RU2402571C1 - Method of producing polymethacrylate pour-point depressant and pour-point depressant obtained using said method - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention describes a method of producing a polymethacrylate pour-point depressant through polymerisation of C₁₂-C₁₈ alkylmethacrylates or their copolymerisation with methylmethacrylate in the presence of a diazo-initiator of radical polymerisation at 70-100°C, characterised by that the process of polymerisation or copolymerisation of C₁₂-C₁₈ alkylmethacrylates with methylmethacrylate in amount of up to 9 wt % of the amount of alkylmethacrylates takes place mineral or synthetic oil at excess pressure of 1-50 mm Hg, content of a monomer mixture which contains methylmethacrylate and alkylmethacrylates in amount of 40-90 wt %and initiator in amount of 0.5-2 wt % of the monomer mass, which are fed into the process at once or in parts before the induction period, defined by increase in temperature of the reaction mass and after its completion. The invention also describes a polymethacrylate pour-point depressant obtained using said method, addition to base oil I-20 and I-40 in amount of 0.16-0.24 wt % and 0.20-0.32 wt % of active substance, respectively, of which provides the following pour point: I-20 oil between -46 and -48°C, and I-40 oil between -40 and -43°C.

EFFECT: high quality and effectiveness of pour-point depressant.

3 cl, 3 tbl, 10 ex

Description

The invention relates to petroleum products, specifically to a method for producing additives designed to reduce the pour point of lubricating oils.

It is known that polymethacrylate depressants are widely used to lower the pour point of lubricating oils. They are obtained by solution polymerization of different fractions of alkyl methacrylates or mixtures thereof, or their copolymerization with other vinyl monomers in the presence of radical polymerization initiators.

Known depressant additive (EP 153209, 1985; CA, 1985, v.103, 197130) obtained by copolymerization of C ₁₂ -C ₂₀ alkyl methacrylates, C ₄ -C ₁₀ alkyl methacrylates and methyl methacrylate in the presence of benzoyl peroxide in oil. The concentration of monomers was 50 wt.%. When 2 wt.% Of such an additive was added to the oil, the pour point decreased from -12 ° C to -40 ° C.

In the patent (PL 124235, 1984; CA, 1985, v.102, 187864), an additive was obtained by copolymerization of C ₁₀ -C ₂₂ alkyl methacrylates with methyl methacrylate and styrene in the presence of azo-bis-isobutyronitrile in residual oil. Adding 10 wt.% Of this additive to the lubricating oil gave a lowering pour point from -16 ° C to -29 ° C.

A depressant additive is described (WO 8901507, 1989; CA, 1989, v. 111, 26162), obtained by the polymerization of alkyl methacrylates with an average number of atoms in the alcohol radical of 12.6 to 13.5. This depressant lowered the pour point of the oil to -35 ° C.

A known method of producing additives to oils by polymerization of more than three and less than five monomers, each monomer taken in an amount equal to or greater than 15%. Monomers are the products of the esterification of methacrylic acid with individual linear alcohols C ₈ -C ₂₀ , preferably C ₁₀ , C ₁₁ , C ₁₂ , C ₁₄ and C ₁₆ . The polymerization is carried out at a temperature of 85-95 ° C in the presence of an initiator - benzoyl peroxide in an organic solvent. The resulting polymer is characterized by a wide distribution of molecular weight, which increases its viscosity, therefore, polymer solutions in oil are used as additives. The additive allows to lower the pour point of the oil to minus 35 ° C (US patent 4956111, C10M 105/22, 1990).

The disadvantage of this method is that the resulting polymer can be used as an additive only in the form of its solution in oil, which reduces the effectiveness of the additive.

There is also known a method of producing additives to oils by radical polymerization of esters of acrylic or methacrylic acid and a mixture of synthetic alcohols of normal structure with the number of carbon atoms 7-20, containing 20-30% of alcohols of isostructure. The polymerization is carried out in the presence of an initiator - a solution of benzoyl peroxide in toluene at a temperature of 95-105 ° C and an excess of organic solvent taken in an amount of 120-350% by weight of the monomer. After polymerization, the polymer is mixed with low-viscosity sulfur dioxide in an amount providing a content of 30-70% of the polymer in the additive (ed. USSR USSR 378403, С10М 145/14, 1973).

In the manufacture of motor oils, in addition to depressant additives, various packages of other additives are used to give the oil the necessary consumer properties. In some brands of oils, the total content of additives reaches 20-25%. At the same time, all the additives that make up the oil should be well combined with each other and not exhibit antagonism during operation.

A common disadvantage of the known polymethacrylate depressant additives is their low effectiveness, which is manifested by high consumption during operation.

Closest to the claimed technical solution is a method of producing additives for lubricating oils by radical polymerization of methacrylic acid esters obtained by esterification of methacrylic acid with fractions of linear alcohols C ₈ -C ₁₂ and C ₁₆ -C ₂₀ , taken in a molar ratio of 1-3: 3-1 , with obtaining a polymer with kinematic viscosity at 50 ° C to 3500 cSt. Moreover, the polymerization is carried out at a temperature of 90-110 ° C in the presence of an initiator, molecular weight regulator and organic solvent, taken in an amount of 90-120% by weight of the monomer. One of the typical initiators of radical polymerization can be used as a polymerization initiator: benzoyl peroxide, dinitrile-azo-bis-butobutyric acid, cumene hydroperoxide, and lauryl mercaptan or tertodecyl mercaptan (RU 2203931, class С10М 145/14, published on May 10, 2003).

The technical result to which the invention is directed is to improve the quality and effectiveness of the resulting product - depressant additives.

To achieve the named technical result, a method for producing a polymethacrylate depressant additive by polymerizing alkyl methacrylates of the C ₁₂ -C ₁₈ fraction or copolymerizing them with methyl methacrylate in the presence of a diazo initiator of radical polymerization at a temperature of 70-100 ° C, characterized in that the polymerization or copolymerization of alkyl methacrylates of the C fraction ₁₂ - with methyl methacrylate in an amount of up to 9 wt.% Of the number of alkyl methacrylates is carried out in mineral or synthetic oil at a residual pressure and 1-50 mm Hg, the content of the monomer mixture, including methyl methacrylate and alkyl methacrylates, in an amount of 40-90 wt.% and initiator 0.5-2 wt.% of the monomer mass, which are introduced into the process immediately or in part to the induction the period determined by the temperature increase of the reaction mass, and after its end.

Distinctive features of the proposed method are the implementation of the polymerization process at a residual pressure of the order of 1-50 mm Hg. in mineral or synthetic oil, the content of the monomer mixture, including methyl methacrylate and alkyl methacrylates, is in the range of 40-90 wt.%, the initiator is 0.5-2.0 wt.% of the monomer mixture, when the monomer mixture and initiator are introduced into the process simultaneously or fractionally ( in parts) before and after the induction period.

The essence of the proposed in the present invention method for producing polymethacrylate depressant additives is illustrated by the following examples of its implementation.

Example 1

In a glass reactor equipped with a stirrer and a thermometer, I-20A oil is loaded in an amount of 127.5 g and 85 g of a monomer mixture consisting of C ₁₂ -C ₁₈ alkyl methacrylates (AMA), the contents of the reactor are heated to 70-80 ° C with stirring and vacuum at a residual pressure of not higher than 50 mm Hg within 3-5 minutes, after which a portion of the azo-bis-isobutyronitrile initiator is introduced into the reaction mixture in an amount of 0.17 g and stirred until the end of the induction period, usually 1-3 minutes. 10 minutes after the end of the induction period, which is determined by the release of heat into the reactor for one hour at 85-90 ° C and a pressure below 50 mm Hg the remainder of the initiator is introduced in an amount of 0.255 g. Then the reaction mass is kept for one hour at 85-90 ° C and for two hours at the same pressure and temperature of 90-95 ° C. Under these conditions, the conversion of monomers is at least 98%. After polymerization is complete, the reaction mass is cooled to 50 ° C and the dynamic viscosity of the obtained polymethacrylate additive is determined.

Example 2

In a glass reactor equipped with a stirrer and a thermometer, I-20A oil in the amount of 127.5 g and 45 g of the monomer mixture (AMA) of the C ₁₂ -C ₁₈ fraction is loaded, the contents of the reactor are heated with stirring to 85-90 ° C and vacuum under residual pressure not higher than 50 mm Hg for 3-5 minutes, after which a portion of the azo-bis-isobutyronitrile initiator is introduced into the reaction mixture in an amount of 1.15 g and stirred until the end of the induction period, usually 1-3 minutes. 10 minutes after the end of the induction period, which is determined by the release of heat into the reactor for one hour at 85-90 ° C and a pressure below 50 mm Hg enter the remaining parts of the initiator in an amount of 0.55 g and monomer in an amount of 40 g. Then the reaction mass is kept for one hour at 85-90 ° C and for two hours at the same pressure and temperature of 90-95 ° C. Under these conditions, the conversion of monomers is at least 98%. After polymerization is complete, the reaction mass is cooled to 50 ° C and the dynamic viscosity of the obtained polymethacrylate additive is determined.

Example 3

In a glass reactor equipped with a stirrer and a thermometer, I-20A oil in the amount of 105 g and a portion of the monomer mixture (AMA) of the C ₁₂ -C ₁₈ fraction in the amount of 45 g are loaded, the contents of the reactor are heated with stirring to 85-90 ° C and vacuum at residual pressure not higher than 50 mm Hg for 3-5 minutes, after which a part of the initiator, azo-bis-isobutyronitrile, in the amount of 1.05 g is introduced into the reaction mixture and is usually mixed for 1-3 minutes until the end of the induction period determined by the heat release. Then into the reactor for one hour at 85-90 ° C and a pressure below 50 mm Hg the remaining parts of the initiator are introduced in an amount of 1.05 g and monomer in an amount of 60 g, after which the reaction mass is maintained for one hour at 85-90 ° C and for two hours at the same pressure and temperature of 90-100 ° C. Under these conditions, the conversion of monomers is at least 98%. After polymerization is complete, the reaction mass is cooled to 50 ° C and the dynamic viscosity of the obtained polymethacrylate additive is determined.

The methods of examples 4-5, 7-10 are carried out similarly to those described above in examples 2 and 3 and differ in the number of monomer mixture, initiator and diluent oil introduced portionwise into the reaction mass.

The method of example 6 differs from other examples by the fractional introduction of methyl methacrylate comonomer (MMA) into the reaction mixture.

Table 1 shows the quantitative data of the portioned monomer mixture and initiator introduced into the reaction mass. In examples 2-8, the synthesis was carried out in the environment of the base oil I-20A, in examples 9-10 in the environment of a synthetic oil - polyalkylbenzene (TU 2414-040-04689375-95).

Testing the properties of samples of depressant additives obtained in accordance with the present invention (examples 1-7), were carried out on the base oils I-20 and I-40 produced by Novokuybyshevsky ZMP with pour points, respectively, -25 ° C and -14 ° C. The choice of these oils for testing is due to their use as the basis for most motor oils.

The test results are presented in table 2.

Tests were also conducted on a series of samples of the additive obtained by the proposed method (examples 8-10) in 10W40SF / CC motor oil in the presence of various additive packages. The bases I-20, I-40 and the residual component KS-19 were used as the base oil. For comparison, the same oil samples were prepared using an imported analogue, V-351 (SAP-110). In addition to low-temperature depression, important indicators such as starting properties and pumpability were determined. Starting properties were characterized by dynamic viscosity at -20 ° C and at a spindle speed of 105 s ^-1 , pumpability at -30 ° C and a speed of 10 s ^-1 . The results are presented in table 3.

As can be seen from the data in Table 3, the use of polymethacrylate depressant additives made according to the present invention allows to achieve better results compared to the imported analogue with smaller inputs of the active component of the depressor component. The depressant additives obtained according to the present invention provide greater depression and, accordingly, lower resistance when starting a cold engine and more favorable conditions for the flow of oil in the engine oil system.

table 2
Checking depressor samples in I-20 and I-40 base oils Example No. Enter depressor, wt.% Oil I-20 T.3. -25 ° C I-40 oil T.z -14 ° С Commodity form Active substance (AMA and MMA) T.z., ° C Depression, hail. T.z., ° C Depression, hail. one 0.1 0.04 -27 13 0.2 0.08 -33 19 0.3 0.12 -42 17 -39 25 0.4 0.16 -43 eighteen -41 27 0.5 0.20 -45 twenty -43 29th 2 0.1 0.04 -thirty 16 0.2 0.08 -32 eighteen 0.3 0.12 -44 19 -35 21 0.4 0.16 -46 21 -38 24 0.5 0.20 -47 22 -40 26 3 0.1 0.05 -29 fifteen 0.2 0.10 -39 fourteen -36 22 0.3 0.15 -43 eighteen -39 25 0.4 0.20 -45 twenty -42 28 0.5 0.25 -47 22 -42 28 four 0.1 0.06 -31 17 0.2 0.12 -40 fifteen -37 23 0.3 0.18 -43 eighteen -41 27 0.4 0.24 -48 23 -43 29th 0.5 0.30 -44 thirty 5 0.1 0,07 -thirty 16 0.2 0.14 -42 17 -32 eighteen 0.3 0.21 -45 twenty -38 24 0.4 0.28 -40 26 6 0.1 0,07 -42 17 -29 fifteen 0.2 0.14 -44 19 -32 eighteen 0.3 0.21 -37 23 0.4 0.28 -40 26 7 0.1 0.08 -40 fifteen -thirty 16 0.2 0.16 -42 17 -37 23 0.3 0.24 -43 eighteen -40 26 0.4 0.32 -43 29th

Table 3
Testing Depressor Samples in 10W40SF / CC Engine Oil 10W40SF / CC 10W40SF / CC 10W40SF / CC 10W40SF / CC 10W40SF / CC 10W40SF / CC 10W40SF / CC 10W40SF / CC 10W40SF / CC one 2 3 four 5 6 7 8 9 Viscosity at 100 ° 12.75 13.61 12,4 13.29 13.29 12.17 13.9 fifteen 12.78 I-20A,% 70 70 89 70 70 89 70 70 70 I-40A,% thirty thirty thirty thirty thirty thirty thirty KS-19,% eleven eleven K-61,% one 1.05 one one 1.05 1.05 1.05 SV-260 one Paratone 8900 1,1 V-351 (SAP-110),% 0.2 0.2 0.2 0.16 PMA according to example 9 0.16 PMA according to example 10 0.16 PMA according to example 8 0.18 0.18 0.18 PAO-4,% 6.5 8 6.5 6.5 6.5 6.5 6.5 6.5 6.5 OLOA-8805% 5.1 5.1 5.1 5.1 5.1 5.1 5.1 5.1 PMS-200A,% 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 0.003 PAP-4,% 0.2 K-483,% 5.5 T., ° C -45 -46 -45 -48 -46 -51 -52 -fifty -57 CCS, no more than 7000 cps at -20 ° C 5700 6070 5700 4450 4700 4800 6400 6800 6500 MVR, no more than 60,000 cps at -30 ° C 61912 52613 45170 47534 47544 18139 38561 23382 25367 KS-19 - residual component
PAO-4 - synthetic polyalphaolefin oil
OLOA-8805 - Western Additive Pack
K-483 - additive package NPP Quality SV-260, K-61, Paratone 8900 - thickeners
PMS-200A - polymethylsiloxane (antifoam)
SSC - starting properties
MVR - pumpability

Claims (3)

1. A method of producing a polymethacrylate depressant additive by polymerizing alkyl methacrylates of the C ₁₂ -C ₁₈ fraction or copolymerizing them with methyl methacrylate in the presence of a diazo initiator of radical polymerization at a temperature of 70-100 ° C, characterized in that the polymerization or copolymerization of alkyl methacrylates of the C ₁₂ -C ₁₈ fraction with methyl methacrylate in an amount of up to 9 wt.% of the number of alkyl methacrylates is carried out in mineral or synthetic oil at a residual pressure of 1-50 mm Hg, the content of the monomer mixture, including methylme acrylate and methacrylates, in an amount of 40-90 wt.% of initiator and 0.5-2 wt.% of the monomer mass which is introduced into the process immediately before or parts of the induction period is determined by raising the reaction mass temperature, and after its closure. 2. The method according to claim 1, characterized in that azo-bis-isobutyronitrile is used as a diazo initiator of radical polymerization. 3. Polymethacrylate depressant additive obtained according to claims 1 and 2, the introduction of which in the base oils I-20 and I-40 in an amount of 0.16-0.24 wt.% And 0.20-0.32 wt.%, Respectively on the active substance it provides a pour point: I-20 oil up to -46 ÷ -48 ° С, and I-40 oil up to -40 ÷ -43 ° С.