DE1226782B - Process for the production of molding compounds from polyethylene and carbon black - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CL:

Number: File number: Registration date: Display day:

C08f

German class: 39 b -22/06

1226782
B80094IVc / 39b
January 13, 1965
October 13, 1966

It is known that substantial amounts of carbon black can be incorporated into polyethylene. First of all a concentrate of polyethylene and carbon black, for example with the HiKe of a kneader or rolling mill and the concentrate is then incorporated homogeneously into polyethylene.

The detour via a concentrate is necessary for the even distribution of the soot in the end product. For the production of the concentrate, a mixture of different can also be used according to a known method Polyolefins with different degrees of crystallization, e.g. B. polyethylene and polyisobutylene are used will.

It is also known (British Patent 890 426 and USA Patent 2 512 459), molding compounds on the basis of polyethylene, which contain finely divided solids, to be produced by first Concentrates of the solids in waxes, as they are obtained by the thermal degradation of polyethylene, wins and the concentrates then mixed with polyethylene ao. However, these known methods can be used especially with regard to the uniformity of the distribution of the carbon black in the molding compositions.

It has now been found that molding compositions made of polyethylene and carbon black can be produced by incorporating a concentrate of the carbon black in an ethylene polymer in the polyethylene can advantageously be produced if one as the ethylene polymer, a copolymer of 50 to 95 percent by weight of ethylene and 50 to 5 percent by weight an ethylenically unsaturated carboxylic acid ester is used.

The new process gives molding compounds in which the carbon black is evenly distributed in the polyethylene is distributed when you add the carbon black concentrate to the polyethylene using screw and shaft machines incorporated. If you work, for example, based on polyethylene or carbon black concentrates Wax in polyethylene in a known manner using worm shaft machines, see above molding compounds are obtained in which the carbon black is unevenly distributed. Thin sections that are known from such Molding compositions are produced, have streaks, and there can be microscopic carbon black agglomerates therein to be observed.

The process is for the production of molding compounds containing carbon black from the usual high molecular weight Polyethylenes are suitable, which are produced by high and low pressure polymerization processes can and the general molecular weights (measured according to Überreiter, Macromolekulare Chemie, Vol. 8 [1952], pp. 21 to 28) over 10,000.

Process for the production of molding compounds
Polyethylene and carbon black

Applicant:

Aniline & Soda Factory in Baden

Aktiengesellschaft, Ludwigshafen / Rhein

Named as inventor:

Dr. Klaus Böttcher, Wesseling;

Dr. Wolfgang Immel,

Dr. Klaus Kinkel, Ludwigshafen / Rhine;

Dr. Friedrich Urban, Limburgerhof

Particularly suitable ethylene copolymers are those composed of vinyl esters, acrylic acid esters and / or methacrylic acid esters. As vinyl esters, for. B. vinyl acetate and vinyl propionate and also vinyl stearate in question. The suitable acrylic and methacrylic acid esters are derived in particular from alkanols having 1 to 4 carbon atoms, such as methanol, ethanol, propanol, isopropanol and tert-butyl alcohol. Maleic acid esters, ζ, are also used as components for the copolymers. B. the diethyl ester into consideration. Ethylene copolymers which contain vinyl acetate and / or ethyl acrylate in polymerized form are preferred. The copolymers contain from 5 to 50 weight percent ethylenically unsaturated Monocarbonsäureester copolymerized units and have usually at 19O ⁰ C melt indexes between 0.1 and 100 on. Particularly good results are achieved with ethylene copolymers which contain 20 to 25 percent by weight of ethylenically unsaturated monocarboxylic acid ester as polymerized units. Several copolymers of the type mentioned can also be used for the carbon black concentrates.

The carbon black content of the concentrate is generally 5 to 50 percent by weight, preferably 30 to 35 weight percent. The usual types of carbon black can be used, mostly one particle size to have 25 ηιμ. Gas black have proven particularly useful and furnace soot.

The carbon black concentrates can be stabilized in the usual way, the content of the concentrate being Stabilizer generally between 0.01 and 5 percent by weight, preferably between 0.1 and 1 percent by weight, lies.

609 670/447

The carbon black concentrates can be mixed into the polyethylene in the usual way using kneaders; Rolling mills, Incorporated screw-shaft extruders or disk kneaders or optionally a stream of molten polyethylene can be added.

The parts given in the following examples are parts by weight. ^; . : = . ■. ...

For example

In a standard stamp kneader ^; "Will 65.4 parts of an ethylene-vinyl acetate Mischcopolymerisates copolymerized form in the melt index 20, 20 percent by weight vinyl acetate, 13.5 parts of carbon black, 20.5 parts of furnace carbon black and 0.66 parts of a commercial stabilizer ge 5 minutes at 15O ⁰ C - * 5 kneads and the mixture is granulated after cooling. The granulate is mixed in an extruder with melted polyethylene with a density of 0.918 and a melt index of 0.5 in an amount such that the carbon black content in the finished molding compound is 2 percent by weight: "A" thin section The product shows even distribution of the soot under the microscope. . ■

If the same amount of polyethylene is used instead of the copolymer for the concentrate Density 0.918 and the melt index 1.5, one obtains under otherwise identical conditions, a molding compound in which the soot forms streaks and agglomerates.

If the same amount of an ethylene-propylene copolymer is used instead of the copolymer for the concentrate according to U.S. Patent 3,137,672 (Example 1, lines 25-28) so obtained under otherwise identical conditions, a molding compound is also used in which the carbon black is unevenly distributed is present.

If the same amount of a mixture is used instead of the copolymer for the concentrate from 75 parts of a Ethyleri-Propylene copolymer and 30 parts of a polypropylene wax according to the laid-open documents "of the Belgian patent 626 813 (example 1, first sentence), a molding compound is obtained under otherwise identical conditions; in the the soot forms agglomerates.

Example 2

65.4 parts of an ethylene-acrylic acid ethyl ester copolymer the melt index 20, which contains 20 percent by weight of ethyl acrylate polymerized, is - as indicated in Example 1 - mixed with carbon black and stabilizer and the concentrate obtained mixed in a worm shaft machine with molten polyethylene in such a way that the carbon black content in of the finished molding compound is 2 percent by weight. A thin section of the product shows under the microscope uniform brown color; Streaks and soot agglomerates cannot be observed.

Claims (1)

Claim: Process for the production of molding compositions from polyethylene and carbon black by incorporating a Concentrates of the carbon black in an ethylene polymer in the polyethylene, characterized in that that the ethylene polymer is a copolymer of 50 to 95 percent by weight of ethylene and 50 to 5 percent by weight of an ethylenic unsaturated carboxylic acid ester is used. Considered publications:
Opened documents of Belgian patent No. 626 813;
U.S. Patent No. 3,137,672. 609 670/447 10.66 © Bundesdruckerei Berlin