JPH04110313A - Fluoropolymer, preparation thereof, and ultrathin polymer film prepared therefrom - Google Patents

Abstract

PURPOSE:To prepare a fluoropolymer which can be formed into an ultrathin film useful for surface modification by reacting a specific polyallylamine with a specific alkyl perfluorocarboxylate and then with a dicarboxylic acid anhydride. CONSTITUTION:A polyallylamine of formula I (wherein m is 10-1500, and 0<n<=0.4m) is reacted with an alkyl perfluorocarboxylate of formula II (wherein Rf is 6-15C perfluoroalkyl; and R is 1-6C alkyl) and then with a dicarboxylic acid anhydride of formula III (wherein k is 2 or 3) to give a fluoropolymer of formula IV (wherein Rf, k, m, and n are each as described above). The polymer is soluble, can be formed into an ultrathin film by Langmuir-Blodgett technique, and can be used as an ultrathin film-forming surface-modifying material formerly unavailable.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention is directed to a novel fluorine-containing polymer compound, a method for producing the same, and a Lanckmuir-Blodgett film thereof.

[Prior art and its problems]

Are polymer compounds modified with long-chain perfluoroalkyl groups water-repellent? It exhibits excellent properties such as +11 properties, dust resistance, and corrosion resistance, and is used as a surface-modifying resin to protect M+ plates. It is also excellent as an oxygen permeable membrane, and the selectivity of oxygen permeation is improved due to the oxygen affinity of the perfluoroalkyl group.

However, polymer compounds into which perfluoroalkyl groups have been introduced are difficult to dissolve in solvents due to the water and oil repellency of perfluoroalkyl groups, and are difficult to handle as a single material. In other words, it is difficult to form ultra-thin films, which are important as surface modification materials and substrate protection materials. In addition, controlling the arrangement of perfluoroalkyl groups, which are functional groups such as water repellency and oxygen affinity, on the polymer surface improves surface modification efficiency and the performance of the oxygen separation membrane. However, it is not easy to control the arrangement on the surface.

The present inventors modified perfluoroalkyl groups through covalent bonds such as polyallylamine or polyvinylamine single-amino bonds, and used this polymer to modify Langmuir
An ultra-thin film with controlled molecular arrangement was fabricated using the Progeno 1 method [JP-A-63-1.70405, JP-A-64-4
608, JP-A]-207311-ri, JP-A-IT/1-
No. 207312, Japanese Patent Application No. 1983-216028, Japanese Patent Application No. 1983. -52655]. Since these are all amine-based polymers, their range of application is limited because the amino groups in the polymers react in the presence of acidic substances.

In order to create a polymer that does not react with acidic substances, the present inventor modified polyacrylic acid, which is a carboxylic acid polymer, with a 1,1-dihy-1heroperfluoroalkyl group by an amine) bond, and modified this polymer with Langmuir A Brodiesso I membrane was prepared [Japanese Patent Application No. 39258/1999]. However, to synthesize this polymer, a dehydration condensation agent such as a 2-halopyridinium salt is required to react the ], ]1-dihydroperfluoroalkyl amide with polyacrylic acid. Therefore, it is desirable to develop ultra-thin film materials that can be synthesized more easily without using such dehydration condensation agents and have excellent functions.

[Problem of invention]

The present inventor has conducted extensive research on a method for producing ultra-thin films that utilizes the hydrophobicity of perfluoroalkyl groups, and has modified the amino groups of polyallylamine with perfluoroalkyl groups and alkyl groups having carboxyl groups at the terminals through amide bonds. It was discovered that the obtained polymer compound is suitable as an ultra-thin film material, and the present invention was completed.

[Means for solving the invention]

According to the present invention, the general formula (wherein Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10 to 1500
(n is a number that satisfies O<n≦0.4m)
A fluorine-containing polymeric substance represented by:

As shown in the following formula, the fluorine-containing polymeric substance according to the present invention, after reacting polyallylamine represented by the following general formula (II) with an alkyl perfluorocarboxylate represented by the general formula (m), It is produced by reacting with a dicarboxylic acid anhydride represented by general formula (IV).

(II) (I[I) -> (General Formula ■) However, in the above formula, Rf, R, k, m and n have the same meanings as above.

The polyallylamine used in the above reaction can be obtained by neutralizing polyallylamine hydrochloride with a base.

In the modification reaction of polyallylamine, an alcohol is used as a reaction solvent in the -stage reaction with an alkyl perfluorocarboxylate, and a mixture of alcohol and N,N-dimethylformamide is used in the second stage reaction with a dicarboxylic acid anhydride. The reaction can be carried out using a solvent at a reaction temperature of 5°C to 50°C, preferably 15°C to 30°C. To carry out this reaction preferably, an alkyl perfluorocarboxylate is added to an alcoholic solution of polyallylamine. At this time, by changing the amount of alkyl perfluorocarboxylate added, the perfluoroalkyl group can be modified with an amide bond to polyallylamine in any ratio. After stirring for several hours, a solution of dicarboxylic anhydride in N,N-dimethylformamide is added to this solution.

After stirring for an additional day, the reaction solution is concentrated and purified to obtain a polymer compound. The obtained fluorine-containing polymer was identified by fluorine analysis and IR spectrum to be a fluorine-containing polymer represented by the above general formula (1).

The fluorine-containing polymer of the present invention is dissolved in an organic solvent, and a Langmuir-Prodgett film can be easily prepared by spreading this dilute solution on pure water. From the measurement of the surface pressure-occupied area curve (FA curve) when this fluorine-containing polymer is spread on pure water, the area occupied by the perfluoroalkyl group can be determined by changing the modification rate of the perfluoroalkyl group. It can be seen that ultrathin films with different values can be fabricated. At this time,
The polymer with a perfluoroalkyl group modification rate of 20% showed the largest value. In the case of this polymer, the area occupied by the carboxyl groups is equal to the cross-sectional area of the hydrocarbon chain, which is 20 mm2, which indicates that the result is an ultra-thin film with an arrangement in which side chains with carboxyl groups stand side by side. Ta.

Moreover, by developing a dilute solution of this fluorine-containing polymer on an aqueous metal salt solution, a Langmuir-Blodgett film containing metal ions can be easily prepared. In this case, the metal ion may be any metal ion that can form a water-insoluble salt with a carboxyl group, and examples of such metal ions include metal ions such as calcium chloride, barium, and cadmium. From the measurement of the F-A curve when this fluorine-containing polymer was developed in an aqueous metal salt solution, it was found that by changing the modification rate of perfluoroalkyl groups, the ultimate area It is possible to create ultra-thin films with different perfluoroalkyl groups, and the modification rate of perfluoroalkyl groups is 20%.
It was found that the polymer of

This ultra-thin film is deposited on a glass substrate in layers or multiple layers, and the film has a critical surface tension γcd for n-alkanes.
yr1/cm was determined. As a result, when developed on pure water, the modification rate of perfluoroalkyl group was 9.20.
The 27% fluorine-containing subpolymer LB film has a γC value of approximately 1.
9.17.16 was shown. In addition, 1, B), which was developed in metal salt-1-, showed almost the same γC value, and when developed in calcium salt aqueous solution, fluorine-containing compound with a perfluoroalkyl group modification rate of 9.20.27% Polymer I and 13 films exhibited γC values of approximately 19.17.17, respectively. These dimensions are comparable to or smaller than the γCC dimension of polytetrafluoroethinone, which is 8.5, and it is an excellent film that exhibits properties such as low surface energy, water and oil repellency, and dust resistance. I can say it.

The film thickness of the film accumulated on the glass substrate was measured by Talystep and χ-ray diffraction 1. As measured from this, the film thickness was about 15 to 50 A per layer, and showed a tendency to become thicker as the modification rate of perfluoroalkyl groups increased.

〔Effect of the invention〕

In the fluorine-containing polymer compound of the present invention, the rate at which perfluoroalkyl groups are introduced can be varied within various ranges by changing the amount of alkyl perfluorocarboxylate reacted with. The ratio (modification rate) (n) is 40% or less (n≦0.4m). This fluorine-containing polymerized material is soluble and can be made into an ultra-thin film by the Langmuir-Prodgett method, and can be used as an unprecedented ultra-NIJ% surface modification material. In addition, by developing a solution of this fluorine-containing polymerized polymer in an aqueous metal salt solution, it is possible to obtain an unprecedented type of ultra-thin I sample incorporating gold Fjc salt.

In this ultra-thin film, the area occupied by one perfluoroalkyl group can be controlled by the modification rate of the perfluoroalkyl group and the presence or absence of a metal salt in the water layer when developing the LB film.

The surfaces of these films contain perfluoroalkyl groups, which are functional groups, and exhibit unique low surface energy properties. The surface state of this film can be controlled by changing the presence or absence of salt. Conventionally, an alkyl group having a fluorine-containing group and a carboxyl group is modified with a covalent bond to polyallylamine, and intramolecular There is no example of producing a functional tumor supermolecule membrane with a controlled arrangement between molecules.

NajG, Langmuir Progeno 1 as referred to herein
The film refers to a sample of the developed and accumulated film obtained by the conventionally well-known Rankmuir-Blodgett method.

〔Example〕

Next, the present invention will be explained in more detail with reference to Examples.

=12- Example "Synthesis of Fluorine-containing Polymer Ethanol], Oml containing metal I-Rium 0.1.2F
, and after hydrogen is no longer generated, add 0.50 g of polyallylamine hydrochloride (average molecular weight, approximately 9000), cover with a lid, and stir. The precipitated sulfur and lithium chlorides are removed by filtration, washed with 6 ml of ethanol, and the washing liquid is the filtrate.
, return it. perfluorooctane quasi-ethyl 0
, 47 g to 5 volumes of ethanol and 7 volumes added at once.

After stirring at room temperature for 5 hours, succinic anhydride 0. B record N.

The mixture was dissolved in 10 m of r4-dimethylformamide F (DMF) and stirred for - days. The solution was removed under reduced pressure, washed with chloroform, then water, and dried.
A polymer was obtained in which 20% of the amino groups in polyallylamine were bonded to perfluorooctyl groups, and 80% of the amine groups were bonded to 2-carboxyethyl groups via amyl bonds. In the infrared absorption spectrum, the obtained polymer shows that perfluorooctyl group is bonded to amide [bond to:
], 7], 7.1557cm-', 2-carboxyethyl group bond: ]655.
13; Mu7cm-', carboxyl group: 1717cm-
", carbon-fluorine bond: The structure was confirmed by the observation of strong absorption at 1300 to 1100 cm-'. Also, the modification rate of the fluoroalkyl group was determined by the fluorine analysis value 2.
Obtained from 6.0.

In a similar manner, a modification reaction of polyallylamine was carried out using ethyl perfluorooctanoate and succinic anhydride, and by varying the amount of ethyl perfluorooctanoate used relative to the amino groups of polyallylamine, the modification rate of polyfluorooctyl groups was 9 .20.27% of the polymer compound was obtained. In addition, a modification reaction of polyallylamine was carried out in the same manner using ethyl perfluorooctanoate and glutaric anhydride, and the modification rate of perfluorooctyl group was 19%.
A high molecular weight compound was obtained. The modification rates of these fluoroalkyl groups were all determined from fluorine analysis values.

Example 2 Preparation of Langmuir-Blodgett Membrane In the following, the fluorine-containing polymer obtained by modifying polyazuramine using ethyl perfluorooctanoate and succinic anhydride shown in Example 1 was modified by the modification rate of perfluorooctyl groups. (M%) is abbreviated as PACF (M).

PACF9.2 in Langmuir-Prodgett method
Relationship between surface pressure and occupied area (F-A curve) for ultra-thin films obtained by preparing dilute mixed solutions of 0.27 methanol and benzene and developing these solutions on pure water at 17°C. The results of the measurements are shown in Figure 1. From this result, the area occupied by one fluoroalkyl group in the membrane, that is, the ultimate area per fluoroalkyl group, is
51.78.3 respectively in the order of PACF9.20.27
The value was 2 for 2 people. Furthermore, the ultimate area per carboxyl group in the membrane was 5.20.12 people2 in the order of PACF9.20.27, respectively.

This ultra-thin film on the water surface was placed on a glass substrate at a surface pressure of 20 mN-
m-1 was transferred as a single layer film and a multilayer film.

These were transparent films.

Example 3 Preparation of Langmuir-Blodgett 1-membrane containing metal salt 15 = PACF9.2 in Langmuir-Blodgett method
0.27 methanol/benzene dilute mixed solutions were prepared, and these solutions were mixed with a calcium chloride aqueous solution containing sodium hydrogen carbonate as a buffer (calcium chloride concentration: 4.OX 10-4 mol 1-1, carbonate) at 17°C. Potassium hydrogen concentration: 4.0X10-4ntol 1-1
FIG. 2 shows the results of measuring the F- curves for the ultra-thin films obtained when each film was developed on the surface of the film. From this result, the ultimate area per fluoroalkyl group is PACF9
．． 20.27 followed by 55.59.30 people, respectively. Furthermore, the ultimate area per carboxyl group in the membrane is 5.15.
11 people showed a value of 2.

This ultra-thin film on the water surface was placed on a glass substrate at a surface pressure of 20 mN-
m-'' was transferred as a -layer film and a multilayer film.

These were transparent films.

Example 4 Measurement of critical surface tension γC The contact angle with n-alkane was measured for the films obtained in Examples 2 and 3, and the results obtained from Zisman Prots 1- are shown in Table 1.

Table 1 Example 5 Measurement of Film Thickness The film thicknesses of the Langmuir-Prodgett films obtained in Examples 2 and 3 were measured using the following two methods.

(1) Measurement by Talystep A part of the thin film was peeled off, and the difference in level with the film was measured by Talystep. As a result, the film thickness of one layer is PAC
14-18, 11-1 respectively in the order of F9.20.27
9.36-62 people, developed on calcium chloride aqueous solution - Norckmuir Blogett I membrane (Example 3),
6 to 13.21 respectively in the order of PACF9.20.27
〜32.47 to 99 people were tested.

(2) Ka of copper measured by X-ray diffraction, 2. =1. 4050.40Kv, 30m
When an X-ray diffraction diagram was measured for A, a diffraction pattern was observed.

From this, the film thickness is calculated from Bragg's formula, and it is 1 of IWj.
The 1ψ thickness is in the order of PACF9.20.27 for the Langmuir-Prodgett membrane developed in pure water.]
5.23.48 people, Calcium chloride aqueous solution” developed in Langmuir Brodziets 1~Itjl, P/
l CF sleep 20.27 respectively approximately 28.30.4
Values were obtained for 8 people.

[Brief explanation of drawings]

Figures 1 and 2 show F-A 111 of the Langmuir Blogett I membrane of the fluorine-containing polymer compound according to the present invention.
11 lines are shown.

Claims (4)

[Claims] (1) General formula▲ Numerical formula, chemical formula, table, etc.▼ (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10 to 1500
(n is a number that satisfies 0<n≦0.4m)
A fluorine-containing polymer compound represented by (2) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10 to 1500
(n is a number that satisfies 0<n≦0.4m)
In the method for producing a fluorine-containing polymer compound represented by the general formula ▲, there are mathematical formulas, chemical formulas, tables, etc. (in the formula, m has the same meaning as above) and polyallylamine represented by the general formula ▲ , chemical formulas, tables, etc.▼ (In the formula, Rf has the same meaning as above, and R has 1 to 1 carbon atoms.
5 shows the alkyl group. ) and further react with a dicarboxylic acid anhydride represented by the general formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (in the formula, k has the same meaning as above) A method characterized by: (3) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10 to 1500
, where n is a number satisfying 0<n≦0.4n. ) A Langmuir-Blodgett film produced by spreading a fluorine-containing polymer compound represented by ) on pure water. (4) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10 to 1500
(n is a number that satisfies 0<n≦0.4m)
A Langmuir-Blodgett film produced by developing a fluorine-containing polymer compound represented by the formula on an aqueous solution of a metal salt that forms a salt with a carboxylic acid.