JP3004090B2 - Fluoropolymer and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluoropolymer.

[0002]

2. Description of the Related Art Fluorine-containing polymers, particularly perfluoropolymers, have excellent chemical stability but lack transparency due to crystallinity. When the proportion of the copolymer component is increased to increase the transparency, there is a problem that the softening temperature is lowered and the elastic modulus at a high temperature is lowered. Usually, the softening point temperature of an amorphous polymer is determined by the glass transition temperature T _g , and before and after this, many physical properties such as mechanical properties and electrical properties greatly change. Therefore, heat resistance, in applications requiring chemical stability remains high transparency was maintained is desired that the glass transition temperature of a polymer of sufficiently high amorphous.

In Japanese Unexamined Patent Publication No. 1-13125, CF ₂ = C
It has been shown that FO (CF ₂ ) _n CF ＝ CF ₂ undergoes cyclopolymerization alone to give a polymer having a cyclic structure, which is excellent in light transmittance and which is soluble in a solvent. However, n = 1
Even when T _g = 69 ° C. and n = 2, the T _g
= 108 ° C, there was a problem that the heat distortion temperature was not so high and it was insufficient for use at high temperatures.

On the other hand, amorphous fluoropolymers having a high T _g include perfluoro (dimethyldioxole) [P
DD] is known (USP 475400).
9).

[0005] PDD polymer has a higher T _g of the above 300 ° C., it was not possible to take the processing means such as a solvent, such fried coating that dissolves it. Also, PD
To increase the solubility of the D polymer, there is a method in which copolymerization of monomers such as tetrafluoroethylene, but there is a problem that T _g is lower.

[0006]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned drawbacks of the fluorine-containing polymer and newly provides a polymer having an appropriate glass transition temperature capable of withstanding high-temperature use while maintaining transparency. It is intended to provide.

[0007]

The present inventors have made intensive studies on various fluorine-containing monomers based on the recognition of the above problems, and as a result, the formula (A) (where n is 1 or 2,
Rf is a polymer having a polymerized unit represented by a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms ) of 290.
It has been newly found that a polymer having a high T _g of not less than ° C and having excellent transparency and being soluble in a solvent can be obtained.

[0008]

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The reason why the polymer of the present invention is soluble in a solvent is not clear, but it is considered that the polymer has a double ring structure. That is, in the ring structure constituting the main chain, in order to further another ring structure is attached, amorphous, and perfluoro (2-butyl tetrahydrofuran) high T _g, perfluoro tetrabutyl amine, hexafluorobenzene It becomes soluble in solvents such as This enables processing means such as coating and dipping.

The fluoropolymer of the present invention has the formula (B)
(However, n is 1 or 2, Rf is a fluorine atom or a C1-C3 perfluoroalkyl group) It is obtained by polymerizing the monomer represented by this. Incidentally, the monomer of formula (B) can be synthesized by the method described in Japanese Patent Application No. 3-146693.

[0011]

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The molecular weight of the fluorinated polymer of the present invention is represented by an intrinsic viscosity at 30 ° C. (unit: dl / g: hereinafter simply referred to as intrinsic viscosity) in perfluoro (2-butyltetrahydrofuran), and this value is 0.1. 5. from the is between 0. If it is less than 0.1, it will not have sufficient strength, and if it exceeds 5.0, its solubility will be significantly reduced. The molecular weight of the fluoropolymer of the present invention can be adjusted by using a conventionally known or known chain transfer agent in the polymerization reaction.

The fluorinated polymer in the present invention may be a copolymer. By changing the copolymer composition, fluorinated copolymers having different T _g can be obtained while maintaining transparency. Further, by selecting the type of the comonomer, it is possible to improve the adhesion of the fluoropolymer to various substrates and to provide a crosslinked site. Fluoropolymer is copolymer
In the case of, the repeating unit represented by the formula (A)
It is preferably from 1 to 99 mol% of the unit.

[0014] Copolymerization allowed to comonomer rather it may also be allowed to free-radical copolymerization alone, rather it may also be in combination of two or more suitable Yibin to perform the multi-component polymerization reaction and has a radical polymerizable If it is a monomer, it is not particularly limited and may be a fluorine-containing system,
Hydrocarbons and the like can be exemplified extensively.

When a hydrocarbon-based monomer is used, it is preferable that the essence of the fluorinated copolymer is not impaired, but it is also possible to increase the fluorine content by fluorination if necessary.

In the present invention, it is usually desirable to select a fluorine-containing monomer such as fluoroolefin or fluorovinyl ether as a comonomer . For example, tetrafluoroethylene, perfluoro (methyl vinyl ether), perfluoro (propyl vinyl ether), or
Perfluorovinylether containing a functional group such as a carboxylic acid group or a sulfonic acid group is a preferred specific example, and examples thereof include vinylidene fluoride, vinyl fluoride, and chlorotrifluoroethylene.

In the case of a copolymer containing these monomers , the content of the repeating unit (A) is desirably at least 10 mol % in order to maintain amorphousness.
Furthermore, considering solubility and T _g , at least 20 m
ol % is desirable.

[0018] Although the copolymer is obtained in high yield in any composition in the case of using tetrafluoroethylene and <br/> copolymerizable allowed to co-monomer in the present invention, the tetrafluoroethylene content often it is a is a transparent <br/> Kunar crystallinity appears. Although the composition which impairs transparency is not clear, the copolymer having a content of the repeating unit (A) of 28 mol% has no crystallinity and is soluble in a solvent.

Furthermore, comonomers which allowed to copolymerization in the present invention
Polymerizable different carbon as mer - cyclization polymerizable fluorinated monomer having one by one carbon double bond at the molecular end are also suitable examples. Examples of the cyclized polymerizable fluorine-containing monomer having one polymerizable carbon-carbon double bond at each molecular terminal include those listed in Chemical formula 6.

[0020]

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When the cyclopolymerizable fluorine-containing monomer is used, an amorphous and transparent solvent-soluble copolymer can be obtained with an arbitrary composition. Also, copolymers having various T _g can be obtained by changing the copolymer composition. in this case,
The content of the repeating unit (A) can be arbitrarily selected in the range of 1 to 99 mol%.

In the present invention, a usual radical polymerization is used as a polymerization method. That is, the polymerization method is not radically means as long as it progresses limit any way, such as organic, inorganic radical initiator, light, ionizing radiation or the like thermal polymerization. As the polymerization method, bulk polymerization, solution polymerization, suspension polymerization, and emulsion polymerization can be used.

In the present invention, the monomer represented by the formula (B) has a higher boiling point (about 1) as compared with other perfluoro monomers.
05 ° C.) and moderate polymerization rate or potting polymerization because of its is possible casting polymerization. Examples of the casting polymerization include, but are not particularly limited to, a method for producing a lens-shaped molded product. Usually, a method is used in which the monomer is mixed with a polymerization initiator, and if necessary, other monomer components are added, and the mixture is injected into a mold and cured by heating. Adopting these polymerization methods has the advantage that optical components such as optical lenses and optical cells can be produced with less optical impurities. That is, although it is very difficult to mold after removing impurities in the polymer mixed in the production process, in the present invention, since the molding is performed directly from the monomer, the removal of impurities by filtration or the like is performed. Is easy.

The potting polymerization, the type of initiator used in cast polymerization is not particularly limited, as a typical, diisopropyl peroxy dicarbonate, bis-2-ethylhexyl peroxydicarbonate carbonate, diallyl peroxydicarbonate Jikaboneito, isobutyryl peroxide Oki shea de, t- butyl peroxypivalate, peroxides such as Bisupafu Luo lob dust helper Oki shea de the <br/> the like azo compounds. The addition amount of these initiators is generally 0.05 to 5% by weight, preferably 0.1 to 3% by weight, based on the total amount of the monomers.

When potting polymerization or casting polymerization is carried out by heating using an initiator, the initial temperature is 0 to 50 ° C.
It is preferable to gradually raise the temperature as the polymerization proceeds, and it is preferable to finally heat to 60 to 150 ° C. The time spent during this period is not particularly limited, but is required to be about 1 to 20 hours. Further, post-cure can be performed after taking out from the mold if necessary.

In the present invention, when performing potting polymerization or casting polymerization, a photopolymerization method can be employed.
In this case, a photosensitizer such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzophenone, acetophenone, or the like is typically added to the monomer in an amount of 0.01 to 5% by weight based on the total amount of each monomer. It is added and polymerized and cured by irradiating ultraviolet rays. In the photopolymerization method, it may also be used in combination the polymerization initiator Ikoto course.

The fluorinated polymer of the present invention is not limited to the above-mentioned potting polymerization and casting polymerization, but may be a polymer obtained by ordinary polymerization, such as melt molding such as extrusion molding and injection molding.
It is possible to employ processing means such as coating with a solution, casting, dipping, etc., whereby the polymer of the present invention has high T _g , high elastic modulus, high light transmittance,
A low refractive index, low dielectric constant, is applied to a low surface free energy, a number of applications the basic physical properties lend active, such as chemical stability.

[0028] For example, a plate, a pipe, for tubes or high modulus such as in other molding PTFE,
Compared to PFA, etc., it has strength up to high temperatures and excellent chemical stability, so structural parts such as piping, valves, and sight windows of various chemical factory plants are directly mixed with chemicals. It is useful in sites that come into contact. Furthermore, the fluorine-containing polymer of the present invention has excellent thermal stability and does not require additives such as a plasticizer and a heat stabilizer at the time of melt-molding the molded article. This has the advantage that contamination of the product with impurities can be avoided.

As applications utilizing light transmittance, in particular,
And at 250nm or more ultraviolet light transmittance of 90% or more and deterioration such damage by ultraviolet rays, the lens in various optical apparatus using a UV, is available as an optical transmission member such as optical fibers. Since the dispersion is small even in visible light, it is used as a lens for correcting chromatic aberration.

Further, the polymer of the present invention has excellent resistance to various chemicals, and thus is useful as a protective coating agent, a photoresist, a masking agent at the time of etching, and the like. In particular, when used as a photoresist or a masking agent at the time of etching, a mixture of a monomer and a polymerization catalyst or a polymerization initiator is applied, and after irradiating a desired pattern with light to polymerize, unnecessary monomers are removed. The polymer can be formed by removing the polymer, and the polymer can be removed by using a specific solvent. Therefore, the process can be simplified as compared with the related art.

The fluoropolymer of the present invention has a low refractive index and is useful as a low-reflection processing agent. An antireflection effect can be obtained by forming a film of the fluoropolymer of the present invention on the surface of an eyeglass lens, an optical lens, various optical members, a photomask dust cover, a show window, a show case, and the like.

Since the fluoropolymer of the present invention has a low dielectric constant, when it is used as a protective film for a semiconductor device, it has the effect of increasing the calculation speed. In addition, there is an effect that the dielectric constant is not affected by humidity because the water absorption is low. Or fluorine-containing polymer alone film of the present invention is film laminated with a resin such as polyimide is useful as a circuit board.

The fluorine-containing polymer of the present invention has a lower surface free energy, it is possible to impart water repellency to various substrates surface. Perfluoro (2-butyl tetrahydrofuran) also <br/> a solvent of the fluorine-containing copolymer of the present invention is perfluoro tetrabutyl amine is not name that invade substrate itself. Therefore, the solution of the fluorine-containing copolymer of the present invention
The substrate is attacked when the medium is coated on the substrate
Has the advantage that there is no, yet formed film is tough.

[0034]

[Action] The fluorine-containing polymer of the present invention is a transparent amorphous in T _g is higher solvent-soluble since it has a bulky double ring structure in its main chain. Further, by changing the content of the repeating unit (A), copolymers having various T _g can be obtained while maintaining transparency and solubility. Homopolymers and copolymers obtained by the present invention are those indicating One high light transmittance exhibited high transparency without have a crystallinity, also because it is a fluorine-containing polymer, a normal hydrocarbon It is considered that it has a lower refractive index than the resin of the series, and is excellent in low water absorption, weather resistance and chemical resistance. However, such description is intended to help the understanding of the present invention, and is not intended to limit the present invention.

[0035]

EXAMPLE 1 perfluoro (6-methyl-1,4,7-trioxa scan
Pyro [4.5] dec-2-ene) 3. 7 g, perfluoro (2-butyl tetrahydrofuran) 7 g and the polymerization initiator as a (C ₃ F ₇ COO) ₂ in 5% trichlorotrifluoroethane solution 0. 16 g was placed in a pressure-resistant glass ampoule having an internal volume of 50 ml. After the system was frozen and degassed three times, it was shaken in a water bath at 30 ° C. for 18 hours. The obtained solution was diluted with trichlorotrifluoroethane, poured into acetone, and the precipitate was dried under vacuum at 100 ° C. for 20 hours.
As a result, 1.4 g of a polymer was obtained.

The intrinsic viscosity of this polymer was 0.42. The thermogravimetric analysis showed that the polymer had a weight loss onset temperature of 338 ° C. and a 10% weight loss temperature of 438 ° C. Perfluoro (2-butyltetrahydrofuran)
The solution was made temper was dissolved in was 1.33 as measured using an Abbe refractometer the refractive index of the resulting film was cast on a glass plate. Further, the glass transition temperature was observed at 292 ° C. by viscoelasticity measurement. Further, in FIG. 1 a diagram of IR spectrum of this polymer, ¹⁹ FN
A diagram of the MR spectrum is shown in FIG.

[0037] Example 2 perfluoro (6-methyl-1,4,7-trioxa scan
Pyro [4.5] dec-2-ene) 5. 0 g, perfluoro (2-butyl tetrahydrofuran) 5 g, as an ion exchange water 50g and the polymerization initiator (C ₃ F ₇ COO) ₂
Of a 5% trichlorotrifluoroethane solution was placed in a 100 ml stainless steel autoclave. After freezing and deaeration of the system, pressurized deaeration with N ₂ gas was repeated three times, and then tetrafluoroethylene was introduced to a gauge pressure of 10 kg / cm ² and reacted at 40 ° C. for 2 hours.
I let it. The contents were taken out and cooled after its water washing, after washing with methanol, a polymer of 8. 1 g was subjected to 20 hours by vacuum drying at 120 ° C. were obtained.

The polymer was press-moldable at 280 ° C. Press molded <br/> perfluoro the polymer in the absorbance around 1880 cm ^-1 of the IR spectrum of the film (6-methyl-1,4,7-trioxa scan
Repeating unit based on pyro [4.5] dec-2-ene )
It was determined the percentage of the 26 mol%. When the refractive index of this film was measured using an Abbe refractometer, it was 1.3.
It was 4. Further, it was confirmed from the result of wide-angle X-ray diffraction measurement that no crystal structure was present. T _g by viscoelasticity measurement
Was 121 ° C. From the measurement by thermogravimetric analysis, the weight loss onset temperature of this copolymer was 390 ° C.
The 10% weight loss temperature was 470 ° C.

[0039] Example 3 perfluoro (6-methyl-1,4,7-trioxa scan
Pyro [4.5] dec-2-ene) 5. 0 g, perfluoro (2-butyl tetrahydrofuran) 5 g, as an ion exchange water 50g and the polymerization initiator (C ₃ F ₇ COO) ₂
Of a 5% trichlorotrifluoroethane solution was placed in a 100 ml stainless steel autoclave. After the system was frozen and degassed, the pressure degassing operation was repeated three times with N ₂ gas, and then tetrafluoroethylene was introduced to a gauge pressure of 5 kg / cm ² and reacted at 40 ° C. for 3 hours.
I let you. The contents were taken out and cooled after its water washing, after washing with methanol, a polymer of 6. 0 g was subjected to 20 hours by vacuum drying at 120 ° C. were obtained.

The intrinsic viscosity of this polymer was 0.91. The perfluoro (6-methyl-1,
4,7 trioxa spiro [4.5] dec-2-ene)
188 The proportion of the repeating units of the IR spectrum based on
It was 28 mol% from the absorbance near 0 cm ^-1 . T _g was 133 ° C. by viscoelasticity measurement. Thermogravimetric analysis showed that the copolymer had a weight loss onset temperature of 415 ° C. and a 10% weight loss temperature of 465 ° C. The refractive index of the press-molded film was measured using an Abbe refractometer and found to be 1.33. FIG. 3 shows an IR spectrum of this polymer.

[0041] Example 4 perfluoro (6-methyl-1,4,7-trioxa scan
Pyro [4.5] dec-2-ene) 5. 0 g, perfluoro (2-butyl tetrahydrofuran) 5 g, as an ion exchange water 50g and the polymerization initiator (C ₃ F ₇ COO) ₂
Of a 5% trichlorotrifluoroethane solution was placed in a 100 ml stainless steel autoclave. After freeze-deaerated in the system, it was repeated three times pressurized degassing operation by N ₂ gas, by introducing tetrafluoroethylene to gauge pressure 1kg / cm ^2, 4. 5 hours reaction at 4 0 ° C.
I responded. The contents were taken out and cooled after its water washing, after washing with methanol, a polymer of 2. 8 g was subjected to 20 hours by vacuum drying at 120 ° C. were obtained.

The intrinsic viscosity of this polymer was 0.54. The perfluoro (6-methyl-1,
4,7 trioxa spiro [4.5] dec-2-ene)
188 The proportion of the repeating units of the IR spectrum based on
It was 79 mol% as determined from the absorbance near 0 cm ^-1 . T _g was 250 ° C. by DSC measurement.
Thermogravimetric analysis showed that the copolymer had a weight loss onset temperature of 415 ° C. and a 10% weight loss temperature of 465 ° C. The refractive index of the press-molded film was measured using an Abbe refractometer and found to be 1.33.

[0043] EXAMPLE 5 perfluoro (6-methyl-1,4,7-trioxa scan
Pyro [4.5] dec-2-ene ) 5.0 g, CF ₂ ＣC
_{FO (CF 2) 3 COOCH 3} 0. 2g, diisopropyl peroxy dicarbonate 0 as perfluoro (2-butyl tetrahydrofuran) 7 g and the polymerization initiator.
01 g was placed in a pressure-resistant glass ampoule having an internal volume of 50 ml. After freezing and degassing the inside of the system three times,
Shake for 8 hours. The resulting solution was diluted with trichlorotrifluoroethane and poured into acetone to precipitate 10%.
Vacuum dried at 0 ° C. for 20 hours. As a result, the polymer was 3.
2 g were obtained.

The intrinsic viscosity of this polymer was 0.38. The perfluoro (6-methyl-1,
4,7 trioxa spiro [4.5] dec-2-ene)
188 The proportion of the repeating units of the IR spectrum based on
It was 97 mol% as determined from the absorbance near 0 cm ^-1 .

[0045] Example 6 perfluoro (6-methyl-1,4,7-trioxa scan
Pyro [4.5] dec-2-ene ) 5.0 g, CF ₂ ＣC
_{FO (CF 2) 2 CF =} CF 2 3. 2g, perfluoro (2-butyl tetrahydrofuran) 20 g and diisopropyl peroxydicarbonate carbonate 0. 03G as a polymerization initiator were placed in a pressure glass ampoule having an inner volume of 50ml Was. After freezing and degassing the inside of the system three times, 40 ° C in a water bath
Shaking for 18 hours. The obtained solution was diluted with trichlorotrifluoroethane, poured into acetone, and the precipitate was dried under vacuum at 100 ° C. for 20 hours. As a result, 6.5 g of a polymer was obtained.

The intrinsic viscosity of this polymer was 0.45. The perfluoro (6-methyl-1,
4,7 trioxa spiro [4.5] dec-2-ene)
188 The proportion of the repeating units of the IR spectrum based on
It was 55 mol% as determined from the absorbance near 0 cm ^-1 . The refractive index of the press-formed film was measured using an Abbe refractometer and found to be 1.34. T _g was 185 ° C. from DSC measurement.

[0047] Example 7 perfluoro (6-methyl-1,4,7-trioxa scan
Pyro [4.5] dec-2-ene) 1. Diisopropyl peroxy dicarbonate 0. 01G placed in Pyrex glass sample bottle as 0g and polymerization initiator, N
_It was left in a gas atmosphere. One week later, it was taken out, washed with acetone, and vacuum-dried at 100 ° C. for 20 hours to obtain a cylindrical polymer having a diameter of 14 mm and a thickness of 2 mm. The light transmittance of this cylindrical polymer is 250 to 700.
It was 90% or more in nm.

[0048] Example 8 perfluoro (6-methyl-1,4,7-trioxa scan
100 parts by weight of pyro [4.5] dec-2-ene ) and 1 part by weight of diisopropyl peroxydicarbonate were mixed, and a lens-shaped mold was assembled using two glass molds and a polyethylene gasket. After the injection port was sealed, the mixture was heated and heated from 25 ° C. to 90 ° C. for 15 hours. Thereafter, the polymerized and cured lens was taken out of the mold and further heat-treated at 150 ° C. for 1 hour to obtain a lens having a diameter of 30 mm. The light transmittance of this lens was 90% or more at 250 to 700 nm.

[0049]

The fluoropolymer of the present invention has a high T _g and is a solvent-soluble and transparent polymer. The polymer had excellent conventional perfluoropolymer has properties, for example heat resistance, chemical stability, low dielectric constant, but also has a like low refractive index, have a very high T _g and also that Yusuke property of being excellent and soluble in a solvent in transparency. From such characteristics, an effect that an ultrathin film having no defects such as pinholes can be obtained is recognized, and application to a coating material, a separation film material, and the like is also possible. Further, it can be applied to optical materials such as an antireflection agent and a cladding material of an optical fiber by utilizing the low refractive index. In addition, an effect that application as an electronic material is possible because of low dielectric constant and low water absorption is also recognized.

[Brief description of the drawings]

FIG. 1 is a diagram of an IR spectrum of a polymer of Example 1.

FIG. 2 is a diagram of a ¹⁹ F NMR spectrum of the polymer of Example 1.

FIG. 3 is a diagram of an IR spectrum of a polymer of Example 3.

Claims (4)

(57) [Claims] (1) Formula (A) (where n is 1 or 2, Rf
Has a repeating unit represented by a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms, and has an intrinsic viscosity of 0.1 to 5.0 dl measured at 30 ° C. in perfluoro (2-butyltetrahydrofuran). / G of fluoropolymer. Embedded image Wherein formula fluoropolymer of claim 1, wherein the repeating unit represented by (A) is a 1～99Mol% of the total repeating units. 3. The formula (B) wherein n is 1 or 2, Rf
Method of producing a fluoropolymer by polymerizing a monomer represented by a fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms) in the presence of a polymerization initiator source. Embedded image 4. The formula (B) wherein n is 1 or 2, Rf
Method of producing a fluoropolymer molded product to injecting monomer and a polymerization initiator represented by fluorine atom or a perfluoroalkyl group having 1 to 3 carbon atoms) in the mold polymerization. Embedded image