JPH08217862A - Oil-soluble polyester, process for producing the same, additive for lubricating oil, and lubricating oil composition - Google Patents

Abstract

(57) [Summary] [Structure] (A) C20 or higher dicarboxylic acid and C2
Mw obtained by polycondensing a dicarboxylic acid component consisting of a dicarboxylic acid of less than 0 and the (B) diol component is 1
An oil-soluble polyester having an acid value of 10,000 to 1,000,000, an acid value of 10 or less, and a hydroxyl value of 30 or less. Lubricating oil additives based on this polyester. A lubricating oil composition containing the oil-soluble polyester. The oil-soluble polyester is produced by first preparing an oligomer from a dicarboxylic acid having less than C20 and a glycol, and then polycondensing the oligomer, the dicarboxylic acid having C20 or more, and a diol. [Effect] The lubricating oil composition to which the oil-soluble polyester is added has improved viscosity index and shear stability, and exhibits good oxidative stability and low low-temperature viscosity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil-soluble polyester, a process for producing the same, a lubricating oil additive containing the polyester as a main component, and a lubricating oil composition containing the oil-soluble polyester. INDUSTRIAL APPLICABILITY The oil-soluble polyester of the present invention is useful as a viscosity index improver or a thickener added to a mineral oil-based lubricating oil and a synthetic lubricating oil, and its viscosity index improving effect is very large, and a lubricating oil composition to which it can be added Has a high viscosity index and is excellent in oxidative stability and shear stability.

[0002]

2. Description of the Related Art As a viscosity index improver or thickener for lubricating oil, polyalkyl methacrylate, polyisobutylene,
Ethylene-propylene copolymers, styrene-diene block copolymers and hydrides thereof are well known. These polymers usually have a weight average molecular weight of 50,
It is used as a chain polymer of 000 or more.

Among these polymers, polyalkylmethacrylates are excellent in viscosity index improvement and pour point depressing action (low temperature viscosity is low), but when a large shearing force is applied to a piston, a gear or a hydraulic pump. Has a drawback that the main chain is cleaved and the viscosity and the viscosity index are lowered. In addition, depending on the type of lubricating oil used, insoluble matter is generated during use, which is one of the drawbacks. Further, olefin-based viscosity index improvers such as polyisobutylene and ethylene-propylene copolymer are excellent in shear stability, but are inferior in viscosity index improvement and merely show viscosity increase.

Further, polyester-based viscosity index improvers are disclosed in JP-A-48-31186 and JP-A-52-1319.
82 and JP-A-53-102307. That is, JP-A-48-31186 discloses a viscosity index improver comprising a polyalkylene succinic acid or a low molecular weight complete ester of a polymerized fatty acid and a dihydric alcohol, which has an effect of improving the viscosity index. Not enough. Japanese Patent Laid-Open No. 52-131982 discloses that
Although a polyester obtained by terminating the end of a polyester composed of a polymerized fatty acid and a dihydric alcohol with an aliphatic alcohol or a carboxylic acid is disclosed, the effect of improving the viscosity index and the low temperature viscosity characteristic are insufficient. In addition, JP-A-53-1
No. 02307 discloses that (1) mineral oil, (2) ester of polyhydric alcohol having neopentyl structure and monocarboxylic acid, and (3) polyhydric alcohol having neopentyl structure, monocarboxylic acid and polycarboxylic acid at the same time. A lubricating oil composition comprising an ester obtained by polycondensation and having excellent thermal stability and excellent viscosity index and load bearing capacity is disclosed, but it is well known that the degree of polycondensation of an ester containing a monocarboxylic acid is low. Like (for example, Encyclopedia of Poly
mer Science and Technology, Vol. 11, Polyester)), the effect of improving the viscosity index is insufficient even if a large amount of this ester component is added.

Further, in Japanese Patent Laid-Open No. 1-311122,
A viscosity index improver comprising a polyester obtained by polycondensing a dimerized fatty acid and a glycol having no hydrogen at the β-position carbon atom of the hydroxyl group with a monoalcohol is described. This polyester viscosity index improver has a low degree of polycondensation and is insufficient in terms of the viscosity index improving effect and the thickening effect.

As described above, conventional polyester-based viscosity index improvers are generally excellent in shear stability, but none of them are sufficiently satisfactory in low-temperature viscosity characteristics and especially the effect of improving the viscosity index, and improvement is demanded.

[0007]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide an oil-soluble polyester having excellent oxidative stability and shear stability, and a viscosity index improving effect remarkably improved, and a lubricant containing the oil-soluble polyester as a main component. To provide an additive for oil and a lubricating oil composition comprising the oil-soluble polyester. Another object of the present invention is to provide an industrially advantageous method for producing an oil-soluble polyester useful as the above-mentioned additive for lubricating oil, particularly as a viscosity index improver for lubricating oil.

[0008]

The object of the present invention is to:
The weight average molecular weight (Mw) obtained by polycondensing (A) a dicarboxylic acid component having 20 or more carbon atoms and a dicarboxylic acid having less than 20 carbon atoms and (B) a diol component is 10,000 to 1 ,, 000,000, an acid value of 10 or less, and a hydroxyl value of 30 or less.

The oil-soluble polyester useful as the viscosity index improver is polycondensed with a carboxylic acid component containing a dicarboxylic acid having a carbon number of less than 20 as a main component and an alcohol component containing a diol as a main component to obtain a weight average. Molecular weight is 500 ~
A polyester oligomer of 10,000 is prepared, and then the polyester oligomer, a carboxylic acid component containing a dicarboxylic acid having 20 or more carbon atoms as a main component, and an alcohol component containing a diol as a main component are polycondensed. Manufactured by the method.

Dicarboxylic acid component (A) used in the present invention
As a dicarboxylic acid having 20 or more carbon atoms and 2 carbon atoms
Both dicarboxylic acids of less than 0 are used. 2 carbon atoms
Examples of the dicarboxylic acid having 0 or more include linear, branched, cyclic and aromatic dicarboxylic acids, which may be used alone or as a mixture. Among these, those containing at least 60% by weight of branched dicarboxylic acid are preferable, and the branched dicarboxylic acid is more preferably at least one selected from alkylene succinic acid and dimer acid of polymerized fatty acid. The most preferred branched dicarboxylic acid is the dimer acid of polymerized fatty acid.

The polymerized fatty acid is obtained by polymerizing a higher fatty acid, and usually has 8 to 24 carbon atoms, preferably 16 to 2 carbon atoms.
It is a general term for polymerized acids obtained by polymerizing a fatty acid having 0 saturated or at least one unsaturated bond or a fatty acid ester derivative thereof. Commercially available polymerized fatty acids are those obtained by polymerizing oleic acid, linoleic acid, ricinoleic acid, eleostearic acid, etc., containing dimer acid as the main component, and polymer acid and monomer acid of trimer acid or more as sub-components. Is what you are doing. The structure analysis method of the polymerized fatty acid is described in D. H. Reported by Macmahon et al. (J. Am. Oil. Chem. Soc., Vol. 51, 52.
2 (1974)). The polymerization product can be separated into polymerized fatty acids having different contents of each component by a distillation method or a solvent extraction method.

Further, by hydrogenating the unsaturated carbon-carbon bonds remaining in these polymerized fatty acids, hydrogenated polymerized fatty acids having good thermal oxidation stability can also be used. In the present invention, any of unpurified polymerized fatty acid, purified polymerized fatty acid or hydrogenated polymerized fatty acid can be used, and preferably purified polymerized fatty acid containing 60% by weight or more of a dimer component or its hydride is used. More preferably, a purified polymerized fatty acid or hydride thereof having a dimer acid content adjusted to 95% or more is used.

Polyalkylene succinic acid has the general formula (R in the formula is a polymer chain of lower alkylene). R is a polymer chain of lower alkylene, preferably the lower alkylene is at least one selected from ethylene, propylene, and butylene, and the degree of polymerization thereof is in the range of 10 to 300.

Examples of the dicarboxylic acid having less than 20 carbon atoms include linear, branched, cyclic and aromatic dicarboxylic acids, which may be used alone or as a mixture. Among these, those containing at least 60% by weight of linear and aromatic dicarboxylic acids are preferable. The carbon number is preferably 1 to 15, more preferably 4 to 10.
Range. If the carbon number is small, it generally tends to be difficult to polycondense.

Specific examples of the dicarboxylic acid having less than 20 carbon atoms include carboxylic acids which are insoluble or hardly soluble in mineral oils such as succinic acid, glutaric acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, terephthalic acid and phthalic acid. An acid is mentioned. The proportion of the dicarboxylic acid having less than 20 carbon atoms in the total carboxylic acid component is usually 1 to 50 mol%, preferably 5 to 30 mol%, more preferably 10 to 20 mol%. If the proportion of the dicarboxylic acid having less than 20 carbon atoms is too small, the effect of improving the viscosity index will be poor, and if it is too large, the solubility in oil will be small.

Examples of the diol component (B) include alkane diol, polyoxyalkylene glycol and polyester diol. As the alkane diol, one having 2 to 50 carbon atoms is usually used,
Specific examples include ethylene glycol, propylene glycol, 1,2-butanediol, and dimer diol. As the polyoxyalkylene glycol, diethylene glycol, dipropylene glycol,
Examples thereof include those having an alkylene group having 2 to 5 carbon atoms such as polyethylene glycol including oligooxyalkylene glycol such as triethylene glycol, polypropylene glycol, polyoxyethylene-polypropylene glycol and the like.

Among the diol components (B) used in the present invention, particularly preferable ones are hindered glycols represented by the following general formula HO—CH ₂ —CR ¹ R ² —CH ₂ —OH where hydrogen is not present at the β-position. Of at least 60 mol%. In the above formula,
R ¹ and R ² are alkyl groups which may be branched, and the carbon number of each of R ¹ and R ² is preferably 1 to 15, more preferably 2 to 10. If the carbon numbers of R ¹ and R ² are excessively large, the reactivity with the carboxylic acid component is poor. By using the hindered glycol, a polyester having particularly high oxidative stability and excellent solubility in a base oil can be obtained.

Specific examples of the alkyl group that may be branched include methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl,
tert-butyl, n-pentyl, n-hexyl, n-
Examples include octyl and 2,2-dimethylhexyl,
Preferably, ethyl, n-propyl, n-butyl, te
Examples include methine proton-free n- or t-alkyl groups such as rt-butyl, n-hexyl, and 2,2-dimethylhexyl, and more preferably ethyl, n-propyl, n-butyl, n-hexyl and the like. And n-alkyl group.

A hindered glycol having no hydrogen at the β-position represented by the above general formula is disclosed in JP-A-3-16145.
In JP-A-2, a method similar to the glycol synthesis method, that is, a synthesis method in which an aldol condensation mechanism and a cannizzaro reaction mechanism are combined, for example, dimethylolheptane is synthesized from n-butyraldehyde, caustic soda and formalin. Specific examples of such glycol include 2-butyl-2-ethyl-1,3-propanediol, 2-pentyl-2-propyl-1,3-propanediol, 2-propyl-2-ethyl-1, Examples thereof include 3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-methyl-1,3-propanediol and 2,3-dimethyl-1,3-propanediol.

The ratio OH / COOH (equivalent ratio) of the carboxylic acid component and the alcohol component is preferably in the range of 0.8 to 1.3, more preferably 1.1 to 0.9,
Most preferably, it is substantially 1.0.

In the present invention, in addition to the dicarboxylic acid component (A) and the diol component (B), at least one trivalent or higher valent component (trivalent or higher carboxylic acid and trivalent or higher valent alcohol) is selected. A small amount of C) can be used.

The viscosity index improving effect is generally found to have a positive correlation with the weight molecular weight of the added polymer. Even with a polyester-based viscosity index improver, the higher the molecular weight, the higher the viscosity index. Therefore, in the polymerization of the dicarboxylic acid component such as polymerized fatty acid or polyalkylene succinic acid and the diol component, it is essential to achieve a high molecular weight. The molecular weight of polyester depends on the OH / COOH ratio. That is, an infinite molecular weight is obtained when the OH / COOH ratio (molar ratio) is 1.0, but in reality, the reaction rate becomes slower as the condensation reaction progresses, and a long reaction time is required, which is economical. Is disadvantageous to In the polycondensation reaction of a dicarboxylic acid component such as dimer acid and a diol component, the present inventors used a small amount of a trivalent or higher alcohol in the diol component or added a small amount of a trivalent or higher carboxylic acid to the dicarboxylic acid component. It has been found that the addition of the can effectively increase the molecular weight.

Specific examples of trivalent or higher carboxylic acids include:
Trimellitic acid, tricarballylic acid (1,2,3-propanetricarboxylic acid), camphoronic acid (2,3-dimethylmethane-1,2,3-tricarboxylic acid), trimesic acid, (1,3,5-benzene) (Tricarboxylic acid), trimer acid of polymerized fatty acid, and the like, preferably trimesic acid, trimer acid, and the like, and more preferably trimer acid.

Specific examples of the carboxylic acid component containing a trivalent or higher carboxylic acid for the purpose of obtaining a high molecular weight polyester include polymerized fatty acid containing 95% or more dimer acid component or its hydride and 15% or more. The polymerized fatty acid containing the trimer acid component or the hydride thereof is used, and the mixing ratio (molar ratio) of the dimer acid and the trimer acid is in the range of 1000/1 to 1000/150. The trihydric or higher alcohol is not particularly limited as long as it has three or more hydroxyl groups, but a trihydric alcohol is usually used. Examples of trihydric or higher alcohols include trimethylolethane, trimethylolpropane, trimethylolbutane, glycerol, pentaerythritol, dipentaerythritol, sorbitol, glucose, mannitol, sucrose, glucose and the like, and preferably trimethylol. Examples thereof include ethane, trimethylolpropane, glycerol, pentaerythritol, dipentaerythritol and sorbitol.

The proportion of trivalent or higher carboxylic acid in the total amount of carboxylic acid components is 15 mol% or less, preferably 0.1 to 1.
The amount of trihydric or higher alcohol in the total amount of alcohol components is 50 mol% or less, and preferably 0.1 to 20 mol%. If the amount of the trivalent or higher carboxylic acid and / or the trivalent or higher valent alcohol used is too large, it becomes difficult to control the condensation reaction.

The dicarboxylic acid component (A) is included in the carboxylic acid component as long as the object of the present invention is not impaired.
In addition to trivalent or higher carboxylic acids, monovalent carboxylic acids, for example, 2-methylpropanoic acid, isooctylic acid, isononanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, arachidic acid, etc. Saturated fatty acids, or unsaturated fatty acids such as linoleic acid, oleic acid, and elaidic acid may be used in combination. Generally, the permissible amount is usually 10 mol% with respect to all carboxylic acid components.
It is the following.

The carboxylic acid component is preferably 50
The following iodine number is more preferable and 20 or less is preferable. When the iodine content is low, the oxidative stability of the polyester produced is improved. Therefore, in the present invention, it is preferable to use a hydride of polymerized fatty acid containing dimer acid and a hydride of polymerized aliphatic acid containing trimer acid. The hydrogenation reaction of the polymerized fatty acid can be achieved by a known method described in the literature. One example is D.I. H. McCahon et al. (J. Am. Oil. Chem. Soc., Vol. 51, P522, 197).
Four).

In addition to the glycol component and the trihydric alcohol, a monohydric alcohol may be used in combination as long as the object of the present invention is not impaired. Examples of monohydric alcohols used in combination include neopentyl alcohol and 3-methyl-
3-pentanol, 3-ethyl-3-pentanol,
2,3,3-trimethyl-2-butanol, 1-decanol, nonyl alcohol and the like can be mentioned. Generally, the allowable amount of monohydric alcohol is usually 10 with respect to all alcohol components.
It is not more than mol%.

In producing the oil-soluble polyester of the present invention, first, a carboxylic acid component containing a dicarboxylic acid having a carbon number of less than 20 as a main component and an alcohol component containing a diol as a main component are polycondensed to obtain an average weight. Molecular weight is 500 ~
A method of preparing 10,000 polyester oligomers, and then polycondensing this polyester oligomer, a carboxylic acid component having a dicarboxylic acid having 20 or more carbon atoms as a main component, and an alcohol component having a diol as a main component are adopted. .

In the oil-soluble polyester of the present invention,
The introduction of the aggregating group into the polymer can improve the shear stability as well as the viscosity index. Here, the aggregating group is a dicarboxylic acid which is insoluble or hardly soluble in oil and has a relatively small number of carbon atoms. According to a usual method, when both a dicarboxylic acid having a relatively small number of carbon atoms and an oil-soluble dicarboxylic acid having a relatively large number of carbon atoms are polycondensed with a diol component,
A dicarboxylic acid having a relatively small number of carbon atoms tends to remain as an unreacted product without being incorporated into the polyester.

In contrast to such a method, as described above, an oligopolyester is first synthesized by polycondensing a dicarboxylic acid, which is insoluble or hardly soluble in oil and has a relatively small number of carbon atoms, and a diol. When a high molecular weight polyester is synthesized by condensing an oligopolyester, an oil-soluble dicarboxylic acid having a relatively large number of carbon atoms and a diol, an oil-insoluble or sparingly soluble dicarboxylic acid component is efficiently introduced into the polyester, and the viscosity index improving effect is obtained. And an oil-soluble polyester having a low viscosity and a low viscosity at a low temperature is obtained.

In the above-mentioned production method, the ratio of the dicarboxylic acid and the diol used in the step of preparing the polyester oligomer and the step of producing the highly polymerized polyester is OH / CO as described above in each step.
It is preferable that the OH equivalent ratio is in the range of 0.8 to 1.3, particularly 1.1 to 0.9. The weight ratio of the polyester oligomer to the dicarboxylic acid having 20 or more carbon atoms and the diol in the production process of the highly polymerized polyester is preferably in the range of 3:97 to 40:60.

The polycondensation reaction of the above-mentioned (A) dicarboxylic acid component, (B) diol component, and other optional components such as monovalent or polyvalent carboxylic acid and monovalent or polyhydric alcohol component is carried out under the conditions under consideration. Can be done. The polycondensation is usually preferably carried out at a reaction temperature of 150 to 280 ° C. in the presence of an inert gas. Toluene, if necessary
A water-insoluble organic solvent that is azeotropic with water such as xylene may be used, or the reaction may be performed under reduced pressure. In the esterification polycondensation reaction, usually, as an esterification catalyst, paratoluenesulfonic acid, sulfuric acid, boron trifluoride complex, phosphoric acid, hydrochloric acid, potassium acetate, zinc stearate, zinc, titanium, tin, butyltin oxide. Although various metal oxides such as titanium oxide are used, it is preferable to use the metal oxide from the viewpoint of the oxidation resistance stability of the obtained polyester.

The weight average molecular weight of the polyester produced is in the range of 10,000 to 1,000,000, preferably 15,000 to 800,000, and more preferably 20,000 to 400,000. is there. If the weight average molecular weight is too small, the effect of improving the viscosity index is low, and if the weight average molecular weight is too large, the shear stability becomes poor and it becomes difficult to dissolve in mineral oil or other lubricating oil.

The polyester of the present invention can be used in combination with polyesters of various molecular weights, and the polyester to be combined is not only the polyester of the present invention but also obtained by polycondensing a general dicarboxylic acid and a dihydric alcohol. Polyester can also be used. The molecular weight of the polyester to be combined may be appropriately selected depending on the purpose of use and the type of polyester used. For example, a weight average molecular weight of 10,000
~ 50,000 polyester and weight average molecular weight 5
A polyester composition having a balance between the effect of improving the viscosity index and the shear stability is obtained by combining the polyester composition with 10,000 to 1,000,000 polyester.

The acid value of the polyester of the present invention is 10 or less,
It is preferably 5 or less, more preferably 3 or less. If the acid value is too large, corrosivity becomes a problem. Further, the hydroxyl value of the polyester of the present invention is 30 or less, preferably 1
It is 0 or less. If the hydroxyl value is too large, there is a problem in solubility in lubricating oil. Further, the iodine value of the polyester of the present invention is preferably 100 or less in view of oxidation stability. The iodine value is more preferably 20 or less, still more preferably 10 or less.

When the oil-soluble polyester of the present invention is used as an additive for lubricating oil such as a viscosity index improver or a thickener, it can be used as it is, but it is necessary in order to enhance the ease of handling. It may be used in a form diluted with a diluting oil. The diluent oil used at this time is optional, but usually has a boiling point of 70 to 700 ° C., preferably 120.
The mineral oil and synthetic oil generally used as a solvent or lubricating oil in the boiling range of -650 degreeC, more preferably 150-600 degreeC can be used.

As the above-mentioned mineral oil, for example, a solvent fraction obtained by distilling crude oil under atmospheric pressure or under reduced pressure is refined by appropriately combining refining treatments such as hydrorefining, sulfuric acid washing, and clay treatment. Solvent fractions such as naphthene type and aromatic type and lubricating oil fractions can be used. Specifically, for example, aromatic hydrocarbons such as benzene, toluene, xylene; petroleum-based solvents such as petroleum benzine, rubber volatile oil, soybean volatile oil, ligroin, mineral spirits, cleaning solvent, stodder solvent; petroleum fraction of mineral oil , Kerosene fraction, light oil fraction, lubricating oil fraction and the like.

On the other hand, as the synthetic oil, specifically, for example,
Poly-α-olefins, which are low molecular weight oligomers obtained by polymerizing olefins such as ethylene, propylene, butene, isobutylene, 1-octene, and 1-decene, alone or by polymerizing a mixture thereof; included in poly-α-olefins So-called synthetic isoparaffins and hydrogenated poly-α-olefins produced by hydrogenating double bonds; hard type alkylbenzenes obtained by alkylating benzene with propylene oligomers, and dehydrogenation of normal paraffins separated from kerosene. Soft benzene produced by alkylating benzene with normal olefin obtained by chlorination or chlorinated paraffin obtained by chlorination of normal paraffin; obtained by alkylating naphthalene with olefin or chlorinated paraffin Alkylnaphthalene; diesters such as ditridecyl glutarate, di-2-ethylhexyl adipate, diisodecyl adipate, ditridecyl adipate, di-2-ethylhexyl sebacate; polyesters such as trimellitic acid ester; trimethylolpropane caprylate, trimethylol Examples include polyol esters such as propane pelargonate, pentaerythritol-2-ethylhexanoate, and pentaerythritol pelargonate; polyoxyalkylene glycols; dialkyldiphenyl ethers; polyphenyl ethers.

These mineral oils and synthetic oils may be used alone or in combination of two or more kinds. Further, since the oil-soluble polyester is used as an additive for lubricating oil, the compounding ratio of the oil-soluble polyester and the diluent oil when diluted with the diluent oil is arbitrary, but usually the diluent oil is added to 100 parts by weight of the oil-soluble polyester. It is desirable to add 10 to 500 parts by weight.

Further, in the present invention, as described above,
By blending the oil-soluble polyester of the present invention as it is or in a form of being diluted with a diluting oil, if necessary, with a lubricating base oil, a lubrication having excellent viscosity-temperature characteristics (viscosity index, low temperature characteristics) and shear stability An oil composition is obtained. The lubricating base oil as used herein is not particularly limited, and is a mineral oil-based if it is usually used as a base oil for lubricating oil,
It can be used regardless of the synthetic system.

As the mineral oil-based lubricating base oil, for example, a lubricating oil fraction obtained by distilling crude oil under atmospheric pressure and vacuum distillation is used.
Oils such as paraffin-based and naphthene-based oils that have been refined by appropriately combining refining treatments such as solvent deasphalting, solvent extraction, hydrocracking, solvent dewaxing, catalytic dewaxing, hydrorefining, sulfuric acid washing, and whitening can be used .

Examples of synthetic lubricating base oils include ethylene, propylene, butene, isobutylene, 1
-Poly-α-olefins, which are low molecular weight oligomers obtained by polymerizing olefins such as octene and 1-decene alone, or a mixture thereof; produced by hydrogenating double bonds contained in poly-α-olefins Hydrogenated poly-α-olefins; hard-type alkylbenzenes obtained by alkylating benzene with propylene oligomers, normal olefins obtained by dehydrogenating normal paraffins separated from kerosene, or chlorinated normal paraffins Soft-type alkylbenzene produced by alkylating benzene with the obtained paraffin; alkylnaphthalene obtained by alkylating naphthalene with olefin or chlorinated paraffin; ditridecyl glutarate, di-2-ethylhexyl adipate Diesters such as diisodecyl adipate, ditridecyl adipate and di-2-ethylhexyl sebacate; polyesters such as trimellitic acid ester; trimethylolpropane caprylate, trimethylolpropane pelargonate, pentaerythritol-2-ethylhexanoate, penta Polyesters such as erythritol pelargonate; polyoxyalkylene glycols; dialkyldiphenyl ethers; polyphenyl ethers;

These base oils may be used alone or in combination of two or more kinds at any ratio. The viscosity of the lubricating base oil used in the present invention is optional,
Kinematic viscosity at 100 ° C. is 1 to 100 mm ² / s, preferably ² to 50 mm ² / s, more preferably ^{2 to 20} m.
Those of m ² / s are preferably used. In addition, it goes without saying that these lubricating base oils can also be used as diluent oils when the oil-soluble polyester of the present invention is used as an additive for lubricating oil.

The amount of the oil-soluble polyester of the present invention to be blended with the lubricating base oil is arbitrary, but the content is usually 0.1 to 40% by weight, preferably the total amount of the lubricating oil composition. Is 0.3 to 30% by weight, more preferably 0.5 to 2
It is desirable to incorporate the oil-soluble polyester in an amount of 0% by weight. In the present invention, by adding the oil-soluble polyester according to the present invention to the lubricating base oil, the viscosity-
It is possible to obtain a lubricating oil composition having excellent temperature characteristics (viscosity index, low temperature characteristics) and shear stability, but for the purpose of further enhancing various performances, known lubricating oil additives are used alone or in combination of several kinds. It can be used in different forms.

Specific examples of these known additives include 2,6-di-tert-butyl-ρ-cresol and 4,4'-methylenebis-2,6-di-tert-.
Antioxidants such as hindered phenol-based compounds such as butylphenol, amine-based compounds such as alkyldiphenylamine and α-phenylnaphthylamine, sulfur-based compounds, zinc dithiophosphate-based compounds, zinc dithiocarbamate-based compounds and phenothiazine-based compounds; alkenyl succinic acid, alkenyl succinic acid esters, Rust inhibitors such as polyhydric alcohol esters, alkaline earth metal petroleum sulfonates, alkaline earth metal alkylbenzene sulfonates, alkaline earth metal dinonylnaphthalene sulfonates; metal deactivators such as benzotriazole and thiadiazole; phosphoric acid Anti-wear agents such as esters, phosphites, sulfurized fats and oils, sulfides, sulfurized phosphopolybutenes, sulfurized phosphoesters, zinc dithiophosphates, extreme pressure agents; aliphatic alcohols, fatty acids, aliphatic amines, aliphatic amines Salts, fatty acid amides, molybdenum dithiophosphate, wear reduction agents, such as molybdenum dithiocarbamate; alkaline earth metal sulfonate, alkaline earth metal phenates, alkaline earth metal salicylate,
Metal-based detergents such as alkaline earth metal phosphonates;
Ashless dispersants such as alkenyl succinimide, alkenyl succinic acid ester, benzylamine, polybutenylamine and amidated products thereof; non-dispersed polymethacrylate, dispersed polymethacrylate, polyisobutylene, ethylene-propylene copolymer, hydrogenated styrene -Butadiene copolymer, hydrogenated styrene-isoprene copolymer,
Viscosity index improvers such as styrene-based polyesters, ethylene-vinyl acetate copolymers, esterified styrene-maleic anhydride copolymers, pour point depressants; methyl silicone,
Defoaming agents such as fluorosilicone and polyacrylate;
And the like.

The amount of these additives added is arbitrary,
Usually, the content of the antifoaming agent is 0.
0005 to 1% by weight, the content of the viscosity index improver is 1 to 3
0% by weight, the content of metal deactivator is 0.005 to 1% by weight, and the content of other additives is 0.1 to 1%, respectively.
It is 5% by weight. Also, in particular, the weight average molecular weight of 10,000
0-50,000, preferably 15,000-40,0
No. 00 dispersed or non-dispersed polymethacrylate of 3 to 45 per 100 parts by weight of the oil-soluble polyester of the present invention.
When used in a ratio of parts by weight, it is effective for reducing the pour point of the lubricating oil composition.

The lubricating oil composition of the present invention containing an additive for lubricating oil containing an oil-soluble polyester as a main component is an engine oil for internal combustion engines such as gasoline engine oil, diesel engine oil and gas engine oil; It is suitable for use as a lubricating oil that requires a high viscosity index, such as gear oils for vehicles such as transmission fluids, manual transmission fluids, and differential oils; hydraulic fluids for automobiles such as shock absorber oils and active suspension oils. , Other, 2-cycle engine oil, ship engine oil, turbine oil; industrial gear oil; compressor oil; refrigerating machine oil; cutting oil, plastic working oil (rolling oil, press oil, forging oil, kneading oil, drawing oil, punching oil Oils, etc.), metal processing oils such as heat treatment oils, electric discharge machining oils; sliding guide surface oils; bearing oils; rust preventive oils; heat carrier oils and other various lubricating oils It is, but preferably used.

[0049]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The parts and% in the examples are based on weight unless otherwise specified. The hydroxyl value, acid value and iodine value of the polyester were measured according to the followings described in “Standard oil and fat analysis test method” (Japan Oil Chemistry Association). Hydroxyl value 2, 4, 9, 2-83 Acid value 2, 4, 1-83 Iodine value 2, 4, 5-71

Example 1 (Preparation of oligoester A) 205.5 g of terephthalic acid (acid value 676) was placed in a 1000 cc four-necked flask equipped with a stirrer, a thermometer, a reflux cooling tube, a water dividing tube and a nitrogen gas introducing tube. , Hydrogenated polymerized fatty acid (Halidimer 300 hydride, iodine value 6, acid value 1
95, monomer acid 0.5%, dimer acid 97.0%, trimer acid 2.5%, manufactured by Harima Kasei Co., Ltd.) 178.1 g, 2
-Butyl-2-ethyl-1,3-propanediol 37
2.1 g. Was charged. The mixture was stirred while introducing nitrogen gas, and the temperature was raised to 100 ° C. Then, the temperature was raised from 100 ° C. to 260 ° C. over 6 hours while removing water generated during the reaction. Then, the reaction was continued for 10 hours while performing dehydration at 260 ° C. Thus an acid value of 0.2,
An oligoester A containing terephthalic acid as a main component and having a hydroxyl value of 105 was obtained.

Example 2 (Preparation of oligoester B) 207.6 g of adipic acid (acid value 768) was placed in a 1000 cc four-necked flask equipped with a stirrer, thermometer, reflux condenser, water diversion tube and nitrogen gas inlet tube. , 204.3 g of hydrogenated polymerized fatty acid (same as used in Example 1), and 2,2-diethyl-1,3-propanediol 35
2.0 g was charged. The mixture was stirred while introducing nitrogen gas, and the temperature was raised to 100 ° C. Then, the temperature was raised from 100 ° C. to 260 ° C. over 6 hours while removing water generated during the reaction. Then, the reaction was continued for 10 hours while performing dehydration at 260 ° C. Thus, an oligoester B containing adipic acid as a main component and having an acid value of 0.2 and a hydroxyl value of 122 was obtained.

Example 3 (Production of Polyester 1) In a 1000 cc four-necked flask equipped with a stirrer, thermometer, reflux condenser, water diversion tube and nitrogen gas inlet tube, 67.1 g of oligoester A, hydrogenated polymerized fatty acid ( The same as used in Example 1) 361.5 g, 2-butyl-2-
91.9 g of ethyl-1,3-propanediol, 2.1 g of trimethylolpropane and 0.26 g of monobutyltin oxide as a catalyst were charged. (OH / COO
H (equivalent ratio) = 1.05) The temperature was raised to 100 ° C. while stirring while introducing nitrogen gas. Then, while removing the water generated during the reaction,
The temperature was raised from 100 ° C to 240 ° C over 6 hours. Then, the reaction was continued for 10 hours while dehydrating at 240 ° C. The obtained polyester 1 has a weight average molecular weight of 68,
000, an acid value of 0.2, and a hydroxyl value of 3.0.

Example 4 62.9 g of oligoester B and hydrogenated polymerized fatty acid (used in Example 1) were placed in a 1000 cc four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water dividing tube and a nitrogen gas introducing tube. Same as the one) 313.6 g (Haridimer 27
0S hydride, iodine value 7.5, acid value 193, monomer acid 0.5%, dimer acid 80.5%, trimer acid 1
96.6%, manufactured by Harima Kasei Co., Ltd., 76.6 g, 2,2-dimethyl-1,3-propanediol 67.6 g, and monobutyltin oxide 0.26 g as a catalyst were charged.
(OH / COOH (equivalent ratio) = 1.05) The temperature was raised to 100 ° C. with stirring while introducing nitrogen gas. Then, while removing the water generated during the reaction,
The temperature was raised from 100 ° C to 240 ° C over 6 hours. Then, the reaction was continued for 10 hours while dehydrating at 240 ° C. The resulting polyester 2 has a weight average molecular weight of 74,
It was a viscous material having an acid value of 000, an acid value of 0.3 and a hydroxyl value of 2.4.

Comparative Example 1 (Production of Polyester 3) Hydrogenated polymerized fatty acid (used in Example 1) was placed in a 1000 cc four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water diversion tube and a nitrogen gas inlet tube. Same as the one). 42
5.8 g, 2,2'-diethyl-1,3-propanediol 98.8 g and trimethylolpropane 2.0 g
Then, 0.26 g of monobutyltin oxide was charged as a catalyst. (OH / COOH (equivalent ratio) = 1.04) With stirring while introducing nitrogen gas, the temperature was raised to 100 ° C. Then, while removing the water generated during the reaction,
The temperature was raised from 100 ° C to 240 ° C over 6 hours. Then, the reaction was continued for 10 hours while dehydrating at 240 ° C. The obtained polyester 3 has a weight average molecular weight of 73,
It was a viscous material having 000, an acid value of 0.2 and a hydroxyl value of 2.8.

Example 5 (Additive for Lubricating Oil) The polyesters synthesized in Examples 3 and 4 and Comparative Example 1 were blended in the proportions shown in Table 1 to prepare Additives I to III for lubricating oil.

[0056]

[Table 1] * Neutral 100: Refined paraffin mineral oil (kinematic viscosity 4.1 mm ² / s, 100 ° C)

Paraffinic refined mineral oil obtained by hydrorefining the additives I to III for lubricating oil (kinematic viscosity 4.1 mm ² / s,
100 ° C; viscosity index 101) and kinematic viscosity at 100 ° C of 10c
It was added so as to have St. The viscosity index (VI) of the obtained lubricating oil composition was evaluated according to JIS-K2283, and the shear stability was evaluated from the viscosity loss rate by ultrasonic wave (calculated by the formula below) according to JPS-5S-29-88. did. V _o : Kinematic viscosity before ultrasonic irradiation (cSt) V _f : Kinematic viscosity after ultrasonic irradiation (cSt) The above results are shown in Table 2.

[0058]

[Table 2] It can be seen from Table 2 that the oil-soluble polyester of the present invention is an additive for lubricating oil having excellent oxidation stability and excellent performance as a viscosity index improver. In the polyester (Comparative Example 1) prepared by using only dicarboxylic acid having 20 or more carbon atoms without using dicarboxylic acid having less than 20 carbon atoms as the dicarboxylic acid component, the viscosity index, the shear stability and the low temperature viscosity characteristics are all the products of the present invention. Is inferior to.

[0059]

INDUSTRIAL APPLICABILITY The oil-soluble polyester of the present invention shows good compatibility with lubricating oils, shows a remarkable effect of improving the viscosity index and shear stability with a small amount of addition, and has excellent oxidation stability and Gives low low temperature viscosity.

[0060]

DETAILED DESCRIPTION OF THE INVENTION

(I) Oil-soluble polyester of the present invention, that is, (A)
Weight average molecular weight (M) obtained by polycondensing a dicarboxylic acid component composed of a dicarboxylic acid having 20 or more carbon atoms and a dicarboxylic acid having less than 20 carbon atoms and a (B) diol component.
w) 10,000 to 1,000,000, acid value 10
Hereinafter, an oil-soluble polyester having a hydroxyl value of 30 or less; (ii) an additive for lubricating oil of the present invention containing this oil-soluble polyester as a main component; (iii) a lubricating oil composition of the present invention containing this oil-soluble polyester And (iv) a method for producing an oil-soluble polyester of the present invention, that is, a carboxylic acid component containing a dicarboxylic acid having a carbon number of less than 20 as a main component and an alcohol component containing a diol as a main component are polycondensed and weighed. Average molecular weight is 500-10,000
A highly polymerized oil characterized in that the polyester oligomer of (1) is prepared, and then the polyester oligomer, a carboxylic acid component containing a dicarboxylic acid having 20 or more carbon atoms as a main component, and an alcohol component containing a diol as a main component are polycondensed. The preferred embodiments of the method for producing the soluble polyester are summarized as follows.

(1) The dicarboxylic acid having 20 or more carbon atoms contains at least 60% by weight of a branched dicarboxylic acid having 20 or more carbon atoms. (2) The branched dicarboxylic acid of (1) above is at least one selected from alkylene succinic acid and dimer acid of polymerized fatty acid. (3) A refined polymerized fatty acid containing a dimer acid component having 60% by weight or more of a dicarboxylic acid having 20 or more carbon atoms or a hydride thereof.

(4) The dicarboxylic acid component (A) having less than 20 carbon atoms contains at least 60% by weight of a linear and / or aromatic dicarboxylic acid. (5) Dicarboxylic acid having less than 20 carbon atoms has 1 to 1 carbon atoms
5, more preferably those having 4 to 10 carbon atoms.

(6) The diol component (B) contains at least 60 mol% of hindered glycol when hydrogen is not present at the β-position represented by the general formula HO-CH ₂ -CR ¹ R ² -CH ₂ -OH. . (In the above formula, R ¹ and R ² are alkyl groups which may be branched, and the carbon number of each of R ¹ and R ² is 1 or more, preferably 1 to 15,
More preferably, it is 2-10. (7) The glycol represented by the general formula is 2-butyl-ethyl-1,3-propanediol, 2-pentyl-
2-propyl-1,3-propanediol, 2-propyl-2-ethyl-1,3-propanediol, 2,2-
Diethyl-1,3-propanediol, 2-ethyl-2
-Methyl-1,3-propanediol, and 2,2-
It is at least one selected from dimethyl-1,3-propanediol.

(8) The ratio OH / COOH (equivalent ratio) of the carboxylic acid component and the alcohol component is in the range of 0.8 to 1.3, more preferably 1.1 to 0.9. (9) Polycondensation is carried out together with the dicarboxylic acid component (A) using 15 mol% or less, more preferably 0.1 to 10 mol% of a trivalent or higher carboxylic acid based on the total of all carboxylic acid components. (10) Polycondensation is carried out together with the diol component (B) using a trihydric or higher alcohol of 50 mol% or less, more preferably 0.1 to 20 mol% based on the total of all alcohol components.

(11) As the carboxylic acid component, a polymerized fatty acid containing 95% or more of a dimer acid component or its hydride and a polymerized fatty acid containing 15% or more of a trimer acid component or its hydride are used to form a dimer acid. Mixing ratio (molar ratio) with trimer acid is 1000/1 to 1000/150
Polycondensation is carried out in the range of. (12) The dicarboxylic acid component (A) and the carboxylic acid component containing a trivalent or higher carboxylic acid have an iodine value of 50 or less, more preferably 20 or less.

(13) The oil-soluble polyester has a weight average molecular weight of 15,000 to 800,000, more preferably 2
It has 50,000 to 400,000. (14) The acid value of the oil-soluble polyester is 5 or less, more preferably 3 or less. (15) The hydroxyl value of the oil-soluble polyester is in the range of 1-10. (16) The iodine value of the oil-soluble polyester is 100 or less,
It is more preferably 20 or less.

(17) The oil-soluble polyester is used as it is as an additive for lubricating oil. (18) The oil-soluble polyester is diluted with a diluent oil and used as an additive for lubricating oil. (19) a base oil of lubricating oil composition, kinematic viscosity 1 to 100 mm ² / s at 100 ° C., preferably from 2 to 50 mm ² /
s, more preferably ^{2 to 20} mm ² / s of mineral oil and /
Or synthetic oil.

(20) The oil-soluble polyester in the lubricating oil composition is 0.1 to 40% by weight, preferably 0.3 to 30% by weight, more preferably 0.5 to 20% by weight based on the total amount of the composition.
It is contained by weight%. (21) The lubricating oil composition is an engine oil for an internal combustion engine, a gear oil for automobiles, a hydraulic oil for automobiles. (22) In the method for producing an oil-soluble polyester, the weight ratio of the polyester oligomer to the carboxylic acid component having 20 or more carbon atoms and the diol component is 3:97 to 40:60.
Range.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication C10M 101: 02 145: 22) C10N 20:00 20:04 30:02 30:10 (72) Invention Author Yoshihide Ishikawa 4 at Harima Kasei Co., Ltd., Central Research Laboratory, 671, Mizuguchi, Noguchi-cho, Kakogawa-shi, Hyogo Prefecture (72) Inventor Shinsuke Hasegawa 4-4 Harima Kasei Co., Ltd., Central Research Laboratory, 671, Mizuguchi, Noguchi-cho, Kakogawa-shi, Hyogo Prefecture ( 72) Inventor Michio Miyamoto 4 Central Research Laboratory, Harima Kasei Co., Ltd., 671, Mizukashi, Noguchi-cho, Kakogawa-shi, Hyogo Prefecture (72) Inventor, Niichi Igarashi, 8th, Chidori-cho, Naka-ku, Yokohama, Japan Nippon Oil & Oil Co., Ltd. Inside the research institute (72) Inventor Hiroshi Shigaya 8th place, Chidori-cho, Naka-ku, Yokohama-shi, Kanagawa Nippon Petroleum Oil Co., Ltd.

Claims (4)

[Claims] 1. A weight average molecular weight (Mw) obtained by polycondensing a dicarboxylic acid component (A) comprising a dicarboxylic acid having 20 or more carbon atoms and a dicarboxylic acid having less than 20 carbon atoms and (B) a diol component. 10,000-1,000,
000, an acid value of 10 or less, a hydroxyl value of 30 or less oil-soluble polyester. 2. A weight average molecular weight of 500 to 1 obtained by polycondensing a carboxylic acid component containing a dicarboxylic acid having a carbon number of less than 20 as a main component and an alcohol component containing a diol as a main component.
50,000 polyester oligomers are prepared, and then the polyester oligomer, a carboxylic acid component containing a dicarboxylic acid having 20 or more carbon atoms as a main component, and an alcohol component containing a diol as a main component are polycondensed. The method for producing the oil-soluble polyester according to claim 1. 3. An additive for lubricating oil, which comprises the oil-soluble polyester according to claim 1 as a main component. 4. A lubricating oil composition comprising the oil-soluble polyester according to claim 1.