JP2000327607A - Production of fluoroalcohol - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a fluoroalcohol suitable for producing information recording media and photoreceptors for films by reaction between methanol and tetrafluoroethylene or the like in the presence of a reaction initiator followed by removing the undecomposed reaction initiator from the system and then carrying out a distillation. SOLUTION: This fluoroalcohol of the formula H(CFR1CF2)nCH2OH (n is 1 or 2, when n=1, R1 is F or CF3, or when n=2, R1 is F) is obtained by reaction between methanol and tetrafluoroethylene or hexafluoropropylene in the presence of a reaction initiator (e.g. di-t-butyl peroxide) followed by removing the undecomposed reaction initiator in the resultant reaction liquid and then carrying out a distillation; wherein removal of the undecomposed reaction initiator is accomplished preferably by decomposing it through heating the reaction liquid, contacting the liquid with an acid catalyst, base or reducing agent, irradiating the liquid with ultraviolet rays, or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a compound represented by the general formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n = 1 or 2. When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. ] The method for producing a fluoroalcohol represented by the formula

[0002]

_2. Description of the Related Art H (CF ₂ CF ₂ ) _n CH ₂ OH (n = 1,
The production method of 2) is described in JP-A-54-154707 and U.S. Pat. No. 2,559,628 by reacting methanol and tetrafluoroethylene in the presence of t-butyloctyl peroxide to obtain H (CF ₂ CF ₂ ).
It is stated that a telomer mixture of _n CH ₂ OH (n up to 12) is obtained.

[0003] However, even if the telomer mixture obtained by the above method is purified by distillation, the evaporation residue of about several hundred ppm cannot be removed.
When used as a solvent in the production of an information recording medium having a recording layer capable of writing and / or reading information by a laser on a substrate such as a DR, a high-quality information recording medium due to the influence of evaporation residue. There is a disadvantage that it is not suitable for the production of

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to substantially eliminate impurities such as evaporation residues and UV absorbing components.
General formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n = 1 or 2. When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. And a method for producing a fluoroalcohol represented by the formula:

[0005]

Means for Solving the Problems The present inventor can achieve the above object by decomposing and removing a reaction initiator remaining in a reaction solution and then distilling a fluorine alcohol of the general formula (1). And completed the present invention. That is, the present invention relates to the inventions described in the following items.

Item 1 Methanol and tetrafluoroethylene or hexafluoropropylene are reacted in the presence of a reaction initiator to obtain the following formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n = 1 or 2 . When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. In the method for producing a fluoroalcohol represented by the formula (1), after removing the undecomposed reaction initiator contained in the reaction solution, distillation of the fluoroalcohol represented by the formula (1) is performed. A method for producing a fluoroalcohol represented by 1).

Item 2 The removal of the undecomposed reaction initiator includes the decomposition of the undecomposed reaction initiator by heating the reaction solution, the decomposition of the undecomposed reaction initiator by contact with an acid catalyst, and the undecomposed reaction by contact with a reducing agent. Item wherein the decomposition is performed using at least one means selected from the group consisting of decomposition of an initiator, decomposition of an undecomposed reaction initiator by UV irradiation, and decomposition of the undecomposed reaction initiator by contact with a base. 2. The method according to 1.

Item 3 Further, in the presence of a base or after contacting a fraction containing a fluoroalcohol represented by the formula (1) with a base, a fraction containing a fluoroalcohol represented by the formula (1) Item 3. The method according to Item 1 or 2, wherein distillation is performed.

[0009]

DETAILED DESCRIPTION OF THE INVENTION In the step of reacting methanol and tetrafluoroethylene or hexafluoropropylene in the presence of a reaction initiator, an excess amount of methanol is used relative to tetrafluoroethylene or hexafluoropropylene. The reaction temperature is about 40 to 140 ° C,
The reaction time is about 3 to 12 hours, and the reaction pressure is 0.2 to 1.
It is about 2 MPa. The reaction can be performed in a high-pressure reactor such as an autoclave. The inside of the reaction system is preferably replaced with an inert gas such as nitrogen or argon.

[0010] Examples of the reaction initiator include peroxides and azo compounds, and have a half-life at a reaction temperature of about 0.5 to 0.5.
A preferred example is a reaction initiator for 10 hours.

Preferred reaction initiators include, for example, peroxides such as di-t-butyl peroxide (available as trade name "Perbutyl D" (manufactured by NOF Corporation)) and t-butylperoxy. -2-ethylhexanoate (available as trade name "Perbutyl O" (manufactured by NOF Corporation)) or t-butylperoxyisopropyl carbonate (trade name "Perbutyl I" (manufactured by NOF Corporation)
Available from the company). Preferred examples of the azo compound include azobisisobutyronitrile and azobiscyclohexanenitrile.

The amount of the reaction initiator used is usually about 0.005 to 0.1 mol per 1 mol of tetrafluoroethylene or hexafluoropropylene.

In the above reaction system, an acid acceptor may be present together with the reaction initiator. Examples of the acid acceptor include carbonates and bicarbonates of alkali metals or alkaline earth metals such as calcium carbonate, magnesium carbonate, sodium carbonate, potassium carbonate, sodium bicarbonate, and potassium bicarbonate, calcium oxide, calcium hydroxide, and soda. Lime, barium carbonate and the like. The acid acceptor is composed of HF generated during the reaction without making the reaction system strongly alkaline.
Those capable of trapping an acid are preferred.

The amount of the acid acceptor used is not particularly limited.
It can be about 0.001 to 0.1 mol per 1 mol of tetrafluoroethylene or hexafluoropropylene.

[0015] The production method of the present invention optionally includes a step of removing excess methanol by distillation after completion of the reaction.

The means for removing the undecomposed reaction initiator remaining in the reaction solution is not particularly limited, but it can be carried out, for example, by decomposing the reaction initiator. Can be

In the following (ii), (iii) and (v), “contact” means that an acid catalyst,
This is performed by adding a reducing agent or a base.

(I) The temperature for heating the decomposition reaction solution by heating can be appropriately set according to the type of the reaction initiator, and is usually 100 to 20.
It is about 0 ° C. Heating should be performed in an open or closed system for 0.5
Perform for about 10 hours.

(Ii) The acid catalyst decomposed by contact with an acid catalyst may be any of an inorganic acid, an organic acid and a solid acid catalyst, and may be used in combination of two or more. Preferred examples of the inorganic acid include sulfuric acid, hydrochloric acid, nitric acid, hydroiodic acid, and hydrobromic acid. Examples of the organic acid include acetic acid and trifluoromethanesulfonic acid. Examples of the solid acid catalyst include silica alumina, silica magnesia; an ion exchange resin or an ion exchange membrane having an acid group such as sulfonic acid and carboxylic acid.
Preferred examples of the ion exchange membrane include Nafion (trade name, manufactured by DuPont, perfluorosulfonic acid ionomer).

The amount of the acid catalyst to be used can be appropriately set according to the amount of the reaction initiator added to the reaction system, the reaction conditions and the like, and is usually from 1 to 100 parts by weight of the added reaction initiator. It is about 500 parts by weight.

The conditions for decomposing the residual reaction initiator by contact with the acid catalyst can be appropriately set according to the type of the reaction initiator and the acid catalyst. It is about 100 ° C. for about 0.5 to 20 hours.

(Iii) Fe (II) salts, Cr (II) salts, C (II) salts,
Transition metal salts such as u (I) or Cu (II) salts and Ag (I) salts; thiosulfates. Specifically, FeSO ₄ , CrCl ₂ , CuCl, Cu (OCOC
_{H 3) 2, [Ag (} NH 3) 2] OH, and the like Na ₂ S ₂ O _3. These reducing agents may be used alone or in combination of two or more.

The amount of the reducing agent to be used can be appropriately set according to the amount of the reaction initiator added to the reaction system, the reaction conditions, and the like, and is usually 0.001 per mol of the added reaction initiator. About 5 mol.

The conditions for decomposing the residual reaction initiator by contact with the reducing agent can be appropriately set according to the type of the reaction initiator and the reducing agent.
It is about 20 to 100 ° C. and about 0.5 to 10 hours.

(Iv) Decomposition by UV irradiation The UV irradiation (UV (about 100 to 390 nm))
Irradiation for about 10 to 10 hours can be performed.
The UV wavelength to be irradiated can be appropriately set according to the type of the reaction initiator. UV irradiation can be performed using an ultra-high pressure mercury lamp, a high pressure mercury lamp, a medium pressure mercury lamp, a low pressure mercury lamp, or the like.

(V) Decomposition bases upon contact with a base include, for example, alkali metal carbonates such as sodium carbonate and potassium carbonate; alkali metal bicarbonates such as sodium hydrogen carbonate and potassium hydrogen carbonate; sodium methylate Alkali metal alcoholates such as sodium, sodium ethylate, sodium propylate, potassium t-butoxide, lithium ethylate; hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, lithium hydroxide; calcium hydroxide, magnesium hydroxide Hydroxides of alkaline earth metals such as barium hydroxide;
Examples include aluminum hydroxide and soda lime. These bases may be used alone or in combination of two or more.

The amount of the base used can be appropriately set according to the amount of the reaction initiator added to the reaction system, the reaction conditions, and the like. It is about 001 to 5 mol.

The conditions for decomposing the residual reaction initiator upon contact with the base can be appropriately set according to the type of the reaction initiator and the base, but are usually 20 to 20 in an open system or a closed system.
This is performed at about 100 ° C. for about 0.5 to 10 hours.

Alternatively, the fluoroalcohol of the general formula (1) may be distilled immediately after adding the base.

When the decomposition of the reaction initiator remaining in the reaction solution is carried out by contact with a base, the decomposition of the fluoroalcohol of the general formula (1) may be carried out after contact with the base or in the presence of the base as described later. Is obtained without further distillation, the resulting fluoroalcohol of the general formula (1) has an extremely low impurity content.

These removal methods may be performed in combination of two or more.

In the step of removing the undecomposed reaction initiator of the present invention, it is preferable to remove all the reaction initiators, but the amount of the undecomposed reaction initiator in the reaction solution containing methanol after removal is 1,1. 000 mass ppm or less, preferably 5
It may be about 0 mass ppm or less.

After the removal of the reaction initiator, the methanol, H (CF) present in the reaction mixture is subjected to a purification step by distillation.
₂ CF ₂ ) _n CH ₂ OH (n is 3 or more), H (CF (C
By removing impurities such as F ₃ ) CF ₂ ) _n CH ₂ OH (n is 2 or more), the general formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n, R ¹ As defined in Is obtained.

In the method of the present invention, after performing the purification step by distillation, the formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) wherein n and R ¹ are as defined above It is on the street. May be carried out in the presence of a base, or after contacting a fraction containing a fluorine alcohol represented by the formula (1) with a base. As the base to be added to or brought into contact with the fraction containing the fluoroalcohol, the base exemplified in the method for decomposing the reaction initiator by contacting with the base of (v) can be used.

The amount of the base used is about 0.05 to 1.0 mol, preferably 0.1 to 0.5 mol per kg of the weight of the fraction containing the fluoroalcohol represented by the general formula (1).
It is about a mole.

The reaction of methanol with tetrafluoroethylene or hexafluoropropylene is usually carried out in a batch process, but the process after the reaction (removal of the reaction initiator and distillation) may be a batch process or a continuous process. There may be.

According to the production method of the present invention, the evaporation residue is 5%.
A fluoroalcohol having a content of 0 ppm or less, preferably 25 ppm or less, more preferably 10 ppm or less is obtained.

The evaporation residue can be obtained as follows. That is, fluorinated alcohol at 40 ° C., 5 mmH
The weight of the residue after evaporation in g is measured and expressed as mass ppm relative to fluoroalcohol.

The UV absorbance of the fluoroalcohol of the general formula (1) obtained in the present invention in methanol at 205 nm is 0.1 abs or less, preferably -0.1 abs or less.
More preferably, it is -0.2 abs or less. The UV absorbance in methanol is 1 m of fluoroalcohol of the general formula (1).
The measurement is made by adding 3 ml of methanol to 1 and using methanol as a reference.

The fact that the fluoroalcohol obtained by the production method of the present invention is "substantially free of impurities" means that (i) the evaporation residue of the fluoroalcohol is 50 ppm or less, preferably 25 ppm or less, more preferably 10 ppm or less. And / or (ii) a UV absorbance (205 nm) in methanol of not more than 0.1 abs, preferably -0.
It means 1 abs or less, more preferably -0.2 abs or less.

An information recording medium in which a recording layer on which information can be written and / or read by a laser is provided on a substrate is a solvent containing a fluoroalcohol of the general formula (1) of the present invention, preferably a fluoroalcohol. Dissolve the dye in a fluorinated solvent containing, apply the resulting solution on the substrate,
It can be manufactured by forming a recording layer containing a dye according to a conventional method such as drying. Examples of the dye include a cyanine dye, a phthalocyanine dye, a pyrylium dye, a thiopyrylium dye, a squalilium dye, an azurenium dye,
Examples include indophenol dyes, indoaniline dyes, triphenylmethane dyes, quinone dyes, aminium dyes, diimmonium dyes, and metal complex salt dyes. Examples of the substrate include plastics such as polycarbonate, polymethyl methacrylate, epoxy resin, amorphous polyolefin, polyester, and polyvinyl chloride, glass, and ceramics. In addition, an undercoat layer may be provided between the recording layer and the substrate for the purpose of improving flatness, improving adhesive strength, preventing deterioration of the recording layer, or a protective layer may be provided on the recording layer. .

[0042]

According to the present invention, an information recording medium (such as an optical disk such as a CD-R or a DVD-R) in which a recording layer capable of writing and / or reading information by a laser is provided on a substrate, a film, and the like. HCF ₂ CF ₂ CH ₂ O which is substantially free of impurities and suitable for manufacturing photoreceptors and the like
H, H (CF ₂ CF ₂ ) ₂ CH ₂ OH and HCF (C
F ₃ ) CF ₂ CH ₂ OH can be easily produced.

[0043]

The present invention will be described below in more detail with reference to examples and comparative examples.

Example 1 An autoclave was charged with calcium carbonate (30 g). After replacing the autoclave with nitrogen and sucking with a vacuum pump, methanol (2 L), tetrafluoroethylene and di-t-butyl peroxide (45 g) as a reaction initiator were charged, and the mixture was heated at 125 ° C. and 0.8 MPa for 6 hours. Reacted. The amount of di-tert-butyl peroxide in the reaction mixture was determined by gas chromatography (SE-30, 3).
When analyzed by m), 1.86% remained. Thereafter, the reaction mixture was stirred at 140 ° C. for 3 hours in order to decompose residual di-t-butyl peroxide. The residual amount of di-t-butyl peroxide was analyzed by gas chromatography, and the detection limit (10 ppm) was obtained.
It was below. After cooling the reaction mixture, it was distilled to separate methanol, which was further distilled to obtain H (CF ₂ CF ₂ ) _n CH _2.
OH (n is an integer of 2 or more) is separated into HCF ₂ CF ₂ CH
_The obtained HCF ₂ CF from which a fraction (1.2 L) of ₂ OH was obtained
The evaporation residue of the ₂ CH ₂ OH fraction was 20 ppm,
The absorbance (205 nm) was -1.0 abs.

Comparative Example 1 The same operation as in Example 1 was carried out except that the reaction mixture was not stirred at 140 ° C. for 3 hours (including no step for decomposing the remaining reaction initiator). HCF ₂ CF ₂ CH obtained
The evaporation residue of the ₂ OH fraction was 590 ppm, and the UV absorbance (205 nm) was 2.0 abs.

[0046] EXAMPLE 2 The reaction mixture instead of stirring for 3 hours at 140 ° C., H ₂
The same operation as in Example 1 was performed except that SO ₄ (40 g) was added and the mixture was stirred at room temperature for 5 hours to decompose the remaining reaction initiator. The evaporation residue of the obtained HCF ₂ CF ₂ CH ₂ OH fraction was 22 ppm, and the UV absorbance (20
5 nm) was -1.0 abs.

Example 3 Instead of stirring the reaction mixture at 140 ° C. for 3 hours, add Nafion (135 g) and stir at 70 ° C. for 1.5 hours to decompose the remaining initiator. The same operation as in Example 1 was performed. HCF ₂ CF ₂ C obtained
The evaporation residue of the H ₂ OH fraction was 19 ppm, and the UV absorbance (205 nm) was -1.0 abs.

Example 4 Instead of di-t-butyl peroxide (45 g), t-
Butyl peroxy-2-ethylhexanoate (67
g), and instead of H ₂ SO ₄ (40 g), FeSO
₄ (94 g), and the same operation as in Example 2 was carried out except that the remaining reaction initiator was decomposed by stirring.
The evaporation residue of the obtained HCF ₂ CF ₂ CH ₂ OH fraction is 1
9 ppm, and the UV absorbance (205 nm) was -1.0.
abs.

Example 5 Instead of stirring the reaction mixture at 140 ° C. for 3 hours, the reaction mixture was irradiated with light from a high-pressure mercury lamp (100 W) at 50 ° C. for 4 hours.
The same operation as in Example 1 was performed except that the mixture was stirred for a period of time to decompose the remaining reaction initiator. HCF ₂ CF ₂ CH _{2 obtained}
The evaporation residue of the OH fraction was 21 ppm, and the UV absorbance (205 nm) was -1.0 abs.

Example 6 The same operation as in Example 4 was carried out except that NaOH (27 g) was added to the reaction mixture instead of FeSO ₄ (94 g), and the mixture was stirred to decompose the remaining reaction initiator. The evaporation residue of the obtained HCF ₂ CF ₂ CH ₂ OH fraction is 18 p.
pm and UV absorbance (205 nm) is -1.0 abs
Met.

Example 7 The reaction, decomposition of the remaining reaction initiator, and distillation were carried out in the same manner as in Example 1, and the obtained H (CF ₂ CF ₂ ) _n CH ₂ OH (n is an integer of 2 or more) was distilled. Fraction is further separated by distillation and
A fraction of (CF ₂ CF ₂ ) ₂ CH ₂ OH was obtained. H obtained
(CF ₂ CF ₂ ) ₂ CH ₂ OH fraction evaporation residue is 25 ppm
And the UV absorbance (205 nm) was -1.0 abs.

Example 8 The reaction, decomposition of the remaining reaction initiator, and purification by distillation were carried out in the same manner as in Example 1 except that hexafluoropropylene was used in place of tetrafluoroethylene. Absorbance (205 nm) -1.0
Abs HCF (CF ₃ ) CF ₂ CH ₂ OH was obtained.

Example 9 The same operation as in Example 1 was carried out except that 28% sodium methoxide (30 g) was added to the reaction mixture, followed by distillation.
The evaporation residue of the obtained HCF ₂ CF ₂ CH ₂ OH fraction is 1
0 ppm, and the UV absorbance (205 nm) is -2.0.
abs.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toru Yoshizawa 1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries, Ltd. Inside Yodogawa Works (72) Eiji Ogura 1-1-1, Nishiichitsuya, Settsu-shi, Osaka Daikin Industries Inside Yodogawa Works (72) Inventor Toshiyuki Katsube 1-1 1-1 Nishi-Itsuya, Settsu-shi, Osaka Daikin Industries, Ltd. F-term in Yodogawa Works (reference) 4H006 AA02 AC21 AD11 AD30 BA50 BA51 BA66 BA83 BA92 BC51 BD60 BD70 BE01 BE02 BE03 BE10 BE11 BE12 BE13 BE62 BE90 FE11 FE71 FE74

Claims (3)

[Claims] 1. Methanol and tetrafluoroethylene or hexafluoropropylene are reacted in the presence of a reaction initiator to obtain the following formula (1) H (CFR ¹ CF ₂ ) _n CH ₂ OH (1) [n = 1 or 2 . When n = 1, R ¹ represents F or CF ₃ . When n = 2, R ¹ indicates F. In the method for producing a fluoroalcohol represented by the formula (1), after removing the undecomposed reaction initiator contained in the reaction solution, distillation of the fluoroalcohol represented by the formula (1) is performed. A method for producing a fluoroalcohol represented by 1). 2. The removal of the undecomposed reaction initiator includes the decomposition of the undecomposed reaction initiator by heating the reaction solution, the decomposition of the undecomposed reaction initiator by contact with an acid catalyst, and the undecomposition reaction by contact with a reducing agent. The method is carried out using at least one means selected from the group consisting of decomposition of an initiator, decomposition of an undecomposed reaction initiator by UV irradiation, and decomposition of an undecomposed reaction initiator by contact with a base. Item 1. The method according to Item 1. 3. A fraction containing a fluoroalcohol represented by the formula (1) in the presence of a base or after contacting a fraction containing a fluoroalcohol represented by the formula (1) with a base. The method according to claim 1, wherein distillation of the product is performed.