JPH0565526B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a novel fluorine-containing polymer compound, a method for producing the same, and a Langmuir Blossom film thereof. [Prior art and its problems] Polymer compounds modified with long-chain perfluoroalkyl groups exhibit excellent properties such as water and oil repellency, dustproofness, and corrosion resistance, and are used as surface-modifying resins to protect substrates. . It is also excellent as a material for oxygen permeable membranes, and the oxygen permeation selectivity 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 the perfluoroalkyl groups, making them difficult to use as membrane materials. 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 and oil repellency and oxygen affinity, on the surface of polymers is important in improving their performance as surface modifiers and oxygen separation membranes. However, controlling the arrangement on the surface is not easy. The present inventor modified polyallylamine or polyvinylamine with a perfluoroalkyl group by a covalent bond such as an amide bond, and used this polymer to fabricate an ultra-thin film with controlled molecular arrangement using the Langmuir-Blodget method [Special Kaisho 63-170405,
JP-A-64-4608, JP-A-1-207311, JP-A-1
−207312, Japanese Patent Application No. 1983-216028, Japanese Patent Application No. 1987-
No. 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-dihydroperfluoroalkyl group using an amide bond, and created a Langmuir-Blodget membrane of this polymer. [Patent Application Hei 2-
No. 39258]. However, to synthesize this polymer,
In order to react the 1,1-dihydroperfluoroalkylamine with polyacrylic acid, a dehydration condensation agent such as a 2-halopyridinium salt is required. Therefore, it is desired to develop an ultra-thin film material that can be synthesized more easily without using such a dehydration condensation agent and has excellent functions. [Problem to be solved by the invention] The present inventor has conducted intensive research on a method for producing an ultra-thin film that utilizes the hydrophobicity of perfluoroalkyl groups, and has created a method for producing an ultra-thin film that utilizes the hydrophobicity of perfluoroalkyl groups, and has created a polyallylamine that has a perfluoroalkyl group and a carboxyl group at the end through an amide bond. The present inventors have discovered that a polymer compound obtained by modifying with an alkyl group is suitable as an ultra-thin film material, and have completed the present invention. [Means for solving the invention] According to the present invention, the general formula (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10
-1500, where n is a number satisfying 0<n≦0.4m). As shown in the following formula, the fluorine-containing polymeric substance according to the present invention is produced by reacting a polyallylamine represented by the following general formula () with an alkyl perfluorocarboxylate represented by the general formula (),
It is produced by reacting with a dicarboxylic acid anhydride represented by the general formula (). However, in the above formula, Rf, R, k, m and n have the same meanings as above. The polyallylamine used in the reaction can be obtained by neutralizing polyallylamine hydrochloride with a base. In the modification reaction of polyallylamine, alcohols are used as reaction solvents in the first reaction with alkyl perfluorocarboxylate, and alcohols and N, N, in the second reaction with dicarboxylic anhydride.
The reaction can be carried out using a mixed solvent of N-dimethylformamide at a reaction temperature of 5°C to 50°C, preferably 15 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 another 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 (). The fluorine-containing polymer of the present invention is dissolved in an organic solvent, and a Langmuir Blossom 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 one 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 a single carboxyl group is equal to the cross-sectional area of the hydrocarbon chain, 20 Å ² , which indicates that the result is an ultra-thin film with an arrangement in which side chains with carboxyl groups stand side by side. . Further, by spreading a dilute solution of this fluorine-containing polymer on an aqueous metal salt solution, a Langmuir Blossom membrane containing metal ions can be easily produced. In this case, the metal ion may be any metal ion as long as it can form a water-insoluble salt with the carboxyl group, and examples of such metal ions include metal ions such as calcium, barium, and cadmium. From the measurement of the F-A curve when this fluorine-containing polymer was developed on a metal salt aqueous solution,
As in the case of spreading on pure water, ultrathin films with different ultimate areas can be created by changing the modification rate of perfluoroalkyl groups, and the polymer with a modification rate of 20% perfluoroalkyl groups has the largest ultimate area. I found out what it shows. One or more layers of this ultra-thin film were accumulated on a glass substrate, and the critical surface tension γc dyn/cm of this film with respect to n-alkane was determined. As a result, when developed on pure water, fluorine-containing polymer LB films with perfluoroalkyl group modification rates of 9, 20, and 27% exhibited γc values of approximately 19, 17, and 16, respectively. In addition, LB films developed on metal salts showed almost the same γc values, and when developed on calcium salt aqueous solutions, fluorine-containing polymer LB films with perfluoroalkyl group modification rates of 9, 20, and 27% had γc values. The values were approximately 19, 17, and 17, respectively. These values are comparable to or smaller than the γc value of polytetrafluoroethylene, which is 18.5, and can be said to be an excellent film exhibiting properties such as low surface energy, water and oil repellency, and dust resistance. When the film thickness of the film accumulated on the glass substrate was measured by Talystep and X-ray diffraction, the film thickness was approximately 15 to 50 Å per layer, and the film thickness tended to increase as the modification rate of perfluoroalkyl groups increased. [Effects of the Invention] In the fluorine-containing polymer compound of the present invention, the introduction ratio of perfluoroalkyl groups can be varied within various ranges by arbitrarily changing the reaction amount of alkyl perfluorocarboxylate.
Generally, the ratio (modification rate) (n) is 40% or less (n≦0.4m). This fluorine-containing polymer compound is soluble and can be made into an ultra-thin film by the Langmuir-Blodget method, and can be used as an unprecedented substance for modifying the surface of an ultra-thin film. Further, by spreading this solution of the fluorine-containing polymer compound on an aqueous metal salt solution, an unprecedented type of ultra-thin polymer film incorporating metal salts can be obtained. 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 the LB film is developed. The surfaces of these films contain perfluoroalkyl groups, which are functional groups, and exhibit excellent low surface energy properties characteristic of fluorine-containing groups. Furthermore, this type of surface condition can be controlled by changing the modification rate of the perfluoroalkyl group and the presence or absence of a metal salt in the aqueous layer. Conventionally, an alkyl group containing a fluorine-containing group and a carboxyl group was modified with a covalent bond to polyallylamine, and a functional ultra-thin polymer film with a controlled arrangement within and between molecules was created using the Langmuir-Blodget method. There are no examples of this happening. The term "Langmeur Blossom film" as used herein refers to a spread film and a cumulative film obtained by the conventionally well-known Langmuir Blossom film. [Example] Next, the present invention will be explained in more detail with reference to Examples. Example 1 Synthesis of fluorine-containing polymer 0.12 g of metallic sodium was added to 10 ml of ethanol, and after no hydrogen was generated, 0.50 g of polyallylamine hydrochloride (average molecular weight, approximately 9000) was added.
Cover and stir. The precipitated sodium chloride is removed by filtration, washed with 6 ml of ethanol, and the washings are returned to the filtrate. To this solution, add 0.47 g of ethyl perfluorooctanoate dissolved in 5 ml of ethanol all at once. After stirring for 5 hours at room temperature, succinic anhydride
0.85g of N,N-dimethylformamide (DMF)
Dissolve and add to 10ml and stir for one day. This solution was stripped of the solvent under reduced pressure, washed with chloroform then water and dried to give a 20% concentration in polyallylamine.
A polymer was obtained in which perfluorooctyl groups were bonded to 80% of the amino groups and 2-carboxyethyl groups were bonded to 80% of the amino groups via amide bonds. In the infrared absorption spectrum of the obtained polymer, amide bonds with perfluorooctyl groups were observed:
1717, 1557cm ^-1 , amide bond with 2-carboxyethyl group: 1655, 1557cm ^-1 , carboxyl group: 1717cm ^-1 , carbon-fluorine bond: 1300-1100cm
The structure was confirmed by the strong absorption of ^-1 . Furthermore, the modification rate of the fluoroalkyl group was determined from the fluorine analysis value of 26.6%. In a similar manner, a modification reaction of polyallylamine was carried out using ethyl perfluorooctanoate and succinic anhydride, and the modification rate of polyfluorooctyl groups was 9 , 20, 27% of polymer compounds were 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 Blossom Digest Membrane In the following, a fluorine-containing polymer obtained by modifying polyallylamine using ethyl perfluorooctanoate and succinic anhydride shown in Example 1 was modified by the modification rate of perfluorooctyl groups ( M%)
It is abbreviated as PACF (M). In the Langmeur Blogger method
The surface pressure-occupied area relationship (FA Figure 1 shows the results of measuring the curve. From this result, the area occupied by one fluoroalkyl group in the membrane, that is, the ultimate area per fluoroalkyl group, is 51, 78, and 32Å ² for PACF9, 20, and 27, respectively.
The value of Furthermore, the ultimate area per cargoxyl group in the film was 5, 20, and 12 Å ² for PACF9, 20, and 27, respectively. This ultra-thin film on the water surface is placed on a glass substrate under surface pressure.
It was transferred as a single layer film and a multilayer film at 20 mN·m ^-1 . These were transparent films. Example 3 Preparation of Langmeur Blossom film containing metal salt In Langmeur Blossom method
Prepare methanol/benzene dilute mixed solutions of PACF9, 20, and 27, and heat these solutions at 17℃.
Calcium chloride aqueous solution containing sodium hydrogen carbonate as a buffer (calcium chloride concentration: 4.0×
10 ^-4 mol1 ^-1 , potassium hydrogen carbonate concentration: 4.0×10 ^-4
Figure 2 shows the results of measuring the F-A curves for the ultra-thin films obtained when each film was developed on a mol1 ^-1 ) surface. From this result, the ultimate area per fluoroalkyl group was 50, 59, and 30 Å ² for PACF9, 20, and 27, respectively. In addition, the ultimate area per carboxyl group in the membrane is PACF9, 20, 27
The values were 5, 15, and 11 Å ² in that order, respectively. This ultra-thin film on the water surface is placed on a glass substrate under surface pressure.
It was transferred as a single layer film and a multilayer film at 20 mN·m ^-1 . These were transparent films. Example 4 Measurement of Critical Surface Tension γc For the films obtained in Examples 2 and 3, the contact angle with n-alkane was measured, and the critical surface tension γc value determined from the Zisman plot was calculated by the least squares method.
These results are shown in Table 1.

[Table] Example 5 Measurement of Film Thickness The film thickness of the Langmuir Blossom films obtained in Examples 2 and 3 was measured using the following two methods. (1) Measurement using Talystep A part of the thin film was peeled off, and the difference in level with the film was measured using Talystep. As a result, the film thickness of one layer was 14 for PACF9, 20, and 27 in the order of PACF9, PACF20, and PACF27 in the Langmiur Blosget film developed on pure water (Example 2).
-18, 11-19, 36-62 Å, and 6-13, 21-32, 47-99 Å for PACF9, 20, and 27 in the order of PACF9, 20, and 27 in the Langmuir-Blodget film developed on an aqueous calcium chloride solution (Example 3), respectively. The value of was obtained. (2) Measurement by X-ray diffraction When the X-ray diffraction diagram of copper was measured at Kα ₁ , λ = 1.54050, 40 Kv, and 30 mA, a diffraction pattern was observed. If the film thickness is calculated from Bragg's equation, the film thickness of one layer is 15, 23, and 48 Å for PACF9, 20, and 27, respectively, in the Langmuir-Blodget film developed on pure water, and 15, 23, and 48 Å for PACF9, 20, and 27, respectively, and a calcium chloride aqueous solution. In the Langmiur Blosget film developed on top, PACF9, 20, and 27 are approximately 28, 30, and 27, respectively.
A value of 48 Å was obtained.

[Brief explanation of the drawing]

FIGS. 1 and 2 show F-
A curve is shown.

Claims (1)

[Claims] 1. General formula (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10
~1500, where n is a number satisfying 0<n≦0.4m). 2 General formula (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10
-1500, where n is a number satisfying <n≦0.4m) In the method for producing a fluorine-containing polymer compound represented by the general formula (In the formula, m has the same meaning as above) and a polyallylamine represented by the general formula (In the formula, Rf has the same meaning as above, and R represents an alkyl group having 1 to 5 carbon atoms.) (In the formula, k has the same meaning as above.) A method characterized by reacting with a dicarboxylic acid anhydride represented by: 3 General formula (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10
-1500, where n is a number satisfying 0<n≦0.4n. Langmuir-Blodget film produced by spreading a fluorine-containing polymer compound represented by ) on pure water. 4 General formula (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, k is 2 or 3, and m is 10
-1500, where n is a number satisfying 0<n≦0.4m) A rung produced by developing a fluorine-containing polymer compound expressed as Miura Blosget Membrane.