Stabilizer for low-temperature-impact-resistant profile and preparation method thereof

Abstract

The invention relates to a stabilizer for a low-temperature-impact-resistant profile and a preparation method of the stabilizer, and belongs to the technical field of stabilizers. The stabilizer comprises the following raw materials in parts by weight: 40-60 parts of a main calcium-zinc stabilizer, 8-15 parts of an auxiliary stabilizer, 5-10 parts of a migration aid, 2-4 parts of a lubricant and 1-2 parts of an antioxidant, wherein the migration auxiliary agent is a modified polyurethane prepolymer, the modified polyurethane prepolymer is obtained by modifying a polyurethane prepolymer through an epoxy group, and the molecular weight of the polyurethane prepolymer is 1000 to 2000. The preparation method comprises the following steps: mixing the raw materials, heating for melting, and cooling for forming. During processing, the modified polyurethane prepolymer is softened and migrated at 160-190 DEG C, calcium and zinc components are synergistically conveyed to a PVC interface, the problems of agglomeration and precipitation of the stabilizer are improved, and the plasticizing uniformity is improved; after cooling, the modified polyurethane prepolymer interacts with PVC to form an interpenetrating network structure to enhance the interface bonding force, meanwhile, calcium and zinc ions inhibit dechlorination reaction, the flexible network structure buffers low-temperature impact, and the low-temperature impact resistance of the PVC profile is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of stabilizer technology, and relates to a low-temperature impact-resistant profile stabilizer and its preparation method. Background Technology

[0002] Polyvinyl chloride (PVC) profiles are widely used in many fields such as construction, home appliances, and automobiles due to their low cost and excellent processing performance. However, in low-temperature environments, the molecular chain mobility of PVC profiles decreases significantly, leading to increased brittleness and a sharp drop in impact strength. This is particularly pronounced in outdoor facilities and cryogenic transportation equipment in cold regions, seriously affecting their safety and service life.

[0003] In existing technologies, common methods for improving the low-temperature toughness of PVC profiles include adding stabilizers, plasticizers, or impact modifiers. Among these, calcium-zinc composite stabilizers are increasingly widely used in PVC processing due to their significant advantages such as good environmental friendliness and non-toxicity. However, calcium-zinc composite stabilizers have obvious limitations: their interfacial bonding with the PVC matrix is ​​insufficient, causing stabilizer particles to easily agglomerate or precipitate from the matrix during high-temperature processing. This results in uneven plasticization of PVC, leaving a large number of unmelted particles inside the PVC material, which in turn form stress concentration points, ultimately making the profiles extremely prone to breakage under low-temperature impact. Summary of the Invention

[0004] The purpose of this invention is to provide a low-temperature impact resistant profile stabilizer and its preparation method, so as to enhance the interfacial bonding force between the stabilizer and the PVC matrix, reduce the problem of stabilizer particle agglomeration and precipitation, and improve the low-temperature impact performance of PVC profiles.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a low-temperature impact resistant profile stabilizer, comprising the following raw materials in parts by weight: 40-60 parts of primary calcium-zinc stabilizer, 8-15 parts of auxiliary stabilizer, 5-10 parts of migration aid, 2-4 parts of lubricant and 1-2 parts of antioxidant;

[0007] The migration aid is a modified polyurethane prepolymer, which is obtained by modifying a polyurethane prepolymer with epoxy groups, and the molecular weight of the polyurethane prepolymer is 1000-2000.

[0008] Preferably, the modified polyurethane prepolymer is prepared as follows: the polyurethane prepolymer is mixed with epoxy resin and reacted to obtain the modified polyurethane prepolymer.

[0009] Preferably, the weight ratio of the polyurethane prepolymer to the epoxy resin is 1:(0.5-1.5).

[0010] Preferably, the primary calcium-zinc stabilizer comprises calcium stearate and zinc stearate, wherein the weight ratio of calcium stearate to zinc stearate is (25-35):(15-25).

[0011] Preferably, the auxiliary stabilizer comprises β-diketone and hydrotalcite, wherein the weight ratio of β-diketone to hydrotalcite is (3-5):(5-10).

[0012] Preferably, the lubricant is PE wax.

[0013] Preferably, the antioxidant is BHT.

[0014] Secondly, the present invention provides a method for preparing the low-temperature impact resistant profile stabilizer as described above, comprising the following steps:

[0015] S1. Mix the main calcium-zinc stabilizer, the auxiliary stabilizer, the migration aid, the lubricant, and the antioxidant, heat to melt, and stir to obtain a homogeneous mixture;

[0016] S2. Cool the homogeneous mixture and grind it into powder or press it into granules to obtain a low-temperature impact resistant profile stabilizer.

[0017] Thirdly, the present invention provides the application of the low-temperature impact resistant profile stabilizer described above in PVC profiles.

[0018] The beneficial effects of this invention are:

[0019] (1) In PVC extrusion processing, when the stabilizer enters the melting zone (zone 2, temperature 160-170℃) to the homogenization zone (zone 3, temperature 180-190℃), the modified polyurethane prepolymer softens into a viscous liquid as the temperature increases. Under the shear force of the screw, the viscous modified polyurethane prepolymer actively migrates into the gaps between PVC molecular chains due to the interfacial tension gradient formed by its own polar groups and the weakly polar segments of PVC. During this migration, it achieves the synergistic delivery of the active components of the calcium-zinc stabilizer through a dual action: on the one hand, the epoxy groups of the modified polyurethane prepolymer undergo a ring-opening reaction with the carboxyl group of calcium stearate to form a chemical bond, while the polar groups of the polyurethane chain segments form hydrogen bonds with zinc stearate, firmly adsorbing the calcium-zinc components through the "chemical + physical" dual anchoring effect; on the other hand, driven by the melt flow, the modified polyurethane prepolymer carries... The calcium and zinc components migrate directionally to the PVC matrix interface, allowing the originally easily agglomerated calcium and zinc particles to be evenly "carried" and anchored in the gaps and surfaces of the PVC molecular chains, forming a continuous and dense active ingredient distribution layer. This effectively solves the problem of insufficient bonding force between traditional calcium and zinc stabilizers and the PVC matrix, and improves the uniformity of stabilizer distribution in the PVC interface layer. This allows the thermal stability and lubrication effects of each area to be fully utilized during the PVC plasticization process, effectively reducing the residue of unmelted particles inside the PVC. This helps to avoid the problem of profile breakage under low-temperature impact caused by stress concentration points formed by uneven stabilizer dispersion.

[0020] (2) When PVC processing enters the cooling and setting stage (water cooling at 30-40℃), the modified polyurethane prepolymer reaching the substrate interface rapidly cures. Its molecular chain active groups interact with PVC segments, unreacted epoxy groups form covalent bonds with active sites on the PVC surface, and linear segments interpenetrate and entangle with each other, forming an interpenetrating network (IPN) structure as it solidifies. This structure is tightly entangled with the PVC segments, acting like a "three-dimensional network skeleton" to enhance interfacial bonding, with calcium and zinc active components uniformly embedded within to form a protective layer. Calcium and zinc ions capture HCl to inhibit degradation, while the IPN structure provides flexible buffering against low-temperature impacts, improving impact resistance. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0022] Example 1

[0023] A low-temperature impact resistant profile stabilizer has the following formulation composition as shown in Table 1:

[0024] Table 1

[0025]

[0026] The modified polyurethane prepolymer is prepared as follows:

[0027] A polyurethane prepolymer with a molecular weight of 1500 was selected and added to an epoxy resin at a weight ratio of 1:1 into a three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Then, triethylamine, accounting for 0.5% of the total mass of the polyurethane prepolymer and epoxy resin, was added to the flask as a catalyst. The stirrer was started, and the reaction system was heated to 80°C and stirred for 3 hours at this temperature. During the reaction, the change in epoxy value was measured to determine the reaction endpoint. When the epoxy value dropped to less than 30% of the initial value, the reaction was stopped, and the modified polyurethane prepolymer was obtained.

[0028] A method for preparing a low-temperature impact resistant profile stabilizer includes the following steps:

[0029] S1. Place the above-mentioned main calcium-zinc stabilizer, auxiliary stabilizer, migration aid, lubricant and antioxidant into a high-speed mixer, set the mixer speed to 800 r / min, heat to 120℃, and continue stirring at this temperature and speed for 40 minutes to fully melt and mix the raw materials evenly to obtain a homogeneous mixture.

[0030] S2. Take out the homogeneous mixture, let it cool naturally to room temperature, and then grind it into powder with a particle size of 100 mesh in a pulverizer to obtain a low-temperature impact resistant profile stabilizer.

[0031] Example 2

[0032] A low-temperature impact resistant profile stabilizer has the following formulation composition as shown in Table 2:

[0033] Table 2

[0034]

[0035] The modified polyurethane prepolymer is prepared as follows:

[0036] A polyurethane prepolymer with a molecular weight of 1200 was selected and added to an epoxy resin at a weight ratio of 1:0.8 into a three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Triethylenediamine, accounting for 0.4% of the total mass of the polyurethane prepolymer and epoxy resin, was added to the flask as a catalyst. The stirrer was started, and the reaction system was heated to 75°C and stirred for 2.5 hours. During the reaction, the change in epoxy value was measured to determine the reaction endpoint. When the epoxy value dropped to below 25% of the initial value, the reaction was stopped, and the modified polyurethane prepolymer was obtained.

[0037] A method for preparing a low-temperature impact resistant profile stabilizer includes the following steps:

[0038] S1. Place the above-mentioned main calcium-zinc stabilizer, auxiliary stabilizer, migration aid, lubricant and antioxidant into a high-speed mixer, set the mixer speed to 750 r / min, heat to 115℃, and continue stirring at this temperature and speed for 35 minutes to fully melt and mix the raw materials evenly to obtain a homogeneous mixture.

[0039] S2. Take out the homogeneous mixture, let it cool naturally to room temperature, and then grind it into powder with a particle size of 90 mesh in a pulverizer to obtain a low-temperature impact resistant profile stabilizer.

[0040] Example 3

[0041] A low-temperature impact resistant profile stabilizer has the following formulation composition as shown in Table 3:

[0042] Table 3

[0043]

[0044] The modified polyurethane prepolymer is prepared as follows:

[0045] A polyurethane prepolymer with a molecular weight of 1800 was selected and added to an epoxy resin at a weight ratio of 1:1.2 into a three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Benzyltriethylammonium chloride, accounting for 0.6% of the total mass of the polyurethane prepolymer and epoxy resin, was added to the flask as a catalyst. The stirrer was started, and the reaction system was heated to 85°C and maintained at this temperature for 3.5 hours. During the reaction, the reaction endpoint was determined by sampling and detecting changes in the epoxy value. The reaction was stopped when the epoxy value dropped to below 28% of the initial value, yielding the modified polyurethane prepolymer.

[0046] A method for preparing a low-temperature impact resistant profile stabilizer includes the following steps:

[0047] S1. Place the above-mentioned main calcium-zinc stabilizer, auxiliary stabilizer, migration aid, lubricant and antioxidant into a high-speed mixer, set the mixer speed to 850 r / min, heat to 125℃, and continue stirring at this temperature and speed for 45 minutes to fully melt and mix the raw materials evenly to obtain a homogeneous mixture.

[0048] S2. Take out the homogeneous mixture, let it cool naturally to room temperature, and then grind it into powder with a particle size of 110 mesh in a pulverizer to obtain a low-temperature impact resistant profile stabilizer.

[0049] Example 4

[0050] A low-temperature impact resistant profile stabilizer has the following formulation composition as shown in Table 4:

[0051] Table 4

[0052]

[0053] The modified polyurethane prepolymer is prepared as follows:

[0054] A polyurethane prepolymer with a molecular weight of 1000 was selected and added to an epoxy resin at a weight ratio of 1:0.5 into a three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Tetramethylammonium chloride, accounting for 0.3% of the total mass of the polyurethane prepolymer and epoxy resin, was added to the flask as a catalyst. The stirrer was started, and the reaction system was heated to 70°C and stirred for 2 hours. During the reaction, the change in epoxy value was measured to determine the reaction endpoint. When the epoxy value dropped to less than 20% of the initial value, the reaction was stopped, and the modified polyurethane prepolymer was obtained.

[0055] A method for preparing a low-temperature impact resistant profile stabilizer includes the following steps:

[0056] S1. Place the above-mentioned main calcium-zinc stabilizer, auxiliary stabilizer, migration aid, lubricant and antioxidant into a high-speed mixer, set the mixer speed to 700 r / min, heat to 110℃, and continue stirring at this temperature and speed for 30 minutes to fully melt and mix the raw materials evenly to obtain a homogeneous mixture.

[0057] S2. Take out the homogeneous mixture, let it cool naturally to room temperature, and then grind it into powder with a particle size of 80 mesh in a pulverizer to obtain a low-temperature impact resistant profile stabilizer.

[0058] Example 5

[0059] A low-temperature impact resistant profile stabilizer has the following formulation composition as shown in Table 5:

[0060] Table 5

[0061]

[0062] The modified polyurethane prepolymer is prepared as follows:

[0063] A polyurethane prepolymer with a molecular weight of 2000 was selected and added to an epoxy resin at a weight ratio of 1:1.5 into a three-necked flask equipped with a stirrer, thermometer, and reflux condenser. Hexadecyltrimethylammonium bromide, accounting for 0.7% of the total mass of the polyurethane prepolymer and epoxy resin, was added as a catalyst. The stirrer was started, and the reaction system was heated to 90°C and maintained at this temperature for 4 hours. During the reaction, the reaction endpoint was determined by sampling and detecting changes in the epoxy value. The reaction was stopped when the epoxy value dropped to below 30% of the initial value, yielding the modified polyurethane prepolymer.

[0064] A method for preparing a low-temperature impact resistant profile stabilizer includes the following steps:

[0065] S1. Place the above-mentioned main calcium-zinc stabilizer, auxiliary stabilizer, migration aid, lubricant and antioxidant into a high-speed mixer, set the mixer speed to 900 r / min, heat to 130℃, and continue stirring at this temperature and speed for 50 minutes to fully melt and mix the raw materials evenly to obtain a homogeneous mixture.

[0066] S2. Take out the homogeneous mixture, let it cool naturally to room temperature, and then grind it into powder with a particle size of 120 mesh in a pulverizer to obtain a low-temperature impact resistant profile stabilizer.

[0067] Comparative Example 1

[0068] The difference from Example 1 is that no migration aids were added to the formulation of the stabilizer for low-temperature impact-resistant profiles.

[0069] Comparative Example 2

[0070] The difference from Example 1 is that the migration aid was not modified.

[0071] Comparative Example 3

[0072] The difference from Example 1 is that a polyurethane prepolymer with a molecular weight of 500 was selected in the preparation of the modified polyurethane prepolymer.

[0073] Comparative Example 4

[0074] The difference from Example 1 is that a polyurethane prepolymer with a molecular weight of 3000 was selected in the preparation of the modified polyurethane prepolymer.

[0075] Preparation Example

[0076] PVC profiles were prepared using the low-temperature impact-resistant profile stabilizers prepared in Examples 1-5 and Comparative Examples 1-4, respectively, resulting in Preparation Examples 1-9. The specific preparation processes are as follows:

[0077] The formulation of PVC profiles includes the following raw materials in parts by weight:

[0078] 100 parts of PVC resin (SG-5 type);

[0079] Five parts of a low-temperature impact-resistant profile stabilizer (Preparation Example 1 was prepared using Example 1, Preparation Example 2 was prepared using Example 2, Preparation Example 3 was prepared using Example 3, Preparation Example 4 was prepared using Example 4, Preparation Example 5 was prepared using Example 5, Preparation Example 6 was prepared using Comparative Example 1, Preparation Example 7 was prepared using Comparative Example 2, Preparation Example 8 was prepared using Comparative Example 3, and Preparation Example 9 was prepared using Comparative Example 4);

[0080] 8 parts of dioctyl phthalate (plasticizer);

[0081] 8 parts of chlorinated polyethylene (impact modifier, CPE135A);

[0082] Stearic acid (lubricant) 0.5 parts;

[0083] 15 parts of calcium carbonate (filler, particle size 1250 mesh).

[0084] The specific manufacturing process of PVC profiles is as follows:

[0085] Y1. Raw material mixing: Add the above-mentioned parts by weight of PVC resin, the low-temperature impact resistant profile stabilizer prepared in the corresponding embodiment, dioctyl phthalate, chlorinated polyethylene, stearic acid and calcium carbonate into a high-speed mixer, control the mixing temperature at 70°C, set the stirring speed to 1200 r / min, and stir at high speed for 12 minutes.

[0086] Y2. Extrusion Processing: The mixed materials are fed into a twin-screw extruder for extrusion processing. Specific parameters are as follows:

[0087] Temperature gradient control: Zone 1 (feeding section): 125℃; Zone 2 (melting section): 165℃; Zone 3 (homogenization section): 185℃; Die head temperature: 180℃;

[0088] Shear force control: The screw speed in zone two is set to 150 rpm, and the screw speed in zone three is reduced to 120 rpm.

[0089] Y3. Cooling and Shaping: The extruded profile immediately enters the water-cooling shaping mold, with the water temperature controlled at 35℃ and the cooling time at 30 seconds. Then, it is pulled by a traction machine and cut by a cutting machine to obtain a 6-meter-long PVC profile.

[0090] Test case

[0091] 1. Test Samples: The PVC profiles prepared in Examples 1-9 were selected as test samples.

[0092] 2. Test Items and Standards:

[0093] a. Low-temperature impact strength test

[0094] Method: The simple beam impact test method was used. Unnotched specimens with dimensions of 80mm × 10mm × 4mm were cut from the PVC profiles of each preparation example and placed in a low temperature environment of -30℃ for 2 hours (to ensure the specimen temperature was stable). The impact test was carried out using a simple beam impact testing machine with a pendulum energy of 2.75J. Each test was performed in parallel for 5 times, and the average value was taken as the final result.

[0095] Evaluation criteria: The higher the low-temperature impact strength value, the better the impact resistance of the profile in a low-temperature environment.

[0096] b. Thermal stability test

[0097] Methods: Thermogravimetric analysis (TGA) was used for testing. Approximately 10 mg of PVC profile samples from each preparation example were taken and heated from room temperature to 300°C at a rate of 10°C / min under a nitrogen atmosphere (flow rate 50 mL / min). The temperature at which the sample weight loss was 5% (T5%) was recorded as the thermal stability evaluation index.

[0098] Evaluation criteria: The higher the T5% value, the better the thermal stability of the PVC profile.

[0099] c. Tensile strength and elongation at break test

[0100] Method: Following GB / T 1040.2-2006 "Determination of Tensile Properties of Plastics", a universal testing machine was used for testing. Dumbbell-shaped Type I specimens were cut from the profile. The test environment temperature was 23℃, and the tensile rate was set to 50 mm / min. The tensile strength and elongation at break of the specimen were recorded. Each group was tested 5 times, and the average value was taken.

[0101] Evaluation criteria: A tensile strength ≥ 40 MPa and an elongation at break ≥ 20% are considered to have excellent mechanical properties; a tensile strength of 35-40 MPa and an elongation at break of 15-20% are considered to be qualified; any indicator below the above range is considered unqualified.

[0102] The test results for the above test cases are shown in Table 6.

[0103] Table 6

[0104]

[0105] As shown in Table 6:

[0106] In terms of low-temperature impact strength, the profiles in Examples 1-5 all exceeded 9.6 kJ / m. 2 Preparation Example 3 even reached 11.5 kJ / m³. 2 It exhibits excellent resistance to low-temperature impact. In contrast, the comparative example, Comparative Example 1, lacks migration aids, and its impact strength is only 6.7 kJ / m. 2 The migration aid in Comparative Example 2 was unmodified, and its strength was 7.9 kJ / m. 2 Comparative Example 3 used a polyurethane prepolymer with a molecular weight of 500 and a strength of 8.1 kJ / m. 2 Comparative Example 4, using a molecular weight of 3000, had a strength of only 7.3 kJ / m. 2This is because the prepolymer in Comparative Example 3 has a low molecular weight, making it prone to excessive migration during processing. Its weak binding force with the calcium and zinc components results in a loose network structure after cooling, with insufficient buffering capacity. Conversely, the prepolymer in Comparative Example 4 has a high molecular weight, making migration difficult during processing. This leads to the aggregation of calcium and zinc components, resulting in an overly rigid network structure after cooling, which is unable to buffer impacts. Therefore, both exhibit poor low-temperature impact resistance. Clearly, adding epoxy-modified polyurethane prepolymers with a molecular weight in the range of 1000-2000 as migration aids can effectively improve the low-temperature impact resistance of PVC profiles.

[0107] Regarding thermal stability, the profiles in Examples 1-5 all exhibited a T5% (temperature at 5% weight loss) above 248°C, reaching a maximum of 260°C, demonstrating good thermal stability. In contrast, the T5% of Comparative Examples 1-4 were all below 240°C, with Comparative Example 4 only reaching 230°C, indicating significantly poorer thermal stability. Comparative Example 3 suffered from uneven distribution of calcium and zinc components, resulting in insufficient localized inhibition of dechlorination; Comparative Example 4 exhibited decreased thermal stability due to calcium and zinc agglomeration, preventing uniform application. This clearly demonstrates that adding epoxy-modified polyurethane prepolymer with a molecular weight in the range of 1000-2000 as a migration aid can synergistically promote the uniform distribution of calcium and zinc components at the PVC interface, effectively inhibiting the dechlorination degradation reaction of PVC and thus improving thermal stability.

[0108] In terms of tensile properties, the profiles in Examples 1-5 all exhibited tensile strengths exceeding 45 MPa and elongations at break exceeding 29.7%, achieving an "excellent" grade. The profiles in Comparative Examples 1-4 had tensile strengths between 41.7 and 43.5 MPa and elongations at break between 21.8 and 24.1%, only achieving a "qualified" grade. Comparative Example 3 suffered from a fragile network structure and insufficient interfacial bonding; Comparative Example 4 exhibited poor tensile properties due to excessive network rigidity and uneven stress transmission. This confirms that adding an interpenetrating network structure formed by cooling a polyurethane prepolymer modified with epoxy groups and a molecular weight in the range of 1000-2000 can enhance the interfacial bonding with the PVC matrix, enabling more uniform stress transmission under load, thereby improving tensile properties.

[0109] In summary, this invention, by adding epoxy-modified polyurethane prepolymer with a molecular weight in the range of 1000-2000 as a migration aid, in conjunction with main calcium-zinc stabilizers and auxiliary stabilizers, effectively solves the problems of insufficient interfacial bonding and easy agglomeration and precipitation of traditional calcium-zinc stabilizers with the PVC matrix. During processing, the modified polyurethane prepolymer can directionally deliver calcium and zinc components to the PVC interface, improving plasticization uniformity; the interpenetrating network structure formed after cooling enhances interfacial bonding, while calcium and zinc ions inhibit dechlorination reactions, and the flexible structure buffers low-temperature impacts, ultimately significantly improving the low-temperature impact performance, thermal stability, and mechanical properties of PVC profiles.

[0110] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A low-temperature impact resistant profile stabilizer, characterized in that, The raw materials include the following parts by weight: 40-60 parts of main calcium-zinc stabilizer, 8-15 parts of auxiliary stabilizer, 5-10 parts of migration aid, 2-4 parts of lubricant and 1-2 parts of antioxidant; The migration aid is a modified polyurethane prepolymer, which is obtained by modifying a polyurethane prepolymer with epoxy groups, and the molecular weight of the polyurethane prepolymer is 1000-2000.

2. The low-temperature impact-resistant profile stabilizer according to claim 1, characterized in that, The modified polyurethane prepolymer is prepared as follows: the polyurethane prepolymer is mixed with epoxy resin and reacted to obtain the modified polyurethane prepolymer.

3. The low-temperature impact-resistant profile stabilizer according to claim 2, characterized in that, The weight ratio of the polyurethane prepolymer to the epoxy resin is 1:(0.5-1.5).

4. The low-temperature impact resistant profile stabilizer according to claim 1, characterized in that, The main calcium-zinc stabilizer includes calcium stearate and zinc stearate, wherein the weight ratio of calcium stearate to zinc stearate is (25-35):(15-25).

5. The low-temperature impact-resistant profile stabilizer according to claim 1, characterized in that, The auxiliary stabilizer includes β-diketone and hydrotalcite, wherein the weight ratio of β-diketone to hydrotalcite is (3-5):(5-10).

6. The low-temperature impact-resistant profile stabilizer according to claim 1, characterized in that, The lubricant is PE wax.

7. The low-temperature impact resistant profile stabilizer according to claim 1, characterized in that, The antioxidant is BHT.

8. The method for preparing the low-temperature impact-resistant profile stabilizer according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Mix the main calcium-zinc stabilizer, the auxiliary stabilizer, the migration aid, the lubricant, and the antioxidant, heat to melt, and stir to obtain a homogeneous mixture; S2. Cool the homogeneous mixture and grind it into powder or press it into granules to obtain a low-temperature impact resistant profile stabilizer.

9. The application of the low-temperature impact resistant profile stabilizer according to any one of claims 1-7 in PVC profiles.

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