JP2014009206A - Alkylene oxide adduct of n-oxyl compound which prevents radical from inactivating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alkylene oxide adduct of an N-oxyl compound which prevents radical from inactivating and is obtained in a simple and efficient producing method.SOLUTION: An alkylene oxide adduct of an N-oxyl compound is produced by a method in which ethylene oxide and/or propylene oxide are added to an N-oxyl compound in the absence of a solvent by using an alkaline catalyst to carry out an addition reaction and therefor solvent removing process and the like are not necessary and a reaction product is obtained at high yield while being easily produced.

Description

  The present invention relates to an alkylene oxide-added N-oxyl compound obtained by suppressing radical deactivation and obtained by a simple and efficient production method. The alkylene oxide-added N-oxyl compound contains a radical polymerization inhibitor, an organic polymer It is useful as a light stabilizer for molecular materials and as a redox catalyst.

  Under normal pressure conditions, iron (III) chloride, an organic solvent, and the corresponding N-oxyl compound are charged into the system as a catalyst, and alkylene oxide is introduced into the system at a rate that does not reflux at −10 to 40 ° C. Then, after reacting at 20 to 50 ° C. to obtain a crude product, an alkylene oxide-added N-oxyl compound obtained by a production method in which the catalyst is removed by washing with water has been proposed (Patent Document 1).

  However, when the N-oxyl compound is dissolved in an organic solvent, the reactivity of the alkylene oxide addition reaction is reduced, and it takes a long time to complete the reaction. Therefore, the radical of the N-oxyl compound is deactivated and the generated alkylene oxide is produced. There existed a problem that the effect as a radical polymerization inhibitor of an addition N- oxyl compound, the light stabilizer for organic polymer materials, and a redox catalyst fell. In addition, when a solvent is used, a step for removing the solvent from the reaction product is required, and further, when the solvent remains in the product, a strange odor is generated, so that a drying step is also required. In addition, a catalyst washing step and a reaction product drying step are also required. As a result, there is a problem that the manufacturing process becomes complicated and the manufacturing cost increases.

Japanese Patent No. 3422987

  The present invention has been made in view of the above-described conventional situation, and an object thereof is to provide an alkylene oxide-added N-oxyl compound obtained by a simple and efficient production method without deactivating radicals. Yes.

  In order to solve the above problems, the present inventors conducted extensive research using ethylene oxide and propylene oxide as the alkylene oxide, and as a result, added the alkylene oxide to the N-oxyl compound using an alkali catalyst in the absence of a solvent. Then, by performing an addition reaction, an alkylene oxide-added N-oxyl compound, for example, when alkylene oxide is ethylene oxide or propylene oxide is used in a simple manner without deactivating radicals, ethylene oxide and / or propylene oxide added N The inventors have found that an oxyl compound can be obtained in high yield, and have completed the present invention.

（Ｒ１、Ｒ２、Ｒ３およびＲ４は直鎖状または分岐状のアルキル基であり、ＥＯはオキシエチレン基、ＰＯはオキシプロピレン基を示す。また、ｍとｎは、平均付加モル数であり、０≦ｍ≦２０、０≦ｎ≦２０であり、ｍとｎは同時に０にならない。なお、（ＥＯ）ｍ（ＰＯ）ｎの付加形式は、ブロック状でもランダム状でもよく、ＥＯとＰＯは順不同である。） That is, the invention according to claim 1 is obtained by a production method characterized in that an addition reaction is carried out by adding ethylene oxide and / or propylene oxide to an N-oxyl compound using an alkali catalyst in the absence of a solvent. These are ethylene oxide and / or propylene oxide addition N-oxyl compounds represented by the following general formula (1).

(R1, R2, R3 and R4 are linear or branched alkyl groups, EO represents an oxyethylene group, PO represents an oxypropylene group, and m and n are average added mole numbers, 0 ≦ m ≦ 20, 0 ≦ n ≦ 20, and m and n are not simultaneously 0. The addition form of (EO) m (PO) n may be block or random, and EO and PO are in no particular order. .)

  The invention according to claim 2 is the ethylene oxide and / or propylene oxide addition N-oxyl compound according to claim 1, wherein the alkali catalyst is potassium hydroxide and / or sodium hydroxide.

The invention according to claim 3 is the ethylene oxide and / or propylene according to claim 1 or 2, wherein the N-oxyl compound is 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl. It is an oxide-added N-oxyl compound.

  The present invention provides an ethylene oxide and / or propylene oxide-added N-oxyl compound obtained by a simple and efficient production method without deactivating radicals.

  Hereinafter, embodiments of the present invention will be described in detail.

（Ｒ１、Ｒ２、Ｒ３およびＲ４は直鎖状または分岐状のアルキル基であり、ＥＯはオキシエチレン基、ＰＯはオキシプロピレン基を示す。また、ｍとｎは、平均付加モル数であり、０≦ｍ≦２０、０≦ｎ≦２０であり、ｍとｎは同時に０にならない。なお、（ＥＯ）ｍ（ＰＯ）ｎの付加形式は、ブロック状でもランダム状でもよく、ＥＯとＰＯは順不同である。） In the present invention, an ethylene oxide and / or propylene oxide-added N-oxyl compound represented by the following general formula (1) can be obtained without deactivating radicals.

(R1, R2, R3 and R4 are linear or branched alkyl groups, EO represents an oxyethylene group, PO represents an oxypropylene group, and m and n are average added mole numbers, 0 ≦ m ≦ 20, 0 ≦ n ≦ 20, and m and n are not simultaneously 0. The addition form of (EO) m (PO) n may be block or random, and EO and PO are in no particular order. .)

  In the general formula (1), EO represents an oxyethylene group, PO represents an oxypropylene group, and the addition form of the oxyethylene group and the oxypropylene group may be block or random. Further, m and n are average added mole numbers, and 0 ≦ m ≦ 20 and 0 ≦ n ≦ 20, and m and n are not 0 at the same time. The values of m and n can be controlled by adjusting the addition amount of ethylene oxide and / or propylene oxide in the alkylene oxide addition reaction.

（Ｒ５、Ｒ６、Ｒ７およびＲ８は直鎖状または分岐状のアルキル基である。） The N-oxyl compound used in the production of the alkylene oxide-added N-oxyl compound of the present invention is represented by the following general formula (2).

(R5, R6, R7 and R8 are linear or branched alkyl groups.)

  In the formula of the compound represented by the general formula (2), R5, R6, R7 and R8 are preferably linear alkyl groups having 1 to 4 carbon atoms, and 4-hydroxyl-2,2,6 among them. , 6-tetramethylpiperidine-1-oxyl (hereinafter referred to as H-TEMPO) is preferable.

One of the features of the present invention is an alkylene oxide addition reaction in the absence of a solvent. Therefore, the process of removing the solvent after the alkylene oxide-added N-oxyl compound generation process can be omitted, and the drying process is not required for countermeasures against the bad smell of the solvent remaining in the generated compound, thereby simplifying the manufacturing process. In addition, manufacturing costs can be reduced. The outline of the production method for obtaining the alkylene oxide-added N-oxyl compound of the present invention is as follows.
(1) A reaction vessel is charged with an N-oxyl compound and an alkali catalyst, and heated to the melting point of the N-oxyl compound or higher.
(2) An alkylene oxide is added and an addition reaction is performed.
(3) After the addition of alkylene oxide, the reaction is continued until no unreacted alkylene oxide is detected in the reaction solution (aging reaction).
(4) After completion of the addition reaction, an adsorbent is added to adsorb the remaining catalyst.
(5) The adsorbent that has adsorbed the catalyst is removed by filtration to obtain the desired alkylene oxide-added N-oxyl compound.

  In the conventional method for producing an alkylene oxide-added N-oxyl compound using a solvent, iron (III) chloride is used as a catalyst. On the other hand, in the production method using no solvent, the present inventors hardly proceed the alkylene oxide addition reaction to the N-oxyl compound when iron (III) chloride is used as a catalyst, but when an alkali catalyst is used, It was found that the alkylene oxide addition reaction proceeded rapidly, and as a result, the entire production time was completed in a short time, and an alkylene oxide addition N-oxyl compound with little radical deactivation was obtained, and the present invention was completed. .

  Examples of the alkali catalyst used in the production of the alkylene oxide-added N-oxyl compound of the present invention include potassium hydroxide and sodium hydroxide, and the addition amount thereof is set to 0. 0 with respect to the total charged amount of the N-oxyl compound and the alkylene oxide. A range of 1% to 1.5% by weight is preferred.

  Further, in the conventional method for producing an alkylene oxide-added N-oxyl compound, the iron (III) chloride catalyst remaining after the completion of the compound production step is removed by washing with water. A drying process for residual moisture was required. Although the alkali catalyst used in the production of the alkylene oxide-added N-oxyl compound of the present invention can be removed by washing the remaining catalyst after completion of the compound production step, adsorption removal with a base adsorbent is also possible based on its basicity. If the adsorption removal method is used, the secondary phase effect that the separation and removal step of the aqueous phase and the drying step of the water can be omitted and the yield reduction due to the distribution of the compound to the aqueous phase can be suppressed.

  As the adsorbent, those known as base adsorbents can be used. For example, inorganic synthetic adsorbents such as Kyoward 600 (manufactured by Kyowa Chemical Co., Ltd.), a product mainly composed of magnesium silicate. , Activated clay, acidic clay, activated carbon, silica gel, activated alumina, and ion exchange resin.

  The adsorbent used in the production of the alkylene oxide-added N-oxyl compound of the present invention is added to and mixed with the compound produced after completion of the alkylene oxide-added N-oxyl compound production step, and then removed by filtration. The application conditions such as the addition amount, mixing time, and temperature are appropriately selected according to the amount of catalyst remaining and the characteristics of the adsorbent used. If necessary, a preliminary test is performed in advance to determine application conditions, and a filter aid may be used in combination.

  The reaction temperature of the alkylene oxide addition reaction in the production of the alkylene oxide addition N-oxyl compound of the present invention is preferably 90 ° C. or higher and 160 ° C. or lower. More preferably, the temperature is 130 ° C. or higher and 150 ° C. or lower. Since this alkylene oxide addition reaction is exothermic, the above temperature range is maintained by adjusting the dropping rate of the alkylene oxide and adjusting the temperature from the outside.

  The progress of the addition reaction is carried out using an analytical instrument such as gas chromatography, and the product is ethylene oxide and / or propylene oxide addition N-oxyl compound, the raw material is alkylene oxide, and N- You can know by tracking oxyl compounds. After confirming that the addition reaction has progressed and no unreacted alkylene oxide has been detected, the compound production step is completed.

  In the present invention, the aging time from the addition of the total amount of alkylene oxide to the end of the compound production step is generally 0.5 to 6 hours.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited only to a following example. In addition, various modifications may be included in the present invention as long as those skilled in the art can easily conceive without departing from the scope of the claims.

Example 1
In an autoclave equipped with a stirrer, a temperature controller, and an automatic introduction device, 172 g of 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl (H-TEMPO) and 0 potassium hydroxide as a catalyst were added. .35 g (= 0.1% vs. (N-oxyl compound + alkylene oxide) total charge) was charged, the system was purged with nitrogen, and the temperature was raised to 130 ° C. while stirring at 400 rpm. Subsequently, 174 g of propylene oxide (hereinafter referred to as PO) was added to the system over 1 hour as alkylene oxide. At this time, the PO addition rate was adjusted to maintain 130 ° C to 140 ° C. After adding the total amount of PO, the reaction was continued at 130 ° C., and it was confirmed that no unreacted PO was detected by gas chromatography, and the reaction was completed. The aging time at this time was about 2 hours. Subsequently, 1.5 g of synthetic adsorbent KYOWARD 600S (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.) was added to the reaction product to adsorb the remaining catalyst, and the filter aid Celite (trade name, (Johns-Manville Sales Corp.) The reaction product was filtered through 1 filter paper to remove the adsorbent adsorbing the catalyst, and the alkylene oxide-added N-oxyl compound having an average PO addition mole number of 3 in Example 1 was obtained.

(Evaluation)
About Example 1, the yield of the alkylene oxide addition N-oxyl compound, the residual rate of H-TEMPO in a product, and a radical residual rate were evaluated, and the result was shown in Table 1. For the yield of the alkylene oxide-added N-oxyl compound, the recovered amount of the reaction product with respect to the charged amount of (H-TEMPO + alkylene oxide) was determined by weight ratio. Moreover, H-TEMPO residual rate is the ratio of the amount of H-TEMPO at the time of completion | finish of reaction quantified with the gas chromatography (GC) with respect to the preparation amount of H-TEMPO. Moreover, the radical residual rate was calculated | required with the following method.
(Radical residual rate)
An appropriate amount of the obtained alkylene oxide-added N-oxyl compound of Example 1 was dissolved in xylene, and the ESR spin strength was measured with an ESR measuring instrument (trade name “ES-10W” type, manufactured by Nikkiso Co., Ltd.) The radical concentration per mole of the alkylene oxide-added N-oxyl compound of Example 1 was determined. Next, H-TEMPO was measured in the same manner, and the radical concentration per mole of H-TEMPO was determined. And the radical residual rate was computed according to the following formula. The higher this value, the less radical deactivation.

(Example 2)
172 g of H-TEMPO and 1.0 g of potassium hydroxide as a catalyst (= 0.2% vs. (N-oxyl compound + alkylene oxide) total charge) in an autoclave equipped with a stirrer, temperature controller and automatic introduction device The system was charged and the inside of the system was replaced with nitrogen, and the temperature was raised to 130 ° C. while stirring at 400 rpm. Subsequently, a mixed liquid of 132 g of ethylene oxide (hereinafter referred to as EO) and 174 g of PO was added as alkylene oxide over 1 hour. At this time, the addition rate of the mixed solution was adjusted and maintained at 130 to 140 ° C. After adding the total amount of the mixture, the reaction was continued at 130 ° C., and it was confirmed that unreacted EO and PO were not detected by gas chromatography, and the reaction was completed. The aging time at this time was about 2 hours. Subsequently, 1.5 g of synthetic adsorbent KYOWARD 600S (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.) was added to the reaction product to adsorb the remaining catalyst, and the filter aid Celite (trade name, (Johns-Manville Sales Corp.) The reaction product was filtered through 1 filter paper to remove the adsorbent adsorbing the catalyst, and the average addition mole number of EO and the average addition mole number of PO of Example 2 was 3 moles. An alkylene oxide-added N-oxyl compound to which PO was randomly added was obtained. About Example 2, the yield of the alkylene oxide addition N-oxyl compound, the residual rate of H-TEMPO in a product, and the radical residual rate were evaluated similarly to Example 1, and the result was shown in Table 1. .

(Example 3)
172 g of H-TEMPO and 1.0 g of potassium hydroxide as a catalyst (= 0.2% vs. (N-oxyl compound + alkylene oxide) total charge) in an autoclave equipped with a stirrer, temperature controller and automatic introduction device The system was charged and the inside of the system was replaced with nitrogen, and the temperature was raised to 130 ° C. while stirring at 400 rpm. Subsequently, 132 g of EO was added to the system as an alkylene oxide over 1 hour, and after the total amount of EO was added, the mixture was reacted at 130 ° C. for 1 hour. Next, 174 g of PO was added over 1 hour, and after adding the total amount of PO, the reaction was continued at 130 ° C., and it was confirmed that unreacted EO and PO were not detected by gas chromatography, and the reaction was completed. The aging time at this time was about 2 hours. Subsequently, 1.5 g of synthetic adsorbent KYOWARD 600S (trade name, manufactured by Kyowa Chemical Industry Co., Ltd.) was added to the reaction product to adsorb the remaining catalyst, and the filter aid Celite (trade name, (Johns-Manville Sales Corp.) The reaction product was filtered through 1 filter paper to remove the adsorbent that adsorbed the catalyst, and the average added mole number of EO and the average added mole number of PO in Example 3 was 3 moles. An alkylene oxide-added N-oxyl compound in which PO was added to the block was obtained. About Example 3, the yield of alkylene oxide addition N-oxyl compound, the residual rate of H-TEMPO in a product, and the radical residual rate were evaluated similarly to Example 1, and the result was shown in Table 1. .

(Examples 4 to 19)
The conditions of Example 1 were changed as shown in Table 1, and alkylene oxide-added N-oxyl compounds of Examples 4 to 19 were obtained. The obtained Examples 4 to 19 evaluated the yield of the alkylene oxide-added N-oxyl compound, the residual rate of H-TEMPO in the product, and the radical residual rate in the same manner as in Example 1. It is shown in Table 1.

(Comparative Example 1)
Production of alkylene oxide-added N-oxyl compound under the same conditions as in Example 1 except that the catalyst was changed to 1.0 g of iron (III) oxide (0.3% vs. (N-oxyl compound + alkylene oxide) total charge). Although the reaction was attempted, the reaction hardly proceeded and the yield was extremely low, so the radical residual ratio was not measured.

(Comparative Example 2)
Production of alkylene oxide-added N-oxyl compound under the same conditions as in Example 4 except that the catalyst was changed to 0.9 g of iron (III) oxide (0.3% vs. (N-oxyl compound + alkylene oxide) total charge). Although the reaction was attempted, the reaction hardly proceeded and the yield was extremely low, so the radical residual ratio was not measured.

(Comparative Example 3)
In Comparative Example 3, a method according to the manufacturing method (conventional method) described in Patent Document 1 of the prior art document was used. That is, H-TEMPO, toluene, and iron (III) chloride were charged into a four-necked flask equipped with a stirrer, a thermometer, and a condenser, and PO was blown in over 6 hours while stirring at 15 ° C. The blowing speed of PO was set so as not to be refluxed. The whole amount of PO was press-added and aged for 2 hours. Thereafter, the catalyst was removed by washing with water, and then the solvent was removed under reduced pressure to obtain Comparative Example 3. In Comparative Example 3 obtained, the yield of the alkylene oxide-added N-oxyl compound, the residual rate of H-TEMPO in the product, and the radical residual rate were evaluated in the same manner as in Example 1. The results are shown in Table 1. It was shown to.

(Comparative Examples 4-6)
The conditions of Comparative Example 3 were changed as shown in Table 1 to obtain alkylene oxide-added N-oxyl compounds of Comparative Examples 4-6. The obtained Comparative Examples 4 to 6 evaluated the yield of the alkylene oxide-added N-oxyl compound, the residual ratio of H-TEMPO in the product, and the radical residual ratio in the same manner as in Example 1. It is shown in Table 1.

  From the results of Comparative Examples 1 and 2 in Table 1, it was shown that the alkylene oxide addition reaction with respect to the N-oxyl compound hardly progressed when iron (III) chloride was used as the catalyst in the production method not using a solvent. . Further, as shown in the results of Comparative Examples 3 to 6 in Table 1, in the conventional method using a solvent, the yield of the alkylene oxide-added N-oxyl compound is as low as 80% or less even when the aging time is increased. Furthermore, the radical residual rate was lowered by further increasing the aging time.

  On the other hand, as shown in Table 1, all of the alkylene oxide-added N-oxyl compounds of Examples 1 to 19 can be obtained in a high yield of 90% or more, and the reaction is completed in a short aging time. There was little radical deactivation, and the radical residual ratios were all 95% or more.

  From the comparison of the results of the above Examples and Comparative Examples, by combining an alkali catalyst in the absence of a solvent, the alkylene oxide addition N-oxyl compound formation reaction proceeds rapidly, and is obtained by a production method characterized by this specific combination. The alkylene oxide-added N-oxyl compound of the present invention, which is a simple production method in a short time compared with the alkylene oxide-added N-oxyl compound produced by the conventional method, has a high yield and a radical residual rate. It became clear that it was also expensive.

The alkylene oxide-added N-oxyl compound of the present invention is used in technical fields such as radical polymerization inhibitors, light stabilizers for organic polymer materials, and redox catalysts as alkylene oxide-added N-oxyl compounds with little radical deactivation. Is available.

Claims (3)

It is represented by the following general formula (1), which is obtained by a production method characterized in that an addition reaction is carried out by adding ethylene oxide and / or propylene oxide to an N-oxyl compound using an alkali catalyst in the absence of a solvent. Ethylene oxide and / or propylene oxide addition N-oxyl compound.

(R1, R2, R3 and R4 are linear or branched alkyl groups, EO represents an oxyethylene group, PO represents an oxypropylene group, and m and n are average added mole numbers, 0 ≦ m ≦ 20, 0 ≦ n ≦ 20, and m and n are not simultaneously 0. The addition form of (EO) m (PO) n may be block or random, and EO and PO are in no particular order. .)   The ethylene oxide and / or propylene oxide-added N-oxyl compound according to claim 1, wherein the alkali catalyst is potassium hydroxide and / or sodium hydroxide. The ethylene oxide and / or propylene oxide addition N-oxyl compound according to claim 1 or 2, wherein the N-oxyl compound is 4-hydroxyl-2,2,6,6-tetramethylpiperidine-1-oxyl.