KR101775940B1 - Method for Treating Surface of Metallic Workpiece - Google Patents

Abstract

Disclosed is a surface treatment method for forming a plurality of coating layers capable of simultaneously improving corrosion resistance, blocking resistance, releasability, low friction properties, and the like with respect to the surface of a metal processing material or an ingredient. The surface treatment method comprises: a) providing a metal processing material (workpiece) having steel, stainless steel, titanium, aluminum, copper, or an alloy material thereof; b) forming a phosphate layer in the surface treatment device with respect to the metal processing material, wherein the adhesion weight of the phosphate layer is in the range of 1.5 to 30 g/m^2; c) forming a first lubricant layer comprising a composite containing a polymer and an inorganic material with respect to the phosphate layer; and d) forming a second lubricant layer by plasma-coating an organosilane-based compound on the first lubricant layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for treating a surface of a metal material,

TECHNICAL FIELD The present invention relates to a surface treatment method of a metalworking material. More specifically, the present invention relates to a surface treatment method for forming a plurality of coating layers capable of simultaneously improving corrosion resistance, blocking resistance, releasability, low friction characteristics, and the like on the surface of metal working materials or materials.

Steel, stainless steel, titanium, aluminum, copper alloy, magnesium alloy, etc. are widely known as metal processing materials such as metals and alloys thereof. Such metal materials are widely used in various fields such as construction, . In this regard, metal processing materials are subject to various influences from the surrounding environment as well as the processing process, and can easily be corroded when exposed to corrosive environments such as humidity, pH, temperature, and living organisms.

Thus, in order to minimize the influence from the surrounding environment, various film processing processes are being performed in the art. For example, conventionally, cold-rolled steel sheets, zinc-coated steel sheets and the like have been widely used for pretreatment with a chromate salt and then treating with phosphate for the purpose of improving corrosion resistance and improving paint adhesion.

 However, the chromate treatment involves problems of volatilization of chromium fumarate in the treatment process, an increase in cost due to the wastewater treatment facility, and the problem of hexavalent chromium leaching from the chemical treatment film. Therefore, the phosphate treatment is carried out directly on the surface of the metal material without involving the chromate treatment. In this connection, in the film-forming step by the phosphate treatment, the phosphate treatment agent is a solution mainly containing free phosphoric acid and zinc phosphate as the auxiliary component and further containing various promoters and modifiers as the auxiliary component, and the metal (steel) material Is impregnated with the phosphate solution to form a coating film by a chemical reaction.

For example, when a zinc phosphate film is formed on a steel substrate, the iron component dissolves due to the presence of phosphoric acid as the steel surface is impregnated into the solution bath. At this time, hydrogen is generated during the impregnation of the steel, and at the same time, the pH is increased at the metal-solution interface, which forms an equilibrium between the soluble first phosphate and the insoluble third phosphate on the surface. Such equilibrium can be illustrated by the following Reaction Schemes 1 and 2.

[Reaction Scheme 1]

[Reaction Scheme 2]

That is, the first phosphate is decomposed to form a zinc phosphate film according to the reaction formula 1, and the free phosphoric acid consumed in the preceding dissolution process is recovered. However, since Fe (H ₂ PO ₄ ) ₂ formed from the reaction carried out prior to the formation of the zinc phosphate coating is decomposed to produce waste such as sludge expressed by FePO ₄ , the waste liquid containing the sludge is removed from the bath vessel Processing is performed. Therefore, a considerable cost is incurred in such a waste liquid treatment.

Recently, pretreatment without chromate has been carried out prior to phosphate treatment such as zinc phosphate, but there is a problem that the pretreatment effect is lower than that of the conventional chromate.

On the other hand, for the plastic working of the metal material, a lubricating layer is formed by using a liquid or solid lubricating component for the purpose of reducing friction caused by metal contact between the work piece and the tool and preventing firing or abrasion. In this case, the lubricating component used is largely divided into two types, one of which is a lubricating component that is physically attached directly to a metal surface, and the other that is a lubricating component that generates a carrier coating on a metal surface by a chemical reaction, .

In the case of the former, as a lubricating component, a mineral oil, a vegetable oil, or a synthetic oil is mixed with various additives with a base oil, which is adhered to the surface of the metal and is then subjected to plastic working as it is, or a solid lubricant component such as metal soap, graphite or molybdenum disulfide Is attached to a metal surface in the form of dispersed in water together with a binder, dried, and then subjected to plastic working. In the latter, a phosphate coating is formed on the metal surface by a chemical reaction as exemplified in the following Reaction Scheme 3, and then a reactive soap such as sodium stearate or calcium stearate as a lubricating component or Non-reactive soaps are used to form additional layer structures.

[Reaction Scheme 3]

In the manner illustrated above, the zinc phosphate layer, which is a phosphate, not only provides corrosion resistance, but also acts as a carrier of the lubricating component.

However, when the metal soap is used, not only is the pH of the treatment liquid greatly affected, but also the unreacted sodium stearate layer adheres to the metal soap layer, which acts as a factor for lowering the lubricity. Furthermore, the lubricating layer of the metal soap layer has to be apparently improved since the surface is not smooth.

Therefore, recently, a technique has been developed in which a coating layer using a polymer is formed on a phosphate layer to impart lubricity or low friction characteristics. However, since the polymer layer is basically flammable, a considerable amount of inorganic flame retardant filler is added to the coating composition. However, due to the inorganic filler, the processability of the polymer coating liquid is lowered and the polymer is aged.

In addition, when the organic layer is directly attached to the metal layer such as the zinc phosphate layer on the lower side, unlike the case of using the metallic soap described above, the binding effect is insufficient and the compatibility between the organic component and the inorganic component is poor, It is difficult to do. As a result, the polymer coating layer may be separated from the underlying phosphate layer, which may cause serious defects in the metal substrate in the metal forming process, particularly the cold forging process.

As described above, the prior art for providing corrosion resistance to metal materials such as steel and securing lubricity during the molding process such as cold casting lowers economical efficiency such as an increase in manufacturing process inefficiency or processing cost, When a polymer coating is introduced as a lubricating layer, it is pointed out that the compatibility with the lower phosphate layer is lowered, and the workability or the aging phenomenon is accompanied by the use of the inorganic filler.

Accordingly, there is a demand for a method of solving the above-described problems of the prior art by applying a polymer coating layer.

The inventor of the present invention has conducted research to solve the problems of the prior art described above, and as a result, the inventor has developed a solution to solve the problems of the related art.

Accordingly, in the present invention, in the surface treatment step for imparting corrosion resistance, lubricity (low friction property), releasability, blocking resistance, etc. to the metal material or material for cold forming, the by- To provide a process capable of solving at the same time degradation of economical efficiency caused by separate treatment, deterioration of interlayer adhesion due to direct application of a polymer coating layer to a phosphate layer, deterioration of workability due to the inclusion of an inorganic filler in a polymer coating solution, and aging phenomenon.

According to the present invention,

A surface treatment method for a metal material,

a) providing a metal workpiece having steel, stainless steel, titanium, aluminum, copper or alloys thereof;

b) forming a phosphate layer in the surface treatment apparatus for the metalworking material, wherein the adhesion weight of the phosphate layer is in the range of about 1.5 to 30 g / m 2;

c) forming a first lubricant layer comprising a complex containing a polymer and an inorganic material for the phosphate layer; And

d) plasma-coating an organosilane compound on the first lubricant layer to form a second lubricant layer;

/ RTI >

Here, the first lubricant layer is a coating layer formed on the phosphate layer at an adhesion weight of 1 to 3 g / m < 2 >, and the silane compound is added to the main chain of the epoxy polymer by a sol- To 3% by weight of the composite,

Wherein the second lubricant layer is formed by coating a phosphorus-containing organosilane-based compound on the first lubricant layer with a coating weight of 2 to 6 g / m < 2 >

The surface treatment apparatus used in the step b)

A container for containing an aqueous solution as the metal-working material and the liquid-phase phosphorus-containing treatment agent;

A pump for circulating at least a portion of the treatment agent;

A temperature control member disposed in one side region of the container under the control of a temperature controller;

An ultrasonic irradiation member; And

Filter element:

/ RTI >

Here,

A metal processing material receiving space formed on the upper side for introducing the metal processing material and providing a space for accommodating the introduced metal processing material;

 A first auxiliary storage space which is spaced apart from the metal processing material receiving space at a predetermined interval and is in fluid communication with the metal processing material receiving space by a first grating structure formed therein, ;

A second auxiliary accommodation space defining a boundary between the metal processing material accommodation space and the space separated by the second grating structure provided in the longitudinal direction or the vertical direction while providing a space for installing the temperature adjusting member, Wherein the second grating structure is in fluid communication with the metal processing material receiving space by the second grating structure and the spacing between the metal processing material receiving space and the first auxiliary receiving space is smaller than the first auxiliary Wherein the first grating structure of the accommodation space is adjusted in such a manner that the first grating structure is inserted and the temperature adjustment member is installed in the second auxiliary accommodation space; And

A collection space which is defined by a space defined between the partition wall and the inner surface of the container by a boundary defined in the longitudinal direction or the vertical direction and opposite to the second auxiliary accommodation space side of the metal processing material accommodation space, Wherein an upper end of the partition wall is spaced apart from an upper surface of the container by a predetermined distance so that an amount of the treating agent exceeding the maximum receiving space of the metal processing material receiving space is transferred to the collecting space beyond the upper end of the partition wall;

/ RTI >

Wherein the ultrasonic wave irradiating member is provided on an inner surface of the partition wall,

The filter device includes a circulation line communicating with the collection space and moving upward by the pump to filter the filtrate from which the impurities in the treatment agent transferred to the collection space have been removed by passing through the filter device to the metal material accommodating space , And

A method is provided in which a makeup line for supplementing the treatment agent is added to the filtrate passed through the filter device.

According to an exemplary embodiment, the phosphorus-containing organosilane compound is at least one compound selected from the group consisting of 2- (diphenylphosphino) ethyltriethoxysilane, 2- (dimethylphosphino) ethyltriethoxysilane, 2- (diethylphosphino) (Diethylphosphino) methyldiethoxysilane, 3- (diphenylphosphino) methyldiethoxysilane, 2- (dimethylphosphino) methyldiethoxysilane, 2- (Diphenylphosphino) methyldiethoxysilane, 3- (dimethylphosphino) methyldiethoxysilane, 3- (dimethylphosphino) ethyltriethoxysilane, 3- (Dicyclohexylphosphinoethyl) triethoxysilane, 2- (dicyclohexylphosphinoethyl) methyldiethoxysilane, 3- (dicyclohexylphosphinoethyl) triethoxysilane, (Dicyclohexylphosphinoethyl) methyldiethoxysilane, (2-diethylphosphatoethyl) methyldiethoxysilane, (2-dimethylphosphine) (2-diphenylphosphatoethyl) methyldiethoxysilane, (2-dicyclophosphatoethyl) methyldiethoxysilane, (3-dimethylphosphatoethyl) methyldiethoxysilane, Silane, (3-diphenylphosphatoethyl) methyldiethoxysilane, (3-dicyclophosphatoethyl) methyldiethoxysilane, (2-diethylphosphatoethyl) triethoxysilane, (2- (2-dipropylphosphatoethyl) triethoxysilane, 3- (diethylphosphatoethyl) triethoxysilane, (3-dimethylphosphatoethyl) Triethoxysilane, and (3-dipropylphosphatoethyl) triethoxysilane can be selected.

According to an illustrative embodiment, the phosphorus-containing organosilane-based compound may be represented by the following formula (1), (2), or a combination thereof:

[Chemical Formula 1]

(2)

.

.

According to an exemplary embodiment, the metal workpiece may be in the form of a sheet, a plate, an extrusion or a casting.

According to an exemplary embodiment, the metal working material may be wire or rod-shaped.

According to an exemplary embodiment, the material of the metal working material is selected from the group consisting of cold rolled steel, hot rolled steel, zinc (or zinc alloy) plated steel, molten galvanized steel, aluminum alloy, aluminum alloy plated steel, magnesium or magnesium alloy, .

According to an exemplary embodiment, prior to said step b)

(i) a metal-containing compound selected from the group consisting of zirconium, titanium, hafnium and combinations thereof, (ii) inositol hexaphosphoric acid represented by the following formula (3) or a salt thereof, and (iii) hydrofluoric acid, , A fluoride compound selected from the group consisting of ammonium fluoride, complex fluoride, and combinations thereof,

Here, the content of the metal-containing compound in the aqueous composition is in the range of 10 to 800 ppm based on the metal element, the molar ratio of the component (i) to the component (ii) is in the range of 4 to 10, In the range of 20 to 300 ppm based on the fluorine element, and

The pH of the composition may range from 2.5 to 4.5:

(3)

.

.

The surface treatment method of the metal workpiece provided according to the present invention minimizes the damage caused by external force applied to the metal workpiece during the processing of the metal material, particularly the cold forming (for example, cold forging), and at the same time, . Particularly, by effectively treating the by-product-containing waste fluid generated in the formation of the phosphate layer providing corrosion resistance and further reducing the interlayer adhesion due to the application of the polymer coating layer directly to the phosphate layer and the content of the inorganic filler having the flame retardant property in the polymer coating liquid It is possible to simultaneously solve the degradation of workability and the aging phenomenon.

Therefore, it is expected to be widely applied in the future.

1 is a cross-sectional view schematically showing a coating formed on a metal workpiece according to one embodiment of the present invention;
2 is a diagram showing the internal structure of an apparatus for forming a phosphate coating on a metal workpiece according to an exemplary embodiment of the present invention;
3 is a cross-sectional view schematically showing a coating formed on a metal working material according to another embodiment of the present invention; And
Figure 4 is the FT-IR spectrum for the second lubricating layer formed in the example.

The present invention can be all accomplished by the following description. The following description should be understood to describe preferred embodiments of the present invention, but the present invention is not necessarily limited thereto. It is to be understood that the accompanying drawings are included to provide a further understanding of the invention and are not to be construed as limiting the present invention. The details of the individual components may be properly understood by reference to the following detailed description of the related description.

In this specification, when an element is referred to as "comprising ", it means that it may further include other elements unless otherwise stated.

Also, in this specification, the terms "located on the upper side" or "located on the lower side" can be understood to express a relative positional relationship in a state of being in contact with not only a state in contact with a specific object.

Where reference is made herein to any component or element that is "connected" or "communicating" with another component or element, unless otherwise stated, the component or element is directly connected or in communication with the other component The present invention can be understood to include not only the case but also the case where it is connected or communicated under the interposition of another component or member.

Similarly, the term "contacting" may also be understood to include not only direct contact, but also contact in the presence of other components or members.

"Forging" refers broadly to a forming process of deforming a shape by applying an external force to a metal, that is, a process of deforming a metal in a state of calcination. Specifically, the forging step may mean a step of improving the mechanical properties of the steel material through annealing and manufacturing the steel material into a predetermined shape by molding.

"Cold forging" may mean a forging process carried out at room temperature or near room temperature without heating the material.

According to the present invention, the surface of the metal working material forms a coating layer according to each processing step in the order of a plurality of processing steps, which will be described in detail below.

First embodiment

Figure 1 schematically shows a coating formed on a metal workpiece according to one embodiment of the present invention.

According to the figure, a laminated structure 10 in which a phosphate layer 12, a first lubricating layer 13 and a second lubricating layer 14 are sequentially formed on the surface of the metal working material 11 is formed.

According to one embodiment, the shape of the metal workpiece 11 is not particularly limited, and may be, for example, a sheet, a plate, an extrusion or a casting shape. The material of the metal material 11 may be cold rolled steel, hot rolled steel, zinc (or zinc alloy) plated steel, molten galvanized steel, aluminum alloy, aluminum alloy plated steel, magnesium or magnesium alloy or a combination thereof. According to an exemplary embodiment, the metal workpiece 11 may be wire or rod-shaped.

According to an exemplary embodiment, prior to the formation of the phosphate layer, a plurality of pretreatment steps may be taken. One of the main functions of the pretreatment step is to perform the phosphate treatment at the post-stage by removing the oil component (for example, rust-preventive oil and processing oil) existing on the surface of the metalworking material. For example, the metal workpiece 11 may be prepared by (i) dip rinsing with cooling water, (ii) acid pickling using an aqueous acid solution such as hydrochloric acid, (iii) , And (iv) a deep rinse step using cooling water. In step (ii), a multi-stage acid cleaning step with different acid concentrations can be performed, for example, about 6 to 9% acid solution, about 12 to 16% acid solution, about 18 to 22% About 24 to 28% acid solution. Through such pretreatment, effects such as degrease and descale can be obtained and, if necessary, grinding, peeling, brushing, blasting using an abrasive and annealing At least one can be selectively performed.

Formation of Phosphate Layer

As described above, the step of forming the phosphate coating 12 on the surface of the metal workpiece 11 that has undergone the normal pre-treatment step for the metal workpiece 11 is performed. At this time, the phosphate may be, for example, zinc phosphate, calcium zinc phosphate, manganese phosphate, or a combination thereof. The treating agent for forming such a phosphate coating is an aqueous treating solution.

As an example, a phosphate film forming solution, i. E. A phosphate treatment solution, can be prepared by (i) providing about 0.1 to 5 g / l zinc ion (specifically about 0.2-4 g / l, more specifically about 0.5-2 g / ii) 0 to 10 g / l (specifically about 0.2 to 5 g / l, more specifically about 0.5 to 4 g / l) of additional metal ions selected from at least one group selected from the group consisting of calcium, magnesium and manganese; ) About 5 to 60 g / l of phosphate ions (specifically about 10 to 50 g / l, more particularly about 15 to 40 g / l) and (iv) nitrate ions, nitrite ions and peroxide ions (Specifically about 0.5 to 7 g / l, more particularly about 1 to 5 g / l) of an accelerator selected from the group consisting of:

Examples of zinc ion sources may be zinc oxide, zinc carbonate, zinc nitrate, combinations thereof. In the case of sources of additional metal ions, it may be a carbonate, nitrate, chloride, combinations thereof, etc. of calcium, magnesium and / or manganese. In addition, the source of the phosphate ion may be, for example, phosphoric acid, zinc phosphate, zinc hydrogen phosphate, zinc dihydrogenphosphate, manganese phosphate, manganese phosphate, manganese phosphate, manganese phosphate and combinations thereof.

In this regard, if the zinc ion content does not reach a certain level, a uniform phosphate layer is not formed on the surface of the metal working material, whereas if it is excessively high, buildup phenomenon of the phosphate layer is caused and the phosphate layer and the lower metal The adhesion between the surfaces of the work pieces can be reduced. Therefore, it may be advantageous to suitably select within the above-mentioned zinc ion content range.

On the other hand, in the case of the additional metal ions, if the content in the treating agent is too low, it is difficult to expect the effect due to the incorporation of additional metal ions. On the other hand, when the content is too high, further improvement effect is not provided, It may be difficult to obtain a stabilized treating agent solution.

In addition, when the phosphate ion content is excessively low, a non-uniform phosphate layer is formed, whereas when the phosphate ion content is excessively high, an effect due to excessive addition may be obtained, which may be undesirable from the economical point of view. Therefore, it may be advantageous to control within the above-mentioned content range.

According to an exemplary embodiment, the weight ratio of zinc ion: additional metal (Ca, Mg and / or Mn) ion: phosphate ions in the phosphate treatment solution is, for example, from about 0.1 to 3: about 0 to about 3: To about 40 (specifically 0.2 to 2: about 0.5 to 2: about 10 to 30).

In an exemplary embodiment, the phosphate treatment agent may optionally further comprise nickel ions, wherein the content of nickel ions is, for example, about 0.1 to 3 g / l, specifically about 0.2 to 2.5 g / l, More specifically from about 0.5 to 2 g / l. Examples of such nickel ion sources include nickel carbonate, nickel nitrate, nickel chloride, nickel phosphate and the like, which can be used singly or in combination.

According to an exemplary embodiment, the total acidity of the aqueous solution as the phosphate treatment agent can be, for example, in the range of about 10 to 50, specifically about 20 to 40, more specifically about 25 to 35, The free acidity can range, for example, from about 0.2 to 2, specifically from about 0.5 to 1.5, more specifically from about 0.7 to 1.2. A uniform phosphate layer can be readily formed without undue etching on the surface of the metalworking material within the range of computational and free acid ranges. Therefore, base components such as sodium hydroxide, potassium hydroxide, ammonium hydroxide and the like can be selectively added so as to have an acidity in the above-mentioned range, if necessary.

In addition to the above-mentioned components, the components used in forming the phosphate layer in the art, such as free acids, complexing agents, heavy metals, fluorine compounds, etc., can be incorporated alone or in combination.

On the other hand, according to embodiments of the present invention, the phosphate treatment temperature may be in the range of, for example, about 30 to 80 캜, specifically about 35 to 70 캜, more specifically about 40 to 60 캜, While it is difficult to produce the desired level of coating, at excessively high temperatures, the accelerator may decompose to form precipitates in the solution. Therefore, it may be advantageous to suitably select within the above-mentioned temperature range. The phosphate treatment time is not particularly limited, but may be, for example, in the range of about 0.5 to 30 minutes, specifically about 1 to 15 minutes, more specifically about 3 to 10 minutes.

The phosphate layer through the phosphate treatment solution described above may be formed with an adhesion weight in the range of, for example, from about 1.5 to 30 g / m 2, specifically from about 2.5 to 20 g / m 2, more specifically from about 5 to 15 g / m 2 have.

Figure 2 shows the internal structure of an apparatus for forming a phosphate coating on a metal workpiece according to embodiments of the present invention.

In the illustrated example, the surface treatment apparatus 100 for forming a phosphate coating mainly includes a container 102, a filter member 110, and a pump 111. At this time, the container 102 is provided with an opening on the upper side so that the metal processing material 101 can be introduced. The introduced metal processing material 101 is accommodated in the metal processing material receiving space 103, Impregnated or immersed in the filled liquid treating agent. The lower end of the metal processing material receiving space 103 is defined by the first grating structure 107 spaced apart from the lower surface of the container 102 with a predetermined interval therebetween while being extended in the horizontal direction. At this time, the space between the first grating structure 107 and the bottom surface of the container forms the first auxiliary storage space 104 and is in fluid communication with the metal processing material receiving space 103, The first auxiliary accommodation space 104 is filled with the treatment agent introduced from the first auxiliary accommodation space 104. [

On the other hand, both side boundaries of the metal processing material receiving space 103 in the container 102 are defined by the second grating structure 108 and the partition wall 109. [ Specifically, the second grating structure 108 is spaced apart from the one side of the container by a predetermined distance in the longitudinal direction or the vertical direction, and as a result, between the one side of the container 102 and the second grating structure 108 A second auxiliary storage space 105 is formed, which is a space separated from the metal processing material receiving space 103. [ Particularly, since the second auxiliary accommodation space 105 is in fluid communication with the metalworking material accommodation space 103 by the second grating structure 108, the treatment agent solution is supplied not only to the metalworking material accommodation space 103, (104) and the second auxiliary storage space (105). At this time, the spacing between the metal processing material accommodating space 103 and the first auxiliary accommodating space 104 is equal to the distance between the metal working material accommodating space 103 and the first auxiliary accommodating space 104 in the second grating structure 108 of the second auxiliary accommodating space 105 The first grating structure 107 can be adjusted in such a manner that the first grating structure 107 is inserted and installed.

According to the illustrated embodiment, a temperature regulating member 115 is provided in the second auxiliary receiving space 105, wherein the temperature regulating member 115 is typically a coil-type thermostat. This temperature regulating member 115 operates under the control of the temperature controller 114 so that the upper portion of the second grating structure 108 forms a closed surface and the temperature controller 114 and the temperature regulating member 115 A flat plate member 116 provided in a horizontal direction is provided to provide an installation space for the temperature controller 114. Therefore, it is considered that the installation space of the temperature controller 114 is substantially closed except for the connection portion between the temperature controller 114 and the temperature control member 115. According to the illustrated embodiment, since the metal processing material receiving space 103 and the second auxiliary receiving space 105 are communicated with each other with the second grating structure 108 as a boundary, The liquid treating agent whose temperature is controlled by the temperature controlling member 115 moves with the metal processing material receiving space 103, and as a result, the processing temperature of the metal working material 101 can be controlled.

The partition wall 109 defining the boundary in the direction opposite to the second auxiliary accommodation space 105 side of the metal processing material accommodation space 103 is also provided in the longitudinal or vertical direction, The treatment agent does not pass through the partition wall 109 in the thickness direction. At this time, the partition wall 109 does not extend to the upper surface of the metal processing material accommodating space 103, and the upper end of the partition wall 109 is separated from the upper surface of the metal processing material accommodating space 103 by a predetermined distance, So that the amount of the liquid treatment agent exceeding the maximum accommodation space of the partition wall (103) flows over the upper end of the partition wall (109). As a result, the liquid treating agent flowing into the collecting space 106 of the treating agent bounded by the interval between the partition wall 109 and the inner surface (side surface) of the container flows.

It should be noted that the height of the partition wall 109 is set to be lower than the height of the plate member 116 so that the liquid treating agent is prevented from flowing into the installation space of the temperature controller 114. Therefore, even if there is a gap in the connection portion between the temperature controller 114 and the temperature regulating member 115, the risk of the liquid treating agent flowing back into the installation space of the temperature controller 114 is reduced.

2, the liquid processing solution transferred to the collecting space 106 through the upper end of the partition wall 109 passes through a conduit 117 connected to the collecting space 106 and is recycled through the circulating line 118 And is introduced into the metal processing material accommodation space 103 by the injection nozzle 112. The treatment agent transferred to the conduit 117 contains by-products such as sludge or waste generated during the formation of the phosphate layer. At this time, a pump 111 for sucking the treatment agent from the collection space 106 is installed in the middle region of the circulation line 118. At this time, the filter member 110 is provided at the front end of the pump 111 in the circulation line 118, So that at least a part of the byproducts or wastes in the treatment agent are filtered and removed. Therefore, the processing agent recycled to the container 102 through the circulation line 118 and introduced into the metal processing material receiving space 103 is in a state in which at least a part of the byproducts or waste such as sludge is removed. A makeup line 119 is installed in the circulation line 118 where the processed material filtered through the filter member 110 is recycled to supplement the liquid processing agent lost during the processing of the metal processing material 101, And is combined with a treatment agent which is introduced and recycled.

According to the illustrated embodiment, the ultrasonic wave irradiating device 113 is installed on the inner surface (that is, the surface facing the metal processing material accommodating space) of the partition wall 109. At this time, Provides ultrasonic vibration energy. As described above, when ultrasonic vibration is applied to the liquid processing agent, a phosphate layer having a smaller crystal size can be formed on the surface of the metal working material 101.

Illustratively, the frequency of the ultrasonic energy irradiated from the ultrasonic wave irradiating device 113 may be, for example, about 150 kHz or less, specifically about 20 to 50 kHz, and the ultrasonic wave power delivered to the liquid treatment agent may be, For example, from about 70 to 150 Watts, specifically about 80 to 120 Watts, more specifically about 90 to 110 Watts. If the ultrasonic frequency and / or the ultrasonic output is below a certain level, it may be difficult to form a dense phosphate layer having a small crystal size. Therefore, it may be preferable to irradiate ultrasonic waves adjusted within the above-described ultrasonic frequency and ultrasonic output range .

First lubricant layer formation

1, an epoxy polymer coating layer is formed as a first lubricating layer 13 on the phosphate layer formed according to the above-described method, specifically, a coating layer of a composite material having a silane-based compound grafted on the main chain of the epoxy polymer .

As described above, when the phosphate layer is a coating layer made of an inorganic material and a polymer layer, which is a pure organic substance, is formed as a lubricant layer on the upper surface of the phosphate layer, the adhesion between the inorganic layer and the organic layer is lowered due to the lowered compatibility thereof . Therefore, in the present invention, it should be noted that the epoxy resin is used as the main component of the lubricating layer, and the epoxy resin is modified by grafting with an inorganic silane compound to improve the adhesive force with the lower phosphate layer, It is possible to provide a lubrication function using the inherent characteristics of the epoxy resin. In particular, even when a small amount of silane-based compound is used, a remarkably improved adhesion between the epoxy resin layer and the lower phosphate layer can be ensured.

In this connection, "epoxy" may mean a group in which oxygen is bonded to two bonded carbon atoms, and the simplest epoxy structure has a three-membered ring structure as shown in the following formula (3).

(3)

According to one embodiment, a bisphenol type epoxy resin obtained by reacting bisphenols, specifically, bisphenol A with epichlorohydrin as an epoxy resin, a bisphenol A type epoxy resin represented by the following Formula 4 (that is, bisphenol A Of diglycidyl ether).

[Chemical Formula 4]

According to another embodiment, a novolak type epoxy resin obtained by glycidyl etherating a phenolic hydroxyl group of a novolac resin, a glycidyl ester of an aromatic carboxylic acid, a peroxidized epoxidized double bond of an ethylenically unsaturated compound, Epoxy type or the like can be used. In addition, a resin obtained by adding ethylene oxide or propylene oxide to the resin skeleton of the above-mentioned epoxy resin, a glycidyl ether of a polyhydric alcohol, and the like can also be mentioned.

However, it may be advantageous to use the above-mentioned bisphenol A type epoxy resin, and the molecular weight (Mw) of the epoxy resin is, for example, about 300 to 10000, specifically about 400 to 7000, more specifically about 1000 to 5000 Lt; / RTI >

In the present invention, the above-mentioned epoxy resin is subjected to a grafting reaction by a sol-gel method of a silane compound. At this time, polyamide may be mixed as a curing agent in the epoxy resin, and the silane compound may be subjected to a grafting reaction. According to exemplary embodiments, the weight ratio of epoxy resin to the curing agent may range, for example, from about 1 to 2, specifically from about 1.1 to 1.5, and more specifically from about 1.2 to 1.4. The mixture of the epoxy resin and the curing agent can be reacted in combination with a coating solution containing a silane compound after being dispersed (diluted) with water (for example, deionized water) at a weight ratio of, for example, about 0.5 to 1.5: 1 .

Such a silane-based compound may specifically be a silane-based compound containing an alkoxy group, examples of which include (3-glycidyloxypropyl) triethoxysilane, methyltriethoxysilane, phenyl-amino- 3-mercaptopropyltriethoxysilane, or a combination thereof. According to an illustrative embodiment, a combination of (3-glycidyloxypropyl) triethoxysilane, methyltriethoxysilane and phenyl-amino-propyltriethoxysilane may be used as such silane-based compounds.

According to one embodiment, the sol-gel coating solution for performing the grafting reaction on the main chain of the epoxy resin can be prepared by hydrolysis and condensation reaction of the silane compound in the presence of water. At this time, the temperature of the hydrolysis and condensation reaction is not particularly limited, but can be carried out, for example, at about 15 to 40 ° C, specifically about 20 to 35 ° C, more specifically at room temperature, For example, methanol, ethanol and / or isopropyl alcohol in a volume ratio relative to the silane-based compound, for example, about 3 to 6 times, specifically about 4 to 5 times, for hydrolysis and condensation Water can be added. At this time, an appropriate amount of an acid catalyst such as acetic acid may be optionally added.

The above-mentioned silane compound contains a silane group terminal and an organic terminal. Specifically, an alkoxy group is connected to the terminal of the silane group, and a reactive organic group capable of easily reacting with the organic polymer is contained on the organic terminal. At this time, the alkoxy group directly substituted on the silicon atom in the silane compound easily hydrolyzes to form a silanol group. This silanol group is condensed with other silanol groups to react with the extended Si-O-Si network and the metal (M) of the lower phosphate layer to form an M-O-Si bond. Thus, it is believed that the silane compound functions as a linking agent between the lower phosphate layer and the organic polymer matrix.

According to the present invention, the silane compound is grafted to the main chain of the epoxy polymer by a sol-gel method. The amount of the silane compound to be grafted is about 1 to 3 wt% based on the weight of the epoxy polymer %, Specifically about 1.5 to 2.5, more specifically about 2. At this time, when the amount of the silane compound used in the grafting reaction (that is, the reforming reaction) is excessively large, an excessively rigid layer may be formed to lower the adhesion property with the phosphate layer or reduce the lubricating property. Therefore, it is advantageous to perform grafting in the range of the above-mentioned ratio.

According to the exemplary embodiment, when performing the grafting reaction on the combination of the coating liquid containing the silane compound and the epoxy-based polymer-containing dispersion as described above, the coating is first applied to the phosphate layer through the coating process The curing reaction can be carried out. During the curing reaction process, the silane component may be grafted to the backbone of the epoxy resin by the curing agent contained in the combination.

According to an illustrative embodiment, the coated structure may be cured at a temperature of, for example, about 20 to 40 占 폚, specifically about 25 to 30 占 폚. Here, the curing time may typically range from about 10 to 20 hours, specifically from about 12 to 18 hours. However, for complete ring curing, a process of curing under elevated temperature conditions can additionally be performed, wherein the elevated temperature condition is, for example, about 80 to 120 ° C, specifically about 85 to 110 ° C, more specifically about 95 to < RTI ID = 0.0 > 105 C. < / RTI > At this time, the temperature rise holding time is not limited to a specific range, and sufficient time for full curing is sufficient.

On the other hand, the layer containing the composite in which the silane compound is grafted to the main chain of the epoxy-based polymer as the first lubricant layer is, for example, about 1 to 3 g / m 2, specifically about 1.5 to 2.5 g / More specifically from about 1.7 to about 2.2 g / m < 2 >. The layer containing the composite described above can significantly increase the adhesion to the underlying phosphate layer while providing the lubrication properties of the polymer.

Formation of second lubricant layer

According to the embodiment of the present invention, as described above, the first lubricant layer 13 composed of a composite of an epoxy resin grafted with a silane compound as the main chain is formed by plasma-coating a phosphorus-containing organosilane compound 2 lubricating layer 14 is attached. That is, the first lubricating layer 13 is made of a composite material in which the epoxy resin is modified with a silane-based compound, and a coating layer of a phosphorus-containing organosilane compound is formed thereon, so that the first lubricating layer 13, Adhesion property can be ensured, and in particular, the flammability caused by forming the polymer-based layer as the first lubricating layer 13 can be suppressed (i.e., the flame retardancy can be improved without incorporating the inorganic filler Lt; / RTI >

"Plasma" means that when energy is continuously applied to a material, the temperature of the material is changed from a solid phase to a liquid phase and a gas phase as the temperature of the material is increased. When sustained energy is applied, the atomic shell decomposes, , This mixture can be considered to be in a plasma state.

According to the present invention, by adhering a second lubricating layer having such flame retardancy to the first lubricating layer, the printing tendency due to the epoxy polymer in the first lubricating layer can be suppressed. At this time, a phosphorus-containing organosilane-based compound is used as a precursor for forming the second lubricant layer.

Examples of such phosphorus-containing organosilane compounds are 2- (diphenylphosphino) ethyltriethoxysilane, 2- (dimethylphosphino) ethyltriethoxysilane, 2- (diethylphosphino) ethyltriethoxy (Diethylphosphino) methyldiethoxysilane, 3- (diphenylphosphino) methyltriethoxysilane, 2- (dimethylphosphino) methyldiethoxysilane, 2- (Dimethylphosphino) methyldiethoxysilane, 3- (dimethylphosphino) ethyltriethoxysilane, 3- (diphenylphosphino) methyldiethoxysilane, 3- Methyldiethoxysilane, 2- (dicyclohexylphosphinoethyl) triethoxysilane, 2- (dicyclohexylphosphinoethyl) methyldiethoxysilane, 3- (dicyclohexylphosphinoethyl) Methyldiethoxysilane, (2-diethylphosphatoethyl) methyldiethoxysilane, (2-dimethylphosphatoethyl) methyl (2-diphenylphosphatoethyl) methyldiethoxysilane, (2-dicyclophosphatoethyl) methyldiethoxysilane, (3-dimethylphosphatoethyl) methyldiethoxysilane, ( 3-diphenylphosphatoethyl) methyldiethoxysilane, (3-dicyclophosphatoethyl) methyldiethoxysilane, (2-diethylphosphatoethyl) triethoxysilane, (2-dimethylphosphate) (2-dipropylphosphatoethyl) triethoxysilane, 3- (diethylphosphatoethyl) triethoxysilane, (3-dimethylphosphatoethyl) triethoxysilane, Silane, and (3-dipropylphosphatoethyl) triethoxysilane, which may be used alone or in combination.

More specifically, the phosphorus-containing organosilane-based compound is (2-diethylphosphatoethyl) methyldiethoxysilane, (2-dimethylphosphatoethyl) methyldiethoxysilane, (2-diphenylphosphatoethyl ) Methyldiethoxysilane, (2-dicyclophosphatoethyl) methyldiethoxysilane, (3-dimethylphosphatoethyl) methyldiethoxysilane, (3-diphenylphosphatoethyl) (2-dimethylphosphatoethyl) triethoxysilane, (2-diethylphosphatoethyl) triethoxysilane, (2-dimethylphosphatoethyl) (3-dimethylphosphatoethyl) triethoxysilane, 3- (diethylphosphatoethyl) triethoxysilane, (3-dimethylphosphatoethyl) Ethoxysilane, or a combination thereof.

In this regard, the plasma coating process of the phosphorus-containing organosilane-based compound comprises: For example under the conditions of high pressure, for example about 0.01 to 10 mbar, specifically about 0.1 to 5 mbar, more specifically about 0.5 to 5 mbar. At this time, the frequency of the energy (AC frequency) applied in the plasma coating is lower than the frequency of the normal plasma generation energy, for example, about 4 to 40 kHz, specifically about 5 to 20 kHz, And may range from about 6 to 15 kHz. The output density may also be in the range of, for example, about 2 to 5000 mW / cm 2, specifically about 500 to 4000 mW / cm 2, more specifically about 1000 to 3000 mW / cm 2. In addition, the peak-to-peak voltage may range, for example, from about 20 to 50 kV, specifically about 25 to 40 kV, and more specifically about 30 to 25 kV.

On the other hand, the temperature in the plasma coating chamber may be in the range of, for example, about 50 to 200 DEG C, specifically about 70 to 150 DEG C, more specifically about 80 to 120 DEG C, for example about 3 to 10 ms About 4 to 8 milliseconds) in alternating on-off states.

The adhesion weight of the second lubricant layer thus formed may be in the range of, for example, about 2 to 6 g / m 2, specifically about 2.5 to 5 g / m 2, more specifically about 3 to 4 g / m 2, Since the second lubricating layer 14 forms the outermost layer among a plurality of coating layers formed on the metal working material 11 and receives the external stress directly in the molding process of the metal material, particularly the cold forging process, An external force is transmitted to the first lubricant layer 13 made of a polymer material of the first lubricant layer so that the function such as effective low friction can be exerted in the first lubricant layer. Particularly, since the second lubricant layer is strongly bonded to the silane component bonded to the epoxy polymer in the first lubricant layer as the silane-based coating material, it is possible to secure not only the flame retardancy due to the material itself but also the excellent adhesion with the first lubricant layer Respectively.

Second Embodiment

Figure 3 schematically shows a coating formed on a metal workpiece according to another embodiment of the present invention.

In the illustrated embodiment, the phosphate layer 22, the first lubricating layer 23 and the second lubricating layer 24 are sequentially formed or attached on the metal workpiece 21, It is practically the same as the technical one. However, in the case of this embodiment, prior to the formation of the phosphate layer 22, a pretreatment layer 25 formed through a specific pretreatment, not a typical pretreatment step, is interposed between the metal workpiece 21 and the phosphate layer 22, It should be noted that the adhesion between the layer 22 and the metal workpiece 21 is significantly improved. Accordingly, at least a part of the conventional preprocessing process through a plurality of steps can be omitted.

According to this embodiment, the coating liquid for forming the precoat layer 25 is an aqueous composition comprising (i) a metal-containing compound selected from the group consisting of zirconium, titanium, hafnium and combinations thereof, (ii) (Iii) a fluorine compound selected from the group consisting of hydrofluoric acid, an alkali fluoride salt, ammonium fluoride, hydrogen fluoride, and combinations thereof. The composition for forming the preliminary coating layer may be a composition capable of reacting with the surface of the lower substrate, that is, the surface of the metal processing material 21, chemically modifying the material, and further binding with the surface of the metal processing material to form a film or a layer.

In this regard, in component (i), the metal-containing compound is zirconium, titanium, hafnium or a combination thereof. Examples of zirconium-containing compounds may be hexafluorozirconic acid, its alkali or ammonium salts, zirconium carbonate, zirconium nitrate, zirconium sulfate, zirconium carboxylate, zirconium hydroxycarboxylate, or mixtures thereof. Examples of titanium-containing compounds may be fluorotitanic acid and its salts. An example of a hafnium-containing compound may also be hafnium nitrate. The classes listed above should be understood in an exemplary sense.

According to this embodiment, the content of the metal-containing compound is in the range of, for example, about 10 to 800 ppm, specifically about 50 to 700 ppm, more specifically about 100 to 500 ppm .

With regard to the component (ii), an acid component containing a plurality of phosphorus or a salt thereof can be used. Specifically, such an acid component is inositol hexaphosphoric acid represented by the following formula (3).

 (3)

According to an exemplary embodiment, the content of component (ii) is controlled depending on the content of the metal-containing compound of component (i), and the molar ratio of component (i) to component (ii) Can be adjusted within the range of about 4 to 10, specifically about 5 to 9, and more specifically about 6 to 8.

In the case of the component (iii), the fluorine compound may be a fluorine compound which does not overlap with the component (i), for example, a free fluorine compound (fluorine compound not covalently bonded or ion- Hydrofluoric acid, an alkali salt or ammonium salt thereof, and a complex fluoride (for example, hydrofluoric acid and / or borofluoric acid). According to one embodiment, the content of component (iii) in the aqueous composition may range from about 20 to 300 ppm, specifically about 50 to 200 ppm, more specifically about 80 to 150 ppm, based on the fluorine element.

The pH of the water-based coating composition for forming a precoat layer described above can be adjusted within a range of, for example, about 2.5 to 4.5, specifically about 3 to 4. To this end, acid components such as nitric acid, sulfuric acid and / or phosphoric acid, or base components such as sodium hydroxide, sodium carbonate, potassium hydroxide, ammonium hydroxide and / or ammonia may optionally be added.

 According to an exemplary embodiment, the formation temperature of the precoat layer 25 may be, for example, in the range of about 15 to 70 DEG C, specifically about 20 to 50 DEG C, more specifically about 25 to 40 DEG C, Impregnation or deposition method, spray method or the like can be applied, but more typically, impregnation or deposition method can be adopted.

It is not preferable that the precoat layer 25 is formed to be excessively thick, since it functions to strengthen adhesion between the phosphate layer 22 and the metal working material 21 as much as possible. Thus, the exemplary thickness of the precoat layer 25 can be selected within the range of up to about 1 [mu] m, specifically about 0.01 to 0.5 [mu] m, more specifically about 0.1 to 0.4 [mu] m, have.

Since a significant improvement in bonding strength between the phosphate layer and the metalworking material can be provided through the interposition of the precoating layer, some of the conventional pretreatment steps may be omitted in some cases.

The present invention can be more clearly understood by the following examples, and the following examples are merely illustrative of the present invention and are not intended to limit the scope of the invention.

Example 1

As the specimen of the metal working material used in this embodiment, commercially available alloy steel of trade name SCM440 was used, and its size was 100 mm x 80 mm x 5 mm. Prior to the formation of the phosphate layer, the surface of the specimen was wiped with a cloth, cleaned using a cleaning agent and water, and then the surface of the specimen was dried by spraying compressed air.

Formation of Phosphate Layer

The composition of the aqueous treatment liquid for formation of the phosphate layer is shown in Table 1 below.

Component (ion) Zn Ca PO ₄ NO ₃ NO ₂ Ni Computational chart Free acidity Content (g / l) 1.5 1.0 15 3.1 0.09 0.3 19.4 0.9

The aqueous treatment solution was treated at 50 ° C for 20 minutes, resulting in a calcium zinc phosphate layer with an adhered weight of 10 g / m 2.

Formation of first lubricant layer

(3-glycidyloxypropyl) triethoxysilane (Sigma-Aldrich) and methyltriethoxysilane (Sigma-Aldrich) in a molar ratio of 1.1: 1, Condensation reaction. At this time, the reaction was carried out at room temperature. Then, 1.5% by weight of phenyl-amino-propyltriethoxysilane (Sigma-Aldrich) was added to the hydrolyzed coating solution to prepare a silane-based compound coating solution. At this time, the volume ratio of the silane compound: water was about 21: 79.

Separately, a diglycidyl ether of bisphenol A (weight average molecular weight: 3700; glass transition temperature: 59.6 ° C) and a polyamide-based curing agent were respectively purchased as the epoxy resin, and the weight ratio of the epoxy resin to the curing agent was adjusted to 10: 8 A mixture was prepared. The mixture was combined with deionized water in a weight ratio of 1: 1 to prepare an epoxy polymer-containing dispersion.

Thereafter, the coating solution of the silane compound was added to the epoxy polymer-containing dispersion. The amount of the silane compound in the coating solution was 1.5 wt%, 2.5 wt% and 5 wt% based on the epoxy polymer, (Formulation-1, Formulation-2 and Formulation-3). At this time, the combination 3 is provided for comparison purposes.

Each of the formulations 1 to 3 was then coated with a spin coater onto a specimen on which the phosphate layer was previously formed. The coated specimens were cured at room temperature for 12 hours, and then heat treated in an oven maintained at 100 ° C for 5 minutes to completely cure the coating layer-1, coating layer-2 and coating layer-3. The adhesion amounts of the three coated specimens were measured, and the results are shown in Table 2 below.

- Friction test

In order to evaluate the lubrication ability of the first lubricant layer, friction coefficient was measured by Bowden test. At this time, the friction test was performed under the conditions of (i) a test load of 5 kg, (ii) test temperature: room temperature, and (iii) test steel: φ 5 mm. The principle and details of the Bowden test are described in F.P. Bowden, D. Tabor, The friction and lubrication of solids, Clarendon Press 1986, p. 88-100.

On the other hand, the average friction coefficient was calculated from the average value of ten times. The results are shown in Table 2 below.

The first lubricant layer Silane content
(weight%) Adhesion amount (g / m 2) Average coefficient of friction Coating-1 1.5 2.1 0.12 Coating-2 2.5 2.3 0.11 Coating-3 5 2.4 0.18

According to the above table, as the content of the silane compound grafted to the main chain of the epoxy polymer increases from 1 wt% to 2.5 wt%, the average coefficient of friction decreases, which means that the lubricity increases. However, as the content of the silane-based compound exceeded 3% by weight, the average coefficient of friction increased sharply. Therefore, in order to obtain a more effective lubrication characteristic, it is required to control the content of the silane-based compound to a certain level or less.

- Peel test (ASTM D 4541)

As described above, the adhesion of the phosphate layer-coated specimen and the three coating layers (Coating-1, Coating-2 and Coating-3) The results are shown in Table 3 below.

The first lubricant layer Adhesive strength (MPa) Failure Type Coating-1 7.1 Cohesive failure Coating-2 9.1 Negative damage Coating-3 5.8 Partial cohesive failure and partial adhesion failure

According to the above table, when the silane compound was grafted on the main chain of the epoxy polymer to modify it, good bonding strength could be obtained. Particularly, as the content of the silane-based compound grafted increases from 1.5 wt% to 2.5 wt%, the adhesive strength gradually increases, but the adhesive strength decreases sharply as it exceeds 3 wt%.

Formation of second lubricant layer

A second lubricating layer was attached to the specimen with Coating-2 as a first lubricating layer through a plasma coating. The plasma coating was performed under atmospheric pressure with (2-diethylphosphatoethyl) triethoxysilane as a precursor. Specifically, the precursor was atomized under a nitrogen atmosphere of 2 bar, and nitrogen was introduced as a carrier gas into the plasma region. At this time, the flow rate of the nitrogen gas was 25 L / min. At this time, no solvent was used for the plasma treatment, and the coating thickness was adjusted according to the plasma treatment time. Also, the plasma treatment was performed in a repeating on-off state at 5 ms intervals, with the peak-to-peak voltage and frequency being 30 kV and 6 kHz, respectively. The adhesion amount of the second lubricant layer was about 3.2 g / m 2.

FT-IR spectrum analysis (Fourier transform infrared spectroscopy)

Fourier transform infrared (FT-IR) spectrum analysis (Perkin Elmer Spectrum One, Perkin Elmer, Beaconsfield, UK) was performed on the second lubricant layer. The results are shown in Fig. According to the figure, bands were found at v = 2975 cm ^-1 , 1390 cm ^-1 , 1240 cm ^-1 , 1155 cm ^-1 , 1055 cm ^-1 , 955 cm ^-1 and 785 cm ^-1 . Specifically, the band at 1240 cm ^-1 was found to correspond to the phosphate P = O bond in the precursor, which is a lower frequency (1215 cm) that suggests hydrogen bonding between the P = O and hydroxy groups in the resulting plasma polymer ^-1 ) side. Further, the complex band shape in the range of 1000 to 1250 cm ^-1 corresponds to the Si-P, PO and CO stretching vibrations. In this regard, it can be seen that the band corresponding to the Si-O-Si stretching appeared at about 1100 cm ^-1 in the final structure.

As a result of the FT-IR analysis, the plasma polymerization of the phosphorus-containing organosilane showed Si-O-Si bonds on one side and P-O-P bonds on the other side. This suggests that the silicon contained in the second lubricant layer and the silicon contained in the first lubricant layer on the lower side are bonded and closely attached.

Flammability evaluation

The specimens coated with the second lubricant layer and the second lubricant layer were evaluated for flame retardancy according to ISO 5660 using a cone calorimeter. As a result, time-to-ignition (TTI) increased from 65 to 141 before and after the formation of the second lubricant layer. Considering this increase in TTI, it can be confirmed that a barrier layer having resistance to heat is formed due to the coating of the second lubricant layer. This improvement in flame retardancy is presumed to be attributable to the crosslinked structure of the plasma-coated phosphorus-containing organosilane, since such a plasma polymer can be regarded as containing not only the siloxane structure but also phosphate and phosphonate groups.

As described above, according to the present invention, a series of surface treatments, that is, a phosphate layer, a first lubricating layer, and a second lubricating layer are sequentially formed on a metal working material. As a result, It is possible to simultaneously secure firm adhesion with the phosphate layer and low friction characteristics as a result of using the epoxy-based polymer layer modified with the compound, and improve the adhesion with the first lubricant layer and the flame retardant effect as the second lubricant layer. Particularly, when a surface treatment apparatus having a specific structure is used for forming the phosphate layer, it is possible to remarkably reduce the treatment cost of the waste generated during the surface treatment process.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims (7)

A surface treatment method for a metal material,
a) providing a metal workpiece having steel, stainless steel, titanium, aluminum, copper or alloys thereof;
b) forming a phosphate layer in the surface treatment device for the metalworking material, wherein the adhesion weight of the phosphate layer is in the range of 1.5 to 30 g / m 2;
c) forming a first lubricant layer comprising a complex containing a polymer and an inorganic material for the phosphate layer; And
d) plasma-coating an organosilane compound on the first lubricant layer to form a second lubricant layer;
/ RTI >
Here, the first lubricant layer is a coating layer formed on the phosphate layer at an adhesion weight of 1 to 3 g / m < 2 >, and the silane compound is added to the main chain of the epoxy polymer by a sol- To 3% by weight of the composite,
Wherein the second lubricant layer is formed by coating a phosphorus-containing organosilane-based compound on the first lubricant layer with a coating weight of 2 to 6 g / m < 2 >
The surface treatment apparatus used in the step b)
A container for containing an aqueous solution as the metal-working material and the liquid-phase phosphorus-containing treatment agent;
A pump for circulating at least a portion of the treatment agent;
A temperature regulating member disposed in one side region of the container under the control of a temperature controller;
An ultrasonic irradiation member; And
Filter element:
/ RTI >
Here,
A metal processing material receiving space formed on the upper side for introducing the metal processing material and providing a space for accommodating the introduced metal processing material;
A first auxiliary storage space which is spaced apart from the metal processing material receiving space at a predetermined interval and is in fluid communication with the metal processing material receiving space by a first grating structure formed therein, ;
A second auxiliary accommodation space defining a boundary between the metal processing material accommodation space and the space separated by the second grating structure provided in the longitudinal direction or the vertical direction while providing a space for installing the temperature adjusting member, Wherein the second grating structure is in fluid communication with the metal processing material receiving space by the second grating structure and the spacing between the metal processing material receiving space and the first auxiliary receiving space is smaller than the first auxiliary The first grating structure of the accommodation space is adjusted in such a manner that the first grating structure is inserted into the accommodation space, and the temperature adjustment member is installed in the second auxiliary accommodation space; And
A collection space which is defined by a space defined between the partition wall and the inner surface of the container by a boundary defined in the longitudinal direction or the vertical direction and opposite to the second auxiliary accommodation space side of the metal processing material accommodation space, Wherein an upper end of the partition wall is spaced apart from an upper surface of the container by a predetermined distance so that an amount of the treating agent exceeding the maximum receiving space of the metal processing material receiving space is transferred to the collecting space beyond the upper end of the partition wall;
/ RTI >
Wherein the ultrasonic wave irradiating member is provided on an inner surface of the partition wall,
Wherein the filter member is provided with a circulation line for communicating with the collection space and moving upward by the pump and passing the filter member to recycle the filtrate from which the impurities in the treatment agent transferred to the collection space have been removed to the metal processing material accommodation space , And
Wherein a makeup line for replenishing the treatment agent is added to the filtrate passed through the filter member. The surface treatment method according to claim 1, wherein the phosphorus-containing organosilane compound is represented by the following general formula (1), (2)
[Chemical Formula 1]

(2)

. 3. The method of claim 2, wherein prior to step b)
(i) a metal-containing compound selected from the group consisting of zirconium, titanium, hafnium and combinations thereof, (ii) inositol hexaphosphoric acid represented by the following formula (3) or a salt thereof, and (iii) hydrofluoric acid, , A fluoride compound selected from the group consisting of ammonium fluoride, complex fluoride, and combinations thereof,
Here, the content of the metal-containing compound in the aqueous composition is in the range of 10 to 800 ppm based on the metal element, the molar ratio of the component (i) to the component (ii) is in the range of 4 to 10, In the range of 20 to 300 ppm based on the fluorine element, and
Wherein the pH of the composition is in the range of 2.5 to 4.5.
(3)

. The method according to claim 2, wherein the phosphate treatment agent for forming the phosphate layer is an aqueous solution,
The degree of acidity of the aqueous solution is 10 to 50 and the free acidity is 0.2 to 2,
Wherein the phosphate layer is formed at a temperature of 30 to 80 DEG C over a period of 0.5 to 30 minutes. 5. The method of claim 4, wherein the phosphate treatment agent for forming the phosphate layer comprises: (i) from 0.1 to 5 g / l zinc ion; (ii) an additional metal ion selected from the group consisting of calcium, magnesium and manganese, (Iii) 0.1 to 10 g / l of an accelerator selected from the group consisting of nitrate ions, nitrite ions and peroxide ions, and (iv) 5 to 60 g / l of phosphate ions and
Wherein the weight ratio of the zinc ion to the additional metal (Ca, Mg, Mn, or a combination thereof) ion: phosphate ion in the phosphate treatment agent is in the range of 0.1 to 3: 0 to 3: 5 to 40. delete The method of claim 1, wherein in step d) the plasma coating is performed under reduced pressure conditions of from 0.01 to 10 mbar and temperature conditions of from 50 to 200 캜,
Characterized in that the frequency (AC frequency) of the energy applied in the plasma coating is in the range of 4 to 40 kHz, the power density is in the range of 1000 to 5000 mW / cm2, and the peak to peak voltage is in the range of 20 to 50 kV. .

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