A kind of preparation method of surface cladding type composite inorganic fire retardant
Technical field
That the present invention relates to is a kind of preparation method of surface cladding type composite inorganic fire retardant, more precisely be the preparation method of a kind of aqua oxidation zinc clad magnesium hydroxide type and aqua oxidation zinc cladded aluminium hydroxide composite inorganic fire retardant, belong to field of chemical engineering.
Background technology
At present world's fire retardant development field presents the trend of non-halogenated, compoundization, harmless or low evilization and low fuming.Inorganic combustion inhibitor such as aluminium hydroxide, magnesium hydroxide chemical stability is good, not volatile, toxicity is low or nontoxic, do not produce obnoxious flavoures such as corrodibility, environmentally friendly, and raw material sources are abundant, cheap, meet the megatrend of current fire retardant, become the main direction of flame-retarded technology development to the environment-friendly type development.The dehydration of aqua oxidation zinc decomposes generates zinc oxide, generates a large amount of water vapour in the decomposition course and can dilute inflammable gas and concentration of oxygen, helps the fire-retardant of material; The zinc oxide that reaction generates has higher activity, can adsorb soot dust granule, promotes into charcoal and forms seemingly ceramic protective layer and condensed phase fire retardation at material surface; In addition, aqua oxidation zinc also have concurrently reinforcement, wear-resisting, increase effects such as goods elasticity and sulfuration.But single inorganic combustion inhibitor (as magnesium hydroxide, aluminium hydroxide) flame retarding efficiency is low, generally all wants high filler loading capacity could produce good flame retardant effect.In addition, because poor with the superpolymer consistency, interface binding power is little and be difficult for disperseing in the polymer matrix material, has a strong impact on the machine-shaping property of superpolymer base packing material and causes being filled mechanical property and other degradation of material.So usually be together composite in actual applications two or more fire retardant, make composite flame-retardant agent and use, make their mutual synergy, learn from other's strong points to offset one's weaknesses, thereby reach the consumption that reduces fire retardant, improve the purpose of Flame Retardancy energy, processing characteristics and mechanical property.But the compound or composite of current inorganic combustion inhibitor mostly just carries out the mechanical-physical mixing with various fire retardants in use or before using, and generally all exists and disperses uneven problem, can not bring into play the synergistic effect between fire retardant fully.
The objective of the invention is weak point at present composite inorganic fire retardant preparation method, a kind of particle surface that aqua oxidation zinc is coated on magnesium hydroxide or aluminium hydroxide fire retardant is provided, make the aqua oxidation zinc clad magnesium hydroxide type of high flame retardant efficient and the method for aqua oxidation zinc cladded aluminium hydroxide composite inorganic fire retardant, realize the chemically composited of magnesium hydroxide and aqua oxidation zinc or aluminium hydroxide and aqua oxidation zinc, farthest bring into play magnesium hydroxide, the cooperative flame retardant effect of aluminium hydroxide and these several inorganic components of aqua oxidation zinc greatly improves the flame retarding efficiency of composite inorganic fire retardant.
Summary of the invention
Content of the present invention is to adopt chemical heterogeneous precipitation method, with square raw materials such as ultrafine aluminium hydroxide, zinc salts, at the coating hydrous zinc oxide film of ultrafine aluminium hydroxide particle surface, the aqua oxidation zinc of preparation high flame retardant efficient coats ultrafine aluminium hydroxide type composite inorganic fire retardant and is raw material with super fine magnesium hydroxide (brucite), zinc salt etc., at the coating hydrous zinc oxide film of super fine magnesium hydroxide (brucite) particle surface, the aqua oxidation zinc of preparation high flame retardant efficient coats super fine magnesium hydroxide type composite inorganic fire retardant.
Its processing step is:
(1) super fine magnesium hydroxide (brucite) or aluminium hydroxide powder are dispersed in the water that contains dispersion agents such as Sodium hexametaphosphate 99, make the suspension of stable dispersion;
(2) zinc solution that will prepare in advance, alkaline solution add in the stock suspension and the required pH of control reaction simultaneously;
(3) reaction products resulting is filtered, washing, dry, break up and separate coalescence and carry out surface modification treatment with coupling agent, obtain aqua oxidation zinc clad magnesium hydroxide type or aqua oxidation zinc cladded aluminium hydroxide composite inorganic fire retardant.
Suspension preparation described in the above-mentioned processing step (1), its principal character is: the granularity of aluminium hydroxide and magnesium hydroxide (brucite) powder is d
97≤ 10 μ m; Aluminium hydroxide and magnesium hydroxide concentration are 0.25mol/L~2mol/L; Sodium hexametaphosphate dispersant concentration is 0.05g/L~0.5g/L.
Zinc solution described in the above-mentioned processing step (2) is characterized in that, added zinc salt is a zinc sulfate, and add-on is 2.5%~40% of an aluminium hydroxide powder quality, is mixed with the aqueous solution before the interpolation, and concentration is 0.05~1mol/L; Add-on is 4%~60% of a magnesium hydrate powder quality, is mixed with the aqueous solution before the interpolation, and concentration is 0.05~1mol/L.
Alkaline solution described in the above-mentioned processing step (2) is characterized in that, added alkali is caustic soda, and add-on is 0.7%~10% of an aluminium hydroxide powder quality, is mixed with the aqueous solution before the interpolation, and concentration is 0.05~1mol/L; Add-on is 0.9%~14% of a magnesium hydrate powder quality, is mixed with the aqueous solution before the interpolation, and concentration is 0.05~0.5mol/L.
The pH value that reaction described in the above-mentioned processing step (2) is required is characterized in that, span of control is a magnesium magma: 9.5~12.5; Aluminium hydroxide suspension: 8.5~11.0.
Surface modification described in the above-mentioned processing step (3) is characterized in that, surface-modifying agent is silane coupling agent or aluminate coupling agent, 50~150 ℃ of modification temperatures.
Accompanying drawing 1 is the process flow sheet of the inventive method.
With the composite inorganic fire retardant of the inventive method preparation, its particle diameter d
97≤ 10 μ m, oil absorbency≤0.50ml/g; Be applied to the EVA CABLE MATERIALS, its main performance index: flame retardant rating V-O, smokeless or few cigarette (smoke density≤100); Oxygen index>38; Tensile strength>12MPa; Elongation at break>150%.
Can significantly improve flame retarding efficiency and improve the mechanical property of packing material and can overcome existing ultra-fine brucite flame-retardant agent and use that back material whiteness descends, this deficiency that darkens with the composite inorganic fire retardant of the inventive method preparation, promote with the brucite to be the development of the magnesium hydroxide based flameproofing of main raw material.
Below be embodiments of the invention.
Embodiment 1:
Add 11.6kg super fine magnesium hydroxide (brucite) powder in the 395L tap water and add 421g technical grade Sodium hexametaphosphate 99 ((NaPO
3)
6Content is 95%), high-speed stirring 20min is made into homodisperse suspension, adds small amount of alkali hydraulic control system pH between 10.5~11; With 391 gram technical grade zinc sulfate (ZnSO
47H
2O content is 98%) be dissolved in and be made into 0.1mol/L solution in the tap water, the 111 industrial caustic alkali of gram (NaOH content is 96%) are dissolved in are made into 0.1mol/L solution in the tap water; Same traffic with 1.8L/min adds solution of zinc sulfate and alkaline solution simultaneously in the magnesium magma then.Press filtration washing after reaction is at room temperature finished, the laggard promoting the circulation of qi stream of filtration cakes torrefaction is pulverized, and carries out surface modification with silane coupling agent under 90 ℃ at last and obtains product 1.The main application performance of the key technical indexes of this product and filling EVA CABLE MATERIALS sees Table 1.
Embodiment 2:
Add 46.8kg ultra fine aluminium hydroxide material in the 281L tap water and add 421g technical grade Sodium hexametaphosphate 99 ((NaPO
3)
6Content is 95%), high-speed stirring 20min is made into homodisperse suspension, adds small amount of alkali hydraulic control system pH between 9~9.5; With 1.2kg technical grade zinc sulfate (ZnSO
47H
2O content is 98%) be dissolved in and be made into 0.1mol/L solution in the tap water, 333g industry caustic alkali (NaOH content is 96%) is dissolved in is made into 0.1mol/L solution in the tap water; Then simultaneously in the aluminium hydroxide suspension flow with 4.6L/min add solution of zinc sulfate, with the flow adding alkaline solution of 9.13L/min.Press filtration washing after reaction is at room temperature finished, the laggard promoting the circulation of qi stream of filtration cakes torrefaction is pulverized, and carries out surface modification with silane coupling agent under 90 ℃ at last and obtains product 2.The main application performance of the key technical indexes of this product and filling EVA CABLE MATERIALS sees Table 1.
Embodiment 3:
Add 13.9kg super fine magnesium hydroxide (brucite) powder in the 394L tap water and add 465g technical grade Sodium hexametaphosphate 99 ((NaPO
3)
6Content is 95%), high-speed stirring 20min is made into homodisperse suspension, adds small amount of alkali hydraulic control system pH between 10.5~11; With 469g technical grade zinc sulfate (ZnSO
47H
2O content is 98%) be made into 0.1mol/L solution in the tap water, 133g industry caustic alkali (NaOH content is 96%) is dissolved in is made into 0.1mol/L solution in the tap water; Same traffic with 1.8L/min adds solution of zinc sulfate and alkaline solution simultaneously in the magnesium magma then.Press filtration washing after reaction is at room temperature finished, the laggard promoting the circulation of qi stream of filtration cakes torrefaction is pulverized, and carries out surface modification with aluminate coupling agent under 90 ℃ at last and obtains product 3.The application performance of the key technical indexes of this product and filling EVA CABLE MATERIALS sees Table 1.
Embodiment 4:
Add 37.4kg ultra fine aluminium hydroxide material in the 464L tap water and add 421g technical grade Sodium hexametaphosphate 99 ((NaPO
3)
6Content is 95%), high-speed stirring 20min is made into homodisperse suspension, adds small amount of alkali hydraulic control system pH between 9~9.5; With 939g technical grade zinc sulfate (ZnSO
47H
2O content is 98%) be dissolved in and be made into 0.1mol/L solution in the tap water, 267g industry caustic alkali (NaOH content is 96%) is dissolved in is made into 0.1mol/L solution in the tap water; Then simultaneously in the aluminium hydroxide suspension flow with 4.6L/min add solution of zinc sulfate, with the flow adding alkaline solution of 9.13L/min.Press filtration washing after reaction is at room temperature finished, the laggard promoting the circulation of qi stream of filtration cakes torrefaction is pulverized, and carries out surface modification with aluminate coupling agent under 90 ℃ at last and obtains product 4.The application performance of the key technical indexes of this product and filling EVA CABLE MATERIALS sees Table 1.
Table 1 product is filled the application performance of EVA CABLE MATERIALS
Embodiment |
Particle diameter |
Oil absorbency ml/g |
Oxygen index LOI, % |
Tensile strength MPa |
Elongation at break % |
Embodiment 1 |
d
97≤10μm
|
0.49 |
39.6 |
13.8 |
210 |
Embodiment 2 |
d
97≤10μm
|
0.44 |
39.8 |
13.3 |
240 |
Embodiment 3 |
d
97≤10μm
|
0.46 |
39.3 |
12.8 |
190 |
Embodiment 4 |
d
97≤10μm
|
0.43 |
39.3 |
13.3 |
200 |
Annotate: the plastic formula that product is filled the EVA CABLE MATERIALS is: 140 parts of fire retardants, EVA100 part, respectively 1 part of oxidation inhibitor, compatilizer, lubricant.