WO2008029722A1

WO2008029722A1 - Wear-resistant low-friction-resistant electrodeposition coating film

Info

Publication number: WO2008029722A1
Application number: PCT/JP2007/066973
Authority: WO
Inventors: Fumitaka Yoshioka; Takuya Tsujimori
Original assignee: Okitsumo Incorporated
Priority date: 2006-09-04
Filing date: 2007-08-31
Publication date: 2008-03-13

Abstract

Disclosed is an electrodeposition coating material for forming a high-load-resistant lubricating coating film, which is obtained by dispersing a solid lubricant composed of a mixture of molybdenum disulfide (MoS2) and polytetrafluoroethylene (PTFE) having a weight ratio of from 5:95 to 70:30 into an electrodeposition coating material so that the weight ratio between the electrodeposition coating resin solid content to the solid lubricant is from 95:5 to 50:50. Also disclosed is a method for forming a lubricating coating film exhibiting wear resistance under high load conditions, which is characterized in that the electrodeposition coating material is electrodeposited on a base.

Description

Specification

Wear resistant low friction resistance electrodeposition coating

Technical field

[0001] The present invention relates to an improvement in the wear resistance of a lubricating electrodeposition coating film containing a fluororesin, particularly polytetrafluoroethylene (PTFE), under high load conditions.

Background art

[0002] Electrodeposition coating is a traditional method that includes electrostatic coating because it can be applied to an object with a complex shape with a uniform film thickness, and because it uses water-based paint, VOC can be reduced. It is popular instead of spray painting. On the other hand, fluororesins, especially PTFE, are known for their excellent adhesion and low heat resistance and low heat resistance. Using this characteristic of fluororesin, fine powder of fluororesin is dispersed in electrodeposition paint to form an electrodeposition coating with low friction resistance, and molybdenum disulfide (MoS), a solid lubricant, is applied to electrodeposition paint. )

2

It is known to form rubbing resistant coatings.

[0003] In the present invention, an electrodeposition paint for forming a paint film exhibiting high friction resistance and a paint film forming method using the electrodeposition paint are disclosed in JP-A-1 201373 (Patent Document 1). Kaihei 5-117556 (Patent Document 2), JP-A 2001-19897 (Patent Document 3), JP-A 2002-38078 (Patent Document 4), JP-A 2002-275393 (Patent Document 5) ), JP-A-2004-277565 (Patent Document 6), JP-A-6-287485 (Patent Document 7), JP-A-2005-154579 (Patent Document 8). You

[0004] Of these, Patent Documents 5 and 6 contain a layered inorganic compound such as an alkali metal titanate in addition to a fluororesin, and measure the static friction coefficient and wear resistance of the coating film using the same probe. is doing. However, for example, sliding parts of automobile parts as listed in Patent Document 7 are required to have wear resistance under a load condition much higher than the load applied to the probe for measuring the static friction coefficient.

[0005] In Patent Document 8, an electrodeposition paint is blended with a fluororesin fine powder and graphite, and this paint is electrodeposited on a card reader to improve card slip and antistatic performance. As a comparison An electrodeposition coating using molybdenum disulfide in combination with PTFE instead of Graphite is also disclosed. The 1S test is evaluated by the number of passes when a squeak (squeak) starts to occur when a card is passed through a card reader. However, under such test conditions, the load applied perpendicular to the card reader's card path is almost negligible.

[0006] Unlike card readers, automotive parts such as engine pistons, compressor pistons, intermediate shafts, steering joints, door hinges, window regulators, seat adjusters, seat belt brackets, and similar general machine parts and molds For example, a lubricious electrodeposition coating is required to have higher wear resistance under higher load conditions. Disclosure of the invention

[0007] The present invention relates to an electrodeposition coating material comprising molybdenum disulfide (MoS) and polytetrafluoroethylene (PTF).

2

E) The solid lubricant comprising a mixture having a weight ratio of 5:95 to 70:30 is adjusted so that the weight ratio of the electrodeposition coating resin solids to the solid lubricant is 95: 5 to 50:50. Dispersed electrodeposition paint for forming high-load-resistant lubricating coatings, and lubrication that exhibits wear resistance under high-load conditions characterized by electrodeposition-coating the electrodeposition paint on a substrate The present invention relates to a method for forming a conductive film.

[0008] Further, the present invention relates to molybdenum disulfide based on the resin solid content of a coating material comprising an alkyd resin.

An electrodeposition paint containing 2 wt% and a method for forming a lubricating film that exhibits wear resistance under high load conditions, characterized by electrodeposition coating the electrodeposition paint on a substrate about

[0009] Furthermore, the present invention relates to molybdenum disulfide (MoS) 2.5-33.3 wt% and polytetrafluoroethylene (PTFE) based on the resin solid content of a coating made of polybutadiene resin.

2

) 5.3-95. Lubricating film that exhibits wear resistance under high load conditions characterized by electrodeposition coating containing Owt% and electrodeposition coating of the electrodeposition coating on the substrate Relates to a method of forming the.

[0010] PTFE is the force S having the lowest friction coefficient among solid lubricants, the usable temperature is up to about 260 ° C, and the load resistance decreases at high temperatures. MoS is PT

2

Although it is inferior to FE, it is an inorganic material. The weight does not decrease. Therefore, the ratio of MoS to PTFE is critical when trying to obtain a coating film with a high load capacity with a friction coefficient as low as possible by using both together.

2

. It is also important that these solid lubricants are present in the coating film as much as possible. The present invention provides a ratio of MoS to PTFE that provides a good balance between a low coefficient of friction and load resistance.

2 Including PTFE and MoS at a ratio that provides a balanced coefficient of friction and load resistance.

2 Provide the electrodeposition coating film.

BEST MODE FOR CARRYING OUT THE INVENTION

[0011] The paint used in the present invention is composed of an electrodeposition paint which is a matrix of a solid lubricant and fine powders of PTFE and MoS as a solid lubricant added thereto. Electrodeposition paint and its coating method

2

Is well known in the paint field and does not itself constitute a part of the present invention, so a detailed description will not be necessary here. Electrodeposition paints are classified into anion type and cationic type, each containing a water-soluble or water-dispersible vehicle resin that is negatively or positively charged, and optionally a curing agent thereof. Since the electrodeposition paint serves as a matrix for the solid lubricant, it may be either an anion type or a cation type. In the present invention, the term “resin solids” refers to the total amount of this vehicle resin and, if present, the curing agent.

[0012] The paint generally contains conventional additive components! Examples thereof are coloring and anti-glare pigments, neutralizing agents, water-miscible organic solvents, surfactants and the like, but the electrodeposition coating used in the present invention can of course also contain these conventional additive components. .

[0013] PTFE and MoS are well known as solid lubricants and are commercially available. To paint

2

In view of the ease of dispersion, the average particle size is preferably in the range of 0.2 to 10 m.

[0014] As described above, there is a certain blend ratio between PTFE having a relatively low coefficient of friction and MoS having a relatively high load capacity, which satisfies a low coefficient of friction and load resistance. But

2

Exists. According to the present invention, in order to obtain a high-load-resistant lubricating coating, the electrodeposition paint is a solid made of a mixture of molybdenum disulfide and polytetrafluoroethylene having a weight ratio of 5: 95-70: 30. It is necessary to disperse the lubricant such that the weight ratio of the electrodeposition coating resin solids to the solid lubricant is 95: 5 to 50:50.

[0015] Further, according to the present invention, in the case of a coating material comprising an alkyd resin, the resin solid content is used as a reference. MoS 0.3 to 15 wt% and PTFE 3 to 23.8 wt%, more preferably MoS 3

twenty two

It is necessary to contain ˜7.5 wt% and PTFE 5.0 to 23.8 wt%. At that time, it is preferable that the total amount of both is adjusted within the range of 5.3 to 25 wt% of the solid content. In other words, in order to satisfy the high load resistance, MoS has a resin solid content of at least 0.3w.

2

t% or more is necessary, and in order to satisfy the low friction property, PTFE is required to be at least 3 wt% based on the solid content of the resin. However, if the total amount of these solid lubricants is too large, the dispersibility and the film-forming property are adversely affected. Therefore, it is preferable that the solid lubricant does not exceed 50 wt%, preferably 25 wt%. Graphite may be used in combination with PTFE and MoS in this range.

2

Yes

[0016] Further, according to the present invention, in the case of a paint made of a polybutadiene resin, based on the resin solid content, it contains MoS 2.5-33.3 wt% and PTFE 5.3-95.0 wt%. Even more preferred

2

Or MoS 4.3-31.4 wt% and PTFE 8. 8-90.0 wt%.

2

is there. At that time, the total amount of both is preferably adjusted within the range of 17.6 to 100 wt% of the solid content. In other words, in order to satisfy the high load resistance, MoS is a resin solid

At least 2.5 wt% of the two forms is necessary. To satisfy the low friction property, PTFE needs to be at least 5.3 wt% with respect to the solid content of the resin. However, if the total amount of these solid lubricants is too large, the dispersibility and film forming properties are adversely affected. In addition to this range of PTFE and MoS, graphite may be used in combination with paint made of alkyd resin.

2

[0017] The base material, that is, the object to be coated with the electrodeposition paint, is a mechanical part made of steel, a mold, or the like that requires surface lubricity. Electrodeposition coating of these substrates as a cathode in the case of a cationic electrodeposition coating, and an anode in the case of an anion electrodeposition coating can be performed to form the electrodeposition coating film of the present invention by washing with water and then heat-curing. The dry film thickness of the coating is generally 5-30 m.

Example

[0018] The following examples are illustrative of the invention and are not intended to be limiting. In these, “parts” and “%” are based on weight unless otherwise specified.

[0019] [Part I]

Example 1 Product name S-161—LP canyon type alkyd resin manufactured by Dainippon Ink & Chemicals, Inc. 10 parts MoS (12.5% solids) and 10 parts PTFE (solids) for 80 parts resin solids

2

12.5%) was added, and this was electrodeposited onto a blasted steel sheet to a dry coating thickness of 10 m, washed with water and heated at 230 ° C for 20 minutes to obtain a test coating.

[0020] Example 2

In Example 1, 6 parts MoS (7.5% solids) and 14 parts PTFE (17% solids)

2

5%), and a test coating film having a dry film thickness of 10 ΐη was obtained under the same conditions.

[0021] Example 3

In Example 1, 5 parts of MoS (5.6% based on solids) and 90 parts of resin solids and

2

And PTFE 5 parts (5.6% with respect to solid content), and electrodeposition was applied under the same conditions to obtain a test coating film with a dry film thickness of 10 ΐη.

[0022] Example 4

In Example 1, 3 parts of MoS (3.3% based on solid content) and 7 parts of PTFE (7.

2

8%) and electrodeposition was applied under the same conditions as in Example 1 to obtain a test coating film having a dry film thickness of 10.

[0023] Comparative Example 1

In Example 1, MoS was not added and PTFE was changed to 20 parts (25% of solid content).

2

Then, electrodeposition was applied under the same conditions as in Example 1 to obtain a test coating film having a dry film thickness of 10.

[0024] Comparative Example 2

In Example 1, 14 parts MoS (17.5% solids) and 6 parts PTFE (7.5% solids)

2

) And electrodeposited under the same conditions to obtain a test coated plate.

[0025] Comparative Example 3

In Example 1, 7 parts of MoS (7 · 8% solids) and 3 parts of PTFE (3 · 3% solids)

2

And electrodeposited under the same conditions to obtain a test coated plate with a dry film thickness of 10.

[0026] Measurement of coefficient of static friction

Using a surface testing machine equipped with a probe with a 5 mm diameter SUS304 ball attached to the tip (Tribogear type HEIDON 14FW manufactured by Shinto Kagaku Co., Ltd.), with a load of 1 kg (9 · 8 N), the ball is 600 mm / direction By sliding 10mm at a min speed, The static friction coefficient was measured. The results are shown in Table 1.

[0027] Wear test under high load conditions

Friction tester equipped with a probe with an outer diameter of 25.6 mm and a radial width of 2. 8 mm at the tip (SFWT—PD (RD) —SM5000—N2000— P5. 5 -OB150, manufactured by Shinko Engineering Co., Ltd.) (D300) —L1000—SS), rotating the ring in one direction at a load of 350 N and 3,500 N at a speed of 5 OOrpm, and wear resistance with the total number of revolutions until the film thickness reaches 50% of the initial value. Sex was evaluated. The results are shown in Table 2.

[0028] [Table 1]

[0029] [Table 2]

Generally, the coefficient of static friction is inversely proportional to the MoS / PTFE ratio, as shown in Tables 1 and 2.

2

However, the wear resistance tends to be directly proportional to MoS / PTFE. The resin has a MoS force of ¾ to the solid content of resin; 15wt%, when PTFE is in the range of 3 to 20wt%

2

The power that can be obtained. Also, the sum of MoS and PTFE for the resin solids at this time

2

It has been found that the amount is preferably in the range of 10-25 wt%.

[0031] [Part II]

Example 5

MoS fine powder and PTFE fine powder by weight 0/100, 5/95, 10/90, 30/70, 50 /

2

Mixing ratios of 50, 70/30, 90/10 and 100/0 were used to prepare various proportions of solid lubricant mixtures.

[0032] The product name S-161-LP made by Dainippon Ink & Chemicals, Inc., the weight ratio of resin solids to solid lubricant is 95/5, 90/10, 80/20, Each lubricant mixture was added to 70/30 and 60/40, and this paint was electrodeposited onto a steel plate degreased with a solvent to a dry film thickness of 10, then washed with water and baked at 230 ° C for 20 minutes. A test coating film was obtained.

[0033] Example 6

The solid lubricant mixture prepared in Example 5 was added to an anion type polybutadiene resin having a trade name of BN-1015 manufactured by Nippon Soda Co., Ltd., and the weight ratio of the resin solid content to the solid lubricant was 95/5, 90/10, Each f-sliding IJ mixture was added to 85/15, 80/20, 70/30, 60/40, and 50/50, and this coating was applied to a steel plate that had been degreased with a solvent. Electrodeposition coating was applied to m, washed with water and baked at 230 ° C for 20 minutes to obtain a test coating film.

[0034] In Examples 5 and 6, the weight ratio of paint resin solids, MoS, and PTFE is shown in Table 3.

2

It is shown.

[0035] [Table 3] Paint distribution ^

Note) 1. νΖΡ ·· 'Resin solid lubricant (Mo S ₂ + PTFE)

2. M / F '-' Mo S ₂ / PTFE

[0036] Metaphysical examination

Using a surface tester equipped with a probe with a 5 mm diameter SUS304 ball attached to the tip (Tribogear type HEIDON 14FW manufactured by Shinto Kagaku Co., Ltd.), with a load of 1 kg (9.8 N), the ball is 3000 mm / direction The test machine was set in advance so that it would stop automatically when the static friction coefficient of the test coating reached 0.4 by reciprocating a distance of 10 mm at a speed of min (50 mm / s). The durability of the friction resistance was evaluated by the number of back and forth sliding until the static friction coefficient reached 0.4. The results are shown in Table 4 for Example 5 and Table 5 for Example 6.

[0037] Table 6 shows the blending ratio (wt%) of MoS to the resin.

2

From the test results in Table 4 and Table 5, the area where the number of sliding is 1800 times or more with the alkyd resin base of Example 5 is shown in a bold line frame, and the number of sliding times with the polybutadiene resin base of Example 6 is ¾200 times or more. The area is indicated by a dotted line. Table 7 shows the blending ratio (wt%) of PTFE with respect to the resin. In addition, as in Table 6, the alkyd resin base of Example 5 has a sliding frequency of 1800 times or more. The region is indicated by a bold frame, and the region where the number of sliding is 3200 times or more based on the polybutadiene resin base of Example 6 is indicated by a dotted line.

[0038] [Table 4] Number of sliding with alkyd resin base of Example 5 (times)

1.? '''Resin solid lubricant (Mo S ₂ + PTFE)

3. Inside the bold frame · · 'The area where the number of sliding is 1800 times or more

[0039] [Table 5] Number of sliding on the polybutadiene resin base of Example 6 (times)

3. In the dotted frame · ■ 'Area where the number of sliding is 3200 times or more

[0040] [Table 6] Mixing ratio of Mo S _{2 to} resin (wt%)

Note) 1. V / Ρ ··· Resin Z solid lubricant (Mo S ₂ + PTFE)

2. M / F --- MO S no PTFE

3. Inside the thick line frame ··· The region where the sliding frequency is 1800 times or more with the alkyd resin base of Example 5 4. Within the dotted line frame ··· The sliding frequency is 3200 times with the polybutadiene resin base of Example 6 The above areas ■

[Table 7] Blending ratio of PTFE to resin (wt%)

Note) 1. /? , Resin Solid lubricant (MoS ₂ + PTFE)

3. Inside the thick frame ··· The alkyd resin base of Example 5 is the area where the number of sliding is 1800 times or more

4. Inside the dotted frame '··························································· Based on the polybutadiene resin base of Example 6, the number of sliding is 3200 times or more

From Table 6 and Table 7, it can be seen that in order to obtain a desired high-load-resistant lubricating coating even in the case of electrodeposition coatings based on alkyd resin and / or polybutadiene resin! With MoS? Ding? A solid lubricant with a weight ratio of 5:95 to 70:30

2

The weight ratio between the coating resin solids and the solid lubricant (MoS + PTFE) is 95: 5 to 50: 5

2

It was found that it was effective to disperse to 0.

[0043] In addition, considering the types of resins used as the base material for electrodeposition paints, Table 4 and Tables 6 and 7 show that the alkyd resin base has a high friction resistance of 1800 times or more. Show MoS and

The blending ratio of the solid lubricant consisting of 2 and PTFE is 0.3 to 1 for MoS with respect to the resin solid content.

2

2. Solid lubricant with 5 wt% range, PTFE within 4.7-73.8 wt% range (refer to the bold line frame) and higher friction resistance with more than 2000 sliding times The blending ratio is within the range of 0.3 to 7.5 wt% of MoS with respect to the resin solids.

2

PTFE force. 0-23. It was found to be in the range of 8 wt%. In addition, the total amount of MoS and PTFE with respect to the resin solids at this time should be adjusted within the range of 5.3-12.5 wt%.

2

Are preferred (see Table 4).

Therefore, considering the above results in light of the results of Part I, the blending ratio of the solid lubricant exhibiting high friction resistance based on the alkyd resin is 0. 3 ~; 15wt% is preferred, PTFE is preferably 3 ~ 23.8wt%

2

More preferably, the MoS force is in the range of ¾ to 7.5 wt% and the PTFE is in the range of 4.7-73.8 wt%.

2

It is to adjust within the range. Also, the combination of MoS and PTFE for the resin solids at this time

2

The metering is preferably adjusted within the range of 5.3 to 25 wt%.

[0045] Further, from Table 5, Table 6, and Table 7, the blending ratio of the solid lubricant composed of MoS and PTFE, which is based on polybutadiene resin and exhibits high friction resistance of 3200 times or more, is the resin

2

MoS force with respect to solid content in the range of 5-33.3 wt%, PTFE is 5.3-95.0 wt%

2

The blending ratio of the solid lubricant that is within the range (refer to the one-dot chain line frame) and has a higher friction resistance of 5800 times or more of sliding is such that MoS is 4.3 to 21. 4w

2

in the range of t%,

PTFE force was found to be in the range of 8-90. The total amount of MoS and PTFE with respect to the resin solids at this time should be adjusted within the range of 17.6 to 100 wt%.

2

Are preferred (see Table 5).

Claims

The scope of the claims

[I] The weight ratio of molybdenum disulfide to polytetrafluoroethylene in the electrodeposition paint is 5: 95-70:

Forming a high-load-resistant lubricating coating film by dispersing a solid lubricant consisting of 30 mixtures so that the weight ratio of the electrodeposition coating resin solids to the solid lubricant is 95: 5 to 50:50 Electrodeposition paint.

[2] The electrodeposition paint according to claim 1, wherein the resin is an electrodepositable alkyd resin.

3. The electrodeposition paint according to claim 1, wherein the resin is an electrodepositable polybutadiene resin.

[4] Forming a lubricating coating film that exhibits wear resistance under high load conditions, characterized in that the electrodeposition coating composition according to any one of claims 1 to 3 is electrodeposited onto a substrate. Method.

[5] Based on the resin solid content of a coating made of alkyd resin, an electrodeposition coating containing 0.3 to 15 wt% molybdenum disulfide and 3 to 23.8 wt% polytetrafluoroethylene is applied to the substrate. A method of forming a lubricating coating film that exhibits wear resistance under high load conditions, characterized by electrodeposition coating.

6. The electrodeposition paint contains 3 to 7.5 wt% molybdenum disulfide and 5.0 to 23.8 wt% molybdenum disulfide, based on the resin solid content of the paint. the method of.

7. The method according to claim 5, wherein the total amount of molybdenum disulfide and polytetrafluoroethylene is 5.3 to 25 wt% with respect to the resin solid content of the coating material comprising the alkyd resin.

[8] Based on the resin solid content of coatings made of alkyd resin, high load resistance moisture is obtained by adding 0.3-15 wt% molybdenum disulfide and 3-23.8 wt% polytetrafluoroethylene. Electrodeposition paint for slip film formation.

[9] The electrodeposition coating composition contains 3 to 7.5 wt% of molybdenum disulfide and 5.0 to 23.8 wt% of polytetrafluoroethylene based on the resin solid content of the coating material. Electrodeposition coating.

[10] The electrodeposition coating material according to claim 8, wherein the total amount of molybdenum disulfide and polytetrafluoroethylene is 5 to 25 wt% with respect to the resin solid content of the coating material comprising the alkyd resin.

[II] Based on the electrodeposited paint containing 2.5 to 33.3 wt% of molybdenum disulfide and 5.3 to 95. Owt% of molybdenum disulfide, based on the resin solid content of the paint made of polybutadiene resin. Moisture that exhibits wear resistance under high load conditions characterized by electrodeposition coating on materials A method of forming a lubricious coating film.

[12] The electrodeposition paint contains molybdenum disulfide 4.3 to 21.4 wt% and polytetrafluoroethylene 8.8—90. Owt%, based on the resin solid content of the paint. The method of claim 11.

13. The method according to claim 11, wherein the total amount of molybdenum disulfide and polytetrafluoroethylene is 17.6 to 100 wt% with respect to the resin solid content of the coating made of polybutadiene resin.

[14] Molybdenum disulfide 2.5 based on the resin solid content of paints made of polybutadiene resin

-33.3 wt% and polytetrafluoroethylene 5.3 3-95. Electrodeposition paint for forming high-load-resistant lubricating coatings with the addition of Owt%.

[15] The electrodeposition paint contains molybdenum disulfide 4.3 to 21.4 wt% and polytetrafluoroethylene 8.8—90. Owt%, based on the resin solid content of the paint. The electrodeposition paint according to claim 14.

16. The electrodeposition coating material according to claim 14, wherein the total amount of molybdenum disulfide and polytetrafluoroethylene is 17.6 to 100 wt% with respect to the resin solid content of the coating material comprising a polybutadiene resin.