JPH047376A - Coating composition for sliding part - Google Patents

Abstract

PURPOSE:To obtain a coating composition for a sliding part which is improved in low frictional properties and abrasion resistance by compounding a polyphenylene sulfide resin, a polyether sulfone resin, a fluorocarbon polymer and lead fluoride. CONSTITUTION:100 parts, by weight, low molecular weight polyphenylene sulfide resin with an average particle size of 5mum or less is compound with 20-100 parts, by weight, polyether sulfone resin with an average particle size of 10mum or less, 10 to 100 parts, by weight, fluorocarbon polymer with an average particle size of 20mum or less and an average molecular weight of 50,000 or less (e.g. a tetrafluoroethylene-ethylene copolymer) and 20-50 parts, by weight, lead fluoride with an average particle size of 10mum or less.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] This invention relates to a coating composition for sliding parts used as a coating for sliding parts of industrial equipment.

[Conventional technology] In general, sliding parts such as sliding surfaces and sliding bearings in industrial equipment in the mechanical, chemical, electrical, food, space, and aviation industries have good low-friction properties and wear resistance even in the unlubricated state. Paints for sliding parts with good slip properties are used to maintain durability and heat resistance.

There are two types of paints for sliding parts. The first type includes tetrafluoroethylene resin (hereinafter abbreviated as PTFE), tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer (hereinafter abbreviated as PFA), and tetrafluoroethylene/hexafluoropropylene copolymer. Another fluoropolymer (hereinafter abbreviated as FEP) is dispersed in an organic solvent together with a binder resin. Examples of the binder resin include epoxy resin, phenol resin, polyamideimide resin, and polyimide resin. The first type, which contains such a binder resin, has good adhesion because the binder resin is biased toward the substrate due to the difference in surface roughness during firing, and the fluoropolymer moves toward the surface layer and is bonded to the substrate. Non-stick properties appear on the surface layer. This type does not require melting of the fluoropolymer during firing, and the firing temperature is the above-mentioned melting/hardening temperature of the binder resin (18
(about 0 to 250°C), processing is easy.

However, this first type of friction property and wear resistance is limited to 2 to 3 kgf/c in office equipment, etc.
Although it can withstand use under a low load of about 4, it cannot be said to be sufficient for use under a high load of 10 kgf/(-4 or more, such as in sliding parts for automobiles. Also, there is no binder resin on the surface layer. Because of the mixture, the excellent non-stick properties inherent to fluororesins could not be obtained.

To address these drawbacks, a method using polyphenylene sulfide resin (hereinafter abbreviated as PPS), which has excellent non-adhesive properties, is also known (Japanese Patent Laid-Open No. 57-90
No. 043, JP-A No. 57-90044), and those blended with PTFE are also known.

However, PPS had a glass transition point of about 100'C and was inferior in heat resistance. Also, a mixture of PPS and a polyether sulfide resin (hereinafter abbreviated as PES) having a glass transition point of 230°C is known, but the heat resistance is not satisfactory.

The second type is PTFE, PFA, FEP or tetrafluoroethylene-ethylene copolymer (hereinafter referred to as E
There are products in which TFE (abbreviated as TFE) is blended alone or with a filler into the above-mentioned fluoropolymer. This paint for sliding parts is used by applying a predetermined primer and heat-sealing it using the melting of the fluoropolymer in order to make it adhere to the underlying sliding part. Examples of use include frying pans, pots, knives, or scissors such as Silverstone (manufactured by DuPont).

The above-mentioned second type has excellent non-adhesiveness because the fluoropolymer forms a film on the surface layer.

However, it is inferior to the above-mentioned first type in wear resistance,
It could not be used as an industrial sliding material because it caused problems such as tearing and peeling.

[Problem to be solved by the invention]

As mentioned above, there is a problem in that a coating composition for sliding parts that has excellent low friction and wear resistance while having the good non-adhesive properties inherent to fluoropolymer in the surface layer has not been obtained. The challenge was to solve this problem.

[Means to solve the problem]

In order to solve the above problems, the present invention consists of 100 parts by weight of polyphenylene sulfide resin, 20 to 100 parts by weight of polyether sulfone resin, and 10 to 100 parts by weight of fluoropolymer.
A coating composition for sliding parts containing 100 parts by weight and 20 to 50 parts by weight as essential components is employed.

Furthermore, the above fluorine-based polymer is selected from the group consisting of tetrafluoroethylene/ethylene copolymer, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/hexafluoropropylene copolymer, and tetrafluoroethylene polymer. It is sufficient that the selected polymer has an IN or more, and the polyether sulfone resin, fluoropolymer, and fluoropolymer are fine particles having an average particle diameter of 1101r or less. The details will be described below.

PPS in this invention is not particularly limited, and is a polymer consisting of a repeating unit represented by the formula - as a main structural unit.

Since PPS is used after being uniformly dispersed in an organic solvent or water during spray painting, it is preferable to use a low molecular weight one with an average particle size of 5 nm or less. As a commercially available PPS that satisfies these conditions, it is desirable to use Rydon Sea 1 manufactured by Phillips Petroleum in the United States or the PPS oligomer described in U.S. Patent No. 4,046,749. Linear pps (for example, manufactured by Kureha Chemical Industry Co., Ltd.: KS
P), cross-linked PPS (for example, T-
4) may also be used.

Moreover, the polyether sulfone tree yJ in this invention
Fj (hereinafter abbreviated as PES) is not particularly limited, and is a non-grade thermoplastic resin consisting of repeating units shown as main structural units. Such PE
S preferably has an average particle size of 10 or less, and may be made into fine particles by a method such as freezing and pulverization. In addition, the blending ratio is 20 to 100 parts by weight of PPS.
The reason why it is set at 100 parts by weight is that if the amount is less than 20 parts by weight, the formed coating film will not have sufficient wear resistance, and if the amount is more than 100 parts by weight, the adhesion strength with the sliding base material will be weakened. This is because the wear resistance is inferior.

Further, the fluoropolymer in this invention includes PTFE,
Any one or more polymers selected from the group consisting of PFA, ETFE, and FEP may be used. The average molecular weight of the fluoropolymer is preferably 5000 or less, particularly preferably 5,000 to 30,000, in consideration of dispersibility during blending. Similarly,
The average particle diameter is preferably 20 or less, particularly preferably 5 to 10. Commercially available fluoropolymers that meet these conditions include the following. That is, P.T.
As FE, Lubricant L169 manufactured by Asahi Glass, TF9502 manufactured by Hoechst, Cepral Lube manufactured by Central Glass, and Aflon COP manufactured by Asahi Glass, PFA as ETFE.
Examples include MPIO manufactured by DuPont Mitsui Fluorochemical Company.

If the amount of thread polymer is less than 10 parts by weight, sufficient non-adhesion and sliding properties cannot be obtained, and if it is more than 100 parts by weight, the adhesion strength with the sliding base material will be weakened and the abrasion resistance will be poor. It is from. Examples of combined use of fluoropolymer include ET
Examples include FE and PTFE or PFA and PTFE.

The lead fluoride used in this invention may be a general industrial type having an average particle size of Ion or less in order to maintain the smoothness of the surface of the coating film formed. The blending ratio is 20 to 50 parts by weight based on 5100 parts by weight of PP. This is because if the amount is less than 20 parts by weight, the coating film will not have sufficient sliding properties.
This is because if the amount exceeds 50 layers, the adhesion strength with the sliding base material will be weakened and the wear resistance will be poor.

Additionally, commonly used additives may be added to the resin composition within a range that does not impair the purpose of the present invention.

Since each additive has a different specific gravity, the appropriate blending ratio of the additives is preferably 5 to 50 parts by volume, particularly preferably 15 to 35 parts by volume, based on 100 parts by volume of PPS. Typical additives are listed below.

Lubricant: graphite, molybdenum disulfide, reinforcing agent Niglass fiber, carbon fiber, boron fiber, silicon carbide fiber, carbon whisker, asbestos, metal fiber, rock wool, etc. Flame retardant: antimony oxide, magnesium carbonate, calcium carbonate, etc., electricity Characteristic improvers: clay, mica, etc., thermal conductivity improvers, diiron, zinc, aluminum, copper and other metal compounds, other fillers, glass beads, glass spheres, alumina,
To produce a composition containing talc, diatomaceous earth, hydrated alumina, shirasu balloon, zinc oxide, titanium oxide, and other metal oxides, natural or synthetic compounds that are stable at temperatures above 500°C, Disperse in water or organic solvent, pulverize with a magnetic ball, etc., and mix homogeneously. The thus obtained coating composition for sliding parts can be used for spray coating, fluid dipping, and static coating. Paint by painting, etc.

[Effect]

As described above, the coating composition for sliding parts of the present invention is
By using PPS, PES, fluoropolymer, and lead fluoride as essential components in the prescribed proportions,
The surface layer has the non-adhesive properties of a fluoropolymer to form a coating film with low friction and excellent abrasion resistance.

[Example] The raw materials used in Examples and Comparative Examples 1 to 4 are listed below.

■PPS (1-1 manufactured by Philips, USA) ■ETFE
(Near Floon cop manufactured by Asahi Glass Co., Ltd.) ■PFA (Mitsui,
Manufactured by DuPont Fluorochemical Company: Teflon PF＾mon P-1
0) ■FEP (manufactured by Mitsui DuPont Fluorochemical Company: Teflon 100) ■PTFE (manufactured by Hoechst Company: TF9205) ■Polyether sulfone resin (manufactured by IC1 Company: vICTREX)
5003P ) (P E S ) ■Lead fluoride (general reagent) ■Graphite (manufactured by Nippon Graphite Co., Ltd.: ACP) ■Surfactant (manufactured by Rohm & Hass Co., Ltd.: Nidrydon X100) [Phase] Propylene glycol (general reagent) Example 1 ~4: The above-mentioned organic powder, inorganic filler, surfactant, and solvent were added together in the composition shown in Table 1 to form a paint shown in Table 1. That is, assuming that PPS is 250 g, the entire amount of the composition of each example is placed in a 1.5 liter container, a large number of magnetic poles (205 m+ diameter or 25 ma+ diameter, 0.54 kg each) are mixed, and the rotation speed is adjusted. The composition was ground and mixed by rotating the magnetic ball at 8 rpm for 80 hours.

The composition ratios in Table 1 are expressed in parts by weight based on 5100 parts by weight of PP.

Spray the resulting paint into a ring shape with an outer diameter of 33 mm.
Spray on a 5UJ2 plate with an inner diameter of 6m and a length of 6m, 3
A smooth coating was obtained by baking at 70°C for 45 minutes. The *S wear characteristics, adhesion, surface hardness, non-adhesiveness, and heat resistance of this coating film were investigated using the following methods, and the obtained results were used in the second test.
They are summarized in the table.

(1) Friction test partner material: 5UJ2 inner diameter 17cm, outer diameter 21+m+,
A ring specimen with a length of 10cm is used, and the sliding speed is 12.0m.
/min, surface pressure 5. Thrust type open S under Okgf/cd conditions
The coefficient of dynamic friction was measured using a testing machine.

(2) A 5UJ2 ring specimen with an inner diameter of 17 m, an outer diameter of 21 aw, and a length of 10 mm was used as the wear test partner material, and the sliding speed was 1.0 m/
min, surface pressure 30. The amount of wear (■) after 50 hours was measured using a thrust type friction tester under the condition of okgf/cd.

(3) Adhesion test Make 10 rows of 1m11 square cross-cuts on the coating film.
A peel strength test was conducted using a pressure-sensitive adhesive tape. For example, the evaluation is 100 for crosscut.
When the a-eye peeled off, it was evaluated by displaying it as (100-a)/100.

(4) - Surface hardness test Using a pencil hardness tester, the occurrence of paint film scratch marks at a load of 500 g was evaluated by pencil hardness.

(5) Non-adhesion test When water was dropped onto the surface of the coating film, the contact angle at the boundary between the two was measured using a contact angle measuring device.

Comparative Examples 1 to 4: The above-mentioned organic powder, inorganic filler, surfactant, and solvent were charged at once in the composition shown in Table 1, and paints and coatings were formed in exactly the same manner as in Examples 1 to 4. Obtained. Furthermore, for comparison with Examples, the above-mentioned tests (1) to (6) were conducted, and the results are also listed in Table 2.

Comparative Example 5: PTFE heat fusion heat fusion type Primer a manufactured by Company A was sprayed onto a SUJ 2 plate with an outer diameter of 33 mm, an inner diameter of 6 IfiI11, and a length of 6 rIm at 100°C.
Primer b manufactured by the same company was separately sprayed thereon in the same manner, and dried at 100° C. for 10 minutes. Furthermore, a PTFE dispersion was sprayed as a top coat and baked at 370°C for 45 minutes.

Comparative Example 6: Using a spray gun, use a spray gun to apply a PFA-based thermal fusion type primer manufactured by Sales Company B with an outer diameter of 33s1 an inner diameter of 6IIIl11 and a length of 6wn.
It was sprayed onto a SUJ 2 plate, dried at 100°C for 10 minutes, and then a PFA-based dispersion was sprayed on top as a top coat, and baked at 350″C for 30 minutes.

Comparative Example 7: An enamel-type commercially available paint manufactured by Company C made of polyamideimide and PTFE was sprayed with an outer diameter of 33 mm and an inner diameter of 6 mm.
m, length 6W, sprayed on SUJ 2, 1 at 100°C.
It was dried for 0 minutes and then baked at 230°C for 45 minutes.

The above test (1) was applied to the coating films obtained in Comparative Examples 5 to 7.
- (6) were carried out, and the obtained results are also listed in Table 2.

As is clear from Table 2, Examples 1 to 4 made of PPS, PES, fluoropolymer, and lead fluoride had a low dynamic friction coefficient of 0.150 to 0.180, and a contact angle of 110. The non-adhesive nature of the fluoropolymer was sufficiently exhibited on the surface layer, and the amount of wear was less than 0.7 cm, showing extremely excellent abrasion resistance. Such characteristics were particularly remarkable in Example 2 in which PTEF and ETFE were used together.

However, Comparative Example 1 in which only 40 parts by weight of PES was blended with PPS. Comparative example 2 containing 30 parts by weight of PTEF, PTE
Comparative Example 3, which blended 30 parts by weight of F and 30 parts by weight of lead fluoride, and Comparative Example 4, which blended 30 parts by weight of PTEF and 40 parts by weight of PES, had better durability than Examples 1 to 4. The abrasion properties were poor, and in particular, Comparative Example 1 was also poor in non-adhesion properties. In addition, Comparative Example 5, which is a PTFE-based heat-sealing type, and Comparative Example 6, which is a PFA-based type,
Although they were excellent in non-adhesion, they were both inferior in abrasion resistance and surface hardness, and the base was exposed about 1 hour after the start of the abrasion loss test. Comparative Example 7, which was an enamel type in which binder resin and PTFE were mixed, had a high friction coefficient and was inferior in abrasion resistance and non-adhesion.

〔effect〕

As explained above, the coating composition for sliding parts of the present invention has the non-adhesive property inherent to the fluoropolymer in the surface layer, and is capable of producing a coating film that has low friction and excellent wear resistance. It exhibits far superior properties compared to conventional coating compositions, and is suitable as a coating for industrial sliding parts. Therefore, it can be said that the significance of this invention is extremely large.

Claims (3)

[Claims] (1) 100 parts by weight of polyphenylene sulfide resin,
20 to 100 parts by weight of polyether sulfone resin, 10 to 100 parts by weight of fluoropolymer, and 20 to 100 parts by weight of lead fluoride
A coating composition for sliding parts containing 50 parts by weight as an essential component. (2) The fluoropolymer is selected from the group consisting of tetrafluoroethylene/ethylene copolymer, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer, tetrafluoroethylene/hexafluoropropylene copolymer, and tetrafluoroethylene polymer The coating composition for sliding parts according to claim 1, which is one or more kinds of polymers. (3) The coating composition for sliding parts according to claim 1, wherein the polyether sulfone resin, the fluorine-based polymer, and the lead fluoride are fine particles with an average particle size of 10 μm or less.