Lubricant composition and application thereof in processing of high-weather-resistance PC hollow plate

Abstract

The invention discloses a lubricant composition and application thereof in processing of a high-weather-resistance PC hollow plate, and relates to the technical field of lubricant compositions. The lubricant composition comprises the following components in parts by mass: 40-60 parts of base oil, 5-15 parts of a weather-resistant stable additive, 3-8 parts of an anti-wear reagent at extreme pressure, 2-6 parts of a dispersing agent, 1-4 parts of an antioxidant, 0.5-2 parts of a coupling agent and 20-30 parts of a solvent. Through the molecular collaborative design of the polar base oil and the solvent, the thermal decomposition tendency in the processing process is remarkably reduced, and a lubricating system is promoted to be upgraded to a low-volatilization and low-pollution green process direction. A weather-resistant additive molecular skeleton with anti-oxidation and anti-ultraviolet characteristics is innovatively constructed, integration of multiple protection mechanisms in material processing and service stages is realized, and dependence on secondary addition of auxiliaries in a traditional process is reduced.

Description

Technical Field

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

[0002] Polycarbonate (PC) hollow plates are widely used in fields such as building lighting, advertising signs, agricultural greenhouses, and transportation due to their excellent light transmittance, impact resistance, light weight, and processability. However, when PC materials are exposed to harsh environments such as ultraviolet rays, temperature fluctuations, and humidity changes outdoors 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 performance. To improve the weather resistance of PC hollow plates, the industry generally adopts modification methods such as adding ultraviolet absorbers and antioxidants. However, in the processing process, especially in the extrusion molding stage, the selection of lubricants plays a key role in the stability of material properties.

[0003] Traditional PC processing lubricants are mostly based on mineral oils or silicone oils, supplemented with fatty acid ester lubricating components. Although such lubricants can reduce the melt viscosity and improve the processing fluidity, they have obvious defects: First, mineral oil-based lubricants have insufficient high-temperature resistance and are prone to thermal decomposition at the PC processing temperature, resulting in the release of volatile organic compounds (VOCs), which not only pollutes the environment but also forms a foggy residue on the surface of the plates, affecting the light transmittance; Second, the compatibility of conventional lubricants with PC resins is poor, which is prone to cause the migration or precipitation of additives, and after long-term use, the surface of the plates appears "sticky" or "white spots" phenomena, reducing the product yield; Third, existing lubricants generally lack a targeted weather resistance protection mechanism and cannot simultaneously improve the antioxidant and anti-ultraviolet capabilities of PC molecular chains during the processing process, resulting in the final products still relying on post-added additives to achieve weather resistance improvement, increasing the process complexity.

[0004] In recent years, there have been studies attempting to introduce hindered amine light stabilizers (HALS) into the lubrication system. However, due to the difference in molecular polarity, the dispersion of such additives in non-polar base oils is poor and they are prone to agglomeration, which instead exacerbates the accumulation of frictional heat during the processing process. In addition, although some extreme pressure and anti-wear agents can improve the wear of processing equipment, they will react with PC molecules, resulting in a decrease in the impact strength of the material. Therefore, developing a new type of lubricant with both high lubrication performance, excellent thermal stability, and the ability to form a long-term synergistic weather resistance protection with PC resin has become an important direction to break through the performance bottleneck of PC hollow plates. 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 resistance synergistic protection functions, to solve the problems of insufficient VOCs release, stability, and weather resistance of traditional lubricants, and to be applicable to the processing of high-weather-resistant PC hollow plates.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a lubricant composition, comprising the following components by mass parts: 40 - 60 parts of base oil, 5 - 15 parts of weather-resistant stabilizer additive, 3 - 8 parts of extreme pressure and 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 weather-resistant stabilizer additive has the structure shown in Formula 1: Formula 1; R1 is selected from: methyl, ethyl, methoxy, tert-butyl, phenyl, propyl.

[0007] Further, the extreme pressure and anti-wear agent is selected from: tricresyl phosphate.

[0008] Further, the dispersant is selected from: polyisobutylene succinimide.

[0009] Further, the antioxidant is selected from: n-octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0010] Further, the coupling agent is selected from: γ-aminopropyltriethoxysilane.

[0011] Further, the solvent is selected from: benzyl alcohol.

[0012] Further, the base oil is selected from: trimethylolpropane ester.

[0013] Further, the weather-resistant stabilizer additive is any one of the compounds shown in the following structures: .

[0014] Further, the synthesis method of the weather-resistant stabilizer additive is: ; The first step: Intermediate 1 is synthesized by the Williamson reaction of Raw material 1 and Raw material 2; The second step: The weather-resistant stabilizer additive is synthesized by the Buchwald-Hartwig arylamination reaction of Intermediate 1 and Raw material 3.

[0015] A preparation method of a lubricant composition, comprising the following steps: S1. Add the base oil and the solvent into a reaction kettle, heat up to 40 - 60 °C, and stir and mix at a rotation speed of 300 - 500 r / min for 10 - 20 minutes to form a homogeneous oil phase; S2. Add the weather-resistant stabilizing additive, extreme pressure and anti-wear agent, and antioxidant to the homogeneous oil phase in sequence, control the temperature within the range of 50 - 70 °C, and maintain stirring for 30 - 60 minutes until completely dissolved; S3. Add the dispersant and coupling agent, raise the temperature of the system to 70 - 80 °C, and stir at a high speed of 800 - 1000 r / min for 40 - 90 minutes to form a transparent homogeneous system; S4. Stop heating, and after natural cooling to room temperature, the lubricant composition is obtained.

[0016] Application of a lubricant composition in the processing of high weather-resistant PC hollow plates.

[0017] The lubricant of the present invention shows a trend of evolving towards high efficiency, environmental protection and function integration in the processing of high weather-resistant PC hollow plates. 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; a weather-resistant additive with adjustable molecular structure is innovatively introduced to realize the integration of antioxidant, anti-ultraviolet function and lubrication performance; with the directional action of the coupling agent and dispersant, the compatibility of the additive and the resin is improved, migration and precipitation are inhibited, and at the same time, the flow uniformity of the processing melt is optimized; its preparation process precisely matches the material properties, promotes the development of PC products towards long-term weather resistance, lightweight and green manufacturing, and meets the upgrading requirements of the high-end engineering plastics processing industry for multifunctional composite additives.

[0018] The nucleus of the weather-resistant stabilizing additive of the present invention is based on a benzazacyclic structure, and its core is composed of a biaryl ring bridged by an ether bond and an arylamine group: the steric hindrance formed by the rigid biaryl ring inhibits the thermal movement of molecular chains at high temperatures and enhances thermal stability; the nitrogen atom in the arylamine serves as a free radical capture site, and quenches the active free radicals generated during processing and use through a single electron transfer mechanism; at the same time, the extended π-π conjugate system can absorb ultraviolet light in the 280 - 400 nm band, convert the light energy into harmless thermal vibration energy dissipation, and the triple action mechanism synergistically inhibits the thermal oxygen aging and photodegradation of polycarbonate materials at the molecular level. This nucleus structure establishes an intrinsic weather protection functional unit through the combination of the rigidity of the aryl ring and the characteristics of electron delocalization without relying on substituent modification.

[0019] During the processing stage, γ-aminopropylsilane preferentially bonds with the hydroxyl groups on the polycarbonate surface to form anchor points. Trimethylolpropane ester base oil achieves intermolecular lubrication through the polar matching of ester groups and carbonyl groups. Meanwhile, tricresyl phosphate coordinates with the ester groups of the base oil to construct an antifriction layer at the metal processing interface. The long-chain entanglement of polyisobutylene succinimide maintains the stable dispersion of nanomicelles, and benzyl alcohol induces the ordered assembly of additive molecules through a hydrogen bond network. After entering the service stage, the hindered phenol antioxidant and the parent nucleus arylamine group form a redox cycle, converting the captured free radicals into stable products. The ultraviolet light energy absorbed by benzazacyclic compounds is dissipated through the vibration mode of the ester groups in the base oil, while the silane coupling interface layer inhibits the migration of small molecules through steric hindrance effects. This multi-scale synergistic action network forms dynamic protection from three dimensions: molecular lubrication (phosphate-base oil coordination), interface anchoring (silane chemical bonding), and energy conversion (photo-thermal conversion of π-conjugated systems), ensuring both the shear fluidity during processing and the structural stability during the service life of the material, and ultimately achieving the synergistic optimization of processing performance and weather resistance life.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Synergistic improvement of high-temperature stability and environmental protection: Through the molecular co-design of polar base oils and solvents, the thermal decomposition tendency during the processing process is significantly reduced, promoting the upgrading of the lubrication system towards a green process with low volatility and low pollution.

[0021] 2. Integrated integration of weather protection functions: Innovatively construct a weather-resistant additive molecular skeleton with both antioxidant and anti-ultraviolet characteristics, realizing the integration of multiple protection mechanisms during the material processing and service stages, and reducing the dependence on secondary additives in traditional processes.

[0022] 3. Breakthrough in long-term interface stability: Based on the structural matching of coupling agents and weather-resistant agents, a dynamic anchoring network is formed to effectively inhibit the migration and precipitation of additives, promoting the evolution of PC products towards a long-term weather resistance direction with zero surface defects and extended service life. Description of the Drawings

[0023] Figure 1 It is the synthesis method of the weather-resistant stable additive described in the present invention. Detailed Embodiments

[0024] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art without creative efforts based on the embodiments in the present invention belong to the scope of protection of the present invention.

[0025] Synthesis Example 1: As Figure 1As shown, the synthesis of weathering stabilizing additive 1: ; 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 h; 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 washed twice with a saturated NaCl solution; finally, the combined organic phase was dried over anhydrous magnesium sulfate, spin-dried, and column chromatographed using a mixture of petroleum ether and dichloromethane as an eluent to obtain 21.84 g of intermediate 1.

[0026] Step 2: Under nitrogen atmosphere, add 21.84g of intermediate 1, 28.15g of raw material 3, 10.38g of sodium tert-butoxide, 1.48g of tri(dibenzylideneacetone)dipalladium, 0.5g of tri-tert-butylphosphine and 220g of toluene into the reaction system, stir evenly, heat to 105°C, and reflux for 12h; after the reaction, slightly lower the temperature, filter with diatomaceous earth to remove salt and catalyst, cool the filtrate to room temperature, wash three times with water, retain the organic phase, and then extract the aqueous phase with ethyl acetate; after combining the organic phases, dry with anhydrous magnesium sulfate, and remove the solvent with a rotary evaporator; dissolve in petroleum ether / ethanol, recrystallize, filter, rinse the filter cake with petroleum ether several times, put it in a 60°C oven and dry for 7h, and obtain 31.44g of weather-resistant stabilizing additive 1. MS (MS+1): 758.

[0027] 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).

[0028] Synthesis Example 2-Synthesis Example 6: The synthesis of the weather resistant stabilizing additive refers to the synthesis method of Synthesis Example 1, replacing the raw material 1 therein, and the rest remains the same as Synthesis Example 1. The specific structure of the raw material 1, the structure of the weather resistant stabilizing additive and the MS (MS+1) data are shown in Table 1.

[0029] Table 1. Structure of raw material 1, structure of weathering stabilizing additive and MS (MS+1) data involved in Synthesis Examples 2 to 6.

[0030] Example 1: A lubricant composition consists of the following components by mass: 50 parts of trimethylolpropane ester (base oil), 10 parts of weather-resistant stabilizer 1 (prepared in Synthesis Example 1), 5 parts of tricresyl phosphate (extreme pressure and anti-wear agent), 4 parts of polyisobutylene succinimide (dispersant), 2 parts of n-octadecyl 3,5-di-tert-butyl-4-hydroxyphenylpropionate (antioxidant), 1 part of γ-aminopropyltriethoxysilane (coupling agent), and 25 parts of benzyl alcohol (solvent).

[0031] The preparation method includes the following steps: S1. Add trimethylolpropane ester and benzyl alcohol into a reaction kettle with a temperature control device, heat up to 50 °C and keep it constant, and mechanically stir at a speed of 400 r / min for 15 minutes to form a transparent and homogeneous oil phase; S2. Sequentially add weather-resistant stabilizer 1, tricresyl phosphate, and antioxidant into the homogeneous oil phase, control the reaction temperature at 60 °C, maintain stirring at 350 r / min for 45 minutes, and observe that the system changes from turbid to a clear solution; S3. Add polyisobutylene succinimide and γ-aminopropyltriethoxysilane, heat up the system to 75 °C, switch to a high-speed disperser and strongly stir at 900 r / min for 60 minutes to obtain an amber transparent liquid with a viscosity of 220 mPa·s (25 °C); S4. Stop heating, and after natural cooling to room temperature, obtain a lubricant composition.

[0032] Examples 2 - 6: A lubricant composition, referring to the preparation method of Example 1, sequentially replaces weather-resistant stabilizer 1 therein with weather-resistant stabilizers 2 - 6 prepared in Synthesis Examples 2 - 6, and the rest remains the same as in Example 1.

[0033] Comparative Example 1: A lubricant composition, referring to the preparation method of Example 1, replaces weather-resistant stabilizer 1 therein with Comparative Compound 1, and the rest remains the same as in Example 1.

[0034] Comparative Compound 1: .

[0035] Comparative Example 2: A lubricant composition, referring to the preparation method of Example 1, does not add weather-resistant stabilizer 1 therein, and the rest remains the same as in Example 1.

[0036] Performance Test: 1. High-temperature stability test: The thermal decomposition temperature of the lubricant composition was determined using a thermogravimetric analyzer. 10 mg of the sample was placed in a platinum crucible and heated to 600 °C at a rate of 10 °C / min under a nitrogen atmosphere, and the temperature corresponding to a 5% mass loss (T 5% ) and the temperature of the maximum decomposition rate (T max ) were recorded. The data are shown in Table 2.

[0037] 2. Determination of volatile organic compound (VOCs) emissions: 1 g of the lubricant composition was evenly coated on a glass substrate (10 cm × 10 cm) and placed in a constant-temperature oven and heated at 250 °C for 30 minutes. A gas chromatography-mass spectrometry (GC-MS) instrument was used to collect and quantify the total amount of VOCs released (μg / g). The data are shown in Table 2.

[0038] 3. Long-term stability verification: The lubricant composition (1 wt%) was melt-blended with PC resin to form a sheet. The PC sheet was placed in a constant-temperature and humidity chamber at 85 °C / 85% RH for accelerated aging for 1000 h. A Fourier transform infrared spectrometer was used to detect the migration and precipitation of surface additives, and the change rate of the characteristic peak intensity (%) was calculated. The data are shown in Table 2.

[0039] Table 2. High-temperature stability test data, volatile organic compound (VOCs) emissions data, and long-term stability verification data of a lubricant composition prepared in the examples and comparative examples.

[0040] The weather-resistant stable additive system significantly improves the thermal stability of the material, and its high-temperature decomposition threshold increases systematically with the strengthening of the conjugation of the aromatic ring substituents of the parent nucleus; the release amount of volatile organic compounds decreases by an order of magnitude due to the synergistic effect of the intermolecular hydrogen bond network and thermal stability, verifying the effectiveness of the component polarity matching for solvent locking; the extremely low fluctuation of the change rate of the characteristic peak intensity indicates that the anchoring design of the coupling agent and weathering agent successfully inhibits the migration of additives. In particular, the system containing phenyl substitution further strengthens the interfacial bonding through the π-π stacking effect. In contrast, the comparative example shows accelerated deterioration characteristics in terms of thermal decomposition, volatility control, and interfacial stability due to the lack of molecular-level synergistic design, confirming the structural defects of the traditional system in the long-term weather-resistant protection mechanism. This cross-dimensional performance improvement trend fully maps the innovative path of the "molecular rigidification design - interfacial anchoring strengthening - energy dissipation synergy" trinity of the present invention.

[0041] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made therein without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A lubricant composition, characterized in that, It comprises the following components by mass parts: 40 - 60 parts of base oil, 5 - 15 parts of weather-resistant stabilizer additive, 3 - 8 parts of extreme pressure and 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 weather-resistant stabilizer additive has the structure shown in Formula 1: Formula 1; The R1 is selected from: methyl, ethyl, methoxy, tert-butyl, phenyl, propyl.

2. The lubricant composition according to claim 1, characterized in that The extreme pressure and anti-wear agent is selected from: tricresyl phosphate.

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

4. A lubricant composition according to claim 1, wherein The antioxidant is selected from: n-octadecyl 3-(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. The 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 lubricant composition according to claim 1, wherein The weather-resistant stabilizer additive is any one of the compounds shown in the following structure: 。 9. A method for preparing a lubricant composition according to any one of claims 1-8, characterized in that, It includes the following steps: S1. Add the base oil and the solvent into a reaction kettle, heat up to 40 - 60 °C, stir and mix at a speed of 300 - 500 r / min for 10 - 20 minutes to form a homogeneous oil phase; S2. Sequentially add the weather-resistant stabilizer additive, extreme pressure and anti-wear agent, and antioxidant into the homogeneous oil phase, control the temperature within the range of 50 - 70 °C, and maintain stirring for 30 - 60 minutes until completely dissolved; S3. Add the dispersant and the coupling agent, heat up the system to 70 - 80 °C, and stir at a high speed of 800 - 1000 r / min for 40 - 90 minutes to form a transparent homogeneous system; S4. Stop heating, and after natural cooling to room temperature, the lubricant composition is obtained.

10. Use of a lubricant composition according to any one of claims 1 - 8 in the processing of high weather-resistant PC hollow plates.

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