Preparation method and application of titanium dioxide coated hollow glass microspheres

Abstract

The present invention relates to a preparation method and application of titanium dioxide coated hollow glass microspheres, belonging to the technical field of hollow glass microspheres. 0.1 to 1 parts by weight of a titanate coupling agent is added to 80 to 90 parts by weight of an organic solvent, stirred for 1 to 3 hours, and a titanium solution is obtained; 10 to 20 parts by weight of hollow glass microspheres are added to the titanium solution prepared by S1, stirred for 1 to 3 hours, and a glass microsphere titanium solution is obtained; the organic solvent in the glass microsphere titanium solution prepared in S2 is evaporated by a low-temperature reduced pressure distillation method, and a freeze dryer or a vacuum oven is used for drying to obtain a pre-coated material; the pre-coated material prepared by S3 is sieved and calcined at 400 to 600°C for 2 to 6 hours, and cooled to obtain a titanium dioxide coated hollow glass microsphere product. The present invention has a simple process, is easy to mass produce, and can ensure coating uniformity and performance stability; in addition, the thermal insulation coating to which the titanium dioxide coated hollow glass microspheres of the present invention are added has significant thermal insulation performance, and good water resistance, stain resistance, and corrosion resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of hollow glass microspheres, and particularly relates to a preparation method and application of titanium dioxide-coated hollow glass microspheres. Background Art

[0002] Hollow glass microspheres are a lightweight, hollow, ultrafine inorganic powder material with a series of excellent properties such as low thermal conductivity, insulation, high stability, sound resistance, fire resistance, and radiation resistance. At the same time, hollow glass microspheres can be directly added to the coating system as fillers to form a tightly arranged hollow isolation layer, which can play a barrier role and produce a good thermal insulation effect. Most of the solar energy is in the visible and near-infrared regions, which can be divided into three parts according to the wavelength: the energy proportion of thermal radiation in the ultraviolet region is 5%, the proportion of thermal radiation in the visible region is 45%, and the proportion of thermal radiation in the near-infrared region is 50%. Therefore, in addition to the hollow structure of glass microspheres used as fillers in thermal insulation coatings, if the reflection efficiency of the surface to visible light and near-infrared light is higher, the better the thermal insulation effect can be achieved.

[0003] There are currently two technical methods for loading titanium dioxide onto the surface of hollow glass microspheres: 1. sol-gel method, 2. heterogeneous precipitation method; the principle of the sol-gel method is to use highly active substances such as tetrabutyl titanate to obtain a uniform gel through hydrolysis, condensation, and aging. The titanium dioxide generated after mixing and reacting with the microspheres is adsorbed on the surface of the microspheres through electrostatic adsorption, and then filtered, dried, and calcined to obtain nano-level titanium dioxide; the principle of the heterogeneous precipitation method is to use the reaction of titanium salts and precipitants, and the microspheres are added by controlling the reaction rate and then the titanium dioxide is attached to the surface of the microspheres.

[0004] However, these two methods have the following shortcomings: 1. The coating uniformity is poor, and larger particles are easily formed on the surface of the microbeads; 2. The titanium dioxide obtained by the reaction cannot be effectively loaded onto the microbeads; 3. The coating layer is prone to breakage when it is coated to a certain thickness at one time; 4. Industrial production is relatively difficult.

[0005] Therefore, an effective method is urgently needed to ensure coating uniformity and performance stability under a certain coating thickness. At the same time, due to environmental issues and production process stability limitations, large-scale production is still not possible. Summary of the invention

[0006] In view of this, the present invention aims at the deficiencies of the prior art and provides a method for preparing hollow glass microspheres coated with titanium dioxide and its application, which has simple process, is easy to mass produce, and can ensure coating uniformity and performance stability.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for preparing titanium dioxide-coated hollow glass microspheres, comprising the following steps:

[0008] S1, adding 0.1 to 1 parts by weight of a titanate coupling agent into 80 to 90 parts by weight of an organic solvent, stirring for 1 to 3 hours to obtain a titanium solution;

[0009] S2, adding 10 to 20 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 1 to 3 hours to obtain a glass microsphere titanium solution;

[0010] S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying it using a freeze dryer or a vacuum oven to obtain a pre-coated material;

[0011] S4. The pre-coated material obtained in S3 is screened, calcined at 400-600° C. for 2-6 hours, and cooled to obtain a titanium dioxide-coated hollow glass microsphere product.

[0012] Furthermore, the titanate coupling agent is at least one of butyl orthotitanate, ethyl titanate, isopropyl titanate, non-acetylacetone type titanate chelate, di(triethanolamine) diisopropyl titanate, and tetraisopropyl di(dioctylphosphite) titanate.

[0013] Furthermore, the organic solvent is at least one of solvent oil, petroleum ether, isopropanol, benzyl alcohol, and liquid paraffin.

[0014] Another object of the present invention is to provide a titanium dioxide-coated hollow glass microsphere, which is prepared by the above-mentioned method for preparing titanium dioxide-coated hollow glass microsphere.

[0015] Furthermore, another object of the present invention is to provide an application of titanium dioxide coated hollow glass microspheres. During the preparation of thermal insulation coating, the titanium dioxide coated hollow glass microspheres prepared above are added to the coating in a weight ratio of 3 to 5%.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The method for preparing hollow glass microspheres coated with titanium dioxide comprises the following steps: fully dispersing a titanate coupling agent in an organic solvent, then adding the hollow glass microspheres and stirring them fully, so that the titanate coupling agent and the hollow glass microspheres are fully dispersed and contacted in the organic solvent, and then removing the organic solvent by low-temperature reduced-pressure distillation, and removing the residual organic solvent by using a freeze dryer or a vacuum oven, so that a pre-coated material of hollow glass microspheres coated with the titanate coupling agent is obtained, and the pre-coated material is fully calcined at high temperature after screening, so that the titanate coupling agent is cracked into titanium dioxide, and the titanium dioxide is fully coated on the hollow glass microspheres. The process is simple, the stability is strong, and the environmental protection problems such as sewage treatment are not involved, and the large-scale production is easy. In addition, the hollow glass microspheres coated with titanium dioxide prepared by the method of the present invention are uniformly coated and have stable performance, and the coating thickness can be conveniently controlled by using the same process for multiple coatings.

[0018] The preparation method of hollow glass microspheres coated with titanium dioxide adopts a method of dispersing and contacting a titanate coupling agent with hollow glass microspheres in an organic solvent; during stirring, the titanate coupling agent is adsorbed on the surface of the hollow glass microspheres to block the pores on the surface of the particles, thereby reducing the surface area of ​​the hollow glass microsphere particles and increasing the density; the particles are calcined at high temperature to decompose, further reducing the specific surface area of ​​the particles, and forming a uniform and dense titanium dioxide film on the surface of the hollow glass microspheres.

[0019] The titanium dioxide-coated hollow glass microspheres of the present invention are used in the preparation of thermal insulation coatings. By adding 3 to 5% by weight of the titanium dioxide-coated hollow glass microspheres to the coating, a tightly arranged hollow isolation layer is formed, which has a good insulation effect on heat and sound. In addition, the titanium dioxide-coated hollow glass microspheres form a protective film on the surface of the coating that has a barrier effect on moisture and corrosive ions, and has strong waterproof, anti-fouling and anti-corrosion properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a scanning electron microscope image of titanium dioxide-coated hollow glass microspheres prepared in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0022] Example 1

[0023] A method for preparing titanium dioxide-coated hollow glass microspheres comprises the following steps:

[0024] S1, adding 0.1 parts by weight of a titanate coupling agent into 80 parts by weight of an organic solvent, stirring for 1 hour, to obtain a titanium solution;

[0025] S2, adding 10 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 1 hour to obtain a glass microsphere titanium solution;

[0026] S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying it using a freeze dryer to obtain a pre-coated material;

[0027] S4. The pre-coated material obtained in S3 is screened and calcined at 400° C. for 2 hours, and then cooled to obtain a titanium dioxide-coated hollow glass microsphere product.

[0028] The titanate coupling agent is butyl orthotitanate, and the organic solvent is solvent oil.

[0029] Example 2

[0030] A method for preparing titanium dioxide-coated hollow glass microspheres comprises the following steps:

[0031] S1, adding 0.5 parts by weight of a titanate coupling agent to 85 parts by weight of an organic solvent, stirring for 2 hours to obtain a titanium solution;

[0032] S2, adding 15 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 2 hours to obtain a glass microsphere titanium solution;

[0033] S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a pre-coated material;

[0034] S4. The pre-coated material obtained in S3 is screened and calcined at 500° C. for 4 hours, and then cooled to obtain a titanium dioxide-coated hollow glass microsphere product.

[0035] The titanate coupling agent is ethyl titanate, and the organic solvent is petroleum ether.

[0036] Example 3

[0037] A method for preparing titanium dioxide-coated hollow glass microspheres comprises the following steps:

[0038] S1, adding 1 part by weight of a titanate coupling agent to 90 parts by weight of an organic solvent, stirring for 3 hours to obtain a titanium solution;

[0039] S2, adding 20 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 3 hours to obtain a glass microsphere titanium solution;

[0040] S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying it using a freeze dryer to obtain a pre-coated material;

[0041] S4. The pre-coated material obtained in S3 is screened and calcined at 600° C. for 6 hours, and then cooled to obtain a titanium dioxide-coated hollow glass microsphere product.

[0042] The titanate coupling agent is a mixture of equal amounts of butyl orthotitanate, ethyl titanate and isopropyl titanate.

[0043] The organic solvent is a mixture of equal amounts of 6# solvent oil, petroleum ether and isopropanol.

[0044] Example 4

[0045] A method for preparing titanium dioxide-coated hollow glass microspheres comprises the following steps:

[0046] S1, adding 0.1 parts by weight of a titanate coupling agent to 80 parts by weight of an organic solvent, stirring for 2 hours, to obtain a titanium solution;

[0047] S2, adding 10 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 2 hours to obtain a glass microsphere titanium solution;

[0048] S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a pre-coated material;

[0049] S4. The pre-coated material obtained in S3 is screened and calcined at 500° C. for 4 hours, and then cooled to obtain a titanium dioxide-coated hollow glass microsphere product.

[0050] The titanate coupling agent is tetraisopropyl di(dioctylphosphite acyloxy) titanate, and the organic solvent is benzyl alcohol.

[0051] Example 5

[0052] A method for preparing titanium dioxide-coated hollow glass microspheres comprises the following steps:

[0053] S1, adding 0.1 parts by weight of a titanate coupling agent to 80 parts by weight of an organic solvent, stirring for 3 hours to obtain a titanium solution;

[0054] S2, adding 10 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 3 hours to obtain a glass microsphere titanium solution;

[0055] S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a pre-coated material;

[0056] S4, sieving the pre-coated material obtained in S3, calcining at 600° C. for 6 hours, and cooling to obtain a titanium dioxide-coated hollow glass microsphere product;

[0057] S5, preparing the same titanium solution as in S1 again;

[0058] S6, taking 10 parts by weight of the titanium dioxide-coated hollow glass microsphere product prepared in S4, adding it to the titanium solution in S5, and stirring for 3 hours;

[0059] S7, evaporating the organic solvent in S6 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a thickened pre-coated material;

[0060] S8. The thickened pre-coated material obtained in S7 is screened and calcined at 600° C. for 6 hours, and then cooled to obtain a thickened titanium dioxide-coated hollow glass microsphere product.

[0061] The titanate coupling agent is a mixture of equal amounts of non-acetylacetone type titanate chelate, di(triethanolamine)titanate diisopropyl, and tetraisopropyl di(dioctylphosphite acyloxy)titanate.

[0062] The organic solvent is a mixture of equal amounts of benzyl alcohol and liquid paraffin.

[0063] Example 6

[0064] A method for preparing titanium dioxide-coated hollow glass microspheres comprises the following steps:

[0065] S1, adding 1 part by weight of a titanate coupling agent to 90 parts by weight of an organic solvent, stirring for 3 hours to obtain a titanium solution;

[0066] S2, adding 20 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 3 hours to obtain a glass microsphere titanium solution;

[0067] S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a pre-coated material;

[0068] S4, sieving the pre-coated material obtained in S3, calcining at 600° C. for 6 hours, and cooling to obtain a titanium dioxide-coated hollow glass microsphere product;

[0069] S5, preparing the same titanium solution as in S1 again;

[0070] S6, taking 20 parts by weight of the titanium dioxide-coated hollow glass microsphere product prepared in S4, adding it to the titanium solution in S5, and stirring for 3 hours;

[0071] S7, evaporating the organic solvent in S6 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a thickened pre-coated material;

[0072] S8. The thickened pre-coated material obtained in S7 is screened and calcined at 600° C. for 6 hours, and then cooled to obtain a thickened titanium dioxide-coated hollow glass microsphere product.

[0073] The titanate coupling agent is a mixture of equal amounts of ethyl titanate and isopropyl titanate, and the organic solvent is a mixture of equal amounts of petroleum ether and isopropanol.

[0074] The titanium dioxide coated hollow glass microspheres prepared in Examples 1 to 6 were tested using a laser particle size analyzer, a densitometer, and a scanning electron microscope. The results are shown in Table 1:

[0075]

[0076] Example 1 The scanning electron microscope image of the titanium dioxide coated hollow glass microspheres obtained is as follows: Figure 1 shown.

[0077] Combined with Table 1, Figure 1 It can be seen that: (1) the titanium dioxide coated hollow glass microspheres prepared by the preparation method of Examples 1 to 4 are uniformly coated and have a smooth surface, forming a stable coating thickness; (2) By comparing Example 1 and Example 5, based on the titanium dioxide coated hollow glass microspheres prepared in Example 1, the coating is repeated once by the same method to obtain titanium dioxide coated hollow glass microspheres with a doubled thickness, and the surface is uniform and stable; (3) By comparing Example 3 and Example 6, based on the titanium dioxide coated hollow glass microspheres prepared in Example 1, the coating is repeated once by the same method to obtain titanium dioxide coated hollow glass microspheres with a doubled thickness, and the surface is uniform and stable.

[0078] Example 7

[0079] The titanium dioxide-coated hollow glass microsphere product obtained in Example 1 was added to the raw materials for preparing the thermal insulation coating at a weight ratio of 3%, that is, the composition of the thermal insulation coating (by weight):

[0080] 40 parts of acrylic emulsion, 10 parts of rutile titanium dioxide, 2.2 parts of titanium dioxide coated hollow glass microspheres, 1 part of dispersant (CP88), 0.1 part of defoaming agent (DF-8205), 0.1 part of cosolvent (n-butanol), 0.1 part of wetting agent (acetylenic glycol), 0.1 part of film-forming aid (Semek), 0.5 part of leveling agent (polyether modified silicone oil), 0.1 part of associative agent (polyethylene glycol), 0.1 part of preservative (Wanhua Tianhe), and 20 parts of deionized water.

[0081] Preparation method: put deionized water and dispersant into a container according to the formula and stir to mix evenly; add rutile titanium dioxide under slow stirring, and then stir at high speed to mix evenly; add acrylic emulsion, defoamer, cosolvent, wetting agent, film-forming aid, leveling agent, associative agent, preservative under slow stirring, and stir evenly; under slow stirring, slowly add titanium dioxide-coated hollow glass microspheres, and stir until the mixed system is evenly dispersed.

[0082] Example 8

[0083] The titanium dioxide-coated hollow glass microsphere product obtained in Example 3 was added to the raw materials for preparing the thermal insulation coating at a weight ratio of 5%, that is, the composition of the thermal insulation coating was (by weight):

[0084] 40 parts of acrylic emulsion, 10 parts of rutile titanium dioxide, 3.8 parts of titanium dioxide coated hollow glass microspheres, 1 part of dispersant (CP88), 0.1 part of defoaming agent (DF-8205), 0.1 part of cosolvent (n-butanol), 0.1 part of wetting agent (acetylenic glycol), 0.1 part of film-forming aid (Simek), 0.5 part of leveling agent (polyether modified silicone oil), 0.1 part of associative agent (polyethylene glycol), 0.1 part of preservative (Wanhua Tianhe), and 20 parts of deionized water.

[0085] Preparation method: put deionized water and dispersant into a container according to the formula and stir to mix evenly; add rutile titanium dioxide under slow stirring, and then stir at high speed to mix evenly; add acrylic emulsion, defoamer, cosolvent, wetting agent, film-forming aid, leveling agent, associative agent, preservative under slow stirring, and stir evenly; under slow stirring, slowly add titanium dioxide-coated hollow glass microspheres, and stir until the mixed system is evenly dispersed.

[0086] Comparative Example

[0087] No titanium dioxide-coated hollow glass microspheres were added, and the remaining components were the same as those in Examples 7 and 8.

[0088] The thermal insulation coatings prepared in Example 7, Example 8 and the comparative example were tested for performance, and the performance of the thermal insulation coatings was investigated with reference to GB / T9755-2001. The results are shown in Table 2:

[0089] Table 2

[0090]

[0091] It can be seen from the above table that after adding 3-5% titanium dioxide coated hollow glass microspheres to the thermal insulation coating, the heat reflectivity reaches more than 90%, the thermal insulation effect is significant, and the more added within the appropriate range, the better the thermal insulation effect; in addition, after adding titanium dioxide coated hollow glass microspheres, the coating is flat and smooth, with good water resistance, alkali corrosion resistance, and good stain resistance.

[0092] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing titanium dioxide coated hollow glass microspheres, characterized in that: The following steps are involved: S1, adding 1 part by weight of a titanate coupling agent to 90 parts by weight of an organic solvent, stirring for 3 hours to obtain a titanium solution; S2, adding 20 parts by weight of hollow glass microspheres to the titanium solution prepared in S1, stirring for 3 hours to obtain a glass microsphere titanium solution; S3, evaporating the organic solvent in the glass microbead titanium solution obtained in S2 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a pre-coated material; S4, sieving the pre-coated material obtained in S3, calcining at 600° C. for 6 hours, and cooling to obtain a titanium dioxide-coated hollow glass microsphere product; S5, preparing the same titanium solution as in S1 again; S6, taking 20 parts by weight of the titanium dioxide-coated hollow glass microsphere product prepared in S4, adding it to the titanium solution in S5, and stirring for 3 hours; S7, evaporating the organic solvent in S6 by low-temperature reduced-pressure distillation, and drying in a vacuum oven to obtain a thickened pre-coated material; S8, screening the thickened pre-coated material obtained in S7, calcining at 600° C. for 6 hours, and cooling to obtain a thickened titanium dioxide-coated hollow glass microsphere product; The titanate coupling agent is a mixture of equal amounts of ethyl titanate and isopropyl titanate, and the organic solvent is a mixture of equal amounts of petroleum ether and isopropanol.

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