Background technology
As everyone knows, most of metals corrode under field conditions (factors) easily, it is carried out the surfacecti proteon processing after, the speed of the metallic corrosion of can slowing down greatly.In various treatment processs, traditional technology has chromating, phosphate conversion processing and rare-earth conversion coatings processing etc., yet preceding two kinds of technologies exist than the serious environmental pollution problem, as the high valence chrome ion very strong toxicity and carinogenicity are arranged, phosphoric acid salt then is one of main arch-criminal of body eutrophication; And rare-earth conversion coatings technical matters more complicated.In recent years, along with the raising of various countries' environmental requirement, development of new green metal process for treating surface has become the focus of this area research.Wherein, the organic-silylation processing is pollution-free because of it, processing part corrosion resisting property is good and preparation technology simply enjoys favor.
The metallic surface silanization treatment technology is to utilize silane reagent (with single silane is example, and its general formula is X-Si (OR)
3, wherein X represents functional group, one or more in alkyl or alkenyl, methoxyl group, oxyethyl group or the benzyl that replaces for alkyl, thiazolinyl, by at least one amino, epoxy group(ing) or sulfydryl; R is an alkyl, is generally methyl, ethyl, propyl group, sec.-propyl, butyl, isobutyl-, sec-butyl, the tertiary butyl or ethanoyl etc.) hydrolysis generation silanol (X-Si (OH)
n(OR)
3-n), silanol by combine with metal (Me) surface hydroxyl and silanol between after the self-crosslinking condensation, form one deck compact protective film in the metallic surface, thus the barrier propterty of providing.
A large amount of experiments show that the hydrolyzed solution after the simple silane dilution of ordinary method preparation is handled part surface filming very thin thickness, is generally tens to hundreds of nanometers, and the rete not even compact that distributes, and the corrosion resisting property of metal are improved can not reach good effect.The compactness that how to increase thickness, raising surface film improves new direction, the fresh target that metal corrosion resisting property this purpose becomes the investigator to reach.So far, the technology that obtains better effect has: double-deck silane film technique, the polynary compound silane membrane technique of disposable deposition and add the inertia nano particle (as SiO in solution
2, ZnO
2, Al
2O
3), add rare earths salt (as Ce (NO
3)
3) out-phase improvement technology etc.
Summary of the invention
The objective of the invention is at the deficiencies in the prior art, a kind of preparation method and its usage of homogeneous phase modified silane solution is provided.
The objective of the invention is to be achieved through the following technical solutions:
The preparation method of modified silane solution joins in the mixed system of water and water-miscible organic solvent constantly the additive that agitation condition slowly adds the different content behind the same organic solvent diluting down with silane, silane: water: volume of organic solvent is than being m: n: (100-m-n), wherein m/n is 0.1-1, silane: the mol ratio of additive is 10: 1-10000: 1, after stirring, with the solution left standstill, the constant temperature hydrolysis that configure 0.1-48 hour.
Described silane is single silane and two silane, and single silane structure general formula is:
Wherein, R is methyl, ethyl, propyl group, sec.-propyl, butyl, isobutyl-, sec-butyl, the tertiary butyl or ethanoyl, and X is one or more in alkyl, thiazolinyl or the alkyl or alkenyl, methoxyl group, oxyethyl group or the benzyl that are replaced by at least one amino, epoxy group(ing) or sulfydryl.
Two silane structure general formulas are:
Wherein, R is methyl, ethyl, propyl group, sec.-propyl, butyl, isobutyl-, sec-butyl, the tertiary butyl or ethanoyl, and Y is CH
2CH
2, (CH
2)
3-NH-(CH
2)
3Or (CH
2)
3-S
4-(CH
2)
3
Described organic solvent is methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, ethyl acetate or tetrahydrofuran (THF).Described additive is zirconic acid alkyl ester, alkyl titanate, stannic acid alkyl ester, lead acetate, Co (acac)
2, Cu (acac)
2Or Zn (acac)
2
Solution of silane is used for the protective of metal base surface to be handled.
Described metallic matrix is an iron and steel, galvanized steel, aluminium, zinc, magnesium, copper, tin and alloy thereof.The protective treatment process of described metal base surface is spread coating, dip coating, spin-coating method or electrochemistry assistant depositing method.
Homogeneous phase modified silane formulations prepared from solutions technology provided by the invention is simple, and cost is lower.Compare with the simple solution of silane of ordinary method preparation, silane hydrolyzate rapidly, the condensation film forming is easier on the processing part carries out, handle the part corrosion resisting property under the same hydrolysis time and obviously improve, and in certain additive concentration scope with under the long period, hydrolyzed silane solution has good stability.The present invention can be used for the protective pre-treatment of multiple metal and alloy.
Embodiment
The preparation method of modified silane solution joins in the mixed system of water and water-miscible organic solvent constantly the additive that agitation condition slowly adds the different content behind the same organic solvent diluting down with silane, silane: water: volume of organic solvent is than being m: n: (100-m-n), wherein m/n is 0.1-1, silane: the mol ratio of additive is 10: 1-10000: 1, after stirring, with the solution left standstill, the constant temperature hydrolysis that configure 0.1-48 hour.
Described silane is single silane and two silane, and single silane structure general formula is:
Wherein, R is methyl, ethyl, propyl group, sec.-propyl, butyl, isobutyl-, sec-butyl, the tertiary butyl or ethanoyl, and X is one or more in alkyl, thiazolinyl or the alkyl or alkenyl, methoxyl group, oxyethyl group or the benzyl that are replaced by at least one amino, epoxy group(ing) or sulfydryl.
Two silane structure general formulas are:
Wherein, R is methyl, ethyl, propyl group, sec.-propyl, butyl, isobutyl-, sec-butyl, the tertiary butyl or ethanoyl, and Y is CH
2CH
2, (CH
2)
3-NH-(CH
2)
3Or (CH
2)
3-S
4-(CH
2)
3
Described organic solvent is methyl alcohol, ethanol, n-propyl alcohol, Virahol, propyl carbinol, ethyl acetate or tetrahydrofuran (THF).Described additive is zirconic acid alkyl ester, alkyl titanate, stannic acid alkyl ester, lead acetate, Co (acac)
2, Cu (acac)
2Or Zn (acac)
2
Solution of silane is used for the protective of metal base surface to be handled.
Described metallic matrix is an iron and steel, galvanized steel, aluminium, zinc, magnesium, copper, tin and alloy thereof.The protective treatment process of described metal base surface is spread coating, dip coating, spin-coating method or electrochemistry assistant depositing method.
Embodiment 1
Get methyltrimethoxy silane (MTMS) solution 5mL and join in ethanol (50mL)-water (5mL) mixed solution system, stir the back and add about 0.035mL Glacial acetic acid (solution A); Getting 0,1,10,100,1000 μ L tetra-n-butyl titanates respectively joins in the 40mL ethanolic soln and stir (solution B).A, B two solution are mixed, obtain tetra-n-butyl titanate concentration and be respectively 0,2.9 * 10
-5, 2.9 * 10
-4, 2.9 * 10
-3And 2.9 * 10
-2The series modified solution of silane of M, wherein pH value of solution is~4.5, silane concentration is~0.35M.It is stand-by that solution is put into 35 ℃ of Water Tank with Temp.-controlled hydrolysis 48 hours.
Matrix is handled: stainless steel base is successively after 400,600, No. 800 abrasive paper for metallograph polishings, putting into degreasing fluid descended ultrasonic 15 minutes in 45 ℃, wash away the residual alkali lye of electrode surface with tap water, dry up behind the deionized water rinsing electrode surface and place moisture eliminator stand-by.
Matrix silanization: matrix is immersed 200s in the good solution of silane of hydrolysis, blow away behind the unnecessary solution of silane in surface promptly in 100 ℃ of drying in oven 1 hour with high pressure nitrogen.
The stainless steel that solution coats before and after modification is handled the typical infrared spectrum of part silane surface rete and is seen accompanying drawing 1.As seen from the figure, solution of silane modification aftertreatment part silane film layer thickness increases, the infrared absorption peak intensity enhancing.786cm wherein
-1Corresponding to the absorption of Si-C stretching vibration, 923cm
-1Corresponding to the absorption of Si-OH, 1158cm
-1Corresponding to the absorption of Si-O-Si key, 1276cm
-1Corresponding to-CH
3Formation vibration absorb.
Adopt electrochemical impedance spectroscopy test evaluation silanization to handle, see accompanying drawing 2 the stainless steel effect on corrosion.Show among the figure that after silanization was handled, the resistance value of stainless steel in NaCl solution was greatly improved, the resistance value of system is further enhanced after the solution of silane of tetra-n-butyl titanate modification is handled simultaneously, for example, compare, add 2.3 * 10 with pure 0.35M solution of silane
-2A small amount of tetra-n-butyl titanate of M can make the barrier propterty of silane film improve 1 most magnitude.Concrete modulus of impedance value (| Z|
10mHz, promptly get the data under the 10mHZ) list in the following table 1.
Table 1 different additive consumption experimental result (stainless steel is that matrix, used silane are that MTMS, additive are tetra-n-butyl titanate)
Sample |
??|Z|
10mHz |
Stainless steel is untreated |
??4.81E5 |
Only contain 2.3 * 10
-2The solution of silane of M tetra-n-butyl titanate is handled part
|
??4.88E5 |
Pure silane solution-treated part |
??4.22E6 |
Add 2.3 * 10
-5The solution of silane of M tetra-n-butyl titanate is handled part
|
??6.82E6 |
Add 2.3 * 10
-4The solution of silane of M tetra-n-butyl titanate is handled part
|
??8.95E6 |
Add 2.3 * 10
-3The solution of silane of M tetra-n-butyl titanate is handled part
|
??2.25E8 |
Add 2.3 * 10
-2The solution of silane of M tetra-n-butyl titanate is handled part
|
??2.32E8 |
Embodiment 2
The step preparation interpolation content that repeats embodiment 1 is 2.3 * 10
-2The methyltrimethoxy silane solution of M tetra-n-butyl titanate is used to handle cold-rolled steel sheet, steel plate galvanized and LY12 duralumin etc., with the suitability of explanation to multiple matrix.The pre-treatment of cold-rolled steel sheet is identical with stainless steel, and steel plate galvanized and alloy matrix aluminum adopt the alkali-free degreasing fluid to wash the removal oil stain before use, and wherein aluminium alloy need carry out mechanical grinding before cleaning.According to the difference of body material, adopt different corrosion evaluation methods to handling sample.Immersion test adopts the NaCl aqueous solution of 0.1M, observation sample surface appearance; Testing impedance carries out in 3.5 (wt) %NaCl aqueous solution.The results are shown in Table 2.
The experimental result of table 2 different matrix (solution of silane: 0.35M MTMS/2.3 * 10
-2The M titanium
Embodiment 3
Similar embodiment 1 is got Union carbide A-162 (MTEOS) solution 4mL and is joined in ethanol (50mL)-water (5mL) mixed solution system, stirs the back and adds about 0.035mL Glacial acetic acid (solution A); Different is to get 600 μ L zirconic acids, four n-propyls and join in the 40mL ethanolic soln and stir (solution B).A, B two solution are mixed, and obtaining zirconic acid four n-propyl concentration is 1.38 * 10
-2M, pH value of solution are~4.5, and silane concentration is~0.19M.It is stand-by that solution is put into 35 ℃ of Water Tank with Temp.-controlled hydrolysis 36 hours.
Matrix is handled: the stainless steel base pre-treatment is with reference to embodiment 1, and the pre-treatment of steel plate galvanized is with reference to embodiment 2.
Matrix silanization: matrix is immersed 200s in the good solution of silane of hydrolysis, blow away behind the unnecessary solution of silane in surface promptly in 100 ℃ of drying in oven 1 hour with high pressure nitrogen.The evaluation result of treatment samples sees Table the experimental result (solution of silane: 0.19M MTEOS/1.38 * 10 that 3. table 3 additives are zirconic acid four n-propyls
-2M zirconic acid four n-propyls)
Embodiment 4
Similar embodiment 1, different is changes used silane reagent for combine the functional silane γ-An Bingjisanyiyangjiguiwan used always preferably (γ-APTMS) with coating, get γ-APTMS solution 2mL and join in ethanol (38mL)-water (20mL) mixed solution system, stir the back and add a certain amount of Glacial acetic acid (solution A); Getting the 1.0mL tetra-n-butyl titanate joins in the 39mL ethanolic soln and stir (solution B).A, B two solution are mixed, and obtaining tetra-n-butyl titanate concentration is 2.3 * 10
-2M, pH value of solution are~5, and silane concentration is~0.115M.It is stand-by that solution is put into 35 ℃ of Water Tank with Temp.-controlled hydrolysis 0.1 hour.
Matrix is handled: the pre-treatment of aluminium alloy is with reference to embodiment 2.
The matrix silanization: get the good modified silane drips of solution of 200 μ L hydrolysis in aluminium alloy matrix surface, rotating speed is that 3000r/min films solution rotating to be deposited on the back, surface 100 ℃ of drying in oven 1 hour.
Silanization is handled the back matrix surface and is brushed organic coating: Resins, epoxy/polymeric amide (1: 0.8/v: v), coat-thickness 40 μ m, simultaneously with the non-modified silanization handle matrix and not silanization to handle matrix brushing coating be contrast.
The performance evaluation of coating adopts the method for accelerated test, and used experiment is Machu test and boiling water Soak Test.The Machu test: the back side and the side of coating to be measured are sealed with paraffin wax, drawn two dark metallic matrix, mutually perpendicular two cuts of reaching with blade on coating, cut length all is 4cm, and corrosive medium is 5%NaCl+0.6%H
2O
2Solution after soaking 24 hours under 37 ℃, upgrades etchant solution, soaks 24 hours again.Take out sample, along the cut release coating, observe coating shedding degree and cut situation with adhesive tape.Boiling water test: coating/metal system is placed the ebullient deionized water, after 4 hours, stop to soak, take out sample, observe the layering and the foaming phenomenon of coating.The evaluation result of treatment samples sees Table 4.
The test result of table 4 aluminum alloy surface coating performance after the pre-treatment of Different Silicon alkanisation
Sample |
The Machu test |
The boiling water test |
The pure epoxy coating of brushing is handled on the surface without silanization |
Coating almost integral body is peeled off, and undercut corrosion is serious |
4-5 bubble |
The epoxy coat that brush after γ-APS handles on the surface |
Near coating wide the peeling off of 1 cm of the having an appointment cut, cut obviously corrodes |
2 bubbles |
The epoxy coat that brush after modification γ-APS handles on the surface |
Near coating wide the peeling off of 0.6cm of the having an appointment cut, cut slightly corrodes |
1 bubble |
The foregoing description is used for the present invention that explains, rather than limits the invention, and in the protection domain of spirit of the present invention and claim, any modification and change to the present invention makes all fall into protection scope of the present invention.