtained by dehydrochlorinating a chlorinated paraflin having about 48 carbon atoms'in the molecule and 6 gram atoms of chlorine per mol according to the process of claim 1.

References Cited in the file ofthis pawn UNITED STATES PATENTS Krause et a1 July 13, 1926 Hull et a1 July 2, 1946 Sias May 10, 1955 Kolling et a1 June 11, 1957 FOREIGN PATENTS Great Britain May 12, v1939

Claims

1. PROCESS FOR THE PRODUCTION OF RUBBER-LIKE PRODUCTS FROM PARAFFIN WHICH COMPRISES CHLORINATING A PARAFFIN HAVING MORE THAN 20 CARBON ATOMS IN THE MOLECULE WITH AN AMOUNT OF CHLORINE CORRESPONDING TO AT LEAST 10 GRAM ATOMS OF CHLORINE PER MOL OF PARAFFIN HAVING ABOUT 22 CARBON ATOMS IN ITS MOLECULE, AT LEAST 8 GRAM ATOMS OF CHLORINE PER MOL OF PARAFFIN HAVING ABOUT 28 CARBON ATOMS IN ITS MOLECULE AND AT LEAST 6 GRAM ATOMS OF CHLORINE PER MOL OF PARAFFIN HAVING ABOUT 48 CARBON ATOMS IN ITS MOLECULE, THEREAFTER DEHYDROCHLORINATING THE CHLORINATED REACTION PRODUCT BY HEATING TO A TEMPERATURE BETWEEN ABOUT 250-320*C. FROM AT LEAST SEVERAL HOURS AND RECOVERING THE RUBBER-LIKE PRODUCT FORMED.