An anti-aging polyvinyl chloride sheet and its preparation method

Abstract

The present invention relates to the technical field of polyvinyl chloride, and specifically relates to an anti-aging polyvinyl chloride sheet and a preparation method thereof. An organotin stabilizer or a liquid calcium-zinc stabilizer is introduced into a polyvinyl chloride base material as a stabilizer, and an ACR auxiliary agent is selected to improve its processability. Ethylene bisstearamide is used as an anti-sticking agent, and one or several of oxidized polyethylene wax, polyol ester, and stearate are used as lubricants; 2-carboxyethyl phenylphosphinic acid and 1,1,1-trimethylolpropane are used as raw materials to synthesize a hyperbranched polyester, and then a hydroxyl-containing s-triazine ultraviolet absorber is grafted to obtain a modified hyperbranched polyester plasticizer for plasticizing the sheet; a hydrotalcite-like material is selected as a filler, and carboxylated sesquisiloxane is selected as a modifier through a peeling and recombination method to obtain carboxylated hydrotalcite-like material, and then a hydroxyl-containing s-triazine ultraviolet absorber is grafted, greatly improving the flame retardancy and weather resistance of the sheet and improving the use safety of the sheet.

Description

Technical Field

[0001] The present invention relates to the technical field of polyvinyl chloride, and specifically relates to an anti-aging polyvinyl chloride sheet and a preparation method thereof. Background Art

[0002] Polyvinyl chloride, which has the characteristics of high strength, good corrosion resistance, good insulation, low price, etc., is widely used in various fields of daily life. Affected by the synthesis process and conditions, under long-term light exposure, polyvinyl chloride is prone to surface discoloration, reduction of mechanical properties, and even cracking and powdering.

[0003] In the existing market, anti-aging agents and antioxidants are usually added to improve the anti-aging performance of polyvinyl chloride. However, adding a large amount easily affects the comprehensive performance of polyvinyl chloride materials. At the same time, in order to further expand the use range of polyvinyl chloride sheets, the functional requirements for flame retardancy and fire prevention are also gradually increasing. Summary of the Invention

[0004] The purpose of the present invention is to provide an anti-aging polyvinyl chloride sheet and a preparation method thereof to solve the problems in the prior art.

[0005] To solve the above technical problems, the present invention provides the following technical solutions:

[0006] An anti-aging polyvinyl chloride sheet, in parts by weight, comprises the following components: 88 - 102 parts of polyvinyl chloride resin, 2 - 4 parts of stabilizer, 6 - 9 parts of ACR additive, 3 - 7 parts of composite hydrotalcite, 5 - 10 parts of modified hyperbranched polyester plasticizer, 0.5 - 1 part of ethylene bisstearamide, and 0.2 - 0.6 part of lubricant.

[0007] Further, the stabilizer is one or a compound of organic tin stabilizer and liquid calcium zinc stabilizer.

[0008] Further, the lubricant is one or several of polyethylene wax oxide, polyol ester, and stearate.

[0009] Further, the preparation of the modified hyperbranched polyester plasticizer comprises the following steps:

[0010] 1) Under a nitrogen atmosphere, mix 2 - carboxyethylphenylphosphinic acid and 1,1,1 - trimethylolpropane, heat up to 158 - 162 °C and keep warm for 7 - 8 h, stop passing nitrogen, evacuate to 0.098 MPa and continue to keep warm for 2 h, pour out while it is hot, and cool to obtain hyperbranched polyester;

[0011] 2) Heat the hyperbranched polyester to melting, add a mixed solution of a hydroxyl-containing s-triazine ultraviolet absorber, toluene, and p-toluenesulfonic acid, keep it warm at 108 - 110 °C for 5 - 6 h, evacuate to 0.098 MPa, stir for 1 - 2 h, cool and dry to obtain a modified hyperbranched polyester-based plasticizer.

[0012] Furthermore, the mass ratio of the hyperbranched polyester to the hydroxyl-containing s-triazine ultraviolet absorber is 11:3.

[0013] Furthermore, the preparation of the composite hydrotalcite includes the following steps:

[0014] (1) Mix vinyltrimethoxysilane, acetone, concentrated hydrochloric acid, and deionized water, keep it warm at 40 - 50 °C for 44 - 48 h, wash and filter to obtain vinylated sesquisiloxane; mix vinylated sesquisiloxane, methacrylic acid, sodium dodecylsulfonate, and deionized water, perform ultrasonic treatment for 10 - 15 min, add ammonium persulfate, keep it warm at 55 - 65 °C for 25 - 35 min, add ammonium persulfate, sodium bisulfate, deionized water, and methacrylic acid, and continue to keep it warm for 3 - 4 h to obtain carboxylated sesquisiloxane;

[0015] (2) Mix carboxylated sesquisiloxane and deionized water, add hydrotalcite-like powder, perform ultrasonic treatment for 10 - 15 min to obtain a suspension; add the suspension to carboxylated sesquisiloxane, stir at 55 - 65 °C for 1 - 2 h, and dry to obtain carboxylated hydrotalcite-like material;

[0016] (3) Mix carboxylated hydrotalcite-like material, hydroxyl-containing s-triazine ultraviolet absorber, and toluene, add p-toluenesulfonic acid, heat to 108 - 110 °C and keep it warm for 2 - 3 h to obtain the composite hydrotalcite.

[0017] Furthermore, the mass ratio of carboxylated hydrotalcite-like material to hydroxyl-containing s-triazine ultraviolet absorber is 2.5:1.4.

[0018] Furthermore, the preparation of the hydroxyl-containing s-triazine ultraviolet absorber includes the following steps:

[0019] A. Mix cyanuric chloride and chlorobenzene, add anhydrous aluminum trichloride in an ice-water bath, stir for 20 - 30 min, add m-xylene, keep it warm for 2 - 3 h, add dilute hydrochloric acid, extract twice with chlorobenzene, dry, rotary evaporate, cool, and filter to obtain 2-chloro-4,6-bis(2',4'-dimethylphenyl)-1,3,5-s-triazine;

[0020] B. Mix 2-chloro-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine and chlorobenzene, add anhydrous aluminum trichloride in an ice-water bath, stir for 20 - 30 min, add resorcinol, heat up to 78 - 82 °C and keep warm for 1 - 2 h, add dilute hydrochloric acid, distill and filter by suction, and recrystallize twice with toluene to obtain 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine;

[0021] C. Mix 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine, N,N-dimethylformamide and sodium hydroxide, heat up to 78 - 82 °C in a water bath, add epichlorohydrin, continue to keep warm for 5 - 6 h, reduce the pressure, add ammonium chloride aqueous solution, extract 3 times with dichloromethane, dry and concentrate, and recrystallize with an ethanol and dichloromethane solution with a volume ratio of 10:1 to obtain 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol;

[0022] D. Mix 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol, N,N-dimethylformamide, ethyltriphenylphosphonium bromide, n-dodecanol and n-tridecanol, heat up to 88 - 92 °C in a water bath and keep warm for 22 - 24 h, reduce the pressure, add deionized water, extract with ethyl acetate, dry and concentrate, reflux with ethanol for 10 - 20 min, and cool to obtain a hydroxylated triazine-based ultraviolet absorber.

[0023] Furthermore, a preparation method of an anti-aging polyvinyl chloride sheet comprises the following steps:

[0024] Put polyvinyl chloride resin, stabilizer, ACR auxiliary agent, modified hyperbranched polyester plasticizer, composite hydrotalcite, ethylene bisstearamide and lubricant into a high-speed mixer and mix evenly, then extrude and pelletize and press into sheets to obtain an anti-aging polyvinyl chloride sheet.

[0025] Furthermore, the working conditions of the high-speed mixer: feed materials after preheating to 118 °C.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] The present invention provides an anti-aging polyvinyl chloride sheet and a preparation method thereof. By optimizing the components and processes, an anti-aging polyvinyl chloride sheet with good mechanical strength, high flame retardancy and anti-aging performance is prepared.

[0028] Introduce one of organic tin stabilizer and liquid calcium-zinc stabilizer into the polyvinyl chloride base material as a stabilizer to improve the thermal stability of polyvinyl chloride. Select ACR additives to improve its processability. Use ethylene bisstearamide as an anti-sticking agent, and use one or several of oxidized polyethylene wax, polyol ester, and stearate as lubricants to improve the fluidity of the base material and improve its plastic processing performance.

[0029] To improve the negative impacts such as migration and decline in mechanical properties caused by the addition of a large number of existing small molecule plasticizers, and to simultaneously meet the requirements of improving processing fluidity, maintaining mechanical properties, and enhancing anti-aging performance, the present invention synthesizes hyperbranched polyester using 2-carboxyethylphenylphosphinic acid and 1,1,1-trimethylolpropane as raw materials, and then grafts a hydroxyl-containing s-triazine ultraviolet absorber to obtain a modified hyperbranched polyester plasticizer for plasticizing polyvinyl chloride sheets, while significantly improving the flame retardancy and weather resistance of the sheets; among them, the hydroxyl-containing s-triazine ultraviolet absorber is prepared by reacting cyanuric chloride through a Friedel-Crafts reaction to generate 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine, then condensing with epichlorohydrin and reacting with dodecanol and tridecanol. Compared with the commonly used benzotriazole and benzophenone ultraviolet absorbers in the market, it has strong ultraviolet absorption at 280-380 nm, lighter color, better high temperature resistance and solubility.

[0030] In the present invention, hydrotalcite-like compounds are selected as fillers to improve the thermal stability and flame retardancy of the sheets. To further improve the uniformity of the dispersion of hydrotalcite-like compounds in the sheets, the hydrotalcite-like compounds are modified. By using the exfoliation-reassembly method, carboxylated sesquisiloxane with a flame retardant effect is selected as a modifier to obtain synergistic flame retardancy, resulting in carboxylated hydrotalcite-like compounds, and then grafting a hydroxyl-containing s-triazine ultraviolet absorber, significantly improving the flame retardancy and fire resistance and weather resistance of the sheets, enhancing the safety in use of the sheets, and extending the service life of the sheets. Specific embodiments

[0031] The following will clearly and completely describe the technical solutions in the present invention in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0032] It should be noted that if there are directional indications in the embodiments of the present invention, such as up, down, left, right, front, and back, these directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0033] The technical solutions of the present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0034] Example 1: A preparation method of an anti-aging polyvinyl chloride sheet, comprising the following steps: putting polyvinyl chloride resin, stabilizer, ACR auxiliary agent, modified hyperbranched polyester plasticizer, composite hydrotalcite, ethylene bisstearamide, and lubricant into a high-speed mixer for mixing and stirring evenly, then extrusion granulation and sheet pressing to obtain an anti-aging polyvinyl chloride sheet;

[0035] Working conditions of the high-speed mixer: feeding after preheating to 118°C;

[0036] By weight, it includes the following components: 88 parts of polyvinyl chloride resin, 2 parts of stabilizer, 6 parts of ACR auxiliary agent, 3 parts of composite hydrotalcite, 5 parts of modified hyperbranched polyester plasticizer, 0.5 part of ethylene bisstearamide, and 0.2 part of lubricant;

[0037] The stabilizer is methyl mercaptan tin; the lubricant is oxidized polyethylene wax;

[0038] The preparation of the modified hyperbranched polyester plasticizer includes the following steps:

[0039] 1) Under a nitrogen atmosphere, 0.3 mol of 2-carboxyethyl phenylphosphinic acid and 0.2 mol of 1,1,1-trimethylolpropane are mixed, heated to 158°C and kept warm for 8 h, stop passing nitrogen, evacuate to 0.098 MPa and continue to keep warm for 2 h, pour out while it is hot, and cool to obtain hyperbranched polyester;

[0040] 2) Heat 11 g of hyperbranched polyester to melt, add a mixed solution of 3 g of hydroxy-containing s-triazine ultraviolet absorber, 250 mL of toluene, and 0.5 g of p-toluenesulfonic acid, heat to 108°C and keep warm for 5 h, evacuate to 0.098 MPa, stir for 1 h, cool and dry to obtain the modified hyperbranched polyester plasticizer;

[0041] The preparation of the composite hydrotalcite includes the following steps:

[0042] (1) Mix 14 mL of vinyltrimethoxysilane, 135 mL of acetone, 22 mL of concentrated hydrochloric acid, and 25 mL of deionized water, keep warm at 40 °C for 48 h, wash and filter to obtain vinylated sesquisiloxane; mix 0.2 g of vinylated sesquisiloxane, 3.3 g of methacrylic acid, 0.2 g of sodium dodecylsulfonate, and 16 mL of deionized water, perform ultrasonic treatment for 15 min, add 0.4 g of ammonium persulfate, keep warm at 55 °C for 35 min, add 0.7 g of ammonium persulfate, 0.2 g of sodium bisulfate, 8 mL of deionized water, and 3.3 g of methacrylic acid, and continue to keep warm for 3 h to obtain carboxylated sesquisiloxane;

[0043] (2) Mix 10 g of carboxylated sesquisiloxane and 25 mL of deionized water, add 1 g of hydrotalcite-like powder, and perform ultrasonic treatment for 10 min to obtain a suspension; add the suspension to 7.5 g of carboxylated sesquisiloxane and stir at 55 °C for 2 h to obtain carboxylated hydrotalcite-like material;

[0044] (3) Mix 2.5 g of carboxylated hydrotalcite-like material, 1.4 g of hydroxyl-containing s-triazine ultraviolet absorber, and 50 mL of toluene, add 0.1 g of p-toluenesulfonic acid, heat up to 108 °C and keep warm for 3 h to obtain composite hydrotalcite-like material;

[0045] The preparation of the hydroxyl-containing s-triazine ultraviolet absorber includes the following steps:

[0046] A. Mix 9.2 g of cyanuric chloride and 125 mL of chlorobenzene, add 20 g of anhydrous aluminum trichloride in an ice-water bath, stir for 20 min, add 10.6 g of m-xylene, keep warm for 2 h, add 100 mL of 2% dilute hydrochloric acid, extract twice with 100 mL of chlorobenzene, dry, rotary evaporate, cool, and filter to obtain 2-chloro-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine;

[0047] B. Mix 9.7 g of 2-chloro-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine and 100 mL of chlorobenzene, add 4 g of anhydrous aluminum trichloride in an ice-water bath, stir for 20 min, add 3.6 g of resorcinol, heat up to 78 °C and keep warm for 2 h, add 100 mL of 2% dilute hydrochloric acid, distill and filter, and recrystallize twice with toluene to obtain 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine;

[0048] C. Mix 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine, 35 mL of N,N-dimethylformamide, and 0.5 g of sodium hydroxide. Heat the mixture in a water bath to 78 °C, add 1.2 g of epichlorohydrin, and continue to keep warm for 6 h. Reduce the pressure, add 100 mL of ammonium chloride aqueous solution, extract with dichloromethane three times, dry and concentrate, and recrystallize with an ethanol and dichloromethane solution with a volume ratio of 10:1 to obtain 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol;

[0049] D. Mix 4.5 g of 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol, 50 mL of N,N-dimethylformamide, 0.8 g of ethyltriphenylphosphonium bromide, 1.5 g of n-dodecanol, and 0.8 g of n-tridecanol. Heat the mixture in a water bath to 88 °C and keep warm for 24 h. Reduce the pressure, add 75 mL of deionized water, extract with ethyl acetate, dry and concentrate, reflux with ethanol for 10 min, and cool to obtain a hydroxyl-containing triazine ultraviolet absorber.

[0050] Example 2: A preparation method of an anti-aging polyvinyl chloride sheet, comprising the following steps: Put polyvinyl chloride resin, stabilizer, ACR auxiliary agent, modified hyperbranched polyester plasticizer, composite hydrotalcite, ethylene bisstearamide, and lubricant into a high-speed mixer and mix evenly, then extrude and pelletize, and press into sheets to obtain an anti-aging polyvinyl chloride sheet;

[0051] Working conditions of the high-speed mixer: Feed materials after preheating to 118 °C;

[0052] By weight, it includes the following components: 93 parts of polyvinyl chloride resin, 3 parts of stabilizer, 7 parts of ACR auxiliary agent, 5 parts of composite hydrotalcite, 8 parts of modified hyperbranched polyester plasticizer, 0.8 part of ethylene bisstearamide, and 0.4 part of lubricant;

[0053] The stabilizer is methyl mercaptan tin; the lubricant is polyethylene oxide wax;

[0054] The preparation of the modified hyperbranched polyester plasticizer includes the following steps:

[0055] 1) Under a nitrogen atmosphere, mix 0.3 mol of 2-carboxyethylphenylphosphinic acid and 0.2 mol of 1,1,1-trimethylolpropane, heat to 160 °C and keep warm for 7.5 h, stop passing nitrogen, evacuate to 0.098 MPa and continue to keep warm for 2 h, pour out while it is hot, and cool to obtain hyperbranched polyester;

[0056] 2) Heat 11 g of hyperbranched polyester to melting, add a mixture of 3 g of a hydroxyl-containing s-triazine ultraviolet absorber, 250 mL of toluene, and 0.5 g of p-toluenesulfonic acid, heat to 109 °C and hold for 5.5 h, evacuate to 0.098 MPa, stir for 1.5 h, cool and dry to obtain a modified hyperbranched polyester plasticizer;

[0057] The preparation of the composite hydrotalcite includes the following steps:

[0058] (1) Mix 14 mL of vinyltrimethoxysilane, 135 mL of acetone, 22 mL of concentrated hydrochloric acid, and 25 mL of deionized water, hold at 45 °C for 46 h, wash and filter to obtain vinylated sesquisiloxane; Mix 0.2 g of vinylated sesquisiloxane, 3.3 g of methacrylic acid, 0.2 g of sodium dodecylsulfonate, and 16 mL of deionized water, ultrasonically treat for 13 min, add 0.4 g of ammonium persulfate, hold at 60 °C for 30 min, add 0.7 g of ammonium persulfate, 0.2 g of sodium bisulfate, 8 mL of deionized water, and 3.3 g of methacrylic acid, and continue to hold for 3.5 h to obtain carboxylated sesquisiloxane;

[0059] (2) Mix 10 g of carboxylated sesquisiloxane and 25 mL of deionized water, add 1 g of hydrotalcite powder, ultrasonically treat for 13 min to obtain a suspension; Add the suspension to 7.5 g of carboxylated sesquisiloxane and stir at 60 °C for 1.5 h to obtain carboxylated hydrotalcite;

[0060] (3) Mix 2.5 g of carboxylated hydrotalcite, 1.4 g of a hydroxyl-containing s-triazine ultraviolet absorber, and 50 mL of toluene, add 0.1 g of p-toluenesulfonic acid, heat to 109 °C and hold for 2.5 h to obtain the composite hydrotalcite;

[0061] The preparation of the hydroxyl-containing s-triazine ultraviolet absorber includes the following steps:

[0062] A. Mix 9.2 g of cyanuric chloride and 125 mL of chlorobenzene, add 20 g of anhydrous aluminum trichloride in an ice-water bath, stir for 25 min, add 10.6 g of m-xylene, hold for 2.5 h, add 100 mL of 2% dilute hydrochloric acid, extract twice with 100 mL of chlorobenzene, dry, rotary evaporate, cool, and filter to obtain 2-chloro-4,6-bis(2',4'-dimethylphenyl)-1,3,5-s-triazine;

[0063] B. Mix 9.7 g of 2-chloro-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine and 100 mL of chlorobenzene. Add 4 g of anhydrous aluminum trichloride in an ice-water bath, stir for 20 - 30 min, add 3.6 g of resorcinol, heat up to 80 °C and keep warm for 1.5 h. Add 100 mL of 2% dilute hydrochloric acid, distill and filter by suction, and recrystallize twice with toluene to obtain 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine;

[0064] C. Mix 4 g of 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine, 35 mL of N,N-dimethylformamide, and 0.5 g of sodium hydroxide. Heat up to 80 °C in a water bath, add 1.2 g of epichlorohydrin, continue to keep warm for 5.5 h, reduce the pressure, add 100 mL of ammonium chloride aqueous solution, extract 3 times with dichloromethane, dry and concentrate, and recrystallize with a 10:1 volume ratio of ethanol and dichloromethane solution to obtain 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol;

[0065] D. Mix 4.5 g of 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol, 50 mL of N,N-dimethylformamide, 0.8 g of ethyltriphenylphosphonium bromide, 1.5 g of n-dodecanol, and 0.8 g of n-tridecanol. Heat up to 90 °C in a water bath and keep warm for 23 h, reduce the pressure, add 75 mL of deionized water, extract with ethyl acetate, dry and concentrate, reflux with ethanol for 15 min, and cool to obtain a hydroxyl-containing triazine-based ultraviolet absorber.

[0066] Example 3: A preparation method of an anti-aging polyvinyl chloride sheet, comprising the following steps: Put polyvinyl chloride resin, stabilizer, ACR auxiliary agent, modified hyperbranched polyester plasticizer, composite hydrotalcite, ethylene bisstearamide, and lubricant into a high-speed mixer and mix evenly, then extrude and pelletize, and press into sheets to obtain an anti-aging polyvinyl chloride sheet;

[0067] Working conditions of the high-speed mixer: Feed materials after preheating to 118 °C;

[0068] By weight, it includes the following components: 102 parts of polyvinyl chloride resin, 4 parts of stabilizer, 9 parts of ACR auxiliary agent, 7 parts of composite hydrotalcite, 10 parts of modified hyperbranched polyester plasticizer, 1 part of ethylene bisstearamide, and 0.6 part of lubricant;

[0069] The stabilizer is methyl mercaptan tin; the lubricant is oxidized polyethylene wax;

[0070] The preparation of the modified hyperbranched polyester plasticizer includes the following steps:

[0071] 1) Under a nitrogen atmosphere, 0.3 mol of 2 - carboxyethylphenylphosphinic acid and 0.2 mol of 1,1,1 - trimethylolpropane were mixed, heated to 162 °C and kept warm for 7 h. Then, the nitrogen supply was stopped, the vacuum was pumped to 0.098 MPa and it was kept warm for another 2 h. It was quickly poured out while it was hot, cooled, and a hyperbranched polyester was obtained.

[0072] 2) 11 g of the hyperbranched polyester was heated to melting, and a mixed solution of 3 g of a hydroxyl - containing s - triazine - type ultraviolet absorber, 250 mL of toluene, and 0.5 g of p - toluenesulfonic acid was added. It was heated to 110 °C and kept warm for 6 h, the vacuum was pumped to 0.098 MPa, stirred for 2 h, cooled and dried to obtain a modified hyperbranched polyester - type plasticizer.

[0073] The preparation of the composite - type hydrotalcite includes the following steps:

[0074] (1) 14 mL of vinyltrimethoxysilane, 135 mL of acetone, 22 mL of concentrated hydrochloric acid, and 25 mL of deionized water were mixed, kept warm at 50 °C for 44 h, washed and filtered to obtain vinylated sesquisiloxane; 0.2 g of vinylated sesquisiloxane, 3.3 g of methacrylic acid, 0.2 g of sodium dodecylsulfonate, and 16 mL of deionized water were mixed, ultrasonically treated for 15 min, 0.4 g of ammonium persulfate was added, kept warm at 65 °C for 25 min, 0.7 g of ammonium persulfate, 0.2 g of sodium bisulfate, 8 mL of deionized water, and 3.3 g of methacrylic acid were added, and it was kept warm for another 4 h to obtain carboxylated sesquisiloxane.

[0075] (2) 10 g of carboxylated sesquisiloxane and 25 mL of deionized water were mixed, 1 g of hydrotalcite - like powder was added, and ultrasonically treated for 15 min to obtain a suspension; the suspension was added to 7.5 g of carboxylated sesquisiloxane, and stirred at 65 °C for 1 h to obtain carboxylated hydrotalcite - like.

[0076] (3) 2.5 g of carboxylated hydrotalcite - like, 1.4 g of a hydroxyl - containing s - triazine - type ultraviolet absorber, and 50 mL of toluene were mixed, 0.1 g of p - toluenesulfonic acid was added, heated to 110 °C and kept warm for 2 h to obtain the composite - type hydrotalcite.

[0077] The preparation of the hydroxyl - containing s - triazine - type ultraviolet absorber includes the following steps:

[0078] A. 9.2 g of cyanuric chloride and 125 mL of chlorobenzene were mixed, 20 g of anhydrous aluminum trichloride was added in an ice - water bath, stirred for 30 min, 10.6 g of m - xylene was added, kept warm for 3 h, 100 mL of 2% dilute hydrochloric acid was added, extracted twice with 100 mL of chlorobenzene, dried, rotary evaporated, cooled, and filtered to obtain 2 - chloro - 4,6 - bis(2',4' - dimethylphenyl) - 1,3,5 - s - triazine.

[0079] B. 9.7 g of 2-chloro-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine and 100 mL of chlorobenzene were mixed. 4 g of anhydrous aluminum trichloride was added in an ice-water bath, and the mixture was stirred for 30 min. Then 3.6 g of resorcinol was added, and the temperature was raised to 82 °C and kept for 1 h. 100 mL of 2% dilute hydrochloric acid was added, and the mixture was distilled and filtered by suction. It was recrystallized twice with toluene to obtain 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine;

[0080] C. 4 g of 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine, 35 mL of N,N-dimethylformamide, and 0.5 g of sodium hydroxide were mixed. The temperature was raised to 82 °C in a water bath, 1.2 g of epichlorohydrin was added, and the mixture was kept for 6 h under reduced pressure. 100 mL of ammonium chloride aqueous solution was added, and the mixture was extracted 3 times with dichloromethane, dried, concentrated, and recrystallized with an ethanol and dichloromethane solution with a volume ratio of 10:1 to obtain 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol;

[0081] D. 4.5 g of 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazin-2-yl)-5-glycidyl ether phenol, 50 mL of N,N-dimethylformamide, 0.8 g of ethyltriphenylphosphonium bromide, 1.5 g of n-dodecanol, and 0.8 g of n-tridecanol were mixed. The temperature was raised to 92 °C in a water bath and kept for 22 h under reduced pressure. 75 mL of deionized water was added, and the mixture was extracted with ethyl acetate, dried, concentrated, refluxed with ethanol for 20 min, and cooled to obtain a hydroxyl-containing triazine-based ultraviolet absorber.

[0082] Comparative Example 1: Taking Example 3 as the control group, hydrotalcite-like was replaced with composite hydrotalcite-like, and other processes were normal.

[0083] Comparative Example 2: Taking Example 3 as the control group, dioctyl phthalate (99%) was replaced with a modified hyperbranched polyester-based plasticizer, and other processes were normal.

[0084] The preparation of the hydrotalcite-like powder in the examples and comparative examples includes the following steps:

[0085] 6.7 g of magnesium chloride hexahydrate, 4 g of aluminum chloride hexahydrate, and 50 mL of deionized water were mixed to prepare solution A. 2 g of sodium hydroxide, 1.2 g of sodium carbonate, and 50 mL of deionized water were mixed to prepare solution B. While stirring, solutions A and B were dropped into a large beaker, the pH was adjusted to 10, and the mixture was aged at 80 °C for 12 h, washed, dried, and ground to obtain hydrotalcite-like powder.

[0086] Sources of the raw materials used (only for demonstration examples):

[0087] Polyvinyl chloride resin C2000: Dongguan Jinshixiang Plastic Raw Materials Co., Ltd.; ACR additive (acrylic additive): Kaneka Corporation of Japan; Oxidized polyethylene wax ZC-316A: Jiaxing Zhongcheng Environmental Protection Technology Co., Ltd.; 2-Carboxyethylphenylphosphinic acid S70357: Shanghai Yuanye Bio-Technology Co., Ltd.; Ethylene bisstearamide N159314, Methyltin mercaptide M304039, 1,1,1-Tris(hydroxymethyl)propane T110597, Vinyltrimethoxysilane V162969, Methacrylic acid M434201, Cyanuric chloride C118499, m-Xylene X103350, Resorcinol R661274, Epichlorohydrin E108182, Ethyltriphenylphosphonium bromide E110246, n-Dodecanol D112298, n-Tridecanol T105003: Aladdin Reagent; N,N-Dimethylformamide, Toluene, p-Toluenesulfonic acid, Acetone, Hydrochloric acid, Sodium dodecylsulfonate, Ammonium persulfate, Sodium bisulfate, Chlorobenzene, Anhydrous aluminum trichloride, Sodium hydroxide, Ammonium chloride, Magnesium chloride hexahydrate, Aluminum chloride hexahydrate, Sodium carbonate, Ethanol, Dichloromethane, Ethyl acetate, analytical grade, purchased from the market.

[0088] Performance test: The sheets prepared in the examples and comparative examples were tested:

[0089] Impact resistance: The sheet size was 50 mm in length, 120 mm in width, and 2 mm in thickness, characterized by the notched impact strength, and tested according to GB / T 1043.1-2008.

[0090] Flame retardancy: UL-94 vertical burning rating test was carried out.

[0091] Aging resistance: The specimen was irradiated with 365 nm ultraviolet light for 168 h, and the notched impact strength was measured again. If the change rate compared with the initial notched impact strength was within 0-1% (including 1%), it was considered qualified, otherwise unqualified; the results are shown in Table 1.

[0092] Table 1

[0093]

[0094] The present invention provides an aging-resistant polyvinyl chloride sheet and its preparation method. By optimizing the composition and process, an aging-resistant polyvinyl chloride sheet with good mechanical strength, high flame retardancy, and aging resistance is prepared.

[0095] Comparing Example 3 with Comparative Example 1, it can be seen that in the present invention, hydrotalcite-like is selected as the filler to improve the thermal stability and flame retardancy of the sheet. To further improve the uniformity of the dispersion of hydrotalcite-like in the sheet, the hydrotalcite-like is modified. By the exfoliation-reassembly method, carboxylated sesquisiloxane with flame retardant effect is selected as the modifier to obtain synergistic flame retardancy, and carboxylated hydrotalcite-like is obtained. Then, a hydroxyl-containing s-triazine ultraviolet absorber is grafted, greatly improving the flame retardancy and weather resistance of the sheet, enhancing the use safety of the sheet, and extending the service life of the sheet.

[0096] Comparing Example 3 with Comparative Example 2, it can be seen that in order to improve the negative impacts such as migration and decline in mechanical properties caused by the addition of a large amount of existing small molecule plasticizers, and to simultaneously meet the requirements of improving processing fluidity, maintaining mechanical properties and enhancing anti-aging properties, the present invention synthesizes hyperbranched polyester using 2-carboxyethylphenylphosphinic acid and 1,1,1-trimethylolpropane as raw materials, and then grafts a hydroxyl-containing s-triazine ultraviolet absorber to obtain a modified hyperbranched polyester plasticizer for plasticizing polyvinyl chloride sheets, while greatly improving the flame retardancy and weather resistance of the sheets; the hydroxyl-containing s-triazine ultraviolet absorber is prepared by reacting cyanuric chloride with 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine through the Friedel-Crafts reaction, and then condensing with epichlorohydrin and reacting with dodecanol and tridecanol. Compared with the commonly used benzotriazole-based and benzophenone-based ultraviolet absorbers in the market, it has strong ultraviolet absorption at 280-380 nm, lighter color, high temperature resistance and good solubility.

[0097] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made using the description of the present invention under the inventive concept of the present invention, or direct / indirect application in other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. An aging-resistant polyvinyl chloride sheet, characterized in that: The composition comprises the following components by weight: 88-102 parts of polyvinyl chloride resin, 2-4 parts of stabilizer, 6-9 parts of ACR additive, 3-7 parts of composite hydrotalcite, 5-10 parts of modified hyperbranched polyester plasticizer, 0.5-1 parts of ethylene bis stearamide, and 0.2-0.6 parts of lubricant; The preparation of the modified hyperbranched polyester plasticizer comprises the following steps: 1) In a nitrogen atmosphere, 2-carboxyethylphenylphosphinic acid and 1,1,1-trimethylolpropane were mixed, the temperature was raised to 158-162°C and kept warm for 7-8 hours, the nitrogen was stopped, the vacuum was evacuated to 0.098MPa and kept warm for 2 hours, the mixture was poured out while hot, and cooled to obtain a hyperbranched polyester; 2) heating the hyperbranched polyester until it is melted, adding a mixed solution of a hydroxyl-containing s-triazine ultraviolet absorber, toluene, and p-toluenesulfonic acid, keeping the temperature at 108-110° C. for 5-6 hours, evacuating to 0.098 MPa, stirring for 1-2 hours, cooling, and drying to obtain a modified hyperbranched polyester plasticizer; The preparation of the composite hydrotalcite-like material comprises the following steps: (1) Vinyl trimethoxysilane, acetone, concentrated hydrochloric acid and deionized water are mixed, kept at 40-50°C for 44-48 hours, washed and filtered to obtain vinyl silsesquioxane; vinyl silsesquioxane, methacrylic acid, sodium dodecyl sulfonate and deionized water are mixed, ultrasonically treated for 10-15 minutes, ammonium persulfate is added, kept at 55-65°C for 25-35 minutes, ammonium persulfate, sodium bisulfate, deionized water and methacrylic acid are added, and kept warm for 3-4 hours to obtain carboxylated silsesquioxane; (2) Mixing carboxylated silsesquioxane and deionized water, adding hydrotalcite-like powder, and ultrasonically treating for 10-15 minutes to obtain a suspension; adding the suspension to carboxylated silsesquioxane, stirring at 55-65° C. for 1-2 hours, and drying to obtain a carboxylated hydrotalcite-like powder; (3) Mix the carboxylated hydrotalcite, the hydroxyl-containing s-triazine ultraviolet absorber and toluene, add p-toluenesulfonic acid, raise the temperature to 108-110°C and keep it for 2-3 hours to obtain a composite hydrotalcite.

2. The aging-resistant polyvinyl chloride sheet according to claim 1, characterized in that: The stabilizer is one of an organic tin stabilizer and a liquid calcium zinc stabilizer or a combination thereof.

3. The aging-resistant polyvinyl chloride sheet according to claim 1, characterized in that: The lubricant is one or more of oxidized polyethylene wax, polyol ester and stearate.

4. The aging-resistant polyvinyl chloride sheet according to claim 1, characterized in that: In the preparation of the modified hyperbranched polyester plasticizer, the mass ratio of the hyperbranched polyester to the hydroxyl-containing s-triazine ultraviolet absorber is 11:

3.

5. The aging-resistant polyvinyl chloride sheet according to claim 1, characterized in that: In the preparation of the composite hydrotalcite, the mass ratio of the carboxylated hydrotalcite to the hydroxyl-containing s-triazine ultraviolet absorber is 2.5:1.

4.

6. The aging-resistant polyvinyl chloride sheet according to claim 1, characterized in that: The preparation of the hydroxyl-containing s-triazine ultraviolet absorber comprises the following steps: A. Mix cyanuric chloride and chlorobenzene, add anhydrous aluminum chloride in an ice water bath, stir for 20-30 minutes, add m-xylene, keep warm for 2-3 hours, add dilute hydrochloric acid, extract with chlorobenzene twice, dry, rotary evaporate, cool, and filter to obtain 2-chloro-4,6-di(2',4'-dimethylphenyl)-1,3,5-s-triazine; B. Mix 2-chloro-4,6-di(2',4'-dimethylphenyl)-1,3,5-s-triazine and chlorobenzene, add anhydrous aluminum chloride in an ice-water bath, stir for 20-30 minutes, add resorcinol, heat to 78-82℃ and keep warm for 1-2 hours, add dilute hydrochloric acid, distill, filter, and recrystallize twice with toluene to obtain 2-(2',4'-dihydroxyphenyl)-4,6-di(2',4'-dimethylphenyl)-1,3,5-s-triazine; C. Mix 2-(2',4'-dihydroxyphenyl)-4,6-bis(2',4'-dimethylphenyl)-1,3,5-s-triazine, N,N-dimethylformamide and sodium hydroxide, heat to 78-82°C in a water bath, add epichlorohydrin, keep warm for 5-6h, reduce pressure, add aqueous ammonium chloride solution, extract with dichloromethane for 3 times, dry, concentrate, recrystallize with ethanol and dichloromethane solution with a volume ratio of 10:1 to obtain 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine-2-yl)-5-glycidyl ether phenol; D. Mix 2-(4,6-bis(2',4'-dimethylphenyl)-1,3,5-triazine-2-yl)-5-glycidyl ether phenol, N,N-dimethylformamide, ethyltriphenylphosphonium bromide, n-dodecanol and n-tridecanol, heat to 88-92°C in a water bath and keep warm for 22-24 hours, reduce the pressure, add deionized water, extract with ethyl acetate, dry and concentrate, reflux with ethanol for 10-20 minutes, cool and obtain a hydroxyl-containing s-triazine ultraviolet absorber.

7. A method for preparing an aging-resistant polyvinyl chloride sheet according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: putting polyvinyl chloride resin, stabilizer, ACR auxiliary agent, modified hyperbranched polyester plasticizer, composite hydrotalcite, ethylene bis stearamide and lubricant into a high-speed mixer, mixing and stirring evenly, and then extruding and granulating, and pressing and tableting to obtain an aging-resistant polyvinyl chloride sheet.

8. The method for preparing an ageing-resistant polyvinyl chloride sheet according to claim 7, characterized in that: Working conditions of high-speed mixer: preheat to 118℃ before adding materials.

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