JPH0725876B2 - Polyfluoropolyether - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel polyfluoropolyether excellent in heat resistance and chemical resistance.

[Prior art]

Various compounds have been known so far regarding polyfluoropolyethers. For example, JP-B-36-20599 and JP-B-41-16798 disclose monofunctional perfluoropolyethers having a single acid fluoride group at the terminal, which is a polymer of hexafluoropropylene oxide. There is. Further, in Japanese Patent Publication No. 26707/39, a monofunctional perfluoropolyether having one acid fluoride group at the terminal, which is obtained by addition-polymerizing hexafluoropropylene oxide to perfluoroalkyl monocarbonyl fluoride, or perfluoropolyether. A bifunctional perfluoropolyether having acid fluoride groups at both ends, which is obtained by addition-polymerizing hexafluoropropylene oxide to fluoroalkyldicarbonyl fluoride, is shown.

Further, U.S. Pat. No. 3,367,868 shows a monofunctional perfluoropolyether obtained by addition-polymerizing oxafluoropropylene oxide to perfluoroacetone.

[Means for solving problems]

If it becomes possible for the present inventors to react a compound having three carbonyl groups in one molecule with a fluoroolefin epoxide such as hexafluoropropylene oxide, the conventional monofunctional and bifunctional compounds can be treated with hexafluorohexene. It was thought that a compound having a high molecular weight can be easily obtained as compared with addition polymerization of fluoropropylene oxide, and that various derivatives utilizing three functional groups can be expected to be synthesized.

As a result of earnest studies on the synthesis of trifunctional polyfluoropolyether, the inventors of the present invention reacted 3-ketotetofluoroglutaryl fluoride with hexafluoropropylene oxide. A polyfluoropolyether having three groups can be obtained by a simple means, and a trifunctional polyfluoropolyether in which the fluorocarbonyl group is substituted with another functional group by utilizing the reactivity of the fluorocarbonyl group is obtained. It was found that they can be easily synthesized, and shown in the completion of the present invention.

That is, the present invention provides the following general formula [1] Is a polyfluoropolyether.

Examples of the halogen atom represented by X, Y, Z and A in the general formula [I] include fluorine atom, chlorine atom, bromine atom and iodine atom. In the general formula [I], M
Examples of the alkali metal represented by include lithium, sodium, potassium and rubidium. Furthermore, R ₁ , R
_The number of carbon atoms of the alkyl group represented by ₂ and R ₃ and the alkoxy group represented by A is not particularly limited,
Generally, it is preferably in the range of 1 to 4 from the viewpoint of easy availability of raw materials. Suitable alkyl groups include methyl group, ethyl group, n-propyl group, 1-propyl group, n-butyl group, 1-
Examples thereof include a butyl group and a t-butyl group, and examples of the alkoxy group include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, an i-butoxy group and a t-butoxy group. be able to. The number of carbon atoms of the alkenyloxy group represented by A is not particularly limited, but it is generally preferably in the range of 2 to 4 from the viewpoint of easy availability of raw materials. Suitable alkenyloxy groups in the present invention include vinyloxy group, allyloxy group, methallyloxy group, propenyloxy group, butenyloxy group and the like. In the general formula [I],
Although the carbon number of the alkylol group represented by X, Y and Z is not particularly limited, it is generally preferably in the range of 1 to 4. Suitable alkylol groups include methylol group, ethylol group, n-butyrol group and the like. Furthermore, l, m and n may be integers of 0 or more, but in general, compounds having integers of 0 to 30 are easily produced. Particularly when the polyfluoropolyether of the present invention is produced by the method described below, a mixture of compounds in which the sum of l, m and n is mainly an integer of 0 to 60 is obtained.

The chemical structure of the polyfluoropolyether represented by the above general formula [I] of the present invention can be determined by the following method.

(B) by measuring the infrared absorption spectrum (IR), C-H bonds in the vicinity of 3150~2800cm ^-1, 1900~1880cm ^-1
C = O bond due to fluorocarbonyl group in the vicinity, 1800-
1780 cm ^-1 to C = O bond due to polyfluoroketone group, carboxylic acid ester group and carboxylic acid group, 1680 to 1670 cm ^-1
Carboxylate group, C = O bond by amide group, 13
50～1050Cm ^-1 to C-F bond was observed each characteristic absorption based on the polyfluoro ether bond 1000~960cm ^-1.

(B) By measuring the fluorine nuclear magnetic resonance spectrum (F-NMR), the bonding mode of the fluorine atom present in the compound of the present invention can be known. The chemical shifts (PPm) of F-NMR of the compounds of the following [A] and [B] are shown as typical examples of the F-NMR (based on CFCl ₃ ) of the compound represented by the general formula [I].

The fluorocarbonyl group of the compound [A] is Spectrum derived from -23ppm, The spectrum derived from is at -26 ppm, and its intensity ratio is
It was 1: 2. When it becomes the compound of [B], the spectrum of -23 ppm disappears, the spectrum of 110-134 ppm becomes smaller, and it is a repeating unit of hexanefluoropropylene oxide at 142 ppm. The spectrum due to From these results,
It can be identified as a polyfluoropolyether having three fluorocarbonyl groups obtained by addition-polymerizing hexafluoropropylene oxide to the three carbonyl groups of 3-ketotetrafluorocurtaryl fluoride.

(C) By measuring the proton nuclear magnetic resonance spectrum (H-NMR), the bonding mode of hydrogen atoms present in the compound of the present invention represented by the general formula [I] can be known. From H-NMR (based on tetramethylsilane), The methyl protons 3.8ppm, -OCF H CF ₃ is 5.7ppm and 6.2
Observed at ppm.

(D) Neutralization Titration For the compound having a fluorocarbonyl group among the compounds of the present invention, an excess of NaOH remaining after reacting the fluorocarbonyl group with NaOH is back-titrated with H ₂ SO ₄ , The average molecular weight of the compound can be determined by measuring the molecular weight per fluorocarbonyl group.

The method for producing the polyfluoropolyether of the present invention is not particularly limited, but the method described below is preferably adopted.

That is, by reacting 3-ketrafluoroglutaryl fluoride with hexafluoropropylene oxide, it is possible to obtain the polyfluoropolyether of the present invention having a fluorocarbonyl group at the terminal.

The starting material 3-ketratrafluoroglutaryl fluoride (hereinafter abbreviated as FGF) is a known method, for example, a reaction of 1.5-dialkoxyperfluoro-3-pentanone represented by the following formula with sulfur trioxide. It can be easily obtained by the method.

The amount of hexafluoropropylene oxide (hereinafter abbreviated as HFPO) used as the other raw material is generally in the range of 3 to 200 times by mole with respect to FGF.

The reaction between FGF and HFPO is preferably carried out in an aprotic solvent. Examples of the aprotic solvent include diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, acetonitrile, adiponitrile,
Examples include pyropionitrile, tetrahydrofuran, dioxane, benzonitrile, nitroethane, tetramethylene sulfone, acetone and the like. In addition to aprotic solvent, hexafluoropropylene, dimer of hexafluoropropylene, perfluorobutadiene, perfluorobutane, perfluorohexane, trichlorotrifluoroethane, etc. are added to reduce the viscosity of the reaction solution. It is also possible to add the fluorine-based solvent.
These solvents are used in an amount of 0.5 to 10 times the weight of FGF.

The reaction between FGF and HFPO is usually carried out in the presence of an anionic polymerization catalyst. Examples of anionic polymerization catalysts preferably used in the present invention include alkali metal fluorides such as cesium fluoride, potassium fluoride, sodium fluoride and rubidium fluoride; tetramethylammonium fluoride, tetraethylammonium fluoride, Tetraalkylammonium fluoride such as tetrabutylammonium fluoride is used. It is preferable to use an alkali metal fluoride having a particle size of 0.1 to 100 μm and composed of potassium fluoride and cesium fluoride. The amount of the catalyst used is usually 0.0001 to 0.2 mol per 1 mol of FGF,
It is preferably in the range of 0.001 to 0.1 mol.

The conditions for the reaction between FGF and HFPO are generally 0-10 atm pressure,
A reaction time of 1 to 120 hours is usually employed, preferably under a pressure of 0 to 3 atm and at a temperature of -50 ° C to 100 ° C, preferably -30 ° C to 50 ° C.

By the above method, a compound in which X, Y and Z are fluorocarbonyl groups can be obtained among the polyfluoropolyethers represented by the general formula [I]. Among the polyfluoropolyethers represented by the general formula [I], X, Y and Z
The compound having no fluorocarbonyl group can be produced by carrying out various reactions by utilizing the reactivity of the fluorocarbonyl group of the compound in which X, Y and Z are fluorocarbonyl groups.

For example, a fluorocarbonyl group is reacted with water to form a carboxylic acid group, which is then reacted with fluorine gas to replace fluorine, or to react with hydrogen in NaOH-ethylene glycol to replace hydrogen. Heat resistance due to reactions such as replacing hydrogen with chlorine using chlorine gas,
A polyfluoropolyether having chemical resistance can be synthesized. Also, the fluorocarbonyl group has 1 carbon atom.
The ester derivative can be synthesized by reacting an alcohol of -6, a phenol, or an allyl alcohol. Further, after converting the fluorocarbonyl group into an alcohol with lithium aluminum hydride or the like, it can be converted into an acrylic acid derivative by reacting with acrylic acid, methacrylic acid, acrylic acid chloride or methacrylic acid chloride, or reacted with epichlorohydrin or glycidol. By doing so, it can be converted into an epoxy group derivative. Further, the fluorocarbonyl group can be converted to a carboxylic acid amide group by reacting with a primary or secondary amine having 1 to 5 carbon atoms.
Alternatively, a fluorocarbonyl group may be reacted with ammonia to form a carboxylic acid amide group and then reacted with phosphorus pentoxide to convert it into a cyano group.

〔effect〕

Since the polyfluoropolyether of the present invention is trifunctional, it can be applied to various fields by utilizing the characteristics of its functional group. For example, a polyfluoropolyether having a polycondensable functional group such as a vinyl group, an allyl group, a hydroxyl group or a cyano group can be used as a resin, a rubber, or a paint by polycondensation. Further, polyfluoropolyether having a hydrophilic group such as a carboxyl group can be used as a surfactant.

Furthermore, since the polyfluoropolyether of the present invention generally has a high boiling point and also has heat resistance and chemical resistance peculiar to fluorine-containing compounds, it is used as a vacuum pump oil, a heat carrier, a lubricating oil, a gas-liquid separation liquid. , Can be used as.

〔Example〕

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 55 parts by weight of 3-ketotetrafluoroglutaryl fluoride, 100 parts by weight of tetraethylene glycol dimethyl ether, and 1 part by weight of potassium fluoride were charged into a stainless autoclave, deaerated, and then 110 parts by weight of hexafluoropropylene oxide. 1-2 kg / c at 0 ° C reaction temperature
The reaction was carried out for 2 days under a pressure of m ² . After completion of the reaction, a layer composed of tetraethylene glycol dimethyl ether and a fluorine compound was separated, and the fluorine compound layer was separated by distillation. 85 parts by weight of a compound having a boiling point of ˜67 ° C./25 mmHg was obtained. 61 ~ 67 ℃ / 25mmH
The result of IR measurement of a compound having a boiling point in g is shown in FIG. As a result, the absorption of the carbonyl at 1795 cm ⁻¹ derived from the ketone of the starting material, 3-ketotetrafluoroglutaryl fluoride, was very small, indicating that hexafluoropropylene oxide was added to this carbonyl. There is. Furthermore, the result of having measured F-NMR is shown in FIG. As a result of analyzing the chemical shift, it was found to be the above-mentioned compound [A]. Further, the molecular weight of this compound was determined by measuring the amount of NaOH consumed by exchanging the fluorocarbonyl group with a sodium carboxylate group using a neutralization titration method. As a result, the molecular weight was 550. The sodium carboxylate-type compound was a substance that had an infrared absorption at 1680 cm ⁻¹ and was easily soluble in water.

On the other hand, the molecular weight calculated from the structure measured by F-NMR was 554.

Example 2 20 parts by weight of the compound of [A] obtained in Example 1, 20 parts by weight of tetraethylene glycol dimethyl ether, and 1 part by weight of cesium fluoride were charged into a stainless steel autoclave, and 120 parts by weight of hexafluoropropylene oxide were added. The reaction was carried out at a reaction temperature of 5 ° C. under a pressure of 1-2 kg / cm ² for 2 days. After the reaction, the tetraethylene glycol dimethyl ether layer and the fluorine compound layer were separated, and the fluorine compound layer was separated by distillation. As a result, 56 parts by weight of hexafluoropropylene oxide trimer to pentamer was obtained. An addition polymer of hexafluoropropylene oxide with respect to the compound [A] of Example 1 was obtained at a pressure of 0.3 mmHg to 0.15 mmHg and 75 parts by weight as a compound having a boiling point of 50 to 200 ° C. 0.3 mm
F- of 30 parts by weight of a compound having a boiling point of 100 to 123 ° C. in Hg
The result of having measured NMR is shown in FIG. As a result, the compound was identified as the compound [B] described above, and the compound was a trifunctional perfluoropolyether having three fluorocarbonyl groups in one molecule.

The molecular weight of this compound determined by the neutralization titration method was 1,400, and it was a compound in which seven hexfluoropropylene oxides were added to perfluoro-3-ketoglutaryl fluoride.

Furthermore, when F-NMR of 32 parts by weight of a fraction having a boiling point of 120 to 150 ° C. at 0.15 mmHg was measured, it was found that the compound had more hexafluoropropylene oxide added than the compound [B]. The molecular weight of this compound by neutralization titration is
It was 2200. From this, it was found that it was a compound in which 12 hexafluoropropylene oxides were added to 3-ketotetrafluoroglutaryl fluoride.
Further, 5 parts by weight of a fraction of 150 to 250 ° C. at 0.15 mmHg was obtained. This compound had a molecular weight of 4300 as determined by the neutralization titration method, and was found to be a compound obtained by addition-polymerizing 25 hexafluoropyropyrene oxides to 3-ketotetrafluoroglutaryl fluoride. After distillation, 3 parts by weight of a viscous compound was obtained in the bottom. The molecular weight of this compound was 5500, and it was found that 32 hexafluoropropylene oxides were addition-polymerized.

Example 3 To 5 parts by weight of a perfluoropolyether having a fluorocarbonyl group having a molecular weight of 2200 and obtained in Example 2, 0.2 parts by weight of water was added with stirring at room temperature, followed by distillation under reduced pressure. 4 ether carboxylic acids
Parts by weight were obtained. In this compound, infrared absorption due to carboxylic acid group was newly present at 1780 cm ^-1 . This compound was placed in a three-necked flask, and fluorine gas diluted to 20% with nitrogen gas was reacted at a rate of 40 ml / min at a temperature of 150 to 200 ° C. for 10 hours. After the reaction, blow nitrogen gas to expel fluorine gas, and then perform vacuum distillation to obtain 130 mm at 0.2 mmHg.
3 parts by weight of a 150 ° C. fraction was obtained. In the infrared absorption spectrum of this compound, no fluorocarbonyl group or carboxylic acid group was present. When F-NMR was measured, it was 86 ppm and 87 pp.
A new peak appeared at m. This is because the end of polyfluoroether It has changed to.

Example 4 1 part by weight of NaOH and 6 parts by weight of ethylene glycol were added to 4 parts by weight of the perfluoropolyterecarboxylic acid obtained by the method of Example 3.
After adding parts by weight and treating at 150 ° C. for 8 hours, the carboxylic acid group was replaced with hydrogen by washing with water and drying. When the H-NMR of this compound was measured, there was a chemical shift at 5.7 ppm and 6.2 ppm, and the infrared absorption spectrum was 3000 cm ^-1.
Since there was absorption due to C—H bond at 900 cm ⁻¹ , it was found that the carboxylic acid group was hydrogen-modified polyfluoropolyether.

Example 5 3 parts by weight of the hydrogen-modified polyfluoropolyether obtained in Example 4 and 4 parts by weight of 1,1,2-trichloro-1,2,2-trifluoroethane were placed in a quartz tube, and an ultrahigh pressure of 100 W was applied. 10 hours 2 while introducing chlorine gas at a rate of 40cc / min using a mercury lamp
The reaction was carried out at 00 ° C. After the reaction, 1,1,2-trichloro-1,2,2
-Trifluoroethane was distilled off to obtain 2.5 parts by weight of a reaction product. The infrared absorption spectrum of this compound is 3000
cm ^-1 and 900cm no absorption to ^-1, the absorption of hydrogen in H-NMR was little. Further elemental analysis of this compound revealed that it contained 4.5% chlorine. From this, it was found that hydrogen was a polyfluoropolyether in which chlorine was modified.

Example 6 To 5 parts by weight of the compound of [A] obtained in Example 1 was added 2 parts by weight of methanol with stirring at 0 ° C., and the mixture was reacted for 2 hours, then washed with water, dehydrated and distilled to obtain 4 parts by weight. Part of reaction product was obtained. When the infrared absorption spectrum of this substance was measured, the absorption based on C—H at 3000 cm ⁻¹ was found to be 17
Absorption of the carbonyl group based on carboxylic acid ester in 80 cm ^-1, characteristic absorption spectrum based on C-F bond was observed at 1350~1050cm ^-1. In addition, as a result of measuring H-NMR,
A chemical shift of methyl based on carboxylic acid methyl ester was observed at 3.8 ppm. From these results, it was revealed that the compound had three methyl ester groups in one molecule.

Example 7 To 5 parts by weight of the compound of [A] obtained in Example 1 was added 2 parts by weight of alkali alcohol with stirring at 0 ° C., and the mixture was reacted for 2 hours, washed with water, dehydrated and distilled to obtain 4 parts by weight. Part of reaction product was obtained. The reaction product was identified by IR, H-NMR and found to be a triallyl ester. When 1 part by weight of this triallyl ester and 0.03 part by weight of diisopropyl peroxydicarbonate were enclosed in a glass ampoule and polymerized at 30 ° C. for 8 hours, an insoluble and infusible hard resin was obtained.

Example 8 10 parts by weight of the compound of [A] obtained in Example 1 was blown with ammonia gas at room temperature, washed with water and dried to obtain 9 parts by weight of an amide compound. To this, 10 parts by weight of phosphorus pentoxide was added and reacted at 160 ° C. for 1 day, and after the reaction, 6 parts by weight of the reaction product was recovered by washing with water and distillation. When the infrared absorption spectrum of this compound was measured, an absorption peak of a nitrile group was present at 2270 cm ^-1 . From this result, it is clear that the compound is a perfluoropolyether compound having a cyano group.

Example 9 10 parts by weight of the compound of [A] obtained in Example 1 was gradually added dropwise to a solution in which 20 parts by weight of diethyl ether and 5 parts by weight of lithium aluminum hydride were dispersed and reacted. After reacting at room temperature for 8 hours, the fluorocarbonyl group was converted into an alcohol by washing with water, dehydration and distillation, and 5 parts by weight of a compound was obtained.
It was confirmed to be polyfluoroalcohol with characteristic peaks at 4.3 ppm and 4.4 ppm. To 2 parts by weight of this polyfluoropolyalcohol, 1 part by weight of acrylic acid chloride was added dropwise at room temperature and reacted for 1 day. After the reaction, distillation is performed,
1.5 parts by weight of a compound having 3 acryloyl groups in one molecule was synthesized. This compound had an infrared absorption spectrum at 1720 cm ^-1 based on the carboxylic acid ester group and 1640 cm ^-1 based on the vinyl group. Similarly, 2 parts by weight of the polyfluoroalcohol obtained above was reacted with 1.2 parts by weight of methacryloyl chloride at room temperature for 1 day, washed with water and dried,
Distillation was performed to obtain 1.6 parts by weight of a compound having 3 methacryloyl groups in one molecule. This compound also contains 1725 cm ^-1 based on the carboxylic acid ester group and 1640 based on the vinyl group.
There was an infrared absorption spectrum at cm ^-1 .

Example 10 5 parts by weight of the compound of [A] having a molecular weight of 550 obtained in Example 1 was gradually added dropwise to a mixed solution of 2 parts by weight of diethylamine and 10 parts by weight of diethyl ether, and then the solvent was removed. A polyfluoropolyether having a carboxamide group was synthesized. Elemental analysis of this compound showed 5.5% nitrogen was present. Infrared absorption due to carboxylic acid amide was observed at 1680 cm ^-1 .

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 show the infrared absorption spectrum and F-nuclear magnetic resonance spectrum of the polyfluoropolyether of the present invention obtained in Example 1, respectively. FIG. 3 shows the F-nuclear magnetic resonance spectrum of the polyfluoropolyether of the present invention having a molecular weight of 1400 obtained in Example 2.

Claims (1)

[Claims] 1. The following general formula Polyfluoropolyether represented by.