JPS6347760B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing calcium-based grease from paraffinic hydrocarbon base oil. Calcium-based greases that use calcium soap as the main thickener are difficult to form into grease when paraffin-based hydrocarbon oils are used as the base oil.
There is a restriction that the base oil is actually limited to naphthenic hydrocarbon oil. In other words, in the case of calcium-based grease, it is difficult to obtain a satisfactory grease when paraffin-based lubricating oil is used as the base oil, and the normal method produces granular lumps and has an uneven appearance, resulting in poor performance and product quality. However, it is difficult to produce a satisfactory grease. As a result of various studies regarding these problems, the present inventors have found that by saponifying polyhydric alcohols and alicyclic carboxylic acids or their salts in the coexistence, paraffinic hydrocarbon base oils, which have been considered extremely difficult, can be produced. The present invention was completed based on the discovery that calcium-based grease can be produced using the above-described method. That is, the gist of the present invention is that a paraffinic hydrocarbon base oil is saponified in the presence of 0.1 to 2.0% by weight of a polyhydric alcohol and at least 0.1% by weight of an alicyclic carboxylic acid or an alkaline earth metal salt thereof. The present invention relates to a method for producing a calcium-based grease, which comprises saponifying a fatty material to be processed using a calcium saponifying agent. The paraffinic hydrocarbon oil used as the base oil in the present invention has a viscosity index of about 70 or more and a paraffin content (n-
Cp content (Cp content determined by dM analysis method) of approximately 55% or more can be used. The viscosity of the base oil is about 8 cSt or more, preferably about 8 to 850 cSt, more preferably about 30 to 400 cSt.
(40°C) is suitable, and in addition to mineral oil lubricating oil, synthetic lubricating oil belonging to the paraffinic hydrocarbon oils such as liquid polyolefin can also be used. The base oil may also contain a small amount of naphthenic hydrocarbon oil, etc., if it is entirely paraffinic as defined above, or it may contain mainly paraffinic hydrocarbon oil (about 70% or more of the base oil, preferably about 80% by weight). % or more), synthetic lubricating oils other than hydrocarbon oils such as ester-based synthetic lubricating oils and silicone oils can also be included, and these are preferably added after the saponification reaction. When performing a saponification reaction in a paraffinic base oil to form a calcium soap thickener, examples of polyhydric alcohols present in the system include ethylene glycol, propylene glycol, glycerin, diethylene glycol, dipropylene glycol, and liquid polyethylene glycol. Examples include glycol, liquid polypropylene glycol, polyoxyalkylene-based polyether polyols such as polyoxyethylene-oxypropylene glycol, and polyglycerin. The number of carbon atoms in polyhydric alcohol is 2~
500, especially about 2 to 70, especially about 2 to 6 is preferred. The amount of polyhydric alcohol used in the reaction mixture is approx.
0.1-2.0% by weight, preferably about 0.3-1.5% by weight. Examples of alicyclic carboxylic acids or alkaline earth metal salts thereof used in combination with this polyhydric alcohol include cyclopentanecarboxylic acid, cyclohexanecarboxylic acid, cycloheptanecarboxylic acid, cyclopropanecarboxylic acid, naphthenic acid, cyclopentyl acetate, and cyclohexyl. Examples include acetic acid, cyclopentylpropionic acid (these acids may have a hydrocarbon substituent such as an alkyl group in the nucleus), and their alkaline earth metal salts such as barium, magnesium, and calcium. The preferred carbon number of the alicyclic carboxylic acid or its alkaline earth metal salt is 4 to 4.
60, especially about 4 to 30. Alkali metal salts of alicyclic carboxylic acids have a high consistency yield even when used in combination with polyhydric alcohols (if the amount of thickener is kept constant, a grease with a lower consistency value than others can be obtained, or if the consistency is kept constant) If a given grease can be obtained with a smaller amount of thickener than the others, it is said to have a high consistency yield or high yield.In the opposite case, it is said to have a low consistency yield or yield. “NLGI SPOKESMAN” Magazine, vol. 22, p. 509
February 1959 and “Maruzen Oil Technical Report” No. 20, p. 75,
See 1975. ) is low and inappropriate. The amount of the alicyclic carboxylic acid or alkaline earth metal salt used in the reaction mixture must be at least 0.1% by weight, and preferably about 0.5 to 5% by weight. If the amount of polyhydric alcohol and alicyclic carboxylic acid or its alkaline earth metal salt used is less than the above specified amount, it will be ineffective and difficult to form a grease, and if it is too much, a satisfactory grease structure will not be formed. The object of the present invention cannot be achieved because the mixing consistency value suddenly becomes large, or foaming occurs during the dehydration process and satisfactory greasing cannot be achieved. The addition ratio of these additives is 1 part polyhydric alcohol by weight.
The preferred ratio is about 2 to 10 parts of the alicyclic carboxylic acid or its alkaline earth metal salt. If the polyhydric alcohol and the alicyclic carboxylic acid or its alkaline earth metal salt are used alone, the purpose will not be achieved, and if added after saponification is substantially completed, there will be no effect. The fatty materials to be saponified can be those normally used in the production of calcium soap based greases, examples of which include aliphatic carboxylic acids, cycloaliphatic carboxylic acids, and resin acids. When using an alicyclic carboxylic acid, it is preferable not to use too much as mentioned above, and therefore it is preferable to use it as a mixture with an aliphatic carboxylic acid. The use of fats and oils as the fatty material to be saponified is not preferred because it causes difficulties in the saponification reaction and also causes problems such as foaming during the dehydration process, making dehydration difficult. When using fats and oils as part of the fat ingredients, it is best to limit the amount to a small amount. Aliphatic carboxylic acids may be linear, branched, saturated, or unsaturated, and generally have about 10 to 30 carbon atoms, especially about 12 to 24 carbon atoms.
Preferred examples include palm oil acid, beef tallow acid, pork fat acid, vegetable oil acid, fish oil acid, hydrides thereof, lauric acid, palmitic acid, myristic acid, stearic acid, behenic acid, oleic acid, and linoleic acid. , hydroxystearic acid, and synthetic fatty acids produced by the oxo synthesis method and the Kotsuho reaction method. Alicyclic carboxylic acids and resin acids have 4 to 60 carbon atoms, especially 10 carbon atoms.
~30 is preferred. Examples of calcium-based saponifying agents for saponifying these fatty materials include calcium hydroxide and calcium oxide. Mainly calcium saponifiers (about 70% of saponifiers)
(% weight % or more, preferably about 80 weight % or more)
To this, lithium, sodium, barium,
Other metal saponifying agents such as oxides and hydroxides such as magnesium may also be used in combination. The amount of calcium-based soap thickener formed by the saponification reaction is about 2 to 50% by weight in the saponification reaction mixture, especially about 5% by weight.
~20% by weight is suitable. Greasing according to the present invention can be carried out by any conventional method except that a paraffinic base oil is used instead of a naphthenic base oil and a polyhydric alcohol and an alicyclic carboxylic acid or an alkaline earth metal salt thereof are present. can. An example of making a grease is to put the base oil, fatty material, polyhydric alcohol, and alicyclic carboxylic acid or its alkaline earth metal salt into a pressure cooker or an open cooker, heat it to about 60-80℃, and stir. Mix. Add calcium-based saponification agent and water to this and heat the contents to about 80 to 160℃ while stirring.
The mixture is heated for about 0.5 to 4 hours to carry out the saponification reaction. Thereafter, the temperature is maintained at about 80 to 110°C to allow calcium soap to form crystals. At this stage, the amount of water in the reaction mixture is adjusted (evaporated or replenished. The appropriate amount of water can be determined by appropriate experiments. Usually, the amount of water is preferably about 0.3 to 3.0% by weight), and Add the remaining base oil if necessary. The contents are then cooled and further additions of base oil are added if necessary to adjust the consistency, as well as antioxidants, corrosion inhibitors, and other conventional grease additives, if necessary. The contents can be stirred during the reaction or in subsequent steps by using a stirring blade installed inside the reaction vessel, by extracting the contents from one end of the reaction vessel and circulating them back into the vessel, or by passing the contents through a mill for milling. There are methods etc. Naturally, methods other than those described above can also be used for the greasing method of the present invention as long as calcium soap and crystals can be produced in paraffinic base oil. In the present invention, as described above, appropriate grease additives such as diphenylamine,
Antioxidants such as dibutyl para-cresol, extreme pressure agents such as tricresyl phosphate, other oiliness improvers, rust preventives, structural stabilizers, viscosity index improvers, etc. may be added, and these additives are usually about 5% by weight or less each. According to the present invention, a calcium-based grease with good appearance can be produced using a paraffinic hydrocarbon base oil, and the consistency yield is also good. The manufactured grease has almost the same appearance and performance as conventional calcium-based grease manufactured using naphthenic base oil, and it is now possible to easily manufacture calcium-based grease from paraffinic base oil, which has traditionally been considered extremely difficult. The fact that it has been successful is very advantageous from an industrial perspective. Next, the present invention will be explained with reference to Examples and Comparative Examples.
The base oils A to E used in Examples and Comparative Examples have the properties shown in Table 1, and contain polyhydric alcohols a to d, alicyclic carboxylic acids e to i, and alkaline base oils of alicyclic carboxylic acids. The metal salts j to l shown in Table 2 were used. Hereinafter, the polyhydric alcohol may be abbreviated as additive (1), and the alicyclic carboxylic acid or its alkaline earth metal salt may be abbreviated as additive (2).

【table】

[Table] The appearance of the produced grease was evaluated on the following five scales. 5... Appears to be similar in appearance to calcium-based grease manufactured using high-quality naphthenic base oil, and has no visible particles. 4... Items with an evaluation between 5 and 3 that are judged to fall under neither. 3... Particles with a diameter of 0.5m/m or less exist in a proportion of 50% or more of the total. 2... Those whose evaluation is between 3 and 1 and are judged to fall under neither. 1... Particles with a diameter of 1.0 m/m or more exist in a proportion of 50% or more of the total, or 24 days after sample preparation.
Items that show 1% by weight or more of oil separating over time. The hardness of the generated grease is 5.3 of JLS K2220-1980.
Evaluation was made using the mixing consistency value specified in Section 1. The smaller the value, the harder it is. Example 1 A heated autoclave with a capacity of 4 and equipped with a single stirring blade (rotation speed 15 rpm) was used as the saponification reaction vessel, and all raw materials, that is, base oil, which were blended in the reaction vessel in a total amount of 2 kg, were saponified. A saponifying agent, a saponifying accelerator, a polyhydric alcohol, and an alicyclic carboxylic acid or an alkaline earth metal salt thereof were added. The fat material is beef tallow directly decomposed fatty acids with a neutralization value of 202 and an iodine value of 47.7.
12.5% by weight, and 0.05% by weight of caustic soda (grade 1 reagent) was used as a saponification accelerator. Slaked lime with a purity of 96.2% by weight was used as the saponification agent, and the amount was adjusted so that the free alkali value (as Ca(OH) ₂ ) remained in the product after the saponification reaction was 0.05 to 0.10% by weight. I put it in. In addition, 5% by weight of water was added to the above raw materials to pressurize the autoclave. After that, the autoclave was sealed and heated and stirred for 60 minutes to keep the contents at a temperature of 135°C and a pressure of about 2.2 kg/kg.
Once cm ³ (gauge pressure) was reached, the contents were drained into the open kettle. The open pot was of a heating type and had a capacity of 5 and had multiple stirring blades (inner blade 20 rpm, outer blade 15 rpm). After the contents are poured into an open pot, the moisture content of the contents is reduced at a temperature of 100 to 105℃.
Excess water was evaporated and dehydrated to a concentration of 0.8 to 1.2% by weight. After adjusting the moisture content, the contents were slowly cooled to 60°C over about 30 minutes while stirring, and then the contents were taken out from the open pot and left to cool to room temperature for finishing. Table 3 shows the base oil used, the types of additive (1) and additive (2), and the properties of the resulting grease.

【table】

[Table] As shown above, when paraffinic base oil is used, polyhydric alcohols and alicyclic carboxylic acids or their alkaline earth metal salts can be used together, either alone or without their addition. It was possible to obtain a calcium-based grease with good appearance and hardness, which was completely impossible to obtain using the method (see Comparative Example below). The resulting grease had normal properties other than appearance and hardness. The amount of polyhydric alcohol added in the above table is 0.5% by weight.
Experiments were conducted with the amount of alicyclic carboxylic acid or its alkaline earth metal salt added at 2% by weight, but when the amount of these additives added was changed, the amount of polyhydric alcohol added was is effective at 0.1 to 2% by weight, alicyclic carboxylic acid or its alkaline earth metal salt at 0.1% by weight or more, and if the amount is less than this range, it is ineffective, and too much dehydration process may cause foaming or increase the consistency. Greasing could not be achieved satisfactorily due to poor yield. polyhydric alcohol
Addition ranges of 0.1 to 1.5% by weight and 0.5 to 5% by weight of alicyclic carboxylic acid or its alkaline earth metal salt are particularly effective. It was most effective when the metal salt was added in an amount of 2 to 10 parts by weight. In addition, in the same manner as in Experiment No. 6 above, an experiment was conducted in which magnesium naphthenate and barium naphthenate were added in addition to calcium naphthenate, and good calcium-based greases were obtained in both cases. Among the alkaline earth metal salts, calcium salts were the most effective. Example 2 Calcium-based grease was produced in the same manner as in Experiment Nos. 1 to 6 of Example 1, using another base oil instead of base oil C. The results are shown in Table 4. Even when a paraffinic hydrocarbon base oil other than base oil C was used, a good calcium-based grease was obtained.

[Table] Comparative Example 1 A calcium-based grease was produced in the same manner as in Example 1 except that no polyhydric alcohol, alicyclic carboxylic acid, or alkaline earth metal salt thereof was added. The results are shown in Table 5. When a high-quality naphthenic base oil with a viscosity index of 20 was used, a good calcium-based grease was obtained, but when a paraffinic base oil was used, a satisfactory grease could not be obtained.

[Table] Comparative Example 2 A calcium-based grease was produced from a paraffinic base oil in the same manner as in Example 1 except that an alicyclic carboxylic acid and its alkaline earth metal salt were not added. The results are shown in Table 6. When only polyhydric alcohol was added, no outstanding effect was observed to the extent that it could be commercialized as a grease.

[Table] (Note) Additive (1); Addition amount: 1% by weight.
Calcium-based grease was produced in the same manner except that the amount of polyhydric alcohol added was changed, but a satisfactory grease could not be obtained even if the amount of polyhydric alcohol added was changed. When the amount of polyhydric alcohol added exceeds 2% by weight, foaming occurred during the dehydration process, making the dehydration operation difficult. Comparative Example 3 Example 1 except that polyhydric alcohol was not added
Calcium-based grease was produced from paraffinic base oil in the same manner as above. The results are shown in Table 7. Even when only the alicyclic carboxylic acid was added, no improvement effect was observed to the extent that it could be commercialized as a grease.

[Table] (Note) Additive (2); Addition amount: 1% by weight.
In addition, calcium-based grease was manufactured in the same manner as in Experiment No. 25 except that the amount of alicyclic carboxylic acid h added was changed, and by increasing the amount of alicyclic carboxylic acid added to 3% by weight, the appearance rating was 4. was obtained, but the consistency yield was poor, with a mixing consistency of 347, and the product was of poor industrial practicality. The trend was the same for the other additives e, f, g, and i as for the additive h. Comparative Example 4 Example 1 except that polyhydric alcohol was not added
Calcium-based grease was produced from paraffinic base oil in the same manner as above. The results are shown in Table 8. Even when only an alkaline earth metal salt of an alicyclic carboxylic acid was added, a satisfactory grease could not be obtained.

[Table] (Note) Additive (2); Added amount: 3% by weight.
Comparative Example 5 A calcium-based grease was produced from a paraffinic base oil in the same manner as in Example 1 except that an alkali metal salt of an alicyclic carboxylic acid was used instead of the alicyclic carboxylic acid or its alkaline earth metal salt. The results are shown in Table 9. I still couldn't get a satisfactory amount of grease.

[Table] Additive (3); Alkali metal naphthene
The amount added is 2.5% by weight.
Comparative Example 6 Examples except that beef tallow was used instead of dihydric alcohol, and the total amount of beef tallow and tallow directly decomposed fatty acids was 13.0% by weight (beef tallow becomes a calcium soap thickener when it is saponified). Calcium-based grease was produced from paraffinic base oil in the same manner as in Example 1. The results are shown in Table 10. When fats and oils are used as the fatty material without using dihydric alcohol, there are problems such as the saponification reaction is difficult and foaming occurs during the dehydration process, making dehydration difficult, and the expected effects cannot be obtained.

[Table] (Note) Additive (2); Added amount 2% by weight.
Example 3 Calcium-based grease was produced from paraffinic base oil in the same manner as in Example 1, except that 12-hydroxystearic acid was used instead of beef tallow directly decomposed fatty acids. A good calcium-based grease almost equivalent to that obtained in Example 1 was obtained.

Claims (1)

[Claims] 1 In paraffin hydrocarbon base oil, 0.1
~2.0% by weight polyhydric alcohol and at least
A method for producing calcium-based grease, which comprises saponifying a fatty material to be saponified with a calcium saponifying agent in the presence of 0.1% by weight of an alicyclic carboxylic acid or an alkaline earth metal salt thereof.