阅读说明：本技术 一种制动液及其制备方法 (Brake fluid and preparation method thereof ) 是由 陈炳耀 杨善杰 董颖 于 2020-06-17 设计创作，主要内容包括：本发明公开了一种制动液及其制备方法。该制动液由以下重量份的各组分制备而成：硼酸酯20～60份、硅酯1～15份、稀释剂5～38份、复合添加剂包0.5～5份。本发明制动液组合物,有效平衡了产品润滑性、防腐性、防锈性及橡胶相容性,产品各项指标达到和超过现有各级别指标要求,可以兼容各等级产品。(The invention discloses a brake fluid and a preparation method thereof. The brake fluid is prepared from the following components in parts by weight: 20-60 parts of borate ester, 1-15 parts of silicon ester, 5-38 parts of diluent and 0.5-5 parts of composite additive package. The brake fluid composition of the invention effectively balances the lubricity, the corrosion resistance, the rust resistance and the rubber compatibility of the product, and each index of the product reaches or exceeds the index requirements of each level in the prior art, so that the brake fluid composition can be compatible with each level of product.)

1. The brake fluid is prepared from the following components in parts by weight:

20-60 parts of borate ester, 1-15 parts of silicon ester, 5-38 parts of diluent and 0.5-5 parts of composite additive package.

2. The brake fluid according to claim 1, wherein the borate is one or more selected from the group consisting of diethylene glycol methyl ether borate, diethylene glycol ethyl ether borate, diethylene glycol propyl ether borate, diethylene glycol butyl ether borate, triethylene glycol methyl ether borate, triethylene glycol ethyl ether borate, triethylene glycol propyl ether borate, triethylene glycol butyl ether borate, tetraethylene glycol methyl ether borate, tetraethylene glycol ethyl ether borate, tetraethylene glycol propyl ether borate, tetraethylene glycol butyl ether borate, preferably triethylene glycol butyl ether borate.

3. The brake fluid according to claim 1 or 2, wherein the general structural formula of the silicone ester is R₃SiOR 'or (R' O)₂SiR₂Wherein R is alkyl and R' is ethylene glycol or glycol ether-containingA group; preferably, R is selected from C1-C6-containing hydrocarbon groups and naphthenic hydrocarbon groups.

4. The brake fluid according to any one of claims 1 to 3, wherein the diluent is one or more selected from the group consisting of diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol propyl ether, triethylene glycol butyl ether, tetraethylene glycol methyl ether, tetraethylene glycol ethyl ether, tetraethylene glycol propyl ether, and tetraethylene glycol butyl ether, and preferably is a mixture of triethylene glycol butyl ether and triethylene glycol methyl ether at a volume ratio of 1: 1.

5. The brake fluid according to any one of claims 1 to 4, wherein the composite additive package is prepared from the following components in parts by weight:

30-70 parts of corrosion inhibitor, 15-30 parts of antioxidant, 5-15 parts of pH regulator and 0.2-5 parts of defoaming agent.

6. The brake fluid of any of claims 1-5, wherein the corrosion inhibitor comprises at least one of benzotriazole, tolyltriazole, cationic emulsion of polydimethylsiloxane, inorganic borate;

preferably, the weight ratio of at least one of the benzotriazole and the tolyltriazole to the polydimethylsiloxane cationic emulsion and the inorganic borate is 2:2: 1.

7. The brake fluid according to any one of claims 1 to 6, wherein the antioxidant is a phenolic antioxidant.

8. The brake fluid according to any one of claims 1 to 7, wherein the pH adjuster is an organic amine compound selected from one or more of di-n-butylamine, triethanolamine, ethanolamine, cyclohexylamine, diisopropanolamine, butyldiethanolamine, and a salt thereof;

and/or the defoaming agent is one or more of low molecular weight polysiloxane and low molecular weight polyether.

9. A method for preparing the brake fluid according to any one of claims 1 to 8, comprising the steps of:

s1, mixing the required amount of boric acid ester, silicone ester, diluent and antioxidant, heating, and keeping the vacuum at negative pressure for a certain time;

s2, cooling to a first temperature, and mixing with a required amount of corrosion inhibitor;

s3, cooling to a second temperature, and mixing with the required amount of the pH regulator and the defoaming agent;

preferably, the temperature is raised to 90-103 ℃;

preferably, the first temperature is 45-52 ℃;

preferably, the second temperature is room temperature.

10. The brake fluid preparation method according to claim 9, wherein the brake fluid should be detected after the brake fluid is prepared, and the detecting step includes:

firstly, taking a small amount of brake fluid to be balanced with atmospheric pressure in a flask, and boiling at a certain reflux speed to obtain a balanced reflux boiling point of the brake fluid;

then, a small amount of the brake fluid is filled into a clean capillary, and is put into an SSH32CX environmental condition test box, and the absolute verticality of a viscometer is adjusted to obtain the flowing time;

then, heating a small amount of the brake fluid to 180 ℃, keeping the temperature for 2 hours, and then heating to measure the equilibrium reflux boiling point of the brake fluid; mixing a small amount of the brake fluid with the compatible liquid with the same amount to determine the equilibrium reflux boiling point of the mixture;

thirdly, placing the detection metal test piece into the brake fluid to be submerged, covering the detection metal test piece, placing the detection metal test piece into a 100 ℃ drying oven, keeping the temperature for 120 hours, taking out the detection metal test piece, and cooling the detection metal test piece to obtain the quality of the detection metal test piece;

finally, the brake fluid is rated according to the following formula:

b＝γ*t

β＝(a-b)+(v-d)

F＝f₁(Q)+f₂(b)+f₃(η)+f₄(β)

in the above formula, F is the rating score, F₁As a function of boiling point score, f₂As a kinematic viscosity score function, f₃As a function of the corrosivity score, f₄Q is the equilibrium reflux boiling point of the brake fluid in the flask, η is the corrosivity of the brake fluid, m is the stability score function₁M is the mass of the test metal specimen before the test₂B is the kinematic viscosity of the brake fluid, gamma is the capillary constant of a viscometer, t is the flow time, β is the stability of the brake fluid, a is the equilibrium reflux boiling point of the brake fluid when the temperature is raised, b is the boiling point at constant temperature, v is the highest boiling point of the mixture, and d is the average boiling point of the mixture;

when F is larger than or equal to a preset threshold value, the brake fluid safety is good, the brake fluid can be put on the market, otherwise, the brake fluid safety does not reach the standard.

Technical Field

The invention relates to the field of motor vehicles, in particular to a brake fluid and a preparation method thereof.

Background

With the progress of human society and the development of automobile industry, the requirement for vehicle safety is higher and higher. The performance of the vehicle brake fluid, which is one of the safety components of the automobile, is directly related to the driving safety, and with the continuous improvement of the structure of the vehicle brake system, the performance requirement of the brake fluid playing a role of transmitting pressure in the brake system is higher and higher. The research on novel brake fluid with stable performance, long service life and prominent technical indexes is the focus and the direction of effort of technical research and development personnel.

Compared with various product standards (such as ISO 4925: 2005, GB12981-2012, JIS K2233 and the like) of brake fluid, the high-temperature and low-temperature performances of the brake fluid are improved along with the improvement of the product grade, and the high grade can be used instead of the low grade; however, the highest grade such as HZY6 in China only improves the low-temperature performance, but the high-temperature performance is reduced on the basis of the previous grade, such as that ERBP (equilibrium reflux boiling point) is reduced from 260 ℃ required by HZY5 to 250 ℃ required by HZY6, and WERBP (wet equilibrium reflux boiling point) is reduced from 180 ℃ to 165 ℃. Products meeting the high-grade index cannot completely replace the low-grade, and the existing products with the highest grade specification can only improve the low-temperature fluidity on the basis of sacrificing the high-temperature performance index. Because the existing scheme basically adopts a system of alcohol ether and alcohol ether borate, the synergy of the high and low temperature performances of the product is difficult to be considered.

Therefore, how to fully solve the high and low temperature performance of the brake fluid product is a difficult problem for technical developers. For example, in the patent of the invention with the patent publication number of CN104611092A advanced motor vehicle brake fluid composition, the proposal that triethylene glycol monomethyl ether borate accounts for 60-74% and diethylene glycol dibutyl ether accounts for 10-21% is adopted, and the final result is that the high-temperature performance can not meet the requirement of HZY 5; CN106281591A A novel all-weather automobile brake fluid uses polyalkylene glycol silicate as the base fluid of the brake fluid, the high temperature performance meets the requirement, but the low temperature performance (-40 ℃ kinematic viscosity) exceeds 1000mm²And/s, the performance requirements of HZY5/HZY6 cannot be met.

Disclosure of Invention

The invention aims to provide a high-performance brake fluid which meets all the existing standard index requirements, has extremely low water absorption and long service life.

The invention provides a brake fluid which is prepared from the following components in parts by weight:

20-60 parts of borate ester, 1-15 parts of silicon ester, 5-38 parts of diluent and 0.5-5 parts of composite additive package.

In some embodiments of the invention, the borate is selected from one or more of diethylene glycol methyl ether borate, diethylene glycol ethyl ether borate, diethylene glycol propyl ether borate, diethylene glycol butyl ether borate, triethylene glycol methyl ether borate, triethylene glycol ethyl ether borate, triethylene glycol propyl ether borate, triethylene glycol butyl ether borate, tetraethylene glycol methyl ether borate, tetraethylene glycol ethyl ether borate, tetraethylene glycol propyl ether borate, tetraethylene glycol butyl ether borate, preferably triethylene glycol butyl ether borate.

In some embodiments of the present invention, the silicone ester has the general structural formula R₃SiOR 'or (R' O)₂SiR₂Wherein R is an alkyl group and R' is ethylene glycol or a group containing a glycol ether; preferably, R is selected from C1-C6-containing hydrocarbon groups and naphthenic hydrocarbon groups.

In some embodiments of the invention, the diluent is selected from one or more of diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol propyl ether, triethylene glycol butyl ether, tetraethylene glycol methyl ether, tetraethylene glycol ethyl ether, tetraethylene glycol propyl ether, tetraethylene glycol butyl ether, preferably a mixture of triethylene glycol butyl ether and triethylene glycol methyl ether in a 1: 1 volume ratio.

In some embodiments of the present invention, the composite additive package is prepared from the following components in parts by weight:

30-70 parts of corrosion inhibitor, 15-30 parts of antioxidant, 5-15 parts of pH regulator and 0.2-5 parts of defoaming agent.

In some embodiments of the invention, the corrosion inhibitor comprises at least one of benzotriazole, tolyltriazole, and polydimethylsiloxane cationic emulsion, inorganic borate; preferably, the weight ratio of at least one of the benzotriazole and the tolyltriazole to the polydimethylsiloxane cationic emulsion and the inorganic borate is 2:2: 1.

In some embodiments of the invention, the antioxidant is a phenolic antioxidant.

In some embodiments of the present invention, the pH adjuster is an organic amine compound selected from one or more of di-n-butylamine, triethanolamine, ethanolamine, cyclohexylamine, diisopropanolamine, butyldiethanolamine, and salts thereof.

In some embodiments of the invention, the defoamer is one or more of a low molecular weight polysiloxane, a low molecular weight polyether.

A second aspect of the present invention provides the brake fluid preparation method of the first aspect, including the steps of:

s1, mixing the required amount of boric acid ester, silicone ester, diluent and antioxidant, heating, and keeping the vacuum at negative pressure for a certain time;

s2, cooling to a first temperature, and mixing with a required amount of corrosion inhibitor;

and S3, cooling to a second temperature, and mixing with required amount of pH regulator and defoaming agent.

In some embodiments of the invention, the temperature increase is to 90-103 ℃.

In some embodiments of the invention, the first temperature is 45-52 ℃. (ii) a

In some embodiments of the invention, the second temperature is room temperature.

In some embodiments of the present invention, after preparing the brake fluid, the brake fluid should be detected, and the detecting step includes:

firstly, taking a small amount of brake fluid to be balanced with atmospheric pressure in a flask, and boiling at a certain reflux speed to obtain a balanced reflux boiling point of the brake fluid;

then, a small amount of the brake fluid is filled into a clean capillary, and is put into an SSH32CX environmental condition test box, and the absolute verticality of a viscometer is adjusted to obtain the flowing time;

then, heating a small amount of the brake fluid to 180 ℃, keeping the temperature for 2 hours, and then heating to measure the equilibrium reflux boiling point of the brake fluid; mixing a small amount of the brake fluid with the compatible liquid with the same amount to determine the equilibrium reflux boiling point of the mixture;

thirdly, placing the detection metal test piece into the brake fluid to be submerged, covering the detection metal test piece, placing the detection metal test piece into a 100 ℃ drying oven, keeping the temperature for 120 hours, taking out the detection metal test piece, and cooling the detection metal test piece to obtain the quality of the detection metal test piece;

finally, the brake fluid is rated according to the following formula:

b＝γ*t

β＝(a-b)+(v-d)

F＝f₁(Q)+f₂(b)+f₃(η)+f₄(β)

in the above formula, F is the rating score, F₁As a function of boiling point score, f₂As a kinematic viscosity score function, f₃As a function of the corrosivity score, f₄Q is the equilibrium reflux boiling point of the brake fluid in the flask, η is the corrosivity of the brake fluid, m is the stability score function₁M is the mass of the test metal specimen before the test₂The mass of the test metal test piece after the test, b the kinematic viscosity of the brake fluid,_γis the capillary constant of the viscometer, t is the flow time, β is the stability of the brake fluid, a is the equilibrium reflux boiling point for temperature rise measurement, b is the boiling point at constant temperature, v is the maximum boiling point of the mixture, d is the average boiling point of the mixture;

when F is larger than or equal to a preset threshold value, the brake fluid safety is good, the brake fluid can be put on the market, otherwise, the brake fluid safety does not reach the standard.

The invention has the beneficial effects that:

the invention provides a high-performance brake fluid composition containing silicon ester and boric acid ester. The combination of single triethylene glycol monobutyl ether borate and silicone ester is adopted, the contradiction that the high-low temperature performance of the final product cannot be well coordinated is solved, and simultaneously, the low water sensitivity and the hydrolysis resistance of the product are ensured due to the synergistic effect, and the service life of the product can be greatly prolonged. The optimized silicon ester component is similar to the structures of alcohol ether and alcohol ether borate systems and can be completely compatible with each other, so that the brake fluid composition can be mixed with other synthetic brake fluids for use, and the market risk is reduced; the brake fluid composition of the invention effectively balances the lubricity, the corrosion resistance, the rust resistance and the rubber compatibility of the product, and each index of the product reaches or exceeds the index requirements of each level in the prior art, so that the brake fluid composition can be compatible with each level of product.

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

The following examples and comparative examples are parallel runs, with the same processing steps and parameters, unless otherwise indicated. Cationic polydimethylsiloxane emulsions in cationic emulsifiers such as dodecyldimethylbenzylammonium bromide (C)₁₂H₂₅Me₂C₆H₅CH₂N)⁺Br^-In the presence of alkali metal hydroxide as catalyst, at 50-100 deg.c, making cyclodimethyl siloxane D_nRing-opening polymerization in an aqueous system to obtain HO (Me) having a high degree of polymerization₂SiO)_nH, finally, the cyclosiloxane and the linear siloxane reach an equilibrium state. After the reaction is finished, neutralizing the base catalyst with acid, and terminating the reaction to obtain the final product. The solids content was 33%.

For simplicity of implementation, we cured the composite additive package in the examples, by weight:

the sum of the above components is 100.