Inorganic flame retardant particles and method for manufacturing same

Abstract

The present invention enables the simple and economical manufacture of a flame retardant that has a higher thermal decomposition temperature than simple aluminum hydroxide and magnesium hydroxide, which are mainly used as construction flame retardants, and exhibits superior flame retardancy, thus having great industrial applicability.

Description

Inorganic flame retardant particles and their manufacturing method

[0001] The present invention relates to an inorganic composite flame retardant capable of significantly improving flame retardancy.

[0002] Flame retardants, which are substances added to or applied to organic materials such as plastics that are prone to ignition to suppress or mitigate combustion, contain lethal toxicity to the human body and generate a lot of harmful gases when a fire occurs, raising many safety concerns.

[0003] Furthermore, most chemicals used as flame retardants have been confirmed to have direct or indirect effects, including hormone imbalance and disruption, brain damage, liver damage, and cancer. In Korea, flame retardants containing hazardous substances like chlorine and bromine are widely used. Brominated flame retardants are known to cause cancer and disrupt hormones.

[0004] In order to fundamentally resolve these shortcomings, there has been a need to develop a new type of non-toxic flame retardant that is harmless to the human body, matches the decomposition temperature of various plastics, has excellent flame retardancy, does not generate toxic gases, and has the effect of suppressing smoke generation.

[0005] The purpose of the present invention is to provide a method for manufacturing an inorganic composite flame retardant that can significantly improve flame retardancy by applying it to construction materials requiring flame retardancy as well as polymer materials, artificial leather, textile materials, electronic components, and various plastic products.

[0006] In addition, the present invention aims to provide a method for producing a ceramic composite flame retardant that can significantly improve the flame retardancy of general inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide.

[0007] In addition, another object of the present invention is to provide construction materials, polymer materials, artificial leather, textile materials, electronic components, and various plastics that have excellent flame retardancy by being processed with the flame retardant.

[0008] The present invention comprises the steps of: crushing dolomite [CaMg(CO3)2] particles having a whiteness of 60 or more, a purity of Mg(OH)2·Ca(OH)2 of 90% or more, and an average particle size of 5 to 8 mm;

[0009] A step of hydrating the above-mentioned crushed dolomite [CaMg(CO3)2] particles with alkali through an AAR (Alkari Aggreate Reaction) reaction;

[0010] Step of hydrophobicizing the surface of the complex by adding a surface treatment agent to the aqueous dispersion of the complex of calcium hydroxide and magnesium hydroxide, which has completed the above hydration:

[0011] A step of recovering a composite through a filter from an aqueous dispersion of a hydrophobic surface-treated composite: and

[0012] a step of drying the above complex; comprising;

[0013] A method for manufacturing inorganic flame retardant particles having a whiteness of 60 or higher, an average particle diameter of 0.2 to 3 ㎛, a specific surface area of ​​1 to 20 m2 / g, and a Mg(OH)2·Ca(OH)2 purity of 90% or higher is provided.

[0014] In the above hydration step, the pH is adjusted to 8 to 12 and hydration is carried out by stirring at a temperature of 45 to 55°C for 3 to 4 hours.

[0015] The complex synthesized by the above manufacturing method is characterized by having a molar ratio of Ca(OH)2: Mg(OH)2= 1:0.9 to 1.1:1.

[0016] In addition, the particles of the present invention are characterized in that they have a hydrophobicity of a contact angle of 90 degrees or more by treating the surface of an inorganic flame retardant with a hydrophobic agent such as a fatty acid and a silane compound, and the silane compound contains at least one functional group selected from the group consisting of vinyl, epoxy, styryl, methacryloxy, acryloxy, amino, ureide, mercapto, and isocyanate, and are characterized in that they are hydrolyzed for 1 to 3 hours using water or a solvent having a hydroxyl group before being treated on a ceramic.

[0017] The inorganic flame retardant particles manufactured by the manufacturing method of the present invention are characterized by having a whiteness of 60 or more, an average particle diameter of 0.2 to 3 ㎛, a specific surface area of ​​1 to 20 m2 / g, and a Mg(OH)2·Ca(OH)2 purity of 90% or more.

[0018] According to the manufacturing method of the present invention utilizing dolomite, an inorganic composite flame retardant with excellent flame retardancy can be manufactured by accelerating flame retardancy properties through complexation of magnesium and carbon, thereby maximizing the synergistic effect.

[0019] Furthermore, inorganic composite flame retardants can be manufactured with high productivity through an environmentally friendly and streamlined manufacturing process. This allows the production of inorganic flame retardants with reduced toxicity while improving commercial viability, flame retardancy, and economic feasibility.

[0020] Figure 1 is a TEM photograph of the flame retardant particles of the present invention.

[0021] Figure 2 is TG-DTA of Mg(OH)2,

[0022] Figure 3 is TG-DTA of Ca(OH)2,

[0023] Figure 4 is TG-DTA of CaMg(OH)2.

[0024] Figure 5 is an inorganic flame retardant manufactured from dolomite through AAR.

[0025] The present invention relates to a method for producing a ceramic composite flame retardant capable of improving flame retardancy and physical properties using a 5-8 mm dolomite [CaMg(CO3)2] raw material, and to a ceramic flame retardant composition produced thereby.

[0026] The manufacturing method of the present invention is described below.

[0027] 1. Dolomite crushing

[0028] To manufacture a ceramic composite flame retardant, dolomite [CaMg{CO3}2] particles having a whiteness of 60 or higher, a purity of 90% or higher, and an average particle size of 5 to 8 mm, obtained from Sambo Mining, are crushed using a jaw crusher ceramic crusher.

[0029]

[0030] 2. Firing

[0031] Dolomite particles crushed using a jaw crusher are placed in a general heat treatment electric furnace and heat treated at 1000℃ or higher for 4 hours to produce light dolomite.

[0032]

[0033] 3. Sign language

[0034] The dolomite powder obtained after the above heat treatment is hydrated using pure water.

[0035] To ensure the hydration rates of CaO and MgO are the same, the temperature of the hydration water is adjusted to between 45 and 55°C and stirred for 3 to 4 hours.

[0036]

[0037] 4. Hydration without calcination process

[0038] The dolomite powder obtained by the above crushing is hydrated by adding caustic soda using pure water to adjust the pH to 8 to 12.

[0039] To ensure the hydration rates of Ca and Mg in dolomite are the same, the temperature of the hydration water is adjusted to between 45 and 55°C and stirred for 3 to 4 hours.

[0040]

[0041] 5. Surface treatment

[0042] The nano-inorganic ceramic flame retardant prepared according to the above process can be surface-treated with a silane compound as needed.

[0043] The ceramic flame retardant surface is in a hydrated form with -OH, and by using a silane compound having organic functional groups as a coupling agent, the ceramic surface can be surface-treated with a silane having a desired functional group. It is preferable to select the silane compound that has excellent compatibility with the ceramic composite flame retardant, and may include, for example, at least one functional group selected from the group consisting of vinyl, epoxy, styryl, methacryloxy, acryloxy, amino, ureide, mercapto, and isocyanate, but is not limited thereto. It is preferable to select an amino silane compound among the silane compounds.

[0044] The silane coupling agent can be hydrolyzed before being applied to the ceramic. The hydrolysis can be performed using water or a solvent containing a hydroxyl group, preferably alcohol or ethanol for stability. The hydrolysis time is preferably at least 1 hour, and preferably 1 to 3 hours.

[0045] The above surface treatment can be performed using either a dry or wet method. Preferably, the wet method is used to enhance process efficiency. Surface treatment can be performed using both dry and wet methods, with 0.5-10 wt% of the powder (filler) added.

[0046]

[0047] 6. Drying

[0048] The wet-surface-treated inorganic flame retardant can be recovered as a cake through a filter and dried at 90°C for 24 hours to obtain the final inorganic flame retardant. Furthermore, to simplify the process, the surface treatment can be performed through a dry process.

[0049]

[0050] 7. Flame retardant properties

[0051] As can be seen from the TG-DTA results, hydrated dolomite exhibits excellent flame retardancy due to the release of moisture due to thermal decomposition of the compound twice, at around 323°C and around 421.5°C, depending on the temperature of the combustible.

[0052]

[0053] Example 1; Synthesis of hydrated dolomite particles and hydrophobic coating

[0054] (1) Load dolomite [CaMg(CO3)2] to about 80% of alumina Saggar and fire at 3℃ / min for 1000℃*2hr.

[0055] (2) 100 g of the fine dolomite obtained in (1) is slowly added to 500 g of ultrapure water (H2O) and stirred at approximately 50°C for 4 hours to hydrate.

[0056] (3) The obtained dolomite hydroxide (Ca(OH)2·Mg(OH)2) is then surface treated by hydrolyzing a silane coupling agent.

[0057] (4) The obtained coating hydrate is filtered and the obtained cake is placed in a convection dryer and dried at 90°C for 24 hours.

[0058] (5) After drying, dolomite hydroxide was obtained.

[0059] (6) (5) TG-DTA, XRD, and SEM analyses of the hydrated dolomite obtained in the process were performed, and in particular, an inorganic composite flame retardant that released water at around 300℃ and 400℃ during thermal analysis was synthesized.

[0060]

[0061] Example 2: Synthesis of hydrated dolomite particles and hydrophobic coating

[0062] (1) Slowly add crushed dolomite [CaMg(CO3)2] to ultrapure water (H2O), add caustic soda, adjust the pH to 11, and stir for 4 hours.

[0063] (2) The obtained dolomite hydroxide (Ca(OH)2·Mg(OH)2) is then surface treated by hydrolyzing a silane coupling agent.

[0064] (3) The obtained coating hydrate is filtered and the obtained cake is placed in a convection dryer and dried at 90°C for 24 hours.

[0065] (4) After drying, dolomite hydroxide was obtained.

[0066] (5) (4) TG-DTA, XRD, and SEM analyses of the hydrated dolomite obtained in the process were performed, and in particular, an inorganic composite flame retardant that released water at around 300℃ and 400℃ during thermal analysis was synthesized.

Claims

1. A step of crushing dolomite [CaMg(CO3)2] particles having a whiteness of 60 or higher, a Mg(OH)2·Ca(OH)2 purity of 90% or higher, and an average particle size of 5 to 8 mm; A step of hydrating the above-mentioned crushed dolomite [CaMg(CO3)2] particles with alkali through an AAR (Alkari Aggreate Reaction) reaction; Step of hydrophobicizing the surface of the complex by adding a surface treatment agent to the aqueous dispersion of the complex of calcium hydroxide and magnesium hydroxide, which has completed the above hydration: A step of recovering a composite through a filter from an aqueous dispersion of a hydrophobic surface-treated composite: and a step of drying the above complex; comprising; A method for manufacturing Mg(OH)2·Ca(OH)2 inorganic flame retardant particles having a whiteness of 60 or higher, an average particle diameter of 0.2 to 3 ㎛, a specific surface area of ​​1 to 20 m2 / g, and a purity of 90% or higher.

2. In paragraph 1, A method for manufacturing inorganic flame retardant particles, characterized in that the pH is adjusted to 8 to 12 and the particles are hydrated by stirring at a temperature of 45 to 55°C for 3 to 4 hours.

3. In paragraph 1, A method for producing inorganic flame retardant particles, characterized in that the above-mentioned synthesized complex has a molar ratio of Ca(OH)2: Mg(OH)2= 1:0.9 to 1.1:

1.

4. In paragraph 1, A method for producing inorganic flame retardant particles characterized by having a hydrophobicity of a contact angle of 90 degrees or more by treating the surface of the inorganic flame retardant with a hydrophobic agent such as a fatty acid or a silane compound.

5. In paragraph 1, A method for producing inorganic flame retardant particles, characterized in that the silane compound contains at least one functional group selected from the group consisting of vinyl, epoxy, styryl, methacryloxy, acryloxy, amino, ureide, mercapto, and isocyanate, and is hydrolyzed for 1 to 3 hours using water or a solvent having a hydroxyl group before being treated on a ceramic.

6. Mg(OH)2·Ca(OH)2 inorganic flame retardant particles with a whiteness of 60 or higher, an average particle size of 0.2 to 3 ㎛, a specific surface area of ​​1 to 20 m2 / g, and a purity of 90% or higher.

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