Organosilicon coloring agent for rail transit and preparation method thereof

Abstract

The invention discloses an organosilicon coloring agent for rail transit and a preparation method thereof, and belongs to the technical field of fine chemical engineering, the organosilicon coloring agent for rail transit comprises the following raw materials by weight: 45-55 parts of a modified inorganic pigment, 30-45 parts of silicone oil, and 3-8 parts of a dispersant; the modified inorganic pigment is obtained by the following modification method: ultrasonically dispersing an inorganic pigment in water, then adding sepiolite powder, ultrasonically dispersing for 50-60 minutes at the temperature of 40-50 DEG C, then adding an amino silane coupling agent, ultrasonically dispersing to form a suspension, reacting for 0.5-1.5 hours at the temperature of 70-100 DEG C, filtering, washing and drying to obtain the modified inorganic pigment. After the reaction is completed, centrifuging, washing, drying, grinding and sieving with a 200-mesh sieve to obtain the modified inorganic pigment. The technical effect that the coloring property is poor due to the fact that the inorganic pigment is easy to form aggregates is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of fine chemicals, and in particular to an organosilicon colorant for rail transportation and a preparation method thereof. Background Art

[0002] Silicone compounds and the silicone materials made from them have unique functions and have been widely used in defense, industry, agriculture, medical and health, rail transit and other industries, and have shown irreplaceable advantages. In the field of rail transit, silicone coatings for vehicle painting and road marking materials require silicone rubber to be colored, and the selection of appropriate colorants is the key to improving the appearance and overall quality of silicone products.

[0003] Pigments of various colors decorate the colorful world and are also indispensable in the field of rail transportation. There are two types of colorants used in silicone rubber: inorganic pigments and organic pigments. Organic pigment colorants have bright colors, strong coloring ability, and are non-toxic. However, organic pigments are less resistant to migration, heat, and light than inorganic pigments. Therefore, inorganic pigments have better thermal stability and weather resistance than organic pigments, and they play an important role in the coloring of silicone rubber. However, the compatibility between inorganic pigments and resins is poor, resulting in poor dispersion of inorganic pigments in resins, which causes the problem of reduced coloring ability of inorganic pigments during application. Summary of the invention

[0004] In order to solve the problem that inorganic pigments easily form agglomerates and thus lead to poor coloring performance, the present invention provides an organosilicon colorant for rail transit and a preparation method thereof.

[0005] The first aspect of the present invention is to provide a silicone colorant for rail transit, which adopts the following technical solution:

[0006] A silicone colorant for rail transit, the silicone colorant comprises the following raw materials in parts by weight: 45-55 parts of modified inorganic pigment, 30-45 parts of silicone oil, and 3-8 parts of dispersant; the modified inorganic pigment is obtained by the following modification method: ultrasonically dispersing the inorganic pigment in water, then adding sepiolite powder and ultrasonically dispersing it at a temperature of 45±5°C for 50-60 minutes, then adding an aminosilane coupling agent and ultrasonically dispersing it to form a suspension, reacting it at a temperature of 70-100°C for 0.5-1.5 hours, and after the reaction is completed, centrifuging, washing, drying, grinding and passing through a 200-mesh sieve to obtain the modified inorganic pigment.

[0007] By adopting the above technical scheme, after the inorganic pigment is improved by sepiolite powder and aminosilane coupling agent, the compatibility between the inorganic pigment and silicone oil can be effectively improved. After the organic silicon colorant obtained in the present application is applied to the organic silicon resin, the organic silicon colorant can be evenly dispersed in the organic silicon resin. The reason may be that after the inorganic pigment and sepiolite powder are first dispersed by ultrasonic, the porous structure of the sepiolite powder provides a good attachment base for the dispersion of the inorganic pigment, so that the inorganic pigment is adsorbed on the surface of the sepiolite powder under the action of electrostatic adsorption and hydrogen bonding, thereby improving The dispersibility of inorganic pigments is improved. Then, the adsorbed sepiolite powder reacts with the aminosilane coupling agent at high temperature. The reactive groups in the aminosilane coupling agent are hydrolyzed to generate some silanol groups that react with the active hydroxyl groups on the surface of sepiolite to form a condensation and dehydration reaction. It can be seen that the aminosilane coupling agent reacts with the active groups on the surface of sepiolite powder to form a stable chemical bond. This chemical bond not only helps to enhance the interfacial bonding between sepiolite powder and the aminosilane coupling agent, but also improves the compatibility between sepiolite powder and silicone oil, providing strong support for the dispersion and stability of inorganic pigment particles. Therefore, a stable composite system is formed between sepiolite powder, amino coupling agent and inorganic pigment particles, and the presence of the aminosilane coupling agent effectively reduces the separation between inorganic pigments and sepiolite powder, and improves the storage stability of silicone colorants.

[0008] In a preferred embodiment, the weight ratio of the inorganic pigment to the sepiolite powder and the aminosilane coupling agent is 1:(0.4-0.7):(0.05-0.2).

[0009] In a preferred embodiment, the aminosilane coupling agent is one of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

[0010] In a preferred embodiment, the sepiolite powder is obtained by the following modification method: the sepiolite powder is added to hydrochloric acid with a concentration of 1.8-3.2 mol / L and stirred for 5-6 hours, then washed with water until neutral and with a chloride ion content of less than 0.001%, centrifuged and dried at 80-90°C, and crushed through a 200 mesh sieve to obtain modified sepiolite powder, wherein the material-liquid ratio of the sepiolite powder to the hydrochloric acid is 1 g: (7-10) mL.

[0011] By adopting the above technical scheme, after the sepiolite powder is acid-modified, the multi-component carbonate impurities in the sepiolite pores will be removed, so that the pores in the sepiolite can be unblocked and the structural units can be connected with each other, so that there are more reactive sites in the sepiolite, which is conducive to the adsorption of inorganic pigments and sepiolite and improves the dispersion efficiency of inorganic pigments; in the process of acid-modification of sepiolite powder, if the acid concentration is too high, the structure of the sepiolite will be destroyed; if the acid concentration is too low, the acid radical ions will react with the magnesium ions in the sepiolite to form precipitates, which will block the pores and affect the efficient utilization of the sepiolite. Therefore, in the present application, the concentration of hydrochloric acid is 1.8-3.2 mol / L, which ensures the efficient adsorption of inorganic pigments in the modified sepiolite powder.

[0012] In a preferred embodiment, the silicone oil is obtained by the following modification method: silicone oil and water are mixed in a weight ratio of 1:2, and then a composite emulsifier of 35% by weight of the silicone oil is added to react at a temperature of 45±5°C for 40±5 minutes, and then the pH of the emulsion is adjusted to 6.5 to obtain the modified silicone oil, wherein the composite emulsifier is composed of Tween 80 and AEO-9 in a weight ratio of 0.5:0.4.

[0013] By adopting the above technical solution, after the silicone oil is modified by the composite emulsifier, its compatibility with the sepiolite powder can be increased, so that the dispersibility of the colorant is improved and the coloring ability is improved.

[0014] In a preferred embodiment, the dispersant is composed of a polymer dispersant and a styrene-maleic anhydride copolymer in a weight ratio of 1:(0.8-1.6).

[0015] By adopting the above technical scheme, when the dispersant is composed of a polymer dispersant and a styrene-maleic anhydride copolymer in synergistic combination, the dispersibility and stability of the inorganic pigment in the silicone resin can be significantly improved. The reason is that the sepiolite powder will have a certain adsorption effect on the styrene-maleic anhydride copolymer, so that its molecular chains form an orderly arrangement on the surface of the sepiolite powder. This orderly arrangement structure improves the thermal stability of the silicone colorant, so that the final silicone colorant has a certain heat resistance, and the effect of the surface aminosilane further improves the adhesion stability of the inorganic pigment on the surface of the sepiolite. The anchoring group contained in the polymer dispersant can provide a steric hindrance effect on the surface of the sepiolite powder, reducing the possibility of aggregation between the sepiolite powders. The silicon-containing group of the polymer dispersant also further improves the dispersibility of the sepiolite powder in the silicone oil.

[0016] In a preferred embodiment, the styrene-maleic anhydride copolymer is obtained by the following modification method: under the protection of a nitrogen atmosphere, toluene, a catalyst, a styrene-maleic anhydride copolymer and isobutyl alcohol are mixed, and the mixture is reacted at a constant temperature of 80±5° C. for 5-6 hours. After the reaction is completed, the product is rotary evaporated to remove toluene, and then precipitated in petroleum ether to obtain a precipitate, and the precipitate is vacuum dried at 30° C. to obtain a modified styrene-maleic anhydride copolymer, wherein the mass ratio of the styrene-maleic anhydride copolymer to isobutyl alcohol is 1:(2-2.5).

[0017] By adopting the above technical scheme, the thermal stability of the silicone colorant can be improved after the styrene-maleic anhydride copolymer is esterified with isobutyl alcohol. The reason may be that after the esterification reaction of the styrene-maleic anhydride copolymer, an ester group is introduced into the copolymer molecular chain, which improves the compatibility with the polymer dispersant and achieves a better synergistic dispersion effect. On the other hand, the ester group is combined with the polar group on the surface of the inorganic pigment through the action of hydrogen bonds, and based on the adsorption effect of sepiolite, the styrene-maleic anhydride copolymer is strengthened to wrap the modified pigment to form a protective layer, thereby blocking harmful factors such as oxygen and moisture in a high temperature environment from direct contact with the inorganic pigment, thereby slowing down the thermal oxidation or hydrolysis process of the inorganic pigment and improving the thermal stability of the silicone colorant.

[0018] In a preferred embodiment, the catalyst is p-toluenesulfonic acid.

[0019] In a preferred embodiment, the polymer dispersant is obtained by the following preparation method: isooctyl acrylate, toluene, and azobisisobutyronitrile are mixed, stirred and heated to 85±2°C, and then a mixed monomer solution of methyl methacrylate and vinyltrimethoxysilane is added dropwise. After the addition is complete, azobisisobutyronitrile is added, and the temperature is maintained at 85±2°C for 5-6 hours, followed by precipitation with methanol, and the precipitate is vacuum dried to obtain a polymer dispersant, wherein the weight ratio of isooctyl acrylate, methyl methacrylate, and vinyltrimethoxysilane is 2:1:1.

[0020] By adopting the above technical scheme, when the monomers are selected as isooctyl acrylate, methyl methacrylate and vinyltrimethoxysilane and are composed in a weight ratio of 2:1:1, the polymer dispersant can be effectively grafted on the surface of the sepiolite powder to achieve effective encapsulation of the sepiolite powder, thereby preventing the mutual attraction between the particles, achieving effective dispersion of the sepiolite powder in the silicone oil, and maintaining the stable dispersion state of the sepiolite powder particles.

[0021] The second aspect of the present invention is to provide a method for preparing an organosilicon colorant for rail transit, comprising the following steps:

[0022] S1. Adding modified inorganic pigment and dispersant into silicone oil and stirring and mixing;

[0023] S2. Grind the mixture obtained in step S1 at a temperature of 50-60° C. for 20-30 min to obtain an organosilicon colorant for rail transit.

[0024] In summary, the present invention has the following beneficial effects:

[0025] 1. After the aminosilane coupling agent is used to modify the sepiolite powder adsorbed with inorganic pigments, the dispersion stability of the inorganic pigments is improved, thereby improving the color ability of the silicone colorant. Furthermore, the chemical bond between the aminosilane coupling agent and the sepiolite powder helps to evenly disperse the sepiolite powder in the silicone oil, thereby effectively improving the heat resistance and insulation properties of the silicone colorant.

[0026] 2. The synergistic combination of the polymer dispersant prepared in a specific manner and the modified styrene-maleic anhydride copolymer promotes the uniform dispersion of the inorganic pigment in the silicone resin. At the same time, the anhydride groups in the styrene-maleic anhydride copolymer react chemically with the surface of the modified inorganic pigment and the sepiolite powder to form a stable chemical bond, which further enhances the dispersion stability of the inorganic pigment particles. In addition, the combination of styrene-maleic anhydride copolymer and sepiolite powder makes the silicone colorant have good heat resistance. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the embodiments.

[0028] The raw materials used in this application are all commercially available.

[0029] A silicone colorant for rail transit, the silicone colorant comprises the following raw materials in parts by weight: 45-55 parts of modified inorganic pigment, 30-45 parts of silicone oil, and 3-8 parts of dispersant; the modified inorganic pigment is obtained by the following modification method: ultrasonically dispersing the inorganic pigment in water, then adding sepiolite powder and ultrasonically dispersing it at a temperature of 45±5°C for 50-60 minutes, then adding an aminosilane coupling agent and ultrasonically dispersing it to form a suspension, reacting it at a temperature of 70-100°C for 0.5-1.5 hours, and after the reaction is completed, centrifuging, washing, drying, grinding and passing through a 200-mesh sieve to obtain the modified inorganic pigment.

[0030] In a preferred embodiment, the weight ratio of the inorganic pigment to the sepiolite powder and the aminosilane coupling agent is 1:(0.4-0.7):(0.05-0.2).

[0031] In a preferred embodiment, the aminosilane coupling agent is one of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

[0032] In a preferred embodiment, the sepiolite powder is obtained by the following modification method: the sepiolite powder is added to hydrochloric acid with a concentration of 1.8-3.2 mol / L and stirred for 5-6 hours, then washed with water until it is neutral and the chloride ion content is less than 0.001%, dried at 80-90°C after centrifugal separation, and crushed through a 200 mesh sieve to obtain modified sepiolite powder.

[0033] In a preferred embodiment, the material-liquid ratio of sepiolite powder to hydrochloric acid is 1 g: (7-10) mL.

[0034] In a preferred embodiment, the silicone oil is obtained by the following modification method: silicone oil and water are mixed in a weight ratio of 1:2, and then a composite emulsifier of 35% by weight of the silicone oil is added to react at a temperature of 45±5°C for 40±5 minutes, and then the pH of the emulsion is adjusted to 6.5 to obtain the modified silicone oil, wherein the composite emulsifier is composed of Tween 80 and AEO-9 in a weight ratio of 0.5:0.4.

[0035] In a preferred embodiment, the dispersant is composed of a polymer dispersant and a styrene-maleic anhydride copolymer in a weight ratio of 1:(0.8-1.6).

[0036] In a preferred embodiment, the styrene-maleic anhydride copolymer is obtained by the following modification method: under the protection of a nitrogen atmosphere, toluene, a catalyst, a styrene-maleic anhydride copolymer, and isobutyl alcohol are mixed, and the mixture is reacted at a constant temperature of 80±5° C. for 5-6 hours. After the reaction, the product is rotary evaporated to remove toluene, and then precipitated in petroleum ether to obtain a precipitate, and the precipitate is vacuum dried at 30° C. to obtain a modified styrene-maleic anhydride copolymer, wherein the mass ratio of the styrene-maleic anhydride copolymer to isobutyl alcohol is 1:(2-2.5).

[0037] In a preferred embodiment, p-toluenesulfonic acid is used as the catalyst.

[0038] In a preferred embodiment, the polymer dispersant is obtained by the following preparation method: isooctyl acrylate, toluene, and azobisisobutyronitrile are mixed, stirred and heated to 85±2°C, and then a mixed monomer solution of methyl methacrylate and vinyltrimethoxysilane is added dropwise. After the addition is complete, azobisisobutyronitrile is added, and the temperature is maintained at 85±2°C for 5-6 hours, followed by precipitation with methanol, and the precipitate is vacuum dried to obtain a polymer dispersant, wherein the weight ratio of isooctyl acrylate, methyl methacrylate, and vinyltrimethoxysilane is 2:1:1.

[0039] A method for preparing an organosilicon colorant for rail transit comprises the following steps:

[0040] S1. Adding modified inorganic pigment and dispersant into silicone oil and stirring and mixing;

[0041] S2. Grind the mixture obtained in step S1 at a temperature of 50-60° C. for 20-30 min to obtain an organosilicon colorant for rail transit.

[0042] The inorganic pigments in the following preparation examples and embodiments of the present application are described by taking iron oxide yellow as an example. The styrene-maleic anhydride copolymers in the preparation examples and embodiments of the present application are all purchased from Guangzhou Shanshan New Materials SMA125.

[0043] Preparation Example 1.1

[0044] A modified inorganic pigment modification method comprises the following steps: ultrasonically dispersing the inorganic pigment in water for 20 minutes, then adding sepiolite powder and ultrasonically dispersing it at a temperature of 40°C for 50 minutes, adding 3-aminopropyltrimethoxysilane and ultrasonically dispersing it to form a suspension, stirring it for 30 minutes, reacting it at a temperature of 70°C for 0.5 hours, and after the reaction is completed, centrifuging, washing, drying, and grinding it through a 200-mesh sieve to obtain the modified inorganic pigment, wherein the weight ratio of the inorganic pigment to the sepiolite powder and the 3-aminopropyltrimethoxysilane is 1:0.4:0.05.

[0045] Preparation Example 1.2

[0046] A modified inorganic pigment modification method comprises the following steps: ultrasonically dispersing the inorganic pigment in water for 20 minutes, then adding sepiolite powder and ultrasonically dispersing it at a temperature of 50°C for 55 minutes, adding 3-aminopropyltrimethoxysilane and ultrasonically dispersing it to form a suspension, stirring it for 25 minutes, reacting it at a temperature of 70°C for 0.5 hours, centrifuging, washing, drying and grinding it through a 200-mesh sieve after the reaction is completed to obtain the modified inorganic pigment, wherein the weight ratio of the inorganic pigment to the sepiolite powder and the 3-aminopropyltrimethoxysilane is 1:0.6:0.12.

[0047] Preparation Example 1.3

[0048] A modified inorganic pigment modification method comprises the following steps: ultrasonically dispersing the inorganic pigment in water for 20 minutes, then adding sepiolite powder and ultrasonically dispersing it at a temperature of 50°C for 60 minutes, adding 3-aminopropyltriethoxysilane and ultrasonically dispersing it to form a suspension, stirring it for 35 minutes, reacting it at a temperature of 70°C for 0.5 hours, centrifuging it after the reaction is completed, washing it, drying it, grinding it through a 200-mesh sieve to obtain the modified inorganic pigment, wherein the weight ratio of the inorganic pigment to the sepiolite powder and the 3-aminopropyltrimethoxysilane is 1:0.7:0.2.

[0049] Preparation Example 1.4

[0050] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.2 is that the reaction temperature is 80°C for 1 hour. After the reaction is completed, the modified inorganic pigment is obtained by centrifugation, washing, drying, and grinding through a 200-mesh sieve. The rest is the same as Preparation Example 1.2.

[0051] Preparation Example 1.5

[0052] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.2 is that the reaction temperature is 100°C for 1.5 hours. After the reaction is completed, the modified inorganic pigment is obtained by centrifugation, washing, drying, and grinding through a 200-mesh sieve. The rest is the same as Preparation Example 1.2.

[0053] Preparation Example 1.6

[0054] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.4 is that the sepiolite powder used is modified sepiolite powder. The modification method of the modified sepiolite powder comprises the following steps: adding the sepiolite powder to 1.8 mol / L hydrochloric acid and stirring for 5 hours, washing with water until it is neutral and the chloride ion content is less than 0.001%, drying at 80°C after centrifugal separation, and crushing through a 200 mesh sieve to obtain modified sepiolite powder, wherein the liquid ratio of sepiolite powder to hydrochloric acid is 1:7 g / ml.

[0055] Preparation Example 1.7

[0056] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.4 is that the modified sepiolite powder is used. The modification method of the modified sepiolite powder includes the following steps: adding the sepiolite powder to 2.5 mol / L hydrochloric acid and stirring for 5.5 hours, washing with water until it is neutral and the chloride ion content is less than 0.001%, drying at 80°C after centrifugal separation, and crushing through a 200 mesh sieve to obtain modified sepiolite powder, wherein the liquid ratio of sepiolite powder to hydrochloric acid is 1:7 g / ml.

[0057] Preparation Example 1.8

[0058] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.4 is that the sepiolite powder used is modified sepiolite powder. The modification method of the modified sepiolite powder comprises the following steps: adding the sepiolite powder to 3.2 mol / L hydrochloric acid and stirring for 6 hours, washing with water until it is neutral and the chloride ion content is less than 0.001%, drying at 90°C after centrifugal separation, and crushing through a 200 mesh sieve to obtain modified sepiolite powder, wherein the liquid ratio of sepiolite powder to hydrochloric acid is 1:7 g / ml.

[0059] Preparation Example 1.9

[0060] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.7 is that the sepiolite powder used is modified sepiolite powder, the material-liquid ratio of sepiolite powder to hydrochloric acid is 1:10 g / ml, and the rest is the same as Preparation Example 1.7.

[0061] Comparative Preparation Example 1.1

[0062] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.4 is that an equal amount of attapulgite is used instead of sepiolite powder, and the rest is the same as Preparation Example 1.4.

[0063] Comparative Preparation Example 1.2

[0064] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.4 is that an equal amount of vinyltriethoxysilane is used instead of 3-aminopropyltrimethoxysilane, and the rest is the same as Preparation Example 1.4.

[0065] Comparative Preparation Example 1.3

[0066] A method for modifying a modified inorganic pigment: The difference from Preparation Example 1.4 is that no sepiolite powder is added during the modification, and the rest is the same as Preparation Example 1.4.

[0067] Comparative Preparation Example 1.4

[0068] A modification method for a modified inorganic pigment: The difference from Preparation Example 1.4 is that 3-aminopropyltrimethoxysilane is not added during the modification, and the rest is the same as Preparation Example 1.4.

[0069] Preparation Example 2.1

[0070] The modification method of styrene-maleic anhydride copolymer comprises the following steps: under the protection of nitrogen atmosphere, 80 mL of toluene, 0.1 g of p-toluenesulfonic acid, 6 g of styrene-maleic anhydride copolymer and 12 g of isobutyl alcohol are mixed, and the mixture is reacted at a constant temperature of 80° C. for 5 hours. After the reaction is completed, the product is rotary evaporated to remove toluene, and then precipitated in petroleum ether to obtain a precipitate, and the precipitate is vacuum dried at 30° C. to obtain the modified styrene-maleic anhydride copolymer.

[0071] Preparation Example 2.2

[0072] The modification method of styrene-maleic anhydride copolymer comprises the following steps: under the protection of nitrogen atmosphere, 80 mL of toluene, 0.1 g of p-toluenesulfonic acid, 6 g of styrene-maleic anhydride copolymer and 13.8 g of isobutyl alcohol are mixed, and the mixture is reacted at a constant temperature of 85° C. for 5 hours. After the reaction is completed, the product is rotary evaporated to remove toluene, and then precipitated in petroleum ether to obtain a precipitate, and the precipitate is vacuum dried at 30° C. to obtain the modified styrene-maleic anhydride copolymer.

[0073] Preparation Example 2.3

[0074] The modification method of styrene-maleic anhydride copolymer comprises the following steps: under the protection of nitrogen atmosphere, 80 mL of toluene, 0.1 g of p-toluenesulfonic acid, 6 g of styrene-maleic anhydride copolymer and 15 g of isobutyl alcohol are mixed, and the mixture is reacted at a constant temperature of 85° C. for 5 hours. After the reaction is completed, the product is rotary evaporated to remove toluene, and then precipitated in petroleum ether to obtain a precipitate, and the precipitate is vacuum dried at 30° C. to obtain the modified styrene-maleic anhydride copolymer.

[0075] Preparation Example 3.1

[0076] The preparation method of a polymer dispersant comprises the following steps: mixing isooctyl acrylate, toluene and azobisisobutyronitrile, stirring and heating to 85±2°C, then dripping a mixed monomer solution of methyl methacrylate and vinyltrimethoxysilane, adding azobisisobutyronitrile again after the dripping is completed, reacting for 5 hours under the condition of keeping the temperature at 85±2°C, and then precipitating with methanol, and vacuum drying the precipitate to obtain the polymer dispersant, wherein the weight ratio of isooctyl acrylate, methyl methacrylate and vinyltrimethoxysilane is 2:1:1, the total amount of azobisisobutyronitrile added is 1% of the total amount of isooctyl acrylate, methyl methacrylate and vinyltrimethoxysilane, and the amounts of azobisisobutyronitrile added twice are respectively: 30% of the total amount added in the first time and the rest added in the second time.

[0077] Preparation Example 3.2

[0078] The preparation method of a polymer dispersant comprises the following steps: mixing isooctyl acrylate, toluene and azobisisobutyronitrile, stirring and heating to 85±2°C, then dripping a mixed monomer solution of methyl methacrylate and vinyltrimethoxysilane, adding azobisisobutyronitrile again after the dripping is completed, reacting for 6 hours under the condition of keeping the temperature at 85±2°C, and then precipitating with methanol, and vacuum drying the precipitate to obtain the polymer dispersant, wherein the weight ratio of isooctyl acrylate, methyl methacrylate and vinyltrimethoxysilane is 2:1:1, the total amount of azobisisobutyronitrile added is 1% of the total amount of isooctyl acrylate, methyl methacrylate and vinyltrimethoxysilane, and the amounts of azobisisobutyronitrile added twice are respectively: 30% of the total amount added in the first time and the rest added in the second time.

[0079] Preparation Example 4

[0080] The modification method of silicone oil comprises the following steps: mixing silicone oil and water in a weight ratio of 1:2, then adding a composite emulsifier of 35% by weight of the silicone oil to react at a temperature of 45±5°C for 40±5 minutes, and then adjusting the pH of the emulsion to 6.5 to obtain the modified silicone oil, wherein the composite emulsifier is composed of Tween 80 and AEO-9 in a weight ratio of 0.5:0.4.

[0081] Example 1

[0082] A method for preparing an organosilicon colorant for rail transit comprises the following steps:

[0083] S1. Add 45 g of the modified inorganic pigment obtained in Preparation Example 1.1 and 3 g of the polymer dispersant obtained in Preparation Example 3.1 to 30 g of silicone oil and stir and mix;

[0084] S2. Grind the mixture obtained in step S1 at a temperature of 50° C. for 30 min to obtain an organosilicon colorant for rail transit.

[0085] Example 2

[0086] A method for preparing an organosilicon colorant for rail transit comprises the following steps:

[0087] S1. Add 50 g of the modified inorganic pigment obtained in Preparation Example 1.1 and 5 g of the polymer dispersant obtained in Preparation Example 3.1 to 39 g of silicone oil and stir and mix;

[0088] S2. Grind the mixture obtained in step S1 at a temperature of 55° C. for 25 min to obtain an organosilicon colorant for rail transit.

[0089] Example 3

[0090] A method for preparing an organosilicon colorant for rail transit comprises the following steps:

[0091] S1. Add 55 g of the modified inorganic pigment obtained in Preparation Example 1.1 and 8 g of the polymer dispersant obtained in Preparation Example 3.2 to 45 g of silicone oil and stir and mix;

[0092] S2. Grind the mixture obtained in step S1 at 60° C. for 20 min to obtain an organosilicon colorant for rail transit.

[0093] Example 4

[0094] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.2, and the rest is the same as Example 2.

[0095] Example 5

[0096] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.3, and the rest is the same as Example 2.

[0097] Example 6

[0098] A method for preparing an organosilicon colorant for rail transit, which is different from Example 4 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.4, and the rest is the same as Example 4.

[0099] Example 7

[0100] A method for preparing an organosilicon colorant for rail transit, which is different from Example 4 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.5, and the rest is the same as Example 4.

[0101] Example 8

[0102] A method for preparing an organosilicon colorant for rail transit, which is different from Example 6 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.6, and the rest is the same as Example 6.

[0103] Example 9

[0104] A method for preparing an organosilicon colorant for rail transit, which is different from Example 6 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.7, and the rest is the same as Example 6.

[0105] Example 10

[0106] A method for preparing an organosilicon colorant for rail transit, which is different from Example 6 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.8, and the rest is the same as Example 6.

[0107] Embodiment 11

[0108] A method for preparing an organosilicon colorant for rail transit, which is different from Example 9 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Example 1.9, and the rest is the same as Example 9.

[0109] Example 12

[0110] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that an equal amount of styrene-maleic anhydride copolymer is used to replace the polymer dispersant obtained in Preparation Example 3.1, and the rest is the same as Example 2.

[0111] Example 13

[0112] A method for preparing an organosilicon colorant for rail transit, which is different from Example 9 in that the dispersant is prepared by mixing the polymer dispersant obtained in Preparation Example 3.1 with a styrene-maleic anhydride copolymer in a ratio of 1:0.8.

[0113] Embodiment 14

[0114] A method for preparing an organosilicon colorant for rail transit, which is different from Example 9 in that the dispersant is prepared by mixing the polymer dispersant obtained in Preparation Example 3.1 with a styrene-maleic anhydride copolymer in a ratio of 1:1.2.

[0115] Embodiment 15

[0116] A method for preparing an organosilicon colorant for rail transit, which is different from Example 9 in that the dispersant is prepared by mixing the polymer dispersant obtained in Preparation Example 3.1 with a styrene-maleic anhydride copolymer in a ratio of 1:1.6.

[0117] Example 16

[0118] A method for preparing an organosilicon colorant for rail transit, which is different from Example 14 in that the styrene-maleic anhydride copolymer is the styrene-maleic anhydride copolymer modified by Preparation Example 2.1, and the rest is the same as Example 14.

[0119] Embodiment 17

[0120] A method for preparing an organosilicon colorant for rail transit, which is different from Example 14 in that the styrene-maleic anhydride copolymer is the styrene-maleic anhydride copolymer modified by Preparation Example 2.2, and the rest is the same as Example 14.

[0121] Embodiment 18

[0122] A method for preparing an organosilicon colorant for rail transit, which is different from Example 14 in that the styrene-maleic anhydride copolymer is the styrene-maleic anhydride copolymer modified by Preparation Example 2.3, and the rest is the same as Example 14.

[0123] Embodiment 19

[0124] A method for preparing an organosilicon colorant for rail transit, which is different from Example 17 in that the silicone oil uses the modified silicone oil obtained in Preparation Example 4, and the rest is the same as Example 17.

[0125] Comparative Example 1

[0126] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that an unmodified inorganic pigment is used as the inorganic pigment, and the rest is the same as Example 2.

[0127] Comparative Example 2

[0128] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Comparative Preparation Example 1.1, and the rest is the same as Example 2.

[0129] Comparative Example 3

[0130] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Comparative Preparation Example 1.2, and the rest is the same as Example 2.

[0131] Comparative Example 4

[0132] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Comparative Preparation Example 1.3, and the rest is the same as Example 2.

[0133] Comparative Example 5

[0134] A method for preparing an organosilicon colorant for rail transit, which is different from Example 2 in that the modified inorganic pigment adopts the modified inorganic pigment obtained in Comparative Preparation Example 1.4, and the rest is the same as Example 2.

[0135] Performance Testing

[0136] The dispersibility, thermal stability, and insulation performance of the organosilicon colorants obtained in the above examples and comparative examples were tested, and the test results are shown in Table 1.

[0137] The dispersion performance test is to inject a small amount of the colorant obtained above into a transparent glass cup and observe the suspension state. If the suspension state is stable, the color is uniform, and there is no precipitation or color spot, it means that the colorant has good dispersion performance.

[0138] The thermal stability test is to add 1g of silicone colorant to 100g of silicone rubber for vulcanization / curing, place it in a 250℃ oven, keep the temperature constant for 6h, take it out and cool it, and use a colorimeter to detect the color difference change, where ΔE (comprehensive color difference) = (ΔL 2 +Δa 2 +Δb 2 ) 1 / 2 .

[0139] Table 1 Performance test results of silicone colorants

[0140]

[0141]

[0142] From the table above we can see that:

[0143] The organosilicon colorant obtained in Examples 1-3 has good dispersibility and insulation performance, and the comprehensive color difference value ΔE≤1.30, indicating that the organosilicon colorant obtained in this application has certain heat resistance.

[0144] Compared with Example 2, in Example 4-5, the modified inorganic pigment adopts the modified inorganic pigment obtained in Preparation Examples 1.2-1.3. After adjusting the ratio of sepiolite powder to 3-aminopropyltrimethoxysilane in the modified inorganic pigment, the fineness of the silicone colorant obtained in Example 4-5 is reduced compared with that in Example 2, indicating that the dispersion performance of the silicone colorant obtained in Example 4-5 is better than the dispersion performance of the silicone colorant obtained in Example 2. At the same time, the comprehensive color difference value of the silicone colorant obtained in Example 4-5 is further reduced, indicating that after adjusting the ratio of sepiolite powder and 3-aminopropyltrimethoxysilane, the heat resistance of the silicone colorant is further improved.

[0145] Compared with Example 2, after the modified inorganic pigments were prepared using the modified inorganic pigments obtained in Preparation Examples 1.4-1.5, the comprehensive color difference value ΔE of the silicone colorant obtained in Examples 6-7 was lower than that in Example 2, and was also lower than the comprehensive color difference value ΔE of the silicone colorant in Example 4, indicating that the reaction temperature of the inorganic pigment, sepiolite powder and 3-aminopropyltrimethoxysilane has a certain influence on the heat resistance of the silicone colorant.

[0146] Compared with Example 6, after the modified sepiolite powder is used in the preparation of the modified inorganic pigment, the fineness of the silicone colorant obtained in Examples 8-10 is further reduced, and the comprehensive color difference value ΔE is further reduced, indicating that after the modified sepiolite powder is used, the dispersion performance of the inorganic pigment and the heat resistance of the final colorant can be further improved.

[0147] In Examples 13-15, when the dispersant is a mixture of the polymer dispersant obtained in Preparation Example 3.1 and styrene-maleic acid copolymer, the dispersing performance of the polymer dispersant obtained in Preparation Example 3.1 obtained in Examples 13-15 is further improved compared to using the polymer dispersant obtained in Preparation Example 3.1 or styrene-maleic anhydride copolymer alone, and the comprehensive color difference value is reduced, indicating that the heat resistance is also improved.

[0148] Compared with Example 14, after the styrene-maleic anhydride copolymer is further esterified, the dispersibility and heat resistance of the organosilicon colorants obtained in Examples 16-18 are further improved compared with those in Example 14.

[0149] Compared with Example 17, when the silicone oil is modified silicone oil, the fineness of the pigment is further reduced, indicating that the modified silicone oil has better compatibility with the dispersant and sepiolite powder, which improves the dispersion performance of the pigment in the silicone oil. At the same time, due to the good dispersibility of the pigment in the silicone oil, the comprehensive color difference value of the colorant is smaller and the coloring ability is stronger.

[0150] Compared with Example 2, when the inorganic pigment is not modified, the dispersion performance of the silicone colorant obtained in Comparative Example 1 is poor, and the comprehensive color difference value is high, indicating that the heat resistance is also poor. Therefore, after the inorganic pigment is modified, the dispersion performance of the inorganic pigment in silicone oil can be effectively improved, thereby improving the dispersion performance and heat resistance of the silicone colorant.

[0151] Compared with Example 2, when the modified inorganic pigments of Comparative Examples 2-5 are respectively the modified inorganic pigments obtained by Comparative Preparation Examples 1.1-1.4, the various properties of the organosilicon colorants obtained in Comparative Examples 2-5 are all reduced compared with those in Example 2. It can be seen that the combined use of the components in the present application can effectively ensure that the organosilicon colorant has good dispersibility, heat resistance and insulation properties.

[0152] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An organosilicon colorant for rail transit, characterized in that: The organosilicon colorant comprises the following raw materials in parts by weight: 45-55 parts of modified inorganic pigment, 30-45 parts of silicone oil, and 3-8 parts of dispersant; the modified inorganic pigment is obtained by the following modification method: the inorganic pigment is ultrasonically dispersed in water, and then sepiolite powder is added and ultrasonically dispersed for 50-60 minutes at a temperature of 40-50° C., and then an aminosilane coupling agent is added and ultrasonically dispersed to form a suspension, and then the suspension is reacted at a temperature of 70-100° C. for 0.5-1.5 hours, and after the reaction is completed, the modified inorganic pigment is obtained by centrifugation, washing, drying, grinding, and sieving through a 200-mesh sieve.

2. The organic silicon colorant for rail transit according to claim 1, characterized in that: The weight ratio of the inorganic pigment to the sepiolite powder and the aminosilane coupling agent is 1:(0.4-0.7):(0.05-0.2).

3. The organosilicon colorant for rail transit according to claim 1 or 2, characterized in that: The aminosilane coupling agent is one of 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane.

4. The organic silicon colorant for rail transit according to claim 1, characterized in that: The sepiolite powder is obtained by the following modification method: the sepiolite powder is added to hydrochloric acid with a concentration of 1.8-3.2 mol / L and stirred for 5-6 hours, then washed with water until it is neutral and the chloride ion content is less than 0.001%, dried at 80-90° C. after centrifugal separation, and crushed through a 200-mesh sieve to obtain modified sepiolite powder, wherein the material-liquid ratio of the sepiolite powder to the hydrochloric acid is 1 g: (7-10) mL.

5. The organosilicon colorant for rail transit according to claim 1, characterized in that: The silicone oil is obtained by the following modification method: silicone oil and water are mixed in a weight ratio of 1:2, and then a composite emulsifier of 35% by weight of the silicone oil is added to react at a temperature of 45±5°C for 40±5 minutes, and then the pH of the emulsion is adjusted to 6.5 to obtain the modified silicone oil, wherein the composite emulsifier is composed of Tween 80 and AEO-9 in a weight ratio of 0.5:0.

4.

6. The organosilicon colorant for rail transit according to claim 1, characterized in that: The dispersant is composed of a polymer dispersant and a styrene-maleic anhydride copolymer in a weight ratio of 1:(0.8-1.6).

7. The organosilicon colorant for rail transit according to claim 6, characterized in that: The styrene-maleic anhydride copolymer is obtained by the following modification method: under the protection of nitrogen atmosphere, toluene, catalyst, styrene-maleic anhydride copolymer and isobutyl alcohol are mixed, and the mixture is reacted at a constant temperature of 80±5° C. for 5-6 hours. After the reaction is completed, the product is rotary evaporated to remove toluene, and then precipitated in petroleum ether to obtain a precipitate, and the precipitate is vacuum dried at 30° C. to obtain the modified styrene-maleic anhydride copolymer, wherein the mass ratio of the styrene-maleic anhydride copolymer to the isobutyl alcohol is 1:(2-2.5).

8. The organosilicon colorant for rail transit according to claim 7, characterized in that: The catalyst is p-toluenesulfonic acid.

9. The organosilicon colorant for rail transit according to claim 6, characterized in that: The polymer dispersant is obtained by the following preparation method: isooctyl acrylate, toluene and azobisisobutyronitrile are mixed, stirred and heated to 85±2°C, and then a mixed monomer solution of methyl methacrylate and vinyltrimethoxysilane is added dropwise, and after the addition is completed, azobisisobutyronitrile is added, and the temperature is maintained at 85±2°C for 5-6 hours, and then methanol is used for precipitation, and the precipitate is vacuum dried to obtain the polymer dispersant, wherein the weight ratio of isooctyl acrylate, methyl methacrylate and vinyltrimethoxysilane is 2:1:

1.

10. A method for preparing an organosilicon colorant for rail transit according to any one of claims 1 to 9, characterized in that: The steps include: S1. Adding modified inorganic pigment and dispersant into silicone oil and stirring and mixing; S2. Grind the mixture obtained in step S1 at a temperature of 50-60° C. for 20-30 min to obtain an organosilicon colorant for rail transit.

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