JPH07119431B2 - Oil-soluble additive for addition to base oil and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel oil-soluble additive to be added to a base oil, which has a high friction coefficient and a surface smoothing effect, and a method for producing the same.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, powdery finely divided silica or colloidal silica dispersion aqueous solutions have been used to increase the friction of fibers, paper, and the like. On the other hand, a continuously variable transmission for machines, wet brakes for automobiles, tractors and the like, wet clutches, and lubricating oils such as special fiber oil agents often require a high friction coefficient. For this reason, synthetic high-performance oils have been proposed that utilize the high-pressure viscosity characteristics of oils and additives such as calcium sulfonate, but none of these have satisfactory performance.

There is also an example in which colloidal silica is added to grease etc., but the silica used here has undergone secondary agglomeration, the compounded liquid cannot be transparent, and also has a surface smoothing action. It wasn't.

Therefore, an object of the present invention is to provide an oil-soluble additive for addition to a novel base oil, which has a high friction coefficient and a surface smoothing effect, and a method for producing the same.

[Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive research to achieve the above object.

That is, the present invention, as an essential component, the primary particle size is 400 m
μ or less, containing less secondary aggregation colloidal silica and an oil-soluble surfactant, substantially the absence of water,
The present invention relates to an oil-soluble additive to be added to a base oil, which comprises at least 0.5 part by weight of an oil-soluble surfactant with respect to 1 part by weight of the colloidal silica.

Furthermore, the present invention has a primary particle diameter of 400 mμ or less, to the secondary colloidal silica aqueous solution with little aggregation, a water-soluble organic solvent is added, and then water is obtained by distilling the resulting mixture under reduced pressure. A water-soluble organic solvent is distilled off to prepare a substantially water-free colloidal silica organic solvent solution, and the oil-soluble active agent is added to the colloidal silica organic solvent solution at 0.5 parts by weight or more per 1 part by weight of the colloidal silica. In the ratio of 1) and then distilling the resulting mixture under reduced pressure to distill off the organic solvent, and to a method for producing an oil-soluble additive for adding to a base oil.

[Operation] The oil-soluble additive to be added to the base oil of the present invention is a colloidal silica in the additive which can be dissolved in the oil by solubilizing substantially spherical colloidal silica which does not cause secondary aggregation. It is an oil-soluble additive that does not agglomerate and has a surface smoothing action even though it has a high coefficient of friction, and thus has little wear, rather than the conventional one.

In the present invention, the primary particle size means a basic particle size without considering an apparent increase in particle size due to aggregation or the like.

The oil-soluble additive to be added to the base oil of the present invention can be produced by various methods, and one example thereof is as follows.

That is, methanol, ethanol, propanol, lower alcohols such as isopropanol, methyl cellosolve, ethyl cellosolve, cellosolves such as butyl cellosolve, water-soluble organic solvents such as acetone, acenitrile, etc. are added to a colloidal silica aqueous solution with little secondary aggregation. First, water is distilled under reduced pressure. When the amount of the mixture of water and the organic solvent distilled off at this time is smaller than the amount of the added organic solvent, secondary aggregation of colloidal silica in the additive is extremely reduced, which is preferable.

By repeating the addition of the above-mentioned organic solvent and the reduced pressure state of water, an organic solvent solution of colloidal silica is obtained once. To this, 0.5 part by weight or more of an oil-soluble surfactant is added to 1 part by weight of colloidal silica, and then the organic solvent is distilled off under reduced pressure to obtain the oil-soluble additive for base oil of the present invention. At this time, if necessary, an appropriate amount of mineral oil or the additive of the present invention may be diluted with an oil agent (base oil) to be added.

The oil-soluble surfactant used in the present invention is not particularly limited and any one can be used. For example, higher alcohol alkoxylate such as higher alcohol ethoxylate, sorbitan ester and alkylene oxide thereof. Addition products, fatty acid alkoxylates such as fatty acid ethoxylates, fatty acid amide alkoxylates such as fatty amide ethoxylates, fatty acid amine alkoxylates such as fatty acid amine ethoxylates, nonionic surfactants such as block polymers of propylene oxide and ethylene oxide, Examples thereof include metal-based dispersants such as calcium sulfonate, magnesium sulfonate, and barium finate, and ashless dispersants such as alkylsuccinimide-based and benzylamine-based dispersants.

The amount of the oil-soluble surfactant used varies depending on the type of the surfactant used, but at least 0.5 part by weight is necessary for 1 part by weight of the colloidal silica.

If the amount of the oil-soluble surfactant is less than the above amount, the secondary aggregation of the colloidal silica in the additive will occur and the surface smoothing effect cannot be obtained.

There is no particular upper limit to the amount of the oil-soluble surfactant used, and it can be freely added depending on the purpose of solubilizing the colloidal silica and the nature of the oil agent to which the additive of the present invention should be added.
It may be 100 parts by weight with respect to 1 part by weight of colloidal silica, but about 4 parts by weight with respect to 1 part by weight of colloidal silica is sufficient to solubilize the colloidal silica. However, this is just a cost disadvantage. Incidentally, as described above, there is no problem in adding a surfactant for other purposes.

The colloidal silica used in the present invention has a small secondary aggregation particle size of 400 mμ or less, and a particle size of 100 mμ or less can be extremely safe, and the separation and precipitation of silica can be performed. It is also preferable because it does not cause clogging of filters and the like in various devices.

"Secondary agglomeration is small" in the present invention, by centrifugation conditions 700G × 60 minutes, (to total SiO ₂ minutes, the weight percent of the total SiO ₂ minutes precipitated) ratio of the precipitated silica is 10 wt% , Preferably 3% by weight or less, more preferably 1% by weight
It is as follows. Therefore, the colloidal silica used as a raw material of the present invention is less secondary agglomerate, and the colloidal silica in the oil-soluble additive to be added to the base oil of the present invention has less secondary agglomeration. It is a thing.

The oil-soluble additive to be added to the base oil of the present invention is useful as an additive for lubricating oil such as automobiles, wet brakes of mechanical devices such as tractors, wet clutches, etc. It may be appropriately selected depending on the required performance, etc., but when used, a sufficiently good performance can be obtained if the SiO ₂ concentration is about 0.1% by weight or more.

Since the oil-soluble additive for addition to the base oil of the present invention contains colloidal silica, it not only has a high friction coefficient, but also because the particles of colloidal silica are not secondary aggregated. Since the colloidal silica particles exist in the original fine particle size (primary particle size), the wear surface is made very smooth, and so-called running oil for smoothing the lubrication surface of machinery is used. Is also useful for the addition of.

The oil-soluble additive to be added to the base oil of the present invention may be used in combination with other additives within the scope of the object of the present invention. Examples of such additives include phosphorus-based, sulfur-based, and chlorine-based extreme pressure additives in lubricating oils, ash-forming or ashless-type dispersants and detergents, corrosion inhibitors for various metals, and antioxidants. Agents, pour point curing agents, viscosity index improvers, colorants, anti-coloring agents, defoamers and the like.

The base oil to which the oil-soluble additive for adding to the base oil of the present invention can be added is not particularly limited,
For example, mineral oil, ester-based synthetic oil, polyalpha-olefin, polyoxyalkylene glycol-based synthetic oil and the like can be used, and may be appropriately selected according to the purpose of use.

[Examples] The present invention will be further described below with reference to Examples, but it should be understood that the present invention is not limited to these Examples.

Example 1 SiO ₂ content in a one-neck flask equipped with a distillation apparatus and a stirrer
30% aqueous colloidal silica (Aderide manufactured by Asahi Denka Co., Ltd.
AT-30, particle size 10 to 20 mμ, 700 G × 60 minutes (not precipitated by centrifugation test) 200 g and ethyl cellosolve 200 g were charged,
200 g of a mixture of water and ethyl cellosolve was distilled off at 80 ° C. under reduced pressure with stirring. Further, 200 g of ethyl cellosolve was charged, and similarly, a mixture of 200 g of water and ethyl cellosolve was distilled off.

Next, 90 g of diethylenetriamine polybutenyl succinimide (monotype, formula weight of polybutenyl group 960) as an oil-soluble surfactant and 100 g of 100 neutral oil were added and mixed, and the remaining water and ethyl cellosolve were added under final conditions.
It was distilled off at 100 ° C to 5 mmHg. Finally 100 Neutral Oil 2
50g was added and mixed to obtain a reddish brown transparent liquid. SiO of this liquid
_{The 2} content was 12%.

No precipitation was observed in this liquid in the centrifugation test of 700 G × 60 minutes and 2000 G × 60 minutes.

Example 2 A reddish brown transparent body was obtained in the same manner as in Example 1 except that triethylenetetramine polybutenyl succinimide (bis type, polybutenyl group formula: 960) was used as the oil-soluble surfactant. The SiO ₂ content of this liquid was 12%.

No precipitation was observed in this liquid in the centrifugation test of 700 G × 60 minutes and 2000 G × 60 minutes.

Example 3 The same operation as in Example 1 was performed until the addition of the oil-soluble surfactant,
Next, ashless dispersant (Amoco 9250 manufactured by Amoco Chemical Co.) 19
0 g was added and mixed.

Next, the remaining water, ethyl cellosolve, is added under the final conditions.
It was distilled off at 100 ° C to 5 mmHg.

Finally, 250 g of 100 neutral oil was added and mixed to obtain a reddish brown transparent liquid. The SiO ₂ content of this liquid was 12%.

No precipitation was observed in this liquid in the centrifugation test of 700 G × 60 minutes and 2000 G × 60 minutes.

Example 4 The same operation as in Example 1 was performed until the addition of the oil-soluble surfactant, and then 60 g of alcohol ethoxylate (Adecatol SO-80 manufactured by Asahi Denka Co., Ltd.) was added and mixed.

Next, the remaining water, ethyl cellosolve, is added under the final conditions.
It was distilled off at 100 ° C to 5 mmHg.

Finally, 80 g of 100 neutral oil was added and mixed to obtain a pale yellow transparent liquid. The SiO ₂ content of this liquid was 30%.

No precipitation was observed in this liquid in the centrifugation test of 700 G × 60 minutes and 2000 G × 60 minutes.

Example 5 The same operation as in Example 1 was performed until the addition of the oil-soluble surfactant, and then 120 g of nonylphenyl ethoxylate (Adecatol NP-650 manufactured by Asahi Denka Kogyo) was added and mixed.

Next, the remaining water, ethyl cellosolve, is added under the final conditions.
It was distilled off at 100 ° C. to 5 mmHg to obtain a pale yellow transparent liquid. The SiO ₂ content of this liquid was 33%.

No precipitation was observed in this liquid in the centrifugation test of 700 G × 60 minutes and 2000 G × 60 minutes.

Reference Example (Oil-Soluble Additive Performance Test for Adding to Base Oil) The oil-soluble additive for base oil of the present invention obtained in Examples 1 to 5 and powdery fine particle silica (comparative product) ( Shionogi Pharmaceutical Carplex FPS-3, primary particle size about 7mμ) 60g
And 90 g of the oil-soluble surfactant used in Example 1 were mixed well and then diluted with 350 g of 100 neutral oil to give a slightly turbid reddish brown liquid (SiO ₂ content 12% by weight, surfactant content 18% by weight, 700 G × 60). Minute precipitation test, 70% by weight of SiO ₂ precipitated) in 100 neutral oil as SiO ₂
%, 1.0%, and the friction coefficient, wear, and mineral oil solubility were evaluated.

The results are shown in Table-1.

Conditions High-speed four-ball tester Temperature 80 ℃ Load 45kg Rotation speed 1800rpm Time 60 minutes Average wear coefficient 60 minutes Wear mark diameter after wear test (mm) Solubility Visual judgment [Effect of the Invention] The effect of the present invention is to provide a novel oil-soluble additive to be added to a base oil, which has a high friction coefficient and a surface smoothing effect.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location C10N 30:00 Z 40:04 40:08 (72) Inventor Fukushima Aged 7 Hisashi Higashio, Arakawa-ku, Tokyo Asahi Denka Kogyo Co., Ltd. 2-35 35 Masanori Konishi 7-35 Higashiohisa Arakawa-ku, Tokyo Asahi Denka Kogyo Co., Ltd. (56) Reference JP-A-1-108299 (JP , A) Japanese Patent Publication No. 45-10048 (JP, B1)

Claims (2)

[Claims] 1. A colloidal silica and an oil-soluble surface active agent which have an essential particle size of 400 mμ or less and a silica content of 10% by weight or less precipitated under a centrifugation condition of 700 G × 60 minutes. For adding to a base oil characterized by containing an agent, being substantially free of water, and containing at least 0.5 part by weight of an oil-soluble surfactant per 1 part by weight of the colloidal silica. Oil soluble additives. 2. The primary particle size is 400 mμ or less, 700 G ×
A water-soluble organic solvent was added to a colloidal silica aqueous solution in which the proportion of silica precipitated under the conditions of centrifugation for 60 minutes was 10% by weight or less, and then the resulting mixture was distilled under reduced pressure to dissolve water and water. Of a water-soluble organic solvent to prepare a colloidal silica organic solvent solution which is substantially free of water, and an oil-soluble active agent is added to the colloidal silica organic solvent solution.
0.5 parts by weight or more with respect to parts by weight, then, the resulting mixture is distilled under reduced pressure to distill off the organic solvent to remove the organic solvent of the oil-soluble additive for addition to the base oil Production method.