CN112341558A

CN112341558A - Polymer microsphere, preparation method thereof and lubricating grease composition

Info

Publication number: CN112341558A
Application number: CN202011181344.9A
Authority: CN
Inventors: 童蓉; 李士成; 胡秋波; 岳风树; 池丽林
Original assignee: Shenzhen Eubo New Material Technology Co ltd
Current assignee: Shenzhen Eubo New Material Technology Co ltd
Priority date: 2020-10-29
Filing date: 2020-10-29
Publication date: 2021-02-09
Anticipated expiration: 2040-10-29
Also published as: CN112341558B

Abstract

The application belongs to the technical field of noise-reducing and wear-resisting materials, and particularly relates to a polymer microsphere, a preparation method thereof and a lubricating grease composition. The preparation method of the polymer microsphere comprises the following steps: dissolving an initiator, a styrene monomer and an alkenyl-containing anti-wear compound in a hydrophobic solvent to obtain an oil phase solution; dissolving an emulsifier in water to obtain an aqueous phase solution; and mixing the oil phase solution and the water phase solution, carrying out polymerization reaction under the stirring condition, and then carrying out solid-liquid separation to obtain the polymer microsphere. The preparation method can obtain the hollow polymer microspheres with excellent noise reduction performance and friction and wear resistance, and the prepared polymer microspheres are used in the lubricating grease, so that the noise reduction and wear resistance effects of the lubricating grease can be improved, the service life of the lubricating grease can be prolonged, and the lubricating grease has a good application prospect.

Description

Polymer microsphere, preparation method thereof and lubricating grease composition

Technical Field

The application belongs to the technical field of noise-reducing and wear-resisting materials, and particularly relates to a polymer microsphere, a preparation method thereof and a lubricating grease composition.

Background

The gear transmission has the characteristics of compact structure, high transmission efficiency, large speed range and the like, and is widely applied to mechanical devices such as vehicles, machine tools and the like. However, noise generated by gear transmissions is a major contributor to noise generated by such machines. The frequency of noise generated by transmission gears of a transmission, a reducer and the like is 400-2000 hertz (Hz), and the frequency range is easy to feel by human hearing.

Porous polymers and hollow microspheres are widely concerned and applied in the fields of sound absorption and damping and the like. The hollow microsphere material has low density, large effective area, heat insulation, sound absorption and light shielding performance, and the hollow microsphere structure material can weaken the transmission of sound by utilizing the transmission difference of sound waves in different media.

With the development of the industry, mechanical transmission puts higher requirements on the silence and the service life of lubricating grease, and also puts high requirements on the lubrication durability and the wear resistance of the lubricating grease. In order to ensure the precision and reliability of gear transmission, the selection of the lubricating grease for the gear is extremely important, the silencing and noise reducing effects of the gear transmission are ensured, and the lubricating grease has good wear resistance, so that the corresponding service life requirement is met. However, the comprehensive effect of the corresponding grease is still not ideal at present.

Disclosure of Invention

The application aims to provide a polymer microsphere, a preparation method thereof and a lubricating grease composition, and aims to solve the problem of how to improve the noise reduction and wear resistance of lubricating grease.

In order to achieve the purpose of the application, the technical scheme adopted by the application is as follows:

in a first aspect, the present application provides a method for preparing polymeric microspheres, comprising the steps of:

dissolving an initiator, a styrene monomer and an alkenyl-containing anti-wear compound in a hydrophobic solvent to obtain an oil phase solution;

dissolving an emulsifier in water to obtain an aqueous phase solution;

and mixing the oil phase solution and the water phase solution, carrying out polymerization reaction under the stirring condition, and then carrying out solid-liquid separation to obtain the polymer microsphere.

In a second aspect, the present application provides a polymeric microsphere, which is prepared by the above-mentioned preparation method of the present application.

The polymer microsphere provided by the application is prepared by a preparation method of the polymer microsphere, and the preparation method is obtained by two-phase polymerization reaction, specifically, an oil phase solution containing an initiator, a styrene monomer and an alkenyl-containing anti-wear compound and a water phase solution containing an emulsifier are mixed and subjected to polymerization reaction under stirring conditions, so that the hollow polymer microsphere is obtained. The preparation method has simple process and low cost, can obtain the hollow polymer microspheres with excellent noise reduction performance and friction and wear resistance, and when the prepared polymer microspheres are used in lubricating grease, the noise reduction and wear resistance effects of the lubricating grease can be improved, the service life of the lubricating grease can be prolonged, and the preparation method has good application prospects.

In a third aspect, the present application provides a grease composition, comprising the following components in the following weight percentages, based on the total weight of the grease composition as 100%:

the third aspect of the present application provides a grease composition, wherein the polymer microspheres specific to the present application are added on the basis of the base oil and the thickener, and the polymer microspheres have excellent noise reduction performance and friction and wear resistance, so that the noise reduction and wear resistance effects of the grease composition can be significantly improved, and the grease composition has a very good service life.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic flow chart of a method for preparing polymeric microspheres according to embodiments of the present disclosure.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application more clearly apparent, the present application is further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The weight of the related components mentioned in the description of the embodiments of the present application may not only refer to the specific content of each component, but also represent the proportional relationship of the weight among the components, and therefore, the content of the related components is scaled up or down within the scope disclosed in the description of the embodiments of the present application as long as it is scaled up or down according to the description of the embodiments of the present application. Specifically, the mass described in the specification of the embodiments of the present application may be a mass unit known in the chemical industry field such as μ g, mg, g, kg, etc.

In a first aspect, embodiments of the present application provide a method for preparing a polymer microsphere, as shown in fig. 1, the method includes the following steps:

s01: dissolving an initiator, a styrene monomer and an alkenyl-containing anti-wear compound in a hydrophobic solvent to obtain an oil phase solution;

s02: dissolving an emulsifier in water to obtain an aqueous phase solution;

s03: and mixing the oil phase solution and the water phase solution, carrying out polymerization reaction under the stirring condition, and then carrying out solid-liquid separation to obtain the polymer microsphere.

The preparation method of the polymer microsphere provided by the application is prepared through two-phase polymerization, and specifically, an oil phase solution containing an initiator, a styrene monomer and an alkenyl-containing wear-resistant compound and a water phase solution containing an emulsifier are mixed and subjected to polymerization reaction under stirring conditions, so that the hollow polymer microsphere is obtained. The preparation method has simple process and low cost, can obtain the hollow polymer microspheres with excellent noise reduction performance and friction and wear resistance, and when the prepared polymer microspheres are used in lubricating grease, the noise reduction and wear resistance effects of the lubricating grease can be improved, the service life of the lubricating grease can be prolonged, and the preparation method has good application prospects.

Specifically, the polymer microspheres obtained by the preparation method are hollow polystyrene microspheres. In some embodiments, the initiator is selected from at least one of azo-type initiators, organic peroxy-type initiators, and oxidation-reduction type initiators; specifically, the azo-based initiator includes azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptonitrile, azobisisobutyronitrile formamide, azobiscyclohexylcarbonitrile, dimethyl azobisisobutyrate, and the like, the organic peroxy-based initiator includes benzoyl peroxide, peroxydicarbonate, dicumyl peroxide, di-t-butyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, and the like, and the oxidation-reduction-based initiator includes ammonium persulfate/sodium bisulfite, potassium persulfate/sodium bisulfite, hydrogen peroxide/tartaric acid, ammonium persulfate/ferrous sulfate, hydrogen peroxide/ferrous sulfate, potassium persulfate/ferrous chloride, hydrogen peroxide/ferrous chloride, and the like. Further, azobisisobutyronitrile or benzoyl peroxide is preferable. Further, the weight ratio of the initiator to the styrene monomer is 0.1-2: 100, respectively; mixing the initiator with the weight of 0.1-2.0% of the weight of the styrene monomer, preferably 0.5-1.5%, wherein if the proportion of the initiator is too low, the active free radicals are insufficient, and the molding of the polystyrene microspheres is possibly influenced; if the proportion of the initiator is too high, the reaction system becomes unstable and the occurrence of blocking is liable to occur, so that the effects are more excellent within the above-mentioned preferred proportion range.

In some embodiments, the alkenyl-containing antiwear compound is selected from at least one of an alkenyl phosphate and an alkenyl borate; specifically, the alkenyl phosphate may be vinyl phosphate, dimethyl vinyl phosphate, propylene diphosphate, or the like, and the alkenyl borate may be dibutyl vinyl borate, or the like. Further, the weight ratio of the alkenyl-containing antiwear compound to the styrene monomer is 1-3: 10, namely, the weight of the alkenyl-containing anti-wear compound is 10-30% of the weight of the styrene monomer, preferably 10-20%, the higher the content of the alkenyl-containing anti-wear compound is, more anti-wear groups can be introduced into the microsphere, so that the anti-wear effect of the microsphere is better enhanced, but the higher the content is, the particle size and polymerization degree of the polystyrene microsphere can be influenced, the content of the anti-wear compound groups and the particle size of the polystyrene are comprehensively considered, and the proportion is preferably selected.

In some embodiments, the hydrophobic solvent is selected from a C8-C16 linear alkane and/or a C8-C16 isoparaffin, such as isooctane or hexadecane, and the like. Further, the weight ratio of the hydrophobic solvent to the total weight of the styrene monomer and the alkenyl-containing antiwear compound is 0.5-2: 1, mixing and dissolving a hydrophobic solvent which is 0.5-2 times of the total weight of a styrene monomer and an alkenyl-containing anti-wear compound into an oil phase solution; the hydrophobic solvent influences the formation of the hollow structure of the styrene microsphere, the proportion is too small, the formed hollow structure is not ideal, the proportion is too high, the polymerization of the polystyrene is influenced, and the effect of the hydrophobic solvent in the proportion range is optimal.

In some embodiments, the emulsifier is selected from at least one of sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, span 80, and span 60; further, the weight ratio of the emulsifier to the oil phase solution is 3-5: 100, namely mixing the oil phase solution with the water phase solution according to the weight of the emulsifier accounting for 3-5% of the total weight of the oil phase solution; the proportion of the emulsifier influences the particle size of the polystyrene microspheres, the more the emulsifier is used, the smaller the particle size is, but the too much emulsifier is accumulated on the surfaces of the microspheres to influence the reaction, and the purification of the later-stage product is difficult; therefore, the emulsification effect is better in the above proportion.

In some embodiments, the polymerization reaction is at a temperature of 50 ℃ to 90 ℃ for a time of at least 15 hours; and under the action of mechanical stirring, heating to 50-90 ℃ for polymerization reaction. Further, the time of the polymerization reaction is 20 to 24 hours.

In some embodiments, the solid-liquid separation is centrifugation, specifically, centrifugation and vacuum drying, to obtain the powdery polymer microspheres.

In one embodiment, a method for preparing polystyrene polymer microspheres comprises:

1) preparing an oil phase solution: dissolving an initiator in a styrene monomer, an alkenyl-containing anti-wear compound and a hydrophobic solvent, and uniformly stirring to obtain an oil phase solution;

2) preparing an aqueous phase solution: the emulsifier is dissolved in distilled water to obtain an aqueous solution.

3) Adding the oil phase into the water phase at room temperature (25 ℃), uniformly dispersing by ultrasonic, heating to 50-90 ℃ under the action of mechanical stirring, carrying out polymerization reaction for 20-24 hours, carrying out centrifugal separation and vacuum drying, and releasing a hydrophobic solvent to obtain the powdery noise-reduction and wear-resistance polystyrene hollow polymer microspheres.

In a second aspect, embodiments of the present application provide a polymeric microsphere, which is prepared by the above preparation method of the present application.

The polymer microsphere is prepared by the preparation method of the polymer microsphere, is a sound-deadening and wear-resistant polystyrene hollow polymer microsphere, can be used in lubricating grease, can improve the sound-deadening and wear-resistant effects of the lubricating grease, can prolong the service life of the lubricating grease, and has a good application prospect.

In a third aspect of the embodiments of the present application, there is provided a grease composition, including the following components in the following weight percentages, based on the total weight of the grease composition as 100%:

the lubricating grease composition provided by the application is added with the polymer microspheres specific to the application on the basis of base oil and a thickening agent, and the polymer microspheres have excellent noise reduction performance and friction and abrasion resistance, so that the noise reduction and abrasion resistance effects of the lubricating grease composition can be obviously improved, and the lubricating grease composition has a long service life.

In some embodiments, the base oil in the grease composition is selected from at least one of poly-alpha olefins, silicone oils, and ester oils; specifically, the viscosity of the base oil at 40 ℃ is 16-50 mm²(ii)/S, pour point less than-50 ℃. The content of the base oil is 40 to 90%, and specifically 40%, 45%, 50%, 60%, 70%, 80%, 90%, or the like.

In some embodiments, the thickener in the grease composition is a soap-based thickener selected from at least one of a lithium-based thickener (e.g., a composite lithium-based thickener), an aluminum-based thickener (e.g., a composite aluminum-based thickener), Melamine Cyanurate (MCA), Polytetrafluoroethylene (PTFE), and silica gel; the content of the thickener is 4-50%, specifically 4%, 5%, 10%, 20%, 30%, 40%, 50% and the like.

In some embodiments, the other additive in the grease composition is selected from at least one of an antioxidant and a rust inhibitor. For example, the antioxidant is an amine antioxidant or a high-molecular phenol antioxidant, and the rust inhibitor is a benzotriazole derivative. The content of other additives is 0.1-3%, specifically 0.1%, 0.5%, 1%, 2%, 3%, etc.

In some embodiments, the polymer microspheres in the grease composition are polymer microspheres obtained by the above-mentioned preparation method of the present application. Specifically, the content of the polymer microspheres can be 4-20%, such as 4%, 5%, 15%, 18%, 20%, and the like.

In some embodiments, the grease composition is prepared by a method comprising: mixing and saponifying the base oil and the thickening agent, homogenizing, then mixing and stirring uniformly with the polymer microspheres and other additives, grinding and filtering to obtain the gear lubricating grease product.

The application develops the silencing and wear-resistant lubricating grease which has excellent silencing and noise-reducing performances and good wear resistance, and the lubricating grease meets the market demand very well. Polystyrene hollow polymer microspheres with sound absorption function are modified by using an alkenyl-containing anti-wear compound, and the material is applied to lubricating grease to form the lubricating grease with excellent noise reduction and anti-wear properties. The lubricating grease composition is applied to the noise reduction and the noise reduction of metal or plastic gears of various machines, automobiles, office equipment and the like, and plays roles of lubrication and friction reduction.

The following description will be given with reference to specific examples.

Example 1

1. Preparation of noise-reducing wear-resistant polymer microsphere

(1) Preparing an oil phase: dissolving 5.0g of benzoyl peroxide in 500.0g of styrene monomer, 75.0g of vinyl phosphate and 580.0g of isooctane, and uniformly stirring to obtain an oil phase;

(2) preparing an aqueous phase: 46.4g of sodium dodecylbenzenesulfonate was dissolved in 3.5kg of distilled water to obtain an aqueous phase.

(3) Adding the oil phase into the water phase at room temperature, ultrasonically dispersing for 20min, uniformly dispersing, heating to 65 ℃, reacting for 22 h under the mechanical stirring action of 900r/min, and cooling to room temperature. And centrifugally separating the obtained emulsion, and then drying in vacuum at 60 ℃ to obtain the powdery wear-resistant polystyrene hollow polymer microspheres.

2. Preparation of grease composition

(1) 320g of PAO6 poly-alpha olefin synthetic base oil and 80g of 12 hydroxystearic acid are added into a 1L reaction kettle and heated to 90-95 ℃ for dissolution.

(2) Slowly adding 12g of lithium hydroxide monohydrate (dissolved by heating with 70g of water) into a reaction kettle with the volume of 1L, and stirring and saponifying for 1h at 90-110 ℃.

(3) After the saponification reaction is finished, heating to 140-160 ℃, dehydrating for 30min until no water vapor escapes, and adding 160g of PAO 6.

(4) Heating and stirring are continued, the heating and the temperature rise are stopped when the temperature rises to 210-220 ℃ under normal pressure, the temperature is kept constant for 5-10min, 160g of PAO6 is added, and the temperature is reduced to form grease.

(5) Stirring and cooling to 110 ℃ and 120 ℃, and homogenizing by a homogenizer under the pressure of 25-35 MPa.

(6) Adding 80g of the wear-resistant polystyrene hollow polymer microspheres prepared in the step 1, and a small amount of amine antioxidant L57 and benzotriazole derivative T551 (accounting for about 1% of the total weight of the lubricating grease composition), and uniformly stirring.

(7) And grinding the lubricating grease for three times at medium speed by a three-roller grinder, and filtering by a 300-mesh sieve to obtain the gear lubricating grease product.

Example 2

1. Preparation of noise-reducing wear-resistant polymer microsphere

(1) Preparing an oil phase: dissolving 2.5g of benzoyl peroxide in 500.0g of styrene monomer, 100.0 g of dibutyl vinylborate and 900g of hexadecane, and uniformly stirring to obtain an oil phase;

(2) preparing an aqueous phase: 75.0g of sodium dodecylbenzenesulfonate was dissolved in 6.0kg of distilled water to obtain an aqueous phase.

(3) Adding the oil phase into the water phase at room temperature, ultrasonically dispersing for 20min, uniformly dispersing, heating to 85 ℃, reacting for 24 hours under the mechanical stirring action of 900r/min, and cooling to room temperature. And centrifugally separating the obtained emulsion, and then drying in vacuum at 65 ℃ to obtain the powdery wear-resistant polystyrene hollow polymer microspheres.

2. Preparation of grease composition

Comparative example

Preparation of grease composition

(1) Adding 360g of PAO6 poly-alpha olefin synthetic base oil and 80g of 12 hydroxystearic acid into a 1L reaction kettle, and heating to 90-95 ℃ for dissolution.

(2) Slowly adding 15g of lithium hydroxide monohydrate (dissolved by heating with 75g of water) into a reaction kettle with the volume of 1L, and stirring and saponifying for 1h at 90-110 ℃.

(3) After the saponification reaction is finished, heating to 140-160 ℃, dehydrating for 30min until no water vapor escapes, and adding 180g of PAO 6.

(4) Heating and stirring are continued, the heating and the temperature rise are stopped when the temperature rises to 210-220 ℃ under normal pressure, the temperature is kept constant for 5-10min, then 180g of PAO6 is added, and the temperature is reduced to form grease.

(6) Adding amine antioxidant L57 and benzotriazole derivative T551, and stirring.

Comparison of Performance test results

The grease compositions obtained in the above examples and comparative examples were subjected to performance tests by the following methods:

the cone penetration tester is used for testing the cone penetration of the lubricating grease, the lubricating grease steel mesh oil distribution tester is used for testing the oil distribution amount of the lubricating grease steel mesh, the universal friction wear testing machine is used for testing the friction wear performance (the diameter of a grinding spot and the friction coefficient) of the lubricating grease, and the noise meter is used for testing the running noise of the lubricating grease in the gearbox.

The results are shown in Table 1.

TABLE 1

From the above, the grease composition prepared in the examples of the present application has better noise reduction and wear resistance effects.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A preparation method of polymer microspheres is characterized by comprising the following steps:

dissolving an emulsifier in water to obtain an aqueous phase solution;

2. The method of claim 1, wherein the polymeric microspheres are hollow polystyrene microspheres.

3. The method of claim 1, wherein the polymerization is at a temperature of 50 to 90 ℃ for at least 15 hours.

4. The method according to claim 1, wherein the initiator is at least one selected from the group consisting of azo type initiators, organic peroxy type initiators, and oxidation-reduction type initiators; and/or the presence of a gas in the gas,

the alkenyl-containing antiwear compound is selected from at least one of alkenyl phosphate and alkenyl borate; and/or the presence of a gas in the gas,

the emulsifier is at least one selected from sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium dodecyl sulfate, span 80 and span 60; and/or the presence of a gas in the gas,

the hydrophobic solvent is selected from C8-C16 straight-chain alkane and/or C8-C16 isoparaffin.

5. The method according to any one of claims 1 to 4, wherein the weight ratio of the initiator to the styrene monomer is 0.1 to 2: 100, respectively; and/or the presence of a gas in the gas,

the weight ratio of the alkenyl-containing antiwear compound to the styrene monomer is 1-3: 10.

6. the method of any one of claims 1-4, wherein the weight ratio of the hydrophobic solvent to the total weight of the styrene monomer and the alkenyl-containing antiwear compound is from 0.5 to 2: 1; and/or the presence of a gas in the gas,

the weight ratio of the emulsifier to the oil phase solution is 3-5: 100.

7. a polymer microsphere, wherein the polymer microsphere is prepared by the preparation method of any one of claims 1 to 6.

8. A lubricating grease composition is characterized by comprising the following components in percentage by weight based on the total weight of the lubricating grease composition as 100 percent:

9. a grease composition according to claim 8, wherein the base oil is selected from at least one of poly-alpha olefins, silicone oils, and ester oils; and/or the presence of a gas in the gas,

the viscosity of the base oil at 40 ℃ is 16-50 mm²(ii)/S, pour point less than-50 ℃.

10. The grease composition according to claim 8, wherein the thickener is a soap-based thickener selected from at least one of a lithium-based thickener, an aluminum-based thickener, melamine cyanurate, polytetrafluoroethylene, and silica gel; and/or the presence of a gas in the gas,

the other additive is at least one selected from an antioxidant and a rust inhibitor.