WO2007097139A1

WO2007097139A1 - Process for producing hot-dip galvanized steel sheet with zinc phosphate coat

Info

Publication number: WO2007097139A1
Application number: PCT/JP2007/050650
Authority: WO
Inventors: Hajime Ishigaki; Masaru Takahashi; Katsuji Kawanishi; Tooru Kuroda; Katsuhiro Nishihara
Original assignee: Sumitomo Metal Industries, Ltd.
Priority date: 2006-02-20
Filing date: 2007-01-18
Publication date: 2007-08-30
Also published as: KR20080094039A; TW200732510A; EP1988189B1; KR101068708B1; EP1988189A4; TWI348500B; EP1988189A1

Abstract

A process for producing a hot-dip galvanized steel sheet with zinc phosphate coat, which realizes stabilizing of the composition balance of treating agent and realizes reducing of production cost and lessening of influences on environment. A galvanized steel sheet with zinc phosphate coat excelling in lubricity and adherence is provided through the process. There is provided a process for continuously producing a hot-dip galvanized steel sheet with zinc phosphate coat, comprising the surface regulating agent supply step of feeding a surface regulating agent onto a hot-dip galvanized surface; the predrying step of drying the surface regulating agent as a post-step of the surface regulating agent supply step; and the treating agent supply step of feeding a treating agent containing an aqueous solution of zinc phosphate onto the hot-dip galvanized surface as a post-step of the predrying step.

Description

Specification

Method for producing hot dip galvanized steel sheet having zinc phosphate coating

Technical field

[oooi] The present invention relates to a method for producing a hot-dip galvanized steel sheet having excellent lubricity and Z or adhesion, which is used for improving press formability in the automotive field and the like. Specifically, in a continuous hot-dip galvanized steel sheet production line, a hot-dip galvanized steel sheet with a zinc phosphate coating that can also improve productivity represented by the operability of hot-dip galvanized steel sheet production with the above performance. The present invention relates to a method for manufacturing a steel sheet with a shell.

Background art

[0002] In recent years, zinc-based plated steel sheets have been used as an anti-corrosion measure for steel sheets used in automobiles and the like. In most cases of use in automobiles, the zinc-based steel sheet is press-formed. However, it is known that zinc-plated steel sheets are inferior in press formability compared to cold-rolled steel sheets. This is because electrogalvanized (EG) steel sheet or hot dip galvanized (GI) steel sheet, because the surface zinc is soft, it causes mold and seizure phenomenon when sliding, or hot dip galvanized steel sheet. In this case, the soft r? Phase remains and the sliding property is lowered. In addition, for alloyed hot-dip galvanized (GA) steel sheets, a soft alloy layer such as ζ phase is formed on the surface of the galvanized steel during alloying. .

[0003] As a means for solving these problems, Patent Document 1 discloses a technique for improving lubricity by further providing an iron-zinc alloy electroplating film on the zinc plating film. It has been put into practical use. However, this technology requires an electrical plating facility, which greatly increases manufacturing costs.

[0004] Further, the viewpoint power for reducing the manufacturing cost As described in Patent Document 1, the hot dip galvanized steel sheet having excellent lubricity is obtained by eliminating the galling film and forming the upper layer as a zinc phosphate film. This technique is disclosed in Patent Document 2. This can be achieved by providing a zinc phosphate coating, for example when manufacturing automobile bodies! It constitutes a zinc-containing metal-plated steel plate composite with excellent high-speed press formability. [0005] However, in the production of a steel sheet having these zinc phosphate coatings, since the desired performance cannot be obtained without pretreatment, various pretreatment steps are required. For example, in Patent Document 2 and Patent Document 3 described above, in order to prevent the steel sheet from being produced in the pretreatment agent zinc carbonate aqueous solution when the steel sheet is produced on the continuous molten zinc-based plated steel sheet production line, Has a process.

[0006] In addition, Patent Documents 4 and 5 disclose that a substrate is washed and then immersed in a surface conditioner such as an aqueous titanium colloid solution for surface conditioning before contacting with a zinc phosphate aqueous solution. Yes. On the other hand, a technique for applying an organic solid lubricating film such as wax or fat to a zinc-based surface has been disclosed for a long time (Patent Publication No. 3006455 etc.). Due to the occurrence of pressed product defects, there are also odor problems during welding and joining (organic matter is decomposed by the heat of welding and adversely affects the work environment).

[0007] For these reasons, in response to the demand for manufacturing cost reduction, as an alternative to the above-mentioned iron-zinc electroplating film, a phosphate-based film (materials and processes, ll (1998) p. 546 ), Mn—P oxide coating (Materials and Processes, 6 (1993) p. 1545) and Ni-based coatings (Materials and Processes, ll (1998) p. 384), etc. The application is being expanded.

[0008] The inorganic lubricating film is characterized in that stable formability can be obtained without problems such as offensive odor even during welding joining. Among them, phosphoric acid-based coatings have been used in the past, and various techniques have been proposed. For example, Patent Document 6 discloses that a zinc phosphate coating containing Mg is provided on the surface of zinc plating and is suitably used for automobile bodies.

[0009] However, the inorganic lubricating film sometimes has a problem in adhesion to other members.

This adhesiveness is a very important issue because zinc-plated steel sheets with an inorganic lubricating film often assemble products by being bonded to other members. Since the past, studies have been conducted on the adhesiveness of steel plates with this in-organic lubrication film. For example, in Patent Document 7 and Patent Document 8, a ZnO oxide is formed on the surface of the adhesive layer, and an Mn—Zn OH—P crystalline oxide is formed on the surface, thereby providing lubricity, chemical conversion treatment, and adhesive. It discloses that a zinc-based steel sheet with excellent compatibility can be obtained. [0010] Further, Patent Document 9 discloses a steel sheet having an inorganic lubricating film that exhibits sufficient adhesive strength even in various adhesives including mastic type.

[0011] Further, in such a zinc-based plated steel sheet having a zinc phosphate film, in particular, a uniform film-forming state is ensured and various performances are secured as a fender for automobiles. It is necessary. In addition, other properties such as weldability and adhesiveness, which are achieved only by improving slidability and lubricity, are required to have the same or higher performance as before. From this point of view, the method for producing a zinc-based plated steel sheet having a zinc phosphate film is complicated and highly accurate.

V, required a manufacturing process.

[0012] Specifically, the technology for forming these phosphoric acid-based films is referred to as so-called reactive surface chemical conversion treatment, and includes primary phosphoric acid, zinc, Ni, Mn, Mg, nitric acid, nitrous acid, and fluorine compounds. This is a technique for forming a film by contacting and reacting a treatment agent containing the above with the surface of a zinc-plated steel plate. More specifically, the treatment agent is supplied to the surface of the zinc plating by spraying or the like, and the film forming reaction proceeds while etching the zinc plating. At this time, the zinc eluted in the etching is a force that exists as zinc ions in the treatment agent. As the zinc ion concentration increases, the pH of the treatment agent rises and the etching reaction becomes difficult to occur. Keeping pH and Zn concentration at a certain value by replenishing with acid is necessary to maintain a uniform film formation state.

[0013] Usually, the capacity of a tank or the like for storing the treatment agent is limited, and in order to keep the increased zinc concentration and pH constant, a replenisher is added while discharging a part of the treatment agent as a drain. It was a lot of work to be done.

Patent Document 1: JP-A-1-319661

Patent Document 2: Japanese Patent Laid-Open No. 7-138764

Patent Document 3: JP 2001-98383 A

Patent Document 4: Japanese Patent Laid-Open No. 2005-54202

Patent Document 5: Japanese Unexamined Patent Application Publication No. 2005-54203

Patent Document 6: Japanese Patent Laid-Open No. 11-315386

Patent Document 7: Japanese Patent No. 3153097

Patent Document 8: Japanese Patent No. 3199980 Patent Document 9: Japanese Patent Laid-Open No. 2002-53974

Disclosure of the invention

Problems to be solved by the invention

[0014] In the manufacturing methods described in Patent Documents 1 to 4, when water washing is performed, a liquid agent such as a surface conditioner is brought into the step of supplying the zinc phosphate aqueous solution when water washing is not performed. The composition balance of the aqueous zinc phosphate solution as the treatment agent is varied. In addition, when not washed with water, the steel sheet is activated with a surface conditioner, etc., so that the reaction with the treatment liquid in the subsequent process is promoted, and the zinc plating film from the steel sheet, especially the zinc component The variation in the composition balance of the treatment liquid with large elution was increased. Normally, the capacity of tanks for storing treatment agents is limited, and in order to keep the composition balance of the changed treatment agents constant, it is possible to add a replenishing solution while discharging a part of the treatment agent as a drain. There is much power to be taken. Therefore, the replenishment cost of zinc phosphate aqueous solution and the drainage facilities were required, and the waste liquid of P increased, so it was necessary to provide drainage facilities.

[0015] In view of environmental considerations in recent years, there is a social demand to suppress the waste liquid of P as much as possible. Furthermore, conventionally, it has been common knowledge that the surface of a water-based treatment is usually not dried. This is because it was thought that when dried, the surface became acidic and the reactivity deteriorated, and the performance deteriorated.

[0016] Further, regarding the adhesiveness of zinc-based plated steel sheets having an inorganic lubricating film, the ones described in Patent Documents 7 and 8 have only one type of adhesive that has been confirmed, and there are a wide variety of sub-types. The current automobile body manufacturing process in which materials are used is not necessarily compatible.

[0017] And, in the case of a steel sheet having an inorganic lubricating film described in Patent Document 9, particularly in the case of an amorphous phosphate-based film, the steel sheet is subjected to a forming or sliding test in which a high surface pressure is applied particularly during processing. And there was a risk that the performance would be insufficient. Therefore, there has been no galvanized steel sheet having an inorganic lubricating film that can secure sufficient adhesion to various adhesives and has sufficient slidability and formability.

[0018] Therefore, the present invention provides a method for producing a hot-dip zinc-based steel sheet having a zinc phosphate coating that can keep the composition balance of the treatment agent constant, reduce the production cost, and reduce the influence on the environment. It is an issue to provide. And this improves lubricity and adhesion It is an object to provide a zinc-based steel sheet having an excellent zinc phosphate coating. Means for solving the problem

[0019] As a result of intensive studies, the present inventors have obtained the following knowledge and developed a method for producing a hot-dip zinc-based steel sheet having a zinc phosphate coating according to the present invention in order to solve the above problems.

(a) By bringing the surface conditioner into a dry state before the step of supplying the zinc phosphate solution, it is possible to suppress the surface conditioner from being brought into the zinc phosphate solution. This is because it is possible to suppress the activity of the zinc plating surface by drying the surface conditioner. Here, the surface conditioner is an aqueous liquid containing a crystal nucleating agent of zinc phosphate. For example, an aqueous liquid in which Ti colloid is dispersed in an aqueous solution of sodium pyrophosphate, or particles of zinc phosphate are dispersed. Aqueous solution.

(b) By using an aqueous liquid in which zinc phosphate particles are dispersed among the surface conditioning agents, and drying the aqueous liquid, it is possible to suppress fluctuations in the composition balance of the aqueous zinc phosphate solution that is the treatment agent. it can. This is because by drying an aqueous liquid containing zinc phosphate particles, the zinc phosphate particles are adsorbed on the surface of the molten zinc base without agglomerating while maintaining the particle size, and the particle morphology is maintained. This is because the plating surface can be reacted in the next drying step while suppressing the oxidization reaction on the surface of the steel sheet until the treatment agent step by the action of the protective film. On the other hand, in the case of an aqueous liquid in which Ti colloid is dispersed in an aqueous solution of sodium pyrophosphate, the crystal nucleating agent may dry and aggregate.

[0020] Further, regarding the obtained zinc-based plated steel sheet, the following knowledge was obtained and the present invention was completed.

(c) If the orientation of P—O bond of zinc phosphate formed on the surface of the zinc-plated steel sheet is on the steel sheet surface, and the orientation in the direction perpendicular to the steel sheet surface is large, excellent lubricity is maintained. Adhesion can be improved. This is thought to be due to an increase in the interaction between the P—O bond and the C—O bond of the adhesive (mainly resin). In addition, the orientation of the P—o bond of zinc phosphate is an absorption spectrum measurement method in which infrared light is incident on the surface normal of the steel plate from the direction of 60 ° and absorbed from the surface. In the spectrum obtained by the following, the absorption ratio of P—O bond stretching vibration, the integral absorption intensity ratio of P-polarized light (polarized light component perpendicular to the steel plate surface) and s-polarized light (polarized light component horizontal to the steel plate surface) Can be judged. (d) In order to know the orientation of the P—O bond in more detail, it is possible to accurately determine the ratio of the absorbance with respect to the P-polarized light and s-polarized light by paying attention to the absorption related to the specific P—O bond. In the spectral absorption of crystalline zinc phosphate on the surface of the zinc-plated steel sheet of the present invention, there is a characteristic absorption band in the wavelength range from 8.4 to 9. and in the wavelength range from 10.2 to L 1.0 m. Yes. Therefore, by measuring the ratio of the absorbance of p-polarized light and the absorbance of s-polarized light in this range of absorption band, the adhesiveness can be judged in more detail. In other words, by increasing the absorbance ratio between the P-polarized light and the s-polarized light in the absorption band, it is possible to obtain a zinc-based steel sheet having a zinc phosphate film with better lubricity and adhesion.

[0021] The present invention has been made based on the above findings. The present invention will be described below.

The invention described in claim 1 is a method for continuously producing a hot dip zinc-based steel plate having a zinc phosphate coating, and supplying a surface conditioner to the surface of the hot dip zinc surface. Supply agent containing zinc phosphate aqueous solution on the surface of molten zinc plating in the pre-drying step for drying the surface conditioner in the pre-drying step and the post-drying step in the pre-drying step. The said subject is solved by the manufacturing method of the hot dip zinc-based steel plate which has a zinc-phosphate film | membrane including the processing agent supply process to perform.

Here, the “hot galvanized steel sheet” is a concept including “alloyed molten galvanized steel sheet” in addition to “hot galvanized steel sheet”. Is a generic term including “electrogalvanized steel sheet”, “hot dip galvanized steel sheet” and “alloyed hot dip galvanized steel sheet”.

[0023] The term "zinc phosphate" in "zinc phosphate coating" means crystalline zinc phosphate (Zn (PO) · 4Η 生じる) that produces Hopete diffraction in normal X-ray diffraction analysis. To do.

3 4 2 2

[0024] The invention described in claim 2 is the surface adjuster in the surface adjuster supply step of the method for producing a hot-dip galvanized steel sheet having a zinc phosphate coating according to claim 1. It is an aqueous liquid containing zinc phosphate particles.

[0025] The invention described in claim 3 is used as a surface conditioner in the surface conditioner supply step of the method for producing a hot dip galvanized steel sheet having a zinc phosphate coating according to claim 2. The zinc phosphate particles contained have an average particle size of 10 μm or less. [0026] The invention described in claim 4 is a surface conditioner in the surface conditioner supply step of the method for producing a hot dip galvanized steel sheet having a zinc phosphate coating according to claim 2. The zinc phosphate particles contained have an average particle size of 10 m or less, and the pH of the surface conditioner is 5 or more.

[0027] The invention according to claim 5 is the surface of the method for producing a hot-dip galvanized steel sheet having the zinc phosphate coating according to any one of claims 1 to 4. The surface conditioner in the conditioner supply process contains zinc phosphate particles greater than Omol / L and 0.5 mol / L or less, and is selected from the group consisting of Li, Na, K, Be, Mg and Ca 1 It is characterized by containing not less than 0.3 molZL of seeds or more in total.

[0028] The invention according to claim 6 is a treatment of a method for producing a hot-dip galvanized steel sheet having a zinc phosphate coating according to any one of claims 1 to 5. The treatment agent in the agent supply step contains 0.001 to 0.7 molZL of phosphate radicals and contains zinc ions in a molar ratio of 0.7 or less with respect to the phosphate radicals.

[0029] The invention according to claim 7 is a process for producing a hot-dip galvanized steel sheet having a zinc phosphate coating according to any one of claims 1 to 6. The zinc phosphate aqueous solution of the treatment agent in the agent supply process contains zinc ions and phosphate radicals, has a pH of 4 or less, and has a molar ratio of 0.2 or less with respect to the phosphate radicals other than the zinc ions and phosphate radicals. It is characterized by containing one or more kinds selected from the group power of strong electrolysis-ion power of nitrate group, nitrite group of 0.2 or less, hydrofluoric acid group of 0.1 or less, and sulfate group of 0.05 or less. To do.

[0030] The invention according to claim 8 is the surface of the method for producing a hot-dip galvanized steel sheet having the zinc phosphate coating according to any one of claims 1 to 7. It is characterized in that P adhering to the surface of the molten zinc-based plating is adjusted to 30 to 500 mg / m ² in terms of P by the adjusting agent supplying process and the treating agent supplying process.

[0031] Here, the P adhesion amount in "P conversion" can be measured by chemical dissolution or by measuring force by fluorescent X-rays. In the chemical dissolution method, a plating layer of a zinc-plated steel sheet having a predetermined area is dissolved with a predetermined amount of strong acid (for example, hydrochloric acid), and the solution is dissolved in the solution by ICP (inductively coupled plasma emission analysis). P concentration is measured and converted. On the other hand, the method using fluorescent X-rays produces samples with various P adhesion amounts, and the fluorescence caused by ΡΚα by the fluorescent X-ray method. By measuring the X-ray intensity, obtaining the amount of P adhesion by the above chemical dissolution method, and creating a calibration curve, the fluorescent X-ray intensity is obtained for the subsequent samples by the same method. According to this, it is possible to obtain the P adhesion amount without destruction.

[0032] The invention described in claim 9 is the surface adjuster in the surface adjuster supply step of the method for producing a hot dip galvanized steel sheet having a zinc phosphate coating according to claim 2. The pH is 5 or more, and the average particle size of the zinc phosphate particles is 0.1 to 3 / ζ πι.

[0033] The invention described in claim 10 is a process for supplying a surface conditioner in the method for producing a hot-dip galvanized steel sheet having a zinc phosphate coating according to claim 2 or 9. The zinc phosphate particles adhere to 0.01 to ⁵ mgZm ^{2 in} terms of soot on the surface of a zinc-based steel plate that has been subjected to a pre-drying step.

[0034] The invention according to claim 11 is a hot dip galvanized steel sheet having the zinc phosphate coating according to any one of claims 2, 9, or 10. The treating agent in the treating agent supply step of the production method of the present invention contains zinc and phosphate radicals, has a pH of 4 or less, and, other than zinc and phosphate radicals, nitrate radicals in a molar ratio with respect to phosphate radical 1 are 0.2. In the following, it is characterized in that it contains at least one or more selected strong electrolytes of which nitrous acid group is 0.2 or less, hydrofluoric acid group is 0.1 or less, and sulfate group is 0.05 or less.

[0035] The invention according to claim 12 is a molten zinc-based metal plate having the zinc phosphate coating according to any one of claims 2, 9 to 11. It has a post-drying step to dry the treatment agent in the post-treatment step of the processing agent supply step of the steel sheet manufacturing method, and after the post-drying step, 30 to 250 mg / m ² of the zinc phosphate coating in terms of P is adhered. It is characterized by

[0036] The invention described in claim 13 is the surface of the method for producing a hot-dip galvanized steel sheet having the zinc phosphate coating according to any one of claims 1 to 12. Any one or both of the method for supplying the surface adjusting agent in the adjusting agent supplying step and the method for supplying the treating agent in the treating agent supplying step is a roll coating method.

[0037] In the invention described in claim 14, the crystalline zinc phosphate film is formed on the surface manufactured by the manufacturing method described in any one of claims 9 to 13. Was A hot-dip zinc-based steel sheet with a zinc phosphate coating, which reflects the reflected light power of infrared light incident on the surface from the direction normal to the surface of the zinc phosphate coating at 60 °. Has a plurality of absorption bands in the wavelength range of 8 to 12 m, and further has an integrated absorption intensity ratio of s-polarized light to p-polarized light in the wavelength range of 1.2 or more. The above-mentioned problem is solved by providing a hot-dip galvanized steel sheet having the following.

Here, “p-polarized light” refers to polarized light with a component perpendicular to the surface, and “s-polarized light” refers to polarized light with a component parallel to the surface. “Integral absorption intensity ratio” means the integral intensity ratio of the absorption spectrum of P-polarized light and s-polarized light.

[0039] In the invention described in claim 15, a crystalline zinc phosphate film is formed on the surface manufactured by the manufacturing method described in any one of claims 9 to 13. A hot-dip zinc-based steel sheet having a zinc phosphate coating that is absorbed by the reflected light force of infrared light incident on the surface from the direction normal to the surface of the zinc phosphate coating from 60 °. The light vector has a plurality of absorption bands in the wavelength range of 8 to 12 m, and the absorbance power of p-polarized light in the wavelength range of 8.4 to 9.2 m is more than twice the absorbance of polarized light. In addition, the absorbance power of p-polarized light in the wavelength range of 10.2 to L 1.0 m is greater than or equal to twice the absorbance of polarized light. The above-mentioned problems are solved by providing a steel plate with a glue.

The invention's effect

[0040] According to the invention described in claim 1, the composition of the treatment agent is not balanced because the surface adjustment agent is not brought into the treatment agent supply step as a liquid agent, and the treatment agent is not mixed in the treatment agent. Is maintained for a long time. As a result, it is possible to obtain effects such as a reduction in manufacturing cost, a reduction in the amount of treatment agent supplied, a reduction in waste liquid discharge, and an improvement in productivity. Furthermore, it is possible to manufacture a hot-dip zinc-based steel sheet having a zinc phosphate coating in consideration of the environment. Therefore, since the reduction of the treatment agent is only the amount adhering to the plate, the manufacturing process can be established only by supplying the reduced treatment agent, and the zinc phosphate film is continuously formed in a closed system. It can be formed with a hot dip galvanizing line.

[0041] According to the invention described in claim 2, the crystal nucleation agent contained in the surface conditioner Therefore, the zinc phosphate film to be coated can be formed more stably.

[0042] According to the invention described in claim 3, it is possible to improve the operability and stability of the surface conditioner.

[0043] According to the invention of claim 4, it is possible to further improve the operability and stability of the surface conditioner.

[0044] According to the invention described in claim 5, the stability of the surface conditioner is improved.

It is possible to make the reaction of the substrate surface more uniform in the pre-drying step.

[0045] According to the invention described in claim 6, the operability and stability of the treatment agent can be improved.

[0046] According to the invention described in claim 7, it is possible to further improve the stability of the treatment agent and the homogeneity of the film.

According to the invention described in claim 8, since two supply source forces P are supplied, the adjustment can be easily performed, and an appropriate amount can be adjusted with high accuracy. .

[0048] According to the invention described in claim 9, the stability of the surface conditioner can be further improved, and the molten zinc having a zinc phosphate coating with further gain from the viewpoint of cost and environment The manufacturing method of a steel plate can be provided. Further, the supplied zinc phosphate particles are more uniformly supplied to the zinc plating surface.

[0049] According to the invention of claim 10, the stability of the surface conditioner is improved, and the total amount of the P adhesion amount at the time of supplying the treatment agent can be easily adjusted. As a result, lubricity can be improved.

[0050] According to the invention of claim 11, the stability of the treating agent can be improved, and the molten zinc-based material having a zinc phosphate coating with further gain from the viewpoint of cost and environment. A method for manufacturing a steel sheet with a shell can be provided.

[0051] According to the invention of claim 12, lubricity can be improved.

[0052] According to the invention described in claim 13, since the surface conditioner and Z or the treatment agent are supplied by the roll coater, it is necessary to replenish these agents with a concentration higher than necessary. Since this replenishment itself is also less, it is further from the viewpoint of cost and environment. It is possible to provide a method for producing a hot-dip galvanized steel sheet having a zinc phosphate coating having a high gain.

[0053] According to the invention described in claim 14, it is possible to provide a hot-dip zinc-based steel sheet having a zinc phosphate coating that has excellent adhesion and excellent lubricity.

[0054] According to the invention described in claim 15, it is possible to provide a hot-dip zinc-based steel sheet having a zinc phosphate coating that is further excellent in adhesion while maintaining slidability. is there. Brief Description of Drawings

FIG. 1 is a diagram schematically showing a flow of a method for producing a zinc-based plated steel sheet having a zinc phosphate coating according to the present invention.

FIG. 2 is a graph showing an example of the relationship between wavelength and absorbance obtained from an infrared absorption spectrum.

FIG. 3 is a schematic diagram of a T peel test method.

FIG. 4 is a schematic diagram of a shear tensile test method.

Explanation of symbols

[0056] 1 Zinc-based steel plate

2 Adhesive

3 Zinc-based steel plate

4 Adhesive

S1 Surface conditioner supply process

S2 Pre-drying process

S3 Treatment agent supply process

S4 Post-drying process

BEST MODE FOR CARRYING OUT THE INVENTION

[0057] Hereinafter, a method for producing a zinc-based steel sheet having a zinc phosphate coating according to the present invention will be described. FIG. 1 shows a flow of a method for producing a zinc-based plated steel sheet having a zinc phosphate coating according to the present invention, which is effective in one embodiment. This manufacturing method includes a surface conditioning agent supply step (S1) for supplying a surface conditioning agent to a substrate, a pre-drying step (S2) for drying the supplied surface conditioning agent, and a processing agent supply step for supplying a processing agent. (S3) and after the treatment agent supply step (S3) And a post-drying step (S4). Each step will be described below. The “base material” is a zinc-based plated steel sheet having a base material that is a steel sheet and a zinc-based plated layer coated on the surface of the base material.

[0058] The surface conditioning agent supplying step (S1) is a step of supplying a surface conditioning agent containing a crystal nucleating agent to the zinc-based plated steel sheet. The method for supplying the surface conditioning agent in the surface conditioning agent supply step (S1) is not particularly limited. Examples of this include a roll coater, spray coating, and post-spray air knife, post-spray ringer roll, squeeze roll squeeze, etc. From the viewpoint of operability, a roll coater and squeeze roll squeeze after spray are preferred. Furthermore, among these, the roll coater method is preferable because the contact time between the zinc-based plating and the surface conditioner can be made shorter than other methods. This eliminates the need for complicated component adjustment and complicated pH control of the surface conditioner, and it is sufficient to add a surface conditioner with exactly the same composition to the reduced amount of the surface conditioner. It is only necessary to control the surface conditioner component, concentration and pH. Further, since the fluctuation of the surface modifier component is suppressed, it is not necessary to discharge the surface modifier, which is preferable from the viewpoint of cost and environmental load reduction.

[0059] The crystal nucleating agent contained in the surface conditioner is not particularly limited, and those used in the usual paint substrate treatment process for automobile bodies can be used. Examples thereof include an aqueous liquid in which Ti colloid is dispersed in an aqueous solution of sodium pyrophosphate, or an aqueous liquid in which particles of zinc phosphate are dispersed. Among these, an aqueous liquid in which zinc phosphate particles are dispersed is particularly preferable. When the aqueous liquid is supplied, it can be adsorbed on the zinc-based surface without agglomeration while maintaining the particle size even when dried in the pre-drying step (S2) described later, and the particle form can be maintained. Because. On the other hand, for Ti colloids and the like, the crystal nucleating agent may dry and aggregate in the pre-drying step (S2).

[0060] adhesion amount of the surface modifier is less than 30MgZm ² is preferred. This is because when 30 mgZm ² or more, surface treatment spots occur and the appearance may be impaired. Preferably it is 15 mg Zm ² or less, more preferably 10 mgZm ² or less. In addition, the upper limit is preferred because the effect as a base treatment is saturated even if it adheres more than that, and conversely it may affect the treatment agent in the subsequent process.

[0061] In addition, in the case of a zinc-based plated steel sheet having excellent adhesiveness described later, zinc phosphate particles are The supply amount of the dispersed aqueous liquid is preferably 0.01 to ⁵ mgZm ^{2 in} terms of P in the zinc phosphate at the time of drying. If it is less than 0.01 mg / m ^2, it is difficult to obtain adhesiveness, and if it exceeds 5 mg Zm ² , the effect is saturated. Preferably is 0. l~2mgZm ^2. The concentration of zinc phosphate may be 0.05 to 5 molZL. The reason for this is that if it is less than 0.05 molZL, the wet film thickness becomes too large in order to obtain a predetermined amount of adhesion, and uneven coating tends to occur. On the other hand, if it exceeds 5 molZL, the viscosity of the surface conditioner becomes too high and uneven coating tends to occur.

[0062] The zinc phosphate particles used for crystal nucleus formation may be crystalline, amorphous, or a mixture thereof. Whether it is crystalline or not can be judged by general X-ray diffraction analysis.

[0063] The pH of the surface conditioner is preferably 5 or more. This is because, when the pH is less than 5, elution of zinc from the zinc-based metal occurs when the surface conditioner is supplied to the zinc-based metal. Furthermore, since the aqueous solution itself in which the zinc phosphate particles are dispersed may cause a slight reaction in the dissolution reaction of the zinc phosphate particles, the stability of the particles themselves may be impaired. More preferably, the pH is 7 to LO. This is because when the pH is higher than 10, a dissolution reaction of zinc phosphate itself occurs. Further, a buffer solution for adjusting the pH may be added to the surface conditioner. Examples of buffer solutions include buffer solutions consisting of K HPO and NaOH.

twenty four

You can. The concentration of the buffer solution in the surface conditioner is preferably from 0.1 to 2 gZL. This is because it is difficult to obtain a desired supply amount if less than 0.lgZL, and there is a possibility that uniform supply may be affected if it exceeds 2gZL.

[0064] The dispersed zinc phosphate particles preferably have a particle size of 10 µm or less. This is because the dispersion becomes unstable when it exceeds 10 m and the life of the aqueous liquid is reduced. Preferably, it is 5 μm or less, more preferably 3 μm or less. The lower limit of the particle diameter is not particularly limited, but is preferably 0.1 l ^ m or more from the viewpoint of the viscosity of the aqueous liquid. The following is preferable for the zinc-based steel plate having excellent adhesiveness described later. More preferably, it is 1 μm or less. The particle size can be investigated with a laser diffractometer in the state of a dispersed aqueous liquid.

[0065] The content of zinc phosphate particles is 0.5 molZL or less. This is the concentration of zinc phosphate particles This is because the content of the dispersion becomes too high when the content exceeds 0.5 molZL, and the life of the aqueous liquid may be reduced. The viewpoint power of the stability of the aqueous liquid is also preferably 0.3 molZL or less. The content of zinc phosphate particles can be converted to atomic force as Zn (PO 4) by measuring the zinc concentration.

3 4 2

[0066] At least one or two or more selected from alkali metals of Li, Na and K and alkaline earth metals of Be, Mg and Ca may be added to the aqueous liquid. This is because the reaction of the substrate surface in the pre-drying step described later becomes more uniform, and a stable hot-dip galvanized steel sheet can be produced. The concentration of these alkali metals and alkaline earth metals shall be 0.3 molZL or less in total for the above alkali metals and alkaline earth metals. This is because, if added in excess of 0.3mo 1ZL, these additives adhere to the substrate surface and carry over, and the stability of the processing agent and the like in the subsequent process may be reduced. The alkali metal and alkaline earth metal can be added as orthophosphate, metaphosphate, pyrophosphate, orthosilicate, metasilicate, carbonate, bicarbonate, borate and the like. In addition, an ammonium salt or an aqueous ammonium solution may be used for pH adjustment. Furthermore, if the total is about 0.05 molZL or less, metal or metal salt particles such as Fe, Co, Ni, Cu, Mn, and Cr may be contained. It is preferable to mix a pH buffer or the like in the aqueous liquid. An example is a buffer solution consisting of K HPO and NaOH. this

twenty four

In some cases, the pH change is reduced and stable production is possible. As the aqueous liquid, if the above composition is satisfied, a commercially available surface conditioner used for coating surface treatment or the like can be used.

[0067] Next, the pre-drying step (S2) will be described. The pre-drying step (S2) is a step in which the surface conditioner supplied to the substrate surface is dried without being washed with water. The drying temperature is not particularly limited, but from the viewpoint of manufacturing cost and the like, it is preferable that the maximum temperature reached by the steel sheet is less than 200 ° C. More preferably, it is less than 150 ° C. Most preferably, it is 50 to 120 ° C. The drying time is not particularly limited, but is preferably less than 30 seconds from the viewpoint of surface appearance and productivity. More preferably, it is less than 10 seconds. The method for drying is not particularly limited and can be appropriately selected. Examples thereof include an air knife, a dryer, and an oven.

[0068] In the pre-drying step (S2), the surface conditioning agent is added to the treatment agent supply step (S3) described later. As a result, it is possible to reduce the variation in the composition balance of the processing agent by suppressing the mixing of the surface conditioning agent into the processing agent circulated and used in the processing agent supply step (S3). This makes it possible to suppress the supply and discharge of processing agents, which was conventionally necessary to maintain the composition balance of the processing agents.

[0069] This is because the activity of the zinc-based steel sheet can be temporarily stopped by drying after supplying the surface conditioner. In addition, the zinc phosphate particles can be adsorbed on the zinc-based surface without agglomeration while maintaining the particle size by the drying, and the particle form can be maintained, and the action of the protective film can be applied to the treatment agent process. It is also possible to react the plating surface in the next drying process while suppressing the oxidation reaction on the steel sheet surface. On the other hand, in the case of an aqueous solution in which Ti colloid is dispersed in an aqueous solution of sodium pyrophosphate, the crystal nucleating agent may be dried and aggregated.

Next, the treatment agent supply step (S3) will be described. The treatment agent supply step (S3) is a step of supplying a treatment agent for forming a zinc phosphate film on the substrate subjected to the above-mentioned pre-drying step (S2). Although the supply method of the processing agent to a base material is not specifically limited, For example, a spray ringer method, a roll coat method, etc. can be mentioned. Among these, the combination with the pre-drying step (S2) described above can effectively simplify the equipment, and the roll coating method can be used from the viewpoint that hot-dip galvanized steel sheets can be produced at a lower cost. It can be preferably applied. From the viewpoint of the operability of the treatment agent, treatment by a roll coating method is most preferable. Further, the temperature of the intruding material when the steel plate that has undergone the pre-drying step (S2) is allowed to enter the treatment material supplying step (S3) is preferably less than 80 ° C. This is because, when the steel sheet temperature is high, the activity of the steel sheet exceeds the protective film action of the surface conditioner, and the zinc plating film may be eluted into the treated material. Preferably it is less than 60 ° C. The lower limit is preferably 30 ° C or higher. This is because if it is less than 30 ° C., the reaction due to heating in the drying step after the treatment step does not sufficiently occur, and the film formation may be non-uniform. Adjustment of the temperature of the ingress material can also be achieved by providing a cooling section of the steel plate. Temperature control by roll cooling such as a water-cooled roll is also possible.

[0071] The treatment agent supplied in the treatment agent supply step (S3) is an aqueous zinc phosphate solution. The zinc phosphate aqueous solution is an aqueous solution containing phosphate groups and zinc ions. Here, phosphate group H PO _, HPO, PO is a generic term for [PO].

2 4 4 4 4

[0072] Here, the zinc phosphate aqueous solution contains 0.001 to 0.7 molZL of phosphate radicals [containing ^three POs,

Four

Further, it contains zinc ions having a molar ratio of 0.7 or less with respect to the phosphate group. The reason why the concentration range of phosphate radicals was set to 0.001 to 0.7 molZL is that the stability of the treatment agent may be lowered if the phosphate radicals are increased beyond 0.7 molZL. On the other hand, if it is less than 0. OOlmol ZL, the pH of the treatment agent becomes high, and the reaction may be hindered and the desired performance may not be obtained. The reason why the zinc ion is contained in a molar ratio of 0.7 or less with respect to the phosphate group is that a homogeneous crystalline film can be formed by containing the zinc ion. This is also because sludge is generated, and the surface quality may be impaired. Preferably it is 0.5 or less. Here, “sludge” means that Zn (PO 4) solidifies in an aqueous solution.

3 4 2

It is.

[0073] More specifically, the formation reaction of crystalline zinc phosphate is a reaction represented by the following formula (A) or (B), in which a zinc atom is present relative to the phosphate radical in the treating agent. 1. 5 times required.

2H PO + Zn Zn (H PO) + H (A)

3 4 2 4 2 2

3Zn (H PO) Zn (PO) -4H O (B)

2 4 2 3 4 2 2

For this reason, originally, the treatment agent in the treatment agent supply step (S3) must further contain excess zinc.However, if zinc is contained excessively, the pH increases and the treatment agent solidifies. Pine.

[0074] The treatment agent preferably has a pH of 4 or less. When the pH is higher than 4, the stability of the treatment agent decreases, and there is a high possibility that sludge is generated and the surface quality is impaired, and the reaction does not proceed smoothly and a zinc phosphate film is not formed. Because there is a fear. More preferably, it is not more than pH3.

[0075] In addition to zinc ion and phosphate radical, nitrate radical (NO ³ —) is 0.2 or less, nitrite radical (NO ² —) is 0.2 or less, and hydrofluoric acid radical (F_ ) Is 0.1 or less, and sulfate radical (SO ² "

Four

The reason for adding one or more strong electrolytes with a) of 0.05 or less is to react with the treating agent stably in order to improve the uniformity of the film. Specifically, an etching action and an oxidation action can be obtained by the reaction. When the strong electrolyte ion is added more than the above upper limit, the stability of the treatment agent is lowered and the life of the treatment agent may be shortened. [0076] In addition, an ammonium salt or an aqueous ammonia solution may be added to the aqueous zinc phosphate solution for pH adjustment. The concentration of ammonium ions is preferably 0.02 or less in molar ratio to the phosphate radical. In addition, other metal ions other than zinc may be mixed as long as the configuration of the zinc phosphate aqueous solution is satisfied. At this time, it is preferable that the total molar ratio of the metal ions to phosphate groups is 0.2 or less.

[0077] The amount of zinc phosphate aqueous solution attached depends on the amount of the film formed in the final step, and the amount of supply in the surface conditioning agent supply step (S1) and the treatment agent supply step (S3) described above. It is preferably 30 to 500 mgZm ² in terms of P in total. This lubricating effect of the film is less than 30MgZm ² is not reflected in the formability of the steel sheet, exceeds 500MgZm ^2, the effect is to saturation. More preferably from 30~400mgZm ^2.

[0078] By providing the pre-drying step (S2), which is a pre-step of the treatment agent supply step (S3), a treatment that prevents the surface conditioner from being brought into the treatment agent supply step (S3) as a liquid agent. The balance of the agent can be properly maintained over a long period of time. As a result, treatment agent management and drainage facilities can be simplified.

[0079] Next, the post-drying step (S4) will be described. The post-drying step (S4) is a step in which the treatment agent supplied to the substrate surface is dried without being washed with water. The drying temperature is not particularly limited! /, But from the viewpoint of manufacturing cost, it is preferable that the maximum temperature of the steel sheet is less than 250 ° C. More preferably, it is less than 180 ° C. The drying time is not particularly limited! / Is preferably less than 100 seconds after coating from the viewpoint of surface appearance and productivity. More preferably, it is less than 50 seconds. The method for drying is not particularly limited and can be appropriately selected. Examples thereof include an air knife, a dryer, and an oven. A homogeneous zinc phosphate crystal film is formed by the post-drying step (S4).

Next, a zinc-based steel sheet having a zinc phosphate coating according to one embodiment of the present invention will be described. A zinc-based plated steel sheet having a zinc phosphate coating has a base material, a zinc-based plating coated on the surface of the base material, and a zinc phosphate coating formed on the outside of the zinc-based coating. ing. Each will be described below.

[0081] (1) Base material The kind of steel plate used as a base material is not particularly limited, and any kind of cold-rolled steel plate or hot-rolled steel plate can be applied. The chemical composition of the base material is not particularly limited. Extremely low carbon steel, low carbon steel, or Sarakuko containing Si, Nb, etc., as required, Si, Mn, P, Cr, Ni, Cu High-strength steel or high-strength steel containing V, V, etc. as appropriate can be applied.

[0082] (2) Zinc-based metal

For the zinc-based plating of the zinc-based plated steel sheet having the zinc phosphate coating of the present invention, molten zinc-based plating or electrozinc plating can be applied. A zinc-based steel plate is obtained by applying the zinc-based plating to the base material.

[0083] Examples of the hot-dip galvanized steel sheet include a GI steel sheet not subjected to alloying treatment by heating and a GA steel sheet subjected to alloying treatment by heating. A GI steel sheet is a steel sheet that has not been alloyed after hot-dip galvanizing and has an Fe content of 2% by mass or less. This is because if it exceeds 2% by mass, a part of the Fe—Zn alloy layer appears on the surface, which is not preferable in appearance. On the other hand, GA steel sheet is a steel sheet that has been alloyed after hot-dip galvanizing, and the Fe content is 7 to 15 mass% with respect to the galvanized layer. When the Fe content is less than 7% by mass, the 7-phase remains in the vicinity of the surface of the alloyed hot-dip zinc plating layer, which is not preferable in appearance. Preferably it is 8 mass% or more. When the Fe content exceeds 15% by mass, powdering tends to occur during press forming. Preferably it is 13 mass% or less.

[0084] The molten zinc-based adhesion layer of the GI steel sheet and GA steel sheet may contain 0.05% by mass of A1. As a result, the adhesion between the molten zinc-based plating and the base material can be improved. In addition, Cu, Ni, Cr, Si, Mn, Pb, Sb, Sn, misch metal, and the like may be contained or added in a small amount in the molten zinc-based plating layer. Also, the alloy phase is not particularly limited. The GI steel sheet contains η, ζ, and δ phases, and the GA steel sheet contains ζ, δ 1, Γ 1 and Γ phases. Also good.

[0085] Further, the amount of adhesion of the molten zinc-based metal is not particularly limited. However, from the viewpoint of cacheability, weldability, and productivity, the adhesion amount of the molten zinc-based metal is preferably 150 gZm2 or less. [0086] Here, the forces described for GI steel sheet and GA steel sheet are 5 mass ⁰ / oAl—Zn plated steel sheet (GF steel sheet), 55 mass% A1-Zn plated steel sheet (GL), and 3 mass% Mg. —Al—Z n-plated steel sheet (MZ steel sheet) etc.

[0087] Examples of electrogalvanized steel sheet include EG steel sheet, 10 mass% Fe-Zn electrogalvanized steel sheet (FZ steel sheet), 13 mass% Ni-Zn (ZnNi steel sheet), etc. be able to. Among these, it is preferable to apply the zinc phosphate coating of the present invention to the EG steel sheet.

[0088] Any zinc-based plating method can be applied to the production of the zinc-based steel sheet used in the present invention. For example, with a GI steel plate, it is immersed in a fitting bath and cooled as it is. On the other hand, the GA steel sheet is immersed in a mating bath and then alloyed. Moreover, various temper rolling (skin pass), flat wrinkle treatment (leveler) and the like may be applied as necessary. In addition, the surface condition and surface roughness of the GI steel sheet and GA steel sheet are variously changed by temper rolling, but these may be changed. This change does not affect the adhesion or the like.

[0089] (3) Zinc phosphate coating

The zinc phosphate coating is a crystalline zinc phosphate coating formed on the outer layer of the zinc-based metal. The zinc phosphate coating of a zinc-based plated steel sheet having a zinc phosphate coating according to the present invention has one of the following configurations.

(i) A spectrum obtained by an absorption spectrum measurement method for measuring the surface reflected light of infrared light incident from a direction inclined by 60 ° with respect to the normal direction of the zinc-based steel sheet having the zinc phosphate coating, and having a wavelength It has multiple absorption bands in the range of 8 to 12 m, and the integral intensity ratio (PZS) of the absorption spectrum of p-polarized light (P) and s-polarized light (S) in the wavelength range is 1.2 or more. .

(ii) A spectrum obtained by an absorption spectrum measurement method that measures the surface reflected light of infrared light incident from a direction inclined by 60 ° with respect to the normal direction of the zinc-based steel sheet having the zinc phosphate coating, and has a wavelength P-polarized light absorbance (Pa) and s-polarized light absorbance (Sa) at absorptions (absorption A) at wavelengths of 8.4 to 9.2 m, with multiple absorption bands in the range of 8 to 12 m. , And wavelength 10.2: The ratio (PaZSa and PbZSb) between the absorbance of p-polarized light (Pb) and the absorbance of s-polarized light (Sb) at the absorption (absorption B) of LI.O / zm is Both are 2 or more.

[0090] In the above cases (i) and (ii), in the case of misalignment, the sub-phase having the zinc phosphate coating of the present invention is used. The zinc phosphate coating on the lead-based plated steel sheet is an absorption that measures the surface reflected light of infrared light incident from a direction inclined by 60 ° with respect to the normal direction of the zinc-based plated steel sheet having the zinc phosphate coating. It is a spectrum obtained by the spectrum measurement method and has multiple absorption bands in the wavelength range of 8 to 12 m. This is due to the P—O bond of zinc phosphate forming the zinc phosphate film, and usually has about 5 absorption bands.

Here, the reason why the infrared light is incident in the direction of 60 ° is to prevent the reflected light of the zinc-based steel plate force from affecting the absorption spectrum. As a result, a spectrum with a good SN ratio can be obtained. The reflected light is detected from the 60 ° direction corresponding to the incident light. Since the reflected light is irregularly reflected by the roughness of the surface of the steel sheet and the reflected light entering the detector is small, there is a case where the light collecting device may be provided in front of the detector.

[0092] The zinc phosphate coating described in (i) above has a configuration in which the integrated intensity ratio (PZS) of the absorption spectrum of p-polarized light (P) and s-polarized light (S) is 1.2 or more. This represents the degree of orientation of P—O bonds constituting the zinc phosphate coating. That is, PZS of 1.2 or more means p-polarization power stronger than polarization. Accordingly, the zinc phosphate coating of the zinc-based plated steel plate having the zinc phosphate coating of the present invention has a configuration in which it is close to perpendicular to the steel plate and strongly oriented. More preferably, PZS is 2 or more.

A more preferable orientation of the P—O bond is a zinc phosphate coating having a configuration in the range described in (ii). The orientation described in (ii) focuses on two wavelength ranges of wavelengths 8.4 to 9. and wavelengths 10.2 to LI. The structure of the absorbance of the zinc phosphate coating used in the zinc-based plated steel sheet having the zinc phosphate coating of the present invention is shown. The two wavelength ranges are due to the characteristic absorption of the spectrum.

[0093] Specifically, the ratio (PaZSa) of (absorption A) p-polarized light absorbance (Pa) to s-polarized light absorbance (Sa) in the absorption spectrum of wavelength 8.4 to 9.2 m is 2 or more. And the ratio (PbZSb) of (absorption B) p-polarized light absorbance (Pb) to s-polarized light absorbance (Sb) in the absorption spectrum of wavelengths 10.2 to 11. Ο μm is 2 or more. It has been. More preferably, the deviation is 3 or more.

[0094] As described above, in either of the configurations (i) and (ii), the orientation of the P—O bond is a steel plate. The surface is highly oriented in the direction perpendicular to the surface of the steel sheet, and by using a zinc phosphate coating (with strong P-polarized light!), Excellent lubricity and excellent adhesion are maintained. A zinc-based steel sheet having a zinc phosphate coating can be provided. This is due to the orientation

This is thought to be due to an increase in the interaction between the P—O bond and the C 2 O bond of the secondary material (mainly resin). As a result, a zinc-based steel sheet having a zinc phosphate coating excellent in compatibility with auxiliary materials for automobiles, in particular, a vinyl chloride-based adhesive used for structural bonding, and a mastic-based adhesive having a sealing function. Can be provided.

[0095] The adhesion amount of the zinc phosphate film may be 30 mgZm ² or more. More preferably, it is 50 mgZ m ² or more. This is because the lubricity is affected, and if it is less than 30 mgZm ² , good lubricity may not be obtained. Further, the adhesion amount of the zinc phosphate coating is most preferably more preferably tool 150MgZm ² below it 250MgZm ² or less is preferred instrument 200MgZm ² below. This is due to the fact that the adhesiveness may decrease when the amount of zinc phosphate coating is large.

[0096] With the zinc-based plated steel plate having the zinc phosphate film having the above-described configuration, it is possible to provide a steel plate excellent in lubricity and adhesiveness.

[0097] Hereinafter, the embodiment will be described in more detail.

Example

[Example 1]

Ultra low carbon steel sheet GI steel sheet is a switching plate of 200 mm X 250 mm in thickness 0. 8 mm as in Example 1 (coating weight 90gZm ^2, film A1 concentration: 0.4 wt%, Fe concentration:. 1 5 wt%) And galvanized steel sheets (plating weight 60gZm ² , coating A1 concentration: 0.30% by mass, Fe concentration: 9.5% by mass), operability evaluation and lubricity evaluation were performed. Natsuta. In this example, evaluation is performed based on the presence or absence of the pre-drying step when the component of the surface conditioner and the component of the treatment agent are changed. Table 1 shows the components of the surface conditioner, and Table 2 shows the components of the treatment agent.

[0099] [Table 1] ^ Ingredients in surface conditioner

[] 0100

Ingredients in treatment agent

[0101] The conditions of each step are as follows.

Surface conditioner supply process

Surface conditioner supply method: spray or roll coater

Amount of deposit: 3mgZm ^{2 in} terms of P

Pre-drying process

Drying equipment: hair dryer

Drying temperature: Maximum steel sheet temperature 60 ° C

Drying time: 10 seconds

Treatment agent supply process

Supply method: Roll coater (Intruder temperature 50 ° C)

Total adhesion amount: 80mg / m ^{2 in} terms of P

Post-drying process

Drying equipment: oven

Drying temperature: Maximum steel sheet temperature 70 ° C

Drying time: 30 seconds

[0102] Further, as a conventional example, the case where the conventional cleaning with alkali and acid is performed is also shown. Specifically, in this case, the substrate that has been washed with water after washing is introduced into the treatment agent supplying step. In this example, the presence / absence of a drying step before being introduced into the treatment agent supplying step after washing with water was also shown. The conditions are shown below.

Pre-cleaning conditions: 7 wt% NaOH and 2 wt% H 2 SO (No. 13, 14 in Table 1)

twenty four

Immersion conditions: Immerse in 7% NaOH aqueous solution (70 ° C) for 5 seconds

Immerse in 2% aqueous solution of SO (50 ° C) for 5 seconds

twenty four

[0103] (1) Evaluation items

Based on the above conditions, the following evaluation was performed.

(1 1) Operability evaluation

Runnability is bringing components from the surface control agent in the treatment agent when the 10 m ² (total area of the cutting plate is 10 m ²⁾ was fed treatment agent to the substrate with respect to 10L of treatment agent (surface adjustment Seizai Measure the concentration of mainly zinc contained in the processing agent and supply the processing agent. The concentration change from before was evaluated. The evaluation criteria for operability are as follows. The need for concentration adjustment in the following evaluation criteria means that no water washing facilities, replenishers, or waste liquid treatment facilities are required.

○: Concentration increase of alkali metals and zinc in the treatment agent is 2% by mass or less of the initial concentration (concentration adjustment is not required)

Δ: Concentration increase of alkali metal and zinc in the treatment agent exceeds 2% by mass of the initial concentration, and 4% by mass or less (concentration adjustment is almost unnecessary)

X: Concentration increase of alkali metals and zinc in the treatment agent exceeds 4% by mass of the initial concentration (concentration adjustment required)

[0104] (1 2) Lubricity evaluation method

Using a pin-on-disk friction wear tester, the coefficient of friction was measured under the following conditions using a pin-on-disk friction wear tester for the obtained hot-dip galvanized steel sheet having a zinc phosphate coating. Lubricity was evaluated by the coefficient of friction. The evaluation criteria for the friction coefficient are as follows. Test conditions

Load: 30kN

Slider material: SKD steel

Slider shape: 5mm diameter steel spherical surface

Test temperature: 60 ° C

Turning radius: 10mm

Sliding speed: lrpm

Test speed: 20 times

Number of measurement points: Twelve measured force values per rotation are also averaged and averaged 20 times Evaluation criteria

A: Coefficient of friction less than 0.12 (very good lubrication)

○: Friction coefficient 0.12 or more and less than 0.15 (good lubrication)

X: Friction coefficient 0.15 or more (unsuitable for lubrication)

[0105] (1 3) Stability of surface conditioner and treatment agent The stability of each surface conditioner and treatment was obtained by a 40 ° C. X 7 day test. This is to maintain each adjuster and treatment at 40 ° C for 7 days. The stability of the surface conditioner and the treatment agent is evaluated as follows.

Surface conditioner 〇: Maintain dispersion state

X: Precipitation occurs

Treatment agent 〇： No sludge generation

X: Sludge is generated

[0106] (2) Evaluation results

The results of Example 1 evaluated based on the above conditions will be described below.

(2-1) Operability and lubricity

Table 3 lists the results.

[0107] [Table 3]

Process Operability Platen surface conditioner supply process Treatment agent supply process

Typhoon Preparation Type Pre-drying Surface tone

Treatment agent Lubricity Process Preparation

Surface adjustment

Supply method ffi agent

Supply method

Agent No.

R1 Gl 1 Spray Yes a Roll coater O o © Example of the present invention

R2 GA 1 Π—3: Yes Yes 0 d—3: 0 o o This invention 俩

R3 GI 1 With spray d Roll coater o o ◎ Example of the present invention

R4 OA 1 No spray d C3—Lukotor 0 X Comparison 5 GA 1 Spray present e Mouth coater ○ ○ ◎ Example of the present invention

R6 GA 1 With roll coater f Single-piece coater 0 ○ ◎ Example of the present invention

R7 GA 2 Roll coater Yes y a Rucoator o 〇 Example of the present invention

R8 GA 2 With roll coater b Roll coater 0 o ◎ Example of the present invention

R9 OA 2 Mouth rucota None b Mouth rucota o X © Comparison animal

RIO GA 2 With spray e Mouth coater o o ◎ Example of the present invention

R11 GI 2 mouthpiece Yes Y f α—Luc coater o o ◎ Example of the present invention t 2 GA 3 Spray a □ —Lucometer o X

R13 GA 3 With roll coater b Roll coater o o ◎ Example of the present invention

R14 GI 4 With spray b: 3-t o o ◎ Example of the present invention

R15 GA 4 Mouth coater None c Roll coater o X Comparative example

R16 GA 4 With spray d Mouth coater o O ◎ Example of the present invention 17 GI 4 α-Luco class e Roll coater 0 0 Example of the present invention

R18 GA 4 No spray f d-L] -T o X ◎ Comparative example

R19 GA 4 Mouth converter Yes y f Mouth converter o O ◎ Example of the present invention

R16 GA 5 Spray Yes a Mouth Locator o O Example of the Invention 17 GA 5 Mouth Locator Available d Roll Coat o o ◎ Example of the Invention

R18 GI 6 spray ^ f mouth-couter o X © Comparative example

R19 GI 6 With spray d Roll coater o O ◎ Example of the present invention

R20 GA 8 Mouth Locator Yes b Mouth Locator o O

R21 GA S Spray Yes d

R22 GA 9 With spray d Mouth converter o o © The present invention «

R23 GA 9 Roll coater f

R24 GA 11 with spray a mouth counter X o ◎ present invention Λ

R25 GI 11 Roll coater provided f Roll coater X o @ Example of the present invention

R26 QI 13 With spray b Mouth-colator X o X Conventional ft

R27 GA 13 No spray b Roll coater X X X Conventional 侧 8 GI 14 Roll coater Available d Mouth-col coater X o X Conventional example

R29 GA 14 Roll coater None d Roll coater X X X Conventional 洌

R30 GA 15 With roll coater a Roll coater 0 Δ ○ Example of the present invention

R31 GA 1 mouth-coater available a Spray 0 X Ο Comparative example

[0108] Looking at this, when the surface conditioning agent is supplied and dried in the pre-drying step, the lubricity of the hot dip galvanized steel sheet, which is high in operability of the treatment agent, is also good. Thus, the effects of the present invention are remarkably exhibited. It can also be seen that it does not depend on the surface conditioning agent supply method.

[0109] On the other hand, as a conventional example, the case of using the conventional cleaning shown in the symbols R26 to R29 is also used. Due to the pre-drying step, only the operability of the treatment agent is good. This means that the pre-drying process has a great effect on improving the operability of the treatment agent. However, under the conditions of R2 6 to R29, the desired lubricity should be obtained for the hot dip galvanized steel sheet, so it is also necessary to supply a surface conditioner.

[0110] Further, under the conditions indicated by reference marks R24 and R25 as reference examples, the operability of the surface treatment agent is not good, while the operability of the treatment agent is not affected. This is thought to be due to the fact that the surface treatment agent shown in No. 11 in Table 1 used for the symbol R24, 25 has a pH of 4.5, which is lower than the others. Therefore, the operability of the surface conditioner can be improved by increasing the pH to at least 4.5.

[0111] (2-2) Stability of surface conditioners and treatment agents

Next, the stability results of the surface conditioners and treatment agents shown in Table 1 and Table 2 will be explained. Table 4 shows the stability evaluation results of the surface conditioner, and Table 5 shows the stability evaluation results of the treatment agent.

[0112] [Table 4]

[0113] [Table 5] Processing

[0114] The surface conditioning agents shown in Table 4 had poor stability in No. 7, No. 10, and No. 12. This is considered to be because the total of alkali metals and alkaline earth metals reached 0.401 molZL for No. 7 as shown in Table 1. In addition, for No. 10 and No. 12, the reason is that the particle size is large and the zinc phosphate content is large. These do not necessarily affect the operability of the treatment agent, but stability is preferred.

[0115] Among the treatment agents shown in Table 5, the stability for g to m was good. This is thought to be due to the large ratio of zinc ions to phosphate radicals for g to i. Moreover, the pH of i is 4.1, indicating a high value. For j to m, it is considered that the added strong electrolyte-on ratio is large! /. These do not necessarily affect the operability of the treatment agent, but higher stability is preferred.

[0116] (Example 2)

As Example 2, in a continuous molten zinc-based steel plate production line, a 0.8 mm thick GA steel plate (very low carbon steel plate, 45 gZm ² coating weight, coating A1 concentration: 0.25 mass%, Fe concentration: 9.0 mass%) is subjected to a skin pass (rolling ratio 1.0%), and in the surface conditioning agent supply process, the surface conditioning agents No. 1, 4, and 6 shown in Table 1 are supplied, and the processing agent is supplied. Processes are a, d, e in Table 2. And the zinc-phosphate film | membrane process was performed using the processing agent of i. The conditions for each process are as shown below.

Surface conditioner supply process

Supply method: spray or roll coater

Drying equipment: hair dryer

Amount of deposit: 3mgZm ^{2 in} terms of P

Pre-drying process

Drying temperature: Maximum steel sheet temperature 70 ° C

Drying time: 5 seconds

Treatment agent supply process

Supply method: Roll coater (Intruder temperature 50 ° C)

Post-drying process

Drying equipment: oven

Drying temperature: Maximum steel sheet temperature 80 ° C

Drying time: 30 seconds

In addition, as a comparative example, a pre-drying step was performed.

(3) Evaluation items

Based on the above conditions, the following evaluation was performed.

(3-1) Evaluation of operability

In each treatment, when a steel plate with a thickness of 0.8 mm and a width of lm is passed 100 m for a treatment agent of 100 liters, the components brought in from the surface conditioner (alkali metal of the surface conditioner) and the treatment agent The concentration of mainly contained zinc was measured, and the change in concentration before treatment agent supply was evaluated. The evaluation criteria for operability are as follows. In the following evaluation criteria, no concentration adjustment means that no water washing facilities, replenishers, or waste liquid treatment facilities are required.

Δ: Concentration increase of alkali metal and zinc in the treatment agent exceeds 2% by mass of the initial concentration, and 4% by mass or less (concentration adjustment is almost unnecessary) X: Concentration increase of alkali metals and zinc in the treatment agent exceeds 4% by mass of the initial concentration (concentration adjustment required)

[0118] (3-2) Lubricity evaluation

Using a pin-on-disk friction wear tester, the coefficient of friction was measured under the following conditions using a pin-on-disk friction wear tester for the obtained hot-dip galvanized steel sheet having a zinc phosphate coating. The validity as a lubrication treatment was evaluated by the friction coefficient. The evaluation criteria for the friction coefficient are shown below.

Test conditions

Load: 30kN

Slider material SKD steel

Slider shape: 5mm diameter steel spherical surface

Test temperature: 60 ° C

Turning radius: 10mm

Sliding speed: lrpm

Test speed: 20 times

Number of measurement points: The average value is calculated from 12 measurement values per rotation, and the maximum average value is obtained for 20 times.

Evaluation criteria

A: Coefficient of friction less than 0.12 (very good lubrication)

○: Friction coefficient 0.12 or more and less than 0.15 (good lubrication)

X: Friction coefficient 0.15 or more (unsuitable for lubrication)

[0119] (3-3) Spot weldability evaluation

Spot welding was performed on the hot-dip galvanized steel sheet having the zinc phosphate coating obtained using a spot welder under the following conditions, and the nugget diameter (mm) was 4 tlZ2 (t: steel sheet thickness (mm)) The number of hits to the following was evaluated.

Evaluation conditions

Electrode diameter: 6mm

Electrode tip diameter: 40R dome shape Electrode material: 1% by mass Cr—Cu

Applied pressure: 2kN

Up slope: 3 cycles

Energizing time: 10 cycles (frequency: 50Hz)

Cooling flow rate: 3LZ

Welding current: 10.5kA

Evaluation criteria

○: More than 2000 RBI (appropriate)

X: Less than 2000 RBI (unsuitable)

[0120] (3-4) Corrosion resistance evaluation

The corrosion resistance was evaluated by a method generally used as a performance evaluation method for automobile steel sheets. Specifically, after chemical conversion treatment, electrodeposition was applied, and then a single cut was applied, and the maximum swell width after 500 hours of 5 mass% salt spray test was evaluated. The chemical conversion treatment and electrodeposition treatment conditions are shown below.

[0121] The chemical conversion treatment is carried out in the order of chemical conversion treatment (zinc phosphate treatment) after alkali degreasing, water washing and surface conditioning. The conditions in each order will be described next.

Alkaline degreasing: Fine cleaner E2001 (manufactured by Nihon Parkerizing Co., Ltd.) 200 g / L solution (50 ° C) for 2 minutes

Washing with water: 30 seconds

Surface adjustment: Barcolen Z (manufactured by Nihon Parkerizing) Immersion in lgZL solution (room temperature) for 10 seconds

Chemical conversion: PB—L3080 (manufactured by Nihon Parkerizing, liquid temperature 43 ° C) sprayed for 2 minutes

[0122] Following the chemical conversion treatment, GT-10 (cationic electrodeposition coating: 20) was electrodeposition coated.

The evaluation criteria are as follows.

Evaluation criteria: One side maximum paint film swelling width

Re: Less than 3mm (suitable)

X: 3mm or more (unsuitable) [0123] (4) Evaluation results

The results for the above conditions and evaluation items will be described. Table 6 shows the results.

[0124] [Table 6]

As can be seen from Table 6, the operability of the treatment agent is good for those having the pre-drying step shown in the remarks as examples of the present invention. On the other hand, those without pre-drying (compared to remarks) In all cases, the operability of the treatment agent is not good. Therefore, if the effect of the present invention appears remarkably, it can be achieved.

[0126] Further, it can be said that various performances with the pre-drying step are generally good. With regard to the syllable Zl 1 and the syllable Z16, the lubricity is good, and the reason is that the adhesion amount of P is small! / ヽ. This is not affected by the presence or absence of the pre-drying step included in the present invention.

[0127] (Example 3)

Spray degrease for 30 seconds with FCL4480 (20gZL, 45 ° C) made by Nihon Parkerizing Co., Ltd. on a steel plate with various zinc-based plating on both sides of an ultra-low carbon steel plate with a thickness of 0.8mm, followed by washing and drying And used as a test material. Thereafter, a surface conditioning agent supply step (S1) to a post-drying step (S4) were performed to produce a zinc-based steel sheet having a zinc phosphate coating. Various evaluations were performed on the zinc-based plated steel sheet having the zinc phosphate coating. The conditions, evaluation items, evaluation results, etc. will be described below. In addition, as a comparison, the surface conditioning agent supply step (S1) and the pre-drying step (S2) only, and the treatment agent supply step (S 3) and the post-drying step (S4) only were produced, respectively. . Furthermore, as a conventional example, a sample in which an electroplating layer having a composition of 80 mass% Fe-20 mass% Zn ( ² gZm ^{2 on} one side) was formed on the zinc plating upper layer was also prepared. Table 7 shows the various zinc-based plated steel plates used in this example. Furthermore, Table 8 shows the surface conditioner used in this example, and Table 9 shows the treatment agent.

[0128] [Table 7] Messa adhesion to plating components (excluding Zn (per side), mass%) Abbreviation: Zinc plating method

(m m> F e A 1 Mg

G A

50 9. 5 0. 3 0

→ Alloying in a heating furnace

G I Hot dip zinc 70 0. 2 0. 4 0

E G Electro zinc plating 50 0 0 0

MZ hot dip zinc 60 0 3. 4 3 [0129] [Table 8]

Concentration values represent the TI concentration for the alternative 1 A and the zinc phosphate concentration for the others.

[0130] [Table 9]

Manufacturing conditions

Manufacturing conditions will be described.

Surface conditioner supply process

The surface conditioner shown in the table was supplied to the zinc-based steel plate. Supply method is spray (in the table, squeeze roll squeeze after spray (in the table, air nozzle after spraying) The offset force of IFF (AK in Table 10) and roll coat (RC in Table 10) was taken as the displacement force. The amount of adhesion was obtained by fluorescent X-ray.

[0132] (1 2) Pre-drying step (S2)

A hot air dryer was used for drying in the pre-drying step (S2). The drying temperature was set based on the steel plate temperature, and was carried out in the range of no drying to 150 ° C. The drying time was standardized for 10 seconds for those that performed the pre-drying process.

[0133] (1 3) Treatment agent supply process (S3)

The treatment agents shown in Table 9 were supplied to the zinc-based plated steel sheet. The supply method was either squeeze roll squeezing after spraying or roll coating.

[0134] (1 4) Post-drying step (S4)

A hot air oven was used for drying in the post-drying step (S4). The drying temperature was set based on the steel plate temperature, and was standardized at 80 ° C for post-drying. The drying time was standardized for 10 seconds for the post drying.

[0135] (2) Evaluation items and evaluation methods

(2-1) PZS calculation by infrared absorption spectroscopy

The obtained zinc-based steel sheet having a coating was cut into 25 × 100 mm and measured by the following method. For measurement, QS-300 manufactured by BiO-Rad was used.

[0136] In the measurement, infrared light is incident from a direction of 60 ° from the normal direction of the surface of the steel plate to be measured, and reflected infrared light reflected in the corresponding 60 ° direction is detected. By doing. At this time, incident infrared light was polarized in a direction perpendicular to the surface (p-polarized light) and parallel (s-polarized light) by a KRS-5 polarizer, and all reflected infrared light was detected. Specifically, the following procedure was used.

[0137] First, infrared reflectance spectra of p-polarized light and s-polarized light are measured using an Au evaporated film as a standard sample. Next, for p-polarized light, the p-polarized relative reflectance spectrum of the steel sheet surface with respect to the p-polarized reflectance of the Au deposited film is measured. For s-polarized light, the relative reflectance spectrum of the steel sheet surface with respect to the s-polarized reflectance of the Au deposited film is measured. And the following formula (C), (D)

P-polarized absorbance = -log (p-polarized relative reflectance) (C)

s-polarized absorbance = -log (s-polarized relative reflectance) (D) To obtain infrared absorption (absorbance) spectra of P-polarized light and s-polarized light. Figure 2 shows an example of a graph showing the relationship between the obtained wavelength and absorbance. Figure 2 (a) is a graph for p-polarized light, and Fig. 2 (b) is a graph for s-polarized light. Where Pa and Sa are ρ-polarized light and s-polarized light absorbance at wavelengths of 8.4 to 9.2 μm, and Pb and Sb are p-polarized light and s-polarized light absorbance at wavelengths 10.2 and LI. .

[0138] In addition, the integrated intensities P and S indicate the absorbance power at each wavelength in the wavelength range of 8 μm to 12 m and the absorbance at the wavelength 12 m for the obtained p-polarized and s-polarized infrared absorption spectra. The background was corrected by subtraction, and the absorbance at each wavelength was calculated by calorie calculation. Specifically, the following formulas (E) and (F) are used.

S = (S8 m— S12 m) H h (S12 m— S12 m) (F)

From the obtained P and S, PZS can be calculated.

[0139] (2-2) Evaluation of adhesion and crystallinity of zinc phosphate coating

The adhesion amount of the zinc phosphate film was obtained by obtaining the adhesion amount of P by the fluorescent X-ray measurement method on the obtained steel sheet.

The crystallinity of zinc phosphate was evaluated by the following method using a RINT2500 measuring device manufactured by Rigaku Corporation.

2 Θ (COKQ;) X-ray diffraction measurement at 5-60 ° to confirm two diffraction lines A and B caused by zinc phosphate tetrahydrate. Both A and B have diffraction lines Was judged to be crystalline. Where A and B are

A (020) face of zinc phosphate tetrahydrate 20 = 10.8 °

亜鉛 Zinc phosphate tetrahydrate (311 + 241 + 151) face 20 = 36.7 °

It is.

[0140] (2-3) Adhesiveness

(2-3-1) Evaluation using PVC adhesive

After cutting the obtained steel plate to 25 X 200 mm and applying ² gZm ^{2 of} anti-rust oil per side, apply the adhesive of Cemedine Henkel PV5308 at an application area of 25 X 150 mm and an application thickness of 0.15 mm, Then baked. Baking is at 170 ° C, 20 minutes, 30 minutes, 40 minutes, 50 minutes Then, a T peel test was performed after baking. Figure 3 shows a schematic diagram of the test method for soot peeling. In the test, as shown in FIG. 3, among the bonded steel plates 1 and 1, each end portion to which the adhesive 2 is not applied is gripped, and each end portion is perpendicular to the bonding surface. This is done by pulling in the directions indicated by arrows Τ and Τ, which are opposite to each other. The evaluation was as follows based on the baking time at which the cohesive failure area ratio was 90% or more.

: 20 minutes or less

○: More than 20 minutes and less than 30 minutes

△: Over 30 minutes and under 40 minutes

X: Over 40 minutes

[0141] (2-3-2) Evaluation using mastic adhesive

After cutting the obtained steel plate to 25 x 100 mm and applying ² gZm ^{2 of} anti-rust oil per side, apply Iida Sangyo OROTEX 580 adhesive with a coating area of 25 x 25 mm and a coating thickness of 0.1 mm. Then baked. Baking was performed at 170 ° C for 20 minutes, 30 minutes, and 40 minutes, and a shear tensile test was performed after baking. Figure 4 shows an overview of the shear tensile test method. As shown in Fig. 4, the test was performed by grasping each end of the bonded steel plates 3, 3 where the adhesive 4 was not applied, and making each end parallel to the bonding surface and opposite each other. This is done by pulling in the direction indicated by the arrows S and S. The evaluation was as follows based on the baking time at which the cohesive failure area ratio was 90% or more.

: 20 minutes or less

○: More than 20 minutes and less than 30 minutes

△: Over 30 minutes and under 40 minutes

X: Over 40 minutes

[0142] (2-4) Lubricity

The lubricity of the obtained zinc-based steel sheet having the coating was measured by measuring the coefficient of friction. Specifically, using a pin-on-disk friction tester, the coefficient of friction was measured in a state where ² gZm ² per side of Pengchu Kosan fossil oil Nox Last 550S was applied to the steel sheet. The test conditions and evaluation criteria are shown below.

Test conditions Load: 30kN

Slider material: SUJ2 (bearing steel)

Slider shape: φ 5πιπι

Test temperature: 60 ° C

Turning radius: 10mm

Sliding speed: lrpm

Test rotation speed: 20 rotations

Number of measurements, etc .: The average value of twelve measured value forces per rotation is calculated and the maximum of the 20 times

Evaluation criteria

◎: Coefficient of friction 0.12 or less (Excellent as lubrication treatment (equivalent to Fe—Zn upper plating)

))

○: Friction coefficient 0.12 to 0.15 or less (good lubrication)

X: Coefficient of friction exceeding 0.15 (unsuitable for lubrication (usually equivalent to steel plate))

[0143] (2-5) Operability

(2- 5-1) Concentration change of zinc and alkali metal in treatment agent

One of the operability evaluations was the retention of the components of the treatment agent, which was measured by measuring the concentration of zinc and the concentration of alkali metals in the treatment agent. Specifically, the concentration of zinc and alkali metal in the treatment agent when a total of 10 m ² of cut steel sheet with zinc base was applied to 10 L of treatment agent in the treatment agent supply process was measured. The concentration change was compared. The evaluation criteria are as follows.

X: Concentration increase of alkali metals and zinc in the treatment agent exceeds 2% by mass of the initial concentration (concentration adjustment required)

[0144] (2— 5— 2) Paintability

If the condition of the surface conditioner is unstable or insufficiently dried during the surface conditioner supply process and pre-drying process, the surface condition of the zinc-based steel sheet after the post-drying process will be reduced. Adversely affect

There is a case. This was visually evaluated as unevenness. The evaluation criteria are as follows.

◯: Visually uneven

X: Visually uniform

[0145] (3) Results

The results of the implementation based on the above conditions and evaluation items are shown in Tables 10-12. Table 10 shows the conditions of each example, comparative example, and reference example. In Table 10, the different processes are represented by S1, S2, S3 and S4. Step S1 means a surface conditioning agent supply step, step S2 means a pre-drying step, step S3 means a treatment agent supply step, and step S4 means a post-drying step. In addition, the types of plating are abbreviations shown in Table 7, the types of surface conditioning agents are the symbols shown in Table 8, and the types of treatment agents are indicated by the numbers shown in Table 9. Furthermore, the supply method of the surface conditioner and treatment agent is indicated by S for spray, SR for squeeze roll aperture after spray, AK for air knife after spray, and RC for roll coater. Tables 11 and 12 show the results for each of the conditions shown in Table 10.

[0146] [Table 10]

SI process S2 process S3 process S4 process Plating

Test number Surface adjustment Supply Steel plate temperature Treatment agent Supply Dry Yes Remarks

Agent Type Method Amount (.c) Type Method

1 GA 1A S 0.1 60-Comparative example

2 GA-2D RC Yes Comparative example

3 GA-2D SR Yes Comparative example

4 GA 1A s 0.1-2D SR Yes Comparative example

5 GA 1A RC 0.1 60 2D RC Yes Example

6 GA 1B RC 1 60 2D RC Yes Example

7 GA 1C RC 1 80 2D RC Yes Example

8 GA ID RC 1 60 2D C Yes Example

9 GA IE RC 1 60 2D RC Yes Example

10 GA 1F RC 1 60 2D RC Yes Example

11 GA 1G RC 1 60 2D RC Yes Example

12 GA 1H RC 1 60 2D RC Yes Reference example

13 GA 1 J RC 1 60 2D RC Yes Example

14 GA IK RC 1 60 2D RC Yes Reference Example

15 GA 1 RC 0,05 60 2D RC Existence Example

16 GA 1M RC 0.3 60 2D RC Yes Example

17 GA 1P RC 2.4 60 2D RC Yes Example

18 GA 1Q RC 4.7 60 2D RC Yes Example

19 GA 1R RC 19,3 60 2D RC Yes Example

20 GA 1C RC 1 60 2D C Yes Example

21 GA 1C RC 1 60 2D RC Yes Example

22 GA 1C RC 1 60 2D RC Yes Example

23 GA 1C RC 1 60 2D RC Yes Example

24 GA 1C RC 1 60 2D RC Yes Example

25 GA 1C RC 1 60 2D RC Yes Example

26 GA 1C RC 1 60 2D C Yes Example

27 GA 1C S 1 80 2D RC Yes Example

28 GA 1C S 1 60 2D RC Yes Example

29 GA 1C AK 1 60 2D RC Yes Example

30 GA 1C RC 1 60 2 Α C Yes Example

31 GA 1C F? C 1 60 2Β C Yes Example

32 GA 1C RC 1 60 2C RC Yes Yes 1 row

33 GA 1C RC 1 80 2Ε RC Yes Yes 1 row

34 GA 1C RC 1 60 2F RC Yes Implementation column

35 GA 1C RC 1 60 2G RC Yes Implemented 1 row

36 GA 1C RC 1 80 2Η RC Yes Implemented 1 row

37 GA 1C RC 1 60 2J RC Yes Implemented 1 row

38 GA 1C RC 1 30 2D RC Yes Example

39 GA 1C RC 1 50 2D RC Yes Example

40 GA 1C RC 1 110 2D RC Yes Example

41 GA 1C RC 1 150 2D RC Yes Example

42 GA 1C RC 1 80 2Κ RC Yes Reference example

43 GA 1C RC 1 60 2 and RC Yes Reference Example

44 GA 80% by mass Fe— 20% by mass Zn electroplating layer on one side y2 _K / m ² comparative example

Comparative example of 45 GA GA steel plate

46 Comparative example of cold-rolled steel sheet

47 GI ID J RC 1 60 2D RC Existence Example

48 EG 1D RC 1 80 2D RC Yes Reference example

49 MZ 1D I RC 1 60 2D RC Existence Example Infrared absorption Compatibility with secondary materials

P adhesion B 曰 Lubrication

Test number P / S Pa / Sa Pb / Sb Sex Mass Remarks PVC

Integral intensity tic

1 ― ― ― 0 X X Δ X Comparative example

2 0.3 0.5 0.5 80 X o X X Comparative example

3 0.2 0.3 0.3 80 X ○ X X Comparative example

4 0.7 1.3 1.3 80 o ○ Δ Δ Comparative example

5 1.2 2.2 2.0 80 O ○ ○ ○ Example

6 2.1 3.8 3.2 80 ○ ○ ○ Example

7 2.1 4.9 4.1 80 O ◎ ◎ ◎ Examples

8 3.0 5.4 4.5 80 O ◎ ◎ ◎ Examples

9 1.7 3.0 2.5 80 O ◎ ◎ ◎ Examples

10 1.3 2.4 2.0 80 O ○ ○ ○ Example

1 1 1.7 3.0 2.5 80 o ○ ○ ○ Example

12 0.1 0.2 0.2 80 o o X X Reference example

13 1.3 2.3 1.9 80 o o o 〇 Example

14 0.3 0.5 0.5 80 o o X X Reference example

15 1.2 1.9 1.6 80 o o o Δ Example

16 2.0 3.6 3.0 80 ○ ◎ ◎ ◎ Examples

1 7 3.1 5.6 4.7 80 ○ ◎ ◎ ◎ Examples

18 2,6 4.6 3.9 100 ○ ◎ ◎ ◎ Examples

1 9 1.4 2.5 2.1 120 ○ ○ ○ O Example

20 1.3 2.4 2.0 20 ○ Δ ◎ ◎ Examples

21 1.3 2.4 2.0 40 〇 ◎ ◎ Examples

22 1 .9 3.5 2.9 50 〇 o ◎ ◎ Examples

23 3.9 7.0 5.9 1 10 o ◎ ◎ ◎ Examples

24 4.5 8.1 6.8 150 o ◎ ◎ o Example

25 5.1 9.2 7.7 200 ○ ○ ○ ○ Example

26 3.7 6.7 5.6 250 ○ o ○ ○ Example

27 1.3 2.4 2.0 80 ○ ◎ ◎ 〇 Example

28 3.1 5.6 4.7 80 ○ ◎ ◎ 〇 Example

29 2.3 4.1 3.4 80 ○ ◎ ◎ ○ Example

30 1.5 2.7 2.3 60 ○ o o ○ Examples

31 1.7 3.0 2.5 60 ○ ◎ ◎ 〇 Example

32 1.9 3.5 2.9 60 ○ ◎ ○ Example

33 1.6 2.8 2.3 60 ○ ◎ ◎ 〇 Example

34 2.3 4.1 3.4 70 ○ ◎ ◎ ◎ Examples

35 1.7 3.0 2.5 70 o ◎ ○ Examples

36 1.4 2.5 2.1 70 ○ ◎ ○ Example

37 1.3 2.3 2.0 70 0 o 〇 Example

38 2.7 4.9 4.1 80 ○ ◎ ◎ ○ Example

39 2.5 4.5 3.8 80 ○ ◎ ◎ ◎ Examples

40 2.9 5.2 4.3 80 o ◎ ◎ ◎ Examples

41 2.5 4.5 3.8 80 o ◎ ◎ ◎ Examples

42 0.7 1 .3 1.1 80 o 厶 Δ X Reference example

43 0.8 1.4 1.2 80 o △ △ X Reference example

44 ― ― ― ― ― ◎ ◎ ◎ Comparative example

46 ― ― ― ― ― ○ ◎ ◎ Comparative example

47 2.8 4.2 4.5 80 o ◎ ◎ ◎ Examples

48 2.6 5.5 3.6 80 ○ ◎ ◎ Reference example

49 2.4 4.8 4.2 80 o ◎ Example

[0149] As shown in Table 10 and Table 11, in the examples described as examples in the remarks column, PZS is 1.2 or more, and the adhesiveness at this time is both PVC and mastic. Good. In test No. 15, the strength of the mastic is good. Of those dried in the S2 process, the other comparative examples with a PZS smaller than 1.2 and the reference example are X evaluations, so it is good. In addition, the zinc-based steel sheet having the zinc phosphate coating according to the present invention is equivalent to the comparative example as compared with the comparative examples of trial numbers 45 to 47, which are conventionally considered to have better adhesion than the zinc phosphate coating. The effect of the present invention that the adhesiveness and lubricity equivalent to the conventional one can be obtained at a lower cost than the conventional ones is remarkable.

[0150] Further, looking at the adhesion between the examples having PZS of 1.2 or more, the larger the values of the PZS, Pa / Sa, and PbZSb, the higher the adhesion. Therefore, the stronger the orientation perpendicular to the surface in the P—O bond, the better the adhesion.

[0151] Further, trial numbers 1 to 4 show the results of examples when any of the steps S1 to S4, which is a step of producing a zinc-based steel sheet having a zinc phosphate coating, is omitted. It is a thing. According to this, if one of the steps is omitted, an appropriate value of PZS cannot be obtained, and adhesion is not preferable. Therefore, a zinc-based plated steel sheet having a zinc phosphate coating excellent in reproducibility, adhesiveness and lubricity can be produced by providing the production steps S1 to S4. Here, the trial number 12 where the process is not omitted has only PZS of 0.1. This is because the pH of the surface conditioner is 5 or less, so in order to obtain a more appropriate PZ S, it is preferable not to omit the process and to control the pH of the surface conditioner.

[0152] Table 12 shows the results related to operability. From this, it can be seen that the operability differs depending on the surface conditioner, the type of treatment agent applied in each process, and the drying conditions before and after. Therefore, by providing a manufacturing process under appropriate conditions, a zinc-based steel sheet having a zinc phosphate coating that is further superior in terms of cost and environment can be manufactured.

[0153] While the present invention has been described in connection with the most practical and preferred embodiments at present, the present invention is not limited to the embodiments disclosed herein. The scope of the claims and the overall specification of the invention, which can be appropriately changed without departing from the gist or philosophy of the invention which can be read, and the molten zinc accompanying such changes It should be understood that the production method of the steel plate and the steel plate are also included in the technical scope of the present invention.

Claims

The scope of the claims

[1] A method for continuously producing a molten zinc-based plated steel sheet having a zinc phosphate coating, a surface conditioner supplying step for supplying a surface conditioner to the surface of the molten zinc plated, and the surface conditioner supplying step A pre-drying step of drying the surface conditioning agent in a subsequent step, and a treatment agent supplying step of supplying a treatment agent containing a zinc phosphate aqueous solution to the surface of the molten zinc plating in a post-step of the pre-drying step; A method for producing a hot-dip zinc-based steel sheet having a zinc phosphate coating containing

[2] The hot dip galvanized plating having a zinc phosphate coating according to claim 1, wherein the surface conditioner in the surface conditioner supply step is an aqueous liquid containing zinc phosphate particles. A method of manufacturing a steel sheet.

[3] The zinc phosphate coating according to claim 2, wherein the zinc phosphate particles contained in the surface conditioner in the surface conditioner supply step have an average particle size of 10 μm or less. A method for producing a hot-dip galvanized steel sheet.

[4] or less average particle size force SLO / zm zinc phosphate particles contained in the surface conditioning agent of the surface conditioning agent supply process, and said the _P H of the surface control agent is 5 or more A method for producing a hot-dip galvanized steel sheet having the zinc phosphate coating according to claim 2.

[5] The surface conditioner in the surface conditioner supply step contains zinc phosphate particles in an amount of 0.5 molZL or less than OmolZL, and is selected from the group consisting of Li, Na, K, Be, Mg and Ca 1 The method for producing a hot dip galvanized steel sheet having a zinc phosphate coating according to any one of claims 1 to 4, characterized in that it contains 0.3 molZL or less in total of at least seeds. .

[6] The treatment agent in the treatment agent supply step contains 0.001-0. 7 mol / L of phosphate radicals and contains zinc ions having a molar ratio of 0.7 or less with respect to the phosphate radicals. A method for producing a hot-dip galvanized steel sheet having a zinc phosphate coating according to any one of claims 1 to 5.

[7] The zinc phosphate aqueous solution of the treatment agent in the treatment agent supply step contains zinc ions and phosphate radicals, has a pH of 4 or less, and has a molar ratio to the phosphate radicals other than the zinc ions and phosphate radicals. Contains one or more selected from the group consisting of strong electrolytes of less than 0.2 nitrate groups, less than 0.2 nitrite groups, less than 0.1 hydrofluoric acid groups, and less than 0.05 sulfate groups A method for producing a hot-dip galvanized steel sheet having a zinc phosphate coating according to any one of claims 1 to 6.

[8] The P attached to the surface of the molten zinc-based plating is adjusted to 30 to 500 mgZm ² in terms of P by the surface conditioning agent supply step and the treatment agent supply step. A method for producing a hot-dip galvanized steel sheet having the zinc phosphate coating according to any one of claims 7 to 10.

[9] The pH of the surface conditioner in the surface conditioner supply step is 5 or more, and the average particle diameter of the zinc phosphate particles is 0.1 to 3 μm. A method for producing a hot dip galvanized steel sheet having the zinc phosphate coating according to Item 2.

[10] The zinc phosphate particles adhere to 0.01 to 5 mgZm ^{2 in} terms of P on the surface of the zinc-based plated steel sheet that has undergone the pre-drying step from the surface conditioning agent supply step. A method for producing a hot dip galvanized steel sheet having a zinc phosphate coating according to claim 2 or 9.

[11] The treatment agent in the treatment agent supply step contains zinc and phosphate radicals and has a pH value or lower, and other than the zinc and phosphate radicals, the nitrate radical is 0. 2 or less, a strong electrolyte with a nitrite group of 0.2 or less, a hydrofluoric acid group of 0.1 or less, and a sulfate group of 0.05 or less. A method for producing a molten zinc-based steel sheet having a zinc phosphate coating according to any one of items 2 to 9, or 10 of the range.

[12] A post-drying step of drying the treatment agent in a post-step of the treatment agent supplying step, and 30 to 250 mgZm ² of the zinc phosphate coating in terms of P is attached after the post-drying step, The method for producing a hot-dip galvanized steel sheet having a zinc phosphate coating as set forth in any one of claims 2 to 9 and 11.

[13] The method for supplying the surface conditioning agent in the surface conditioning agent supply step, and the processing agent supply The zinc phosphate coating according to any one of claims 1 to 12, wherein any one or all of the methods for supplying the treating agent in the step is a roll coating method. The manufacturing method of the hot dip galvanized steel plate which has this.

[14] Hot-dip galvanized plating having a zinc phosphate coating on which a crystalline zinc phosphate coating is formed on the surface, which is manufactured by the manufacturing method according to any one of claims 9 to 13 Maoka plate,

The absorption spectrum for obtaining reflected light power of infrared light incident on the surface from the direction normal to the surface of the zinc phosphate coating from 60 ° has a plurality of absorption bands in the wavelength range of 8 to 12 m. Further, a hot-dip zinc-based steel sheet having a zinc phosphate coating, wherein the integrated absorption intensity ratio of s-polarized light to P-polarized light in the wavelength range is 1.2 or more.

[15] Hot-dip galvanized plating having a zinc phosphate coating on which a crystalline zinc phosphate coating is formed on the surface, which is manufactured by the manufacturing method according to any one of claims 9 to 13 Maoka plate,

The absorption spectrum for obtaining reflected light power of infrared light incident on the surface from the direction normal to the surface of the zinc phosphate coating from 60 ° has a plurality of absorption bands in the wavelength range of 8 to 12 m. The absorbance of p-polarized light in the wavelength range of 8.4 to 9.2 m of the absorption spectrum is more than twice the absorbance of s-polarized light, and the wavelength of p-polarized light in the range of 10.2 to: L I. A molten zinc-based steel sheet having a zinc phosphate coating characterized in that the absorbance is at least twice that of s-polarized light.