JPH057747A - Fluorine-containing high-molecular compound having cyclodextrin residue, ultrathin membrane and its production - Google Patents

Abstract

PURPOSE:To prepare an ultrathin membrane of a fluorine-containing high- molecular compound having a cyclodextrin residue showing excellent low surface energy properties and usable as a surface modifying substance by developing a specific fluorine-containing polymer on an aqueous solution of a specific cyclodextrin derivative. CONSTITUTION:A langmuir-Blodgett's film composed of a fluorine-containing higth-molecular compound represented by formula I (wherein Rf is a 6-15C perfluoroalkyl group, (m) is 10-1500, (n) is 0<n<= 0.4m, P is 0<P<=(m-n) and (k) is 5-8) is provided. In this case, a fluorine-containing polymer represented by formula II (wherein Rf, (m) and (n) are same as aforementioned ones) is developed on an aqueous solution of a cyclodextrin derivative represented by formula III (wherein (k) is 5-8) to provide the ultrathin membrane represented by the formula I. This membrane shows excellent low surface energy properties and can take in other compounds by the inclusion action of cyclodextrin and can be used as a surface modifying substance.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel fluorine-containing polymer compound, a method for producing the same and a Langmuir-Blodgett membrane thereof.

[0002]

2. Description of the Related Art Cyclodextrins have the property of incorporating various other molecules into their own molecules to form inclusion compounds. Utilizing this property, various inclusion compounds are formed and volatile substances are formed. It is used for various applications such as preventing the dissipation of water, stabilizing substances that are unstable to oxygen and light, and holding fragrances and drugs. For example, one application for this is ultrathin films containing cyclodextrins, which
By introducing a functional molecule into cyclodextrin, it is possible to obtain an ultrathin film having that function. As such an ultrathin film, a thin film of a cyclodextrin derivative modified with an alkyl group by the Langmuir-Blodgett method is known [A. Yabe
et al. Thin Solid Films,
160, 33 (1988)], since this is an ultrathin film of low molecular weight, it has practically problems in mechanical strength, corrosion resistance and the like.

On the other hand, a polymer compound modified with a long-chain perfluoroalkyl group exhibits excellent properties such as water repellency, oil repellency, dust resistance, and corrosion resistance, and is used as a surface-modifying resin for substrate protection. It is also an excellent material for the oxygen permeable membrane, and the oxygen affinity of the perfluoroalkyl group improves the selectivity of oxygen permeation. However, a polymer compound having a perfluoroalkyl group introduced therein is difficult to dissolve in a solvent due to the water / oil repellency of the perfluoroalkyl group, and it is difficult to handle as a film material and difficult to handle. That is, it is difficult to form an ultra-thin film, which is important as a surface modifying material and a substrate protecting material. Further, it is important to control the arrangement of perfluoroalkyl groups, which are functional groups such as water / oil repellency and oxygen affinity, on the polymer surface in order to enhance the performance of the function as a surface modifier or an oxygen separation membrane. However, controlling the alignment to the surface is not easy. In order to solve this point, the present inventors introduced a perfluoroalkyl group into a hydrophilic polymer through a covalent bond such as an amide bond, and used this polymer to control the molecular arrangement by the Langmuir-Blodgett method. Of the above-mentioned ultra thin film [JP-A-63-170405, JP-A-64-4608, JP-A-1-207311, JP-A1-270312, JP-A-2-64114, JP-A-2-258801]. , Japanese Patent Application No. 2-39258, Japanese Patent Application No. 2-231280].

[0004]

However, such an ultrathin film using a polymer having a perfluoroalkyl group introduced by a covalent bond such as an amide bond has a controlled alignment within and between molecules, and Although it is an ultrathin film that exhibits excellent low surface energy properties peculiar to fluorine-containing groups, it was not possible to introduce a new functional molecule by introducing other functional molecules. Therefore, it is an object of the present invention to provide a novel fluorine-containing polymer which is suitable as an ultrathin film material and contains cyclodextrin, and a Langmuir-Blodgett film thereof.

[0005]

Means for Solving the Problems The present inventor has conducted extensive studies on the development of an excellent ultrathin film material containing cyclodextrin and a method for producing an ultrathin film utilizing the hydrophobicity of a perfluoroalkyl group. The polymer compound obtained by introducing a cyclodextrin derivative by an ionic bond into a polymer obtained by modifying a part of the amino groups of the above with a perfluoroalkyl group by an amide bond was found to be suitable as an ultrathin film material, and the present invention was completed. Came to do.

That is, the present invention is (1) The following general formula (I)

[0007]

[Chemical 6] (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, m represents a number of 10 to 1500, and n represents 0 <n.
≦ 0.4 m, p is a number satisfying 0 <p ≦ m−n, and k is a number from 5 to 8. ) A fluorine-containing polymer compound represented by

(2) Langmuir characterized by comprising a fluorine-containing polymer represented by the general formula (I)
Blodgett film,

(3) In the method for producing the Langmuir-Blodgett film of the fluorine-containing polymer represented by the general formula (I), the general formula (II)

[0010]

[Chemical 7] (Wherein Rf, m and n have the same meanings as described above), the fluoropolymer represented by the formula (III)

[0011]

[Chemical 8] And a method for producing a Langmuir-Blodgett film, which comprises developing on a water solution of a cyclodextrin derivative represented by the formula (wherein k has the same meaning as described above), and

(4) General formula (IV)

[Chemical 9] (In the formula, Rf, m, n, p and k have the same meanings as described above, and G is a compound capable of forming an inclusion compound with cyclodextrin.). A Langmuir-Blodgett film, which is a feature of the present invention.

The Langmuir-Blodgett film referred to in the present specification means a water-spreading film and a cumulative film obtained by the well-known Langmuir-Blodgett method.

The fluorine-containing polymer compound represented by the general formula (I) according to the present invention is represented by the following general formula (II) and the formula (II
It is produced by reacting with a cyclodextrin derivative represented by I).

[0015]

[Chemical 10] However, in the above formula, Rf, m, n, p and k have the same meanings as described above.

The fluorine-containing polymer represented by the general formula (II) used as one of the reaction components in the above reaction is already known [JP-A-63-170405], and polyallylamine is used in a reaction solvent such as alcohol. It can be synthesized by the reaction of with an alkyl perfluorocarboxylate.

The fluorine-containing polymer represented by the general formula (I) of the present invention is prepared by using the general formula (II) in an organic solvent such as alcohol.
Polymers and cyclodextrin derivatives (III)
It is also possible to obtain the fluorine-containing polymer (I) by developing a dilute solution of the polymer (II) in an organic solvent on an aqueous solution of the cyclodextrin derivative (III). Is obtained as an ultra-thin film on the water surface. According to this method, the modification reaction of the cyclodextrin derivative (III) to the polymer (II) proceeds on the water surface, whereby a fluorine-containing polymer can be produced and, at the same time, a Langmuir-Blodgett film of this polymer can be produced. The method for producing the ultrathin film itself can be carried out according to a conventional method. For example, the cyclodextrin derivative (III) of 1 × 10 ⁻⁴ to
A 1 × 10 ^-1 % aqueous solution was prepared, and the concentration of the polymer compound (II) represented by the general formula (II) on the water surface of the aqueous solution was 0.1.
When a 1-5% solution is developed, the fluorine-containing polymer (I) is synthesized on the water surface, and at the same time, Langmuir
A Blodgett film is produced. At this time, the water temperature is 5 to 50
C is preferred.

From the measurement of the surface pressure-occupancy area curve (FA curve) when the fluoropolymer (II) was developed on the aqueous solution of the cyclodextrin derivative (III), the modification ratio of the perfluoroalkyl group and the cyclodextrin were measured. It can be seen that by changing the concentration of the derivative (III) aqueous solution, ultrathin films in which the area occupied by one perfluoroalkyl group is different can be prepared. At this time, the area occupied by one perfluoroalkyl group is smaller in the polymer having a modification rate of the perfluoroalkyl group of 10% than in the polymer having a modification rate of the perfluoroalkyl group of 20%.
(III) The concentration of the aqueous solution is 2 × 10 ^{−5 to} 5 × 10 ⁻⁵ mol ·
In the case of l ⁻¹ , the smallest value is shown. The modification ratio of the perfluoroalkyl group in the fluorine-containing polymer represented by the general formula (II) is usually 1% or more, preferably 5 to 40%, more preferably 10 to 30%.

This ultrathin film is accumulated in a single layer or multiple layers on a glass substrate. When the critical surface tension γ _c dyn · cm ⁻¹ of this film with respect to n-alkane is obtained, the result is 5 ×.
When a polymer having a modification ratio of a perfluoroalkyl group of 10% was developed in an aqueous solution of 10 ⁻³ mol·l ⁻¹ cyclodextrin derivative (III), the γ _c values of a single-layer film and a five-layer film were about 19 and 17, respectively. When a polymer having a modification ratio of perfluoroalkyl groups of 20% was developed, the γ _c values of the single-layer film and the five-layer film were about 17 and 18, respectively. These values are similar to or smaller than the γ _c value of polytetrafluoroethylene, and have low surface energy, water and oil repellency,
It shows that it is an excellent film showing properties such as dustproofness. When the film thickness of the film accumulated on these glass substrates was measured by the stylus method and X-ray diffraction, the film thickness was about 4 nm per layer in both cases where the modification ratio of the perfluoroalkyl group was 10% or 20%. It was

By using an inclusion compound with the cyclodextrin derivative (III), another compound can be introduced into the fluorine-containing polymer film. This polymer film is represented by the general formula (IV). That is, the target compound G is dissolved in an aqueous solution of the cyclodextrin derivative (III), and the solution of the fluoropolymer (II) is developed on this aqueous solution to give the cyclodextrin derivative (III).
An LB film of a fluorine-containing polymer represented by the general formula (IV), which incorporates this compound as an inclusion compound with, can be obtained. The compound G may be any compound that forms an inclusion compound with cyclodextrin. Examples of the compound G include p-nitroaniline and the like.

[0021]

EXAMPLES Next, the present invention will be described in more detail by way of examples.

Example 1 Fabrication of Langmuir-Blodgett films of fluoropolymers

0.5 ml of metallic sodium was added to 15 ml of methanol.
20 g was added, and after the generation of hydrogen ceased, 0.81 g of polyallylamine hydrochloride (average molecular weight, about 9000) was added, and the mixture was covered and stirred. Precipitated sodium chloride is removed by filtration, washed with 10 ml of methanol, and the washing solution is returned to the filtrate. To this solution, 0.38 g of ethyl perfluorooctanoate was dissolved in 7 ml of methanol and added all at once, and the mixture was stirred at room temperature for 5 hours. When 10% of amino groups in polyallylamine were linked with perfluoroalkyl groups through amide bonds ( Hereinafter, abbreviated as PAAF10)
A solution of was obtained. A solution of this polymer was diluted to prepare a dilute mixed solution of methanol and benzene (concentration of perfluoroalkyl group: 0.5 × 10 ⁻³ mol·l ⁻¹ ) at 17 ° C. by the Langmuir-Blodgett method. 6 ^A-
When developed on an aqueous solution (5 × 10 ⁻⁵ mol·l ⁻¹ ) of carboxymethylthio-6 ^A -deoxy-β-cyclodextrin (hereinafter abbreviated as CDSCH ₂ COOH), CDSCH ₂ COOH was high on the water surface. Ultra thin films of fluoropolymers containing cyclodextrin incorporated into the molecule were obtained. The ultrathin film on the water surface was transferred onto a calcium fluoride substrate at a surface pressure of 20 mN · m ⁻¹ and the infrared absorption spectrum was measured. As a result, strong absorption of carbon-oxygen bond derived from the cyclodextrin skeleton (1154, 1081 ,
1033 cm ^-1 ), CDSCH ₂ COOH
It was confirmed that was introduced into the polymer.

Surface area-occupancy area relationship (F-) for ultrathin films obtained when a solution of PAAF10 was developed at 17 ° C. on various concentrations of CDSCH ₂ COOH aqueous solution.
The result of measurement of (A curve) is shown in FIG. From this result,
The area occupied by one perfluoroalkyl group in the film, that is, the limit area per perfluoroalkyl group is the CDS.
CH ₂ COOH concentration 1 × 10 ⁻⁶ , 5 × 10 ⁻⁶ , 1 × 1
0 ^-5 , 2 x 10 ^-5 , 5 x 10 ^-5 , 1 x 10 ^-4 mol·l
^-1 for 0.62, 0.56, 0.50,
The values were 0.43, 0.44 and 0.52 nm. In addition, a solution of a polymer (hereinafter, abbreviated as PAAF20) in which a perfluoroalkyl group is bonded to 20% of amino groups in polyallylamine through an amide bond is used as PAAF.
Prepared in the same manner as in the case of 10 and CDS at 17 ° C.
The F-A curve of the ultrathin film obtained when developed on a CH ₂ COOH aqueous solution (5 × 10 ⁻⁵ mol·l ⁻¹ ) was measured. The result is shown in FIG. In this case, the limiting area per perfluoroalkyl group showed a value of 0.66 nm.

Example 2 Measurement of critical surface tension γ _c A solution of PAAF10 and PAAF20 was added to CDSCH ₂ C.
An ultrathin film on the water surface obtained by developing on an OOH aqueous solution (5 × 10 ⁻⁵ mol·l ⁻¹ ) (hereinafter referred to as PAAF1
0 / CD and PAAF20 / CD) are transferred onto a glass substrate at a surface pressure of 20 mN · m ^{−1 as} a single layer film and a multilayer film. For these, the contact angle with the n-alkane was measured, and the value of the critical surface tension γ _c obtained from the Zisman plot was calculated by the method of least squares. The results are shown in Table 1.

[0026]

[Table 1]

Example 3 Measurement of film thickness PAAF10 / CD and PAAF20 / obtained in Example 2
The film thickness of the Langmuir-Blodgett film of CD was measured by the following two methods.

(1) Measurement by the stylus method Part of the thin film was peeled off, and the level difference with the film was measured by the stylus method.
As a result, the thickness of one layer is 2.6 in PAAF10 / CD.
~ 4.2 nm, 2.8-4.9 for PAAF20 / CD
The value in nm was obtained.

(2) Measurement by X-ray diffraction Kα _{1 of} copper, λ = 1.54050, 40 kV, 30 mA
When an X-ray diffraction pattern was measured with, a diffraction pattern was observed. When the film thickness is calculated from the Bragg equation from this, the film thickness of one layer is about 4.4 nm in PAAF10 / CD, P
A value of about 4.2 nm was obtained with AAF20 / CD.

Example 4 Preparation of Fluorine-Containing Polymer Langmuir-Blodgett Film Incorporating p-Nitroaniline

A dilute methanol / benzene mixed solution of PAAF10 (concentration of perfluoroalkyl group: 0.5 × 1)
0 ^-3 mol·l ^-1 ) at 17 ° C in an aqueous solution of CDSCH ₂ COOH containing p-nitroaniline (CDSCH ₂ CO
OH concentration: 5 × 10 ⁻⁵ mol·l ⁻¹ , p-nitroaniline concentration: 3 × 10 ⁻³ mol·l ⁻¹ ) was applied to obtain an ultra thin film of a fluorine-containing polymer. This ultra-thin film on the water surface is applied to a calcium fluoride substrate and a quartz substrate with a surface pressure of 20 mN.
The sample was transferred at m ⁻¹ and the infrared absorption spectrum and the ultraviolet absorption spectrum were measured. As a result, in the infrared absorption spectrum, strong absorption of nitro group (1601, 1311 cm
^-1 ), but an absorption (380 nm) due to the π-π * transition of p-nitroaniline was observed in the ultraviolet absorption spectrum, and p
It was confirmed that -nitroaniline was introduced into this fluorine-containing polymer ultrathin film.

[0032]

INDUSTRIAL APPLICABILITY According to the present invention, a novel fluorine-containing polymer containing cyclodextrin is provided, which can be made into an ultra-thin film by the Langmuir-Blodgett method, and is an unprecedented ultra-thin film surface modifying substance Can be used as Since this film contains cyclodextrin, a compound capable of forming an inclusion compound with cyclodextrin can be introduced into the ultrathin film. Moreover, a perfluoroalkyl group, which is a functional group, is present on the surface of this film, and exhibits excellent low surface energy characteristic of a fluorine-containing group. Furthermore, by changing the modification ratio of the perfluoroalkyl group and the concentration of the cyclodextrin derivative (III) in the aqueous layer, the area occupied by one perfluoroalkyl group can be changed, and the surface state of this film is controlled. be able to. As described above, the present invention introduces a fluorine-containing group and a cyclodextrin into a polymer, and an unprecedented functional polymer ultrathin film in which the sequence is controlled intramolecularly or intermolecularly by the Langmuir-Blodgett method. It has an excellent effect that it can be manufactured.

[Brief description of drawings]

FIG. 1 is an FA curve of a Langmuir-Blodgett film of a fluorine-containing polymer compound according to the present invention (PAAF10 represents C
(When developed in a DSCH ₂ COOH aqueous solution).

FIG. 2 shows an FA curve of a Langmuir-Blodgett film of a fluorine-containing polymer compound according to the present invention (PAAF20 represents C
(When developed in a DSCH ₂ COOH aqueous solution).

Claims (4)

[Claims] 1. A compound represented by the general formula (I): (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, m represents a number of 10 to 1500, and n represents 0 <n.
≦ 0.4 m, p is a number satisfying 0 <p ≦ m−n, and k is a number from 5 to 8. ) A fluorine-containing polymer compound represented by: 2. A Langmuir-Blodgett film formed from the fluorine-containing polymer compound represented by the general formula (I). 3. A compound represented by the general formula (I): (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, m represents a number of 10 to 1500, and n represents 0 <n.
≦ 0.4 m, p is a number satisfying 0 <p ≦ m−n, and k is a number from 5 to 8. In producing a Langmuir-Blodgett film composed of a fluorine-containing polymer represented by the general formula (2), a general formula (II): (Wherein Rf, m and n have the same meanings as described above), the fluoropolymer represented by the formula (III) Of a Langmuir-Blodgett film of a fluorine-containing polymer represented by the general formula (I), which is developed on an aqueous solution of a cyclodextrin derivative represented by the formula (wherein k has the same meaning as described above). Production method. 4. A compound represented by the general formula (IV): (In the formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, m represents a number of 10 to 1500, and n represents 0 <n.
≦ 0.4 m, p is a number satisfying 0 <p ≦ m−n, k is a number from 5 to 8, and G is a compound capable of forming an inclusion compound with cyclodextrin. . ) A Langmuir-Blodgett film of a fluorine-containing polymer represented by