Summary of the invention
The objective of the invention is to, emulsion of a kind of composite nano materials modification and preparation method thereof is provided, and the package stability of this emulsion increases substantially, and the water tolerance and the alkali resistance of filming after the film forming are obviously improved, the preparation method is simple, and the modified effect of nano material is obvious.
Realize the technical scheme of the object of the invention: a kind of emulsion of composite nano materials modification, it is to use inorganic nano material modified acrylic emulsion, inorganic nano material is nano alumina powder jointed and compound Nano silica sol, consumption is 250~2500 weight parts, nano alumina powder jointed 5~30% of the Nano silica sol solids content that accounts for; The acrylic emulsion consumption is 2500 weight parts, and the solids content of emulsion is 40 ± 5%, and above-mentioned percentage ratio is weight percentage.
In the above-mentioned emulsion, described nano alumina powder jointed particle diameter is 5~50 nanometers; The grain graininess of described Nano silica sol is 5~30 nanometers, and solids content is 20~40%.
In the above-mentioned emulsion, described acrylic emulsion is one or more in acrylic ester emulsion, benzene emulsion, the acrylate and vinyl acetate emulsion.Can form by the raw material of following weight parts: 1000 parts of monomers; 10~25 parts of emulsifying agents; 5~20 parts of initiators; 0.1~20 part of coupling agent; 1500 parts of deionized waters.
In the above-mentioned emulsion, described acrylic emulsion adopts semicontinuous synthesis technique, concrete steps are, in reactor, add partial emulsifier, initiator and deionized water, be warming up to 84~88 ℃ under stirring, drip the mixed solution of remaining emulsifying agent, initiator and deionized water mixed solution and monomer and coupling agent after 10 minutes simultaneously, 1.5~2 hours dropping time, polymerization temperature is at 84~88 ℃, dropwise again in 86~90 ℃ of insulations 1 hour, be cooled to 40~50 ℃, filtration, blowing are acrylic emulsion.
In the above-mentioned emulsion, described monomer is one or more in methyl methacrylate, Jia Jibingxisuanyizhi, butyl methacrylate, Isooctyl methacrylate, methyl acrylate, ethyl propenoate, butyl acrylate, Isooctyl acrylate monomer, methacrylic acid, vinylformic acid, vinylbenzene, the vinyl acetate.Described emulsifying agent is nonionic emulsifier or anionic emulsifier.For example, sodium lauryl sulphate, Sodium dodecylbenzene sulfonate, MS-1, HMPS, alkylphenol polyoxyethylene etc.Described initiator is ammonium persulphate or Potassium Persulphate.Described coupling agent is silane coupling agent or titanate coupling agent.Wherein silane coupling agent can be to contain in the silane coupling agent of amino, vinyl, epoxy group(ing) or methacryloxy one or more.
The method for preparing the emulsion of above-mentioned composite nano materials modification, at first pressing formula rate mixes nano alumina powder jointed and Nano silica sol, be that 100~200nm obtains compound further again, with compound acrylic emulsion carried out modification by formula rate then and get final product with ultrasonic dispersing to dispersion particle size.
In above-mentioned preparation method, described method with compound modification acrylate class emulsion is, under agitation be added to and mixed the assembly finish modification in the synthetic acrylic emulsion, or compound is added in the reactor, with each component of forming acrylic emulsion, carry out letex polymerization together and finish modification.
Technique effect of the present invention: the acrylic ester emulsion that adopts the composite nano materials modification of technical scheme of the present invention, because used nano material is nano alumina powder jointed and Nano silica sol, it can make emulsion obtain the characteristic of two kinds of nano materials simultaneously, particularly when preparation emulsion of the present invention, composite two kinds of nano materials, for nano alumina powder jointed, Nano silica sol plays the effect of dispersion agent in fact, because silica sol particle be nano level and most of grain graininess about 15nm, there is great amount of hydroxy group on the surface.This silica sol particle porous is in nano alumina powder jointed coacervate gap and be adsorbed on nano alumina powder jointed particle surface, under the ultrasonic dispersing effect, and nano alumina powder jointed can well the dispersion and be stabilized in the Nano silica sol.Overcome in the prior art and assembled the various disadvantages of being brought because of nano-powder.Also has collaborative stabilization mutually between finely disseminated two kinds of nano materials simultaneously, thereby the further again modification acrylate class emulsion of the compound that obtains in this way, its package stability is better than being used alone nano-material modified similar emulsion greatly, after film forming, the water tolerance aspect obviously is better than unmodified similar emulsion.In addition, no matter adopt the composite nano material of aforesaid method, when modification acrylate class emulsion, be with the organic monomer polymerization, still directly with compound and synthetic emulsion mechanically mixing, the emulsion package stability of modification of the present invention all is significantly improved.
Embodiment
Below in conjunction with embodiment the present invention is further described in detail, but is not limited to this.The consumption of each raw material is weight part among the embodiment, unless otherwise indicated, is commercially available industrial goods.
Embodiment 1
1, the preparation of nano material compound
With 10 weight parts nano alumina powder jointed (granularity 20nm), with 400 weight part Nano silica sol (solids contents 25%, mean particle size 10nm), even in container for stirring, place ultrasonic dispersing instrument (power: 800 watts) to be dispersed to granularity<120nm then and obtain compound, wherein nano alumina powder jointed 10% of the Nano silica sol amount of solid that accounts for is stored standby.
2, the prescription of acrylic ester emulsion sees Table 1.
Table 1
Component | Material name | Consumption |
Monomer | Butyl acrylate | 435 |
Methyl methacrylate | 532 |
Vinylformic acid | 33 |
Coupling agent | KH570 | 2 |
Emulsifying agent | Sodium lauryl sulphate | 20 |
Initiator | Ammonium persulphate | 6 |
| Deionized water | 1500 |
3, the preparation of modified emulsion
To heat up in 2/3 the deionized water adding reactor, when temperature reaches 84~88 ℃, add 20% of emulsifying agent, initiator and 500 parts of deionized water mixture, after 10 minutes, beginning drips the mixed solution of emulsifying agent, initiator and 500 parts of deionized waters of the mixed solution of monomer and coupling agent and residual content simultaneously, be controlled in 1.5~2 hours and dropwise, be warming up to 86~90 ℃ of insulations 1 hour, be cooled to 40~50 ℃ of filtrations, blowings and make acrylic ester emulsion.Stir the nano material compound that adding has down made, mix the acrylic ester emulsion that obtained the composite nano materials modification in 0.5 hour.
Embodiment 2
1, adopt embodiment 1 same recipe and method to prepare the nano material compound.
2, the prescription of acrylic ester emulsion is identical with embodiment 1.
3, the preparation of modified emulsion
Compound that will make by embodiment 1 prescription and method and 2/3 deionized water (1000 parts) are added to intensification in the reactor, when temperature reaches 84~88 ℃, below in the presence of compound, finish letex polymerization by the emulsion polymerisation process of embodiment 1 again, make the acrylic ester emulsion of composite nano materials modification.
Comparative example 1
Repeat the process of embodiment 1, just replace nano material compound and the acrylic ester emulsion mechanical stirring identical and mix and piece together with embodiment 1 with Nano silica sol.
Comparative example 2
Repeat the process of embodiment 2, just replace the nano material compound, with each component polymerization of forming acrylic ester emulsion with Nano silica sol.
Comparative example 3
Press the prescription and the method for embodiment 1 acrylic ester emulsion, the preparation acrylic ester emulsion does not add any nano material.
Embodiment 3
1, the compound for preparing nano material by prescription and the method for embodiment 1.
2, the prescription of benzene emulsion sees Table 2.
Table 2
Component | Material name | Consumption |
Monomer | Butyl acrylate | 435 |
Methyl methacrylate | 100 |
Toluylic acid | 432 |
Vinylformic acid | 33 |
Coupling agent | KH570 | 2 |
Emulsifying agent | MS-1 | 40 |
Initiator | Ammonium persulphate | 8 |
| Deionized water | 1500 |
3, the preparation of modified emulsion.
Except that the monomer that adopts table 2 replaced the monomer of embodiment 1 table 1, all the other were operated all with embodiment 1, and the benzene emulsion that makes stirs the nano material compound that adding has down made, mixes the benzene emulsion that obtained the composite nano materials modification in 0.5 hour.
Embodiment 4
1, the compound for preparing nano material by identical prescription and the method for embodiment 1.
2, the prescription of benzene emulsion is identical with embodiment 3.
3, the preparation of modified emulsion.
Deionized water with 2/3 and compound add reactor and heat up, and when temperature reaches 84~88 ℃, below finish letex polymerization by the emulsion polymerisation process of embodiment 3 in the presence of compound again, obtain the benzene emulsion of composite nano materials modification.
Comparative example 4
Repeat the process of embodiment 3, just replace the nano material compound, and the propyl benzene emulsion mechanical stirring identical with embodiment 3 mixed and pieced together with Nano silica sol.
Comparative example 5
Repeat the process of embodiment 4, just replace the nano material compound with Nano silica sol, and with each component polymerization of forming benzene emulsion.
Comparative example 6
Prescription and method by embodiment 3 benzene emulsions prepare benzene emulsion, do not add any nano material.
The emulsion property of the foregoing description 1~4 and comparative example 1~6 detects as follows, the results are shown in Table 3.
Table 3
Project | Embodiment 1 | Embodiment 2 | Comparative example 1 | Comparative example 2 | Comparative example 3 |
Package stability | 120 days no abnormal | 120 days no abnormal | Flocculation in 30 days | Flocculation after 7 days | 120 days no abnormal |
Water tolerance | 48h is no abnormal | 72h is no abnormal | 48h is no abnormal | 48h is no abnormal | 16h has vesicle |
| Embodiment 3 | Embodiment 4 | Comparative example 4 | Comparative example 5 | Comparative example 6 |
Package stability | 120 days no abnormal | 120 days no abnormal | Flocculation in 21 days | Flocculation in 3 days | 120 days no abnormal |
Water tolerance | 72h is no abnormal | 96h is no abnormal | 48h is no abnormal | 48h is no abnormal | 24h has vesicle |
The performance of the emulsion of check composite nano materials modification.
1, storage stability test.
In the container (glass or plastics system) of about 100ml, pack into the sample to be checked and the sealed vessel of a certain amount of (leaving 5% space).Container was put into 40 ° ± 2 ℃ thermostat containers 20 hours, take out the back and placed 3 hours, weigh again at 23 ± 2 ℃.Differ before and after sample is stored and be no more than 1% of the preceding weight of weighing, open container, observation has or not lump, flocculation and demixing phenomenon.
2, water tolerance evaluation test
With 60 μ m blade coating devices above-mentioned emulsion is coated on the sheet glass,, places 48 hours film forming in normal temperature again 60 ℃ of dryings 30 minutes.To film and immerse in the water foaming situation that visual observation is filmed.
Assay sees Table 3
By above-mentioned assay as can be known, the emulsion of composite nano materials modification of the present invention, package stability obviously is better than with single nano-material modified emulsion (comparative example 1,2,4 and 5), and the emulsion water tolerance of composite nano materials modification obviously is better than unmodified emulsion (comparative example 3 and 6).Therefore, modified emulsion over-all properties of the present invention is better.
With the modified emulsion preparation exterior coating of the embodiment of the invention 1~4, its water tolerance of filming, alkali resistance and artificial ageing resistance all obviously are better than the index of GB/T9755-2001 premium grads.