A high-temperature resistant and antibacterial colored PVC sheet and its preparation method

Abstract

The present invention relates to the field of polyvinyl chloride sheets, and specifically to a high-temperature resistant and antibacterial colored PVC sheet and a preparation method thereof. The present invention first reacts 8-bromo-1-octene with tetramethylhexanediamine to obtain a quaternary ammonium salt monomer; then, using nano-calcium carbonate, sodium lauryl sulfate, and butyl acrylate as raw materials and potassium persulfate as an initiator, a reaction is performed to obtain a seed emulsion containing nano-calcium carbonate; a mixture of the quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate is added to the seed emulsion containing nano-calcium carbonate as a shell emulsion, and a polymerization reaction is carried out using potassium persulfate as an initiator. After demulsification, filtration, drying, and pulverization, polyacrylate-modified nano-calcium carbonate is obtained; finally, polyvinyl chloride resin, polyacrylate-modified nano-calcium carbonate, an auxiliary plasticizer, an antioxidant, an ultraviolet absorber, a lubricant, and a masterbatch are mixed, and the mixture is refined and pressed into sheets to obtain a high-temperature resistant and antibacterial colored PVC sheet.

Description

Technical Field

[0001] The invention relates to the technical field of polyvinyl chloride sheets, in particular to a high-temperature resistant and antibacterial colored PVC sheet and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a material made from the polymerization of vinyl chloride monomers. It exhibits excellent flame retardancy, mechanical properties, and chemical resistance. With the continuous development of industry, PVC production has also increased. It is widely used in industries such as chemicals, petroleum, electroplating, water purification equipment, environmental protection equipment, mining, medicine, electronics, communications, and interior decoration. In the interior decoration industry, colored PVC sheets not only add color and beauty to interiors, but are also less susceptible to moisture and deformation than traditional plywood and wood boards, making them more economical and practical.

[0003] However, due to the large number of molecular isomers and weak structures produced during the polymerization process of PVC materials, PVC materials have disadvantages such as high brittleness and poor heat resistance, which affect their performance in actual use and often require further modification to meet application needs. Therefore, it is very necessary to develop a high-temperature resistant and antibacterial colored PVC sheet. Summary of the Invention

[0004] The object of the present invention is to provide a high-temperature resistant and antibacterial colored PVC sheet and a preparation method thereof, so as to solve the problems raised in the above background technology.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a high temperature resistant and antibacterial colored PVC sheet and a preparation method thereof, comprising the following steps:

[0006] Step 1:

[0007] 8-bromo-1-octene and tetramethylhexanediamine are mixed and dispersed in isopropanol, heated to 50-60° C., and stirred for reaction for 40-48 hours; after the reaction is completed, the isopropanol solvent in the reaction system is removed by rotary evaporation, and the reactants are added to petroleum ether, stirred at 25-30° C. for 5-10 minutes, centrifuged for 2-3 minutes, and a precipitate is separated; the precipitate is vacuum dried for 48 hours to obtain a quaternary ammonium salt monomer;

[0008] Step 2:

[0009] S1: washing butyl acrylate, methyl methacrylate, and quaternary ammonium salt monomers with sodium hydroxide solution, then washing with deionized water until the pH value reaches 7, adding anhydrous calcium chloride to dry, and setting aside;

[0010] S2: Add nano-calcium carbonate to deionized water, add sodium lauryl sulfate and butyl acrylate, stir for 15 to 30 minutes, use potassium persulfate as an initiator, raise the temperature to 70 to 80°C, add butyl acrylate, and react for 2 to 3 hours to obtain a seed emulsion containing nano-calcium carbonate;

[0011] S3: mixing a quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate to obtain a monomer mixture; mixing the monomer mixture with deionized water to obtain a shell emulsion;

[0012] S4: Using potassium persulfate as an initiator, adding the shell emulsion to the seed emulsion, reacting at 70-80°C for 2-3 hours to obtain a core-shell emulsion; after naturally cooling the core-shell emulsion, placing it at 25-30°C for demulsification, filtering, drying, and pulverizing to obtain polyacrylate-modified nano-calcium carbonate;

[0013] Step 3:

[0014] The high-temperature resistant and antibacterial colored PVC sheet is obtained by mixing polyvinyl chloride resin, polyacrylate modified nano calcium carbonate, auxiliary plasticizer, antioxidant, ultraviolet absorber, lubricant and masterbatch, then refining the mixture and pressing the mixture into sheets.

[0015] Furthermore, in step 1, the molar ratio of 8-bromo-1-octene to tetramethylhexanediamine is 1:2.

[0016] Furthermore, in S1, the mass concentration of the sodium hydroxide solution is 8-10%.

[0017] Furthermore, in S2, the specific preparation method of the seed emulsion containing nano-calcium carbonate is as follows: by weight, 8 to 10 parts of nano-calcium carbonate are added to 100 parts of deionized water, 0.5 to 1 part of sodium lauryl sulfate and 15 to 20 parts of butyl acrylate are added, and after stirring for 15 to 30 minutes, potassium persulfate is used as an initiator, the temperature is raised to 70 to 80° C., 10 to 15 parts of butyl acrylate are added, and the reaction is carried out for 2 to 3 hours to obtain the seed emulsion containing nano-calcium carbonate.

[0018] Furthermore, in S3, the quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate are mixed in a weight ratio of 1:(1-2):(2-3) to obtain a monomer mixture.

[0019] Furthermore, in S3, the contents of the components in the shell emulsion are, by weight percentage, 30-40% of the monomer mixture and 60-70% of deionized water.

[0020] Furthermore, in S4, the mass ratio of the seed emulsion to the shell emulsion is 1:(2-3).

[0021] Furthermore, in step 3, the amount of each component used, by weight, is 100 parts of polyvinyl chloride resin, 40 to 50 parts of polyacrylate-modified nano-calcium carbonate, 1.5 to 4.5 parts of auxiliary plasticizer, 3 to 5 parts of antioxidant, 1 to 3 parts of ultraviolet absorber, 2 to 5 parts of lubricant, and 15 to 20 parts of masterbatch.

[0022] Furthermore, in step 3, the auxiliary plasticizer is epoxidized soybean oil; the antioxidant is at least one of antioxidant 1010, antioxidant 168, and antioxidant 1098; the ultraviolet absorber is at least one of UV-P, UV-531, and UV-1577; the lubricant is at least one of paraffin wax, microcrystalline wax, polyethylene wax, and oxidized polyethylene wax; and the masterbatch carrier is PVC, and the color is any one of red, blue, yellow, and green.

[0023] Furthermore, in step 3, the mixing temperature is 30-60°C; the refining temperature is 150-190°C; and the pressing temperature is 180-200°C.

[0024] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention provides a PVC sheet material, which has better high temperature resistance, antibacterial properties and mechanical properties than conventional PVC sheets. When preparing the PVC sheet material, the present invention mixes polyvinyl chloride resin, polyacrylate-modified nano-calcium carbonate, auxiliary plasticizer, antioxidant, ultraviolet absorber, lubricant and masterbatch, then performs open refining and finally presses into sheets. Among them, polyacrylate-modified nano-calcium carbonate is used as a modifying material for nano-calcium carbonate and has the properties of nano-calcium carbonate and polyacrylate. PVC molecules will produce a large number of isomeric forms and structural defects during the formation process. These defects cause the softening temperature of PVC molecules to be low. Nano-calcium carbonate is an inorganic substance with excellent thermal stability. Adding it to PVC sheets will increase the softening temperature of PVC sheets. Polyacrylate, as a processing aid for PVC materials, can improve the processing properties of PVC and promote and improve the toughness and strength of PVC sheets. Using polyacrylate to modify nano-calcium carbonate and polymerize it on the surface of nano-calcium carbonate to form a polymer layer can also avoid the uneven dispersion and easy agglomeration of nano-calcium carbonate, and at the same time can also improve the compatibility between nano-calcium carbonate and the organic resin matrix.

[0025] In order to further impart good antimicrobial properties to PVC sheets, the present invention uses 8-bromo-1-octene and tetramethyl hexanediamine as raw materials, reacts the two in a molar ratio of 2:1, and obtains a quaternary ammonium salt monomer. The quaternary ammonium salt monomer contains two carbon-carbon double bonds and two quaternary ammonium salt groups, has good antimicrobial properties, and simultaneously has the performance of a similar gemini surfactant. After the quaternary ammonium salt monomer is mixed with methyl methacrylate and butyl acrylate, it is added into water to form a shell emulsion. On the one hand, the shell emulsion is endowed with good antimicrobial properties of the shell polyacrylate. On the other hand, when the shell emulsion is mixed with a seed emulsion of nano-calcium carbonate, due to the presence of the quaternary ammonium salt monomer, the mixed emulsion has a good emulsifying effect, which is conducive to the shell emulsion coating the seed emulsion. As the reaction proceeds, the quaternary ammonium salt monomer, methyl methacrylate and butyl acrylate polymerize on the surface of the nano-calcium carbonate to form a polyacrylate shell. At this time, the polyacrylate shell has properties similar to those of polyquaternary ammonium salt and has good demulsification performance. Therefore, the aqueous phase and the organic phase can be separated by cooling the emulsion, overcoming the difficulty of separating the viscous polymer and the aqueous phase in the mixed emulsion during the modification of nano-calcium carbonate. DETAILED DESCRIPTION

[0026] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0027] Materials used in the present invention and their sources: polyvinyl chloride comes from Nantong Runfeng Petrochemical Co., Ltd., item number SG-5; nano-calcium carbonate with an average particle size of 30 nm is from Anhui Xueling Powder Technology Co., Ltd.; the auxiliary plasticizer is epoxy soybean oil, from Zibo Kailian Chemical Co., Ltd., item number ESO-KLO1; the antioxidant is antioxidant 1010, and the ultraviolet absorber is UV-531, both from Changzhou Youfeng Chemical Co., Ltd.; the lubricant is Yunding brand No. 64 fully refined paraffin, from Fushun Yun Chemical Co., Ltd.; the masterbatch is from Zhejiang Hengyang Masterbatch Co., Ltd., item number 703.

[0028] Example 1: A high-temperature resistant and antibacterial colored PVC sheet and a preparation method thereof, comprising the following steps:

[0029] Step 1:

[0030] 8-bromo-1-octene and tetramethylhexanediamine were mixed and dispersed in isopropanol, heated to 50°C, and stirred for 40 hours. After the reaction was completed, the isopropanol solvent in the reaction system was removed by rotary evaporation, and the reactants were added to petroleum ether, stirred at 25°C for 5 minutes, centrifuged for 2 minutes, and the precipitate was separated. The precipitate was vacuum dried for 48 hours to obtain a quaternary ammonium salt monomer. The molar ratio of 8-bromo-1-octene to tetramethylhexanediamine was 1:2.

[0031] Step 2:

[0032] S1: washing butyl acrylate, methyl methacrylate, and quaternary ammonium salt monomers with 10% sodium hydroxide solution, then washing with deionized water until the pH value reaches 7, adding anhydrous calcium chloride to dry, and setting aside;

[0033] S2: 10 g of nano-calcium carbonate was added to 100 g of deionized water, followed by 1 g of sodium lauryl sulfate and 20 g of butyl acrylate. The mixture was stirred for 15 min, and then potassium persulfate was used as an initiator. The temperature was raised to 70°C, 15 g of butyl acrylate was added, and the mixture was reacted for 2 h to obtain a seed emulsion containing nano-calcium carbonate.

[0034] S3: mixing a quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate in a weight ratio of 1:1:2 to obtain a monomer mixture; and mixing 40% of the monomer mixture and 60% of deionized water by weight to obtain a shell emulsion;

[0035] S4: Using potassium persulfate as an initiator, the shell emulsion was added to the seed emulsion, and the reaction was carried out at 70°C for 2 hours to obtain a core-shell emulsion; after the core-shell emulsion was naturally cooled, it was placed at 25°C for demulsification, filtered, dried, and pulverized to obtain polyacrylate-modified nano-calcium carbonate; wherein the mass ratio of the seed emulsion to the shell emulsion was 1:2;

[0036] Step 3:

[0037] 100 kg of polyvinyl chloride resin, 30 kg of polyacrylate-modified nano-calcium carbonate, 1.5 kg of auxiliary plasticizer, 5 kg of antioxidant, 1 kg of ultraviolet absorber, 2 kg of lubricant, and 15 kg of masterbatch are mixed at a mixing temperature of 30° C.; then, the mixture is open-milled at a refining temperature of 150° C.; and finally, the mixture is pressed into sheets at a pressing temperature of 180° C. to obtain the high-temperature resistant and antibacterial colored PVC sheet.

[0038] Example 2: A high-temperature resistant and antibacterial colored PVC sheet and a preparation method thereof, comprising the following steps:

[0039] Step 1:

[0040] 8-bromo-1-octene and tetramethylhexanediamine were mixed and dispersed in isopropanol, heated to 55°C, and stirred for 44 hours. After the reaction was completed, the isopropanol solvent in the reaction system was removed by rotary evaporation, and the reactants were added to petroleum ether, stirred at 28°C for 8 minutes, centrifuged for 2.5 minutes, and the precipitate was separated. The precipitate was vacuum dried for 48 hours to obtain a quaternary ammonium salt monomer. The molar ratio of 8-bromo-1-octene to tetramethylhexanediamine was 1:2.

[0041] Step 2:

[0042] S1: washing butyl acrylate, methyl methacrylate, and quaternary ammonium salt monomers with 10% sodium hydroxide solution, then washing with deionized water until the pH value reaches 7, adding anhydrous calcium chloride to dry, and setting aside;

[0043] S2: 10 g of nano-calcium carbonate was added to 100 g of deionized water, followed by 1 g of sodium lauryl sulfate and 20 g of butyl acrylate. The mixture was stirred for 25 min, and then potassium persulfate was used as an initiator. The temperature was raised to 75°C, 15 g of butyl acrylate was added, and the mixture was reacted for 2.5 h to obtain a seed emulsion containing nano-calcium carbonate.

[0044] S3: mixing a quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate in a weight ratio of 1:1:2 to obtain a monomer mixture; and mixing 40% of the monomer mixture and 60% of deionized water by weight to obtain a shell emulsion;

[0045] S4: Using potassium persulfate as an initiator, the shell emulsion was added to the seed emulsion, and the reaction was carried out at 75°C for 2.5 hours to obtain a core-shell emulsion; after the core-shell emulsion was naturally cooled, it was placed at 28°C for demulsification, filtered, dried, and pulverized to obtain polyacrylate-modified nano-calcium carbonate; wherein the mass ratio of the seed emulsion to the shell emulsion was 1:2;

[0046] Step 3:

[0047] 100 kg of polyvinyl chloride resin, 35 kg of polyacrylate-modified nano-calcium carbonate, 1.5 kg of auxiliary plasticizer, 5 kg of antioxidant, 1 kg of ultraviolet absorber, 2 kg of lubricant, and 15 kg of masterbatch are mixed at a mixing temperature of 45° C.; then, the mixture is open-milled at a refining temperature of 180° C.; and finally, the mixture is pressed into sheets at a pressing temperature of 190° C. to obtain the high-temperature resistant and antibacterial colored PVC sheet.

[0048] Example 3: A high-temperature resistant and antibacterial colored PVC sheet and a preparation method thereof, comprising the following steps:

[0049] Step 1:

[0050] 8-bromo-1-octene and tetramethylhexanediamine were mixed and dispersed in isopropanol, heated to 60°C, and stirred for 48 hours. After the reaction was completed, the isopropanol solvent in the reaction system was removed by rotary evaporation, and the reactants were added to petroleum ether, stirred at 30°C for 10 minutes, centrifuged for 3 minutes, and the precipitate was separated. The precipitate was vacuum dried for 48 hours to obtain a quaternary ammonium salt monomer. The molar ratio of 8-bromo-1-octene to tetramethylhexanediamine was 1:2.

[0051] Step 2:

[0052] S1: washing butyl acrylate, methyl methacrylate, and quaternary ammonium salt monomers with 10% sodium hydroxide solution, then washing with deionized water until the pH value reaches 7, adding anhydrous calcium chloride to dry, and setting aside;

[0053] S2: 10 g of nano-calcium carbonate was added to 100 g of deionized water, followed by 1 g of sodium lauryl sulfate and 20 g of butyl acrylate. The mixture was stirred for 30 min, and then potassium persulfate was used as an initiator. The temperature was raised to 80°C, 15 g of butyl acrylate was added, and the mixture was reacted for 3 h to obtain a seed emulsion containing nano-calcium carbonate.

[0054] S3: mixing a quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate in a weight ratio of 1:1:2 to obtain a monomer mixture; and mixing 40% of the monomer mixture and 60% of deionized water by weight to obtain a shell emulsion;

[0055] S4: Using potassium persulfate as an initiator, the shell emulsion was added to the seed emulsion, and the reaction was carried out at 80°C for 3 hours to obtain a core-shell emulsion; after the core-shell emulsion was naturally cooled, it was placed at 30°C for demulsification, filtered, dried, and pulverized to obtain polyacrylate-modified nano-calcium carbonate; wherein the mass ratio of the seed emulsion to the shell emulsion was 1:2;

[0056] Step 3:

[0057] 100 kg of polyvinyl chloride resin, 40 kg of polyacrylate-modified nano-calcium carbonate, 1.5 kg of auxiliary plasticizer, 5 kg of antioxidant, 1 kg of ultraviolet absorber, 2 kg of lubricant, and 15 kg of masterbatch are mixed at a mixing temperature of 60° C.; then, the mixture is open-milled at a refining temperature of 190° C.; and finally, the mixture is pressed into sheets at a pressing temperature of 200° C. to obtain the high-temperature resistant and antibacterial colored PVC sheet.

[0058] Example 4: A high-temperature resistant and antibacterial colored PVC sheet and a preparation method thereof, comprising the following steps:

[0059] Step 1:

[0060] 8-bromo-1-octene and tetramethylhexanediamine were mixed and dispersed in isopropanol, heated to 60°C, and stirred for 48 hours. After the reaction was completed, the isopropanol solvent in the reaction system was removed by rotary evaporation, and the reactants were added to petroleum ether, stirred at 30°C for 10 minutes, centrifuged for 3 minutes, and the precipitate was separated. The precipitate was vacuum dried for 48 hours to obtain a quaternary ammonium salt monomer. The molar ratio of 8-bromo-1-octene to tetramethylhexanediamine was 1:2.

[0061] Step 2:

[0062] S1: washing butyl acrylate, methyl methacrylate, and quaternary ammonium salt monomers with 10% sodium hydroxide solution, then washing with deionized water until the pH value reaches 7, adding anhydrous calcium chloride to dry, and setting aside;

[0063] S2: 10 g of nano-calcium carbonate was added to 100 g of deionized water, followed by 1 g of sodium lauryl sulfate and 20 g of butyl acrylate. The mixture was stirred for 30 min, and then potassium persulfate was used as an initiator. The temperature was raised to 80°C, 15 g of butyl acrylate was added, and the mixture was reacted for 3 h to obtain a seed emulsion containing nano-calcium carbonate.

[0064] S3: mixing a quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate in a weight ratio of 1:1:2 to obtain a monomer mixture; and mixing 40% of the monomer mixture and 60% of deionized water by weight to obtain a shell emulsion;

[0065] S4: Using potassium persulfate as an initiator, the shell emulsion was added to the seed emulsion, and the reaction was carried out at 80°C for 3 hours to obtain a core-shell emulsion; after the core-shell emulsion was naturally cooled, it was placed at 30°C for demulsification, filtered, dried, and pulverized to obtain polyacrylate-modified nano-calcium carbonate; wherein the mass ratio of the seed emulsion to the shell emulsion was 1:2;

[0066] Step 3:

[0067] 100 kg of polyvinyl chloride resin, 45 kg of polyacrylate-modified nano-calcium carbonate, 1.5 kg of auxiliary plasticizer, 5 kg of antioxidant, 1 kg of ultraviolet absorber, 2 kg of lubricant, and 15 kg of masterbatch are mixed at a mixing temperature of 60° C.; then, the mixture is open-milled at a refining temperature of 190° C.; and finally, the mixture is pressed into sheets at a pressing temperature of 200° C. to obtain the high-temperature resistant and antibacterial colored PVC sheet.

[0068] Comparative Example 1: No polyacrylate-modified nano-calcium carbonate was added, and the remaining parameters were the same as those in Example 1.

[0069] 100 kg of polyvinyl chloride resin, 1.5 kg of auxiliary plasticizer, 5 kg of antioxidant, 1 kg of ultraviolet absorber, 2 kg of lubricant and 15 kg of masterbatch were mixed at a mixing temperature of 30°C; then the mixture was opened for refining at a refining temperature of 150°C; and finally, the mixture was pressed into sheets at a pressing temperature of 180°C.

[0070] Comparative Example 2: Polyacrylate was not used to modify the nano-calcium carbonate, and the other parameters were the same as those in Example 2.

[0071] 100kg polyvinyl chloride resin, 40kg nano calcium carbonate, 1.5kg auxiliary plasticizer, 5kg antioxidant, 1kg ultraviolet absorber, 2kg lubricant and 15kg masterbatch were mixed at a mixing temperature of 45°C; then the mixture was opened for refining at a refining temperature of 180°C; and finally, the mixture was pressed into sheets at a pressing temperature of 190°C.

[0072] Comparative Example 3: No quaternary ammonium salt monomer was added, and the remaining parameters were the same as those in Example 3.

[0073] Step 1:

[0074] S1: washing butyl acrylate and methyl methacrylate with 10% sodium hydroxide solution, then washing with deionized water until the pH value reaches 7, adding anhydrous calcium chloride to dry, and setting aside;

[0075] S2: 10 g of nano-calcium carbonate was added to 100 g of deionized water, followed by 1 g of sodium lauryl sulfate and 20 g of butyl acrylate. The mixture was stirred for 30 min, and then potassium persulfate was used as an initiator. The temperature was raised to 80°C, 15 g of butyl acrylate was added, and the mixture was reacted for 3 h to obtain a seed emulsion containing nano-calcium carbonate.

[0076] S3: Methyl methacrylate and butyl acrylate are mixed in a weight ratio of 1:2 to obtain a monomer mixture; and 40% of the monomer mixture and 60% of deionized water are mixed by weight to obtain a shell emulsion;

[0077] S4: Using potassium persulfate as an initiator, the shell emulsion was added to the seed emulsion, and the reaction was carried out at 80°C for 3 hours to obtain a core-shell emulsion; after the core-shell emulsion was naturally cooled, it was placed at 30°C for demulsification, filtered, dried, and pulverized to obtain polyacrylate-modified nano-calcium carbonate; wherein the mass ratio of the seed emulsion to the shell emulsion was 1:2;

[0078] Step 2:

[0079] 100 kg of polyvinyl chloride resin, 40 kg of polyacrylate-modified nano-calcium carbonate, 1.5 kg of auxiliary plasticizer, 5 kg of antioxidant, 1 kg of ultraviolet absorber, 2 kg of lubricant and 15 kg of masterbatch were mixed at a mixing temperature of 60°C; then the mixture was opened for refining at a refining temperature of 190°C; and finally, the mixture was pressed into sheets at a pressing temperature of 200°C.

[0080] Experiment: The performance of the PVC sheets prepared in Examples 1 to 4 and Comparative Examples 1 to 3 was tested, and the experimental results are shown in the following table.

[0081] Antibacterial performance: The film method was used for testing. The operation method was as follows: the sample was cut into 2×2 cm pieces, and after cleaning, it was sterilized under ultraviolet light; the Escherichia coli stock solution was diluted to 1×10 4 CFU / mL; then put the cut PVC samples into a six-well plate, with well No. 1 of each six-well plate as a pure bacterial solution control sample, and the others are all PVC samples. Each group of samples is tested in parallel with 3 samples; use a pipette to drop 32μL of diluted bacterial solution in the middle of the sample in each well, and then cover it with a coverslip to ensure that the sample is evenly covered on the surface of the material. After incubation at 37°C for 24 hours, add 5mL PBS to each well, and repeatedly rinse the bacteria on the surface of the coverslip and PVC sheet, and then shake it in a shaker for half an hour to rinse the bacteria from the PVC sheet and coverslip into PBS, and make the bacteria in PBS more evenly distributed; dilute the diluted bacterial solution in the six-well plate 200 times with PBS, and then use a spiral plate spreader to take 50mL of the diluted bacterial solution and evenly coat it on the surface of a solid culture medium with a diameter of 9cm; take pictures and count them after 24 hours, and substitute them into the formula to calculate the antibacterial rate = (CFU C -CFU Q ) / CFU C ×100%(CFU C is the number of colonies on the surface of the control group, CFU Q is the number of surviving colonies on the sample surface).

[0082] Tensile strength: refer to GB / T1040.1-2018, and use a universal material testing machine to test the tensile properties of the sample. The operating temperature is 25 ° C and the tensile speed is 25 cm / min.

[0083] Heat resistance: Refer to GB / T1633-2000, heating rate 50℃ / h, load 5kg, test sample Vicat softening temperature test.

[0084]

[0085] Conclusion: The data of Examples 1 to 4 show that the colored PVC sheets prepared by the present invention have good performance. The data of Example 1 and Comparative Example 1 show that after adding polyacrylate-modified nano-calcium carbonate, the antibacterial properties of the PVC sheet are improved, while the tensile strength and elongation at break are significantly increased, the Vicat softening temperature is also higher, and the heat resistance is better. The data of Example 2 and Comparative Example 2 show that compared with Example 2, in Comparative Example 2, nano-calcium carbonate is easily agglomerated when blended with PVC, resulting in uneven dispersion in the PVC; on the other hand, the inorganic nano-calcium carbonate material has poor compatibility with the organic PVC sheet matrix, so the modification effect is limited. The data of Example 3 and Comparative Example 3 show that the quaternary ammonium salt monomer prepared by the present invention has good antibacterial properties, and because the quaternary ammonium salt monomer contains two carbon-carbon double bonds, it can be used as a cross-linking monomer in the polymerization process to improve the coating effect. At the same time, the quaternary ammonium salt monomer has a structure similar to that of a gemini surfactant and is added to the shell emulsion to have a good emulsifying effect, thereby improving the stability of the emulsion. After the polymerization reaction is completed, a macromolecular polyacrylate coating layer containing the quaternary ammonium salt is formed on the surface of the nano-calcium carbonate, and at this time, the coating layer has an effect similar to that of a demulsifier, thereby being conducive to demulsification and achieving separation, thereby having a better modification effect on calcium carbonate and being applied to PVC sheets to be conducive to improving the performance of the PVC sheets.

[0086] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for preparing a high-temperature resistant and antibacterial colored PVC sheet, characterized in that: The following steps are involved: The polyvinyl chloride resin, polyacrylate-modified nano-calcium carbonate, auxiliary plasticizer, antioxidant, ultraviolet absorber, lubricant and masterbatch are mixed, then the mixture is open-milled, and finally pressed into sheets to obtain the high-temperature resistant and antibacterial colored PVC sheet; The preparation method of polyacrylate-modified nano-calcium carbonate comprises the following steps: Step 1: 8-bromo-1-octene and tetramethylhexanediamine are mixed and dispersed in isopropanol, heated to 50-60° C., and stirred for reaction for 40-48 hours; after the reaction is completed, the isopropanol solvent in the reaction system is removed by rotary evaporation, and the reactants are added to petroleum ether, stirred at 25-30° C. for 5-10 minutes, centrifuged for 2-3 minutes, and a precipitate is separated; the precipitate is vacuum dried for 48 hours to obtain a quaternary ammonium salt monomer; Step 2: S1: washing butyl acrylate, methyl methacrylate, and quaternary ammonium salt monomers with sodium hydroxide solution, then washing with deionized water until the pH value reaches 7, adding anhydrous calcium chloride to dry, and setting aside; S2: Add nano-calcium carbonate to deionized water, add sodium lauryl sulfate and butyl acrylate, stir for 15 to 30 minutes, use potassium persulfate as an initiator, raise the temperature to 70 to 80°C, add butyl acrylate, and react for 2 to 3 hours to obtain a seed emulsion containing nano-calcium carbonate; S3: mixing a quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate to obtain a monomer mixture; and mixing the monomer mixture with deionized water to obtain a shell emulsion; S4: Using potassium persulfate as an initiator, add the shell emulsion to the seed emulsion, react at 70-80°C for 2-3 hours to obtain a core-shell emulsion; after the core-shell emulsion is naturally cooled, it is placed at 25-30°C for demulsification, filtered, dried, and pulverized to obtain polyacrylate-modified nano-calcium carbonate.

2. The method for preparing a high-temperature resistant and antibacterial colored PVC sheet according to claim 1, characterized in that: The amount of each component, calculated by weight, is 100 parts of polyvinyl chloride resin, 40-50 parts of polyacrylate modified nano calcium carbonate, 1.5-4.5 parts of auxiliary plasticizer, 3-5 parts of antioxidant, 1-3 parts of ultraviolet absorber, 2-5 parts of lubricant and 15-20 parts of masterbatch.

3. The method for preparing a high-temperature resistant and antibacterial colored PVC sheet according to claim 1, characterized in that: The auxiliary plasticizer is epoxidized soybean oil; the antioxidant is at least one of antioxidant 1010, antioxidant 168, and antioxidant 1098; the ultraviolet absorber is at least one of UV-P, UV-531, and UV-1577; the lubricant is at least one of paraffin wax, microcrystalline wax, polyethylene wax, and oxidized polyethylene wax; the masterbatch carrier is PVC, and the color is any one of red, blue, yellow, and green.

4. The method for preparing a high-temperature resistant and antibacterial colored PVC sheet according to claim 1, characterized in that: The mixing temperature when mixing polyvinyl chloride resin, polyacrylate modified nano calcium carbonate, auxiliary plasticizer, antioxidant, ultraviolet absorber, lubricant and masterbatch is 30-60°C; the refining temperature is 150-190°C; and the pressing temperature is 180-200°C.

5. The method for preparing a high-temperature resistant and antibacterial colored PVC sheet according to claim 1, characterized in that: In step 1, the molar ratio of 8-bromo-1-octene to tetramethylhexanediamine is 1:

2.

6. The method for preparing a high-temperature resistant and antibacterial colored PVC sheet according to claim 1, characterized in that: In S2, the specific preparation method of the seed emulsion containing nano-calcium carbonate is as follows: by weight, 8 to 10 parts of nano-calcium carbonate are added to 100 parts of deionized water, 0.5 to 1 part of sodium lauryl sulfate and 15 to 20 parts of butyl acrylate are added, and after stirring for 15 to 30 minutes, potassium persulfate is used as an initiator, the temperature is raised to 70 to 80° C., 10 to 15 parts of butyl acrylate are added, and the reaction is carried out for 2 to 3 hours to obtain the seed emulsion containing nano-calcium carbonate.

7. The method for preparing a high-temperature resistant and antibacterial colored PVC sheet according to claim 1, characterized in that: In S3, the contents of the components in the shell emulsion are, by weight percentage, 30-40% of the monomer mixture and 60-70% of deionized water; wherein the quaternary ammonium salt monomer, methyl methacrylate, and butyl acrylate are mixed in a weight ratio of 1:(1-2):(2-3) to obtain the monomer mixture.

8. The method for preparing a high-temperature resistant and antibacterial colored PVC sheet according to claim 1, characterized in that: In S4, the mass ratio of the seed emulsion to the shell emulsion is 1:(2-3).

9. The high temperature resistant and antibacterial colored PVC sheet prepared by the preparation method according to any one of claims 1 to 8.

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