DE1420219A1 - Process for the production of oil-soluble copolymers - Google Patents

Description

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. _Q telegrams: BASF Ludwigshafenrhein

J? '14 · 20219 · O Bankers: State Central Bank

'ι ι - Ludwigshafen am Rhein, current account 51/82

o.z »19 091

6700 Ludwigshafen, the

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Process for the production of oil-soluble copolymers

It is known that the viscosity index of lubricating oils, which is a hatred for the temperature dependence of the viscosity of oils (for a definition see Lunge-Berl "Chemischtechnische investigationsverbindungen" III (1923) p. 3> 4 ff.), By adding oil-soluble oils Can improve polymers. The addition of the polymers not only increases the viscosity index, but also increases the viscosity of the oil at the same time. This can be in special cases, e.g. when using very thin oils, this may occasionally be desirable; As a rule, however, a viscosity index is required that changes the viscosity of the oil as little as possible.

It is now relatively easy to use oil-soluble polymers and cn copolymers with a good viscosity index-increasing effect

«5 to determine the sharp increase in viscosity of the oils bees

Tj- act · In contrast, the production of

O ₀ oil-soluble polymers or copolymers with good vises
ο viscosity index improvement, the addition of which increases the oil viscosity

is increased only a little.

38/57 ^weue VRwMeQen. Ι * «· 7 & t Abe, 2 No. 1 sentence 3 of the amendment, * ν. «♦. a. Um / j _ ρ -

Among the substances with good solubility in mineral oils and stronger Increase in viscosity includes, for example, the homopolymers of acrylic acid esters known from British patent 6,18,691 higher fatty alcohols. In contrast, copolymers of acrylic acid esters of higher viscosity have a slight viscosity-increasing effect Fatty alcohols with lower acrylic acid esters, such as acrylic acid methyl ester, -ethyl ester, -butyl ester, or with acrylic acid esters of Glycol ethers such as those known from US Pat. No. 2,6θ4,453 are. However, these copolymers have the major disadvantage that they are insoluble in numerous mineral oils or cause cloudiness. when the content of lower acrylic acid esters is relatively high, so that a certain viscosity limit in mineral oils cannot be exceeded by adding them. If you reduce the content of lower acrylic acid esters in the With copolymers, clearly soluble products are obtained, but a greater increase in viscosity has to be accepted. On the other hand, if one tries to improve the solubility of the copolymers by reducing the degree of polymerization, so this also has the effect of improving the viscosity index significantly deteriorated.

Finally, from the published documents of the Belgian Patent 552,975 copolymers from heterocyclic basic nitrogen compounds and other monomers that do not contain a heterocyclic nitrogen atom are known as additives are intended for oils and are intended to have a cleaning effect on the oils. The published documents

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of the Belgian patent 53J2 975 cannot give any information about it the extent to which the copolymers disclosed therein increase the viscosity index of oils without at the same time bring about a strong increase in the viscosity of the oil, and these copolymers generally do not have this effect either.

It has now been found, surprisingly, that readily oil-soluble copolymers are obtained which, with good viscosity index-improving properties, increase the viscosity of the oil only slightly if acrylic acid esters of alcohols with at least 8 carbon atoms in the molecule are about ^ O to 1 % Miseh polymerized N-vinyl lactams. It is known that acrylic acid esters of higher fatty alcohols can be copolymerized with N-vinylpyrrolidone. The known copolymers contain predominant amounts of N-vinylpyrrolidone and are water-soluble. Such copolymers are of no interest as additives to mineral oils, since they are insoluble in mineral oils.

In this invention, both copolymers of esters of unsubstituted acrylic acid and of esters of substituted Acrylic acid can be used. Copolymers of acrylic esters of the general formula are preferred

X ^0R

where X is hydrogen or a methyl radical and R is a straight-chain or branched alkyl radical with 8 to 20 carbon atoms.

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Such esters are, for example, the esters of acrylic acid or methacrylic acid with 2-A "ethylhexanol, branched-chain nonyl and Decyl alcohols (e.g. obtained by oxo synthesis and subsequent reduction) or with alcohol mixtures with 10 to 18 carbon atoms « as obtained technically by hydrogenating coconut fatty acids, or with sperm oil alcohol. Mixtures of these esters can also be used.

Suitable N-vinyllactams are, for example, N-vinylpyrrolidone, N-vinyl-6-caprolactam and N-vinyl-aJ-capryllactam. The copolymers can also contain several N-vinyl lactams; however, the total proportion of these monomers should remain within the specified limits of 1 to 10%. Copolymers which contain about 5 to 15 % N-vinyllactam are preferred. All percentages are based on the total weight of the copolymers.

In addition to the acrylic esters and N-vinyllactams mentioned, the copolymers according to this invention can also contain other monomers, for example methyl acrylate or butyl acrylate. The amount of these comonomers is given by the solubility limit of the copolymers in mineral oils and can easily be determined from case to case by simple trial and error. The proportion of the copolymers of acrylic esters of alcohols with at least 8 carbon atoms should not fall below a limit of 60 % as far as possible. '

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The copolymerization is expedient in the presence of a solvent carried out, whereby light-colored mineral oils with low viscosity have particularly proven themselves as solvents. The other known polymerization processes, such as emulsion, suspension and block polymerization, can also be used. The polymerization can be carried out continuously or batchwise. In general, it is advantageous to use a radical-forming catalyst, such as peroxides or azo compounds, e.g. lauroyl peroxide or azoisobutyronitrile, for excitation add to the polymerization.

The degree of polymerization of the copolymer is also from Influence on its quality as a viscosity index improver. In general, the higher the degree of polymerization, the higher the higher the viscosity index Effect too. But since the copolymers become and also more insoluble with increasing degree of polymerization their shear resistance decreases with increasing degree of polymerization, As a rule, interpolymers of medium molecular weight are most useful. Viscosity index improvers are preferred Copolymers with a K value according to Pikentscher between 40 and 70 (measured in benzene).

The setting of the most favorable molecular weight succeeds in a known manner Easily by varying the polymerization temperature and the ratio of monomers to solvent.

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If the copolymers produced according to this invention are used as additives for mineral oils, their concentration in the mineral oils should preferably be between 2 and 8 %, based on the weight of the mineral oil.

Although the new copolymers are primarily used as additives of mineral oils are valuable, there are other areas of technology in which they can be used with benefit. For example, due to their high flexibility, they are suitable as high-molecular plasticizers for brittle plastics. Also for treating They can be used for textiles and other fiber materials such as paper or leather.

The quantities given in the following example are parts by weight.

example

65 parts of acrylic acid lorol ester (Lorol alcohol = technical mixture of alcohols with 12 and 14 carbon atoms, obtained by hydrogenation of coconut fatty alloys)

Parts of butyl acrylate
2 parts of ethyl acrylate
10 parts of N-vinylpyrrolidone and
50 parts spindle oil (viscosity 4.1 ° Engler at 50 °)

are under nitrogen after the addition of 0.2 part of azoisobutyronitrile Maintained at 60 ° for 10 hours. The polymerization is

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practically ended after this time. To remove monomer residues, the viscous polymer solution is heated to 120 ° for 1 hour while passing a vigorous stream of nitrogen. A further 50 parts of spindle oil are then added so that the solution contains about 50 % of the copolymer.

The effect of the preparation is shown in the following tableϊ

Viscosity viscosity

at 38 ° c St at 99 ° c St ^{m Stp} *

Test oil B 110 11.2 95 -21

Test oil B with 4 % of the
50 # polymer solution. 117 14 O 122 -32

Test oil B with 4 % of a
comparable copolymer without
Vinyl pyrrolidone 125 15-9 122-32

The copolymer used for comparison was among the same Conditions, but without N-vinylpyrrolidone from 65 parts of acrylic acid lorolester, 12 parts of methyl acrylate and 23 parts Acrylic acid ethylhexyl ester has been produced.

The comparison clearly shows the surprising effect of ' N-vinylpyrrolidone. With the same amount of copolymer and at the same viscosity index improver, the viscosity increasing effect at 38 ⁰ at copolymer with N-vinylpyrrolidone

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only half as high. The pour point-lowering effect of the copolymers is not affected by the content of N-vinylpyrrolidone.

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Claims (2)

1. Oil-soluble copolymers based on acrylic esters or methacrylic esters and ethyierically unsaturated monomers containing heterocyclic nitrogen atoms, characterized in that they contain acrylic esters or methacrylic esters of alcohols with min- - Contain at least 8 carbon atoms in the molecule and about 1 to JQ% of their weight of an N-vinyl lactam in polymerized form. 2. Oil-soluble copolymers according to claim 1, characterized in that »they contain acrylic esters or methacrylic esters of alcohols having 8 to 20 carbon atoms and 5 to 15 β of their weight of an N-vinyl lactam in copolymerized form. · ') Process for the production of oil-soluble copolymers based on acrylic esters or methacrylic esters and monomers containing ethylenically unsaturated heterocyclic nitrogen atoms, characterized in that acrylic esters or methacrylic esters of alcohols having 8 to 20 carbon atoms are used with 1 to 30 % of an N-vinyl lactam mixed polymerized. Badische Anilin- & Soda-Fabrik AG New allocationsΐΑΛί. 809808/0679