JP2001187755A - Method for recovering fluorine-based solvent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recovering fluorine-based solvent substantially free from impurities. SOLUTION: This method for recovering the fluorine-based solvent from a mixture containing the fluorine-based solvent and a coloring matter comprises (1) a method for recovering the fluorine-based solvent by distillation, and (2) a method for recovering the fluorine-based solvent by adding a second solvent homogeneously mixed with the fluorine-based solvent and not dissolving the coloring matter, to the mixture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for recovering a fluorine-based solvent.

[0002]

2. Description of the Related Art Fluorinated solvents include, for example, CD-R and DV.
It is used as a solvent for dissolving a dye at the time of manufacturing an information recording medium in which a recording layer capable of writing and / or reading information by a laser is provided on a substrate such as a DR. Since the fluorinated solvent has a higher global warming potential than carbon dioxide, it is desirable to recover and reuse it after use. However, the fluorinated solvent recovered after use contains a dye, and has drawbacks such as deterioration of the dye and difficulty in adjusting the dye concentration, and it is not preferable to reuse it as it is after recovery. Further, the dye cannot be changed to another kind by reusing it as it is. Therefore, in order to reuse the fluorinated solvent, it is necessary to separate impurities such as dyes. However, in the production of an information recording medium such as a CD-R, an extremely high-purity fluorinated solvent is required. It was not considered that a fluorine-based solvent satisfying the purity could be easily recovered.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for recovering a fluorinated solvent containing substantially no impurities.

[0004]

Means for Solving the Problems The present inventors have intensively studied a method of separating a dye from a fluorinated solvent, and surprisingly, these mixtures can be easily separated by distillation, and the dye can be substantially removed. It has been found that a fluorine-based solvent containing no impurities such as can be recovered. Furthermore, they have found that if a specific second solvent is added to these mixtures, the dye can be easily separated from the fluorinated solvent and a high-purity fluorinated solvent can be recovered. The present invention has been completed based on such findings.

That is, the present invention relates to the inventions described in the following items. Item 1. A method for recovering a fluorine-based solvent from a mixture containing a fluorine-based solvent and a dye, wherein the fluorine-based solvent is recovered by distillation. Item 2 The method according to Item 1, wherein the distillation is performed under reduced pressure. Item 3. The dye is a cyanine dye, a phthalocyanine dye, an azo dye, a pyrylium dye, a thiopyrylium dye, a squarylium dye, an azulenium dye, an indophenol dye, an indoaniline dye, a triphenylmethane dye, or quinone. Item 1. The method according to Item 1, which is at least one selected from the group consisting of a dye, an aminium dye, a diimmonium dye, and a metal complex dye. Item 4. The fluorine-based solvent has a dye solubility of about 1 to 10 mass.
%. The method according to any one of Items 1 to 3, which is a fluorine-based solvent. Item 5: The fluorinated solvent is a fluorinated alcohol.
A method according to any one of claims 1 to 3. Item 6. The fluorinated alcohol is represented by the following general formula 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. 6. The method according to item 5, which is a fluorinated alcohol represented by the formula: Item 7. A method for recovering a fluorine-based solvent from a mixture containing a fluorine-based solvent and a dye, comprising adding a second solvent that is uniformly mixed with the fluorine-based solvent and does not dissolve the dye to the mixture, and precipitates from the obtained mixture. Separated and then the second
A method of recovering a fluorinated solvent by separating the solvent. Item 8 The method according to Item 7, wherein the second solvent is at least one selected from the group consisting of water, fluorinated ethers and fluorinated alkanes. Item 9. The fluorine-based solvent has a solubility of the dye of about 1 to 10 mass.
Item 10. The method according to Item 7 or 8, which is a fluorine-based solvent. Item 10. The method according to Item 7 or 8, wherein the fluorinated solvent is a fluorinated alcohol. Item 11. The fluorinated alcohol is represented by the following general formula 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. Item 10. The method according to Item 10, which is a fluorinated alcohol represented by the formula:

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a fluorine-based solvent, at least
Is not particularly limited as long as the solvent contains one fluorine atom.
Fluorinated alcohols [eg,
General formula (1) H (CFR¹CF_Two)_nCH_TwoOH [n = 1 or
Is 2. R when n = 1¹Is F or CF_ThreeIs shown. n = 2
When R¹Indicates F. Fluorinated alcohol represented by
]; Fluorinated ketone [CF_ThreeCOCF_Three, CF_ThreeCO
CH_TwoCOCF_Three, CF_ThreeCOCH_TwoCOCH_ThreeEtc.];
Substituted esters (CF_ThreeCOOCH_Three, CF_ThreeCOOC_TwoH
_Five, CH_ThreeCOOCH_TwoCF_Three, CF_ThreeCOOCH_TwoCF_Three,
CH_ThreeCOOCH_TwoCF_TwoCF_TwoH, CF_ThreeCF_TwoCF_TwoCF_Two
COOC_TwoH_FiveFluorinated carboxylic acid [CF_Three(C
F_Two)_mCOOH [m represents an integer of 2 to 4. ] Etc .;
Fluorinated alkane [CCl_TwoF_Two, CCl_ThreeF, ClF_TwoC-
CCIF_TwoAnd the like. Among these
Even the method of the present invention can be applied to fluorinated alcohol
And the general formula (1) H (CFR¹CF_Two)_nCH_Two
OH [n = 1 or 2. R when n = 1 ¹Is F or
CF_ThreeIs shown. R when n = 2¹Indicates F. ]
More preferably, it is applied to fluorinated alcohols.

Alternatively, it is preferable to use a fluorine-based solvent having a solubility of a dye (a dye contained in a mixture) of about 1 to 10 mass%.

The dye contained in the mixture is not particularly limited, but is usually used in the production of an information recording medium having a substrate on which a recording layer capable of writing and / or reading information by a laser is provided. Dyes to be used are exemplified. Such dyes include cyanine dyes, phthalocyanine dyes, azo dyes, pyrylium dyes,
Thiopyrylium dyes, squarylium dyes, azurenium dyes, indophenol dyes, indoaniline dyes, triphenylmethane dyes, quinone dyes,
Aminium dyes, diimmonium dyes: nickel,
Examples include complex salt dyes of metals such as copper, cobalt, palladium, platinum, and chromium. Specific examples of these dyes include JP-B-7-96333 and JP-A-9-274.
732 and JP-A-9-59529.

For example, as a cyanine dye, (CH
_{3) 2 N- (CH = CH} ) 5 -CH = + N (CH 3) l ClO
₄ ^-,

[0010]

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[P = 2 or 3] and the like.

The phthalocyanine dyes include, for example,

[0013]

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[0014]

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[0015]

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And the like.

As the azo dye, for example,

[0018]

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And the like.

Some of these dyes are used as a quencher for preventing deterioration or decomposition of the dye during the production and storage of the information recording medium.

The distillation is usually carried out by heating at about 30 to 150 ° C. under normal pressure or under reduced pressure (usually 0.0001 to 150 ° C.).
(About 0.1 MPa).

When a fluorine-based solvent used as a solvent for dissolving a dye at the time of manufacturing an information recording medium such as a CD-R or a DVD-R is recovered, the recovered fluorine-based solvent includes, in addition to the dye, Other solvents (eg, diacetone alcohol) used to remove the dye attached to the side surface (periphery) of the substrate may be included. Therefore, when other solvents are contained, after separating the fluorine-based solvent and impurities such as dyes, the other solvents are removed by rectification,
A fluorinated solvent containing substantially no impurities can be obtained. Alternatively, the recovered fluorinated solvent can be directly rectified to simultaneously separate impurities such as dyes and remove other solvents, thereby obtaining a fluorinated solvent containing substantially no impurities.

The rectification can be performed under appropriate conditions according to the combination of the fluorine-based solvent and another solvent, for example, by heating to about 30 to 150 ° C. under normal pressure or under reduced pressure ( Usually, it can be carried out at about 0.0001 to 0.1 MPa).

Water, fluorinated ethers, fluorinated alkanes and the like are listed as the second solvent which is uniformly mixed with the fluorinated solvent but does not dissolve the dye. The second solvent may be a fluorine-based solvent containing a fluorine atom in the molecule as long as it is different from the fluorine-based solvent originally contained in the mixture.

Specific examples of the fluorinated ether include CF
₃ CF ₂ CF ₂ CF ₂ OCH ₃ , CF ₃ CF ₂ CF ₂ CF ₂ OC
H ₂ CH _{3 and the} like. Specific examples of the fluorinated alkane include CCl ₂ F ₂ , CCl ₃ F, and ClF ₂ C-CCLF ₂
And the like.

Preferred combinations of the first solvent (fluorine solvent originally contained in the mixture) and the second solvent include, for example, fluorinated alcohol and water; fluorinated alcohol and fluorinated ether; fluorinated alcohol and fluorine Alkane and the like.

In these combinations, the fluorinated alcohol is particularly preferably a fluorinated alcohol represented by the general formula (1).

The amount of the second solvent is usually about 0.1 to 10 kg per 1 kg of the fluorine-based solvent.

Since the dye precipitates when the second solvent is added, the mixture of the fluorinated solvent and the second solvent is separated from the precipitate by an appropriate method such as decantation.

After the separation from the precipitate (dye), the fluorine-based solvent and the second solvent are further separated, whereby a fluorine-based solvent containing substantially no impurities can be recovered.
Separation of the fluorinated solvent and the second solvent is performed by distillation, membrane separation,
It can be performed by a suitable method such as a dehydration method and a pervaporation method.

According to the method of the present invention, the evaporation residue is 50 m
A fluorinated solvent having an ass ppm or less, preferably 25 mass ppm or less, more preferably 10 mass ppm or less can be recovered.

The evaporation residue can be obtained as follows. That is, a fluorinated solvent is heated at 40 ° C. and 6.65 hP.
The weight of the residue after evaporation at a (5 mmHg) is measured and expressed in mass ppm relative to the fluorine-based solvent.

The UV absorbance of the fluorinated solvent obtained by the method of the present invention in methanol at 205 nm is
0.1 abs or less, preferably -0.1 abs or less, more preferably -0.2 abs or less. The UV absorbance in methanol is measured using 1 ml of a fluorinated solvent and 3 ml of methanol as a measurement sample and using methanol as a reference.

The fact that the fluorine-based solvent obtained by the method of the present invention is "substantially free of impurities" means that (i) the evaporation residue of the fluorine-based solvent is 50 mass ppm or less, preferably 25 ma
ss ppm or less, more preferably 10 mass ppm or less, and / or (ii) UV absorbance (205 nm) in methanol of 0.1 abs or less, preferably -0.
It means 1 abs or less, more preferably -0.2 abs or less.

[0035]

According to the present invention, impurities such as dyes, other solvents, and their decomposition products can be easily separated from the fluorine-based solvent, and the fluorine-based solvent containing substantially no impurities can be recovered.

[0036]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

Example 1 Cyanine dye OM-55 [Fuji Photo Film Co., Ltd.
10g) and 5g of IRG-002 [manufactured by Nippon Kayaku Co., Ltd.]
500 g of HCF ₂ CF ₂ CH ₂ OH solution containing 15 g of diacetone alcohol (DAA) used as a cleaning agent for discs such as
g was charged into a glass flask (1 L) equipped with a thermometer, a stirrer and a vacuum distillation apparatus, and 133 hPa (100 m
Distilled under reduced pressure (mHg). A fraction having a boiling point of 48 ° C. to 60 ° C. was recovered, and its purity was 99.9 mass%.
As described above, it was HCF ₂ CF ₂ CH ₂ OH having an evaporation residue of 10 mass ppm or less and containing substantially no impurities.

Example 2 500 g of the HCF ₂ CF ₂ CH ₂ OH solution of Example 1 containing the dye (including the dye used as a quencher) and DAA
Was added with 300 g of water. As a result, the dye precipitated as a solid. When the supernatant was separated by decantation to simple distillation, to recover a fraction of 93 ° C. from 80 ° C., HCF ₂ CF
631 g of a mixture containing about 7: 3 (weight ratio) of ₂ CH ₂ OH: water
I got This mixture was heated to 70 ° C. and dehydrated using a polyamide resin pervaporation membrane.
Purity is 99.9 mass% or more, and evaporation residue is 10 mass%
HCF ₂ CF ₂ CH ₂ O with s ppm or less and substantially no impurities
370 g of H were obtained.

Example 3 A dye was precipitated in the same manner as in Example 2 except that CF ₃ CF ₂ CF ₂ CF ₂ OCH ₃ was used as the second solvent instead of water. The supernatant separated by the gradient method was subjected to simple distillation, and 105 ° C.
When the fraction at 0 ° C. was recovered, HCF ₂ CF ₂ CH ₂ OH having a purity of 99.9 mass% or more, an evaporation residue of 10 mass ppm or less and substantially containing no impurities was obtained.

Example 4 A dye was precipitated in the same manner as in Example 2 except that CF ₃ CF ₂ CF ₂ CF ₂ OCH ₂ CH ₃ was used as the second solvent instead of water. The supernatant separated by the gradient method was subjected to simple distillation, and a fraction at 105 ° C. to 110 ° C. was recovered. The purity was 99.9 mass.
%, HCF ₂ CF ₂ CH ₂ OH having an evaporation residue of 10 mass ppm or less and containing substantially no impurities was obtained.

Example 5 Distillation was carried out in the same manner as in Example 1 except that HCF ₂ CF ₂ CF ₂ CF ₂ CH ₂ OH was used as the fluorinated solvent. Boiling point 75 ° C to 80 ° C
When the distillate discharged in the above was recovered, the purity was 99.9 mass
%, HCF ₂ CF ₂ CF ₂ CF ₂ CH ₂ OH having an evaporation residue of 10 mass ppm or less and containing substantially no impurities.

Example 6 A dye was precipitated in the same manner as in Example 3 except that HCF ₂ CF ₂ CF ₂ CF ₂ CH ₂ OH was used as the fluorinated solvent. The supernatant separated by the gradient method was subjected to simple distillation, and a fraction at 135 ° C to 145 ° C was recovered. The purity was 99.9 mass% or more, the evaporation residue was 10 massppm or less, and impurities were substantially eliminated. HCF ₂ CF ₂ CF ₂ CF ₂ CH ₂ OH not containing was obtained.

Example 7 Distillation was carried out in the same manner as in Example 1 except that CF ₃ CHFCF ₂ CH ₂ OH was used as a fluorinated solvent. When a fraction having a boiling point of 50 ° C. to 60 ° C. was collected, the purity was 99.9 mass% or more, the evaporation residue was 10 mass ppm or less, and CF ₃ CHFCF ₂ CH ₂ OH containing substantially no impurities. was gotten.

Example 8 A dye was precipitated in the same manner as in Example 4 except that CF ₃ CHFCF ₂ CH ₂ OH was used as the fluorinated solvent. The supernatant separated by the gradient method was subjected to simple distillation, and a fraction at 110 ° C. to 125 ° C. was collected. The purity was 99.9 mass% or more, the evaporation residue was 10 mass ppm or less, and impurities were substantially eliminated. Was obtained without CF ₃ CHFCF ₂ CH ₂ OH.

Claims (11)

[Claims] 1. A method for recovering a fluorinated solvent from a mixture containing a fluorinated solvent and a dye, wherein the fluorinated solvent is recovered by distillation. 2. The method according to claim 1, wherein the distillation is performed under reduced pressure. 3. The dye is a cyanine dye, a phthalocyanine dye, an azo dye, a pyrylium dye, a thiopyrylium dye, a squarylium dye, an azulenium dye, an indophenol dye, an indoaniline dye,
The method according to claim 1, wherein the method is at least one selected from the group consisting of a triphenylmethane dye, a quinone dye, an aminium dye, a diimmonium dye, and a metal complex dye. 4. A fluorine-based solvent having a dye solubility of about 1 to about 1.
The method according to any one of claims 1 to 3, which is a 10 mass% fluorine-based solvent. 5. The method according to claim 1, wherein the fluorinated solvent is a fluorinated alcohol. 6. A fluorinated alcohol represented by the following general formula 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 according to claim 5, which is a fluorinated alcohol represented by the formula: 7. A method for recovering a fluorinated solvent from a mixture containing a fluorinated solvent and a dye, wherein a second solvent which is uniformly mixed with the fluorinated solvent and does not dissolve the dye is added to the mixture. A method in which a precipitate is separated from the mixture, and then the second solvent is separated to recover the fluorinated solvent. 8. The method according to claim 1, wherein the second solvent is at least one selected from the group consisting of water, fluorinated ethers and fluorinated alkanes.
8. The method of claim 7, which is a species. 9. A fluorine-based solvent having a solubility of a dye of about 1 to about 10.
The method according to claim 7 or 8, wherein the solvent is 10 mass% of a fluorinated solvent. 10. The method according to claim 7, wherein the fluorinated solvent is a fluorinated alcohol. 11. The fluorinated alcohol is represented by the following general formula 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 according to claim 10, which is a fluorinated alcohol represented by the formula: