JPH0749564B2 - Process for producing castor oil polymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel method for obtaining a high-viscosity castor oil polymer by using castor oil as a raw material.

Conventional technology <Castor oil, its characteristic value, application> Castor oil is Ricinoleic acid (that is, 12-hydroxy-9
-Octadecenoic acid) as the main component of fatty acid tolglyceride, less than 90% of its constituent fatty acids are ricinoleic acid, and most of the remaining fatty acids do not have hydroxyl groups, so one molecule of castor oil is It has about 2.7 hydroxyl groups.

The characteristic values of a typical commercially available castor oil vary depending on the degree of refining, but are as follows.

Hue: Gardner Helige 1-3 Acid value: 0.2-4.0 mg KOH / g Hydroxyl value: 155-163 mg KOH / g Saponification value: 176-191 mg KOH / g Iodine value: 80-90 I ₂ g / 100g Viscosity: 6.7-6.9 ps / 25 ℃ Castor oil is used as a raw material for polyurethane production, paint raw material, lubricating oil, electrical insulating oil, thixotropic agent, cosmetics, plasticizer, etc. In particular, the use of castor oil as a raw material for producing polyurethane, that is, the use as urethane polyol is important because it has a wide range of applications such as sealants, molding materials, electric insulating paints, inks, adhesives, and medical materials.

<Blown castor oil, its advantages> Conventionally, attempts have been made to increase the molecular weight of castor oil,
As one of them, the castor oil is heated while being blown with air to obtain an oxidative polymer having a high viscosity.

This oxidative polymer is generally called blown castor oil, and is used as a plasticizer for nitrocellulose lacquer, a pigment dispersant, and is also used as a urethane polyol.

Blown castor oil has low bleed when used as a plasticizer for nitrocellulose lacquer (difficult to sweat), has excellent dispersibility when used as a pigment dispersant, and is used as a urethane polyol. When it is used, there is an advantage that a cured product having excellent mechanical properties of polyurethane can be obtained.

Problems to be Solved by the Invention However, blown castor oil undergoes a polymerization reaction for a long period of time (for example, 24 to 64 hours) under the conditions of blowing air during its production, and therefore its productivity is low. There are problems that it is extremely bad and easily causes side reactions, that the obtained product has an unnecessarily high acid value, the hue is extremely dark, and the odor due to oxidative decomposition is strong.

It is an object of the present invention to provide a method for obtaining a castor oil polymer which does not have the above problems in such a background.

Means for Solving the Problems In the method for producing a castor oil polymer of the present invention, 100 parts by weight of castor oil and 1 to 20 parts by weight of an organic peroxide (especially di-t-butyl peroxide) are reacted by heating. It is characterized by that.

As castor oil as a starting material, commercially available castor oil having various degrees of refinement can be used as it is.

About 90% of castor oil constituent fatty acids are formula The remaining is oleic acid (about 7%), linoleic acid (about 3%), dioxystearic acid (1% or less), and other saturated acids (about 2%). Therefore, 3 in 1 molecule of castor oil, which is a fatty acid triglyceride
It can be said that each of the three constituent fatty acids is mainly ricinoleic acid, and two is ricinoleic acid and the other one is a fatty acid other than ricinoleic acid.

Examples of the organic peroxide to be reacted with castor oil include di-t-butyl peroxide, t-butyl cumyl peroxide, methyl ethyl ketone peroxide,
Examples thereof include cyclohexanone peroxide, dicumyl peroxide, cumene hydroperoxide and t-butyl perbenzoate. Among these, the formula The di-t-butyl peroxide represented by is particularly useful and practically limited thereto.

The ratio of castor oil and organic peroxide to be charged is selected from the range of 1 to 20 parts by weight for the former 100 parts by weight. When the ratio of the latter is less than 1 part by weight, the degree of polymerization becomes low and the intended polymerization purpose cannot be achieved. On the other hand, when it exceeds 20 parts by weight, side reactions become excessive and the quality of the target polymer deteriorates.

At the time of charging, castor oil and organic peroxide may be charged all at once, but for control of the reaction, it is better to charge castor oil in the reactor first and add organic peroxide dropwise to it. Is.

The reaction temperature is preferably 110 to 180 ° C. If the reaction temperature is lower than 110 ° C, it is difficult to obtain the target polymer because the reaction rate is slow, while if it exceeds 180 ° C, a side reaction occurs and the quality of the target polymer is deteriorated. Get inferior.

The reaction is preferably performed in an atmosphere of an inert gas such as nitrogen gas.

Typical reaction operations include stirrers, thermometers, refluxers,
Castor oil was charged into a reactor equipped with a receiver, an inert gas introducing pipe, a dropping funnel, etc., and the temperature was 110 to 180 ° C., preferably 12
Maintaining the temperature at 0 to 160 ° C., while blowing an inert gas, the organic peroxide is added dropwise thereto over 0.2 to 2 hours, and after completion of the dropping, the decomposition product is further decomposed at a temperature of 110 to 180 ° C., preferably 120 to 170 ° C. A method of continuing the reaction for 1 to 6 hours while collecting in a receiver is adopted.

By the above reaction, a light-colored and transparent castor oil polymer is typically obtained.

This castor oil polymer can be used not only for the conventional use of blown castor oil, but also for various other uses. Also, various derivatives can be obtained by hydrogenating the double bond of the castor oil polymer, transesterifying with other triglyceride, acetylating the hydroxyl group, or dehydration reaction.

The castor oil polymer obtained by the method of the present invention can be used for applications such as polyurethane production raw materials (urethane polyol), coating raw materials, lubricating oils, electrical insulating oils, thixotropic agents, cosmetics, and plasticizers.

When used as a urethane polyol, it is used alone or in combination with castor oil, polyether polyol, polyester polyol, hydrocarbon-based polyol, etc., for reaction with a polyisocyanate compound.

As the polyisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate or a carbodiimide modified product thereof, naphthalene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, various polyisocyanates including phenylene diisocyanate,
Alternatively, adducts with these polyhydric alcohols (trimethylolpropane, etc.) are used.

The blending ratio of the urethane polyol and the polyisocyanate is preferably 0.8 to 1.4 equivalents of the isocyanate groups in the polyisocyanate with respect to the total amount of the hydroxyl groups in the urethane polyol because sufficient curing can be achieved.

Action In the present invention, during polymerization, dehydration (reduction of hydroxyl value),
Side reactions such as saponification (increased acid value), decomposition (increased saponification value), oxidation (decreased iodine value) hardly proceed,
Only the polymerization proceeds while maintaining the functional group of castor oil as it is.

The castor oil polymer obtained by the method of the present invention has the general formula Indicated by.

In the formula, RCO is a fatty acid residue constituting castor oil. However,
One or two of the three RCOs are radicals in which one H atom of the fatty acid residues constituting castor oil is eliminated.

n is 2, 3, 4, etc., and n = 1 (when the reaction temperature is relatively low, the reaction time is short, the amount of organic peroxide charged is small, etc.). Those not)
Seems to be included. It is not impossible to separate the reaction products according to the degree of polymerization, but it is not significant to separate the reaction products according to the degree of polymerization in consideration of practical use, and therefore, a mixture having various n is usually used as it is. The average value of n of the reaction product is about 1.2 to 20, preferably about 1.5 to 10.

In the castor oil polymer represented by the above formula (I), it is not always possible to specify which H atom of the castor oil-constituting fatty acid residue RCO- is eliminated to form a radical. Of the ricinoleic acid residue shown by, the H atom mainly bonded to the C atom adjacent to CH = CH is released, and a part of the H atom bonded to another C atom is released. It seems to be there.

EXAMPLES Next, the present invention will be further described with reference to Examples.

(A) Production of castor oil polymer A starting material Castor oil having the following characteristics was used as a starting material.

Hue: Gardner Helly gate 2 acid value: 0.8 mg KOH / g hydroxyl value: 160.5mgKOH / g saponification value: 182.3mgKOH / g Iodine value: 86.7I ₂ g / 100g (Uisu Method) Viscosity: 6.8ps / 25 ℃ Example 1 200 g of castor oil was charged into a 500 cc flask equipped with a stirrer, a thermometer, a reflux machine, a receiver, a nitrogen gas introduction tube and a dropping funnel, and the temperature was raised to 140 ° C.

The internal temperature was kept at 140 to 150 ° C. while blowing nitrogen gas, and 12 g of di-t-butyl peroxide (6% based on castor oil) was added dropwise thereto over about 20 minutes.

After completion of the dropping, the reaction was continued for another 4 hours while collecting the decomposed product in a receiver at 150 to 160 ° C.

Then, the decomposed product was removed in a vacuum, and 0.5% each of clay and celite were added, followed by filtration to obtain a light-colored transparent viscous castor oil polymer.

Example 2 A flask was charged with 200 g of castor oil and the temperature was raised to 140 ° C.

The internal temperature was maintained at 140 to 150 ° C. while blowing nitrogen gas, and 14 g of di-t-butyl peroxide (7% based on castor oil) was added dropwise thereto over about 30 minutes.

After completion of the dropping, the reaction was continued for another 4 hours while collecting the decomposed product in a receiver at 150 to 160 ° C.

Then, the decomposed product was removed in a vacuum, and 0.5% each of clay and celite were added, followed by filtration to obtain a light-colored transparent viscous castor oil polymer.

Example 3 200 g of castor oil was charged into a flask and the temperature was raised to 140 ° C.

While blowing nitrogen gas, the internal temperature was kept at 140 to 150 ° C., and 18 g of di-t-butyl peroxide (9% based on castor oil) was added dropwise thereto over about 40 minutes.

After completion of the dropping, the reaction was continued for another 4 hours while collecting the decomposed product in a receiver at 150 to 160 ° C.

Then, the decomposed product was removed in a vacuum, and 0.5% each of clay and celite were added, followed by filtration to obtain a light-colored transparent viscous castor oil polymer.

Comparative Example 1 200 g of castor oil was charged into a flask with a stirrer set so that the tip of the air introduction tube reached the bottom of the flask.
Air was blown at a rate of 50cc per minute with an air compressor while heating to 150 ° C and stirring. This air oxidation reaction was continued for 24 hours.

Comparative Example 2 In the same manner as in Comparative Example 1, the air oxidation reaction was continued for 38 hours.

Comparative Example 3 In the same manner as in Comparative Example 1, the air oxidation reaction was continued for 60 hours.

Castor oil polymer obtained in Examples 1 to 3, Comparative Examples 1 to 3
Table 1 shows various characteristics of the blown castor oil obtained in the above. In addition, various characteristics of the raw castor oil are shown in Table 1.

(See Table 1) From Table 1, the castor oil polymer obtained by the method of the present invention obtained in Examples 1 to 3 has a rather good hue compared to the raw castor oil, and has an acid value and a hydroxyl group. It can be seen that there is almost no change in the valency, saponification number and iodine value, and only the viscosity is high.

From this, in Examples 1 to 3, during polymerization, dehydration (decrease in hydroxyl value), saponification (increase in acid value), decomposition (increase in saponification value), oxidation (decrease in iodine value), etc. It can be seen that the side reaction hardly progressed, and only the polymerization proceeded while maintaining the functional group of castor oil as it was.

On the other hand, the blown castor oils obtained in Comparative Examples 1 to 3 are:
Although the viscosity is increased to the same level as in Examples 1 to 3, the hue is remarkably deeper than that of the raw castor oil, the acid value is high, the hydroxyl value is low, and the saponification value is high. It can be seen that the iodine value is low and the change is large.

From this, the blown castor oils obtained in Comparative Examples 1 to 3 are common to the castor oil polymers obtained in Examples 1 to 3 in that they are polymerized, but during the polymerization, dehydration ( Decrease in hydroxyl value), saponification (increase in acid value), decomposition (increase in saponification value), oxidation (decrease in iodine value), etc., and as a result, the functional groups of castor oil are considerably Turns out to be damaged.

Example 4 A 500 cc flask was charged with 200 g of castor oil and the temperature was raised to 140 ° C.

While blowing nitrogen gas, the internal temperature was kept at 140 to 150 ° C., and 24 g of t-cumylbutyl peroxide (12% based on castor oil) was added dropwise over about 40 minutes.

After completion of the dropping, the reaction was continued for another 5 hours while collecting the decomposed product in a receiver at 150 to 160 ° C.

Then, the decomposed product was removed in a vacuum, and after adding 0.5% each of clay and celite, the mixture was filtered to obtain a light yellow transparent viscous castor oil polymer.

Example 5 200 g of castor oil was charged into a 500 cc flask, and the temperature was raised to 140 ° C.

The internal temperature was kept at 140 to 150 ° C. while blowing nitrogen gas, and 14 g of methyl ethyl ketone peroxide (diluted to 55% with dimethyl phthalate) was added dropwise thereto over about 30 minutes.

After completion of the dropping, the reaction was continued for another 5 hours while collecting the decomposed product in a receiver at 150 to 160 ° C.

Then, the decomposed product was removed in vacuum, and after adding 0.5% each of clay and Celite, the mixture was filtered to obtain a slightly viscous castor oil polymer.

Example 6 500 g of castor oil was charged into the flask of 1 and heated to 110 ° C.

The internal temperature was maintained at 110 to 120 ° C. while blowing nitrogen gas, and 30 g of di-t-butyl peroxide (6% based on castor oil) was added dropwise thereto over about 1 hour.

After the dropwise addition was completed, the reaction was continued at the same temperature for 30 hours, the decomposed product and unreacted di-t-butyl peroxide were removed in vacuo, and after adding 0.5% of each of clay and celite, the mixture was filtered.

The viscosity of the obtained castor oil polymer was 7.0 ps / 25 ° C.,
The castor oil used as a raw material was almost unchanged.

The characteristics of the castor oil polymers obtained in Examples 4 to 6 are described below.
Shown in the table.

(B) Production of Polyurethane Production Example 1 Castor oil polymer obtained in Example 2 was modified with carbodiimide 4,
4-diphenylmethane diisocyanate (Millionate MTL manufactured by Nippon Polyurethane Industry Co., Ltd.) was blended so that the NCO / OH equivalent ratio was 1.05, poured into a mold immediately after stirring for 2 minutes, and cured at a temperature of 120 ° C. for 1 hour to give a thickness of 3 mm. A polyurethane sheet was obtained.

Comparative Production Example 1 Production Example 1 except that the blown castor oil obtained in Comparative Example 2 was used.
A polyurethane sheet was obtained in the same manner as in.

Reference Production Example 1 A polyurethane sheet was obtained in the same manner as in Production Example 1 except that castor oil was used instead of the castor oil polymer.

Table 3 shows the physical properties of the polyurethane sheets obtained in Production Example 1, Comparative Production Example 1 and Reference Production Example 1.

It can be seen from Table 3 that the polyurethane sheet obtained in Production Example 1 has more preferable mechanical properties than the polyurethane sheet obtained in Comparative Production Example 1.

EFFECTS OF THE INVENTION The method of the present invention is suitable for industrial production because a polymer having a high viscosity can be obtained in a reaction in an extremely short time as compared with the conventional production of blown castor oil.

In addition, the obtained polymer has a light hue, and the polymerization proceeds while maintaining the functional groups of the raw castor oil as it is to increase the viscosity.

In addition, when this castor oil polymer is used as a urethane polyol, the mechanical properties of the resulting polyurethane cured product are superior to those when a conventional blown castor oil is used as a urethane polyol, and it is also colored. small.

Therefore, the method of the present invention is extremely useful industrially.

Claims (3)

[Claims] 1. Castor oil 100 parts by weight and organic peroxide 1 to 20.
A method for producing a castor oil polymer, which comprises reacting with parts by weight by heating. 2. The heating reaction is conducted under an inert gas atmosphere at a temperature.
Claim 1 characterized by performing at 110-180 ℃
The manufacturing method described in the item. 3. The method according to claim 1, wherein the organic peroxide is di-t-butyl peroxide.