Fireproof pigment and preparation method thereof

Abstract

The fireproof pigment is obtained by adsorbing an organic pigment and a flame retardant with modified sepiolite, and is specifically prepared by the following steps: putting an azo pigment into a beaker, adding an ethanol aqueous solution, adding the flame retardant, uniformly stirring and mixing, adjusting the pH value of the solution to 4-9 by adopting a hydrochloric acid aqueous solution or a sodium hydroxide aqueous solution in mass fraction, and stirring uniformly; adding the modified sepiolite, stirring for 2-3 hours at room temperature, performing centrifugal separation, drying, and grinding to obtain the fireproof pigment. The azo pigment and the flame retardant are adsorbed into the modified sepiolite, are not easy to separate out and fade, are good in dispersion, can maintain color for a long time, and maintain good fireproof and flame-retardant properties.

Description

Technical Field

[0001] The invention belongs to the technical field of fine chemical industry, and in particular relates to a fire retardant pigment and a preparation method thereof. Background Art

[0002] Organic pigments are colored, fine-grained powdered organic compounds that are widely used in inks, paints, synthetic fiber pulp coloring, fabric coating printing, plastics, rubber, leather coloring, etc., and their output accounts for about a quarter of the total output of dyes. Among them, azo pigments are insoluble organic compounds containing azo groups in their molecular structure. They have bright colors and strong coloring power. Although azo pigments have good heat resistance, they are not flame retardant. Simply mixing azo pigments with flame retardants will result in uneven mixing and easy discoloration.

[0003] Composite pigments are composed of organic dyes or pigments and inorganic materials. The use of inorganic materials can more effectively improve the weather resistance, temperature resistance and dispersibility of organic dyes or pigments. Sepiolite belongs to the orthorhombic or monorhombic crystal system, with a variety of colors, generally light white or grayish white, with a silky luster, sometimes a waxy luster; the streak is white and opaque. Sepiolite has extremely strong adsorption, decolorization and dispersion properties, and also has extremely high thermal stability. It can withstand high temperatures of up to 1500-1700℃, and has very good modeling, insulation and salinity resistance. Using it in pigments can improve the high temperature resistance of the pigment. Summary of the invention

[0004] The object of the present invention is to provide a fire retardant pigment and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] The invention discloses a fireproof pigment, which is obtained by adsorbing an organic pigment and a flame retardant on modified sepiolite.

[0007] Furthermore, the organic pigment is an azo pigment, and the azo pigment includes Pigment Yellow 93, Pigment Yellow 95, Pigment Red 166, Pigment Red 214, and Pigment Red 242.

[0008] Furthermore, the preparation method of the modified sepiolite is as follows: 15-17g of sepiolite is weighed, ground and placed in a reactor, then 180-200ml of a 10-15% by mass hydrochloric acid aqueous solution is placed, stirred at room temperature for 12-15h, heavy metals and other impurities are removed, filtered, washed and dried, the dried sepiolite is placed in a muffle furnace for calcination for 3-4h, taken out and naturally cooled to room temperature, and the modified sepiolite is obtained.

[0009] Furthermore, the calcination temperature is 600-700°C.

[0010] Furthermore, the preparation method of the flame retardant is: weigh 7.0-7.5g DOPO, 2.5-2.6g trivinyltrimethylcyclotrisilazane, and 1.2-1.4g azobisisobutyronitrile and add them to a reaction bottle, introduce nitrogen to replace the air in the reactor, add 100-130ml solvent toluene under a nitrogen environment, continue to introduce nitrogen for 3-5 minutes, then heat to react, and after the reaction is completed, naturally cool to room temperature, rotary evaporate to remove the solvent, add anhydrous ether to the crude product for washing, and the solid finally obtained is the flame retardant.

[0011] Furthermore, the heating reaction temperature is 75-85°C and the reaction time is 8-10h.

[0012] A method for preparing a fire-retardant pigment comprises the following steps: weighing 10-15 mg of an azo pigment into a beaker, adding an ethanol aqueous solution with a mass fraction of 40-45%, adding 5-8 mg of a flame retardant, stirring and mixing evenly, using a hydrochloric acid aqueous solution with a mass fraction of 10% or a sodium hydroxide aqueous solution with a mass fraction of 10%, adjusting the pH value of the solution to 4-9, then adding 0.3-0.35 g of modified sepiolite, stirring at room temperature for 2-3 hours, then centrifugally separating, drying, and grinding to obtain the fire-retardant pigment.

[0013] Furthermore, the average particle size of the fire retardant pigment is 21.25um-23.37um.

[0014] Beneficial effects of the present invention:

[0015] The invention provides a fireproof pigment, which is obtained by adsorbing an organic pigment and a flame retardant on a modified sepiolite. The sepiolite is treated with hydrochloric acid to filter out metal ions from the sepiolite to form micropores, thereby increasing the void volume and the specific surface area, so that the sepiolite has a better adsorption effect. In order to improve the high temperature resistance and flame retardant properties, it is found that DOPO and trivinyltrimethylcyclotrisilazane undergo an addition reaction to obtain a flame retardant. During combustion, P can cover the surface of an object to form protection, and N element can generate nitric oxide or nitrogen dioxide to block the air and prevent further combustion. In addition, the flame retardant contains silicon element, which further improves the high temperature resistance of the fireproof pigment.

[0016] Azo pigments and flame retardants are adsorbed into modified sepiolite, which makes them difficult to precipitate and fade, and are well dispersed. They can maintain color for a long time and have good fire retardant properties.

[0017] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0019] Figure 1 A is the SEM image of modified sepiolite; B is the SEM image of fire retardant pigment. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Example 1

[0022] The preparation method of the flame retardant is as follows: 7.1g DOPO, 2.55g trivinyltrimethylcyclotrisilazane, and 1.25g azobisisobutyronitrile are weighed and added to a reaction bottle, nitrogen is introduced to replace the air in the reactor, 110ml of solvent toluene is added under a nitrogen environment, nitrogen is continued to be introduced for 5 minutes, and then heated to 75°C and kept warm for 8 hours. After the reaction is completed, it is naturally cooled to room temperature, the solvent is removed by rotary evaporation, anhydrous ether is added to the crude product for washing, and the solid obtained at last is the flame retardant. The structural test results of the flame retardant are as follows: 1 H NMR (500 MHz, CDCl 3 )δ:7.96(d,J=7.2Hz,6H),7.63(d,J=8.0Hz,6H),7.39-7.53(m,J=8.0,4.5Hz,12H),3.52(s,3H),1.84(t,6H),1.26(t,6H),0.84(s,9H); HRMS ca l cd for C 45 H 48 N 3 O 6 P 3 Si 6 [M+H] + 903.2106,found903.5126.

[0023]

[0024] Example 2

[0025] Preparation of modified sepiolite

[0026] Weigh 15g of sepiolite, grind it and put it into a reactor, then put it into 200ml of 15% hydrochloric acid aqueous solution, stir it overnight (12-15h) at room temperature to remove impurities such as heavy metals, filter it, wash it with water and then dry it, put the dried sepiolite into a muffle furnace, calcine it at a temperature of 600℃ for 3h, take it out and cool it naturally to room temperature, and then obtain the modified sepiolite; the sepiolite treated with hydrochloric acid can filter out metal ions from the sepiolite to form micropores, increase the void volume, increase the specific surface area, and make it have better adsorption effect; Figure 1 A in the figure is a SEM image of modified sepiolite. The surface of the sepiolite crystal is smooth and the sepiolite fiber is in a straight line shape.

[0027] Example 3

[0028] The preparation of fire retardant pigment specifically comprises the following steps:

[0029] Weigh 12 mg of azo pigment into a beaker, add 40% ethanol aqueous solution by mass, add 6 mg of flame retardant, stir and mix evenly, use 10% hydrochloric acid aqueous solution by mass or 10% sodium hydroxide aqueous solution by mass to adjust the solution pH to 4-9, then add 0.32 g of modified sepiolite, stir at room temperature for 2 hours, then centrifuge, dry and grind to obtain a fire-retardant pigment with an average particle size of 21.25 um-23.37 um; perform a vertical combustion test on the prepared fire-retardant pigment: V-0 grade (UL94 grade).

[0030] like Figure 1 Figure B is the SEM image of the fire-retardant pigment. The surface becomes rough due to the adsorption of pigment and flame retardant.

[0031] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A fire retardant pigment, characterized in that: The fireproof pigment is obtained by adsorbing organic pigment and flame retardant on modified sepiolite.

2. A fire retardant pigment according to claim 1, characterized in that: The organic pigment is an azo pigment, and the azo pigment includes pigment yellow 93, pigment yellow 95, pigment red 166, pigment red 214, and pigment red 242.

3. A fire retardant pigment according to claim 1, characterized in that: The preparation method of the modified sepiolite is as follows: 15-17g of sepiolite is weighed, ground and placed in a reactor, then 180-200ml of a 10-15% by mass hydrochloric acid aqueous solution is placed, stirred at room temperature for 12-15h, heavy metals and other impurities are removed, filtered, washed and dried, the dried sepiolite is placed in a muffle furnace for calcination for 3-4h, taken out and naturally cooled to room temperature, and the modified sepiolite is obtained.

4. A fire retardant pigment according to claim 3, characterized in that: The calcination temperature is 600-700°C.

5. A fire retardant pigment according to claim 1, characterized in that: The preparation method of the flame retardant is as follows: 7.0-7.5g DOPO, 2.5-2.6g trivinyltrimethylcyclotrisilazane and 1.2-1.4g azobisisobutyronitrile are weighed and added into a reaction bottle, nitrogen is introduced to replace the air in the reactor, 100-130ml of solvent toluene is added under a nitrogen environment, nitrogen is continuously introduced for 3-5min, and then heating is performed for reaction. After the reaction is completed, the mixture is naturally cooled to room temperature, the solvent is removed by rotary evaporation, anhydrous ether is added to the crude product for washing, and the solid obtained is the flame retardant.

6. A fire retardant pigment according to claim 5, characterized in that: The heating reaction temperature is 75-85°C and the reaction time is 8-10h.

7. A method for preparing a fire retardant pigment as claimed in claims 1 to 6, characterized in that: Specifically, 10-15 mg of azo pigment is weighed into a beaker, and an ethanol aqueous solution with a mass fraction of 40-45% is added, and 5-8 mg of a flame retardant is added, and the mixture is stirred and evenly mixed, and a hydrochloric acid aqueous solution with a mass fraction of 10% or a sodium hydroxide aqueous solution with a mass fraction of 10% is used to adjust the pH value of the solution to 4-9, and then 0.3-0.35 g of modified sepiolite is added, and the mixture is stirred at room temperature for 2-3 hours, and then centrifuged, dried, and ground to obtain the fire-retardant pigment.

8. The method for preparing a fire retardant pigment according to claim 7, characterized in that: The average particle size of the fire retardant pigment is 21.25um-23.37um.

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