FLUORINE-CONTAINING POLYMER AND PROCESS FOR PREPARING THE SAME

Abstract: A fluorine-containing polymer represented by formula (I) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; R represents a hy­ drogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; p represents an integer of from 1 to 100; and Y represents a group represented by formula (II) or formula (III) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z represents an iodine atom, a sulfonate group, or a sulfate group, wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z′ represents an iodine atom, a bromine atom, a chlorine atom, or a hydroxyl group; and a process for prepar­ ing the same.

Description: FIELD OF THE INVENTION The present invention relates to a fluorine-containing polymer and a process for preparing the same. BACKGROUND OF THE INVENTION Hitherto, polymers containing fluorine are used as a releasing agent, an additive for a foam fire extinguisher, a foam stabilizer for expanded materials, a mixing assistant for resins, an antistatic agent, etc. as described, e.g., in Japanese Patent Publcation No. 11325/82. However, the performance thereof is not fully sufficiently for practical use. Furthermore, such conventional fluorine-containing polymers are water-insoluble, thus they cannot be used for the purpose of reducing surface tension of water. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a fluorine-containing polymer which is advantageously used as surface active agents. Another object of the present invention is to provide a process for preparing a fluorine-containing polymer which is advantageously used as surface active agents. As the result of various investigations conducted by the present inventors, it is found that the above and the other objects of the present invention are achieved by a fluorine-containing polymer having a specific repeating unit, and process for preparing the same. That is, the present invention is to provide a fluorine-containing polymer represented by formula (I) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; p represents an integer of up to 100; and Y represents a group represented by formula (II) or formula (III) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z represents an iodine atom, a sulfonate group, or a sulfate group, wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z¹ represents an iodine atom, a bromine atom, a chlorine atom, or a hydroxyl group, and a process for preparing the same. DETAILED DESCRIPTION OF THE INVENTION The present invention provides a process for preparing a fluorine-containing polymer represented by formula (IV) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; p represents an integer of up to 100; and Y¹ represents a group represented by formula (II) or formula (V) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z represents an iodine atom, a sulfonate group, or a sulfate group, wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z³ represents an iodine atom, a bromine atom, or a chlorine atom, the process comprising a step of ring opening polymerizing a cyclic iminoether represented by formula (VI) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms, by the use of a polymerization initiator represented by formula (VII) X―Z² (VII) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; and Z² represents a sulfonate group, a sulfate group, an iodine atom, a bromine atom, or a chlorine atom; and a process for preparing a fluorine-containing polymer represented by formula (VIII) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and p represents an integer of up to 100 the process comprising steps of (1) ring opening polymerizing a cyclic iminoether represented by formula (VI) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms, by the use of a polymerization initiator represented by formula (IX) X―Z⁴ (IX) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; and Z⁴ represents an iodine atom, a sulfonate group, or a sulfate group; and (2) reacting the thus obtained polymer with an aqueous alkaline solution. The fluorine-containing polymer according to the present invention, in which Y in formula (I) represents a group represented by formula (II) or formula (III) while Z¹ in formula (III) represents an iodine atom, a bromine atom, a chlorine atom, can be obtained by the step (1) only. In the step (2), when the polymer obtained in the step (1) has the propagating end group represented by formula (II), such polymer can be converted into the fluorine-containing polymer of the present invention in which Y in formula (I) is represented by formula (III) wherein Z¹ is a hydroxyl group by reacting with a aqueous alkaline solution. The number of the carbon atoms contained in the group represented by X is preferably from 5 to 15 in view of the performance as surface active agent of the polymer obtained. In the group represented by X, the number of the fluorine atoms is preferably the same number as the carbon atoms contained therein or more, and more preferably 1.5 times the number of the carbon atoms contained therein or more. The number of n is not limited, but if n is from 2 to 3, the raw material can be obtained easily. The number of the repeating units p can be controlled by adjusting the ratio of the polymerization initiator to the cyclic iminoether upon polymerization. The fluorine-containing polymer of the present invention preferably has a number of the repeating units p of 50 or less. As the polymerization initiator represented by formula (IV), any compounds having an ionic property, e.g., represented by (X)⁺·(Z²)⁻, and having no adverse effect on the ring opening polymerization of the present invention can be used. Upon polymerization, X⁺ attacks the nitrogen atom of the cyclic iminoether. Then, if Z² is an iodine atom, a sulfonate group, or a sulfate group, the corresponding onium salt is formed, and (Z²)⁻ becomes the counter ion of the propagating end group of the polymer (formula (II)). Examples of the group represented by X include groups represented by formula (X-1), (X-2), (X-3), (X-4), or (X-5) C i F 2i+1 (CH₂) j - (X-1) HC i F 2i (CH₂) j - (X-2) C i F 2i+1 (CH₂) k OCHR²CHR³- (X-3) C i F 2i+1 COOCH₂CHR³- (X-4) C i F 2i+1 (CH₂) k OCH₂CH(OH)CH₂- (X-5) wherein i represents an integer of from 4 to 22, j represents an integer of from 1 to 4, k represents 1 or 2, and R² and R³, which may be the same or different, each represents a hydrogen atom or a methyl group. Preferably, X represents a group represented by formula (X-1) above wherein j represents 2. Examples of the sulfonate group represented by Z include a trifluoromethane sulfonate group, a benzene sulfonate group, a p-toluene sulfonate group (tosyl group), etc. Examples of the sulfate group represented by Z include an alkyl sulfonate group such as a methyl sulfonate group, an ethyl sulfonate group, etc. Preferably, Z represents a p-toluene sulfonate group (tosyl group). In the ring opening polymerization of the step (1), the molar ratio of the cyclic iminoether to the polymerization initiator (iminoether/initiator) can be freely varied, but preferably is from 0.1/1 to 500/1, and more preferably from 0.5/1 to 50/1. The polymerization temperature is preferably from 0 to 200°C, and more preferably from 60 to 120°C. As the solvents used in the polymerization, an aprotic solvent such as dimethyl formamide, acetonitrile is preferably used. In the step (2), the aqueous alkaline solution preferably has a concentration of from 1 to 20 wt%, and preferably used in large excess based on the amount of the polymer obtained in the step (1). The reaction temperature in the step (2) is preferably from 10 to 50°C. The present invention will be described specifically in examples hereinafter, but the invention is not construed as being limited to the examples. EXAMPLE 1 A fluorine-containing polymer of the present invention was produced by the steps (1) and (2). Step (1) A mixture of 1.00 g (1.62 mmol) of a polymerization initiator represented by n-C₈F₁₇CH₂CH₂OTs (Ts represents a tosyl group), 1.60 g (16.2 mmol) of a cyclic iminoether represented by formula (A), and 5 ml of dimethylformamide was placed in a test tube provided with a magnetic stirrer and a three-way cock. Then the test tube was sealed and heated to 100°C for 100 hours while stirring. Thereafter, the reaction mixture was poured into a mixed solvent of diethyl ether and chloroform (1/1 by volume) to precipitate thus formed polymer. The polymer was collected by decantation, dissolved in chloroform, and repreciptated from the above mixed solvent, followed by drying under reduced pressure to obtain 1.66 g of yellow waxy polymer (yield: 64%). The results of a nuclear magnetic resonance (NMR) analysis of the onium salt at the propagating end of the polymer are indicated below. δ(ppm)= 2.20(b), 2.29(e), 2.40(d), 3.60(a), 4.53(c) (a) to (e) correspond to the hydrogen atoms in the following formula. (Ph represents a phenylene group.) Step (2) The waxy polymer obtained in the step (1) was added to 20 ml of a sodium hydroxide aqueous solution (5 wt%), and stirred for 30 minutes at 20°C. Then, the components other than the desired polymer were extracted by dichloromethane, and the polymer was dried under reduced pressure to obtain 1.50 g of the polymer A′ represented by formula (A′) (yield: 64%). The results of the analysis of the polymer A′ are indicated below. Average molecular weight: 1,600 Average number of repeating units (q): 11.5 NMR analysis: δ(ppm)= 1.4-2.3 (C-CH₂-C and C(O)-CH₃) 2.6-4.0 (-CH₂-CF₂- and N-CH₂) Infrared absorption spectrum (IR) analysis (cm⁻¹): 3,400 (ν OH ), 2,940, 1,620 (ν C=O ), 1,484, 1,422, 1,380 (ν CF ), 1,243, 1,205, 1,143 The molecular weight analysis was carried out by using an osmometer (Hitachi, Ltd., Model 117, solvent: chloroform, at 40°C). The average number of the repeating units was calculated from the molecular weight. The NMR analysis was carried out by using an NMR spectrometer (Hitachi, Ltd., Model R-200). The IR analysis was carried out by using an infrared absorption spectrometer (Hitachi, Ltd., Model 260-20). EXAMPLES 2 TO 4 The same procedures as in Example 1 including the steps (1) and (2) were repeated except that: 4.86 mmol of a cyclic iminoether represented by formula (B) was used instead of the cyclic iminoether of Example 1 (Example 2); 9.23 mmol of a cyclic iminoether represented by formula (C) was used instead of the cyclic iminoether of Example 1 (Example 3); and 3.24 mmol of a cyclic iminoether represented by formula (D) was used instead of the cyclic iminoether of Example 1 (Example 4). The thus obtained polymers in Examples 2, 3, and 4 were designated the polymers B′, C′, and D′, respectively. The polymers B′ to D′ were analyzed in the same manner as in Example 1, and the results obtained were indicated below. Polymer B′ Average molecular weight: 830 Average number of repeating units (q): 3.2 NMR analysis: δ(ppm)= 0.9-1.4 (C(O)-C-CH₃), 1.4-2.1 (C-CH₂-C), 2.1-2.6 (C(O)-CH₂), 2.7-4.1 (-CH₂-CF₂- and N-CH₂) IR analysis (cm⁻¹): 3,420 (ν OH ), 1,620 (ν C=O ), 1,483, 1,432, 1,380 (ν CF ), 1,240, 1,146, 1,065 Polymer C′ Average molecular weight: 770 Average number of repeating units (q): 2.5 NMR analysis: δ(ppm)= 0.8-1.2 (CH₃), 1.3-2.1 (C-CH₂-C), 2.2-2.8 (C(O)-CH and -CH₂-CF₂), 3.0-4.1 (N-CH₂) IR analysis (cm⁻¹): 3,500 (ν OH ), 2,960, 2,870, 1,632 (ν C=O ), 1,467, 1,380 (ν CF ), 1,220, 1,070 Polymer D′ Average molecular weight: 1,730 Average number of repeating units (q): 10.0 NMR analysis: δ(ppm)= 0.8-1.3 (CH₃), 1.4-2.2 (C-CH₂-C), 2.3-2.9 (-CH₂-CF₂), 2.9-4.2 (N-CH₂) IR analysis (cm⁻¹): 3,450 (ν OH ), 2,980, 2,945, 2,880, 1,630 (ν C=O ), 1,485, 1,450, 1,384 (ν CF ), 1,245, 1,085 EXAMPLE 5 A fluorine-containing polymer of the present invention was produced by the steps (1) and (2). Step (1) A mixture of 1.00 g (1.62 mmol) of a polymerization initiator represented by n-C₈F₁₇CH₂CH₂OTs, 0.14 g (1.64 mmol) of a cyclic iminoether represented by formula (E), and 10 ml of dimethylformamide was placed in a test tube provided with a magnetic stirrer and a three-way cock. Then the test tube was sealed and heated to 80°C for 40 hours while stirring. Thereafter, the reaction mixture was poured into a mixed solvent of diethyl ether and hexane (1/1 by volume) to precipitate thus formed polymer. The polymer was collected by decantation, dissolved in chloroform, and repreciptated from the above mixed solvent, followed by drying under reduced pressure to obtain 0.26 g of yellow waxy polymer (yield: 23%). The results of an NMR analysis of the onium salt at the propagating end of the polymer are indicated below. δ(ppm)= 2.31(d), 2.40(c), 2.20(a), 4.90(b) (a) to (d) correspond to the hydrogen atoms in the following formula. Step (2) The waxy polymer obtained in the step (1) was added to 20 ml of a sodium hydroxide aqueous solution (5 wt%), and stirred for 30 minutes at 20°C. Then, the components other than the desired polymer were extracted by dichloromethane, and the polymer was dried under reduced pressure to obtain 0.22 g of the polymer E′ represented by formula (E′) (yield: 23%). The results of the same analysis as in Example 1 of the polymer E′ are indicated below. Average molecular weight: 1,200 Average number of repeating units (q): 6.2 NMR analysis: δ(ppm)= 1.8-2.3 (C(O)-CH₃ 2.7-4.1 (-CH₂-CF₂- and N-CH₂) IR analysis (cm⁻¹): 3,400 (ν OH ), 1,620 (ν C=O ), 1,484, 1,422, 1,364 (ν CF ), 1,250, 1,010 EXAMPLE 6 A fluorine-containing polymer of the present invention was produced only by the step (1). A mixture of 1.62 mmol of a polymerization initiator represented by n-C₈F₁₇CH₂CH₂I, 32.4 mmol of a cyclic iminoether represented by formula (E), and 10 ml of dimethylformamide was placed in a test tube provided with a magnetic stirrer and a three-way cock. Then the test tube was sealed and heated to 80°C for 40 hours while stirring. Thereafter, the reaction mixture was poured into 200 ml of a mixed solvent of diethyl ether and hexane (1/1 by volume) to precipitate thus formed polymer. The polymer was collected by decantation, dissolved in chloroform, and repreciptated from the above mixed solvent, followed by drying under reduced pressure to obtain a polymer E″ represented by formula (E″). (yield: 88%). The results of the same analysis as in Example 1 of the polymer E″ are indicated below. Average molecular weight: 4,600 Average number of repeating units (s): 48 NMR analysis: δ(ppm)= 1.8-2.4 (C(O)-CH₃) 2.7-4.1 (-CH₂-CF₂- and N-CH₂) IR analysis (cm⁻¹): 2,920, 1,630 (ν C=O ), 1,480, 1,415, 1,360 (ν CF ), 1,240, 1,010, 740 EXAMPLE 7 The same procedures as in Example 6 including the step (1) were repeated except that 1.62 mmol of a cyclic iminoether represented by formula (F) was used instead of the cyclic iminoether of Example 6 to obtain the polymer F′ according to the present invention. The results of the same analysis as in Example 6 of the polymer F′ are indicated below. Average molecular weight: 760 Average number of repeating units (s): 1.9 NMR analysis: δ(ppm)= 0.8-1.4 (CH₃), 2.0-2.6 (C(O)-CH₂), 2.7-3.1 (-CH₂-CF₂-), 3.2-4.0 (N-CH₂) IR analysis (cm⁻¹): 3,410 (ν OH ), 2,920, 1,640 (ν C=O ), 1,443, 1,364 (ν CF ), 1,240, 1,036, 740, 690 EXAMPLE 8 A fluorine-containing polymer of the present invention was produced by the steps (1) and (2). Step (1) A mixture of 1.00 g (1.62 mmol) of a polymerization initiator represented by n-C₈F₁₇CH₂CH₂OTs, 0.58 g (8.10 mmol) of a cyclic iminoether represented by formula (G), and 5 ml of dimethylformamide was placed in a test tube provided with a magnetic stirrer and a three-way cock. Then the test tube was sealed and heated to 80°C for 8 hours while stirring. Thereafter, the reaction mixture was poured into a mixed solvent of diethyl ether and hexane (1/1 by volume) to precipitate thus formed polymer. The polymer was collected by decantation, dissolved in chloroform, and repreciptated from the above mixed solvent, followed by drying under reduced pressure to obtain a polymer. Step (2) The polymer obtained in the step (1) was added to 20 ml of a sodium hydroxide aqueous solution (5 wt%), and stirred for 30 minutes at 20°C. Then, the components other than the desired polymer were extracted by dichloromethane, and the polymer was dried under reduced pressure to obtain the polymer G′ according to the present invention. EXAMPLE 9 The polymers A′, B′, C′, D′, E′, E″, F′, and G′ obtained in Examples 1 to 8, respectively, each were dissolved in water to make 0.1 wt% aqueous solutions, and measured for the surface tension of the aqueous solutions by Wilhelmy method at 20°C, by using Kyowa CBVP Surface Tension Meter Al. The results obtained are mentioned in the following Table 1. From the results shown in Table 1 above, The fluorine-containing polymer according to the present invention can greatly reduce surface tension of water by an small amount. Therefore, the fluorine-containing polymer of the present invention is used advantageously as an additive for a foam fire extinguisher, a mixing assistant for resins, an antistatic agent, a foam stabilizer for expanded materials, a releasing agent, an antisticking agent, etc. Furthermore, by the process according to the present invention, the fluorine-containing polymer of the present invention can be prepared easily.

Claims: 1. A fluorine-containing polymer represented by formula (I) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; p represents an integer of up to 100; and Y represents a group represented by formula (II) or formula (III) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z represents an iodine atom, a sulfonate group, or a sulfate group, wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and Z¹ represents an iodine atom, a bromine atom, a chlorine atom, or a hydroxyl group. 2. A fluorine-containing polymer as in claim 1, wherein X represents formula (X-1) C i F 2i+1 (CH₂) j - (X-1) wherein i represents an integer of from 4 to 22; and j represents 2. 3. A fluorine-containing polymer as in claim 1, wherein said group represented by X has from 5 to 15 carbon atoms. 4. A fluorine-containing polymer as in claim 1, wherein said group represented by X contains the same number as the carbon atoms contained therein or more of fluorine atoms. 5. A fluorine-containing polymer as in claim 4, wherein said group represented by X contains 1.5 times the number of the carbon atoms contained therein or more of fluorine atoms. 6. A fluorine-containing polymer as in claim 1, wherein Z represents a p-toluene sulfonate group. 7. A fluorine-containing polymer as in claim 1, wherein p represents an integer of from 2 to 6. 8. A process for preparing a fluorine-containing polymer as defined in claim 1 said process comprising a step of ring opening polymerizing a cyclic iminoether represented by formula (VI) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms, by the use of a polymerization initiator represented by formula (VII) X―Z² (VII) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; and Z² represents a sulfonate group, a sulfate group, an iodine atom, a bromine atom, or a chlorine atom. 9. A process for preparing a fluorine-containing polymer as in claim 8, wherein the ratio of said cyclic iminoether to said polymerization initiator is from 0.1/1 to 500/1. 10. A process for preparing a fluorine-containing polymer as in claim 9, wherein the ratio of said cyclic iminoether to said polymerization initiator is from 0.5/1 to 50/1. 11. A process for preparing a fluorine-containing polymer as in claim 8, wherein the temperature at which said cyclic iminoether is ring opening polymerized is from 0 to 200°C. 12. A process for preparing a fluorine-containing polymer as in claim 11, wherein the temperature at which said cyclic iminoether is ring opening polymerized is from 60 to 120°C. 13. A process for preparing a fluorine-containing polymer represented by formula (VIII) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms; n represents an integer of from 2 to 3; and p represents an integer of up to 100 said process comprising steps of (1) ring opening polymerizing a cyclic iminoether represented by formula (VI) wherein R represents a hydrogen atom or an aliphatic group having from 1 to 3 carbon atoms, by the use of a polymerization initiator represented by formula (IX) X―Z⁴ (IX) wherein X represents a group containing a polyfluoroaliphatic group having from 3 to 26 carbon atoms; and Z⁴ represents an iodine atom, a sulfonate group, or a sulfate group; and (2) reacting the thus obtained polymer with an aqueous alkaline solution. 14. A process for preparing a fluorine-containing polymer as in claim 13, wherein the concentration of said aqueous alkaline solution is from 1 to 20 wt%. 15. A process for preparing a fluorine-containing polymer as in claim 13, wherein the temperature at which the thus obtained polymer is reacted with said aqueous alkaline solution is from 10 to 50°C.

Inventors: MIYAMOTO, MASATOSHI, SAEGUSA, TAKEO, SANO, YOSHIYUKI
Applicants: DAIKIN INDUSTRIES, LIMITED
Application year: 1987
Main classification: C08G73
IPC codes: C10N40, C10M107, B01F17, C09K3, C08G73