Nitrogenous fluorocarbon copolymer, its production and its use

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Industrial application field]

The present invention relates to a novel nitrogen-containing fluorocarbon copolymer useful as a fluoropolymer, a method for producing the same, a derivative thereof, an ion exchange resin, and a gas selective permeable copolymer.

【0002】

[Conventional technology]

Conventionally, as nitrogen-containing fluorocarbon polymers, Japanese Patent Publication No. 3-48928, Japanese Patent Application Laid-Open No. 4-75246, Japanese Patent Application Laid-Open No. 62-103385 and the like are known.

【0003】

However, all of these known polymers have insufficient heat resistance, chemical resistance, and the like because the alkyl group in the amino group at the end of the side chain is a hydrocarbon.

【0004】

[Problems to be Solved by the Invention]

An object of the present invention is a nitrogen-containing fluorocarbon copolymer which can be expected to have heat resistance and chemical resistance, has a low crystallinity, and can be induced in various useful uses, a method for producing the same, and ion exchange. An object of the present invention is to provide a derivative such as a resin and a gas selective permeable copolymer.

【0005】

[Means for solving problems]

That is, the present invention [Chemical 2]

<img file="JPH07118348A_D0001.tif" />Nitrogen-containing fluorocarbons represented by (b) Nitrogen-containing fluorocarbon copolymer containing at least one ethylenically unsaturated compound selected from the group consisting of tetrafluoroethylene, vinylidene fluoride, vinyl fluoride, chlorotrifluoroethylene and ethylene as a constituent monomer. It is related to coalescence.

【0006】

The nitrogen-containing fluorocarbon copolymer of the present invention preferably has a melt viscosity of about 100,000 to about 5 million poisons, or a molecular weight of about 5,000 to about 150,000. Further, it is desirable to contain 1 to 50 mol% of a constituent component composed of a monomer composed of nitrogen-containing fluorocarbon.

【0007】

The nitrogen-containing fluorocarbon copolymer of the present invention can be easily produced by addition polymerization of the above-mentioned nitrogen-containing fluorocarbon and an ethylenically unsaturated compound.

【0008】

The nitrogen-containing fluorocarbon copolymer of the present invention can lead to various useful compounds. For example, this nitrogen-containing fluorocarbon copolymer can be treated with fuming sulfuric acid at a high temperature to obtain a modified copolymer. In this case, since nitrogen is present in the copolymer molecule of the present invention, the side chain is oxidized and hydrolyzed by fuming sulfuric acid, and a functional group can be introduced into the side chain while retaining the main chain. This modified copolymer becomes useful as an ion exchange resin due to its functional group.

【0009】

Further, since the nitrogen-containing fluorocarbon copolymer of the present invention has a bulky tertiary amino group in the side chain, it has a low crystallinity and can be formed into a film. It is useful as a permeable copolymer.

【0010】

Specifically, the nitrogen-containing fluorocarbon copolymer of the present invention includes tetrafluoroethylene (TFE), vinylidene fluoride (VdF), vinyl fluoride (VF), chlorotrifluoroethylene (CTFE) and ethylene as monomers. It is a copolymer containing at least one of the following monomers as a comonomer and at least one of the following monomers as a comonomer. In this case, the polymerization ratio is a molar ratio, and monomer: comonomer = (99: 1) to (50:50) is preferable.

【0011】

[Chemical 3]

<img file="JPH07118348A_D0002.tif" />【0012】

Next, the above-mentioned method for synthesizing the monomer will be described. For example, it can be shown by the following reaction formula.

【0013】

Synthesis of perfluorovinyl amines: [Chemical 4]

<img file="JPH07118348A_D0003.tif" />【0014】

In this perfluorovinylamine synthesis reaction, for example, 3-dialkylaminopropionic acid ester is obtained by Michael reaction of methyl acrylate with dialkylamine or cyclic amine, and further electrolytic fluorination in phosphoric acid anhydride. By doing so, perfluoro (3-dialkylaminopropionic acid fluoride) is obtained. This acid fluoride is potassium chlorided and thermally decomposed and decarbonated to obtain the desired monomer.

【0015】

Synthesis of nitrogen-containing perfluorovinyl ether: [Chemical 5]

<img file="JPH07118348A_D0004.tif" />【0016】

In this nitrogen-containing fluorovinyl ether synthesis reaction, the starting material acid fluoride is obtained as an intermediate in the above-mentioned perfluorovinylamine synthesis reaction, and this is used. 6FO (hexafluoropropylene oxide) is added to this acid fluoride in the presence of KF or CsF in tetraglime. The addition product is converted to a potassium salt and then thermally decomposed and decarbonated to obtain a vinyl ether monomer.

【0017】

Synthesis of perfluoropropenylamine: [Chemical 6]

<img file="JPH07118348A_D0005.tif" />【0018】

This synthesis reaction of perfluoropropenylamine is almost the same as the synthesis of perfluorovinylamine described above except that methyl methacrylate is used instead of methyl acrylate, but internal olefins are used during thermal decomposition decarbonation. (E / Z) and external olefins are formed. The internal olefin is almost completely removed by distillation before being used for polymerization.

【0019】

Next, a method for producing the nitrogen-containing fluorocarbon copolymer of the present invention using the above-mentioned monomer and comonomer will be illustrated.

【0020】

This copolymer can be obtained by radical polymerization in solution, emulsified or suspended. For example, a nitrogen-containing monomer, an oil-soluble radical initiator, a fluorine-based solvent such as R113 is added to an autoclave, and then degassed to charge a certain amount of gas monomer. Place the autoclave in a constant temperature water tank (20-40 ° C) and stir with a shake or magnetic stir bar. After a certain period of time (5 to 70 hours), remove, wash and dry.

【0021】

Also, for example, a nitrogen-containing monomer, a water-soluble radical initiator, an emulsifier, and water are put into an autoclave with a stirring blade, heated to a constant temperature (65 ° C), and the gas monomer is pressurized to a constant pressure (3 to 3 to 3) while stirring. 8kg / cm²) Prepare. When the gas monomer is consumed to some extent, the pressure is increased to a predetermined pressure. This operation is repeated for a certain period of time (10 to 50 cycles). The obtained emulsion is coagulated, filtered, thoroughly washed, and then dried.

【0022】

INDUSTRIAL APPLICABILITY

Since the nitrogen-containing fluorocarbon copolymer of the present invention has a bulky perfluorodialkylamino group in the side chain, heat resistance and chemical resistance can be expected, and the degree of crystallinity is low. , Gas selective permeable membrane, etc. are expected to be used. In addition, since the molecule has nitrogen, when treated with fuming sulfuric acid at high temperature, the side chain is oxidized and hydrolyzed, and it is possible to introduce a functional group into the side chain while retaining the main chain, and ion exchange. It can be applied to resins and the like.

【0023】

[Example]

Hereinafter, examples of the present invention will be described, but the following examples do not limit the present invention and can be variously modified based on the technical idea thereof.

【0024】

Example 1 Put 10.0 g of R113 (trifluorotrichloroethane), 6.1 g of perfluoro-N-vinylmorpholine, and 0.2 g of initiator IPP (diisopropylperoxydicarbonate) in a 50 ml stainless autoclave, and freeze and remove in a dry ice / acetone mixed bath. Qi and nitrogen filling were repeated 6 times. VdF (Viniliden Fluolide) 8.5kg / cm²It was press-fitted and stirred with a magnetic stirrer in a constant temperature bath at 40 ° C. After 17 hours, it was reprecipitated with acetone / methanol and dried in a vacuum dryer.

【0025】

The polymerization yield was 10%, and the composition ratio of perfluoro-N-vinylmorpholine was 5 mol% from NMR in deuterated acetone. From the styrene-based GPC, the weight average molecular weight was 15,000, the molecular weight distribution was 1.6, the melting point was 140 ° C from DSC, and the decomposition start temperature was 360 ° C from DTGA.

【0026】

Example 2 When perfluoro-N-vinylpiperidine was used instead of perfluoro-N-vinylmorpholine in the same manner as in Example 1, the polymerization yield was 8%, and the NMR in deuterated acetone showed that perfluoro-N-vinylpiperidine. The composition ratio was 3 mol%. From the styrene-based GPC, the weight average molecular weight was 10,000, the molecular weight distribution was 1.6, the melting point was 139 ° C from DSC, and the decomposition start temperature was 350 ° C from DTGA.

【0027】

Example 3 When perfluoro-N-vinylpyrrolidine was used instead of perfluoro-N-vinylmorpholine in the same manner as in Example 1, the polymerization yield was 33%, and the NMR in deuterated acetone showed that perfluoro-N-vinylpyrrolidine. The composition ratio was 5 mol%. From the styrene-based GPC, the weight average molecular weight was 113,000 (only in the THF-soluble part), the molecular weight distribution was 4.6, the melting point was 145 ° C from DSC, and the decomposition start temperature was 350 ° C from DTGA.

【0028】

Example 4 When perfluoro-N-propenyl morpholine was used instead of perfluoro-N-vinyl morpholine in the same operation as in Example 1, the polymerization yield after 21 hours was 60%, and the polymerization yield was 60% from NMR in deuterated acetone to perfluoro-N. -The composition ratio of propenylmorpholine was 5.5 mol%. From the styrene-based GPC, the weight average molecular weight was 36,000, the molecular weight distribution was 1.8, the melting point was 140 ° C from DSC, and the decomposition start temperature was 330 ° C from DTGA.

【0029】

Example 5 100 ml of water, 10 g of emulsifier, 70 mg of initiator APS, and 7.4 g of perfluoro-2-morpholino ethyl vinyl ether were placed in a 200 ml stainless steel autoclave with a stirring blade, degassed, replaced with nitrogen, and then tetrafluoroethylene (TFE) was press-fitted. Heat the reaction vessel to 65 ° C, stir at 400 rpm, tetrafluoroethylene 5 to 6 kg / cm.²It was a cycle preparation. After 4.3 hours, when 21 cycles were charged, stirring was stopped and the mixture was allowed to cool. The dispersion was taken out, frozen and coagulated, washed with water and washed with methanol repeatedly, and then dried in a vacuum dryer.

【0030】

The polymer yield was 28.2 g, the composition ratio of vinyl ether was 10.3 mol% from the elemental analysis value, the melting point was 317 ° C from DSC, and the decomposition start temperature from DTGA was 350 ° C. Melt viscosity is 1.0 x 10⁶It was poise (340 ° C).

【0031】

Example 6 Using 6.4 g of perfluoro-3-dimethylaminopropyl vinyl ether instead of perfluoro-2-morpholinoethyl vinyl ether in the same manner as in Example 5, the polymer yield after 5.3 hours (18 cycles) was 22.5 g, elemental analysis. From the values, the composition ratio of vinyl ether was 7.5 mol%, the boiling point from DTGA was 322 ° C, and the decomposition start temperature was 350 ° C. Melt viscosity is 4.0 × 10⁶It was poise (340 ° C).

【0032】

Example 7 Using 7.2 g of perfluoro-3-pyrrolidinopropyl vinyl ether instead of perfluoro-2-morpholinoethyl vinyl ether in the same manner as in Example 5, the polymer yield after 6.3 hours (20 cycles) was 25.5 g, elemental analysis. From the values, the composition ratio of vinyl ether was 8.8 mol%, the boiling point from DTGA was 324 ° C, and the decomposition start temperature was 300 ° C.

【0033】

The physical characteristics of the polymers obtained in each of the above Examples 1 to 7 (and other polymers obtained in the same manner) are summarized in Table 1 below.

【0034】

[Chemical 7]

<img file="JPH07118348A_D0006.tif" />【0035】

Next, the selective permeability of gas was investigated for the nitrogen-containing fluorocarbon copolymer (nitrogen-containing perfluorovinyl ether-tetrafluoroethylene copolymer) based on the present invention. Upon measurement, the sample was prepared by melt compression molding the polymer powder. The obtained white translucent film was cut into a disk shape having a diameter of 40 mm, and the permeability coefficients of oxygen and nitrogen were measured at 25 ° C. using a gas permeability measuring device (GTR-10 type manufactured by Yanaco Co., Ltd.). The results are shown in Table 2 below.

【0036】

[Chemical 8]

<img file="JPH07118348A_D0007.tif" />【0037】

According to this measurement result, the polymer of the present invention has a PN as compared with PFA, which has a low crystallinity and a high gas permeability among general-purpose fluoropolymers.₂, PO₂Both show large values, indicating excellent gas permeability and selectivity.

【0038】

Next, 2 g of a nitrogen-containing perfluorovinyl ether-tetrafluoroethylene copolymer powder or a melt-compression-molded film based on the present invention was placed in a 50 ml eggplant flask, and 30 g of 30% fuming sulfuric acid was added. A cooling tube was attached, and the mixture was heated under reflux (140 to 160 ° C) in an oil bath while stirring with a magnetic stirrer. After a certain period of time, the polymer was taken out, washed with water, and then dried in a vacuum dryer. The composition of the constituent polymers of each sample was as follows.

【0039】

Sample: NEFPr2: Perfluoro-3-pyrrolidinopropyl vinyl ether 4.3 mol% NEFPr5: Perfluoro-3-pyrrolidinopropyl vinyl ether 22.8 mol% NEFMII1: Perfluoro-2-morpholino ethyl vinyl ether 10.3 mol% NEFMII2: Perfluoro-2-morpholino ethyl vinyl ether 17.2 mol% [0040]

NEFPr2 and NEFPr5 were reacted with powder and then melt-compressed. NEFMII1 and NEFMII2 were reacted with a film. The following measurements were made for each sample.

【0041】

1) Contact angle The contact angle with water was measured before and after the reaction with fuming sulfuric acid. The results are shown in Tables 3 and 4 below.

【0042】

<img file="JPH07118348A_D0008.tif" />【0043】

<img file="JPH07118348A_D0009.tif" />【0044】

2) Infrared absorption spectrum Taking an infrared absorption spectrum before and after the above reaction, C = O (1750 ~ 1800 cm) after the reaction.^-1) And OH (2800 ~ 3300cm)^-1) Peak increased.

【0045】

3) ESCA ESCA was measured before and after the above reaction. In NEFMII1, C_1SAs the reaction proceeded in, a peak (284 eV) of carbonyl, which was thought to be C, was formed. Also O_1SThen, the peak of 535eV, which is considered to be O of morpholine, became smaller as the reaction proceeded, and the peak of O of carboxylic acid was generated at 530 to 533eV.

【0046】

The ternary polymers shown in Table 5 below were synthesized under the following polymerization conditions. Polymerization conditions: NFM (perfluoro-N-vinylmorpholine), 25 g of solvent (R-113), 1 mol% of initiator (IPP) are charged in a 25 cc pressure-resistant container made of SUS-316, and after degassing, a gas monomer is press-fitted. did. Polymerization was carried out overnight in a shaking water tank (40 ° C). Post-treatment: The obtained polymer was filtered off with a glass filter, washed with R-113, and dried.

【0047】

<img file="JPH07118348A_D0010.tif" />【0048】

From the above results, although the above polymer is a perfluoropolymer, it has a perfluoroamino group in the side chain, so that it can be oxidatively hydrolyzed by reacting with fuming sulfuric acid to introduce a carboxylic acid at the end of the side chain. It is possible and can be chemically modified to impart hydrophilicity. Then, due to the presence of the carboxylic acid in the side chain or the introduction of another specific functional group into the carboxylic acid, application to an ion exchange resin can be considered.