WO2014000527A1

WO2014000527A1 - Galvanized steel strip with good conductivity, high corrosion resistance and fingerprint resistance, and surface treatment agent and treatment method

Info

Publication number: WO2014000527A1
Application number: PCT/CN2013/075783
Authority: WO
Inventors: 张剑萍; 陈�光; 戴毅刚; 朱岚; 赵艳亮; 黄胜标; 陈卓人; 牟战旗
Original assignee: 宝山钢铁股份有限公司
Priority date: 2012-06-29
Filing date: 2013-05-17
Publication date: 2014-01-03
Also published as: CN102746778B; CN102746778A

Abstract

A galvanized steel strip with a coating composition covered on the surface, a surface treatment agent for a galvanized steel strip, and a surface treatment method for a galvanized steel strip. The surface treatment agent comprises: polyurethane and/or acrylic organic resin (A); an organic silane coupling agent (Ba) containing one or more amino functional groups, each amino functional group having at least one active hydrogen; an organic silane coupling agent (Bb) containing at least one kind of epoxy functional group, the number of epoxy functional groups being more than one; an organo phosphorous compound (C); a vanadium compound (D); a titanium compound or a fluorine-containing titanium compound (E); and polyethylene wax. The surface treatment method for a galvanized steel strip comprises coating the surface treatment agent to two surfaces of a galvanized substrate, an arithmetic mean roughness Ra value of the galvanized substrate being 0.4 to 1.2 μm, and preferably 0.5 to 0.8 μm, and the number of crests RPc value being 50 to 150, and preferably 60 to 100; and heating and curing, to form a dry film having a thickness of 0.5 to 1.5 μm, and preferably a fingerprint-resisting coating having a thickness of 0.7 to 1.0 μm, on the surface of the galvanized substrate.

Description

Good conductivity, high corrosion resistance and fingerprint resistant galvanized steel strip and surface treatment agent, treatment method

The invention relates to a galvanized steel strip and a surface treatment technology thereof, in particular to a good conductive, high corrosion resistance and fingerprint resistant galvanized steel strip, a surface treatment agent and a treatment method, which can meet the previous non-chromate coating technology and is difficult to realize. At the same time, it satisfies the characteristics of excellent electrical conductivity and high corrosion resistance, and has the heat resistance, heat resistance, fingerprint resistance, weldability, paintability and resistance to processing blackening of general non-chromate coatings. All performance. Background technique

Galvanized steel strip is one of the most widely used metal products in the world and is widely used in home appliances, construction and automotive. In order to further improve the corrosion resistance of galvanized steel strips, many types of chromium-free and fingerprint-resistant galvanized steel strips with different characteristics have been developed. Chinese Patent Publication No. CN101435078A discloses a chromium-free resin composition having both good corrosion resistance, alkali resistance, processability, electrical conductivity and chemical resistance, and a method for treating a galvanized steel strip using the composition. The composition is composed of a polyurethane resin, an organic oxide of Ti and Zr, an inorganic salt, and a water-based solvent, but the galvanized steel strip treated by such a composition has corrosion resistance and electrical conductivity and other useful properties, However, the examples show that the conductivity is only ΙιηΩ (surface resistance) or less, and the corrosion resistance (in a neutral salt spray test) is 96 hours. Such performance is not sufficient in industries where electrical conductivity and corrosion resistance are required to be higher, such as office automation appliances such as copiers and facsimile machines.

U.S. Patent No. 2005/0058843 A1 provides a method for treating a galvanized steel sheet with an aqueous composition obtained by mixing two kinds of silanes such as vinyl silane and aminosilane, and has certain moist heat resistance and corrosion resistance (with a neutral salt). Fog tester), but the treatment method is to soak the steel sheet in the above aqueous composition and dry for 5 minutes. Such a method cannot achieve continuous treatment of the galvanized steel strip.

Chinese Patent Publication No. CN101228294A provides a non-chromate surface-treated metal material having both corrosion resistance, heat resistance, fingerprint resistance, electrical conductivity, paintability, and resistance to processing blackening, in a metal material. The surface of the water-based metal surface treatment agent is coated and dried to form a composite film containing various components, but the conductivity provided by the patent only guarantees the interlayer resistance value, and does not involve the surface resistance value of particular interest to the home appliance industry.

Chinese Patent Publication No. CN 101688309A provides an aqueous surface for galvanized steel sheets Chemical and galvanized steel sheets, by processing GI and GA surfaces, can achieve good electrical conductivity and high corrosion resistance, as well as coating and alkali resistance, but the technical route adopted is inorganic salt as coating. In the film-forming skeleton, only a part of the organic acrylic resin is mixed in the coating layer, and such a coating structure is difficult to ensure excellent fingerprint resistance.

Chinese Patent Publication No. CN 1887449A provides a surface treatment agent for galvanized steel sheets having excellent alkali resistance and solvent resistance, and is treated by an aqueous treatment agent composed of polyurethane, silane, specific inorganic salt and a small amount of auxiliary agents. The galvanized steel sheet can obtain a chromium-free and fingerprint-resistant steel strip which is excellent in alkali resistance, solvent resistance, corrosion resistance, fingerprint resistance, paintability and resistance to processing blackening, but the patent cannot guarantee that the coating has The above properties have good surface conductivity while film thickness conditions. In summary, various chrome-free surface treatment technologies that are currently available are difficult to integrate chrome-free fingerprint-resistant galvanized steel strips that meet the needs of high-end home appliance users with comprehensive performances such as good electrical conductivity, high corrosion resistance, and fingerprint resistance. Summary of the invention

The object of the invention is a good conductive, high corrosion-resistant and fingerprint-resistant galvanized steel strip, a surface treatment agent and a treatment method, and has excellent comprehensive properties such as electrical conductivity (grounding property), corrosion resistance, weldability and processing. Applicable to home appliances and office supplies, etc., the electrical products are in line with the relevant international standards for electromagnetic wave leakage testing.

In order to achieve the above object, the technical solution of the present invention is:

A good conductive, high corrosion and fingerprint resistant galvanized steel strip, the surface of which is covered with a fingerprint resistant film, the film composition comprising:

a) polyurethane and / or acrylic organic resin (A), the weight percentage is 40~60% _; b) at least one organosilane coupling agent (Ba) containing at least one amino functional group, amino functional group and containing At least one organosilane coupling agent (Bb) having at least one epoxy functional group or more epoxy functional groups, and a weight ratio of (Ba) I (Bb ) of 0.3 to 0.5; the above organic resin (A) and organosilane The weight ratio of the coupling agent ((Ba) + (Bb)) is 1.0 to 2.0; the weight percentage of the organosilane coupling agent is 38 to 53% _; c) the organophosphorus compound, the weight percentage based on the phosphorus element is 0.01~0.1%;

d) the vanadium compound (D), which is 0.1 to 1.0% by weight based on the vanadium element; e) the titanium compound or the fluorine-containing titanium compound (E), which is based on the weight of the titanium element 0.1—3.0%;

f) Polyethylene wax, which accounts for 1~3% of the film content.

Further, the arithmetic mean roughness of the galvanized substrate has a Ra value of 0.4~1.2μιη, and the peak number RPc is between 50 and 150.

The treatment agent for the good conductive, high corrosion resistant and fingerprint resistant galvanized steel strip of the invention is an aqueous solution, the solid content of which is 10-20% by weight, and the weight percentage of each component in the solid fraction is : Polyurethane and/or acrylic organic resin (A), 40~60% _; organosilane coupling agent (Ba), containing more than one amino functional group, at least one active amino group; organic silane coupling agent (Bb), Containing at least one epoxy functional group, the number of epoxy functional groups is more than one; the weight ratio of (Ba) I (Bb) is from 0.3 to 0.5; the above organic resin (A) and organosilane coupling agent ((Ba) + The weight ratio of (Bb) ) is 1·0~2·0; (Ba) + (Bb), the content in the solid part is 38~53% _{; the} organophosphorus compound (C), the phosphorus element accounts for the total solids The weight percentage is 0.01~0.1%; the vanadium compound (D), the weight percentage of vanadium element based on the total solid content, 0.1~1.0%; the titanium compound or the fluorine-containing titanium compound (E), the titanium element parts total solids weight percentage basis of _0.1~3.0%; polyethylene wax (F.), representing a solid Parts by weight of the total percentage of ~ 3%.

Further, the polyurethane and/or acrylic organic resin (A) has a glass transition temperature of 30 to 80 ° C and is water-soluble or water-dispersible.

Further, the polyurethane resin is a polymer of a polyalcohol and a polyisocyanate, and the polyalcohol is a polyester polyglycol, a polyether polyglycol, a polycarbonate polyglycol, and an N,N-dimethylaminodihydroxy group. A polyalcohol of an amino group such as methyl propane; a polyalcohol containing a polyethylene oxide chain similar to polyethylene glycol; and a polyisocyanate is an aliphatic poly diisocyanate or an aromatic poly diisocyanate.

The acrylic resin is ruthenium, osmium-dimethylaminopropyl acrylate, Ν-methylaminoethyl methacrylate monomer, polyethylene glycol methacrylate, hydroxyethyl methacrylate monomer, acrylic acid A copolymerized acrylic resin of a monomer and a styrene, acrylonitrile or vinyl acetate monomer.

The polyurethane and/or acrylic organic resin (Α) has an average molecular weight in the range of 1,000 to 1,000,000, preferably in the range of 2,000 to 500,000.

Further, the phosphonic acid containing a hydroxyl group in the organophosphorus compound (C) is hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonic acid; and the phosphonic acid containing a carboxylic acid group is a phosphonohydroxyacetic acid.

The vanadium compound (D) includes a sulfate, a fluoride salt or an oxide. The titanium compound (E) is a titanium compound containing at least four fluorine atoms.

Further, the polyethylene wax (F) is obtained by an ethylene polymerization method or a polyethylene wax produced as a thermal decomposition product of polyethylene, and has a carboxyl group and a hydroxyl functional group in its structure.

The polyethylene wax (F) has a molecular weight in the range of 1000 to 10,000 and an average particle diameter of 0.1 to 1 · 6 μm.

The surface treatment method of the good conductive, high corrosion resistance and fingerprint resistant galvanized steel strip according to the invention adopts a two-roll or three-roll roll coater to coat the above-mentioned aqueous treatment agent with a solid content percentage of 10-20% by weight Covering both sides of the galvanized substrate, the galvanized substrate has an arithmetic mean roughness Ra of 0.4 to 1.2 μm, preferably 0.5 to 0.8, and a peak number of RPc of 50 to 150, preferably 60 to 100; using hot air or infrared induction heated and cured, the plate temperature is controlled to 80~140 ° C, preferably 100~120 ° _C; 0.5~1.5μιη form a dry film thickness of the zinc-plated substrate surface after cooling, preferably 0.7~1.0μιη fingerprint resistant film.

In the design of the galvanized steel strip of the present invention:

The galvanized metal material which can be used in the present invention is not particularly limited and may include a pure zinc plating layer or a zinc-based alloy plating layer. As the pure zinc-coated steel strip, it may be an electrogalvanized steel strip or a steel strip such as an electrogalvanized nickel alloy, hot-dip galvanized or hot-dip aluminized zinc.

In the present invention, the surface physical profile such as roughness of the galvanized steel strip is mainly achieved by controlling the surface topography of the substrate before plating, and the surface profile is mainly transmitted after galvanizing. When the cold-rolled strip passes through the rolling mill, the surface roughness of the substrate is controlled by the roll surface roughness of each of the front and rear rack rolls, and then the electroplating of the strip is completed in the continuous galvanizing unit.

The surface profile of the galvanized substrate is controlled to have an arithmetic mean roughness Ra of 0.4 to 1.2 μm and a number of peaks (depending on the intersection lines C1 and C2, per centimeter (or per inch) exceeding the upper intersection line C1 and less than the lower intersection line C2. The number of contours) RPc value between 50 and 120 (according to the definition of GB3505-1983, the same below), the preferred range is between Ra value 0.5~0.8, RPc value 60~100.

For the organic thin coating layer having a dry film thickness of 0.5 to 1.5 μm and having excellent corrosion resistance and electrical conductivity, when the surface roughness of the galvanized layer is too large, the aqueous treatment applied to the surface thereof The agent will not form a uniform coating film on the surface of the steel strip, resulting in uneven corrosion resistance on the surface of the steel strip. The film at the trough will be thicker and the coating will be relatively thin at the peak. The uneven thickness will cause the coating at the peak to fail prematurely in the corrosive environment. See Figure 1, which shows the surface roughness of the galvanized substrate is too large, 1 is the galvanized base. The surface profile of the material, 2 is the contour of the coating surface. When the roughness is too small, the coating on the surface of the steel strip will be relatively continuous and dense. The insulating properties of the organic coating may increase the surface resistance and affect the conductivity, especially when the surface resistance is less than Ο. ΙιηΩ and distribution. In the case where the uniformity is critical, see Fig. 2, which shows the surface roughness of the galvanized substrate is too small, 1 is the surface profile of the galvanized substrate, and 2 is the surface profile of the coating.

Therefore, the control of the surface profile and film thickness of the substrate should be within a correspondingly balanced range. The invention is used for the surface treatment agent of the excellent conductive, high corrosion-resistant chromium-free fingerprint-resistant galvanized steel strip: the organic resin portion (Α) refers to acrylic acid and/or polyurethane having a glass transition temperature Tg of 30 to 80 ° C. If the Tg is less than 30 ° C, the overall hardness of the organic composite film is insufficient, which may cause deterioration in abrasion resistance and press formability. However, if Tg > 80 ° C, the overall hardness of the organic composite film becomes too high and becomes brittle, and the film is easily destroyed during processing.

The polyurethane and/or acrylic organic resin is water-soluble or water-dispersible, that is, the resin has an ionic functional group as a hydrophilic group, and/or a non-ionic functional group can be dissolved in water or form a self-emulsifying sol. Alternatively, it may be made water-soluble by using a surfactant or may be forcedly dispersed into an aqueous resin.

The polyurethane resin is a polymer of a polyalcohol and a polyisocyanate, and the polyalcohol is a polyester polyglycol, a polyether polyglycol, a polycarbonate polyglycol, and a N,N-dimethylamino dimethylol group. A polyalcohol of an amino group such as propane or a polyalcohol having a polyethylene oxide chain similar to polyethylene glycol; and the polyisocyanate is an aliphatic polydiisocyanate or an aromatic polyisocyanate.

The above aqueous resin has an average molecular weight in the range of 1,000 to 1,000,000, preferably in the range of 2,000 to 500,000. The above-mentioned resin has a molecular weight of less than 1,000, and the film formation property of the film may be poor, and when the molecular weight exceeds 1,000,000, the surface treatment composition may be unstable.

The organosilane coupling agent (Ba) used in the treating agent of the present invention contains at least one active hydrogen-containing amino group as a reactive functional group per molecule. The configuration is not particularly limited. For example, a composition similar to N-(2-aminoethyl) 3-aminopropylmethyldimethoxysilane or 3-aminopropyltriethoxysilane can be used. The organosilane coupling agent (Bb) used in the present invention contains at least one epoxy group as a reactive functional group per molecule, and is not particularly limited in structure. example For example, 3-glycidoxypropyltrimethoxysilane, 2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane and the like can be used.

In the organic composite film, the weight ratio of the organosilane compound (Ba) to (Bb) (Ba) / (BbM is preferably in the range of 0.3 - 0.5. If less than 0.3, that is, the organosilane compound (Ba) is less When the organic composite film has poor adhesion to the galvanized steel sheet, peeling of the film may occur during press forming. If it is more than 0.5, that is, when the amount of the organosilane compound (Bb) is large, the corrosion resistance may be deteriorated. In the organic composite film, the weight ratio (A) / ((Ba) + (Bb)) of the total amount of the organosilane compound to the resin (Α) is preferably between 1.0 and 2.0. If it is less than 1.0, that is, the amount of resin is small, the solvent resistance and coating adhesion of the coating are deteriorated. If the weight ratio is higher than 2.0, that is, when the resin is large, corrosion resistance, workability, and Performance such as conductivity is lowered.

The phosphonic acid containing a hydroxyl group in the organophosphorus compound (C) in the treating agent of the present invention is hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonic acid; and the phosphonic acid containing a carboxylic acid group is a phosphonohydroxyglycolic acid.

The organophosphorus compound (C) in the aqueous treatment agent is an organic compound containing a C-P bond, and the phosphorus atom can be in a valence state, which has a high inhibitory effect on corrosion of the metal. Specific examples thereof include a hydroxyl group-containing phosphonic acid such as hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonic acid, and a carboxylic acid group-containing phosphonic acid such as phosphonohydroxyacetic acid, and salts thereof. Further, the weight percentage of the C component (in terms of phosphorus) in the total solid content is preferably 0.01 to 0.1%. When the weight percentage is less than 0.01%, the effect of addition is not satisfactory, the corrosion resistance is lowered, and especially the corrosion resistance after alkali washing is insufficient; when the weight percentage exceeds 0.1%, the system stability of the treating agent is affected.

The vanadium compound (D) in the aqueous treatment agent is water-soluble and oxidizing, and has an inhibitory effect on corrosion of the galvanized steel sheet. As the vanadium compound D, the vanadium ion has a good valence state of 2+, 3+, 4+, and 5+, and thus does not limit the source of the vanadium element. Specific examples may be sulfates, fluoride salts and oxides. These compounds may be anhydrous or hydrated. The total weight percent of the vanadium-containing compound is 0.1 to 1.0% by weight, preferably 0.2 to 0.5%. If the weight percentage is less than 0.2%, the oxidation of vanadium has a poor passivation effect on the galvanized surface, and the corrosion resistance is not improved; if the weight percentage is higher than 1%, the stability of the treatment agent is deteriorated. Moreover, the surface of the coating is easily yellowed and the heat resistance is lowered.

The titanium compound (E) involved in the aqueous treatment agent contains a titanium compound having at least four fluorine atoms. Its function is to etch the galvanized surface oxide film to improve the adhesion of the film. This titanium The compound (E) is 0.1 to 3% by weight in terms of Ti in the organic film. When it is less than 0.1%, the effect of addition cannot be achieved, resulting in deterioration of film adhesion and corrosion resistance. If it exceeds 3%, the film composition is stably reduced, and it may also cause a decrease in the surface quality of the galvanized steel sheet.

Further, a polyethylene wax (F) is added to the aqueous treatment agent, and a polyethylene wax produced by an ethylene polymerization method or a thermal decomposition product of polyethylene is obtained by an oxidation method, and has a functional group such as a carboxyl group or a hydroxyl group. Generally, the molecular weight is in the range of 1000 to 10,000. The polyethylene wax of the present invention has an average particle diameter of 0.1 to 1.6 μm. Further, the content of the polyethylene wax (F) in the film is 1 to 3 % by weight, and the content of the polyethylene wax (F) in the film is preferably 1.5 to 2.5%. If the content is less than 1%, sufficient abrasion resistance cannot be obtained. If the content exceeds 3%, it may cause deterioration in properties such as corrosion resistance, solvent resistance, and paintability.

The surface treatment method of the galvanized steel strip of the invention is to apply the above aqueous treatment agent to both sides of the strip by a two-roll or three-roll roll coater, to control the proper solid content and viscosity of the treatment agent, and to adjust the roll coating process. Parameters such as liquid roller/coating roller speed ratio and coating roller pressure to obtain a suitable film thickness, controlled by a curing oven (hot air or infrared induction heating), curing at 80 to 140 ° C, rapid cooling (water cooling or air cooling) After drying, the film is formed, and finally the strip is crimped into a steel coil. The sheet temperature (PMT) for heat curing after coating is 80 to 140 ° C, preferably 100 to 120 ° C. PMT is lower than 80 °C, the moisture volatilization in the wet film does not affect the curing effect, and it is unfavorable for corrosion resistance and solvent resistance. When the PMT is higher than 140 °C, the cooling of the strip before crimping is insufficient, and the energy consumption is not conducive to Cost Control.

The aqueous treating agent of the present invention forms a fingerprint-resistant coating of 0.5 to 1.5 μm (dry film) on a galvanized surface, preferably 0.7 to 1.0 μm. The film thickness is less than 0.5μιη, and the galvanized surface is difficult to be completely covered by the anti-fingerprint coating. No matter whether the galvanized surface roughness is too large or too small, although it can have excellent conductivity, it has corrosion resistance and alkali resistance. The performance such as fingerprint resistance is lowered. If the film thickness exceeds 1.5 μm, the conductivity is lowered, and the uniformity of the entire strip surface is deteriorated even if the surface roughness of the galvanized substrate is at an upper limit of about 1.2 μm. Moreover, as the film thickness increases, the processing cost per unit area increases, and the coating adhesion is also affected.

Advantageous effects of the present invention

The galvanized steel strip of the invention has excellent electrical conductivity and corrosion resistance, and the surface resistance of the steel sheet can reach Ο. ΙιηΩ or less, the surface white rust area of the neutral salt spray test is less than 5%, and the steel has excellent fingerprint resistance. Characteristics such as sex, paintability, weldability, wear resistance, etc., suitable for use in areas such as electronic equipment with harsh grounding, such as copiers, printers, etc. DRAWINGS

Fig. 1 and Fig. 2 are schematic views showing the surface profile formed by coating the surface treatment of the two steel strips with a coating agent. detailed description

The present invention will be further described below in conjunction with the embodiments.

The substrate of the embodiment of the present invention is exemplified by an electrogalvanized or hot-dip galvanized steel sheet. Table 1 shows the ingredients of the examples of the present invention. Table 2 shows the performance of the present invention. Table 3, Table 4, and Table 5 are specific materials corresponding to the examples of the present invention.

Among them, the performance evaluation test is as follows:

1, flat plate corrosion resistance

According to JIS Z2371 Neutral Salt Spray Test (SST) for 120 hours, the sample size is 75x l50mm, and the white rust rate of the board surface is observed.

<Evaluation Criteria> White rust rate is less than 5%

o : White rust rate is 5% or more but less than 10%

Δ : White rust rate is 10% or more but less than 30%

X. White rust rate is more than 30%

2. Corrosion resistance of the processed part

After the sample was subjected to the Eriksson test (the cup height was 7 mm), it was subjected to the neutral salt spray test standard of JIS Z2371 for 72 hours, and the white rust formation state of the processed portion (the cup-shaped portion) was observed.

<Evaluation Criteria> White rust of the cup-shaped mutant part is less than 10%

o : White rust in the cup-shaped mutant is greater than 10% but less than 30%

Δ : White rust in the cup-shaped mutant is greater than 30% but less than 50%

X: White rust in the cup-shaped mutant is greater than 50%

3, conductivity

A 4-probe surface contact impedance measurement method is used. The principle is shown in Figure 1. When current flows through probe A and probe D, a potential difference (V) between probe B and probe C is generated. It is detected, and thus the resistance V/I is the measured surface impedance value.

The conductivity of the material is characterized by a 9 point (uniform distribution) surface contact resistance value in an area of 300 < 300 mm2.

<Evaluation Criteria> The arithmetic mean value of the 9-point surface contact resistance is less than 0.05 ηηΩ, and the single point value shall not be greater than 0.05 ηηΩ _;

ο : The arithmetic mean value of the 9-point surface contact resistance is greater than 0.05 ηηΩ but less than Ο. ΙιηΩ, and the single point value shall not be greater than Ο. ΙιηΩ;

Δ : The arithmetic mean value of the 9-point surface contact resistance is greater than Ο. ΙιηΩ but less than Ι.ΟιηΩ, and the single point value shall not be greater than Ι.ΟιηΩ;

: 9-point surface contact impedance arithmetic mean is greater than Ι.ΟιηΩ;

4, coating adhesion

Apply ink by screen printing or bar coating (recommended brand Japan Seiko Ink # 1300

SEIKO ADVANCE) on the surface of the clean sample to control the dry film thickness of 10 ± 3 microns; coat the melamine alkyd resin coating with a bar or other means (no limit), to control the dry film thickness of 20 ± 5 microns;

The above two prepared coating samples were subjected to the following adhesion test after being allowed to stand at room temperature for 24 hours. The prepared coating sample plate is placed in boiling water, and more than half of the sample must be immersed in boiling water; kept boiled for 30 minutes, taken out, and left at room temperature for 2 hours;

Select the sample in the boiling water soaking area, use the paint film cross-hatch in the 1mm interval of 100 squares; affix the transparent tape on the grid, press it with your fingers or clamp until it is completely tight, then pull the end of the tape perpendicular to the sample The surface was torn open instantaneously, and the adhesion was observed after peeling (adhesion = number of squares not peeled off / 100).

<Evaluation Criteria> Adhesion is 100/100 90/100 or more

5, solvent resistance At room temperature, the sample was immersed in an organic solvent such as isopropyl alcohol, ethanol, butanone, dichloromethane, n-hexane, toluene, volatile oil, etc. for 168 hours, and the surface of the coating was observed to be swollen, and the color difference before and after measurement was measured (ΔΕ*). Value).

<Evaluation Criteria> The coating has no swelling, and the color difference is AE*<1.0

o : The coating is not swollen, and the color difference is AE*>1. (HS<3.0

Δ : No swelling of the coating, and color difference AE*>3. (HS<5.0

: The coating has swelling, and the color difference AE*>5.0. The results of the examples show that the galvanized surface treatment product of the invention has excellent electrical conductivity and corrosion resistance, and at the same time satisfies fingerprint resistance, abrasion resistance, paintability and Comprehensive performance such as processing.

Table 1

Table 2

Table 3 resin type

Table 4 organosilane coupling agent

E2 tetrabutyl titanate

Claims

Claim

1. A good conductive, high corrosion resistant and fingerprint resistant galvanized steel strip, characterized in that: the surface is covered with a fingerprint resistant film, and the film composition comprises:

a) polyurethane and / or acrylic organic resin (A), the weight percentage is 40~60%; b) at least one organosilane coupling agent (Ba) containing more than one amino functional group, amino functional group and containing At least one organosilane coupling agent (Bb) having at least one epoxy functional group or more epoxy functional groups, and a weight ratio of (Ba) I (Bb) of 0.3 to 0.5; the above organic resin (A) and organosilane The weight ratio of the coupling agent ((Ba) + (Bb) ) is 1.0 to 2.0; the weight percentage of the organosilane coupling agent is 38 to 53%; c) the organophosphorus compound (C), which accounts for phosphorus The weight percentage is 0.01~0.1%; d) the vanadium compound (D), the weight percentage of the vanadium element is 0.1~1.0%; e) the titanium compound or the fluorine-containing titanium compound (E), which accounts for the titanium element The weight percentage is 0.1 - 3.0%;

f) Polyethylene wax, which accounts for 1~3% of the film content.

2. The good conductive, high corrosion and fingerprint resistant galvanized steel strip according to claim 1, wherein the galvanized base material has an arithmetic mean roughness Ra of 0.4 to 1.2 μm and a peak number of RPc of 50 to 150. between.

3. A surface treatment agent for a good conductive, high corrosion-resistant and fingerprint-resistant galvanized steel strip according to claim 1, which is an aqueous solution, and the solid content thereof is 10 to 20% by weight, and each component in the solid portion The weight percentage is: polyurethane and/or acrylic organic resin (A), 40~60% _; organosilane coupling agent (Ba), containing more than one amino functional group, at least one active hydrogen of amino functional group; organosilane coupling agent (Bb), containing at least one epoxy functional group, having more than one epoxy functional group; (Ba) I (Bb) by weight ratio of 0.3 to 0.5; the above organic resin (A) and an organosilane coupling agent ( The weight ratio of (Ba) + (Bb) ) is 1.0 to 2.0; (Ba) + (Bb), the content in the solid portion is 38 to 53%; the organophosphorus compound (C), the total amount of phosphorus in the solid portion The weight percentage is 0.01~0.1%; the vanadium compound (D), the weight percentage of vanadium element based on the total solid content, 0.1~1.0%; the titanium compound or the fluorine-containing titanium compound (E), the titanium element Percent by weight of total solids, 0.1-3.0%; polyethylene wax F.), Representing parts of the total solids weight percentage, 1~3%.

The surface treatment agent according to claim 3, wherein the polyurethane and/or propylene The acid-based organic resin (A) has a glass transition temperature of 30 to 80 ° C and is water-soluble or water-dispersible.

The surface treatment agent according to claim 3, wherein the polyurethane resin is a polymer of a polyalcohol and a polyisocyanate, and the polyalcohol is a polyester polyglycol, a polyether polyglycol, or a polycarbonate. a polyglycol, a polyalcohol containing an amino group such as N,N-dimethylamino dimethylolpropane, a polyalcohol having a polyethylene oxide chain similar to polyethylene glycol; a polyisocyanate is an aliphatic poly Isocyanate, aromatic polyisocyanate.

The surface treatment agent according to claim 3, wherein the acrylic resin is ruthenium, osmium-dimethylaminopropyl acrylate, fluorene-methylaminoethyl methacrylate monomer, polyethyl b. A diol methacrylate, a hydroxyethyl methacrylate monomer, a copolymerized acrylic resin of an acrylic monomer and a styrene, acrylonitrile or vinyl acetate monomer.

The surface treatment agent according to claim 3, wherein the polyurethane and/or the acrylic organic resin (Α) has an average molecular weight in the range of 1,000 to 1,000,000, preferably in the range of 2,000 to 500,000.

The surface treatment agent according to claim 3, wherein the phosphonic acid having a hydroxyl group in the organophosphorus compound (C) is hydroxyethylidene diphosphonic acid or hydroxyethylidene diphosphonic acid; The acid-based phosphonic acid is a phosphonohydroxyacetic acid.

The surface treatment agent according to claim 3, wherein the vanadium compound (D) comprises a sulfate, a fluoride salt or an oxide.

The surface treatment agent according to claim 3, wherein the titanium compound (Ε) contains a titanium compound having at least four fluorine atoms.

The surface treatment agent according to claim 3, wherein the polyethylene wax (F) is obtained by an oxidation method from an ethylene polymerization method or a polyethylene wax formed as a thermal decomposition product of polyethylene. It has a carboxyl group and a hydroxyl functional group in its structure.

The surface treatment agent according to claim 3 or 11, wherein the polyethylene wax (F) has a molecular weight of from 1,000 to 10,000 and an average particle diameter of from 0.1 to 1.6 μm.

The surface treatment method for a good conductive, high corrosion-resistant and fingerprint-resistant galvanized steel strip according to claim 1, wherein the weight fraction of the solid content is determined by using a two-roller or a three-roller coater.

10~20% of the surface treatment agent is applied to both sides of the galvanized substrate, and the galvanized substrate has an arithmetic mean roughness Ra value of 0.4~1.2μιη, preferably 0.5~0.8, peak number RPc value 50~

Between 150, preferably 60~100; heat-cured by hot air or infrared induction, the temperature of the plate is controlled to 80 to 140 ° C, preferably 100 to 120 ° C; After cooling, a fingerprint-resistant film having a dry thickness of 0.5 to 1.5 μm, preferably 0.7 to 1.0 μm is formed on the surface of the galvanized substrate.