DE1720570A1 - Process for the manufacture of elastomer products from ethylene and other alpha-olefins - Google Patents

Description

Our Ho. 15 424

Esso Research and Engineering Company, "

Elizabeth-B., N.J., 7th St.A.

Process for the production of elastomer products from ethylene and others <x-01efinen

The present invention relates to a process for the production of elastomeric copolymers from ethylene and other α-olefins, in particular propylene, which have a high proportion of head-to-head bonds in the microstructure and a high degree of crystallinity. The novel elastomers produced with the aid of the process according to the invention can be used as additives for ί hydrocarbon oils.

It is known that xethylene and other α-olefins, e.g. propylene, at relatively low pressures and temperatures with so-called Ziegler catalysts can be copolymerized. Ziegler catalysts consist of transition metal compounds that come together can be used with metal alkyls. In this way, elastomers are obtained which have the same properties as natural rubber, clearly distinguish.

Are such copolymers under critical conditions and produced with certain catalysts of the Ziegler type, so aind eie practically free from any crystallinity and as a result

10S8U / 20U / 2

highly stretchable and highly elastic and also resistant to embrittlement even at temperatures below 0 °.

In the usual polymerization of ethylene with other α-olefins, e.g. propylene, are formed in the resulting ethylene-propylene rubber by combining the propylene in the molecule with itself even to a considerable extent head-to-tail ties. This is understood to mean bonds represented by the following schematic formula can be represented:

CH - CH ₂ - CH - CH ₂

CH

CH,

It has now been found that, according to the invention, it is possible for the first time to produce ethylene-propylene copolymers which have a high Have a degree of head-to-head ties. Under head-to-head ties one understands bonds, which can be explained by the following schematic formula:

CHo - CH -. CH - CH,

CH

3. ^CH 3

If, in general, an α-olefin is used instead of propylene , the schematic formula can be represented as follows :

CH ₀ - CH - CH - CH ₀ RR

In the above formula, R denotes an alkyl radical with 1 to θ Carbon atoms. In general, the polymers prepared according to the invention have about 3 to 80, preferably 25 to 60 and am. best 30 to 50? * head-to-head ties. The minimum Kopian head ties should be £ 1. With common catalysts On the other hand, only polymers of the Ziegler type can be produced their content of head-to-head ties below

109ÖU / 2043

Tail-to-tail bonds are also formed in the polymers. By tail-to-tail bonds are meant bonds represented by the following schematic formula v / ground: '-

GH - OH ₉ - CH ₉ - CH CH ₅

The ethylene-oc-olefin copolymers of the present invention have a high degree of crystallinity, in particular in the ranges in which the molar ratio of ethylene to propylene is 35 to 65 to 65 to 35. It has been shown that the Ethylene-propylene copolymers have a degree of crystallinity can that up to 25 / <> and even above it. The ethylene-propylene copolymers, which are particularly good for various purposes can be used have a degree of crystallinity between about 1 and about $ 20 on.

The copolymers that can be prepared according to the invention are underdifferent of conventional block copolymers that are inherently long-chain There are sections with very different polarity. In contrast to block copolymers, in which longer sections are made two different monomers follow one another along the main polymer chain and, in contrast to graft copolymers, in which to long chains of one type of monomer that form the backbone, one second type of monomer is grafted, the probability is at the copolymers produced according to the invention, longer sections to be found from one and the same type of monomer, proportionally small.

The ethylene-α-olefin copolymers, e.g. the ethylene-propylene copolymers, with the desired degree of crystallinity and the microstructure described above can therefore be used as crystalline amorphous, low molecular weight, essentially unbranched copolymers in which relatively small ranges of ethylene or other α-olefins, e.g., propylene, are referred to as homopolymer segments are included in an arbitrary distribution.

/ 4 1098U / 2043

The inventive method also has the advantage that .a high level of C ^ conversion achieved and the catalyst very can be exploited well.

The process is generally carried out in such a way that 2 to 98 percent by weight of ethylene with 98 to 2 percent by weight of another α-01efins, preferably propylene, in the presence of a soluble one Ziegler catalyst, preferably a catalyst made by activating VCl ^ or VOCT * with dialkyl aluminum chloride has been implemented. Anhydrous hydrogen halide such as hydrogen fluoride, hydrogen chloride, hydrogen bromide is added to the monomer mixture or hydrogen iodide (or mixtures of these hydrogen halides). The resulting product has average

^ Molecular weights (Mv; measured in viscosity) from 20,000 to 250.uüü,

"preferably from 40,000 to 150,000.

The molecular weights given in the present context are based on viscosity measurements. Molecular weights were estimated on the basis of viscosity measurements at 135 ^Ω on solutions containing 0.5 milligrams of polymer in milliliters of decalin.

A compilation of the preferred catalyst concentrations used and hydrogen halide concentrations as well as the other process variables and the percentage of monomer in the end product can be found in the following table:

Tabel

preferably better best

■ catalyst composition:
Al / V molar ratio 0.5-25 1-12 2-7

Catalyst concentration in
Solvent, parts per million by weight 1-1000 ^ -5OO 10-200

Hydrogen halide concentration in mol ^; based on the total r molar amount of monomer fed

Procedural variables
Temper acids, ⁰ C
Pressure, kg / cm ²

Response or contact time

in minutes 1-300 3-60 10-35

Percentage composition of the resulting elastomer

Weight percent ethylene 2-98 10-95 30-80

, Percent by weight propylene and / or
other «-olefins 109814/204 Ψ ~ ² ^ ~ ⁹ ° ² ° ~ ^7N

0.001-10 0.01-5 0.2-2 0-200 0-60 20- ^ 5 0-141 0-211 0-70

- ¹ Y-

The presence of the hydrogen halide in the reaction mixture "causes datf the a-01efin, e.g. propylene, the head-to-head addition and does not enter into the usual head-to-tail attachment. Conventional chain transfer agents are not suitable for the purposes of the present invention, if not simultaneously Hydrogen halide is also used. Such unsuitable chain transfer agents are, for example, carbon tetrachloride, Chloroform and other alkyl analogs, especially those in which the number of carbon atoms is between 1 and 5. It has been shown that such agents, like hydrogen, have no effect on the microstructure of the resulting polymer and also do not affect the rate of polymer production.

The soluble catalysts required for the process according to the invention can generally be used by mixing an organo-aluminum halide with various vanadium compounds getting produced. The vanadium compounds are then reacted with an aluminum alkyl compound to form the final catalyst mixture to create. The preparation of catalysts which are particularly suitable for the purposes of the present invention can for example, do the following:

About 0.05 to 10 moles, preferably 0.15 to 1.5 moles of a vanadium compound are reacted with one mole of an aluminum alkyl compound, i

The vanadium compound can be a vanadium oxyhalide, be a vanadium oxyacetylaeetonate or an alkyl vanadate. That Vanadium oxyhalide corresponds to the lOrmal VOX ,, in which X is a Halogen atom with an atomic number above 17 »i.e. chlorine, bromine or iodine. VOGl ^ is preferably used as the vanadium oxyhalide.

The vanadium oxyacetyiacetonate corresponds to the formula VOA ,, where A is the Corresponds to acetylacetonate radical or a halogenacetylacetonate radical; Halogen in this pail can be chlorine, bromine, iodine or fluorine. Examples suitable compounds of this type are vanadinoxytriacetylacetonafc, VanadinoxytriCtrihalogenacetylacetonat) as well as Vanadinoxytri (hexahalogenacetylacetonat). Preferably one uses from this

10Ö-8U / 2043/6

Group of compounds Vanadinoxytriacetylaeetonat.

The alkyl vanadate corresponds to the formula TO (OR) ,, where R is an alkyl group with 1 to 12, preferably 2 to 6, carbon atoms. Examples of suitable alkyl vanadates are V0 (OCH ₃ ) ₅ , VO (OC ₂ H ₅ ). ,, VO (OC ₄ H ₉ ) ₅ and VO (OCgH ₁₇ ) ₅ . Of the alkyl vanadates, VO (OC ₂ HV), is preferably used. Of all the vanadium compounds as a whole, VOGl ₅ (vanadium oxychloride) is best suited for the purposes of the present invention.

It is emphasized again that insoluble catalysts such as vanadium trihalides, in particular VC1 ~, which are often used as catalysts used for the interpolymerization of oc-01efinen, for the P purposes of the present invention are not useful.

The use of titanium compounds in Considered that can be reacted with selected vanadium compounds to form complex compounds. Suitable titanium compounds according to the formula Ti (OR)., Where R is an alkyl radical with 1 to 12 carbon atoms, preferably 2 to 6 carbon atoms. R can therefore be a methyl, propyl, butyl, pentyl, isopentyl, octyl or hexyl group. Most preferably R is a butyl group; the The preferred titanium compound was therefore tetrabutyl titanate. This titanium compound (or possibly another Titanium compound) is converted to a soluble complex with one of the vanadium compounds listed above (excluding VCl.) puts. In general, about 0.05 to 10 mol "preferably 0.15 to 1.5 mol of vanadium compound are reacted with 1 mol of titanium compound"

Alkyl aluminum compounds which can be used for the catalysts which can be used according to the invention correspond to the formula R _n AlX _n , in which R is a monovalent hydrocarbon radical with 1 to 12, preferably 1 to 8 carbon atoms, Z is a halogen atom with an atomic number of more than 17 ( ie chlorine, bromine or iodine) or a monovalent hydrocarbon radical with 1 to 12, preferably 1 to 8 carbon atoms or hydrogen, m is an integer between 1 and 3 and the sum of m plus η is 3.

109IU / 2043

172057C

Examples of R and / or X are, for example, the following groups: Methyl, ethyl, propyl, η-butyl, n-amyl, isoamyl, phenyl, ololyl and cyclopentyl. Most suitable are alkyl groups with 1 "to 5 Carbon atoms, especially ethyl and butyl groups. In the cheapest Pail it is "with the Alky! Group to Ethyl and with the Halogen atom around chlorine.

The following alkyl aluminum compounds can be used with particular advantage: diethyl aluminum chloride, ethyl aluminum dichloride, aluminum sesquichloride, aluminum trialkyl, aluminum monoalkyl dihalides, etc. Diethyl aluminum chloride is most suitable. If desired, to use mixtures of different alkyl aluminum as well as aluminum hydrides, for example Diäthylaluminiumhydrid, Äthylaluminiumdihydrid among other things, with the help of the inventive process can be ethylene and copolymerizing CU to CQ-cc-olefins like. The α-olefin can be a straight-chain or branched-chain olefin; in the latter case the branch should occur 3 or more carbon atoms away from the double bond. In general, it is preferable to use a single olefin, but it is also possible, if necessary, to work with mixtures of the C ~ to C, Q-olefins mentioned. Examples of suitable Ο, - to CjQ-oc-olefins are: propylene, 1-butene. 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene »1-decene, 4-methyl-i-pen-geri., 4-methyl-1-hexene, 5-methyl-1-hexene , 4,4-dimethyl-1-pentene, 4-methyl-i-heptene, 5-methyl-i-heptene, 6-methyl-i-heptene, 4,4-dimethyl-i-hexene, 5,6,6 -2 trimethyl-1-heptene, 5,5-dimethyl-i-octene, 5-methyl-1-nonene and others; propylene is preferably used. The concentration of CU to C _1n olefin monomer units in the end product is generally from about 2 to 98 mol / l, preferably from 5 to 90, more preferably from 20 to 70, most preferably from 35 to 65 mol / l.

If propylene is used together with ethylene to produce the copolymers, according to a preferred embodiment of the present invention, a G ^, - to C ₁₂ -a-olefin and / or diolefin, polyolefin, etc. together with the ethylene and propylene can also be subjected to the copolymerization so that you get »1's end product. terpolymers. These unsaturated monomers should preferably be linear; if they have a branch, these three or more carbon atoms should be located away from the double bond. Also, in this case, it is preferable to use a single olefinic monomer; but optionally can also. Mixtures

1098U / 2CH3

/8th

various C.- to C.o-olefin monomers can be used.

They manufacture and use the catalysts for the "" '■ Process according to the invention should be harmful at all stages in the absence of oxygen, moisture, carbon dioxide and other harmful substances Impurities occur. This can be done, for example be achieved that all starting materials including the Catalyst ingredients, monomers and inert diluents covered with an inert gas such as dry nitrogen or irgon will. Preferably all starting materials are moderated (e.g. by drying, distilling, etc.) state.

The conditions under which the actual polymerization reaction can be changed as required within wide limits. The reaction vessel can be made of any material, so far this is inert to the reactants and diluents and is able to withstand the operating pressures that occur. in the In general, reaction vessels made of glass, stainless steel or glass-lined steel can be used.

If the mixed polymer does not contain any unsaturation, ie if no monomeric diolefin has been used for the polymerization, the mixed polymer can be cured or vulcanized with the aid of certain radical-forming catalysts, such as organic peroxides, e.g. dicumyl peroxide, selected haloaliphatic compounds, e.g. octachlorocyclopentene. The copolymer contains a certain degree of unsaturation, a curing or vulcanization in a conventional manner with sulfur ¹ is possible.

Various solvents can be used for the process according to the invention can be used, for example aliphatic ^, naphthenic, aromatic and halogenated hydrocarbons. If necessary, you can. also work with an excess of the higher α-olefins than propylene. Examples of individually suitable solvents are n-hexane, heptane, propane, cyclohexane, toluene, xylenes, tetrachlorethylene, Decalin and chlorobenzenes, preferably n-hexane.

1098U / 2043

An essential factor of the polymerization process according to the invention for producing the copolymers with the specified properties consists in controlling the polymerization with the aid of a third catalyst component, namely a hydrogen halide. The importance of the use of hydrogen halides can be seen from a comparison of the infrared spectra of copolymers which have been produced in processes with hydrogen halide and in processes without hydrogen halide. In the comparison it can be seen that copolymers which have been prepared with the use of hydrogen halide have absorption peaks at about 8.95 and 1U. Head-to-tail attachment of the propylene units results in absorption peaks at 8.7 microns. The percentage of head-to-head addition in the total polymer was calculated from the IR data in a manner discussed in detail below; the disappearance or reduction of the head-to-tail addition of propylene was determined by measuring the absorption at 8.7 microns, ΐ / ie already indicated, make the head-to-head bonds in the polymers according to the present invention 3 to 8i) % of the total α-olefin, with the remainder of the bonds corresponding to those in conventional copolymers with random distribution or that of homopolymers.

With regard to the crystallinity of the copolymers according to the invention, two independent analytical methods which were used for the determination (were used, found values that corresponded well. The two methods were the X-ray diffraction analysis and the thermal differential analysis the relative amounts of crystalline and amorphous material in a sample can be calculated by reading the distribution of the two types of structure from the X-ray diffraction diagram. In general, one compares the areas of the various main bands associated with the various crystalline and amorphous areas in the determination. Another method, such as comparing the height of the bands, can also be used nature of polymers

In differential thermal analysis, a sample of the substance to be tested and a sample of a control substance which does not undergo thermal transformation in the area under consideration, at exactly the same rate, e.g. 1 to 2 ° C per minute, heated in a temperature controlled bath. The temperature difference between the sample to be tested and the Control sample is applied as a puncture of the temperature of the sample. The temperature difference is only final when heat develops as a result of the exothermic or endothermic reaction in a sample of three or is absorbed or when the heat capacity of the sample suddenly changes. Since the temperature difference of the Heat capacity is directly proportional, the curves correspond fc inverse specific heat curves because the heat generation as an upward peak and the heat absorption al3 downward directional tip is displayed.

The X-ray diffraction diagrams and the differential thermal analysis prove that the degree of crystallinity of the invention Copolymers up to about 25 $, generally about 1 to amounts to; usually the degree of crystallinity is between 3 and These crystallinity values are completely surprising, in particular because, based on previous experience, the formation of copolymers had to be expected are practically amorphous and have no crystalline content. With respect to the relatively high propylene content in the copolymers * As with the catalyst used, one should have expected that the bulk of the low molecular weight copolymers would be arise that are practically completely amorphous and have no crystallinity at all. As can be seen from the analysis values below results, result in the copolymers produced according to the invention, which have a significant degree of crystallinity, a better viscosity index than usual copolymers without Micro structure of the type mentioned or crystallinity. "

The polymer latex used in the process according to the invention as the end product Anfälit, can be processed with various oils, fines, clays and silica as fillers. The amount of soot which can be incorporated, can be between 0 and 300 parts by weight, preferably 0 to 200 parts by weight a per 100 parts of elastomer.

100414/204 *

υ to 250 parts by weight of oil can also be added to To achieve the desired balance between the physical properties and the workability of the end product.

It is known that polypropylene has poor impact resistance at low temperatures, which is why it is generally used with Ethylene is blended to reduce this disadvantage. However, the mixing results in other properties of the polypropylene adversely affected, so that the selection of the admixture Elastomers must be carried out particularly carefully. It has been found that the ethylene-propylene elastomers that are can be produced with the aid of the present invention and which have the novel microstructure, mixed with polypropylene can be without being in the finished blends of polypropylene and ethylene-propylene elastomer show a deterioration in properties compared to pure / polypropylene (with the exception of brittleness at low! temperatures) must be accepted.

example 1

A series of interpolymerization reactions with ethylene took place and propylene, working in 3 »8 l autoclaves made of stainless steel with stirring and at a pressure of 4> 2 kg / cm The catalyst consisted of various types of vanadium compounds with diethyl aluminum chloride; the catalyst was in amounts of about 0.2 weight percent in a solvent based on the Weight of solvent used. The working conditions at the Experiments and the properties of the bind polymers produced are compiled in Table I below.

1O90U / 2O43

TABLE 1 Preparation of polymers with anhydrous hydrogen halide

Amount supplied

Temp. Ver Supplied 2 weight
roaent Supplied kata Molar ratio ⁰ C search- Monomer lyser nis Al / V Ver duration g / 100g G g / 100g search in Hin. Lsgsm. ρ
(a) 22nd Lsgsm. 38 15th 22nd 3.0 38 15th 7.0 2ü 3.0 A. 38 15th 7.0 20th 0.008 4.0 B. 38 15th 8, ü 34 0.008 4, o C. 38 15th 8, ü 34 0.006 5.0 D. 38 15th 9.0 24 0.006 5.0 Ξ 38 15th 9.0 24 0.004 7.0 P. 33 15th 10.0 31.9 0.004 7.0 ΰ 35 13th 10.0 - 0.0063 5.1 H 32 13th 11.0 0.0063 5.0 Ke) 14.0 0.020 J 0.012

- Dieyclopenta-

serve; g / 1oog ^ t
Solvent * '

0.255
0.255

Polymeric Catal l ± \ j J.
(b) station gate out speed use Ü g / h g / gV 0.40 318 398 0 385 482 0.15 309 516 υ 437 728 0.27 438 1095 0 ;> 2b 1315 0.79 323 512, 1.2 341 542 ^ 0.34 890 445, 998 82υ '

o (a) All experiments were carried out at a pressure of 4.2 kg / cm in normal hexane as a solvent. ω (b) anhydrous HCl: percent by weight, based on the total amount of monomer fed. (e) Anhydrous HBr: percent by weight based on the total amount of monomer fed

ro

ο cn -J

! EABEIiTiT] I

conversion C - 3 Production of Polymers 75 > with anhydrous Hydrogen halide Conc. ) catalyst Sc * 33, Composition e τ Zung
of the mixed polymer 35 > increase
the ) Ver
search 88.4 37 3 05 viscosity
Average, -
Mole weight (1u-2) Catal.
effective 11 ) J. 95 (d) 27 5 42.8 Inner vis
viscosity (c) 30th 290 - ) YOCl, EthpAlCl B. 83.8 44, 1 38.0 (f) 3, 10 77 21st 63 ) C. 95 (d) 29 43.4 1, 67 320 - - ) D. 86.7 40 9 34.7 (f) τ, 65 75 41 37 ) YCl.Eth ₂ AlCl E. 95 (d) H, 8th 60.6 1, 30th 280 - - ) P. 87.6 16, z> 55.2 (f) 4, 85 20th 11 ) VCl.ÄthgAlCT G 89.2 74, 63.0 1, 150 - - ) VOCl ₃ AtIi ₂ AlCl-HBr H 95 (d) 70 62.7 2, 122 6th - YCl.EthgAlCl Ke) 97 (d) - 2, - J - - - -

(c) Viscosity in decalin at approximately 135 ^° C.

(d) Assumed conversion of ethylene.

(e) Anhydrous HBr: percent by weight based on the total amount of monomer fed. (£) Calculated amount of ethylene.

ro ο cn

The above values show that the use of hydrogen halide leads to a considerable increase in the rate of polymerization, the percentage conversion of both C ₂ and C, and catalyst utilization and a reduction in the intrinsic viscosity of the elastomer formed. In experiment 1, in which HBr was used, results were obtained which were comparable to those obtained when using HCl. With most dienes, for example dicyclopentadiene, it was possible to produce lerpolymers in a satisfactory manner; Compounds of the norbornylene type are an exception, because no prepolymers are formed with IhBn when using hydrogen halide.

Of those in experiment E (without hydrogen halide) and in experiment 7 (with Copolymers produced by hydrogen halide were given IR spectra recovered and compared. The IR spectrum for the product according to experiment E. is shown in Figure 1; the IR spectrum of the product according to experiment P is treated in FIG. If one compares the two IR spectra, thus it can be seen that in Figure 2 there is a faint peak at about 8.95 microns and there is a strong peak at about 10.0 microns indicating the presence of head-to-head bonds. The percentage these bonds in the overall polymer can be calculated from the IR spectra will.

The percentage of ethylene can be determined as follows: thin polymer films are poured from dilute solutions (1jfc in tetrachlorethylene, benzene or heptane) or onto NaCl plates. The IR spectrum is measured. The logarithm ratio of the 1,150cm (8.7 / 0 methylene vibration to the 720cm (13.9 / i) methylene vibration is determined. The value changes depending on the percentage of propylene in the ethylene-propylene copolymer · the logarithm ratio is plotted against the percentage composition of the polymer

_{The C 2} content of a certain polymer can be determined in tests in which ethylene marked with C., or propylene is also used in order to relate _{the actual G 2} content to the logarithmic ratio. j

If the extinction coefficients are known, then quantitative Use solutions for IR analysis and trace the curve in an enteprtOAl

1O90U / 2O43 - 15 -

" ° ~ 172057C

get the way.

Example 2

This example serves to explain the method of calculating the valued head-to-head bonds made in an ethylene-propylene copolymer, which has been produced with the aid of the method according to the invention are included. The method used is it is the one in "Spectroscopic Analysis of Ethylene-Propylene Copolymers" by Harry V. Drushel and Frank A. Ladings, Analytical Chemistry, 35, 28 (1963).

First, a sample was prepared by evaporating a solution of the poly- mer d (reactor cement) on a suitable KBr Seheibchen. Possibly. an HaCl disk can be used instead of a KBr disk; the sample can also be made by making a thin picture using a hydraulic press.

The IR spectrum of the film sample produced in this way was between 5000 cm "

and 650 cm (15 μ) measured. The ratio of the band intensities at 1150 cm " ¹ (3.7 y.) And 720 cm" ¹ (13.9 u) was used for the analysis. The absorption at 1,150 cm "from the propylene units (methyl vibration frequency) and the absorption at 720 cm" derived from the ethylene units (methyl chain oscillation frequency). The ratios thus obtained were applied to a standard curve which had been drawn up with the aid of Cj / - labeled standard interpolymer samples. It was found that the sample to be tested contained 51% ethylene and 7% propylene with head-to-tail bonds.

The amount of head-to-head propylene bonds can be represented as the remainder of the total bonds, which is $ 100, after subtracting the amount of ethylene bonds, which is $ 51, and the head-to-tail propylene bonds, which is $ 7. In other words, the percentage of head-to-head propylene bonds equals $ 100 minus ($ 51 C ₂ plus $ 7 C ₅ HTT) = $ 42.

The polymers according to the present invention therefore contain a considerable amount Amount of head-to-head ties. The average value

109SU / 2043

- 16 -

is, as could be determined from the examples, at about 30 to 5096 head-to-head bonds. In this context, reference is made to a work by Schooten, Duck and Berkenboech in the journal "Polymer" 2, 357 (1961) with the title "! Ehe Constitution of Ethylene / Propylene Copolymers", in which it is stated that copolymers of ethylene and propylene, which have been produced with vanadium-containing catalysts, have only a low level of head-to-head bonding. In the head-to-head polymerization observed by these authors, however, it is only the appearance of ethylene units between a head-to-head polymerization, which can be represented, for example, by the following scheme:

Propylene- 'ethylene-. Propylene-J Ethylene- 'Propylene-' unit 'unit J unit unit _f unit I - CH ₀ - CH + CH ₀ - CH ₀ + CH- CH ₀ + CH ₀ - CH ₀ + CH ₀ - CH +

^0H 3 | i ^0H 3 I! !

This configuration is necessary for the observation of (CHg) ₂ "" poles. Head-to-head propylene bonds of the type under consideration, those of the formula

HH

t I

CH ₉ - C C-CH ₉ -

were not observed · This type of binding results in the R peaks at around 8.95 microns and 10.0 microns, which have never been observed before · The peaks at around 8.95 microns are ■ anyway higher than the peaks at about 10.0 microns.

In a later article by Van Sohooten * Mostert in the ZeIt Bohrift “Polymer · ¹ vol. 4 page 135 tt (1963) the authors feat dos In“ a polypropylene have a maximum of head-to-head bonds of only 5 ble £ 15 is observed in the amorphous fraction. With pure polypropylene, every head-to-head bond is accompanied by a Sohwanzan-Sohwane bond «

The IR absorption spectrum found by these authors "at 8.8 to 9.0 is characteristic of the

- OH ₂ - CH - OH - OH ₂

Structure; the spectrum was, however, not sharp and at most indicated the presence of miniature head-to-head bonds of the type in question, which can be explained by the fact that isolated ethylene groups are often found between head-to-head oriented propylene groups are.

In accordance with the present invention, head-to-head bonds occur without intervening switched on ethylene groups, resulting in a copolymer with a much higher proportion of direct head-to-head bonding leads than "could ever be produced so far.

In this connection it should be emphasized again that when using VOGl ₅ without HGl no peaks at about 8.95 and 10.0 microns, which indicate op? -To-head binding, occur. Compare FIG. 1. These peaks occur only after using HIL. Compare Pigur 2.

Example 3

In order to prove that the compounds known to the Paohmanial chain transfer agent are not useful for the purposes of the present invention, a series of copolymerization reactions of ethylene with propylene were carried out; stainless steel was used and operated at a pressure of 4 t 2 kg / cm. The catalyst system used consisted of various vanadium compounds with diethylaluminum chloride. The catalyst was used in amounts of about 0.2 percent by weight in a solvent, based on the amount of the solvent. The working conditions and the properties of the polymers produced in this way are summarized in Table II below:

109814/2043

- 18 -

Supplied monomer

Supplied catalytic converter

Ver teap. T "p g / 1OOg C" weight g / 1 OOG Molverhält- supplied Kettenttber- polymerisation catalyst BvustL C enche- Lsgsa. percent store «as Al / V service user usage

station utilization speed g / g V g / h

38 38

11.1 11.1

22 22

0.006 0.006

0
(a)

663
680

. 740 755

38 38

38

38

ff U

14th
14th

9.0

9 * 2
9.2

30 30

26 26

0.006 0.006

0.0065 4.3 0.0065 4.3

0.18 0.18

0.19 0.19

(a)

418
368

1112
940

698 613

570 482

Wed »

f tf Π Iftn Ropes

-t _; 2.0 g / 100 g solvent DUeotnrtylaain: 0.00086 g / 100 g solvent

mmim - ^ * -

ro ο

TABETRY II (Ports.)

conversion

Composition of the copolymer

Mooney viscosity

Ver
search O / lau miii * L C, -
Wv , 5
, 4 M§l-? 6 GSw .- # Inner vis
kosity 10-3 100 ⁰ O
1 + 8 127 ⁰ O
1 + 8 inserted
Catalyst catal.vsatorsvstem K
Il £ ^P 91
92 25th
26th 60.1
59.6 50.1
49.6 3.0
2.2 198
130 62
36 - Control vers. V01 _A
m. hydrogen eth / AlCl M. »Α
O 85 30th __ 54.9 3.9 266 75 Control vers. V01 _A IT 84.5 22nd - 62.0 2.9 170 52 with 1-butene AthpAlOl 93 22nd 60.0 3.4 _I - _m - _am 50 Control vers. VOCl, / Ti 90 14th - 69.2 3.3 - - - '- 41 m. diisotutyl- (OGO./EthpAl
amine 01

It can be seen from Table II that three pairs of experiments were carried out, of which each pair from a control experiment and an experiment with a chain terminator or chain transfer agent. Bas Chain transfer agent consisted of hydrogen, butene-1 in turn and diisobutylamine. It can also be seen that the addition of the chain transfer agent does not lead to an increase in the percentage conversion or the rate of polymerisation (apart from an insignificant one the increase in the use of hydrogen). In case of Use of butene-1 and diisobutylamine were the rates of polymerization and the degree of conversion is lower than in the Kontrollvez Looking for.

Purely the hydrogen experiment, except for the use of 25 parts per million Hp, based on the amount of solvent, the experiment L an infrared spectrum was made; this is shown in FIG. One recognizes from the figure. 3 that those for head-to-head figuration characteristic peaks at 8.95 and 10.0 microns are absent when hydrogen is used as the chain transfer agent will. Hydrogen also has the further disadvantage that it makes the polymer "soupy" because it drastically lowers the viscosity. Extremely low levels of Hg are commonly used, i.e. levels on the order of 2 to 50 parts per million based on the solvent. But even these small amounts make the polymer already "soupy" to an undesirable extent, i.e. thinly liquid. This disadvantage does not arise when hydrogen halide is used.

Example 4

Various elastomers have been blended with commercially available polypropylene to make products with different properties. the Composition of the mixtures and their properties are in the Table III below. *

TABLE III Composition Jl B ^ ' C ^ '

Elastomer commercial EPT EPR EPR

Elastomer I.V., - »2.1 1.65 1.50

Elastomer concentration, 10 10 10

10-9814 / 2043

A. 14.5 _B (D 1720570 composition 37.5 0 <2) ]? film properties 86,700 70.1 shine 2.6 84.2 ! Turbidity 85,400 1.7 86,600

-6.67 0 pt. ib / MIC

(1) H ₂ as a chain transfer agent Ί

The same procedure aside from the use of H «and \ H01

(2) HCl according to the present invention 'conditions

The most important properties for films are! Haze, gloss, impact strength and rigidity. Limit values are: .— / 90 gloss,> 1.0 Ir exercise,> 0.035 impact strength and ^ - ^ 90,000 stiffness.

It can be seen from Table III above that the copolymers which have been prepared according to the invention using HCl result in mixtures in products which have the best overall properties with regard to the technical and commercial requirements. The gloss and haze properties, which are extremely important for resins that are to be further processed into films, are particularly excellent. Ee can also be used to produce practically 100% homopolymers from O ₂ - Gg-oc-olefins with a high proportion of head-to-head bonds in the microstructure, if crystallinity is not desired.

Example 5

In accordance with the manner indicated in Example 1, a number of further tests were carried out to determine the suitability of the invention Process for the production of copolymers which have a high degree of crystallinity to show. The copolymers, which were used in all experiments and are summarized in the following! Table IV, were in the already described! Way made. The particular catalyst used as well as the The ethylene content in the resulting copolymer is shown in Table ΙΊ specified.

. The ethylene-propylene misohpolymers according to this example were examined for their degree of crystallinity with the aid of the X-ray diffraction method. The method used corresponded to that of WeI-dinger and Hermana makromolekulare Chemie, ££, 98 (1961) was carried out as follows »

1) A diffractogram of the ethylene-propylene copolymer sample was produced.

2) The amorphous and crystalline areas of the Diffraktograeaea were ■ ^ measured.

3) The percentage degree of crystallinity was calculated from these two measurements.

The method is based on the recording of a series of Tim Diffraktograeaen of ethylene-propylene misohpolymer leate samples which vary in terms of XrI stability. The data will be on the same A4 »o * bans normal! · eggs. Carries the normalized crystalline areas against the normalized amorphous regions graphically, there is a linear relationship between the two quantities. The »allows the calculation of the crystalline and amorphous areas.

ψ The crystallinity values determined with the aid of the X-ray diffraction method and calculated as described above are compiled in Table 17 below.

IT

Trial catalyst calculated ethylene percentage crystal:

salary (Oew.-Jl) linitat (Röntgen |

Q Y01 _4th AUth ₂ 01 ^ HBr 40.3

■ R VOOl ₃ . Al JUh ₂ Gl. HBr 38.8

S VOOl ₃ .Alith ₂ 01.HO ^ 35.3 X VOOl ₃ . AL) Uh ₂ Ol. HOl 40.8 U VOCl ₃ .AllthgOl.HOl 41.7

From the data in Table IV one can easily see that with With the aid of the process according to the invention, ethylene-propylene copolymers can be produced with a surprisingly high degree of crystallinity. This is mainly in connection with the ethylene-propylene proportions noteworthy in the samples examined. According to further Embodiments of the present invention are these copolymers oily products added to their viscosity indices as a result of the varnishing properties they possess and their To increase resistance to attacking shear forces. The invention Copolymers are superior to conventional additives in this regard.

The interpolymers or terpolymers of the present invention are ™ as additives of the type mentioned above in concentrations of about 0.1 to 10 percent by weight, preferably about 0.5 to 5.0 percent by weight, based on the amount of oily product used. In no case, however, is more copolymer or terpolymer added than dissolves in the oily product. The additives are usually marketed as concentrates in which they are used in amounts of about 5 to 50 percent by weight, preferably 10 to 25 percent by weight, based on the total amount of :; Solvent, e.g. mineral oils, hexane, heptane, etc. are present.

The mixed polymers or terpolymers according to the present invention can in the oily products alone or, if so desired, together with J. used with other means of improving the viscosity index. Possibly. the mixed polymers or terpolymers can also be mixed with other additives, e.g. pour point depressants ^ dispersants, Corrosion inhibitors, antioxidants, agents to prevent sludge formation, metal deactivators, etc. can be used.

Another embodiment of the present invention also relates to the addition of the copolymers described here to fuels such as gasoline, medium distillate oils, transformer oils, lubricating oils, etc.

According to yet another embodiment of the present invention the copolymers or terpolymers described can also be a Nad are subjected to treatment that they are used for special purposes

1098U / 2CU3

- 24 -

makes it suitable and makes them additional with regard to the particular purpose imparts desirable properties. In. this gathering; The copolymers according to the invention can e.g. see aftercare, B.B. a halogenation, a halogenation with subsequent dehalogenation, a sulfohalogenation with suIforyl chloride or mixtures of chlorine and sulfur dioxide, sulfonation or other treatment methods usually based on hydrocarbons be applied, be subjected. The copolymers or terpolymers according to the invention can also be used with others Copolymers or terpolymers are mixed, so that products with certain desired properties arise.

Example 6

In this example, the aim is to improve the viscosity index (abbr. V.l.) Properties and the thickening properties of the copolymers according to the invention are shown. There were seven Experiments carried out at constant catalyst feed rate and constant aluminum to vanadium ratios. The HOl was in two stages, i.e. 10 and 15 cm / min. fed.

Heptane was saturated with ethylene and propylene in the molar ratio given in the table below. The saturated heptane was introduced into a reaction vessel into which a stream of vanadium oxychloride and a stream of diethylaluminum chloride (each diluted with heptane) were also introduced so as to give an aluminum to vanadium ratio of about 4: 1. Nitrogen gas containing hydrogen chloride was introduced into the reaction vessel in amounts of 10 or 15 emv min. As indicated in the following table. The residence time of the reaction mixture was about 15 minutes. The reaction ^{temperature was about 30 °} C .; the pressure was one atmosphere. The reaction mixture was then washed and subjected to steam distillation.

The copolymers obtained were in amounts of about 1.5 to 3.0 percent by weight in a base oil, that is a solvent-extracted, 01 neutral paraffin type with about 46.53 SUS at 100 ⁰ C and about 189.9 SUS at 38 ° C, which Has a viscosity index of about 109 incorporated in order to improve their maturities

1098U / 2043

- 25 -

To determine the viscosity index and its thickening force. The obtained Values are compiled in Table V.

TABLE V Ethylene-propylene copolymers as additives '

HOl feeding speed (cm / min)

10 15

Ethylene / propylene thickening thickening E.

management relationship Y.I. power * from left force*

»" ■■■ "" «■■■■■■■ •• ■« ■ • ■ "• ■« "» ■ • ■■! ■■ l · * ^ "" "» BMBBBBBBMBBBBBBMMBM HiHBakHaaaaViWMMa ^ MBNi ^ MMMMMBMMaWi IBMMaBMMVB BMa ^ BBMHBBMBMBMBHMMBB P

50/50 150 1.0 145 1.0

55/45 136 1.4 132 1.6

60/40 140 1.6 136 1.1 {

65/35 133 1.6

* Thickening power = percent by weight of polyisobutylene required

Percentage by weight of ethylene / propylene thickening

Base oil on K ¹ V 100 ⁰ G = 12 + O, 5c £

Sixt results from the viscosity indices and the thickening properties clearly that the copolymers according to the invention are better than usual V.I. improvers. The improvement will be even more apparent the data of the next example, in which additives according to the present invention with conventional additives, e.g., polyisobutylene, are used different base oils are compared.

Example 7

In order to show the extent of the improvement in the viscosity indices by the ethylene-propylene copolymers according to the invention, a series of copolymers were prepared in the manner described in Example 8, but with a different ethylene / propylene molar ratio. Pur each experiment, were used in the ethylene and propylene, the molar percentage of ethylene is the encoder in the following Table VI In each Pail was added as much copolymer that Bsö-söl to a viscosity of 12 ^ 0.5 it at 100 ⁰ C was thickened. The related base oils are specified in the table.

- 26 1098U / 2043

nc.

TABEIiIiE YI

Comparison of ethylene-propylene copolymers (BPG) with polyisobutylene as a V.I. improver

V.l. improvers Mole of 5έ ethylene A. BsaL oil C. Mixed polymer 104 B. 99 no 77 139 109 134 Attempt 1 71 137 137 132 Attempt 2 80 143 136 132 Attempt 3 77 139 130 134 Attempt 4 134 Polyisobutylene __ 130 124 (Paratone N) 128

Bas is oil A: a solvent-extracted, neutral paraffin type oil having about 44,52SJS at 100 ⁰ C and 166 SUS at 38 ⁰ O

B: a solvent-extracted, neutral paraffin type oil having about 46.53 SUS at 100 ⁰ O and 189.9 SUS at 38 ⁰ O

0: a solvent-extracted, paraffin-type neutral oil with about 44.10 SUS at 100 ⁰ O and 166 SUS at 38 ⁰ O.

The values in Table VI show that the ethylene-propylene copolymers according to the present invention are far superior to conventional viscosity index improvers. This advantage is even greater by the fact that it can be achieved with a large number of different base oils.

Example 8

A further series of experiments was carried out in order to demonstrate the superiority of the process according to the invention for the production of mixed polymer} to show seeds that can be used as V.I. improvers. The copolymers used in the experiments were all in the prepared in the manner described above. she Reaction participants as well as the reaction conditions are compiled in the following Table VII, in which the properties of the Copolymers are mentioned · The copolymers were in quantities

1Q98U / 2CU3

- 27 - *

172057C

of about 2.0 percent by weight in a paraffin-type base oil with about 46 _f 53 SUS at 10O ⁰ G and about 189.9 SUS at 38 ⁰ G, which had a viscosity index of about 109.

109814/20 ^ 3

- 28 -

Temp. σ ₂ Ausffanesstoffe Hexane HBr lABEUJ B VII V.l. p (1) # SB. ^{(2) δ} σ 3.50 r / 100 r VOOl * 0.9 138 1.3 20th Ver 35 3.50 0.020 1.4 Al / V
Mole Ge
Schwin 142 1.3 - search 35 3.50 7.50 0.020 2.0 Prosecution age 141 1.3 1A 35 3.50 7.50 0.020 1.25 4.5 850 138 1.3 16 1B 35 3.50 7.50 0.020 1.25 4.5 890 135 1.2 - 10 40 3.50 7.50 0.020 1.25 4.5 865 139 1.2 18th 2A 35 3.50 7.50 0.020 1.25 4.5 876 143 1.2 - 2 B 35 3.50 7.50 0.020 1.25 4.5 870 138 1.2 17th 3A 35 3.50 7.50 0.025 1.25 5.0 873 137 1.3 - ο ^3B 35 3.50 7.50 0.020 1.25 5.5 883 133 1.4 - to
οα 4Α 35 3.50 7.50 0.0125 1.1 4.5 907 136 1.2 19th Ji 43 35 3.50 7.50 0.020 1.4 4.5 884 143 1.5 21st -40 35 3.50 7.50 0.020 2.0 4.5 814 144 1.2 20th ΪΪ5Α 35 4.00 7.50 0.020 1.25 5.1 908 139 1.3 18th ^ω 5Β 35 7.50 0.020 5.1 912 5G 7.50 5.1 906 5D 5.1 960

(1) Thickening power compared to polyisobutylene

(2) percentage breakdown when exposed to sound

The vorsteta. Ending data show that copolymers with improved VI, higher thickening power and greater shear resistance (determined by the breakdown on sonication) are obtained when the catalyst system is used according to the invention together with hydrogen bromide
will. The viscosity indices given in Table VII are significantly higher than the values obtained with conventional VI improvers. This advantage is further enhanced by the thickening power of the agents according to the invention, so that it is possible to use fewer additives
use. The greater shear stability also contributes to improving the overall properties of the product.

Example 9

In this example, the effect of copolymers which have been produced according to the invention with hydrogen halide is to be compared with that of copolymers which have been produced without hydrogen halide. The reaction conditions and the ratios of
Ethylene (O ₂ ) to propylene (CU) are given in Table VIII below.

109814/2043

TABLE VIII

Comparison of the ethylene-propylene copolymers

Attempt Co g / min. C. g / min. HCl ^ mg / min. Vl

1 1.30 1.59 O gel

2 1.22 1.69 O 128 72.2

3 1.14 1.75 Ö 126 65.5

4 1.22 1.69 29.8 140 8.8

5 1.22 1.69 29.8 138 8.5

6 1.30 1.59 38.8 140 20.5 _ψ 7 1.14 1.75 '50.7 137 18.5

ο (1) Beaktionsbedingungen: temperature 27 ⁰ C, catalyst -ÄthgAlCl (11.3 mg / min) VOCl ₅ (3.53 mg / min); C £ molar ratio = 4.57, solvent = heptane 40 cm ⁵ / min.

(2) in 25-year concentration (nitrogen as a core if necessary)

The above values indicate a. Problem with ITi ent use of HCl can occur, namely the possible gel formation. While in the other experiments in which no HCl was used, one A satisfactory V.I. improvement was achieved was the shear strength persistence - represented by the collapse when exposed to ultrasound high and therefore undesirable. You can see this easily if you look at the copolymers, which have a high percentage breakdown when exposed to sonication compare with copolymers which, apart from the HCl modification, are produced under the same conditions became.

Example 10

A series of experiments was carried out under practically the same conditions except for the changes in the HCl feed rate guided. The reactants and the reaction conditions are in of Table IX. The resulting viscosity indices, thickening properties and seer resistances are the corresponding ones Properties of polyisobutylene compared to a common V.I.-Improver (Paratone N).

2 (U 3

Jl ^ ² ^ (ms / Μη) v.i. <3) as viscosity index improver ^ ' io SB 20.7 137 (4}
Thickening power ^v ^ ^J 20.6 TABLE IX 20.7 139 1.5 - Ethylene-propylene copolymers 14.7 138 1.2 16.7 Try HC 14.7 135 1.7 - 1 8.4 135 1.5 13.5 2 8.4 137 1.8 3 0.72 130 1.8 4874 4th 0.72 132 2.9 - 5 0.72 131 2.8 - 6th 2.7 7th 130 25.0 8th 1.0 9 Polyisobutylene (Paratone IT)

all cases equal to 11.3 mg / min.,

(2) 24 volume # HC1 / H ₂

(3) determined in reference oil 150A; A is a solvent-extracted, neutral paraffin-type oil with approximately 46.53 SUS at ^{10O 0} C and 189.9 SUS at 38 C.

(4) ThickeningBlcraft compared to polyisobutylene.

From the above fourth it follows that with the copolymers according to the present invention regularly an improvement in Verdiclairf properties and an increase in shear resistance can be achieved. Copolymers produced at an HCl feed rate of only 0.72 mg / min., did not yet show any salient Properties; but this amount of HCl is - compared with the commonly used amounts - relatively small and represents the lower limit for the feasibility of the process.

Example 11

This example is intended to show the relationship between the degree of crystallinity of a copolymer according to the present invention and its property as a VI improver. A number of ethylene-propylene copolymers were prepared and examined for their degree of crystallinity with the aid of X-ray diffraction metals. The method again corresponded to that of Weidinger and Hermans in "Makromolekulare Chemie" 50 « 98 (1961). The determination of the crystalline content in the ethylene-propylene copolymers was carried out in the manner already described above (page 22).

The V.I. 'of the above ethylene-propylene copolymer samples was decided.

The values obtained in both examinations, namely percentage " Crystallinity and V.l., are compiled in Table X below.

Sample No.

iCatalyst systems

VOOl ₃ . AlA'thgCl. HOl VOOl ,. AlXtIi _n Ol.HOl

VOCl

Ol.HOl

VOl ₄ .AlXthgOl.HBr

VOOl

. HOl

calculated amount of ethylene (wt

(D

(D

(D

40.3

47.0

39.0

.1. percentage
Crystalline
ity (X-ray
method 128 0 128 0 132 4.2 136 5.7 136 5.8 138 6.2

109814/2043

sample
No.

Catalyst system

VOCl ₅ .AlIthgCl.HCl VOCl ₅ AlAtIi ₅ CT. HBr

VOCl

₅ .

. HCl

VOCl ₅ .AlÄth ₂ Cl.HCl VOCl ₅ . AlEthgCl. HCl

1 V.l. 720570 calculated ethy
amount of oil (weight-ji) 133 percentage
Crystallinity
(Hönt & en method> 35.0 150 6.4 38.8 152 8.9 35.3 162 12.1 40.8 165 18.6 41.7 19.9

(1) 30 to 50 percent by weight (estimated)

The values contained in Table Z are shown graphically in FIG shown. The graph shows a defined relationship between the degree of equality of the ethylene-propylene copolymers and their effect as a V.I. improver. This is surprising insofar as it has hitherto always been suggested to produce polymeric V.I. improvers in oil-soluble and non-crystalline form so that they can impart the desired properties. However, the values in Table X and FIG. 4 indicate that different Ethylene-propylene copolymers, which have a relatively high Have a degree of crystallinity, yet are particularly good viscosity index improvers. Besides the improvement of the viscosity index it will a higher degree of digestion and a greater resistance to shear is also achieved. The catalyst system, olefin content, etc. are different on the connection between viscosity index and crietallinity obviously no influence.

101114/1043

Claims (10)

Claims - | 720570 1) Process for the production of copolymers from ethylene and G, Ms Cj ₀ «-olefins, the molecular weights of about 20,000 to about 250,000 and a degree of crystallinity up to about $ 25 and in which about 3 to about 80 ^ of the oc-olefin molecules through Head-to-head bond according to the formula CH ₀ - CH - GH - CH ₀ * ■ ι ι * - R Il are linked - where R is alkyl groups of 1 to 8 carbon atoms represents - dadureh. marked that one (1) Introduces a mixture of ethylene and a G ^ to C ^ _Q oc-olefin in a reaction zone and there (2) this mixture in the presence of a) an organic solvent, b) an anhydrous hydrogen halide as well c) a vanadium-containing catalyst polymerized, the catalyst being an alkylali metal compound used, which is soluble in the solvent used and corresponds to the formula R AlX, in which R is a monovalent Hydrocarbon radical with 1 to 12, preferably 1 to 8 carbon atoms X is a halogen atom with an atomic number of 17 or more or also a monovalent hydrocarbon radical with 1 to 12, preferably 1 to 8 carbon atoms or hydrogen, m is an integer between 1 and 3 and the Sum of m + n is 3. 2) Method according to claim 1, characterized in that the oc-Olefij consists of propylene and the hydrogen halide of HCl or HBr. 3) Method according to claim 1, characterized in that one (1) a mixture of 2 to 98 percent by weight ethylene and 98 to Percent by weight of the α-olefin introduced into the reaction zone unc (2) the polymerization of the mixture at a temperature of 0 to 20O ⁰ C a bridge of 0 to 140.6 kg / cm and a residence time of 1 to 300 minutes 1Ö98U / 2CU3 undertakes, with the hydrogen halide in amounts of 0.001 ibis 10 Mol #, "based on the total molar amount of monomer and the soluble, vanadium-containing aluminum dialkyl activated catalyst, its Al / V molar ratio is between 0.3 and 25, in amounts from 1 "to 500 parts per million by weight based on the solvent can be used. 4) Method according to claim 3 »characterized in that 'that the α-olefin from propylene, the vanadium compound from VCl., the aluminum compound of diethylaluminum chloride and the hydrogen halide of · HOl or HBr. 5) Method according to claim 3, characterized in that the vanadium compound consists of VOOl. 6) Process according to claims 1 to 5 »characterized in that in addition at least "in0" during the polymerization until C ^ "olefin monomer is also used. 7) Process according to claims 1 to 5 »characterized in that a diolefin or polyolefin is also used in the polymerization. t 8) The use of viscosity index improvers in oils, thereby characterized in that as the viscosity index improving agent the copolymers prepared by the process according to claims 1 to 7 used, directly or in the form of a Concentrates in which the copolymers are dissolved in a mineral oil. 9) The use of viscosity index improvers according to claim 8, . characterized in that the Ul is a lubricating oil. 10) The use of viscosity index improvers according to the claims 8 and 9, characterized in that one according to the method copolymers prepared according to claims 1 to 7 Added to lubricating oils in amounts from about 0.1 "to about 10 percent by weight. Esso Research anä Engineering Company Elizabeth-B, N.Y., V.St.A. attorney 109814/2043 Blank page