JPS62201912A - Chlorotrifluoroetylene/perfluoropropyl vinyl ether copolymer - Google Patents

Abstract

PURPOSE:To obtain a copolymer which is rendered solvent-soluble without detriment to high chemical stability and heat stability, by forming it from chlorotrifluoroethylene and perfluoropropyl vinyl ether as essential components so that the content of the latter may be specified value or larger. CONSTITUTION:This copolymer contains chlorotrifluoroethylene (A) and perfluoropropyl vinyl ether (B) as essential principal components and has a number-average MW >=3,000 and a content of component B >=5mol%. It is desirable that the total of the molar fractions of components A and B is 95% or above and the content of component B is 5-40mol% in order for the polymer to maintain said characteristics.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a chlorotrifluoroethylene/perfluoropropyl vinyl ether copolymer,
Specifically, the present invention relates to a novel copolymer which contains chlorotrifluoroethylene and perfluoropropyl vinyl ether as essential main components and has a perfluoropropyl vinyl ether content of 5 mol % or more.

[Prior Art] Conventionally, many copolymers of perfluoropropyl vinyl ether and fluoroolefins are known (US Pat. No. 3,132,123 and others). The patent describes a copolymer of perfluoropropyl vinyl ether and tetrafluoroethylene, but since this copolymer is insoluble in solvents, it cannot be weighted into a thin film or coated on other materials. The disadvantage is that it is difficult.

[Problems to be Solved by the Invention] Based on the recognition of the above-mentioned problems, the present invention solves the problems of chlorotrifluoroethylene and chlorotrifluoroethylene, which were previously unknown, and which were discovered as a result of various studies on copolymers of fluoroolefins. An object of the present invention is to provide a novel copolymer comprising perfluoropropyl vinyl ether, in which the content of perfluoropropyl vinyl ether is 5 mol% or more. In other words, this copolymer is a copolymer that is unique in its chemical and physical properties, and is a fluoropolymer with particularly high chemical stability, but it also has the property of being solvent-compatible. The good processability obtained from the above demonstrates the versatile utility of this copolymer. Specific application fields showing the usefulness of this copolymer include, for example, coating materials, painting materials, insulation film materials, weather-resistant film materials, and molecular il-simulating materials.

[Means for Solving the Problems] The present invention has been completed based on the findings described in .
This invention provides a novel chlorotrifluoroethylene/perfluoropropyl vinyl ether copolymer, which is a copolymer of 00 or less, and is characterized in that the content of perfluoropropyl vinyl ether is 5 mol% or more -L. be.

The present invention will be explained in more detail below.

The structure of this copolymer may vary depending on the content ratio of constituent molecules, molecular weight, etc., but it is essential that it essentially contains chlorotrifluoroethylene units and perfluoropropyl vinyl ether units. Regarding the content ratio of the constituent monomers, it is essential that the molar fraction of perfluoropropyl vinyl ether is 5% or more. In order to make the contribution of each component sufficient, the molar fraction of perfluoropropyl vinyl ether is 5 to 40%, preferably 6 to 30%.
It is desirable that Too low a molar fraction of perfluoropropyl vinyl ether is undesirable from the viewpoint of solubility. Furthermore, if the molar fraction of perfluoropropyl vinyl ether is too high, it may generally be undesirable from the viewpoint of physical properties such as mechanical strength. Furthermore, if necessary, it is also possible to copolymerize a third or more component of Ki and Shi, which can impart, for example, crosslinking properties and adhesion to substrates. In order not to lose the characteristics of the polymer, it is desirable that the total molar fraction of chlorotrifluoroethylene and perfluoropropyl vinyl ether be 85% or more. Other comonomers introduced for this purpose include fluorovinyl ethers such as perfluorobromoethyl vinyl ether, fluoroolefins such as promotrifluoroethylene,
Examples include vinyl esters such as vinyl acetate, vinyl acetate, vinyl yojo, and vinyl acetate, α-olefins such as ethylene, propylene, and imbutylene, and vinyl ethers such as ethyl vinyl ether, butyl vinyl ether, and hydroxyalkyl vinyl ether. . The preferred molecular weight of the copolymer is not particularly limited, as it varies depending on the application, but in general, from the viewpoint of mechanical strength, it is not desirable to have a molecular weight that is too small.

A number average molecular weight of 3,000 or more, particularly about 5,000 or more is preferably used for various purposes.

The copolymer of the present invention can be advantageously produced by conventionally known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, etc. without particular limitation.

Examples of radical initiators that can be used in solution polymerization include di(chlorofluoroacyl) peroxide, di(perfluoroacyl) peroxide, and di(ω-hydroperfluoroacyl) peroxide described in Japanese Patent Publication No. 47-44031. oxide, di(chlorofluoroacyl) peroxide, t-butylperoxyisobutyrate, diisobrobyl baroxydicarponate, azobisbutyronitrile, and the like. Further, as the solvent, for example, various chlorofluoroalkanes, various alcohols, various esters, etc. can be used. Examples of chlorofluoroalkanes include trichlorofluoromethane, dichlorodifluoromethane, dichlorofluoromethane, chlorodifluoromethane, trifluoromethane,
Examples include trichlorotrifluoroethane, dichlorotetrafluoroethane, chloropentafluoroethane, difluoroethane, and the like. As alcohol, for example, E
-butanol and the like, and examples of the ester include methyl acetate and ethyl acetate. Furthermore, a chain transfer agent can be added if necessary to adjust the molecular weight. Examples of chain transfer agents include carbon tetrachloride, n-pentane, n-hexane, impentane, trichlorofluoromethane, methanol, and the like.

In the suspension combination, the radical initiators listed above for solution polymerization can be used, and the solvent used is a mixture of water and the chlorofluoroalkanes listed for solution polymerization, and the mixing ratio is water:chlorofluoroalkane in a weight ratio. Fluoroalkane = 1
:9 to 9:1, preferably l:5 to 5:1.

Furthermore, it is possible to add a chain transfer agent for solution polymerization depending on the center spacing. Also, desirably, a fluorocarbon emulsifier, such as C1h5COONHa, is used as a stabilizer.
It is desirable to add C8F+rC0ONH4 or the like.

Radical polymerization initiators that can be used in emulsion polymerization include:
Common water-soluble radical polymerization initiators are used. For example, disuccinin quacid peroxide, potassium persulfate, ammonium persulfate, t-butylperoxyisobutyrate, 2,2'-diguanyl-2,2'- Examples include asopropane dihydrochloride. When using a persulfate, it can be used in combination with an appropriate reducing component as a so-called redox system. Examples of the reducing component include reducing agents such as sodium bisulfite, sodium thiosulfate, and Rongalit. Furthermore, it is possible to coexist a small amount of iron, ferrous salt, and silver sulfate alone or in combination with a stabilizer such as disodium ethylenediaminetetraacetate, especially when Rongalit is used as a reducing component. This is desirable.

It is also possible to use ionizing radiation as a radical initiation source.

In carrying out such emulsion polymerization, it is also suitable to use commonly used emulsion stabilizers, pH 8a buffers, pH 7A regulators, polymerization promoters and other additives. Furthermore, if necessary, a chain transfer agent for the solution polymerization can be added. Furthermore, from the viewpoint of promoting polymerization or stabilizing the latex, it is preferable to use a mixed solvent in which an organic solvent is added to water. Suitable examples of such additive solvents include t-butanol, methyl acetate, trichlorotrifluoroethane, and the like. As the emulsifier, for example, hydrocarbon surfactants such as sodium lauryl sulfate can be used, but fluorocarbon emulsifiers are preferable from the viewpoint of stabilizing the latex, such as C1h5COONh, C8F.
It is preferable to use +rCOONH4 or the like.

Regarding the polymerization temperature, it may be appropriately selected depending on the initiator system used, and is not particularly limited, but generally O to 1
A temperature of about 00°C is used.

In addition, the pressure is not particularly limited as it can change depending on the ingredients and temperature, but it is generally 0.
．． A pressure of about 1 to 100 atm is practical.

The present copolymer obtained by such a method has, for example, high chemical stability, which perfluoropolymers such as tetrafluoroethylene/perfluoropropyl vinyl ether copolymer and tetrafluoroethylene/hexafluoropropylene copolymer have. In addition to properties such as stability and thermal stability, it is soluble in fluorine-based solvents such as trichlorotrifluoroethane and tetrachlorodifluoroethane at room temperature.

Due to the physical property of solvent solubility, this copolymer can be formed into thin films of several sizes or less without defects such as pinholes, and can be coated onto materials with a thickness of several microns or less and complex shapes. etc. is easy.

Specific application fields showing the usefulness of this copolymer include:
Examples include coating materials, painting materials, insulation film materials, and separation membrane materials.

The composition of the obtained copolymer can be confirmed by conventional methods such as elemental analysis and NMR. The number average molecular weight was determined by dissolving the copolymer in trichlorotrifluoroethane and performing gel ψ permeation chromatography (GPC). In addition, the decomposition temperature, which is an index of thermal stability, was measured using a thermogravimetric analyzer.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but it goes without saying that the present invention is not limited by such explanations.

Example 1 90 g of ion-exchanged water, 10 g of t-butanol,
Ammonium perfluorononanoate (CsFuCOON
Ha) Ig, 2 g of disl.lium phosphate (decahydrate)
, caustic soda 0.22g, ammonium persulfate 1g,
Ethylenediaminetetraacetic acid disodium (dihydrate) 0.0
After charging 18 g of ferrous sulfate (7 ice salt) and 0.015 g of perfluoropropyl vinyl ether, the flange of the autoclave was closed. Repeat freezing and degassing three times 1. After that, 114 g of chlorotrifluoroethylene was charged into the degassed autoclave. After stirring and heating the autoclave to 25°C, 0.04 g of Rongalito dissolved in 2 g of degassed ion-exchanged water was press-fitted. The reaction temperature is maintained at 25°C. After 32 hours, 0.04 g of Rongalit was added in the same manner.

After 64 hours from the initial addition of Rongalit, unreacted chlorotrifluoroethylene is purged while the autoclave is cooled, and the flange is opened to collect the latex. After the latex is coagulated using methanol and hydrochloric acid, the precipitated polymer is collected by anchorage. The polymer is dissolved in trichlorotrifluoroethane, and after the disease has passed, it is reprecipitated into methanol. After thoroughly washing the reprecipitated polymer with methanol and ion-exchanged water, it was washed under reduced pressure at room temperature for 18 hours.
Further drying at 35°C for 2 hours yielded 13.3 g of a resinous chlorotrifluoronithylene/perfluoropropyl vinyl ether copolymer. The decomposition initiation temperature of the polymer was 356°C, and the number average molecular weight determined by GPC was 6. The composition of the polymer determined by elemental analysis was chlorotrifluoroethylene/perfluoropropyl vinyl ether = 84.4/15.8 (molar ratio).

The polymer was dissolved in trichlorotrifluoroethane at room temperature, cast on a glass plate using an applicator, dried, and then peeled off from the glass surface to form a transparent self-supporting 7;,'j with a thickness of 25μ. I made 4jl.

The chemical stability of the thin film was investigated by acid and alkali immersion tests, and the results are shown in Table 1.

From the properties shown in Table 1, it can be seen that this copolymer is suitable as a material for thin films and the like.

Furthermore, the polymer was dissolved in trichlorotrifluoroethane, coated on an iron plate, and dried to a thickness of 3.
A coating layer of μ was obtained. No pinholes were detected when examined using a wet type 7 pinhole tester.

The following properties show that the present copolymer is not only suitable as a material for coatings, but also useful as a material for separation membranes since a defect-free coating layer can be obtained.

Example 2 After charging 130 g of trichlorotrifluoroethane into a stainless steel autoclave with an internal volume of 280 cc and equipped with a stirrer, and charging 7 g of 4B perfluoropropyl vinyl ether, the flange of the autoclave was closed. After repeating freezing and degassing three times, 20.8 g of chlorotrifluoroethylene was charged into the degassing autoclave. After stirring and heating the autoclave to 50° C., 0.17 g of heptafluorobutyl peroxide dissolved in 2 g of degassed trichlorotrifluoroethane is introduced under pressure. The reaction temperature is maintained at 50°C. 7.2 hours after the addition of peroxide, while cooling the autoclave, unreacted chlorotrifluoroethylene was purged, the flange was opened, and the polymer solution was recovered. Discard the polymer solution and reprecipitate into methanol. After thoroughly washing the precipitated polymer 11f with methanol and ion-exchanged water, the resin-like chlorotrifluoroethylene/perfluoropropyl vinyl ether copolymer 4 was obtained by drying it under reduced pressure at room temperature for 16 hours and then at 35°C for 2 hours. .3g was obtained. The molecular weight of the polymer was 30,000. The composition of the polyamide determined by elemental analysis was chlorotrifluoroethane/perfluoropropyl vinyl ether = 72.
The molar ratio was 2/27.8.

The polymer was dissolved in trichlorotrifluoroethane at room temperature to prepare a 10% polymer solution, which was then cast onto an aluminum plate-L using an applicator to obtain a uniform coating film. From these results, it is clear that the present co-yellow coalescence is useful as a paint resin.

Example 3 In a stainless steel autoclave with an internal volume of 100 cc and equipped with a stirrer, 50 g of ion-exchanged water, 5 g of t-butanol, and ammonium barfluorononanoate (CsF+7GOON) were placed.
H4) 0.3g, sodium 41phosphate (dihydrate I
IX) 0.15g, enodium phosphate (12
water salt) 0.25g, ammonium peroxide 0.05g
After charging 0.025 g of sodium bisulfite and 10 g of perfluoropropyl vinyl ether,
Close the autoclave flange. After repeating freeze degassing three times and heating to 45 °C, the autoclave was stirred and chlorotrifluoroethylene was constantly added at 4 g pressure.
．． It will be introduced so that it will be 5 ATM. The reaction temperature is maintained at 45°C. After 6 o'clock fin, while cooling the autoclave, unreacted chlorotrifluoroethylene was purged, and the flange was opened to collect the latex. After the latex is coagulated using methanol and hydrochloric acid, the precipitated polymer is recovered. The polymer is dissolved in trichlorotrifluoroethane, and after the disease has passed, it is reprecipitated in methanol. After thoroughly washing the reprecipitated polyester with methanol and ion-exchanged water, it was dried under reduced pressure at room temperature for 16 hours and then at 35°C for 2 hours to obtain a resin-like chlorotrifluoroethylene/perfluoropropyl vinyl ether copolymer. Combine 1
．． 3g was obtained. The number average molecular weight of the polymer was 50,000. The composition of the polymer determined by elemental analysis was trichlorotrifluoroethylene/perfluoropropyl vinyl ether = 92.0/8.0 (molar ratio).

The polymer is dissolved in trichlorotrifluoroethane at room temperature to prepare a 10% polymer solution, which is then cast onto an aluminum plate using an applicator.

After drying, this coating film was subjected to an accelerated weathering test using a sunshine weatherometer, and the gloss retention rate after 4000 hours was 90% or more, indicating good weather resistance. This result shows that the wood copolymer is useful as a molding coating resin.

Comparative Example 1 130 g of trichlorotrifluoroethane was placed in a stainless steel autoclave with an internal volume of 2fiOce and equipped with a stirrer.
Preparation, perfluoropropyl vinyl ether at 37.
After charging 2g, close the flange of the autoclave.

After repeating freezing and degassing three times, 5.1 g of chlorotrifluoroethylene was charged into the degassing autoclave.

After stirring and heating the autoclave to 70° C., 0.15 g of azobisbutyronitrile dispersed in 2 g of degassed trichlorotrifluoroethane is introduced under pressure. The reaction temperature is maintained at 70°C. 3.5 hours after adding azobisbutyronitrile, while cooling the autoclave, purge unreacted chlorotrifluoroethylene, open the flange, collect the cloudy polymer solution, and reprecipitate it in methanol. let After thoroughly washing the reprecipitated polymer with methanol and ion-exchanged water, it was placed in a vacuum chamber at room temperature for 1 hour.
By drying for 6 hours and further at 35°C for 2 hours, 2.5 g of a resinous chlorotrifluoroethylene/perfluoropropyl vinyl ether copolymer was obtained. Fluoroethylene/perfluoropropyl vinyl ether = 95
．． It was 8/4.2.

The polymer was virtually insoluble in trichlorotrifluoroethane.

[Effects of the Invention] The chlorotrifluoroethylene/perfluoropropyl vinyl ether copolymer 1f of the present invention.

It is a copolymer with unparalleled chemical and physical properties, and is a fluorine-based copolymer with particularly high chemical and thermal stability, but it is also solvent-compatible. The good processability obtained indicates the versatility of this copolymer.Specific application fields showing the usefulness of this single copolymer include, for example, coating materials, painting materials, Examples include materials for insulating films, materials for weather-resistant films, and materials for separation membranes.

Claims (1)

[Claims] 1. Number average molecular weight 3 containing chlorotrifluoroethylene and perfluoropropyl vinyl ether as essential main components
,000 or more, and the content of perfluoropropyl vinyl ether is 5 mol% or more. 2. The content of perfluoropropyl vinyl ether is 5.
The copolymer according to claim 1, wherein the copolymer has a content of 40% by mole. 3. The copolymer according to any one of claims 1 to 2, wherein the total molar fraction of chlorotrifluoroethylene and perfluoropropyl vinyl ether is 95% or more.