JPS6359405B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluorine-containing segmented polymer and a method for producing the same, particularly a multi-component segment comprising at least two types of polymer chain segments, at least one of which is a fluorine-containing polymer chain segment. The present invention relates to chemical polymers and methods for producing the same.

The fluorine-containing segmented polymer that is the object of the present invention basically consists of an iodine atom liberated from an iodide compound having an iodine atom bonded to a carbon atom, a residue obtained by removing the iodine atom from the iodide compound, and the iodine atom. It consists of at least two types of polymer chain segments (at least one of which is a fluorine-containing polymer chain segment) interposed between the atoms and the residues. In other words, the fluorine-containing segmented polymer of the present invention basically consists of a chain consisting of at least two polymer chain segments and an iodide compound having iodine atoms bonded to carbon atoms present at both ends of the chain. It consists of an iodine atom and a residue obtained by removing the iodine atom from the iodide compound as essential components. That is, a typical structure of the fluorine-containing segmented polymer of the present invention can be represented by _the following formula: The removed residues A, B, ... are respectively polymer chain segments (at least one of which is a fluorine-containing polymer chain segment), I
represents an iodine atom liberated from the iodide compound, and n represents the number of bonds of Q (corresponding to the number of iodine atoms removed from the iodide compound). ] Polymers having such a structure are generally called block or graft polymers. Conventionally, these have been synthesized by various methods, such as the sequential growth method used in the production of living polymers, the coupling method in which two or more types of polymers are coupled, the polyaddition or polycondensation method using terminal functional groups, Radical polymerization methods using polymer initiators or polymer transfer agents are known. While all of these methods require a prepolymer having a specific functional group at the end, various difficulties are generally involved in synthesizing such a prepolymer with high purity.

On the other hand, various methods are already known for producing fluorine-containing segmented polymers having two or more types of polymer chain segments, at least one of which is a fluorine-containing polymer chain segment. . For example, a method for producing blocked telomers having low molecular weight polymer chain segments using Hg or ultraviolet rays as reaction accelerators (U.S. Pat. No. 3,900,380), A method for producing a block copolymer by polymerizing an unsaturated compound (Japanese Patent Application Laid-Open No. 47-6193), a method for producing a co-telomer by reacting a bromine-containing telomer of tetrafluoroethylene with ethylene (Japanese Patent Application Laid-Open No. 1983-1999)
50-30984) are known. Also,
A method of telomerizing fluoroolefins using polyfluoroalkyl iodide as a telogen in the presence of a radical initiator is also well known (for example, "telomerization" US Naval Res.Rab.Rept.PB131930 , UK Patent No. 824229, etc.).

JP-A-53-86786 discloses a method for producing a fluorine-containing segmented polymer using a radical method, which is different from the above-mentioned telomerization. A fluorine-containing multi-segmented polymer of molecular species that could not be obtained is provided.

The method described in the above publication is applicable because the carbon-iodine bond in the iodide compound is a relatively weak bond, easily radically cleaved by a radical source, and the radicals generated by the cleavage are highly reactive. In the presence of radically polymerizable monomers, the addition-growth reaction can occur, and the chain reaction is subsequently terminated by the so-called chain transfer reaction, which abstracts iodine from the iodide compound. Since the bond between the polymer end and iodine has the same reactivity as the carbon-iodine bond of the iodide compound, it is easily radicalized again by a radical generating source, and its addition growth reaction occurs in the presence of other radically polymerizable monomers. This is based on the knowledge that it is possible to carry out this process, and it is possible to make the polymer chain of a polymer continue as if it were a growing living terminal in ionic polymerization.

The present invention is based on the invention described in JP-A-53-86786, and has been made for the purpose of providing a new fluorine-containing segmented polymer that is not described in the same publication. The gist is: Formula: Q[-(A ₁ -...-A _n )I] _o [where Q is a residue obtained by removing at least one iodine atom from an iodide compound, and A ₁ to A _n are each a polymer chain. segment, m is 2 or 3,
n represents a number corresponding to the number of iodine atoms removed from the iodide compound. However, if m is 2, one of A ₁ and A ₂ , or if m is 3, A ₁
One or two of ~ _A3 are (1) vinylidene fluoride/hexafluoropropylene or pentafluoropropylene/tetrafluoroethylene (molar ratio 45-90:5-50:0-35) polymer and (2)
Elastomeric random polymer chains of molecular weight 30000-1200000 selected from perfluoro( _C1 - _C3 alkyl vinyl ether)/tetrafluoroethylene/vinylidene fluoride (molar ratio 15-75:0-85:0-25) polymers The remaining polymer chain segments are (3) ethylene/tetrafluoroethylene/hexafluoropropylene, pentafluoropropylene, 3,3,3-trifluoropropylene-1,2-trifluoromethyl-3,3,3 -Trifluoropropylene-1
or perfluoro( _C1 - _C3 alkyl vinyl ether) (molar ratio 35-60:60-35:1-30) polymers with a molecular weight of 3,000-400,000, non-elastomeric random polymer chain segments, and have elastomeric properties. The weight ratio of random polymer chain segments to non-elastomeric random polymer chain segments is 40-95:5-60. ] is indicated.

Exists in fluorine-containing segmented polymers.

The fluorine-containing segmented polymer provided by the present invention basically consists of a chain consisting of at least two types of polymer chain segments, an iodine atom and an iodide compound bonded to both ends of the chain, and at least one iodine atom from an iodide compound. Consists of residues excluding atoms as essential constituents. Therefore, the at least two types of polymer chain segments are different from each other (for example, the structures and compositions of the monomer units that constitute them are different) from the adjacent polymer chain segments, and each polymer Although each chain segment has a molecular weight of 3000 or more, at least one polymer chain segment has a molecular weight of 3000 or more.
30,000 or more, excluding the so-called telomer region. Furthermore, in the case where a polymerizable double bond exists in the iodide compound, the residue obtained by removing at least an iodine atom from the iodide compound is a monomer constituting the polymer chain segment or some substitution derived from the iodide compound. It is possible to have a certain amount of time.

The fluorine-containing segmented polymer of the present invention not only exhibits excellent properties as a thermoplastic rubber, but also contains a third monomer in the non-elastomeric polymer chain segment. can be adjusted, and the molding temperature can be lowered, so polymer decomposition can be effectively suppressed during molding, and the molded product also has excellent coloring stability. Furthermore, the polymer of the present invention has excellent transparency.

The fluorine-containing segmented polymer of the present invention can be produced as follows. That is, first, at least one monomer selected from the group (A) described below is radically polymerized in the presence of a radical generating source and an iodide compound to form a polymer chain having a molecular weight of 3000 or more and composed of the monomer units. A segment, an iodine atom free from the iodide compound, and a residue from which at least one iodine atom has been removed from the iodide compound, which is bonded to both ends of the segment (if the residue is not polymerized into the iodide compound). (If a double bond is present, it may have some substituents derived from the monomer or the iodide compound.) A presegmented polymer is produced (first step).

Next, at least one monomer selected from group (A) and group (B) described below is added to the radical generating source and the first monomer.
A chain consisting of a polymer chain segment having a molecular weight of 3000 or more, which is radically polymerized in the presence of the pre-segmented polymer produced in the process, and is composed of the polymer chain segment present in the pre-segmented polymer and the monomer unit, The iodine atoms free from the iodide compound and the residues from which at least one iodine atom has been removed from the iodide compound (provided that the residues are polymerizable to the presegmented polymer) are bonded to both ends thereof. If a double bond is present, it may have some substituents derived from the monomer or the presegmented polymer.)
A bisegmented polymer is produced (second step).

If necessary, at least one monomer selected from Groups (A) and (B) described later is radically polymerized in the presence of a radical generating source and the bisegmented polymer produced in the second step. The bisegmented polymer has a molecular weight of 3000, which is composed of the polymer chain segments and the monomer units present in the bisegmented polymer.
A chain consisting of the above polymer chain segments, an iodine atom free from the iodide compound bonded to both ends thereof, and a residue obtained by removing at least one iodine atom from the iodide compound (if the residue may have some substituents derived from the monomer or the bisegmented polymer, if the bisegmented polymer has a polymerizable double bond.
producing a trisegmented polymer (third
process).

If necessary, at least one monomer selected from Groups (A) and (B) described later is radically polymerized in the presence of a radical generating source and the trisegmented polymer produced in the third step. The molecular weight is composed of the polymer chain segments present in the trisegmented polymer and the monomer units.
A chain consisting of 3,000 or more polymer chain segments, and an iodine atom free from the iodide compound bonded to both ends of the chain, and a residue obtained by removing at least one iodine atom from the iodide compound (if the remaining The group may have some substituent derived from the monomer or the trisegmented polymer if a polymerizable double bond is present in the trisegmented polymer.)
(4th step).

If necessary, the polymer chain segments can be successively grown by further repeating the radical polymerization in the same manner as above.

In addition, in the fluorine-containing segmented polymer obtained as the final product, the molecular weight of each polymer chain segment is 3000 or more, but at least one polymer chain segment should have a molecular weight of 30000 or more, and the above-mentioned It is also necessary that the radical polymerization reactions in each step of the process be carried out so as to obtain such polymer chain segments. Also, although adjacent polymer chain segments are required to be dissimilar from each other, this does not mean that all polymer chain segments are dissimilar from each other. In short, it is sufficient that at least two types of polymer chain segments and at least one type of fluorine-containing polymer chain segment exist in the fluorine-containing segmented polymer.

The iodide compound used in the first step described above has 1 to 16 carbon atoms (preferably 1 to 8 carbon atoms).
is a perhalohydrocarbon in which at least one of its halogen atoms (preferably only one on two mutually adjacent carbon atoms) is an iodine atom, and the other halogen atoms are a fluorine atom or a fluorine atom. Consisting of elementary atoms and chlorine atoms (if chlorine atoms exist, their number is not greater than the number of fluorine atoms, and there are only 1 on one carbon atom)
There can never be more than one chlorine atom. ). However, the iodide compound may have an oxygen bond (-O-) between any two carbon atoms, and may also have a substituent represented by _-CF2H or = _CF2 . I can do it.

The number of iodine atoms in the above perhalohydrocarbon is 1
It is preferable that the number is one or two, but the number is not necessarily limited to this. If the perhalohydrocarbon is totally unsaturated, such as when it has =CF ₂ , it is itself polymerizable and will undergo radical polymerization reactions. Therefore, unsaturated perhalohydrocarbons, i.e., unsaturated iodide compounds, have C--I bonds that participate in chain initiation of radical polymerization reactions, and at the same time, unsaturated bonds that participate in chain initiation of radical polymerization reactions. It is also useful as a monomer. Therefore, when using such iodide compounds,
The resulting fluorine-containing segmented polymer will have a more or less complex structure.

Specific examples of iodide compounds include: monoiodoperfluoromethane, monoiodoperfluoroethane, monoiodoperfluoropropane, monoiodoperfluorobutane (e.g. 2-iodoperfluorobutane, 1-iodoperfluorobutane). iodoperfluoro(1,1-dimethylethane)), monoiodoperfluoropentane (e.g. 1-iodoperfluoro(4-methylbutane)), 1-iodoperfluoro-n-nonane, monoiodoperfluorocyclobutane, 2-
Iodoperfluoro(1-cyclobutyl)ethane, monoiodoperfluorocyclohexane, 2
-Iodo-1-hydroperfluoroethane, 3
-Iodo-1-hydroperfluoropropane,
Monoiodomonochlorodifluoromethane, monoiodomonochlorodifluoromethane, 2-iodo-
1,2-dichloro-1,1,2-trifluoroethane, 4-iodo-1,2-dichloroperfluorobutane, 6-iodo-1,2-dichloroperfluorohexane, 4-iodo-1,2, 4-trichloroperfluorobutane, 1-iodo-2-hydroperfluoropropane, monoiodotrifluoroethylene, 3-iodoperfluoropropene-1,4-iodoperfluoropentene-1,
4-Iodo-5-chloroperfluoropentene-
1,2-iodoperfluoro(1-cyclobutenyl)ethane, 1,2-diiodoperfluoroethane, 1,3-diiodoperfluoro-n-propane, 1,4-diiodoperfluoro-n-butane, 1,3 - diiodo-2-chloroperfluoro-n-propane, 1,5-diiodo-2,4-dichloroperfluoro-n-pentane, 1,7-diiodoperfluoro-n-octane, 1-iodoperfluorodecane, 1,12-diiodoperfluorododecane, 1,16-diiodoperfluorohexadecane, 1,2-di(iododifluoromethyl)perfluorocyclobutane, 2-iodo-
2,2-dichloro-1,1,1-trifluoroethane, 2-iodoperfluoroethyl perfluorovinyl ether, 2-iodoperfluoroethyl perfluoroisopropyl ether, etc.

In each of the above steps, monomers used to form polymer chain segments by radical polymerization include the following groups (A) and (B).

That is, examples of group (A) include tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, pentafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), etc. can.
Group (B) includes ethylene, tetrafluoroethylene, hexafluoropropylene, pentafluoropropylene, 3,3,3-trifluoropropylene-1,2-trifluoromethyl-3,3,
Examples include 3-trifluoropropylene-1, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), and perfluoro(propyl vinyl ether).

In the radical polymerization reaction of each step, the number of monomers used may be one or more. When one type of monomer is used, the polymer chain segment formed is a homopolymer, and when two or more types of monomer are used, the polymer chain segment formed is a copolymer. By selecting and using appropriate monomers, the polymer chain segment formed can be made to be different from the polymer chain segments formed in the steps before and after it, for example, in steric structure and monomer composition. Bye.

As the radical generating source, conventionally known sources can be used as they are. Preferred radical generating sources are light and heat, which can selectively cleave I--C bonds in iodide compounds. As the light, it is possible to use a wide range of light ranging from the infrared region to the ultraviolet region. Although it is not impossible to use chemical ultraviolet light, it has the drawback of sometimes generating radicals not only from I--C bonds but also from other bonds. Similar defects are observed when using ionizing radiation. When only heat is used as a radical generation source, heating to 200°C or higher is desirable.

As other radical generation sources, it is also possible to use known radical initiators that do not substantially cause chain transfer reactions and exhibit an appropriate decomposition rate under radical polymerization reaction conditions. Examples of such radical initiators include inorganic or organic peroxides, azo compounds, organometallic compounds, and metals. Among these, organometallic compounds are not necessarily good because they may extract not only iodine atoms but also other atoms or atomic groups to generate radicals. Particularly recommended are persulfates, hydrogen peroxide (R _f CO) ₂ O ₂ ,
R _f OOR _f , R _f C(O)OOR _f , (R _f ) ₃ COOC(O)OC
(R _f ) ₃ , N ₂ F ₂ , R _f −N=N−R _f , HgR _f2 , Li,
Examples include K, Na, Mg, Zn, Hg, Al, etc. (R _f : polyfluoroalkyl group). When using these radical initiators, it is desirable to keep their concentration as low as possible, to suppress termination due to bonding between radicals as much as possible, and to give priority to chain growth reactions.

The quantitative ratio of the iodide compound and the monomer in the radical polymerization reaction may be appropriately determined so that the formed polymer chain segment has a desired molecular weight. In this case, the chain transfer constant of the iodide compound can be used as an index. For example, if the chain transfer constant of the iodide compound is relatively large, most of the iodide compound will bind to the polymer chain segment at the beginning of the radical polymerization reaction, so the reaction will proceed smoothly without special precautions. proceed. On the other hand, if the chain transfer constant is relatively small, the excess amount of iodide compound is used in the early stages of the reaction to form relatively low molecular weight polymer chain segments, and at this stage unreacted iodide is removed. It is desirable to remove the compound and perform further reactions to reach the desired molecular weight. Such sequential polymerization is generally effective in forming polymer chain segments with a narrow molecular weight distribution.

The temperature of the radical polymerization reaction can be freely selected as long as the reaction occurs and the resulting polymer chains are not thermally decomposed, but is usually about -20 to 150°C. However, when heat is used as a radical generation source, even higher temperatures are used, and a high temperature of about 250°C may be required.

Although the pressure is not limited at all, a pressure below the autogenous pressure of the monomer involved in polymerization is generally employed.

The radical polymerization reaction can be carried out in any form, including bulk, solution, suspension, and emulsion. The shape may be the same throughout all steps, or a different shape may be adopted for each step.
In view of the uniformity of the reaction system, emulsion polymerization is usually most recommended. Next to emulsion polymerization,
Solution or suspension polymerization in the presence of a solvent essentially inert to radical attack may be employed. Specific examples of such solvents include perfluoro(dimethylcyclobutane), perfluorocyclohexane, dichlorotetrafluoroethane, trichlorotrifluoropropane, polyfluoroalkanes, and perfluoro(ethylene glycol methyl ethyl ether). .

In the case of emulsion polymerization, it is generally desirable to use emulsifiers. However, the formed polymer chain segments are −COOM′, −OH, −
Because it has a hydrophilic group such as SO ₃ M′ (M′ is a cation such as hydrogen, sodium, or potassium), the use of an emulsifier is not necessarily necessary when it exhibits a surfactant effect. . Specific examples of emulsifiers include fluorine-containing carboxylic acids, fluorine-containing sulfonates, and the like. The emulsifier may be added to the reaction system all at once in the initial stage, or may be added in appropriate amounts continuously or intermittently. It is generally desirable that the amount of emulsifier used is 5% by weight or less based on the weight of the reaction mixture. Use of excess emulsifier should be avoided. In addition to the emulsifier, an appropriate emulsion stabilizer may be used if necessary.

As mentioned above, the fluorine-containing segmented polymer is
Usually, it can be advantageously produced by emulsion polymerization, but
When the iodide compound is present in a relatively large amount in a reaction system for producing a presegmented polymer, the particles of the produced presegmented polymer easily aggregate, resulting in a significant reduction in the reaction rate. Additionally, non-segmented polymer species may be formed. Such disadvantages can be avoided by adding appropriate amounts of polymer particles corresponding to the polymer chain segments in the presegmented polymer as a seed polymer to the reaction system prior to the polymerization reaction.

One feature of the fluorine-containing segmented polymer produced as described above is that it has an iodine atom at its terminal position. The terminal iodine atom can be appropriately substituted with another atom or atomic group to stabilize or activate the fluorine-containing segmented polymer. For example, by reacting with a compound having an atom or atomic group such as fluorine, fluorine, chlorine, bromine, hydroxy, amino, carboxyl, alkyl, thioalkyl, silyl, or fluorine-containing alkyl, the terminal iodine atom can be converted to these atoms. Alternatively, it can be substituted by an atomic group. Also, allyl alcohol,
It is also possible to add compounds having unsaturated bonds such as α-methylstyrene, diallyl phthalate, and tetraallyl pyromellitate.

Traditionally, block copolymers, such as cis-
It is well known that block copolymers comprising a middle segment of 1,4-polyisoprene and end segments of polystyrene are useful as thermoplastic rubbers. However, although various attempts have been made to synthesize these types of fluorine-containing polymers, some of them have substantially lower molecular weights than the intended polymers, and others have undesirable structures. The current situation is that nothing that can withstand practical use has yet been found.

However, the fluorine-containing segmented polymer provided by the present invention has sufficient practical properties as a thermoplastic rubber, and can be vulcanized as in the case of fluorine-containing thermoplastic resins. The molded article can be molded by direct compression or other methods without vulcanized rubber, and the molded article has desirable elastomeric properties about the same as vulcanized rubber. However, if desired, the polymer may be vulcanized by heating in the presence of certain vulcanizing agents, such as peroxides, amine compounds, and the like. In addition, the molded product generally exhibits excellent properties such as heat resistance, oil resistance, solvent resistance, and chemical resistance, like ordinary vulcanized fluororubber. Furthermore, mechanical properties such as strength can be further improved by incorporating fillers such as carbon black and magnesium oxide into this polymer.

The fluorine-containing segmented polymer of the present invention can be used not only as compression molded products, injection molded products, and extrusion molded products, but also as paints, adhesives, foam materials, etc.
It can also be used to improve the physical properties of latex or other rubbers.

The present invention will be specifically explained below with reference to Examples. In addition, the abbreviations in the examples have the following meanings: VdF, vinylidene fluoride;
HFP, hexafluoropropylene; HFiB, hexafluoroisobutene; APS, ammonium persulfate; PVdF, polyvinylidene fluoride;
TFE, tetrafluoroethylene; E, ethylene; PPVE, perfluoropropyl vinyl ether; PMVE, perfluoromethyl vinyl ether.

In addition, parts and % represent parts by weight and % by weight unless otherwise specified.

Note that the repeated stress-elongation curve (hysteresis) was measured using a Tensilon at 100 mm/min and 23°C for a 3.5 mmφ×26.5 mmφ O-ring.

Reference Example 1 3000 parts of pure water and 6 parts of ammonium perfluorooctanoate are charged into a pressure-resistant reaction tank that can hold 6000 parts of water, and after completely replacing the internal space with pure nitrogen gas, VdF/HFP (50/50 molar ratio) is charged. ) 80 with mixed gas
℃ and pressurized to 12 Kg/cm ² G while stirring. 1%APS
When 4 parts of the aqueous solution is injected into the tank, the pressure immediately drops, so the reaction is continued while VdF/HFP (78/22 molar ratio) mixed gas is injected to maintain the pressure until the reaction amount reaches 2 parts. At this stage, 3.1 parts of 1,4-diiodoperfluorobutane was press-fitted. Thereafter, the reaction was carried out for 28 hours while injecting 2 parts of a 1% APS aqueous solution every 3 hours, and then the reaction was terminated by rapidly lowering the temperature and releasing gas. A white aqueous dispersion with a solids content of 25% is obtained. This dispersion could be coagulated using a line mixer with strong shearing force, and the coagulated product was washed with water and dried to obtain a colorless and transparent elastic polymer. iodine content
0.18%. [η] = 0.65 (d/g, 35°C, MEK).
Mooney viscosity ML ₁₊₂₀ (100℃) = 75. The flow characteristics are shown in Figure 6d.

Reference Example 2 In Reference Example 1, 3 parts of ammonium perfluorooctanoate, initial mixed gas composition VdF/
HFP/TFE (20/69/11 molar ratio), additional injection mixed gas composition VdF/HFP/TFE (50/30/20 molar ratio),
A colorless and transparent elastic polymer was obtained by carrying out the same procedure except that the reaction pressure was 15 Kg/cm ² G and the reaction time was 15 hours. Iodine content 0.18%. [η] = 0.45. ML1 ₊₂₀
(100℃) = 104. This flow characteristic is shown in Figure 1c.

Example 1 1,500 ml of the aqueous dispersion obtained in Reference Example 2 was charged into a pressure-resistant reaction tank with an internal volume of 3,000 ml, and the internal space was sufficiently replaced with nitrogen gas, then the mixture was removed, and then HFP/TFE/E ( Pressurize with a mixed gas (17/76/7 molar ratio) and set to 14Kg/cm ² G at 80°C.
When 10ml of 0.1% APS aqueous solution is injected, the pressure begins to drop immediately and drops to 13Kg/cm ² G after about 10 minutes, so the HFP/TFE/E (8/49/43 molar ratio) mixed gas reduces the pressure to 14Kg/cm ² G. The pressure is restored to . Thereafter, this process is repeated to continue the reaction for 4.5 hours, and then the reaction is stopped by rapidly cooling and releasing the pressure. A white aqueous dispersion with a solids content of 27.7% was obtained. HFP/TFE/
The E copolymer segment content is approximately 15%.

This aqueous dispersion was diluted twice and coagulated using an aqueous magnesium chloride solution in a household mixer, and the coagulated product was washed with water and dried to obtain a powdered rubber. This rubber is a thermoplastic rubber with a melting point of 230°C according to differential thermal analysis. The measurement results of differential thermal analysis (DSC), melt flow characteristics, stress-elongation curve, and dynamic viscoelasticity (mechanical loss) are shown in Figure 13a, Figure 1a, Figure 2, and Figure 3, respectively. .

Comparative Example 1500 ml of the aqueous dispersion obtained in Reference Example 2 was charged into a pressure-resistant reaction tank with an internal volume of 3000 ml, and the internal space was sufficiently replaced with nitrogen gas, then removed, and then TFE/E (90/10 Molar ratio) Pressurize with mixed gas and set to 14Kg/cm ² G at 80℃. When 10ml of 0.1% APS aqueous solution is injected, the pressure starts to drop immediately.
After about 10 minutes, it drops to 13Kg/cm ² G, so
14Kg/ by TFE/E (53/47 molar ratio) mixed gas
The pressure is restored to cm ² G. After that, repeat this and react
After continuing for 3.8 hours, the reaction is stopped by rapid cooling and pressure release. A white aqueous dispersion with a solids content of 27.2% was obtained. The TFE/E copolymer segment content is approximately 15%.

This aqueous dispersion was diluted twice and coagulated using an aqueous magnesium chloride solution in a household mixer, and the coagulated product was washed with water and dried to obtain a powdered rubber. The molecular weight determined from melt flow characteristics was almost the same as the rubber of Example 1.

A composition for vulcanization was prepared by mixing 100 parts by weight of the rubber obtained in Example 1 or Comparative Example, 2.5 parts by weight of Perhexa, and 2 parts by weight of triallyl isocyanurate. , 40
A P-24O-ring was compression molded under the condition of kg/cm ² G.

When the rubber of Example 1 was used, no cracks were observed in the O-ring and an O-ring with the dimensions according to the mold could be molded, but when the rubber of Comparative Example was used, the O-ring did not show any cracks.
- Numerous cracks were seen in the ring, and it shrunk considerably from the specified mold shape.

Example 2 The procedure was repeated in the same manner as in Example 1, except that the dispersion obtained in Reference Example 2 was charged in an amount of 500 ml, diluted three times with pure water, and the polymerization pressure was adjusted to 14 to 15 Kg/cm ² G. Polymerize for 6 hours and post-process.
HFP/TFE/E copolymer segment content 23%
of polymer powder was obtained. This polymer had a melting point of 230°C according to differential thermal analysis. The measurement results of the DSC behavior, melt flow characteristics, stress-elongation curve, and dynamic viscoelasticity (mechanical loss) of this polymer are shown in FIG. 13b, FIG. 1b, FIG. 4, and FIG. 5.

Example 3 (1) A reaction tank with an internal volume of 35 cm was charged with 1 g of pure water and 2 g of perfluorooctanoic acid, and after the space inside the tank was sufficiently replaced with pure nitrogen gas, the reactor was heated at 80°C with stirring.
Pressurize to 12Kg/cm ² G with HFP/TFE/VdF (63/12/25 molar ratio) mixed gas. 1% APS aqueous solution
As soon as 20ml is injected, the pressure begins to drop. 11
When the temperature reached Kg/cm ² G, 18 g of 1,4-diiodoperfluorobutane was injected, and at the same time
The pressure is restored to 12Kg/cm ² G using HFP/TFE/VdF (25/20/55 molar ratio) mixed gas. Thereafter, the reaction was continued for 14.5 hours at the same pressure while adding 10 ml of 1% APS solution every 3 hours to obtain an aqueous dispersion with a solid content of 25%. This dispersion is easily broken down to give a rubbery crumb by gradually adding a 1% potassium alum aqueous solution with vigorous stirring. [η] = 0.82 (d/g, 35℃,
MEK). The flow characteristics are shown in Figure 6e.

(2) Pour 750 ml of the dispersion obtained in (1) into a reaction tank with an internal volume of 3, dilute it with pure water, add 1 g of ammonium perfluorooctanoate, and fill the space with HFiB/TFE/E (3 /90/7 molar ratio) After sufficiently replacing the mixture with the mixed gas, the mixture was pressurized to 10 Kg/cm ² G with the same mixed gas at 80° C. and with stirring.
When 10ml of 0.2% APS aqueous solution is injected, the pressure starts to drop immediately, so HFiB/TFE/E (3/
The reaction is continued while restoring the pressure with a mixed gas (50/47 molar ratio) and adding 10 ml of 0.2% APS aqueous solution under pressure every 3 hours. After 5 hours, the reaction was stopped to obtain a thermoplastic rubber dispersion with a HFiB/TFE/E copolymer segment content of 15%. The rubber obtained by destroying (coagulating) the dispersion with an aqueous magnesium chloride solution is also insoluble in the solvent in which the rubber obtained in (1) is dissolved. The measurement results of DSC behavior, melt fluidity, elongation-stress curve, and dynamic viscoelasticity (mechanical loss) are shown in FIG. 14a, FIG. 6a, FIG. 7, and FIG. 8, respectively.

(3) Dilute the dispersion amount to 500ml by 3 times and set the reaction pressure to 14.5-15.5Kg/cm ²
G. A thermoplastic rubber having a HFiB/TFE/E copolymer segment content of 30% was obtained by repeating the same procedure as in (2) above except that the reaction time was 9 hours. The various properties of this rubber are shown in Figure 14b and Figure 6b.
and shown in FIG.

(4) Aqueous dispersion obtained in Reference Example 1
Pour 1500ml and set the polymerization pressure to 10.0-10.5Kg/cm ²
G, reaction time is 18 hours, 0.1% every 3 hours
HFiB/TFE/E (3/
50/47 molar ratio) copolymer segment content 15%
Thermoplastic rubber was obtained. The results of differential thermal analysis, melt flowability and mechanical properties of this rubber are shown in FIG. 10, FIG. 6c, FIG. 11 and FIG. 12, respectively.

Example 4 PPVE/
TFE/E (3/50/47) copolymer segment 15
% bonded to the rubber of Example 3(1) was obtained. The melt fluidity, mechanical properties, etc. of this rubber were equivalent to those of the rubber obtained in Example 1.

Example 5 (1) In a reaction tank with an internal volume of 500 ml, add 350 ml of pure water and
After charging 0.7g of Rimar and replacing the space with TFE, PMVE and TFE were added while stirring at 80℃.
were prepared in a molar ratio of 2:1 at a pressure of 12.5 Kg/cm ² G, and injected into 10 ml of 0.2% APS aqueous solution. After 5 hours, when the pressure decreased to 10.5 Kg/cm ² G, 0.4 ml of 1,4-diiodoperfluorobutane was injected, and thereafter, 0.2% APS aqueous solution was injected every 5 hours.
The reaction was continued for 20 hours by adding 10 ml under pressure and gradually lowering the pressure while supplementing the pressure drop with TFE, to obtain an aqueous dispersion with a solids content of 17%. The rubber obtained by coagulation with an aqueous magnesium chloride solution is rubber-like and can be kneaded with a rubber kneading roll, and the results of its elemental analysis are C,
It was 22.6% and H, 0%.

(2) Dilute 175ml of the dispersion obtained in (1) twice and place it in the same reaction tank, making sure to make enough space.
After replacing with TFE, use a mixed gas of TFE/PMVE (2/1 molar ratio) at 80℃ with stirring at 13Kg/cm ² G
3 ml of 0.1% APS aqueous solution was pressurized to start polymerization. After 1 hour, when the pressure decreased to 9 kg/cm ² G, the pressure was released to stop the reaction.
The rubber obtained by coagulating the resulting transparent dispersion by freezing could be formed into a sheet by heat pressing at 250°C, and exhibited mechanical strength as a vulcanized rubber. According to differential thermal analysis, an endothermic peak was observed at 230°C.

[Brief explanation of drawings]

FIG. 1 shows the melt flow characteristics of the rubbers of Examples 1 to 2 and Reference Example 2, and FIGS. 2 and 3 show the stress-elongation curve and dynamic viscoelasticity (mechanics) of the rubber of Example 1. Figures 4 and 5 are diagrams respectively showing the stress-elongation curve and dynamic viscoelasticity (mechanical loss) of the rubber of Example 2, and Figure 6 is a diagram showing the stress-elongation curve and dynamic viscoelasticity (mechanical loss) of the rubber of Example 3 (1 ) to (4) and diagrams showing the melt fluidity of the rubber of Reference Example 1, Figures 7 and 8 show the stress-elongation curve and dynamic viscoelasticity (mechanical loss) of the rubber of Example 3 (2). FIG. 9 is a diagram showing the stress-elongation curve of the rubber of Example 3 (3), and FIGS. 10, 11, and 12 are the differences of the rubber of Example 3 (4). Figures showing the thermal analysis, stress-elongation curves and dynamic viscoelasticity, respectively. Figure 13 is a differential thermal analysis diagram of the rubbers of Examples 1 and 2. Figure 14 is the diagram of the differential thermal analysis of the rubbers of Examples 3 (2) and (3). It is a differential thermal analysis diagram of rubber.

Claims (1)

[Claims] 1 Formula: Q[-(A ₁ -...-A _n )I] _o [wherein Q is a residue obtained by removing at least one iodine atom from an iodide compound, A ₁ to A _n are each a polymer chain segment, m is 2 or 3,
n represents a number corresponding to the number of iodine atoms removed from the iodide compound. However, if m is 2, one of A ₁ and A ₂ , or if m is 3, A ₁
One or two of ~ _A3 are (1) vinylidene fluoride/hexafluoropropylene or pentafluoropropylene/tetrafluoroethylene (molar ratio 45-90:5-50:0-35) polymer and (2)
Elastomeric random polymer chains of molecular weight 30000-1200000 selected from perfluoro( _C1 - _C3 alkyl vinyl ether)/tetrafluoroethylene/vinylidene fluoride (molar ratio 15-75:0-85:0-25) polymers The remaining polymer chain segments are (3) ethylene/tetrafluoroethylene/hexafluoropropylene, pentafluoropropylene, 3,3,3-trifluoropropylene-1,2-trifluoromethyl-3,3,3 -Trifluoropropylene-1
or perfluoro( _C1 - _C3 alkyl vinyl ether) (molar ratio 35-60:60-35:1-30) polymers with a molecular weight of 3,000-400,000, non-elastomeric random polymer chain segments, and have elastomeric properties. The weight ratio of random polymer chain segments to non-elastomeric random polymer chain segments is 40-95:5-60. ] A fluorine-containing segmented polymer represented by: 2 At least one type of monomer is radically polymerized in the presence of a radical generating source and an iodide compound to obtain a monomer unit with a molecular weight of 3000.
The above polymer chain segment, the iodine atom free from the iodide compound bonded to both ends thereof, and the residue obtained by removing at least one iodine atom from the iodide compound (however, the residue is If there is a polymerizable double bond in , it may have a substituent derived from the monomer or the iodide compound.)
a first step of producing a pre-segmented polymer comprising: radically polymerizing at least one monomer in the presence of a radical generator and the pre-segmented polymer produced in the first step; The molecular weight is 3000, which is composed of the polymer chain segment that existed in the polymer and the monomer unit.
A chain consisting of the above polymer chain segments, an iodine atom free from the iodide compound bonded to both ends thereof, and a residue obtained by removing at least one iodine atom from the iodide compound (however, the residue is If the pre-segmented polymer has a polymerizable double bond, it may have a substituent derived from the monomer or the pre-segmented polymer.) A second step of producing a bisegmented polymer. is an essential step, and if necessary, at least one monomer is radically polymerized in the presence of a radical generating source and the bisegmented polymer produced in the second step to remove the polymer present in the bisegmented polymer. composed of a chain segment and the monomer unit,
A chain consisting of polymer chain segments with a molecular weight of 3000 or more, an iodine atom free from the iodide compound bonded to both ends of the chain, and a residue obtained by removing at least one iodine atom from the iodide compound (however, the residue may have a substituent derived from the monomer or the bisegmented polymer, if the bisegmented polymer has a polymerizable double bond.
One or two of the three steps include (1) vinylidene fluoride/hexafluoropropylene or pentafluoropropylene/tetrafluoroethylene (molar ratio 45 ~90:5~50:0~35) polymer and (2) perfluoro( _C1 ~ _C3 alkyl vinyl ether)/tetrafluoroethylene/vinylidene fluoride (molar ratio 15~75:0~85:
0-85) Molecular weight selected from polymer bodies
30,000 to 1,200,000 elastomeric polymer chain segments are formed, and the remaining steps are (3)
Ethylene/tetrafluoroethylene/hexafluoropropylene, pentafluoropropylene,
3,3,3-trifluoropropylene-1,2-
Trifluoromethyl-3,3,3-trifluoropropylene-1 or perfluoro( _C1 - _C3 alkyl vinyl ether) (molar ratio 35-60:60-
35:1-30) selected from polymers, molecular weight
3,000 to 400,000 non-elastomeric polymer chain segments are formed, and the weight ratio of elastomeric polymer chain segments to non-elastomeric polymer chain segments is 40 to 400,000.
A method for producing a fluorine-containing segmented polymer having a ratio of 95:5 to 60.