阅读说明：本技术 用于金属切削液的大粘度酯及其制备方法 (High-viscosity ester for metal cutting fluid and preparation method thereof ) 是由 钱莙 陈曦 尹艳洪 于 2020-12-31 设计创作，主要内容包括：本发明涉及一种用于金属切削液的大粘度酯及其制备方法,每个大粘度酯分子中包含2个聚乙二醇链段,2个环氧乙烷-环氧丙烷嵌段聚醚,3个苯环,不同链段均通过酯基相互连接。本大粘度酯粘度大又稳定,润滑效果强。制备方法包括步骤：(一)将含芳环二羧酸与聚乙二醇进行酯化反应；(二)配置环氧乙烷和环氧丙烷的混合物；(三)聚醚酯通入环氧乙烷和环氧丙烷进行链增长反应；(四)获得改性聚醚酯；(五)封端酯化反应；(六)将目标大粘度酯出料。本方法防止产生管道堵塞,方便控制化合物分子量。(The invention relates to a high-viscosity ester for metal cutting fluid and a preparation method thereof, wherein each high-viscosity ester molecule comprises 2 polyethylene glycol chain segments, 2 ethylene oxide-propylene oxide block polyethers and 3 benzene rings, and different chain segments are mutually connected through ester groups. The high-viscosity ester has high and stable viscosity and strong lubricating effect. The preparation method comprises the following steps: firstly, carrying out esterification reaction on dicarboxylic acid containing aromatic rings and polyethylene glycol; preparing a mixture of ethylene oxide and propylene oxide; (III) introducing ethylene oxide and propylene oxide into the polyether ester to carry out chain growth reaction; (IV) obtaining modified polyether ester; (V) end-capping esterification reaction; and (VI) discharging the target high-viscosity ester. The method prevents pipeline blockage and facilitates control of the molecular weight of the compound.)

1. A high viscosity ester for use in a metal cutting fluid, characterized by: each molecule comprises 2 polyethylene glycol (PEG) chain segments, 2 Ethylene Oxide (EO) -Propylene Oxide (PO) block polyethers and 3 benzene rings, and the different chain segments are connected with each other through ester groups.

2. The high viscosity ester for metal cutting fluid according to claim 1, characterized in that: the molecular structural formula is as follows:

。

3. a preparation method of high-viscosity ester for metal cutting fluid is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: adding a catalyst a, carrying out esterification reaction on aromatic ring-containing dicarboxylic acid and polyethylene glycol (PEG), combining hydroxyl in aromatic ring-containing dicarboxylic acid molecules and hydrogen atoms of hydroxyl in polyethylene glycol molecules into water, and combining the rest into polyether ester;

step two: preparing a mixture of ethylene oxide and propylene oxide according to the viscosity requirement or the freezing point requirement;

step three: putting the polyether ester generated in the step one into a reaction kettle, putting a catalyst b, vacuumizing and dehydrating until the moisture content is less than 0.1%, heating to 120-140 ℃, introducing a mixture of ethylene oxide and propylene oxide, opening an epoxy ring on an ethylene oxide or propylene oxide molecule by using alkoxy on a polyether ester molecule to generate new ester, and performing an epoxy ring opening reaction on the new ester and unreacted ethylene oxide or propylene oxide, wherein a polyether chain is continuously increased after the chain growth reaction is performed for many times;

step four: aging to constant pressure after the reaction in the third step to ensure that the polyether ester completely reacts with the ethylene oxide and the propylene oxide to obtain modified polyether ester, measuring the hydroxyl value of the modified polyether ester, and calculating the molecular weight;

step five: after the molecular weight of the hydroxyl value of the modified polyether ester obtained in the fourth step is calculated, adding benzoic acid with the molar ratio of 1: 4-4: 1 to the modified polyether ester obtained in the fourth step, adding a catalyst c, heating, carrying out end-capping esterification reaction, and replacing the hydroxyl at the tail end of the modified polyether ester with a functional group obtained after dehydrogenation of benzoic acid to generate corresponding ester;

step six: and fifthly, obtaining the target high-viscosity ester after the reaction is completed, and discharging the target high-viscosity ester.

4. The method of preparing a high viscosity ester for a metal cutting fluid according to claim 1, wherein: in the first step, the reaction temperature is 165-180 ℃, and the reaction time is 4-10 h.

5. The method of preparing a high viscosity ester for a metal cutting fluid according to claim 1, wherein: in the first step, the aromatic ring-containing dicarboxylic acid is phthalic acid, the polyethylene glycol is polyethylene glycol 200, and the phthalic acid and the polyethylene glycol are subjected to esterification reaction according to a molar ratio of 1: 4-4: 1, wherein the reaction formula is as follows:

。

6. the method of preparing a high viscosity ester for a metal cutting fluid according to claim 1, wherein: the molar ratio of ethylene oxide to propylene oxide in the second step is 1:1, and the reaction time in the third step is 4-10 h.

7. The method of preparing a high viscosity ester for a metal cutting fluid according to claim 1, wherein: and in the third step, the catalyst b is a catalyst used in the polyether synthesis process, and the catalyst is any one or any combination of alkoxide, hydroxide and bimetallic complex of alkali metal.

8. The method of preparing a high viscosity ester for a metal cutting fluid according to claim 7, wherein: the catalyst b is a bimetallic complex, and the added mass is one hundred thousandth to one ten thousandth of the total feeding mass.

9. The method of preparing a high viscosity ester for a metal cutting fluid according to claim 1, wherein: the catalyst a put in the step one and the catalyst c put in the step five are acid catalysts which are mixtures of any protonic acid and Lewis acid, the mass ratio of the protonic acid to the Lewis acid is 1: 4-4: 1, and the mass of the added catalyst is 0.1-0.5% of the total mass.

10. The method of preparing a high viscosity ester for a metal cutting fluid according to claim 9, wherein: the catalyst a added in the step one and the catalyst c added in the step five are a mixture of p-toluenesulfonic acid and dibutyltin dilaurate, wherein the mass ratio of the p-toluenesulfonic acid to the dibutyltin dilaurate is 1: 1.

Technical Field

The invention relates to a high-viscosity ester for a metal cutting fluid and a preparation method thereof, belonging to the technical field of organic chemistry.

Background

The polyether and the ester are common metal working fluid components, the ester compound has excellent lubricating property due to the property of the ester group and can form a stable oil film, and the polyether can obtain compounds with different viscosities, freezing points and cloud points by adjusting the molecular weight and the composition ratio of ethylene oxide EO-propylene oxide PO in the polyether. However, the current process for preparing polyethers and esters has the following problems: 1. when carboxylic acid and alcohol are esterified, the carboxylic acid is easy to sublimate, the reaction is uneven when the carboxylic acid is sublimated, the reaction can be further crosslinked, a plurality of other substances which are not needed are generated and mixed together, a material passing pipeline is blocked, danger is easily caused, the subsequent steps are more complicated, the production time is prolonged, and the production cost is increased. 2. The viscosity of the existing metal working fluid is not large enough, the lubricating effect is general, and certain processing requirements cannot be met. 3. The viscosity and freezing point of the resulting metalworking fluid cannot be well controlled, resulting in increased costs.

Disclosure of Invention

In order to solve the technical problems, the invention provides a high-viscosity ester for metal cutting fluid and a preparation method thereof, and the specific technical scheme is as follows:

a high-viscosity ester for metal cutting fluid contains 2 polyethylene glycol (PEG) segments, 2 Ethylene Oxide (EO) -Propylene Oxide (PO) block polyethers and 3 benzene rings in each molecule, wherein different segments are connected with each other through ester groups.

Further, the molecular structural formula is as follows:

a preparation method of high-viscosity ester for metal cutting fluid comprises the following steps:

the method comprises the following steps: adding a catalyst a, carrying out esterification reaction on aromatic ring-containing dicarboxylic acid and polyethylene glycol (PEG), combining hydroxyl in aromatic ring-containing dicarboxylic acid molecules and hydrogen atoms of hydroxyl in polyethylene glycol molecules into water, and combining the rest into polyether ester;

step two: preparing a mixture of ethylene oxide and propylene oxide according to the viscosity requirement or the freezing point requirement;

step three: putting the polyether ester generated in the step one into a reaction kettle, putting a catalyst b, vacuumizing and dehydrating until the moisture content is less than 0.1%, heating to 120-140 ℃, introducing a mixture of ethylene oxide and propylene oxide, opening an epoxy ring on an ethylene oxide or propylene oxide molecule by using alkoxy on a polyether ester molecule to generate new ester, and performing an epoxy ring opening reaction on the new ester and unreacted ethylene oxide or propylene oxide, wherein a polyether chain is continuously increased after the chain growth reaction is performed for many times;

step four: aging to constant pressure after the reaction in the third step to ensure that the polyether ester completely reacts with the ethylene oxide and the propylene oxide to obtain modified polyether ester, measuring the hydroxyl value of the modified polyether ester, and calculating the molecular weight;

step five: after the molecular weight of the hydroxyl value of the modified polyether ester obtained in the fourth step is calculated, adding benzoic acid with the molar ratio of 1: 4-4: 1 to the modified polyether ester obtained in the fourth step, adding a catalyst c, heating, carrying out end-capping esterification reaction, and replacing the hydroxyl at the tail end of the modified polyether ester with a functional group obtained after dehydrogenation of benzoic acid to generate corresponding ester;

step six: and fifthly, obtaining the target high-viscosity ester after the reaction is completed, and discharging the target high-viscosity ester.

Further, in the first step, the reaction temperature is 165-180 ℃, and the reaction time is 4-10 hours.

Further, in the step one, the aromatic ring-containing dicarboxylic acid is phthalic acid, the polyethylene glycol is polyethylene glycol 200, and the phthalic acid and the polyethylene glycol are subjected to esterification reaction according to a molar ratio of 1: 4-4: 1, wherein the reaction formula is as follows:

furthermore, the molar ratio of ethylene oxide to propylene oxide in the second step is 1:1, and the reaction time in the third step is 4-10 h.

Further, the catalyst b in the third step is a catalyst used in the polyether synthesis process, and the catalyst is any one or any combination of alkoxide, hydroxide and bimetallic complex of alkali metal.

Further, the catalyst b is a bimetallic complex, and the added mass is one hundred thousandth to one ten thousandth of the total feeding mass.

Further, the catalyst a put in the step one and the catalyst c put in the step five are acid catalysts which are mixtures of any protonic acid and Lewis acid, the mass ratio of the protonic acid to the Lewis acid is 1: 4-4: 1, and the mass of the added catalyst is 0.1-0.5% of the total mass.

Further, the catalyst a added in the step one and the catalyst c added in the step five are a mixture of p-toluenesulfonic acid and dibutyltin dilaurate, wherein the mass ratio of the p-toluenesulfonic acid to the dibutyltin dilaurate is 1: 1.

The invention has the beneficial effects that: the high-viscosity ester disclosed by the patent has the advantages of high and stable viscosity and strong lubricating effect. The preparation method of the high-viscosity ester can avoid substrate sublimation, reduce production waste and danger and reduce the influence on subsequent steps. The benzoic acid is used as a capping agent, so that the intermolecular interaction is enhanced, and a high-viscosity product is obtained. Products of different viscosities and freezing points can also be obtained by adjusting the ratio of ethylene oxide EO to propylene oxide PO. Can be prepared according to the needs, and is convenient for production.

Detailed Description

The high-viscosity ester for the metal cutting fluid has the following molecular structural formula:

of molecular structures of the initial reactant phthalic acidIs an intermediate functional group generated by the reaction of phthalic acid and polyethylene glycol (PEG) in the step one, and is in a molecular structural formulaThe intermediate functional group is an intermediate functional group which is increased by the chain extension reaction after the corresponding polyether ester reacts with the mixture of the ethylene oxide and the propylene oxide and then the ring opening of the epoxy ring of the ethylene oxide and the propylene oxide occurs,neutralizing the functional group connected after the benzoic acid reaction in the step five.

The preparation method of the high-viscosity ester for the metal cutting fluid comprises the following steps:

the method comprises the following steps: adding a catalyst a, carrying out esterification reaction on aromatic ring-containing dicarboxylic acid and polyethylene glycol (PEG), combining hydroxyl in aromatic ring-containing dicarboxylic acid molecules and hydrogen atoms of hydroxyl in polyethylene glycol molecules into water, and combining the rest into polyether ester, wherein the reaction temperature is 165-180 ℃, and the reaction time is 4-10 h. The aromatic ring-containing dicarboxylic acid is phthalic acid, the polyethylene glycol is polyethylene glycol 200, the phthalic acid and the polyethylene glycol are subjected to esterification reaction according to the molar ratio of 1: 4-4: 1, the added catalyst a is an acidic catalyst which is a mixture of any protonic acid and Lewis acid, the mass ratio of the protonic acid to the Lewis acid is 1: 4-4: 1, and the mass of the added catalyst is 0.1-0.5% of the total mass. The catalyst a is a mixture of p-toluenesulfonic acid and dibutyltin dilaurate, wherein the mass ratio of the p-toluenesulfonic acid to the dibutyltin dilaurate is 1: 1. The first reaction formula is as follows:

step two: and preparing a mixture of ethylene oxide and propylene oxide according to the viscosity requirement or the freezing point requirement, wherein the molar ratio of the ethylene oxide to the propylene oxide is 1: 1.

Step three: putting the polyether ester generated in the step one into a reaction kettle, putting a catalyst b, vacuumizing and dehydrating until the moisture is less than 0.1%, heating to 120-140 ℃, introducing a mixture of ethylene oxide and propylene oxide, opening an epoxy ring on an ethylene oxide or propylene oxide molecule by alkoxy on a polyether ester molecule to generate new ester, and performing an epoxy ring opening reaction on the new ester and unreacted ethylene oxide or propylene oxide, wherein the polyether chain is continuously increased after the chain extension reaction is performed for many times, the reaction time is 4-10 h, the catalyst b is a catalyst used in a polyether synthesis process, and any one or any combination of alkali metal alkoxide, hydroxide and a bimetallic complex is selected. The catalyst b is preferably a bimetallic complex, the mass added being one hundred thousandths to one ten thousandth of the total charge mass.

Step four: aging to constant pressure after the reaction in the third step to ensure that the polyether ester completely reacts with the ethylene oxide and the propylene oxide to obtain modified polyether ester, measuring the hydroxyl value of the modified polyether ester, and calculating the molecular weight;

step five: after the molecular weight of the hydroxyl value of the modified polyether ester obtained in the fourth step is calculated, adding benzoic acid, the molar ratio of which to the modified polyether ester obtained in the fourth step is 1: 4-4: 1, adding a catalyst c, heating, carrying out end-capping esterification reaction, replacing the hydroxyl at the tail end of the modified polyether ester with a functional group obtained after the benzoic acid is dehydrogenated to generate a corresponding ester, wherein the catalyst a added in the first step and the catalyst c added in the fifth step are acid catalysts which are mixtures of any protonic acid and Lewis acid, the mass ratio of the protonic acid to the Lewis acid is 1: 4-4: 1, the mass of the added catalysts is 0.1-0.5% of the total mass, and the added catalyst c is a mixture of p-toluenesulfonic acid and dibutyltin dilaurate, wherein the mass ratio of the p-toluenesulfonic acid to the dibutyltin dilaurate is 1: 1.

Step six: and fifthly, obtaining the target high-viscosity ester after the reaction is completed, and discharging the target high-viscosity ester.

The invention synthesizes ester with high viscosity by taking phthalic acid and other carboxylic acids containing aromatic rings as an initiator, benzoic acid as a capping agent and esterification and alkoxylation, and the product is firstly introduced with a section of ethylene oxide EO through esterification reaction to form a primary alcohol structure, so that the problem of inconvenient process caused by sublimation of the carboxylic acids when the phthalic acid and other carboxylic acids containing aromatic rings are directly connected with the ethylene oxide EO as the initiator is avoided. And once the initiator sublimes, the material passing is uneven in reaction, great influence is brought to the subsequent process, and the sublimed material may further perform a cross-linking reaction to block a material passing pipeline, so that danger is caused.

The invention takes phthalic acid and other carboxylic acids containing aromatic rings as an initiator and benzoic acid as an end-capping agent, and a large number of products containing aromatic rings as rigid structures mutually enhance intermolecular interaction through pi-pi accumulation, thereby being beneficial to obtaining products with high viscosity.

The preparation method can adjust the parameters of the product by adjusting different proportions of EO-PO, and can form a series of products according to the requirements of customers.

The following examples illustrate the beneficial effects achieved by the present invention:

blank comparative example: and (3) the metal workpiece without adding any cutting fluid.

Control group: and adding a conventional metal cutting fluid based on pentaerythritol tetraoleate to the metal workpiece.

Example 1:

the method comprises the following steps: 1mol of phthalic acid is taken, 2mol of polyethylene glycol 400 is added, 0.3 mass percent of a mixture of p-toluenesulfonic acid and dibutyltin dilaurate is added, and the mixture is heated and placed at 165 ℃ for reaction for 4 hours to obtain polyether ester.

Step two: preparing a mixture of 5mol of ethylene oxide and 5mol of propylene oxide,

step three: putting polyether ester into a reaction kettle, adding DMC with the total feeding amount of 0.08g as a catalyst, vacuumizing and dehydrating until the moisture content is less than 0.1%, heating and placing at 130 ℃ after the polyether ester is dehydrated, introducing a mixture of ethylene oxide and propylene oxide for reaction,

step four: and (3) aging until the pressure is unchanged after the reaction in the third step, so that the polyether ester completely reacts with the ethylene oxide and the propylene oxide to obtain modified polyether ester, measuring the hydroxyl value of the modified polyether ester, and calculating the molecular weight.

Step five: 2mol of benzoic acid and a mixture of 0.3 mass percent of p-toluenesulfonic acid and dibutyltin dilaurate are added into the modified polyether ester, and the mixture is heated and placed at 165 ℃ for reaction for 4 hours to obtain a final product.

Step six: and fifthly, obtaining the target high-viscosity ester after the reaction is completed, and discharging the target high-viscosity ester.

Example 2:

the method comprises the following steps: 1mol of phthalic acid is taken, 4mol of polyethylene glycol 200 is added, 0.3 mass percent of a mixture of p-toluenesulfonic acid and dibutyltin dilaurate is added, and the mixture is heated and placed at 165 ℃ for reaction for 4 hours to obtain polyether ester.

Step two: preparing a mixture of 5mol of ethylene oxide and 5mol of propylene oxide,

step three: putting polyether ester into a reaction kettle, adding DMC with the total feeding amount of 0.08g as a catalyst, vacuumizing and dehydrating until the moisture content is less than 0.1%, heating and placing at 130 ℃ after the polyether ester is dehydrated, introducing a mixture of ethylene oxide and propylene oxide for reaction,

step four: and (3) aging until the pressure is unchanged after the reaction in the third step, so that the polyether ester completely reacts with the ethylene oxide and the propylene oxide to obtain modified polyether ester, measuring the hydroxyl value of the modified polyether ester, and calculating the molecular weight.

Step five: 2mol of benzoic acid and a mixture of 0.3 mass percent of p-toluenesulfonic acid and dibutyltin dilaurate are added into the modified polyether ester, and the mixture is heated and placed at 165 ℃ for reaction for 4 hours to obtain a final product.

Step six: and fifthly, obtaining the target high-viscosity ester after the reaction is completed, and discharging the target high-viscosity ester.

Example 3:

the method comprises the following steps: 1mol of phthalic acid is taken, 2mol of polyethylene glycol 200 is added, 0.3 mass percent of a mixture of p-toluenesulfonic acid and dibutyltin dilaurate is added, and the mixture is heated and placed at 165 ℃ for reaction for 4 hours to obtain polyether ester.

Step two: preparing a mixture of 5mol of ethylene oxide and 5mol of propylene oxide,

step three: putting polyether ester into a reaction kettle, adding DMC with the total feeding amount of 0.08g as a catalyst, vacuumizing and dehydrating until the moisture content is less than 0.1%, heating and placing at 130 ℃ after the polyether ester is dehydrated, introducing a mixture of ethylene oxide and propylene oxide for reaction,

step four: and (3) aging until the pressure is unchanged after the reaction in the third step, so that the polyether ester completely reacts with the ethylene oxide and the propylene oxide to obtain modified polyether ester, measuring the hydroxyl value of the modified polyether ester, and calculating the molecular weight.

Step five: 2mol of benzoic acid and a mixture of 0.3 mass percent of p-toluenesulfonic acid and dibutyltin dilaurate are added into the modified polyether ester, and the mixture is heated and placed at 165 ℃ for reaction for 4 hours to obtain a final product.

Step six: and fifthly, obtaining the target high-viscosity ester after the reaction is completed, and discharging the target high-viscosity ester.

The preparations obtained in examples 1 to 3 were added to metal workpieces to measure different indices. As shown in table 1 below:

TABLE 1

From table 1, it can be seen that when no cutting agent is used, the four-ball PB value is low, the tapping torque is small, the viscosity at 40 ℃ is 1600mpa.s, both are small, and the strength is low; when the conventional metal cutting fluid based on pentaerythritol tetraoleate is used, the PB value, the tapping torque and the viscosity at 40 ℃ of the four balls are improved to different degrees; after the high-viscosity ester for the metal cutting fluid disclosed by the invention is used, the four-ball PB value, the tapping torque and the viscosity at 40 ℃ are greatly increased, and researches show that the high-viscosity ester for the metal cutting fluid disclosed by the invention has the characteristics of high viscosity and strong lubricating force, and has a better application prospect.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.