WO2002018307A1

WO2002018307A1 - Process for producing fluoroalcohol compound

Info

Publication number: WO2002018307A1
Application number: PCT/JP2001/006073
Authority: WO
Inventors: Toru Yoshizawa; Shouji Takaki
Original assignee: Daikin Industries, Ltd.
Priority date: 2000-08-28
Filing date: 2001-07-13
Publication date: 2002-03-07
Also published as: TW572876B; CN1203038C; CN1441761A; JP2002069018A

Abstract

A process for producing a fluoroalcohol represented by the general formula (1) H(CF2CF2)nCH2OH (1) (wherein n is 1 or 2) from tetrafluoroethylene and methanol as starting materials in the presence of a free-radical generator, characterized by comprising the steps of: (i) reacting tetrafluoroethylene with methanol; and (ii) distilling the resultant crude reaction product either in the presence of a base and water or after bringing it into contact with a base and water to thereby recover the fluoroalcohol represented by the general formula (1). Thus, a fluoroalcohol can be produced which contains substantially no impurities and is suitable for use in producing information recording media (e.g., optical disks such as CD-R and DVD-R), etc.

Description

Specification

Method for producing fluorine-containing alcohol compounds

Technical field

The present invention relates to a method for producing a fluorine-containing alcohol compound.

Background technology

As a method for producing H (CF2CF2) nCHzOH (n = l, 2), JP-A No. 54-154707, U.S. Pat. No. 2559628, etc. disclose an excess of methanol and It is described that by reacting ethylene, a telomer mixture of H (CF ₂ CF ₂ ) _n CH ₂ OH (n is up to 12) can be obtained.

However, the telomer mixture obtained by this method cannot remove evaporation residues of several hundred ppm even by purification by distillation. When used as a solvent in the production of an information recording medium provided with a writable and Z- or readable recording layer, there is a drawback that it is not suitable for producing a high-quality information recording medium due to the influence of evaporation residue.

Further, it is known that a fluorinated alcohol having a low impurity content can be obtained by a method of distilling the telomer mixture in the presence of a base or after bringing the telomer mixture into contact with the base (Japanese Patent No. 3029618). However, when used as a solvent in the production of an information recording medium, a fluorinated alcohol having a lower impurity content is desired.

Disclosure of the invention

A main object of the present invention is to manufacture information recording media (optical discs such as CD-R and DVD-R) having a recording layer on which information can be written and / or read by a laser on a substrate. It is an object of the present invention to provide a method for producing a fluorine-containing alcohol which is substantially free from impurities.

The present inventor has conducted intensive studies in view of the above-described problems, and as a result, obtained a reaction crude product obtained by reacting tetrafluoroethylene with methanol in the presence of a base and water or in contact with a base and water. After that, the amount of impurities is further reduced as compared with the case where the crude reaction product is distilled in the presence of or in contact with a base. And found that it was possible to obtain a fluorinated alcohol substantially free of impurities, and completed the present invention.

That is, the present invention provides the following method for producing a fluorinated alcohol.

1. Using tetrafluoroethylene and methanol as starting materials in the presence of a radical source, the following formula (1)

H (CF ₂ CF ₂ ) nCH ₂ OH (1)

(Wherein n is 1 or 2), wherein the method comprises the following steps (i) and (ii):

(i) reacting tetra'fluoroethylene with methanol,

(ii) Distilling the obtained reaction crude product in the presence of a base and water, or contacting the reaction crude product with a base and water followed by distillation to recover the fluorinated alcohol of the formula (1) Process.

2. In the presence of a radical generating source, using tetrafluoroethylene and methanol as starting materials, the following formula (1)

H (CF ₂ CF ₂ ) nCH ₂ 〇H (1)

(Wherein n is 1 or 2), wherein the method comprises the following steps (i) to (iii):

(i) reacting tetrafluoroethylene with methanol;

(ii) The obtained reaction crude product is distilled, and methanol obtained from the top of the distillation column is returned to the reactor and reused, and the fluorine-containing alcohol of the formula (1) obtained as the bottom component is obtained. Collecting the

(iii) distilling the obtained fluorinated alcohol in the presence of a base and water, or contacting the fluorinated alcohol with a base and water followed by distillation to obtain a fluorinated alcohol of the formula (1) Recovering.

3. Starting from tetrafluoroethylene and methanol in the presence of a radical generator and an acid acceptor, the following formula (1)

H (CF2CF2) nCH ₂ 〇H (1)

(Wherein n is 1 or 2), wherein the method comprises the following steps (i) to (iv): (i) reacting tetrafluoroethylene with methanol;

(ii) removing the reaction product of the acid acceptor and the unreacted acid acceptor from the obtained reaction crude product,

(iii) Distill the obtained reaction crude product, return the methanol obtained from the top of the distillation column to the reactor and reuse it, and obtain the fluorine-containing alcohol of the formula (1) obtained as the bottom component. The process of collecting,

(iv) the ability to distill the obtained fluorinated alcohol in the presence of a base and water, or the contact of the fluorinated alcohol with a base and water followed by distillation to recover the fluorinated alcohol of formula (1) Process.

4. Starting from tetrafluoroethylene and methanol in the presence of a radical generator and an acid acceptor,

Formula: HCF ₂ CF ₂ CH ₂ 〇H

A method for producing a fluorinated alcohol represented by the following formula, characterized by comprising the following steps (i) to (V):

(i) reacting tetrafluoroethylene with methanol;

(iii) The obtained reaction crude product is distilled, methanol obtained from the top of the distillation column is returned to the reactor and reused, and the formula (1) obtained as the bottom component is obtained.

(Where n is 1 or 2) a step of recovering the fluorinated alcohol represented by

(iv) Ji 11_Rei ₂ Ji ₂ fluorinated Arukoru distilled obtained 11 ₂ Rei_11 steps you separated,

(v) Distilling the separated HCF ₂ CF ₂ CH ₂ OH in the presence of a base and water, or contacting the fluorinated alcohol with a base and water followed by distillation to obtain HCF ₂ CF

Step of recovering ₂ CH ₂ OH.

5. In the method of the above item 4, the method of recovering HCF ₂ CF ₂ CH ₂ OH in the step (V) is as follows: after distilling components containing HCF ₂ CF ₂ CH ₂ OH to remove low boiling components, The component containing HCF ₂ CF ₂ CH ₂ OH obtained as the bottom component was A method for producing a fluorinated alcohol, which is a method of recovering HCF ₂ CF ₂ CH ₂ OH by distillation. In the method of the present invention, first, tetrafluoroethylene and methanol are reacted in the presence of a radical generation source to obtain the following formula (1)

H (CF ₂ CF ₂ ) nCH ₂ OH (1)

(Wherein, n is 1 or 2). As the radical generating source, at least one selected from the group consisting of a reaction initiator, UV and heat can be used. When the radical source is UV, for example, UV from a medium or high pressure mercury lamp can be used. When the radical generating source is heat, heating may be performed at a temperature of 250 to 300. As the reaction initiator, a peroxide can be exemplified, and a reaction initiator having a half-life at the reaction temperature of about 10 hours is preferably exemplified.

Preferred reaction initiators are perbutyl D (di-tert-butyl peroxyside), perbutyl II (t-butyl peroxy-12-ethylhexanoate), and perbutyl I (t-butyl peroxyisopropyl carbonate). Etc. can be exemplified. The amount of the reaction initiator used is usually about 0.005 to 0.1 mol per 1 mol of tetrafluoroethylene.

In the above reaction, methanol is used in an excess amount based on tetrafluoroethylene. The reaction temperature may be about 40 to 1401: about, the reaction time may be about 3 to 12 hours, and the reaction pressure may be about 0.2 to 1.2 MPa. The reaction can be performed, for example, in a high-pressure reactor. It is preferable to replace the inside of the reaction system with an inert gas such as nitrogen or argon. The production reaction of the fluorinated alcohol is preferably performed in the presence of an acid acceptor. Examples of the acid acceptor include carbonates and bicarbonates of alkali metals or alkaline earth metals such as calcium carbonate, magnesium carbonate, sodium carbonate, lithium carbonate, sodium hydrogen carbonate, potassium hydrogen carbonate, calcium oxide, and calcium hydroxide. , Soda lime, barium carbonate and the like. The acid acceptor is preferably one that can trap an acid such as HF generated during the reaction without making the reaction system strongly alkaline.

The amount of the acid acceptor used is not particularly limited, but 1 mole of tetrafluoroethylene The amount may be about 0.001 to 0.1 mol.

In the method for producing a fluorinated alcohol of the present invention, after the fluorinated alcohol represented by the formula (1) is produced by the above-described method, the obtained reaction crude product is treated in the presence of a base and water, or a base. And after contacting with water, distillation is carried out to obtain a fluorinated alcohol containing substantially no evaporation residue.

As the base, a base having a pKb of 2 or less is preferable. Such bases include, for example, alkali metal alcoholates such as sodium methylate, sodium ethylate, sodium propylate, potassium t-butoxide, lithium ethylate, and alkali metals such as sodium hydroxide, potassium hydroxide, and lithium hydroxide. Examples include hydroxide, calcium hydroxide, aluminum hydroxide, barium hydroxide, magnesium hydroxide, and soda lime. Of these, alkali metal alcoholates are particularly preferred.

The amount of the base to be used is preferably about 0.1 to 10 parts by weight, more preferably about 1 to 3 parts by weight, based on 100 parts by weight of the fluorinated alcohol. The amount of water used is preferably about 0.1 to 10 parts by weight, more preferably about 1 to 3 parts by weight, based on 100 parts by weight of the fluorinated alcohol. No.

When the crude reaction product is distilled in the presence of a base and water, the base and water may be added to the middle stage of the distillation column or to the still. When the crude reaction product is brought into contact with a base and water and then distilled, a treatment tank (base treatment tank) may be provided in front of the distillation column. In this case, the operating conditions in the base treatment tank are not particularly limited, but usually, after the addition of the base, the reaction may be performed at about 20 to about 50 ° C. for about 0.5 to 3 hours. .

In this way, by separating and recovering the fluorinated alcohol by distillation in the presence of a base and water or after contact with the base and water, the above-mentioned formula (1) Can be obtained.

This distillation treatment may be performed after the reaction crude product is distilled to remove excess methanol. In the distillation operation for removing methanol, methanol is distilled off from the top of the distillation column, and fluorine-containing alcohol is contained in the bottom liquid. The obtained methanol can be used effectively by returning it to the reactor and reusing it.

In the method of the present invention, after the reaction of tetrafluoroethylene with methanol, the reaction product of the acid acceptor such as CaF ₂ and NaF and the unreacted acid acceptor are removed from the crude reaction product. Preferably. The operation is not particularly limited, and any method may be used as long as the reaction product of the acid acceptor and the unreacted acid acceptor, which are solid components, can be removed from the crude reaction product.For example, by using a centrifuge, It can be removed efficiently.

In addition, when tetrafluoropropanol, which is a fluorine-containing alcohol with n = 1 in the formula (1), is obtained as a final product, if necessary, excess methanol is removed from the crude reaction product by a method such as distillation. After separation into tetrafluoropropanol of n = 1 in formula (1) and a fluorinated alcohol having n of 2 or more by a method such as distillation, the tetrafluoropropanol separated and recovered is as follows. According to the conditions described above, tetrafluoropropanol may be recovered by distillation in the presence of a base and water, or after contact with a base and water.

In this case, in the distillation operation for separating tetrafluoropropanol where n = 1 in Formula (1) and a fluorinated alcohol where n is 2 or more, tetrafluoropropanol is distilled from the top of the distillation column. Since the fluorinated alcohol having n≥2 is contained in the bottom component, the distillation operation may be performed on the tetrafluoropropanol obtained from the top according to the method described above.

Tetrafluoropropanol substantially free of impurities can be obtained by distilling tetrafluoropropanol in the presence of a base and water, or after bringing it into contact with a base and water, followed by distillation.

When treating with a base and water, alcohol and water are produced as reaction products depending on the type of base used, and the reaction products, water, and low-boiling components such as alcohol used as a solvent for the base are removed. Mix in tetrafluoropropanol. Therefore, in order to obtain high-purity tetrafluoropropanol, first, as a first-stage distillation operation, alcohol, water, etc., which are low-boiling components, are separated and removed from tetrafluoro alcohol. Distillation is carried out, and then, as a second step, a component containing tetrafluoroalcohol obtained as a bottom component by the distillation operation of the first step is distilled to obtain a solution. It is preferred to recover the lafluoro alcohol. According to such a distillation method, it is possible to obtain tetrafluoropropanol which is substantially free from impurities and contains no alcohol or water.

Instead of such a two-stage distillation operation, it is also possible to sequentially remove low-boiling components such as alcohol and water by distillation, and then recover tetrafluoroalcohol from the top or middle stage of the distillation column. However, the two-stage distillation method described above can easily recover high-purity tetrafluoropropanol.

Here, "substantially free of impurities" means that the evaporation residue of the fluoroalcohol is 50 ppm or less, preferably 25 ppm or less, more preferably 10 ppm or less. The absorbance in methanol (205 nm), which is an indicator of the content of evaporation residue, is 0.1 abs or less, preferably -0.1 abs or less, more preferably -0.2 abs or less. More preferably, it is less than 0.4 abs.

Here, the evaporation residue is obtained by measuring the weight of the residue obtained when the fluorinated alcohol is concentrated at 40 :, 5 mmHg (0.665 kPa), and the ss, p pm relative to HCF ₂ CF ₂ CH ₂ OH is measured. Expressed by

The absorbance in methanol is measured using a sample obtained by adding 3 ml of methanol to lm 1 of the fluorinated alcohol of the general formula (1), and using methanol as a reference.

The tetrafluoropropanol substantially free from impurities obtained by the method of the present invention can be used, for example, to produce an information recording medium in which a substrate is provided with a recording layer on which information can be written and Z or readable by a laser. It is suitable as a solvent at that time. An information recording medium in which a recording layer capable of writing and Z or reading information by a laser is provided on a substrate is a solvent containing tetrafluoropropanol obtained by the method of the present invention, preferably tetrafluoropropanol. It can be produced by dissolving a dye in a fluorinated solvent containing olopropanol and using the resulting solution to form a recording layer containing a dye by a method such as coating and drying on a substrate according to a conventional method. Examples of the dye include cyanine dyes, phthalocyanine dyes, pyrylium dyes, thiopyrylium dyes, squarylium dyes, azurenium dyes, indophenol dyes, Indoor dyes, triphenylmethane dyes, quinone dyes, aluminum dyes, diimmonium dyes, metal complex dyes, and the like. Examples of the substrate include plastics such as polycarbonate, polymethyl methacrylate, epoxy resin, amorphous polyolefin, polyester, and polyvinyl chloride, glass, and ceramics. 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, and a protective layer may be provided on the recording layer. .

According to the method of the present invention, it is possible to obtain a fluorinated alcohol of the formula (1) substantially free of impurities and having a smaller evaporation residue as compared with the case of distillation in the presence of a base.

The tetrafluoropropanol separated and recovered by the method of the present invention does not substantially contain impurities, and has an information recording structure in which a recording layer on which information can be written and / or read by a laser is provided on a substrate. It is a suitable solvent for producing media (such as optical discs such as CD-R and DVD-R) and film photoreceptors. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a flowchart showing a continuous distillation step in Example 1. In the figure, 1 is a reaction vessel, 2 is a centrifuge, 3 is a first distillation column, 4 is a second distillation column, 5 is a base treatment tank, 6 is an alkali distillation column, and 7 is an alkali distillation column.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1

A high-pressure reactor was charged with methanol (2 liters), perbutyl D (45 g) and calcium carbonate (30 g), and the reactor was replaced with nitrogen. Then, tetrafluoroethylene was charged at an initial rate of 600 gZhr, and the temperature was lowered. The reaction was controlled at 125 and a pressure of 0.8 MPa for 6 hours.

The obtained reaction crude product (HF: 130 Omass. Ppm, tetrafluoropropanol 27% (GC analysis value), t-butanol: 0.16% (GC analysis value)) In the continuous distillation process shown in the flow chart, treatment was performed in the following manner. First, the crude reaction product was introduced into the centrifugal separator 2 from the reaction vessel 1, and the unreacted acid acceptor and the reactant of the acid acceptor were removed by centrifugation, and then sent to the first distillation column 3.

Next, in the first distillation column 3, methanol was distilled off and recycled to the reactor 1. The bottom component containing a fluorinated alcohol is sent to the second distillation column 4 and contains a fraction containing tetrafluoropropanol (n = l) and a fluorinated alcohol with n ≥ 2 or more in the formula (1) Separated from the bottom component.

Next, the separated tetrafluoropropanol is sent to the base treatment tank 5, and 45 g of sodium methylate (28% methanol solution) and 30 g of water are added to tetrafluoropropanol (1 liter). g was added, and the mixture was heated at 110 for 2 hours, and then introduced into the alkaline distillation column 6.

Then, distillation was carried out in an alkali distillation column 6 to distill methanol and water from the top of the column, and the bottom component containing tetrafluoropropanol was sent to the alkali distillation column 7. Then, by distillation in an alkali distillation column 7, tetrafluoropropanol having a purity of 99.9% or more was obtained as a middle-stage fraction.

Comparative example 1

To 220 g of tetrafluoropropanol obtained in the same manner as in Example 1, 66 g of sodium methylate (28% methanol solution) was added, followed by distillation. Absorbance analysis of the obtained fluoroalcohol fraction showed that the minimum value of absorbance was 10.2 (abs) in the absorption band of 200 to 220 nm.

Experimental example 1

To 300 g of tetrafluoropropanol obtained in Example 1, 90 g of sodium methylate (28% methanol solution) and 62 g of water were added, followed by distillation.

When the absorbance analysis was performed on the obtained fluoroalcohol fraction, the minimum value of the absorbance was 10.4 (abs) in the absorption band of 200 to 220 nm. It was confirmed that the minimum value of absorbance was small and the amount of impurities (evaporation residue) was small.

Claims

The scope of the claims

-(i) reacting tetrafluoroethylene with methanol,

H (CF2CF2) nCH ₂ 〇H (1)

(i) reacting tetrafluoroethylene with methanol,

(ii) The obtained reaction crude product is distilled, and methanol obtained from the top of the distillation column is returned to the reactor and reused, and the fluorine-containing alcohol of the formula (1) obtained as the bottom component is obtained. The process of collecting,

(iii) The obtained fluorinated alcohol is distilled in the presence of a base and water, or the fluorinated alcohol is contacted with a base and water and then distilled to recover the fluorinated alcohol of the formula (1). Process.

H (CF ₂ CF ₂ ) nCH ₂ 〇H (1)

(Wherein n is 1 or 2) A method for producing a fluorinated alcohol represented by the formula: wherein the method comprises the following steps (i) to (iv): (i) reacting tetrafluoroethylene with methanol;

(iv) Distilling the obtained fluorinated alcohol in the presence of a base and water, or contacting the fluorinated alcohol with a base and water followed by distillation to recover the fluorinated alcohol of the formula (1) Process.

4. Starting from tetrafluoroethylene and methanol in the presence of a radical source and an acid acceptor,

Formula: HCF ₂ CF ₂ CH ₂ OH

(i) reacting tetrafluoroethylene with methanol;

H (CF2CF2) nCH ₂ 〇H (1)

(Where n is 1 or 2) a step of recovering the fluorinated alcohol represented by

(iv) a step of distilling the obtained fluorinated alcohol to separate HCF ₂ CF ₂ CH ₂ 〇H,

(v) Distilling the separated HCF ₂ CF ₂ CH ₂ OH in the presence of a base and water, or contacting the fluorinated alcohol with a base and water followed by distillation to obtain HCF ₂ CF ₂ CH ₂ OH Recovering.

5. The method according to claim 4, wherein the HCF ₂ CF ₂ CH ₂ OH in the step (V) is The method of recovery is to distill components containing HCF 2 CF ₂ CH ₂ OH to remove low boiling components, and then distill components containing HCF ₂ CF ₂ CH ₂ 〇H obtained as bottom components again. HCF ₂ CF ₂ A method for producing fluorinated alcohol by recovering CH ₂ OH.