JPS6112791A - Grease containing solid lubricant - Google Patents

Abstract

PURPOSE:The titled grease, obtained by incorporating a lubricant consisting of a melamine (iso)cyanuric acid adduct, etc., in a specific amount in a grease, and having improved load resistance, lubrication performance, e.g. abrasion resistance and abrasion coefficient. CONSTITUTION:A grease obtained by incorporating (A)100pts.wt. grease with (B)1-20pts.wt. solid lubricant containing (i)100pts.wt. melamine (iso)cyanuric acid adduct and (ii)5-1,000pts.wt. substance selected from polytetrafluoroethylene, molybdenum disulfide and molybdenum dithiocarbomate. EFFECT:Capable of exhibiting improved lubrication performance when used for hard metal, particularly steel based metal, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to provide a solid lubricant-containing grease with excellent lubricating performance such as load carrying capacity, wear resistance and/or wear coefficient, particularly for hard metals such as copper metals. It is an object of the present invention to provide a solid lubricant-containing grease that exhibits excellent lubrication performance when used in the following applications.

In recent years, as industrial machinery and equipment have become more efficient, more efficient, and smaller and lighter, the performance required of lubricants used in them has become increasingly strict. For example, the requirements for lubrication performance of grease, such as longer running times, improved heat resistance, improved load resistance, and lower coefficient of friction, are becoming increasingly severe.

Adducts of melamine and noanuric acid, and adducts of melamine and isocyanuric acid (herein, these meat adducts are referred to as "melamine (iso)cyanuric acid adducts").

Collectively called. ) is known as a solid lubricant, and grease containing it shows excellent lubrication performance for soft metals such as copper-based metals, but it has poor lubricating performance for hard metals such as copper-based metals. Melamine (yne) cyanuric acid adduct 25
Unless it is blended in a large amount, such as % by weight or more, a sufficient lubricating effect cannot be exhibited, especially under load. However, greases containing 25% or more of melamine (iso)cyanuric acid adducts have low consistency and poor fluidity, making it difficult to supply the grease to sliding parts using an air gun. Become.

On the other hand, since polytetrafluoroethylene-containing grease is white in color, it is generally used in sliding parts in low-load areas and in places where dirt is averse.

However, this has poor lubricating properties such as load resistance, making it difficult to use particularly in high load ranges. Greases containing molybdenum disulfide or molybdenum dithiocarbamate are used under extremely harsh conditions that involve slipping, rolling, and vibration under high loads. Solid lubricants generally have the disadvantage of being expensive.

In order to obtain an economical grease that exhibits excellent lubrication performance, especially for hard metals such as copper-based metals, the inventors of the present invention have developed a melamine (iso)cyanuric acid adduct. and a solid lubricant selected from the group consisting of polytetrafluoroethylene, molybdenum disulfide and molybdenum dithiocarbamate.
I learned that if the two solid lubricants are contained in a specific ratio, the purpose can be achieved through the synergistic action of both solid lubricants.
This has led to the present invention.

That is, the solid lubricant-containing grease of the present invention contains 1'-20 parts by weight of a solid lubricant per 100 parts by weight of the grease, and the solid lubricant contains 100 parts by weight of a melamine(yne)cyanuric acid adduct. 5 to 1 solid lubricant selected from the group consisting of polytetrafluoroethylene, molybdenum disulfide, and molybdenum dithiocarbamate.
It is characterized in that it is used in combination with a fine of 000 parts by weight.

The melamine (ino)cyanuric acid adduct used in the present invention is a compound obtained by reacting melamine with cyanuric acid or incyanuric acid.

It is usually a white powder with a particle size of 0.1 to 1 μm.

The mefumi/(yn)cyanuric acid adduct is, for example, a melamine aqueous solution and cyanuric acid or incyanuric acid, and hereinafter both may be collectively referred to as "(iso)cyanuric acid." ), it will easily precipitate out as a white precipitate.

Furthermore, melamine (iso)cyanuric acid adducts can also be easily obtained by reacting with one or both of melamine and cyanuric acid dispersed as a solid phase in water. Melamine (iso)cyanuric acid adduct (an adduct of 1 mole of melamine and 1 mole of isocyanuric acid is a chemically stable compound with a sublimation temperature of approximately 440°C measured by differential thermal analysis (for details) , Japanese Patent Publication No. 54-141
(See Publication No. 792).

Polyfluoroethylene, molybdenum disulfide, and molybdenum dithiocarbamate used in the present invention are all already known as solid lubricants and are easily available as commercial products. Below, these three types of solid lubricants used in the present invention may be collectively referred to as "other solid lubricants" to distinguish them from the melamine (iso)cyanuric acid adduct.

The grease containing the solid lubricant in the present invention is not particularly limited, and may include various greases obtained from various base oils, thickeners, antioxidants, etc.
Any grease to which various additives such as extreme pressure agents, rust preventives, dispersants, etc. are added can be used in the present invention.

Examples of the base oil for the grease include mineral oil, olefin polymerized oil, alkylated aromatic oil, polyalkylene oxide polymerized oil, polyether oil, diester oil of basic acid or dibasic acid, silicone oil, and various other synthetic oils. etc. can be mentioned.

Thickeners added to these base oils to maintain their grease properties include soap-type thickeners using metal soaps such as calcium soap, sodium soap, lithium soap, calcium complex soap, and aluminum complex soap. Agents: Inorganic non-climbable thickeners using organically modified bentonite, silica gel, etc.; Organic non-climbable thickeners such as polyurea, sodium terephthalamate, etc. Furthermore, other additives that impart various properties to the grease include, for example, oil-based agents, extreme pressure agents, antioxidants, rust inhibitors, and adhesives.

The solid lubricant-containing grease of the present invention is a grease containing melamine and another solid lubricant in combination in a specific ratio, as described above. That is, in the present invention, the solid lubricant contained in the grease contains a melamine (iso)cyanuric acid adduct and another solid lubricant.
The latter is used in combination at a ratio of 5 to 1000 parts by weight per 100 parts by weight of the former. The reason why both solid lubricants are used together in such a specific ratio is that only when used together in such a specific ratio, both solid lubricants synergistically improve the grease properties, especially the grease against hard metals such as steel. It is possible to improve at least one of the lubrication performance such as load carrying capacity, wear resistance, and low friction when used as a solid lubricant. This is because such an effect of improving lubrication performance cannot be obtained even if the agent is used in combination.

Melamine (iso)cyanuric acid adducts and other solid lubricants exhibit an excellent lubrication performance improvement effect on grease when used in combination in the specific proportions mentioned above, but the lubrication performance can be improved depending on the proportions in which they are used. Depending on the type of other solid lubricants, there are thousands of differences (discrepancies) in performance as shown below.

That is, (1) polytetrafluoroethylene is used in an amount of 5 to 5 parts by weight per 100 parts by weight of the melamine (iso)cyanuric acid adduct.
Within the range of 1000 parts by weight, wear resistance and load carrying capacity can be improved compared to when using a solid lubricant alone,
Particularly resistant to seizure (seizure) within the range of 10 to 300 parts by weight.
The loadability can be improved, and within the range of 100 to 1000 parts by weight, the coefficient of friction can be effectively reduced. 2 Still, (2) molybdenum disulfide is used in an amount of 5 to 100 parts by weight per 100 parts by weight of the melamine (iso)cyanuric acid adduct.
The friction coefficient can be effectively lowered within the range of 30 to 1000 parts by weight, and the
Load performance can be improved.

Furthermore, (3) molybdenum dithiocarbamate is 5 parts by weight per 100 parts by weight of the melamine (iso)cyanuric acid adduct.
The friction coefficient can be effectively reduced within the range of ~1000 parts by weight, the load resistance (seizure) can be improved within the range of 30 to 1000 parts by weight, and the friction coefficient can be improved within the range of 30 to 1000 parts by weight.
Abrasion resistance can be improved within a range of approximately 10 parts by weight.

Next, the solid lubricant-containing grease of the present invention contains 1 to 20 parts by weight, preferably 3 to 15 parts by weight of the solid lubricant (total solid lubricant) used in the above-mentioned specific ratio based on 100 parts by weight of the grease. It is contained in the proportion of parts by weight. If the content of the solid lubricant is too small, sufficient lubrication performance (particularly lubrication performance during long-term repeated use at high speed and medium to low load areas) cannot be improved; if it is too large, the lubrication performance cannot be improved accordingly. Either the effectiveness cannot be expected to increase, or the grease consistency becomes too high (poor fluidity), resulting in negative effects.

The solid lubricant-containing grease of the present invention may further contain various additives other than the above-mentioned components, if necessary. For example, a surfactant or a surface treatment agent may be added for the purpose of increasing the dispersibility of the solid lubricant. Examples of surfactants and surface treatment agents include anionic, cationic, nonionic, and amphoteric surfactants, metal soaps such as sodium stearate and zinc stearate, fatty acid esters, fatty acid amides, higher alcohols, Examples include oils and fats. These additives are 2
Combination use of more than one species is also possible.

The method for preparing the solid lubricant-containing grease of the present invention is not particularly limited, and various methods can be used. for example,
The above-mentioned essential components and each component to be blended as necessary may be mixed in advance and thoroughly kneaded using a kneader such as a three-roll kneader, or the above-mentioned components may be added sequentially as appropriate. Alternatively, the mixture may be prepared by thoroughly kneading it using a mixer such as a three-roll mixer. What is important in this case is to uniformly disperse the solid lubricant in the grease.

As mentioned above, the solid lubricant-containing grease of the present invention is significantly improved in at least one of the lubricating properties such as load carrying capacity, wear resistance, and friction coefficient. It can be advantageously used as a lubricant for various machines and devices suitable for this purpose.

In general, lubricant performance is determined by, for example, friction conditions (e.g. speed, load, travel distance, etc.), contact shape length (e.g. point,
line, surface, area ratio, etc.), friction type (e.g. roller,
Under comprehensive conditions that combine various conditions such as sliding, rolling, one-way, reciprocating, etc., material combinations, and atmosphere (e.g. air, hot water, water, vacuum, etc.), It is evaluated by conducting performance tests such as properties (for example, seizure load resistance), wear resistance (for example, wear amount, specific wear rate, etc.), friction properties (for example, friction coefficient), and the shape of the friction surface. If a lubricant exhibits excellent lubricating performance in any of these performance tests, the lubricant can be effectively used for purposes appropriate to its performance and has industrial value.

Note that isocyanuric acid and cyanuric acid are isomers of each other, and the cyanuric acid that is usually commercially available is a keto-type isocyanuric acid. Moreover, the melamine cyanuric acid adduct that is generally commercially available is a melamine isocyanuric acid adduct.

Next, the present invention will be explained in further detail by giving Examples and Comparative Examples.

Example 1 Commercially available polytetrafluoroethylene powder with an average particle size of 3.5 microns was mixed in various ratios shown in Table 1 to 100 parts by weight of a melamine isocyanuric acid adduct with an average particle size of 2 microns and a sublimation temperature of about 440°C. and mixed uniformly using a ball mill. Each of the obtained mixtures was added to 100 parts by weight of lithium soap grease for rolling bearings (JISK 22201 class No. 2), 6 parts by weight each, and thoroughly kneaded with three rolls to be uniformly dispersed in the grease.

Each of the obtained solid lubricant-containing greases was subjected to various tests such as seizure load, acceptable limit load, and wear using an improved Farex and a four-ball tester. Steel specimens were used for both test machines. The test results were as shown in Table 2.

Comparative Examples 1 to 3 For comparison, 6 parts by weight of melamine isocyanuric acid adduct alone (Comparative Example 1) or 6 parts by weight of polytetrafluoroethylene powder alone was added to 100 parts by weight of the same grease used in Example 1. (Comparative Example 2) were mixed together and thoroughly kneaded using three rolls.

The same tests as in Example 1 were conducted on each of the obtained greases and only the grease used in Example 1 (Comparative Example 3). The test results are shown in Table 2 and were 9.

Table 1 Notes to Table 2: (1) The following test pieces were used (the same applies to the following tables).

Farex test piece: ■-Block Al5I-1137 steel rotating pin
S A E-3135 steel Soda type test piece: JIS B 1501 steel balls for ball bearings (2) for both rotating and fixed balls (2) Passing limit load means that no seizure occurs when exposed to the same load for 20 minutes. (The same applies to the table below).

Further, each of the greases obtained in Example 1 (Jikkenya 1) and Comparative Examples 1 to 3 was tested for the relationship between the load oil pressure and the coefficient of friction using a four-ball tester. The results were as shown in Figure 1.

As is clear from the results shown in Table 2 and FIG. 1, the grease containing only melamine isocyanuric acid adduct and polytetrafluoroethylene adduct), the grease of Comparative Example 2 (grease containing only polytetrafluoroethylene), Compared to the grease of Comparative Example 3 (grease only), it has excellent properties such as seizure load, abrasion resistance, and coefficient of friction.
It can be seen that the melamine incyanuric acid adduct and polytetrafluoroethylene have an excellent synergistic effect.

Example 2 Melamine isocyanuric acid adduct 1 with an average particle size of 2 microns
Molybdenum disulfide (MoS2) powder having an average particle size of 0.5 microns was prepared at each ratio shown in Table 3, and mixed uniformly with a ball mill.

Each of the obtained solid lubricant mixtures was mixed into a lithium soap grease for rolling bearings (JIS K22201 Type No. 2) 100
6 parts by weight of each were added to each part by weight and thoroughly kneaded with three rolls to uniformly disperse them in the grease.

Each of the obtained greases was subjected to the same test as in Example 1, and the results are shown in Table 4.

Comparative Example 4 For comparison, 6 parts by weight of molybdenum disulfide powder alone was added to 100 parts by weight of the same grease used in Example 2, and a grease was produced in the same manner as in Example 2 except for the following. Grease performance was tested.

The results were as shown in Table 4. Note that Table 4 also lists the test results of Comparative Example 1 and Comparative Example 3.

Table 3 Examples, Example 2 (Experimental Plane 2), Comparative Example 1, Comparative Example 3
For each of the greases obtained in Comparative Example 4, the relationship between oil pressure and friction coefficient was tested using an export type four-ball tester. The results were as shown in Figure 2.

As is clear from the results shown in Table 4 and FIG. blended grease)
, Grease of Comparative Example 3 (grease only), and Comparative Example 4
Compared to the grease (grease containing only molybdenum disulfide), it is superior in terms of seizure load and coefficient of friction, and it can be seen that the melamine isocyanuric acid adduct and molybdenum disulfide have an excellent synergistic effect.

Example 3 Based on 100 parts by weight of the ramine isocyanuric acid adduct,
Molybdenum dithiocarbamate was prepared in the proportions shown in Table 5 and mixed uniformly in a ball mill.
They were added in an amount of 6 parts by weight per 0 part by weight, and thoroughly kneaded with three rolls to uniformly disperse them in the grease.

The results of testing each of the obtained greases are shown in Table 6.

Comparative Example 5 For comparison, the same grease 10 used in Example 3 was used.
Grease was prepared in the same manner as in Example 3, except that 6 parts by weight of molybdenum dithiocarbide powder with an average particle size of 2 microns was added to 0 parts by weight, and the results of the same test are shown in Table 6. Met. Note that Table 6 also lists test results for the greases of Comparative Examples 1 and 3.

Table 5 Table 6 The greases obtained in Example 3 (Jikkenya 3), Comparative Example 1, Comparative Example 3, and Comparative Example 5 were still tested for the relationship between oil pressure and friction coefficient using an export type four-ball tester. The results were as shown in Figure 3.

As is clear from the results shown in Table 6 and FIG. Compared to the grease of Comparative Example 3 (grease containing only molybdenum dithiocarbamate), the grease of Comparative Example 3 (grease containing only molybdenum dithiocarbamate), it was superior in terms of seizure load, wear, and coefficient of friction. It can be seen that the melamine isocyanuric acid adduct and molybdenum dithiocarbamate have an excellent synergistic effect.

Example 4 Molybdenum disulfide (MoS) powder was prepared in the ratios shown in Table 7 to 10 parts by weight of melamine incyanuric acid adduct, and mixed uniformly in a ball mill.

Add 5 parts by weight of each of the obtained solid lubricant mixtures to 100 parts by weight of benton grease for rolling bearings (JIS K2220), and thoroughly knead with three rolls to uniformly disperse in the grease. Ta.

The obtained solid lubricant-containing greases were subjected to seizure load and wear tests using an export type four-ball tester, and the results are shown in Table 8.

Comparative Examples 6 to 8 For comparison, 5 parts by weight of melamine isocyanuric acid adduct alone (Comparative Example 6) or 5 parts by weight of molybdenum disulfide powder alone was added to 100 parts by weight of the same grease used in Example 4. (Comparative Example 7).

Each was blended and kneaded well using a triple roll.

The same tests as in Example 4 were conducted on each of the obtained greases and only the grease used in Example 4 (Comparative Example 8). The test results are shown in Table 8.

Table 7 Table 8 As is clear from the results shown in Table 8 and FIG. The characteristics of seizure load, abrasion resistance, and coefficient of friction compared with the grease of Comparative Example 7 (grease containing only acid adducts), the grease of Comparative Example 7 (grease containing only molybdenum disulfide), and the grease of Comparative Example 8 (grease only) It can be seen that the melamine isocyanuric acid adduct and molybdenum disulfide have an excellent synergistic effect.

Example 5 300 parts by weight of polytetrafluoroethylene powder was prepared with respect to 100 parts by weight of the melamine isocyanuric acid adduct, and the mixture was uniformly mixed in a ball mill.

10 parts by weight of each solid lubricant mulberry compound obtained was added to 100 parts by weight of alpha olefin oil-based grease and thoroughly kneaded with a triple roll to uniformly disperse it in the grease.

The obtained solid lubricant-containing grease was subjected to seizure load, wear, and friction coefficient tests using an export type four-ball tester, and the results are shown in Table 9.

Comparative Examples 9 to 11 For comparison, 10 parts by weight of the same grease used in Example 5 was overlaid with 10 parts by weight of melamine incyanuric acid adduct (Comparative Example 9), or 10 parts by weight of polytetrafluoroethylene alone. parts (Comparative Example 10) were each blended,
Thoroughly kneaded with three rolls.

The same tests as in Example 5 were conducted for each of the obtained greases and only the grease used in Example 5 (Comparative Example 11). The test results are shown in Table 9.

Table 9 As is clear from the results shown in Table 9, the grease of Example 5, which was formulated using a combination of melamine isocyanuric acid adduct and polytetrafluoroethylene, was different from the grease of Comparative Example 9 (which contained only melamine isocyanuric acid adduct). Mixed grease) 1. Compared to the grease of Comparative Example 10 (grease containing only polytetrafluoroethylene) and the grease of Comparative Example 11 (grease only), it is superior in the properties of seizure load, abrasion resistance, and coefficient of friction, and is superior in properties such as melamine isocyanuric acid addition. It can be seen that the compound and polytetrafluoroethylene have an excellent synergistic effect.

[Brief explanation of the drawing]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are drawings showing the relationship between oil pressure and friction coefficient of the greases obtained in Examples and Comparative Examples. Patent applicant Yuka Melamine Co., Ltd. Figure 1 Hydraulic pressure (-krrL2) Figure 2 Hydraulic pressure (kgklll”) Hydraulic pressure (kg/ca2) Procedural amendment 7wa 59 September 77, Commissioner of the Patent Office Manabu Shiga 1. Indication of the case Patent Application No. 131863 filed in 1982 2. Name of the invention: Grease containing solid lubricant 3. Relationship with the case by the person making the amendment Name of patent applicant: Yuka Melamine Co., Ltd. Haga 1 person 7. Amendment Contents (as shown in the attached sheet) Contents of the amendment (1) In Table 6 on page 23 of the specification, ro, o037J of the friction coefficient of experiment AI was corrected to rO,037J, and the friction coefficient of experiment A2 was corrected to rO,037J. Correct the numerical value rO,0033J to rO,033J.

Claims (1)

[Claims] 1) 1 to 2 parts of solid lubricant per 100 parts by weight of grease
The solid lubricant contains 0 parts by weight of melamine (
A solid lubricant selected from the group consisting of polytetrafluoroethylene, molybdenum disulfide, and molybdenum dithiocarbamate is used in combination at a ratio of 5 to 1000 parts by weight per 100 parts by weight of the iso)cyanuric acid adduct. Grease containing a solid lubricant.