A lubricant composition and its application in processing high weather-resistant PC hollow board

Abstract

The present invention discloses a lubricant composition and its application in the processing of highly weather-resistant PC hollow boards, and relates to the technical field of lubricant compositions. A lubricant composition comprises the following components, by mass: 40-60 parts of base oil, 5-15 parts of weather-resistant stabilizing additive, 3-8 parts of extreme pressure anti-wear agent, 2-6 parts of dispersant, 1-4 parts of antioxidant, 0.5-2 parts of coupling agent, and 20-30 parts of solvent. Through the molecular collaborative design of polar base oil and solvent, the thermal decomposition tendency of the processing process is significantly reduced, and the lubrication system is promoted to upgrade to a low-volatility, low-pollution green process. An innovative construction of a weather-resistant additive molecular skeleton with both antioxidant and anti-ultraviolet properties is achieved, realizing the integration of multiple protection mechanisms in the material processing and service stages, and reducing the dependence of traditional processes on the addition of secondary additives.

Description

Technical Field

[0001] The present invention relates to the technical field of lubricant compositions, and in particular to a lubricant composition and its application in the processing of highly weather-resistant PC hollow boards. Background Art

[0002] Polycarbonate (PC) hollow sheets are widely used in architectural lighting, advertising signs, agricultural greenhouses, transportation, and other fields due to their excellent light transmittance, impact resistance, lightweightness, and processability. However, when PC materials are exposed to harsh outdoor environments such as ultraviolet rays, temperature fluctuations, and humidity changes for a long time, they are prone to aging phenomena such as yellowing, embrittlement, and surface powdering, which seriously affect their service life and appearance. To improve the weather resistance of PC hollow sheets, the industry generally adopts modification methods such as adding UV absorbers and antioxidants. However, during the processing process, especially the extrusion molding stage, the choice of lubricant plays a key role in the stability of material properties.

[0003] Traditional PC processing lubricants are mostly based on mineral oil or silicone oil, supplemented with fatty acid ester lubricating components. While these lubricants can reduce melt viscosity and improve processing fluidity, they have significant drawbacks: First, mineral oil lubricants lack high-temperature resistance and are prone to thermal decomposition at PC processing temperatures, leading to the release of volatile organic compounds (VOCs). This not only pollutes the environment but also forms a foggy residue on the sheet surface, affecting light transmittance. Second, conventional lubricants have poor compatibility with PC resins, which can easily cause additive migration or precipitation. After long-term use, the sheet surface can become "sticky" or "white spots" appear, reducing product yield. Third, existing lubricants generally lack targeted weathering protection mechanisms and are unable to simultaneously enhance the antioxidant and UV resistance of the PC molecular chain during processing. Consequently, the final product still requires the addition of additives to achieve improved weathering resistance, increasing process complexity.

[0004] In recent years, some studies have attempted to introduce hindered amine light stabilizers (HALS) into lubrication systems. However, due to differences in molecular polarity, these additives have poor dispersion in non-polar base oils and are prone to agglomeration, which in turn exacerbates frictional heat accumulation during processing. Furthermore, while some extreme pressure anti-wear agents can improve wear on processing equipment, they can also react with PC molecules, resulting in a decrease in the material's impact strength. Therefore, developing a new lubricant that combines efficient lubrication with excellent thermal stability and forms long-lasting, synergistic weathering protection with PC resin has become an important approach to breaking through the performance bottleneck of PC hollow board. Summary of the Invention

[0005] The purpose of the present invention is to provide a lubricant composition with high-temperature stability, excellent compatibility and weather-resistant synergistic protection functions, which solves the problems of VOCs release, stability and insufficient weather resistance of traditional lubricants and is suitable for the processing of highly weather-resistant PC hollow boards.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a lubricant composition, comprising the following components, by mass: 40-60 parts of base oil, 5-15 parts of weathering stabilizing additive, 3-8 parts of extreme pressure anti-wear agent, 2-6 parts of dispersant, 1-4 parts of antioxidant, 0.5-2 parts of coupling agent, and 20-30 parts of solvent;

[0007] The weather-resistant stabilizing additive has a structure shown in Formula 1:

[0008] Formula 1;

[0009] The R1 is selected from the group consisting of: methyl, ethyl, methoxy, tert-butyl, phenyl, and propyl.

[0010] Furthermore, the extreme pressure anti-wear agent is selected from: tricresyl phosphate.

[0011] Furthermore, the dispersant is selected from: polyisobutylene succinimide.

[0012] Furthermore, the antioxidant is selected from: β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate.

[0013] Furthermore, the coupling agent is selected from: γ-aminopropyltriethoxysilane.

[0014] Furthermore, the solvent is selected from benzyl alcohol.

[0015] Furthermore, the base oil is selected from: trimethylolpropane ester.

[0016] Furthermore, the weather resistance stabilizing additive is any one of the compounds shown in the following structures:

[0017]

[0018] .

[0019] Furthermore, the synthesis method of the weather resistance stabilizing additive is:

[0020] ;

[0021] Step 1: Raw materials 1 and 2 are subjected to Williamson reaction to synthesize intermediate 1;

[0022] Step 2: Intermediate 1 and raw material 3 are subjected to Buchwald-Hartwig aromatic amination reaction to synthesize a weathering stabilizing additive.

[0023] A method for preparing a lubricant composition comprises the following steps:

[0024] S1. The base oil and solvent were added to the reactor, heated to 40-60 ° C, stirred and mixed at a speed of 300-500r / min for 10-20 minutes to form a homogeneous oil phase;

[0025] S2. The weathering stabilizer, extreme pressure anti-wear agent and antioxidant are sequentially added to the homogeneous oil phase, the temperature is controlled within the range of 50-70 ° C, and stirring is maintained for 30-60 minutes until completely dissolved;

[0026] S3. The dispersant and coupling agent are added, the system is heated to 70-80 ° C, stirred at 800-1000r / min for 40-90 minutes to form a transparent homogeneous system;

[0027] S4. Stop heating and cool naturally to room temperature to obtain the lubricant composition.

[0028] The invention discloses an application of a lubricant composition in the processing of highly weather-resistant PC hollow boards.

[0029] The lubricant of the present invention shows a trend of evolving towards high efficiency, environmental protection and functional integration in the processing of highly weather-resistant PC hollow boards. Through the synergy of high-temperature resistant base oil and polar solvent, the thermal stability of the lubrication system is enhanced and volatile pollution is reduced; innovative weather-resistant additives with adjustable molecular structures are introduced to achieve the integrated integration of antioxidant, anti-ultraviolet functions and lubrication performance; with the help of the directional effect of coupling agents and dispersants, the compatibility of additives and resins is improved, migration and precipitation are suppressed, and the flow uniformity of the processed melt is optimized; its preparation process accurately matches the material properties, promoting the development of PC products towards long-term weather resistance, lightweight and green manufacturing, which is in line with the upgrade needs of the high-end engineering plastics processing industry for multifunctional composite additives.

[0030] The core of the weathering stabilizing additive described in this invention is based on a benzene-nitrogen heterocyclic ring structure, consisting of a diaryl ring bridged by an ether bond and an aromatic amine group. The rigid diaryl rings create steric hindrance that inhibits thermal motion of the molecular chain at high temperatures, enhancing thermal stability. The nitrogen atom in the aromatic amine acts as a free radical capture site, quenching active free radicals generated during processing and use through a single electron transfer mechanism. Furthermore, the extended π-π conjugated system absorbs ultraviolet light in the 280-400 nm wavelength range, converting the light energy into harmless thermal vibrational energy dissipation. This triple mechanism achieves synergistic inhibition of thermal oxidative aging and photodegradation of polycarbonate materials at the molecular level. By combining the rigidity of the aromatic rings with the delocalized electrons, this core structure establishes an intrinsic weathering protection functional unit independent of substituent modification.

[0031] During the processing phase, γ-aminopropylsilane preferentially bonds with the polycarbonate surface hydroxyl groups to form anchor points. The trimethylolpropane ester base oil achieves intermolecular lubrication through ester-carbonyl polarity matching. Tricresol phosphate coordinates with the base oil's ester groups to construct a friction-reducing layer at the metalworking interface. The long-chain entanglement of polyisobutylene succinimide maintains the stable dispersion of the nanomicelles, while benzyl alcohol induces orderly assembly of the additive molecules through a hydrogen-bonding network. During the application phase, the hindered phenol antioxidant forms a redox cycle with the parent aromatic amine group, converting trapped free radicals into stable products. Ultraviolet light absorbed by the benzene nitrogen heterocycle is dissipated through the vibrational modes of the base oil's ester groups, while the silane-coupled interface layer inhibits the migration of small molecules through steric hindrance. This multi-scale synergistic network forms dynamic protection from three dimensions: molecular lubrication (phosphate-base oil coordination), interface anchoring (silane chemical bonding) and energy conversion (π-conjugated system photothermal conversion). It not only ensures the shear fluidity during the processing process, but also realizes the structural stability of the material during its service life, ultimately achieving the synergistic optimization of processing performance and weather resistance life.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] 1. Synergistic improvement of high-temperature stability and environmental protection: Through the molecular synergistic design of polar base oil and solvent, the tendency of thermal decomposition in the processing process is significantly reduced, and the lubrication system is promoted to upgrade to a low-volatility, low-pollution green process.

[0034] 2. Integrated integration of weathering protection functions: Innovatively construct a molecular framework of weathering additives with both antioxidant and UV resistance properties to achieve the integration of multiple protection mechanisms in the material processing and service stages, reducing the reliance on secondary additives in traditional processes.

[0035] 3. Breakthrough in long-term interface stability: Based on the structural matching of coupling agents and weathering agents, a dynamic anchoring network is formed, which effectively inhibits the migration and precipitation of additives, and promotes the evolution of PC products towards long-term weathering resistance with zero surface defects and extended service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The invention provides a method for synthesizing the weather-resistant stabilizing additive. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0038] Synthesis example 1:

[0039] like Figure 1 As shown, the synthesis of weathering stabilizing additive 1:

[0040] ;

[0041] Step 1: Under a nitrogen atmosphere, 20 g of raw material 1, 20.78 g of raw material 2, 40.98 g of potassium phosphate trihydrate, 0.7 g of CuI, 0.09 g of pyridine-2-carboxylic acid, and 250 g of DMSO were added to the reaction system, and the mixture was heated to 85° C. and reacted for 16 hours; after cooling, the reaction mixture was extracted with an ammonia solution and methyl tert-butyl ether, and the organic phase was washed five times with water and then twice with a saturated NaCl solution; finally, the combined organic phase was dried over anhydrous magnesium sulfate, spin-dried, and column chromatography was performed using a mixture of petroleum ether and dichloromethane as an eluent to obtain 21.84 g of intermediate 1.

[0042] Step 2: Under a nitrogen atmosphere, 21.84 g of intermediate 1, 28.15 g of raw material 3, 10.38 g of sodium tert-butoxide, 1.48 g of tris(dibenzylideneacetone)dipalladium, 0.5 g of tri-tert-butylphosphine, and 220 g of toluene were added to the reaction system, stirred evenly, heated to 105°C, and refluxed for 12 h. After the reaction, the temperature was slightly lowered, and the mixture was filtered through diatomaceous earth to remove salts and catalyst. The filtrate was cooled to room temperature and washed three times with water. The organic phase was retained, and the aqueous phase was extracted with ethyl acetate. The organic phases were combined, dried over anhydrous magnesium sulfate, and the solvent was removed using a rotary evaporator. The mixture was dissolved in petroleum ether / ethanol, recrystallized, filtered, and the filter cake was rinsed with petroleum ether multiple times and dried in a 60°C oven for 7 h to obtain 31.44 g of weathering stabilizing additive 1. MS (MS+1): 758.

[0043] 1 HNMR (deuterated chloroform) δ7.99-7.91 (m, 3H), 7.91-7.79 (m, 3H), 7.79-7.70 (m, 2H), 7.60-7.49 (m, 4H), 7.54-7.38 (m, 3H), 7.12-6.96 (m, 4H), 2.49 (s, 3H), 2.34 (t, 3H), 1.58-1.17 (m, 22H).

[0044] Synthesis Example 2-Synthesis Example 6:

[0045] The synthesis of the weathering stabilizing additive was carried out by referring to the synthesis method of Synthesis Example 1, except that the raw material 1 was replaced, and the rest of the process remained the same as Synthesis Example 1. The specific structure of the raw material 1, the structure of the weathering stabilizing additive, and the MS (MS+1) data are shown in Table 1.

[0046] Table 1. Structure of raw material 1, structure of weathering stabilizing additive and MS (MS+1) data involved in Synthesis Examples 2-6.

[0047]

[0048]

[0049] Example 1:

[0050] A lubricant composition consists of the following components, in parts by mass: 50 parts of trimethylolpropane ester (base oil), 10 parts of weathering stabilizing additive 1 (prepared in Synthesis Example 1), 5 parts of tricresyl phosphate (extreme pressure anti-wear agent), 4 parts of polyisobutylene succinimide (dispersant), 2 parts of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (antioxidant), 1 part of γ-aminopropyltriethoxysilane (coupling agent), and 25 parts of benzyl alcohol (solvent).

[0051] The preparation method comprises the following steps:

[0052] S1. Trimethylolpropane ester and benzyl alcohol were added to a reactor with a temperature control device, heated to a constant temperature of 50 ° C, and mechanically stirred at a speed of 400 r / min for 15 minutes to form a transparent homogeneous oil phase;

[0053] S2. Weathering stabilizer additive 1, tricresol phosphate, and antioxidant were sequentially added to the homogeneous oil phase. The reaction temperature was controlled at 60°C and stirred at 350 r / min for 45 minutes. The system was observed to change from a turbid solution to a clear solution.

[0054] S3. Polyisobutylene succinimide and γ-aminopropyltriethoxysilane were added, the system was heated to 75 ° C, switched to a high-speed disperser and stirred vigorously at 900 r / min for 60 minutes to obtain an amber transparent liquid with a viscosity of 220 mPa · s (25 ° C);

[0055] S4. Stop heating and cool naturally to room temperature to obtain a lubricant composition.

[0056] Example 2-Example 6:

[0057] A lubricant composition is prepared according to the method of Example 1, wherein the weather resistant stabilizing additive 1 is replaced by the weather resistant stabilizing additive 2 to the weather resistant stabilizing additive 6 prepared in Synthesis Examples 2 to 6, respectively, and the rest remains the same as in Example 1.

[0058] Comparative Example 1:

[0059] A lubricant composition is prepared according to the method of Example 1, except that the weathering stabilizing additive 1 is replaced with the comparative compound 1, and the rest of the ingredients remain the same as those of Example 1.

[0060] Comparative compound 1: .

[0061] Comparative Example 2:

[0062] A lubricant composition is prepared according to the method of Example 1, except that the weathering stabilizing additive 1 is not added, and the rest of the preparation is the same as in Example 1.

[0063] Performance testing:

[0064] 1. High temperature stability test: The thermal decomposition temperature of the lubricant composition was measured using a thermogravimetric analyzer. 10 mg of the sample was placed in a platinum crucible and heated at 10°C / min to 600°C under a nitrogen atmosphere. The temperature corresponding to 5% mass loss (T 5% ) and the maximum decomposition rate temperature (T max ), data see Table 2.

[0065] 2. Volatile Organic Compound (VOC) Emission Measurement: 1 g of the lubricant composition was evenly applied to a glass substrate (10 cm x 10 cm) and heated in a constant temperature oven at 250°C for 30 minutes. The total amount of VOCs released (μg / g) was collected and quantified using gas chromatography-mass spectrometry. The data are shown in Table 2.

[0066] 3. Long-term stability verification: The lubricant composition (1 wt%) was blended with PC resin and extruded into sheets. The PC sheets were then placed in a constant temperature and humidity chamber at 85°C / 85% RH for accelerated aging for 1000 h. The migration and precipitation of the surface additives were detected using Fourier transform infrared spectroscopy, and the change rate (%) of the characteristic peak intensity was calculated. The data are shown in Table 2.

[0067] Table 2. High temperature stability test data, volatile organic compound (VOCs) emission measurement data, and long-term stability verification data of a lubricant composition prepared in Examples and Comparative Examples.

[0068]

[0069] The weathering stabilization additive system significantly improves the thermal stability of the material, and its high-temperature decomposition threshold is systematically increased with the conjugation strengthening of the parent nucleus aromatic ring substituents; the release of volatile organic compounds is reduced by orders of magnitude due to the synergistic effect of the intermolecular hydrogen bond network and thermal stability, verifying the effectiveness of the component polarity matching on solvent locking; the extremely low fluctuation of the characteristic peak intensity change rate shows that the anchoring design of the coupling agent and the weathering agent successfully inhibits the migration of the additive, especially the system containing phenyl substitution further strengthens the interface bonding through the π-π stacking effect. However, due to the lack of collaborative design at the molecular level, the comparative example shows accelerated degradation characteristics in thermal decomposition, volatilization control and interface stability, confirming the structural defects of the traditional system in the long-term weathering protection mechanism. This cross-dimensional performance improvement trend fully reflects the innovative path of the trinity of "molecular rigidity design-interface anchoring strengthening-energy dissipation synergy" of the present invention.

[0070] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A lubricant composition, characterized in that The following components are included by mass: 40-60 parts of base oil, 5-15 parts of weathering stabilizing additive, 3-8 parts of extreme pressure anti-wear agent, 2-6 parts of dispersant, 1-4 parts of antioxidant, 0.5-2 parts of coupling agent, and 20-30 parts of solvent; The weathering stabilizing additive is any one of the compounds shown in the following structures: 。 2. A lubricant composition according to claim 1, characterized in that The extreme pressure anti-wear agent is selected from: tricresyl phosphate.

3. A lubricant composition according to claim 1, characterized in that: The dispersant is selected from the group consisting of polyisobutylene succinimide.

4. A lubricant composition according to claim 1, characterized in that The antioxidant is selected from: β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate.

5. A lubricant composition according to claim 1, characterized in that: The coupling agent is selected from: γ-aminopropyltriethoxysilane.

6. A lubricant composition according to claim 1, characterized in that: The solvent is selected from benzyl alcohol.

7. A lubricant composition according to claim 1, characterized in that: The base oil is selected from: trimethylolpropane ester.

8. A method for preparing a lubricant composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. The base oil and solvent were added to the reactor, heated to 40-60 ° C, stirred and mixed at a speed of 300-500r / min for 10-20 minutes to form a homogeneous oil phase; S2. The weathering stabilizer additive, extreme pressure anti-wear agent and antioxidant are sequentially added to the homogeneous oil phase, the temperature is controlled in the range of 50-70 ° C, and stirring is maintained for 30-60 minutes until completely dissolved; S3. The dispersant and coupling agent are added, the system is heated to 70-80 ° C, stirred at 800-1000r / min for 40-90 minutes to form a transparent homogeneous system; S4. Stop heating and cool naturally to room temperature to obtain the lubricant composition.

9. Use of the lubricant composition according to any one of claims 1 to 7 in the processing of highly weather-resistant PC hollow boards.

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