JP2012111815A - Resin composition for dry lubrication coat film formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composite for dry lubrication coat film formation which can form a dry lubrication coat film having excellent durability against repeated friction and high adhesion while exhibiting superior sliding characteristics without requiring heat treatment at a high temperature.SOLUTION: The resin composition used for forming a dry lubrication coat film on a metal surface comprises: a normal temperature-drying resin for coat film formation, such as a fluororesin; a powdery filler; an organic solvent; and an additive. The resin composite contains 5-50 wt.% of the normal temperature-drying resin, 0.1-5 wt.% of an inorganic-based powdery filler, and 0.1-1 wt.% of an organic-based powdery filler based on the total amount of the composition.

Description

  The present invention relates to a resin composition for forming a dry lubricating film suitable for low friction sliding, and more specifically, can form a film without heat treatment in a high temperature region, and is excellent in durability and suitable for low friction sliding. The present invention relates to a resin composition for forming a dry lubricating film.

  When two members make relative motion while slidably contacting each other, high lubricity is required between the members from the viewpoint of wear resistance, low friction, and the like. The degree of lubricity varies depending on the type of equipment, the usage environment, the surface condition of the sliding member, and the like. For example, in machinery and the like, lubricating oil or grease is often used as a lubricant between the sliding members. . However, depending on the usage environment, there may be cases where lubricating oil, grease, etc. cannot be used, or sufficient sliding characteristics may not be obtained by themselves.

  Therefore, in order to ensure and improve the sliding characteristics between the sliding members even in the case of the use environment as described above, a lubricating film made of a solid lubricant may be provided on the surface of the sliding members. Generally done widely. However, it is difficult to make the solid lubricant adhere to the surface of the member alone. For this reason, the lubricating coating is usually formed by bringing a solid lubricant into close contact with the surface of the member with a binder resin.

  For example, in parts that require lubricity, such as electronic materials, precision equipment, automobiles, and office equipment, it is widely practiced to form a dry lubricating film by applying a lubricating paint to the surface. For the formation of such a dry lubricating film, a solid lubricant such as molybdenum disulfide, PTFE (polytetrafluoroethylene), graphite, or boron nitride is used in a solution of a thermosetting resin such as an epoxy resin or a polyamideimide resin. A paint in which fine particles are dispersed is used.

  Specifically, Patent Document 1 contains 50 to 73% by weight of at least one of polyamideimide and polyimide as a binder resin, 3 to 15% by weight of PTFE as a solid lubricant, and 20 to 30% by weight of molybdenum disulfide. And a sliding resin composition in which graphite is added in a total amount of 27 to 50% by weight in the range of 2 to 8% by weight. Patent Document 2 discloses a coating composition for iron-based products having an excellent lubricity consisting of 45 to 65% by weight of an epoxy resin as a binder resin, 2 to 20% by weight of a rust preventive pigment, and 2 to 20% by weight of PTFE. Has been.

  However, since the composition for forming a dry lubricating film uses a thermosetting resin as a binder resin, it must be heat-treated in a high temperature region of about 200 ° C. or higher in order to form a dry lubricating film. Use is limited due to problems such as a decrease in hardness and cost increase in the material of the member at high temperature firing. Moreover, the dry lubricating film obtained has a problem that durability due to repeated friction is not sufficient.

Japanese Patent No. 3017626 JP 2003-160756 A

  The present invention has been made in view of the above-described problems of the prior art, and can form a dry lubricating film without the need for heat treatment in a high temperature region, and can provide a sliding property such as wear resistance and a low friction coefficient. An object of the present invention is to provide a resin composition for forming a dry lubricating film, which is excellent in dynamic characteristics and capable of forming a dry lubricating film excellent in durability against repeated friction and adhesion.

  In order to achieve the above object, a dry lubricating film forming resin composition provided by the present invention is a resin composition used for forming a dry lubricating film on a metal surface, and is a room temperature drying type film forming resin and powder. 5 to 50% by mass of a room temperature dry resin, 0.1 to 5% by mass of an inorganic powder filler, and 0.1 to 1% based on the total amount of the composition. It contains an organic powder filler of mass%.

  According to the present invention, a dry lubricating film having a low coefficient of friction, excellent sliding characteristics such as wear resistance, and excellent durability and adhesion to repeated friction can be obtained without requiring heat treatment in a high temperature region. Can be formed easily. In addition, by reducing the friction coefficient of the dry lubricating coating, it is possible to improve efficiency by reducing various losses, and to expect the effect of suppressing the temperature rise and noise from the sliding portion due to heat generation. Therefore, the resin composition for forming a dry lubricating film of the present invention is optimal for a sliding member of equipment used under severe sliding conditions.

  The dry lubricating film forming resin composition according to the present invention basically includes a room temperature drying type film forming resin, two kinds of powder fillers, an inorganic powder filler and an organic powder filler, and an organic solvent. And additives. Here, the room temperature drying type film forming resin is a resin that forms a film and holds various fillers in the film (also referred to as a binder resin). It means one that solidifies only by drying (generally about 10 to 35 ° C.).

  The room temperature dry resin is a component that is a main component of the coating film that holds the inorganic filler and the organic filler on the surface of the metal member. For example, a fluororesin, an acrylic urethane resin, a ketone resin, an acrylic resin, a petroleum resin, a urethane resin, or a polyester resin can be suitably used as the room temperature dry resin. In particular, fluororesins are particularly preferred because they have good solvent solubility and filler dispersibility, high adhesion to the metal surface, and excellent sliding properties. Among them, fluoroethylene / vinyl ether alternating copolymer fluororesins are preferred. It is particularly preferred to use it.

  The blending amount of the room temperature dry resin is 5 to 50% by mass with respect to the total amount of the composition. When the blending amount of the room temperature dry resin is less than 5% by weight, the dispersion stability of the powder filler is lowered. On the other hand, if the blending amount exceeds 50% by mass, the liquid viscosity becomes high, so that the leveling property at the time of application is lowered and the low friction property is hindered.

  The powder filler contributes to the reduction of the friction coefficient and the development of excellent wear resistance, and is used in combination of two kinds of inorganic powder filler and organic powder filler. The powder filler is preferably an inorganic or organic type or a fine particle having an average particle size of 0.5 to 30 μm, although it varies depending on the production method. This is because if the average particle size of the powdery filler is less than 0.5 μm, the wear resistance is deteriorated, whereas if it exceeds 30 μm, the coated surface becomes rough and the lubricity tends to be hindered.

As the inorganic powder filler, zinc oxide, silicone, molybdenum, graphite, mica, diamond, talc, boron nitride, titanium oxide, or the like can be used. In particular, silicone powder is excellent in terms of sliding characteristics. As a specific example of the silicone powder, there is a true sphere having an average particle diameter of 2 μm made of polymethylsilsesquioxane (CH ₃ SiO ₁₅ ), which is excellent in wear resistance and lubricity.

  Examples of the organic powder filler include nylon, PTFE, urethane, polyethylene, and acrylic. Among these, nylon powder and polyethylene powder are preferable from the viewpoint of sliding properties. Specific examples of nylon powder include true spheres with an average particle diameter of 5 μm, and specific examples of polyethylene powder include ultra-high molecular weight polyethylene powder with an average particle diameter of 30 μm, both wear resistance and lubrication. Excellent in properties.

  The compounding quantity of the said inorganic type powder-form filler shall be 0.1-5 mass% with respect to the composition whole quantity. If the blending amount of the inorganic powder filler is less than 0.1% by mass, the friction coefficient of the dry lubricating film will be insufficient, and conversely if it exceeds 1% by mass, the wear resistance will be reduced. Moreover, the compounding quantity of the said organic type powdery filler shall be 0.1-1.0 mass% with respect to the composition whole quantity. If the blending amount of the organic powder filler is less than 0.1% by mass, the dry lubricating coating will not be sufficiently reduced in friction coefficient. Conversely, if it exceeds 1.0% by mass, the wear resistance will be reduced.

  By combining the inorganic powder filler and the organic powder filler, the characteristics of both can be utilized, and a resin composition having required performance in accordance with the purpose can be obtained by changing the blending amount of both. For example, if the blending amount of the inorganic powder filler is increased, the lubricity tends to be improved. Conversely, if the blending amount of the organic powder filler is increased, the wear resistance tends to be improved. Therefore, by adjusting the blending amount of both, a composition having the required performance according to the purpose can be obtained.

  The dry lubricating film forming resin composition of the present invention contains, in addition to the above-described components, an organic solvent for dissolving the film forming resin and various additives usually used in the field. . As the organic solvent, dimethyl carbonate, propylene glycol monomethyl ether, or the like can be suitably used. As the additive, a surfactant, a reaggregation inhibitor, a wetting and dispersing agent, a leveling agent, an antisettling agent, and the like can be used depending on purposes such as dispersibility, paintability, and film quality improvement. In particular, when a surfactant or a reaggregation inhibitor is added, it is preferable to add any of them in the range of 0.1 to 5% by mass with respect to the total amount of the composition.

  The dry lubricating film of the resin composition of the present invention can be formed by the same method as that for ordinary lubricating paints. That is, after performing a pretreatment on the surface of the metal material to be a base material by a known method according to the material and purpose, after applying a resin composition by a method such as spraying, printing, dipping, tumbling, A dry lubricating film can be obtained by drying at room temperature for 10 minutes or more. When the applied resin composition is dried, it is not necessary to positively heat it, but when shortening the drying time, it is preferable to dry in a heating atmosphere up to about 50 ° C.

[Example 1]
10% by mass of fluororesin (fluoroethylene / vinyl ether alternating copolymer) as a resin for forming a film at room temperature drying type, 2% by mass of fine silicone powder as an inorganic powder filler, and fine nylon powder 0 as an organic powder filler Add 2.5 wt% each of wetting and dispersing agents, leveling agents, and anti-settling agents as additives, and add 80.2 wt% of dimethyl carbonate as a solvent, and thoroughly stir and disperse each component. Thus, the resin composition of Example 1 was produced.

  About the obtained resin composition of Example 1, the lubricating performance was evaluated using a surface property test apparatus. The surface property test is a test method for evaluating the friction characteristics in a point contact with a ball and a plate-shaped test piece. A plate-shaped test piece having a thickness of 70 × 0.8 mm was used. The setting conditions of the surface property test were a sliding speed of 1200 mm / min, a sliding distance of 100 mm, a load of 1 kgf, and the moving method was single acting, and the static friction coefficient and the average dynamic friction coefficient were measured.

  Specifically, the resin composition of Example 1 was coated on a plate-shaped test piece by air spray at room temperature, and dried at room temperature for about 15 minutes to form a dry lubricating film. With respect to the dry lubricating film of the obtained test piece, the lubricating performance was evaluated by the above surface property test apparatus. As a result, the static friction coefficient was 0.08 and the average dynamic friction coefficient was 0.06.

[Example 2]
10% by mass of fluororesin (alternate copolymer of fluoroethylene and vinyl ether) as a resin for forming a film at room temperature drying type, 2% by mass of fine particle silicone powder as an inorganic powder filler, and ultrahigh molecular weight polyethylene as an organic powder filler Wet dispersant, leveling agent and anti-settling agent are added to 0.3% by mass of powder, and 2.5% by mass of dimethyl carbonate is added as a solvent, and the components are fully dispersed. Thus, the resin composition of Example 2 was produced.

  The obtained resin composition of Example 2 was coated on a plate-shaped test piece by air spray at room temperature and dried at room temperature for about 15 minutes to form a dry lubricating film. About the dry lubricating film of the obtained test piece, as a result of evaluating the lubricating performance with a surface property test apparatus in the same manner as in Example 1, the static friction coefficient was 0.09 and the average dynamic friction coefficient was 0.07.

[Comparative Example 1]
10% by mass of fluororesin (fluoroethylene / vinyl ether alternating copolymer) as a room temperature drying type film-forming resin, 8% by mass of fine particle silicone powder as an inorganic powder filler, and 2% of nylon powder as an organic powder filler %, 5% by weight each of a wetting and dispersing agent, a leveling agent, and an anti-settling agent are added as additives, and 65% by weight of dimethyl carbonate is further added as a solvent to sufficiently disperse each component, and the resin composition of Comparative Example 1 Was made.

  The obtained resin composition of Comparative Example 1 was coated on a plate-shaped test piece by air spray at room temperature and dried at room temperature for about 15 minutes to form a dry lubricating film. About the dry lubricating film of the obtained test piece, as a result of evaluating the lubricating performance with a surface property test apparatus in the same manner as in Example 1, the static friction coefficient was 0.14 and the average dynamic friction coefficient was 0.09.

[Comparative Example 2]
As a resin composition for forming a dry lubricating film, a commercially available Molycoat D321R (trade name) manufactured by Toray Dow Corning Co., Ltd. was used. This resin composition is an aerosol product in which constituent components include titanate resin as a resin, molybdenum disulfide and graphite as a solid lubricant, and DME gas is blended in a propellant.

  This resin composition was spray-coated on a plate-shaped test piece at room temperature, and dried at room temperature for about 15 minutes to form a dry lubricating film. About the dry lubricating film of the obtained test piece, as a result of evaluating the lubricating performance with a surface property test apparatus in the same manner as in Example 1, the static friction coefficient was 0.28 and the average dynamic friction coefficient was 0.20.

[Comparative Example 3]
As a resin composition for forming a dry lubricating film, a commercially available New TFE coat spray (trade name) manufactured by Fine Chemical Japan Co., Ltd. was used. This resin composition is an aerosol product in which constituent components include a cellulose-based resin as a resin, PTFE as a solid lubricant, toluene and IPA as a solvent, and DME gas is blended in a propellant.

  This resin composition was spray-coated on a plate-shaped test piece at room temperature, and dried at room temperature for about 15 minutes to form a dry lubricating film. About the dry lubricating film of the obtained test piece, as a result of evaluating the lubricating performance using a surface property test apparatus in the same manner as in Example 1, the static friction coefficient was 0.11 and the average dynamic friction coefficient was 0.09.

  As can be seen from the evaluation results of the lubricating performance of the examples and comparative examples described above, the static friction coefficient and the average friction coefficient of the dry lubricating film by the resin compositions of Examples 1 and 2 show lower values than those of the comparative examples, In particular, the resin composition of Example 1 shows the smallest values of both the static friction coefficient and the average friction coefficient. Therefore, by using the resin composition of the present invention, it is possible to easily form a dry lubricating film having excellent durability against repeated friction and adhesion and suitable for low friction sliding at room temperature.

Claims (5)

  A resin composition used for forming a dry lubricating film on a metal surface, comprising a room temperature drying type film forming resin, a powdery filler, an organic solvent and an additive, and 5 to 50 mass based on the total amount of the composition % Dry resin, 0.1-5 mass% inorganic powder filler, and 0.1-1 mass% organic powder filler, characterized in that Composition.   2. The room temperature drying type film forming resin is at least one selected from a fluororesin, an acrylic urethane resin, a ketone resin, an acrylic resin, a petroleum resin, a urethane resin, and a polyester resin. A resin composition for forming a dry lubricating film as described in 1.   The inorganic powder filler is at least one selected from zinc oxide, silicone, molybdenum, graphite, mica, diamond, talc, boron nitride, and titanium oxide, according to claim 1 or 2. A resin composition for forming a dry lubricating film.   The resin composition for forming a dry lubricating film according to any one of claims 1 to 3, wherein the organic powder filler is at least one selected from nylon, PTFE, urethane, polyethylene, and acrylic. object.   5. The resin composition for forming a dry lubricating film according to claim 1, wherein an average particle size of the powder filler is 0.5 to 30 μm.