A kind of method that improves inorganic oxide powder dispersiveness in organic medium
Technical field
The present invention relates to a kind of preparation method of inorganic oxide powder, be specifically related to improve the method for inorganic oxide powder dispersiveness in organic medium or nonpolar medium and low-pole medium, relate in particular to a kind of employing powder particle surface in situ polymeric method modification is carried out on its surface, improve the interface compatibility of particle and organic medium.
Background technology
Along with the rise of the upsurge of nano material exploitation in recent years, the super-refinement research of inorganic oxide powder is like a raging fire.Compare with massive material, superfine powder shows the character of many uniquenesses in optics, calorifics, electricity, magnetics and terms of mechanics.For example, nano titanium oxide has unique functions such as color, photochemical catalysis and ultraviolet screener, at aspects such as automotive industry, makeup, water treatment, sterilization, environmental protection wide application prospect is arranged; Alpha-iron oxide nano-powder is when using as pigment, common ferric oxide is acidproof, alkaline-resisting except having, the advantage of strong coloring force, also has characteristic transparent, high uv-absorbing, this has opened up new world for iron oxide pigment in the application in car surface application, the contour decoration of woodenware external coating field, become functional pigment of new generation, market potential is huge.But along with reducing of particle size, powder has very high surfactivity under the effect of surface effects, small-size effect and quantum tunneling effect, and effect is very easily reunited between particle.In actual applications, often because particle aggregation has been lost the due specific function of super-fine material itself.In superfine powdery material technology of preparing perfect day by day today, how to be uniformly dispersed, stable and superfine powder that do not reunite has become a key issue in its applied research.
In general, the dispersion of superfine powder comprises three steps, and promptly wetting, shearing separates and stably dispersing.In recent years, under numerous scientists' effort, developed multiple powder surface modification method.Mostly existent method is by methods such as physical adsorption, chemisorption or mechanically mixing surface treatment agent to be adsorbed in the surface of processed powder body material, form surface reforming layer, thereby improve powder body material surface character, reach different effects, satisfy different requirements.At present, the superfine powder that is applied in the aqueous medium adopts the method for chemical precipitation inorganic substance coating to carry out surface modification more, surface commonly used coats material aerobic silicon, aluminum oxide or their mixture, and titanium dioxide manufacturing firm has adopted this technology that particle surface is handled both at home and abroad.In oil medium such as oil paint, plastics, the application of inorganic superfine powder body faces very big obstacle, mainly from the particle self character.Inorganic powder surface is strong polarity, and many hydroxyls are poor with oiliness apolar substance consistency.In recent years, the development and application of macromolecule dispersing agent is very in vogue, and also be proved to be its dispersion to superfine powder in a plurality of fields very effective.For example, United States Patent (USP) 6,413,306 (2002.6) have announced the macromolecule dispersing agent synthetic method that contains ABC three blocks; U.S. Patent application 2002123558 (2002.9) has been announced and has been adopted macromolecule dispersing agent to do the method that base-material comes the dispersed color powder; U.S. Patent application 20020019459 (2002.2) has been announced the synthetic method of the macromolecule dispersing agent that water-based system is suitable for.But the manufacturing cost of macromolecule dispersing agent is higher, and in use to consume big energy and the cost long time could obtain good dispersion effect.These have all limited the widespread use of macromolecule dispersing agent greatly.And often adopt tensio-active agent that simple process is carried out on the progenitor surface in conjunction with the surface modifying method of powder manufacturing processed, commonly used have organic amine, sodium laurate, phosphoric acid ester, a polyalcohols dispersion agent, though these tensio-active agents are cheap and easy to get, but because its oleophylic section of stretching in the medium is shorter, generally only have several or tens atoms, entropy repulsion can not satisfy the needs of stable dispersion far away between particle.So the scattering problem that solves the inorganic superfine powder body still demands developing new technology and method urgently.
It is the important channel that fundamentally solves the superfine powder scattering problem that progenitor is carried out surface modification, and the research in this field at present is very popular, has obtained certain achievement, but forms the few of patent.United States Patent (USP) 6,194,488 (2001.2) have discussed in the mixture of reactive monomer and organic solvent and to have dropped into through the surface-treated pigment particles of initiator, form the pigment treatment process of coating layer at the particle surface initiated polymerization.This method can successfully be used for the modification of part surface of pigments, but because initiator mostly is unstable compound, with it inorganic particulate being carried out surface treatment certainly will run into very big difficulty or need specific installation, the organic solvent recycling is very expensive, and easily form fine and close coating layer, change the form and aspect of the multiple oxide powder that uses as color stuffing at particle surface.Therefore, use this method to realize that inorganic oxide powder surface-treated industrialization possibility is little.
Along with the solid surface fundamental research deepens continuously, find that the hydroxyl on inorganic oxide powder surface has broad variety, wherein contain and the incomplete exposed hydroxyl of main element coordination, this type of hydroxyl character is more active, and easy and other atoms form chemical bonds.In other words, the hydroxyl on inorganic oxide powder surface is for providing binding site at other long chain molecules of its surface bond.The present invention is just in conjunction with the experience accumulation of this theoretical research result and hyper-dispersant exploitation, develop the method for utilizing the unsaturated monomer in-situ polymerization inorganic oxide powder has been carried out surface modification, improved its dispersiveness in organic medium or nonpolar medium and low-pole medium.
Summary of the invention
The technical issues that need to address of the present invention are a kind of methods that improve inorganic oxide powder dispersiveness in organic medium or nonpolar medium and low-pole medium of exploitation, improve the consistency between inorganic oxide powder and the nonpolar medium, improve its dispersiveness in media such as coating, plastics, rubber, tackiness agent, and satisfy the association area demands of applications.
Technical conceive of the present invention is such: the contriver imagines the method for employing particle surface original position emulsifier-free emulsion polymerization inorganic oxide powder is carried out surface modification, to improve the consistency between inorganic oxide powder and the nonpolar medium, improve its dispersiveness in media such as coating, plastics, rubber, tackiness agent.
Technical scheme of the present invention:
Method of the present invention comprises the steps:
Inorganic oxide powder is placed water and tensio-active agent, disperse, obtain slurry, in said slurry, add unsaturated polymer monomer and peroxide initiator initiated polymerization, polymerization temperature is generally 40~120 ℃, and preferred 50~100 ℃, polymerization time is generally 1~8hr, preferred 2~5hr, insulation 1~8hr collects product, drying, preferred drying temperature is 80~150 ℃, promptly obtains inorganic oxide powder.
Inorganic oxide powder involved in the present invention comprises: titanium dioxide (TiO
2), iron oxide yellow (alpha-feooh), red iron oxide (α-Fe
2O
3), iron oxide black (Fe
3O
4), transparent yellow iron oxide, transparent iron oxide red, zinc oxide (ZnO
2), aluminum oxide (Al
2O
3), silicon oxide (SiO
2), stannic oxide (SnO
2) wait the synthesis oxide powdered material.
Unsaturated polymer monomer involved in the present invention comprises: vinylformic acid, ethyl propenoate, methacrylic acid, methyl methacrylate, Jia Jibingxisuanyizhi, butyl methacrylate, vinylbenzene, alpha-methyl styrene, propylene cyanogen, vinyl ether.
Tensio-active agent of the present invention comprises: sodium laurylsulfonate, sodium lauryl sulphate, Sodium dodecylbenzene sulfonate, sodium alkyl naphthalene sulfonate, the hexadecanol sodium sulfonate, secondary alkyl six sour sodium, ammonium lauryl sulfate, fatty alcohol-polyoxyethylene ether, lauric acid, trisodium phosphate.
Cause radical polymerization and can adopt following initiator: Potassium Persulphate, ammonium persulphate, hydrogen peroxide, hydrogen peroxide-ferrous salt, Potassium Persulphate-ferrous salt.
According to optimized technical scheme of the present invention, heating up under nitrogen protection adds initiator initiation particle surface monomer polymerization;
According to the preferred scheme of the present invention, occur in particle surface in order to guarantee polyreaction, prevent that as far as possible polyreaction from occurring in the aqueous media, the addition of tensio-active agent need be lower than its micelle-forming concentration (CMC) in solution system.With the sodium laurylsulfonate is example, and general dosage is 0.1%~10% heavy (weight) of powder, and ideal is 0.5%~8% heavy (weight) of powder;
According to the preferred scheme of the present invention, the addition of polymer monomer changes according to required surface coating layer thickness, is generally 0.5%~150% heavy (weight) of powder, and ideal is 1%~100% heavy (weight) of powder;
According to the preferred scheme of the present invention, the initiator addition is generally and is monomeric 0.01%~15% (weight), and ideal is 0.05%~10% (weight);
The present invention is that dispersion medium disperses inorganic oxide powder with water, adopts tensio-active agent that powder surface is carried out pre-treatment, obtains the dispersed particle that the surface forms oleophilic layer.This technology needs to avoid disperseing the back particle to reunite once more because of size of particles, the different solids contents that change dispersed paste of specific surface area as far as possible.Generally speaking, needle-shaped particle is lower than the solids content of spheroidal particle; The solids content of the particle that the particle that particle diameter is little is bigger than particle diameter is low; The solids content of the particle that the particle that specific surface area is big is littler than specific surface area is low; The particle that density is little wants the solids content of the big particle of specific density low.The present invention under agitation adds polymer monomer in the powder dispersed paste, keeps certain hour, makes polymer monomer enter tensio-active agent and forms oleophilic layer at particle surface, forms the polymerization place at particle surface.
Raising inorganic oxide powder of the present invention dispersed method in organic medium can be improved its consistency to nonpolar organic medium greatly.Go for Application Areass such as coating, plastics, rubber and tackiness agent fully.
Description of drawings
Fig. 1 is the titania powder stereoscan photograph before handling.
Fig. 2 is the titania powder stereoscan photograph after handling.
Fig. 3 is the iron oxide yellow powder stereoscan photograph before handling.
Fig. 4 is the iron oxide yellow powder stereoscan photograph after handling.
Fig. 5 is the red iron oxide powder stereoscan photograph before handling.
Fig. 6 is that the red iron oxide powder after handling is dispersed in the state in the xylene solvent.
Fig. 7 is the micro-hot first-order derivative graphic representation of transparent yellow iron oxide powder.
Embodiment
Embodiment 1
200g places the 5000ml plastic beaker with titania powder (R902 of Du Pont type), adds 3000ml deionized water and sodium laurylsulfonate 8g, and high speed dispersor 1000r/min disperses 0.5hr down.Scattered slurry is changed in the device that has stirring, heating and nitrogen protection, add the 60g methyl methacrylate, be warming up to 100 ℃ behind the stirring 15min.Add the aqueous solution initiated polymerization that contains the 3g Potassium Persulphate, 100 ℃ of insulation 2hr.The discharging suction filtration places 70 ℃ of dry 5hr down.The dispersed test result of dry back powder sees Table 1.Electromicroscopic photograph is seen Fig. 1 and Fig. 2.
Embodiment 2
200g places the 5000ml plastic beaker with common iron oxide yellow (Shanghai Yipin International Pigments Co., Ltd.'s 313 types), adds 3000ml deionized water and Sodium dodecylbenzene sulfonate 15g, and high speed dispersor 1000r/min disperses 0.5hr down.Scattered slurry is changed in the device that has stirring, heating and nitrogen protection, add 45g butyl methacrylate and 30g methacrylic acid in batches, be warming up to 40 ℃ behind the stirring 15min.Add the aqueous solution initiated polymerization that contains the 3g Potassium Persulphate, 50 ℃ of insulation 5hr.The discharging suction filtration places 60 ℃ of dry 5hr down.The dispersed test result of dry back powder sees Table 1, and resistance toheat sees Table 2.Electromicroscopic photograph is seen Fig. 3 and Fig. 4.
Embodiment 3
150g places the 5000ml plastic beaker with common red iron oxide (Shanghai Yipin International Pigments Co., Ltd.'s 130 types), adds 3000ml deionized water and ammonium lauryl sulfate 7g, and high speed dispersor 1000r/min disperses 0.5hr down.Scattered slurry is changed in the device that has stirring, heating and nitrogen protection, add 10g vinylformic acid, 20g ethyl propenoate and 25g methyl acrylate in batches, be warming up to 60 ℃ behind the stirring 15min.Add the aqueous solution initiated polymerization that contains the 3g Potassium Persulphate, 60 ℃ of insulation 4hr.The discharging suction filtration places 70 ℃ of dry 5hr down.The dispersed test result of dry back powder sees Table 1.Electromicroscopic photograph is seen Fig. 5 and Fig. 6.
Embodiment 4
25g places the 5000ml plastic beaker with transparent yellow iron oxide (the just strange chemical industry company limited in Shangyu, Zhejiang 608 types), adds 4000ml deionized water and sodium laurylsulfonate 4g, and high speed dispersor 1000r/min disperses 0.5hr down.Scattered slurry is changed in the device that has stirring, heating and nitrogen protection, add the 7.5g methyl methacrylate, be warming up to 60 ℃ behind the stirring 15min.Add the aqueous solution initiated polymerization that contains the 0.375g Potassium Persulphate, 60 ℃ of insulation 4hr.The discharging suction filtration places 70 ℃ of dry 5hr down.The dispersed test result of dry back powder sees Table 1, and resistance toheat sees Table 2 and Fig. 7.
Embodiment 5
30g places the 5000ml plastic beaker with transparent iron oxide red (the just strange chemical industry company limited in Shangyu, Zhejiang 708 types), adds 4000ml deionized water and sodium laurylsulfonate 4g, and high speed dispersor 1000r/min disperses 0.5hr down.Scattered slurry is changed in the device that has stirring, heating and nitrogen protection, add 4g vinylbenzene and 6g alpha-methyl styrene in batches, be warming up to 80 ℃ behind the stirring 25min.Add the aqueous solution initiated polymerization that contains the 0.425g Potassium Persulphate, 80 ℃ of insulation 6hr.The discharging suction filtration places 70 ℃ of dry 5hr down.The dispersed test result of dry back powder sees Table 1, and resistance toheat sees Table 2.
Embodiment 6
150g places the 6000ml plastic beaker with titanium dioxide (R902 of Du Pont type), adds 4000ml deionized water and sodium laurylsulfonate 10g, and high speed dispersor 1000r/min disperses 0.5hr down.Scattered slurry is changed in the device that has stirring, heating and nitrogen protection, add 45g vinylbenzene, be warming up to 80 ℃ behind the stirring 15min.Add the aqueous solution initiated polymerization that contains the 0.87g ammonium persulphate, 80 ℃ of insulation 6hr.The discharging suction filtration places 100 ℃ of dry 5hr down.The dispersed test result of dry back powder sees Table 1.
Embodiment 7
Tindioxide (Shanghai Lai Ze fine chemicals factory) 100g places the 6000ml plastic beaker, adds 4000ml deionized water and trisodium phosphate 10g, and high speed dispersor 1000r/min disperses 0.5hr down.Scattered slurry is changed in the device that has stirring, heating and nitrogen protection, add 100g vinylbenzene, be warming up to 80 ℃ behind the stirring 15min.Add the aqueous solution initiated polymerization that contains the 0.87g ammonium persulphate, 80 ℃ of insulation 6hr.The discharging suction filtration places 70 ℃ of dry 5hr down.The dispersed test result of dry back powder sees Table 1.
The wetting angle of table 1 embodiment 1~7 powder-product
The method that the amphipathic property of inorganic oxide powder adopts capillary tube technique to measure wetting angle after the surface aggregate modification is estimated, and choosing widely used toluene is organic solvent.Principle and method are in harmony referring to yellow ancestral and fourth E Jiang " surface infiltration and infiltration phase transformation " in detail, and Shanghai science tech publishing house published in 1994.
The resistance toheat of table 2 embodiment 2,4 iron oxide yellow products
Represent the thermotolerance of iron oxide yellow pigments with the initial dehydration temperaturre of iron oxide yellow pigments.Obtain the initial dehydration temperaturre of iron oxide yellow by micro-thermal analysis, under this temperature, the crystal water in the iron oxide yellow begins to remove, and the color of pigment begins to take place tangible rust.The micro-hot first-order derivative curve of embodiment 4 samples as shown in Figure 7.Curve TTC-0 represents the preceding sample of modification among the figure, and former iron oxide yellow particle crystalline phase changes in the time of 282.4 ℃, becomes red α-Fe rapidly
2O
3TT-PMMA represents sample after the modification, because particle surface is introduced polymkeric substance, moves to 297.9 ℃ behind the phase transition temperature, and occurs the weightless peak of thermolysis of PMMA in the time of 318.08 ℃.
Embodiment 8
Join lacquer:
Get before the modification and each 50g of transparent iron oxide pigment embodiment 4 (the just strange chemical industry company limited in Shangyu, Zhejiang 608 types), add 2000g acrylic resin soln (the thunderbolt coating WP98 of company limited of Shanghai section type respectively, solids content 50%), add defoamer (202 type) 0.5g.Slurry mixes and is placed in the ball mill (QM-1, Nanjing Univ. Instrument Factory) ball milling 8hr under the 250r/min.
Test:
Because the transparent ferric oxide particle is aciculiform, big (the about 140m of specific surface area
2/ g), this particle disperses difficulty the most.Its dispersed quality can be by measuring its transparency evaluation of filming.Good dispersion, particle aggregation is little, the transparency height; Bad dispersibility, particle is big, and light wave sees through few, the poor transparency of promptly filming.Utilize this principle, adopt the wet film applicator will make slurry and be applied on the clear PET film, after drying naturally, it is the light wave transmitance of 600nm that the clip film sample is gone up the test wavelength in spectrophotometer (722 type), gets 5 place's transmitance mean values.Preestablishing clear PET film transmittance is 100%.The result is as follows: