Preparation method and application of high-weather-resistance chlorinated polyethylene rubber and plastic material

Abstract

The invention relates to the technical field of high polymer materials, and discloses a preparation method and application of a high-weather-resistance chlorinated polyethylene rubber and plastic material. The preparation method comprises the following steps: adding 1-butyl-3-methylimidazole acetate; cerium trifluoromethanesulfonate; dibenzoyl methane; the invention further provides a preparation method of the high-weather-resistance chlorinated polyethylene rubber and plastic material, and the preparation method comprises the following steps: firstly, preparing each stabilizer into a uniform liquid premixed master batch, and then carrying out melt blending on the liquid premixed master batch and resin, so that effective construction of a micro-reaction region is ensured. Through the synergetic stable system, intelligent response and long-acting catalysis of a stable function are realized, the problems of easy migration, non-uniform dispersion and short action period of a traditional auxiliary agent are fundamentally solved, the material is endowed with excellent long-term weather resistance and color stability, and the material is suitable for preparing products such as outdoor profiles and pipes.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a method for preparing a highly weather-resistant chlorinated polyethylene rubber-plastic material and its application. Background Technology

[0002] Chlorinated polyethylene (CPE) is widely used in outdoor polymer products such as building profiles, pipes, cable sheaths, and waterproof membranes due to its excellent weather resistance, chemical corrosion resistance, ozone resistance, and flame retardancy. However, the active chlorine atoms in the CPE molecular chain and the small number of unsaturated bonds formed during processing or use make it prone to dechlorination and oxidative degradation when exposed to harsh environments such as ultraviolet light, high temperature, oxygen, and humid heat for a long time. This leads to a rapid decline in the mechanical properties of the material, embrittlement of the product, yellowing of the surface, and other aging phenomena, which seriously limit its long-term outdoor application. To address this challenge, improving the durability and service life of CPE materials is a key focus of the industry.

[0003] In existing technologies, various stabilizers are typically added to inhibit the aging and degradation of CPE materials. Common stabilizer systems include heat stabilizers such as calcium-zinc composite stabilizers and organotin stabilizers, as well as auxiliary antioxidants such as hindered amine light stabilizers, UV absorbers, and phosphites. These stabilizers are usually dry-mixed with CPE resin in powder or liquid form and then melt-processed. These stabilizers delay the degradation process of the material through their respective mechanisms, such as capturing hydrogen chloride, quenching excited-state oxygen molecules, or capturing free radicals.

[0004] While existing technologies have improved the weather resistance of chlorinated polyethylene materials to some extent, several shortcomings remain. First, most traditional stabilizers are either consumable or single-function. For example, heat stabilizers primarily inhibit chain degradation by reacting with the released hydrogen chloride, but they are eventually consumed and have limited protection against free radicals. Light stabilizers mainly function by capturing free radicals or absorbing ultraviolet light, but their inhibitory effect on the dehydrochlorination reaction is insufficient. This lack of synergistic and catalytic regeneration cycle in the stabilization mechanism leads to the rapid depletion of stabilizers under long-term photothermal exposure, failing to provide durable protection. Consequently, the material still exhibits significant degradation in mechanical properties and severe yellowing of the surface during long-term outdoor use.

[0005] Secondly, chlorinated polyethylene matrix is ​​a non-polar polymer, while some high-efficiency stabilizers (especially metal salts or ionic compounds) have a certain degree of polarity, resulting in poor compatibility with the matrix and difficulty in achieving uniform dispersion. This uneven dispersion not only affects the efficiency of the stabilizer, but may also cause the auxiliary molecules to migrate from the interior of the material to the surface during high-temperature processing or long-term service, causing the internal stabilizer to be depleted and precipitated on the surface, which affects both the appearance of the product and reduces the overall protective performance.

[0006] Furthermore, when trace amounts of powdered additives are directly melt-blended with bulk polymer resins, it is difficult to achieve ideal micro-mixing due to differences in specific gravity, particle size, and polarity, and agglomeration is prone to occur. This further exacerbates the problems of uneven dispersion and low efficiency of stabilizers. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides a method for preparing high weather-resistant chlorinated polyethylene rubber and plastic materials and their application, solving the problems of insufficient weather resistance and structural stability of chlorinated polyethylene rubber and plastic materials caused by poor compatibility between stabilizers and the matrix, easy migration, and consumption-type effects of stabilizers in existing technologies.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] In a first aspect, the present invention provides a high weather-resistant chlorinated polyethylene rubber-plastic material, the rubber-plastic material comprising the following components in parts by weight:

[0010] Chlorinated polyethylene resin: 95-105 parts;

[0011] 1-Butyl-3-methylimidazolium acetate: 0.5-3.0 parts;

[0012] Cerium trifluoromethanesulfonate: 0.2-1.5 parts;

[0013] Benzoylmethane: 0.2-1.6 parts;

[0014] Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate: 0.3-1.5 parts.

[0015] By adopting the above technical solution, the present invention establishes a synergistic stable system based on in-situ self-assembly and catalytic regeneration cycle, wherein 1-butyl-3-methylimidazolium acetate forms physically isolated micron- or nano-scale polar regions in a non-polar chlorinated polyethylene resin matrix. These regions can efficiently dissolve and enrich cerium trifluoromethanesulfonate, dibenzoylmethane, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate.

[0016] This structural design effectively prevents the migration and premature deterioration of various functional additives in the resin matrix, and provides a high-concentration reaction site for subsequent in-situ reactions. When the material degrades under light and heat, releasing trace amounts of hydrogen chloride (HCl), this stabilizing system is activated and exerts a synergistic stabilizing effect according to the following steps:

[0017] Step 1: In-situ self-assembly generates active centers. HCl entering the polar microreaction domain triggers a coordination reaction between cerium trifluoromethanesulfonate and dibenzoylmethane, generating a highly active organometallic complex in situ. This reaction not only consumes the HCl that initiates the chain degradation but also generates the organometallic complex that truly assumes stabilizing function. It includes the following two steps:

[0018] 1. In a polar microreaction domain, dibenzoylmethane is rapidly converted from a stable keto form to a highly reactive enol form by proton acid excitation from trace amounts of HCl.

[0019] The reaction formula is expressed as:

[0020]

[0021] 2. The activated ligand undergoes a coordination reaction with cerium ions, while HCl is adsorbed or converted into counterions / adducts of the complex, forming the final organometallic complex.

[0022] The reaction formula is expressed as:

[0023]

[0024] Step 2: Multi-effect synergistic stabilization. The generated organometallic complex can effectively replace the unstable allyl chloride atoms on the chlorinated polyethylene molecular chain, inhibiting the continued progress of the deHCl reaction. At the same time, the metal ions (such as cerium ions) in the complex can capture free radicals generated during the degradation process through redox reactions.

[0025] Step 3: Catalytic regeneration cycle. After the metal ions capture free radicals, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate can reduce them, thus regenerating the active center. At the same time, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate itself is transformed into a species with the same free radical capturing ability. This catalytic cycle process allows the stabilizer to work in a non-stoichiometric manner for a long time.

[0026] Therefore, by constructing micro-reaction domains, this invention achieves the intelligent transformation of the stabilizer from a latent state to an active state and subsequent catalytic regeneration, fundamentally improving the long-term weather resistance of the material.

[0027] Preferably, the chlorinated polyethylene resin has a chlorine content of 25-45 wt% and a Mooney viscosity ML1+4 of 50-100 at 121°C.

[0028] By adopting the above technical solutions, 1-butyl-3-methylimidazolium acetate, as an ionic liquid, has high polarity, low volatility, and good thermal stability, making it an ideal carrier for constructing stable microreaction domains. The combination of cerium(III) trifluoromethanesulfonate and dibenzoylmethane is sensitive to acidic environments and can be efficiently triggered by trace amounts of HCl in the early stages of degradation. The cerium-dibenzoylmethane complex generated in situ has both excellent chlorine atom substitution ability and redox activity. Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate is a highly efficient hindered amine light stabilizer that can form an efficient catalytic regeneration cycle with the cerium complex, thereby optimizing the synergistic effect of each component.

[0029] By adopting the above technical solution and limiting the key physical properties of chlorinated polyethylene resin, it is possible to ensure that the material matrix itself has good flexibility, processing fluidity, and physical compatibility with the stabilizer system, thus providing a foundation for achieving excellent comprehensive performance.

[0030] Preferably, the rubber and plastic material further includes 0.1-0.9 parts by weight of an auxiliary stabilizer.

[0031] Preferably, the auxiliary stabilizer is tris(2,4-di-tert-butylphenyl) phosphite.

[0032] By adopting the above technical solution and introducing tris(2,4-di-tert-butylphenyl) phosphite as an auxiliary stabilizer, it is possible to effectively decompose the hydrogen peroxides generated by oxidation during the processing and long-term use of materials, thus eliminating an important source of free radicals.

[0033] This component complements the main stabilizing system in function, forming a more comprehensive protection mechanism and further improving the material's processing stability and long-term thermo-oxidative aging performance.

[0034] Secondly, the present invention provides a method for preparing a highly weather-resistant chlorinated polyethylene rubber-plastic material, comprising the following steps:

[0035] Preparation of stabilizer premix masterbatch: 1-Butyl-3-methylimidazolium acetate, cerium trifluoromethanesulfonate, dibenzoylmethane and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate are mixed under heating and stirring conditions to obtain liquid stabilizer premix masterbatch;

[0036] Melt blending: The chlorinated polyethylene resin and the liquid stabilizer premix masterbatch are melt blended and then extruded and granulated to obtain a granular finished product;

[0037] Material forming: The granular finished product is obtained by hot pressing or injection molding to obtain the final product.

[0038] By adopting the above technical solution, the core of this preparation method lies in first preparing a uniform liquid stabilizer premix masterbatch. In this step, a variety of solid, low-dosage functional additives are pre-dissolved in liquid 1-butyl-3-methylimidazolium acetate to form a high-concentration, molecularly dispersed homogeneous system.

[0039] In the subsequent melt blending step, the liquid masterbatch is dispersed in the form of tiny droplets in the non-polar chlorinated polyethylene melt, thereby constructing physically isolated and stable micro-reaction domains in the matrix.

[0040] This method fundamentally solves the technical problem of the difficulty in uniformly dispersing and easy migration of various functional additives in polymer matrices, ensuring that key components such as latent catalytic centers and active ligands are effectively enriched and coexist in the same micro-region, providing a structural basis and necessary conditions for subsequent efficient in-situ self-assembly reactions and catalytic regeneration cycles.

[0041] Preferably, the preparation steps of the stabilizer premix masterbatch include: firstly, adding the 1-butyl-3-methylimidazolium acetate and heating it to 60-80°C while stirring at 200-500 rpm; then adding the cerium trifluoromethanesulfonate, dibenzoylmethane, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and stirring continuously at this temperature for 30-60 minutes to obtain the liquid stabilizer premix masterbatch.

[0042] By adopting the above technical solution, the specific process parameters for preparing stabilizer premixed masterbatch are defined. The temperature range and stirring conditions can ensure that all solid components are completely dissolved in 1-butyl-3-methylimidazolium acetate without thermal decomposition, forming a stable and uniform liquid masterbatch, which provides high-quality functional additives for subsequent melt blending steps.

[0043] Preferably, the melt blending step includes: using a co-rotating twin-screw extruder, adding the chlorinated polyethylene resin through a solid feeding system at a main screw speed of 200-400 rpm, and simultaneously injecting the liquid stabilizer premix masterbatch through a liquid metering pump; the barrel temperature of the extruder is set to 150-185℃, and the die temperature is set to 165-175℃.

[0044] By adopting the above technical solution, using a co-rotating twin-screw extruder and injecting stabilizer masterbatch using an independent liquid metering pump, precise and stable feeding of solid and liquid two-phase materials can be achieved. The specific screw speed and barrel temperature distribution can provide appropriate shear force while ensuring full plasticization of chlorinated polyethylene resin, efficiently dispersing the liquid stabilizer masterbatch into micron-sized droplets and uniformly distributing them in the resin matrix, ultimately obtaining a granular finished product with uniform composition and stable performance.

[0045] By adopting the above technical solution, using a co-rotating twin-screw extruder and injecting stabilizer masterbatch using an independent liquid metering pump, precise and stable feeding of solid and liquid two-phase materials can be achieved. The specific screw speed and barrel temperature distribution can provide appropriate shear force while ensuring full plasticization of chlorinated polyethylene resin, efficiently dispersing the liquid stabilizer masterbatch into micron-sized droplets and uniformly distributing them in the resin matrix, ultimately obtaining a granular finished product with uniform composition and stable performance.

[0046] Preferably, the material forming step is hot pressing, which includes a pretreatment step of drying the granular finished product at 60-80°C for 2-4 hours; then preheating at 170-190°C for 3-5 minutes, increasing the pressure to 10-15MPa and holding the pressure for 5-8 minutes, and then cooling to below 40°C while maintaining the pressure.

[0047] By adopting the above technical solution, the granular finished product is dried before material molding, which can effectively remove the moisture adsorbed on the surface and inside of the material, and avoid defects such as bubbles and silver lines caused by moisture vaporization during high-temperature molding.

[0048] The subsequent hot pressing process parameters ensure that the granules are fully melted, completely fill the mold cavity, and form a dense internal structure, ultimately resulting in a final product with stable dimensions and no internal defects.

[0049] Thirdly, the present invention provides an application of the high weather-resistant chlorinated polyethylene rubber and plastic material as described in the first aspect in profiles, pipes, cable sheaths or waterproof membranes used in outdoor sunlight and humid and hot environments.

[0050] By adopting the above technical solution, the high weather-resistant chlorinated polyethylene rubber and plastic material provided by the present invention has a synergistic stable system based on in-situ self-assembly and catalytic regeneration cycle, which can effectively resist aging and degradation under the combined action of long-term ultraviolet light, heat, oxygen and moisture, and shows obvious advantages in mechanical property retention rate and color stability.

[0051] Therefore, this material is particularly suitable for manufacturing outdoor products with stringent weather resistance requirements, such as building window frame profiles, outdoor water pipes, outdoor protective layers for communication or power cables, and roof waterproofing membranes, ensuring the structural integrity and service life of these products during long-term service.

[0052] This invention provides a method for preparing a high weather-resistant chlorinated polyethylene rubber-plastic material and its application, which has the following beneficial effects:

[0053] 1. This invention improves the long-term weather resistance of chlorinated polyethylene rubber and plastic materials by constructing a synergistic stabilization system based on in-situ self-assembly and catalytic regeneration cycle. In the technical solution, the active center of the metal-organic complex can be reduced and regenerated by bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate after capturing free radicals, forming a catalytic cycle. This mechanism enables the stabilizer to play a long-term role in a non-stoichiometric manner, effectively inhibiting the degradation of mechanical properties and surface yellowing of the material during long-term light, heat and oxygen aging, thereby significantly extending the effective service life of the material.

[0054] 2. The stable system designed in this invention features intelligent response and efficient synergy. 1-Butyl-3-methylimidazolium acetate forms stable microregions in the non-polar resin matrix, enriching various functional additives therein. This not only physically inhibits the migration and premature failure of the additives, but also provides a high-concentration site for subsequent reactions. The system generates highly active stable substances in situ only under the triggering effect of trace amounts of hydrogen chloride generated in the early stage of material degradation, realizing the on-demand activation of the stabilizing function and ensuring the maximum utilization of the stabilizing potential and the efficient synergistic effect between the components.

[0055] 3. The preparation method provided by the present invention first prepares a uniform liquid stabilizer premix masterbatch, and then uses a high-precision liquid metering pump to inject it into the extruder in a melt blending process. This fundamentally solves the technical problem that it is difficult to uniformly disperse various trace powder additives in the polymer matrix. This method can stably prepare high-performance, uniform weather-resistant chlorinated polyethylene rubber and plastic materials. Attached Figure Description

[0056] Figure 1 This is a comparison of the UV-Vis absorption spectra of the stabilizer premix masterbatch of the present invention before and after acid triggering;

[0057] Figure 2 The tensile strength retention rate of each sample of the present invention after 2000 hours of xenon lamp aging;

[0058] Figure 3 The elongation at break of each sample of the present invention after 2000 hours of xenon lamp aging is the retention rate.

[0059] Figure 4 The total color difference of each sample in this invention after 2000 hours of xenon lamp aging. Detailed Implementation

[0060] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0061] Example 1:

[0062] Weigh the following raw materials by weight: 100 parts of chlorinated polyethylene resin; 1.75 parts of 1-butyl-3-methylimidazolium acetate; 0.85 parts of cerium(III) trifluoromethanesulfonate; 0.85 parts of dibenzoylmethane; 0.9 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; and 0.5 parts of tris(2,4-di-tert-butylphenyl) phosphite.

[0063] The specific preparation method is as follows:

[0064] The first step is the preparation of the stabilizer premix masterbatch: In a jacketed glass reactor equipped with mechanical stirring, 1.75 parts of 1-butyl-3-methylimidazolium acetate are added first, stirring is started, the speed is set to 350 rpm, and the temperature inside the reactor is controlled at 70℃ by the jacket.

[0065] While stirring, 0.85 parts of cerium(III) trifluoromethanesulfonate, 0.85 parts of dibenzoylmethane, 0.9 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and 0.5 parts of tris(2,4-di-tert-butylphenyl) phosphite were added slowly in sequence. The mixture was stirred continuously at 70°C for 45 minutes until all solid components were completely dissolved, yielding a homogeneous liquid stabilizer premix masterbatch. The prepared masterbatch was cooled to room temperature for later use.

[0066] The second step, melt blending: This is done using a co-rotating twin-screw extruder. The temperatures of each zone in the extruder barrel are set as follows: Zone 1 (feed zone) 160℃, Zones 2-4 (compression and melting zones) 180℃, Zones 5-7 (metering and homogenization zones) 180℃, and the die temperature is 170℃. The main screw speed is set to 300 rpm. 100 parts of chlorinated polyethylene resin are continuously added to the extruder using a loss-in-weight main feeder. The loss-in-weight main feeder and the extruder are electrically linked, and the feed rate is automatically adjusted according to fluctuations in the main screw speed. Simultaneously, a high-precision loss-in-weight liquid metering pump or a closed-loop control pump with a mass flow meter is used to inject the stabilizer premix masterbatch prepared in the first step into the liquid inlet of the extruder.

[0067] The liquid metering pump and the loss-in-weight main feeder are connected by a PLC control system to establish proportional control. The liquid addition rate is set to strictly track the real-time feeding rate of the solid resin, ensuring that the solid-liquid ratio remains constant when the extruder speed or solid feed fluctuates.

[0068] A high-precision constant-speed liquid metering pump is used to inject the stabilizer premix masterbatch, prepared in the first step and in the corresponding proportion, into the liquid feed port of the extruder. The masterbatch is mixed with the molten chlorinated polyethylene resin to obtain a melt mixture. The melt mixture is then sheared, conveyed, kneaded and dispersed by the screw, and extruded into strips from the die head. After being cooled in a water tank, the extruded material is cut into uniform granular products with a diameter of about 2-3 mm and a length of about 3-4 mm by a rotary cutter.

[0069] The third step is material forming: the granular finished product obtained in the second step is dried in a forced-air drying oven at 70°C for 3 hours. The dried granules are placed in a metal mold of a specific shape. The mold filled with the material is placed in a flat vulcanizing machine, and the hot press plate temperature is set to 180°C.

[0070] First, preheat the mold for 4 minutes at a contact pressure of 0.5 MPa to fully melt and fill the mold cavity. Then, increase the pressure to 12.5 MPa and hold it at this pressure for 6 minutes to ensure the internal density of the product. While maintaining the pressure of 12.5 MPa, circulate cooling water into the hot press platen to force-cool the mold until the mold temperature drops below 40°C. Release the pressure, open the mold, and remove the molded sample.

[0071] Example 2:

[0072] Weigh the following raw materials by weight: 95 parts of chlorinated polyethylene resin; 0.5 parts of 1-butyl-3-methylimidazolium acetate; 0.2 parts of cerium(III) trifluoromethanesulfonate; 0.2 parts of dibenzoylmethane; 0.3 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; and 0.1 parts of tris(2,4-di-tert-butylphenyl) phosphite.

[0073] The specific preparation method is as follows:

[0074] The first step is the preparation of the stabilizer premix masterbatch: In a jacketed glass reactor with magnetic stirring, 0.5 parts of 1-butyl-3-methylimidazolium acetate are added first, stirring is started, the speed is set to 200 rpm, and the temperature inside the reactor is controlled at 60℃ by the jacket.

[0075] While stirring, slowly add 0.2 parts of cerium(III) trifluoromethanesulfonate, 0.2 parts of dibenzoylmethane, 0.3 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 0.1 parts of tris(2,4-di-tert-butylphenyl) phosphite in sequence, and continue stirring at 60°C for 30 minutes until all solid components are completely dissolved to obtain a homogeneous liquid stabilizer premix masterbatch. Cool the prepared masterbatch to room temperature for later use.

[0076] The second step, melt blending: This is performed using a co-rotating twin-screw extruder. The temperatures of each zone in the extruder barrel are set as follows: Zone 1 (feed zone) 150℃, Zones 2-4 (compression and melting zones) 170℃, Zones 5-7 (metering and homogenization zones) 170℃, and the die temperature is 165℃. The main screw speed is set to 200 rpm. 95 parts of chlorinated polyethylene resin are continuously added to the first section of the extruder barrel at the set rate using a loss-in-weight main feeder.

[0077] Similarly, a high-precision loss-in-weight liquid metering pump with PLC proportional follow control function is used to inject the stabilizer premix masterbatch prepared in the first step and in the corresponding proportion from the liquid feed port of the extruder, so as to ensure that the solid-liquid ratio is adjusted synchronously with the speed of the main machine.

[0078] The mixed melt mixture is sheared, conveyed, kneaded and dispersed by the screw, and extruded into strips from the die head. After being cooled by a water tank, the extruded material is cut into uniform granular products with a diameter of about 2-3 mm and a length of about 3-4 mm by a rotary pelletizer.

[0079] The third step is material forming: the granular finished product obtained in the second step is dried in a 60°C forced-air drying oven for 2 hours. The dried granules are placed in a metal mold of a specific shape. The mold filled with the material is placed in a flat vulcanizing machine, and the hot press plate temperature is set to 170°C.

[0080] First, preheat the mold for 3 minutes at a contact pressure of 0 MPa to fully melt the material and fill the mold cavity. Then, increase the pressure to 10 MPa and hold it at this pressure for 5 minutes to ensure the internal density of the product. While maintaining a pressure of 10 MPa, circulate cooling water into the hot press platen to force-cool the mold until the mold temperature drops below 40°C. Then, release the pressure, open the mold, and take out the molded sample.

[0081] Example 3:

[0082] Weigh the following raw materials by weight: 105 parts of chlorinated polyethylene resin; 3.0 parts of 1-butyl-3-methylimidazolium acetate; 1.5 parts of cerium(III) trifluoromethanesulfonate; 1.6 parts of dibenzoylmethane; 1.5 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate; and 0.9 parts of tris(2,4-di-tert-butylphenyl) phosphite.

[0083] The specific preparation method is as follows:

[0084] The first step is the preparation of the stabilizer premix masterbatch: In a jacketed glass reactor equipped with mechanical stirring, 3.0 parts of 1-butyl-3-methylimidazolium acetate are added first, stirring is started, the speed is set to 500 rpm, and the temperature inside the reactor is controlled at 80℃ by the jacket.

[0085] While stirring, 1.5 parts of cerium(III) trifluoromethanesulfonate, 1.6 parts of dibenzoylmethane, 1.5 parts of bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and 0.9 parts of tris(2,4-di-tert-butylphenyl) phosphite were added slowly in sequence. The mixture was stirred continuously at 80°C for 60 minutes until all solid components were completely dissolved, resulting in a homogeneous liquid stabilizer premix masterbatch. The prepared masterbatch was then cooled to room temperature for later use.

[0086] The second step is melt blending: the process is carried out using a co-rotating twin-screw extruder. The temperatures of each zone of the extruder barrel are set as follows: zone 1 (feeding zone) is 165℃, zones 2-4 (compression and melting zone) is 185℃, zones 5-7 (metering and homogenization zone) is 185℃, and the die temperature is 175℃.

[0087] The main screw speed is set to 400 rpm, and 105 parts of chlorinated polyethylene resin are continuously added to the extruder via a loss-in-weight main feeder. A high-precision loss-in-weight liquid metering pump with PLC proportional control is used to inject the premixed stabilizer masterbatch prepared in the first step, with the corresponding proportions, into the extruder's liquid feed port, mixing it with the molten chlorinated polyethylene resin to obtain a melt mixture. The melt mixture is then sheared, conveyed, kneaded, and dispersed by the screw, and extruded into strips from the die head. After being cooled in a water tank, the extruded material is cut into uniform granules with a diameter of approximately 2-3 mm and a length of approximately 3-4 mm by a rotary pelletizer.

[0088] The melt mixture is sheared, conveyed, kneaded and dispersed by the screw, and extruded into strips from the die head. After being cooled by a water tank, the extruded material is cut into uniform granular products with a diameter of about 2-3 mm and a length of about 3-4 mm by a rotary cutter.

[0089] The third step is material forming: the granular finished product obtained in the second step is dried in an 80°C forced-air drying oven for 4 hours. The dried granules are placed in a metal mold of a specific shape. The mold filled with the material is then placed in a flat vulcanizing machine, and the hot press plate temperature is set to 190°C.

[0090] First, preheat at a contact pressure of 1.0 MPa for 5 minutes to fully melt the material and fill the mold cavity. Then, increase the pressure to 15 MPa and hold it at this pressure for 8 minutes to ensure the internal density of the product. While maintaining a pressure of 15 MPa, circulate cooling water into the hot press platen to force-cool the mold until the mold temperature drops below 40°C.

[0091] Release the pressure, open the mold, and remove the formed sample.

[0092] Comparative Example 1:

[0093] Compared with Example 1, the difference is that 1-butyl-3-methylimidazolium acetate, cerium(III) trifluoromethanesulfonate, dibenzoylmethane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and tris(2,4-di-tert-butylphenyl) phosphite are not added. Only 100 parts of chlorinated polyethylene resin are melt-blended and granulated, and the subsequent material molding is carried out. All other aspects are the same.

[0094] Comparative Example 2:

[0095] Compared with Example 1, the difference is that the stabilizer system of the present invention is not used, but a conventional heat stabilizer system with equivalent weight parts is used, that is, 1.5 parts calcium stearate and 1.5 parts zinc stearate replace cerium(III) trifluoromethanesulfonate and dibenzoylmethane;

[0096] Furthermore, all stabilizer components (including bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and tris(2,4-di-tert-butylphenyl) phosphite) were not prepared as premixed masterbatches, but were directly dry-mixed with chlorinated polyethylene resin and then fed into the extruder, with the rest being the same.

[0097] Comparative Example 3:

[0098] Compared with Example 1, the differences are as follows: 1-Butyl-3-methylimidazolium acetate is not added to the formulation; in terms of preparation method, the preparation of stabilizer premix masterbatch is not carried out, but four powdered additives, namely cerium(III) trifluoromethanesulfonate, dibenzoylmethane, bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate and tris(2,4-di-tert-butylphenyl) phosphite, are directly dry-mixed with chlorinated polyethylene resin and then added to an extruder for melt blending. The rest are the same.

[0099] Comparative Example 4:

[0100] The difference from Example 1 is that cerium(III) trifluoromethanesulfonate and dibenzoylmethane are not added to the formulation, but all other aspects are the same.

[0101] Comparative Example 5:

[0102] The difference from Example 1 is that benzoylmethane is not added to the formulation, but all other aspects are the same.

[0103] Test Example 1:

[0104] Objective: To verify, by UV-Vis spectrophotometry, that cerium trifluoromethanesulfonate and dibenzoylmethane can undergo an in-situ reaction under acidic conditions to generate a metal-organic complex with novel characteristic absorption peaks.

[0105] Experimental instruments and reagents: UV-Vis spectrophotometer; stabilizer premix masterbatch prepared in Example 1; anhydrous ethanol (analytical grade); anhydrous ethanol solution of hydrogen chloride (concentration 1.0 mol / L).

[0106] Experimental steps:

[0107] Solution preparation: Accurately weigh 0.10 g of the stabilizer premix masterbatch prepared in Example 1, place it in a 100 mL volumetric flask, dilute to volume with anhydrous ethanol and mix thoroughly to obtain the test solution.

[0108] Reference spectrum scanning: Take a portion of the test solution and inject it into a 1cm quartz cuvette. Use anhydrous ethanol as a blank reference and perform a spectral scan in the wavelength range of 250-500nm, and record its absorption spectrum data.

[0109] Acid-triggered reaction and spectral scanning: Accurately transfer 0.1 mL of a 1.0 mol / L anhydrous ethanol solution of hydrogen chloride into the quartz cuvette described above, and shake quickly. After standing for 1 minute, immediately perform a spectral scan again under the same conditions, and record the absorption spectrum data after acid triggering.

[0110] Experimental data: The collected key band data are organized in Table 1 below.

[0111] Table 1. UV-Vis absorption spectra of stabilizer premix masterbatch before and after acid triggering. Wavelength (nm) Pre-trigger absorbance (au) Absorbance (au) after triggering 350 0.203 0.354 360 0.225 0.518 370 0.231 0.796 380 0.228 1.157 390 0.219 1.282 400 0.207 1.123 410 0.194 0.811 420 0.186 0.535 430 0.175 0.369 440 0.168 0.243 450 0.159 0.181

[0112] From Table 1, we can obtain:

[0113] The experimental data in Table 1 show that the initial ethanol solution of the stabilizer premix masterbatch has no obvious characteristic absorption peak in the wavelength range of 350-450 nm. After the addition of an acidic medium, the absorption spectrum of the solution changes significantly, with a new strong absorption band appearing in the wavelength range of 370-420 nm, and its maximum absorption peak located near 390 nm. The appearance of this new absorption peak confirms that the presence of acid induces a structural transformation of the chemical substances in the solution, namely, a ligand exchange reaction occurs between cerium(III) trifluoromethanesulfonate and dibenzoylmethane, resulting in the in-situ formation of a cerium-dibenzoylmethane complex with a conjugated system.

[0114] This result directly verifies the core technical concept proposed in this invention: the trace amounts of hydrogen chloride produced in the early stage of chlorinated polyethylene degradation can act as signal molecules to trigger the in-situ self-assembly reaction of latent precursors in the stabilizer system, thereby generating active substances that truly exert a highly efficient stabilizing effect.

[0115] Test Example 2:

[0116] Objective: To evaluate the weather resistance of the materials prepared in the embodiments of the present invention and the materials of each comparative example under simulated light, heat, humidity and other climatic conditions, and to assess the long-term stability of the materials by quantifying the changes in key performance indicators.

[0117] Experimental standards and instruments: The test methods are based on GB / T16422.2-2022 "Laboratory Light Source Exposure Test Methods for Plastics - Part 2: Xenon Arc Lamp".

[0118] Main instruments: Xenon lamp aging test chamber; universal testing machine; integrating sphere colorimeter.

[0119] Experimental steps:

[0120] Sample preparation: The granules prepared in Examples 1-3 and Comparative Examples 1-5 were molded into sheets with a thickness of 2 mm according to the material forming method in Example 1. The sheets were then cut into tensile test strips conforming to the ASTM D638 Type IV standard and color difference test strips with a size of 50 mm × 50 mm using a cutter.

[0121] Initial performance testing: Initial performance characterization was performed on each set of unaged strips and specimens. Tensile strength and elongation at break of the strips were tested according to ASTM D63 8 at room temperature and a tensile rate of 50 mm / min.

[0122] According to ASTM D2244 standard, the initial CIELAB colorimetric value (L0) of the sample surface was measured using a colorimeter. * ,a0 * ,b0 * Five samples were tested in each group, and the average result was taken.

[0123] Accelerated aging: Place the remaining strips and samples in a xenon lamp aging test chamber and set the aging conditions to: irradiation intensity 0.55 W / (m²). 2 ·nm)@340nm, blackboard temperature 63±2℃, relative humidity inside the chamber 50±5%, spray cycle is 102 minutes of light exposure plus 18 minutes of light exposure spray.

[0124] Post-aging performance testing: Samples from the corresponding batches were removed from the test chamber at 1000 hours and 2000 hours of aging, respectively. After the samples were placed in a standard laboratory environment (23±2℃, 50±5%RH) for 24 hours, the tensile properties and color difference tests in step 2 were repeated.

[0125] Data processing: Based on the test data, calculate the tensile strength retention rate, elongation at break retention rate, and total color difference (ΔE) compared to the initial state for each sample at different aging stages. * ).

[0126] Experimental data: The collected and calculated data are organized in Table 2 below.

[0127] Table 2 Performance data of each embodiment and comparative sample before and after xenon lamp aging.

[0128] From Table 2, we can obtain:

[0129] After 2000 hours of xenon lamp aging, the samples in Examples 1, 2, and 3 maintained a tensile strength retention rate and elongation at break retention rate of over 80%, and the total surface color difference ΔE was also minimal. * The values ​​are all less than 3.5, indicating excellent weather resistance.

[0130] The comparative analysis with Comparative Examples 1-5 is as follows:

[0131] Compared to Comparative Example 1, which does not contain any stabilizers, the performance of each embodiment is fundamentally improved, proving the necessity of the stabilization system of the present invention. Comparative Example 1 was essentially ineffective after aging for 1000 hours.

[0132] Compared to Comparative Example 2, which uses a traditional calcium-zinc stabilizer system, the mechanical property retention rate of each example after aging for 2000 hours is nearly twice as high, and the color difference value is only about one-tenth of that of Comparative Example 2, showing that the synergistic stabilization system of the present invention is far superior to traditional technology.

[0133] Compared to Comparative Example 3, which lacks 1-butyl-3-methylimidazolium acetate, Example 1 exhibits significant advantages in weather resistance. This result confirms that enriching each active component within the microreaction domain is key to achieving efficient synergistic effects and preventing the migration and failure of adjuvants.

[0134] Compared to Comparative Example 4, which lacks a catalytic center precursor, Example 1 exhibits superior long-term stability. This indicates that although hindered amines themselves have a stabilizing effect, the protective effect and durability are significantly reduced in catalytic regeneration cycles lacking a metal center.

[0135] Compared to Comparative Example 5, which lacks dibenzoylmethane, Example 1 exhibits significant performance advantages. The rapid failure of Comparative Example 5 demonstrates that without an active ligand to form a stable, highly active complex with the metal ions in situ, the metal ions themselves cannot effectively exert their catalytic effect and may even accelerate material degradation.

[0136] In summary, the test results confirm that the technical concept of this invention, which involves constructing micro-reaction domains, realizing in-situ self-assembly of stabilizers, and catalytic regeneration cycle, can effectively inhibit the degradation of chlorinated polyethylene materials during photothermal and oxidative aging processes and extend their service life.

[0137] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high weather-resistant chlorinated polyethylene rubber-plastic material, characterized in that, The rubber and plastic material comprises the following components in parts by weight: Chlorinated polyethylene resin: 95-105 parts; 1-Butyl-3-methylimidazolium acetate: 0.5-3.0 parts; Cerium trifluoromethanesulfonate: 0.2-1.5 parts; Benzoylmethane: 0.2-1.6 parts; Bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate: 0.3-1.5 parts.

2. The high weather-resistant chlorinated polyethylene rubber-plastic material according to claim 1, characterized in that, The chlorinated polyethylene resin has a chlorine content of 25-45 wt% and a Mooney viscosity ML1+4 of 50-100 at 121°C.

3. The high weather-resistant chlorinated polyethylene rubber-plastic material according to claim 1, characterized in that, The rubber and plastic material also includes 0.1-0.9 parts by weight of auxiliary stabilizer.

4. The high weather-resistant chlorinated polyethylene rubber-plastic material according to claim 3, characterized in that, The auxiliary stabilizer is tris(2,4-di-tert-butylphenyl) phosphite.

5. A method for preparing a high weather-resistant chlorinated polyethylene rubber-plastic material, characterized in that, The method for preparing a high weather-resistant chlorinated polyethylene rubber-plastic material according to any one of claims 1-4 includes the following steps: Preparation of stabilizer premix masterbatch: 1-Butyl-3-methylimidazolium acetate, cerium trifluoromethanesulfonate, dibenzoylmethane and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate are mixed under heating and stirring conditions to obtain liquid stabilizer premix masterbatch; Melt blending: The chlorinated polyethylene resin and the liquid stabilizer premix masterbatch are melt blended and then extruded and granulated to obtain a granular finished product; Material forming: The granular finished product is obtained by hot pressing or injection molding to obtain the final product.

6. The method for preparing a high weather-resistant chlorinated polyethylene rubber-plastic material according to claim 5, characterized in that, The preparation steps of the stabilizer premix masterbatch include: First, add the 1-butyl-3-methylimidazolium acetate and heat to 60-80°C while stirring at 200-500 rpm; Then, add the cerium trifluoromethanesulfonate, dibenzoylmethane, and bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacate, and continue stirring at this temperature for 30-60 minutes to obtain the liquid stabilizer premix masterbatch.

7. The method for preparing a high weather-resistant chlorinated polyethylene rubber-plastic material according to claim 5, characterized in that, The melt blending step includes: A co-rotating twin-screw extruder is used. Under the condition that the main screw speed is 200-400 rpm, the chlorinated polyethylene resin is added through a solid feeding system, and the liquid stabilizer premix masterbatch is injected through a liquid metering pump. The barrel temperature of the extruder is set to 150-185℃, and the die temperature is set to 165-175℃.

8. The method for preparing a high weather-resistant chlorinated polyethylene rubber-plastic material according to claim 5, characterized in that, The material forming step is specifically hot pressing, including a pretreatment step of drying the granular finished product at 60-80℃ for 2-4 hours. Then, after preheating at 170-190℃ for 3-5 minutes, pressurize to 10-15MPa and hold for 5-8 minutes, then cool to below 40℃ while maintaining the pressure.

9. The application of a high weather-resistant chlorinated polyethylene rubber and plastic material as described in any one of claims 1-4 in profiles, pipes, cable sheaths, or waterproof membranes used in outdoor sunlight and humid environments.

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