CN100448964C - A kind of continuously variable transmission transmission fluid composition - Google Patents

Abstract

The invention provides a transmission fluid composition for a continuously variable variable speed changer, which comprises: (1) a dicyclohexyl cycloaliphatic base oil; (2) an alkaline earth metal salt detergent with a content of 0.05 to 3% by weight; (3) Ashless dispersant, the content is 1 to 15% by weight; (4) Phenolic or amine antioxidant, the content is 0.01 to 1% by weight; (5) Anti-wear agent, the content is 0.05-2% by weight; (6) Friction modifier, the content is 0.05-3% by weight; (7) Viscosity index improver, the content is 0-20% by weight; (8) Antifoaming agent, the content is 0-1000ppm. The continuously variable transmission fluid composition provided by the invention has excellent viscosity-temperature performance and low-temperature fluidity, high traction coefficient at normal temperature, excellent comprehensive performance, and can fully meet the requirements for use of CVT.

Description

A kind of continuously variable transmission transmission fluid composition

technical field

The invention relates to a lubricating oil composition, in particular to a CVT special-purpose transmission fluid composition with high viscosity index and high traction coefficient and excellent performance.

technical background

In recent years, improving fuel economy, reducing emissions, and improving handling flexibility have become the development trend of automobile development, and the technology of continuously variable transmission (CVT for short) is one of the most promising. Common types of CVT for vehicles are: Belt CVT (Belt/Chain-CVT, B-CVT) and Ring CVT (Torodial-CVT, T-CVT). CVT technology has significant advantages in terms of fuel economy, overtaking acceleration, ride comfort, and cost. Therefore, more and more automatic transmissions of automobiles adopt CVT design.

The transmission of CVT power actually depends on the shearing force of the oil film in the contact area of elastohydrodynamic lubrication (EHL). Therefore, the performance of mechanical continuously variable transmission depends to a large extent on the traction of traction fluid (CVTF). performance. CVTF is a versatile traction transmission fluid. In the contact area of the force transmission element of the continuously variable transmission, the lubricating oil film bears high pressure, high shear strain rate, and heat due to shearing, so there are many special requirements for the oil. In addition to the lubricating high and low temperature viscosity requirements, oxidation stability, dispersibility, anti-foaming properties, and material compatibility of ordinary lubricating oils, CVTF also has strict requirements on shear stability and wear resistance, especially for traction coefficient and anti-stick-slip properties are very high requirements. These properties are contradictory, such as traction coefficient and low temperature viscosity, high and low temperature viscosity and shear stability, traction coefficient and wear resistance, etc.

不同处在环己环间的亚甲基个数的差异、以及亚甲基之间的联接方式的不同；此外，环己环上短链烷基R₁、R₂的类型、数量也各不相同。Synthetic transmission fluids can be roughly divided into the following molecular structures: (1) Polycyclic alicyclic type (multiple six-membered ring); (2) Synthetic polyolefin type (high degree of branching); (3) Mineral oil type ; (4) Esters, ethers (containing multiple six-membered rings in the molecular structure); (5) Silicone oil type, etc. Among them, polycyclohexyl cycloaliphatic traction fluid has good traction performance, especially high-temperature traction coefficient, so it has been widely used. US 5043497 discloses the synthesis of bis(3,4,6-trimethylcyclohexyl)methane transmission fluid. US 3975278 discloses the synthesis of 2-methyl-2,4-dicyclohexylpentane transmission fluid. In addition, Japan has also proposed a large number of invention patents around this type of molecular structure, such as JP2001294880, JP11349968, etc., wherein the disclosed transmission fluid has a common structural formula:

The difference in the number of methylene groups between different cyclohexyl rings, and the difference in the connection mode between methylene groups; in addition, the types and quantities of short-chain alkyl groups R ₁ and R ₂ on the cyclohexyl rings are also different. same.

In addition to the research on base oils and the synthesis of new base oils, people have also done a lot of research on CVTF formulations. Patent Publication 2000-63878, Patent Publication 2000-1687, Patent Publication 11-293272, Patent Publication 11-181464, Patent Publication 9-263782, US 6809069, US 6746993, US6465399, US 6337309, US 6329327, US 6225266, etc. The patent provides CVTF formulations based on mineral oil with various additives such as viscosity index improvers, detergents, dispersants, and friction modifiers. These CVTFs have high traction coefficients, and the traction coefficients at room temperature are the highest Reaching about 0.07, it can be used in B-CVT, but its traction coefficient is difficult to meet the requirements of T-CVT. Patents such as JP2000239682, JP62001115178, JP2001019988, and JP2000169866 have provided hydrogenated dihydroindanes such as 1-cyclohexyl-1,3,3-trimethyldihydroindan, 2,4-dicyclohexyl-2-methyl-pentane, etc. CVTF formulations based on polymethylstyrene synthetic oil, these CVTFs have a higher traction coefficient than mineral oil-based CVTFs, and the maximum traction coefficient at room temperature can reach about 0.12, which can meet the requirements of T-CVT. More successful commercial transmission fluids are mostly polycyclohexyl cycloaliphatic hydrocarbons, such as Santotrac series products. These traction fluids generally have good traction coefficients, but their low-temperature flow properties and viscosities under working conditions vary, and some of them cannot meet the special requirements of continuously variable variables. In particular, there is a contradiction between traction coefficient and low-temperature fluidity, and high traction coefficient is often accompanied by high viscosity and high pour point.

Contents of the invention

The invention provides a continuously variable variable transmission fluid composition with high viscosity index, high traction coefficient, good low-temperature fluidity and normal viscosity characteristics.

The continuously variable variable transmission fluid composition provided by the present invention, based on the weight of the base oil as 100%, comprises:

(1) Bicyclohexyl cycloaliphatic base oil;

(2) alkaline earth metal salt detergent, the content of which is 0.05 to 3% by weight;

(3) Ashless dispersant, the content is 1-15% by weight;

(4) phenolic or amine antioxidants, the content of which is 0.01 to 1% by weight;

(5) anti-wear agent, the content is 0.05-2% by weight;

(6) Friction modifier, the content of which is 0.05 to 3% by weight;

(7) Viscosity index improver, the content is 0～20% by weight;

(8) Anti-foaming agent, the content is 0-1000ppm.

The alkaline earth metal salt detergent is one or more of alkaline earth metal sulfonate, sulfurized alkylphenate and alkyl salicylate. The alkaline earth metals are calcium, magnesium or barium. The base number of the alkaline earth metal salt can be high base number (>300TBN), medium base number (100-300TBN) and low base number (<100TBN). Preferred alkaline earth metal salt detergents are medium base number sulfurized calcium alkylphenates and high base number sulfurized calcium alkylphenates. The content of the detergent is 0.05-3% by weight, preferably 0.5-2% by weight.

The ashless dispersant is one or more of succinimide dispersant, succinate dispersant, oil-soluble phosphorus-containing or boron-containing ashless dispersant. Preferred are boronated ashless dispersants and succinimide dispersants. The content of the ashless dispersant is 1-15% by weight, preferably 3-6% by weight.

The antioxidant is one or more of phenolic or amine antioxidants, preferably amine antioxidants. The content of antioxidant is 0.01-1% by weight, preferably 0.1-0.8% by weight.

The antiwear agent is one or more of zinc alkyl dithiophosphate, dibenzyl disulfide, isobutylene sulfide, tricresyl phosphate, and borated oleamide. Preferred are dibenzyl disulfide and zinc alkyl dithiophosphates. The content of the antiwear agent is 0.05-2% by weight, preferably 0.1-1% by weight.

Friction modifiers are benzotriazole fatty acid ammonium salt (T406), ethylene glycol oleate (T403), sulfurized olefin cottonseed oil (T405), trioctyl phosphate, oleic acid, lauramide diethanolamine, hydroxyethyl seventeen One or more of alkyl imidazoline and ethoxylated tallow diamine. Preferred is benzotriazole fatty acid ammonium salt (T406), or the combination of hydroxyethyl heptadecyl imidazoline and ethoxylated tallow diamine, in the combination, the ratio of the two is 1:1～5:1, Preferably 1:1 to 3:1. The content of the friction modifier is 0.05-3% by weight, preferably 0.1-1% by weight.

The viscosity index improver is one or more of polymethacrylate, ethylene-propylene copolymer, polyvinyl n-butyl ether, polyisobutylene, and styrene maleate. It is preferable to use polymethacrylate having a molecular weight in the range of 10,000 to 100,000. The content of the viscosity index improver can be 0-20% by weight, preferably 1-20% by weight, most preferably 1-10% by weight.

The antifoaming agent is one or more of methyl silicone oil, ethyl silicone oil, acrylate and ether copolymer (T911, T912). T912 is preferred, the content can be 0-1000ppm, preferably 50-1000ppm, most preferably 100-500ppm.

Said base oil is dicyclohexyl cycloaliphatic cyclohydrocarbon, preferably a novel structure bicyclohexyl cycloaliphatic cyclohydrocarbon, its 2 cyclohexyls are connected by 1 methylene, and each cyclohexyl cyclohexyl There are 1 to 3 short-chain alkyl substituent groups containing a geminal dimethyl structure, such as isopropyl, tert-butyl, isopentyl, etc. Its structural formula is:

Wherein R is a C3-C5 short-chain alkyl group containing a geminal dimethyl structure, and n is a positive integer of 1-3.

The preparation of said bicyclohexylcycloalicyclic hydrocarbon can be divided into two steps: the synthesis of the aromatic intermediate and the hydrogenation saturation of the aromatic intermediate.

(1) Synthesis of aromatic intermediates

Using C1-C3 alkylbenzenes and formaldehyde containing geminal dimethyl structures as raw materials, under the action of acidic catalysts, diarylmethane-type aromatic intermediates are produced through condensation reactions.

The catalyst can be selected concentrated sulfuric acid, sulfonic acid or heteropoly acid, preferably concentrated sulfuric acid. The formaldehyde raw material can be selected paraformaldehyde or formaldehyde aqueous solution, preferably 37% formaldehyde aqueous solution. The reaction temperature may be 106-130°C.

The general formula of diarylmethane-type aromatic intermediates is as follows:

Since multiple isomers exist at the same time due to the different substitution positions of the alkyl group, the aromatic intermediate is actually a mixture, but the mixture has little effect on the performance of the final product.

(2) Hydrogenation saturation of aromatic intermediates

The aromatic intermediate is mixed with a hydrogenation catalyst, placed in an autoclave, and subjected to hydrogenation saturation at a temperature of 150-200° C. and a hydrogen pressure of 5.0-10.0 MPa. The final product is obtained after the product is decompressed and decapitated. Said hydrogenation catalyst can be the following three categories: 1) Group VIII metals (Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt) and skeleton catalysts or amorphous alloy catalysts made of alloys ; 2) metal oxides (MgO, ZnO, Cr ₂ O ₃ , Fe ₂ O _{3 ,} etc.); 3) composite oxides or sulfides. The above substances, especially the metal itself, except for the skeleton catalyst, are preferably dispersed on porous supports such as activated carbon and molecular sieves to enhance the activity.

Taking bis(cumyl)methane as an example to illustrate the product composition of aromatic intermediates after hydrogenation. The composition of its final product is bis(isopropylcyclohexyl)methane. It mainly contains the following two isomers:

Bis(4-isopropylcyclohexyl)methane

双(3-异丙基环己基)甲烷

Bis(3-isopropylcyclohexyl)methane

Due to the relationship of steric hindrance, the content of the former is higher. Separation of the above-mentioned mixture is difficult and at the same time meaningless for the present invention.

The continuously variable transmission fluid composition provided by the invention has excellent viscosity-temperature performance and low-temperature fluidity, high traction coefficient at normal temperature, excellent comprehensive performance, and can fully meet the requirements for use of CVT.

Detailed ways

(1) Determination of traction coefficient

The measurement of the traction curve uses the Mini Traction Machine (MTM) instrument produced by British PCS Instruments, and its geometric contact type is ball-disk type. The test conditions and specimen parameters are shown in Table 1 and Table 2.

Table 1 Traction performance test conditions

Specimen contact area Hertz pressure (GPa) Slip-to-roll ratio (%) Rolling speed (m/s) Temperature (°C) Sample volume (ml) ball-disk Ellipse 0.75～1.25 -10～+10 2.5 40 40

Table 2 Test piece parameters

name material Diameter (mm) Hardness (HRC) Smoothness (μm) Contact radius (mm) Elastic modulus (10^11＊N/m²) ball AISI52100 19.05 63 0.02 none 2.07 plate AISI52100 46.0 63 0.02 21.2 2.07

(2) Example

The compositions suitable for use when implementing the present invention are listed in the Examples and Comparative Examples of the following tables. The Examples and Comparative Examples have adopted the same combination of additives, and the percentages therein are expressed by weight, based on the weight of the base oil is 100%.

Base oil I: Bis(4-isopropylcyclohexyl)methane, prepared according to the method of Example 1.

Base oil II: Bis(4-tert-butylcyclohexyl)methane, prepared according to the method in Example 2.

Base oil III: bis(3,4,6-trimethylcyclohexyl)methane, synthesized according to US 5043497.

Base oil IV: 2-methyl-2,4-dicyclohexylpentane, synthesized according to US 3975278.

Example 1

Get cumene (purity 99w%) 240 grams, formaldehyde (37% aqueous solution) 47.8 grams, sulfuric acid (concentration 98w%) 58.2 grams are raw materials. Among them, cumene and sulfuric acid were mixed and stirred in a four-necked bottle, and the temperature was raised from room temperature to 120°C. After reaching the set temperature, the formaldehyde solution placed in the dropping funnel was slowly dropped into the four-necked bottle. After the dropwise addition of formaldehyde is completed, after the heat preservation reaction for about 1 hour, the material is discharged into a separatory funnel, extracted and washed with distilled water and n-butanol mixture (water:alcohol volume ratio is about 4:1) at about 80°C until pH = 7, Cut out the upper oil phase product. After the oil phase products are collected, the unreacted raw material cumene is first distilled under the condition of residual pressure of 24-40mmHg, and then under the condition of residual pressure of less than 1mmHg, the decompression distillate at 176-186°C is taken as the target intermediate body product.

Mix 139.6 grams of the above-mentioned intermediate, bis(isopropylphenyl)methane, with 6.5 grams of 10% Pd/C catalyst and place in an autoclave. Under the conditions of temperature 190° C., hydrogen pressure 7.0 MPa, and stirring speed 250 RPM, hydrogenation saturation was carried out. The product was decapitated under reduced pressure to obtain 126.2 g of the final product, and the degree of hydrogenation saturation was 98.6% as determined by ¹ H-NMR. ¹³ C-NMR molecular structure identification shows that bis(4-isopropylcyclohexyl)methane is its main component.

Example 2

The synthesis process is the same as in Example 1, except that the raw material is changed to 268 grams of tert-butylbenzene, and the quality of formaldehyde and concentrated sulfuric acid remains unchanged. Condensation reaction was carried out at 120°C, followed by extraction, separation and vacuum distillation to obtain 125.5 grams of the intermediate bis(tert-butylphenyl)methane product. It was mixed with 6.7 g of 10% Pd/C catalyst and placed in an autoclave. Under the conditions of temperature 190° C., hydrogen pressure 7.0 MPa, and stirring speed 250 RPM, hydrogenation saturation was carried out. The product was decapitated under reduced pressure to obtain 115.3 g of the final product, and the degree of hydrogenation saturation was 97.3% as determined by ¹ H-NMR. ¹³ C-NMR molecular structure identification shows that bis(4-tert-butylcyclohexyl)methane is its main component.

The composition of table 3 embodiment and comparative example

component Example 3 Example 4 Comparative example 1 Comparative example 2 base oil Base oil I Base Oil II Base Oil III Base Oil IV Polymethacrylate 8% 8% 8% 8% High base value sulfurized calcium alkylphenate 0.8% 0.8% 0.8% 0.8% Boronated ashless dispersant 2% 2% 2% 2% Amine antioxidants 0.3% 0.3% 0.3% 0.3% Dibenzyl disulfide 0.9% 0.9% 0.9% 0.9% Hydroxyethylheptadecylimidazoline 0.2% 0.2% 0.2% 0.2% Ethoxylated tallow diamine 0.1% 0.1% 0.1% 0.1% T912 200ppm 200ppm 200ppm 200ppm

The composition of table 3 embodiment and comparative example continues

component Example 5 Example 6 Comparative example 3 Comparative example 4 base oil Base oil I Base Oil II Base Oil III Base Oil IV Polymethacrylate 1% 1% 1% 1% High base value sulfurized calcium alkylphenate 1.6% 1.6% 1.6% 1.6% Boronated ashless dispersant 6% 6% 6% 6% Amine antioxidants 0.6% 0.6% 0.6% 0.6% Zinc Alkyl Dithiophosphate 0.9% 0.9% 0.9% 0.9% Hydroxyethylheptadecylimidazoline 0.2% 0.2% 0.2% 0.2% Ethoxylated tallow diamine 0.1% 0.1% 0.1% 0.1% T912 400ppm 400ppm 400ppm 400ppm

The composition of table 3 embodiment and comparative example continues

component Example 7 Example 8 Comparative Example 5 Comparative example 6 base oil Base oil I Base Oil II Base Oil III Base Oil IV Polymethacrylate 8% 8% 8% 8% High base value sulfurized calcium alkylphenate 0.8% 0.8% 0.8% 0.8% Succinimide Dispersant 2% 2% 2% 2% Amine antioxidants 0.3% 0.3% 0.3% 0.3% Dibenzyl disulfide 0.1% 0.1% 0.1% 0.1% Hydroxyethylheptadecylimidazoline 0.2% 0.2% 0.2% 0.2% Ethoxylated tallow diamine 0.1% 0.1% 0.1% 0.1% T912 200ppm 200ppm 200ppm 200ppm

The composition of table 3 embodiment and comparative example continues

component Example 9 Example 10 Comparative example 7 Comparative example 8 base oil Base oil I Base Oil II Base Oil III Base Oil IV Polymethacrylate 8% 8% 8% 8% High base value sulfurized calcium alkylphenate 0.8% 0.8% 0.8% 0.8% Succinimide Dispersant 6% 6% 6% 6% Amine antioxidants 0.3% 0.3% 0.3% 0.3% Zinc Alkyl Dithiophosphate 0.1% 0.1% 0.9% 0.9% Hydroxyethylheptadecylimidazoline 0.8% 0.8% 0.8% 0.8% Ethoxylated tallow diamine 0.8% 0.8% 0.8% 0.8% T912 200ppm 200ppm 200ppm 200ppm

The composition of table 3 embodiment and comparative example continues

component Example 11 Example 12 Comparative example 9 Comparative Example 10 base oil Base oil I Base Oil II Base Oil III Base Oil IV Polymethacrylate 8% 8% 8% 8% High base value sulfurized calcium alkylphenate 0.8% 0.8% 0.8% 0.8% Succinimide Dispersant 6% 6% 6% 6% Amine antioxidants 0.3% 0.3% 0.3% 0.3% Zinc Alkyl Dithiophosphate 0.5% 0.5% 0.5% 0.5% T406 0.2% 0.8% 0.2% 0.2% T912 200ppm 200ppm 200ppm 200ppm

The composition of above-mentioned embodiment and comparative example is carried out performance test, and the results are shown in Table 4

Table 4 embodiment and comparative example data comparison table

υ40_℃(cSt) VI Pour point (℃) Traction coefficient μ_max(P_Hz＝0.75GPa) Traction coefficient μ_max(P_Hz＝1.25GPa) Example 3 42.99 186 -60 0.07948 0.09839 Example 4 42.35 190 -52 0.08678 0.10698 Example 5 18.88 51 -55 0.08023 0.09897 Example 6 18.78 55 -48 0.08704 0.10945 Example 7 42.96 186 -60 0.07812 0.09801 Example 8 42.38 190 -52 0.08684 0.10867 Example 9 42.98 186 -60 0.07988 0.09845 Example 10 42.33 190 -52 0.08691 0.10715 Example 11 42.29 190 -52 0.08632 0.10675 Example 12 42.31 190 -52 0.08561 0.10625 Comparative example 1 65.35 102 -45 0.08273 0.09274 Comparative example 2 59.59 121 -46 0.10987 0.12632 Comparative example 3 14.6 -50 -32 0.08342 0.09351 Comparative example 4 21.88 5 -41 0.11078 0.12932 Comparative Example 5 65.35 102 -45 0.08126 0.09274 Comparative example 6 59.62 121 -47 0.10945 0.12598 Comparative example 7 65.35 102 -45 0.08295 0.09288 Comparative example 8 59.59 121 -46 0.10988 0.12646 Comparative example 9 59.66 118 -43 0.10322 0.11954 Comparative Example 10 59.61 120 -42 0.10287 0.11926

Note: P _Hz is the average hertz contact pressure.

As can be seen from Table 4, the continuously variable transmission fluid composition provided by the present invention has a much higher viscosity index and lower pour point than the comparative examples, and shows excellent viscosity-temperature performance and better low-temperature fluidity , has a relatively high traction coefficient at room temperature, although it is slightly lower than that of the comparative example, it can fully meet the requirements of CVT use. The comprehensive performance of the continuously variable transmission fluid composition provided by the present invention is better than that of the comparative example.

Claims (22)

1. A continuously variable variable transmission fluid composition, based on the weight of base oil as 100%, comprising: (1) Bicyclohexyl cycloaliphatic base oil, in which the two cyclohexyl groups of the base oil are connected by a methylene group, and each cyclohexyl ring has 1 to 3 geminal dimethyl groups C3-C5 short-chain alkyl group; (2) alkaline earth metal salt detergent, the content of which is 0.05 to 3% by weight; (3) Ashless dispersant, the content is 1-15% by weight; (4) phenolic or amine antioxidants, the content of which is 0.01 to 1% by weight; (5) anti-wear agent, the content is 0.05-2% by weight; (6) Friction modifier, the content of which is 0.05 to 3% by weight; (7) Viscosity index improver, the content is 0～20% by weight; (8) Anti-foaming agent, the content is 0-1000ppm. 2. The composition according to claim 1, wherein the alkaline earth metal salt detergent is one or more of alkaline earth metal sulfonates, sulfurized alkylphenates and alkyl salicylates. 3. The composition of claim 1, wherein the alkaline earth metal is calcium, magnesium or barium. 4. The composition of claim 1 wherein the alkaline earth metal salt detergent is a medium base number sulfurized calcium alkylphenate or a high base number sulfurized calcium alkylphenate. 5. The composition according to claim 1, wherein the content of the detergent is 0.5 to 2% by weight. 6. according to the described composition of claim 1, it is characterized in that, ashless dispersant is a kind of in succinimide dispersant, succinate dispersant, oil-soluble phosphorus-containing or boron-containing ashless dispersant or several. 7. The composition according to claim 1, wherein the ashless dispersant is a boronated ashless dispersant or a succinimide dispersant. 8. The composition according to claim 1, characterized in that the content of ashless dispersant is 3-6% by weight. 9. The composition according to claim 1, characterized in that the content of antioxidant is 0.1-0.8% by weight. 10. according to the composition described in claim 1, it is characterized in that, anti-wear agent is one in zinc alkyl dithiophosphate, dibenzyl disulfide, sulfurized isobutylene, tricresyl phosphate, borated oleamide species or several. 11. Composition according to claim 1, characterized in that the antiwear agent is dibenzyl disulfide or zinc alkyl dithiophosphate. 12. The composition according to claim 1, characterized in that the content of antiwear agent is 0.1 to 1% by weight. 13. The composition according to claim 1, wherein the friction modifier is benzotriazole fatty acid ammonium salt, ethylene glycol oleate, vulcanized olefin cottonseed oil, trioctyl phosphate, oleic acid, laurylamide One or more of ethanolamine, hydroxyethylheptadecyl imidazoline, and ethoxylated tallow diamine. 14. The composition according to claim 1, wherein the friction modifier is a combination of hydroxyethyl heptadecyl imidazoline and ethoxylated tallow diamine, and the mass ratio of the two is 1: 1～ 5:1. 15. The composition according to claim 1, characterized in that the content of friction modifier is 0.1 to 1% by weight. 16. according to the composition described in claim 1, it is characterized in that, viscosity index improver is polymethacrylate, ethylene-propylene copolymer, polyvinyl n-butyl ether, polyisobutylene, styrene maleate one or several. 17. The composition of claim 1, wherein the viscosity index improver is a polymethacrylate having a molecular weight in the range of 10,000 to 100,000. 18. The composition according to claim 1, wherein the viscosity index improver is present in an amount of 1 to 20% by weight. 19. The composition according to claim 1, wherein the antifoaming agent is one or more of methyl silicone oil, ethyl silicone oil, acrylate and ether copolymer. 20. The composition according to claim 1, wherein the content of antifoaming agent is 50-1000 ppm. 21. according to the composition described in claim 1, it is characterized in that, the preparation of said bicyclohexylcycloalicyclic hydrocarbon comprises: (1) C1～C3 alkylbenzene and formaldehyde containing geminal dimethyl structure , under the action of 106-130°C and acidic catalyst, the diarylmethane-type aromatic intermediate is formed through condensation reaction; (2) Mix the aromatic intermediate and hydrogenation catalyst at a temperature of 150-200°C and a hydrogen pressure of 5.0- Under the condition of 10.0MPa, carry out hydrogenation saturation. 22. The composition according to claim 21, wherein the acidic catalyst is concentrated sulfuric acid, sulfonic acid or heteropolyacid.