A puncture-resistant and tear-resistant EVA waterproof sheet and preparation method thereof

Abstract

The present invention relates to the technical field of waterproof materials for railway tunnels, and in particular to a puncture-resistant and tear-resistant EVA waterproof sheet and a preparation method thereof. The EVA waterproof sheet is made by uniformly mixing a variety of raw materials through a counter-rotating twin-screw extruder and a cooling calendering roller; the raw materials of the EVA waterproof sheet include, by weight: 15 to 35 parts of ethylene-vinyl acetate copolymer, 20 to 40 parts of ultra-high molecular weight polyethylene, 20 to 30 parts of modified polypropylene, 10 to 25 parts of ethylene-octene copolymer, 3 to 5 parts of silicon dioxide particles, 3 to 5 parts of compatibilizers, and 3 to 5 parts of antioxidant masterbatches. The EVA waterproof sheet has excellent puncture-resistant and tear-resistant properties.

Description

Technical Field

[0001] The invention relates to the technical field of waterproof materials for railway tunnels, and in particular to a puncture-resistant and tear-resistant EVA waterproof board and a preparation method thereof. Background Art

[0002] With the rapid development of my country's economy, road modernization has reached a new level. Due to the complex terrain of my country, traffic tunnels have become an important part of road construction, among which railway tunnels and urban rail transit occupy an important part of traffic tunnels. Railway tunnels are structures under the surface, and they inevitably face various complex geological conditions. Problems such as groundwater development, frost heaving rocks, and high temperature heat damage of rocks in tunnels are endless. Among them, high temperature heat damage of rocks in tunnels is one of the hazards of tunnels, which directly affects the safety of driving. This requires the waterproof board to have excellent high temperature puncture resistance.

[0003] The development of waterproof materials on the market is relatively slow and can no longer meet the complex tunnel problems. Upgrading waterproof materials has become one of the important directions in tunnel engineering. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a puncture-resistant and tear-resistant EVA waterproof board and a preparation method thereof.

[0005] On the one hand, a puncture-resistant and tear-resistant EVA waterproof sheet is provided, wherein the EVA waterproof sheet is made by uniformly mixing a plurality of raw materials and then passing through a counter-rotating twin-screw extruder and a cooling calender roller;

[0006] The raw materials of the EVA waterproof board include, by weight: 15-35 parts of ethylene-vinyl acetate copolymer, 20-40 parts of ultra-high molecular weight polyethylene, 20-30 parts of modified polypropylene, 10-25 parts of ethylene-octene copolymer, 3-5 parts of silicon dioxide particles, 3-5 parts of compatibilizer, and 3-5 parts of antioxidant masterbatch.

[0007] As an embodiment of the present invention, the vinyl acetate content in the ethylene-vinyl acetate copolymer is 15wt%~35wt%, and the melt flow rate thereof is 5.8~6.5g / 10min under the experimental conditions of 190°C and 2.16kg weight; the density of the ultra-high molecular weight polyethylene is 0.920~0.969g / cm³.

[0008] As an embodiment of the present invention, the modified polypropylene is a modified polypropylene containing a styrene-butadiene-styrene block copolymer segment; the particle diameter of the silica particles is 10-30 μm; and the compatibilizer is a maleic anhydride grafted compatibilizer or a carboxylic acid type compatibilizer.

[0009] As an embodiment of the present invention, the density of the ethylene-octene copolymer is 0.901-0.920 g / cm³, and the melt flow rate thereof is 0.80-1.10 g / 10 min under the experimental conditions of 190° C. and 2.16 kg weight.

[0010] As an embodiment of the present invention, the raw materials of the antioxidant masterbatch include, by weight: 50-70 parts of linear low-density polyethylene, 20-30 parts of antioxidant, and 10-20 parts of light stabilizer;

[0011] The density of the linear low-density polyethylene is 0.918-0.923 g / cm³, and the melt flow rate is 0.60-1.30 g / 10 min at 190°C and 2.16 kg weight.

[0012] The light stabilizer is a hindered amine light stabilizer; the antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 1010 or antioxidant 2246; the phosphorus antioxidant is selected from one or a mixture of (2,4-di-tert-butylphenyl) phosphite triester and dioctadecyl alcohol pentaerythritol diphosphite.

[0013] On the other hand, a method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet as described in the first aspect is provided, the method comprising:

[0014] Step S1, adding an antioxidant, a light stabilizer, and a linear low-density polyethylene into a high-speed mixer, and stirring at 25±5° C. to prepare an antioxidant premix, wherein the antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2;

[0015] Step S2, preparing antioxidant masterbatch by underwater pelletizing the antioxidant premix;

[0016] Step S3, adding the antioxidant masterbatch, ethylene-vinyl acetate copolymer, ultra-high molecular weight polyethylene, modified polypropylene, ethylene-octene copolymer, silica particles, and compatibilizer into a blender and mixing them evenly to prepare a sheet material premix;

[0017] Step S4, the plate premix is ​​passed through a counter-rotating twin-screw extruder and a cooling calendering roller to achieve continuous production of a 4 m wide puncture-resistant and tear-resistant EVA waterproof board at a rate of 3.7-4.3 m / min.

[0018] As an embodiment of the present invention, in step S1, an antioxidant, a light stabilizer and a linear low-density polyethylene are mixed in a high-speed mixer for 5 minutes.

[0019] As an embodiment of the present invention, in step S2, the antioxidant premix is ​​melt-blended in an underwater pelletizer, the melt extrusion temperature is 190-200°C, and the rotation speed is 200-350r / min; the melt extrusion equipment is a counter-rotating twin-screw extruder.

[0020] As an embodiment of the present invention, in step S3, the antioxidant masterbatch, ethylene-vinyl acetate copolymer, ultra-high molecular weight polyethylene, modified polypropylene, ethylene-octene copolymer, silica particles and compatibilizer are mixed in a high-speed mixer for 10 minutes.

[0021] As an embodiment of the present invention, in step S4, the operating temperature of the counter-rotating twin-screw extruder is 200-220° C., and the screw speed is 300 r / min;

[0022] The roller temperature of the cooling calendering roller is 55±5° C., and the diameter of the cooling calendering roller is 600 mm.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The ultra-high molecular weight polyethylene of the puncture-resistant and tear-resistant EVA waterproof board formula of the present invention enables the waterproof board to have a higher tensile strength, the modified polypropylene enables the waterproof board to have a higher puncture resistance, the ethylene-octene copolymer enables the waterproof board to have a higher tear strength, and the silicon dioxide particles and compatibilizer can effectively enhance the connection between each molecule, so that the various properties of the waterproof board are effectively improved. The antioxidant masterbatch enables the waterproof board to greatly prolong the oxidation time, and the content of vinyl acetate in the waterproof board is not less than 5%, which effectively guarantees the welding performance of the waterproof board and is convenient for subsequent use.

[0025] By reasonably controlling the mass ratio of each component in the formula, appropriate interaction between the components is obtained, and the synergistic effect between the components is maximized, so that 4m wide puncture and tear resistant EVA waterproof board can achieve high-speed continuous production of up to 4.3m / min, and ensure that the EVA waterproof board has significantly better tensile properties and puncture resistance. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clear, the present invention is clearly and completely described below in conjunction with specific embodiments.

[0027] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0028] Example 1

[0029] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0030] Step S1, adding 70 parts of linear low-density polyethylene, 20 parts of antioxidant, and 10 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 20° C. to prepare an antioxidant premix;

[0031] The linear low-density polyethylene is Saudi Sabic 118W, with a density of 0.918 g / cm³ and a melt flow rate of 1.0 g / 10 min at 190°C and a 2.16 kg weight. The antioxidant is a mixture of antioxidant 1010 and dioctadecyl alcohol pentaerythritol diphosphite in a weight ratio of 1:2. The light stabilizer is hindered amine light stabilizer 770.

[0032] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 190° C. and the rotation speed is 350 r / min;

[0033] Step S3, adding 15 parts of ethylene-vinyl acetate copolymer, 20 parts of ultra-high molecular weight polyethylene, 20 parts of modified polypropylene, 10 parts of ethylene-octene copolymer POE, 3 parts of silica particles, 3 parts of maleic anhydride grafted compatibilizer, and 3 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix;

[0034] The vinyl acetate content in the ethylene-vinyl acetate copolymer is 28wt%, and the melt flow rate is 6.2g / 10min at 190°C and 2.16kg weight. The ultra-high molecular weight polyethylene is Mitsui Chemicals L3000 from Japan, with a density of 0.969g / cm 3 ; The particle diameter of the silica particles is 20 μm; The density of the ethylene-octene copolymer POE is 0.904 g / cm 3 , its melt flow rate is 1.0 g / 10 min at 190°C and 2.16 kg weight;

[0035] The modified polypropylene is a modified PP granular material, and its preparation method adopts the method disclosed in the Chinese patent with publication number CN113667419A, and its formula is the same as the formula of the middle layer in Example 2 of the patent; the weight composition of the raw materials is 100 parts of polypropylene, 10 parts of styrene-butadiene-styrene block copolymer, and 0.13 parts of diisopropylbenzene peroxide. It is produced by a one-step grafting blending method of polypropylene, styrene-butadiene-styrene block copolymer, and diisopropylbenzene peroxide through high-temperature extrusion.

[0036] Step S4, the board premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 200°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 50°C, and the diameter of the cooling calendering roller is 600mm.

[0037] Example 2

[0038] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0039] Step S1, adding 60 parts of linear low-density polyethylene, 25 parts of antioxidant, and 15 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 25° C. to prepare an antioxidant premix;

[0040] The antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 2246, and the phosphorus antioxidant is a mixture of (2,4-di-tert-butylphenyl) phosphite triester and dioctadecyl alcohol pentaerythritol diphosphite; the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0041] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 195° C. and the rotation speed is 300 r / min;

[0042] Step S3, adding 23 parts of ethylene-vinyl acetate copolymer, 31 parts of ultra-high molecular weight polyethylene, 24 parts of modified polypropylene, 16 parts of ethylene-octene copolymer, 4 parts of silica particles, 4 parts of carboxylic acid type compatibilizer, and 4 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0043] Step S4, the plate premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof plate through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 210°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 55°C, and the diameter of the cooling calendering roller is 600mm.

[0044] Example 3

[0045] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0046] Step S1, adding 50 parts of linear low-density polyethylene, 30 parts of antioxidant, and 20 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 30° C. to prepare an antioxidant premix;

[0047] The antioxidant is a mixture of antioxidant 2246 and (2,4-di-tert-butylphenyl) triester phosphite in a weight ratio of 1:2, and the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0048] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 200° C. and the rotation speed is 200 r / min;

[0049] Step S3, adding 35 parts of ethylene-vinyl acetate copolymer, 40 parts of ultra-high molecular weight polyethylene, 30 parts of modified polypropylene, 25 parts of ethylene-octene copolymer, 5 parts of silica particles, 5 parts of carboxylic acid type compatibilizer, and 5 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0050] Step S4, the board premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 200°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 60°C, and the diameter of the cooling calendering roller is 600mm.

[0051] Example 4

[0052] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0053] Step S1, adding 55 parts of linear low-density polyethylene, 22 parts of antioxidant, and 26 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 27° C. to prepare an antioxidant premix;

[0054] The antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 2246, and the phosphorus antioxidant is (2,4-di-tert-butylphenyl) triester phosphite; the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0055] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 193° C. and the rotation speed is 300 r / min;

[0056] Step S3, adding 18 parts of ethylene-vinyl acetate copolymer, 22 parts of ultra-high molecular weight polyethylene, 23 parts of modified polypropylene, 13 parts of ethylene-octene copolymer, 3 parts of silica particles, 4 parts of carboxylic acid type compatibilizer, and 5 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0057] Step S4, the board premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 208°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 55°C, and the diameter of the cooling calendering roller is 600mm.

[0058] Example 5

[0059] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0060] Step S1, adding 58 parts of linear low-density polyethylene, 26 parts of antioxidant, and 13 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 25° C. to prepare an antioxidant premix;

[0061] The antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 2246, and the phosphorus antioxidant is dioctadecyl alcohol pentaerythritol diphosphite; the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0062] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the temperature of melt extrusion is 200° C. and the rotation speed is 320 r / min;

[0063] Step S3, adding 20 parts of ethylene-vinyl acetate copolymer, 35 parts of ultra-high molecular weight polyethylene, 27 parts of modified polypropylene, 17 parts of ethylene-octene copolymer, 4 parts of silica particles, 3 parts of carboxylic acid type compatibilizer, and 5 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0064] Step S4, the board premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 215°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 55°C, and the diameter of the cooling calendering roller is 600mm.

[0065] Example 6

[0066] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0067] Step S1, adding 62 parts of linear low-density polyethylene, 29 parts of antioxidant, and 17 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 26° C. to prepare an antioxidant premix;

[0068] The antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 2246, and the phosphorus antioxidant is a mixture of (2,4-di-tert-butylphenyl) phosphite triester and dioctadecyl alcohol pentaerythritol diphosphite; the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0069] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the temperature of melt extrusion is 198° C. and the rotation speed is 310 r / min;

[0070] Step S3, adding 30 parts of ethylene-vinyl acetate copolymer, 29 parts of ultra-high molecular weight polyethylene, 25 parts of modified polypropylene, 22 parts of ethylene-octene copolymer, 5 parts of silica particles, 3 parts of carboxylic acid type compatibilizer, and 4 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0071] Step S4, the board premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 220°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 55°C, and the diameter of the cooling calendering roller is 600mm.

[0072] Example 7

[0073] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0074] Step S1, adding 70 parts of linear low-density polyethylene, 20 parts of antioxidant, and 10 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 20° C. to prepare an antioxidant premix;

[0075] The density of the linear low-density polyethylene is 0.920 g / cm³, and the melt flow rate thereof is 0.60 g / 10 min at 190°C and 2.16 kg weight. The antioxidant is a mixture of antioxidant 1010 and dioctadecyl alcohol pentaerythritol diphosphite in a weight ratio of 1:2. The light stabilizer is hindered amine light stabilizer 770.

[0076] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 190° C. and the rotation speed is 350 r / min;

[0077] Step S3, adding 15 parts of ethylene-vinyl acetate copolymer, 20 parts of ultra-high molecular weight polyethylene, 20 parts of modified polypropylene, 10 parts of ethylene-octene copolymer POE, 3 parts of silica particles, 3 parts of maleic anhydride grafted compatibilizer, and 3 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix;

[0078] Among them, the vinyl acetate content in the ethylene-vinyl acetate copolymer is 15wt%, and its melt flow rate is 5.8g / 10min under the experimental conditions of 190°C and 2.16kg weight; the density of the ultra-high molecular weight polyethylene is 0.920g / cm³; the particle diameter of the silicon dioxide particles is 10μm; the density of the ethylene-octene copolymer is 0.901g / cm³, and its melt flow rate is 1.1g / 10min under the experimental conditions of 190°C and 2.16kg weight; the modified polypropylene is the same as that in Example 1;

[0079] Step S4, the board premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 200°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 50°C, and the diameter of the cooling calendering roller is 600mm.

[0080] Example 8

[0081] A puncture-resistant and tear-resistant EVA waterproof sheet, the preparation method of which comprises:

[0082] Step S1, adding 70 parts of linear low-density polyethylene, 20 parts of antioxidant, and 10 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 20° C. to prepare an antioxidant premix;

[0083] The density of the linear low-density polyethylene is 0.923 g / cm³, and the melt flow rate thereof is 1.30 g / 10 min at 190°C and 2.16 kg weight. The antioxidant is a mixture of antioxidant 1010 and dioctadecyl alcohol pentaerythritol diphosphite in a weight ratio of 1:2. The light stabilizer is hindered amine light stabilizer 770.

[0084] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 190° C. and the rotation speed is 350 r / min;

[0085] Step S3, adding 15 parts of ethylene-vinyl acetate copolymer, 20 parts of ultra-high molecular weight polyethylene, 20 parts of modified polypropylene, 10 parts of ethylene-octene copolymer POE, 3 parts of silica particles, 3 parts of maleic anhydride grafted compatibilizer, and 3 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a plate premix;

[0086] Among them, the vinyl acetate content in the ethylene-vinyl acetate copolymer is 35wt%, and its melt flow rate is 6.5g / 10min under the experimental conditions of 190°C and 2.16kg weight; the density of the ultra-high molecular weight polyethylene is 0.940g / cm³; the particle diameter of the silicon dioxide particles is 30μm; the density of the ethylene-octene copolymer is 0.901g / cm³, and its melt flow rate is 0.80g / 10min under the experimental conditions of 190°C and 2.16kg weight; the modified polypropylene is the same as that in Example 1;

[0087] Step S4, the board premix is ​​made into a 4m wide puncture-resistant and tear-resistant EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 200°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 50°C, and the diameter of the cooling calendering roller is 600mm.

[0088] Comparative Example 1

[0089] An EVA waterproof board, the preparation method of which comprises:

[0090] Step S1, adding 60 parts of linear low-density polyethylene, 25 parts of antioxidant, and 15 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 25° C. to prepare an antioxidant premix;

[0091] The antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 2246, and the phosphorus antioxidant is a mixture of (2,4-di-tert-butylphenyl) phosphite triester and dioctadecyl alcohol pentaerythritol diphosphite; the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0092] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 195° C. and the rotation speed is 300 r / min;

[0093] Step S3, adding 23 parts of ethylene-vinyl acetate copolymer, 31 parts of ultra-high molecular weight polyethylene, 16 parts of ethylene-octene copolymer, 4 parts of silica particles, 4 parts of carboxylic acid type compatibilizer, and 4 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0094] Step S4, the board premix is ​​made into a 4m wide EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 210°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 55°C, and the diameter of the cooling calendering roller is 600mm.

[0095] Comparative Example 2

[0096] An EVA waterproof board, the preparation method of which comprises:

[0097] Step S1, adding 60 parts of linear low-density polyethylene, 25 parts of antioxidant, and 15 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 25° C. to prepare an antioxidant premix;

[0098] The antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 2246, and the phosphorus antioxidant is a mixture of (2,4-di-tert-butylphenyl) phosphite triester and dioctadecyl alcohol pentaerythritol diphosphite; the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0099] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 195° C. and the rotation speed is 300 r / min;

[0100] Step S3, adding 23 parts of ethylene-vinyl acetate copolymer, 31 parts of ultra-high molecular weight polyethylene, 24 parts of modified polypropylene, 4 parts of silica particles, 4 parts of carboxylic acid type compatibilizer, and 4 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0101] Step S4, the board premix is ​​made into a 4m wide EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 210°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 55°C, and the diameter of the cooling calendering roller is 600mm.

[0102] Comparative Example 3

[0103] An EVA waterproof board, the preparation method of which comprises:

[0104] Step S1, adding 60 parts of linear low-density polyethylene, 25 parts of antioxidant, and 15 parts of light stabilizer into a high-speed mixer and mixing for 5 minutes, stirring at 25° C. to prepare an antioxidant premix;

[0105] The antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight ratio of 1:2, the phenolic antioxidant is antioxidant 2246, and the phosphorus antioxidant is a mixture of (2,4-di-tert-butylphenyl) phosphite triester and dioctadecyl alcohol pentaerythritol diphosphite; the linear low-density polyethylene and the light stabilizer are the same as those in Example 1;

[0106] Step S2, the antioxidant premix is ​​processed into antioxidant masterbatch by an underwater pelletizer, and the melt extrusion temperature is 195° C. and the rotation speed is 300 r / min;

[0107] Step S3, adding 23 parts of ethylene-vinyl acetate copolymer, 31 parts of ultra-high molecular weight polyethylene, 24 parts of modified polypropylene, 16 parts of ethylene-octene copolymer, 4 parts of carboxylic acid type compatibilizer, and 4 parts of antioxidant masterbatch into a blender and mixing for 10 minutes to prepare a sheet premix; wherein, except for the compatibilizer and antioxidant masterbatch, the rest are the same as in Example 1;

[0108] Step S4, the board premix is ​​made into a 4m wide EVA waterproof board through a counter-rotating twin-screw extruder and a cooling calendering roller, the extruder operating temperature is 210°C, the screw speed is 300r / min; the roller temperature of the cooling calendering roller is 55°C, and the diameter of the cooling calendering roller is 600mm.

[0109] Effect Example 1

[0110] The production rate of 4m wide EVA waterproof board in Examples 1 to 6 and Comparative Examples 1 to 3 was obtained in the following manner, and the results are shown in Table 1.

[0111] Preparation rate test method: For any roll of waterproof sheet, the production rate of the roll of EVA waterproof sheet is obtained by using the formula v=S / t, where S is the length of the roll of EVA waterproof sheet and t is the preparation time of the roll of EVA waterproof sheet;

[0112] Repeat the above steps to obtain the production rate of each roll of EVA waterproof board, and average all the production rates to obtain the final production rate.

[0113] Table 1 Production rate of 4m wide EVA waterproof board

[0114]

[0115] It can be seen from Table 1 that the production rate of the 4 m wide EVA waterproof board in Examples 1 to 6 is as high as 3.7-4.3 m / min.

[0116] Effect Example 2

[0117] The products obtained from Examples 1 to 6 and Comparative Examples 1 to 3 were tested for tear strength, tensile strength at break, elongation at break, puncture strength, high temperature puncture, and VA content. The results are shown in Table 2.

[0118] The performance test indicators and methods are as follows: tear strength, tensile strength at break, elongation at break, and puncture strength are tested in accordance with the standard of QCR562.1-2018; high temperature puncture: first place it in a 70℃ oven for 1h, and then perform a puncture test in a 70℃ environmental chamber; VA content is tested in accordance with the standard method of GB / T 30925-2014.

[0119] Table 2 Performance test results of products obtained in various embodiments and comparative examples

[0120]

[0121] As can be seen from Table 2, the EVA waterproof sheets obtained in Examples 1 to 6 of the present invention have excellent mechanical properties. In addition, the addition of modified polypropylene has an enhancing effect on various properties of the material, among which the puncture strength and high-temperature puncture have the greatest impact; ethylene-octene copolymer has good compatibility with polyolefins and can effectively improve the tear strength of the material; silicon dioxide particles help to increase the compatibility of various materials during processing, thereby improving the mechanical properties of the material.

Claims

1. A method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet, characterized in that: The EVA waterproof board is made by uniformly mixing a variety of raw materials through a counter-rotating twin-screw extruder and a cooling calender roller; The raw materials of the EVA waterproof board include, by weight: 15-35 parts of ethylene-vinyl acetate copolymer, 20-40 parts of ultra-high molecular weight polyethylene, 20-30 parts of modified polypropylene, 10-25 parts of ethylene-octene copolymer, 3-5 parts of silicon dioxide particles, 3-5 parts of compatibilizer, and 3-5 parts of antioxidant masterbatch; the modified polypropylene is a modified polypropylene containing styrene-butadiene-styrene block copolymer segments, and the weight composition of the raw materials is 100 parts of polypropylene, 10 parts of styrene-butadiene-styrene block copolymer, and 0.13 parts of diisopropylbenzene peroxide, which is produced by a high-temperature extrusion one-step graft blending method of polypropylene, styrene-butadiene-styrene block copolymer, and diisopropylbenzene peroxide; The raw materials of the antioxidant masterbatch include, by weight: 50-70 parts of linear low-density polyethylene, 20-30 parts of antioxidant, and 10-20 parts of light stabilizer; the antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight content ratio of 1:

2. The preparation method of the puncture-resistant and tear-resistant EVA waterproof sheet comprises: Step S1, adding an antioxidant, a light stabilizer, and a linear low-density polyethylene into a high-speed mixer, and stirring at 25±5° C. to prepare an antioxidant premix, wherein the antioxidant is a mixture of a phenolic antioxidant and a phosphorus antioxidant in a weight content ratio of 1:2; Step S2, preparing antioxidant masterbatch by underwater pelletizing the antioxidant premix; Step S3, adding the antioxidant masterbatch, ethylene-vinyl acetate copolymer, ultra-high molecular weight polyethylene, modified polypropylene, ethylene-octene copolymer, silica particles, and compatibilizer into a blender and mixing them evenly to prepare a sheet material premix; Step S4, the plate premix is ​​passed through a counter-rotating twin-screw extruder and a cooling calendering roller to achieve continuous production of a 4 m wide puncture-resistant and tear-resistant EVA waterproof sheet at a rate of 3.7-4.3 m / min; In step S4, the operating temperature of the counter-rotating twin-screw extruder is 200-220° C., and the screw speed is 300 r / min; The roller temperature of the cooling calendering roller is 55±5° C., and the diameter of the cooling calendering roller is 600 mm.

2. The method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet according to claim 1, characterized in that: The vinyl acetate content in the ethylene-vinyl acetate copolymer is 15wt%-35wt%, and the melt flow rate thereof is 5.8-6.5g / 10min under the experimental conditions of 190°C and 2.16kg weight; the density of the ultra-high molecular weight polyethylene is 0.920-0.969g / cm³.

3. The method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet according to claim 1, characterized in that: The particle diameter of the silicon dioxide particles is 10-30 μm; the compatibilizer is a maleic anhydride grafted compatibilizer or a carboxylic acid type compatibilizer.

4. The method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet according to claim 1, characterized in that: The density of the ethylene-octene copolymer is 0.901-0.920 g / cm³, and the melt flow rate thereof is 0.80-1.10 g / 10 min under the experimental conditions of 190° C. and 2.16 kg weight.

5. The method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet according to claim 1, characterized in that: The linear low-density polyethylene has a density of 0.918-0.923 g / cm³ and a melt flow rate of 0.60-1.30 g / 10 min at 190° C. and 2.16 kg weight. The light stabilizer is a hindered amine light stabilizer; the phenolic antioxidant is antioxidant 1010 or antioxidant 2246; the phosphorus antioxidant is selected from one or a mixture of (2,4-di-tert-butylphenyl) phosphite triester and dioctadecyl alcohol pentaerythritol diphosphite.

6. The method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet according to claim 1, characterized in that: In step S1, an antioxidant, a light stabilizer, and a linear low-density polyethylene are mixed in a high-speed mixer for 5 minutes.

7. The method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet according to claim 1, characterized in that: In step S2, the antioxidant premix is ​​melt-blended in an underwater pelletizer, and the temperature of the melt extrusion is 190-200°C and the rotation speed is 200-350 r / min; the melt extrusion equipment is a counter-rotating twin-screw extruder.

8. The method for preparing a puncture-resistant and tear-resistant EVA waterproof sheet according to claim 1, characterized in that: In step S3, the antioxidant masterbatch, ethylene-vinyl acetate copolymer, ultra-high molecular weight polyethylene, modified polypropylene, ethylene-octene copolymer, silica particles and compatibilizer are mixed in a mixer for 10 minutes.

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