Fluorine-containing polyether and nonionic surfactant comprising the same

Abstract: A fluorine-containing polyether of the formula: R f -X-A (I) or A-X-R′ f -X-A (II) wherein R f and R′ f are a group containing a perfluoroalkyl polyether group, X is -CF₂COO-, -C₂F₄COO- or -CF₂CF₂ and A is a group containing a polyalkylene glycol group, can be used as a nonionic surfactant which is compatible with a perfluoroalkyl polyether.

Description: The present invention relates to a novel fluorine-containing polyether and a nonionic surfactant comprising the same fluorine-containing polyether. Since a perfluoroalkyl polyether has high electrical insulation and non-flammability, it is used in various applications, particularly an electrical application. However, the perfluoroalkyl polyether is statically charged to collect dusts. Therefore, a surfactant which can be used as an antistatic agent in the perfluoroalkyl polyether is required. However, conventional surfactants are not compatible with the perfluoroalkyl polyether and cannot be used as the antistatic agent. US-A-3,644,492 discloses and claims fluorine-containing polyethers, for example as represented by the following formula (example 1): F(CF₂CF₂CF₂O)[C₃F₆O]₈C₂F₄COO(CH₂CH₂O)₇CH₃ The known compounds can be used as non-ionic surfactants. An object of the present invention is to provide a fluorine-containing polyether which can be used as the surfactant compatible with the perfluoroalkyl polyether. The present invention comprises a fluorine-containing polyether of the formula: R f -X-A (I) or A-X-R' f -X-A (II) wherein R f is a group containing at least one repeating unit of the formula: -CF₂CF₂CF₂O- R' f is a group containing at least one repeating unit selected from the group consisting of a repeating unit of the formula: -CF₂CF₂CF₂O- (a) a repeating unit of the formula: -CF₂CF₂O- (b) and a repeating unit of the formula: -CF₂O- (c) provided that at least one of the repeating units (a) and (b) is contained and the total number of the repeating units (a), (b) and (c) is at least three, X is -CF₂COO-, -C₂F₄COO-or -CF₂CF₂- and A is a group containing a polyalkylene glycol group. Also, the present invention provides a non-ionic surfactant comprising said fluorine-containing polyether. The figure is an IR chart of the fluorine-containing polyether of Example 1. The R f group is, for example, wherein l is 1 to 500, m is 0 to 200 and n is 0 to 200. The R' f group is, for example, -O(CF₂CF₂CF₂O) m CF₂CF₂CF₂CF₂(OCF₂CF₂CF₂) m O- wherein m is 1 to 200. An alkylene glycol which forms the polyalkylene glycol group in the A group may be ethylene glycol or propylene glycol. The polyalkylene glycol group contains at least one repeating unit selected from the group consisting of a repeating unit of the formula: -C₂H₄O- and a repeating unit of the formula: -C₃H₆O- provided that total number of said repeating units is 2 to 500. The repeating unit: -C₃H₆O- includes -CH₂CH₂CH₂O- and -CH(CH₃)CH₂O-. The repeating unit: -C₂H₄O- is usually -CH₂CH₂O-. The A group is, for example, -(CH₂CH₂O) m CH₃ wherein m is 2 to 500, -(CH₂CH₂O) m H wherein m is 2 to 500, or wherein m is 2 to 500. Specific examples of the fluorine-containing polyethers (I) and (II) are F(CF₂CF₂CF₂O) m CF₂CF₂COO(CH₂CH₂O) n CH₃ wherein m is 2 to 200, preferably 9 on the average and n is 2 to 500, preferably 9 on the average, wherein m + n is 1 to 200, preferably 10 on the average and l is 2 to 500, preferably 9 on the average, -[CF₂CF₂-(OCF₂CF₂CF₂) m -OCF₂CF₂-(CH₂CH₂O) n -CH₃]₂ wherein m is 2 to 200, preferably 10 on the average and n is 2 to 500, preferably 9 on the average, and wherein m is 2 to 200, preferably 20 on the average and n is 2 to 500, preferably 10 on the average. The fluorine-containing polyether (I) can be prepared by reacting a fluorine-containing compound of the formula: R f -X-H with a compound of the formula: HO-A or reacting a fluorine-containing compound of the formula: R f -X-I with a compound of the formula: M-A wherein A, R f and X are the same as described above and M is an alkaline metal. The fluorine-containing polyether (II) can be prepared by reacting a fluorine-containing compound of the formula: H-X-R′ f -X-H with a compound of the formula: HO-A wherein A, R′ f and X are the same as described above. The reaction is usually carried out at a temperature of 20 to 150°C for 1 to 10 hours. The fluorine-containing polyether according to the present invention is water-soluble and can be used as a nonionic surfactant. The nonionic surfactant according to the present invention can be used as an antistatic agent, a surfactant for polymerization, car wax and an additive for film. The fluorine-containing polyether according to the present invention is compatible with a perfluoroalkyl polyether and thus can be used as an antistatic agent for the perfluoroalkyl polyether. It can improve properties of a resin surface when used as an additive for resin, particularly a resin film. PREFERRED EMBODIMENTS OF THE INVENTION The present invention is illustrated by following Examples. Example 1 To the fluorine-containing carboxylic acid: F(CF₂CF₂CF₂O) m CF₂CF₂COOH wherein m is 30 on the average (51.3 g, 10 mmol), the polyethylene glycol methyl ether: CH₃(OCH₂CH₂) n OCH₂CH₂OH wherein n is 8 on the average (10 g, 25 mmol) (Uniox 400 manufactured by Nippon oil & fats Co., Ltd.) was added and stirred. Then, concentrated sulfuric acid (5 ml) was added and the reaction was carried out at 100°C for 6 hours while stirring. The completion of the reaction was confirmed by disappearance of the absorption peak at 1780 cm⁻¹ for the carboxylic acid and appearance of the absorption peak at 1700 cm⁻¹ for the ester linkage in IR analysis. After the completion of the reaction, the reaction product was washed with a 2% aqueous solution of NaHCO₃ (50 ml) twice. A lower phase was separated and filtrated through a filter having a pore diameter of 0.2 µm to obtain the fluorine-containing polyether: F(CF₂CF₂CF₂O) m CF₂CF₂COO(CH₂CH₂O) n+1 CH₃ wherein m is 30 and n is 8 on the average. Yield: 47 g (87%). The IR chart of the resultant fluorine-containing polyether is shown in Figure. Example 2 A perfluoropolyether (Demnum S-65 manufactured by Daikin Industries Ltd.) (10 g) was mixed with the fluorine-containing polyether: F(CF₂CF₂CF₂O) m CF₂CF₂COO(CH₂CH₂O) n+1 CH₃ wherein m is 30 and n is 8 on the average prepared in Example 1 (0.3 g), and then dissolved in trichlorotrifluoroethane (100 g). A slide glass (15 cm x 5 cm) was dipped in the solution, and dried in the air to form a film having a thickness of not less than 10 µm on the slide glass. A potential difference was measured by a potentiometer, while violently rubbing the film with a styrene resin. The potential difference was 0 V. Comparative Example A film was formed and a potential difference was measured in the same manner as in Example 2 but the fluorine-containing polyether was not used. The potential difference was 400 V.

Claims: A fluorine-containing polyether of the formula: R f -X-A (I) or A-X-R' f -X-A (II) wherein R f is a group containing at least one repeating unit of the formula: -CF₂CF₂CF₂O- R' f is a group containing at least one repeating unit selected from the group consisting of a repeating unit of the formula: -CF₂CF₂CF₂O- (a) a repeating unit of the formula: -CF₂CF₂O- (b) and a repeating unit of the formula: -CF₂O- (c) provided that at least one of the repeating units (a) and (b) is contained and the total number of the repeating units (a), (b) and (c) is at least three, X is -CF₂COO-, -C₂F₄COO-or -CF₂CF₂- and A is a group containing a polyalkylene glycol group. The fluorine-containing polyether according to claim 1, wherein the polyalkylene glycol group in the A group contains at least one repeating unit selected from the group consisting of a repeating unit of the formula: -C₂H₄O- and a repeating unit of the formula: -C₃H₆O- provided that total number of said repeating units is 2 to 500. The fluorine-containing polyether according to claim 1, therein the R f group is F(CF₂CF₂CF₂O) m - wherein m is an integer of 2 to 200, the X group is -C₂F₄COO- and the A group is -(CH₂CH₂O) n CH₃ wherein n is an integer of 2 to 500. A nonionic surfactant comprising the fluorine-containing polyether according to claim 1.

Inventors: ISHIKAWA SUEYOSHI, TOHZUKA TAKASHI, YAMAMOTO IKUO, ISHIKAWA, SUEYOSHI, TOHZUKA, TAKASHI, YAMAMOTO, IKUO
Applicants: DAIKIN IND LTD, DAIKIN INDUSTRIES, LIMITED
Application year: 1989
Main classification: C08G65
IPC codes: C07C41, C07C67, C08G65, C07C43, B01F17, C09K3, C07C69