The invention discloses a flame-retardant polyethylene for producing fireproof aluminum-plastic board cores and a preparation method thereof, which is grafted with aluminum hydroxide, magnesium hydroxide, zinc borate, monoalkoxy titanate, and maleic anhydride Polyethylene and polyethylene are used as raw materials and prepared by high-temperature melting. The invention has reasonable formula design, simple preparation process and low production cost, and the prepared flame-retardant polyethylene has good flame-retardant performance when used to produce fire-proof aluminum-plastic board cores, and solves the problem of poor fire-proof performance of aluminum-plastic boards produced in the prior art question.
Flame-retardant polyethylene for producing fireproof aluminum-plastic board core and preparation method thereof
Technical field The invention belongs to the technical field of producing fireproof aluminum-plastic board core material, relates to a kind of production fireproof aluminum-plastic
Flame-retardant polyethylene for board core and its preparation method.
Background technology: Aluminum-plastic composite board is a new type of decorative material, which is a plate made of aluminum and plastic core material bonded and compounded by special adhesive under certain process conditions. Because of its excellent properties such as low density, good rigidity, rich colors and high surface smoothness, it is widely used in curtain wall, indoor and outdoor decoration and other fields. The polyethylene plastic used for the plastic core of the prior art is flammable and has the technical problem of poor fire performance.
SUMMARY OF THE INVENTION The object of the present invention is to solve the technical problem of poor fireproof performance in the prior art, and provide a flame-retardant polyethylene for producing fire-resistant aluminum-plastic panel core and its preparation method to overcome the deficiencies of the prior art.
In order to achieve the above object, the flame retardant polyethylene used in the production of the fireproof aluminum-plastic board core of the present invention is prepared by high-temperature melting of the following raw materials according to their weight proportions: aluminum hydroxide 34.5, magnesium hydroxide 34.5, Zinc borate 6, monoalkoxy titanate 0.6, maleic anhydride grafted polyethylene 4.5 and polyethylene 20;
The present invention produces the preparation method of the flame-retardant polyethylene that fire-proof aluminum-plastic plate core is used to carry out by following processing step:
1), 2500 mesh aluminum oxide, magnesium hydroxide and zinc borate are weighed by described weight ratio, drop into high-speed mixer, heat and stir;
2), When the temperature of the high-speed mixer rises to 100°C, the monoalkoxy titanate coupling agent is dropped into to continue stirring and heated to 125°C, then the maleic anhydride grafted polyethylene compatibilizer and the The polyethylene carrier is stirred and heated to 170-175t: the material is discharged to obtain flame-retardant polyethylene, which is used as a raw material for producing fire-resistant aluminum-plastic board cores.
The invention has reasonable formula design, simple preparation process and low production cost, and the prepared flame-retardant polyethylene has good flame-retardant performance when used to produce fire-proof aluminum-plastic board cores, and solves the problem of poor fire-proof performance of aluminum-plastic boards produced in the prior art question.
1), take aluminum hydroxide 345Kg, magnesium hydroxide 345Kg, zinc borate 60Kg, monoalkoxy titanate 6Kg, maleic anhydride grafted polyethylene 45Kg and polyethylene 200Kg;
2), 2500 purpose aluminum oxide, magnesium hydroxide and zinc borate are put into 1.5mm high-speed mixer, heat and stir;
3), When the temperature of the high-speed mixer rises to 100°C, the monoalkoxy titanate coupling agent is dropped into to continue stirring and heated to 125°C, then the maleic anhydride grafted polyethylene compatibilizer and the The polyethylene carrier is stirred and heated to 170-175 ° C for discharging, that is, to obtain flame-retardant polyethylene.
Raw material selection principle of the present invention is described in detail as follows:
1, the matching of flame retardant: adopting aluminum hydroxide or magnesium hydroxide flame retardant system alone all is difficult to reach approximately harsh flame retardant requirement, in order to obtain better flame retardant effect, through a large amount of test screening , when 46% aluminum hydroxide is combined with 46% magnesium hydroxide and 8% zinc borate for synergy, the best flame retardant effect can be obtained. Because the thermal decomposition temperature of aluminum hydroxide is 220 ℃, and the thermal decomposition temperature of magnesium hydroxide is 330 ℃, the two are compounded together, can suppress the burning of macromolecule material in wide temperature range. Boric acid The addition of zinc can improve the thermal stability and smoke suppression effect of flame retardant materials. The synergistic flame retardant effect of this system is to form a hard and dense carbonized layer like inorganic ceramics when burning, which acts as a barrier to heat transfer , thereby improving flame retardancy, reducing smoke concentration and preventing melt dripping.
2, the impact of flame retardant particle size on mechanical processability: in the flame retardant filling system containing more than 80%, the decline of mechanics and processability is inevitable, in order to reduce this trend, select particle diameter The smaller the flame retardant powder, the better the mechanical and processing properties of the system. The smaller the particle size of the flame retardant powder, the larger the specific surface area, and the larger the bonding surface with the matrix. In addition, there are more chemically active points on the large specific surface area, which is more conducive to the coupling agent and high polymer. The combination of compound and graft compatibilizer can get better mechanical properties. After being fully coated, the flame retardant powder with smaller particle size shows good fluidity and improves processing performance. Considering the cost factor, we choose flame retardant powder with a particle size of about um, magnesium hydroxide brucite powder.
3, the interface modification of flame retardant powder particle and matrix resin: we adopt coupling agent as the surface modifier of flame retardant powder. The coupling agent is a surface modifier with an amphoteric structure. It can be divided into several types such as silane, titanic acid, zircoaluminate and its complexes. Some functional groups in the molecule can react with various groups on the surface of the powder to form a strong chemical bond. The other part is a carbon chain, which can chemically react or physically entangle with organic polymers, thereby firmly connecting two materials with very different properties. By comparing the effects of several types of coupling agents, it is found that monoalkoxy titanate coupling agent TC-114 (produced by Changzhou Jiangnan Auxiliary Factory) has the best effect, and its optimal dosage is 0.8 %.
4. Introduce compatibilizer to improve the mechanical properties and aluminum-plastic composite bonding performance of flame retardant system: in the matrix resin, a large amount of flame retardant powder is filled, and its excellent dispersibility is the most important. Adding maleic anhydride grafted polyethylene to the flame retardant system can strengthen the debonding effect of the interface flexible layer, facilitate the uniform dispersion of the flame retardant in the matrix resin, and effectively improve its compatibility with the matrix resin, thereby It solves the problem of the decline in mechanical properties caused by a large amount of flame retardant powder filling and improves the adhesion with the polymer adhesive film. When the amount of maleic anhydride grafted polyethylene is 6%, the overall performance of the composite material is better. The tensile strength is 7.0Mpa.