JPS6149327B2 - - 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 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. and at least two types of polymer chain segments (at least one of which is a fluorine-containing polymer chain segment) interposed between the residues. In other words, the fluorine-containing segmented polymer of the present invention basically comprises at least two types of polymer chain segments (at least one of which is a fluorine-containing polymer chain segment).
It consists of such a chain, iodine atoms liberated from an iodide compound having iodine atoms bonded to carbon atoms present at both ends thereof, and residues obtained by removing the iodine atoms 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 released from the iodide compound, and n represents the number of bonds of Q. ].

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, at least one of them is a fluorine-containing polymer chain segment. Various methods are already known for producing fluorine-containing segmented polymers having two or more types of polymer chain segments. 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. In addition, a method of telomerizing fluoroolefins in the presence of a radical initiator using polyfluoroalkyl iodide as a telogen is also well known (for example, "telomerization" US Naval Res.Rab.Rept. .PB
131930, UK Patent No. 824229, etc.).

Although the method of the present invention is carried out by a radical method, it is achieved by the method described below, which is different from the conventional telomerization method, and it also achieves the results that cannot be obtained by the conventional method described above. A new general method is provided by which molecular species of fluorine-containing multi-segmented polymers can be obtained.

That is, in the method of the present invention, the carbon-iodine bond of the iodide compound is a relatively weak bond, which is easily radically cleaved by a radical generation source, and the radicals generated by the cleavage have high reactivity, so that radical polymerization is not possible. The addition-growth reaction can be caused to occur in the presence of a monomer with a specific property, and the chain reaction is then terminated by a so-called chain transfer reaction, which abstracts iodine from the iodide compound, but the resulting polymer end Since the bond between 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 an addition growth reaction is carried out in the presence of other radically polymerizable monomers. This is based on the new knowledge that it is possible to continue the polymer chain as if it were a growing living terminal in ionic polymerization. In this way, the present invention is a new method for producing a fluorine-containing multi-segmented polymer by applying a previously unknown principle.

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, and at least one iodine atom from an iodine atom and an iodide compound bonded to both ends of the chain. Consists of residues excluding atoms as essential constituents. However, the at least two
The seed polymer chain segments are different from the adjacent polymer chain segments (for example, the structure and composition of the monomer units that constitute them are different), and at least one of them is different from the adjacent polymer chain segments. It is a fluorine-containing polymer chain segment, and each polymer chain segment has a molecular weight of 3,000 or more, but at least one of the polymer chain segments has a molecular weight of 30,000 or more, excluding the so-called telomer region. be. 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 can be produced as follows. In other words, first,
At least one monomer selected from group (A) below is radically polymerized in the presence of a radical generating source and an iodide compound to obtain a polymer chain segment having a molecular weight of 3000 or more and composed of the monomer units, and both of them. An iodine atom free from the iodide compound bound to the terminal and a residue obtained by removing at least one iodine atom from the iodide compound (provided that the residue has a polymerizable double bond in the iodide compound). If present, it may have some substituent derived from the monomer or the iodide compound.) A pre-segmented 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 substituent 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 pore stage).

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. The radical polymerization reaction in each step also needs to be carried out in such a way that such polymer chain segments are obtained. 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 16 carbon atoms).
8) is a perhalohydrocarbon in which at least one of the halogen atoms (preferably only one on two mutually adjacent carbon atoms) is an iodine atom, and the other halogen atoms are fluorine atoms. or consisting of a fluorine atom and a chlorine atom (if chlorine atoms are present, their number is not greater than the number of fluorine atoms, and there is no more than one chlorine atom on a carbon atom) There is no chlorine atom present.) However, the iodide compound has an oxygen bond (-
O-), and may also have a substituent represented by -CF ₂ H or =CF ₂ .

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, monoiodoperfluoromethane, monoiodoperfluoropropane, monoiodoperfluorobutane (e.g. 2-iodoperfluorobutane, 1- 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, monoiododichloromonofluoromethane, 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-iodoperfluoropropane-1, 4-iodoperfluoropentene-1,
4-Iodo-5-chloroperfluoropentene-
1,2-iodoperfluoro(1-cyclobutenyl)ethane, 1,2-diiodoperfluoroethane, 13,-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-diiodoperfluorodecane, 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-described steps, polymers used to form polymer chain segments by radical polymerization include the following groups (A) and (B).

That is, the (A) group includes fluorine-containing unsaturated polymerizable monomers represented by the formula: CF ₂ =CXY. Here, X represents a hydrogen atom or a fluorine atom; when X is a hydrogen atom, Y is a hydrogen atom; when X is a fluorine atom, Y is a fluorine atom, trifluoromethyl group, difluoromethyl group, or perfluoroalkoxy group having 1 to 3 carbon atoms. Specific examples of monomers belonging to group (A) include tetrafluoroethylene, vinylidene fluoride, hexafluoropropylene, perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), and perfluoro(propyl vinyl ether). can.
Group (B) also includes unsaturated polymerizable monomers that do not have a fluorine atom on a carbon atom constituting a double bond, with ethylene being a preferred example.

However, when using the above monomers included in group (B), it is difficult to grow a chain of polymer chain segments under normal reaction conditions after the radical polymerization reaction has once stopped. Therefore, it is desirable to avoid the use of such monomers except in final steps where further chain growth is not required. In other words, for radical polymerization reactions other than the final step, it is preferable to use monomers selected from group (A) alone or together with monomers selected from group (B).

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, 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 monomers involved in polymerization is generally employed. However, if the chain growth reaction does not occur unless it is under extremely high pressure (for example, hexafluoropropylene or hexafluoropropylene is polymerized with tetrafluoroethylene to form a hexafluoropropylene homopolymer or a hexafluoropropylene/tetrafluoroethylene copolymer with a large proportion of hexafluoropropylene). (in the case of manufacturing 1), it may require several thousand atmospheres of pressure, and if the monomer is non-volatile under the reaction conditions, pressurization is virtually not required, so the range cannot be set unambiguously.

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. 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, hydrogen, fluorine, chlorine, bromine, hydroxy, amino, carboxyl, alkyl, thioalkyl,
By acting with a compound having an atom or atomic group such as silyl or fluorine-containing alkyl, the terminal iodine atom can be substituted with such an atom or atomic group. In addition, allyl alcohol, α-methylstyrene, diallyl phthalate,
It is also possible to add a compound having an unsaturated bond such as tetraallyl pyromellitate to the terminal.

The fluorine-containing segmented polymer of the present invention exhibits various remarkable properties depending on the chain structure and composition of its polymer chain segments.

In particular, a fluorine-containing segmented polymer having the following structure exhibits excellent properties as a thermoplastic rubber: A chain consisting of two or three polymer chain segments, an iodine atom present at one end of the chain, and an iodine atom at one end of the chain. consisting of the residue of the iodide compound present at the other end with at least one iodine atom removed, and one (if the chain consists of two polymer chain segments) or one or two ( (1) vinylidene fluoride/hexafluoropropylene or/tetrafluoroethylene (mole ratio 45-90:5-50:0)
35) Polymer and (2) perfluoro(alkyl vinyl ether) (the number of carbon atoms in the alkyl group is 1 to
3) / tetrafluoroethylene / vinylidene fluoride (molar ratio 15-75: 0-85 (excluding 0): 0-85) is an elastomeric polymer chain segment with a molecular weight of 30,000 to 1,200,000. , the remainder of the polymer chain segments are (3) vinylidene fluoride/tetrafluoroethylene (molar ratio 0-100:0-100) polymer and (4) ethylene/tetrafluoroethylene (molar ratio 40-60:40).
~60) Selected from polymers, molecular weight ~3000
400,000 non-elastomeric polymer chain segments, with a weight ratio of elastomeric to non-elastomeric polymer chain segments of 40 to
95; 5 to 60: Traditionally, block copolymers in which non-elastomeric polymer chain segments are attached at both ends of an elastomeric polymer chain segment, 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.

In order to produce the above-mentioned fluorine-containing segmented polymer useful as a thermoplastic rubber, the monomers constituting each polymer chain segment are sequentially polymerized in the presence of a radical generating source and an iodide compound as described above. good. That is, first, at least one monomer is radically polymerized in the presence of a radical generating source and an iodide compound, and a polymer chain segment having a molecular weight of 3000 or more and composed of the monomer units is bonded to both ends thereof. , an iodine atom liberated from the iodide compound, and a residue obtained by removing at least one iodine atom from the iodide compound (if the iodide compound has a polymerizable double bond, may have some substituent derived from the monomer or the iodide compound).

Next, at least one monomer is radically polymerized in the presence of a radical generating source and the pre-segmented polymer produced in the first step, so that the polymer chain segments present in the pre-segmented polymer and the monomer units are A chain consisting of polymer chain segments with a molecular weight of 3,000 or more, and an iodine atom released 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, if the presegmented polymer has a polymerizable double bond, the residue may have some substituent derived from the monomer or the presegmented polymer.)
A bisegmented polymer consisting of:

Furthermore, 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, so that the polymer chain segments present in the bisegmented polymer and the A chain consisting of a polymer chain segment having a molecular weight of 3000 or more and composed of monomer units, an iodine atom released 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. group (if the bisegmented polymer has a polymerizable double bond, the residue may have some substituent derived from the monomer or the bisegmented polymer) A trisegmented polymer is produced.

One step (in the case of two steps) or one or two steps (in the case of three steps) of all the above steps is (1) vinylidene fluoride/hexafluoropropylene or/tetrafluoroethylene (mole ratio 45 to 90 :5-50:0-35) polymer and (2) perfluoro(alkyl vinyl ether)
(The number of carbon atoms in the alkyl group is 1 to 3) / Tetrafluoroethylene / Vinylidene fluoride (molar ratio 15
~75:0~85:0~85) to form an elastomeric polymer chain segment with a molecular weight of 30,000 to 1200,000, and the remaining steps are (3) vinylidene fluoride/tetrafluoroethylene (molar (4) ethylene/tetrafluoroethylene (molar ratio 40-60: 40-60) polymers with a molecular weight of 3000-400000. and the weight ratio of such elastomeric polymer chain segments to non-elastomeric polymer chain segments is
The type and ratio of monomers and the conditions of the radical polymerization reaction are appropriately selected so that the ratio is 40 to 95:5 to 60.

The present invention will be specifically described below with reference to Examples. In addition, the abbreviations in the examples have the following meanings: VdF, vinylidene fluoride;
HFP, hexafluoropropylene; APS, ammonium persulfate; PVdF, polyvinylidene fluoride; TFE, tetrafluoroethylene.

Example 1 (1) Put 1500 ml of pure water and 7.5 g of ammonium perfluorooctanoate into a 3000 ml internal volume pressure-resistant reaction tank, and fill the internal space with VdF/HFP (45/55 molar ratio).
After sufficient replacement with the mixed gas, the pressure was increased to 14 kg/cm ² G. Pour 0.5 ml of CF ₂ (CFClCF ₂ I) ₂ (at 25 °C) and bring to 80 °C under stirring to add 10 ml of APS 10% aqueous solution.
was press-fitted. The polymerization reaction starts immediately and the pressure drops, so when it drops to 13Kg/cm ² G,
15 with VdF/HFP (78/22 molar ratio) mixed gas
Repressurize to Kg/cm ² G, and use this method from now on to 13~15
Polymerization was continued while maintaining the pressure in the Kg/cm ² G range. After 2 hours, the temperature was rapidly lowered and the pressure was released to stop the polymerization. The product was a highly foaming white translucent dispersion with a solids concentration of 11% by weight. After freezing and coagulating, the rubber obtained by washing with water and drying has an iodine content of 0.31% by weight, and an intrinsic viscosity of the rubber obtained using methyl ethyl ketone as a solvent is [η] = 0.34.
(dl/g, 35°C).

(2) Next, in the same reaction tank, 550 ml of the dispersion produced in (1) and 450 ml of pure water were added, and polymerization was carried out for 4.5 hours in exactly the same manner except that APS was not added. The rate of polymerization slowed as the initial dispersion was diluted and was clearly proportional to the number of polymer particles in the dispersion. Solids concentration in the produced dispersion is 24% by weight
The iodine content of the rubber obtained after freezing and coagulation, washing with water, and drying is 0.051% by weight, and the intrinsic viscosity [η] = 0.86 using methyl ethyl ketone as a solvent.
(dl/g, 35°C).

(3) In the same reaction tank, add 500 ml of dispersion from (2).
500 ml of pure water was added and polymerization was carried out for 14.5 hours in the same manner as in (2). During this period, the polymerization rate remained almost constant, but since there was a slight tendency for the rate to decrease, an additional 6 ml of 0.4% by weight APS aqueous solution was injected every 4 hours after the start. The solids concentration in the produced dispersion was 37% by weight, and the intrinsic viscosity of rubber using methyl ethyl ketone as a solvent [η] = 1.51.
(dl/g, 35°C).

(4) Place the dispersion obtained in (2) in the same reaction tank.
Add 500ml of pure water and 500ml of pure water, replace the space sufficiently with VdF, and then heat to 80℃ without adding an initiator.
When pressure is applied to Kg/cm ² G, polymerization starts immediately,
A pressure drop of 2.4 Kg/cm ² G occurred after 50 minutes.
At this point, the polymerization was stopped by rapidly lowering the temperature and releasing pressure. The product was an aqueous dispersion with a solids content of 15% by weight. After freezing coagulation, washing with water, and drying, the obtained polymer was a rubbery powder with low stickiness, an iodine content of 0.047% by weight, and an intrinsic viscosity in dimethylformamide [η] = 1.26 (dl/g, 35 ℃).
The content of PVdF segment was 9.7% by weight and was dissolved in hot acetone.

(5) Place the dispersion obtained in (3) in the same reaction tank.
500 ml and 500 ml of pure water were added, and polymerization was started in the same manner as in (4). After 20 minutes, there was no pressure drop, so when 10ml of APS 0.2% by weight aqueous solution was injected, the pressure started to drop immediately, and after 80 minutes, the pressure was 5Kg/cm ²
G descended. At this point, polymerization was stopped. The solids concentration of the produced Days Pursion was 23% by weight.
The powdered rubber obtained after freezing coagulation, water washing and drying had an intrinsic viscosity [η] of 1.64 (dl/g, 35°C) when dimethylacetamide was used as a solvent. In addition,
The content of PVdF segments corresponds to 12% by weight.

(6) Place the dispersion obtained in (3) in the same reaction tank.
After adding 250 ml and 750 ml of pure water, the space was sufficiently replaced with TFE, and the pressure was increased to 9.3 Kg/cm ² G while stirring at room temperature. Next, after pressurizing to 12.2Kg/cm ² G with VdF, the temperature was immediately raised to 70℃ (14Kg/cm ² G), and the APS
When 10 ml of a 0.1% by weight aqueous solution was injected, the pressure immediately began to drop. After 11 minutes, when the temperature decreased to 12.3 Kg/cm ² G, the temperature was rapidly lowered, the pressure was released, and the polymerization was stopped. The rubber obtained by coagulating, washing and drying the produced dispersion was hardly soluble even in hot acetone. The TFE/VdF segment content was 10% by weight, and the TFE/VdF monomer ratio within the segment was 75/25 (molar ratio).

FIG. 1 shows the temperature increase and decrease patterns of the differential thermal analysis obtained for the rubbers obtained in (5) and (6). The temperature difference between melting and crystallization of the PVdF segment was uniquely large, and delayed crystallization or supercooling phenomena were observed.

The melting and crystallization temperatures of crystalline segmented polymers are also influenced by changes in the proportions and distribution of polymer chain segments, molecular weight, incorporation of non-segmented polymer molecules, etc. For example, in the case of a segmented polymer of VdF/HFP (78/22 molar ratio) rubber and PVdF, there is a relationship as shown in Figure 2.

A transparent rubber sheet was easily obtained by compression molding the polymer obtained in (5) at 200°C. X-ray wide-angle diffraction and small-angle scattering measurements were performed on a sample in which the PVdF segment was sufficiently crystallized by slow cooling during molding, and a pattern as shown in FIG. 3 was obtained. At a wide angle, a peak shape can be seen at 2θ = 20° as a shoulder of the amorphous peak that has the highest value at 2θ = 17 to 18°. In addition, in small-angle scattering, 2θ=
A peak considered to be based on a regular structural unit of 150 Å was observed at 35′ according to Bragg's formula, and this is considered to be related to the spacing of the PVdF segments.

The rubber obtained in (5) was insoluble in methyl ethyl ketone even when heated, but soluble in hot acetone and dissolved in dimethylacetamide at room temperature.
Therefore, the intrinsic viscosity (dl/g, 35° C.) of the polymers (3) and (5) above was measured using acetone and dimethylacetamide as solvents.

Acetone Dimethylacetamide (3) 1.41 1.40 (5) 1.55 1.64 This result shows that the PVdF segment bonded to the rubber segment tends to form a stringy shape because acetone is a poorer solvent than dimethylacetamide.

12% by weight of the PVdF obtained in Reference Example 1 below was blended in the form of a dispersion with the rubber segmented polymer of (3) above (indicated by 3 in Figure 4).
The rubber segmented polymers obtained in (7), (4), (5), and (6) were hot-plate molded at 220°C, respectively, and dumbbell-shaped samples were obtained from sheets with a thickness of 0.4 to 0.7 mm obtained by rapid cooling. was punched out and subjected to an elongation to tension test at a tensile speed of 100 mm/min using a Tensilon UT type universal tensile testing machine. The results are shown in Figure 4.

In addition, with the dispersion blend, a transparent sheet could not be obtained even by melt molding.

Compared to (3) and (7), the tension effect or vulcanization effect due to the segmented polymer is obvious, and (4)
The molecular weight effect in (5) and the effect of the type of hard segment in (5) and (6) can be understood. However, the conditions for preparing the segmented polymer in this example were not necessarily optimal, and impure molecules were also contained. In other words, it must be taken into account that the effect is diluted because it also contains molecules that do not have a three-block structure in which rubber is sandwiched between hard segments.

(5) and (6) segmented polymers from 100 to 130
When masticated for about 5 minutes with a rubber kneading roll whose temperature was adjusted to 0.degree. C., a soft sheet with a feeling that the vulcanized rubber was stretched and fixed was obtained.

Furthermore, when this sheet is molded on a hot plate at 200℃, the stretched rubber properties are lost and it becomes a normal rubber molded sheet, but when this sample is subjected to an elongation to tension test using a Tensilon UT model universal tensile tester, The result will be as shown in Figures 5 and 6. The broken lines and solid lines in the middle of the curve indicate hysteresis loops, and it can be seen that the TFE/VdF hard segment undergoes considerable plastic deformation.

That is, at room temperature, polymer molecules mainly break and deteriorate, but by masticating at a high temperature of 100°C or higher, the tensile properties of the molded rubber as a vulcanizate were improved. Note that this sheet was soluble in dimethylacetamide. In addition, an increase in strength was observed when carbon black (MT-carbon) and magnesium oxide were mixed as fillers using a hot roll or mixed during coagulation.

Example 2 (1) The pre-operation was exactly the same as in Example 1 (1), but 10 ml of the initiator APS as a 3% by weight aqueous solution was injected under pressure to initiate polymerization. After about an hour of induction time,
The pressure began to drop, and the reaction continued for the next 10.8 hours. At the 7-hour mark, 10 ml of a 0.5% by weight aqueous solution of APS was injected, but the polymerization rate was slightly accelerated and remained almost constant throughout the polymerization. The solids content in the resulting dispersion was 11% by weight.

(2) The dispersion obtained in (1) is placed in the same reaction tank.
After adding 500 ml and 500 ml of pure water and carrying out the same pre-operation as in (1), 10 ml of a 0.2% by weight aqueous solution of APS was introduced under pressure to start polymerization. The polymerization rate became slower than in (1) as the number of particles decreased with dilution. APS every 4 hours
14 by press-fitting 5 ml of a 0.2% aqueous solution of
After reacting for some time, the polymerization was stopped by rapidly cooling and releasing the pressure. The solids content in the produced dispersion was 20.8% by weight, and the rubbery polymer obtained by freezing and coagulating, washing with water, and drying had an intrinsic viscosity [η] of 1.09 in methyl ethyl ketone solvent.

(3) The dispersion obtained in (2) is placed in the same reaction tank.
Add 400ml and 600ml of pure water, replace the space sufficiently with TFE, pressurize to 9.5Kg/cm ² G while stirring at room temperature, and then add TFE/ethylene (55/45 molar ratio).
After pressurizing to 13.5Kg/cm ² G with mixed monomer, 70℃
Rapidly raise the temperature to 10 ml of APS 0.1% by weight aqueous solution.
was press-fitted. 15.5 to 16 as the pressure drop begins
The reaction was continued for 3 hours while additionally pressurizing a mixed monomer of TFE/ethylene (55/45 molar ratio) in the range of Kg/cm ² G. During this time, a gradual decrease in the polymerization rate was observed. The solid content of the produced dispersion was 8.8% by weight, and the rubbery powder obtained by freezing and coagulating, washing with water, and drying was insoluble in acetone. Note that the ratio of TFE/ethylene polymer chain segment was 13% by weight.
The pattern of differential thermal analysis of this rubbery polymer is as shown in Figure 7. Compared to the case of PVdF hard segmentation in Example 1, the crystallization temperature did not decrease significantly, and the TFE/ethylene polymer chain segment It seems that the compatibility between the HFP/VdF polymer chain segment and the HFP/VdF polymer chain segment is relatively poor.

In addition, when a dumbbell-shaped sample prepared from a 0.6 mm thick rubber sheet obtained by hot plate molding at 260°C and slow cooling was performed in the same tensile test as above (10 cm/mm), the results were as follows. The hysteresis loop and elongation ratio to tension master curve are shown in Figure 8.

In this example, the effect of improving the tensile strength properties of the vulcanized rubber by the hot roll treatment was not so great.

Example 3 (1) Add 3000 parts of pure water to a pressure-resistant reaction tank that can hold 600 parts of water.
After charging 3 parts of ammonium perfluorooctanoate and completely replacing the internal space with pure nitrogen gas, VdF/HFP/TFE (20/69/11
molar ratio) mixed gas at 80℃, 15Kg/cm ² G while stirring
Pressure was applied. When 4 parts of a 1% APS aqueous solution is injected into the tank, the pressure immediately drops, so the reaction is continued while injecting a mixed gas of VdF/HFP/TFE (50/30/20 molar ratio) to maintain the pressure. When the reaction amount reached 2 parts, 3.1 parts of 1,4-diiodoperfluorobutane was introduced under pressure. From then on, 3
While pressurizing 2 parts of 1% aqueous solution of APS every hour.
After carrying out the reaction for 15 hours, the reaction was terminated by rapidly lowering the temperature and releasing gas. solids content
A 25% white aqueous dispersion was obtained.
This dispersion can be coagulated by a line mixer with strong shearing force,
The coagulated product was washed with water and dried to obtain a colorless and transparent elastic polymer. Iodine content 0.18%. [η]=0.45
(dl/ ₈ , 35°C, MEK).

(2) Put 1,500 ml of the dispersion obtained in (1) into a reaction tank with an internal volume of 3,000 ml, and after thoroughly replacing the internal space with TFE, add TFE/ethylene (90/10
molar ratio) mixed gas at 80℃, 15Kg/cm ² G while stirring
Pressure was applied. When 10 ml of 0.1% aqueous solution of APS was injected, the pressure started to drop, so the reaction was continued by restoring the pressure with a TFE/ethylene (52/48 molar ratio) mixed gas, and after 3.5 hours, the rubber segment of the copolymer segment The proportion is 15% by weight
At the stage when the reaction temperature was reached, the reaction was stopped by lowering the temperature and releasing the pressure. The resulting aqueous dispersion was coagulated with a 2% aqueous magnesium chloride solution, washed with water, and dried to form a fine granular powder. According to DSC analysis, this powder exhibits an endotherm at 260°C due to the melting of TFE/ethylene copolymer crystals, and at 270°C.
A colorless and transparent sheet could be made by hot plate molding at ℃. It was insoluble in acetone and its mechanical properties were similar to the rubbery copolymer obtained in Example 2.

Example 4 In a stirred reaction tank with an internal volume of 400 ml, 200 ml of pure water, 1 g of ammonium perfluorooctanoate, and
After adding 10mg of APS and thoroughly replacing the internal space with TFE, 1,4-diiodoperfluorobutane was added.
0.1g and VdF/TFE/perfluoro(methyl vinyl ether) (PMVE) (60/20/20 molar ratio)
Immediately after injecting 27.5 g of the mixture, under stirring,
The temperature was raised to 60°C. The pressure rises to a maximum of 34Kg/cm ² G, but gradually decreases to 4Kg/cm ² after 2.5 hours.
It dropped to G. Here, 27.5 g of the above monomer mixture was again pressurized, and the reaction continued. After 2 hours, the pressure decreased again to 4 kg/cm ² G, so the pressure was released, the temperature was lowered, and the contents were taken out to obtain a white aqueous dispersion. A portion of the dispersion was broken with a 2% aqueous magnesium chloride solution, washed with water, and dried to obtain a rubbery copolymer. The solid content concentration of the dispersion was 20.5%.

100 ml of this aqueous dispersion was diluted twice, placed in the same reaction tank, the internal space was sufficiently replaced with TFE, and the temperature was raised to 70°C with stirring.
15Kg/cm ² G with ethylene (90/10 molar ratio) mixed gas
Pressure was applied. The start of the reaction can be detected by a drop in pressure, so the reaction was continued at the same pressure for 3 hours while recovering the pressure with a TFE/ethylene (60/40 molar ratio) mixed gas. When the proportion to the segment reached 15% by weight, the pressure was released and the temperature was lowered to complete the process. The resulting aqueous dispersion could be easily coagulated with a 2% aqueous magnesium chloride solution to obtain a fine granular powder. This powder is heated at 260℃
It could be molded into a sheet by hot plate molding, and exhibited mechanical properties similar to those of the rubbery copolymer obtained in Example 2.

Example 5 (1) Put 1.5 g of pure water and 30 g of ammonium perfluorooctanoate into a pressure-resistant reaction tank with an internal volume of 3, and after sufficiently purging the internal space with nitrogen gas, perfluoro(propyl vinyl ether)
(PPVE) 300g was press-fitted and the temperature was raised to 50℃ while stirring.
The pressure was adjusted to 3.5 Kg/cm ² G using TFE. Here, when 20 ml of a 1% aqueous solution of APS was pressurized, the pressure started to drop, and when the pressure decreased to 3 kg/cm ² G, 1.6 g of 1,4-diiodoperfluorobutane was pressurized. The reaction rate will decrease slightly, but by continuously pressurizing TFE, the reaction rate will decrease to 3.0.
When the reaction was continued at ~3.5 Kg/cm ² G, the reaction rate gradually recovered. After continuing the reaction for 14 hours, the internal pressure was released, the temperature was lowered to room temperature, and the polymerization reaction was stopped. The product was a white aqueous dispersion with a small amount of vinyl ether remaining in liquid form. The solids content of the aqueous dispersion is 20.7
It was %. After removing volatile components under a reduced pressure of 200 mmHg at 60°C, a portion was added to a large amount of acetone and treated with a mixer to destroy the dispersion, washed with water, and dried to obtain a rubbery crumb. . PPVE by high temperature NMR analysis
The content is 38 mol%, and the number average molecular weight by GPC (solvent: trichlorotrifluoroethane) is 1.1
×10 ⁵ , and the glass transition temperature determined by DSC was 2°C. Also, the iodine content according to chemical analysis is 0.22%
It was hot.

(2) Dilute 500ml of the dispersion obtained in (1) twice with pure water, put it in the same reaction tank as in (1), and after fully replacing the internal space with TFE at room temperature,
Pressurize to Kg/cm ² G, then further add ethylene to 10
The pressure was increased to Kg/cm ² G, and the temperature was immediately raised to 80° C. while stirring. The pressure rose to 14.5Kg/cm ² G, but due to the remaining APS, the pressure gradually decreased, so TFE/ethylene (50/50 molar ratio)
After maintaining the pressure at 14 to 15 Kg/cm ² G with a mixed gas and continuing the reaction for 3.5 hours, the pressure was released and the temperature was lowered to stop the polymerization reaction. A fine granular powder was easily obtained from the obtained white aqueous dispersion by treating it with a mixer while adding a 2% aqueous magnesium chloride solution. It is also insoluble in trichlorotrifluoroethane, has an iodine content of 0.19% by weight according to chemical analysis, and a content of TFE/ethylene copolymer segment of about 16%, based on the melting of this segment at 260 °C according to DSC analysis. It had an endothermic peak and could be compression molded into a transparent sheet at 260°C, exhibiting the properties of a vulcanized rubber.

(3) Dilute 500ml of the dispersion obtained in (1) twice, place it in the same reaction tank as in (1), replace the internal space with TFE at room temperature, and then raise the temperature to 60℃ while stirring. However, when pressurized to 8 kg/cm ² G with TFE, the pressure immediately begins to drop, so the reaction is continued while maintaining pressure with TFE, and after 1.5 hours, the polytetrafluoroethylene segment becomes 15% by weight based on the rubber segment. At this stage, the pressure was released and the temperature was lowered to stop the reaction. The resulting dispersion was treated in the same manner as in (2) to obtain a granular powder.
This was dissolved in trichlorotrifluoroethane, but it was quite cloudy. However, no phenomenon of precipitation of cloudy components was observed.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the temperature increase and decrease patterns of differential thermal analysis, where 5 is for the rubber obtained in (5) of Example 1, and 6 is for the rubber obtained in (6) of Example 1. . The temperature increase/decrease rate is 10℃/min. FIG. 2 is a graph showing changes in melting point a and crystallization temperature peak b with respect to block segments (wt%), and the temperature increase/decrease rate was 10° C./min. FIG. 3 is a graph showing the X-ray wide-angle diffraction A and small-angle scattering B patterns of a sample in which the PVdF segment of the polymer obtained in Example 1 (5) was sufficiently crystallized. Figures 4 to 6 are elongation ratio-tension curves showing the results of elongation-tension tests of samples, but at a temperature of 23
℃, and the tensile speed was 10 cm/min. Note that (3) to (7) indicate each sample. FIG. 7 is a graph showing the pattern of differential thermal analysis of the rubbery polymer obtained in Example 2, where the heating rate was 10° C./min. FIG. 8 is an elongation ratio-tension curve of the dumbbell-shaped sample of Example 2.

Claims (1)

[Claims] 1. A chain consisting of two or three polymer chain segments, an iodine atom present at one end of the chain, and an iodide compound present at the other end of the chain, with at least one iodine atom removed. one (if the chain consists of two polymer chain segments) or one or two (if the chain consists of three polymer chain segments) of said polymer chain segments; Vinylidene fluoride/hexafluoropropylene/tetrafluoroethylene (molar ratio 45-90:5-50:0-35) polymer and (2) perfluoro(alkyl vinyl ether) (alkyl group has 1 to 3 carbon atoms)/tetra Fluoroethylene/vinylidene fluoride (molar ratio 15-75: 0-85 (excluding 0): 0-
85) Selected from polymers, molecular weight 30000 ~
1200000 elastomeric polymer chain segments, the remainder of said polymer segments being (3) vinylidene fluoride/tetrafluoroethylene (molar ratio 0-100:0-100) polymer and (4) ethylene/
Tetrafluoroethylene (molar ratio 40-60:40-
60) Selected from polymers, molecular weight 3000~
400,000 non-elastomeric polymer chain segments, with a weight ratio of elastomeric to non-elastomeric polymer chain segments of 40 to
A fluorine-containing segmented polymer having a ratio of 95:5 to 60.