JPH05194654A - Production of polymer of fumaric or maleic acid dialkyl ester - Google Patents

Abstract

PURPOSE:To produce the polymer from fumaric or maleic acid dialkyl ester in high yield. CONSTITUTION:The radical polymerization initiator is added batchwise which at least 4 portions or continuously over at least 2 hours where over 2/3 amount of the total initiator is not added in a specific 1/5 interval of the above- mentioned addition time. The polymer yield can attain more than 70%, particularly 80 to 100%.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a polymer from a fumaric acid dialkyl ester or a maleic acid dialkyl ester.

[0002]

It is known to polymerize a dialkyl fumaric acid ester in the presence of a radical polymerization initiator (A
cta Polymerica 39 (1988) No. 1, 5-8 and Polymer Jo
urnal, Vol. 15, No. 4, pp 255-260, 1983). Also,
It is also known to polymerize a maleic acid dialkyl ester in the presence of an isomerization catalyst and a radical polymerization initiator (supra). Maleic acid dialkyl ester is said to be polymerized after being isomerized to fumaric acid dialkyl ester.

In the above, the yield of the obtained polymer is as low as several% to 30% when the alkyl group is a linear alkyl group (methyl group, ethyl group, n-propyl group, n-butyl group). ..

[0004]

The object of the present invention is to improve the yield in the above polymerization reaction.

[0005]

The present invention provides a method for producing a polymer by polymerizing a dialkyl fumaric acid ester or a dialkyl maleic acid ester in the presence of a radical polymerization initiator, wherein at least 2 radical polymerization initiators are used. Added batchwise or continuously in at least 4 times over the addition time of time, provided that the amount exceeds 2/3 of the total amount of radical polymerization initiator at a specific 1/5 time interval of the above addition time. The method is characterized by not adding.

The total amount of radical polymerization initiator (hereinafter sometimes referred to simply as "initiator") added is preferably at least 1/100, particularly at least 3/100, of the starting ester. Is. If the total amount is too large, there is no particular advantageous effect, and the molar ratio is generally 2/10 or less.

The present invention is characterized in that the initiator is not added all at once to the polymerization reaction system, but batchwise or continuously. This gives a yield of preferably 70%
Above all, it can be 80 to 100% in particular.

The initiator is added over a period of at least 2 hours, preferably 3 to 12 hours. During this addition time, the total amount of initiator is added batchwise or continuously in at least 4 times, preferably at least 10 times. Ultimately, continuous addition will occur as the number of batches is increased. If the number of batches is increased, the total amount of the initiator tends to be decreased.

It is not necessary to add the same amount of initiator in each batch, but if they are too different, the effect of the present invention will be lost due to the addition of a large amount of initiator at once. At a specific time interval corresponding to 1/5 of the initiator addition time,
Do not add more than 2/3 of the total amount of initiator. Preferably, no more than 1/5 of the total initiator is added in a particular time interval corresponding to 1/10 of the addition time. It is also a preferred embodiment that the total amount of the initiator is divided into 10 to 20 times, and the initiator is added at substantially equal time intervals. In industrial mass production, it is easy to add the initiator continuously at a constant flow rate.

The alkyl group in the fumaric acid dialkyl ester and maleic acid dialkyl ester as the starting materials in the present invention preferably has 8 or less carbon atoms, and particularly 4 carbon atoms.
Up to and including 4 alkyl groups. When the alkyl group has a straight chain, the yield of the conventional method was particularly poor, so that the effect of the present invention is more remarkable.

As the radical polymerization initiator itself, known ones can be used. Azonitrile compounds, such as 2,
2'-azobisisobutyronitrile, 1-1'-azobiscyclohexanecarbonitrile, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (2, 4-dimethylvaleronitrile) and the like; azoamidine compounds such as 2,2'-azobis (2-methyl-N-phenylpropionamidine, 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2 ' -Azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, etc .; Azoamide compounds, such as 2,2'-azobis (isobutyramide) dihydrochloride, 2,2'-azobis {2-methyl- N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide} and the like; alkylazo compounds such as azodi-tert-octane, azodi-tert-butane, dimethyl 2,2 ′
-Azobisisobutyrate and the like. Further, organic peroxides are also preferably used, and ketone peroxides,
For example, methyl ethyl ketone peroxide, cyclohexanone peroxide, methyl cyclohexanone peroxide, etc .; peroxyketals such as 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, 1,1-bis (t-butyl) Peroxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, etc .; hydroperoxides such as t-butyl hydroperoxide, di-isopropylbenzene hydroperoxide, etc .; dialkyl peroxides such as di-t
-Butyl peroxide, di-cumyl peroxide,
t-butyl cumyl peroxide, etc .; diacyl peroxide, such as acetyl peroxide, isobutyryl peroxide, benzoyl peroxide, etc .; peroxydicarbonate, such as di-isopropyl
Peroxydicarbonate, di-n-propyldicarbonate, di-methoxyisopropyl peroxydicarbonate, etc .; peroxyesters such as t-butylperoxyacetate, t-butylperoxyisobutyrate, cumylperoxyneodecanate , T-butyl peroxybenzoate, t-hexyl peroxy neodecanoate and the like. However, it is not limited to these. Preferred initiators are 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), and di-t-butylperoxide.

The polymerization temperature is preferably 50 to 180 ° C.,
Particularly, it is 80 to 160 ° C. After all of the initiator has been added, it is preferable to continue the reflux stirring while maintaining this temperature. It takes preferably 6 to 40 hours, particularly 10 to 30 hours from the start of addition of the initiator to the termination of the polymerization reaction.

When the starting ester is maleic acid dialkyl ester, the polymerization reaction hardly progresses only by adding the initiator, and the polymerization reaction proceeds by adding the isomerization catalyst. This is known per se. It is believed that when an isomerization catalyst is added, the maleic acid dialkyl ester first isomerizes to the fumaric acid dialkyl ester, which then polymerizes. The isomerization catalyst may be added to the polymerization reaction system at a molar ratio of 1/27 to 1/2700 with respect to the starting ester, and otherwise the same as in the case of the above-described polymerization of the dialkyl fumarate ester. As an isomerization catalyst,
Known morpholine, piperidine, dipropylamine, propylamine, preferably morpholine can be used.

The polymerization reaction system may further contain a solvent,
The amount of the solvent is preferably such that the starting ester concentration is 10% by weight or more. As the solvent, those generally used for radical polymerization, for example, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, p-xylene, o-xylene, benzene, toluene, tetrahydrofuran and the like can be used.

The polymers produced according to the present invention are generally 400 to 30,000, preferably 400 to 3,000.
Is a mixture of polymers having a number average molecular weight in the range.
Various reaction conditions such as the concentration of the starting ester in the polymerization reaction system, the type of initiator and the mode of addition, the reaction temperature and the time may influence the molecular weight. Since the product polymer is liquid and stable at room temperature, it can be used as a lubricating oil or a refrigerating machine oil.

The present invention will be further described below with reference to examples. The molecular weight of the produced polymer was determined by the vapor pressure measurement method (VPO). The yield was determined as the ratio of the weight of the residue to the weight of the starting ester after removing the light components from the polymerization reaction system by vacuum distillation.

[0017]

Example 1 305 mmol of diethyl fumarate (52.5 g, 50 ml) was placed in a 100 ml one-necked flask, a dropping funnel and a cooling tube were attached, and the flask was set in an oil bath. While stirring with a magnetic stirrer and keeping the temperature at 135 ° C, 2,2'-azobisisobutyronitrile (AIBN) 10m mo
A solution of 1 (1.6 g) in tetrahydrofuran (20 ml) was added dropwise over 4 hours, and heating was continued for another 20 hours. Then, the light fraction was distilled off under reduced pressure to obtain 42 g of a polymer (yield 80
%). Number average molecular weight (Mn) = 840

[0018]

Example 2 The procedure of Example 1 was repeated, except that the reaction temperature was 145 ° C. 47 g of a polymer was obtained (yield 90%).
Mn = 840

[0019]

Example 3 In a 200 ml one-necked flask, 305 mmol of diethyl fumarate (52.5 g, 50 ml) and 50 ml of p-xylene were placed, a dropping funnel and a cooling pipe were attached, and the flask was set in an oil bath. While stirring and refluxing with a magnetic stirrer, keeping the temperature at 135 ° C., 2,2′-azobisisobutyronitrile (AIBN) 35 mmol (5.8 g) of p-xylene (5
The solution (0 ml) was continuously added dropwise in a constant amount over 12 hours, and heating under reflux was continued for another 12 hours. Then, the light fraction was distilled off under reduced pressure to obtain 57 g of a polymer (yield 100%). Mn =
570

[0020]

Example 4 Example 3 was repeated except that the amount of p-xylene was 100 ml. 52 g of a polymer was obtained (yield 100
%). Mn = 570

[0021]

Example 5 Example 3 was repeated except that the amount of p-xylene was 200 ml. 54 g of a polymer was obtained (yield 100
%). Mn = 520

[0022]

Example 6 Example 3 was repeated except that the amount of p-xylene was 400 ml and heating and refluxing were continued for 19 hours after the addition of AIBN was completed. 49.1 g of a polymer was obtained (94% yield). Mn =
440

[0023]

Example 7 Example 3 was repeated except that 50 ml of o-xylene was used instead of p-xylene and the reaction temperature was 145 ° C. 54 g of a polymer was obtained (yield 100%).

[0024]

Example 8 2-butanone (MEK) 50 instead of p-xylene
Example 3 was repeated except that ml was used and the reaction temperature was 80 ° C. 48.8 g of a polymer was obtained (yield 93%).

[0025]

Example 9 Example 3 was repeated except that 50 ml of 4-methyl-2-pentanone (MIBK) was used in place of p-xylene and the reaction temperature was 118 ° C. 54 g of a polymer was obtained (yield 1
00%).

[0026]

Example 10 Cyclohexanone 5 instead of p-xylene
Example 3 was repeated except that 0 ml was used and the reaction temperature was 155 ° C. 52.5 g of polymer was obtained (yield 100
%).

[0027]

Example 11 217 mmol of di-n-butyl fumarate (49.5 g) was used as a starting ester, and the amount of AIBN was 27.5 mm.
Example 7 was repeated except that ol (4.5 g) was used. Polymer 5
0 g was obtained (yield 100%).

[0028]

Example 12 Using 310 mmol of diethyl maleate (53.5 g, 50 ml) as the starting ester, morpholine 1.1
Other than adding 4 mmol (0.1 ml) to the reaction system at the beginning,
Example 3 was repeated. 53 g of a polymer was obtained (yield 100
%).

[0029]

[Comparative Example 1] 100 ml of diethyl fumarate (305 mmol, 52.5 g, 50 ml) was placed in a three-necked flask, a cooling pipe was attached, and the mixture was set in an oil bath. Stir with a magnetic stirrer and maintain the temperature at 135 ° C while refluxing for 2,2-
5 mmol (8.2 g) of azobisisobutyronitrile (AIBN) was added all at once, and heating under reflux was continued for 12 hours. Then, the light fraction was distilled off under reduced pressure to obtain 36 g of a polymer (yield 68%).

[0030]

[Comparative Example 2] 305 mmol of diethyl fumarate (52.5 g, 50 ml) and 250 ml of p-xylene were placed in a 300 ml four-necked flask, a cooling pipe was attached, and the flask was set in an oil bath. The mixture was stirred with a magnetic stirrer, the temperature was kept at 135 ° C. while refluxing, 50 mmol (8.2 g) of AIBN (2,2′-azobisisobutyronitrile) was added at once, and the mixture was heated under reflux for 12 hours. Then, the light fraction was distilled off under reduced pressure to obtain a polymer 2
0.4 g was obtained (38% yield).

[0031]

Comparative Example 3 Comparative Example 1 was repeated except that 250 ml of o-xylene was used instead of p-xylene and the reaction temperature was 145 ° C. 35.5 g of a polymer was obtained (yield 68%).

[0032]

[Comparative Example 4] 2-butanone (MEK) 25 instead of p-xylene
Comparative Example 1 except that 0 ml was used and the reaction temperature was 80.degree.
Was repeated. 23.5 g of a polymer was obtained (yield 45%).

[0033]

Comparative Example 5 Comparative Example 1 was repeated except that 250 ml of 4-methyl-2-pentanone (MIBK) was used instead of p-xylene and the reaction temperature was 118 ° C. 14.7 g of a polymer was obtained (yield 28%).

[0034]

[Comparative Example 6] Cyclohexanone 25 instead of p-xylene
Comparative Example 1 was repeated except that 0 ml was used and the reaction temperature was 155 ° C. 21.6 g of a polymer was obtained (yield 43%).

[0035]

Example 13 In a 500 ml four-necked flask, 305 mmol of diethyl fumarate (52.5 g) and 400 ml of p-xylene were placed, a cooling pipe was attached, and an oil bath was set. Stir with a magnetic stirrer and bring the temperature to 13 with reflux.
Keep at 5 ℃, 2,2-azobisisobutyronitrile (AIBN) 5
m mol (0.82 g) was added in 7 portions every 4 hours, that is, a total of 35 mmol was added over 30 hours, and then the light fraction was distilled off under reduced pressure to obtain 37.5 g of a polymer. (Yield 71
%).

Claims (1)

[Claims] 1. A method for producing a polymer by polymerizing a fumaric acid dialkyl ester or a maleic acid dialkyl ester in the presence of a radical polymerization initiator, wherein the radical polymerization initiator is reduced for at least 2 hours. Both are added batchwise or continuously in four times, provided that an amount exceeding 2/3 of the total amount of radical polymerization initiator is not added at a specific time interval of 1/5 of the above addition time. Method.