JP2007008848A - Method for producing organic peroxide - Google Patents

Abstract

The present invention provides a fluorine-based solvent solution of a peroxy ester that does not hinder the improvement of molecular weight in the production of a fluorine-containing polymer.
The compound B represented by the formula 1 is reacted with the peroxide C represented by the formula 2 in the presence of a basic catalyst A in a fluorinated solvent. A method for producing organic peroxide D.
RC (= O) -X Formula 1
R'-OOH Formula 2
R−C (═O) −OOR ′ (Formula 3)
However, in Formulas 1-3, R and R ′ each independently represent an alkyl group having 1 to 12 carbon atoms, a phenyl group, a phenylalkyl group or an alkylphenyl group, and X represents a halogen atom.
[Selection figure] None

Description

  The present invention relates to a method for producing an organic peroxide used as a polymerization initiator.

Conventionally, when producing an organic peroxide such as a peroxyester, it is known to use a hydrocarbon solvent as a reaction solvent. For example, pivaloyl chloride and 1,1-dimethylpropyl hydroperoxide It is known that (C ₂ H ₅ ) (CH ₃ ) ₂ COO—C (═O) —C (CH ₃ ) ₃ was produced by reacting in a petroleum ether (see Non-Patent Document 1). .

  When the reaction is carried out by such a method, the peroxyester as the target product is obtained as a solution dissolved in a hydrocarbon solvent. However, when this solution is used as a polymerization initiator for polymerizing a fluorinated monomer to produce a fluorinated polymer, the hydrocarbon solvent has high chain mobility, so that the molecular weight of the fluorinated polymer is sufficient. There was a problem that it was difficult to raise it.

Bull. Chem. Soc. Jpn. , 61, 1641 (1988)

  An object of this invention is to provide the peroxyester solution which does not prevent the improvement of molecular weight in manufacture of a fluorine-containing polymer.

  In the present invention, an organic peroxide represented by Formula 3 is prepared by reacting a compound represented by Formula 1 with a peroxide represented by Formula 2 in the presence of a basic catalyst in a fluorinated solvent. A method for producing an oxide is provided.

RC (= O) -X Formula 1
R'-OOH Formula 2
R−C (═O) −OOR ′ (Formula 3)
However, in Formulas 1-3, R and R ′ each independently represent an alkyl group having 1 to 12 carbon atoms, a phenyl group, a phenylalkyl group or an alkylphenyl group, and X represents a halogen atom. The alkyl group may be linear or branched.
The present inventors have found that the above reaction can be carried out efficiently in a fluorinated solvent, and have arrived at the present invention.

  According to the present invention, a peroxyester can be produced in a fluorine-containing solvent, and as a result, a fluorine-based solvent solution of a peroxyester having low chain transferability is obtained. Further, when the fluorinated solvent is hydrofluorocarbon or hydrofluoroether, there is an advantage that there is almost no influence on the environment.

  In the production method of the present invention, the compound represented by Formula 1 is used as a raw material.

The compound represented by Formula 1 is a compound in which R is an alkyl group having 3 to 9 carbon atoms from the viewpoint of solubility in a fluorine-based solvent, or a phenylalkyl group having 1 to 3 carbon atoms other than a phenyl group. Certain compounds are preferred, and those in which X is a chlorine atom are preferred. _{Specifically, (CH 3) 3 C-} C (= O) -Cl ( pivaloyl _{chloride), (CH 3) 2 CH} -C (= O) -Cl, (C 6 H 13) (CH 3 ) ₂ C—C (═O) —Cl is preferred.

Another peroxide represented by Formula 2 includes (CH ₃ ) ₃ COOH (hereinafter referred to as TBHP), (C ₃ H ₇ ) (CH ₃ ) ₂ COOH, Ph (CH ₃ ). ₂ COOH (Ph represents a phenyl group. cumene _{hydroperoxide), (CH 3) 2 CHCH} 2 COOH is preferable.

As the basic catalyst used in the present invention, an alkali metal hydroxide is preferably used from the viewpoint of basic strength and versatility, and specifically, NaOH or KOH is preferable. As the basic catalyst, alkali metal hydrogen carbonates such as NaHCO ₃ and KHCO ₃ , alkali metal carbonates such as Na ₂ CO ₃ and K ₂ CO _{3, and the} like can also be used.

In the present invention, the organic peroxide represented by the formula 3 is synthesized by reacting the compound represented by the formula 1 and the peroxide represented by the formula 2, and among them, (CH ₃ ) A method of synthesizing (CH ₃ ) ₃ C—C (═O) —OOC (CH ₃ ) ₃ (hereinafter referred to as TBPP) by reacting ₃ C—C (═O) —Cl with TBHP; C ₆ H ₁₃ ) (CH ₃ ) ₂ C—C (═O) —Cl and Ph (CH ₃ ) ₂ COOH are reacted to give (C ₆ H ₁₃ ) (CH ₃ ) ₂ C—C (═O) A method of synthesizing —OOC (CH ₃ ) ₂ Ph, by reacting (C ₆ H ₁₃ ) (CH ₃ ) ₂ C—C (═O) —Cl with (C ₃ H ₇ ) (CH ₃ ) ₂ COOH. Te synthesized _{(C 6 H 13) (CH} 3) 2 C-C (= O) -OOC (CH 3) 2 (C 3 H 7) It can be preferably applied in that way.

  As the fluorinated solvent used in the present invention, hydrochlorofluorocarbon, hydrofluorocarbon, hydrofluoroether, perfluorocarbon and the like can be used, but hydrofluorocarbon or hydrofluoroether is preferably used from the viewpoint of having a small influence on the environment.

The _{hydrofluorocarbon, C 4 F 5 H 5,} C 4 F 6 H 4, C 4 F 7 H 3, C 4 F 8 H 2, C 4 F 9 H, C 5 F 6 H 6, C 5 F 7 _{H 5, C 5 F 8 H} 4, C 5 F 9 H 3, C 5 F 10 H 2, C 5 F 11 H, C 6 F 7 H 7, C 6 F 8 H 6, C 6 F 9 H 5 , C ₆ F ₁₀ H ₄ , C ₆ F ₁₁ H ₃ , C ₆ F ₁₂ H ₂ , C ₆ F ₁₃ H, and cyclic C ₅ F ₇ H ₃ , specifically, 1,1,1,3,3-pentafluorobutane, 1,1,1,2,2,3,4,5,5,5-decafluoropentane, 1,1,1,2,2,3 , 3,4,4,5,5,6,6-tridecafluorohexane, 1,1,1,2,2,3,3,4,4-nonafluorohexane, 2 Include trifluoromethyl -1,1,1,2,3,4,5,5,5- nonafluorobutyl pentane. Of these, 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane (hereinafter referred to as C6H) is particularly preferable.

  Specific examples of the hydrofluoroether include 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether, 2,2,3,3-tetrafluoro-1- ( 1,1,2,2-tetrafluoroethoxy) propane, (perfluorobutoxy) methane, and (perfluorobutoxy) ethane.

In the present invention, the ratio of the compound represented by Formula 1 and the peroxide represented by Formula 2 is a molar ratio of the compound represented by Formula 1 / the peroxide represented by Formula 2 = 1. /0.5 to 1/20 is preferable. When the charging ratio is in the above range, the yield is high and the reaction time is short.
The addition amount of the basic catalyst is preferably 30 to 1000 parts by mass with respect to 100 parts by mass of the compound represented by Formula 1 from the viewpoint of improving the yield and shortening the reaction time.

Moreover, it is preferable that the addition amount of a solvent shall be 10-5000 mass parts with respect to 100 mass parts of compounds represented by Formula 1 from a viewpoint of improving a yield and shortening reaction time.
In the present invention, usually, the reaction temperature is −30 to 50 ° C., and the reaction pressure is a normal pressure. When the reaction temperature is within the above range, the reaction time is short, and the produced peroxide is difficult to decompose, so that a high yield can be obtained.

  The present invention may be performed in either a batch reaction or a continuous reaction. The continuous reaction can be carried out by using a tubular reactor such as a microreactor. A microreactor is a three-dimensional structure in which a channel is formed on the surface of a substrate by a method such as lamination, sticking, etching, LIGA process, cutting, or molding, or a channel is formed using a thin tube. Reactor such as body.

  The microreactor has one or more flow paths connected to a fluid supply port and a fluid discharge port, and has a continuous reaction unit in contact with a plurality of fluids. The continuous reaction section is not particularly limited as long as it is a space where a plurality of fluids can contact or mix while maintaining a laminar flow. For example, a structure in which a flow path is formed in a T shape or a Y shape, and these layers are stacked in multiple layers. The structure etc. are preferable. In addition, as the microreactor, a structure capable of constructing a flow in which an immiscible aqueous fluid and an organic fluid are alternately in contact in a laminar flow state is more preferable.

<Synthesis of TBPP>
[Example 1]
In a three-necked flask equipped with a thermometer and a dropping funnel, 10 ml of distilled water in which 0.94 g (12 mmol) of KOH was dissolved and 10 ml of C6H were added, and the temperature in the three-necked flask was adjusted to about 2 ° C. with an ice bath. To this, 1.54 g of 70 mass% TBHP aqueous solution (corresponding to 12 mmol of TBHP) was added, and then 1.21 g (10 mmol) of pivaloyl chloride was added from a dropping funnel over 20 minutes.
The temperature was adjusted so that the temperature in the three-necked flask was maintained at about 2 ° C., and stirring was continued for 30 minutes. Next, the obtained crude liquid was transferred to a separatory funnel, the organic phase was separated, washed with an aqueous sodium hydrogen carbonate solution, washed with brine, and then dehydrated with magnesium sulfate to obtain a TBPP solution. . It was 82 mass% when content of TBPP in the obtained solution was analyzed by the iodometry method (detailed below).

[Example 2]
4 ml of distilled water A in which 1.88 g (24 mmol) of KOH was dissolved was sealed in the syringe 1, 2.6 ml of C6H solution C in which 2.42 g (20 mmol) of pivaloyl chloride was dissolved was sealed in the syringe 3, and 70% by mass. 6.18 g of TBHP aqueous solution B (corresponding to 48 mmol of TBHP) was sealed in a syringe 2. Each solution was introduced into a multi-lamination microreactor having a channel width of 500 μm and a reaction channel length of 450 mm using a syringe pump, and reacted at room temperature (see FIG. 1).

  The obtained reaction crude liquid D was transferred to a separatory funnel, the organic phase was separated, washed with an aqueous sodium hydrogen carbonate solution, washed with brine, and then dehydrated with magnesium sulfate. The TBPP content in the obtained solution was analyzed by the iodometry method (described in detail below) in the same manner as in Example 1, and found to be 86% by mass.

<Iodometry method>
Take 30 ml of benzene in a 300 ml Erlenmeyer flask, accurately weigh about 0.15 g of sample and add to it. Furthermore, 2 ml of saturated potassium iodide aqueous solution and 70 m of ferric chloride acetic acid solution are added in this order. Seal the Erlenmeyer flask to mix the contents and allow to react for 10 minutes in the dark. Next, 80 ml of water is added thereto, and titration is performed with an aqueous 0.1 mol / L sodium thiosulfate solution until the color of iodine disappears.
The total amount of active oxygen is calculated by the following formula a.

On the other hand, about 100 g of crushed ice is put in another Erlenmeyer flask with an internal volume of 300 ml, and 50 ml of acetic acid and 6 ml of 6N sulfuric acid are added to this and mixed. Next, 5 to 6 drops of the ferroin solution are added, and a 0.1 mol / L ceric ammonium sulfate solution is added dropwise until the color becomes light blue. About 2 g of a sample is accurately weighed, 5 drops of a ferroin solution is added, and titrated with a 0.1 mol / L ceric ammonium sulfate solution until a light blue color is obtained.
The content of TBHP which is a raw material is calculated by the following formula b.
The weight percentage of TBPP contained in the sample is calculated by the following formula c.

Total active oxygen amount (%) = (V ₁ × 0.08) / S ₁ Formula a
(V ₁ : Volume (ml) of 0.1 mol / L sodium thiosulfate aqueous solution required for titration, S ₁ : Weight of sample (g))
TBHP content (%) = (V ₂ × 0.9) / S ₂ Formula b
(V ₂ : Volume (ml) of 0.1 mol / L ceric ammonium sulfate solution required for titration, S ₂ : Weight of sample (g))
TBPP content (%) = (total active oxygen content−TBHP content × 0.1775) × 100 / 9.18 Formula c
In formula c, 0.1775 is the ratio of theoretical active oxygen of TBHP (no unit), and 9.18 is the theoretical active oxygen amount (%) of TBPP.

  The organic peroxide fluorine-based solvent solution obtained by the present invention is useful as a polymerization initiator for a fluorine-based polymer.

Diagram showing the microreactor used in Example 2

Explanation of symbols

1: Syringe 1
2: Syringe 2
3: Syringe 3
4: Continuous reaction part A: KOH aqueous solution B: TBHP aqueous solution C: C6H solution of pivaloyl chloride D: Reaction crude liquid

Claims (4)

Production of the organic peroxide represented by the formula 3 characterized by reacting the compound represented by the formula 1 and the peroxide represented by the formula 2 in the presence of a basic catalyst in a fluorinated solvent. Method.
RC (= O) -X Formula 1
R'-OOH Formula 2
R−C (═O) −OOR ′ (Formula 3)
However, in Formulas 1-3, R and R ′ each independently represent an alkyl group having 1 to 12 carbon atoms, a phenyl group, a phenylalkyl group or an alkylphenyl group, and X represents a halogen atom.   The method for producing an organic peroxide according to claim 1, wherein the fluorinated solvent is a hydrofluorocarbon.   The method for producing an organic peroxide according to claim 1, wherein the fluorinated solvent is 1,1,1,2,2,3,3,4,4,5,5,6,6-tridecafluorohexane. The compound represented by Formula 1 is (CH ₃ ) ₃ C—C (═O) —X, the compound represented by Formula 2 is (CH ₃ ) ₃ COOH, and the organic compound represented by Formula 3 is used. method of manufacturing an oxide is _{(CH 3) 3 C-C} (= O) -OOC (CH 3) 3 an organic peroxide according to claim 1, 2 or 3.

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