JPH0573765B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a novel fluorine-containing polymeric substance, a method for producing the same, and a Langmuir Blossom film thereof. [Prior Art] 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 materials to protect substrates. It is also excellent as a material for oxygen permeable membranes, and the oxygen permeability of the perfluoroalkyl group improves the selectivity of oxygen permeation. 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 an ultra-thin film, which is important as a surface modification material and a substrate protection plate. Also,
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 for improving the performance of the polymer as a surface modification material and oxygen separation membrane. Controlling the arrangement on a surface is not easy. The present inventor modified polyallylamine with a perfluoroalkyl group, and used this polymer to create an ultra-thin film with controlled molecular arrangement using the Langmuir-Blodget technique [Patent Application No. 1350, 1988].
However, when the introduction rate of perfluoroalkyl groups is high, the polymer solution becomes insoluble in the solvent, making it impossible to form a thin film, and this polymer solution has drawbacks such as gradual hydrolysis of amide bonds. [Purpose] The present inventor has conducted intensive research on a method for creating an ultra-thin film that utilizes the hydrophobicity of perfluoroalkyl groups, and has developed a polymer obtained by 1,1-dihydroperfluoroalkylation of the amino group of polyallylamine with a urea bond. We found that the compound is soluble even at a high modification rate of perfluoroalkyl groups, has excellent hydrolysis resistance, and is suitable as an ultra-thin film material. The present invention was completed by clarifying that the present invention has a specific sequence. [Configuration] According to the present invention, the general formula

[Formula, Rf represents a perfluoroalkyl group having 6 to 15 carbon atoms, m represents a number of 10 to 1500, and n represents 0
The number satisfies <n<0.6m. ) is provided. The fluorine-containing polymer compound according to the present invention can be obtained by reacting polyallylamine represented by the following general formula () with 1,1-dihydroperfluoroalkyl isocyanate represented by the general formula () according to the following formula. It is manufactured by

[Chemical formula] (In the formula, Rf, m and n have the same meanings as above.) The polyallylamine used in the above reaction was obtained by neutralizing polyallylamine hydrochloride (average molecular weight about 9000) with a base. . The modification reaction of polyallylamine can be carried out using a mixed solvent of dimethyl sulfoxide and benzene as a reaction solvent at a reaction temperature of 10°C to 50°C, preferably 15°C to 30°C. To carry out this reaction preferably, 1,
Add 1-dihydroperfluoroalkyl isocyanate. By changing the amount of 1,1-dihydroperfluoroalkyl isocyanate to be added, the 1,1-dihydroperfluoroalkyl group can be modified with a urea bond to polyallylamine at an arbitrary ratio. After stirring for several minutes to several hours, the reaction solution is concentrated, washed with water, and the resulting polymer compound is dried. The obtained fluorine-containing polymer was identified to be a fluorine-containing polyallylamine represented by the above general formula () based on the fluorine analysis value and the IR spectrum. This polymer is a polymer in which fluorine-containing groups are modified with urea bonds, and has better hydrolysis resistance than the previous modification method using amide bonds [Patent Application No. 1350 of 1988]. The fluorine-containing polyallylamine of the present invention having a modification rate of amino groups (hereinafter referred to as modification rate) of 60% or less is soluble in a mixed solvent of tolylfluoroethanol and benzene, and this dilute solution By spreading it on the water surface, a monomolecular film can be easily formed and a Langmuir Blossom film can be created. From the measurement of the surface pressure-area curve (FA curve) when this fluorine-containing polymer was spread on the water surface, it was found that the area occupied by one 1,1-dihydroperfluoroalkyl group decreased due to the decrease in the modification rate to polyallylamine. It can be seen that an ultra-thin film with a large size can be created. In addition, the modification rate of 1,1-dihydroperfluoroalkyl group to polyallylamine is 24
% or more, the area occupied by one 1,1-dihydroperfluoroalkyl group was found to be more than half of the cross-sectional area of the perfluoroalkyl group, 28 Å. This means that this thin film is 1,
It was found that this is an ultra-thin film with a new arrangement in which 1-dihydroperfluoroalkyl groups overlap. Furthermore, from the rise of the F-A curve, it can be seen that this Langmuir-Blodget film is a stable film. One layer or multiple layers of this ultra-thin film were scooped out onto a glass substrate, and the film thickness and critical surface tension γcdyn/cm for n-alkanes were determined. As a result, the modification rate to polyallylamine was 12, 16, 24 , 38% fluorine-containing polymer LB film showed a γc value of about 16 for one layer, and about 15 for three layers. In addition, the 58% modified polymer LB film has approximately 1 layer and 3 layers.
Only the γc value showed a small value. These γc values are lower than the γc value of polytetrafluoroethylene, which is 18.5, and can be said to be excellent values. Also,
Even when this film was heat-treated at 80°C, the γc value did not change significantly from that of the unheated thin film. In addition, the γc value of the 58% modified three-layer membrane decreased to 9.7 by soaking it in trifluoroethanol.
The 1,1-dihydroperfluoroalkyl groups are rearranged on the membrane surface using a fluorine-based solvent, and
It can be said that it exhibited excellent low surface energy properties. When the film thickness was measured by Talystep and X-ray diffraction, the thin film of polyallylamine modified by 12% was approximately 30 Å per layer, while that of polyallylamine modified by 24% or more was 40 to 100 Å per layer.
It can be said that the thickness is increased due to the overlapping of 1,1-dihydroperfluoroalkyl groups. [Effect] That is, according to the present invention, a long-chain 1,1-dihydroperfluoroalkyl group can be introduced into polyallylamine through a urea bond by arbitrarily changing the amount of 1,1-dihydroperfluoroalkyl isocyanate, which is a reagent. It can be modified by the percentage of Modification rate of amino groups in polyallylamine is 60%
The following fluorine-containing polymers are soluble and can be made into ultra-thin films by the Langmuir-Blodget method, and can be used as unprecedented ultra-thin film surface-modifying substances. In addition, this ultra-thin film has one 1,
The area occupied by the 1-dihydroperfluoroalkyl group and the film thickness can be controlled by the modification rate of the 1,1-dihydroperfluoroalkyl group to polyallylamine. Furthermore, this ultra-thin film has a modification rate of 1,1-dihydroperfluoroalkyl group to polyallylamine of 24
% or more, the film forms a monomolecular film with a structure in which 1,1-dihydroperfluoroalkyl groups are overlapped, and has a new molecular arrangement. Furthermore, the surface of these films contains perfluoroalkyl groups, which are functional groups, and exhibits lower surface energy properties than polytetrafluoroethylene. Previously, polyallylamine was modified with fluorine-containing groups using urea bonds with excellent hydrolysis resistance, and the Langmuir-Blodget method was used to create ultra-thin functional polymer films with controlled alignment within and between molecules. There are no examples. In this specification, the term "Langmeur Blossom film" refers to a monomolecular film or 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 1.14 g of metallic sodium was added to 30 ml of methanol, and after hydrogen was no longer generated, 4.94 g of polyallylamine hydrochloride (average molecular weight, approximately 9000) was added.
Cover and stir. The precipitated sodium chloride is removed by filtration, washed with 15 ml of methanol, and the washings are returned to the filtrate. Add more methanol to bring the solution volume to 50
ml and prepare a methanol solution of polyallylamine. Take 5.0 ml of this solution, remove the solvent under reduced pressure, and add 20 ml of dry dimethyl sulfoxide and 12 ml of dry benzene under a nitrogen atmosphere to make a homogeneous solution. While stirring this solution vigorously, add 0.125 g of 1,1-dihydroperfluorononyl isocyanate.
50ml of dry dimethyl sulfoxide and dry benzene
Dissolve in 30ml of mixed solvent and add at once. At this time, a part of the fluorinated polyallylamine is precipitated. The solvent was removed from the reaction mixture under reduced pressure, and the polymer was further washed with ether and water and dried to obtain a polymer in which 16% of the amino groups in polyallylamine were modified with 1,1-dihydroperfluorononyl groups by urea bonds. Ta. The obtained polymer was confirmed by infrared absorption spectrum, which showed strong absorption at 1660 and 1585 cm ^-1 for urea bonds and 1300 to 1100 cm ^-1 for carbonate-fluorine bonds. Furthermore, the modification rate of the fluoroalkyl group was determined from the fluorine analysis value of 38.7%. In a similar manner, 0.298 g of 1,1-dihydroperfluorononyl isocyanate was used for 3.0 ml of a methanol solution of polyallylamine to obtain a polymer compound with a fluoroalkyl group modification rate of 24% (fluorine analysis value 45.1%). . Example 2 In the same manner as in Example 1, a fluoroalkyl group-modified polymer compound was synthesized using 0.057 g of 1,1-dihydroperfluorononyl isocyanate per 5.0 ml of a methanol solution of polyallylamine. 52.5 mg of the obtained polymer compound was added to 100 ml of trifluoroethanol, stirred, and the insoluble components were filtered out. The filtrate was removed from the solvent under reduced pressure. The elementary analysis value was 34.6%). In a similar manner, 0.298 g of 1,1-dihydroperfluorononyl isocyanate was used for 3.0 ml of a methanol solution of polyallylamine to obtain a polymer compound with a fluoroalkyl group modification rate of 38% (fluorine analysis value 51.5%). Ta. Example 3 A fluoroalkyl group-modified polymer compound was obtained in the same manner as in Example 2 using 0.296 g of 1,1-dihydroperfluorononyl isocyanate per 2.0 ml of a methanol solution of polyallylamine. 150 mg of this polymer compound was washed with a mixed solvent of 10 ml of trifluoroethanol and 50 ml of benzene to remove polymers with a low fluorination rate, resulting in a polymer compound with a fluoroalkyl group modification rate of 58% (fluorine analysis value 56.3%). I got it. Example 4 Preparation of Langmeur Blossom film The fluorine-containing polymers synthesized in Examples 1, 2, and 3 were evaluated at the modification rate of each fluoroalkyl group (M
%) is abbreviated as PAAURF(M). In the Langmiur Blosget method,
Surface pressure-area relationship (F-A curve) when dilute mixed solutions of trifluoroethanol and benzene of PAAURF12, 16, 24, 38, and 58 were prepared and each of these solutions was spread on a water surface at 17°C. The results of the measurements are shown in Figure 1. With this result,
Area occupied by one molecule of fluoroalkyl group in the membrane,
So the limiting areas are PAAURF12, 16, 24, 38, 58
The values were 40, 28, 14, 13, and 12 ^Å2, respectively, in that order. This ultra-thin film on the water surface was placed on a glass substrate at a surface pressure of 20
It was transferred as a monomolecular film and a cumulative film at mN·m ^-1 . These were transparent films. Example 5 Measurement of critical surface tension γc For the monomolecular film and cumulative film transferred onto the glass substrate in Example 4, a film soaked in trifluoroethanol, and a heat-treated film, n-
The contact angle with the alkane was measured, and the critical surface tension γc value obtained from the Zisman plot was calculated using the least squares method. These results are shown in the table.

[Table] Ivy.
2) 5-Layer Example 6 Measurement of Film Thickness The film thickness of the 10-layer cumulative film of the Langmuir Blossom film obtained in Example 4 was measured using the following two methods. (1) Measurement using Talystep: Part of the thin film was peeled off and the difference in level with the film was measured using Talystep.
A value of 250 ± 50 Å was obtained, PAAURF24, 38, 58
For the thin film, the film thickness was thick, and values of 400 to 1000 Å were obtained. The film thickness of one layer is one-tenth of the above film thickness. (2) Measurement by X-ray diffraction: Kα ₁ , λ= of copper
When the X-ray diffraction pattern was measured at 1.54050, 40 Kv, and 30 mA, a diffraction pattern was observed. If the film thickness is calculated from this using Bragg's formula, the film thickness of one layer is
About 28Å for PAAURF12 and about 35Å for PAAURF16
Å, and for PAAURF24 and 58 it was about 55-90 Å.

[Brief explanation of the drawing]

FIG. 1 shows the F-A curve of the fluorine-containing polymer Langmeur Blossom film according to the present invention.

Claims (1)

[Claims] 1 General formula
The number satisfies <n<0.6m. ) A fluorine-containing polymer compound represented by 2 General formula
The number satisfies <n<0.6m. ), a polyallylamine represented by the general formula [formula] (where m has the same meaning as above) and a polyallylamine represented by the general formula RfCH ₂ NCO (in the formula , Rf has the same meaning as above). 3 General formula
The number satisfies <n<0.6m. ) is expressed by Langmeur Blosget membrane.