Summary of the invention
The present invention provides one kind without toxic Cr VI to solve above-mentioned technical problem and is easily recycled, and has excellent performance
Chrome-free insulating masking liquid and preparation method thereof and directional silicon steel.
The object of the invention is realized using following proposal:
A kind of chrome-free insulating masking liquid, the chrome-free insulating masking liquid includes following components: phosphate solution 150-200 weight
Part, citric acid 8-15 parts by weight, magnesium hydroxide 2-8 parts by weight, boric acid 6-10, silica solution 150-250 parts by weight, tartaric acid 1-10
Parts by weight, antimony trifluoride 1-10 parts by weight, phosphotungstic acid 1-10 parts by weight and water 100-300 parts by weight.
In above scheme, the solid content of the chrome-free insulating masking liquid is 20%~40%, and specific gravity is 1.1g/ml~1.3g/
Ml, viscosity are 10s~30s.
In above scheme, the silica solution is that acid or alkaline silica sol, the partial size of silicon dioxide granule are received for 1-10
Rice.
In above scheme, the phosphate solution is the mixing of phosphate dihydrogen aluminum solution and biphosphate magnesium solution.
The preparation method of the chrome-free insulating masking liquid, includes the following steps:
Phosphate solution, boric acid and water, stirring is added;
Antimony trifluoride, citric acid and tartaric acid are sequentially added, is stirred;
Magnesium hydroxide and phosphotungstic acid is added, makes pH 1-5,
Silica solution is added, stirs to get the chrome-free insulating masking liquid is arrived.
A kind of directional silicon steel comprising substrate and the chrome-free insulating coating for being formed in the substrate surface, the Chrome-free
Insulating coating is by the way that the chrome-free insulating masking liquid to be coated in obtained by substrate surface.
In above scheme, the preparation method of the chrome-free insulating coating specifically:
The chrome-free insulating masking liquid is coated on orientation silicon steel steel plate, by the coating composition of coating at 350-500 DEG C
At a temperature of dry 30s~80s, then in 800 DEG C~1000 DEG C of at a temperature of sintering curing 50s~150s, i.e., in orientation silicon steel
Surface of steel plate forms chrome-free insulating coating.
In above scheme, the chrome-free insulating coating with a thickness of 1-5 microns.
In above scheme, dry film coated weight is controlled in 2.0-7.0g/m2In range.
Compared with prior art, the present invention having the positive effect that:
1. chrome-free insulating coating of the invention is free of chromium compound (+6 valence Cr and+trivalent Cr), without RoHS defined
The toxic substance such as (Pb, Cr, Hg, Cd, PBB, PBDA), is easily recycled.
2. chrome-free insulating coating of the invention can stablize preservation 3 months or more (viscosity change value is less than 5s) at normal temperature,
Levelability and wetability are good, are easy to coat in orientation silicon steel surface of steel plate, and can satisfy 800 DEG C~1000 DEG C after coating operation
Silicon steel plate sintering curing temperature and directly cooling.
3. chrome-free insulating coating coating of the invention shows outstanding adhesion, corrosion resistance, resistance to skin on the steel plate
The exudative and outstanding adhesion resistance of film, lubricity, stampability, the excellent in performance such as weldability.
4. chrome-free insulating coating of the invention has high interface resistance and surface hardness, and has extremely strong surface
Tension shows brilliant magnetic property improved effect.Its oriented silicon steel can fully meet high-power transformer and extra-high
The requirements such as pressure transformer.
Specific embodiment
It is further below in conjunction with specific embodiment for the contents of the present invention, technical solution and advantage is more clearly understood
Illustrate the present invention, these embodiments are merely to illustrate the present invention, and the present invention is not limited only to following embodiment.
The present invention provides a kind of chrome-free insulating masking liquid, and the chrome-free insulating masking liquid includes following components: phosphate solution
150-200 parts by weight, citric acid 8-15 parts by weight, magnesium hydroxide 2-8 parts by weight, boric acid 7-10, silica solution 160-250 weight
Part, tartaric acid 1-10 parts by weight, antimony trifluoride 1-10 parts by weight, phosphotungstic acid 1-10 parts by weight and water 100-300 parts by weight.
The solid content of the coating composition be 20%~40%, specific gravity be 1.1g/ml~1.3g/ml, viscosity be 10s~
30s (4# Ford cup);The quality of water is mainly adjusted according to the viscosity of composition.
The solid content of phosphate solution is 40%-60%, and phosphate is preferably dihydric phosphate.Dihydric phosphate is preferably
Any one in aluminium dihydrogen phosphate, calcium dihydrogen phosphate, biphosphate nickel, phosphate dihydrogen manganese, magnesium dihydrogen phosphate or zinc dihydrogen phosphate
Or the mixed solution of two or more arbitrary proportions.Further, phosphate solution is preferably phosphate dihydrogen aluminum solution and di(2-ethylhexyl)phosphate
The mixing of hydrogen magnesium solution.
The partial size of silicon dioxide granule is 1-10 nanometers in silica solution.The quality percentage of silica dioxide granule contains in silica solution
Amount is 20-30%.Silicon dioxide granule is acid or alkaline silicon dioxide particle, preferably acid silicon dioxide particle.
The present invention also provides the preparation methods of the chrome-free insulating masking liquid, include the following steps:
Phosphate solution, boric acid and water, stirring is added;
Antimony trifluoride, citric acid and tartaric acid are sequentially added, is stirred;
Magnesium hydroxide and phosphotungstic acid is added, makes pH 1-5;
Silica solution is added, stirs to get the chrome-free insulating masking liquid is arrived.
The present invention also provides a kind of directional silicon steels comprising substrate and the chrome-free insulating for being formed in the substrate surface apply
Layer, the chrome-free insulating coating be as by chrome-free insulating masking liquid be coated in substrate surface obtained by, method particularly includes: in orientation silicon steel
The chrome-free insulating masking liquid is coated on steel plate, at a temperature of drying 30s~80s by the coating composition of coating at 350-500 DEG C,
Then in 800 DEG C~1000 DEG C of at a temperature of sintering curing 50s~150s, i.e., chrome-free insulating is formed in orientation silicon steel surface of steel plate
Coating controls dry film coated weight in 2.0-7.0g/m2In range.Chrome-free insulating coating with a thickness of 1-5 microns.
With specific embodiment, invention is further explained below, and table 1 lists the chrome-free insulating of different formulations
Masking liquid.
The chrome-free insulating masking liquid of the different compositions of 1 embodiment of the present invention of table and comparative example
It should be noted that the quality of water can be added according to the requirement of the viscosity of composition and solid content.
Being coated in orientation silicon steel plate surface by coating made from examples and comparative examples of the present invention, (orientation silicon steel presses thickness
There are 0.18mm, 0.2mm, 0.23mm, 0.27mm, 0.3mm equal-specification, test, which is chosen, passes through the annealing of high temperature secondary recrystallization
0.23mm grain-oriented Si steel sheet), before coating, grain-oriented Si steel sheet is put into soak at room temperature 1min in 3.0% dilution heat of sulfuric acid,
Then cleaning scrub is carried out with deionized water and fur brush, quickly dries up surface moisture, it is floating grey to remove surface oxidation magnesium etc.
The coating experiment is carried out to clean directional silicon steel.
Insulating coating solution is coated to orientation silicon steel surface of steel plate by coating machine paint roller, the coating composition of obtained coating
Steel plate is directly entered in 450 DEG C of continuous stove and dries, and coated weight is controlled in 2.0-7.0g/m2In range;And it is continuously moving back
900 DEG C of progress 1min sintering in stove form uniform chrome-free insulating coating, work after progress in surface of steel plate after taking out cooling
Continuous processing.
After the completion of coated test, salt fog, the test such as interface resistance and magnetic property are carried out to breadboard.
The test of 2 coating performance of table
The specific test method is as follows for the measurement performance being related in table 2:
1) test method of epithelium tension are as follows:
Double-coated coating composition is formed into the silicon steel sheet of chrome-free insulating coating by the examination rolled to cutting 30mm × 280mm
Piece is tested, the insulating coating of test film one side is removed, test film recumbency is erected, one end is fixed with 30mm, measures the curved of the other end
Qu great little brings data into following equation and calculates:
σ (MPa)=1.2152 × 105 (MPa) × plate thickness (mm) × bending (mm)/250 (mm)/250 (mm).
2) test method that substance oozes out in resistance to epithelium are as follows:
30 minutes 100 DEG C of vapor is sprayed to test film, observes the appearance color change situation of coating.
Evaluation method: zero: substantially constant color △: a part discoloration ×: discoloration completely.
3) test method of coating adhesion are as follows:
Evaluation method: test film is bent to20, the circle of 30mm is stained with transparent rubberized fabric in bending section, then again
Transparent rubberized fabric is opened, to visually observe the peeling situation of insulating coating.
Evaluation criterion: zero: a little without peeling off △: a part peeling ×: it is a large amount of to peel off
4) test method of corrosion resistance are as follows:
Evaluation method: before annealing: SST 12 hours;After annealing: SST 5 hours.
Evaluation criterion: applicable is 10 methods.
10: red rust area 0%9: red rust area 0~1%8: red rust area 1~5%7: red rust area 5~10%6: red rust
Area 10~15%5: red rust area 15~25%4: red rust area 25~35%3: red rust area 35~45%2: red rust area
45~65%1: 65% or more red rust area.
It should be noted that the foregoing is merely presently preferred embodiments of the present invention, various modifications to these embodiments pair
Will be apparent for those skilled in the art, therefore, the present invention be not intended to be limited to it is shown in this article this
A little embodiments, any changes and modifications in accordance with the scope of the present application should belong to patent of the invention and cover
Within the scope of.