JPS6351138B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to new products obtained by esterification of hexahydrobenzoic acid and other carboxylic acids with polyhydric alcohols, and to a process for their preparation. The above products are used in the fields of lubricating oils, hydraulic fluids, oily emulsions, thermal fluids and especially EP (high pressure) fluids. Synthetic lubricants based on long-chain linear fatty acid esters obtained from pelargonic acid, lauric acid, palmitic acid, etc. are known, but since the above acids are natural, they are expensive, and lubricants obtained from these acids are expensive. economically cannot compete with mineral oil. Benzoic acid esters are cheap, but when used in combustion engines, they have the disadvantage of forming partially non-combustible products and producing large amounts of smoke in the exhaust gas, and also have poor lubrication and viscoelastic properties. There are some disadvantages that are not so good. The present invention provides a novel product consisting essentially of an alpha ester, which alpha ester comprises (A) hexahydrobenzoic acid and other fatty acids or cycloaliphatic carboxylic acids having from 6 to 20 carbon atoms; (B) General formula R--CH ₂ OH...(1) (However, in the formula, R represents an --OH group and a linear or branched aliphatic chain having one or more ether oxygen bonds.) and at least one type of polyhydric alcohol having the following, wherein the average number of moles of the acid is 0 to 2 per mole of the polyhydric alcohol. In the preferred polyhydric alcohol, R is selected from the following radicals in the above general formula (1). a -C(Y) ₂ CH ₂ CH ₃ b -CY(CH ₃ ) ₂ c -CH(CH ₃ )OH d -C(Y) ₃ e -C(Y) ₂ -CH ₂ -O-CH ₂ C (Y) ₃ f —CH ₂ —(OCH ₂ CH ₂ ) _o —OH g —[CH(CH ₃ )—OCH ₂ ] _o CH(CH ₃ )—OH (However, Y represents a —CH ₂ OH group. , and n is a number from 1 to 20.) As the above acid (A) other than hexahydrobenzoic acid,
Lauric acid, stearic acid, palmitic acid, myristic acid, pelargonic acid, 2-ethylhexylic acid, caproic acid and/or oleic acid are preferably used, and more preferably branched acids. The method for producing the above α-ester is to prepare a mixture of at least one acid of the above (A) excluding hexahydrobenzoic acid and hexahydrobenzoic acid, and one selected from the group consisting of hexahydrobenzoic acid according to the general formula (1). at least one alcohol of
It consists of reacting at a temperature of 80-250°C. At the initial stage of the reaction, it is desirable to carry out the reaction at normal pressure, and then it is desirable to carry out the reaction under reduced pressure. Ester production involves mixing calculated amounts of each component and heating the mixture to an appropriate temperature. At this time, an entrainer may be used to easily and continuously remove the water produced. . When cyclohexane is used as a water separation promoter from the reaction system, it is necessary that a sufficient amount is employed to maintain the reaction temperature at the desired value. For example, to maintain a temperature of 200 DEG C., 10 to 100 g of cyclohexane are used per Kg of reactants (acid or acid and alcohol). It is advisable to use a slight excess of one of the components of the acid mixture relative to the theoretical value calculated from the number of OH groups in the alcohol or alcohol mixture. It is generally advantageous to use an excess of the acid that has the greatest relative volatility relative to the other components of the acid mixture. Esterification may be carried out intermittently or continuously in the presence or absence of customary esterification catalysts. The reaction time is preferably 5 to 50 hours depending on the presence or absence of a catalyst. If no catalyst is used, the reaction is advantageously carried out intermittently due to the long reaction time, whereas if a catalyst such as sulfuric or phosphoric acid is used, the reaction is carried out continuously. is advantageous. The method for producing α-ester will be described below.
One mole of a polyfunctional polyhydroxy compound, such as neopentyl glycol, was mixed with 1 to 2 moles of hexahydrobenzoic acid and 0.2 to 2.0 moles of a linear aliphatic monocarboxylic acid, such as lauric acid. In this case, the total amount of the above two acids is 0.8 to 1.5 mol, preferably 0.9 to 1.2 mol, per mol of hydroxyl group of the polyhydric alcohol. The mixture is typically heated to 195° C. and this temperature is maintained for 2 to 8 hours, after which 0.1 to 1.0% by weight of cyclohexane is added to the reaction system;
Heating is then continued until the water has been released. Excess amounts of carboxylic acid and entrainer may be removed under vacuum. If the carboxylic acid is not in excess relative to the hydroxyl groups, neutralizing agents such as aluminum hydroxide, magnesium hydroxide, or basic organic sulfonates of calcium or barium may be added. The product obtained is then cooled and removed. The alpha esters of the present invention are used in lubricants, hydraulic fluids, oily emulsions, thermal fluids, EP fluids, and the like. When the α-ester of the present invention is used as a lubricant, the above-mentioned drawbacks of conventional synthetic esters are eliminated. Because the α-esters of the present invention have low viscosities (e.g., 10 cst or less at 100°C), they can be used in mixtures with paraffin oils, in which case the more volatile portions (which generally reduce the viscosity of the oil) can be used in combination with paraffin oils. ) is replaced by the α-ester of the present invention, which has a low viscosity but relatively high volatility. The alpha esters of the present invention have good flammability, are inexpensive, and have excellent viscosity properties at various temperatures, which are desirable properties as a versatile oil. The above alpha esters are used alone or mixed with other esters or mineral oil lubricants to lubricate engines or turbines. The alpha ester may be mixed with mineral oil obtained from crude oil in a ratio of 100:0 to 20:80. Conventional additives that increase the viscosity index, detergents, dispersants, anti-smoke agents, etc. may be added in an amount of 0 to 25% relative to the α-ester. In internal combustion engine lubrication, alpha esters may be employed in two-stroke engines where the lubricant is mixed with the fuel and emitted with the exhaust gases. Since the alpha esters of the present invention do not contain sulfur compounds or aromatic hydrocarbons that generate carbon particles or acidic compounds (inorganic compounds derived from sulfur), engine cleanliness and reduced air pollution are achieved. When α-olefin is used as a cutting fluid, it does not release aromatic hydrocarbons into the working chamber. Examples are shown below. In the examples, unless otherwise indicated, parts are given by weight. Group A examples demonstrate the preparation of alpha esters. Example 1/A 0.95 Kg of trimethylolpropane, 0.1 Kg of cyclohexane, 1.8 Kg of hexahydrobenzoic acid, and 1.4 Kg of lauric acid were charged into a 6 four-necked glass reactor.
The reactor is equipped with means for refluxing the light component (cyclohexane) and means for removing the heavy component (water) from the bottom. The mixture was heated to 195° C. and in this reaction state water and cyclohexane were released, the latter being refluxed. 67% of the theoretical amount of water was collected in the first 6 hours. 0.3 Kg of cyclohexane was again added to the mixture during the reaction to maintain the above temperature. The reaction was completed in about 30 hours. After the reaction, the reaction mixture was cooled to 120° C. and 9.3 g of aluminum oxide was added. The solvent was removed by distillation under reduced pressure, resulting in 3.7Kg of α-ester. The kinematic viscosity of this product at 99; 38; 0; -28℃ is
They were 10.3; 91.4; 1000; 2900 (in centistokes). The residual total acidity is the
Corresponds to 0.28mgKOH/g. The solidification temperature of the product was -38°C. Example 2/A 0.27 Kg trimethylolpropane, 0.32 Kg pelargonic acid, and 0.51 Kg hexahydrobenzoic acid were placed in a 34-neck glass reactor of the same type as Example 1/A. The mixture was heated to 210°C. 3
After an hour of reaction, 70% of the theoretical amount of water was collected. At this point 0.14Kg of cyclohexane was added to reduce residual reaction water and the organic solvent was recycled. The reaction was completed in 18 hours. After the reaction was completed, the reactants were cooled to 120 °C and 1.6
g of aluminum oxide was added. Finally, the solvent was removed by vacuum distillation to obtain 0.925 g of ester. The kinematic viscosities at 100°C, 25°C, 0°C, and -20°C were 70, 300, 600, and 22,000 centistokes, respectively. The residual total acidity is 0.19mgKOH/
Corresponds to g. Example 3/A A mixture of trimethylolpropane (268.3 g), lauric acid (801.2 g) and hexahydrobenzoic acid (256.0 g) in a mixing ratio of 1:2:1 was prepared using the apparatus of Example 1/A. 1211 g of an esterified product suitable as a lubricant base was obtained. Example 4/A A mixture consisting of hexahydrobenzoic acid (4 mol), 1,12-decanedicarboxylic acid (1 mol), neopentyl glycol (1 mol) and 2-ethylhexyl alcohol (2 mol) was prepared in Example 1/A.
The reaction was carried out using the apparatus described in . The result was an esterified product useful as a lubricant base. Group B examples are Examples 1/A and 2/
A lubricating oil obtained from the ester of A is shown. Example 1/B 430 g of the ester obtained in Example 1/A were mixed with 430 g of mineral oil of the following characteristics. a The viscosity at 98.9; 50; 37.8℃ is respectively
10.19; 49.0; 86.5cst. b Neutralization number: 1.0 mg KOH/g of product c Flow temperature: -10°C 60 g poly-α-olefin, 80 g detergent, dispensing agent, and smoke retardant were added to the above mixture to determine the viscosity.
A lubricating oil having a molecular weight of 152 was obtained. Example 2/B A lubricating oil having a viscosity index of 165 is Example 2/A
Using the ester obtained in Example 1/B
It was prepared based on the method of Examples 5/A to 14/A The alpha esters of Examples 5/A to 14/A were produced in a similar manner to the method for producing the alpha esters of Examples 1/A to 4/A. The reactants, weight ratios, and properties of the α-ester obtained are shown in Table 1 below.

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Claims (1)

[Scope of Claims] 1 (A) hexahydrobenzoic acid and an aliphatic or alicyclic carboxylic acid having 6 to 20 carbon atoms, (B) general formula R—CH ₂ OH …(1) (However, In the formula, R represents a linear or branched aliphatic chain having an -OH group. The average number of moles of acid is greater than 0 and less than or equal to 2. 2. The α-ester according to claim 1, wherein R in the above general formula contains at least one ether oxygen atom. 3 R in the above general formula is a -C(Y) ₂ CH ₂ CH ₃ b -CY(CH ₃ ) ₂ c -CH(CH ₃ )OH d -C(Y) ₃ e -C(Y) ₂ -CH ₂ -O-CH ₂ C(Y) ₃ f -CH ₂ -(O-CH ₂ -CH ₂ )n-OH g -[CH(CH ₃ )-CH ₂ ]nCH(CH ₃ )-OH 2. The α-ester according to claim 1, wherein Y represents a —CH ₂ OH group, and n is a number from 1 to 20. 4. Claim 1 in which stearic acid, palmitic acid, myristic acid, lauric acid, pelargonic acid, 2-ethylhexylic acid, caproic acid, and/or oleic acid is used as the acid (A) other than hexahydrobenzoic acid. The alpha ester according to any one of Items 1 to 3. 5 Trimethylolpropane, pentaerythritol, or pentaerythritol diether has the above formula
The α ester according to any one of claims 1 to 4, which is used as the alcohol in (1). 6 One type selected from the group consisting of a mixture of an aliphatic or alicyclic carboxylic acid having 6 to 20 carbon atoms other than hexahydrobenzoic acid and hexahydrobenzoic acid, and hexahydrobenzoic acid with the general formula R-CH ₂ OH ...(1) (wherein R represents a linear or branched aliphatic chain having an -OH group) at a temperature of 80 to 250°C. A method for producing an α-ester characterized by: 7. The method according to claim 6, wherein the reaction is carried out in the presence of an entrainer. 8. The method according to claim 7, wherein cyclohexane is used as an entrainer. 9. Process according to claim 7 or 8, wherein the reaction is carried out in the presence of acid catalysts known in this type of esterification. 10 A patent claim in which the α ester is obtained by an esterification reaction between 1 mole of pentaerythritol or trimethylolpropane, 1 to 4 moles of hexahydrobenzoic acid, and 0.5 to 2.5 moles of a linear aliphatic monocarboxylic acid. The method according to any one of items 6 to 9.