Fluorine-containing resin composition for plastic optical fiber, plastic optical fiber or resin rod for plastic optical fiber, and method for producing resin molded body for plastic optical fiber

Abstract

The invention provides a fluorine-containing resin composition for a plastic optical fiber, a plastic optical fiber or a resin rod for a plastic optical fiber, and a method for producing a resin molded body for a plastic optical fiber. This fluorine-containing resin composition contains a fluorine-containing resin and a solvent that dissolves the fluorine-containing resin. The solvent is perfluoroolefin. The fluorine-containing resin contains a fluorine-containing polymer containing a structural unit (A) represented by formula (1). # imgabs0 # (In 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 may be linked to form a ring. )

Description

Technical Field

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

[0002] Fluorine-containing resins are used in various applications such as materials for optical components such as resin materials used in photolithography, plastic optical fibers (hereinafter, recorded as "POFs"), etc. When fluorine-containing resins are used for various applications, for example, a composition obtained by dissolving fluorine-containing resins in a solvent is used. For example, when fluorine-containing resins are used as materials for anti-reflection films formed on photoresist layers in photolithography, a composition obtained by dissolving fluorine-containing resins in a solvent is used as a coating composition for making anti-reflection films. In addition, when fluorine-containing resins are used for optical applications, in order to suppress the degradation of the quality of optical components caused by mixed foreign matter, a purification process for removing foreign matter from the resin is required. In this case, in order to remove foreign matter from fluorine-containing resins, the following method is generally used: a composition obtained by dissolving fluorine-containing resins in a solvent is prepared and filtered. In this way, a fluorine-containing resin composition comprising a fluorine-containing resin and a solvent is used in various ways when the fluorine-containing resin is used for various applications.

[0003] Patent Document 1 discloses a composition containing a fluorinated polymer and an aprotic solvent, which contains a fluorinated polymer at a high concentration (specifically, 20% by mass or more). In Patent Document 1, examples of the aprotic solvent include perfluoroaromatic compounds, perfluorotrialkylamines, perfluoroalkanes, hydrofluorocarbons, perfluorocyclic ethers, hydrofluoroethers, and olefin compounds containing at least one chlorine atom.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 7014987 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In recent years, it is required to further reduce the environmental load for compositions containing fluorine-containing resins. In addition, as mentioned above, compositions containing fluorine-containing resins may be used in various processes depending on the application. For compositions containing fluorine-containing resins used for optical components, especially POF, it is required that the dissolution of materials with a high possibility of being used as process materials is small, that is, the mixing of impurities caused by the process is small.

[0009] The object of the present invention is to provide a novel fluorine-containing resin composition for POF that can reduce environmental load and can also reduce the mixing of impurities caused by the process. In addition, according to the present invention, it is also an object to provide a POF or a POF resin rod containing such a novel fluorine-containing resin composition for POF. In addition, it is also an object of the present invention to provide the following method for producing a POF resin molded body, which uses a novel fluorine-containing resin composition for POF that can reduce environmental load and can also reduce the mixing of impurities caused by the process.

[0010] Means for solving problems

[0011] A fluorine-containing resin composition according to a first aspect of the present invention is a fluorine-containing resin composition for POF, comprising a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin.

[0012] The above solvent is a perfluoroolefin,

[0013] The fluorine-containing resin comprises a fluorine-containing polymer containing a structural unit (A) represented by the following formula (1).

[0014] [Chemical formula 1]

[0015]

[0016] (In formula (1), R ff 1 ~R ff 4 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 Can be connected to form a ring.)

[0017] A fluorine-containing resin composition according to a second aspect of the present invention is a fluorine-containing resin composition for POF, comprising a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin.

[0018] The above solvent is a perfluoroolefin,

[0019] The fluorine-containing resin comprises a fluorine-containing polymer containing a structural unit (D) represented by the following formula (4).

[0020] [Chemical formula 4]

[0021]

[0022] (In formula (4), Z represents 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. A portion of the fluorine atoms may be replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkoxy group may be replaced by a halogen atom other than a fluorine atom. s and t are each independently 0 to 5, and s+t represents an integer of 1 to 6 (wherein, when Z is -OC(R 19 R 20 )O-, s+t can be 0).

[0023] A POF or a resin rod for POF according to a third aspect of the present invention comprises the fluorine-containing resin composition for POF according to the first aspect or the second aspect.

[0024] A method for producing a resin molded article for POF according to a fourth aspect of the present invention comprises the step of (i) using the fluorine-containing resin composition for POF according to the first aspect or the second aspect to produce a resin molded article for POF containing the fluorine-containing resin.

[0025] Effects of the Invention

[0026] According to the present invention, a novel fluorine-containing resin composition for POF can be provided, which can reduce the environmental load and can also reduce the mixing of impurities caused by the process. In addition, according to the present invention, a POF or a resin rod for POF containing such a novel fluorine-containing resin composition for POF can be provided. In addition, according to the present invention, the following method for manufacturing a resin molded body for POF can be provided, which uses a novel fluorine-containing resin composition for POF that can reduce the environmental load and can also reduce the mixing of impurities caused by the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a flowchart showing an example of a method for producing a resin molded body for POF according to the second embodiment.

[0028] Figure 2 This is a cross-sectional view showing an example of a POF manufactured by the method for manufacturing a POF resin molded body according to the second embodiment. DETAILED DESCRIPTION

[0029] (Implementation Method 1)

[0030] Embodiments of the fluorine-containing resin composition for POF of the present invention will be described.

[0031] The fluorine-containing resin composition for POF of this embodiment contains a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin. The solvent contains a perfluoroolefin. Here, "perfluoro" means that all hydrogen atoms bonded to carbon atoms are replaced by fluorine atoms. Hereinafter, the fluorine-containing resin composition for POF is abbreviated as "fluorine-containing resin composition".

[0032] In the fluorine-containing resin composition of the present embodiment, perfluoroolefin is used as a solvent. If compared with the fluorine-containing solvent used as a solvent in the previous fluorine-containing resin composition such as hydrofluorocarbons, hydrofluoroethers and perfluoroalkanes, perfluoroolefin has a lower global warming potential (hereinafter, sometimes referred to as GWP.). Perfluoroolefin can have, for example, a GWP of less than 150, less than 100, less than 50 or less than 10. In addition, perfluoroolefin has a low ozone depletion coefficient (hereinafter, sometimes referred to as ODP.) of zero in the same manner as the previous fluorine-containing solvents as described above. Therefore, regarding the fluorine-containing resin composition of the present embodiment using a perfluoroolefin with a lower GWP and zero ODP than the previous fluorine-containing solvent as a solvent, relative to the previous fluorine-containing resin composition, it is possible to reduce the environmental load.

[0033] Here, GWP is an index used to predict the relative burden of global warming caused by the emission of kilograms of a specific greenhouse gas into the atmosphere compared to the emission of kilograms of carbon dioxide. GWP can be calculated for different time horizons, indicating the impact on the atmospheric lifetime of a specified gas. The GWP for a 100-year time horizon is usually a reference value.

[0034] As one of the reasons why perfluoroolefins can have low GWP, it is believed that perfluoroolefins do not contain CH bonds. Since they do not contain CH bonds, perfluoroolefins have low ability to absorb infrared rays, i.e., small infrared absorption. Therefore, it is believed that, for perfluoroolefins, GWP can be reduced compared with fluorinated solvents containing CH bonds. In addition, as another reason why perfluoroolefins can have low GWP, it is believed that the atmospheric life is short. Since perfluoroolefins have double bonds, the OH radical reactivity is high. Therefore, it is believed that, compared with fluorinated solvents without double bonds, GWP can be reduced. It should be noted that GWP is not only related to infrared absorption and atmospheric life, but also to various factors, so it is believed that it is difficult to determine the size relationship of GWP based only on the discussion of infrared absorption or only on the discussion of atmospheric life. However, the infrared absorption and atmospheric life of perfluoroolefins are both better than those of conventional fluorinated solvents, so it is believed that they can have a lower GWP than conventional fluorinated solvents.

[0035] In addition, perfluoroolefins do not contain protons in the skeleton structure. Therefore, even when the fluorine-containing resin composition of the present embodiment is used in various processes according to various uses, the dissolution of the material used as the process material is small. That is, the fluorine-containing resin composition of the present embodiment can reduce the mixing of impurities caused by the process. As materials used as process materials, for example, resin materials and metal materials can be cited.

[0036] As described above, the fluorine-containing resin composition of the present embodiment can reduce environmental load and can also reduce the mixing of impurities caused by the process.

[0037] In the fluorine-containing resin composition of the present embodiment, the solvent preferably contains perfluoroolefin as a main component. Thus, the fluorine-containing resin composition of the present embodiment can further reduce the environmental load, and can also further reduce the mixing of impurities caused by the process. Here, in this specification, the solvent contains perfluoroolefin as a main component means that, among the solvents contained in the fluorine-containing resin composition of the present embodiment, the component contained most by mass ratio is perfluoroolefin. It should be noted that when a plurality of perfluoroolefins are contained in the solvent, the mass ratio of the perfluoroolefin in the solvent is obtained based on the total mass of the perfluoroolefin.

[0038] In order to further reduce the environmental load and reduce the mixing of impurities, in the fluorine-containing resin composition of the present embodiment, the solvent may be substantially composed of perfluoroolefins. Here, in this specification, the solvent is substantially composed of perfluoroolefins, which means that the content of perfluoroolefins in the solvent is 90% by mass or more, preferably 95% by mass or more. It should be noted that, when multiple perfluoroolefins are included, the content of perfluoroolefins in the solvent is calculated based on the total mass of perfluoroolefins. In the fluorine-containing resin composition of the present embodiment, the solvent may be composed only of perfluoroolefins.

[0039] The solubility and dissolution rate of fluorinated resin in perfluoroolefin are higher than those of conventional fluorinated solvents. Therefore, by including perfluoroolefin as a solvent, the fluorinated resin composition of the present embodiment can improve the solubility of the fluorinated resin in the solvent.

[0040] In addition, the fluorine-containing resin composition of the present embodiment has excellent filterability. Therefore, the fluorine-containing resin composition of the present embodiment can be efficiently filtered even when filtering, for example, for the purification treatment of a resin material containing a fluorine-containing resin. It should be noted that the fluorine-containing resin composition has excellent filterability, which means that even if the concentration of the fluorine-containing resin is increased, the viscosity of the fluorine-containing resin composition is not easy to increase, and when fluorine-containing resin compositions with the same fluorine-containing resin concentration are compared with each other, they can have a lower viscosity, and there is no problem with the liquid permeability during filtration. In order to achieve excellent filterability, for the fluorine-containing resin composition of the present embodiment, for example, the solution viscosity at 25°C is preferably 1 mPa·s or more and less than 110 mPa·s, more preferably 1 mPa·s or more and 100 mPa·s or less, further 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 in accordance with the standard of JIS K 7117-2.

[0041] In the fluorine-containing resin composition of the present embodiment, the concentration of the fluorine-containing resin can be appropriately determined according to the use of the fluorine-containing resin composition, and is therefore not particularly limited. However, in the case where 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, further 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.

[0042] Hereinafter, the fluorine-containing resin in the fluorine-containing resin composition of the present embodiment and the perfluoroolefin used as a solvent will be described in more detail.

[0043] [Fluorine-containing resin]

[0044] The fluorine-containing resin includes a fluorine-containing polymer. Since the fluorine-containing resin composition of the present embodiment is for POF, from the viewpoint of suppressing light absorption caused by the stretching energy of the CH bond, the fluorine-containing polymer contained in the fluorine-containing resin preferably does not substantially contain hydrogen atoms, and it is particularly preferred that all hydrogen atoms bonded to carbon atoms are replaced by fluorine atoms. That is, the fluorine-containing polymer preferably does not substantially contain hydrogen atoms and is perfluorinated. 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 less than 1 mol%.

[0045] The fluorinated polymer preferably has a fluorinated aliphatic ring structure. The fluorinated aliphatic ring structure may be contained in the main chain of the fluorinated polymer or in the side chain of the fluorinated polymer.

[0046] An example of the fluorinated polymer (hereinafter referred to as "the first example of the fluorinated polymer") contains, for example, a structural unit (A) represented by the following formula (1).

[0047] [Chemical formula 1]

[0048]

[0049] In formula (1), R ff 1 ~R ff 4 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 Can be connected to form a ring. "Perfluoro" means that all hydrogen atoms bonded to carbon atoms are replaced by 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 further preferably 1. The perfluoroalkyl group may be linear or branched. Examples of the perfluoroalkyl group include trifluoromethyl, pentafluoroethyl, heptafluoropropyl, and the like.

[0050] In formula (1), the number of carbon atoms in the perfluoroalkyl ether group is preferably 1 to 5, more preferably 1 to 3. The perfluoroalkyl ether group may be linear or branched. Examples of the perfluoroalkyl ether group include perfluoromethoxymethyl and the like.

[0051] In R ff 1 and R ff 2 When the rings are connected 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.

[0052] Specific examples of the structural unit (A) include structural units represented by the following formulae (A1) to (A8).

[0053] [Chemical formula 7]

[0054]

[0055] The structural unit (A) is preferably the structural unit (A2) among the structural units represented by the above formulae (A1) to (A8), that is, the structural unit represented by the following formula (5).

[0056] [Chemical formula 5]

[0057]

[0058] The first example of fluoropolymer can include one or more structural units (A). In the first example of fluoropolymer, the content of structural unit (A) can be more than 20 mol% relative to the total of all structural units, and can also be more than 40 mol%. By comprising more than 20 mol% of structural units (A), fluoropolymer thus has a tendency to have higher heat resistance. In the case of comprising more than 40 mol% of structural units (A), fluoropolymer has a tendency to have higher transparency and high mechanical strength in addition to high heat resistance. In the first example of fluoropolymer, the content of structural unit (A) can be less than 95 mol% relative to the total of all structural units, and can also be less than 70 mol%.

[0059] The structural unit (A) is derived from, for example, a compound represented by the following formula (6). In formula (6), R ff 1 ~R ff 4 The same as formula (1). The compound represented by formula (6) can be obtained by a known production method such as the production method disclosed in JP-A-2007-504125.

[0060] [Chemical formula 6]

[0061]

[0062] Specific examples of the compound represented by the above formula (6) include compounds represented by the following formulas (M1) to (M8).

[0063] [Chemical formula 8]

[0064]

[0065] In the first example of the fluorinated polymer, in addition to the structural unit (A), other structural units may be further included. As other structural units, the following structural units (B) to (D) may be cited. That is, the fluorinated polymer containing the structural unit (A) may further contain at least one 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).

[0066] The structural unit (B) is represented by the following formula (2).

[0067] [Chemical formula 2]

[0068]

[0069] In formula (2), R 1 ~R 3 Each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. 4 It represents 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 by a halogen atom other than a fluorine atom. A part of the fluorine atoms in the perfluoroalkyl group may be substituted by a halogen atom other than a fluorine atom.

[0070] The first example of the fluorinated polymer may contain one or more structural units (B). In the first example of the fluorinated polymer, the content of the structural unit (B) is preferably 5 to 10 mol% relative to the total of all structural units. The content of the structural unit (B) may be 9 mol% or less, or 8 mol% or less.

[0071] The structural unit (B) is derived from, for example, a compound represented by the following formula (7). 1 ~R 4 The same as formula (2). The compound represented by formula (7) is a fluorine-containing vinyl ether such as perfluorovinyl ether.

[0072] [Chemical formula 9]

[0073]

[0074] The structural unit (C) is represented by the following formula (3).

[0075] [Chemical formula 3]

[0076]

[0077] 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 portion of the fluorine atoms may be replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom.

[0078] The first example of the fluorinated polymer may contain one or more structural units (C). In the first example of the fluorinated polymer, the content of the structural unit (C) is preferably 5 to 10 mol% relative to the total of all structural units. The content of the structural unit (C) may be 9 mol% or less, or 8 mol% or less.

[0079] The structural unit (C) is derived from, for example, a compound represented by the following formula (8). 5 ~R 8The same as formula (3). The compound represented by formula (8) is a fluorine-containing olefin such as tetrafluoroethylene and chlorotrifluoroethylene.

[0080] [Chemical formula 10]

[0081]

[0082] The structural unit (D) is represented by the following formula (4).

[0083] [Chemical formula 4]

[0084]

[0085] In formula (4), Z represents 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 replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkoxy group may be replaced by a halogen atom other than a fluorine atom. The values ​​of s and t are each independently 0 to 5, and the value of s+t represents an integer of 1 to 6 (wherein, when Z is -OC(R 19 R 20 )O-, the value of s+t can be 0).

[0086] The structural unit (D) is preferably represented by the following formula (9). The structural unit represented by the following formula (9) is the case where Z is an oxygen atom, the value of s is 0, and the value of t is 2 in the above formula (4).

[0087] [Chemical formula 11]

[0088]

[0089] 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. A portion of the fluorine atoms may be substituted with a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkyl group may be substituted with a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkoxy group may be substituted with a halogen atom other than a fluorine atom.

[0090] The first example of the fluorinated polymer may include one or more structural units (D). In the first example of the fluorinated polymer, the content of the structural unit (D) is preferably 30 to 67 mol% relative to the total of all structural units. The content of the structural unit (D) is, for example, 35 mol% or more, 60 mol% or less, or 55 mol% or less.

[0091] The structural unit (D) is derived from, for example, a compound represented by the following formula (10). 9 ~R 18 The values ​​of , s and t are the same as those of formula (4). The compound represented by formula (10) is a fluorine-containing compound having two or more polymerizable double bonds and capable of cyclopolymerization.

[0092] [Chemical formula 12]

[0093]

[0094] The structural unit (D) is preferably derived from a compound represented by the following formula (11). In formula (11), R 141 , R 142 , R 151 and R 152 Same as formula (9).

[0095] [Chemical formula 13]

[0096]

[0097] Specific examples of the compound represented by formula (10) or formula (11) include the following compounds.

[0098] CF2=CFOCF2CF=CF2

[0099] CF2=CFOCF(CF3)CF=CF2

[0100] CF2=CFOCF2CF2CF=CF2

[0101] CF2=CFOCF2CF(CF3)CF=CF2

[0102] CF2=CFOCF(CF3)CF2CF=CF2

[0103] CF2=CFOCFClCF2CF=CF2

[0104] CF2=CFOCCl2CF2CF=CF2

[0105] CF2=CFOCF2OCF=CF2

[0106] CF2=CFOC(CF3)2OCF=CF2

[0107] CF2=CFOCF2CF(OCF3)CF=CF2

[0108] CF2=CFCF2CF=CF2

[0109] CF2=CFCF2CF2CF=CF2

[0110] CF2=CFCF2OCF2CF=CF2

[0111] CF2=CFOCF2CFClCF=CF2

[0112] CF2=CFOCF2CF2CCl=CF2

[0113] CF2=CFOCF2CF2CF=CFCl

[0114] CF2=CFOCF2CF(CF3)CCl=CF2

[0115] CF2=CFOCF2OCF=CF2

[0116] CF2=CFOCCl2OCF=CF2

[0117] CF2=CClOCF2OCCl=CF2

[0118] The first example of the fluorinated polymer may further contain other structural units other than the structural units (A) to (D), but preferably does not substantially contain other structural units other than the structural units (A) to (D). It should be noted that the first example of the fluorinated polymer does not substantially contain other structural units other than the structural units (A) to (D) means that the total amount of the structural units (A) to (D) is 95 mol% or more, preferably 98 mol% or more, relative to the total amount of all structural units in the first example of the fluorinated polymer.

[0119] The fluorinated polymer contained in the fluorinated resin may also be another example different from the first example of the fluorinated polymer (hereinafter, described as "the second example of the fluorinated polymer"). The second example of the fluorinated polymer contains the above-mentioned structural unit (D). The second example of the fluorinated polymer may be composed only of the structural unit (D), or may further contain other structural units other than the structural unit (D). The second example of the fluorinated polymer may contain one or more structural units (D).

[0120] The polymerization method of the first and second examples of the fluorinated polymers is not particularly limited, and for example, a common polymerization method such as radical polymerization may be used. The polymerization initiator used for polymerizing the fluorinated polymer may be a perfluorinated compound.

[0121] [Perfluoroolefins]

[0122] In the fluorine-containing resin composition of the present embodiment, the carbon number of the perfluoroolefin used as the solvent is, for example, 2 to 10. The boiling point of the perfluoroolefin having a carbon number of 2 to 10 is low, so as a result, the solvent can be easily volatilized. Here, "2 to 10" has the same meaning as 2 or more and 10 or less.

[0123] The perfluoroolefin may be a chain perfluoroolefin or a cyclic perfluoroolefin. The chain perfluoroolefin may be a linear perfluoroolefin or a branched perfluoroolefin.

[0124] The perfluoroolefin may be, for example, of the formula (12): n F 2n (n is an integer of 2 or more). In the formula (12), the value of n is, for example, 10 or less, and preferably 8 or less.

[0125] The perfluoroolefin may be of formula (13): R 21 CF=CFR 22 Here, in formula (13), R 21 and R 22 Each independently represents a perfluoroalkyl group having 1 to 6 carbon atoms. The above-mentioned olefin may be either a cis-form (sometimes represented by (Z)) or a trans-form (sometimes represented by (E)).

[0126] The perfluoroolefin is represented by, for example, the formula (14) or (15).

[0127] Formula (14): (E)-R 23 CF=CFR 24 or (Z)-R 23 CF=CFR 24 perfluoroolefin, and in formula (14), R 23 and R 24 are independently F atoms or perfluoroalkyl groups having 1 to 8 carbon atoms, and in formula (14), the total number of carbon atoms in the compound is at least 4

[0128] Formula (15): Cyclo-[CF=CF(CF2) n -] a perfluorocyclic olefin, and in formula (15), the value of n is an integer from 2 to 6

[0129] Examples of perfluoroolefins include 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); 1,1,2,3,3,4,4,5,5,5-decafluoro-1-pentene (CF2=CFCF2CF2CF3); Fluoro-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); 1,1,2,3,3,4,4,5,5,6,6,7,7,7-tetradecafluoro-1-heptene (CF2=CFCF2CF2CF2C2F5); 2F5); 1,1,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9-octafluoro-1-nonene (CF2=CFCF2CF2CF2CF2CF2C2F5); 1,1,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-eightefluoro-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 perfluoroolefin may include at least one selected from the compounds exemplified above. It should be noted that the above compound may be either cis (Z) or trans (E).

[0130] In the fluorine-containing resin composition of the present embodiment, the perfluoroolefin may include 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 structure, the fluorine-containing resin composition of the present 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 not easy to dissolve the materials used as process materials, and the dissolution amount of process materials can be further reduced. Therefore, according to this structure, the fluorine-containing resin composition of the present embodiment can further reduce the mixing of impurities caused by the process.

[0131] 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 including 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.

[0132] In addition, the fluorine-containing resin composition containing 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene as a solvent has a more excellent filterability. Therefore, when 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 be filtered more efficiently.

[0133] The perfluoroolefin 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 perfluoroolefin 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 in the perfluoroolefin in terms of mass ratio is 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene.

[0134] In the fluorine-containing resin composition of the present embodiment, the perfluoroolefin may be substantially composed of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene. Here, in the present specification, the perfluoroolefin substantially composed 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 perfluoroolefin is 90% by mass or more, preferably 95% by mass or more. In the fluorine-containing resin composition of the present embodiment, the perfluoroolefin contained as a solvent may also be composed only of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene.

[0135] [Other ingredients]

[0136] The fluorine-containing resin composition of the present embodiment may further contain other components besides the above-mentioned fluorine-containing resin and perfluoroolefin-containing solvent. The fluorine-containing resin composition of the present embodiment may also contain additives such as a refractive index adjuster.

[0137] (Implementation Method 2)

[0138] An embodiment of the method for producing the resin molded article for POF of the present invention will be described.

[0139] The method for producing a resin molded article for POF according to the present embodiment comprises the step of (i) using the fluorine-containing resin composition according to the first embodiment to produce a resin molded article for POF containing a fluorine-containing resin.

[0140] The fluorine-containing resin composition is as described in Embodiment 1, and therefore detailed description thereof will be omitted here.

[0141] In the above (i), the fluorine-containing resin composition can be used, for example, for purification of a resin material for forming a resin molded body for POF. A flowchart of the production method in this case is shown in FIG. Figure 1 . In this case, in the manufacturing method of the present embodiment, for example, in the above (i), the resin material containing the fluorine-containing resin is purified by filtering the fluorine-containing resin composition (S11), and the resin molded body for POF is obtained by molding the obtained resin material (S12). As described in Embodiment 1, the fluorine-containing resin composition has excellent filterability. Therefore, according to the manufacturing method of the present embodiment, even when the fluorine-containing resin composition is filtered for the purification treatment of the resin material containing the fluorine-containing resin, it can be filtered efficiently. In this way, according to the manufacturing method of the present embodiment, a high-quality resin molded body for POF with foreign matter removed can be efficiently manufactured.

[0142] In the production method of the present embodiment, the method of using the fluorine-containing resin composition for producing the resin molded article for POF is not limited to the filtration for the above-mentioned purification treatment.

[0143] In the POF resin molded article obtained by the production method of this embodiment, the perfluoroolefin contained as a solvent in the fluorine-containing resin composition may remain in a detectable amount. The perfluoroolefin in the POF resin molded article may be detected by, for example, gas chromatography (GC).

[0144] In the manufacturing method of this embodiment, for example, Figure 1 As shown in the flowchart shown in FIG. 1 , the resin material containing the fluorine-containing resin can be purified by filtering the fluorine-containing resin composition (S11), and the resin molded body for POF can be obtained by molding the obtained resin material (S12). Here, the resin molded body for POF can also be the POF itself. That is, in S12, the POF can be manufactured by molding the resin material into a fiber shape. The manufactured POF can also be a refractive index distribution type POF in which the refractive index of the core has a distribution symmetrically about the central axis. The purified resin material containing the fluorine-containing resin can be used as the core material of the POF, and can also be used as a cladding material.

[0145] The specific method of forming the resin material into a fiber to obtain POF is not particularly limited. For example, the resin material obtained in the purification treatment of S11 can be melted by heating at a temperature of 50°C or above from the glass transition temperature of the resin material, and spun by melt extrusion and formed into a fiber to produce POF. It should be noted that when spinning by melt extrusion, the refractive index modifier is diffused in the resin material by heating, so that the core of the refractive index of the core can be produced. The distribution of the refractive index of the core has a distribution symmetrical about the central axis.

[0146] Figure 21 is a cross-sectional view showing an example of a POF that can be manufactured by the manufacturing method of the present embodiment. The POF 10 that can be manufactured by the manufacturing method of the present embodiment, for example, comprises a core 11 and a cladding 12 arranged on the periphery of the core 11. The core 11 is obtained, for example, by melt-extruding a resin material (core material) containing a fluorine-containing resin, and spinning and forming it into a fiber shape. The resin material containing a fluorine-containing resin is obtained by filtering a fluorine-containing resin composition. The cladding 12 can be formed, for example, by melt-extruding a resin material (cladding material) containing a fluorine-containing resin obtained by filtering a fluorine-containing resin composition in a manner that covers the periphery of the core 11. When spinning by the melt extrusion, the refractive index modifier contained in the core material is diffused in the resin material by heating, so that the core 11 of the refractive index distribution type POF can be produced in which the refractive index of the core 11 has a distribution symmetrical about the central axis. When the fluorine-containing resin composition of the first embodiment is used to prepare a core material and a cladding material, the obtained core 11 and cladding 12 may contain a very small amount of perfluoroolefin to such an extent that the performance as the core and the cladding is not affected.

[0147] (Implementation 3)

[0148] Embodiments of the POF or the resin rod for POF of the present invention will be described.

[0149] The POF or POF resin rod of the present embodiment comprises the fluorine-containing resin composition of embodiment 1. The POF resin rod is used when manufacturing POF by melt extrusion. The POF resin rod is heated and melted, and spun by melt extrusion to form a fiber, thereby making POF. The POF or POF resin rod of the present embodiment may contain a solvent containing perfluoroolefin. The perfluoroolefin contained in the solvent can be detected by using gas chromatography (GC).

[0150] [Example]

[0151] Hereinafter, the present invention will be described in further detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0152] (Example 1)

[0153] [Production of fluorinated resin]

[0154] As a fluorine-containing resin, a polymer of perfluoro-4-methyl-2-methylene-1,3-dioxolane (the compound of the above formula (M2), "PFMMD") is prepared. Perfluoro-4-methyl-2-methylene-1,3-dioxolane is synthesized by first synthesizing 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane, fluorinating it, and decarboxylating the resulting carboxylate. In the polymerization of perfluoro-4-methyl-2-methylene-1,3-dioxolane, perfluorobenzoyl peroxide is used as a polymerization initiator.

[0155] The synthesis of 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane, the fluorination of 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane, 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 below.

[0156] <Synthesis of 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane>

[0157] Prepare a 3L three-necked flask, a thermometer, a magnetic stirrer and an isobaric dropping funnel with a water-cooled condenser, and put 139.4g (a total of 1.4 moles) of a mixture of 2-chloro-1-propanol and 1-chloro-2-propanol into a flask. The flask is cooled to 0 ° C, methyl trifluoropyruvate is slowly added thereto, and stirred for another 2 hours. After spending 1 hour to add 100mL of dimethyl sulfoxide (DMSO) and 194g of potassium carbonate thereto, stirring was continued for further 8 hours to obtain a reaction mixture. The generated reaction mixture was mixed with 1L of water, an aqueous phase was separated, and after further extraction with dichloromethane, the dichloromethane solution was mixed with an organic reaction mixture, and the solution was dried over magnesium sulfate. After the solvent was removed, 245.5g of crude product was obtained. The crude product was fractionated under reduced pressure (12 Torr) to obtain 230.9 g of purified 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane. The boiling point of the purified product was 77-78°C, and the yield was 77%. It should be noted that the purified product was obtained by HNMR (Bruker, product name: Biospin, AVANCE III-600 with Cryo Probe) and 19 FNMR (manufactured by Bruker Corporation, product name: Biospin, AVANCE III-400) confirmed that the obtained purified product was 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane.

[0158] HNMR (ppm): 4.2-4.6, 3.8-3.6 (CHCH2, multiplet, 3H), 3.85-3.88 (COOCH3, multiplet, 3H), 1.36-1.43 (CCH3, multiplet, 3H)

[0159] 19 FNMR (ppm): -81.3 (CF3, s, 3F)

[0160] <Fluorination of 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane>

[0161] Inject 4L of 1,1,2-trichlorotrifluoroethane into a 10L stirred reaction tank. In the stirred reaction tank, nitrogen is flowed at a flow rate of 1340cc / min, and fluorine is flowed at a flow rate of 580cc / min, and the atmosphere is set to nitrogen / fluorine. After 5 minutes, 290g of the previously prepared 2-carboxymethyl-2-trifluoromethyl-4-methyl-1,3-dioxolane is dissolved in 750mL of 1,1,2-trichlorotrifluoroethane solution, and the solution is added to the reaction tank at a rate of 0.5ml / min. The reaction tank is cooled to 0°C. After taking 24 hours to add all the dioxolanes, the fluorine gas flow is stopped. After purging nitrogen, potassium hydroxide aqueous solution is added until it becomes weakly alkaline.

[0162] After removing the volatile substances under reduced pressure, the surrounding of the reaction tank 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 500 mL of water, and excess hydrochloric acid was added to separate it into an organic phase and an aqueous phase. 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%.

[0163] <Synthesis of perfluoro-4-methyl-2-methylene-1,3-dioxolane>

[0164] The above distillate was neutralized with an aqueous potassium hydroxide solution to obtain perfluoro-2,4-dimethyl-2-carboxylic acid potassium-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 in a nitrogen or argon atmosphere. Condensation was performed using a cold trap cooled to -78°C to obtain perfluoro-4-methyl-2-methylene-1,3-dioxolane with a yield of 82%. The boiling point of the product is 45°C / 760 mmHg. Use 19The product was identified by FNMR (manufactured by Bruker, product name: Biosipin, AVANCE III-400) and GC-MS (manufactured by Agilent Technologies, product name: 6890plus / 5973N).

[0165] 19 FNMR: -84ppm (3F, CF3), -129ppm (2F, =CF2)

[0166] GC-MS: m / e244 (Molecular ion) 225, 197, 169, 150, 131, 100, 75, 50.

[0167] <Polymerization of perfluoro-4-methyl-2-methylene-1,3-dioxolane>

[0168] 100 g of perfluoro-4-methyl-2-methylene-1,3-dioxolane and 1 g of perfluorobenzoyl peroxide obtained by the above method were sealed in a glass tube. The glass tube was deoxygenated by freeze degassing, then filled with argon and heated at 50°C for several hours. The contents became solid, and after further heating at 70°C overnight, 100 g of a transparent rod was obtained.

[0169] The obtained transparent rod-like substance was dissolved in Fluorinert FC-75 (manufactured by Sumitomo 3M Co.), and the obtained solution was poured into 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 substance was dissolved in hexafluorobenzene, and chloroform was added thereto to precipitate it, thereby purifying the product. The glass transition temperature of the purified polymer was about 131°C. The polymer was used as a fluorine-containing resin.

[0170] [Preparation of fluorine-containing resin composition]

[0171] The fluorine-containing resin and the perfluoroolefin solvent prepared by the above method are mixed in a glass screw tube. The perfluoroolefin used as a solvent is 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene (GWP: less than 10). The fluorine-containing resin and the perfluoroolefin solvent are blended in such a way that the concentration of the fluorine-containing resin in the obtained fluorine-containing resin composition becomes 5% by mass. The glass screw tube is sealed and heated at 50°C for 3 hours to dissolve the fluorine-containing resin in the perfluoroolefin solvent.

[0172] [Evaluation of fluorine-containing resin composition]

[0173] (1) Determination of viscosity

[0174] The viscosity of the fluorine-containing resin composition prepared by the above method at 25° C. was measured. Specifically, the viscosity of the fluorine-containing resin composition at 25° C. was measured using an E-type viscometer ("TVE-22LT", manufactured by Toki Sangyo Co., Ltd.) in accordance with JIS K 7117-2. The measurement results are shown in Table 1.

[0175] (2) Evaluation of filtration performance

[0176] The filterability of the fluorine-containing resin composition prepared by the above method was evaluated. The filterability was evaluated using a stainless steel bracket KST-47 with grooves manufactured by Advantech. The filter used an Omnipore filter membrane manufactured by Merck (characteristics: hydrophilicity, material: PTFE ((polytetrafluoroethylene)), pore size: 0.1 μm). The filterability was determined based on whether the solution in the groove of the stainless steel bracket with grooves could be completely filtered within 8 hours. The evaluation results are shown in Table 1. In Table 1, the case where all the solution can be filtered within the time is indicated as "A", and the case where all the solution cannot be filtered is indicated as "B". The criterion for determining whether the solution can be filtered is based on visual inspection.

[0177] (3) Dissolution test of process materials

[0178] 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, a dissolution test was conducted on polypropylene (PP) and silicone which may be used as process materials. In a screw-threaded vial, a test piece of PP and silicone (a tube with an inner diameter of 9 mm and an outer diameter of 12 mm, and a length of 30 mm) and the solvent were placed so that the unit contact area of ​​the test piece became about 20 mm. 2 / g-solvent (i.e., the area of ​​the test piece relative to 1g of solvent is about 20mm 2 ), the specimen was immersed in the solvent at room temperature for 2 weeks. After 2 weeks, the increase in the material (PP and silicone) of the specimen in the solvent was measured. The increase in the material of the specimen in the solvent was measured by gas chromatography (GC). Regarding the increase in the material of the specimen in the solvent, when PP is less than 10 ppm and silicone is less than 100 ppm, it is judged that the dissolution of the process material is suppressed. The results are shown in Table 1. In Table 1, the case where the dissolution of the process material is suppressed is represented as "A", and the case where the dissolution of the process material is not suppressed is represented as "B".

[0179] (Example 2)

[0180] [Production of fluorinated resin]

[0181] By the same method as in Example 1, a fluorine-containing resin was prepared.

[0182] [Preparation of fluorine-containing resin composition]

[0183] A fluorine-containing resin composition of Example 2 was prepared in the same manner as in Example 1 except that the fluorine-containing resin and the perfluoroolefin solvent were blended so that the concentration of the fluorine-containing resin in the obtained fluorine-containing resin composition became 10 mass %.

[0184] [Evaluation of fluorine-containing resin composition]

[0185] The same evaluation as in Example 1 was performed. Table 1 shows the evaluation results.

[0186] (Example 3)

[0187] [Production of fluorinated resin]

[0188] By the same method as in Example 1, a fluorine-containing resin was produced.

[0189] [Preparation of fluorine-containing resin composition]

[0190] A fluorine-containing resin composition of Example 3 was prepared by the same method as in Example 1 except that the fluorine-containing resin and the perfluoroolefin solvent were blended so that the concentration of the fluorine-containing resin in the obtained fluorine-containing resin composition became 19.5 mass %.

[0191] [Evaluation of fluorine-containing resin composition]

[0192] The same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

[0193] (Example 4)

[0194] [Production of fluorinated resin]

[0195] By the same method as in Example 1, a fluorine-containing resin was produced.

[0196] [Preparation of fluorine-containing resin composition]

[0197] A fluorine-containing resin composition of Example 4 was prepared by the same method as in Example 1 except that the fluorine-containing resin and the perfluoroolefin solvent were blended so that the concentration of the fluorine-containing resin in the obtained fluorine-containing resin composition became 20 mass %.

[0198] [Evaluation of fluorine-containing resin composition]

[0199] The same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

[0200] (Comparative Example 1)

[0201] [Production of fluorinated resin]

[0202] By the same method as in Example 1, a fluorine-containing resin was produced.

[0203] [Preparation of fluorine-containing resin composition]

[0204] A fluorine-containing resin composition of Comparative Example 1 was prepared by the same method as in Example 4, except that 1,1,1,2,2,3,4,5,5,5-decafluoropentane (GWP: 1640) was used as the solvent instead of 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene.

[0205] [Evaluation of fluorine-containing resin composition]

[0206] The same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

[0207] (Comparative Example 2)

[0208] [Production of fluorinated resin]

[0209] By the same method as in Example 1, a fluorine-containing resin was produced.

[0210] [Preparation of fluorine-containing resin composition]

[0211] A fluorine-containing resin composition of Comparative Example 2 was prepared by the same method as in Example 4, except that methyl nonafluoroisobutyl ether (Novec 7100 (manufactured by 3M Co.)) (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.

[0212] [Evaluation of fluorine-containing resin composition]

[0213] The same evaluation as in Example 1 was performed. The evaluation results are shown in Table 1.

[0214] [Table 1]

[0215]

[0216] As shown in Table 1, regarding the fluorine-containing resin compositions of Examples 1 to 4 using perfluoroolefin as a solvent, in the dissolution test of the process materials, the dissolution of any process material of PP and silicone was suppressed. Therefore, it can be confirmed that the fluorine-containing resin compositions of Examples 1 to 4 can reduce the environmental load by using perfluoroolefin with a low GWP as a solvent, and further suppress the dissolution of process materials, and can also reduce the mixing of impurities caused by the process. In contrast, the solvent used in the fluorine-containing resin composition of Comparative Examples 1 and 2 has a higher GWP than the perfluoroolefin used in Examples 1 to 4. Therefore, in terms of environmental load reduction, the fluorine-containing resin compositions of Comparative Examples 1 and 2 are 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 cannot suppress the dissolution of process materials.

[0217] The viscosity of the fluorine-containing resin composition of Examples 1 to 3 at 25°C is less than 110 mPa·s, and excellent filterability can be achieved. It should be noted that the fluorine-containing resin composition of Example 4 cannot achieve a viscosity of less than 110 mPa·s because the concentration of the fluorine-containing resin is higher than that of Examples 1 to 3. However, when the fluorine-containing resin composition of Example 4 is compared with the fluorine-containing resin compositions of Comparative Examples 1 and 2 having the same concentration of fluorine-containing resin, the viscosity is greatly reduced. Therefore, it is believed that the fluorine-containing resin composition of Example 4 is also superior to the fluorine-containing resin compositions of Comparative Examples 1 and 2 in terms of filterability.

[0218] It should be noted that, in the Examples and Comparative Examples, only the results of the dissolution test of PP and silicone as process materials are shown, but the dissolution in the solvent was also confirmed for other process materials such as PTFE, PFA, nylon 66 and Hastelloy C276. In the case of these process materials, the difference between the Examples and the Comparative Examples is smaller than that of PP and silicone, but the perfluoroolefin solvent used in the Examples has a smaller amount of dissolution of the process material than the solvent used in Comparative Examples 1 and 2.

[0219] [Note]

[0220] In summary, one embodiment of the present invention is as follows. (1)

[0222] A fluorine-containing resin composition for POF, comprising a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin.

[0223] The above solvent is a perfluoroolefin,

[0224] The fluorine-containing resin comprises a fluorine-containing polymer containing a structural unit (A) represented by the following formula (1).

[0225] [Chemical formula 1]

[0226]

[0227] (In formula (1), R ff 1 ~R ff 4 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 Can be connected to form a ring.) (2)

[0229] The fluorinated resin composition for POF according to the above (1), wherein the fluorinated 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).

[0230] [Chemical formula 2]

[0231]

[0232] (In formula (2), R 1 ~R 3 Each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms. 4 It represents 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 replaced by a halogen atom other than a fluorine atom. A part of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom.

[0233] [Chemical formula 3]

[0234]

[0235] (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 portion of the fluorine atoms may be replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom.

[0236] [Chemical formula 4]

[0237]

[0238] (In formula (4), Z represents 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 replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkoxy group may be replaced by a halogen atom other than a fluorine atom. The values ​​of s and t are each independently 0 to 5, and the value of s+t represents an integer of 1 to 6 (wherein, when Z is -OC(R 19 R 20 )O-, the value of s+t can be 0). (3)

[0240] The fluorine-containing resin composition for POF according to the above (1) or (2), wherein the structural unit (A) comprises a structural unit represented by the following formula (5).

[0241] [Chemical formula 5]

[0242] (4)

[0244] A fluorine-containing resin composition for POF, comprising a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin.

[0245] The above solvent is a perfluoroolefin,

[0246] The fluorine-containing resin comprises a fluorine-containing polymer containing a structural unit (D) represented by the following formula (4).

[0247] [Chemical formula 4]

[0248]

[0249] (In formula (4), Z represents 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 replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom. A portion of the fluorine atoms in the perfluoroalkoxy group may be replaced by a halogen atom other than a fluorine atom. s and t are each independently 0 to 5, and s+t represents an integer of 1 to 6 (wherein, when Z is -OC(R 19 R 20 )O-, s+t can be 0). (5)

[0251] The fluorine-containing resin composition for POF according to any one of the above (1) to (4), wherein the perfluoroolefin has 2 to 10 carbon atoms. (6)

[0253] The fluorine-containing resin composition for POF according to any one of the above (1) to (5), wherein the perfluoroolefin is represented by the formula (12): n F 2n (the value of n is an integer greater than or equal to 2). (7)

[0255] The fluorine-containing resin composition for POF according to the above (6), wherein the perfluoroolefin is represented by the formula (13): R 21CF=CFR 22 express,

[0256] In the above formula (13), R 21 and R 22 Each is independently a perfluoroalkyl group having 1 to 6 carbon atoms. (8)

[0258] The fluorine-containing resin composition for POF according to the above (6) or (7), wherein the perfluoroolefin comprises 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene. (9)

[0260] The fluorine-containing resin composition for POF according to any one of the above (1) to (4), wherein the perfluoroolefin is a cyclic olefin. (10)

[0262] The fluorine-containing resin composition for POF according to the above (9), wherein the cyclic olefin is represented by the formula (15): cyclo-[CF=CF(CF2) n -] (the value of n is an integer from 2 to 6). (11)

[0264] The fluorine-containing resin composition for POF according to any one of the above (1) to (10), wherein the concentration of the fluorine-containing resin in the fluorine-containing resin composition for POF is less than 20% by mass. (12)

[0266] The fluorine-containing resin composition for POF according to any one of the above (1) to (11), wherein the viscosity of the fluorine-containing resin composition for POF at 25°C is less than 110 mPa·s. (13)

[0268] A POF or a resin rod for POF, comprising the fluorine-containing resin composition for POF as described in any one of (1) to (12) above. (14)

[0270] A method for producing a resin molded article for POF, comprising the step of (i) using the fluorine-containing resin composition for POF described in any one of (1) to (12) above to produce a resin molded article for POF containing the fluorine-containing resin. (15)

[0272] According to the method for producing a resin molded body for POF described in the above (14), in the above (i), the resin material containing the above fluorine-containing resin is purified by filtering the above fluorine-containing resin composition for POF, and the above resin molded body for POF is obtained by molding the obtained above resin material.

[0273] Industrial Applicability

[0274] The fluorine-containing resin composition for POF of the present invention is suitable for the production of POF.

Claims

1. A fluorine-containing resin composition for plastic optical fiber, comprising a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin, The solvent is a perfluoroolefin, The fluorine-containing resin comprises a fluorine-containing polymer containing a structural unit (A) represented by the following formula (1), In formula (1), R ff 1 ~R ff 4 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, and R ff 1 and R ff 2 Optionally linked to form a ring.

2. The fluorine-containing resin composition for plastic optical fiber according to claim 1, wherein The fluorinated 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), In formula (2), R 1 ~R 3 Each independently represents a fluorine atom or a perfluoroalkyl group having 1 to 7 carbon atoms, and R 4 represents 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 a halogen atom other than a fluorine atom, and a part of the fluorine atoms in the perfluoroalkyl group may be substituted with a halogen atom other than a fluorine atom, 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 replaced by a halogen atom other than a fluorine atom, and a part of the fluorine atoms in the perfluoroalkyl group may be replaced by a halogen atom other than a fluorine atom, In formula (4), Z represents 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 by a halogen atom other than a fluorine atom, a portion of the fluorine atoms in the perfluoroalkyl group may be substituted by a halogen atom other than a fluorine atom, a portion of the fluorine atoms in the perfluoroalkoxy group may be substituted by a halogen atom other than a fluorine atom, the values ​​of s and t are each independently 0 to 5, and the value of s+t represents an integer of 1 to 6, wherein Z is -OC(R 19 R 20 )O-, the value of s+t can be arbitrarily set to 0.

3. The fluorine-containing resin composition according to claim 1, wherein The structural unit (A) comprises a structural unit represented by the following formula (5), 4. A fluorine-containing resin composition for plastic optical fiber, comprising a fluorine-containing resin and a solvent for dissolving the fluorine-containing resin, The solvent is a perfluoroolefin, The fluorine-containing resin comprises a fluorine-containing polymer containing a structural unit (D) represented by the following formula (4), In formula (4), Z represents 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 by a halogen atom other than a fluorine atom, a portion of the fluorine atoms in the perfluoroalkyl group may be substituted by a halogen atom other than a fluorine atom, a portion of the fluorine atoms in the perfluoroalkoxy group may be substituted by a halogen atom other than a fluorine atom, s and t are each independently 0 to 5, and s+t represents an integer of 1 to 6, wherein, In Z, -OC(R 19 R 20 )O-, s+t can be 0.

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

6. The fluorine-containing resin composition for plastic optical fiber according to claim 1 or 4, wherein The perfluoroolefin is represented by formula (12): n F 2n Represents, and the value of n is an integer greater than or equal to 2.

7. The fluorine-containing resin composition for plastic optical fiber according to claim 6, wherein The perfluoroolefin is represented by formula (13): R 21 CF=CFR 22 express, In the formula (13), R 21 and R 22 Each is independently a perfluoroalkyl group having 1 to 6 carbon atoms.

8. The fluorine-containing resin composition for plastic optical fiber according to claim 6, wherein The perfluoroolefin comprises 1,1,1,2,2,3,4,5,5,6,6,7,7,7-tetradecafluoro-3-heptene.

9. The fluorine-containing resin composition for plastic optical fiber according to claim 1 or 4, wherein The perfluoroolefin is a cyclic olefin.

10. The fluorine-containing resin composition for plastic optical fiber according to claim 9, wherein The cyclic olefin is represented by the formula (15): cyclo-[CF=CF(CF2) n -], and the value of n is an integer from 2 to 6.

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

12. The fluorine-containing resin composition for plastic optical fiber according to claim 1, wherein The viscosity of the fluorine-containing resin composition for plastic optical fiber at 25° C. is less than 110 mPa·s. 13 . A plastic optical fiber or a resin rod for a plastic optical fiber, comprising the fluorine-containing resin composition for a plastic optical fiber according to claim 1 or 4 .

14. A method for producing a resin molded body for plastic optical fiber, comprising the step of (i) using the fluorine-containing resin composition for plastic optical fiber according to claim 1 or 4 to produce a resin molded body for plastic optical fiber comprising the fluorine-containing resin.

15. The method for producing a resin molded body for a plastic optical fiber according to claim 14, wherein: In the above (i), the resin material containing the fluorine-containing resin is purified by filtering the fluorine-containing resin composition for plastic optical fiber, and the obtained resin material is molded to obtain the resin molded article for plastic optical fiber.

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