JP2653067B2 - Method for producing α-olefin-maleic anhydride copolymer - Google Patents

Description

The present invention relates to a method for producing an α-olefin-maleic anhydride copolymer. More specifically, the present invention relates to an improvement in a method for producing an α-olefin-maleic anhydride copolymer by subjecting an α-olefin and maleic anhydride to a radical copolymerization reaction in the presence of a peroxide.

[Conventional technology]

α-Olefin-maleic anhydride copolymers are widely used in applications such as waxes for thermal transfer inks, fluidity improvers, lubricant additives, rust inhibitors, various dispersants, floor polishes, and the like. The α-olefin-maleic anhydride copolymer is obtained by a radical copolymerization reaction between an α-olefin and maleic anhydride in the presence of a peroxide, and the radical copolymerization reaction involves a rapid exothermic reaction. Therefore, the reaction temperature is adjusted by removing the heat of the reaction with an internal cooling coil or an external cooling jacket.

[Problems to be solved by the invention]

However, it has been found that in the above method, even a slight change in the reaction temperature, for example, a temperature change of 1 ° C., significantly changes the viscosity of the obtained copolymer. Therefore, in order to produce a copolymer having a specific viscosity, it is necessary to precisely control the reaction temperature.

However, the control of the reaction temperature on an industrial scale is not always easy because the method involves an exothermic reaction, and therefore it is difficult to control the viscosity of the resulting copolymer. There was a point.

[Means for solving the problem]

In view of the above problems in the conventional method, the present inventors have considered α-
As a result of intensive studies on the method of adjusting the viscosity of the copolymer at the time of producing a copolymer by performing a radical copolymerization reaction of an olefin and maleic anhydride in the presence of a peroxide, Performing in a multi-step process,
First, in the first step, a peroxide is added to the reaction raw material to produce a copolymer having a viscosity lower than the desired viscosity, and then in the second step, the reaction product of the first step is added to the reactant of the first step. Further, the present inventors have found that the viscosity can be easily adjusted by adding a peroxide to adjust the viscosity of the copolymer, and have reached the present invention.

That is, the present invention provides a method for producing an α-olefin-maleic anhydride copolymer by copolymerizing an α-olefin and maleic anhydride in two steps in the presence of a peroxide, A radical copolymerization reaction of an olefin and maleic anhydride in the presence of a peroxide to first produce a copolymer having a viscosity of 10 to 80% of the finally desired viscosity (No. 1) Stage reaction), and then (b) 10 to 70 mol% of the peroxide added in the first stage reaction to the reaction system of the first stage reaction to add 5 to 5 mol% of the peroxide in the first stage reaction. A method for producing an α-olefin-maleic anhydride copolymer, characterized by further performing a copolymerization reaction at a reaction temperature lower by 60 ° C. to finally produce a copolymer having a desired viscosity (second stage reaction). , Is the gist.

 Hereinafter, the present invention will be described in more detail.

In the present invention, the raw material α-olefin is usually
Those having 5 or more carbon atoms, preferably those having 10 to 100 carbon atoms are used.
-It may be a mixture of olefins. Examples of the production method include α-olefins obtained by pyrolysis of wax or α-olefins obtained by low polymerization of ethylene. As the α-olefin, for example, carbon atoms of 6 to 10
Α-olefin mixture (for example, “Dialen 610 (registered trademark)” manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) and α-olefins having 16 to 18 carbon atoms.
Olefin mixture (also "Dialen" 168), carbon number
Α-olefin mixture of 20 to 28 (also “Dialen” 2
08), and α-olefin mixtures having 30 to 60 carbon atoms (also “Dialen 30”). The molar ratio between maleic anhydride and α-olefin (α-
(Olefin / maleic anhydride) is usually 0.1 to 10.

Examples of the peroxide include benzoyl peroxide, diacetyl peroxide, lauroyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide, cumene hydroperoxide, t-butyl peroxypivalate, and the like.

In the present invention, when the α-olefin and maleic anhydride are subjected to a radical copolymerization reaction in the presence of a peroxide to produce an α-olefin-maleic anhydride copolymer, (a) α-olefin And maleic anhydride are subjected to a radical copolymerization reaction in the presence of a peroxide to produce a copolymer having a viscosity of 10 to 80% of the finally desired viscosity (the first-stage reaction). And (b) 10 to 70 mol% of the peroxide added to the reaction system of the first-stage reaction, which is added in the first-stage reaction, to 5 to 60 ° C. Further copolymerization is performed at a low reaction temperature to finally produce a copolymer having a desired viscosity (second stage reaction).

The reaction conditions for the first-stage reaction are usually selected from a peroxide / maleic anhydride molar ratio of 0.001 to 0.1, a reaction temperature of 100 to 250 ° C, preferably 150 to 200 ° C, and a reaction time of 30 minutes to 10 hours. You. In the first-stage reaction, the reaction is performed at a high temperature for a short time. Even if the reaction proceeds rapidly and the reaction temperature exceeds a predetermined value, the viscosity of the copolymer finally obtained can be adjusted to a predetermined value by selecting the reaction conditions of the second stage reaction accordingly. Can be adjusted to

Next, a peroxide is additionally added to the reaction system of the first-stage reaction and further copolymerized at a lower reaction temperature than the first-stage reaction to finally produce a copolymer having a desired viscosity. (2nd stage reaction). The amount of peroxide added in the second stage reaction depends mainly on the viscosity of the reaction product of the first stage reaction and the viscosity desired for the final product. Usually, the amount of peroxide added in the second stage reaction is 10-70 mol% of the amount added in the first stage reaction. Generally this value is 20-50 mol%
It is desirable to select the viscosity of the reaction product of the first stage reaction such that

The second stage reaction is usually performed at a temperature lower by at least 5 ° C. than the temperature of the first stage reaction. In the second stage reaction, the reaction does not proceed as rapidly as in the first stage reaction even at the same temperature. In order to obtain the final product of the desired viscosity by controlling the reaction and proceeding as quickly as possible to obtain a final product having a desired viscosity, the reaction temperature is 5 to 60 ° C.
In particular, it is preferable to carry out the reaction at a temperature lower by 10 to 40 ° C.

In the first stage reaction, first, a copolymer having a viscosity lower than the finally desired viscosity, usually 10 to 80% of the finally desired viscosity is produced. If the viscosity of the copolymer formed in the first-stage reaction is too low, the required amount of peroxide to be added in the subsequent second-stage reaction is increased, and the reaction time is undesirably increased.

As the viscosity of the copolymer formed in the first-stage reaction is closer to the finally desired viscosity, the load of the second-stage reaction is smaller, but on the contrary, the difficulty in controlling the reaction is increased, and the two-stage process as in the present invention is performed. The benefits of going through are reduced. The preferred ultimate viscosity in the first stage reaction is 20 to 60% of the final desired viscosity.
In particular, it is necessary to control the reaction and the second
It is the most preferable from both aspects of the load of the stage reaction.

The reaction conditions for the second stage reaction in the method of the present invention are usually such that the [peroxide (additional addition) / maleic anhydride] molar ratio is 0.001 to 0.1, preferably 0.001 to 0.05, and the reaction temperature is 50 to 50%.
To 250 ° C. and a reaction time within a range of 30 minutes to 24 hours.

Although the method of the first-stage reaction is not particularly limited, a predetermined amount of α-olefin is previously charged into the reactor, and maleic anhydride and peroxide are continuously or intermittently mixed at a predetermined temperature. A method of adding and reacting, a method of continuously or intermittently adding and reacting an α-olefin, maleic anhydride and peroxide to a reactor, or a method of previously charging maleic anhydride and peroxide to a reactor. Then, a method of continuously or intermittently adding an α-olefin thereto and reacting the mixture is employed. Usually, the reaction is preferably carried out under atmospheric pressure, but can be carried out under increased or reduced pressure.

The second-stage reaction is the same as the first-stage reaction, and is not particularly limited. The second reaction can be a one-stage reaction or can be divided into a multi-stage reaction.

In carrying out the method of the present invention, the method for determining the reaction conditions in each step is not particularly limited, and if the viscosity of the desired copolymer is finally determined, it is determined experimentally by some trial and error. However, as a more reliable method, for example, the following method can be mentioned.

That is, prior to producing an α-olefin maleic anhydride copolymer by the method of the present invention, (a) an α-olefin and maleic anhydride are prepared by using a predetermined amount of a peroxide to obtain a predetermined [α-olefin / Maleic anhydride], and the reaction temperature was changed in various ways, and the reaction temperature was varied. From the viscosity data of the obtained α-olefin-maleic anhydride copolymer and the reaction temperature data, a statistical method was used to determine the reaction temperature. A regression line of the viscosity of the copolymer was obtained. (B) Next, α-
Various amounts of peroxide were added to the olefin-maleic anhydride copolymer, and each was further reacted at a predetermined reaction temperature, and the viscosity data of the resulting α-olefin-maleic anhydride copolymer was obtained. A regression line of the viscosity of the copolymer with respect to the amount of the peroxide is determined by a statistical method from the data of the amount of the peroxide and the amount of the peroxide to be added. -From the viscosity of the olefin-maleic anhydride copolymer, a reaction temperature corresponding to the viscosity is determined using the regression line of (a) above, and at a temperature equal to or higher than the reaction temperature, and [ α-olefin / maleic anhydride] under the reaction conditions of the molar ratio and the amount of peroxide added,
First, a copolymer having a temperature lower than the finally desired viscosity is produced (first-stage reaction). (B) Next, from the viscosity of the copolymer, the regression line of the above (b) is used. The amount of peroxide required to finally produce an α-olefin-maleic anhydride copolymer having a desired viscosity at a predetermined temperature 5 to 60 ° C. lower than that of the first-stage reaction is determined. Is added, and the copolymer obtained in the above (a) is further reacted at the above-mentioned predetermined temperature to finally produce a copolymer having a desired viscosity (second stage reaction). Method. This will be described in more detail as follows.

First, (a) the α-olefin and maleic anhydride used in the production of the present invention are maintained at a constant [α-olefin / maleic anhydride] molar ratio, and a predetermined amount of peroxide used in the production is obtained. The radical copolymerization reaction is carried out by changing the reaction temperature variously. Then, the viscosity of each obtained α-olefin-maleic anhydride copolymer was measured, and the regression line of “viscosity” with respect to “reaction temperature” was obtained by a statistical method from the obtained viscosity data and reaction temperature data. Ask.

Next, (b) α- having different viscosities obtained in the above (a).
Various amounts of peroxide are added to the olefin-maleic anhydride copolymer, and each is further reacted at a predetermined reaction temperature. Then, the viscosity of the obtained higher-viscosity copolymer is measured, and the regression line of "viscosity" with respect to "peroxide addition amount" is obtained from the obtained viscosity data and peroxide addition amount data by a statistical method. Ask.

The concept of a regression line is known in statistics. A set of experimental values (x _i , y _i ) for variables x and y (i =
1 to n), the relation between x and y estimated by a statistical method (for example, the least squares method) is called a regression line. Even for the same set of experimental values (x _i , y _i ), different regression lines can be obtained depending on the assumed regression line shape (linear equation, quadratic equation, etc.), the statistical method used, and the like. In the present invention, the method for obtaining the regression line is not limited at all. Further, in the present invention, it is not essential to obtain a regression line (regression equation) in the form of a mathematical expression, and the “reaction temperature” and the “viscosity” And the functional relationship between the “peroxide addition amount” and the “viscosity” in (b) above.

In order to determine the reaction conditions of the present production using the above-mentioned regression line, the viscosity of the finally desired α-olefin-maleic anhydride copolymer is first determined, and then the regression line of the above (a) is used. To determine a reaction temperature corresponding to the desired viscosity. For example, FIG. 1 of the accompanying drawings can be used as the regression line in the above (a). FIG. 1 shows the results obtained when the reaction temperature was variously changed between an α-olefin and maleic anhydride in a specific [α-olefin / maleic anhydride] molar ratio and in the presence of a specific amount of peroxide. FIG. 1 shows an example of a relationship diagram (reaction temperature-viscosity relationship diagram) between the viscosity of the obtained copolymer and the reaction temperature. Therefore, the reaction temperature corresponding to the desired viscosity of the copolymer can be easily determined using FIG.

Incidentally, since the copolymerization reaction between α-olefin and maleic anhydride greatly depends on the reaction temperature, even if the above-mentioned regression line is obtained using data in which the amount of peroxide added is slightly varied, the actual Often there is no inconvenience.

The specific shape of the regression line in (a) depends on the reaction conditions set for obtaining the regression line, but generally the viscosity of the produced copolymer tends to decrease as the reaction temperature increases.

In the present production, first, at a temperature higher than the reaction temperature determined above, preferably 0.5 to 5 ° C. higher than the reaction temperature, and used to create the regression line (a) as shown in FIG. Under the reaction conditions of the obtained [α-olefin / maleic anhydride] molar ratio and the amount of peroxide added, the α-olefin and maleic anhydride are subjected to a radical copolymerization reaction to obtain a finally desired viscosity of 10 to 10%. A copolymer having a viscosity of 80% is produced (first-stage reaction).

Next, the viscosity of the obtained copolymer is measured, and the amount of peroxide required to produce a copolymer having a desired viscosity is determined from the viscosity and the regression line of the above (b). As the regression line of the above (b), for example, FIG. 2 of the accompanying drawings can be used. FIG. 2 shows the viscosity of the copolymer obtained when the copolymers having different viscosities obtained in the above (a) were further reacted at a specific reaction temperature with various amounts of peroxide added. FIG. 1 shows an example of a relationship diagram (a relationship diagram of peroxide addition amount-viscosity) between the temperature and the amount of peroxide added. The different regression lines in the figure correspond to different initial viscosities (viscosity at the end of the first-stage reaction) of the copolymer. Therefore, the viscosity of the copolymer obtained in the first-stage reaction
From the figures, it is possible to easily determine the amount of peroxide required to produce a copolymer having a desired viscosity.

Finally, under the reaction conditions of the addition amount of peroxide determined as described above and the reaction temperature used for preparing the regression line of (b) as shown in FIG. 2, By further reacting the copolymer obtained in the first-stage reaction, a copolymer having a desired viscosity can be easily produced (second-stage reaction).

〔Example〕

Next, specific embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples unless it exceeds the gist thereof.

Example 1 <Preliminary Experiment 1> After charging 650 g (1 mol) of an α-olefin having 30 to 60 carbon atoms into a flask having a capacity of 1, and sufficiently replacing the flask with nitrogen gas,
At a temperature of 175 DEG C., 162.5 g (1.66 mol) of maleic anhydride and 8.7 g (0.05 g) of di-t-butyl peroxide as peroxide.
8 mol) were continuously added over 2 hours, and the mixture was aged at that temperature for 40 minutes to cause a radical copolymerization reaction. The viscosity of the obtained copolymer was measured at 100 ° C. using a B-type viscometer. The results are shown in Table 1.

<Preliminary Experiments 2 to 5> In Preliminary Experiment 1, the same experiment was performed except that the reaction temperature or the amount of peroxide addition was changed as shown in Table 1. The results are shown in Table 1.

<Preliminary Experiments 6 and 7> The copolymers obtained in Preliminary Experiments 1 and 2 were each treated with a peroxide (di-t-butyl peroxide) in an amount shown in Table 2 at a temperature of 160 ° C. for 34 minutes (preliminary experiment). It was added over Experiment 6) or 51 minutes (Preliminary Experiment 7), aged at that temperature for 40 minutes, and further reacted (first polymerization). The viscosity of the obtained copolymer was measured at 100 ° C. using a B-type viscometer. To the reaction product was added an additional amount of peroxide (di-t-butyl peroxide) as shown in Table 2 over a period of 17 minutes (Preliminary Experiment 6) or 34 minutes (Preliminary Experiment 7), and the temperature was increased by 40 minutes. After aging for 2 minutes, the second polymerization was carried out. Table 2 shows the results.

<Creation of Regression Line> From the results of the preliminary experiments 1 to 3, a diagram showing the relationship between the reaction temperature and the viscosity of the obtained copolymer was prepared. This is the first
Shown in the figure. The data of Preliminary Experiments 4 and 5 are also shown in FIG.

From the results of the preliminary experiments 6 and 7, a diagram showing the relationship between the amount of peroxide added in the additional polymerization and the viscosity of the obtained copolymer was prepared. This is shown in FIG. In the figure, the regression line 1 indicates the case where the copolymer (initial viscosity 36,000 cps) of the preliminary experiment 1 was used.
The regression line 2 is the copolymer of the preliminary experiment 2 (initial viscosity 10,000 cp
s) respectively.

<Production of α-olefin-maleic anhydride copolymer> In order to produce an α-olefin-maleic anhydride copolymer having a viscosity of 40,000 to 50,000 cps (100 ° C.), first, from FIG. The reaction temperature corresponding to 50,000 copolymers is about
174-175 ° C.

Next, an α-olefin having 30 to 60 carbon atoms was placed in a reactor of 80.
After charging 36.0 kg (53.7 mol) and thoroughly replacing the inside of the system with nitrogen gas, 9.0 kg (91.8 mol) of maleic anhydride and 461 g (3.06 mol) of di-t-butyl peroxide were each added at 175 ° C. for 2 hours. And the mixture was aged for 40 minutes to allow a radical copolymerization reaction. During the addition operation, the temperature is temporarily 18
The temperature rose to 2 ° C.

The viscosity of the obtained copolymer was 20,000 cps (100 ° C.). Based on the viscosity and FIG. 2, the amount of peroxide required to obtain a copolymer having a viscosity of 40,000 to 50,000 was determined to be 0.01 mole per mole of maleic anhydride. (Initial viscosity 20,0
The regression line for the 00 cps copolymer was determined from regression lines 1 and 2 by interpolation. ) Then, di-t-butyl peroxide was added to the above copolymer over 34 minutes with maleic anhydride 1.
It was added in an amount of 0.01 mol per mol, and aged at a temperature of 160 ° C. for 40 minutes to cause a polymerization reaction. The viscosity of the obtained copolymer is 46,0
00 cps (100 ° C.).

Example 2 To produce an α-olefin-maleic anhydride copolymer having a viscosity of 80,000 to 100,000 cps (100 ° C.) (corresponding reaction temperature determined from FIG. 1 is 170 to 171 ° C.) in Example 1. The reaction was carried out in the same manner except that a radical copolymerization reaction was carried out at a reaction temperature of 172 ° C. During the addition operation, the temperature temporarily rose to 180 ° C. The viscosity of the obtained copolymer was 30,000 cps (100 ° C.). The required amount of peroxide added was determined in the same manner as in FIG.
[0125] It was a molar amount. Then, di-t-
Butyl peroxide was added over a period of 43 minutes in an amount of 0.0125 mol per mol of maleic anhydride, followed by aging at a temperature of 160 ° C. for 40 minutes to effect a polymerization reaction. The viscosity of the obtained copolymer is 81,0
00 cps (100 ° C.).

〔The invention's effect〕

According to the method of the present invention, the viscosity of an α-olefin-maleic anhydride copolymer, which was conventionally difficult, can be easily adjusted, and the copolymer having a desired viscosity can be economically produced. it can.

[Brief description of the drawings]

FIG. 1 is a graph showing an example of a regression line of a reaction temperature-viscosity when a copolymerization reaction is carried out by changing the reaction temperature variously with a predetermined amount of peroxide and a molar ratio of α-olefin / maleic anhydride. FIG. 2 shows the amount of peroxide when α-olefin-maleic anhydride copolymers having different viscosities were further copolymerized at a predetermined reaction temperature while varying the amount of peroxide added. It is a graph which shows an example of the regression line of a viscosity.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor: Kennobu Nakahara 3-10, Utsudori, Kurashiki-shi, Okayama Prefecture, Mizushima Plant, Mitsubishi Chemical Industry Co., Ltd.

Claims (1)

(57) [Claims] 1. A method for producing an α-olefin-maleic anhydride copolymer by copolymerizing an α-olefin and maleic anhydride in the presence of a peroxide in the presence of a peroxide, comprising the steps of: An olefin and maleic anhydride are subjected to a radical copolymerization reaction in the presence of a peroxide to produce a copolymer having a viscosity of 10 to 80% of the finally desired viscosity (first stage). (B) adding 10 to 70 mol% of peroxide to the reaction system of the first-stage reaction, which is added in the first-stage reaction; A method for producing an α-olefin-maleic anhydride copolymer, wherein a copolymer having a desired viscosity is finally produced by further performing a copolymerization reaction at a low reaction temperature of 2 ° C. (second stage reaction).