JPS6386764A - Coating composition for lubrication - Google Patents

Abstract

PURPOSE:To obtain the titled composition capable of forming a thick lubricating film having improved appearance, adhesivity, impact resistance, etc., on metals, etc., by one coating and low-temperature baking, containing a thermosetting resin solid at normal temperature and a solid lubricant in a specific ratio. CONSTITUTION:The aimed composition containing (A) 20-95wt% thermosetting resin (e.g. acrylic resin, epoxy resin, polyester resin, etc.) solid at normal temperature and (B) 5-80wt% solid lubricant (preferably molybdenum disulfide, tungsten disulfide, graphite, boron nitride, graphite fluoride, mica, metallic powder, metallic oxide, metallic soap or polytetrafluoroethylene).

Description

Detailed Description of the Invention C. Industrial Field of Application The present invention relates to a lubricating coating composition that is applied to the surface of metal etc. to form a continuous film with lubricating properties, especially a thermosetting powder type lubricating composition. The present invention relates to coating compositions.

[Conventional technology]

Conventionally, as a lubricating coating composition that is applied to the surface of metal etc. to form a continuous film with lubricating properties, for example, JP-A-53-1
As shown in Japanese Patent No. 67735, solid lubricants and tetrafluoroethylene resins are dispersed in a solvent solution of polyarylate resin, and for example, "Painting Technology J1
As shown on pages 106 to 113 of the January issue of 1983, a powder type coating material made of powder of a fluororesin such as a copolymer of tetrafluoroethylene and ethylene is known.

[Problem that the invention seeks to solve]

However, when a solid lubricant and a tetrafluoroethylene resin are dispersed in a solvent-soluble resin solution as disclosed in JP-A No. 53-67735, a coating that can be applied in one coat is produced. The maximum thickness is about 60 μm, and if you try to apply a film with a thickness greater than that, there are problems such as sagging during coating and formation of wrinkles or foaming during heating. Furthermore, ``It is possible to apply a thick film with powder-type paints made of fluororesin powder, such as those disclosed in the January 19g3 issue of Painting Technology J, but in order to form a film, fluorine It is necessary to heat the resin to a temperature higher than the melting point of the resin, consuming a large amount of thermal energy, and there is also the problem of poor adhesion when directly applied to metal etc. without forming a primer.

The present invention aims to obtain a lubricating coating composition that can form a thick lubricating film at a relatively low temperature and has excellent adhesion even when applied directly to a substrate without a primer. .

[Means for solving problems]

The present invention is a thermosetting resin that is solid at room temperature in an amount of 20 to 95% by weight.
, and a solid lubricant in an amount of 5 to 80% by weight.

The thermosetting resin used in the lubricating coating composition of the present invention is a resin composition containing a common thermosetting polymer or copolymer that is solid at room temperature, and a curing agent, each of which contains 1 The species may be used alone or in combination of two or more species.

1 as a thermosetting polymer or copolymer that is solid at room temperature
Examples include acrylic resin, epoxy resin, and polyester resin.

Examples of curing agents include isophorone diisocyanate, tolylene diisocyanate, and
xylylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, etc.
ε-caprolactam.

Blocked isocyanate compounds that are solid at room temperature, such as blocked incyanate groups with phenol or benzyl alcohol; or polybasic acids that are solid at room temperature, such as sebacic acid and dodecanoic acid; trimellitic anhydride, pyromellitic anhydride, etc. Examples include solid acid anhydrides; amines that are solid at room temperature such as dicyandiamide; and glycidyl compounds such as triglycidyl isocyanurate.

Examples of solid lubricants used in the lubricating coating composition of the present invention include molybdenum disulfide; tungsten disulfide;
Graphite (graphite); boron nitride; graphite fluoride; mica; metal powders such as lead powder and copper powder; -metal oxides such as lead oxide; metal soaps such as calcium stearate and aluminum stearate; PTFE (polytetrafluoride); ethylene)
These can be used singly or in combination of two or more.

The amount of solid lubricant contained in the lubricating coating composition of the present invention is required to be 5 to 80% by weight.

If the amount of solid lubricant is less than 5% by weight, sufficient lubricity cannot be achieved, and if it exceeds 80% by weight, a smooth coating cannot be obtained unless heated to a high temperature above the melting point of the solid lubricant.

The lubricating coating composition of the present invention contains the above-mentioned thermosetting resin and solid lubricant as essential components.

If necessary, other components such as extender pigments, coloring pigments, and additives (for example, rust preventives, ultraviolet absorbers, leveling agents, anti-armpit agents, etc.) may be contained.

The lubricating coating composition of the present invention is a composition containing these components and is made into a powdered product. Powder particle size is 1-30
A value of about 0μ is preferable.

The method for producing the lubricating coating composition of the present invention is as follows.

It can be obtained by simply mixing the thermosetting resin powder, which is solid at room temperature, and the solid lubricant powder by triblending, but in order to obtain a uniform coating, it is preferable to heat the mixture after mixing, and to crush it after cooling. , in this case, if necessary, the above extender pigment,
Color pigments, additives, etc. can be added.

The lubricating coating composition produced as described above is in powder form and can be coated as is by conventional powder coating methods such as electrostatic coating and fluidized dip coating. The lubricating coating composition can be applied directly onto the material, or after surface treatment, or over a primer coating.

Since the lubricating coating composition of the present invention contains a resin that is solid at room temperature, it does not harden before application, but it hardens to form a lubricating film by baking (heat hardening) after application. Baking temperature and time vary depending on the type of resin and hardening agent, but generally it is 60 minutes to 30 minutes at 160 to 250 degrees Celsius.
It is about seconds.

The lubricating coating composition of the present invention can be widely used as a coating composition for metals and other base materials used as sliding members.

〔Effect of the invention〕

Since the lubricating coating composition of the present invention contains a thermosetting resin and a solid lubricant that are solid at room temperature, it is possible to form a thick lubricating coating with one coating and baking at a relatively low temperature. It is possible, and the resulting coating has excellent coating appearance, adhesion, impact resistance, sliding properties, etc.

〔Example〕

The present invention will be explained below with reference to Examples and Comparative Examples. In addition, "1 part" and "1%" in the examples are all based on weight.

Example 1 79.2 parts of acrylic resin (Aromatex PD-7210, trade name, manufactured by Mitsui Toatsu Chemical Co., Ltd., melting point 90°C),
8.0 parts of PTFE (FLL!ON Li2Q, trade name, manufactured by ICI, melting point 320°C), 2.0 parts of carbon black (Raben 420, trade name, manufactured by Columbia Carbon), dodecanedioic acid (curing agent) , melting point 130
°C) and 2.4 parts of epoxy resin l (Epicote #1002, trade name, manufactured by Yuka Shell Epoxy Co., Ltd., melting point 83 °C) in a mixer (Henschel mixer, trade name, Mitsui Kakoki ( After tri-blending for about 1 minute using an extrusion kneader (Busco Kneader PR-46, trade name, manufactured by Buss Co., Ltd.) at a temperature of 80 to 100°C, after cooling, a hammer type The mixture was pulverized using an impact pulverizer and filtered through a 150-mesh sieve to obtain a powdered lubricating coating composition having a particle weight of 104 μm or less.

The obtained lubricating coating composition was applied to a steel plate (0.8 m +++
70 x 150 mm) using an electrostatic powder coating machine (Model 720, manufactured by Gema Co., Ltd.) (dry film thickness: 40 μm) and baked at 190° C. for 20 minutes in a hot air circulating oven to obtain a test piece.

Examples 2 to 5 Each component shown in Table 1 was mixed, crossed, and mixed in the same manner as in Example 1.
A powdered lubricating coating composition was obtained by pulverization and filtration, and Example 1
A test piece was obtained by painting in the same manner as above.

Comparative Example 1 Acrylic resin (Aromatex PD-7210.Product name,
(manufactured by Mitsui Toatsu Chemical Co., Ltd.) 83.6 parts, molybdenum disulfide (Moly Powder PA, trade name, manufactured by Sumiko Lubricant Co., Ltd.)
3.0 parts of dodecanedioic acid (curing agent), 11.0 parts of epoxy resin I (Epicote #1002, trade name, manufactured by Yuka Shell Epoxy Co., Ltd.) 2.4 parts were mixed in the same manner as in Example 1, and mixed. , pulverized and filtered to obtain a powdered lubricating coating composition. The obtained lubricating coating composition was coated in the same manner as in Example 1 to obtain a test piece.

Comparative Example 2 12.2 parts of polyester resin (ER-6610, trade name, manufactured by Nippon Ester Co., Ltd.), 2.3 parts of blocked isocyanate compound (curing agent, B-1065, trade name, manufactured by Hüls), epoxy Resin work (Epicoat t100
2. Mix, knead, and pulverize 85 parts of graphite (CPF-6, product name, manufactured by Shinetsu Graphite Industry Co., Ltd.) with m>o and s parts manufactured by Yuka Shell Epoxy Co., Ltd. in the same manner as in Example 1. and filtered to obtain a powdered lubricating coating composition.

The obtained lubricating coating composition was coated on a treated steel plate in the same manner as in Example 1 so that the dry film thickness was about 40 μm, and the test piece was obtained by baking at 190°C for 20 minutes in a hot air circulating oven. The resulting coating had irregularities that reached the substrate, had countless holes, lacked uniformity, and could not be used as a lubricating coating.

Comparative Example 3 10.4 parts of polyarylate resin was added to 71.44 parts of methylene chloride.
10.71 parts of tetrafluoroethylene resin and 3.57 parts of graphite powder were added to and mixed with the polyarylate-methylene chloride solution obtained by dissolving 71 parts of polyarylate, and then paraffin wax (melting point 55-65°C) 3.57 parts was added. The mixture was stirred and mixed at room temperature, and then air sprayed onto the same treated steel plate as in Example 1 (dry film thickness: 40 μm) and dried at 20° C. for 24 hours to obtain a test piece.

Comparative Example 4 Fluororesin powder type paint (Neoflon FEP NC-
1519, trade name, manufactured by Daikin Industries, Ltd., tetrafluoroethylene-hexafluoropropylene copolymer) was electrostatically applied to a treated steel plate in the same manner as in Example 1 (dry film thickness: 40 μm) L.

A test piece was obtained by baking at 300° C. for 15 minutes in a hot air circulating oven.

Test Example The coating compositions and test pieces obtained in Examples 1 to 5 and Comparative Examples 1 to 4 were tested according to the following test methods to determine coating appearance, adhesion, impact resistance, coating thickness limit, and sliding property. The results of the (average coefficient of friction) test are shown in Table 2.

Test method It outside the coating film: Visual judgment adhesion: Based on JIS 54006.15 (substrate eye test).

The number of squares remaining when 0100 squares were cut at 1 mm intervals using an NT cutter, cellophane tape was applied, and the cellophane tape was peeled off (relative to 100).

Impact resistance: DuPont impact test (radius 6.35
mm firing type, load 500 g Limit coating film thickness: In Examples 1 to 5 and Comparative Examples 1 to 2, a mild steel plate of 8 mm x 10 tstm x 150 mm preheated to 220°C was stood vertically.

Examples 1-5. The powdered lubricating coating compositions of Comparative Examples 1 and 2 were each applied using an electrostatic coating machine.

Furthermore, it was heated to 190℃ in a hot air circulation oven while standing vertically.

Baking was carried out for 30 minutes, and the maximum film thickness without sagging, wrinkles, foaming, etc. was measured.

In comparative example 3, 8mm x 70+*m x 150m
A +g mild steel plate was stood vertically, and the liquid lubricating coating composition of Comparative Example 3 was applied with air spray, and the plate was placed vertically for 2 hours.
It was dried at 0° C. for 24 hours and evaluated in the same way.

In Comparative Example 4, 8a+m x 70 preheated to 330°C
A mild steel plate of +sm x 150m5+ was stood vertically, coated with the powdered lubricating coating composition of Comparative Example 4 using an electrostatic coating machine, and then heated at 300°C in a hot air circulation furnace while standing vertically.
.

Baking was performed for 25 minutes and the same evaluation was performed.

Sliding properties (average coefficient of friction): FED-5TD (American Federal Standard) 791B Dry Coated Lubricant Wear Life Test (FED-5TD791B) for each coating composition.
), a test piece was prepared and a continuous test was performed for 60 minutes under a constant load of 100 pounds, and the average coefficient of friction was determined from the coefficient of friction over time during that time. Data are average values of two measurements.

As is clear from Table 2, Examples 1 to 5 of the present invention are:
It is possible to apply a thick film in one coat, and it has excellent coating appearance, adhesion, and impact resistance, and has a small average coefficient of friction.
Sliding properties are also good.

On the other hand, in Comparative Example 1 in which the solid lubricant was less than 5% by weight,
Comparative Example 2, which had poor sliding properties and contained more than 80% by weight of the solid lubricant, did not provide a smooth coating.
Comparative Example 3 based on the prior art of Publication No. 735 has a small coating film thickness, and Comparative Example 4 using a powder type paint made of fluororesin according to the prior art shown in "Coating Technology" has a small coating thickness. High baking temperature when forming, good adhesion and ms resistance
It also has poor elasticity and sliding properties.

Claims (3)

[Claims] (1) A lubricating coating composition characterized by containing 20 to 95% by weight of a thermosetting resin that is solid at room temperature and 5 to 80% by weight of a solid lubricant. (2) The lubricating coating composition according to claim 1, wherein the thermosetting resin is a resin composition containing a thermosetting polymer or copolymer that is solid at room temperature, and a curing agent. (3) Claim 1 in which the solid lubricant is molybdenum disulfide, tungsten disulfide, graphite, boron nitride, graphite fluoride, mica, metal powder, metal oxide, metal soap, or polytetrafluoroethylene. The lubricating coating composition according to item 1 or 2.