JPH1088163A - Production of soap-based grease - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for industrially producing soap-based grease, capable of solving various problems caused by solid charge of a fatty acid which have been pending problem hitherto all at one by charging the fatty acid in liquid state in a form of oxyfatty acid oligomer in addition to a raw material oil among the raw material oil, fatty acid and an alkali into a contactor. SOLUTION: At least a raw material oil (A) and an oxyfatty acid oligomer having a structure obtained by condensing a fatty acid having OH group with the same fatty acid having OH or a fatty acid having no OH and derived from two or more identical monomers among the raw material oil (A), the oxyfatty acid oligomer and an alkali (C) are fed in a liquid state to a contactor (1) to react these components and then, the reactant after reaction is discharged from the contactor (1) and fed to the following step. A representative example of the fatty acid having OH group is hydrogenated castor oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for industrially producing a soap-based grease such as a lithium-based grease.

[0002]

2. Description of the Related Art Greases are basically composed of a thickener and a lubricating oil component, and are classified into a soap-based grease and a non-soap-based grease depending on the type of the thickener used. Among them, the former soap-based grease includes lithium-based grease and calcium-based grease, and the non-soap-based grease includes urea-based grease.

[0003] Soap-based greases, especially lithium-based greases, are widely used for lubricating bearings of iron-making equipment, automobile parts, home electric appliances and the like, and are particularly important.

JP-A-1-308496 discloses an alkali metal or alkaline earth metal salt synthesized from a hydroxide of an alkali metal or an alkaline earth metal and a higher fatty acid or a higher hydroxy fatty acid having 10 or more carbon atoms.
A grease composition comprising (a), an ether-based synthetic oil (b), and a specific ester-based synthetic oil is shown. Salt (a)
In the examples, lithium 12-hydroxystearate is used.

[0005] JP-A-1-170691 discloses a lithium complex grease containing lithium soap of dihydroxy fatty acid, lithium soap of fatty acid, dilithium borate and lithium phosphate.

For the production process and production apparatus for lithium-based grease, see “Nisseki Review, Vol. 37, No. 4, (1)
(November 995) "on pages 56-60. FIG. 1 is an explanatory view schematically showing a manufacturing process and a manufacturing apparatus of a soap-based grease (lithium-based grease) described in this document. Raw material oil (A), fatty acid (B) and alkali (C) are charged from the top into a saponification pot or neutralization pot called a contactor (1). Contactor
The heating medium oil (D) is supplied to the jacket (1a) of (1).
The reactant removed from the bottom of the contactor (1) is sent to the finishing pot (2), where the additive (E) is added,
The product grease is passed through a mill (3), a defoamer (4), and a filter (5).

[0007]

In FIG. 1 described above,
Contactor (1) Of the raw oil (A), fatty acid (B) and alkali (C) to be charged, the raw oil (A) is fed by liquid. On the other hand, fatty acid (B) is a solid (often 12-
Hydroxystearic acid has a melting point of about 75 ° C. and is in the form of flakes, powders or beads), and is manually supplied by opening a manhole (hatch) (1b) at the top of the contactor (1).

The fatty acid (B) is used in an amount of about 5 to 20 parts by weight based on 100 parts by weight of the raw material oil (A).
It is consumed by the number of bags, such as bags. However, it is not easy to carry the paper bag filled with fatty acid (B) to the top of the contactor (1), open it, and put it in.If the number of bags is counted incorrectly, the whole lot is wasted. In addition, workers must put on a mask and install an exhaust duct because dust will be scattered (not only during use, but also when manufacturing and filling bags with fatty acid (B) manufacturers). Dust)), it is dangerous because it is an operation at a high place, it is hard work, the surroundings are contaminated by spilled fatty acid (B) at the time of input, and the amount of fatty acid (B) input is exactly Since it is not necessarily a unit, there is also a problem that an odd part must be measured and input. Since the alkali (C) is used in a smaller amount than other raw materials, one bag is sufficient even when it is handled as a solid, and there is no particular problem.

Therefore, instead of using a large number of bags containing fatty acid (B) per batch, the delivery container for fatty acid (B) has been changed from a paper bag to a container pack. (Refer to the above “Nisseki Review” on page 59.) In addition to improving some of the above problems, the one-shot input of fatty acid (B) is
There is a new problem that the uniform mixing operation is difficult in the above, and the fundamental solution has not been reached.

The present inventors have been conducting research on intermolecular oligoesters (oligomers) of oxy fatty acids containing castor oil fatty acid or a hydrogenated product thereof as an essential component for some time. In other words, even when (12-hydroxystearic acid) is used, the intermolecular oligoester (oligomer) becomes liquid at room temperature and has good compatibility with mineral oil and other raw material oils. (Oligomer) was used as a thickener for soap-based grease, and an attempt was made to improve the conventional soap-based grease production process.

[0011] Under such a background, the present invention is to feed a fatty acid of a raw material oil, a fatty acid and an alkali into a contactor by feeding the fatty acid in the form of an oxyfatty acid oligomer, which has been a conventional problem. It is an object of the present invention to provide an industrial method for producing a soap-based grease that can solve various problems caused by charging solids at once.

[0012]

According to the method for producing a soap-based grease of the present invention, the raw material oil (A) is condensed with a fatty acid having an OH group or a fatty acid having an OH group with a fatty acid having no OH group. An oxyfatty acid oligomer (B ′) having at least a dimer having a structure and an alkali (C) are at least
(A) and the oxyfatty acid oligomer (B ') are supplied in liquid form to the contactor (1) to carry out the reaction, and then the reacted product after the reaction is derived from the contactor (1) and used for the subsequent steps. It is assumed that.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

<Prepared Component> In the present invention, the contactor
The components charged in (1) are a feedstock oil (A), an oxyfatty acid oligomer (B ') and an alkali (C). The order of preparation is arbitrary.

The feedstock oil (A) is a base oil, such as mineral oil, hydrocarbon oil, halogenated hydrocarbon oil, alkylbenzene oil), poly-α-olefin oil, synthetic ether oil, synthetic ester oil, silicone oil and the like. Is used.

Examples of the alkali (C) include hydroxides, oxides and salts of lithium, calcium, barium and the like, and two or more of these may be used in combination. Of these, lithium hydroxide is often used. The alkali (C) is a solid, hydrate (eg, LiOH.H ₂
O), aqueous solutions, aqueous dispersions and the like.

In the present invention, the conventional fatty acids
In place of (B), a dimer or more oxyfatty acid oligomer (B ′) having a structure in which fatty acids having an OH group or a fatty acid having an OH group and a fatty acid having no OH group are condensed.
Is used.

As the fatty acid having an OH group, a hydrogenated castor oil fatty acid whose main component is 12-hydroxystearic acid is preferably used, but another fatty acid having an OH group (dihydroxy fatty acid is also usable) is used in combination. You can also.

Fatty acids having no OH group include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, arachiic acid, behenic acid, montanic acid,
Natural or synthetic fatty acids such as coconut oil, palm oil fatty acid, olive oil fatty acid, tallow fatty acid, hydrogenated tallow fatty acid, etc. containing these components such as oleic acid, linoleic acid and linolenic acid can also be used. Lower to intermediate fatty acids such as valeric acid, caproic acid, enanthic acid, caprylic acid and capric acid can also be used.

Dimer or higher oxyfatty acid oligomer (B ') having a structure in which fatty acids having an OH group are condensed with each other or with a fatty acid having an OH group and a fatty acid having no OH group.
Typically, the above-mentioned fatty acids having an OH group or a fatty acid having an OH group and a fatty acid having no OH group are converted under an inert gas atmosphere at a temperature of about 180 to 240 ° C. (particularly under reflux conditions). It is obtained by performing a condensation reaction by heating under (2). In this case, it is preferable that xylene and the like coexist in the system, and water produced as a by-product is removed from the system by azeotropic distillation. The catalyst need not normally be used. Dimer or higher oxy fatty acid oligomer having the above structure (B ')
Alternatively, starting from hydrogenated castor oil, the hydrogenated castor oil can be in the form of capped oxy fatty acid oligomers.

The degree of condensation of the oxyfatty acid oligomer (B ') can be appropriately set as long as a liquid can be obtained, and is usually at least dimer, preferably at least trimer, and the upper limit is octamer or It can be more. It is to be noted that the monomer may be present in a mixed state, but in this case, the whole is kept in a liquid state.

In the above, the fatty acid is selected so that the fatty acid composition satisfying the recipe desired by the customer is obtained after saponification, and the oxyfatty acid oligomer (B ') is produced.

Raw material oil (A), oxy fatty acid oligomer (B ')
And the proportion of alkali (C) depends on the type of target grease. Generally, the oxyfatty acid oligomer (B ') is used in an amount of 2 to 25 parts by weight, particularly 5 to 100 parts by weight of the base oil (A).
It is often 20 parts by weight. The ratio of the alkali (C) is based on an amount sufficient to saponify and neutralize the ester groups and carboxyl groups of the oxyfatty acid oligomer (B ').

<Manufacturing Method of Grease> The grease can be manufactured according to the process shown in FIG. That is, the feedstock (A) is added to the contactor (1),
Oxy fatty acid oligomer (B ') and alkali (C) are charged. In this case, before the preparation,
(B ′) may be partially mixed with the feedstock oil (A). Heat medium oil (D) is supplied to the jacket (1a) of the contactor (1). The reactant is taken out from the bottom of the contactor (1) and sent to the finishing pot (2), where additives (E) such as antioxidants, rust inhibitors and corrosion inhibitors (corrosion agents) are added. ,mill
After passing through (3), defoamer (4) and filter (5), it is converted into product grease.

For charging each component to the contactor (1), the raw material oil (A) is supplied in a liquid state as in the past. In the present invention, since the oxyfatty acid oligomer (B ') is in a liquid state, it is also supplied in a liquid state. It is desirable that the alkali (C) is also fed, but even if it is handled as a solid, only one bag is required per batch, so there is no major problem.

Raw oil (A) and oxy fatty acid oligomer (B ') (preferably also alkali (C)) for contactor (1)
Is supplied using a pipeline, and the charging timing and charging amount can be controlled using an automatic control mechanism.

In the finishing pot (2), the additive (E) added to the base grease is uniformly mixed by the stirring blade. Mill (3) is milled to improve grease quality. In the defoaming machine (4), bubbles in the grease to be sent are vacuum degassed. The filter (5) removes dust in the grease. The grease that has passed through the filter (5) becomes product grease.

<Action> In the present invention, the conventional fatty acids
Since the oxy fatty acid oligomer (B ') is used instead of (B), not only the feed oil (A) but also the oxy fatty acid oligomer
(B ') can also be automatically charged into the contactor (1) by liquid feeding. Therefore, when producing soap-based grease,
Various problems caused by the solid-state injection of fatty acid (B), which has been conventionally pending, can be solved at once. In the contactor (1), the oxy fatty acid oligomer (B ') is saponified and decomposed into its constituent fatty acids, and the carboxyl group is neutralized.

Moreover, the oxyfatty acid oligomer (B ') is intended for the user because the type of the constituent fatty acids can be selected in consideration of the performance of the target grease and the liquefaction can be achieved by adjusting the degree of condensation. It is possible to obtain grease having characteristics suitable for the application.

In the present invention, an oxyfatty acid oligomer (B ') is used in place of the conventional fatty acid (B) for liquid transport, and the oxyfatty acid oligomer (B') is returned to the form of the salt of the constituent fatty acid again in the contactor (1). At first glance, it looks like a complicated process, but it's not. For example, when obtaining hydrogenated castor oil fatty acid (12-hydroxystearic acid), hydrogenated castor oil (hydrogenated castor oil)
Is saponified in a kettle and further neutralized to hydrogenated castor oil fatty acid (melting point about 75 ° C),
After removing glycerin by washing with water, dehydration is performed, then flaked by a flaker, and finally bag-packed. The installation of the flaker, the flake process, and the bagging process alone are complicated, and it is necessary to take measures against dust. On the other hand, the oxyfatty acid oligomer (B ′) is obtained only by heating and condensing using the same kettle after the above-mentioned dehydration step, and thereafter can be handled by liquid feeding and is free of dust. Overall, it is more advantageous than the case of handling solid (flake) hydrogenated castor oil fatty acids.

[0031]

The present invention will be further described with reference to the following examples. Hereinafter, "parts" refers to parts by weight.

<Synthesis of Oxyfatty Acid Oligomer (B ′)> Synthesis Example 1 A reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a reflux condenser equipped with a water sample tube was charged with 1,830 g of hydrogenated castor oil fatty acid having an acid value of 178 ( 6 moles) and xylene 60 to aid reflux
ml and reacted at 200 to 220 ° C. for 6 hours under a nitrogen stream. During this time, water generated by the condensation reaction was distilled out of the system by azeotropic distillation. As a result, an oxyfatty acid oligomer (B ′) having an acid value of 34 and a saponification value of 194 was obtained. This oxy fatty acid oligomer (B ') corresponds to the hexamer of the above hydrogenated castor oil fatty acid.

Synthesis Example 2 915 g (3 mol) of hydrogenated castor oil fatty acid having an acid value of 178 and 284 g (1 mol) of stearic acid were placed in a reactor equipped with a stirrer, a thermometer, a nitrogen inlet tube, and a reflux condenser equipped with a test tube. ) And 60 ml of xylene to assist reflux,
The reaction was carried out at 200 to 220 ° C. for 6 hours under a nitrogen stream. During this time, water generated by the condensation reaction was distilled out of the system by azeotropic distillation. As a result, an oxyfatty acid oligomer (B ′) having an acid value of 58 and a saponification value of 195 was obtained. This oxy fatty acid oligomer (B ′) corresponds to a trimer or tetramer of the above fatty acid mixture.

Synthesis Example 3 An oxyfatty acid oligomer (B ′) having an acid value of 42 and a saponification value of 192 corresponding to the hydrogenated castor oil fatty acid tetramer was prepared in the same manner as in Synthesis Example 1 except that the reaction conditions were slightly changed. ) Was synthesized.

Synthesis Example 4 An oxy fatty acid having an acid value of 90 and a saponification value of 216 corresponding to a dimer of a fatty acid mixture was prepared according to Synthesis Example 2, except that 2 mol of hydrogenated castor oil fatty acid and 1 mol of lauric acid were used. Oligomers (B ') were synthesized.

<Summary of Synthesis Examples> The synthesis conditions and characteristic values of the oxyfatty acid oligomer (B ') in Synthesis Examples 1 to 4 are summarized in Table 1. In Table 1, the numbers in parentheses are the charged moles. HCOFA is hydrogenated castor oil fatty acid, Ste is stearic acid, Lau is lauric acid. AV is the acid value (neutralization value)
(mgKOH / g), SV is saponification value (total of ester value and acid value)
(mgKOH / g) and Vis. are viscosity (cps / 25 ° C).

[0037]

[Table 1] Synthesis conditions Characteristic value AV SV Vis. Appearance synthesis example 1 HCOFA (6) → hexamer 34 194 2400 liquid Synthesis example 2 HCOFA (3) + Ste (1) → 3 to tetramer 58 195 870 liquid synthesis example 3 HCOFA (4) → 4 ~ pentamer 42 192 1540 Liquid Synthesis Example 4 HCOFA (2) + Lau (1) → Dimer 90 216 350 Liquid

<Raw Oil (A)> As the raw oil (A), a commercially available mineral oil used for grease was used.

<Alkali (C)> As the alkali (C), an aqueous solution having a lithium hydroxide concentration of 50% by weight in which lithium hydroxide hydrate (LiOH.H ₂ O) was dissolved in water was prepared.

<Production of Soap Grease> In the production process shown in FIG. 1 (using a laboratory-scale apparatus), 100 parts of the above-mentioned raw material oil (A) and oxyfatty acid oligomer (B ′) of Synthesis Examples 1 to 4 were used. 10 parts and a predetermined amount of the alkali (C) (a saponification value of the fatty acid (B)) were charged into the contactor (1) by liquid feeding. Heating the contactor
The heating medium oil (D) was passed through the jacket (1a) of (1). The temperature was gradually increased with stirring until the internal temperature reached 21
The temperature was raised to 0 to 230 ° C. and maintained at this temperature for a predetermined time to sufficiently perform a saponification reaction. After the completion of the reaction, the reaction product was taken out from the bottom of the contactor (1), and passed through a finishing pot (2), a mill (3), a defoamer (4), and a filter (5) to obtain a product grease according to a conventional method.

Oxyfatty acid oligomers of Synthesis Examples 1-4
When any of (B ′) was used, the automatic charging property was good, and grease of the designed quality could be obtained.

[0042]

According to the present invention, an oxyfatty acid oligomer (B ') is used in place of the conventional fatty acid (B).
Not only the feedstock oil (A) but also the oxyfatty acid oligomer (B ') can be automatically charged into the contactor (1) by liquid feeding, so the fatty acid (B) which had been a pending issue in the manufacture of soap-based grease Various problems resulting from the introduction of powder are solved at once.

In addition, the oxy fatty acid oligomer (B ') is intended for the user because the type of constituent fatty acids can be selected in consideration of the performance of the target grease and liquefaction can be achieved by adjusting the degree of condensation. It is possible to obtain grease having characteristics suitable for the application.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a manufacturing process and a manufacturing apparatus of a soap-based grease.

[Explanation of symbols]

(1) ... contactor, (1a) ... jacket, (1b) ... manhole, (2) ... finishing pot, (3) ... mill, (4) ... defoaming machine, (5)
... Filter, (A) ... raw oil, (B) ... fatty acid, (C) ... alkali, (D) ... heating medium oil, (E) ... additive

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukari Taketsuji 13-26, Suehirocho, Yokkaichi, Mie Pref.

Claims (2)

[Claims] 1. A dimer or more oxyfatty acid oligomer (B ') having a structure in which a feed oil (A) and a fatty acid having an OH group or a fatty acid having an OH group and a fatty acid having no OH group are condensed. And alkali (C) at least
(A) and the oxyfatty acid oligomer (B ') are supplied in liquid form to the contactor (1) to carry out the reaction, and then the reacted product after the reaction is derived from the contactor (1) and used for the subsequent steps. Method of producing soap-based grease. 2. The method according to claim 1, wherein the fatty acid having an OH group is a hydrogenated castor oil fatty acid.