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CN-122011628-A - Flame-retardant master batch for low-dust dissipation high-flame-retardance PVC cable material and preparation method thereof

CN122011628ACN 122011628 ACN122011628 ACN 122011628ACN-122011628-A

Abstract

The invention discloses a flame-retardant master batch for a PVC cable material with low dust dissipation and high flame retardance and a preparation method thereof, wherein the flame-retardant master batch is prepared from, by weight, 10-15 parts of polyvinyl chloride resin, 5-10 parts of a plasticizer, 1-3 parts of a filler, 1-2 parts of a stabilizer, 0.5-1.5 parts of a compatilizer, 0.2-0.5 part of a lubricant, 0.1-0.3 part of an antioxidant and 60-90 parts of a flame retardant. The invention prepares the powder arsenic-containing flame retardant into PVC substrate master batch particles, and is matched with a special compatilizer and a standardized production protection system, so that the problem of arsenic oxide dust dissipation is solved fundamentally, meanwhile, the low-temperature softening and mixing process of an internal mixer is adopted, the uniform dispersion of the high-content flame retardant in the PVC substrate is realized, the prepared master batch has good compatibility with PVC cable materials, the oxygen index can be obviously improved by the addition of 3% by mass, the flame retardant efficiency and the production cost are both considered, the preparation process is stable, the problems of superplastic and coke materials are solved, and the industrial large-scale production requirement is met.

Inventors

  • WEI GUOBAO
  • WANG YINFEI
  • WU MIN
  • YE GANG
  • LI WENBIN

Assignees

  • 上海凯波电缆特材股份有限公司

Dates

Publication Date
20260512
Application Date
20260326

Claims (11)

  1. 1. The flame-retardant master batch for the PVC cable material with low dust dissipation and high flame retardance is characterized by being prepared from the following raw materials in parts by weight: 10-15 parts of polyvinyl chloride resin; 5-10 parts of plasticizer; 1-3 parts of filler; 1-2 parts of a stabilizer; 0.5-1.5 parts of compatilizer; 0.2-0.5 parts of lubricant; 0.1-0.3 part of antioxidant; 60-90 parts of flame retardant; the flame retardant is mixed powder of antimony trioxide and arsenic trioxide, the mass ratio of the antimony trioxide to the arsenic trioxide is 1:9, the average particle size D50 of the flame retardant is less than or equal to 2.5 mu m, and the moisture is less than or equal to 0.5%.
  2. 2. The flame-retardant master batch according to claim 1, wherein the polyvinyl chloride resin is an S-60 resin, the average polymerization degree of the polyvinyl chloride resin is 750-850, the number of fish eyes is less than 10/400 cm 2 , and the content of residual polyvinyl chloride monomers is less than or equal to 5 mug/g; The plasticizer is dioctyl terephthalate, the density of the dioctyl terephthalate is 0.980-0.986 g/cm 3 , the flash point is more than 210 ℃, the volume resistivity is more than or equal to 2.0X10. 10 12 Ω cm, and the water content is less than 0.15%; The filler is light active calcium carbonate, the Hunter whiteness of the light active calcium carbonate is more than or equal to 96 percent, the average grain diameter D50 is less than or equal to 1.8 mu m, and the moisture is less than or equal to 0.6 percent; the stabilizer is a calcium-zinc composite stabilizer, the density of the calcium-zinc composite stabilizer is 1.109-1.128 g/cm 3 , and the heating decrement is less than 1.5%; The compatilizer is ethylene-vinyl acetate copolymer grafted maleic anhydride (EVA-g-MAH), the VA content of the compatilizer is 18-28%, and the grafting rate is 0.8-1.2%.
  3. 3. The flame retardant masterbatch according to claim 1, wherein the lubricant is a compounded system of low-density polyethylene wax, stearic acid and barium stearate, and the compounded mass ratio of the low-density polyethylene wax, stearic acid and barium stearate is 1:1:1.5.
  4. 4. The flame retardant masterbatch according to claim 3 wherein the low density polyethylene wax has a density of 0.92g/cm 3 , a melting point of 120-140 ℃, a number average molecular weight of 2000-5000, a viscosity of 1.1 mPa-s at 120 ℃, a density of 0.84-0.88 g/cm 3 , a melting point of 54-60 ℃, a density of 1.14-1.18 g/cm 3 , a melting point of 210-220 ℃ and a barium content of 19.5-21.5%.
  5. 5. The flame retardant masterbatch according to claim 1, characterized in that the antioxidant is a compound system of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate and dilauryl thiodipropionate (DLTP), and the compound mass ratio of pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate to dilauryl thiodipropionate (DLTP) is 1:1.
  6. 6. The flame retardant masterbatch according to claim 5 wherein said pentaerythritol tetrakis [ beta- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionate ] has a density of 1.15-1.20 g/cm 3 , a melting point of 120 ℃, a heating loss of <1.0%, and said dilauryl thiodipropionate (DLTP) has a density of 0.91-0.94 g/cm 3 , a melting point of 40 ℃ and a heating loss of <1.0%.
  7. 7. A method for preparing a flame retardant masterbatch for a PVC cable material having a low dust emission and a high flame retardancy as claimed in any one of claims 1 to 6, comprising the steps of: S1, sequentially adding polyvinyl chloride resin, plasticizer, filler, stabilizer, compatilizer, lubricant and antioxidant into a high-speed kneader according to a proportion, heating, stirring and kneading; S2, mixing the kneaded material obtained in the step S1 and the flame retardant in an internal mixer according to a proportion, granulating by a single screw, drying by a hot air circulation oven, and obtaining the flame-retardant master batch for the PVC cable material with low dust dissipation and high flame retardance, wherein a standardized production protection system is adopted to control dust dissipation in the preparation process.
  8. 8. The method according to claim 7, wherein in the step S1, the kneading temperature is 90-110 ℃, the kneading time is 7-9 min, and the rotational speed of the high-speed kneader is 800r/min.
  9. 9. The preparation method of claim 7, wherein in the step S2, the banburying temperature is 135-145 ℃, the banburying time is 6-8 min, and the press rod is lifted to clean raw powder at corners of the banburying chamber during 3-4 min, and the cleaning time is 10-15S.
  10. 10. The preparation method according to claim 7, wherein in the step S2, the single screw is divided into five heating areas, the temperature of each heating area is 55-60 ℃ in the first area, 65-75 ℃ in the second area, 80-90 ℃ in the third area, 90-100 ℃ in the fourth area and 110-120 ℃ in the fifth area, the screw rotating speed of the single screw granulator is 50r/min, the grain size of the cut grains is 2-3mm, and the moisture of the master batch after drying is less than or equal to 0.3%.
  11. 11. The method of claim 7, wherein the standardized production protection system comprises: 1) The full-automatic metering and proportioning system with the precision of +/-0.1% is adopted to replace manual operation, and workers do not need to operate on site in the metering, material sucking and material mixing stages; 2) Adopting a fully-closed pipeline batching system, wherein the pipeline negative pressure is-0.02 to-0.05 MPa in the material conveying process; 3) An H13-level high-efficiency air filter is arranged in a ventilation system of a production workshop, the filtering efficiency is more than or equal to 99.95%, and the escape amount of arsenic trioxide dust in the production process is less than or equal to 0.03mg/m 3 .

Description

Flame-retardant master batch for low-dust dissipation high-flame-retardance PVC cable material and preparation method thereof Technical Field The invention relates to the technical field of wire and cable materials, in particular to a flame-retardant master batch for a PVC cable material with low dust dissipation and high flame retardance and a preparation method thereof. Background Polyvinyl chloride (PVC) is a core common material for wire and cable insulation jackets due to excellent mechanical properties, chemical corrosion resistance, easy processing and low cost, and is widely applied to the wire and cable industries in the fields of electric power, rail transit, construction and the like. With the continuous promotion of infrastructure construction such as global power grid transformation and urban rail transit, the market scale of PVC cable materials is steadily increased, and the market data of the PVC cable materials in China in 2024 is shown to reach 1400 hundred million yuan, which accounts for 56% of the global market share, and the market scale of the PVC cable materials in 2030 is expected to break through 2500 hundred million yuan. The chlorine content of the pure PVC resin is up to 56.48%, the oxygen index is above 45, the natural high-flame-retardant material is adopted, but when the soft PVC cable material is prepared, a large amount of inflammable plasticizer and other auxiliary agents are required to be added into the resin to meet the flexibility requirements of processing and use, so that the chlorine content of the PVC cable material is relatively reduced, and the flame retardant property is rapidly reduced. The conventional national standard HI-90PVC sheath material is a soft PVC cable material commonly used in industry, and the oxygen index is only 24, so that the flame retardant requirement of bundled combustion can not be met, and the flame retardant modification is required to be carried out by adding a flame retardant, so that the flame retardant is the core direction of industrial technology research and development. In the prior art, the flame retardant for the PVC cable material has the optimal flame retardant effect of the antimony trioxide, and 3-7 parts of the flame retardant can be added to improve the oxygen index by 5-7, but the market price of pure antimony trioxide (the content of which is 99.8%) is as high as 24 ten thousand yuan/ton, so that the formula cost of the PVC cable material is greatly increased, and the flame retardant is difficult to be industrially applied on a large scale. In order to reduce the cost, most attempts are made in the industry to adopt halogen-free flame retardants such as magnesium hydroxide, aluminum hydroxide and the like, but the flame retardant efficiency is extremely low, the oxygen index of the PVC cable material can be slightly improved only by more than 20%, and the mechanical property of the PVC cable material can be seriously reduced by adding a large amount of flame retardants, so that the practical application value is lost, and the industry always fails to find a special flame retardant for the PVC cable material, which has both the flame retardant efficiency and the raw material cost. Meanwhile, the flame retardant is directly added into the PVC cable material in the form of powder, so that the problems of multiple remarkable and difficult solution are caused, namely, firstly, most of high-efficiency flame retardant powder has toxicity or irritation, the powder is extremely easy to float in the air, and far exceeds the occupational contact limit value of all harmful factors of a working field, namely, the occupational contact limit value regulated by chemical harmful factors (GBZ 2.1.1-2019), not only can the health hazard such as the respiratory tract injury of workers be caused, but also the production environment is seriously polluted, secondly, the interface compatibility of the powder flame retardant and PVC resin is generally poor, agglomeration and uneven dispersion are easy to occur, the flame retardant performance of the PVC cable material is greatly fluctuated, the product quality stability is poor, and the quality requirement of industrial production cannot be met, thirdly, the metering and feeding process of the powder flame retardant is easy to generate dust, a large amount of raw material waste, and meanwhile, the powder is easy to absorb moisture and agglomerate, and bring a great inconvenience to transportation, storage and subsequent material feeding operation of the powder flame retardant is multiple, so that the automatic production efficiency cannot be realized, and the standard of production is low. In order to solve the problem of dust dissipation of powder flame retardants, the prior art tries to prepare the flame retardants into a master batch form, but the related technical scheme still has the technical bottleneck that the content of the flame retardants in the existing PVC flame retardant master ba