KR101051702B1 - PET resin / PF resin copolymerized fluororesin solid lubrication board and its manufacturing method - Google Patents

Abstract

An object of the present invention is to be able to strongly adhere the PTFE resin and PFA resin copolymer for injection to the surface of the metal steel sheet by sintering, excellent lubricity, wear resistance, heat resistance and chemical resistance, easy mass production, and at the same time To provide a cost-effective PTFE resin and PFA resin copolymerized fluororesin-based solid lubrication substrate and a method of manufacturing the same.

PTFE resin, PFA resin, extrusion resin, emulsion polymerization

Description

PTF resin and PFA resin copolymerized fluororesin-based solid lubrication substrate and its manufacturing method {Solid lubricate PTFE · PFA co-polymer resin film and manufacturing method}

The present invention relates to a PTFE resin, a polymerized fluororesin-based solid lubrication substrate, and a method for manufacturing the same, which can strongly adhere an injection-molded PTFE resin and a PFA resin copolymer to the surface of a metal steel sheet by sintering, and include lubrication, abrasion resistance, heat resistance, and the like. The present invention relates to a PTFE resin and a PFA resin copolymerized fluororesin-based solid lubrication substrate which is excellent in chemical resistance, can be easily mass-produced, and can reduce manufacturing costs.

Polytetrafluorofluoroethylene (hereinafter referred to as PTFE) resin, a fluorine resin system widely used in the past, has excellent properties to withstand all acids, alkalis, and solvents, and thus has different chemical resistance and weather resistance. Compared with the high melting point of 327 ℃, it can be safely used from low temperature of -100 ℃ to high temperature of 250 ℃. Especially, it has excellent lubricity and abrasion resistance, so it has excellent lubricity, abrasion resistance, heat resistance and chemical resistance. It is widely used as a solid lubrication substrate of this long solid lubrication bearing.

However, since PTFE resin is excellent in heat resistance and chemical resistance, it is impossible to melt processing, and since there is no solvent or adhesive, special processing is required to manufacture a solid lubrication substrate made by attaching a PTFE resin thin film, which is a solid lubricant, on the metal surface. There are many restrictions in terms of use.

Conventionally, in order to manufacture a solid lubrication substrate using fluorine resin, since the fluorine resin has a weak adhesion to the metal surface, the bronze powder is strongly fused by a metallurgy method on the metal steel sheet to form a porous bronze powder sintered layer, and the fluorine resin is formed thereon. The dispersion was dispersed and then dried and cured to prepare a solid lubricating substrate.

However, the solid lubrication substrate prepared in this way has various problems, such as not only cracking the surface or manufacturing the thickness uniformly, but also making the manufacturing process complicated and making the manufacturing cost very expensive.

In addition, the metal-reinforced solid lubrication in which a metal lubricant having a diameter of 0.23 to 0.50 mm of bronze or stainless steel is impregnated with a lot of solid lubrication resin in the space between the woven metal mesh and then pressed to fix the metal mesh and the solid lubricant layer. Although the substrate was being manufactured, when the metal mesh is pulled in a diagonal direction, the contact points between the metal yarns are staggered, so that the tensile strength and mechanical strength are reduced, and the lubrication substrate is damaged, and the manufacturing process is complicated and the manufacturing cost is very expensive. There are several problems.

Accordingly, the present invention has been made to solve the above various problems, and an object of the present invention is a solid lubrication substrate capable of strongly attaching an injection-molded PTFE resin / PFA resin copolymer to a surface of a metal steel sheet by sintering and its manufacture To provide a method.

Another object of the present invention is to provide a fluororesin-based solid lubrication substrate having excellent lubricity, abrasion resistance, heat resistance and chemical resistance, and a method of manufacturing the same.

Still another object of the present invention is to provide a fluororesin-based solid lubrication substrate and a method of manufacturing the same, which can be easily mass-produced and greatly reduce the manufacturing cost.

The present invention has been made to achieve the above object, the method of producing a PTFE resin / PFA resin copolymerized fluorine resin-based solid lubrication of the present invention is 44.5 to 55.50% by weight, fine particles of 0.15 to 0.50㎛ particle size, 0.15 to 0.50 1.5 to 2.50 wt% of fine PFA resin, 2.0 to 2.8 wt% of fine natural graphite powder having a particle size of 0.15 to 0.50 μm, 39.7 to 50.0 wt% of distilled water, and 0.3 to 0.80 wt% of nonionic dispersant were added to a container and stirred A step of preparing a PTFE resin, a PFA resin, and a natural graphite powder mixture, wherein the resin, PFA resin and natural graphite powder are uniformly dispersed and mixed to produce an alkaline mixture having a pH of 9.0; The PTFE resin, PFA resin, and natural graphite powder mixture prepared in the step of preparing the PTFE resin, PFA resin, and natural graphite powder mixture are refrigerated at 24 ° C. at -5 ° C. for 24 hours and then thawed again by a freeze emulsion polymerization method. Frozen emulsion polymerization step of producing water; The viscosity of the rubbery semi-solid polymer having increased polymerization degree by evaporating water while heating the low-polymerization oil polymerized in the freezing emulsion polymerization step for 150 minutes to 210 minutes in a water tank maintained at a temperature of 80 ° C to 100 ° C A step of preparing an extruded PTFE resin and a PFA resin copolymer for producing a high (dough form) extruded PTFE resin and a PFA resin copolymer; A compression roller heated to 100 ° C. to 140 ° C. by placing a rubbery semi-solid extrusion PTFE resin and PFA resin copolymer prepared in the step of manufacturing the extruded PTFE resin and PFA resin copolymer on a steel sheet having a thickness of 0.25 to 0.35 mm. By applying a pressure of 550 to 610 kg / cm 2 to compress and polymerize the fluororesin-based solid lubricant layer on the upper surface of the steel sheet to fix the fluororesin-based solid lubricant layer on the upper surface of the steel sheet. Steps; In the fixing step of the fluororesin-based solid lubricant layer, a conveyor on which a solid lubrication substrate on which a fluororesin-based solid lubricant layer of 0.15 to 0.25 mm thickness is fixed to an upper surface of a steel sheet of 0.25 to 0.35 mm thickness is maintained at a temperature of 300 ° C to 380 ° C. It is characterized in that it comprises a solid lubrication substrate manufacturing step of producing a solid lubrication substrate is attached to the steel plate by curing the fluorine resin by heat-fired for 15 to 25 minutes in the automatic electric furnace of the system.

Further, the PTFE resin / PFA resin copolymerized fluororesin-based solid lubrication substrate of the present invention is produced by the method for producing the PTFE resin / PFA resin copolymerized fluororesin-based solid lubrication substrate of the present invention.

According to the PTFE resin and PFA resin copolymerized fluororesin-based solid lubrication substrate of the present invention and a method for producing the same, the PTFE resin and PFA resin copolymer for injection can be strongly adhered to the surface of the metal steel sheet by sintering, and the lubricity, abrasion resistance, and heat resistance And excellent in chemical resistance, easy mass production, and at the same time has an excellent effect of reducing the manufacturing cost.

A method for producing a PTFE resin / PFA (Per Fluoro Alcoxide resine; PFA) resin copolymerized fluororesin-based solid lubrication substrate according to a preferred embodiment of the present invention will be described in detail with reference to Examples. .

Example 1

44.5% by weight of fine PTFE resin having a particle size (particle size) of 0.15 to 0.50 μm, 2.50% by weight of fine PFA resin having a particle size of 0.15 to 0.50 μm, 2.50% by weight of fine natural graphite powder having a particle size of 0.15 to 0.50 μm, and 50% by weight of distilled water. % And 0.50% by weight of a nonionic dispersant (also called a surfactant) are placed in a vessel (e.g., a stainless vessel, a plastic vessel or a glass vessel) and stirred at low speed (rotational speed; 10-50 rpm) for PTFE resin. PFA resin and natural graphite powder were uniformly dispersed and mixed to prepare an alkaline mixed liquid having a pH of 9.0 (PTFE resin, PFA resin, natural graphite powder mixture preparation step).

The PTFE resin, PFA resin, and natural graphite powder mixture prepared in the step of preparing the PTFE resin, PFA resin, and natural graphite powder mixture are refrigerated at 24 ° C. at -5 ° C. for 24 hours and then thawed again by a freeze emulsion polymerization method. Water was prepared (freezing emulsion polymerization step).

The viscosity of the rubbery semi-solid polymer having increased polymerization degree by evaporating water while heating the low-polymerization oil polymerized in the freezing emulsion polymerization step for 150 minutes to 210 minutes in a water tank maintained at a temperature of 80 ° C to 100 ° C A high (e.g., dough-like) extrusion PTFE resin / PFA resin copolymer was prepared (extrusion step for preparing PTFE resin / PFA resin copolymer).

A compression roller heated to 100 ° C. to 140 ° C. by placing a rubbery semi-solid extrusion PTFE resin and PFA resin copolymer prepared in the step of manufacturing the extruded PTFE resin and PFA resin copolymer on a steel sheet having a thickness of 0.25 to 0.35 mm. By applying a pressure of 550 to 610 kg / cm 2 to compress and polymerize the fluororesin-based solid lubricant layer on the upper surface of the steel plate to fix the fluororesin-based solid lubricant layer on the upper surface of the steel plate (fluorine resin-based solid lubricant layer). Fixation phase).

In the fixing step of the fluororesin-based solid lubricant layer, a conveyor on which a solid lubrication substrate on which a fluororesin-based solid lubricant layer of 0.15 to 0.25 mm thickness is fixed to an upper surface of a steel sheet of 0.25 to 0.35 mm thickness is maintained at a temperature of 300 ° C to 380 ° C. Heat-fired for 15 to 25 minutes in the automatic electric furnace of the system to cure the fluorine resin to prepare a solid lubrication substrate attached to the steel plate (solid lubrication substrate manufacturing step).

Example 2

55.50 wt% of fine PTFE resin with particle size (particle size) of 0.15 to 0.50 μm, 2.00 wt% of fine PFA resin with particle size of 0.15 to 0.50 μm, 2.00 wt% of fine natural graphite powder with particle size of 0.15 to 0.50 μm, and distilled water 39.70 weight % And 0.80% by weight of a nonionic dispersant were put in a container and stirred at a low speed to uniformly disperse and mix PTFE resin, PFA resin and natural graphite powder to prepare an alkaline mixed liquid having a pH of 9.0 (PTFE resin, PFA resin, and natural graphite). Powder mixture preparation step).

The PTFE resin, PFA resin, and natural graphite powder mixture prepared in the step of preparing the PTFE resin, PFA resin, and natural graphite powder mixture are refrigerated at 24 ° C. at -5 ° C. for 24 hours and then thawed again by a freeze emulsion polymerization method. Water was prepared (freezing emulsion polymerization step).

The viscosity of the rubbery semi-solid polymer having increased polymerization degree by evaporating water while heating the low-polymerization oil polymerized in the freezing emulsion polymerization step for 150 minutes to 210 minutes in a water tank maintained at a temperature of 80 ° C to 100 ° C A high extrusion PTFE resin / PFA resin copolymer was prepared (preparation step of PTFE resin / PFA resin copolymer for extrusion).

A compression roller heated to 100 ° C. to 140 ° C. by placing a rubbery semi-solid extrusion PTFE resin and PFA resin copolymer prepared in the step of manufacturing the extruded PTFE resin and PFA resin copolymer on a steel sheet having a thickness of 0.25 to 0.35 mm. By applying a pressure of 550 to 610 kg / cm 2 to compress and polymerize the fluororesin-based solid lubricant layer on the upper surface of the steel plate to fix the fluororesin-based solid lubricant layer on the upper surface of the steel plate (fluorine resin-based solid lubricant layer). Fixation phase).

In the fixing step of the fluororesin-based solid lubricant layer, a conveyor on which a solid lubrication substrate on which a fluororesin-based solid lubricant layer of 0.15 to 0.25 mm thickness is fixed to an upper surface of a steel sheet of 0.25 to 0.35 mm thickness is maintained at a temperature of 300 ° C to 380 ° C. Heat-fired for 15 to 25 minutes in the automatic electric furnace of the system to cure the fluorine resin to prepare a solid lubrication substrate attached to the steel plate (solid lubrication substrate manufacturing step).

Example 3

51.90% by weight of fine PTFE resin having a particle size (particle size) of 0.15 to 0.50 μm, 1.50% by weight of fine PFA resin having a particle size of 0.15 to 0.40 μm, 2.80% by weight of fine natural graphite powder having a particle size of 0.15 to 0.50 μm, and 43.50 weight of distilled water % And 0.30% by weight of a nonionic dispersant were added to a container and stirred at low speed to uniformly disperse and mix PTFE resin, PFA resin and natural graphite powder to prepare an alkaline mixed liquid having a pH of 9.0 (PTFE resin, PFA resin, and natural graphite). Powder mixture preparation step).

The PTFE resin, PFA resin, and natural graphite powder mixture prepared in the step of preparing the PTFE resin, PFA resin, and natural graphite powder mixture are refrigerated at 24 ° C. at -5 ° C. for 24 hours and then thawed again by a freeze emulsion polymerization method. Water was prepared (freezing emulsion polymerization step).

The viscosity of the rubbery semi-solid polymer having increased polymerization degree by evaporating water while heating the low-polymerization oil polymerized in the freezing emulsion polymerization step for 150 minutes to 210 minutes in a water tank maintained at a temperature of 80 ° C to 100 ° C A high extrusion PTFE resin / PFA resin copolymer was prepared (preparation step of PTFE resin / PFA resin copolymer for extrusion).

A compression roller heated to 100 ° C. to 140 ° C. by placing a rubbery semi-solid extrusion PTFE resin and PFA resin copolymer prepared in the step of manufacturing the extruded PTFE resin and PFA resin copolymer on a steel sheet having a thickness of 0.25 to 0.35 mm. By applying a pressure of 550 to 610 kg / cm 2 to compress and polymerize the fluororesin-based solid lubricant layer on the upper surface of the steel plate to fix the fluororesin-based solid lubricant layer on the upper surface of the steel plate (fluorine resin-based solid lubricant layer). Fixation phase).

Comparative example

40.0 wt% of fine PTFE resin having a particle size (particle size) of 0.15 to 0.50 μm, 7.50 wt% of fine PFA resin having a particle size of 0.15 to 0.50 μm, and 3.50 wt% of fine natural graphite powder having a particle size of 0.15 to 0.50 μm. Distilled water and 0.30% by weight of a nonionic dispersant were put in a container and stirred at low speed to uniformly disperse and mix PTFE resin, PFA resin and natural graphite powder to prepare an alkaline mixed liquid having a pH of 9.0 (PTFE resin, PFA resin, Natural graphite powder mixture).

Low-polymerization oil was prepared by freezing emulsion polymerization in which the PTFE, PFA, and graphite powder mixtures prepared in the above PTFE, PFA, and graphite graphite powder mixture were frozen for 24 hours at -5 ° C and thawed again. (Frozen emulsion polymerization step).

The viscosity of the rubbery semi-solid polymer having increased polymerization degree by evaporating water while heating the low-polymerization oil polymerized in the freezing emulsion polymerization step for 150 minutes to 210 minutes in a water tank maintained at a temperature of 80 ° C to 100 ° C A high extrusion PTFE resin / PFA resin copolymer was prepared (preparation step of PTFE resin / PFA resin copolymer for extrusion).

A compression roller heated to 100 ° C. to 140 ° C. by placing a rubbery semi-solid extrusion PTFE resin and PFA resin copolymer prepared in the step of manufacturing the extruded PTFE resin and PFA resin copolymer on a steel sheet having a thickness of 0.25 to 0.35 mm. By applying a pressure of 550 to 610 kg / cm 2 to compress and polymerize the fluororesin-based solid lubricant layer on the upper surface of the steel plate to fix the fluororesin-based solid lubricant layer on the upper surface of the steel plate (fluorine resin-based solid lubricant layer). Fixation phase).

In the fixing step of the fluororesin-based solid lubricant layer, a conveyor on which a solid lubrication substrate on which a fluororesin-based solid lubricant layer of 0.15 to 0.25 mm thickness is fixed to an upper surface of a steel sheet of 0.25 to 0.35 mm thickness is maintained at a temperature of 300 ° C to 380 ° C. Heat-fired for 15 to 25 minutes in the automatic electric furnace of the system to cure the fluorine resin to prepare a solid lubrication substrate attached to the steel plate (solid lubrication substrate manufacturing step).

The thickness of the solid lubrication substrate prepared in the comparative example was 0.50 mm, 0.01 mm less than the thinnest thickness of Example 1 of the present invention, the adhesion between the solid lubricant layer and the steel plate was very good, The condition was rough, and fine cracks were generated on the surface and could not be used as a solid lubrication substrate.

This phenomenon is that the composition of PTFE resin and PFA resin of Example 1 is 44.5% by weight PTFE resin and 2.5% by weight PFA resin with respect to 50% by weight of distilled water, while the composition of PTFE and PFA resin of Comparative Example 2 is 48.70% by weight distilled water. Compared to 40% by weight of PTFE resin and 7.5% by weight of PFA resin, the 7.5% by weight of PFA resin added in Comparative Example contained 3 times as much as 2.5% by weight of PFA resin of Example 1, and the temperature of 300 ° C to 380 ° C. When hardening the fluororesin by heating and baking in an automatic electric furnace of a conveyor system maintained at 15 minutes, the PFA resin component having a low melting point melts quickly and adheres to the iron steel sheet and diffuses into PTFE resin, thereby increasing the degree of polymerization. Is considered to be contracted.

In the above description, the steel sheet used for the solid lubrication substrate may be any one selected from bronze plate, galvanized steel sheet, stainless steel sheet, 55% aluminum-zinc steel sheet to maintain the mechanical strength of PTFE resin and PFA resin. Among them, it was most preferable to use a 55% aluminum-zinc plated steel sheet.

In the above description, when the particle size (particle size) of PTFE resin PFA resin and natural graphite is larger than 0.50 µm, water dispersion is not uniform and some precipitates, which is undesirable, and the particle size of PTFE resin PFA resin and natural graphite is not preferable. If less than 0.15㎛, freezing emulsion polymerization is not well made, the freezing time is long, which is not preferable.

In the above description, when the content of the PTFE resin is more than 55.50% by weight, the solid lubricating polymer is not preferable due to the poor adhesion to the steel plate, and when the content of the PTFE resin is less than 44.5% by weight, the solid lubricating polymer is Although the adhesive force of is strong, cracking occurs in the solid lubricating polymer layer, which is not preferable. If the PFA resin is contained in an amount exceeding 2.50% by weight, the solid lubricating polymer has a strong adhesive force with the steel sheet but cracking occurs in the solid lubricant layer. If the PFA resin is less than 1.50% by weight, it is not preferable because the solid lubricating polymer has poor adhesion to the steel sheet.

In addition, when the content of the natural graphite powder is greater than 2.80% by weight, the lubricity is increased, but the content of other components is insufficient, which is not preferable. If the content of the natural graphite powder is less than 2.00% by weight, the lubricity is not preferable. If it contains more than 50% by weight, it is possible to uniformly disperse PTFE resin, PFA resin and natural graphite powder, but it takes a long time to prepare an oily substance of low polymerization degree by the freeze emulsion polymerization method in the freezing emulsion polymerization step. It is not preferable, and containing less than 39.70% by weight of distilled water is not preferable because it can not uniformly disperse PTFE resin, PFA resin and natural graphite powder.

If it contains more than 0.80% by weight of the nonionic dispersant, PTFE resin, PFA resin and natural graphite powder may be uniformly dispersed, but many bubbles are not preferable, and if less than 0.30% by weight of the nonionic dispersant, no bubbles are generated. However, PTFE resin, PFA resin and natural graphite powder cannot be uniformly dispersed, which is not preferable.

In the above description, when the particle size of the PTFA resin, PFA resin and natural graphite powder is larger than 0.50 µm, since the dispersion of water is not completely performed, some particles of the PTFA resin, PFA resin and natural graphite powder are precipitated, which is not preferable. When the particle size of the PTFA resin, PFA resin and natural graphite is less than 0.15㎛, the freezing emulsion polymerization is not performed well in the freezing emulsion polymerization step, so the freezing time is not long.

In addition, the extruded PTFE resin and PFA resin copolymer having a high viscosity of a rubbery semi-solid type having increased polymerization degree by evaporating water in the extrusion PTFE resin and PFA resin copolymer manufacturing step to a predetermined thickness on the upper surface of the steel sheet. The adhesion between the surface of the steel plate and the resin substrate was very large when the sheet was fixed and hardened by heating and baking for 15 to 25 minutes in a conveyor system maintained at a temperature of 300 ° C. to 380 ° C. in the solid lubrication substrate manufacturing step.

This phenomenon is because the melting point of the PTFE resin is 327 ° C, and the melting point of the PFA resin is 300-310 ° C, so that the PFA resin is melted before the PTFE resin and strongly adheres to the surface of the steel plate without changing the solid lubrication substrate.

Therefore, according to the present invention, the PTFE resin and PFA resin copolymer for injection can be strongly adhered to the surface of the metal sheet by sintering, and excellent in lubricity, abrasion resistance, heat resistance and chemical resistance, and a solid lubricant is conventionally applied to the surface of the metal sheet. It is not necessary to fuse the bronze powder by powder metallurgy to attach the bronze sintered layer on the surface of the metal plate, and to impregnate the PTFE resin polymer impregnated with the empty space of the metal net or the metal perforated plate. Since no perforated network is used, not only mass production can be easily performed, but also manufacturing cost can be greatly reduced.

In the above description, the specific embodiments have been shown and described, but the present invention is not limited thereto, for example, by those skilled in the art without departing from the concept of the present invention. Of course, the design can be changed in many ways.

Claims (3)

44.5 to 55.50 wt% of fine PTFE resin having a particle size of 0.15 to 0.50 μm, 1.5 to 2.50 wt% of fine PFA resin having a particle size of 0.15 to 0.50 μm, 2.0 to 2.8 wt% of fine natural graphite powder having a particle size of 0.15 to 0.50 μm, and distilled water 39.7 to 50.0% by weight of a nonionic dispersant and 0.3 to 0.80% by weight of a PTFE resin, PFA resin to prepare an alkaline mixed solution having a pH of 9.0 by uniformly dispersing and mixing the PTFE resin, PFA resin and natural graphite powder Natural graphite powder mixture preparation step; The PTFE resin, PFA resin, and natural graphite powder mixture prepared in the step of preparing the PTFE resin, PFA resin, and natural graphite powder mixture are refrigerated at 24 ° C. at -5 ° C. for 24 hours and then thawed again by a freeze emulsion polymerization method. Frozen emulsion polymerization step of producing water; Rubber-based semi-solid extrusion PTFE having an increased polymerization degree by evaporating water while heating the low-polymerization oil polymerized in the freezing emulsion polymerization step for 150 to 210 minutes in a water tank maintained at a temperature of 80 ℃ to 100 ℃ A step for producing an extruded PTFE resin and a PFA resin copolymer for producing a resin and a PFA resin copolymer; A compression roller heated to 100 ° C. to 140 ° C. by placing a rubbery semi-solid extrusion PTFE resin and PFA resin copolymer prepared in the step of manufacturing the extruded PTFE resin and PFA resin copolymer on a steel sheet having a thickness of 0.25 to 0.35 mm. By applying a pressure of 550 to 610 kg / cm 2 to compress and polymerize the fluororesin-based solid lubricant layer on the upper surface of the steel sheet to fix the fluororesin-based solid lubricant layer on the upper surface of the steel sheet. Steps; In the fixing step of the fluororesin-based solid lubricant layer, a conveyor on which a solid lubrication substrate on which a fluororesin-based solid lubricant layer of 0.15 to 0.25 mm thickness is fixed to an upper surface of a steel sheet of 0.25 to 0.35 mm thickness is maintained at a temperature of 300 ° C to 380 ° C. PTFE resin and PFA resin, comprising a solid lubrication substrate manufacturing step of curing the fluorine resin by heating and baking in an automatic electric furnace of the system to produce a solid lubrication substrate having fluorine resin attached to the steel sheet. Method for producing a copolymerized fluororesin solid lubrication substrate. The method of claim 1, wherein the steel sheet is PTFE resin, PFA resin copolymer fluorine characterized in that any one selected from bronze plate, galvanized steel sheet, stainless steel sheet, 55% aluminum-zinc steel sheet to maintain mechanical strength Method for producing a resin-based solid lubrication substrate. A PTFE resin / PFA resin copolymerized fluororesin-based solid lubrication substrate produced by the method of claim 1.