Hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film and preparation method thereof

Abstract

The invention discloses a hydrogenated butadiene-acrylonitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film and a preparation method thereof, and the film is prepared by using polypropylene glycol adipate as a plasticizer, hydrogenated butadiene-acrylonitrile rubber as a modifier, compound carbon black and fumed silica as reinforcing agents, and surface-coated modified Mg (OH) 2 and Sb2O3 as assistants such as flame retardants. The prepared film has the characteristics of high elasticity, high limit oxygen index, extremely low smoke density, low surface hardness, high weather resistance and the like, and can meet the multifunctional special requirements of high-end markets on flame-retardant films. The hydrogenated butadiene-acrylonitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film is prepared from the following raw materials in parts by mass: 65-75 parts of polyvinyl chloride resin, 25-35 parts of hydrogenated butadiene-acrylonitrile rubber, 55-65 parts of a plasticizer, 1.2-2.5 parts of a powdery compound stabilizer, 100-150 parts of magnesium hydroxide, 1-2 parts of antimony trioxide, 2-3 parts of fumed silica and 10-30 parts of carbon black.

Description

Technical Field

[0001] The invention relates to a plasticized polyvinyl chloride functional film and a preparation method thereof, and more specifically to a hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film and a preparation method thereof. Background Art

[0002] Polyvinyl chloride (PVC) is one of the most widely used general resin varieties with the largest output. The PVC plastic products made from it have excellent comprehensive performance and extremely high cost performance. This is because the polar chlorine atoms contained in the PVC macromolecular structure increase the intermolecular force, resulting in higher mechanical properties; at the same time, the chlorine atoms with a mass percentage of up to 56% in its structure also make the PVC resin have excellent flame retardant properties, corrosion resistance and weather resistance. On the one hand, toughened rigid PVC products without plasticizers have high mechanical properties and excellent flame retardant properties, such as tensile strength ≥50MPa, elongation at break ≥100%, flexural strength ≥65MPa, flexural modulus ≥2000MPa, notched impact strength ≥15kJ / m 2 , the limiting oxygen index (LOI) is as high as 45%, so rigid PVC products are widely used as engineering materials in the fields of electronics, electrical appliances, automobiles, and construction. On the other hand, plasticized PVC products with plasticizers have good flexibility and appropriate elasticity. For example, according to the type and content of the added plasticizer, the tensile strength of plasticized PVC is 10-25MPa, the elongation at break is 200-500%, and the Shore A hardness is 60-85, showing high elasticity characteristics similar to rubber. It can often replace rubber, especially thermoplastic rubber, in the fields of gloves, wires and cables, sealing materials, and shoe materials.

[0003] The abnormal structures existing in commercial PVC resin, such as internal allyl chloride, are the most unstable, followed by tertiary chlorine, terminal allyl chloride, secondary chlorine, etc., which lead to poor thermal stability of PVC resin and start to produce dehydrochlorination reaction at about 100°C. Studies have shown that the degradation of PVC resin is carried out in two stages characterized by two stable zones. In the first stage (the highest temperature is 267°C), the conversion rate is about 65%, which is mainly related to the generation of hydrogen chloride. The second stage (the highest temperature is 447°C) is caused by the cracking of the conjugated double bonds >C=C< contained in the macromolecules in the polymer. At a temperature higher than 327°C, PVC is carbonized, resulting in the formation of carbon. Since the actual use temperature of PVC products during processing and when used as materials does not exceed 327°C, and as the PVC decomposition process proceeds and the temperature rises, the mechanism of the overall PVC decomposition process gradually becomes complicated, so studying the thermal decomposition of PVC below medium temperature (327°C) is not only of theoretical significance, but also of practical significance. PVC mainly undergoes dehydrochlorination reaction below 327℃, accompanied by the formation of >C=C< and polyene structure. Since the combustion temperature range of plasticized PVC is between 265 and 380℃, the double bonds and polyene structures formed after the dehydrochlorination reaction first produced during the combustion process cause incomplete combustion of plasticized PVC in the later stage of combustion, accompanied by the generation of a large amount of black smoke, which leads to a sharp increase in the smoke density rating (SDR), affecting its practical application in the fields of construction, electronic appliances, and automotive interiors. The types of plasticizers commonly used in plasticized PVC products are mainly divided into three categories based on molecular weight: 1) Small molecule liquid plasticizers, with a relative molecular mass M≤1000, usually between 250 and 600. Such as dibutyl phthalate (DBP) (M = 278.34), di (2-ethylhexyl) phthalate (DEHP) (M = 390.56), di (2-propylheptyl) phthalate (DPHP) (M = 446.66), trioctyl trimellitate (TOTM) (M = 546.76), etc. 2) Medium molecular weight viscous liquid plasticizer, relative molecular mass 1000 ≤ M ≤ 5000, usually between 1000 and 3000, such as polypropylene adipate, liquid nitrile rubber, etc., this type of viscous liquid plasticizer usually uses viscosity to express its relative molecular weight. 3) High molecular weight solid plasticizer, mainly rubber or elastomer materials, commonly used varieties are powdered nitrile rubber (PNBR), nitrile rubber (NBR), chlorinated polyethylene (CPE), thermoplastic polyurethane (TPU), etc. The relative molecular weight of this type of solid plasticizer is relatively high, usually M ≥ 50000, and even up to hundreds of thousands. For solid elastomer plasticizers, the melt mass flow rate or Mooney viscosity is usually used to express the relative molecular weight.Commonly used plasticizers, especially small molecule liquid plasticizers, are mainly composed of two elements, C and H. When added to PVC resin, the limiting oxygen index of plasticized PVC products prepared will drop sharply and have no flame retardant characteristics, which limits their application areas. In general, plasticized PVC plastic products prepared with small molecule plasticizers have the advantages of high plasticization efficiency, simple processing methods, and low cost, but also have the following shortcomings: the surface hardness of the product is highly sensitive to temperature, which is manifested as the same product being soft in summer and hard in winter, affecting the use effect; during long-term use, the hardness of the plasticized PVC increases, and the flexibility and elasticity decrease due to the migration of plasticizers; the elasticity is not good, and its elasticity is quite different from that of thermoplastic rubber or vulcanized rubber, especially the permanent deformation index characterizing the elasticity is relatively large. Compared with small molecule plasticizers, the use of high molecular weight solid plasticizers such as rubber and elastomeric materials to prepare plasticized PVC products has disadvantages such as low plasticization efficiency, relatively complex process and high cost. However, the use of some elastomers and medium molecular weight liquid plasticizers can significantly improve the shortcomings of plasticized PVC products such as hardness sensitivity to temperature, easy migration of plasticizers and poor elasticity.

[0004] In recent years, a large number of literatures have reported relevant research results on flame retardancy and smoke suppression of plasticized PVC in the prior art. The Chinese invention patent with publication number CN106633526A and patent name "A flame retardant transparent plasticized PVC functional film and preparation method" discloses that 100 parts of suspension PVC resin with an average degree of polymerization of 1300 are added with polyester non-flame retardant plasticizer and tri(1-chloro-2-propyl) phosphate (TCPP) flame retardant plasticizer to prepare a flame retardant transparent plasticized PVC functional film with LOI ≥ 30%, and at the same time, ultraviolet light absorber and yellow pigment with special structure are used to achieve an average shielding rate in the ultraviolet light band of 200-400nm and an average suppression rate of 400-500nm high-energy visible light (blue light) of more than 99%, but the functional film has not been tested for smoke density level and maximum smoke density during combustion. The Chinese invention patent with publication number CN114921035B and patent name "A high elastic flame retardant low smoke plasticized polyvinyl chloride transparent film and its preparation method" discloses that a functional transparent film with high elasticity, high wear resistance, flame retardancy, relatively low smoke density and high visible light transmittance is prepared by using 100 parts of a linear PVC resin with an average polymerization degree of 1700 to 2000 and a PVC resin with a 10 to 30% chemical cross-linking structure, and three plasticizers, polypropylene adipate, tributyl acetyl citrate, and trioctyl trimellitate, are used alone or in combination as the main plasticizers (40 to 50 parts), supplemented by a small amount of flame retardant plasticizers TCPP and tris(2-chloroethyl) phosphate) (TCEP) 2-10 parts. The LOI of the functional film is between 28.3% and 30.5%, the UL-94 flame retardant test reaches the V-0 level, the SDR is 61.6% to 62.1%, and the maximum smoke density (MSD) is 74.5% to 75.8%. The above-mentioned prior art that has been disclosed shows that the LOI of the transparent flame retardant plasticized PVC film is 28.3% to 32.0%, SDR ≥ 60%, and MSD ≥ 74%, which can meet the use requirements of specific occasions. In order to further reduce the smoke density of the plasticized PVC functional film, the document Materials Today Communications 2023, 34: 105448 reported that 100 parts of a suspension PVC resin with an average degree of polymerization of 1300 were added with 50 parts of a polyester plasticizer and magnesium hydroxide (Mg(OH) 2 ) 50 parts, antimony trioxide (Sb 2 O 3 )1-3 parts, a flame retardant plasticized PVC composite material with lower smoke density was prepared, wherein LOI 31.7-33.5%, SDR 32.82-46.95%, MSD 55.35-76.00%; it is achieved by reducing the amount of plasticizer used and compounding the inorganic flame retardant Mg(OH) 2 / Sb 2 O 3The LOI of plasticized PVC is increased, and the SDR and MSD are reduced. However, the disadvantage is that the elongation at break of the composite material is only 79-184%, and the hardness is relatively high. For example, the Shore D of the 0s test and the 15s test are 50 and 40 respectively. This flame retardant material obviously has poor elasticity and flexibility.

[0005] In the prior art, the following common methods are mainly used to prepare high elasticity and low hardness plasticized PVC films: ① Increase the dosage of small molecule main plasticizer: The dosage of plasticizer is usually more than 80 parts, or even up to 100 parts. While reducing the hardness of the film and improving the elasticity, this method has the cost of LOI reduction and loss of flame retardant properties of the film. At the same time, the smoke density of the film is large, and the lack of hardness sensitivity to temperature still exists. ② Use some cold-resistant plasticizers: In view of the lack of temperature sensitivity of the above-mentioned film hardness, 10 to 20 parts of small molecule aliphatic cold-resistant plasticizers, such as dioctyl adipate (DOA) and dioctyl sebacate (DOS), can be compounded to prepare plasticized PVC films with high elasticity, low hardness and hardness that is not very sensitive to temperature. However, the SDR and MSD of the films prepared by this method are still large. ③ Use PVC resin with high polymerization degree or partial chemical cross-linking: This method can appropriately improve the elasticity of the film, but it has no effect on reducing the hardness of the film and reducing the smoke density. ④ Use CPE resin: Using part of CPE resin to replace PVC resin in the formula can appropriately improve the elasticity of plasticized PVC film and reduce the hardness, but it is not significant. At the same time, the degradation mechanism of CPE at high temperature is similar to that of PVC, and there is no improvement in reducing the smoke density of the film. ⑤ Use NBR: The industry often uses part of NBR to replace PVC resin in the formula to effectively improve the elasticity and reduce the hardness of plasticized PVC film, and has been applied in many fields, especially the use of part of pre-crosslinked PNBR added to the plasticized PVC formula. The effect is very significant. However, whether NBR or PNBR is used to modify plasticized PVC, there are deficiencies in mechanical properties, especially low tensile strength. This is because NBR is a non-self-reinforcing rubber with poor self-strengthening strength, especially when the amount of NBR or PNBR used is more than 20 parts. In addition, the unsaturated double bonds in the structure of NBR or PNBR produce a large amount of thick smoke during the combustion process, which also leads to higher SDR and MSD values ​​of its plasticized PVC.

[0006] In summary, in the prior art, when preparing plasticized PVC flame retardant film, flame retardant plasticizers TCEP and TCPP are often used in combination with non-flame retardant plasticizers, which results in the film having disadvantages such as high smoke density during combustion. When preparing low-smoke flame retardant plasticized PVC film, non-flame retardant plasticizers and Mg(OH) 2, aluminum hydroxide and other inorganic flame retardants, the shortcomings are poor film elasticity and relatively large smoke density; when preparing low-smoke flame-retardant plasticized PVC elastic film, the main material often uses elastomers (CPE, NBR, PNBR, etc.) as modifiers or directly uses special PVC resins (PVC resins with high polymerization degree or partial chemical cross-linking), and the obtained film still has surface hardness, mechanical properties (tensile strength, elongation at break, permanent deformation), smoke density and other properties that need to be further improved. In short, for functional films with comprehensive properties such as high flame retardancy, extremely low smoke density and high elasticity that meet the needs of special occasions, the existing technology and methods are still insufficient. Therefore, in view of the shortcomings of the existing industry, it is necessary to develop an elastic plasticized PVC film with low-smoke flame retardant and other functions and its preparation method, the film should have extremely high flame retardancy (LOI ≥ 35%), extremely low smoke density (SDR ≤ 15%, MSD ≤ 35%), and at the same time have the characteristics of low surface hardness, high mechanical strength and low permanent deformation, so as to meet the new technical requirements of industries such as construction, automobiles, electronics and electrical appliances. Summary of the invention

[0007] The purpose of the present invention is to solve the problems and shortcomings in the prior art and provide a hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film. The film uses medium molecular weight polypropylene adipate as a plasticizer, highly saturated hydrogenated nitrile rubber (HNBR) as a modifier, a compound of low specific surface area semi-reinforcing carbon black and high specific surface area fumed silica as a reinforcing agent, and a surface-coated modified Mg(OH) 2 and Sb 2 O 3 The plasticized PVC functional film prepared by the multifunctional additives such as flame retardants has the characteristics of high elasticity, high limiting oxygen index, extremely low smoke density, low surface hardness, high weather resistance, excellent mechanical strength, etc., which can meet the special multifunctional needs of the high-end market for flame retardant films.

[0008] The invention also provides a method for preparing the hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film. The method allows the functional filler to be selectively distributed in the PVC and HNBR phases, thereby maximizing the effect of the functional additive.

[0009] The present invention is achieved through the following technical solutions:

[0010] The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention is made of the following raw materials in the following mass ratio:

[0011]

[0012] The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention has a further technical solution that the polyvinyl chloride resin is a linear polyvinyl chloride resin synthesized by a suspension polymerization process and has an average polymerization degree of 1300.

[0013] The above hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention can be further technically provided that the hydrogenated nitrile rubber is a binary random copolymer obtained by a polymerization method using butadiene and acrylonitrile as monomers, and then the unsaturated double bonds of the main chain are hydrogenated to form a product of a saturated structure, wherein the mass percentage of acrylonitrile is 26-41%, the saturation of the double bonds is 95%-99%, and the Mooney viscosity ML(1+4)100°C=30-80. A further technical solution is that the hydrogenated nitrile rubber is preferably a low Mooney viscosity hydrogenated nitrile rubber with ML(1+4)100°C=30-40.

[0014] A further technical solution of the hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention may be that the plasticizer is a medium molecular weight polyester plasticizer, that is, one or a combination of polypropylene adipate with a number average molecular weight of 1000 to 2000.

[0015] A further technical solution of the above-mentioned hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention can also be that the powdery composite stabilizer is a combination of one or more of calcium stearate, barium stearate, and magnesium stearate and zinc stearate, wherein the content of zinc stearate in the total raw materials of the hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film is 0.1 to 0.3 parts by mass.

[0016] A further technical solution of the hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention can be that the magnesium hydroxide has a purity greater than 98%, an average particle size of 1 to 2 μm and is surface-coated with 1% by mass of stearic acid.

[0017] The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention can also be further technically provided that the fumed silicon dioxide has a purity of ≥99.8% and a specific surface area of ​​350-410 m 2 / g, fumed silica with an original particle size of 7 to 10 nm.

[0018] The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention can also be further technically provided that the carbon black has an iodine absorption value of 29±5 g / kg, a DBP oil absorption value of 72±5 mL / 100 g, and a specific surface area of ​​30±5 m 2 / g of semi-reinforcing carbon black.

[0019] The method for preparing the hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film of the present invention comprises the following steps:

[0020] Surface coating modification of magnesium hydroxide: magnesium hydroxide from which surface adsorbed water is dried and removed and stearic acid are added to a high-speed mixer at a mass ratio of 99:1. The low-speed mixing mode is started first, and the speed is controlled at 300-400 rpm. After the mixing time is 2 minutes, the high-speed mixing mode is switched to control the speed to 800-900 rpm and the mixing is continued until the temperature reaches 60°C, when the stearic acid has completely melted and is evenly coated on the magnesium hydroxide. The low-speed mixing is continued at 300 rpm for 2 minutes, and the surface-coated magnesium hydroxide is bagged and weighed for standby use.

[0021] Preparation of hydrogenated nitrile rubber compound: For low Mooney viscosity hydrogenated nitrile rubber with ML (1+4) 100°C = 30-40, it does not need to be plasticized, and can be directly mixed with carbon black to prepare the rubber compound; for medium-high Mooney viscosity hydrogenated nitrile rubber with ML (1+4) 100°C> 40, it is necessary to first plasticize to reduce its Mooney viscosity, and then mix it with carbon black to prepare the rubber compound; the plasticizing steps of medium-high Mooney viscosity hydrogenated nitrile rubber are: plasticize in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 40-50°C, and thin pass After 5 to 15 times, the rubber is rolled down and weighed for use; low Mooney viscosity or medium-high Mooney viscosity hydrogenated nitrile rubber after plasticization, fumed silica and carbon black are added according to the ratio to prepare a mixed rubber in an internal rubber mixer, and when the mixed rubber temperature reaches 130°C, the rubber is discharged to an open mixer; the mixed rubber is cooled while continuing to be mixed in an open mixer with a roller distance of 3 to 4 mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combined metal filter screen, and the filtered rubber is weighed when the temperature drops to 60°C after water cooling to obtain the filtered hydrogenated nitrile rubber for use;

[0022] High-speed mixing and pre-plasticization of plasticized PVC powder: put polyvinyl chloride resin and powdered composite stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300-400rpm, and mix for 1-2min; add plasticizer and switch to high-speed mixing mode for uniform mixing, control the speed to 650-900rpm, and mix for 5-8min. When all the plasticizer is completely absorbed by the resin, add surface-coated modified magnesium hydroxide and antimony trioxide and continue mixing for 2-3min to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and discharge it into the internal mixer;

[0023] Plasticization and filtration of plasticized PVC: ①Control the temperature of the internal mixer at 140-150℃, first add the plasticized PVC powder containing surface-modified magnesium hydroxide into the internal mixer and mix for 3 minutes, then add the filtered hydrogenated nitrile rubber compound and continue mixing for 5 minutes; ②Transport the internally mixed materials to the open mixer for further plasticization, control the roller speed of the open mixer at 40-60r / min, and the temperature of the open mixer at 165-175℃; ③Control the temperature of the filter at 170-180℃, and use a three-layer laminated metal filter with mesh sizes of 20, 100 and 20 to further filter the compound, and control the return water temperature of the machine at 20-40℃;

[0024] Film five-roll calendering: the material filtered by the rubber filter in the plasticizing and filtering step of plasticizing PVC is conveyed to the five-roll calendering main machine along the conveyor belt, and after calendering film formation, desorption and embossing, cooling and winding, a hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film is obtained; wherein, the five-roll calendering film forming parameters are: 1# roller temperature is controlled at 170-180°C, speed 5-15m / min, 2# roller temperature is controlled at 170-185°C, speed 10-30m / min, 3# roller temperature is controlled at 175-190°C, speed 20-40m / min, 4# roller temperature is controlled at 180-200°C, speed 20-30m / min, The temperature of the 5# roller is controlled at 160-180℃ and the speed is 15-30m / min; the temperature of the 5# roller is controlled at 130-160℃ and the speed is 30-50m / min; the parameters for take-off and embossing are: 1 take-off wheel at the first stage, the temperature is controlled at 150-160℃ and the speed is 30-50m / min; 2 take-off wheels at the second stage, the temperature is controlled at 150-165℃ and the speed is 35-60m / min; 2 take-off wheels at the third stage, the temperature is controlled at 150-165℃ and the speed is 35-60m / min; the parameters for cooling and coiling are: the temperature of the cooling roller is controlled at 40-60℃ and the speed is 45-75m / min, and the coiling speed is 45-75m / min.

[0025] In the present invention, the limiting oxygen index test is carried out on the plasticized PVC film using a limiting oxygen index tester (JF-3, Nanjing Jiangning Analytical Instrument Co., Ltd.) according to the standard GB / T 2406.2-2009. The sample size is 80×10×4mm 3 .

[0026] UL-94 (vertical burning) test: According to ISO 1210 standard, the PVC film was tested for UL-94 using the CZF-4 instrument from Nanjing Shangyuan Analytical Instrument Co., Ltd. The sample size is 130×13×2mm 3 Each group of samples was tested 5 times.

[0027] Smoke density test: According to the standard GB / T 8627-2007, the smoke density tester (JCY-3A, Nanjing Jiangning Analytical Instrument Co., Ltd.) was used to test the smoke density of plasticized PVC film. The sample size is 25.4×25.4×4mm 3 Each sample was tested three times and the average value was taken. The instrument measures the degree to which the light beam in the combustion smoke is blocked by solid particles to obtain a curve of light absorption rate changing with time. At the same time, the instrument records the smoke density level (SDR) and the maximum smoke density (MSD).

[0028] Cone calorimeter test: mainly includes tests such as ignition time, total smoke production and mass residual rate after combustion. According to ISO 5660-1 standard, a cone calorimeter (iCone, British Fire Testing Technology Company) was used at 50kW·m -2 Cone calorimeter test of heat flux on plasticized PVC film. Sample size is 100×100×3mm 3 .

[0029] Differential Scanning Calorimetry (DSC) was used to record the glass transition temperature (T g ). First, the sample was heated from -85°C to 150°C at a rate of 40°C / min to eliminate the thermal history, and then kept for 1 min. It was then cooled to -50°C and kept for 2 min. Finally, the sample was heated to 100°C at a rate of 10°C / min.

[0030] Tensile and tear properties test: According to ISO 527-3 and ISO 34-1 standards, the tensile and tear properties of the PVC film were tested at room temperature using a universal testing machine (CMT5254, SANS Testing Machine Co., Ltd.) at a tensile speed of 50 mm / min. Each group of samples was tested three times to obtain the average value.

[0031] Surface hardness test: According to ISO 7619-1:2004, the hardness of the specimen was measured at room temperature using a Shore A durometer (LX-A, Jiangsu Mingzhu Testing Machinery Co., Ltd.) or a Shore D durometer (LX-D, Jiangsu Mingzhu Testing Machinery Co., Ltd.).

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention overcomes the following deficiencies in the prior art in preparing flame-retardant plasticized PVC films, and carries out targeted material selection, formulation and process design, and creatively improves them. The specific effects are as follows: ① In terms of the elastic modification effect on plasticized PVC products, there is no significant difference between NBR and HNBR. Due to the double bonds in the butadiene structure of the NBR main chain, NBR has a lower glass transition temperature (T g ). Therefore, under the same formula, if NBR is selected as the elastic modifier, the plasticized PVC has a lower T g, that is, better cold resistance. However, it is precisely because of the double bonds in the butadiene structure of the NBR main chain that the modified plasticized PVC has a higher smoke density during the combustion process. HNBR, as a rubber-modified plasticized PVC with a saturated main chain structure, can significantly reduce the smoke generated by the plasticized PVC film during the combustion process and reduce the smoke density. ② The saturation of the HNBR main chain has a great influence on the smoke density modification effect of plasticized PVC products. Selecting highly saturated HNBR with a double bond saturation of 95% to 99% in the main chain can significantly reduce the smoke density and have good resistance to ozone aging and hot air aging. In addition, the content of bound acrylonitrile (AN) in the molecular structure of HNBR directly affects the compatibility with the matrix resin PVC and the mechanical properties of the modified plasticized PVC, such as tensile strength, elongation at break and tear strength. After selecting HNBR with a bound AN mass percentage of 26 to 41% to modify the plasticized PVC, the film has the best mechanical properties. When the mass percentage of combined AN in HNBR is ≤20%, the mechanical properties of the film decrease significantly; when the mass percentage of combined AN in HNBR is ≥45%, the elasticity of the rubber itself deteriorates, and its effect on improving the elasticity of plasticized PVC is not good. ③ The Mooney viscosity of rubber indirectly reflects the size of its molecular weight. Generally, the larger the Mooney viscosity, the larger the molecular weight of the rubber, the wider the temperature range of high elastic deformation, and the better the elasticity of the rubber. However, high Mooney viscosity rubber is difficult to mix and process due to its excessive molecular weight, high elasticity, and low plasticity. The solution is to first reduce its molecular weight and improve its plasticity through a plasticizing process to meet the needs of subsequent mixing and processing. The low Mooney viscosity HNBR with a preferred ML (1+4) 100℃ = 30-40 does not need to be plasticized, and can be directly mixed with carbon black (CB) to prepare HNBR / CB mixed rubber, saving energy and reducing costs. At the same time, considering that there are few HNBR varieties on the market, if only medium-high Mooney viscosity HNBR with ML (1+4) 100℃>40 can be selected in actual production, it is necessary to first plasticize (the more times the plasticize is passed, the more the Mooney viscosity decreases), and then mix with carbon black (CB) to prepare HNBR / CB compound rubber. ④ Only one suspension polymerization method is used to synthesize linear PVC resin with an average polymerization degree of 1300, which is mainly based on the elasticity, mechanical properties and processing fluidity of the balanced functional film. This is because if a high-polymerization degree PVC resin with an average polymerization degree of more than 1700 or a partially chemically cross-linked PVC resin is selected to improve the elasticity of the film, the processing fluidity of the plasticized PVC will deteriorate; at the same time, adding more HNBR to the formula will also cause the processing fluidity of the film to further decrease.If you choose a PVC resin with an average degree of polymerization of 1000 or use a resin with an average degree of polymerization of 1300 and an average degree of polymerization of 1000, in a formula system containing HNBR, although the processing flow is slightly improved, it is not significant, but the permanent deformation that characterizes the elasticity of the film will increase and the corresponding elasticity will decrease. ⑤ Using HNBR to modify plasticized PVC can effectively improve the film's low temperature resistance while improving the film's elasticity. For example, the T of the plasticized PVC film prepared by adding 60 parts of polypropylene adipate plasticizer to 100 parts of PVC resin is . g About -10℃, when 100 parts of HNBR / PVC (25~35 / 65~75) are used and 55~65 parts of polypropylene adipate plasticizer are added to prepare HNBR modified plasticized PVC film, the T g The temperature is reduced to -22~-28℃, even if 100~150 parts of Mg(OH) 2 and 10 to 30 parts of semi-reinforced carbon black, high strength, low smoke, flame retardant plasticized PVC film g It still maintains -21 to -25, and the low temperature resistance is significantly improved. ⑥ Although the film modified with HNBR for plasticized PVC has a series of advantages such as good elasticity, excellent low temperature resistance and reduced surface hardness, the characteristics of HNBR itself as a non-self-reinforcing rubber make the tensile strength of the modified plasticized PVC film significantly reduced. Even if the HNBR is vulcanized (chemically cross-linked), it will not significantly improve its own tensile strength. At present, the industry uses NBR, PNBR or HNBR to modify plasticized PVC. There are the above-mentioned deficiencies, among which the modification of plasticized PVC with partially cross-linked PNBR still has the problem of low tensile strength. The present invention creatively uses a small amount of gas-phase silica with a large specific surface area and a large amount of semi-reinforcing carbon black with a relatively small specific surface area to synergistically reinforce HNBR, which effectively improves the tensile strength and elongation at break of the HNBR modified plasticized PVC film. ⑦ Studies have shown that the use of 2 to 5 parts of a specific surface area of ​​350 to 410 m 2 / g, fumed silica with original particle size of 7-10nm has a good reinforcing effect on HNBR. 5-10 parts of fumed silica will increase the hardness of HNBR compound and deteriorate its fluidity. It has no significant improvement on the tensile strength of plasticized PVC modified film, especially the elongation at break decreases. The addition of silica cannot improve the flame retardant properties of the film at the same time. Specific surface area 30±5m 2 / g semi-reinforcing carbon black is a typical low specific surface area soft carbon black. The rubber compound prepared by adding 10 to 30 parts of carbon black to 25 to 35 parts of HNBR has moderate hardness and certain processing fluidity. After the HNBR / CB rubber compound is modified and plasticized PVC, the tensile strength of the film can be effectively improved while maintaining a high elongation at break and a low permanent deformation. It is very interesting that the present invention uses 2 to 3 parts of fumed silica and 10 to 30 parts of semi-reinforcing carbon black to synergistically reinforce HNBR to achieve the best reinforcement effect on the modified plasticized PVC film. ⑧ Many literatures on the preparation methods of rubber modified plasticized PVC materials use a process often referred to as the "one-pot method", that is, the plasticized PVC and all the additives are directly added to the processing equipment (twin-screw extruder, internal mixer or open mixer) for mixing. The characteristic of this method is that the process is simple, but the disadvantage is that for two different polymers containing raw rubber and resin, the effects and functions of different additives are different. The present invention creatively distributes the functional additives selectively in the raw rubber and resin according to the different functions of the functional additives, so as to better play the role of the functional additives. For example, silica and carbon black mainly play a reinforcing role on HNBR. Only by selectively dispersing them in the rubber phase (raw rubber) can the reinforcing role be maximized. ⑨ The molecular structure characteristics of HNBR itself are mainly C and H elements, so it is very easy to burn, and there is less smoke during the combustion process. When 10 to 30 parts of carbon black are added to 25 to 35 parts of HNBR, the content of carbon black is still relatively high compared to HNBR raw rubber. Since carbon materials are relatively non-combustible, adding carbon black to HNBR not only has a reinforcing effect, but also has a flame retardant effect. HNBR / CB compound rubber can improve the elasticity and low temperature resistance of plasticized PVC film while further improving the flame retardant type of the film. The LOI of the film is above 35%. ⑩ Similarly, plasticized PVC produces a large amount of smoke during the combustion process due to the formation of polyene structure, Mg(OH) 2 The flame retardant can effectively reduce the smoke generated during the combustion of plasticized PVC. In the preparation method, the plasticizer, stabilizer, flame retardant and flame retardant synergist Sb are selectively added. 2 O 3 Dispersing in the resin matrix can give full play to the role of these additives, Mg(OH) 2 It can effectively reduce the smoke generated during the combustion of plasticized PVC, and the SDR of the film is less than 15%, and the MSD is less than 35%. 1○1 The cone calorimetry test results of the embodiment and the comparative example show that the functional film of the present invention also has the characteristics of long ignition time, low total smoke production, and high quality residual rate in the late stage of the combustion process in actual fires, and has more practical application value. In the comparative examples: such as plasticized PVC (Comparative Example 1), HNBR modified plasticized PVC (Comparative Examples 2 and 3), silica reinforced HNBR modified plasticized PVC (Comparative Example 4), unmodified Mg(OH) 2The ignition time, total smoke production and quality residual rate of the film obtained by the flame retardant modified plasticized PVC (Comparative Example 6), carbon black reinforced HNBR modified plasticized PVC (Comparative Example 8) and the preparation method not disclosed in the present invention (Comparative Examples 9 and 10) are 19-34s, 9-23m 2 , 3.6~45.3%; and the corresponding functional film ignition time, total smoke production and quality residual rate prepared in Examples 1~10 are 35~44s, 8~10m 2 35.1~51.7%

[0034] In summary, the polymer matrix material in the plasticized PVC functional film of the present invention is produced by a suspension polymerization process, 65-75 parts of PVC resin with an average polymerization degree of 1300 and 25-35 parts of HNBR raw rubber with a Mooney viscosity ML (1+4) of 30-80 at 100° C. are used in combination, 55-65 parts of polypropylene adipate with a molecular weight of 1000-2000 is used as a plasticizer, 2-3 parts of fumed silica and 10-30 parts of semi-reinforcing carbon black are used to synergistically reinforce the non-self-reinforcing rubber HNBR, and the inorganic flame retardant Mg(OH) 2 With flame retardant synergist Sb 2 O 3 The rubber-modified plasticized PVC low-smoke flame-retardant elastic film was prepared by using flame-retardant system and other additives such as compound heat stabilizer. In the preparation method, silica and carbon black are selectively dispersed in HNBR first, and plasticizer, stabilizer, flame retardant and flame retardant synergist are also selectively dispersed in PVC resin matrix, so that the various functions of functional additives can be fully exerted. For example, silica and carbon black are used together to reinforce HNBR and improve flame retardancy, and Mg(OH) 2 Reduce the smoke generated during the combustion of plasticized PVC and further improve the flame retardancy. Use carbon black to compound the surface modified Mg(OH) 2 The LOI of the functional film prepared by the synergistic flame retardant effect is as high as 35% or more, and the smoke density level is reduced to less than 15%. The functional film also has high tensile strength, tear strength and elongation at break, low surface hardness and permanent deformation, and the glass transition temperature of the film is as low as -20°C or less, and has excellent cold resistance. The HNBR modified plasticized PVC low-smoke flame retardant elastic film of the present invention enriches the demand for high-end low hardness, high elasticity, high cold resistance, high flame retardant and extremely low smoke density multifunctional films in the electronics, electrical appliances, automobiles, construction and other markets. DETAILED DESCRIPTION

[0035] The present invention is described below by means of specific examples, but the present invention is not limited to these examples.

[0036] Example 1

[0037] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 70, HNBR (saturation 99%, AN content 26%, Mooney viscosity ML (1 + 4) 100 ° C = 30) 30, polypropylene glycol adipate plasticizer (M n =1500)55, fumed silica (purity 99.8%, specific surface area 350m 2 / g, original particle size 10nm)3, semi-reinforced carbon black (iodine absorption value 30g / kg, DBP oil absorption value 70mL / 100g, specific surface area 30m 2 / g)10, surface modified Mg(OH) 2 (Purity 98.5%, average particle size 1 μm) 100, Sb 2 O 3 2. Barium stearate 1.0, zinc stearate 0.2.

[0038] Preparation method:

[0039] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 300 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 800 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and evenly coated on Mg(OH)2O3. 2 , continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0040] Preparation of hydrogenated nitrile rubber mix: For low Mooney viscosity HNBR with ML (1+4) 100℃ = 30, plasticization is not required and it can be directly mixed with carbon black to prepare the rubber mix. Add low Mooney viscosity HNBR, fumed silica and semi-reinforced carbon black in a rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, discharge the rubber to the open mixer. The rubber mix is ​​cooled and mixed while continuing to be mixed on the open mixer with a roller spacing of 3mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. When the filtered rubber mix is ​​cooled to 60℃ by water cooling, it is weighed to obtain the filtered hydrogenated nitrile rubber for standby use.

[0041] High-speed mixing and pre-plasticization of plasticized PVC powder: Put polyvinyl chloride resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, the speed is controlled at 300rpm, and the mixing time is 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 900rpm, and the mixing time is 5min. When all the plasticizers are completely absorbed by the resin, add the surface-coated modified Mg(OH) 2and Sb 2 O 3 The mixing was continued for 2 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0042] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the surface modified Mg(OH) 2 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 40r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0043] Film five-roll calendering: The material filtered by the rubber filter in the plasticizing and filtering step of the plasticizing PVC is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 180℃ and speed is 5m / min, 2# roller temperature is controlled at 185℃ and speed is 10m / min, 3# roller temperature is controlled at 190℃ and speed is 20m / min, 4# roller temperature is controlled at 180℃ and speed is 15m / min; 5# roller temperature is controlled at 160℃ and speed is 30m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 160℃ and speed at 30m / min; 2 take-off wheels at the second stage, temperature controlled at 165℃ and speed at 35m / min; 2 take-off wheels at the third stage, temperature controlled at 165℃ and speed at 35m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 60℃ and speed at 45m / min, and the winding speed is 45m / min.

[0044] The performances are shown in Table 1.

[0045] Example 2

[0046] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 70, HNBR (saturation 95%, AN content 35%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000) 60, fumed silica (purity 99.9%, specific surface area 410m 2 / g, original particle size 7nm)2, semi-reinforced carbon black (iodine absorption value 24g / kg, DBP oil absorption value 67mL / 100g, specific surface area 25m 2 / g)20, surface modified Mg(OH) 2 (Purity 99%, average particle size 1.5 μm) 100, Sb 2 O 3 1. Barium stearate 1.0, calcium stearate 1.3, zinc stearate 0.2.

[0047] Preparation method:

[0048] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 300 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 900 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and is evenly coated on Mg(OH)2O3. 2 , continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0049] Preparation of hydrogenated nitrile rubber mix: For high Mooney viscosity HNBR with ML (1+4) 100℃=80, it needs to be plasticized first and then mixed with carbon black to prepare the rubber mix. The high Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 40℃. After 15 thin passes, it is rolled down and weighed for standby use. The plasticized HNBR, fumed silica and semi-reinforced carbon black are added to the internal rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, the rubber is discharged to the open mixer. The rubber mix is ​​cooled while continuing to mix in the open mixer with a roller gap of 4mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber mix is ​​weighed when the temperature drops to 60℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0050] High-speed mixing and pre-plasticization of plasticized PVC powder: Put polyvinyl chloride resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, the speed is controlled at 400rpm, and the mixing time is 1min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and the mixing time is 8min. When all the plasticizers are completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 3 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0051] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 145℃, first add the surface modified Mg(OH) 2① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 60r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0052] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering step is conveyed to the five-roll calendering main machine along the conveyor belt, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 175℃ and speed is 10m / min, 2# roller temperature is controlled at 180℃ and speed is 20m / min, 3# roller temperature is controlled at 185℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 150℃ and speed is 40m / min; the take-off and embossing parameters are: 1 first-stage take-off wheel, temperature controlled at 155℃ and speed 40m / min; 2 second-stage take-off wheels, temperature controlled at 160℃ and speed 50m / min; 2 third-stage take-off wheels, 160℃ and speed 50m / min; cooling and winding parameters are: cooling roller temperature controlled at 50℃ and speed 55m / min, winding speed 55m / min.

[0053] The performances are shown in Table 1.

[0054] Example 3

[0055] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 70, HNBR (saturation 95%, AN content 31%, Mooney viscosity ML (1 + 4) 100 ° C = 50) 30, polypropylene adipate plasticizer (M n =2200)65, fumed silica (purity 99.8%, specific surface area 400m 2 / g, original particle size 10nm)2, semi-reinforced carbon black (iodine absorption value 34g / kg, DBP oil absorption value 77mL / 100g, specific surface area 35m 2 / g)30, surface modified Mg(OH) 2 (Purity 99%, average particle size 2μm)110, Sb 2 O 3 1.5, magnesium stearate 0.5, calcium stearate 1.0, zinc stearate 0.3.

[0056] Preparation method:

[0057] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 400 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 800 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and evenly coated on Mg(OH)2O3. 2 , continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0058] Preparation of hydrogenated nitrile rubber mix: For medium Mooney viscosity HNBR with ML (1+4) 100℃ = 50, it needs to be plasticized first and then mixed with carbon black to prepare the rubber mix. The medium Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 45℃. After 5 thin passes, it is rolled down and weighed for standby use. The plasticized HNBR, fumed silica and semi-reinforced carbon black are added to the internal rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, the rubber is discharged to the open mixer. The rubber mix is ​​cooled while continuing to mix in the open mixer with a roller gap of 3.5mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber mix is ​​weighed when the temperature drops to 60℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0059] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 350rpm, and mix for 1.5min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 800rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 2 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0060] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 140℃, first add the surface modified Mg(OH) 2① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0061] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 15m / min, 2# roller temperature is controlled at 185℃ and speed is 30m / min, 3# roller temperature is controlled at 175℃ and speed is 40m / min, 4# roller temperature is controlled at 160℃ and speed is 30m / min; 5# roller temperature is controlled at 150℃ and speed is 50m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 150℃ and speed is 50m / min; 2 take-off wheels at the second stage, temperature controlled at 150℃ and speed is 60m / min; 2 take-off wheels at the third stage, temperature controlled at 165℃ and speed is 60m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 60℃ and speed is 75m / min, and the winding speed is 75m / min.

[0062] The performances are shown in Table 1.

[0063] Example 4

[0064] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 75, HNBR (saturation 99%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 60) 25, polypropylene adipate plasticizer (M n =1500)60, fumed silica (purity 99.8%, specific surface area 380m 2 / g, original particle size 10nm)3, semi-reinforced carbon black (iodine absorption value 30g / kg, DBP oil absorption value 70mL / 100g, specific surface area 30m 2 / g)15, surface modified Mg(OH) 2 (Purity 99%, average particle size 2μm)130, Sb 2 O 3 1. Calcium stearate 1.0, barium stearate 1.0, zinc stearate 0.2.

[0065] Preparation method:

[0066] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 400 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 900 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and is evenly coated on Mg(OH)2O3. 2 , continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0067] Preparation of hydrogenated nitrile rubber mix: For medium Mooney viscosity HNBR with ML (1+4) 100℃ = 60, it needs to be plasticized first and then mixed with carbon black to prepare the rubber mix. The medium Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 40℃. After 10 thin passes, it is rolled down and weighed for standby use. According to the ratio, medium and low Mooney viscosity or plasticized HNBR, fumed silica and semi-reinforced carbon black are added to the internal rubber mixer to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, the rubber is discharged to the open mixer. The rubber mix is ​​cooled while continuing to mix in the open mixer with a roller gap of 3mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber mix is ​​weighed when the temperature drops to 60℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0068] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 400rpm, and mix for 1min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 750rpm, and mix for 7min. When all the plasticizer is completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 2.5 min to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0069] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the surface modified Mg(OH) 2① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 40r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0070] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 5m / min, 2# roller temperature is controlled at 175℃ and speed is 10m / min, 3# roller temperature is controlled at 180℃ and speed is 20m / min, 4# roller temperature is controlled at 160℃ and speed is 15m / min; 5# roller temperature is controlled at 140℃ and speed is 30m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 150℃ and speed at 30m / min; 2 take-off wheels at the second stage, temperature controlled at 150℃ and speed at 35m / min; 2 take-off wheels at the third stage, temperature controlled at 150℃ and speed at 35m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 40℃ and speed at 45m / min, and the winding speed is 45m / min.

[0071] The performances are shown in Table 1.

[0072] Example 5

[0073] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 65, HNBR (saturation 98%, AN content 26%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1500)60, fumed silica (purity 99.8%, specific surface area 400m 2 / g, original particle size 7nm)2, semi-reinforced carbon black (iodine absorption value 29g / kg, DBP oil absorption value 72mL / 100g, specific surface area 35m 2 / g)20, surface modified Mg(OH) 2 (Purity 98.5%, average particle size 1.5 μm) 140, Sb 2 O 3 2. Calcium stearate 0.6, Magnesium stearate 0.5, Barium stearate 0.5, Zinc stearate 0.2.

[0074] Preparation method:

[0075] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 350rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 800rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and evenly coated on Mg(OH)2O3. 2 , continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0076] Preparation of hydrogenated nitrile rubber mix: For high Mooney viscosity HNBR with ML (1+4) 100℃=80, it needs to be plasticized first and then mixed with carbon black to prepare the rubber mix. The high Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 45℃. After 15 thin passes, it is rolled down and weighed for standby use. The plasticized HNBR, fumed silica and semi-reinforced carbon black are added to the internal rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, the rubber is discharged to the open mixer. The rubber mix is ​​cooled while continuing to mix in the open mixer with a roller gap of 3mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber mix is ​​weighed when the temperature drops to 60℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0077] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 850rpm, and mix for 5min. When all the plasticizer is completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 3 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0078] Plasticization and filtration of plasticized PVC: ① Control the temperature of the internal mixer at 150℃, first add the plasticized PVC powder containing surface-modified Mg(OH)2 into the internal mixer and mix for 3 minutes, then add the filtered HNBR compound rubber and continue mixing for 5 minutes; ② The internally mixed materials are transported to the open mixer for further plasticization, and the roller speed of the open mixer is controlled at 60r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh sizes of 20, 100 and 20 respectively to further filter the compound rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0079] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 180℃ and speed is 15m / min, 2# roller temperature is controlled at 185℃ and speed is 30m / min, 3# roller temperature is controlled at 190℃ and speed is 40m / min, 4# roller temperature is controlled at 180℃ and speed is 30m / min; 5# roller temperature is controlled at 160℃ and speed is 50m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 160℃ and speed is 50m / min; 2 take-off wheels at the second stage, temperature controlled at 165℃ and speed is 60m / min; 2 take-off wheels at the third stage, temperature controlled at 165℃ and speed is 60m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 60℃ and speed is 75m / min, and the winding speed is 75m / min.

[0080] The performances are shown in Table 1.

[0081] Example 6

[0082] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 70, HNBR (saturation 98%, AN content 41%, Mooney viscosity ML (1 + 4) 100 ° C = 40) 30, polypropylene adipate plasticizer (M n =1000)65, fumed silica (purity 99.8%, specific surface area 350~410m 2 / g, original particle size 10nm)2, semi-reinforced carbon black (iodine absorption value 30g / kg, DBP oil absorption value 70mL / 100g, specific surface area 30m 2 / g)30, surface modified Mg(OH) 2 (Purity greater than 98%, average particle size 2μm) 150, Sb 2 O 3 1. Calcium stearate 1.5, barium stearate 0.4, zinc stearate 0.1.

[0083] Preparation method:

[0084] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 350rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 850rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and evenly coated on Mg(OH)2O3. 2 , continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0085] Preparation of hydrogenated nitrile rubber compound: For low Mooney viscosity HNBR with ML (1+4) 100℃ = 40, plasticization is not required and it can be directly mixed with carbon black to prepare the rubber compound. Add low Mooney viscosity HNBR, fumed silica and semi-reinforced carbon black in a rubber mixer according to the ratio to prepare the rubber compound. When the temperature of the rubber compound reaches 130℃, discharge the rubber into the open mixer. The rubber compound is cooled down and mixed while continuing to be mixed on the open mixer with a roller spacing of 4mm, and filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. When the filtered rubber compound is cooled to 60℃ by water cooling, it is weighed for use.

[0086] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 400rpm, and mix for 1.5min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 8min. When all the plasticizer is completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 3 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0087] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 145℃, first add the surface modified Mg(OH) 2 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0088] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 5m / min, 2# roller temperature is controlled at 175℃ and speed is 10m / min, 3# roller temperature is controlled at 180℃ and speed is 20m / min, 4# roller temperature is controlled at 160℃ and speed is 15m / min; 5# roller temperature is controlled at 140℃ and speed is 30m / min; the take-off and embossing parameters are: 1 first-stage take-off wheel, temperature controlled at 150℃ and speed at 35m / min; 2 second-stage take-off wheels, temperature controlled at 150℃ and speed at 40m / min; 2 third-stage take-off wheels, 155℃ and speed at 40m / min; the cooling and winding parameters are: cooling roller temperature is controlled at 40℃ and speed at 50m / min, winding speed is 50m / min.

[0089] The performances are shown in Table 1.

[0090] Example 7

[0091] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 70, HNBR (saturation 96%, AN content 26%, Mooney viscosity ML (1 + 4) 100 ° C = 30) 30, polypropylene adipate plasticizer (M n =2000)55, fumed silica (purity 99.9%, specific surface area 350m 2 / g, original particle size 7nm)3, semi-reinforced carbon black (iodine absorption value 29g / kg, DBP oil absorption value 72mL / 100g, specific surface area 30m 2 / g)10, surface modified Mg(OH) 2 (Purity 99%, average particle size 1.5 μm) 150, Sb 2 O 3 1. Calcium stearate 0.8, magnesium stearate 0.5, barium stearate 0.5, zinc stearate 0.3.

[0092] Preparation method:

[0093] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 300 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 800 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and evenly coated on Mg(OH)2O3.2 , continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0094] Preparation of hydrogenated nitrile rubber compound: For low Mooney viscosity HNBR with ML (1+4) 100℃ = 30, plasticization is not required and it can be directly mixed with carbon black to prepare the rubber compound. Add low Mooney viscosity HNBR, fumed silica and semi-reinforced carbon black in a rubber mixer according to the ratio to prepare the rubber compound. When the temperature of the rubber compound reaches 130℃, discharge the rubber to the open mixer. The rubber compound is cooled down and mixed while continuing to be mixed on the open mixer with a roller spacing of 3.5mm, and filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. When the filtered rubber compound is cooled to 60℃ by water cooling, it is weighed for use.

[0095] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 350rpm, and mix for 1min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 900rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 2 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0096] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 145℃, first add the surface modified Mg(OH) 2 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 60r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0097] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 180℃ and speed is 15m / min, 2# roller temperature is controlled at 185℃ and speed is 30m / min, 3# roller temperature is controlled at 190℃ and speed is 40m / min, 4# roller temperature is controlled at 180℃ and speed is 30m / min; 5# roller temperature is controlled at 160℃ and speed is 50m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 160℃ and speed is 50m / min; 2 take-off wheels at the second stage, temperature controlled at 165℃ and speed is 55m / min; 2 take-off wheels at the third stage, temperature controlled at 165℃ and speed is 55m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 60℃ and speed is 70m / min, and the winding speed is 70m / min.

[0098] The performances are shown in Table 1.

[0099] Example 8

[0100] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 75, HNBR (saturation 99%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 50) 25, polypropylene adipate plasticizer (M n =1500)65, fumed silica (purity 99.8%, specific surface area 410m 2 / g, original particle size 7-10nm)3, semi-reinforced carbon black (iodine absorption value 30g / kg, DBP oil absorption value 70mL / 100g, specific surface area 30m 2 / g)25, surface modified Mg(OH) 2 (Purity 98.5%, average particle size 2μm) 150, Sb 2 O 3 2. Barium stearate 2.0, zinc stearate 0.2.

[0101] Preparation method:

[0102] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 400 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 850 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and evenly coated on Mg(OH)2O3. 2, continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0103] Preparation of hydrogenated nitrile rubber mix: For medium Mooney viscosity HNBR with ML (1+4) 100℃ = 50, it needs to be plasticized first and then mixed with carbon black to prepare the rubber mix. The medium Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 50℃. After 10 thin passes, it is rolled down and weighed for standby use. The plasticized HNBR, fumed silica and semi-reinforced carbon black are added to the internal rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, the rubber is discharged to the open mixer. The rubber mix is ​​cooled while continuing to mix in the open mixer with a roller gap of 4mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber mix is ​​weighed when the temperature drops to 60℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0104] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 350rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 800rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 3 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0105] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 140℃, first add the surface modified Mg(OH) 2 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 60r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0106] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 175℃ and speed is 10m / min, 2# roller temperature is controlled at 180℃ and speed is 20m / min, 3# roller temperature is controlled at 185℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 150℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed at 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed at 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed at 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed at 65m / min, and the winding speed is 65m / min.

[0107] The performances are shown in Table 1.

[0108] Example 9

[0109] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 65, HNBR (saturation 99%, AN content 31%, Mooney viscosity ML (1 + 4) 100 ° C = 40) 35, polypropylene adipate plasticizer (M n =2200)60, fumed silica (purity 99.9%, specific surface area 380m 2 / g, original particle size 10nm)2, semi-reinforced carbon black (iodine absorption value 24g / kg, DBP oil absorption value 67mL / 100g, specific surface area 25m 2 / g)20, surface modified Mg(OH) 2 (Purity greater than 99%, average particle size 1 μm) 120, Sb 2 O 3 1. Magnesium stearate 1.8, zinc stearate 0.2.

[0110] Preparation method:

[0111] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 300 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 900 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and is evenly coated on Mg(OH)2O3. 2, continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0112] Preparation of hydrogenated nitrile rubber mix: For low Mooney viscosity HNBR with ML (1+4) 100℃ = 40, plasticization is not required and it can be directly mixed with carbon black to prepare the rubber mix. Add low Mooney viscosity HNBR, fumed silica and semi-reinforced carbon black in a rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, discharge the rubber to the open mixer. The rubber mix is ​​cooled and mixed while continuing to be mixed on the open mixer with a roller spacing of 3mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. When the filtered rubber mix is ​​cooled to 60℃ by water cooling, it is weighed to obtain the filtered hydrogenated nitrile rubber for standby use.

[0113] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 400rpm, and mix for 1.5min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 7min. When all the plasticizer is completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 2.5 min to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0114] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the surface modified Mg(OH) 2 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 40r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0115] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 175℃ and speed is 15m / min, 2# roller temperature is controlled at 180℃ and speed is 30m / min, 3# roller temperature is controlled at 185℃ and speed is 40m / min, 4# roller temperature is controlled at 180℃ and speed is 30m / min; 5# roller temperature is controlled at 165℃ and speed is 50m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 165℃ and speed is 50m / min; 2 take-off wheels at the second stage, temperature controlled at 165℃ and speed is 60m / min; 2 take-off wheels at the third stage, temperature controlled at 165℃ and speed is 60m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 60℃ and speed is 70m / min, and the winding speed is 70m / min.

[0116] The performances are shown in Table 1.

[0117] Example 10

[0118] Raw material formula (mass ratio, parts): PVC resin (DP = 1300) 70, HNBR (saturation 99%, AN content 41%, Mooney viscosity ML (1 + 4) 100 ° C = 30) 30, polypropylene adipate plasticizer (M n =1000)65, fumed silica (purity 99.8%, specific surface area 380m 2 / g, original particle size 8nm)2, semi-reinforced carbon black (iodine absorption value 30g / kg, DBP oil absorption value 70mL / 100g, specific surface area 30m 2 / g)20, surface modified Mg(OH) 2 (Purity greater than 98%, average particle size 1-2 μm) 150, Sb 2 O 3 1.5, calcium stearate 1.0, magnesium stearate 0.5, barium stearate 0.5, zinc stearate 0.1.

[0119] Preparation method:

[0120] Surface coating modification of magnesium hydroxide: Pre-drying to remove the Mg(OH) adsorbed water on the surface 2 Add Mg(OH)2O3 and stearic acid in a mass ratio of 99:1 into a 500L high-speed mixer. Start the low-speed mixing mode with a speed of 400 rpm for 2 minutes. Then switch to the high-speed mixing mode with a speed of 800 rpm and continue mixing until the temperature reaches 60°C. Stearic acid has completely melted and evenly coated on Mg(OH)2O3. 2, continue to mix at a low speed of 300 rpm for 2 minutes, then bag and obtain the surface-coated modified magnesium hydroxide, which is weighed for later use.

[0121] Preparation of hydrogenated nitrile rubber mix: For low Mooney viscosity HNBR with ML (1+4) 100℃ = 30, plasticization is not required and it can be directly mixed with carbon black to prepare the rubber mix. Add low Mooney viscosity HNBR, fumed silica and semi-reinforced carbon black in a rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130℃, discharge the rubber to the open mixer. The rubber mix is ​​cooled and mixed while continuing to be mixed on the open mixer with a roller spacing of 4mm, and filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. When the filtered rubber mix is ​​cooled to 60℃ by water cooling, it is weighed to obtain the filtered hydrogenated nitrile rubber for standby use.

[0122] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, the speed is controlled at 350rpm, and the mixing time is 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 750rpm, and the mixing time is 6min. When all the plasticizers are completely absorbed by the resin, add the surface-coated modified Mg(OH) 2 and Sb 2 O 3 The mixing was continued for 2 minutes to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and the powder was discharged into an internal mixer.

[0123] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the surface modified Mg(OH) 2 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165-175℃; ③ The temperature of the filter is controlled at 170-180℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0124] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC low-smoke flame-retardant elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 175℃ and speed is 10m / min, 2# roller temperature is controlled at 180℃ and speed is 20m / min, 3# roller temperature is controlled at 185℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 150℃ and speed is 40m / min; the take-off and embossing parameters are: 1 first-stage take-off wheel, temperature controlled at 155℃ and speed 40m / min; 2 second-stage take-off wheels, temperature controlled at 155℃ and speed 45m / min; 2 third-stage take-off wheels, 160℃ and speed 50m / min; cooling and winding parameters are: cooling roller temperature is controlled at 55℃ and speed 60m / min, winding speed 60m / min.

[0125] The performances are shown in Table 1.

[0126] Comparative Example 1

[0127] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 100, polypropylene adipate plasticizer (M n =1000) 60, calcium stearate 2.0, zinc stearate 0.5.

[0128] Preparation method:

[0129] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 8min. When all the plasticizer is completely absorbed by the resin, discharge the material into the internal mixer.

[0130] Plasticization and filtration of plasticized PVC: ① Control the temperature of the internal mixer at 150℃, add plasticized PVC powder and mix in the internal mixer for 6 minutes; ② The plasticized PVC material plasticized by internal mixing is transported to the open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0131] Film five-roll calendering: The material after plasticizing and filtering in the filter is conveyed to the five-roll calendering machine along the conveyor belt, and the plasticized PVC film is obtained after calendering, decanting and embossing, cooling and winding. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0132] The performance after testing is shown in Table 2.

[0133] Comparative Example 2

[0134] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 75, HNBR (double bond saturation 85%, AN content 20%, Mooney viscosity ML (1 + 4) 100 ° C = 80), polypropylene glycol adipate plasticizer (M n =1000) 60, calcium stearate 2.0, zinc stearate 0.5.

[0135] Preparation method:

[0136] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 8min. When all the plasticizer is completely absorbed by the resin, discharge the material into the internal mixer.

[0137] Plasticization and filtration of plasticized PVC: ① Control the temperature of the internal mixer at 150℃, first add the plasticized PVC powder and mix in the internal mixer for 3 minutes, then add the filtered HNBR compound rubber and continue mixing for 5 minutes; ② The internally mixed materials are transported to the open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the compound rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0138] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, decanting and embossing, cooling and winding, the HNBR modified plasticized PVC film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0139] The performance after testing is shown in Table 2.

[0140] Comparative Example 3

[0141] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (double bond saturation 85%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000) 60, calcium stearate 2.0, zinc stearate 0.5.

[0142] Preparation method:

[0143] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 8min. When all the plasticizer is completely absorbed by the resin, discharge the material into the internal mixer.

[0144] Plasticization and filtration of plasticized PVC: ① Control the temperature of the internal mixer at 150℃, first add the plasticized PVC powder and mix in the internal mixer for 3 minutes, then add the filtered HNBR compound rubber and continue mixing for 5 minutes; ② The internally mixed materials are transported to the open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the compound rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0145] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, decanting and embossing, cooling and winding, the HNBR modified plasticized PVC film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0146] The performance after testing is shown in Table 2.

[0147] Comparative Example 4

[0148] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (saturation 99%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000) 60, fumed silica (purity 99.9%, specific surface area 400m 2 / g, original particle size 10nm) 10, calcium stearate 2.0, zinc stearate 0.5.

[0149] Preparation method:

[0150] Preparation of hydrogenated nitrile rubber mix: High Mooney viscosity HNBR with ML (1 + 4) 100 ℃ = 80 needs to be plasticized first, and then mixed with fumed silica to prepare the rubber mix. High Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1 mm and a temperature of 40 ℃. After 15 thin passes, it is rolled down and weighed for standby use. The plasticized HNBR and fumed silica are added to the internal rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130 ℃, the rubber is discharged to the open mixer. The rubber mix is ​​cooled while continuing to mix in the open mixer with a roller gap of 3 mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber mix is ​​weighed when the temperature drops to 60 ℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0151] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 8min. When all the plasticizer is completely absorbed by the resin, discharge the material into the internal mixer.

[0152] Plasticization and filtration of plasticized PVC: ① Control the temperature of the internal mixer at 150℃, first add the plasticized PVC powder and mix it in the internal mixer for 3 minutes, then add the filtered HNBR rubber compound containing silica and continue mixing for 5 minutes; ② The internally mixed materials are transported to the open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0153] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, decanting and embossing, cooling and winding, the HNBR modified plasticized PVC film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0154] The performance after testing is shown in Table 2.

[0155] Comparative Example 5

[0156] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (saturation 99%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000)60, unmodified Mg(OH) 2 (purity 99%, average particle size 2 μm) 100, calcium stearate 2.0, zinc stearate 0.5.

[0157] Preparation method:

[0158] HNBR plastication: High Mooney viscosity HNBR with ML (1+4) 100℃=80 needs to be plasticated before use. High Mooney viscosity HNBR is first plasticated in a plasticizer under the conditions of a roll gap of less than 1mm and a temperature of 40℃. After 15 passes, roll it off and weigh it for use.

[0159] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, add unmodified Mg(OH) 2 Continue mixing for 3 minutes and then discharge into the internal mixer.

[0160] Plasticizing and filtration of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the unmodified Mg(OH) 2 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the plasticized HNBR is added and mixed for 5 minutes; ② The internally mixed and blended materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0161] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering step is conveyed to the five-roll calendering main machine along the conveyor belt, and after calendering film formation, decanting and embossing, cooling and winding, the HNBR modified plasticized PVC flame retardant film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0162] The performance after testing is shown in Table 2.

[0163] Comparative Example 6

[0164] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (saturation 99%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000)60, unmodified Mg(OH) 2 (Purity 99%, average particle size 2μm) 150, Sb 2 O 3 2. Calcium stearate 2.0, zinc stearate 0.5.

[0165] Preparation method:

[0166] HNBR plastication: High Mooney viscosity HNBR with ML (1+4) 100℃=80 needs to be plasticated before use. High Mooney viscosity HNBR is first plasticated in a plasticizer under the conditions of a roll gap of less than 1mm and a temperature of 40℃. After 15 passes, roll it off and weigh it for use.

[0167] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, add unmodified Mg(OH) 2 and Sb 2 O 3 Continue mixing for 3 minutes and then discharge into the internal mixer.

[0168] Plasticization and filtration of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the unmodified Mg(OH)2 and Sb 2 O 3 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the plasticized HNBR is added and mixed for 5 minutes; ② The internally mixed and blended materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0169] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering step is conveyed to the five-roll calendering main machine along the conveyor belt, and after calendering film formation, decanting and embossing, cooling and winding, the HNBR modified plasticized PVC flame retardant film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0170] The performance after testing is shown in Table 2.

[0171] Comparative Example 7

[0172] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (saturation 99%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000)60, fumed silica (purity 99.9%, specific surface area 400m 2 / g, original particle size 10nm)10, unmodified Mg(OH) 2 (Purity 99%, average particle size 2μm) 150, Sb 2 O 3 2. Calcium stearate 2.0, zinc stearate 0.5

[0173] Preparation method:

[0174] Preparation of hydrogenated nitrile rubber mix: High Mooney viscosity HNBR with ML (1 + 4) 100 ℃ = 80 needs to be plasticized first, and then mixed with fumed silica to prepare the rubber mix. High Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1 mm and a temperature of 40 ℃. After 15 thin passes, it is rolled down and weighed for standby use. The plasticized HNBR and fumed silica are added to the internal rubber mixer according to the ratio to prepare the rubber mix. When the temperature of the rubber mix reaches 130 ℃, the rubber is discharged to the open mixer. The rubber mix is ​​cooled while continuing to mix in the open mixer with a roller gap of 3 mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber mix is ​​weighed when the temperature drops to 60 ℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0175] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, add unmodified Mg(OH) 2 and Sb 2 O 3 Continue mixing for 3 minutes and then discharge into the internal mixer.

[0176] Plasticizing and filtration of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the unmodified Mg(OH) 2 and Sb 2 O 3 ① The plasticized PVC powder is mixed in an internal mixer for 3 minutes, and then the filtered HNBR rubber compound containing silica is added and mixed for 5 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0177] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering step is conveyed to the five-roll calendering main machine along the conveyor belt, and after calendering film formation, decanting and embossing, cooling and winding, the HNBR modified plasticized PVC flame retardant film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0178] The performance after testing is shown in Table 2.

[0179] Comparative Example 8

[0180] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (saturation 99%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000)60, semi-reinforced carbon black 30, Sb 2 O 3 2. Calcium stearate 2.0, zinc stearate 0.5

[0181] Preparation method:

[0182] Preparation of HNBR plasticized and carbon black-containing rubber compound: High Mooney viscosity HNBR with ML (1 + 4) 100 ℃ = 80 needs to be plasticized before use. High Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 40℃. After 15 thin passes, it is rolled down and weighed for standby use. The plasticized HNBR and semi-reinforced carbon black are added to the internal rubber mixer according to the ratio to prepare the rubber compound. When the temperature of the rubber compound reaches 130℃, the rubber is discharged to the open mixer. The rubber compound is cooled while continuing to be mixed in the open mixer with a roller gap of 4mm, and filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. The filtered rubber compound is weighed when the temperature drops to 60℃ after water cooling to obtain the filtered hydrogenated nitrile rubber for standby use.

[0183] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, discharge it into the internal mixer.

[0184] Plasticization and filtration of plasticized PVC: ① Control the temperature of the internal mixer at 150℃, first add the plasticized PVC powder and mix it in the internal mixer for 3 minutes, then add the HNBR compound containing carbon black and continue mixing for 5 minutes; ② The internally mixed materials are transported to the open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0185] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed to the five-roll calendering machine along the conveyor belt, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0186] The performance is shown in 2.

[0187] Comparative Example 9

[0188] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (saturation 85%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000)60, semi-reinforced carbon black 30, unmodified Mg(OH) 2 100, Sb 2 O 3 3. Calcium stearate 2.0, zinc stearate 0.5.

[0189] Preparation method:

[0190] Preparation of HNBR plasticized and carbon black-containing compound rubber: High Mooney viscosity HNBR with ML (1+4) 100℃ = 80 needs to be plasticized before use. High Mooney viscosity HNBR is first plasticized in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 40℃. After 15 passes, it is rolled down and weighed for use.

[0191] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode to mix evenly, control the speed to 650rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, discharge it into the internal mixer.

[0192] Plasticizing and filtering of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, add plasticized PVC powder, plasticized HNBR, carbon black, unmodified Mg(OH) 2 and Sb 2 O 3 Mix in an internal mixer for 6 minutes; ② The internally mixed materials are transported to an open mixer for further plasticization, and the roller speed of the open mixer is controlled at 50r / min and the temperature of the open mixer is 165℃; ③ The temperature of the filter is controlled at 170℃, and the filter mesh uses a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the blended rubber, and the return water temperature of the machine body is controlled at 20-40℃.

[0193] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed to the five-roll calendering machine along the conveyor belt, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0194] The performance is shown in 2.

[0195] Comparative Example 10

[0196] Raw material formula (mass ratio, parts): PVC resin (DP = 1000) 70, HNBR (saturation 85%, AN content 34%, Mooney viscosity ML (1 + 4) 100 ° C = 80) 30, polypropylene adipate plasticizer (M n =1000)60, semi-reinforced carbon black 30, unmodified Mg(OH) 2 150, Sb 2 O 3 3. Calcium stearate 2.0, zinc stearate 0.5.

[0197] Preparation method:

[0198] HNBR plasticization and Mg(OH) 2Preparation of rubber compound: High Mooney viscosity HNBR with ML(1+4)100℃=80 needs to be plasticized before use. High Mooney viscosity HNBR is first plasticized in a rubber opener under the condition of roller distance less than 1mm and temperature 40℃. After 15 passes, roll it off and weigh it for use. Add plasticized HNBR and unmodified Mg(OH) 2 and Sb 2 O 3 The rubber mixture was prepared in an internal rubber mixer, and when the temperature of the rubber mixture reached 130°C, the rubber mixture was discharged into an open mixer. The rubber mixture was cooled and mixed in an open mixer with a roller distance of 4 mm, and filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combination metal filter. When the filtered rubber mixture was cooled by water and the temperature dropped to 60°C, it was weighed to obtain the filtered hydrogenated nitrile rubber for standby use.

[0199] High-speed mixing and pre-plasticization of plasticized PVC powder: Add PVC resin and powder stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300rpm, and mix for 2min; add polyester plasticizer and switch to high-speed mixing mode for uniform mixing, control the speed to 650rpm, and mix for 6min. When all the plasticizer is completely absorbed by the resin, add carbon black and continue mixing for 3min before discharging into the internal mixer.

[0200] Plasticization and filtration of plasticized PVC: ①Control the temperature of the internal mixer at 150℃, first add the plasticized PVC powder containing carbon black and mix it in the internal mixer for 3 minutes, then add the unmodified Mg(OH) 2 ① The HNBR compound was mixed for 5 minutes; ② The mixed materials were transported to the open mill for further plasticization, and the roller speed of the open mill was controlled at 50r / min and the temperature of the open mill was 165℃; ③ The temperature of the filter was controlled at 170℃, and the filter mesh used a three-layer laminated metal with mesh numbers of 20, 100 and 20 respectively to further filter the mixed rubber, and the return water temperature of the machine body was controlled at 20-40℃.

[0201] Film five-roll calendering: The material after plasticizing and filtering the plasticized PVC in the filtering process is conveyed to the five-roll calendering machine along the conveyor belt, and after calendering film formation, desorption and embossing, cooling and winding, the HNBR modified plasticized PVC elastic film is obtained. The film forming parameters of the five-roll calender are: 1# roller temperature is controlled at 170℃ and speed is 10m / min, 2# roller temperature is controlled at 175℃ and speed is 120m / min, 3# roller temperature is controlled at 180℃ and speed is 30m / min, 4# roller temperature is controlled at 170℃ and speed is 25m / min; 5# roller temperature is controlled at 160℃ and speed is 40m / min; the take-off and embossing parameters are: 1 take-off wheel at the first stage, temperature controlled at 155℃ and speed 40m / min; 2 take-off wheels at the second stage, temperature controlled at 155℃ and speed 45m / min; 2 take-off wheels at the third stage, temperature controlled at 160℃ and speed 50m / min; the cooling and winding parameters are: the cooling roller temperature is controlled at 50℃ and speed 60m / min, and the winding speed is 60m / min.

[0202] The performance is shown in 2.

[0203] Table 1 Summary of properties of films prepared in Examples 1 to 10

[0204]

[0205] Table 2 Performance of the films prepared in Comparative Examples 1 to 10

[0206]

Claims

1. A hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film, characterized in that: Made of the following raw materials in the following mass ratio:

2. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 1, characterized in that: The polyvinyl chloride resin is a linear polyvinyl chloride resin synthesized by a suspension polymerization process and having an average polymerization degree of 1300.

3. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 1, characterized in that: The hydrogenated nitrile rubber is a binary random copolymer obtained by polymerizing butadiene and acrylonitrile as monomers, and then hydrogenating the unsaturated double bonds of the main chain to form a saturated structure, wherein the mass percentage of acrylonitrile is 26-41%, the saturation of the double bonds is 95-99%, and the Mooney viscosity ML (1+4) 100°C is 30-80.

4. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 3, characterized in that: The hydrogenated nitrile rubber is a low Mooney viscosity hydrogenated nitrile rubber with ML (1+4) 100°C = 30-40.

5. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 1, characterized in that: The plasticizer is a polyester plasticizer with a medium molecular weight, that is, one or a combination of polypropylene adipate with a number average molecular weight of 1000 to 2000.

6. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 1, characterized in that: The powdery composite stabilizer is a combination of one or more of calcium stearate, barium stearate, magnesium stearate and zinc stearate, wherein the content of zinc stearate in the total raw materials of hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film is 0.1-0.3 parts by weight.

7. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 1, characterized in that: The magnesium hydroxide has a purity greater than 98%, an average particle size of 1 to 2 micrometers, and is surface-coated and modified with 1% by mass of stearic acid.

8. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 1, characterized in that: The fumed silica has a purity of ≥99.8% and a specific surface area of ​​350-410 m 2 / g, fumed silica with an original particle size of 7 to 10 nm.

9. The hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to claim 1, characterized in that: The carbon black has an iodine absorption value of 29±5 g / kg, a DBP oil absorption value of 72±5 mL / 100 g, and a specific surface area of ​​30±5 m 2 / g of semi-reinforcing carbon black.

10. A method for preparing the hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film according to any one of claims 1 to 9, characterized in that: The following steps are involved: Surface coating modification of magnesium hydroxide: magnesium hydroxide from which surface adsorbed water is dried and removed and stearic acid are added to a high-speed mixer at a mass ratio of 99:

1. The low-speed mixing mode is started first, and the speed is controlled at 300-400 rpm. After the mixing time is 2 minutes, the high-speed mixing mode is switched to control the speed to 800-900 rpm and the mixing is continued until the temperature reaches 60°C, when the stearic acid has completely melted and is evenly coated on the magnesium hydroxide. The low-speed mixing is continued at 300 rpm for 2 minutes, and the surface-coated magnesium hydroxide is bagged and weighed for standby use. Preparation of hydrogenated nitrile rubber compound: For low Mooney viscosity hydrogenated nitrile rubber with ML (1+4) 100°C = 30-40, it does not need to be plasticized, and can be directly mixed with carbon black to prepare the rubber compound; for medium-high Mooney viscosity hydrogenated nitrile rubber with ML (1+4) 100°C> 40, it is necessary to first plasticize to reduce its Mooney viscosity, and then mix it with carbon black to prepare the rubber compound; the plasticizing steps of medium-high Mooney viscosity hydrogenated nitrile rubber are: plasticize in a rubber opener under the conditions of a roller gap of less than 1mm and a temperature of 40-50°C, and thin pass After 5 to 15 times, the rubber is rolled down and weighed for use; low Mooney viscosity or medium-high Mooney viscosity hydrogenated nitrile rubber after plasticization, fumed silica and carbon black are added according to the ratio to prepare a mixed rubber in an internal rubber mixer, and when the mixed rubber temperature reaches 130°C, the rubber is discharged to an open mixer; the mixed rubber is cooled while continuing to be mixed in an open mixer with a roller distance of 3 to 4 mm, and is filtered through a rubber filter through a 20 mesh / 60 mesh / 20 mesh three-layer combined metal filter screen, and the filtered rubber is weighed when the temperature drops to 60°C after water cooling to obtain the filtered hydrogenated nitrile rubber for use; High-speed mixing and pre-plasticization of plasticized PVC powder: put polyvinyl chloride resin and powdered composite stabilizer into a 500L high-speed mixer, start the low-speed mixing mode first, control the speed to 300-400rpm, and mix for 1-2min; add plasticizer and switch to high-speed mixing mode for uniform mixing, control the speed to 650-900rpm, and mix for 5-8min. When all the plasticizer is completely absorbed by the resin, add surface-coated modified magnesium hydroxide and antimony trioxide and continue mixing for 2-3min to obtain plasticized PVC powder containing surface-modified magnesium hydroxide and discharge it into the internal mixer; Plasticization and filtration of plasticized PVC: ①Control the temperature of the internal mixer at 140-150℃, first add the plasticized PVC powder containing surface-modified magnesium hydroxide into the internal mixer and mix for 3 minutes, then add the filtered hydrogenated nitrile rubber compound and continue mixing for 5 minutes; ②Transport the internally mixed materials to the open mixer for further plasticization, control the roller speed of the open mixer at 40-60r / min, and the temperature of the open mixer at 165-175℃; ③Control the temperature of the filter at 170-180℃, and use a three-layer laminated metal filter with mesh sizes of 20, 100 and 20 to further filter the compound, and control the return water temperature of the machine at 20-40℃; Film five-roll calendering: the material after plasticizing the plasticized PVC and filtering the filter in the filter is conveyed along the conveyor belt to the five-roll calendering main machine, and after calendering film formation, desorption and embossing, cooling and winding, a hydrogenated nitrile rubber modified plasticized polyvinyl chloride low-smoke flame-retardant elastic film is obtained; wherein, the five-roll calender film forming parameters are: 1# roller temperature is controlled at 170-180°C, speed 5-15m / min, 2# roller temperature is controlled at 170-185°C, speed 10-30m / min, 3# roller temperature is controlled at 175-190°C, speed 20-40m / min, 4# roller temperature is controlled at 160- 180℃, speed 15~30m / min; 5# roller temperature control 130~160℃, speed 30~50m / min; take-off and embossing parameters are: 1 take-off wheel in the first stage, temperature control 150~160℃, speed 30~50m / min; 2 take-off wheels in the second stage, temperature control 150~165℃, speed 35~60m / min; 2 take-off wheels in the third stage, 150~165℃, speed 35~60m / min; cooling and coiling parameters are: cooling roller temperature control 40~60℃, speed 45~75m / min, coiling speed 45~75m / min.

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