Preparation method of flame-retardant high-temperature-resistant PVC (polyvinyl chloride) material

Abstract

The invention relates to the technical field of materials, and discloses a preparation method of a flame-retardant high-temperature-resistant PVC (polyvinyl chloride) material, the flame-retardant high-temperature-resistant PVC material comprises the following raw materials in parts by weight: polyvinyl chloride resin, a stabilizer, a plasticizer, a charring agent, a flame-retardant smoke suppressant, a lubricant and an anti-aging agent, the flame-retardant smoke suppressant is diatomite of which the surface is modified with a phosphorus-containing flame retardant, and a hydrogen-bond cross-linked network is formed by utilizing the hydrogen-bond interaction between the charring agent and a polyvinyl chloride molecular chain, so that the high-temperature resistance and flame retardance of polyvinyl chloride are improved, and the emission of toxic gas during combustion is reduced; the pollution to air and the harm to a human body are reduced, the environment-friendly and sustainable product design is promoted, and the application field of the polyvinyl chloride is expanded.

Description

Technical Field

[0001] The invention relates to the technical field of polyvinyl chloride composite materials, and in particular to a method for preparing a flame-retardant and high-temperature resistant PVC material. Background Art

[0002] Polyvinyl chloride (PVC for short) has good comprehensive properties such as acid and alkali resistance, electrical insulation, mechanical properties and processing properties. It is used everywhere in daily life and is one of the five most widely used general-purpose resins. Due to the high chlorine content in the structure of polyvinyl chloride, it has good flame retardant properties. However, in the processing of polyvinyl chloride, a large amount of plasticizers are generally added to assist. The presence of these plasticizers greatly affects the flame retardant and high temperature resistance of polyvinyl chloride, causing polyvinyl chloride products to be easy to burn. In addition, a large amount of hydrogen chloride-containing smoke will be released during the combustion process, which is not only easy to cause the fire to spread, but also cause potential property and safety hazards and environmental problems. These shortcomings have greatly limited the further development and application of polyvinyl chloride products. Therefore, flame retardant modification of polyvinyl chloride has great research value and safety benefits.

[0003] In the processing of polyvinyl chloride, adding inorganic flame retardants for flame retardant modification is a commonly used technical means. For example, the invention patent with application number CN201711220083.X discloses a silane cross-linked flame retardant polyvinyl chloride cable material and a preparation method thereof, wherein antimony trioxide or molybdenum trioxide is selected as flame retardant a, and any one or a mixture of two or more of zinc borate, basic magnesium carbonate, silicon stannate, magnesium stannate and montmorillonite is selected as flame retardant b. Although the flame retardant properties of polyvinyl chloride can be improved to a certain extent, these inorganic flame retardants have low flame retardant efficiency, resulting in a large amount of flame retardant added, causing the compatibility of the flame retardant and the matrix to deteriorate, thereby causing a great impact on the mechanical properties of polyvinyl chloride products. From the test results, even if a large amount of inorganic flame retardant is added, the limiting oxygen index of the product is only 27-28%.

[0004] Based on this, the present invention provides a PVC material, which combines the advantages of organic flame retardants and inorganic flame retardants to make the PVC material have excellent flame retardant and high temperature resistance. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a flame-retardant and high-temperature resistant PVC material, which solves the problem that the polyvinyl chloride material has poor flame-retardant and high-temperature resistant properties.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for preparing a flame-retardant and high-temperature resistant PVC material, wherein the flame-retardant and high-temperature resistant PVC material comprises the following raw materials in parts by weight: 85-95 parts of polyvinyl chloride resin, 5-12 parts of stabilizer, 20-35 parts of plasticizer, 2-4.5 parts of carbonizing agent, 4-8 parts of flame-retardant and smoke suppressant, 0.5-1.5 parts of lubricant, and 0.1-0.4 parts of antioxidant;

[0008] The carbon-forming agent is prepared by modifying cellulose by amination and then compounding it with sodium stannate;

[0009] The flame retardant and smoke suppressant is diatomaceous earth with a phosphorus-containing flame retardant modified on the surface;

[0010] The preparation method of the flame retardant and high temperature resistant PVC material comprises the following steps:

[0011] Step 1: Pour parts by weight of polyvinyl chloride resin, stabilizer, plasticizer, carbonizing agent, lubricant and antioxidant into a mixer, set the mixer temperature to 120-130°C, stir and mix evenly, add parts by weight of flame retardant and smoke suppressant, continue stirring until a uniform material is formed to form a premix;

[0012] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at a temperature of 160-200° C. to obtain a flame-retardant and high-temperature resistant PVC material.

[0013] Furthermore, the stabilizer is a calcium zinc stabilizer; the plasticizer is any one of the phthalates; the lubricant is any one of calcium stearate or liquid paraffin; and the antioxidant is any one of antioxidant 1010 or antioxidant 1076.

[0014] Furthermore, the preparation method of the carbon-forming agent comprises the following steps:

[0015] Step ①: Mix cellulose with sodium hydroxide solution, stir and alkalize at 0°C for 12-24h, add it into ethanol, stir until a uniform dispersion is formed, add triethylbenzyl ammonium chloride and mix well, then add 2-chloroethylamine hydrochloride to the dispersion, stir at room temperature for 12-18h, filter out the solid material, and purify it to obtain aminated cellulose;

[0016] Step ②: Stir and disperse the aminated cellulose and purified water evenly to form a dispersion, add sodium stannate to the dispersion and mix well, stir at a temperature of 60-70° C. for 4-8 hours, cool and discharge, wash and freeze-dry to obtain a carbonizing agent.

[0017] Furthermore, in step ①, the average molecular weight of the cellulose is 25,000.

[0018] Furthermore, in step ①, the mass percentage concentration of the sodium hydroxide solution is 40-50%.

[0019] Furthermore, in step ②, the mass ratio of the aminated cellulose to sodium stannate is 1:2.4-3.

[0020] According to the above technical scheme, the hydroxyl groups in the cellulose structure are alkalized by sodium hydroxide, and then can undergo nucleophilic substitution reaction with the active chlorine in the structure of 2-chloroethylamine hydrochloride under the action of triethylbenzyl ammonium chloride, thereby introducing active amino groups into the cellulose structure to prepare aminated cellulose. Since the amino groups are positively charged in aqueous solution, sodium stannate will ionize into negatively charged SnO3 in aqueous solution. 2- Through electrostatic action, they can combine with each other to produce a cellulose-based carbonizing agent.

[0021] Furthermore, the preparation method of the flame retardant and smoke suppressant comprises the following steps:

[0022] Step A: diatomaceous earth and 1,4-dioxane are mixed and dispersed evenly, and then acryloyl chloride is added and mixed evenly, and nitrogen is passed through, and the mixture is stirred at 70-75° C. for 2-4 hours, and the solid material is separated by centrifugation to obtain a diatomaceous earth intermediate material;

[0023] Step B: Mix the diatomite intermediate material with toluene, disperse by ultrasonic, continue to add phosphite compounds and catalysts to the system, stir evenly, pass nitrogen to deoxygenate, stir at 65-70° C. for 6-12 hours, cool and discharge, and obtain a flame retardant and smoke suppressant.

[0024] Furthermore, in step A, the average particle size of the diatomaceous earth is 4 um.

[0025] Furthermore, in step B, the phosphite compound is any one of dimethyl phosphite, diethyl phosphite, diphenyl phosphite or dibenzyl phosphite.

[0026] Furthermore, in step B, the catalyst is azobisisobutyronitrile.

[0027] Through the above technical scheme, the surface of diatomite contains abundant silanol groups, which can undergo esterification reaction with the acyl chloride groups in the acryloyl chloride structure, thereby modifying the unsaturated olefinic functional groups on the surface of diatomite to obtain a diatomite intermediate material. Under the action of the catalyst azobisisobutyronitrile, the unsaturated olefinic functional groups can undergo addition reaction with the PH bonds in the structure of phosphite compounds, thereby modifying the phosphorus-containing flame retardant on the surface of diatomite to obtain a flame retardant and smoke suppressant.

[0028] Beneficial effects of the present invention:

[0029] (1) The carbon-forming agent prepared by the present invention contains aminated cellulose in its structure. Since the aminated cellulose structure contains polyhydroxyl groups and polyamine groups, it can form hydrogen bonds with the polyvinyl chloride substrate, thereby enhancing the interaction between the molecular chains and forming a polyvinyl chloride-cellulose three-dimensional network with a physical cross-linked structure, thereby increasing the cross-linking density of the polyvinyl chloride and thus improving the high temperature resistance of the polyvinyl chloride material. At the same time, the oxygen-containing carbon ring in the cellulose structure is easy to form carbon during the combustion process and can play the role of a carbon-forming agent. Moreover, the inorganic metal tin compound in the structure can react with the hydrogen chloride generated by the combustion of polyvinyl chloride to form tin chloride, thereby achieving the effect of inhibiting the emission of toxic gases. In addition, after the inorganic metal tin compound is compounded with cellulose, its compatibility with the polyvinyl chloride substrate can be improved, thereby avoiding its negative impact on the mechanical properties of the polyvinyl chloride material.

[0030] (2) The present invention prepares a flame retardant and smoke suppressant as a filler for polyvinyl chloride materials. After the diatomaceous earth in the flame retardant and smoke suppressant is organically modified, an organic bonding layer is formed on the surface, which greatly improves the interfacial bonding between the diatomaceous earth and the polyvinyl chloride matrix and reduces the problem of decreased mechanical properties due to the addition of diatomaceous earth. At the same time, the organic bonding layer on the surface of the diatomaceous earth contains a phosphorus-containing flame retardant. When the polyvinyl chloride material burns, the phosphorus-containing flame retardant can cooperate with the carbon-forming agent to quickly form a dense carbon layer on the surface of the polyvinyl chloride, thereby preventing the continuation of combustion and reducing the risk of fire spread. In addition, diatomaceous earth has a rich pore structure and can adsorb gaseous hydrogen chloride and solid carbon particles to prevent them from overflowing, thereby producing a smoke suppression effect, thereby effectively enhancing the flame retardant and smoke suppression properties of the polyvinyl chloride material.

[0031] (3) The present invention significantly improves the flame retardancy and high temperature resistance of polyvinyl chloride by designing the formula of polyvinyl chloride, while reducing the emission of toxic gases when the polyvinyl chloride material is burned, reducing environmental pollution, and avoiding the harm of toxic gas emissions to the human body. It helps to promote environmentally friendly and sustainable engineering and product design and expand the applicable fields of the polyvinyl chloride material.

[0032] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. DETAILED DESCRIPTION

[0033] The technical scheme of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the following examples and comparative examples, the preparation method of the carbon-forming agent is:

[0035] Step ①: 1.2 g of cellulose with an average molecular weight of 25,000 is mixed with 2 mL of a 50% sodium hydroxide solution by mass, and after stirring for alkalization at 0°C for 16 hours, it is put into ethanol and stirred to form a uniform dispersion, 0.2 g of triethylbenzyl ammonium chloride is added and mixed, and then 2 g of 2-chloroethylamine hydrochloride is added to the dispersion. After the addition is completed, it is stirred at room temperature for 16 hours, and the solid material is filtered out and purified to obtain aminated cellulose;

[0036] Step ②: Stir and disperse 1 g of aminated cellulose and purified water evenly to form a dispersion, add 2.5 g of sodium stannate to the dispersion and mix well, stir at 65°C for 6 hours, cool and discharge, wash and freeze-dry to obtain a carbonizing agent.

[0037] The content of each element in the carbon-forming agent was tested using an Escalab 250Xi X-ray photoelectron spectrometer. The test showed that the carbon content was 49.12%, the nitrogen content was 2.59%, and the tin content was 13.61%.

[0038] In the following examples and comparative examples, the preparation method of the flame retardant and smoke suppressant is as follows:

[0039] Step A: 1.8 g of diatomaceous earth with an average particle size of 4 μm was mixed with 1,4-dioxane, and after being evenly dispersed, 2.5 g of acryloyl chloride was added and mixed, nitrogen was passed through, the mixture was kept warm at 70° C. and stirred for 3 h, and the solid material was separated by centrifugation to obtain a diatomaceous earth intermediate material;

[0040] Weigh 0.4g of diatomaceous earth intermediate material as a sample, put it into 15mL of dichloromethane, and disperse it evenly with ultrasound. After forming a dispersion, add 30mL of Wei's solution to the dispersion, shake it well, let it stand for 30min, continue to add 120mL of deionized water and 20mL of 15% potassium iodide solution to the dispersion, and use 0.1mol / L sodium thiosulfate standard solution to titrate until the color of the dispersion changes, continue to add 2mL of 2% starch as an indicator to the dispersion, and continue to titrate until the color of the dispersion no longer changes. Record the volume of sodium thiosulfate standard solution used at this time X1, mL; do a blank control test, record the volume of sodium thiosulfate standard solution consumed X2, mL, through Calculate the molar number of carbon-carbon double bonds in the sample, where C is the concentration of the sodium thiosulfate standard solution, mol / L; M is the mass of the sample, g; after testing, W is 3.613mmol / g;

[0041] Step B: Mix 1.6 g of diatomaceous earth intermediate material with toluene, disperse by ultrasonication, and continue to add 1.5 g of dimethyl phosphite and 0.3 g of azobisisobutyronitrile to the system, stir evenly, pass nitrogen to deoxygenate, stir at 65°C for 8 h, cool and discharge to obtain a flame retardant and smoke suppressant.

[0042] The same test method in step A was used to test the molar number of carbon-carbon double bonds of 0.4g flame retardant and smoke suppressant sample. After testing, W was 0.784mmol / g. It was speculated that the reason for the reduction of carbon-carbon double bonds was the addition reaction between the carbon-carbon double bonds modified on the surface of the diatomaceous earth intermediate material and the PH in the dimethyl phosphite structure.

[0043] Example 1

[0044] A flame retardant and high temperature resistant PVC material, comprising the following raw materials in parts by weight: 85 parts of polyvinyl chloride resin, 5 parts of calcium zinc stabilizer, 20 parts of dioctyl phthalate, 2 parts of carbonizing agent, 4 parts of flame retardant and smoke suppressant, 0.5 parts of calcium stearate, and 10100.1 parts of antioxidant;

[0045] The preparation method of the flame retardant and high temperature resistant PVC material comprises the following steps:

[0046] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, carbonizing agent, calcium stearate and antioxidant 1010 into a mixer, set the mixer temperature to 120°C, stir and mix evenly, add parts by weight of flame retardant and smoke suppressant, continue stirring until a uniform material is formed to form a premix;

[0047] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at a temperature of 160° C. to obtain a flame-retardant and high-temperature resistant PVC material.

[0048] Example 2

[0049] A flame retardant and high temperature resistant PVC material, comprising the following raw materials in parts by weight: 92 parts of polyvinyl chloride resin, 10 parts of calcium zinc stabilizer, 30 parts of dioctyl phthalate, 4 parts of carbonizing agent, 6.5 parts of flame retardant and smoke suppressant, 0.6 parts of liquid paraffin, and 0.2 parts of antioxidant 1076;

[0050] The preparation method of the flame retardant and high temperature resistant PVC material comprises the following steps:

[0051] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, carbonizing agent, liquid paraffin and antioxidant 1076 into a mixer, set the mixer temperature to 130°C, stir and mix evenly, add parts by weight of flame retardant and smoke suppressant, continue stirring until a uniform material is formed to form a premix;

[0052] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at a temperature of 180° C. to obtain a flame-retardant and high-temperature resistant PVC material.

[0053] Example 3

[0054] A flame retardant and high temperature resistant PVC material, comprising the following raw materials in parts by weight: 95 parts of polyvinyl chloride resin, 12 parts of calcium zinc stabilizer, 35 parts of dioctyl phthalate, 4.5 parts of carbonizing agent, 8 parts of flame retardant and smoke suppressant, 1.5 parts of calcium stearate, and 0.4 parts of antioxidant 1010;

[0055] The preparation method of the flame retardant and high temperature resistant PVC material comprises the following steps:

[0056] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, carbonizing agent, calcium stearate and antioxidant 1010 into a mixer, set the mixer temperature to 130° C., stir and mix evenly, add parts by weight of flame retardant and smoke suppressant, continue stirring until a uniform material is formed to form a premix;

[0057] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at 200° C. to obtain a flame-retardant and high-temperature resistant PVC material.

[0058] Comparative Example 1

[0059] A PVC material comprises the following raw materials in parts by weight: 92 parts of polyvinyl chloride resin, 10 parts of calcium zinc stabilizer, 30 parts of dioctyl phthalate, 4 parts of cellulose, 6.5 parts of flame retardant and smoke suppressant, 0.6 parts of liquid paraffin, and 0.2 parts of antioxidant 1076;

[0060] The preparation method of the PVC material comprises the following steps:

[0061] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, cellulose, liquid paraffin and antioxidant 1076 into a mixer, set the mixer temperature to 130° C., stir and mix evenly, add parts by weight of flame retardant and smoke suppressant, continue stirring until a uniform material is formed to form a premix;

[0062] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at 180° C. to obtain a PVC material.

[0063] Comparative Example 2

[0064] A PVC material comprises the following raw materials in parts by weight: 92 parts of polyvinyl chloride resin, 10 parts of calcium zinc stabilizer, 30 parts of dioctyl phthalate, 6.5 parts of flame retardant and smoke suppressant, 0.6 parts of liquid paraffin, and 0.2 parts of antioxidant 1076;

[0065] The preparation method of the PVC material comprises the following steps:

[0066] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, liquid paraffin and antioxidant 1076 into a mixer, set the mixer temperature to 130°C, stir and mix evenly, add parts by weight of flame retardant and smoke suppressant, continue stirring until a uniform material is formed to form a premix;

[0067] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at 180° C. to obtain a PVC material.

[0068] Comparative Example 3

[0069] A PVC material comprises the following raw materials in parts by weight: 92 parts of polyvinyl chloride resin, 10 parts of calcium zinc stabilizer, 30 parts of dioctyl phthalate, 4 parts of carbonizing agent, 6.5 parts of diatomaceous earth, 0.6 parts of liquid paraffin, and 0.2 parts of antioxidant 1076;

[0070] The preparation method of the PVC material comprises the following steps:

[0071] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, carbonizing agent, liquid paraffin and antioxidant 1076 into a mixer, set the mixer temperature to 130° C., stir and mix evenly, add parts by weight of diatomaceous earth, continue stirring until a uniform material is formed to form a premix;

[0072] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at 180° C. to obtain warm PVC material.

[0073] Comparative Example 4

[0074] A PVC material comprises the following raw materials in parts by weight: 92 parts of polyvinyl chloride resin, 10 parts of calcium zinc stabilizer, 30 parts of dioctyl phthalate, 4 parts of carbonizing agent, 0.6 parts of liquid paraffin, and 0.2 parts of antioxidant 1076;

[0075] The preparation method of the PVC material comprises the following steps:

[0076] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, carbonizing agent, liquid paraffin and antioxidant 1076 into a mixer, set the mixer temperature to 130° C., stir and mix evenly to form a premix;

[0077] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at 180° C. to obtain a PVC material.

[0078] Comparative Example 5

[0079] A PVC material comprises the following raw materials in parts by weight: 92 parts of polyvinyl chloride resin, 10 parts of calcium zinc stabilizer, 30 parts of dioctyl phthalate, 0.6 parts of liquid paraffin, and 0.2 parts of antioxidant 1076;

[0080] The preparation method of the PVC material comprises the following steps:

[0081] Step 1: Pour parts by weight of polyvinyl chloride resin, calcium zinc stabilizer, dioctyl phthalate, liquid paraffin and antioxidant 1076 into a mixer, set the mixer temperature to 130° C., stir and mix evenly to form a premix;

[0082] Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at 180° C. to obtain a PVC material.

[0083] The PVC materials prepared in Examples 1 to 3 and Comparative Examples 1 to 4 of the present invention were made into test samples, and the following performance tests were performed:

[0084] Refer to the national standard GB / T 2406.2-2009 to test the limiting oxygen index of the sample; refer to ISO 5660-1:2015 and set the radiation power to 50kW / m 2 , test the smoke release performance of the samples; weigh 0.5 mg of each sample, place it in a STA 7300 thermogravimetric-differential thermal analyzer, pass nitrogen protection, set the heating rate to 10℃ / min, heat from room temperature to 800℃, and record the temperature T corresponding to 5% decomposition of the sample 5wt％ , evaluate its high temperature resistance. Generally speaking, the higher the temperature, the better the high temperature resistance. The test results are shown in the following table:

[0085] Limiting oxygen index / % <![CDATA[Total smoke release amount / m 2 > <![CDATA[T 5wt％ / ℃]]> Example 1 33.5 12.2 285.4 Example 2 33.9 11.7 286.1 Example 3 33.8 11.8 285.5 Comparative Example 1 33.0 15.0 278.9 Comparative Example 2 31.3 16.4 267.1 Comparative Example 3 27.8 23.4 284.0 Comparative Example 4 27.2 26.5 283.5 Comparative Example 5 25.6 28.8 265.8

[0086] It can be seen from the test results in the above table that the PVC materials prepared in Examples 1 to 3 of the present invention have good flame retardancy, smoke suppression and high temperature resistance effects.

[0087] Comparative Example 1 uses unmodified cellulose as a carbonizing agent to prepare PVC material, so the smoke suppression effect is slightly poor. In addition, since the structure does not contain amino groups, the hydrogen bond content between the polyvinyl chloride molecular chain is relatively small, and the cross-linking density is low, resulting in poor high temperature resistance performance.

[0088] The PVC material prepared in Comparative Example 2 does not contain a carbonizing agent, resulting in a slow carbonization rate on its surface during combustion, so the flame retardant and smoke suppression effects are poor. At the same time, since the polyvinyl chloride molecular chain cannot form a cross-linked structure, the high temperature resistance surface is poor.

[0089] In Comparative Example 3, diatomaceous earth without surface modification is used as a flame retardant and smoke suppressant to prepare a PVC material. Therefore, the PVC material does not contain a phosphorus flame retardant, and it is difficult to form an expanded carbon layer, resulting in a significant decrease in the flame retardant and smoke suppression effect.

[0090] The flame retardant and smoke suppressant was not used in the PVC material prepared in Comparative Example 4, so the flame retardant and smoke suppressant effect was further reduced.

[0091] The PVC material prepared in Comparative Example 5 does not contain a charring agent and a flame retardant and smoke suppressant, and therefore all properties are the worst.

[0092] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0093] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a flame retardant and high temperature resistant PVC material, characterized in that: The flame retardant and high temperature resistant PVC material comprises the following raw materials in parts by weight: 85-95 parts of polyvinyl chloride resin, 5-12 parts of stabilizer, 20-35 parts of plasticizer, 2-4.5 parts of carbonizing agent, 4-8 parts of flame retardant and smoke suppressant, 0.5-1.5 parts of lubricant, and 0.1-0.4 parts of antioxidant; The carbon-forming agent is prepared by modifying cellulose by amination and then compounding it with sodium stannate; The flame retardant and smoke suppressant is diatomaceous earth with a phosphorus-containing flame retardant modified on the surface; The preparation method of the flame retardant and high temperature resistant PVC material comprises the following steps: Step 1: Pour parts by weight of polyvinyl chloride resin, stabilizer, plasticizer, carbonizing agent, lubricant and antioxidant into a mixer, set the mixer temperature to 120-130°C, stir and mix evenly, add parts by weight of flame retardant and smoke suppressant, continue stirring until a uniform material is formed to form a premix; Step 2: Transfer the premix to a twin-screw extruder, melt-extrude and granulate at a temperature of 160-200° C. to obtain a flame-retardant and high-temperature resistant PVC material.

2. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 1, characterized in that: The stabilizer is a calcium zinc stabilizer; the plasticizer is any one of the phthalates; the lubricant is any one of calcium stearate or liquid paraffin; and the antioxidant is any one of antioxidant 1010 or antioxidant 1076.

3. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 1, characterized in that: The preparation method of the carbon-forming agent comprises the following steps: Step ①: Mix cellulose with sodium hydroxide solution, stir and alkalize at 0°C for 12-24h, add it into ethanol, stir until a uniform dispersion is formed, add triethylbenzyl ammonium chloride and mix well, then add 2-chloroethylamine hydrochloride to the dispersion, stir at room temperature for 12-18h, filter out the solid material, and purify it to obtain aminated cellulose; Step ②: Stir and disperse the aminated cellulose and purified water evenly to form a dispersion, add sodium stannate to the dispersion and mix well, stir at a temperature of 60-70° C. for 4-8 hours, cool and discharge, wash and freeze-dry to obtain a carbonizing agent.

4. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 3, characterized in that: In step ①, the average molecular weight of the cellulose is 25,000.

5. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 3, characterized in that: In step ①, the mass percentage concentration of the sodium hydroxide solution is 40-50%.

6. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 3, characterized in that: In step ②, the mass ratio of the aminated cellulose to sodium stannate is 1:2.4-3.

7. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 1, characterized in that: The preparation method of the flame retardant and smoke suppressant comprises the following steps: Step A: diatomaceous earth and 1,4-dioxane are mixed and dispersed evenly, and then acryloyl chloride is added and mixed evenly, and nitrogen is passed through, and the mixture is stirred at 70-75° C. for 2-4 hours, and the solid material is separated by centrifugation to obtain a diatomaceous earth intermediate material; Step B: Mix the diatomite intermediate material with toluene, disperse by ultrasonic, continue to add phosphite compounds and catalysts to the system, stir evenly, pass nitrogen to deoxygenate, stir at 65-70° C. for 6-12 hours, cool and discharge, and obtain a flame retardant and smoke suppressant.

8. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 7, characterized in that: In step A, the average particle size of the diatomaceous earth is 4 um.

9. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 7, characterized in that: In step B, the phosphite compound is any one of dimethyl phosphite, diethyl phosphite, diphenyl phosphite or dibenzyl phosphite.

10. The method for preparing a flame retardant and high temperature resistant PVC material according to claim 7, characterized in that: In step B, the catalyst is azobisisobutyronitrile.