An impact-resistant and toughened PVC sheet and its preparation method

Abstract

The present invention belongs to the field of new materials, and specifically discloses an impact-resistant and toughened PVC sheet and its preparation method. By adding raw materials such as ACE toughening agent and modified nano-montmorillonite, the impact resistance and toughness of the PVC sheet are significantly improved. Among them, the introduction of modified nano-montmorillonite enhances the mechanical properties and thermal stability of the material. During the preparation process, a high-speed mixer is used for raw material mixing, and plasticization and molding are achieved through a twin-screw extruder, and finally a PVC sheet with excellent properties is obtained. This material has broad application prospects in fields such as packaging and construction, and its beneficial effects include improving the durability, safety and production efficiency of products, and reducing production costs and scrap rates.

Description

Technical Field

[0001] The invention belongs to the field of new materials and specifically discloses an impact-resistant and toughened PVC sheet and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a widely used polymer material, which is favored for its good processing performance, excellent chemical stability and electrical insulation performance. PVC sheet, as one of the important application forms of PVC materials, plays an important role in many fields such as construction, packaging, electronics, etc. However, despite the many advantages of PVC sheet, it still has shortcomings in impact resistance and toughness, which to some extent limits its application scope and service life.

[0003] In terms of impact resistance, traditional PVC sheets often show low resistance to external impacts and are prone to breakage or deformation. This deficiency makes PVC sheets difficult to use in some situations that require high impact resistance, such as automotive interiors and sports equipment. In addition, the lack of toughness also causes PVC sheets to crack and break easily during use, further affecting their performance and safety. Summary of the invention

[0004] Based on the deficiencies in the prior art, the invention discloses an impact-resistant and toughened PVC sheet and a preparation method thereof.

[0005] The present invention includes the following technical solutions:

[0006] An impact-resistant and toughened PVC sheet is made of the following raw materials by weight:

[0007]

[0008] The modified nano-montmorillonite is subjected to the following modification treatments:

[0009] 1) Acid treatment: At room temperature, the nano-montmorillonite is treated with dilute hydrochloric acid at a mass volume ratio of 1g:5-15mL, stirred for reaction for 1-2h, then centrifuged and dried to obtain nano-montmorillonite powder;

[0010] 2) Coupling: Add nano-montmorillonite powder into deionized water at a mass volume ratio of 1g:3-8mL to form a uniform suspension, and continue stirring at 50-100rpm, increase the temperature to 60-70°C, slowly drop the titanate coupling agent into the suspension, and make the final concentration of the titanate coupling agent 2-4mM / mL, and add a pH adjuster at the same time to make the pH value of the suspension between 3-5, and react for 2-4h;

[0011] 3) Filtration: Filter the above-mentioned suspension, wash it with clear water until neutral, and dry it to obtain modified nano-montmorillonite.

[0012] Further, for the above-mentioned impact-resistant and toughened PVC sheet, the PVC resin is of SG-5 type.

[0013] Further, for the above-mentioned impact-resistant and toughened PVC sheet, the ACE toughening agent is hydrogenated styrene-butadiene-styrene block copolymer SEBS.

[0014] Further, for the above-mentioned impact-resistant and toughened PVC sheet, the heat stabilizer is a composite lead salt stabilizer.

[0015] Further, for the above-mentioned impact-resistant and toughened PVC sheet, the composite lead salt stabilizer is dibasic lead phosphite.

[0016] Further, for the above-mentioned impact-resistant and toughened PVC sheet, the plasticizer is dioctyl phthalate.

[0017] Further, for the above-mentioned impact-resistant and toughened PVC sheet, the lubricant is liquid paraffin.

[0018] The present invention also discloses a preparation method of the above-mentioned impact-resistant and toughened PVC sheet, which includes the following steps:

[0019] 1) Raw material preparation and mixing

[0020] 11) Weighing: Accurately weigh the PVC resin, ACE toughening agent, modified nano-montmorillonite, heat stabilizer, plasticizer and lubricant according to the weight parts in the formula;

[0021] 12). Mixing: Put the weighed various raw materials into a high-speed mixer, heat at 80 - 100 °C, and stir for sufficient mixing to ensure uniform distribution of each component;

[0022] 2), Plasticization and extrusion

[0023] 21) Plasticization: Feed the uniformly mixed raw materials into the hopper of a twin-screw extruder, heat to 190 - 210 °C, and through the heating and shearing actions of the extruder, melt and mix the PVC resin and other additives into a uniform melt;

[0024] 22) Extrusion molding: The plasticized PVC melt enters the mold under the push of the screw of the extruder, the temperature of the extruder is 180 - 200 °C, and a continuous sheet with a certain thickness and width is formed through the shaping action of the mold;

[0025] 3) Cooling and traction

[0026] 31) Cooling: The extruded PVC sheet immediately enters the cooling device and is rapidly cooled to quickly solidify it and maintain a stable shape. The cooling rate is 10 °C / min.

[0027] 32) Traction and cutting: The cooled PVC sheet is pulled out at a constant speed and tension using a traction device, and the impact-resistant and toughened PVC sheet is obtained by cutting.

[0028] Compared with the prior art, the present invention has the following outstanding beneficial effects:

[0029] The present invention discloses an impact-resistant and toughened PVC sheet and its preparation method. Through the carefully designed raw material ratio and the unique treatment process of modified nano-montmorillonite, the comprehensive performance of the material is significantly improved. Specifically, its beneficial effects are mainly reflected in the following aspects:

[0030] 1. Significantly improve impact resistance: The introduced ACE toughening agent (such as hydrogenated styrene-butadiene-styrene block copolymer SEBS) forms an effective interpenetrating network structure with the PVC resin, effectively absorbing and dispersing external impact forces, thereby greatly improving the impact resistance of the sheet.

[0031] 2. Enhance toughness: After acid treatment and coupling modification, the modified nano-montmorillonite not only enhances its dispersibility and compatibility in the PVC matrix, but also further strengthens the overall toughness of the material through the interaction with the PVC molecular chain, making the sheet not easily break or damage when subjected to external forces.

[0032] 3. Improve thermal stability: The use of a composite lead salt stabilizer (such as dibasic lead phosphite) effectively inhibits the degradation reaction of PVC during high-temperature processing, ensuring the dimensional stability and physical properties of the material during long-term use or in a high-temperature environment.

[0033] 4. Optimize processing performance: The reasonable raw material ratio and processing process design enable the PVC sheet to exhibit good fluidity and uniformity during the extrusion and plasticizing molding process, reducing the production difficulty and cost.

[0034] 5. Environmental protection and safety: The selected raw materials are all environmentally friendly materials, meeting the relevant national standards and requirements, and will not cause harm to the environment and human health. At the same time, the present invention also provides new ideas and methods for the modification and application of PVC materials. Description of the drawings

[0035] Figure 1 It is a comparison chart of the toughness test of the PVC sheet in the test example. Detailed implementation manners

[0036] An impact-resistant and toughened PVC sheet, characterized in that it is made of the following raw materials by weight:

[0037]

[0038] The modified nano-montmorillonite is subjected to the following modification treatment:

[0039] 1) Acid treatment: At room temperature, the nano-montmorillonite is put into dilute hydrochloric acid for acid treatment according to the mass-volume ratio of 1 g: 5-15 mL, stirred and reacted for 1-2 h, then centrifuged and dried to obtain nano-montmorillonite powder;

[0040] 2) Coupling: The nano-montmorillonite powder is put into deionized water according to the mass-volume ratio of 1 g: 3-8 mL to form a uniform suspension, and continuously stirred at 50-100 rpm. The temperature is increased to 60-70 °C, and the titanate coupling agent is slowly added dropwise into the suspension to make the final concentration of the titanate coupling agent 2-4 mM / mL. At the same time, a pH regulator is added to make the pH value of the suspension between 3 and 5, and the reaction is carried out for 2-4 h;

[0041] 3) Filtration: Filter the above suspension, wash it with water until neutral, and dry it to obtain the modified nano-montmorillonite;

[0042] The PVC resin is of SG-5 type.

[0043] The ACE toughening agent is hydrogenated styrene-butadiene-styrene block copolymer SEBS;

[0044] The heat stabilizer is a composite lead salt stabilizer;

[0045] The composite lead salt stabilizer is dibasic lead phosphite;

[0046] The plasticizer is dioctyl phthalate;

[0047] The lubricant is liquid paraffin;

[0048] The preparation method of the above impact-resistant and toughened PVC sheet includes the following steps:

[0049] 1) Raw material preparation and mixing

[0050] 11) Weighing: Accurately weigh the PVC resin, ACE toughening agent, modified nano-montmorillonite, heat stabilizer, plasticizer and lubricant according to the weight parts in the formula;

[0051] 12). Mixing: Put the weighed raw materials into a high-speed mixer, heat at 80-100 °C, and stir for full mixing to ensure uniform distribution of each component;

[0052] 2), Plasticization and extrusion

[0053] 21) Plasticization: Feed the uniformly mixed raw materials into the hopper of a twin-screw extruder, heat to 190 - 210 °C, and through the heating and shearing actions of the extruder, melt the PVC resin and other additives and mix them into a uniform melt;

[0054] 22) Extrusion molding: The plasticized PVC melt is pushed by the screw of the extruder into the die. The temperature of the extruder is 180 - 200 °C, and a continuous sheet with a certain thickness and width is formed through the shaping action of the die;

[0055] 3) Cooling and traction

[0056] 31) Cooling: The extruded PVC sheet immediately enters the cooling device to quickly solidify it through rapid cooling and keep its shape stable. The cooling rate is 10 °C / min;

[0057] 32) Traction and cutting: Use the traction device to pull out the cooled PVC sheet at a constant speed and tension, and cut to obtain the impact-resistant and toughened PVC sheet.

[0058] The dilute hydrochloric acid is hydrochloric acid with a concentration of 5%, and the titanate coupling agent is titanate coupling agent TC-27 (purchased from Tengchuan Technology)

[0059] The technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0060] Example 1

[0061] An impact-resistant and toughened PVC sheet, characterized in that it is made of the following raw materials by weight:

[0062]

[0063] The modified nano-montmorillonite has undergone the following modification treatment:

[0064] 1) Acid treatment: At room temperature, put nano-montmorillonite into dilute hydrochloric acid according to the mass-volume ratio of 1 g:10 mL for acid treatment, stir and react for 1.5 h, then centrifuge and dry to obtain nano-montmorillonite powder;

[0065] 2) Coupling: Put the nano-montmorillonite powder into deionized water at a mass-to-volume ratio of 1 g:5 mL to form a uniform suspension, and continuously stir at 75 rpm. Increase the temperature to 65 °C, slowly drop the titanate coupling agent into the suspension to make the final concentration of the titanate coupling agent 3 mM / mL, and at the same time add a pH regulator to make the pH value of the suspension 4, and react for 3 h;

[0066] 3) Filtration: Filter the above suspension, wash it with clear water until neutral, and dry it to obtain modified nano-montmorillonite;

[0067] The PVC resin is of SG-5 type.

[0068] The ACE toughening agent is a hydrogenated styrene-butadiene-styrene block copolymer SEBS;

[0069] The heat stabilizer is a composite lead salt stabilizer;

[0070] The composite lead salt stabilizer is dibasic lead phosphite;

[0071] The plasticizer is dioctyl phthalate;

[0072] The lubricant is liquid paraffin;

[0073] The preparation method of the above impact-resistant and toughened PVC sheet includes the following steps:

[0074] 1) Raw material preparation and mixing

[0075] 11) Weighing: Accurately weigh the PVC resin, ACE toughening agent, modified nano-montmorillonite, heat stabilizer, plasticizer and lubricant according to the weight parts in the formula;

[0076] 12). Mixing: Put the weighed raw materials into a high-speed mixer, heat at 80 - 100 °C, and stir for sufficient mixing to ensure uniform distribution of each component;

[0077] 2), Plasticization and extrusion

[0078] 21) Plasticization: Feed the uniformly mixed raw materials into the hopper of a twin-screw extruder, heat to 190 - 210 °C, and through the heating and shearing action of the extruder, melt and mix the PVC resin and other additives into a uniform melt;

[0079] 22) Extrusion molding: The plasticized PVC melt enters the mold under the push of the screw of the extruder, the temperature of the extruder is 180 - 200 °C, and a continuous sheet with a certain thickness and width is formed through the shaping action of the mold;

[0080] 3) Cooling and traction

[0081] 31) Cooling: The extruded PVC sheet immediately enters the cooling device to rapidly solidify it by rapid cooling and maintain its shape stability. The cooling rate is 10 °C / min;

[0082] 32) Traction and cutting: Use the traction device to pull out the cooled PVC sheet at a constant speed and tension, and cut to obtain the impact-resistant and toughened PVC sheet.

[0083] Example 2

[0084] An impact-resistant and toughened PVC sheet, characterized in that it is made of the following raw materials by weight:

[0085]

[0086] The modified nano-montmorillonite has undergone the following modification treatment:

[0087] 1) Acid treatment: At room temperature, put the nano-montmorillonite into dilute hydrochloric acid according to the mass-volume ratio of 1 g:10 mL for acid treatment, stir and react for 1.5 h, then centrifuge and dry to obtain nano-montmorillonite powder;

[0088] 2) Coupling: Put the nano-montmorillonite powder into deionized water according to the mass-volume ratio of 1 g:5 mL to form a uniform suspension, and continuously stir at 75 rpm. Increase the temperature to 65 °C, slowly add the titanate coupling agent into the suspension to make the final concentration of the titanate coupling agent 3 mM / mL, and at the same time add a pH regulator to make the pH value of the suspension 4, and react for 3 h;

[0089] 3) Filtration: Filter the above suspension, wash it with water until neutral, and dry to obtain the modified nano-montmorillonite;

[0090] The PVC resin is of SG-5 type.

[0091] The ACE toughening agent is hydrogenated styrene-butadiene-styrene block copolymer SEBS;

[0092] The heat stabilizer is a composite lead salt stabilizer;

[0093] The composite lead salt stabilizer is dibasic lead phosphite;

[0094] The plasticizer is dioctyl phthalate;

[0095] The lubricant is liquid paraffin;

[0096] The preparation method of the above impact-resistant and toughened PVC sheet includes the following steps:

[0097] 1) Raw material preparation and mixing

[0098] 11) Weighing: Accurately weigh PVC resin, ACE toughening agent, modified nano-montmorillonite, heat stabilizer, plasticizer and lubricant according to the weight parts in the formula.

[0099] 12). Mixing: Put the weighed raw materials into a high-speed mixer, heat at 80 - 100 °C, and stir for sufficient mixing to ensure uniform distribution of each component.

[0100] 2), Plasticization and Extrusion

[0101] 21) Plasticization: Feed the uniformly mixed raw materials into the hopper of a twin-screw extruder, heat to 190 - 210 °C, and through the heating and shearing action of the extruder, melt the PVC resin and other additives and mix them into a uniform melt.

[0102] 22) Extrusion molding: The plasticized PVC melt enters the mold under the push of the screw of the extruder. The temperature of the extruder is 180 - 200 °C, and a continuous sheet with a certain thickness and width is formed through the shaping effect of the mold.

[0103] 3) Cooling and Traction

[0104] 31) Cooling: The extruded PVC sheet immediately enters the cooling device to rapidly cool it down to make it solidify quickly and maintain a stable shape. The cooling rate is 10 °C / min.

[0105] 32) Traction and Cutting: Use the traction device to pull out the cooled PVC sheet at a constant speed and tension, and cut to obtain the impact-resistant and toughened PVC sheet.

[0106] Example 3

[0107] An impact-resistant and toughened PVC sheet, characterized in that it is made of the following raw materials by weight parts:

[0108]

[0109] The modified nano-montmorillonite is subjected to the following modification treatment:

[0110] 1) Acid treatment: At room temperature, put nano-montmorillonite into dilute hydrochloric acid according to the mass-volume ratio of 1 g:10 mL for acid treatment, stir and react for 1.5 h, then centrifuge and dry to obtain nano-montmorillonite powder.

[0111] 2) Coupling: Put the nano-montmorillonite powder into deionized water according to the mass-volume ratio of 1 g:5 mL to form a uniform suspension, continuously stir at 75 rpm, increase the temperature to 65 °C, slowly drop the titanate coupling agent into the suspension to make the final concentration of the titanate coupling agent 3 mM / mL, and at the same time add a pH regulator to make the pH value of the suspension 4, and react for 3 h.

[0112] 3) Filtration: Filter the above suspension, wash it with clear water until neutral, and dry it to obtain modified nano-montmorillonite;

[0113] The PVC resin is of SG-5 type.

[0114] The ACE toughening agent is hydrogenated styrene-butadiene-styrene block copolymer SEBS;

[0115] The heat stabilizer is a composite lead salt stabilizer;

[0116] The composite lead salt stabilizer is dibasic lead phosphite;

[0117] The plasticizer is dioctyl phthalate;

[0118] The lubricant is liquid paraffin;

[0119] The preparation method of the above impact-resistant and toughened PVC sheet includes the following steps:

[0120] 1) Raw material preparation and mixing

[0121] 11) Weighing: Accurately weigh the PVC resin, ACE toughening agent, modified nano-montmorillonite, heat stabilizer, plasticizer and lubricant according to the weight parts in the formula;

[0122] 12). Mixing: Put the weighed raw materials into a high-speed mixer, heat at 80 - 100 °C, and stir for sufficient mixing to ensure uniform distribution of each component;

[0123] 2), Plasticization and extrusion

[0124] 21) Plasticization: Feed the uniformly mixed raw materials into the hopper of a twin-screw extruder, heat to 190 - 210 °C, and through the heating and shearing actions of the extruder, melt and mix the PVC resin and other additives into a uniform melt;

[0125] 22) Extrusion molding: The plasticized PVC melt enters the die under the push of the screw of the extruder, the temperature of the extruder is 180 - 200 °C, and a continuous sheet with a certain thickness and width is formed through the shaping action of the die;

[0126] 3) Cooling and traction

[0127] 31) Cooling: The extruded PVC sheet immediately enters the cooling device to rapidly cool it down to make it quickly solidify and maintain a stable shape, with a cooling rate of 10 °C / min;

[0128] 32) Traction and cutting: Use the traction device to pull out the cooled PVC sheet at a constant speed and tension, and cut to obtain the impact-resistant and toughened PVC sheet.

[0129] Comparative Example 1

[0130] An impact-resistant and toughened PVC sheet, characterized in that it is made of the following raw materials by weight parts:

[0131]

[0132] The PVC resin is of SG-5 type.

[0133] The ACE toughening agent is a hydrogenated styrene-butadiene-styrene block copolymer SEBS;

[0134] The heat stabilizer is a composite lead salt stabilizer;

[0135] The composite lead salt stabilizer is dibasic lead phosphite;

[0136] The plasticizer is dioctyl phthalate;

[0137] The lubricant is liquid paraffin;

[0138] The preparation method of the above impact-resistant and toughened PVC sheet includes the following steps:

[0139] 1) Raw material preparation and mixing

[0140] 11) Weighing: Accurately weigh the PVC resin, ACE toughening agent, heat stabilizer, plasticizer and lubricant according to the weight parts in the formula;

[0141] 12). Mixing: Put the weighed raw materials into a high-speed mixer, heat at 80-100 °C, and stir for sufficient mixing to ensure uniform distribution of each component;

[0142] 2), Plasticization and extrusion

[0143] 21) Plasticization: Feed the uniformly mixed raw materials into the hopper of a twin-screw extruder, heat to 190-210 °C, and through the heating and shearing action of the extruder, melt the PVC resin and other additives and mix them into a uniform melt;

[0144] 22) Extrusion molding: The plasticized PVC melt enters the mold under the push of the screw of the extruder, the temperature of the extruder is 180-200 °C, and a continuous sheet with a certain thickness and width is formed through the shaping action of the mold;

[0145] 3) Cooling and traction

[0146] 31) Cooling: The extruded PVC sheet immediately enters the cooling device to quickly cool it down to make it solidify quickly and maintain a stable shape, and the cooling rate is 10 °C / min;

[0147] 32) Traction cutting: Use a traction device to pull out the cooled PVC sheet at a constant speed and tension, and cut to obtain an impact-resistant and toughened PVC sheet.

[0148] This comparative example does not contain the filler montmorillonite, and the rest is the same as in Example 2.

[0149] Comparative Example 2

[0150] An impact-resistant and toughened PVC sheet, characterized in that it is made of the following raw materials by weight parts:

[0151]

[0152] The PVC resin is of SG-5 type.

[0153] The ACE toughening agent is a hydrogenated styrene-butadiene-styrene block copolymer SEBS;

[0154] The heat stabilizer is a composite lead salt stabilizer;

[0155] The composite lead salt stabilizer is dibasic lead phosphite;

[0156] The plasticizer is dioctyl phthalate;

[0157] The lubricant is liquid paraffin;

[0158] The preparation method of the above-mentioned impact-resistant and toughened PVC sheet includes the following steps:

[0159] 1) Raw material preparation and mixing

[0160] 11) Weighing: Accurately weigh the PVC resin, ACE toughening agent, nano-montmorillonite, heat stabilizer, plasticizer and lubricant according to the weight parts in the formula;

[0161] 12). Mixing: Put the weighed raw materials into a high-speed mixer, heat at 80-100 °C, and stir for full mixing to ensure uniform distribution of each component;

[0162] 2), Plasticization and extrusion

[0163] 21) Plasticization: Feed the uniformly mixed raw materials into the hopper of a twin-screw extruder, heat to 190-210 °C, and through the heating and shearing actions of the extruder, melt the PVC resin and other additives and mix them into a uniform melt;

[0164] 22) Extrusion molding: The plasticized PVC melt enters the mold under the push of the screw of the extruder, the temperature of the extruder is 180-200 °C, and a continuous sheet with a certain thickness and width is formed through the shaping action of the mold;

[0165] 3) Cooling and Traction

[0166] 31) Cooling: The extruded PVC sheet immediately enters the cooling device, and through rapid cooling, it is quickly solidified and its shape is kept stable. The cooling rate is 10°C / min;

[0167] 32) Traction and Cutting: Use the traction device to pull out the cooled PVC sheet at a constant speed and tension, and cut to obtain the impact-resistant and toughened PVC sheet.

[0168] In this comparative example, the nano-montmorillonite was not modified, and the others were the same as in Example 2.

[0169] Test Example

[0170] Prepare the sheets of Examples 1 - 3 and Comparative Examples 1 - 2 into test blocks with a size of 50x20 cm and a thickness of 10 mm, and conduct mechanical property tests to test their toughness (simple supported beam impact test). The toughness is tested at three temperatures: 25°C, 0°C, and -20°C. The results are shown in Table 1 and Figure 1 as follows.

[0171] Table 1 PVC Toughness Test

[0172] <![CDATA[25℃(kJ / m 2 )]]> <![CDATA[0 °C (kJ / m 2 )]]> <![CDATA[-20℃(kJ / m 2 )]]> Example 1 25.3 21.4 15.2 Example 2 26.7 22.6 15.6 Example 3 24.2 21.2 14.7 Comparative Example 1 20.1 13.6 3.2 Comparative Example 2 24.6 15.2 5.3

[0173] It can be seen from the data in Table 1 above that after the acid treatment and coupling modification of the modified nano-montmorillonite in the examples of the present invention, not only its dispersibility and compatibility in the PVC matrix are enhanced, but also through the interaction with the PVC molecular chain, the overall toughness of the material is further strengthened, making the sheet not easily break or be damaged when subjected to external forces. Especially by comparing the differences between Example 2 and Comparative Example 2 at 0°C and -20°C, it can be seen that the modified nano-montmorillonite filler can greatly increase the toughness of the PVC sheet at low temperatures.

[0174] The above are only several limited preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention.

Claims

1. An impact-resistant and toughened PVC sheet, characterized in that: Calculated by weight, it is made from the following raw materials: PVC resin 80~100 parts ACE toughening agent 4-12 parts 3-10 parts of modified nano-montmorillonite Heat stabilizer 2-3 parts 1-2 parts of plasticizer Lubricant 0.6~1.2 parts The modified nano-montmorillonite is subjected to the following modification treatments: 1) Acid treatment: At room temperature, the nano-montmorillonite is treated with dilute hydrochloric acid at a mass volume ratio of 1g:5-15mL, stirred for 1-2h, then centrifuged and dried to obtain nano-montmorillonite powder; 2) Coupling: Add nano-montmorillonite powder into deionized water at a mass volume ratio of 1g:3-8mL to form a uniform suspension, and continue stirring at 50-100rpm, increase the temperature to 60-70°C, slowly drop the titanate coupling agent into the suspension, and make the final concentration of the titanate coupling agent 2-4mM / mL, and add a pH adjuster at the same time to make the pH value of the suspension between 3-5, and react for 2-4h; 3) Filtration: Filter the above suspension, wash with water until neutral, and dry to obtain modified nano-montmorillonite; The PVC resin is SG-5 type; The ACE toughening agent is hydrogenated styrene-butadiene-styrene block copolymer SEBS.

2. The impact-resistant toughened PVC sheet according to claim 1, characterized in that: The heat stabilizer is a composite lead salt stabilizer.

3. The impact-resistant toughened PVC sheet according to claim 2, characterized in that: The composite lead salt stabilizer is dibasic lead phosphite.

4. The impact-resistant toughened PVC sheet according to claim 1, characterized in that: The plasticizer is dioctyl phthalate.

5. The impact-resistant toughened PVC sheet according to claim 1, characterized in that: The lubricant is liquid paraffin.

6. The method for preparing the impact-resistant toughened PVC sheet according to any one of claims 1 to 5, characterized in that: The following steps are involved: 1) Raw material preparation and mixing 11) Weighing: Accurately weigh the PVC resin, ACE toughening agent, modified nano-montmorillonite, heat stabilizer, plasticizer and lubricant according to the weight proportions in the formula; 12). Mixing: Put the weighed raw materials into a high-speed mixer, heat at 80-100℃, and stir to mix thoroughly to ensure that the components are evenly distributed; 2) Plasticization and extrusion 21) Plasticization: The mixed raw materials are fed into the hopper of the twin-screw extruder and heated to 190-210°C. The heating and shearing action of the extruder melts the PVC resin and other additives and mixes them into a uniform melt; 22) Extrusion molding: The plasticized PVC melt is pushed into the mold by the screw of the extruder. The extruder temperature is 180-200℃, and a continuous sheet with a certain thickness and width is formed through the shaping effect of the mold; 3) Cooling and traction 31) Cooling: The extruded PVC sheet immediately enters the cooling device to rapidly solidify and maintain a stable shape through rapid cooling, with a cooling rate of 10℃ / min; 32) Traction cutting: Use a traction device to pull out the cooled PVC sheet at a constant speed and tension, and cut to obtain impact-resistant and toughened PVC sheet.

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