JPS60142943A - Preparation of perfluorovinylcarboxylic acid ester - Google Patents

Abstract

PURPOSE:To obtain the titled compound useful as a monomer for preparation of especially cation exchange resin of perfluorocarbon type selectively in high yield, by decomposing thermally a specific perfluorodicarboxylic acid ester under specified conditions. CONSTITUTION:A perfluorodicarboxylic acid ester shown by the formula I (R1 and R2 are 1-10C different or same alkyl; m is >=1 integer; l and n are 0 or 1; X1 and X2 are F, or CF3, and at least one of l and n is 0 when both X1 and X2 are F) is thermally decomposed preferably in a gaseous phase at 150- 450 deg.C, preferably at 200-350 deg.C for 1-10,000sec, preferably for 1-1,000sec preferably with adding an alkali substance such as K2CO3, ZnO, etc. to raise thermal decomposition rate, to give a perfluorovinylcarboxylic acid ester such as a compound shown by the formula II, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an alkyl group of the formula CF, =CF-+O-jujube-CF2 boar (0) -CF-C-OR (wherein R is a carbon 11 number 1 to] 0 alkyl group, m is an integer of 1 or more, 1, n is 0 or 1, and X is F or CF3).

'Perfluorovinylcarboxylic acid ester is useful as a monomer for producing perfluoroconvex carbon-based polymers, particularly perfluorocarbon-based corner sulfur exchange resins.

Generally, a method of thermally decomposing a perfluorocarbon having an acid fluoride group is known as a method for introducing a vinyl group into a perfluorocarbon. Therefore, the following method can be considered as a method of utilizing the above reaction for producing the perfluorocarboxylic acid ester.

By partially thermally decomposing the diacid fluorite represented by the formula
CF=CF-0-l:CF2>2-0-CF-CO
A method of producing a carboxylic acid ester by producing a compound represented by F is considered. However, with the above method, it is difficult to generate vinyl groups while selectively leaving one acid fluoride group, and the production rate (decomposition rate) of vinyl groups is fast. It is extremely difficult to obtain esters without producing them. In addition, in the -redistribution method, it is also possible to esterify one of the acid fluorado groups of the diacid fluorado in advance to form a halfester, and then decompose it, but this method does not allow for the selective production of halfesters. As a result of intensive research to develop a method for producing stell with a high yield, the yield is extremely low when based on diacid fluorite. The present inventors have discovered that perfluorodicarboxylic acid esters can be obtained, and have completed the present invention. That is, the present invention provides -01(
(However, R and R2 are different or similar alkyl groups having 1121 to 10 carbon atoms, m is an integer of 1 or more,], n is 0 or l, X, , X2 is a perfluorodicarboxylic acid represented by F or CF3 150 to 4 esters
This is a method for producing perfluorovinylcarboxylic acid ester, which is characterized by heating at 50°C.

The perfluorodicarboxylic acid ester used in the present invention may be obtained by any method, but generally, as described above, a method in which diacid fluoride is esterified by a known method is preferred. Furthermore, in the above formula, those in which R and R2 have 1 to 3 carbon atoms and m has 2 to 6 carbon atoms are particularly preferably used. Further, in order to improve the polymerizability of the obtained perfluorovinylcarboxylic acid ester as a monomer, it is preferable that n or n be 1.

Typical structural formulas of perfluorodicarboxylic acid esters used in the present invention include 0 ( ) OCR and the like. Note that although the above formula only exemplifies a methyl group as an ester group, other compounds such as ethyl and propyl groups may also be mentioned.

In the present invention, the perfluorodicarboxylic acid ester described above is heated at 150 to 450°C, preferably 200 to 35°C.
Heating at 0° C. is extremely important to obtain a high yield of perfluorocarbonic acid ester. That is, if the heating temperature is higher than the above range, side decomposition of the raw perfluorodicarboxylic acid ester is likely to occur, resulting in a problem that the yield of the perfluorodicarboxylic acid ester is significantly reduced. Furthermore, if the heating temperature is lower than the above range, the rate of thermal decomposition will drop significantly, and if the reaction is carried out for a long time under these conditions, the selectivity of the reaction will also drop, making it difficult to obtain perfluorocarboxylic acid ester in high yield. Can not. Further, the heating time may be appropriately determined in consideration of the heating temperature and the like. Generally, a heating time of 0.1 to 10,000 seconds, preferably 1 to 1,000 seconds is appropriate.

In the present invention, it is preferable to heat the perfluorodicarboxylic acid ester in the presence of an alkaline substance in order to accelerate the rate of thermal decomposition and efficiently carry out the reaction. As the alkaline substance, known substances used in decarboxylation reactions are preferably used. For example, oxides such as zinc oxide, lead, calcium oxide, and silicon oxide, and carbonic acid equivalents such as sodium carbonate, potassium carbonate, lithium carbonate, and mu are generally used.

In the present invention, the method of heating the perfluorodicarboxylic acid ester is not particularly limited, but heating is generally performed in a gas phase or a liquid phase. Only (heating, heat temperature, heating time □
□It is easy to control, and it is easily carried out in the gas phase.The preferred method is □.To give a typical example, perfluorodicarboxylic acid ester is vaporized under reduced pressure, under normal pressure, or under pressure. Examples include an embodiment in which the mixture is diluted with an inert gas such as nitrogen, alkali, carbon, helium, etc., and then passed through a heating zone, for example, a heated column, for an appropriate period of time.

'' In the above embodiment, it is preferable that the above-mentioned alkaline substance be present (filled) in the column. The gas that has passed through the column may be cooled and condensed, and the generated perfluorovinyl carboxylic acid ester may be separated if necessary.

After purification, or as it is, or further heated under the above-mentioned Kano conditions to decompose the perfluorocarboxylic acid ester,
Formula CF2=CF-(0SusakiCF2)i+O: Yu C
Perfluorodivinyl represented by F = CF 2 (!, where 0 or 1m is an integer of 1 or more) may be used after being produced in any proportion. Among the above embodiments, the embodiment in which perfluorovinyl carboxylic acid ester to be produced is further decomposed to produce perfluorodivinyl in an arbitrary ratio is such that the mixture is in a state where the monomer and the crosslinking agent are mixed together, so that the polymer It is suitable for the production of

EXAMPLES Below, in order to explain the present invention more specifically, Examples will be shown, but the present invention is not limited to these Examples.

Example 1 (1) Synthesis of perfluorocarboxylic acid ester To 94 parts by weight of oxalyl fluoride, 10 parts by weight of cesium fluoride was used as a catalyst, and 2 parts by weight of tetraglyme was used as a solvent.
Using 0.00 parts by weight, 500 parts by weight of hexafluoropropylene oxide was reacted at 0°C.

After repulsion, the product is distilled and the perfluorodiic acid fluoride FC-CF-0-CF2-CF2-11 is esterified with an alcohol having an alkyl group shown in Table 1 to produce a perfluorodiic acid ester. This was separated, purified, and used as a raw material.

(2) Production of perfluorovinyl carboxylic acid ester - Perfluorodiic acid ester obtained by the distribution method and nitrogen were each simultaneously supplied to a vaporization chamber maintained at 250°C to vaporize the perfluorodiic acid ester as a raw material. The molar ratio of barfluorodiate/nitrogen was adjusted to 1/10. The residue was passed through a column filled with the alkaline substance shown in Table 1 and heated to the temperature shown in Table 1 for the residence time shown in Table 1 to perform thermal decomposition. After the thermal decomposition, the gas was cooled, and the thermal decomposition products, raw materials, etc. were condensed and recovered. -1; The raw material reaction rate and the selectivity of perfluorovinylcarboxylic acid ester were measured from the condensate. The results are also shown in Table 1.

The structure of each component was determined by IR and NMR.

Comparative Example 1 When thermal decomposition was performed under 1° thermal decomposition conditions, the results shown in Table 2 were obtained. It is clear that perfluorodivinyl ether is produced by thermal decomposition or the raw material is recovered, and it is not easy to produce perfluorovinylcarboxylic acid fluoride as the main component. In the same manner as in Example 1, twice the mole of hexafluoropropylene oxide was added to perfluorosuccinyl fluoride, and then esterified with anhydrous methanol. After thermal decomposition in the air conditioner =
The results shown in Table 1 were obtained.

Table 3 A; CF = CFI) (CF2), 10cFcO
1) el1311; CF2=CFI) (CF2)
, IIcF = CF2 Example 3 In a glass autoclave with an internal volume of 500 m1, 10 parts by weight of cesium fluoride and 100 parts by weight of tetraglyme were charged, then 100 parts by weight of FOCCF2COF was charged, and 100 parts by weight of hexafluoropropylene oxide were heated to the reaction temperature. The reaction was allowed to proceed for 1 day at 0°C. After that, distillation P6B
〜681 got 160 heavy weights. Furthermore, by esterifying the 100-mineral part of this perfluorodiic acid fluoride with anhydrous methanol, CH0OCCFOCF2CF2
104 parts by weight of C00CH3 was obtained. When this barfluorodiic acid ester was thermally decomposed under the same thermal decomposition conditions as Nti2 and ;3 of Example 1, the results shown in Table 4 were obtained.

Table 4 C; CF2=, CFllCF2CF2CIIOC11
32, : , :2.

Example 4. ′ Perfluoroazibonyl fluoride esterified with anhydrous methanol CfIo 0 CCF2CF2CF2
CF2.co6CH3 was thermally decomposed under the same thermal decomposition conditions as in Example 1. The results shown in Table 5 were obtained. .

, Table 5 1.・E; CF2=CFCF2CF2C(IIIcII
3F; CF = CFCF = CF2 Patent Applicant Tokuyama Soda Co., Ltd. Procedures Amendment Document March 23, 1980 Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Indication of Case Patent Application 1982-24555. ! S No. 2゜ Title of invention Process for producing perfluorovinyl carboxylic acid ester 3 Relationship with the case of the person making the amendment Patent applicant address 1-1-5 Mikage-cho, Tokuyama-shi, Yamaguchi Prefecture Number of inventions increased by the amendment None 6. [Claim 1 and "Detailed Description of the Invention]" of the specification to be amended
Column 7: Contents of the amendment ■ The claims will be corrected as shown in the appendix.

■ Column for detailed description of the invention α) [Formula (However, R is an alkyl group having 1 to 10 carbon atoms.

m is an integer of 1 or more r Z * n is 0 or 1. x is represented by F or CF, ) and Z' is also deleted.

(2) On page 3, lines 1 and 2, [perfluorocarboxylic acid ester] is corrected to "perfluorovinylcarboxylic acid ester."

(3) On page 5, lines 5-4 from the bottom, "1 acid 70 rad group" is corrected to "acid fluoride group."

(4) Correct "diacid fluoride" in the third line from the bottom of page 6 to "diacid fluoride."

(5) "Di-acid fluoride" in the first line of page 4 is corrected to "dia-acid fluoride."

(6) On page 4, line 2, [acid fluoride group J is corrected to "acid fluoride group."

(7) On page 5, line 3, [ is after F or CF5J,
When xl and xl are both F, at least one of t or n is 0)" is inserted.

(8) The 1st prize on page 8, line 1 is listed. "After the"
In particular, the perfluorodicarboxylic acid ester forms a double bond by thermal decomposition -CF2-CF2-C'-0CR,
A compound having 1 at both ends is preferable because, as described later, the perfluorovinylcarboxylic acid ester produced can be further partially thermally decomposed to produce perfluorodivinyl in any proportion. ” is inserted.

(9) On page 10, line 5, [chill should be separated. ”
[Although the mechanism of double bond formation in the present invention is not clear, it is presumed that double bonds are formed between disubstituted carboxylates as a result of analyzing the product after thermal decomposition.

” is inserted.

(10) On page 10, line 8, insert ``by the product'' after [・river-・as is, or''.

(11) "rm" on page 10, line 11 of the same page is corrected to rpJ.

12) Change “m is 1 or more” to “p” on page 10, line 12 of the same page.
``determined by thermal reaction.''

(13) On page 12, lines 5 and 6, "maintained" is corrected to "maintained."

(14) "It was done by" in the first line from the bottom of page 12.
After rffOt, I measured R of perfluorocarboxylic acid methyl ester, and the absorption at 2950m' indicates the presence of a CH group.The absorption at 1780 indicates the presence of an ester group, and the absorption at 1840i'. Presence of vinyl ether group as shown, 1380-930
The existence of a CF bond was known from the strong and broad absorption of 6n.

Furthermore, by measuring C-NMR, a chemical shift value (δ, ppm) of 15
9.4.147.5.

130.1.118.4, 115.1.100゜9゜5
3.6 shows a total of seven peaks, which can be assigned as follows.

118.4 Through the above measurements, the perfluorovinylcarboxylic acid methyl ester of this example could be identified.

IR measurement of perfluorodivinyl ether revealed the presence of a perfluorodivinyl ether group at 1840rrn.

Jin was able to discover the existence of C-F Yuya from the fact that it exhibits strong and wide absorption from 1380 cm' to 930 cm'.

Furthermore, to measure C-NMR Therefore, the chemical shift values are 147.5 and 130.1.

A total of three peaks are shown at 115.4, and each peak can be assigned as follows.

Through the above measurements, the perfluorodivinyl ether of this example could be identified. ” is inserted.

(15) Page 17, line 2 f) [CF2 = CFOC
Insert "D;" before F=CF2J.

1'IL Attachment Revised claims and R2 is a different or similar argyl group having 1 to 10 carbon atoms, rn is an integer of 1 or more, /, , n is 0 or 1.
xl and x2 are F or CF.

A method for producing fluorodicarboxylic acid ester at a temperature of 150 to fluorovinylcarboxylic acid ester.

2) The method according to claim 1, wherein the heating is performed in the presence of an alkaline substance.

”

Claims (1)

[Claims] and υR are different or similar alkyl groups having 1 to 10 carbon atoms. m is an integer of 1 or more; e, n are 0 or 1; x is F or CF; CF2=CF-(0￥1F)
-(0) - and F -C-'OR (2 * n 11 , R is an alkyl group having 1 to 10 carbon atoms, m is an integer of 1 or more, oligomer, n is () or 1, X is F or CF. 2) The method according to claim 1, wherein the heating is carried out in the presence of a burqa male substance.