JPS5829973B2 - wear resistant paint - Google Patents

Description

[Detailed description of the invention] The present invention relates to wear-resistant paints.

In recent years, tetrafluoroethylene resin, nylon, polycarbonate, polyacecool, polyimide, polyphenylene sulfide resin, and the like have been increasingly used as lubricant-free sliding bearing materials alone or in composite compositions with the addition of auxiliary agents.

All of these are based on the good sliding properties of plastics, or the wear resistance of plastics is generally inferior to that of metals, so plastic bearings have a shorter lifespan than metal bearings. Thus, it can also be used f,
It has the disadvantage that the range of KPV values is very narrow.

That is, since the life of a bearing is determined by its wear resistance, there is a strong desire for plastics that have excellent wear resistance and sliding properties.

In addition, plastic bearings are broadly classified into plastic molded products and plastic coated metal products, but plastic molded products have inferior load bearing capacity and poor dissipation of frictional heat compared to metal bearings. Plastic-coated products made of metal are desired because they have the disadvantage of higher cost because they require more raw materials than plastic-coated products.

However, since plastic coatings have a thin film thickness and the amount of additives added is limited, no satisfactory product has been manufactured yet, and there is a strong need for coatings with excellent abrasion resistance. ing.

An object of the present invention is to provide a wear-resistant coating material that is particularly suitable as a plastic bearing material and has significantly superior wear resistance and good slip properties.

Therefore, the wear-resistant paint of the present invention is made of perfluoroalkoxy (hereinafter referred to as PFA).

) Polyimide (hereinafter referred to as PI) is added to a dispersion of resin powder dispersed in an organic solvent.

) or polyimide amide (hereinafter referred to as PIA).

) in an organic solvent, PFA resin powder 100%
The main component of the coating film is a mixture obtained by adding and mixing less than 50 parts by weight and 400 parts by weight of PI or PIA to parts by weight.

PFA resin is polytetrafluoroethylene F (’j-)＋ F Perfluoroalkoxy group -Rf in the main chain of is combined with the structural formula ftl It is thought to have the structure shown below.

It is obtained by polymerizing a tetrafluoroethylene-perfluorovinyl ether copolymer resin, a type of PFA resin, hydrofluoroethylene CF2-CF2 and perfluorovinyl ether CF3.CF2.CF2.0-CF-CF2.

Polymerization is perfluorocarbon or 0 (J!3F,
This is carried out by solution polymerization using fluorocarbons such as CI (CJ?F2) as a solvent, or by emulsion polymerization or suspension polymerization in water or water to which fluorocarbons are added.

As an initiator, a Freon-soluble organic peroxide or a water-soluble peroxide such as ammonium persulfate is used.

A dispersion obtained by dispersing PFA resin powder in an organic solvent is
A solution obtained by dissolving I or PIA in an organic solvent is added and mixed, and the organic solvent is preferably dimethylformamide, toluene, xylene, or a mixture thereof.

Incidentally, when an organic solvent is roughly mixed into a mixture of PFA resin powder and PI or PIA, the properties of the resulting coating film are poor.

Examples of methods for adding and mixing a PI or PIA solution to a dispersion of PFA resin powder include stirring mixing method, tumbler mixing method, shaking mixing method, ultrasonic mixing method, ball mill mixing method, roller mill mixing method, and stone mill mixing method. It is also possible to use a method of collapsing.

In addition, when using a spherical PFA resin powder, it is preferable to mix it in such a way that the spherical shape of the PFA resin powder is maintained.

Pigments, fillers, etc. may be added to the wear-resistant paint of the present invention, if desired.

Examples of materials to be coated with the wear-resistant paint of the present invention include metals such as iron, steel, stainless steel, aluminum, and aluminum-coated steel, glass, and ceramics.

The wear-resistant paint of the present invention can be coated, dried, and baked by a conventional method.

The coating film obtained from the abrasion-resistant paint of the present invention has outstanding abrasion resistance and good slip properties, as well as excellent adhesion to the object to be coated and corrosion resistance.
It has many advantages such as being able to obtain a coating film with a thickness of ~150μ.

Next, the present invention will be explained using Examples, Reference Examples, and Comparative Examples.

Parts indicate parts by weight. Examples 1-2, Reference Examples 1-8 and Comparative Examples 1-2 Preparation of paint PFA resin powder (manufactured by Mitsui Fluorochemical Co., Ltd. (MP
-10, tetrafluoroethylene-perfluorovinyl ether copolymer resin powder, average particle size 35μ, sphericity 1
．． 05) A dispersion obtained by dispersing 100 parts in 40 parts of a 4:6 weight ratio mixture of dimethylformamide and toluene is referred to as Solution A.

Next, PIA (Hitachi Chemical Co., Ltd. HI-600) 30
A solution obtained by mixing 3 parts of carbon black and 8 parts of red iron oxide, and adding and mixing 28 parts of dimethylformamide, 42 parts of toluene, and 0.1 part of a nonionic surfactant is designated as Solution B.

At the time of use, the above-mentioned liquids A and B are added and mixed in required amounts to obtain a paint.

A stirring mixer was used for mixing. Formation of coating film: 90min×
Spray paint on a 60mm x 1mm aluminum plate to a coating thickness of 100μ and dry at 350° in SO'C.
C. for 20 minutes and then allowed to cool at room temperature.

The properties of Examples t to 2, Reference Examples 1 to 8, and Comparative Examples 1 to 2 are shown in the coating film properties below.

The specific wear amount was measured using a thrust type wear tester under the following conditions.

Compatible material: 5us304 (+500 abrasive paper finish) Surface pressure: 5.1% Sliding speed: 30m/min Peel strength is determined by making a cut in the coating film that reaches the object to be coated with a width of 5 mm.
It is expressed as the peel strength (g) when one end of the coating film is peeled off and pulled in the perpendicular direction.

From the table below, it can be seen that the coating film obtained from the abrasion-resistant paint of the present invention has significantly excellent abrasion resistance and also has significantly excellent adhesion to the object to be coated.

In addition, when the dynamic friction coefficient of the coating film of Reference Example 6 was measured using a thrust type abrasion tester under the following conditions, it was found to be 0.2.
A value of 25 was obtained.

Surface pressure: 5.1% Sliding speed: 30 m/min Compatible material: 5US304 (-#=500 abrasive paper finish) From the above dynamic friction coefficient without lubrication, it can be seen that the wear-resistant paint of the present invention has good sliding properties.

As a polytetrafluoroethylene resin paint, EK-1883GB Polyflon Primer manufactured by Daikin Industries KK was spray-painted on a blasted 90mm x 60mm x 1m door aluminum plate, dried at 800C, baked at 380C for 20 minutes, and left at room temperature. After cooling, polyfront tube enamel EK-4183
GB paint was spray painted and dried and baked in the same way as the primer.

Repeat painting, drying, and baking the top enamel 5 times.
A film thickness of 00μ or more was obtained.

The specific wear amount of the coating film thus obtained was measured in the same manner as in Examples 1 to 2 and Reference Examples 1 to 8, and the values are shown in the above coating film property table.

Comparative Example 4 Polyphenylene sulfide resin paint, Zylan 8610 paint made by Whitsford Co., USA, was spray-painted on a blast-treated 90 mm x 60 g x 1 mm aluminum plate, dried at 80°C, and then heated at 380°C for 30 minutes.
Baking was carried out for 5 minutes to obtain a coating thickness of 50μ.

The specific wear amount of the coating film thus obtained was measured in the same manner as in Examples 1 to 2 and Reference Examples 1 to 8, and the values are shown in the above coating film property table.

Claims (1)

[Claims] 1. An organic solvent solution of polyimide or polyimide amide is added to an organic solvent dispersion of perfluoroalkoxy resin powder in an amount of more than 50 parts by weight and less than 400 parts by weight of polyimide or polyimide amide per 100 parts by weight of perfluoroalkoxy resin powder. A wear-resistant paint characterized by having as its main component a mixture obtained by adding and mixing the same proportions.