KR101762421B1 - Screen printing film type solid lubricant composition and method for manufacturing thereof - Google Patents

Abstract

The present invention discloses a coating-type solid lubricant coating liquid for forming a lubricant coating on the surface of a material subject to mechanical friction and a method of manufacturing the same. The solid lubricating coating solution prepared according to the present invention comprises a liquid binder of 30 to 60% by weight of polyamideimide (PAI) and 10 to 25% by weight of an epoxy resin, 5 to 15% by weight of polytetrafluoroethylene (PTFE) 3 to 10% by weight of solid lubricant powder, 3 to 10% by weight of blocked isocyanate, 1.0 to 3.0% by weight of a leveling agent and 0.5 to 2.0% by weight of a dispersant and 0.5 to 2.0% As shown in FIG. According to such a constitutional feature, since it has the property that it possesses the characteristic of low friction coefficient and can improve the wear resistance, the heat resistance, the tackiness and the lubricity at the same time, for example, It can provide the lubrication performance suitable for the rotating body or the bearing which performs the mechanical friction movement and is excellent in adhesion to the metal material, so that it is possible to easily form the coating film through the screen printing process, so that the productivity and economical efficiency can be efficiently Can be improved.

Description

[0001] The present invention relates to a film-coated solid lubricant coating liquid and a method of manufacturing the same,

More particularly, the present invention relates to a solid lubricating coating liquid which is coated with a coating film to suppress wear and noise from mechanical friction, and more particularly to a solid lubricating coating liquid which is excellent in heat resistance, abrasion resistance and metal adhesion A solid lubricant coating liquid having improved heat resistance, abrasion resistance and low friction coefficient, and a method for producing the solid lubricant coating liquid, and a method for forming a coating layer.

For example, friction and wear caused by sliding parts such as rotors, bearings, or pistons or gears in the driving part during operation of the machinery act as factors that have a great influence on the life or performance of the machinery. Therefore, Or a solid lubricant is used to reduce drive wear.

Generally, solid lubricants have the advantage of being able to lubricate parts that are difficult to reach conventional fluids or semi-solid lubricants such as oil or grease, and are not only easily contaminated by fine contaminant particles such as dust, And the demand for it is gradually increasing due to its advantage of being maintained for a long time.

Furthermore, recently, solid lubricants have been widely used not only in the aerospace field, micro mechanical elements, and mechanical component parts but also in the automobile, heavy equipment, and general industrial machinery fields. According to this trend, the solid lubricant is utilized as a key element technology that plays a role in improving the final performance and durability through friction and wear reduction of the mechanical device. Particularly, in the adhesive solid lubricant technology, The development of high value added solid lubricant technology that gives environmental resistance is actively under way.

On the other hand, conventional conventional solid lubricants include, for example, a base material such as molybdenum disulfide (MoS ₂ ), tungsten disulfide (WS ₂ ), boron nitride (BN) and graphite, In an appropriate ratio is coated on a metal substrate to impart abrasion resistance.

However, molybdenum disulfide has a low coefficient of friction due to the layered particles, and thus has a disadvantage in that adhesion to a metal substrate and abrasion resistance are relatively poor when used as an adhesive for a metal substrate.

The solid lubricant mainly composed of graphite has the advantage of maintaining the lubrication performance over a wide temperature range from room temperature to high temperature. However, since the film forming ability and the life of the coating film against repetitive friction are insufficient, it is not suitable for low speed and high load applications .

In addition, since the solid lubricant coating liquid containing a resin for enhancing the bonding force between the solid lubricant and the substrate has a disadvantage that wear resistance is poor, there is a problem that the coating is worn under severe exercise conditions and the bottom of the substrate is exposed in a short time.

In particular, when various kinds of fillers such as needle-shaped or scale-like materials are added to a wear-resistant material, the degree of sliding on the surface of the coating is reduced, and the non-stickiness and lubricity are deteriorated.

Therefore, the existing solid lubricant has limitations due to frictional heat and abrasion caused by its use conditions and environments, and thus there is room for improvement in the lubrication performance.

SUMMARY OF THE INVENTION The present invention has been made in view of the technical background as described above and it is an object of the present invention to solve the problems of the background art described above, It can not be said to have been publicly known to the general public before.

(Patent Document 1) Korean Patent Publication No. 10-1576780

(Patent Document 2) Korean Patent Publication No. 10-1130026

(Patent Document 3) Korean Patent Registration No. 10-0330689

(Patent Document 4) Korean Patent Registration No. 10-0314514

(Patent Document 5) Korean Patent Laid-Open Publication No. 10-2014-0034140

DISCLOSURE OF THE INVENTION The present invention has been made in order to solve the problems and disadvantages of the conventional solid lubricant as described above, and it is an object of the present invention to provide a lubricant composition having low friction coefficient characteristics and capable of simultaneously imparting abrasion resistance, heat resistance, Coated solid lubricant coating liquid having improved physical properties such that it can be improved and a method for producing the coating liquid and a method for forming a coating layer using the coating liquid.

In order to accomplish the above object, the present invention provides a coating fluid for solid lubricant coating composition, which is applied on the surface of a material subject to mechanical friction to form a lubricant coating, comprising 30 to 60 wt% of polyamideimide (PAI) And 10 to 25% by weight of an epoxy resin, a solid lubricating powder of 5 to 15% by weight of polytetrafluoroethylene (PTFE) and 3 to 10% by weight of graphite, a blocked isocyanate 3 To 10% by weight of a leveling agent, 1.0 to 3.0% by weight of a leveling agent, 0.5 to 2.0% by weight of a dispersant, and 0.5 to 2.0% by weight of a fluorine defoaming agent.

In order to accomplish the above object, the present invention provides a method for producing a coating liquid of a solid lubricant coating liquid, which comprises mixing a raw material, mixing a raw material, and dispersing a raw material.

In the method of producing a coating liquid for a solid lubricant coating composition according to the present invention comprising the above-mentioned process steps, 30 to 60% by weight of polyamideimide (PAI) and 10 to 25% by weight of an epoxy resin are mixed in the raw material mixing step, , Solid lubricant powder of 5 to 15% by weight of polytetrafluoroethylene (PTFE) and 3 to 10% by weight of graphite, 3 to 10% by weight of blocked isocyanate, leveling agent 1.0 To 3.0% by weight, a dispersant in an amount of 0.5 to 2.0% by weight, and a fluorine defoamer in an amount of 0.5 to 2.0% by weight.

In the raw material mixing step, the liquid binder, which is weighed and supplied in the raw material blending step, the solid lubricant powder and the additives are mixed using a high-concentration stirrer.

In the raw material dispersion step, the raw materials mixed in the raw material mixing step are charged into a 3-roll mill for high viscosity and milling is repeatedly performed 3 to 5 times.

The solid lubricant coating liquid of the present invention prepared through the above-described production process preferably has a viscosity in the range of 40,000 to 65,000 cps.

Preferably, the polytetrafluoroethylene is composed of spherical particles having a size of 2.0 to 5.0 탆, and the graphite is preferably composed of particles having a size of 0.1 to 5.0 탆.

Meanwhile, the coating fluid of the present invention is applied to a metal material to form a coating layer, which at least improves wear resistance and lubricity of the metal material.

In the present invention, the metal material in which the coating film-forming solid lubricant coating liquid according to the present invention is formed as a coating layer is not particularly limited, and examples thereof include aluminum, aluminum alloy, stainless steel (SUS), carbon steel and / As one of the preferred embodiments, the coating liquid coating type solid lubricant coating liquid according to the present invention can be effectively applied to a piston skirt made of aluminum or aluminum alloy.

In addition, the film-coated solid lubricant coating solution according to the present invention can be coated on a metal material by, for example, spray coating, roll coating, impregnation coating, or the like.

More preferably, the film-coated solid lubricant coating solution according to the present invention can be coated on a metal material by a screen coating method. For such a screen coating, it is preferred that the coating liquid according to the present invention has a viscosity (at 25 DEG C) in the range of 40,000 to 65,000 cps.

In addition, the film-coated solid lubricant coating solution according to the present invention may further comprise a solvent in addition to the above components, and the solvent may be selected from water, an organic solvent, and a mixture thereof.

For example, alcohols and ketones may be effectively used as the organic solvent, and the solvent may be contained in an amount of 2 to 40% by weight based on the total weight of the coating liquid.

Meanwhile, the method for forming a coating layer of a film-coated solid lubricant coating solution according to the present invention comprises coating and curing a coating solution obtained through the above-described manufacturing process on a metal material by a screen printing process. At this time, the curing can be carried out at a temperature of, for example, 200 to 250 DEG C for 10 to 120 minutes.

According to the coating film-forming solid lubricating coating solution prepared by the present invention, the low friction coefficient characteristic is possessed and it has properties that can simultaneously improve abrasion resistance, heat resistance, tackiness and lubricity. Thus, for example, It is possible to provide a lubricating performance suitable for a rotating body or a bearing which performs a mechanical friction movement in a high temperature and high temperature environment.

 In addition, the coating-type solid lubricant coating solution produced by the present invention is excellent in adhesion to a metal material, so that it is possible to easily form a coating through a screen printing process, thereby effectively improving productivity and economy in a coating process .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart showing a process for producing a film-coated solid lubricant coating liquid according to the present invention. FIG.
FIG. 2A is a photograph showing a three-roll mill apparatus used in a raw material dispersion process for producing a coating liquid-type solid lubricant coating liquid according to the present invention. FIG.
FIG. 2B is a schematic view for explaining a mechanism of dispersion of raw materials by the three-roll mill apparatus illustrated in FIG. 2A. FIG.
FIG. 3 is a photograph showing a sample of the coating-type solid lubricant coating liquid of the present invention, which has been manufactured through the manufacturing process shown in FIG. 1 and FIG.
FIG. 4 is a photograph showing the wear resistance test results of a specimen coated with a coating liquid of a coating type solid lubricant according to an embodiment of the present invention and a comparative example.
FIG. 5 is a graph comparing friction coefficients measured in Examples and Comparative Examples in which a coating film-coated solid lubricant coating liquid according to the present invention was coated.
6 is a schematic view illustrating a process of coating a film-coated solid lubricant coating liquid prepared by the present invention on a curved surface material by a screen printing process.
7A to 7C are photographs of a sample coated with an actual coating liquid of a solid lubricating coating film produced by the present invention on a piston head.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a solid lubricant coating liquid according to the present invention and a method for producing the same will be described in detail with reference to the accompanying drawings. The following description and the accompanying drawings are merely exemplary embodiments of the present invention and are not to be construed as limiting the solid lubricant coating liquid according to the present invention, the method for producing the same, and the method for forming a coating layer.

The solid lubricating coating liquid for coating of the present invention is applied to the surface of a material subject to mechanical friction in the form of a coating to form a lubricating coating, comprising 30 to 60% by weight of polyamideimide (PAI) and 10 to 25% by weight of epoxy resin % Of liquid binder, 5 to 15% by weight of polytetrafluoroethylene (PTFE) and 3 to 10% by weight of graphite, 3 to 10% by weight of blocked isocyanate, 1.0 to 3.0% by weight, 0.5 to 2.0% by weight of a dispersant, and 0.5 to 2.0% by weight of a fluorine defoaming agent as additives.

FIG. 1 is a process flow diagram illustrating a process for producing a film-coated solid lubricant coating solution according to the present invention having the above-described structure. Referring to FIG. 1, the solid coating film- -11), a raw material mixing step (S-12) and a raw material dispersion step (S-13).

According to the present invention, in the raw material mixing step (S-11), a liquid binder of 30 to 60% by weight of polyamideimide (PAI) and 10 to 25% by weight of an epoxy resin and 5 to 15% by weight of polytetrafluoroethylene (PTFE) 3 to 10% by weight of graphite and 3 to 10% by weight of solid lubricant powder, 3 to 10% by weight of blocked isocyanate, 1.0 to 3.0% by weight of leveling agent and 0.5 to 2.0% 2.0% by weight is selected as an additive, weighed by each balance, and quantitatively supplied to a mixing container.

In the raw material mixing step (S-12), the liquid binder weighed and supplied in the raw material mixing step (S-11), the solid lubricating powder and the additives are mixed using a high concentration mixer.

In the raw material dispersion step (S-13), raw materials mixed in the raw material mixing step (S-12) are charged into a high-viscosity 3-roll mill as illustrated in FIG. 2A, Repeat the milling operation five times.

FIG. 2B is a schematic diagram for explaining the raw material dispersion state by the 3-roll mill illustrated in FIG. 2A. Referring to FIG. 2B, in the raw material mixing step (S-12) The inorganic raw materials are thinly crushed into a binder by passing through a first roller R1, a second roller R2 and a third roller R3 which are sequentially disposed on a 3-Roll Mill. The preparation of the coating liquid of the present invention is completed. At this time, it is preferable that the inorganic particles are repeatedly milled three to five times so as to be pulverized into particles having a size of several micrometers. Thus, the dispersibility of the respective components is improved, and at least the wear resistance And adhesion and the like are improved.

The coating-type solid lubricant coating liquid according to the present invention having the above-described structure is applied to a metal material to form a coating layer, which at least improves wear resistance and lubricity of the metal material.

On the other hand, the metal material in which the coating film-forming solid lubricant coating liquid according to the present invention is formed as a coating layer is not particularly limited, and for example, aluminum, aluminum alloy, stainless steel (SUS), carbon steel and / have.

According to one aspect of the present invention, the coating liquid coating type solid lubricant coating liquid according to the present invention can be effectively applied to the formation of a coating layer such as a piston skirt made of aluminum or an aluminum alloy.

The solid lubricant coating liquid for coating according to the present invention is preferably coated on the metal material by a screen coating method. For such a screen coating, it is preferred that the coating liquid according to the present invention has a viscosity (at 25 DEG C) in the range of 40,000 to 65,000 cps.

According to another aspect of the present invention, the film-coated solid lubricant coating solution of the present invention can be coated on a metal material by, for example, spray coating, roll coating, impregnation coating, or the like.

According to the coating liquid-type solid lubricant coating solution of the present invention having the above-described structure, the polyamide-imide (PAI) is a super engineering plastic, which is used for at least wear resistance, Can be improved.

In the present invention, the polyamideimide (PAI) is contained in an amount of 30 wt% to 60 wt% based on the total weight of the coating liquid. At this time, when the content of the polyamideimide (PAI) is less than 30% by weight, abrasion resistance and the like may be insignificant. On the other hand, when the content of the polyamideimide (PAI) is more than 60% by weight, the dispersibility may be deteriorated and the screen coating property may be difficult due to too high viscosity. Accordingly, it is preferable that the coating fluid-solid lubricant coating solution according to the present invention contains polyamideimide (PAI) in an amount of 40 wt% to 55 wt%. In the present invention, the weight% may be the content of each component based on the solid content of the coating liquid.

The polytetrafluoroethylene (PTFE) is used for abrasion resistance and lubricity. In addition, polytetrafluoroethylene (PTFE) can improve heat resistance and the like.

In the present invention, the polytetrafluoroethylene (PTFE) is contained in an amount ranging from 5% by weight to 15% by weight based on the total weight of the coating liquid. When the content of polytetrafluoroethylene (PTFE) is less than 5% by weight, the effect of improving the abrasion resistance and lubricity is insignificant depending on the content thereof. On the other hand, when the content is more than 15% by weight, It can fall. Accordingly, it is preferable that the solid lubricant coating liquid for coating of the present invention contains polytetrafluoroethylene (PTFE) in a range of 8 wt% to 12 wt%.

On the other hand, the polytetrafluoroethylene (PTFE) can use, for example, spherical particles as a granular phase.

In the present invention, the spherical shape does not mean a complete spherical shape. For example, the polytetrafluoroethylene (PTFE) may have an average size of 2 to 5 占 퐉.

The graphite is used for lubrication and strength reinforcement, and for example, particles of an average size of 0.1 mu m to 5 mu m can be used.

According to the present invention, when the particle size of the graphite is too small, the dispersibility may be deteriorated due to aggregation, and when the particle size is too large, the surface property of the coating layer may be deteriorated. Accordingly, the graphite is contained in an amount of 3 wt% to 10 wt% based on the total weight of the coating liquid. When the content of the graphite is less than 3% by weight, the effect of improving the lubricity and strength may be insignificant depending on the use of the graphite. When the graphite content is more than 10% by weight, it may be difficult to obtain desirable characteristics in surface properties .

 The epoxy resin is used for interlayer adhesion between the metal material and the coating layer and for reinforcing the strength of the coating layer. The epoxy resin has a function of a binder in the coating liquid together with the polyamideimide (PAI).

In the present invention, the epoxy resin specifically provides an adhesion force with the metal material while aggregating the particulate components contained in the coating liquid. Such an epoxy resin is contained in an amount of 10% by weight to 25% by weight based on the total weight of the coating liquid. When the content of the epoxy resin is less than 10% by weight, the interlayer adhesion force, the particle aggregation force and the strength reinforcement may be insignificant. When the content of the epoxy resin exceeds 25% by weight, And the content of polyamideimide (PAI) and polytetrafluoroethylene (PTFE) is relatively low, and wear resistance and the like may be lowered.

The curing agent is for curing, which may be selected from, for example, an isocyanate system. In one example, the curing agent may be selected from block isocyanates as a latent curing agent.

The dispersant is not particularly limited as long as it can improve the dispersibility of the respective components and the antifoaming agent can prevent bubbles.

The leveling agent may be any one for the surface smoothness of the coating layer.

In the present invention, the dispersant, defoaming agent and leveling agent can be selected from commonly used ones. In this case, the curing agent may be included in an amount of 3 wt% to 10 wt%, the dispersant may be 0.5 wt% to 2 wt%, the defoaming agent may be 0.2 wt% to 0.5 wt%, and the leveling agent may be 1 wt% to 3 wt% have. When the content of each of the components is out of the above range in the content of the curing agent, the dispersant, the defoaming agent and the leveling agent, the function obtained from each component may be insignificant, the synergistic effect due to excessive use may not be very large, Which may be undesirable.

In addition, the coating solution according to the present invention may further include a solvent in addition to the above components, and the solvent may be selected from water, an organic solvent, and a mixture thereof. Examples of the organic solvent include alcohols and ketones. Such a solvent may be contained in an amount of, for example, 2% by weight to 40% by weight based on the total weight of the coating liquid.

Hereinafter, examples and comparative examples of the film-coated solid lubricant coating liquid according to the present invention having the above-described structure will be described. The following examples are provided to illustrate the present invention in order to facilitate understanding of the present invention, and thus the technical scope of the present invention is not limited thereto. In addition, the following comparative example is not meant to be a prior art, but is provided for comparison with an embodiment only.

[Example 1]

A coating solution was prepared by the ingredients and contents shown in Table 1 below. At this time, each component was mixed in an appropriate amount, and then passed through three roll mills five times, so that sufficient pulverization and dispersion were achieved.

FIG. 3 is a photograph of a sample sample of the coating solution prepared in Example 1, taken as an illustration. FIG.

In the following Table 1, the content (% by weight) of each component is based on the total weight of the coating liquid. The viscosity of the coating solution according to this example was measured using a Broofield viscometer at 55,200 cps (at 25 ° C).

[Examples 2 and 3]

The same procedure as in Example 1 was carried out except that the content of each component was varied. The specific components and contents of the coating liquid according to the present embodiments are as shown in Table 1 below.

[Comparative Examples 1 to 3]

Compared with Example 1, the composition and content of the coating liquid were varied. The specific components and contents of the coating liquid according to each Comparative Example are as shown in Table 1 below.

≪ Component and content of coating liquid, unit: wt% > Composition component Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 PAI 50 32 57.5 62 - 27.5 PTFE 12 14 6 - 20 4.5 Graphite 5 8 3.5 12 5 12 Epoxy resin 15 25 12 8 30 10 Hardener 5 8 8 5 12 5 Dispersant 1.0 1.0 1.0 1.0 1.0 1.0 Defoamer 0.3 0.3 0.3 0.3 0.3 0.3 Leveling agent 1.2 1.2 1.2 1.2 1.2 1.2 menstruum Balance Balance Balance Balance Balance Balance * PAI: Polyamideimide
* PTFE: polytetrafluoroethylene, spherical particles having an average size of 3 mu m
* Graphite: 2μm average size
* Hardener: Block isocyanate
* Dispersant: acid value (mgKOH / g) 53, solid content 52 wt%
* Antifoaming agent: fluorine
* Leveling agent: silicone
Solvent: methyl ethyl ketone (MEK)

  ≪ Abrasion resistance test &

The coating solution according to each of the Examples and Comparative Examples was screen-coated once on an aluminum (Al) plate and then cured at 220 캜 for about 30 minutes. Thereafter, after leaving for about 2 hours, the coefficient of friction and the coefficient of friction for each coated specimen were measured according to the test conditions shown in Table 2 below using a reciprocating abrasion tester (Plint Co., Ltd., The wear rate (%) was measured. The results are shown in Table 3 below.

≪ Abrasion resistance test condition & weight Revolutions Number of tests Distance (Length) 5Kg 50 times / minute 6,000 times 35m

<Adhesion test>

The coating solution according to each of the Examples and Comparative Examples was screen-coated once with an aluminum foil and cured at 220 ° C for about 30 minutes. Thereafter, the film was allowed to stand for about 2 hours, and the adhesion was evaluated by a 90 degree peel test method in a peel strength tester. At this time, when peeling at a speed of 5 m / min, peeling occurred at a load of 20 Kg when the peeling occurred under a load of 10 Kg, and when the peeling occurred at a load between 10 Kg and 20 Kg Quot; &amp; cir &amp;&quot;, and the results are shown in Table 3 below.

&Lt; Evaluation results of abrasion resistance and adhesion of coated specimens > Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Abrasion resistance Average coefficient of friction 0.1193 0.1651 0.1437 0.2310 0.2556 0.2204 Maximum coefficient of friction 0.2061 0.2703 0.2690 0.3183 0.3416 0.3031 Wear rate (%) 0.0033 0.0047 0.0041 0.0074 0.158 0.0053 Attachment 90 degree peeling ◎ ◎ ◎ ○ ◎ △

As shown in [Table 3] and FIG. 1, it can be seen that the coating specimens according to the embodiments are evaluated to have higher abrasion resistance and adhesion strength than the coating specimens according to the comparative examples.

FIG. 4 is a photograph showing the wear resistance test results of a specimen coated with a coating liquid of a coating type solid lubricant coating liquid according to an embodiment of the present invention and a comparative example. FIG. 5 is a graph comparing the abrasion resistance test results of Example 1 and Comparative Examples 1 to 3 Of the coated specimen according to the present invention.

Also, in comparison with Examples 1 to 3 and Comparative Examples 1 and 2, at least wear resistance differs greatly depending on whether polyamideimide (PAI) and polytetrafluoroethylene (PTFE) are used.

5A to 5D, which are photographed, the scratches due to wear of the surface are clearly visible in Comparative Examples 1 and 2. In Comparative Example 3, scratches due to surface wear Is better than those of Comparative Examples 1 and 2, but it can be confirmed that the scratch state due to wear of the surface is somewhat greater than that of Examples.

In contrast to Examples 1 to 3 and Comparative Example 3, when polyamideimide (PAI) and polytetrafluoroethylene (PTFE) were used, it was found that when the respective amounts were used, they were advantageous not only in abrasion resistance but also in adhesion .

On the other hand, the coating-type solid lubricant coating liquid prepared according to the present invention as described above is coated on the surface of the metal material through the screen coating method and cured to perform the role and function of the solid lubricant coating layer.

That is, the method of forming a coating layer of a film-coating type solid lubricant coating liquid according to the present invention comprises the steps of mixing a raw material (S-11), a raw material mixing step (S-12) and a raw material dispersion step (S- 13 to a surface of a part of a metal material, such as a piston head or the like as shown in Fig. 7, which is exposed to mechanical abrasion or noise, through a screen coating method exemplarily shown in Fig. 6, And cured at a temperature in the range of 200 to 250 DEG C for 10 to 120 minutes to form a solid lubricous coating layer.

7 shows a screen printing process for coating the coating liquid 10 of the present invention on a curved surface material such as the piston head 20. The piston head 20 is attached to the rotating body 31 of the pedestal 30, The coating liquid can be formed on the surface of the curved material by pressing the coating liquid 10 supplied to the print panel P by the squeegee S which reciprocates.

The present invention is not limited to the above-described specific preferred embodiments, and various changes and modifications may be made to the present invention without departing from the scope of the present invention as defined in the claims. , And such modifications are within the scope of the claims set forth.

Claims (7)

To form a lubricant coating on the surface of a material subject to mechanical friction in the form of a coating,
A liquid binder comprising 30 to 60% by weight of polyamideimide (PAI) and 10 to 25% by weight of an epoxy resin and 5 to 15% by weight of polytetrafluoroethylene (PTFE) and 3 to 10% by weight of solid graphite And a coating film-forming agent, wherein the coating agent comprises 3 to 10 wt% of a blocked isocyanate, 1.0 to 3.0 wt% of a leveling agent, 0.5 to 2.0 wt% of a dispersant, and 0.5 to 2.0 wt% Solid lubricant coating solution. The method according to claim 1,
Wherein the liquid coating liquid comprising the liquid binder, the solid lubricant powder and the additive has a viscosity of 40,000 to 65,000 cps. The method according to claim 1,
Wherein said polytetrafluoroethylene is spherical particles having a size of 2.0 to 5.0 占 퐉. The method according to claim 1,
Wherein the graphite is composed of particles having a size of 0.1 to 5.0 mu m. A liquid binder comprising 30 to 60% by weight of polyamideimide (PAI) and 10 to 25% by weight of an epoxy resin and 5 to 15% by weight of polytetrafluoroethylene (PTFE) and 3 to 10% by weight of solid graphite 3 to 10% by weight of a blocked isocyanate, 1.0 to 3.0% by weight of a leveling agent, 0.5 to 2.0% by weight of a dispersing agent, and 0.5 to 2.0% by weight of a fluorine defoaming agent as additives;
A mixing step of mixing the liquid binder charged and weighed in the raw material mixing step, the powder for solid lubricating and the additive using a high-concentration stirrer; And
And forming a coating liquid by pulverizing and dispersing the raw materials mixed in the raw material mixing step by a roll mill. 6. The method of claim 5,
In the step of forming the coating liquid by pulverization and dispersion by the roll mill, the coating liquid is passed through a 3-roll mill including three rolls to pulverize the particulate components contained in the coating liquid, By weight based on the total weight of the solid lubricant coating liquid. A method for forming a coating layer of a film-coated solid lubricant coating liquid, which comprises coating and curing a coating liquid according to any one of claims 1 to 4 on a metal material through a screen printing process to form a solid lubricating coating layer.

Images