CA1238448A

CA1238448A - COPOLYMERS OF .alpha.,.beta.-UNSATURATED DICARBOXYLIC ACID ESTERS, PROCESSES FOR THEIR PREPARATION AND THEIR USE

Info

Publication number: CA1238448A
Application number: CA000411264A
Authority: CA
Inventors: Heinz Beck; Karl-Heinz Frassek
Original assignee: Akzo NV
Current assignee: Akzo NV
Priority date: 1981-09-17
Filing date: 1982-09-13
Publication date: 1988-06-21
Also published as: EP0075217A2; ATE60789T1; JPS5865246A; DE3223694C2; JPH0541625B2; EP0075217B1; EP0075217A3; DE3223694A1

Abstract

ABSTRACT OF THE DISCLOSURE

The invention relates to copolymers of ?-.beta.-unsaturated dicarboxylic acid esters and ?-olefins which are built up from ?-olefins having 10-16 C-atoms and from ?-.beta.-unsaturated dicarboxylic acid esters, the alcohol components of which are straight chained and/or branched chain mono-alcohols having 3-10 C-atoms and are, if necessary, cross-linked, the "pour point" lying between -60° and 0°C, the copolymers are used as synthetic lubricating oils, mineral-oil additives, lubricant additives, and as lubricants for the processing of thermoplastic synthetic materials during forming.

Description

The invention relates to copolymers of (I
unsaturated dicarboxylic acid esters and ~-olefins and to the production and use thereof.
Federal Republic of Germany Offenlegungsschrift (Published Patent Specification) 27 27 239 discloses olefin-malefic acid copolymer derivatives which are built up from olefins having an average of 2 - 24 carbon atoms and malefic acid, and which are esterified with monovalent alcohols having a chain length of 2 - 20 carbon atoms in a molar ratio of 1 : 0.5 to 1 : 2 of malefic acid to alcohol The olefin-maleic acid copolymer derivatives are produced by copolymerizing malefic acid or malefic acid android with (-olefins, followed by esterification to the half-ester or to the divester. The olefin-maleic acid copolymer derivatives described therein are particularly suitable as lubricants for forming synthetic materials These products are semi-solid to solid at room temperature. The pour point is well above 0C.
In addition to this, high molecular copolymers of oC-olefins and TV unsaturated dicarboxylic acid esters have become known, for example as hair sprays (Austrian Patent 254 327) and as agents for coating medications (Austrian Patent 263 011). These are produced by Capella-meriting ~-olefins and unstriated dicarboxylic acids and acid androids, followed by esterification of the copolymers, and are solid or wax-like at room temperature.
Federal Republic of Germany OffenlegungsschriEt 17 70 860 discloses a copolymer made of a C22-C28-1-olefin and dibehenyl Malta obtained by polymerizing at 150C and described as a wax-like product. I-t was proposed I

to add hydrocarbons to the product in order to lower the solidification point and to increase fluidity as a whole.
It is stated in Federal Republic of Germany Offenlegungsschrift 17 70 860 -that improvement in fluidity can be obtained only with ester polymers in which the number of carbon atoms in the alkyd portion is greeter than 20.
Austrian Patent 479 746 describes fluidity improvers or modifiers for wax-like hydrocarbon oils which reduce the pour point thereof. Here again , long side chains for the alcohol components of the dicarboxylic acid esters are described as absolutely necessary. The consistency of the products at room temperature is wax-like to solid. In this case, therefore, the pour point is dental above 0C.
Japanese Printed Publication 55-157 687 describes a copolymer consisting of an ~-olefin and a dialkylester of an unstriated dicarboxylic acid as an additive for lubricants.
The unstriated dicarboxylic acids are, in practice, malefic acids or fumaric acid. Mixtures thereof are not described.
The alcohol component should comprise 1 to 18, preferably 1 - 8 carbon atoms; it is highly preferable to use methanol. The alcohols may be branched or unbranched. There is no mention of a mixture.
The ~-olefins contain 4 to 60 carbon atoms, and the copolymers made of ~-olefins having 4 to 18 carbon atoms are fluid at room temperature. In the case of mixtures of ~-olefins having 6 to 10 carbon atoms, the pour point is between 38 and 40C. In the case of mixtures of ~-olefins having 16-18 carbon atoms, it is between 6 and 7C and -17 and -18C, depending upon the alcohol. The copolymer of ~olefins having 12 - 14 carbon atoms has a pour point between 12 and 13 C.

- 2 -I

(see Table l -test 2).
The fluid copolymers have excellent oil properties, both undiluted and dissolved in mineral oil, either as lubricants, as machine oil, as turbine oil or as an oil for metal shaping (cf. bottom of page 7). The oil properties and the resistance to abrasion increase as -the number of carbon atoms in the alcohol component decreases. For this reason, total preference was given -to methanol (page 4, paragraph 2), in which case, -the pour point increases. It indeed increases from between -17 and -18C to between 6 and 7C upon changing over from octanol to methanol.
Lubricating oils having a low pour point and the lowest possible change in viscosity, even without additives, have been sough-t for some considerable time Lubricating oils which have a low pour point even without additives, and which undergo the smallest possible change in viscosity over a wide range of temperatures, have long been sough-t.
These demands are largely me-t by the polymers according to the invention and, as such, they are already outstanding lubricating oils.

- pa -.:

In one preferred embodiment of the invent lion, the copolymers are built up in such a way that the unstriated dicarboxylic acid ester is an unswept-rated dicarboxylic acid divester. Suitable -unsaturated dicarboxylic acid esters include: esters of malefic acid, fumaric acid, citraconic acid, mesa conic acid or itaconic acid. however, preference is given to the esters of malefic acid and Iumaric acid.
Copolymers in which the ~-olefin is unbranched have lower pour points than those in which the ~-olefins are branched. Thus the copolymers preferred according to the invention are those in which the ~-olefin component is unbranched. The mole ratio of ~-olefin to unstriated dicarboxylic ester is preferably Owe : I
It was totally unexpected that the method act cording to the invention would make it possible to build up the fluid copolymers of the invention from an ~-olefin having 10 - 16 C-atoms and a unstriated dicarboxylic acid ester, the alcohol component of which is a straight chain or branched chain moo alcohol having 3 - 10 C-atoms, the said copolymers being fluid and improving the flow and viscosity properties of mineral oils and lubricants to a substantially greater extent than known high molecular weight polymers made of very long chained ~-olefins and unstriated dicarboxylic acid esters with long chained alcohol components. The method according to the invention is characterized in that an ~-olefin having 10 - 16 C-atoms and a unstriated dicarboxylic-acid ester, the alcohol component of which is a straight chain or branched chain monoalcohol having 3 - 10 C-atorns, are copolymerized at a temperature from 140 to 210C, in the presence of a peroxide catalyst, in an inert gas atmosphere.
It is particularly preferred to use us-saturated dicarboxylic acid divesters, more particularly malefic acid divesters or fumaric acid divesters.
The copolymers acquire particularly satisfactory flow and viscosity properties if between 0.005 and 0.05 mole/mole of monomer is added to the peroxide catalyst.
The peroxide catalyst is preferably added in batches at intervals. According to a preferred embodiment of the invention, the addition of the catalyst is effected by initially adding one third of the total amount thereof, the remainder being added in - 12 batches Preferred unstriated dicarboxylic esters are unstriated dicarboxylic acid ductile esters and unstriated dip carboxylic acid dihexyl-esters. The reaction temperature is preferably between 160 and 200~C.
In order to achieve a molar ratio of ~-olefin to unstriated dicarboxylic acid ester ox 0.5 : 4, the monomers are used in a molar ratio of 0.5 : 7.
The copolymers according to the invention are not used as lubricating oils merely because of their viscosity characteristics, the ability to emulsify, and their low pour point. They may also be used as additives to adjust the viscosity characteristics and reduce the pour point of mineral oils and lubricants. The cross-linked polymers are particularly suitable as additives. The cross-linking agents used may be all known bifunctional cross-linking agents, for example divinylbenzene and bus-acrylate, but preference is given to bis-maleates o-f dip alcohols, bis-maleicimides, Delilah ethers, Delilah esters Lo 8 and divinely esters. Mixtures of cross-linking agents may also be used. Suitably between 0.05 and 0.2 mole/mole of unstriated dicarboxylic acid ester is added to the polymerization batch.
Cross-linked copolymers according to the invention may be used directly as gear oils or to improve the viscosity characteristics of lubricants.
Cross-linked copolymers according to the invention fully meet the high demands made upon transformer oils, such as resistance to aging, stability, low pour point, no measurable release of gas, high dielectric strength, and low dielectric loss factor. Furthermore, the low toxicity, as compared with the chlorinated biphenyls normally used as transformer oils and mixed with trichlorobenzolene in order to reduce the viscosity, is a substantial advantage of the copolymers of the invention when used as transformer oils. They may, of course, be used quite generally as in-sulfating oils, copolymers with very low pour points and low viscosity being outstandingly suitable as switch oils.
As regards conventional measuring methods, reference is made to Ullmanns Encyclopedic don technician Chemise, Thea Edition, Volume 20, pages 607 et seq.
Another main use for the copolymers of the invent lion is as lubricants for forming thermoplastic synthetic materials.
The fluid condition at room temperature permits very satisfactory mixing with other aids to processing.
More particularly, it is possible to procure, with the copolymers according to the invention, stabilize lubricant mixtures for PVC processing, for which other lubricants cannot easily be used I

The copolymers of the invention are emulsifiable and provide stable emulsions. They may therefore be used, in admixture with waxes and with the copolymers of Federal Republic of Germany Offenlegungsschrift 27 27 239, in wax polishing preparations for example for shoe polishes, floor polishes, lubricants for metal processing, etc. In the form of aqueous emulsion they may also be used as coolants for machining and forming metal parts.
The invention is illustrated in greater detail and by reference to particular and preferred embodiments in the following examples.
Example 1.
1 Mole of malefic acid android, 3 moles of Allot*
C8 and 0.4 g of p-toluene-sulphonic acid are heated to the boiling point ox the mixture and the reaction water (about 1 mole) is drawn off. After about 4.5 hours, the acid number was still 0.44. The reaction mixture was cooled -to 100C, 1 ml of triethylamine was added, and stirring was carried out at this temperature for about 30 min. The excess Allot* and amine were distilled off by applying a vacuum, 1 Mole of C12 ~-olefin was added to the reaction product obtained. The mixture was heated to 160C and 10 batches of 0.005 moles of Detroit, bottle peroxide were added at intervals of about 30 minutes. 30 Minutes after the addition of the last batch of peroxide, vacuum is a plied and the unpolymerized olefin is distilled off. The last of the olefin was removed in a thin layer evaporator.
The olefin: ester ratio in the copolymer was determined from the oxygen content of the elemental analysis.
The viscosity was measured with an bullied *trade mark I

viscosimeter.
The molecular weight was determined with the aid of gel permeation chromatography.
DIP pry En 6 was used to determine the pour point.
Method B of IS standard 29 09 was used to determine the viscosity index The monomer ratio is to be understood to mean the molar ratio of the ~-olefin used to the unsaturated dicarboxylic acid ester used.
The polymer ratio indicates the ratio of ~-olefin to unsaturated dicarboxylic acid ester in the copolymer.
The copolymer obtained in this example had a pour point of -39~, a molecular weight of 2500, and a viscosity index of 168.
Exam 6 Moles of Colophon and 2 moles of dibutyl Malta were placed in a reaction vessel previously flushed with nitrogen, and were held under a nitrogen atmosphere.
The mixture was heated to 200C. The catalyst used was t bottle hydroperoxide, 0.03 of a mole being added initially, followed by 10 batches of 0.004 mole each. Upon completion of the polymerization, excess olefin and dibu-tyl Malta were distilled off in a vacuum at 0.01 mm Ho.
The results obtained with other olefins, and with a molar ratio of olefin: dibutyl Malta of 1 : 1, are given in the following Table.

I, o .,, o O I I
Q l l l l l l I
I

X
Us O I: I
U H ~11~d' LO Jo I
0 ~Ir-l.--1 I Irk I I
Jo Jo O O O O O O O O
U --l OWE O Owl ) a) n ED

One O I

o P:
Pi m En o 1_1 o .. .. .. .. .. .. .. ..
J

.,1 O O ED
o Us W
En I r l I

Example 3.
As in Example 1, malefic acid divesters were polymerized with Colophon and Colophon in 2 molar ratio of 1 1 and 1 : 3, under otherwise similar conditions.
The L exults appear in Table 2. By way of comparison, dim ethyl Malta was also copolymerized with Colophon in a ratio of 1 . 1 and 1 : 3 under -the same conditions. The results show that this produces polymers with a pour point distinct-lye above 0C. With a 1 : 1 ratio of Colophon, the pour point is -4C, but the viscosity index is 69.

I

O I 0 Us 1 Lo O I Al O 1 Q, C_) I fry I I if) N I if) if) f`J I
O I
I
Al X
rq I fly I I` O if) it) O fly If) d' N Us if) d' d' d' I if) fry O
I H

ray OWE
O to O n O us O O O us rho fly foe O O O
fly Al O (I I O d' 1` I fox of) foe I

3 I I l I l I

a) o rut Irk O f') ED Lo f') 0 0 co I 0 I in d' I I) I l I O cry ID if) It fox 1 I I
O I r-l ~10 0 0 0 Jo 1 0 0 0 0 0 0 I o O' if) I if) Jo l if) if) I
I
it I
fq En r-l I
H O
O
to r-l So a do I foe do ED 0 0 Jo fly r-l r r-I
O
I Jo I Al O fly I) r-l I O O O O O O O O
O Jo r l I r-l r I r-l r-l r-l Al r--1 r-¦ r-¦ r-¦ I r-l I

O H

H X
rq fly I I I fly to fly fly fly I I fly N fly En Example 4.
sing the procedure indicated in Example 1, octal fumarates and octal Maltese, furthermore Huxley fumarates and Huxley Maltese, were copolymerized with C10- and C12-~-olefins. The results are given in Table 3.

~V~3~ to O r; Lo I ) I I) 0 JO of) Al or) I Al d' I '`' o rl X

us a) I I errs r.
O i` d' ED I I) Lo Lo m .

I
I
o o o o o o o o I) L') O Lo O O Lrl O O
~l)-rl Al I I O O ED I Lo') I C) or r,~lr,~l I 1 r.
O I:

rod O I I I rho - O
00 I Dry) no I rod O O O O
O

rye O O
E rl o Jo Jo Jo I: pa o m En rod rod ED rod rod pa I Jo a rod rrJ a) rod E E ,1 I- Jo J
n I
O U C) O O O O O O O O

.,1 H to r:q O
E I o o N I O O (I
O Jo I I , I I I ,-1 I I
to O

m o r:q I rye I I I I
to ~C~3~

Example 5.
36 Moles of Cluck -olefin were mixed with 2-ethylhexyl Malta it a reactor, flushed with nitrogen and heated at 200~C. At 30 minute intervals, 11 batches, each containing 0.08 mole of di-t-butyl peroxide, were added. 30 Minutes after the last addition of peroxide, the volatile products were distilled off with increasing vacuum. Additional copolymers were produced by this method, as shown in Table 4.

Monomer Polymer Molecular Pour Test Jo Ester Ratio Reshoot Point C
-4A2-Ethylhexyl 1 0.6 1500 -39 Malta 4Bdito 3 1.4 1450 -30 4CDibutylmaleate 1 0.78 1600 -29 4D2-Ethylhexyl- 1 0.7 1700 -29 fumarate YE Dibutylfumarate 1 0.7 1700 -23 Example 6.
3 Moles of malefic acid android, 0.6 mole of hexane Doyle and 480 ml. of Tulane are boiled for half an hour under reflex. 9 Moles of buttonhole and 1.2 g. of Tulane sulphonic acid are then added and the reaction water is removed from the circuit. After water has ceased to separate, 3 ml of triethylamine are added for neutral-ration stirring is carried out for half an hour, and all I

volatile elements are distilled off in a water jet vacuum to a sup temperature of 160C. 3 Moles of Colophon are then added, the reaction vessel is flushed with nitrogen, is heated to 160C and 0.016 mole of dl-t-butyl peroxide, 10 batches in all, are added every 30 minutes. 30 Minutes after the last addition, all volatile elements are distilled off in the water jet vacuum. The resulting cross-linked polymer has the following properties:

VI (Viscosity Index) = 179 Pour point = -12C

Example 7.
2 Moles of dibutyl fumarate, 2 moles of C14-C16 -~-olefin (average MY of the mixture = 205) and 0.2 mole of divinylbenzene (50% in ethylvinylbenzene~are heated to 160C under nitrogen. 0.01 Mole of di-t-butyl peroxide is added every 30 minutes, 10 batches in all. 30 Minutes after the last addition, all volatile substances are distilled off in the water jet vacuum. The remaining cross linked polymer has the following properties:

VI = 211 Pour point = -2C

Example 8.
The suitability of the copolymers as lubricants was also demonstrated in a continuous rolling test. To this end, mixtures consisting of 100 parts by weight of a PVC suspension, 1 part by weight of ductile tin Boyce-ethylhexyl thioglycolate, 0.5 and 1 part by weight of the copolymer and of a commercial lubricant, were produced.
The test was carried out under the following conditions:

Roll temperature 1~30C
rum 20 Every 10 minutes samples were taken and the test was interrupted when the sample stuck to the roll or a brown discoloration was observed. The results appear in Table 5.

Furnace Test Transparency Time to Stick Sample At 180C (min.) And Discolor 4C 130 8280 (did not adhere) ED 130 75.6100 (did not adhere) YE 130 79.290 (did not adhere) I 110 65.090 (did not adhere) A sample produced according to the above mentioned formula was reduced to a sheet 0.4 mm in thickness by rolling at 170C. The sample was placed in a furnace having rotating compartments and held at 180C. Discoloration was monitored every 10 minutes and compared with a corresponding sample of commercial lubricant (ethyleneglycolester of montanic acid), until the final discoloration was reached (furnace test).
A sheet 0.4 mm in thickness was produced as de-scribed herein before, was cut, about 20 layers were placed one on top of the other and were pressed to a thickness of about 6 mm. Transparency was measured in a "Hunter lab D25"*
calorimeter.
Oven and transparency test values are also given in Table 5.
Example 9.
The transparency of some of the copolymers was measured with a commercial lubricant in use upon a plastic *Trade Mark cited suspension of PVC.
100 parts by weight of a suspension of PVC, 50 parts by weight of ductile phthalate, 1 part by weight of dibutyl tin dimonomethyl Malta, and 1 part by weight of a copolymer according -to the invention and of a commercial lubricant, were mixed and made into sample sheets about 6 mm. in thickness, as described in Example 7.
The following values were obtained:

Test Piece Transparency %

PA 67.7 4B 54.4 I 41.5 Where the product was used as a lubricant for forming synthetic materials, the following findings were obtained from Examples 8 and 9:
In the furnace test, all of the tested copolymers performed better than the commercial lubricants used by way of comparison.
In the continuous rolling tests, the tested copolymers performed as well as, or better than, the commercial lubricants used by way o-f comparison.
As regards transparency, all of the tested polymers are Ear better than the commercial lubricants used by way of comparison.
.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Copolymers consisting of ?-olefins with 10 - 16 C-atoms, pure or in admixture, and of ?-.beta.- unsaturated dicarboxylic acid esters, the alcohol components of which are straight-chained and/or branched monoalcohols with 3 - 10 carbon atoms, built-up, if necessary cross-linked and having a pourpoint of between -60° and 0°C, it being, in the case of non-cross-linked copolymers, -9°C and lower if the alcohols contain 4 and fewer carbon atoms, and -20°C and lower if the alcohols contain more than 4 C-atoms.

2. A copolymer according to claim 1 being a cross-linked copolymer.

3. A copolymer according to claim 1, wherein said ester is a diester.

4. A copolymer according to claim 1, wherein said ester is selected from the group consisting of maleic acid ester and fumaric acid esters.

5. A copolymer according to claim 3, wherein said diester is selected from the group consisting of maleic acid diesters and fumaric acid diesters.

6. A copolymer according to claims 1, 4 or 5, wherein the ?-olefin is unbranched.

7. A copolymer according to claims 1, 4 or 5, wherein the ?-olefin and ?-.beta.-unsaturated dicarboxylic-acid ester are present in a mole ratio of about 0.5 : 4.

8. A method for producing a copolymer of an ?-.beta.-unsaturated dicarboxylic acid ester and an ?-olefin comprising copolymerizing an ?-olefin having 10 - 16 C-atoms and an ?-.beta.-unsaturated dicarboxylic acid ester, the alcohol component of which is a straight chain or branched chain monoalcohol having 3 - 10 C-atoms, at a temperature of 140° to 210°C, in the presence of a peroxide catalyst, in an inert gas atmosphere.

9. A method according to claim 8 wherein said copolymerizing is carried out with the addition of a cross-linking agent.

10. A method according to claim 8, wherein said ester is an ?-.beta.-unsaturated dicarboxylic acid diester in monomer form.

11. A method according to claim 8 or 9, wherein said ester is selected from the group consisting of maleic acid esters and fumaric acid esters.

12. A method according to claim 10 wherein said ester is selected from the group consisting of maleic acid diesters and fumaric acid diesters.

13. A method according to claim 8, 9, or 10, wherein said ?-olefin is an unbranched ?-olefin.

14. A method according to claim 8 wherein said peroxide catalyst is present in an amount of 0.005 to 0.05 mole/mole of monomer.

15. A method according to claim 14 wherein the peroxide catalyst is added batchwise from time to time.

16. A method according to claim 15, wherein the copolymerization is initiated by the addition of one third of the total amount of the peroxide catalyst, the remainder of the said catalyst being added in 8 to 1.2 batches.

17. A method according to claim 8, wherein said ?-.beta.-unsaturated dicarboxylic-acid ester is selected from the group consisting of ?-.beta.-unsaturated dicarboxylic acid dioctyl esters and ?-.beta.-unsaturated dicarboxylic acid dihexyl esters.

18. A method according to claim 8 or 17, wherein said temperature is between 160 and 200°C.

l9. A method according to claim 8 or 17, wherein the ?-olefin and the ?-.beta.-unsaturated dicarboxylic acid ester is copolymerized in a mole ratio of 0.5 : 7.

20. A method according to claim 9, wherein said cross-linking agent is selected from the group consisting of bis-maleates of dialcohols, bis-maleicimides diallyl ethers, diallyl esters, divinyl esters and divinyl ethers.

21. A method of lubricating which comprises adding a lubricating oil to parts requiring lubrication, wherein said lubricating oil comprises a copolymer according to claims 1, 2 or 3.

22. A method of adjusting the viscosity characteristics and of reducing the pour point of mineral oil which comprises adding a copolymer as defined in claims 1, 2 or 3 to said mineral oil.

23. A method of adjusting the viscosity characteristics and of reducing the pour point of lubricants which comprises adding a copolymer as defined in claims 1, 2 or 3 to said lubricants.

24. A method of processing thermoplastic synthetic materials during forming which comprises adding a copolymer according to claims 1, 2 or 3, as a lubricant, to said thermoplastic materials.

25. The method of reducing toxicity and viscosity in transformer oils, which comprises adding a copolymer according to claims 1, 2 or 3 to a transformer.

26. A mineral oil composition including as an additive thereto, a copolymer as defined in claim 1, 2 or 3.

27. A lubricant composition including as an additive thereto, a copolymer as defined in claim 1, 2 or 3.

28. In a lubricating method employing a lubricating oil, the improvement wherein said lubricating oil is a copolymer as defined in claim 1, 2 or 3.

29. In a transformer including a transformer oil, the improvement wherein said transformer oil is a copolymer as defined in claim 1, 2 or 3.

30. In the processing of thermoplastic, synthetic material employing a lubricant during forming, the im-provement wherein said lubricant is a copolymer as defined in claim 1, 2 or 3.