RU2073692C1 - Method for production of halogen-containing polyether - Google Patents

Abstract

FIELD: production of thermal resistant oils, lubricants, plasticizers and modifying agents. SUBSTANCE: method is carried out by interaction of polyether (having structure units with common formula (CH₂-CF₂-CF₂O)_a where a is 2-200) with 2,2,3,3-tetrafluoroxetone being prepared by polymerization and with gaseous fluorine. EFFECT: improved efficiency. 3 cl

Description

 The invention relates to a method for producing a halogen-containing polyether and, in particular, a fluorine-containing and chlorine-containing polyether.

The closest in technical essence to the proposed is a method for producing perfluoropolyesters with the general formula - (CF ₂ -CF ₂ -0) _n , where n 5-25, by fluorination of the original polyester with gaseous fluorine (1). Fluorine is mixed with an inert gas.

 The aim of the invention is to provide a chemically and thermally stable new halogen-containing simple polyester, as well as a new halogen-containing rectilinear simple polyester.

The halogen-containing polyether obtained according to the invention contains structural units represented by the following formula:
- (CH ₂ CF ₂ CF ₂ O) _a - (CHClCF ₂ CF ₂ O) _b - (CCl ₂ CF ₂ CF ₂ O) _c - (CHFCF ₂ CF ₂ O) _d - (CFClCF ₂ CF ₂ ) _e - ( CF ₂ CF ₂ CF ₂ O) _f (1),
where a, b, c, d, e, f are integers of at least 0 and satisfy the following equations:
2 ≅ a + b + c + d + e + f ≅ 200,
1 ≅ a + c + d + f
Typically, the halogen-containing polyether of the invention includes the following polyethers:
a fluorine-containing polyether containing structural units of the following formula:
- (CH ₂ CF ₂ CF ₂ O) _a - (II),
where a 2-200
a fluorine-containing polyether containing structural units of the following formula:
- (CH ₂ CF ₂ CF ₂ O) _a - (CHFCF ₂ CF ₂ O) _d - (CF ₂ CF ₂ CF ₂ O) _f - (III),
where a, d and f meet the above requirements and the equation:
1 ≅ d + f
fluorine-containing polyether containing structural units of the formula:
- (CH ₂ CF ₂ CF ₂ O) _a - (CHClCF ₂ CF ₂ O) _b - (CCl ₂ CF ₂ CF ₂ O) _c - (CHFCF ₂ CF ₂ O) _d - (CFClCF ₂ O) _e - (CF ₂ CF ₂ CF ₂ O) _f - (IV),
where a, b, c, d, e, f satisfy the above requirements and the equation:
1 ≅ b + c + e
In the formulas, the sequence of structural units may be random and not necessarily as specified in the formulas.

 The fluorine-containing polyether (II) is obtained by polymerization with the opening of the ring of 2,2,3,3-tetrafluoroxetane.

 2,2,3,3-tetrafluoroxetane is a known compound obtained for example by reacting tetrafluoroethylene and paraform in anhydrous hydrogen fluoride.

 Ring opening polymerization is initiated by a polymerization initiator. Examples of such initiators are substances that form active halogen anions in an aprotic solvent (for example, alkali metal halides), as well as substances with strong Lewis acidity.

 The amount of initiator is not critical in the present invention. Preferably, the amount is 0.001-30 mol. more preferably 0.01-10% based on the amount of 2,2,3,3-tetrafluoroxetane.

Specific examples of alkali metal halides are potassium fluoride, potassium iodide, potassium bromide, cesium fluoride, etc. If the polymerization is initiated by an alkali metal halide, the resulting compound usually has the formula:
A- (CH ₂ CF ₂ CF ₂ O) _a - CH ₂ CF ₂ COF (V),
where a is the same as above, and A is fluorine, bromine or iodine.

 The compound (V) with an acyl fluoride end group can be converted to the corresponding acid, salt using an alkali metal, ester or amide using a known method, for example hydrolysis, esterification, etc.

(VII),
где R_f перфтораклиловая группа с 1-10 атомами углерода,
R_f' перфторалкиловая группа с 1-10 атомами углерода или группа с формулой:

р целое число от 0 до 50,
добавляется к полимеризационной системе, в которой фторид щелочного металла используется в качестве инициатора, то получается соединение (V), в котором А представляет собой группу с формулой:
R_fCF₂O(VIII)
или

Если ацилфторид с формулой:
FCH₂CF₂COF (X)
добавляют к реакционной системе, в которой фторид цезия используется в качестве инициатора, то получают соединение, как при использовании только фторида щелочного металла. Этот способ предпочтителен для получения низкомолекулярного олигомера с контролируемым распределением молекулярного веса.If acyl fluoride with the formula:
R _f COF (VI)
or

(Vii)
where R _f perfluoroalkyl group with 1-10 carbon atoms,
R _{f '} perfluoroalkyl group with 1-10 carbon atoms or a group with the formula:

p is an integer from 0 to 50,
added to a polymerization system in which alkali metal fluoride is used as an initiator, a compound (V) is obtained in which A represents a group with the formula:
R _f CF ₂ O (VIII)
or

If acyl fluoride with the formula:
FCH ₂ CF ₂ COF (X)
added to the reaction system in which cesium fluoride is used as an initiator, a compound is obtained, as when using only alkali metal fluoride. This method is preferred for obtaining a low molecular weight oligomer with a controlled distribution of molecular weight.

 As mentioned above, the relatively high volatility low molecular weight compound contained in the high molecular weight product is obtained by distillation and added to the subsequent reaction as an initiator together with alkali metal fluoride.

где р целое число от 0 до 50.Instead of using acyl fluoride, the fluorine-containing epoxide reacts with alkali metal fluoride to produce acyl fluoride, which in turn reacts with 2,2,3,3-tetrafluoroxetane. For example, hexafluoropropylene oxide is reacted with cesium fluoride in an aprotic solvent to obtain a compound of the formula:

where p is an integer from 0 to 50.

 Then 2,2,3,3-tetrafluoroxetane is added to the reaction mixture to obtain the same compound that was obtained using only acyl fluoride.

,
где А то, что было указано выше,
р целое число от 2 до 200,
q целое число от 0 до 50,
приготавливают путем открытия кольца 2,2,3,3-тетрафтороксетана в присутствии инициатора галогенида щелочного металла или инициирующей системы фторида щелочного металла и ацилфторида с последующим добавлением окисла гексафторпропилена.On the other hand, a compound with the formula:

,
where And what was stated above,
p is an integer from 2 to 200,
q is an integer from 0 to 50,
prepared by opening the ring of 2,2,3,3-tetrafluoroxetane in the presence of an alkali metal halide initiator or an alkali metal fluoride and acyl fluoride initiating system, followed by hexafluoropropylene oxide.

In the presence of alkali metal fluoride, any acyl fluoride that forms an equilibrium amount of fluoroalkoxy anion according to the following equation:
-COF + mF ⇄ CF ₂ O ^- m ⁺ (XIV),
can serve as a polymerization initiator with the opening of a ring of 2,2,3,3-tetrafluoroxetane and forms an end group with the formula:
-CF ₂ O- (XV)
A preferred example of an Lewis acid initiator is antimony pentafluoride.

Typically, the reaction is carried out in a liquid reaction medium. If another initiator is used as opposed to a Lewis acid initiator, then an aprotic solvent, for example polyethylene glycol dimethyl ether, for example diglyme, triglyme, tetraglyme, etc., is preferably used. In acetonitrile or glime (CH ₃ OCH ₂ CH ₂ OCH) the reaction is almost not observed or absent altogether, but in these solvents the reaction is accelerated by using a small amount of cyclic polyether. Acetonitrile and glyme are preferred since they have a low boiling point and are easily removed from the reaction mixture by distillation.

 When using an Lewis acid initiator, the solvent can be omitted. Sometimes a dimer or trimer of hexafluoropropylene is used.

The reaction temperature depends on the type of initiator and / or solvent. As a rule, it is -30 +100 ^o C, preferably -30 +50 ^o C.

 The product is recovered from the reaction mixture using a known method. The solid is recovered, for example, by washing the reaction mixture with water to remove the solvent and initiator and filtering the product. The volatile product is recovered, for example, by distillation.

The reaction product has a structure with formula (V) with an acyl fluoride end group with high reactivity and is useful on its own. In some cases, a chemically inactive compound is required. For example, if acyl fluoride (V) is heated in a dimer or trimer of hexafluoropropylene in the presence of antimony pentafluoride as a catalyst, a compound with the formula is obtained:
X (CH ₂ CF ₂ CF ₂ O) _n CH ₂ CF ₃ (XVI)
A fluorine-containing polyether containing structural units with the formula:
(CH ₂ CF ₂ CF ₂ O) _a - (CHFCF ₂ CF ₂ O) _d - (CF ₂ CF ₂ O) _f - (III),
where a, d and f meet the above requirements and the equation:
1 ≅ d + f,
prepared by fluorinating polyether.

Fluorination is carried out due to the reaction of gaseous fluorine (II) at a temperature of 160-300 ^o C, preferably 180-250 ^o C. Fluorination can be carried out at a lower temperature compared to the specified. At such a low temperature, fluorination is accelerated by ultraviolet radiation. In the latter reaction, hydrogen fluoride is inevitably formed. In this regard, the light source must be protected by a material that is resistant to hydrogen fluoride and transmits light with a wavelength of 200-500 nm, preferably 300-400 nm.

 As the translucent material used for the fluorination reaction of the present invention, a single crystal sapphire or a transparent fluorine-containing polymer molded from a melt is used. Specific examples of such a fluorine-containing polymer include tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-perfluoropropylene vinyl ether copolymers, tetrafluoroethylene-ethylene copolymers, polychlorotrifluoroethylene and polyvinylidene fluoride.

 Since single-crystal sapphire is an expensive material and a material with a large area is difficult to access, a fluorine-containing polymer is preferred for industrial purposes.

 If the reactor is irradiated with ultraviolet radiation from inside the reactor, the transparent glass portion is covered with a fluorine-containing polymer. If the reactor is irradiated with an external light source, the transparent window is made of a fluorine-containing polymer film. To impart pressure resistance to such a film, it is applied to a glass plate, for example of quartz glass.

 The reaction system can be irradiated directly or through the gas phase.

 As a rule, ultraviolet radiation has a wavelength of 200-500 nm, preferably 250-350 nm.

If fluorination is carried out using ultraviolet radiation, the reaction temperature is not critical. However, the reaction system is heated to a temperature at which the system is stirred to smoothly accelerate fluorination. Thus, the reaction temperature depends mainly on the molecular weight of the polyether (II). In general, as fluorination proceeds, the pour point and viscosity of the product decrease, and accordingly, the reaction temperature may decrease. In practice, the reaction temperature is 0-120 ^{° C.} , preferably from room temperature to 100 ^° C.

 Fluoridation can be carried out by passing fluorine gas through the reaction system or by injecting this gas into the gas phase. Fluorine gas can be diluted with an inactive gas, such as carbon dioxide, nitrogen, etc.

 Fluorination can be carried out continuously or intermittently.

If a polyether (II) with a terminal group of the formula:
-OCH ₂ CF ₂ COF or -OCH ₂ CF ₂ COOH (XVII)
fluorinated by ultraviolet radiation and almost all hydrogen atoms are replaced by fluorine atoms, a mixture of compounds with the end group of the formula —OCF ₂ CF ₂ —COF and the end group of the formula —OCF ₂ CF _{3 is} obtained. After completion of the introduction of hydrogen fluoride, the internal contents of the reactor are replaced by nitrogen and then irradiated with ultraviolet light. Thus, by fluorinating the polyether (II) using ultraviolet radiation, a polyester (III) with a stable end group is obtained even if the polyester (II) has an unstable end group.

 If the polyether (I) is not fully fluorinated, a mixture of the fully fluorinated and not fully fluorinated compounds is obtained.

 By conventional distillation, it is difficult to separate the fully fluorinated polyether from such a mixture. However, the fully fluorinated polyether is separated from the partial fluorinated polyether using a polar solvent, for example acetone. When this mixture is dissolved in a polar solvent, the fully fluorinated polyether is contained in the lower layer and is easily separated by liquid separation.

Fluorochloride-containing polyether comprising structural units with the formula:
- (CH ₂ CF ₂ CF ₂ O) _a - (CHClCF ₂ CF ₂ O) _b - (CCl ₂ CF ₂ CF ₂ O) _c - (CHFCF ₂ CF ₂ O) _d - (CFClCF ₂ CF ₂ O) _e - (CF ₂ CF ₂ CF ₂ O) _f (IV),
where a, b, c, d, f, e is the same as above
prepared by fluorination or chlorination of polyether (II) or chlorination of polyether (II).

 Fluoridation is performed as described above.

Chlorination is carried out by reacting gaseous chlorine mixed with fluorine with polyether (II) or (III) under ultraviolet irradiation with a wavelength of 200-500 nm. The reaction temperature depends on the molecular weight of the polyester to be chlorinated. Typically, the reaction temperature is 30-200 ^o C, preferably 50-150 ^o C.

Chlorination of polyether (II) allows you to get a halogen-containing simple polyester, including structural units with the formula:
- (CH ₂ CF ₂ CF ₂ O) _a - (CHClCF ₂ CF ₂ O) _b - (CCl ₂ CF ₂ CF ₂ O) _c - (XVIII),
where a, b and c have the above meanings.

 Polyether (IV) is obtained by fluorination of polyether (XVIII).

 The polyether (II) is first fluorinated to obtain a polyether (III) and then chlorinated to obtain a polyether (IV).

 The polyester backbone of the invention is chemically and thermally stable and can be used for the same purposes as conventional fluoropolymers and perfluoropolyether. For example, an acyl fluoride-terminated polyether is used as an intermediate to produce various fluorine-containing compounds. Carboxyl terminated polyethers are used, for example, as a surfactant. These compounds with a stabilized end group are thermally and chemically stable oils and, therefore, can be used as a heat transfer medium, lubricants, plasticizers, modifiers, etc. These compounds with high molecular weight are used as molding material.

Example 1. In 100 ml of steel reactor add 3.0 g of a white powder of fluorine-containing simple polyester of the formula:
F (CH ₂ CF ₂ CF ₂ O) _n CH ₂ CF ₂ COOCH,
where n averages 25,
and gradually heated from 140 to 200 ^o C with stirring in an oil bath. A gaseous mixture of fluorine and nitrogen at a volume ratio of 20/80 is fed into the reactor at a rate of 100 ml / min for 3 hours. After cooling and replacing the inside of the reactor with nitrogen, 2.05 g of a viscous product is obtained.

Using IR and NMR analyzes, the product is identified as a mixture of a compound with the structural units of the formula:
- (CH ₂ CF ₂ CF ₂ O) _p - (CHFCF ₂ CF ₂ O) _q -,
where the p / q ratio is 7/3.

Example 2. According to example 1, but with the loading of 5.20 g of fluorine-containing polyether and injection of a gaseous mixture of fluorine and nitrogen for 4.5 hours, fluorination was carried out to obtain 2.48 g of a liquid product, which was identified as a mixture of compounds with structural units of the formula :
- (CF ₂ CF ₂ CF ₂ O) _v - (CHFCF ₂ CF ₂ O) _q ,
where the v / q ratio is 5/1.

Example 3. In a photochemical reactor with an optically transparent glass made from a copolymer of tetrafluoroethylene-perfluoroalkyl vinyl ether (PFA), 4.9 g of poly- (2,2,3,3-tetrafluoroxetane) of the formula are loaded:
F (CH ₂ CF ₂ CF ₂ O) _n CH ₂ CF ₂ COOH,
where the average value of n is 24,
and the mixture is heated at 100 ^{° C.} in an oil bath under a stream of nitrogen.

 Then the polymer is irradiated with a high-pressure mercury lamp (wavelength - 31.5-577 nm) from a distance of 10 cm while stirring in a stream of a gaseous mixture of fluorine and nitrogen at a volume ratio of 20/80 and a flow rate of 50 ml / min.

After 15 hours, the flow of the gaseous mixture was turned off, and then nitrogen was supplied to the reactor at a rate of 50 ml / min for 12 hours when irradiated with a mercury lamp. After cooling, 5.90 g of an oily product is obtained. The pour point is -55 ^o C.

Elemental analysis:
Estimated, C 21.7; H 0.01; F 68.7
Experimental, C 21.5; H 0; F 69.1.

The resulting oily product is identified as a mixture of compounds of the formula:
F (CF ₂ CF ₂ CF ₂ O) _n CF ₂ CF ₃ ,
where the average value of n is 23. The value is calculated by the integral value of the NMR analysis.

,
где среднее значение n составляет 7,
и облучают с помощью ртутной лампы низкого давления (длина волны - 184,9-546,1 нм) с расстояния 5 см при перемешивании в потоке газообразной смеси фтора и азота при объемном отношении 20/80 и скорости потока 50 мл/мин.Example 4. In the reactor used in example 3, load 6.9 g of a mixture of compounds of the formula:

,
where the average value of n is 7,
and irradiated with a low-pressure mercury lamp (wavelength 184.9-546.1 nm) from a distance of 5 cm while stirring in a stream of a gaseous mixture of fluorine and nitrogen at a volume ratio of 20/80 and a flow rate of 50 ml / min.

,
где среднее значение суммы n и m составляет 7 и объемное отношение m/n - 1/4.After 19 hours, the inside of the reactor was replaced with nitrogen to give 7.0 g of a product that was identified as a mixture (7.0 g) of compounds of the formula:

,
where the average value of the sum of n and m is 7 and the volumetric ratio m / n is 1/4.

,
где среднее значение n составляет 7,
и смесь облучают ртутной лампой высокого давления при перемешивании в потоке газообразной смеси фтора и азота при объемном отношении 20/80 и скорости потока 50 мл/мин.Example 5. In the reactor used in example 3, add 2.6 g of a mixture of compounds of the formula:

,
where the average value of n is 7,
and the mixture is irradiated with a high-pressure mercury lamp while stirring in a stream of a gaseous mixture of fluorine and nitrogen at a volume ratio of 20/80 and a flow rate of 50 ml / min.

,
где среднее значение n составляет 7.After 11 hours, the inside of the reactor was replaced with nitrogen to give 3.3 g of a liquid product, which was identified as a mixture of compounds of the formula:

,
where the average value of n is 7.

Example 6. In 100 ml of a photochemical reactor with a stainless steel refrigerator and an upper window (diameter 30 mm), laminated with a film of polychlorotrifluoroethylene (hereinafter PCTFE), add 10.0 g of a liquid compound of the formula:
F (CH ₂ CF ₂ CF ₂ O) ₂ CH ₂ CF ₂ COF,
the mixture is cooled in a water bath and then irradiated with a high-pressure mercury lamp while stirring and supplying a gaseous mixture of fluorine and nitrogen at a volume ratio of 20/80 and a flow rate of 50 ml / min. The refrigerator is cooled with dry ice. After 15 hours, the inside of the reactor was replaced with nitrogen and the reaction mixture was subjected to fractional distillation to obtain 9.8 g of a compound of the formula:
F (CF ₂ CF ₂ CF ₂ O) ₂ CF ₂ CF ₃
Example 7. By the method of example 6, but using a window laminated with a copolymer of ethylene-tetrafluoroethylene (hereinafter ETFE) instead of PCTFE; fluorination is carried out to obtain the same compound with a yield of 80%
Example 8. By the method of example 6, but using a window laminated with polyvinylidene fluoride instead of PCTFE; fluorination is carried out to obtain the same product with a yield of 28%
Example 9. In a reactor with a window made of single-crystal sapphire, add 130.0 g of a polymer of the formula:
F (CH ₂ CF ₂ CF ₂ O) _n CH ₂ CF ₂ COF,
where the average value of n is 22, the mixture is burned in a stream of nitrogen due to the circulation of the heating medium at 80 ^o C in the jacket of the reactor.

The polymer is irradiated through a window with a high-pressure mercury lamp (wavelength 312.5-577 nm) from a distance of 5 cm while stirring in a stream of a gaseous mixture of fluorine and nitrogen at a volume ratio of 50/50 with a flow rate of 200 ml / min. The temperature inside the reactor is maintained in the range of 100-120 ^{° C.} by controlling the temperature of the heating medium.

After 50 hours, the fluorine supply is completed and only nitrogen is supplied at a rate of 100 ml / min for 24 hours under irradiation and 158 g of a compound of the formula are obtained:
F (CF ₂ CF ₂ O) _n CF ₂ CF ₃ ,
which at room temperature is an oil.

Example 10. In a photochemical reactor with a diameter of 30 cm with a window made of silica glass laminated with a PFA film, 1.5 mg of a polymer of the formula are loaded:
F (CH ₂ CF ₂ CF ₂ O) _n CH ₂ CF ₂ COF,
in which the average value of n is 25,
and the mixture is heated to 100 ^o C in a stream of nitrogen in an oil bath.

Then the polymer is irradiated through a window with a high-pressure mercury lamp from a distance of 5 cm while stirring in a stream of a gaseous mixture of fluorine and nitrogen and a flow rate of 1 l / min. The temperature inside the reactor is maintained no more than 120 ^o With by regulating the temperature of the oil bath.

After 100 hours, the fluorine supply is stopped and only nitrogen is supplied for 50 hours at a speed of 2 l / min during irradiation. After cooling to room temperature, 1.8 kg of an oily compound of the formula are obtained:
F (CF ₂ CF ₂ CF ₂ O) _n CF ₂ CF ₃
Thus obtained product is rectified under reduced pressure at 0.05 torr and 1.2 kg of a fraction is obtained, which is distilled at a temperature in the range of 180-220 ^° C.

Kinematic viscosity at 40 ^o C is 65 cSt.

 Example 11. After connecting a rotary pump and a test plasma generator using a mixture of carbon tetra fluoride, oxygen and hydrogen, the pump is washed with a solvent and filled with the oil obtained in Example 10. Then the plasma generator is driven. After 30 days, the current was not uneven in the motor.

The viscosity of the oil was 65 cSt at 40 ^o C, which corresponds to fresh oil. The results of IR and NMR analyzes were essentially unchanged after use.

Example 12. In a 20 l stainless steel reactor equipped with a mixer and maintained at 100 ^o C, load 10 kg of polyfluoroether of the formula:
F (CH ₂ CF ₂ CF ₂ O) _n CH ₂ CF ₃ ,
where the average value of n is 20,
and gaseous fluorine is supplied at a rate of 5 l / min for 40 hours. After that, the internal contents of the reactor are replaced by nitrogen to obtain 12 kg of a polyether of the formula:
F (CF ₂ CF ₂ CF ₂ O) _x - (CHFCF ₂ CF ₂ O) _y CF ₂ CF ₂ COF,
where the x / y ratio is 2: 1.

The obtained polyether was loaded into a 20 L pyrex glass reactor, maintained at 100 ^° C, and irradiated with a mercury lamp (1 kW) while supplying chlorine gas at a rate of 5 l / min for 48 hours to obtain 12.5 kg of a polyether of the formula:
F (CF ₂ CF ₂ CF ₂ O) _x - (CClFCF ₂ CF ₂ O) _y CF ₂ CF ₂ COF,
where x and y have the meanings indicated above.

The obtained polygaloether is loaded into the reactor, which was used for fluorination, and mixing is carried out with 100 g of water. The reactor is heated to 150 ^{° C.} and fluorine gas is supplied at a rate of 2 l / min for 12 hours. Then the internal contents of the reactor are replaced with nitrogen to obtain 12.0 kg of a polyether of the formula:
F (CF ₂ CF ₂ CF ₂ O) _x - (CClFCF ₂ CF ₂ O) _y CF ₂ CF ₃ ,
where x and y have the above meanings.

 Example 13. After connecting a rotary pump and a test plasma generator using Flon-14, oxygen and hydrogen, the pump is washed with a solvent and filled with the oil obtained in Example 12. The plasma generator is then driven. After 20 days, the current was not uneven in the motor.

The viscosity of the oil is 35 cSt at 40 ^o C, which essentially corresponds to the fresh oil (83 cSt). The results of IR and NMR analyzes remained virtually unchanged after use.

 Example 14. In a 500 ml flask equipped with a dry ice condenser and a dropping funnel, the air was carefully replaced with dry nitrogen gas. Then 100 ml of dry diglyme and 0.01 g of cesium fluoride are introduced, the mixture is left in an ice bath for 30 minutes with stirring. After that, 300 g of 2,2,3,3-tetrafluoroxetane are introduced through a dropper over a period of 5 hours. The ice flask bath is replaced with a water bath, and the reaction mixture is left in this bath for 12 hours. Pour 2 L of water into the reaction mixture, mix thoroughly and separate on a separatory funnel. The lower layer (290 g) is isolated.

The resulting product is defined as a mixture of compounds of the general formula:
F (CH ₂ CF ₂ CF ₂ O) _n CH ₂ CF ₂ COOH,
where the average value of n is 150, while the values of n range from 80 to 200.

This polymer (130.0 g) is placed in a reactor, on the side wall of which there is a window closed with a sapphire single crystal plate, and a heating medium with a constant temperature of 100 ^o C circulates in the shirt in a stream of nitrogen, diluting the polymer.

 A mixture of fluorine with nitrogen gas (in a volume ratio of 3: 1) is introduced into the liquid polymer with stirring with a stirrer at a rate of 200 ml / min, the polymer being irradiated with a high-pressure mercury lamp with a wavelength of 312.5 to 4577 nm from a distance of 5 cm through sapphire window.

The temperature of the heating medium is maintained in the range from 100 to 120 ^o C.

 After 45 hours, the supply of fluorine gas was stopped, and only nitrogen gas was continued to be supplied for 24 hours at a rate of 100 ml / min when irradiated with a mercury lamp.

 The result is a product (140 g), which at room temperature is in an oily state.

The analysis confirms that this product is a mixture of compounds of the general formula:
F (CF ₂ CF ₂ CF ₂ O) _n CF ₂ CF ₃ ,
where the average value of n is 150.8

Claims (3)

1. A method of producing a halogen-containing simple polyester by reacting a polyester with fluorine gas, characterized in that a polyester containing structural units of the general formula - (CH ₂ -CF ₂ -CF ₂ O) _a , where a 2 - 200 is used as a polyether obtained by polymerization of 2,2,3,3-tetrafluoroxetane.  2. The method according to claim 1, characterized in that it further carries out chlorination with gaseous chlorine.  3. The method according to claim 2, characterized in that the chlorination is carried out under ultraviolet radiation with a wavelength of 200 to 500 nm.