JPH0430409B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to the production of a fluorine-containing polymer, which is characterized by polymerizing a fluorine-containing unsaturated ester monomer such as a fluorine-containing acrylate or a fluorine-containing methacrylate in the presence of an organolithium catalyst. (Industrial Application Field) Fluorine-containing acrylates or fluorine-containing methacrylates provide industrially important polymers.
In particular, fields where the functionality of fluorine-based compounds can be utilized, such as fiber treatment agents that take advantage of the water and oil repellency of fluorine-based materials, fluorine-based rubber or plastic materials that take advantage of their chemical and heat resistance, and materials that take advantage of their weather resistance. Applications to film materials and paints, optical materials such as optical fibers that take advantage of low refractive properties, resist materials, and medical materials have been studied and many have been put into practical use. (Prior Art) The polymerization method of the monomers currently in practical use is radical polymerization. oil-soluble peroxides, such as benzoyl peroxide,
Methods include solution polymerization in an organic medium, suspension polymerization in an aqueous system, or emulsion polymerization using an azo compound such as azobisisobutyronitrile, ammonium persulfate, or an inorganic peroxide such as hydrogen peroxide. Common. (Problems to be Solved by the Invention) On the other hand, it is known that hydrocarbon acrylates or methacrylates undergo anionic polymerization using organometallic catalysts such as n-butyllithium. For example, methyl methacrylate undergoes anionic polymerization in toluene with an n-butyllithium catalyst to give a polymer. However, there have been only a few attempts to anionically polymerize fluorine-based acrylates or methacrylates. Based on the above facts, we applied various anionic polymerization catalysts to the fluorine-containing acrylate and fluorine-containing methacrylate monomers and found that certain types of organolithium catalysts have polymerization activity. They discovered this and completed the present invention. (Means for Solving the Problems) The fluorinated acrylate and fluorinated methacrylate monomers used in the present invention have the general formula [However, in the formula, R ₁ =H or CH ₃ .

[Formula] n is an integer from 0 to 5. R _f is a polyfluoroalkyl group having 1 to 20 carbon atoms. R' is a lower alkyl group, H or R _f group. ] It is a compound shown by, specifically 2, 2, 2
-trifluoroethyl acrylate, 2,2,2
-trifluoroethyl methacrylate, 1H,
1H, 3H-tetrafluoropropyl acrylate, 1H, 1H, 3H-tetrafluoropropyl methacrylate, hexafluoroisopropyl acrylate, hexafluoroisopropyl methacrylate, 1H, 1H-heptafluorobutyl acrylate, 1H, 1H-heptafluorobutyl methacrylate, heptafluoro Isopropyl acrylate, heptafluoroisopropyl methacrylate, 1H, 1H, 5H-octafluoropentyl acrylate, 1H, 1H, 5H-octafluoropentyl methacrylate, 1H, 1H, 7H-dodecafluoroheptyl acrylate, 1H, 1H, 7H
-dodecafluoroheptyl methacrylate, 1H,
1H-pentadecafluorooctyl acrylate,
Examples include 1H, 1H-pentadecafluorooctyl methacrylate. The organic lithium compound that is a polymerization catalyst has the general formula R _x R _y Li [where, R _x is C _n H _2n+1 (−CZ ₁ Z ₂ −CH ₂ )− _p , Z ₁ , Z ₂
is hydrogen or a phenyl group, and m is an integer of 1 or more. p
is an integer greater than or equal to 0. R _y is

[Formula], Z ₁ is hydrogen or phenyl group. ] It is a compound shown by, specifically, 1,1-diphenylhexyllithium obtained by the reaction of n-butyllithium and diphenylethylene, n
-1-phenylhexyllithium and polystyryllithium compounds obtained by the reaction of butyllithium and styrene, n-butyllithium and α
- 1-phenyl-1-methylhexyllithium and poly-α-methylstyryllithium obtained by the reaction of methylstyrene, α- produced by the reaction of lithium metal and α-methylstyrene
Examples include methylstyrene tetramer lithium salt. These organolithium compounds are usually used in the form of a hydrocarbon solution such as n-hexane, n-heptane, benzene, or toluene. The manufacturing method of the present invention will be described in detail below. Fluorine-containing acrylates and fluorine-containing methacrylates are purified by distillation under a nitrogen or helium stream, and those with a purity of 99.5% or higher that have been completely deoxidized are used. It is preferable to dehydrate trace amounts of water using a molecular sieve or the like to suppress polymerization. Organic lithium compounds include alkyl lithium such as n-butyl lithium which is commercially available or synthesized by conventional methods, purified 1,1-diphenylethylene,
Synthesized by reaction with styrene etc. Since organolithium compounds react sensitively with air and moisture in the air, they are stored in a sealed nitrogen-based container, but preferably used early after synthesis. A suitable method is to react an alkyllithium and a reaction reagent in a solvent to synthesize the desired organolithium compound, and then add a fluorine-containing unsaturated ester monomer. The amount of the organic lithium compound added is preferably 0.1 to 20 mol% based on the fluorine-containing unsaturated ester monomer. The solvent is preferably an aromatic hydrocarbon or an aliphatic hydrocarbon in terms of catalyst adjustment and polymerization activity for polymer production, and polar solvents such as diethyl ether and tetrahydrofuran do not allow polymerization to proceed even with similar aprotic organic solvents. The appropriate polymerization temperature and catalyst adjustment temperature are -78°C to 100°C, preferably -20°C to 80°C. The polymerization time is not limited and is determined by the type of organolithium catalyst or the combination of the unsaturated ester monomer and the catalyst. In order to terminate the polymerization, a small amount of a protic organic solvent such as methanol, ethanol, isopropanol, etc. is added to the polymerization system. The resulting polymer is washed with an organic solvent such as methanol, filtered repeatedly, and dried. (Function) The above-mentioned fluorine-containing ester monomers may be polymerized singly or in combination of two or more, and may be copolymerized with monomers that are polymerized with organic lithium compounds such as hydrocarbons styrene and butadiene. Good too. Furthermore, the organolithium catalyst of this polymerization system can be extended to polymer catalysts such as polystyryllithium, and block copolymers such as those in which a fluorine-containing unsaturated ester monomer chain is connected to a polystyrene polymer chain can also be produced. Thus, examples of uses of fluorine-containing polymers include water and oil repellents, resist materials, molding materials such as sheets and films, fluorine-containing rubbers, paints, adhesives, and the like. The present invention will be specifically explained below using Examples. Example 1 A glass reaction tube with a capacity of 50 ml was dried and replaced with nitrogen, and 20 ml of purified toluene, 20 mmol of trifluoroethyl methacrylate, and 0.4 mmol of 1,1-diphenylhexyllithium were charged in this order under a nitrogen stream, and the tube was heated at -20°C. Polymerization was carried out for 5 days. To terminate the polymerization, the polymerization system was opened to methanol, and the resulting polymer was filtered and vacuum-dried. The polymer yield was 2.0 g, and the yield was 59.4%. The intrinsic viscosity [η] of the polymer measured in a chloroform solution at 25°C was 0.105. In the infrared absorption spectrum of the polymer, C=0 was observed at 1740 cm ^-1 and C-F absorption was observed at 1100 to 1400 cm ^-1 . The ¹ H-NMR spectrum (TMS) of the deuterated acetone solution shows peaks of -CH ₃ at 1.1 ppm, main chain -CH ₂ - at 2.1 ppm, and side chain -CH ₂ - at 4.4 ppm. The area ratio was 3:2:2. Example 2 Polymerization was carried out at 60° C. for 11 days in the same manner as in Example 1. The polymer yield was 1.13 g, and the yield was 33.7%. The thermal decomposition initiation temperatures of the polymers obtained in Examples 1 and 2 were both 200°C or higher, and the glass transition temperatures were about 78°C. Comparative Example 1 Polymerization was carried out in the same manner as in Examples 1 and 2 by changing the solvent to tetrahydrofuran, but no polymer was produced. Comparative Example 2 Polymerization was carried out in the same manner as in Example 1 using n-butyllithium as a catalyst instead of 1,1-diphenylhexyllithium, but the polymer yield was 0.14 g and the yield was 4.2%. Example 3 In the same manner as in Example 1, 20 ml of toluene, 20 mmol of hexafluoroisopropyl methacrylate,
0.4 mmol of 1,1-diphenylhexyllithium was sequentially charged, and polymerization was carried out at -20°C for 6 days. The polymer yield was 3.24 g, and the yield was 68.7%. twenty five
The intrinsic viscosity [η] of the polymer measured in a chloroform solution at ℃ was 0.015. The infrared absorption spectrum of the polymer is C=0 at 1760 cm ^-1 and 1100 ~
Absorption of C-F was observed at 1400 cm ^-1 . ¹ H-NMR spectrum of deuterated acetone solution (:
TMS) is −CH ₃ at 1.2ppm, −CH ₂ − at 2.2ppm,
A -CH peak was observed at 6.4 ppm, and their area ratio was 3:2:1. Example 4 Polymerization was carried out in the same manner as in Example 3 at room temperature for 11 days. The polymer yield was 2.52 g, and the yield was 53.4%. The thermal decomposition initiation temperatures of the polymers obtained in Examples 3 and 4 were both 300°C or higher, and the glass transition temperatures were about 85°C. Comparative Example 3 Polymerization was carried out in the same manner as in Examples 3 and 4 by changing the solvent to tetrahydrofuran, but no polymer was produced. Comparative Example 4 Polymerization was carried out in the same manner as in Example 1 using n-butyllithium as a catalyst instead of 1,1-diphenylhexyllithium, but the polymer yield was 0.72 g and the yield was 15.3%. Example 5 A glass reaction tube with a capacity of 100 ml was dried and replaced with nitrogen, and 50 ml of purified toluene, 20 mmol of styrene, and 2 mmol of n-butyllithium were sequentially charged under a nitrogen stream, and polymerized at room temperature for one day to produce a polystyllithium compound. I let it happen. Next, this polymerization system was added with trifluoroethyl methacrylate 20 purified under a nitrogen stream.
mmol was added and the polymerization was continued for a further 3 days. To terminate the polymerization, the polymerization system was opened to methanol, and the resulting polymer was filtered and washed, followed by vacuum drying. The polymer yield was 5.3 g, and the yield was 77.9%. The IR spectrum of the resulting polymer showed both trifluoroethyl methacrylate polymer and polystyrene peaks. Example 6 In the same manner as in Example 1, 20 ml of toluene, 20 mmol of trifluoroethyl acrylate, and 0.4 mmol of 1,1-diphenylhexyllithium were charged in this order.
Polymerization was carried out at -20°C for 6 days. Polymer yield is
0.37g, yield 12%.

Claims (1)

[Claims] 1. General formula [However, in the formula, R ₁ = H or CH ₃ ,
[Formula], n is an integer from 0 to 5. R _f is a polyfluoroalkyl group having 1 to 20 carbon atoms. R' is a lower alkyl group, H or R _f group.] A method for producing a fluorine-containing polymer, which comprises polymerizing a fluorine-containing unsaturated ester monomer represented by the following formula in the presence of an organolithium catalyst. 2 General formula R _x R _y Li [However, R _x is CmH _2n+1 (−CZ ₁ Z ₂ −CH ₂ )− _p , Z ₁ ,
Z ₂ is hydrogen or a phenyl group, and m is an integer of 1 or more.
p is an integer of 0 or 1 or more. R _y is [Formula], Z ₁ is hydrogen or phenyl group. ] The method according to claim 1, characterized in that an organolithium catalyst represented by the following is used. 3. The method according to claims 1 and 2, characterized in that aromatic hydrocarbons or aliphatic hydrocarbons are used as the polymerization solvent.