A kind of preparation method of double-layer coated water-based aluminum pigment
One, technical field
The present invention relates to a kind of preparation method of water-based paint, specifically a kind of preparation method of double-layer coated water-based aluminum pigment.
Two, background technology
Along with expanding economy, growth in the living standard, people's environmental consciousness strengthens gradually, and is more and more higher to the requirement of coating.Require not only that its product is attractive in appearance, performance good, also require its pollution little.Therefore, to the improvement of aluminium pigment production technique, develop multi-functional, lowly pollute, nuisanceless, non-dusting aluminium pigment is following developing direction.
Traditional metal flash paint all is solvent-borne type, and volatile organic content is higher.The organic solvent volatile quantity is had strict demand abroad, such as the regulation coating, what have only has coating.At present, China does not also have so strict regulation to the solvent discharge amount, but solvent discharge is required as strict as possible is trend of the times.
High solid, Water-borne modification, powdered are three important channels of low VOC coatings development.The metal flash paint Water-borne modification trend that is inevitable, external this respect technology is ripe, can apply very soon, and domestic estimation also has the demand of water-based metal polychromatic finish in several years.Because aluminium is easy to react with water; its metalluster is destroyed in water-based system; consequent hydrogen also can bring such as Hazard Factor such as burnings, so the aluminium pigment applications must protect its surface when water-based system, also will consider not damage simultaneously its pigment performance.
The aluminium surface of pigments treatment technology of China and European and American developed countries also have very large gap, particularly are wanting in apart from larger at color changeable pigment and aluminium powder Water-borne modification process for treating surface.Therefore, research aluminium surface of pigments treatment technology is further to promote China's aluminium pigment industry development, enlarges the water-miscible paint Application Areas and satisfies the important measures of environmental requirement.
The water tolerance of aluminium powder pigment is not good.Moisture content in the solvent based coating should be controlled at below 0.15%, and tin phenomenon occurs otherwise aluminium and water reaction can cause rising.Even aqueous aluminum powder pigment also has many defectives.Aqueous aluminum powder pigment is made by two kinds of methods usually: the one, and the physical protection method, namely coat the polymkeric substance of one deck inertia on the surface of aluminium powder, the aluminium powder pigment surface is lost activity, but can not guarantee 100% clad ratio, in addition in the paint spraying process, coating film cracky or aluminium scale easily break, and the aluminium that does not coat is exposed in the water; The 2nd, the chemoproection method adopts the reaction of chromic salt or phosphoric acid salt and aluminium powder, makes its surface passivation, and what still this aluminium powder was made films, and its water tolerance descends to some extent.Other chromic salt " passivation " technology, product contains the composition of " chromium "." chromium " is a kind of heavy metal substance, and containing " sexavalent chrome " is absolute prohibition in Europe.The aluminium flake surface metal sense meeting degradation that simultaneously passivation coats, aluminium flake chap, the requirement that does not reach high-grade industrial coating.
Three, summary of the invention
The present invention is for fear of above-mentioned the deficiencies in the prior art part, provides that a kind of coating is thin and even, water-tolerant, does not contain the preparation method of the double-layer coated water-based aluminum pigment of heavy metal.Technical problem to be solved is that the aluminium powder material is carried out double-coated.
Technical solution problem of the present invention adopts following technical scheme:
The preparation method's of double-layer coated water-based aluminum pigment of the present invention characteristics are to operate according to the following steps:
A, the ball aluminum powder that will atomize ball milling get the oiliness flaky aluminum material powder that particle diameter is 8-40 μ m, and described material powder is used ketones solvent soaking and stirring 1-2 hour, in order to wash the physical package coating on flaky aluminum surface, filter to such an extent that solid content is the filter cake of 75-80%;
B, in mass fraction, in the filter cake of 20-30 part, add the alcoholic solvent of 70-80 part in 25-35 ℃ of dispersed with stirring 0.5-1 hour, then drip simultaneously mixed solution a and mixed solution b, in 40 ℃ of stirring reactions 6 hours, filter after at room temperature ageing 6-10 hour and obtain the individual layer metallized aluminum pigment that solid content is 70-80% after being added dropwise to complete;
Obtain after ammoniacal liquor 0.5-1.5 part that described mixed solution a is mass percent 25%, distilled water 2-3 part and 5 parts of mixing of alcoholic solvent;
Described mixed solution b obtains after tetraethoxy 3-5 part and 5 parts of mixing of alcoholic solvent;
C, in mass fraction; individual layer metallized aluminum pigment and 70-80 part ether solvent that 20-30 part step b is obtained mix; drip respectively simultaneously 4-8 part wetting ability esters monomer and 0.01-0.05 part azo-initiator; under nitrogen protection in encloses container stirring reaction 2-4 hour; the control temperature of reaction is filtered after reaction finishes and is obtained the double-coated based aluminum pigment that mass percent is 60-70% at 70-80 ℃.
The preparation method's of double-layer coated water-based aluminum pigment of the present invention characteristics also are: described ketones solvent is one or more in acetone, butanone, the pimelinketone.
The preparation method's of double-layer coated water-based aluminum pigment of the present invention characteristics also are: described alcoholic solvent is ethanol, n-propyl alcohol, one or more in Virahol, the mixed propyl alcohol.
The preparation method's of double-layer coated water-based aluminum pigment of the present invention characteristics also are: described ether solvent is one or more in ethylene glycol monobutyl ether, glycol dimethyl ether, ethylene glycol ethyl ether, ethylene glycol monomethyl ether, the butyl glycol ether.
The preparation method's of double-layer coated water-based aluminum pigment of the present invention characteristics also are: described wetting ability esters monomer is one or more in hydroxyethyl methylacrylate, Hydroxyethyl acrylate, Rocryl 410, the Propylene glycol monoacrylate.
The preparation method's of double-layer coated water-based aluminum pigment of the present invention characteristics also are: described azo-initiator is Diisopropyl azodicarboxylate.
The preparation method's of double-layer coated water-based aluminum pigment of the present invention characteristics also are: the stirring velocity among the described step a is 50-100r/min.
Compared with the prior art beneficial effect of the present invention is embodied in:
1, the double-layer coated water-based aluminum pigment of the present invention's preparation coats closely, and coating layer is difficult for destroyed, water-tolerant;
2, the double-layer coated water-based aluminum pigment good water solubility of the present invention's preparation, directly dilute with water;
3, the coating of the double-layer coated water-based aluminum pigment of the present invention's preparation is thin and even, little on the impact of aluminium flake metalluster, the present invention is multilayer coating structure, outer field organic layer easily and the macromolecule resin in the coating mix, good dispersity in coating is mainly used in various water-borne coatingss and the water color ink.
Four, embodiment
Embodiment 1:
1, take by weighing behind the 100g atomizing ball aluminum powder ball milling to such an extent that particle diameter be the oiliness flaky aluminum material powder of 15 μ m, described material powder is added in the single port flask of 250mL, add again the 300mL acetone solvent, stir 1.5h with the rotating speed of 100r/min, filter to such an extent that solid content is 75% filter cake;
2, take by weighing step 1 gained filter cake 100g, add in the 1000mL there-necked flask, add again the Virahol of 320g in 35 ℃ of dispersed with stirring 0.5h, then drip simultaneously mixed solution a and mixed solution b with two constant pressure funnels, wherein mixed solution a obtains after ammoniacal liquor 4.0g, the distilled water 12g of mass percent 25% and Virahol 20g mix, and mixed solution b obtains after tetraethoxy 20g and Virahol 20g mix; In 40 ℃ of stirring reaction 6h, at room temperature filtering behind the ageing 8h and obtaining solid content is 75% individual layer metallized aluminum pigment after being added dropwise to complete;
3, taking by weighing step 2 obtains in the individual layer metallized aluminum pigment 100g adding 1000mL there-necked flask; add again the 320g butyl glycol ether; airtight logical nitrogen protection; dispersed with stirring 2h; be warmed up to 75 ℃; drip respectively simultaneously 16g hydroxyethyl methylacrylate monomer and 0.2g Diisopropyl azodicarboxylate, dropwise rear insulation reaction 3h, filtering and obtaining massfraction is 60% double-coated based aluminum pigment.
Embodiment 2:
1, take by weighing behind the 150g atomizing ball aluminum powder ball milling to such an extent that particle diameter be the oiliness flaky aluminum material powder of 15 μ m, described material powder is added in the single port flask of 250mL, add again the 300mL butanone solvent, stir 1.5h with the rotating speed of 50r/min, filter to such an extent that solid content is 80% filter cake;
2, take by weighing step 1 gained filter cake 120g, add in the 1000mL there-necked flask, add again the ethanol of 280g in 25 ℃ of dispersed with stirring 1h, then drip simultaneously mixed solution a and mixed solution b with two constant pressure funnels, wherein mixed solution a obtains after ammoniacal liquor 6.0g, the distilled water 8g of mass percent 25% and Virahol 20g mix, and mixed solution b obtains after tetraethoxy 12g and Virahol 20g mix; In 40 ℃ of stirring reaction 6h, at room temperature filtering behind the ageing 6h and obtaining solid content is 75% individual layer metallized aluminum pigment after being added dropwise to complete;
3, taking by weighing step 2 obtains in the individual layer metallized aluminum pigment 120g adding 1000mL there-necked flask; add again the 300g ethylene glycol monobutyl ether; airtight logical nitrogen protection; dispersed with stirring 3h; be warmed up to 70 ℃; drip respectively simultaneously 20g Hydroxyethyl acrylate monomer and 0.1g Diisopropyl azodicarboxylate, dropwise rear insulation reaction 3h, filtering and obtaining massfraction is 65% double-coated based aluminum pigment.
Embodiment 3:
1, take by weighing behind the 100g atomizing ball aluminum powder ball milling to such an extent that particle diameter be the oiliness flaky aluminum material powder of 15 μ m, described material powder is added in the single port flask of 250mL, add again the 300mL cyclohexanone solvent, stir 1.5h with the rotating speed of 75r/min, filter to such an extent that solid content is 75% filter cake;
2, take by weighing step 1 gained filter cake 80g, add in the 1000mL there-necked flask, add again the n-propyl alcohol of 300g in 35 ℃ of dispersed with stirring 0.5h, then drip simultaneously mixed solution a and mixed solution b with two constant pressure funnels, wherein mixed solution a obtains after ammoniacal liquor 2.0g, the distilled water 10g of mass percent 25% and Virahol 20g mix, and mixed solution b obtains after tetraethoxy 16g and Virahol 20g mix; In 40 ℃ of stirring reaction 6h, at room temperature filtering behind the ageing 10h and obtaining solid content is 80% individual layer metallized aluminum pigment after being added dropwise to complete;
3, taking by weighing step 2 obtains in the individual layer metallized aluminum pigment 80g adding 1000mL there-necked flask; add again the 280g glycol dimethyl ether; airtight logical nitrogen protection; dispersed with stirring 4h; be warmed up to 80 ℃; drip respectively simultaneously 32g Rocryl 410 and Propylene glycol monoacrylate mix monomer and 0.04g Diisopropyl azodicarboxylate, dropwise rear insulation reaction 3h, filtering and obtaining massfraction is 70% double-coated based aluminum pigment.