Fluorine-containing resin composition for plastic optical fibers, plastic optical fiber or resin rod for plastic optical fibers, and method for manufacturing resin formed body for plastic optical fibers

Abstract

To provide a novel fluorine-containing resin composition for plastic optical fibers that is capable of lessening environmental impact and also capable of reducing intrusion of impurities through a process.SOLUTION: A fluorine-containing resin composition of the present invention includes: a fluorine-containing resin; and a solvent in which the fluorine-containing resin is dissolved. The solvent is a perfluoroalkene. The fluorine-containing resin includes a fluorine-containing polymer including a structural unit (A) represented by the following formula (1). (In the formula (1), Rff1 to Rff4 each independently represent a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. Rff1 and Rff2 are optionally linked to form a ring).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a fluorine-containing resin composition for plastic optical fibers, a plastic optical fiber or a resin rod for plastic optical fibers, and a method for producing a resin molded article for plastic optical fibers. [Background technology]

[0002] Fluorine-containing resins are used in various applications, such as resin materials used in photolithography technology and materials for optical components such as plastic optical fiber (hereinafter referred to as "POF"). When fluorine-containing resins are used for various applications, for example, compositions in which fluorine-containing resins are dissolved in a solvent are used. For example, when fluorine-containing resins are used as materials for anti-reflective films formed on photoresist layers in photolithography technology, compositions in which fluorine-containing resins are dissolved in a solvent are used as coating compositions for producing anti-reflective films. In addition, when fluorine-containing resins are used for optical applications, a purification process is required to remove foreign matter from the resin in order to suppress deterioration of the quality of optical components due to foreign matter mixed in. In that case, in order to remove foreign matter from the fluorine-containing resin, a method is usually used in which a composition in which the fluorine-containing resin is dissolved in a solvent is prepared and the composition is filtered. In this way, fluorine-containing resin compositions containing a fluorine-containing resin and a solvent are used in various ways when the fluorine-containing resin is used for various applications.

[0003] Patent Document 1 discloses a composition containing a fluoropolymer and an aprotic solvent, in which the fluoropolymer is contained at a high concentration (specifically, 20 mass% or more). Patent Document 1 lists perfluoroaromatic compounds, perfluorotrialkylamines, perfluoroalkanes, hydrofluorocarbons, perfluorocyclic ethers, hydrofluoroethers, and olefin compounds containing at least one chlorine atom as aprotic solvents. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7014987 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for compositions containing fluorine-containing resins to further reduce the environmental load. As described above, compositions containing fluorine-containing resins may be used in various processes depending on the application. Compositions containing fluorine-containing resins used for optical components, particularly for POF, are required to have low elution of materials likely to be used as process materials, that is, to have low contamination with impurities due to the process.

[0006] The present invention aims to provide a novel fluorine-containing resin composition for POF, which can reduce the environmental load and can also reduce the inclusion of impurities during the process. Another object of the present invention is to provide a POF or a resin rod for POF, which contains such a novel fluorine-containing resin composition for POF. Another object of the present invention is to provide a method for producing a resin molded article for POF, which uses the novel fluorine-containing resin composition for POF, which can reduce the environmental load and can also reduce the inclusion of impurities during the process. [Means for solving the problem]

[0007] The fluorine-containing resin composition according to the first aspect of the present invention comprises: A fluorine-containing resin, A solvent for dissolving the fluorine-containing resin; A fluorine-containing resin composition comprising: the solvent is a perfluoroalkene; The fluororesin contains a fluoropolymer containing a structural unit (A) represented by the following formula (1): Fluorine-containing resin composition for POF. [ka] (In formula (1), R ff 1 ~R ff 4 R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring.

[0008] The fluorine-containing resin composition according to the second aspect of the present invention comprises: A fluorine-containing resin, A solvent for dissolving the fluorine-containing resin; A fluorine-containing resin composition comprising: the solvent is a perfluoroalkene; The fluororesin contains a fluoropolymer containing a structural unit (D) represented by the following formula (4): Fluorine-containing resin composition for POF. [ka] (In formula (4), Z is an oxygen atom, a single bond, or -OC(R 19 R 20 )O-, R 9 ~R 20 each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkoxy group may be substituted with halogen atoms other than fluorine atoms. s and t each independently represent an integer of 0 to 5, and s+t represents an integer of 1 to 6 (with the proviso that Z is -OC(R 19 R 20 ) In the case of O-, s+t may be 0.

[0009] The POF or resin rod for POF according to the third aspect of the present invention contains the fluorine-containing resin composition for POF according to the first or second aspect.

[0010] A method for producing a resin molded article for POF according to a fourth aspect of the present invention includes the steps of: (i) preparing a resin molded article for POF containing a fluorine-containing resin by using the fluorine-containing resin composition for POF according to the first or second aspect; Includes. Effect of the Invention

[0011] According to the present invention, it is possible to provide a novel fluorine-containing resin composition for POF, which can reduce the environmental load and the inclusion of impurities due to the process. Furthermore, according to the present invention, it is possible to provide a POF or a resin rod for POF, which contains such a novel fluorine-containing resin composition for POF. Furthermore, according to the present invention, it is also an object to provide a method for producing a resin molded article for POF, which uses the novel fluorine-containing resin composition for POF, which can reduce the environmental load and the inclusion of impurities due to the process. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a flow chart showing an example of a method for producing a resin molded article for POF according to the second embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing an example of a POF manufactured by the method for manufacturing a resin molded article for a POF according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] (Embodiment 1) An embodiment of the fluorine-containing resin composition for POF of the present invention will be described.

[0014] The fluorine-containing resin composition for POF of the present embodiment contains a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin. The solvent contains a perfluoroalkene. Here, "perfluoro" means that all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. Hereinafter, the fluorine-containing resin composition for POF will be simply referred to as "fluorine-containing resin composition".

[0015] In the fluorine-containing resin composition of the present embodiment, a perfluoroalkene is used as a solvent. Compared with fluorine-containing solvents used as solvents in conventional fluorine-containing resin compositions such as hydrofluorocarbons, hydrofluoroethers, and perfluoroalkanes, perfluoroalkene has a lower global warming potential (hereinafter, sometimes referred to as GWP). Perfluoroalkene can have a GWP of, for example, less than 150, less than 100, less than 50, or less than 10. Furthermore, perfluoroalkene has a low ozone depletion potential (hereinafter, sometimes referred to as ODP) of zero, similar to the above-mentioned conventional fluorine-containing solvents. Therefore, the fluorine-containing resin composition of the present embodiment, in which perfluoroalkene having a GWP lower than that of conventional fluorine-containing solvents and zero ODP is used as a solvent, can reduce the environmental load compared to conventional fluorine-containing resin compositions.

[0016] Here, GWP is an index that estimates the relative global warming burden due to the emission of a kilogram of a particular greenhouse gas into the atmosphere compared to the emission of a kilogram of carbon dioxide. GWP can be calculated for different time horizons, showing the atmospheric lifetime impact for a given gas. The GWP for a 100 year time horizon is the value that is usually referenced.

[0017] One of the reasons why perfluoroalkenes may have a low GWP is that they do not contain a CH bond. Since they do not contain a CH bond, perfluoroalkenes have a low ability to absorb infrared rays, that is, they have a small infrared absorption amount. Therefore, it is considered that perfluoroalkenes can have a lower GWP than fluorine-containing solvents that contain a CH bond. Another reason why perfluoroalkenes may have a low GWP is that they have a short atmospheric lifetime. Since perfluoroalkenes have a double bond, they have high OH radical reactivity. Therefore, it is considered that they can have a lower GWP than fluorine-containing solvents that do not have a double bond. Note that GWP is related to various factors other than infrared absorption and atmospheric lifetime, so it is considered difficult to determine the magnitude relationship of GWP from a discussion of only infrared absorption or only atmospheric lifetime. However, since perfluoroalkenes are superior to conventional fluorine-containing solvents in both infrared absorption and atmospheric lifetime, they can have a lower GWP than conventional fluorine-containing solvents.

[0018] In addition, perfluoroalkene does not contain a proton in the skeleton structure. Therefore, even when the fluororesin composition of the present embodiment is used in various processes according to each application, the elution of materials used as processing materials is small. That is, the fluororesin composition of the present embodiment can reduce the inclusion of impurities due to the process. Examples of materials used as processing materials include resin materials and metal materials.

[0019] As described above, the fluorine-containing resin composition of the present embodiment can reduce the environmental load and can also reduce the inclusion of impurities during the process.

[0020] In the fluorine-containing resin composition of the present embodiment, the solvent preferably contains perfluoroalkene as a main component. This allows the fluorine-containing resin composition of the present embodiment to further reduce the environmental load and further reduce the inclusion of impurities due to the process. Here, in this specification, the solvent contains perfluoroalkene as a main component means that the component contained most in the solvent contained in the fluorine-containing resin composition of the present embodiment by mass ratio is perfluoroalkene. Note that, when multiple types of perfluoroalkenes are contained in the solvent, the mass ratio of perfluoroalkene in the solvent is calculated by the total mass of perfluoroalkenes.

[0021] In order to further reduce the environmental load and the inclusion of impurities, the solvent in the fluorine-containing resin composition of the present embodiment may be substantially composed of perfluoroalkene. Here, in this specification, the solvent being substantially composed of perfluoroalkene means that the content of perfluoroalkene in the solvent is 90% by mass or more, preferably 95% by mass or more. When multiple perfluoroolefins are contained, the content of perfluoroalkene in the solvent is determined by the total mass of perfluoroalkene. In the fluorine-containing resin composition of the present embodiment, the solvent may be composed of only perfluoroalkene.

[0022] The solubility and dissolution rate of the fluorine-containing resin in the perfluoroalkene are higher than those in conventional fluorine-containing solvents, and therefore, by containing the perfluoroalkene as a solvent, the fluorine-containing resin composition of the present embodiment can improve the solubility of the fluorine-containing resin in the solvent.

[0023] In addition, the fluororesin composition of the present embodiment has excellent filterability. Therefore, the fluororesin composition of the present embodiment can be efficiently filtered, for example, even when filtered for the purification treatment of a resin material containing a fluororesin. The term "excellent filterability" used herein means that the viscosity of the fluororesin composition does not change even when the concentration of the fluororesin is increased. The viscosity of the fluororesin composition is less likely to increase, and when compared with fluororesin compositions having the same fluororesin concentration, the composition can have a lower viscosity, and there is no problem with liquid permeability during filtration. In order to realize excellent filterability, the fluororesin composition of this embodiment preferably has a solution viscosity at 25°C of 1 mPa·s or more and less than 110 mPa·s, more preferably 1 mPa·s or more and 100 mPa·s or less, even more preferably 1 mPa·s or more and 90 mPa·s or less, particularly preferably 1 mPa·s or more and 50 mPa·s or less, and most preferably 1 mPa·s or more and 15 mPa·s or less. Here, the solution viscosity is measured using an E-type viscometer based on the standard of JIS K 7117-2.

[0024] In the fluorine-containing resin composition of the present embodiment, the concentration of the fluorine-containing resin is not particularly limited, since it can be appropriately determined according to the use of the fluorine-containing resin composition. However, when the fluorine-containing resin composition of the present embodiment is filtered, in order to have excellent filterability, the concentration of the fluorine-containing resin in the fluorine-containing resin composition of the present embodiment is preferably 1% by mass or more and less than 20% by mass, more preferably 1% by mass or more and 19.5% by mass or less, even more preferably 1% by mass or more and 15% by mass or less, particularly preferably 1% by mass or more and 12% by mass or less, and most preferably 1% by mass or more and 8% by mass or less.

[0025] The fluororesin and the perfluoroalkene used as the solvent in the fluororesin composition of this embodiment will be described in more detail below.

[0026] [Fluorine-containing resin] The fluorine-containing resin includes a fluorine-containing polymer. Since the fluorine-containing resin composition of the present embodiment is for POF, the fluorine-containing polymer contained in the fluorine-containing resin preferably does not substantially contain hydrogen atoms from the viewpoint of suppressing light absorption due to the stretching energy of C-H bonds, and it is particularly preferable that all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. That is, the fluorine-containing polymer preferably does not substantially contain hydrogen atoms and is fully fluorinated. In this specification, the fluorine-containing polymer does not substantially contain hydrogen atoms means that the content of hydrogen atoms in the fluorine-containing polymer is 1 mol% or less.

[0027] The fluorine-containing polymer preferably has a fluorine-containing alicyclic structure. The fluorine-containing alicyclic structure may be contained in the main chain of the fluorine-containing polymer or in a side chain of the fluorine-containing polymer.

[0028] An example of the fluorine-containing polymer (hereinafter referred to as "a first example of the fluorine-containing polymer") contains, for example, a structural unit (A) represented by the following formula (1). [ka]

[0029] In formula (1), R ff 1 ~R ff 4 R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring. "Perfluoro" means that all hydrogen atoms bonded to carbon atoms are substituted with fluorine atoms. In formula (1), the number of carbon atoms in the perfluoroalkyl group is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1. The perfluoroalkyl group may be either linear or branched. Examples of the perfluoroalkyl group include a trifluoromethyl group, a pentafluoroethyl group, and a heptafluoropropyl group.

[0030] In the formula (1), the number of carbon atoms in the perfluoroalkyl ether group is preferably 1 to 5, and more preferably 1 to 3. The perfluoroalkyl ether group may be linear or branched. Examples of the perfluoroalkyl ether group include a perfluoromethoxymethyl group.

[0031] R ff 1 and R ff 2 When they are linked to form a ring, the ring may be a 5-membered ring or a 6-membered ring. Examples of the ring include a perfluorotetrahydrofuran ring, a perfluorocyclopentane ring, and a perfluorocyclohexane ring.

[0032] Specific examples of the structural unit (A) include structural units represented by the following formulas (A1) to (A8). [ka]

[0033] Of the structural units represented by the above formulas (A1) to (A8), the structural unit (A) is preferably the structural unit (A2), that is, the structural unit represented by the following formula (5). [ka]

[0034] The first example of the fluorine-containing polymer may contain one or more types of the structural unit (A). In the first example of the fluoropolymer, the content of the structural unit (A) may be 20 mol% or more, or 40 mol% or more, based on the total of all structural units. When the structural unit (A) is contained in an amount of 20 mol% or more, the fluoropolymer tends to have higher heat resistance. When the structural unit (A) is contained in an amount of 40 mol% or more, the fluoropolymer tends to have higher transparency and high mechanical strength in addition to high heat resistance. In the first example of the fluoropolymer, the content of the structural unit (A) may be 95 mol% or less, or 70 mol% or less, based on the total of all structural units.

[0035] The structural unit (A) is derived from a compound represented by the following formula (6), for example. ff 1 ~R ff 4 is the same as formula (1). The compound represented by formula (6) can be obtained by a known production method, for example, the production method disclosed in JP-A-2007-504125. [ka]

[0036] Specific examples of the compound represented by the above formula (6) include compounds represented by the following formulae (M1) to (M8). [ka]

[0037] The first example of the fluorine-containing polymer may further contain other structural units in addition to the structural unit (A). Examples of the other structural units include the following structural units (B) to (D). That is, the fluorine-containing polymer containing the structural unit (A) may further contain at least one selected from the group consisting of the structural unit (B) represented by the following formula (2), the structural unit (C) represented by the following formula (3), and the structural unit (D) represented by the following formula (4).

[0038] The structural unit (B) is represented by the following formula (2). [ka]

[0039] In formula (2), R 1 ~R 3 Each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. 4 represents a perfluoroalkyl group having 1 to 7 carbon atoms. The perfluoroalkyl group may have a ring structure. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms.

[0040] The first example of the fluorine-containing polymer may contain one or more types of structural unit (B). In the first example of the fluorine-containing polymer, the content of the structural unit (B) relative to the total of all structural units is The content of the structural unit (B) is preferably 5 to 10 mol %. The content of the structural unit (B) may be 9 mol % or less, or may be 8 mol % or less.

[0041] The structural unit (B) is derived from a compound represented by the following formula (7), for example. 1 ~R 4 is the same as formula (2). The compound represented by formula (7) is a fluorine-containing vinyl ether such as perfluorovinyl ether. [ka]

[0042] The structural unit (C) is represented by the following formula (3). [ka]

[0043] In formula (3), R 5 ~R 8each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. The perfluoroalkyl group may have a ring structure. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms.

[0044] The first example of the fluorine-containing polymer may contain one or more types of structural units (C). In the first example of the fluorine-containing polymer, the content of the structural units (C) is preferably 5 to 10 mol% based on the total of all structural units. The content of the structural units (C) may be 9 mol% or less, or may be 8 mol% or less.

[0045] The structural unit (C) is derived from a compound represented by the following formula (8), for example. 5 ~R 8 is the same as formula (3). The compound represented by formula (8) is a fluorine-containing olefin such as tetrafluoroethylene or chlorotrifluoroethylene. [ka]

[0046] The structural unit (D) is represented by the following formula (4). [ka]

[0047] In formula (4), Z is an oxygen atom, a single bond, or -OC(R 19 R 20 )O-, R 9 ~R 20each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkoxy group may be substituted with halogen atoms other than fluorine atoms. The values ​​of s and t each independently represent an integer of 0 to 5, and the value of s+t is an integer of 1 to 6 (provided that Z is -OC(R 19 R 20 )O-, the value of s+t may be 0.

[0048] The structural unit (D) is preferably represented by the following formula (9): The structural unit represented by the following formula (9) is a structural unit in which Z is an oxygen atom, s is 0, and t is 2 in the above formula (4). [ka]

[0049] In formula (9), R 141 , R 142 , R 151 , and R 152 each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkoxy group may be substituted with halogen atoms other than fluorine atoms.

[0050] The first example of the fluorine-containing polymer may contain one or more types of structural units (D). In the first example of the fluorine-containing polymer, the content of the structural unit (D) is preferably 30 to 67 mol% based on the total of all structural units. The content of the structural unit (D) is, for example, 35 mol% or more, and may be 60 mol% or less, or may be 55 mol% or less.

[0051] The structural unit (D) is derived from a compound represented by the following formula (10): In Z, R 9 ~R 18 The values ​​of s and t are the same as in formula (4). The compound represented by formula (10) is a fluorine-containing compound which has two or more polymerizable double bonds and is capable of cyclopolymerization. [ka]

[0052] The structural unit (D) is preferably derived from a compound represented by the following formula (11): 141 , R 142 , R 151 , and R 152 is the same as equation (9). [ka]

[0053] Specific examples of the compound represented by formula (10) or formula (11) include the following compounds. CF2=CFCF2CF=CF2 CF2=CFOCF(CF3)CF=CF2 CF2=CF2CF2CF=CF2 CF2=CF0CF2CF(CF3)CF=CF2 CF2=CFFOCF(CF3)CF2CF=CF2 CF2=CFOCFClCF2CF=CF2 CF2=CFOCCl2CF2CF=CF2 CF2=CFOCF2OCF=CF2 CF2=CFOC(CF3)2OCF=CF2 CF2=CF2CF(OCF3)CF=CF2 CF2=CFCF2CF=CF2 CF2=CFCF2CF2CF=CF2 CF2=CFCF2OCF2CF=CF2 CF2=CFOCF2CFClCF=CF2 CF2=CFOCF2CF2CCl=CF2 CF2=CFOCF2CF2CF=CFCl CF2=CFOCF2CF(CF3)CCl=CF2 CF2=CFOCF2OCF=CF2 CF2=CFOCCl2OCF=CF2 CF2=CClOCF2OCCl=CF2

[0054] The first example of the fluoropolymer may further contain other structural units than the structural units (A) to (D), but preferably does not substantially contain other structural units than the structural units (A) to (D). Here, "the first example of the fluoropolymer does not substantially contain other structural units than the structural units (A) to (D)" means that the total of the structural units (A) to (D) is 95 mol % or more, preferably 98 mol % or more, of the total of all structural units in the first example of the fluoropolymer.

[0055] The fluorine-containing polymer contained in the fluorine-containing resin may be another example (hereinafter referred to as "second example of fluorine-containing polymer") different from the above-mentioned first example of fluorine-containing polymer. The second example of fluorine-containing polymer contains the above-mentioned structural unit (D). The second example of fluorine-containing polymer may be composed of only the structural unit (D), or may further contain other structural units other than the structural unit (D). The second example of fluorine-containing polymer may contain one type or two or more types of structural unit (D).

[0056] The polymerization method of the above-mentioned first and second examples of the fluorine-containing polymer is not particularly limited, and for example, a general polymerization method such as radical polymerization can be used. The polymerization initiator for polymerizing the fluorine-containing polymer may be a perfluorinated compound.

[0057] [Perfluoroalkene] In the fluorine-containing resin composition of the present embodiment, the number of carbon atoms in the perfluoroalkene used as the solvent is, for example, 2 to 10. Perfluoroalkene having a carbon number of 2 to 10 has a low boiling point, and as a result, the solvent can be easily volatilized. Here, "2 to 10" is synonymous with 2 or more and 10 or less.

[0058] The perfluoroalkene may be a chain perfluoroalkene or a cyclic perfluoroalkene. The chain perfluoroalkene may be a straight-chain perfluoroalkene or a branched perfluoroalkene.

[0059] Perfluoroalkenes are, for example, those represented by the formula (12): n F 2n (n is an integer of 2 or more). In formula (12), the value of n is, for example, 10 or less, and preferably 8 or less.

[0060] Perfluoroalkenes are represented by the formula (13): R 21 CF=CFR 22 In the formula (13), R 21 and R 22 are each independently a perfluoroalkyl group having 1 to 6 carbon atoms. The above alkenes may be either cis (sometimes represented by (Z)) or trans (sometimes represented by (E)).

[0061] The perfluoroalkene is represented, for example, by formula (14) or (15). Formula (14):(E)-R 23 CF=CFR 24 or (Z)-R 23 CF=CFR 24 In the formula (14), R 23 and R 24 are independently an F atom or a perfluoroalkyl group having 1 to 8 carbon atoms, and in the formula (14), the total number of carbon atoms in the compound is at least 4. Formula (15): Cyclo-[CF=CF(CF2) n -], wherein in formula (15), the value of n is an integer of 2 to 6.

[0062] Examples of perfluoroalkenes include, for example, 1,1,1,2,3,4,4,4-octafluoro-2-butene (CF3CF=CFCF3); 1,1,2,3,3,4,4,4-octafluoro-1-butene (CF3CF2CF=CF2); 1,1,1,2,3,4,4,5,5,5-decafluoro-2-pentene (CF3CF=CFCF2CF3); 1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene (CF2=CFCF2CF2CF3); ,6,6,6-dodecafluoro-1-hexene (CF3(CF2)3CF=CF2);1,1,1,2,2,3,4,5,5,6,6,6-dodecafluoro-3-hexene (CF3CF2CF=CFCF2CF3);1,1,1,4,4,4-hexafluoro-2,3-bis(trifluoromethyl)-2-butene ((CF3)2C=C(CF3)2);1,1,1,2,3,4,5,5,5-nonafluoro-4-(trifluoromethyl)-2-pentene ((CF3)2CFCF=CFCF3);1,1 ,1,2,3,4,4,5,5,6,6,7,7,7-Tetradecafluoro-2-heptene (CF3CF=CFCF2CF2C2F5);1,1,1,2,2,3,4,5,5,6,6,7,7,7-Tetradecafluoro-3-heptene (CF3CF2CF=CFCF2C2F5);1,1,2,3,3,4,4,5,5,6,6,7,7,7-Tetradecafluoro-1-heptene (CF2=CFCF2CF2CF2C2F5);1,1,2,3,3,4,4,5,5,6,6,7,7,8,8,8-Hexadecafluoro-1-octene (CF2=C FCF2CF2CF2CF2C2F5); 1,1,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-octadecafluoro-1-nonene (CF2=CFCF2CF2CF2CF2CF2C2F5); 1,1,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-eicosafluoro-1-decene (CF2=CFCF2CF2CF2CF2CF2CF2C2F5); and 1,2,3,3,4,4,5,5,6,6-decafluorocyclohexene (cyclo-[CF=CF(CF2)4-]). In this embodiment, the perfluoroalkene may contain at least one selected from the compounds exemplified above. The compound may be either cis (Z) or trans (E).

[0063] In the fluorine-containing resin composition of this embodiment, the perfluoroalkene may contain 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene (CF3CF2CF=CFCF2C2F5). The GWP of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene is less than 10, which is very low. Therefore, according to this configuration, the fluorine-containing resin composition of this embodiment can further reduce the environmental load. In addition, 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene is less likely to elute materials used as process materials, and the amount of elution of process materials can be further reduced. Therefore, according to this configuration, the fluorine-containing resin composition of this embodiment can further reduce the inclusion of impurities due to the process.

[0064] The solubility and dissolution rate of the fluorine-containing resin in 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene are very high compared to conventional fluorine-containing solvents. Therefore, by containing 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene as a solvent, the fluorine-containing resin composition of the present embodiment can further improve the solubility of the fluorine-containing resin in the solvent.

[0065] Furthermore, the fluororesin composition containing 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene as a solvent has better filterability. Therefore, when 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene is contained as a solvent, the fluororesin composition of this embodiment can be filtered more efficiently.

[0066] The perfluoroalkene may contain 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene as a main component. Here, the perfluoroalkene containing 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene as a main component means that the component contained most abundantly in the perfluoroalkene by mass ratio is 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene.

[0067] In the fluorine-containing resin composition of the present embodiment, the perfluoroalkene may essentially consist of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene. "Consisting of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene" means that the content of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene in the perfluoroalkene is 90 mass% or more, preferably 95 mass% or more. In the fluorine-containing resin composition of this embodiment, the perfluoroalkene contained as the solvent may consist only of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene.

[0068] [Other ingredients] The fluorine-containing resin composition of the present embodiment may further contain other components in addition to the above-mentioned fluorine-containing resin and the solvent containing the perfluoroalkene. The fluorine-containing resin composition of the present embodiment may further contain an additive such as a refractive index adjuster.

[0069] (Embodiment 2) An embodiment of the method for producing a resin molded article for POF according to the present invention will be described.

[0070] The method for producing a resin molded article for POF according to the present embodiment includes the steps of: (i) producing a resin molded product for POF containing a fluorine-containing resin by using the fluorine-containing resin composition of embodiment 1; Includes.

[0071] The fluorine-containing resin composition is as explained in the first embodiment, and therefore a detailed explanation will be omitted here.

[0072] In the above (i), the fluorine-containing resin composition may be used, for example, for refining a resin material forming a resin molded product for POF. A flow chart of the manufacturing method in this case is shown in FIG. 1. In this case, in the manufacturing method of this embodiment, for example, in the above (i), the fluorine-containing resin composition is filtered to purify a resin material containing a fluorine-containing resin (S11), and the obtained resin material is molded to obtain a resin molded product for POF (S12). As explained in the first embodiment, the fluorine-containing resin composition has excellent filterability. Therefore, according to the manufacturing method of this embodiment, even when the fluorine-containing resin composition is filtered for the purification treatment of the resin material containing a fluorine-containing resin, the filtration can be performed efficiently. Thus, according to the manufacturing method of this embodiment, a high-quality resin molded product for POF from which foreign matter has been removed can be efficiently manufactured.

[0073] In the production method of this embodiment, the method of using the fluorine-containing resin composition for producing a resin molded article for POF is not limited to the above-mentioned filtration for purification treatment.

[0074] In the resin molded product for POF obtained by the manufacturing method of the present embodiment, the perfluoroalkene contained as a solvent in the fluorine-containing resin composition may remain in a detectable small amount. The method for detecting the perfluoroalkene in the resin molded product for POF may be, for example, gas chromatography (GC).

[0075] In the manufacturing method of this embodiment, for example, as shown in the flow chart in FIG. 1, a resin material containing a fluorine-containing resin is purified by filtering a fluorine-containing resin composition (S11), and the obtained resin material is molded to obtain a resin molded product for POF (S12). Here, the resin molded product for POF may be POF itself. That is, in S12, a POF can be manufactured by molding the resin material into a fiber shape. The manufactured POF may be, for example, a refractive index distribution type POF in which the refractive index of the core is distributed symmetrically about the central axis. The fluorine-containing resin obtained by purification may be a POF itself. The resin material may be used as a core material of the POF or as a clad material.

[0076] The specific method of forming the resin material into a fiber to obtain the POF is not particularly limited. For example, the resin material obtained by the purification process in S11 is heated and melted at a temperature, for example, 50° C. higher than the glass transition temperature of the resin material, spun by melt extrusion, and formed into a fiber to produce the POF. During the spinning by melt extrusion, the refractive index adjuster is diffused in the resin material by heating, thereby producing a core of a refractive index distribution type POF in which the refractive index of the core is distributed symmetrically about the central axis.

[0077] FIG. 2 is a cross-sectional view showing an example of a POF that can be manufactured by the manufacturing method of this embodiment. A POF 10 that can be manufactured by the manufacturing method of this embodiment includes, for example, a core 11 and a clad 12 arranged on the outer periphery of the core 11. The core 11 can be obtained, for example, by spinning a resin material (core material) containing a fluorine-containing resin obtained by filtering a fluorine-containing resin composition into a fiber shape by melt extrusion. The clad 12 can be formed, for example, by melt extruding a resin material (clad material) containing a fluorine-containing resin obtained by filtering a fluorine-containing resin composition so as to cover the outer periphery of the core 11. During this spinning by melt extrusion, the refractive index adjuster contained in the core material is diffused in the resin material by heating, thereby making it possible to prepare the core 11 of a refractive index distribution type POF in which the refractive index of the core 11 has a distribution symmetrical about the central axis. When the fluorine-containing resin composition of embodiment 1 is used to prepare the core material and the clad material, the obtained core 11 and clad 12 may contain a very small amount of perfluoroalkene to an extent that does not affect the performance of the core and the clad.

[0078] (Embodiment 3) An embodiment of the POF or the resin rod for a POF of the present invention will be described.

[0079] The POF or resin rod for POF of this embodiment contains the fluorine-containing resin composition of embodiment 1. The resin rod for POF is used when producing POF by melt extrusion. POF can be produced by heating and melting the resin rod for POF, spinning it by melt extrusion, and forming it into a fiber shape. The POF or resin rod for POF of this embodiment can contain a solvent containing perfluoroalkene. The perfluoroalkene contained in this solvent can be detected by using gas chromatography (GC). EXAMPLES

[0080] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0081] Example 1 [Preparation of fluorine-containing resin] As a fluorine-containing resin, a polymer of perfluoro-4-methyl-2-methylene-1,3-dioxolane (the compound of the above formula (M2), "PFMMD") was prepared. Perfluoro-4-methyl-2-methylene-1,3-dioxolane was synthesized by first synthesizing 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane, fluorinating it, and separating the resulting carboxylate by decarboxylation. Perfluoro-4-methyl-2-methylene-1,3-dioxolane was polymerized using perfluorobenzoyl oxide as a polymerization initiator.

[0082] The synthesis of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane and the synthesis of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane are described below. The fluorination of solan, the synthesis of perfluoro-4-methyl-2-methylene-1,3-dioxolane, and the polymerization of perfluoro-4-methyl-2-methylene-1,3-dioxolane are described in detail.

[0083] <Synthesis of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane> A 3L three-neck flask equipped with a water-cooled condenser, a thermometer, a magnetic stirrer, and a pressure-equalizing dropping funnel were prepared, and 139.4 g (total 1.4 moles) of a mixture of 2-chloro-1-propanol and 1-chloro-2-propanol was added to the flask. The flask was cooled to 0°C, and methyl trifluoropyruvate was slowly added thereto and stirred for another 2 hours. 100 mL of dimethyl sulfoxide (DMSO) and 194 g of potassium carbonate were added thereto over 1 hour, and then the mixture was stirred for another 8 hours to obtain a reaction mixture. The reaction mixture thus formed was mixed with 1 L of water, and the aqueous phase was separated and further extracted with dichloromethylene. The dichloromethylene solution was mixed with the organic reaction mixture phase, and the solution was dried over magnesium sulfate. After removing the solvent, 245.5 g of crude product was obtained. This crude product was fractionally distilled under reduced pressure (12 Torr) to obtain 230.9 g of a purified product of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane. The boiling point of the purified product was 77-78°C, and the yield was 77%. The purified product was found to be 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane by HNMR (Bruker, product name: Biospin, AVANCEIII-600 with Cryo Probe) and 19 This was confirmed by FNMR (Bruker, product name: Biospin, AVANCEIII-400).

[0084] HNMR(ppm):4.2-4.6,3.8-3.6(CHCH2,muliplet,3H),3.85-3.88(COOCH3,multiplet,3H),1.36-1.43(CCH3,multiplet,3H) 19 FNMR(ppm):-81.3(CF3,s,3F)

[0085] <Fluorination of 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane> 4 L of 1,1,2-trichlorotrifluoroethane was poured into a 10 L stirred reactor. Nitrogen was flowed at a flow rate of 1340 cc / min and fluorine was flowed at a flow rate of 580 cc / min in the stirred reactor to create a nitrogen / fluorine atmosphere. After 5 minutes, 290 g of the previously prepared 2-carbomethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane was dissolved in 750 mL of 1,1,2-trichlorotrifluoroethane solution, and this solution was added to the reactor at a rate of 0.5 ml / min. The reactor was cooled to 0°C. After all the dioxolane had been added in 24 hours, the fluorine gas flow was stopped. After purging the nitrogen gas, an aqueous potassium hydroxide solution was added until it became weakly alkaline.

[0086] After removing the volatiles under reduced pressure, the reaction vessel was cooled and then dried under reduced pressure at 70°C for 48 hours to obtain a solid reaction product. The solid reaction product was dissolved in 500mL of water and separated into an organic phase and an aqueous phase by adding excess hydrochloric acid. The organic phase was separated and distilled under reduced pressure to obtain perfluoro-2,4-dimethyl-1,3-dioxolane-2-carboxylic acid. The boiling point of the main distillate was 103°C-106°C / 100mmHg. The fluorination yield was 85%.

[0087] <Synthesis of perfluoro-4-methyl-2-methylene-1,3-dioxolane> The distillate was neutralized with an aqueous solution of potassium hydroxide to obtain potassium perfluoro-2,4-dimethyl-2-carboxylate-1,3-dioxolane. The potassium salt was vacuum dried at 70°C for 1 day. The salt was decomposed at 250°C to 280°C under a nitrogen or argon atmosphere. Condensation in a cold trap cooled to -78°C gave perfluoro-4-methyl-2-methylene-1,3-dioxolane in 82% yield, with a boiling point of 45°C / 760mmHg. 19 The product was identified using FNMR (Bruker, product name: Biosipin, AVANCEIII-400) and GC-MS (Agilent Technologies, product name: 6890plus / 5973N).

[0088] 19 FNMR:-84ppm(3F,CF3),-129ppm(2F,=CF2) GC-MS:m / e244(Molecular ion)225,197,169,150,131,100,75,50.

[0089] <Polymerization of perfluoro-4-methyl-2-methylene-1,3-dioxolane> 100 g of the perfluoro-4-methyl-2-methylene-1,3-dioxolane obtained by the above method and 1 g of perfluorofiltered benzoyl oxide were sealed in a glass tube. The glass tube was refilled with argon after the oxygen in the system was removed by freeze degassing, and heated at 50°C for several hours. The contents became solid, but when further heated at 70°C overnight, 100 g of a transparent rod-like product was obtained.

[0090] The obtained transparent rod-like matter was dissolved in Fluorinert FC-75 (manufactured by Sumitomo 3M), and the obtained solution was poured onto a glass plate to obtain a thin film of the polymer. The obtained polymer had a glass transition temperature of 117°C and was completely amorphous. The transparent rod-like matter was dissolved in hexafluorobenzene, and chloroform was added thereto to cause precipitation, thereby purifying the product. The glass transition temperature of the purified polymer was about 131°C. This polymer was used as a fluorine-containing resin.

[0091] [Preparation of Fluorine-Containing Resin Composition] The fluororesin prepared by the above method and a perfluoroalkene solvent were mixed in a glass screw tube. The perfluoroalkene used as the solvent was 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene (GWP: less than 10). The fluororesin and the perfluoroalkene solvent were mixed so that the concentration of the fluororesin in the resulting fluororesin composition was 5% by mass. The glass screw tube was sealed and heated at 50°C for 3 hours to dissolve the fluororesin in the perfluoroalkene solvent.

[0092] [Evaluation of Fluorine-Containing Resin Composition] (1) Viscosity measurement The viscosity of the fluororesin composition prepared by the above method was measured at 25° C. Specifically, the viscosity of the fluororesin composition at 25° C. was measured using an E-type viscometer ("TVE-22LT", manufactured by Toki Sangyo Co., Ltd.) according to the test method of JIS K 7117-2. The measurement results are shown in Table 1.

[0093] (2) Evaluation of filterability The filterability of the fluorine-containing resin composition prepared by the above method was evaluated. A stainless steel holder with tank KST-47 manufactured by Advantech was used for the evaluation of filterability. An Omnipore membrane filter (characteristics: hydrophilic, material: PTFE (polytetrafluoroethylene), pore size: 0.1 μm) manufactured by Merck was used as the filter. The filterability was judged based on whether the solution in the tank of the stainless steel holder with tank could be completely filtered within 8 hours. The evaluation results are shown in Table 1. In Table 1, the case where the entire amount was filtered within the time is indicated as "◯", and the case where the entire amount was not filtered is indicated as "×". The criterion for judging whether or not the entire amount was filtered was based on visual observation.

[0094] (3) Leaching test of process materials A elution test of polypropylene (PP) and silicone, which may be used as a processing material, was carried out for the solvent used in the preparation of the fluorine-containing resin composition, i.e., 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene in Example 1. Test pieces of PP and silicone (tubes with an inner diameter of 9 mm and an outer diameter of 12 mm, length of 30 mm) were placed in a screw cap bottle, and the unit contact area of ​​the test pieces was approximately 20 mm2. 2 / g-solvent (i.e., the area of ​​the test piece is approximately 20 mm for 1 g of solvent). 2The test pieces were immersed in the solvent at room temperature for two weeks. After two weeks, the amount of the test piece materials (PP and silicone) that had increased in the solvent was measured. The amount of the test piece materials that had increased in the solvent was measured by gas chromatography (GC). It was determined that the elution of the process materials had been suppressed when the amount of the test piece materials that had increased in the solvent was 10 ppm or less for PP and 100 ppm or less for silicone. The results are shown in Table 1. In Table 1, the cases where the elution of the process materials had been suppressed are indicated with "Good" and the cases where the elution of the process materials had not been suppressed are indicated with "Poor."

[0095] Example 2 [Preparation of fluorine-containing resin] A fluorine-containing resin was prepared in the same manner as in Example 1.

[0096] [Preparation of Fluorine-Containing Resin Composition] The fluororesin composition of Example 2 was prepared in the same manner as in Example 1, except that the fluororesin and the perfluoroalkene solvent were mixed so that the concentration of the fluororesin in the resulting fluororesin composition was 10 mass%.

[0097] [Evaluation of Fluorine-Containing Resin Composition] The evaluation was carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0098] Example 3 [Preparation of fluorine-containing resin] A fluorine-containing resin was prepared in the same manner as in Example 1.

[0099] [Preparation of Fluorine-Containing Resin Composition] The fluororesin composition of Example 3 was prepared in the same manner as in Example 1, except that the fluororesin and the perfluoroalkene solvent were mixed so that the concentration of the fluororesin in the resulting fluororesin composition was 19.5 mass%.

[0100] [Evaluation of Fluorine-Containing Resin Composition] The evaluation was carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0101] Example 4 [Preparation of fluorine-containing resin] A fluorine-containing resin was prepared in the same manner as in Example 1.

[0102] [Preparation of Fluorine-Containing Resin Composition] The fluororesin composition of Example 4 was prepared in the same manner as in Example 1, except that the fluororesin and the perfluoroalkene solvent were mixed so that the concentration of the fluororesin in the resulting fluororesin composition was 20 mass%.

[0103] [Evaluation of Fluorine-Containing Resin Composition] The evaluation was carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0104] Comparative Example 1 [Preparation of fluorine-containing resin] A fluorine-containing resin was prepared in the same manner as in Example 1.

[0105] [Preparation of Fluorine-Containing Resin Composition] The fluorine-containing resin composition of Comparative Example 1 was prepared in the same manner as in Example 4, except that 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene was replaced with 1,1,1,2,2,3,4,5,5,5-decafluoropentane (GWP: 1640) as the solvent.

[0106] [Evaluation of Fluorine-Containing Resin Composition] The evaluation was carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0107] Comparative Example 2 [Preparation of fluorine-containing resin] A fluorine-containing resin was prepared in the same manner as in Example 1.

[0108] [Preparation of Fluorine-Containing Resin Composition] The fluorine-containing resin composition of Comparative Example 2 was prepared in the same manner as in Example 4, except that methyl nonafluoroisobutyl ether (Novec7100 (manufactured by 3M)) (GWP: 297) was used as the solvent instead of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene.

[0109] [Evaluation of Fluorine-Containing Resin Composition] The evaluation was carried out in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0110] [Table 1]

[0111] As shown in Table 1, the fluorine-containing resin compositions of Examples 1 to 4, in which perfluoroalkene was used as a solvent, suppressed the elution of both PP and silicone processing materials in the processing material elution test. Therefore, the fluorine-containing resin compositions of Examples 1 to 4 use perfluoroalkene, which has a low GWP, as a solvent, thereby reducing the environmental load. It was confirmed that the fluorine-containing resin compositions of Comparative Examples 1 and 2 could reduce the amount of elution of process materials and could also reduce the inclusion of impurities during the process. In contrast, the solvents used in the fluorine-containing resin compositions of Comparative Examples 1 and 2 had higher GWP than the perfluoroalkene used in Examples 1 to 4. Therefore, in terms of reducing the environmental load, the fluorine-containing resin compositions of Comparative Examples 1 and 2 were inferior to the fluorine-containing resin compositions of Examples 1 to 4. In addition, the fluorine-containing resin compositions of Comparative Examples 1 and 2 could not suppress the elution of process materials.

[0112] The fluororesin compositions of Examples 1 to 3 had a viscosity of less than 110 mPa·s at 25°C, and thus achieved excellent filterability. The fluororesin composition of Example 4 had a higher concentration of the fluororesin than those of Examples 1 to 3, and therefore was unable to achieve a viscosity of less than 110 mPa·s. However, when the fluororesin composition of Example 4 was compared with the fluororesin compositions of Comparative Examples 1 and 2, which had the same concentration of the fluororesin, the viscosity was significantly reduced. Therefore, it is considered that the fluororesin composition of Example 4 is also superior in filterability to the fluororesin compositions of Comparative Examples 1 and 2.

[0113] In the Examples and Comparative Examples, only the results of the elution tests for PP and silicone as processing materials are shown, but elution into the solvent was also confirmed for other processing materials, such as PTFE, PFA, nylon 66, and Hastelloy C276. In the case of these processing materials, the difference between the Examples and Comparative Examples was smaller than in the case of PP and silicone, but the perfluoroalkene solvent used in the Examples eluted less processing materials than the solvents used in Comparative Examples 1 and 2.

[0114] [Note] To summarize the above, one aspect of the present disclosure is as follows.

[0115] (1) A fluorine-containing resin, A solvent for dissolving the fluorine-containing resin; A fluorine-containing resin composition comprising: the solvent is a perfluoroalkene; The fluororesin contains a fluoropolymer containing a structural unit (A) represented by the following formula (1): Fluorine-containing resin composition for POF. [ka] (In formula (1), R ff 1 ~R ff 4R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring.

[0116] (2) The fluorine-containing polymer further contains at least one selected from the group consisting of a structural unit (B) represented by the following formula (2), a structural unit (C) represented by the following formula (3), and a structural unit (D) represented by the following formula (4): The fluorine-containing resin composition for POF according to the above (1). [ka] (In formula (2), R 1 ~R 3 Each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. 4 represents a perfluoroalkyl group having 1 to 7 carbon atoms. The perfluoroalkyl group may have a ring structure. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. [ka] (In formula (3), R 5 ~R 8 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. The perfluoroalkyl group may have a ring structure. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. [ka] (In formula (4), Z is an oxygen atom, a single bond, or -OC(R 19 R 20 )O-, R9 ~R 20 each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkoxy group may be substituted with halogen atoms other than fluorine atoms. The values ​​of s and t are each independently 0 to 5, and the value of s+t is an integer of 1 to 6 (provided that Z is -OC(R 19 R 20 ) In the case of O-, the value of s+t may be 0.

[0117] (3) The structural unit (A) contains a structural unit represented by the following formula (5): The fluorine-containing resin composition for POF according to the above (1) or (2). [ka]

[0118] (4) A fluorine-containing resin, A solvent for dissolving the fluorine-containing resin; A fluorine-containing resin composition comprising: the solvent is a perfluoroalkene; The fluororesin contains a fluoropolymer containing a structural unit (D) represented by the following formula (4): Fluorine-containing resin composition for POF. [ka] (In formula (4), Z is an oxygen atom, a single bond, or -OC(R 19 R 20 )O-, R 9 ~R 20each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkoxy group may be substituted with halogen atoms other than fluorine atoms. s and t each independently represent an integer of 0 to 5, and s+t represents an integer of 1 to 6 (with the proviso that Z is -OC(R 19 R 20 ) In the case of O-, s+t may be 0.

[0119] (5) The perfluoroalkene has 2 to 10 carbon atoms. The fluorine-containing resin composition for POF according to any one of the above (1) to (4).

[0120] (6) The perfluoroalkene has the formula (12): n F 2n (n is an integer of 2 or more), The fluorine-containing resin composition for POF according to any one of the above (1) to (5).

[0121] (7) The perfluoroalkene has the formula (13): R 21 CF=CFR 22 It is expressed as In the formula (13), R 21 and R 22 each independently represents a perfluoroalkyl group having 1 to 6 carbon atoms; The fluorine-containing resin composition for POF according to the above (6).

[0122] (8) The perfluoroalkene includes 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene; The fluorine-containing resin composition for POF according to the above (6) or (7).

[0123] (9) The perfluoroalkene is a cyclic alkene. The fluorine-containing resin composition for POF according to any one of the above (1) to (4).

[0124] (10) The cyclic alkene has the formula (15): cyclo-[CF=CF(CF2) n -] (where n is an integer between 2 and 6), The fluorine-containing resin composition for POF according to (9) above.

[0125] (11) The concentration of the fluorine-containing resin in the fluorine-containing resin composition for POF is less than 20% by mass. The fluorine-containing resin composition for POF according to any one of the above (1) to (10).

[0126] (12) The viscosity of the fluorine-containing resin composition for POF at 25°C is less than 110 mPa s. The fluorine-containing resin composition for POF according to any one of the above (1) to (11).

[0127] (13) A POF or a resin rod for a POF, comprising the fluorine-containing resin composition for a POF according to any one of the above (1) to (12).

[0128] (14) (i) producing a resin molded article for POF containing a fluorine-containing resin by using the fluorine-containing resin composition for POF according to any one of the above (1) to (12); The present invention relates to a method for producing a resin molded article for POF, comprising the steps of:

[0129] (15) In the step (i), the fluorine-containing resin composition for POF is filtered to purify a resin material containing the fluorine-containing resin, and the resin material thus obtained is molded to obtain the resin molded article for POF. A method for producing a resin molded article for POF according to the above (14). [Industrial Applicability]

[0130] The fluorine-containing resin composition for POF of the present invention is suitable for producing POF. [Explanation of symbols]

[0131] 10 POF 11 cores 12 Clad

Claims

1. A fluorine-containing resin, A solvent for dissolving the fluorine-containing resin; A fluorine-containing resin composition comprising: the solvent is a perfluoroalkene; The fluororesin contains a fluoropolymer containing a structural unit (A) represented by the following formula (1): Fluorine-containing resin composition for plastic optical fiber. 【Chemistry 1】 (In formula (1), R ff 1 ~R ff 4 R each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 7 carbon atoms, or a perfluoroalkyl ether group having 1 to 7 carbon atoms. ff 1 and R ff 2 may be linked to form a ring.)

2. The fluorine-containing polymer further contains at least one selected from the group consisting of a structural unit (B) represented by the following formula (2), a structural unit (C) represented by the following formula (3), and a structural unit (D) represented by the following formula (4): The fluorine-containing resin composition for plastic optical fibers according to claim 1. 【Chemistry 2】 (In formula (2), R 1 ~R 3 Each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. 4 represents a perfluoroalkyl group having 1 to 7 carbon atoms. The perfluoroalkyl group may have a ring structure. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. 【Chemistry 3】 (In formula (3), R 5 ~R 8 each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. The perfluoroalkyl group may have a ring structure. A part of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. A part of the fluorine atoms in the group may be substituted with halogen atoms other than fluorine atoms. 【Chemistry 4】 (In formula (4), Z is an oxygen atom, a single bond, or —OC(R 19 R 20 ) O-, R 9 ~R 20 each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms. A portion of the fluorine atoms may be substituted with a halogen atom other than fluorine atoms. A portion of the fluorine atoms in the perfluoroalkyl group may be substituted with a halogen atom other than fluorine atoms. A portion of the fluorine atoms in the perfluoroalkoxy group may be substituted with a halogen atom other than fluorine atoms. The values ​​of s and t are each independently 0 to 5, and the value of s+t is an integer of 1 to 6 (with the proviso that Z is -OC(R 19 R 20 ) In the case of O-, the value of s+t may be 0.

3. The structural unit (A) contains a structural unit represented by the following formula (5): The fluorine-containing resin composition according to claim 1. 【Chemistry 5】

4. A fluorine-containing resin, A solvent for dissolving the fluorine-containing resin; A fluorine-containing resin composition comprising: the solvent is a perfluoroalkene; The fluororesin contains a fluoropolymer containing a structural unit (D) represented by the following formula (4): Fluorine-containing resin composition for plastic optical fiber. 【Chemistry 4】 (In formula (4), Z is an oxygen atom, a single bond, or —OC(R 19 R 20 ) O-, R 9 ~R 20 each independently represents a fluorine atom, a perfluoroalkyl group having 1 to 5 carbon atoms, or a perfluoroalkoxy group having 1 to 5 carbon atoms. Some of the fluorine atoms may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkyl group may be substituted with halogen atoms other than fluorine atoms. Some of the fluorine atoms in the perfluoroalkoxy group may be substituted with halogen atoms other than fluorine atoms. s and t each independently represent 0 to 5, and s+t is an integer of 1 to 6 (with the proviso that Z is -OC(R 19 R 20 ) In the case of O-, s+t may be 0.

5. The perfluoroalkene has 2 to 10 carbon atoms. The fluorine-containing resin composition for plastic optical fiber according to claim 1 or 4.

6. The perfluoroalkene has the formula (12): n F 2n (the value of n is an integer of 2 or more), The fluorine-containing resin composition for plastic optical fiber according to claim 1 or 4.

7. The perfluoroalkene has the formula (13): R 21 CF = CFR 22 It is expressed as In the formula (13), R 21 and R 22 each independently represents a perfluoroalkyl group having 1 to 6 carbon atoms; The fluorine-containing resin composition for plastic optical fibers according to claim 6.

8. The perfluoroalkene includes 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene; The fluorine-containing resin composition for plastic optical fibers according to claim 6.

9. The perfluoroalkene is a cyclic alkene. The fluorine-containing resin composition for plastic optical fiber according to claim 1 or 4.

10. The cyclic alkene has the formula (15): cyclo-[CF=CF(CF 2 ) n −] (wherein the value of n is an integer from 2 to 6), The fluorine-containing resin composition for plastic optical fibers according to claim 9.

11. The concentration of the fluorine-containing resin in the fluorine-containing resin composition for plastic optical fiber is less than 20% by mass. The fluorine-containing resin composition for plastic optical fibers according to claim 1.

12. The viscosity of the fluorine-containing resin composition for plastic optical fiber at 25°C is less than 110 mPa s. The fluorine-containing resin composition for plastic optical fibers according to claim 1.

13. The fluorine-containing resin composition for plastic optical fiber according to claim 1 or 4 is contained. Plastic optical fiber or resin rod for plastic optical fiber.

14. (i) producing a resin molding for a plastic optical fiber containing a fluorine-containing resin by using the fluorine-containing resin composition for a plastic optical fiber according to claim 1 or 4; A method for producing a resin molding for a plastic optical fiber, comprising the steps of:

15. In the step (i), the fluorine-containing resin composition for plastic optical fiber is filtered to purify a resin material containing the fluorine-containing resin, and the resin material thus obtained is molded to obtain a resin molded product for plastic optical fiber. A method for producing the resin molding for a plastic optical fiber according to claim 14.

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