TW201835120A - Fluoropolymer, method for producing cured product thereof, and light-emitting device - Google Patents

Abstract

Provided are: a thermosetting fluoropolymer having melt moldability and heat resistance as well as UV resistance; a method for producing a cured product of the fluoropolymer; and a light-emitting device using the cured product. The fluoropolymer contains a unit represented by formula (1) and a unit represented by formula (2). (In formula (1), Rf1 is a fluoroalkylene group, or a fluoroalkylene group having 2 or more carbon atoms and having etheric oxygen atoms between carbon atoms, and R1 and R2 are, each independently, a hydrogen atom or an alkyl group. In formula (2), X1, X2, and X3 are, each independently, a fluorine atom or a hydrogen atom, the two Q2's are, each independently, a single bond or an etheric oxygen atom, and Rf2 is a C1-6 fluoroalkylene group, or a C2-25 fluoroalkylene group having etheric oxygen atoms between carbon atoms).

Description

Fluoropolymer, method for producing hardened product thereof, and light emitting device

The invention relates to a fluorinated polymer, a method for manufacturing the fluorinated polymer, and a light emitting device.

BACKGROUND OF THE INVENTION In recent years, white LEDs (Light Emitting Diodes) have replaced incandescent and fluorescent lamps in practical applications as light sources for high-efficiency lighting. In addition, ultraviolet (UV) LEDs have also begun to increase in output, and have been used in various industrial processes instead of mercury lamps. In the case of LED lamps using white LEDs or UVLEDs, in order to protect the LED elements from external physical and chemical effects, the LED elements are sealed (moulded) with a light-transmitting resin such as silicone. However, in UVLED, the translucent resin is deteriorated by the ultraviolet rays and heat emitted from the LED. In addition, with regard to white LEDs, for example, LED lamps that require high output, such as automotive headlights or outdoor lighting, the translucent resin used to seal the LED elements is also deteriorated. Therefore, a glass cover or a glass cover is used to protect the LED elements without using a resin, which causes the structure of the LED lamp to become complicated, but raises the problem of increasing costs.

For high heat resistance of the light transmitting resin seal such as a white LED or a UVLED for high output of the LED, such prior document proposes a curable fluorine-containing polymer of the COOCH ₃ group (such as a carboxylic acid having an alkyl ester group See Patent Document 1). This hardenable fluoropolymer is hardened by irradiating active energy rays, so that a hardened product having excellent stability and ultraviolet light transmittance can be obtained.

Prior Art Literature Patent Literature Patent Literature 1: International Publication No. 2015/098773

SUMMARY OF THE INVENTION Problems to be Solved by the Invention However, according to the study by the present inventors, the fluoropolymer described in Patent Document 1 requires ultraviolet (UV) radiation to harden. When there is a shaded portion in the LED element structure that cannot be illuminated by UV light, In this part, the problem of insufficient hardening will occur.

An object of the present invention is to provide a fluorinated polymer that can be heat-cured and has good melt moldability, and can impart high heat resistance, UV resistance, and high transparency to a cured product and a method for producing the cured product. Means to solve the problem

The present invention provides a fluorinated polymer having the following structures [1] to [11], a method for producing a cured product of a fluorinated polymer, a light-emitting element, and a light-emitting device. [1] A fluoropolymer including a unit represented by the following formula (1) and a unit represented by the following formula (2);

[Chemical Formula 1] (In formula (1), R ^f1 is a fluoroalkylene group or a fluoroalkylene group having 2 or more carbon atoms having an etheric oxygen atom between carbon and carbon atoms, and R ¹ and R ² are each independently a hydrogen atom or an alkyl group. );

[Chemical Formula 2] (In the formula (2), X ¹ , X ² , and X ³ are each independently a fluorine atom or a hydrogen atom, two Q ² are each independently a single bond or an etheric oxygen atom, and R ^f2 is a fluorine atom having 1 to 6 carbon atoms. An alkyl group or a fluoroalkylene group having 2 to 25 carbon atoms having an etheric oxygen atom between carbon and carbon atoms). The [2] [1] according to the fluoropolymer, wherein the formula (1) is a unit represented by at least part of _{- [CF 2 -CF (O (} CF 2) 3 CONHNH 2)] -. [3] The fluoropolymer according to [1] or [2], further comprising a unit derived from vinyl fluoride.

[4] The fluorinated polymer according to any one of [1] to [3], further comprising a unit represented by the following formula (3) (except for units derived from fluoroethylene);-[CX ⁴ X ⁵ -CY ¹ Y ² ] -... (3) (In the formula (3), X ⁴ and X ⁵ are each independently a hydrogen atom, a fluorine atom or a chlorine atom, Y ¹ is a hydrogen atom, a fluorine atom or a chlorine atom, and Y ² is a hydrogen atom, a fluoroalkyl group, a fluoroalkyl group having 2 or more carbon atoms having etheric oxygen atoms, a fluoroalkoxy group, or a carbon number 2 having an etheric oxygen atom between carbon atoms Above fluoroalkoxy).

[5] The fluorinated polymer according to any one of [1] to [4], wherein the ratio of the unit represented by formula (1) is 0.1 to 20 mol relative to the total amount of the units contained in the fluoropolymer. %, And the ratio of the unit represented by the formula (2) is 0.05 to 3 mol%. [6] The fluorinated polymer according to any one of [1] to [4], wherein the ratio of the unit represented by the formula (1) is 0.1 to 5 mol relative to the total amount of the units contained in the fluoropolymer. %, And the ratio of the unit represented by the formula (2) is 0.05 to 3 mol%. [7] The fluorinated polymer according to any one of [1] to [6], whose mass average molecular weight is 3,000 to 100,000. [8] The fluorinated polymer according to any one of [1] to [6], whose mass average molecular weight is 5,000 to 100,000.

[9] A method for producing a cured product of a fluoropolymer, characterized in that the fluoropolymer according to any one of [1] to [8] is heated at 150 to 300 ° C. [10] A light-emitting device comprising a light-emitting element and a cured product of a fluoropolymer according to any one of [1] to [8]. [11] The light-emitting device according to [10], wherein the light-emitting element is a white LED or an ultraviolet LED.

ADVANTAGE OF THE INVENTION According to this invention, the fluoropolymer which can heat-harden, has good melt moldability, and can provide the hardened | cured material with high heat resistance, UV resistance, and high transparency, and the manufacturing method of the hardened | cured material of a fluoropolymer can be provided. .

Embodiments for Carrying Out the Invention Embodiments of the present invention will be described below. The present invention is not limited to the following description.

[Meaning of terms in this specification] The compound represented by formula (a) may be expressed as compound (a). Compounds represented by other formulas are also expressed in the same manner. The unit represented by formula (b) may be expressed as unit (b). Units expressed in other formulas are also expressed in the same way.

"Translucent seal" means a seal that has both the function of transmitting light and the function of sealing.

A "unit" in a polymer means a portion derived from a monomer formed by polymerization of the monomer. Monomer-derived units are sometimes labeled only as monomer units.

"Fluoroethylene" means a compound in which 0 to 3 fluorine atoms of tetrafluoroethylene (CF ₂ = CF ₂ ) are replaced by a hydrogen atom or a halogen atom (such as chlorine, bromine, and iodine) other than fluorine.

The group having a carbon atom chain such as an alkyl group, a fluoroalkyl group, a fluoroalkylene group, a fluoroalkoxy group, or a fluoroalkenyl group may be linear or branched.

"Fluoroalkyl" means a group in which one or more hydrogen atoms of an alkyl group are substituted with fluorine atoms. When the ratio of fluorine atoms in a fluoroalkyl group is expressed as (the number of fluorine atoms in a fluoroalkyl group) / (the number of hydrogen atoms in an alkyl group having the same number of carbon atoms as the fluoroalkyl group) × 100 (%), the ratio is preferably Above 50%, and preferably 100%, that is, perfluoroalkyl. The same applies to the fluoroalkylene group and the fluoroalkoxy group, and a perfluoroalkylene group and a perfluoroalkoxy group are preferable. "Hardening" before being specifically mentioned means hardening by crosslinking.

[Fluoropolymer] The fluoropolymer of this embodiment includes a unit represented by the following formula (1) and a unit represented by the following formula (2).

[Chemical Formula 3]

(In the formula (1), R ¹ and R ² are each independently a hydrogen atom or an alkyl group, and R ^f1 is a fluoroalkylene group or a fluoroalkylene group having 2 or more carbon atoms having an etheric oxygen atom between carbon and carbon atoms. ).

[Chemical Formula 4]

(Formula 2) ^{(, X 1, X 2,} X 3 are independently a hydrogen atom or a fluorine atom, 2 Q ² are independently a single bond or an ether oxygen atom, R ^f2 is a C 1 to 6 fluoro extension of An alkyl group or a fluoroalkylene group having 2 to 25 carbon atoms having an etheric oxygen atom between carbon and carbon atoms).

The inventors have newly discovered that a fluoropolymer having units (1) and (2) can be cross-linked by reacting -CONHNH ₂ with each other by heating. Since the fluoropolymer of this embodiment is only cross-linked with -CONHNH ₂ , the fluoropolymer can be hardened with a small amount of crosslinking groups. Therefore, the cured product has excellent transparency and heat resistance, and has excellent light resistance, especially UV resistance. In addition, the fluorinated polymer of this embodiment can harden a small amount of cross-linking groups by including the unit (1) and the unit (2). Therefore, it is possible to suppress foaming without impairing melt fluidity during LED molding, and Melt moldability is also good.

The present inventors have previously studied a fluoropolymer having -CONHNH ₂ and -COOCH ₃ . We believe that the crosslinking reaction represented by the following formula (11) is caused by heating in this fluoropolymer. -CONHNH ₂ + -COOCH ₃ → -CONHNHCO -... (11)

The crosslinking reaction mechanism of the fluoropolymer of this embodiment is not clear, but we think it is as follows. For example, a compound having -CONHNH ₂ similar to the fluoropolymer of this embodiment, such as dihydrazine phthalate, is known to be oxidatively coupled with a oxidizing agent in a polar solvent as shown in the following formula (12) to obtain a polymer. (Dimethylhydrazine).

[Chemical Formula 5]

In contrast, a fluorinated polymer having a fluorenylhydrazine hydrazine structure in this embodiment in a side chain can be hardened by heating in air. Further, the N ₂ gas atmosphere by fluoropolymer may present invention prepared cured by heating, such as by heating to above 150 ℃ or active energy rays, can be prepared without the use of an oxidizing agent cured . We believe that the cross-linking reaction mechanism of the fluoropolymer is as shown in the following formula (13). The hydrazine can be thermally decomposed and coupled without forming an oxidation reaction to form dihydrazylhydrazine. In addition, as shown in the following formula (14), four may be formed by the dehydration cyclization reaction. . In order to obtain a hardened product from the fluoropolymer of this embodiment, the hardened product is less colored, and it is more suitable to heat in an N ₂ gas environment than heating in air.

2-CONHNH ₂ → -CONHNHCO -... (13)

[Chemical Formula 6]

Each unit contained in the fluoropolymer of this embodiment will be described below.

<Unit (1)> The unit (1) is a unit represented by the following formula (1).

[Chemical Formula 7]

In the unit (1), R ¹ and R ² are each independently a hydrogen atom or an alkyl group, and R ^f1 is a fluoroalkylene group or a fluoroalkylene group having 2 or more carbon atoms having an etheric oxygen atom between carbon and carbon atoms.

When R ^f1 in the unit (1) is a fluoroalkylene group, the carbon number thereof should preferably be 1 to 6, and particularly preferably 1 to 4. When R ^f1 has a carbon number of 3 or more, a linear structure is preferred from the viewpoint of excellent thermal stability. From the viewpoint of excellent thermal stability, the fluoroalkylene group is preferably a perfluoroalkylene group. That is, R ^{f1 is} preferably a perfluoroalkylene group having 1 to 6 carbon atoms, and a perfluoroalkylene group having 1 to 4 carbon atoms is particularly preferred.

When R ^f1 in the unit (1) is a fluoroalkylene group having 2 or more carbon atoms having an etheric oxygen atom between carbon and carbon atoms, the carbon number of R ^f1 is preferably 2 to 10, and 2 to 6 is particularly preferred. R ^f1 when 3 or more carbon atoms, preferably from the viewpoint of excellent thermal stability in view of a linear structure. From the viewpoint of excellent thermal stability, the fluoroalkylene group is preferably a perfluoroalkylene group. That is, R ^f1 is preferably a perfluoroalkylene group having 2 to 10 carbon atoms having an etheric oxygen atom between carbon-carbon atoms, and 2 to 6 carbon atoms having an ethereal oxygen atom between carbon-carbon atoms. Perfluoroalkylene is particularly preferred.

From the viewpoint of excellent heat hardenability, R ¹ and R ^{2 are} preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 or 2 carbon atoms, and particularly preferably a hydrogen atom.

Specific examples of the unit (1) include the following units. -[CF ₂ -CF (O (CF ₂ ) ₂ CONHNH ₂ )]-,-[CF ₂ -CF (O (CF ₂ ) ₂ CON (CH ₃ ) NH ₂ )]-,-[CF ₂ -CF ( O (CF ₂ ) ₂ CONHNHCH ₃ )]-,-[CF ₂ -CF (O (CF ₂ ) ₃ CONHNH ₂ )]-,-[CF ₂ -CF (O (CF ₂ ) ₃ CON (CH ₃ ) NH _{2)] -, - [CF} 2 -CF (O (CF 2) 3 CONHNHCH 3)] -, - [CF 2 -CF (O (CF 2) 4 CONHNH 2)] -, - [CF 2 -CF ( O (CF ₂ ) ₄ CON (CH ₃ ) NH ₂ )]--[CF ₂ -CF (O (CF ₂ ) ₄ CONHNHCH ₃ )]-,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CONHNH ₂ )]-,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CON (CH ₃ ) NH ₂ )]-,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CONHNHCH ₃ )]-,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ CONHNH ₂ )]-,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ CON (CH ₃ ) NH ₂ )]-,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₃ CONHNHCH ₃ )]- -[CF ₂ -CF (O (CF ₂ ) ₃ O (CF ₂ ) ₂ CONHNH ₂ )]-,-[CF ₂ -CF (O (CF ₂ ) ₃ O (CF ₂ ) ₂ CON (CH ₃ ) NH ₂ )]-,-[CF ₂ -CF (O (CF ₂ ) ₃ O (CF ₂ ) ₂ CONHNHCH ₃ )]-,-[CF ₂ -CF (O (CF ₂ ) ₂ O (CF ₂ ) ₂ CONHNH ₂ )]-,-[CF ₂ -CF (O (CF ₂ ) ₂ O (CF ₂ ) ₂ CON (CH ₃ ) NH ₂ )]-,-[CF ₂ -CF (O (CF ₂ ) ₂ O ( CF ₂ ) ₂ CONHNHCH ₃ )]- . From the standpoint of starting point, the unit (1) is particularly preferably-[CF ₂ -CF (O (CF ₂ ) ₃ CONHNH ₂ )]-.

The fluoropolymer may contain one unit (1) alone or may contain two or more units (1).

<Unit (2)> The unit (2) is a unit represented by the following formula (2).

[Chemical Formula 8]

Unit (2), X ¹ , X ² , and X ³ are each independently a fluorine atom or a hydrogen atom, two Q ² are each independently a single bond or an etheric oxygen atom, and R ^f2 is a fluoroalkyl group having 1 to 6 carbon atoms Or a fluoroalkylene group having 2 to 25 carbon atoms having an etheric oxygen atom between carbon and carbon atoms. The two X ¹ in the unit (2) may be the same or different from each other. The same applies to two X ² and two X ³ . The two Q ² in the unit (2) may be the same or different from each other.

In the unit (2), it is preferable that X ¹ , X ² , and X ³ are all fluorine atoms or all hydrogen atoms. When X ¹ , X ² , and X ³ are all fluorine atoms, 2 Q ^{2 are} preferably etheric oxygen atoms; when X ¹ , X ² , and X ³ are all hydrogen atoms, 2 Q ² are preferably single bonds .

In the unit (2), when R ^f2 is a fluoroalkylene group having 1 to 6 carbon atoms, its carbon number should preferably be 2 or more. When R ^f2 has a carbon number of 3 or more, a linear structure is preferred from the viewpoint of excellent thermal stability. From the viewpoint of excellent thermal stability, the fluoroalkylene group is preferably a perfluoroalkylene group. That is, R ^f2 is preferably a perfluoroalkylene group having 1 to 6 carbon atoms, and more preferably a perfluoroalkylene group having 2 or more carbon atoms.

When R ^f2 is a fluoroalkylene group having 2 to 25 carbon atoms having an etheric oxygen atom between carbon and carbon atoms, the carbon number is preferably 2 to 10, and 2 to 6 is particularly preferred. When R ^f2 has a carbon number of 3 or more, a linear structure is preferred from the viewpoint of excellent thermal stability. From the viewpoint of excellent thermal stability, the fluoroalkylene group is preferably a perfluoroalkylene group. That is, R ^f2 is preferably a perfluoroalkylene group having 2 to 10 carbon atoms having an etheric oxygen atom between carbon-carbon atoms, and 2 to 6 carbon atoms having an ethereal oxygen atom between carbon-carbon atoms. Perfluoroalkylene is preferred. A perfluoroalkylene group having 2 to 6 carbon atoms having an etheric oxygen atom between carbon and carbon atoms preferably contains-(CF ₂ O)-,-(CF ₂ CF ₂ O)-,-(CF ₂ CF (CF ₃ ) One or more of the perfluoropolyether units represented by O)-and-(CF ₂ CF ₂ CF ₂ O)-.

Specific examples of the unit (2) include, for example, X ¹ , X ² , and X ³ are each a fluorine atom, two Q ² are etheric oxygen atoms, and R ^{f2 is-} (CF ₂ ) ₂ -,-(CF ₂ ) ₃ -,-(CF ₂ ) ₄ -,-(CF ₂ ) ₆ -,-(CF ₂ ) ₄ OCF (CF ₃ ) CF ₂ -,-(CF ₂ ) ₂ OCF (CF ₃ ) CF ₂ -,- (CF ₂ CF ₂ O) _2- , -CF ₂ O (CF ₂ CF ₂ O) ₂ -or -CF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ OCF (CF ₃ ) CF _2- , or X ¹ , X ² , X ³ are all hydrogen atoms, 2 Q ² are single bonds and R ^{f2 is-} (CF ₂ ) ₂ -,-(CF ₂ ) ₄ -or-(CF ₂ ) _6- unit.

From the standpoint of easy access, the unit (2) is particularly preferably a unit represented by the following formulae (21) and (22). [Chemical Formula 9]

The unit (2) is represented by the following formula (2a) and can be formed by polymerizing a fluorinated monomer having two polymerizable unsaturated bonds. Hereinafter, the fluorine-containing monomer represented by the formula (2a) is also referred to as a monomer (2a).

X ¹ X ² C = CX ³ -Q ² -R ^f2 -Q ² -CX ³ = CX ¹ X ² … (2a) In formula (2a), X ¹ , X ² , X ³ , Q ² , R ^{f2 are} as The same applies to the definition, illustration, and ideal range of formula (2).

Specific examples of the monomer (2a) include the following monomers. CF ₂ = CFO (CF ₂ ) ₂ OCF = CF ₂ , CF ₂ = CFO (CF ₂ ) ₃ OCF = CF ₂ , CF ₂ = CFO (CF ₂ ) ₄ OCF = CF ₂ , CF ₂ = CFO (CF ₂ ) ₆ OCF = CF ₂ , CF ₂ = CFO (CF ₂ ) ₄ OCF (CF ₃ ) CF ₂ OCF = CF ₂ , CF ₂ = CFO (CF ₂ ) ₂ OCF (CF ₃ ) CF ₂ OCF = CF ₂ , CF ₂ = CFO (CF ₂ CF ₂ O) ₂ OCF = CF ₂ , CF ₂ = CFOCF ₂ O (CF ₂ CF ₂ O) ₂ OCF = CF ₂ , CF ₂ = CFOCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ OCF (CF ₃ ) CF ₂ OCF = CF ₂ , CH ₂ = CH- (CF ₂ ) ₂ -CH = CH ₂ , CH ₂ = CH- (CF ₂ ) ₄ -CH = CH ₂ , CH ₂ = CH- ( CF ₂ ) ₆ -CH = CH ₂ .

<Remaining Units> The fluoropolymer of this embodiment may further include a fluoroethylene unit and a unit (3) described later.

(Fluorinated ethylene unit) Specific examples of the fluorinated ethylene unit include tetrafluoroethylene (CF ₂ = CF ₂ ) (TFE), trifluoroethylene (CF ₂ = CHF) (TrFE), and chlorotrifluoroethylene (CFCl = CF ₂ ), difluoroethylene (CF ₂ = CH ₂ ) and the like. From the viewpoint of excellent light resistance, the fluoroethylene unit is preferably a TFE unit, a TrFE unit, and a chlorotrifluoroethylene unit. From the viewpoint of excellent heat resistance, the vinyl fluoride unit is preferably a TFE unit. From the viewpoint that the highly polar -CONR ¹ NR ² H group is easily present at the interface, the fluorinated polymer hardened product has excellent adhesion to the substrate, wettability, etc., and the TFE unit is particularly preferred for the fluoroethylene unit. From the viewpoints that the fluorinated polymer is not as high in crystallinity as the TFE unit, is less prone to light scattering, and has high transparency, the fluoroethylene unit is preferably a TrFE unit or a chlorotrifluoroethylene unit. From the viewpoint of excellent solubility in various organic solvents, the fluoroethylene unit is particularly preferably a TrFE unit. The wettability means that the surface tension of the fluoropolymer is low, so that it is easy to wet and spread on the substrate.

The fluoropolymer may contain one kind of fluoroethylene unit alone or may contain two or more kinds of fluoroethylene units.

(Unit (3)) The unit (3) is a unit represented by the following formula (3) (except for a fluoroethylene unit). -[CX ⁴ X ⁵ -CY ¹ Y ² ] -... (3)

Of formula (3), X ⁴ and X ^{5 are} each independently a hydrogen atom, a fluorine atom or a chlorine atom, Y ¹ is a hydrogen atom, a fluorine atom or a chlorine atom, Y ² is a hydrogen atom, a fluoroalkyl group, a carbon - carbon atoms A fluoroalkyl group having 2 or more carbon atoms having an etheric oxygen atom between them, a fluoroalkoxy group, and a fluoroalkoxy group having 2 or more carbon atoms having an etheric oxygen atom between carbon and carbon atoms.

The number of fluoroalkyl carbons in Y ² is preferably 1 to 15, and particularly preferably 1 to 6. From the viewpoint of excellent thermal stability, the fluoroalkyl group is preferably a perfluoroalkyl group, and a perfluoroalkyl group having 1 to 6 carbon atoms is preferred, and -CF _{3 is} particularly preferred. In the carbon of Y ² - fluoroalkyl group having a carbon number of a carbon number of etheric oxygen atom between carbon atoms 2 or more should be from 2 to 15, and 2 to 6 is preferred. From the viewpoint of excellent thermal stability, a perfluoroalkyl group having 2 or more carbon atoms having etheric oxygen atoms between carbon-carbon atoms is preferred, and 2 to 6 carbon atoms having etheric oxygen atoms between carbon-carbon atoms. Perfluoroalkyl of 6 is particularly preferred.

The number of fluoroalkoxy carbons in Y ² is preferably 1 to 15, and particularly preferably 1 to 6. From the viewpoint of excellent thermal stability, the fluoroalkoxy group is preferably a perfluoroalkoxy group having 1 to 6 carbon atoms, and -OCF ₃ , -OCF ₂ CF ₃ , -O (CF ₂ ) ₂ CF ₃ ,- O (CF ₂ ) ₃ CF _{3 is} particularly preferred. The number of fluoroalkoxy carbons in Y ² having a carbon number of 2 or more having etheric oxygen atoms between carbon and carbon atoms is preferably 2 to 15, and 2 to 6 is particularly preferred. From the viewpoint of excellent thermal stability, the fluoroalkoxy group is preferably a perfluoroalkoxy group having 2 or more carbon atoms having an etheric oxygen atom between carbon-carbon atoms, and has ethericity between the carbon-carbon atoms. A perfluoroalkoxy group having 2 to 6 carbon atoms of an oxygen atom is preferred, and -OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CF _{3 is} particularly preferred.

Specific examples of the unit (3) include the following units. -[CH ₂ -CH ₂ ]-,-[CF ₂ -CF (CF ₃ )]-,-[CH ₂ -CF (CF ₃ )]-,-[CF ₂ -CF (OCF ₃ )]-,- _{[CF 2 -CF (OCF 2 CF} 3)] -, - [CF 2 -CF (O (CF 2) 2 CF 3)] -, - [CF 2 -CF (O (CF 2) 3 CF 3)] -,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CF ₃ )]-,-[CF ₂ -CF (OCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ )]- .

From the viewpoint of low glass transition temperature, good fluidity, and excellent moldability of the fluoropolymer, and the point that the mobility of the fluoropolymer is high when the fluoropolymer is hardened, and the cross-linking reaction between molecules is easy, the unit (3 ) Should be-[CH ₂ -CH ₂ ]-,-[CF ₂ -CF (CF ₃ )]-,-[CF ₂ -CF (OCF ₃ )]-,-[CF ₂ -CF (O (CF ₂ ) ₂ CF ₃ )]-,-[CF ₂ -CF (OCF ₂ CF (CF ₃ ) O (CF ₂ ) ₂ CF ₃ )]-or- [CF ₂ -CF (OCF ₂ CF ₂ OCF ₂ CF ₂ OCF ₂ CF ₃ )].

The fluoropolymer may contain one unit (3) alone or may contain two or more units (3).

The unit (3) can be formed by polymerizing the compound (3a) as a monomer. CX ⁴ X ⁵ = CY ¹ Y ² … (3a) In formula (3a), X ⁴ , X ⁵ , Y ¹ and Y ^{2 are} as defined in formula (3), and the examples and ideal ranges are also the same.

<Ideal state of fluoropolymer> As long as the effect of the present invention is not impaired, the fluoropolymer of this embodiment is in addition to the unit (1), the unit (2), and the fluoroethylene unit and unit (3) arbitrarily contained. It may also include a unit having a group represented by -COOR ⁷ or -C (O) NR ⁸ OR ⁹ (R ⁷ is an alkyl group, and R ⁸ and R ⁹ are each independently a hydrogen atom or an alkyl group). The fluoropolymer of this embodiment is preferably composed of only the unit (1), the unit (2), and the fluoroethylene unit and unit (3) arbitrarily contained. From the viewpoint of improving the hardenability, the number of units (1) contained in the fluoropolymer is preferably three or more units (1) per molecule of the fluoropolymer.

In the total fluoropolymer units of this embodiment, the ratio of the units (1) is preferably 0.1 mol% or more. The ratio of the unit (1) is preferably 20 mol% or less, and more preferably 10 mol% or less. Among the total units of the fluoropolymer, the ratio of the unit (1) can be determined according to the molecular weight of the fluoropolymer, and the number of each molecule of the fluoropolymer is adjusted to the above-mentioned ideal value (3 or more). For example, when the molecular weight of the fluoropolymer is small, the ratio of the unit (1) can be increased; when the molecular weight of the fluoropolymer is large, the ratio of the unit (1) can be decreased. Specifically, when the molecular weight of the fluoropolymer is about 3,000 to less than about 10,000, the ratio of the unit (1) may be set to account for 1 to 10 mol% of the total units of the fluoropolymer. In addition, when the molecular weight of the fluoropolymer is about 10,000 to 10,0000, the ratio of the unit (1) is preferably 0.1 to 5 mol%, more preferably 0.5 to 2 mol%, and particularly preferably 1 to 1.5 mol%.

If the ratio of the unit (1) is above the lower limit of the above range, even if the fluoropolymer does not contain -COOCH _3, it tends to cause heat hardening to produce a solvent-insoluble hardened product. When the ratio of the unit (1) is below the upper limit of the aforementioned range, the coloration and foaming of the fluoropolymer during thermal curing can be suppressed, and a transparent cured product can be obtained.

In the total fluoropolymer unit of this embodiment, the ratio of the unit (2) is preferably 0.05 to 3 mol%, and more preferably 0.1 to 1 mol%. The fluoropolymer contains the unit (2), so that the content ratio of the unit (1) can be reduced. Therefore, coloration and foaming during thermal curing can be suppressed, so the fluoropolymer of this embodiment is particularly suitable as an LED sealing material.

When the fluoropolymer in this embodiment has a fluoroethylene unit, the ratio of fluoroethylene units in the total unit is preferably 50 to 90 mol%, and more preferably 60 to 80 mol%. Especially when the fluoroethylene unit is a TFE unit, the ratio is preferably 50 to 70 mol%. If it is above the lower limit, it is easy to improve the light resistance and various characteristics obtained based on the fluoroethylene unit (for example, when the TFE unit is the fluoroethylene unit, it is easy to improve the heat resistance and adhesion to the substrate or wettability, etc. If it is less than the upper limit and light scattering due to crystallinity can be suppressed, when a fluoropolymer is used to seal the UV-LED, the UV light has a high transmittance, thereby ensuring the output of the UV-LED.

The content of the unit (1), the unit (3) and the fluoroethylene unit in the fluoropolymer can be calculated by ¹⁹ F-NMR and ¹ H-NMR measurement. Since the content of the unit (2) is not easy to measure, and the unit (1) and the unit (2) share the same structure CF ₂ = CFO-CF _2- , the polymerization reactivity is considered to be the same degree. The feed ratio of the monomer (1) (monomer (1a) described later) to the monomer (2a) is estimated from the content of the unit (1) in the fluoropolymer to estimate the content of the unit (2).

(Molecular Weight) The mass average molecular weight of the fluoropolymer in this embodiment is preferably 3,000 to 100,000, and more preferably 5,000 to 100,000. The mass average molecular weight is more preferably 10,000 to 50,000, and more preferably 10,000 to 30,000.

When the fluoropolymer is formed by casting, the mass average molecular weight of the fluoropolymer is preferably 3,000 to 50,000, preferably 5,000 to 50,000, and particularly preferably 10,000 to 30,000. If the mass average molecular weight of the fluoropolymer is above the lower limit of this range, the cured product tends to have excellent mechanical strength and heat resistance; if it is below the upper limit of this range, the fluoropolymer can be ensured during molding. Of liquidity. In particular, SMD type LEDs (LED modules with cup reflectors) are very fluid when sealed. If the mass average molecular weight is too large, when the SMD LED is molded, the melting temperature will increase and the curing reaction speed will be accelerated, resulting in a decrease in melt fluidity over time and making it difficult to defoam. If the mass average molecular weight of the fluoropolymer is within this range, the fluoropolymer is suitable for sealing of SMD LEDs.

When a fluoropolymer is used to form a shaped body such as a sheet, the mass average molecular weight of the fluoropolymer is preferably 10,000 to 100,000, and more preferably 20,000 to 50,000. For example, when sealing a COB type LED (an LED without a reflector and sealing a plurality of elements in a batch with a sealing resin), a sheet-shaped sealing resin may be used for heat sealing. At this time, the sheet-shaped fluoropolymer is laminated on the substrate on which the LED element is mounted, heated to 100 to 150 ° C to flow, and the fluoropolymer is coated on the LED element and cross-linked to seal the LED element. . At this time, in order to seal without leaving gaps or bubbles, it is preferable to apply pressure while covering the fluoropolymer sheet. If the mass average molecular weight of the fluoropolymer is within this range, the fluoropolymer is suitable for sealing of the COB type LED as described above.

The mass average molecular weight can be determined by gel permeation chromatography (GPC) in terms of molecular weight in terms of PMMA (polymethyl methacrylate).

[Production Method of Fluoropolymer] The fluoropolymer can be used by combining a fluoropolymer containing a unit represented by the following formula (1a) and unit (2) with a hydrazine compound represented by the following formula (5) (hereinafter also Prepared by a method described as "hydrazine compound").

[Chemical Formula 10] HR ¹ N-NR ² H ... (5)

In the formula (1a), R ³ is an alkyl group, and R ^f1 is as defined in the formula (1), and the same applies to the examples and ideal ranges. In the formula (5), R ¹ and R ^{2 are} as defined in the formula (1), and the examples and ideal ranges are also the same.

The completion of the reaction in which the fluoropolymer having the unit (1a) is converted into the unit (1) by reacting with the hydrazine compound can be confirmed by the disappearance of the infrared (IR) absorption of the -COOR ³ group.

(Fluoropolymer containing unit (1a)) The fluoropolymer containing unit (1a) in this embodiment can be formed by a known method (for example, the method described in International Publication No. 2015/098773) to enable the monomer to form the aforementioned unit. Prepared by polymerization.

(Hydrazine compound) Examples of the hydrazine compound include hydrazine, hydrazine monohydrate, methylhydrazine, and 1,2-dimethylhydrazine. From the viewpoints of safety and excellent heat curing properties of the obtained fluoropolymer, hydrazine monohydrate is preferred. The form of the hydrazine compound to be reacted may be an aqueous solution or a salt. A commercially available hydrazine compound can be used.

(Reaction conditions) The amount of the hydrazine compound is preferably 1 to 20 moles, preferably 1.2 to 10 moles, and 1.5 to 1.5 moles of the group represented by -COOR ³ of the fluoropolymer containing the unit (1a). ~ 5 Mol is especially preferred.

The reaction of the fluoropolymer having the unit (1a) with a hydrazine compound can be performed in the presence of a solvent. The solvent is preferably one capable of dissolving raw material components (a fluoropolymer containing a unit (1a) and a unit (2), a hydrazine compound). A fluorine-containing solvent capable of dissolving at least the fluorine-containing polymer containing the unit (1a) and the unit (2) is preferable. To disperse the hydrazine compound, an alcohol may be added to the fluorine-containing solvent.

The fluorine-containing solvent contains fluorine and carbon, and may also contain chlorine, oxygen, and hydrogen. Examples of the fluorine-containing solvent include fluorinated alkanes, fluorinated aromatic compounds, fluoroalkyl ethers, fluorinated alkylamines, and fluoroalcohols.

The carbon number of the fluorinated alkane is preferably 4 to 8. Examples of commercially available fluorinated alkanes include CF ₃ CH ₂ CF ₂ H (HFC-245fa), CF ₃ CH ₂ CF ₂ CH ₃ (HFC-365mfc), perfluorohexane, 1H-perfluorohexane, Fluoroctane, C ₆ F ₁₃ H (manufactured by Asahi Glass Co., Ltd., ASAHIKLIN (registered trademark) AC-2000), C ₆ F ₁₃ C ₂ H ₅ (manufactured by Asahi Glass Co., Ltd., ASAHIKLIN (registered trademark) AC-6000), C ₂ F ₅ CHFCHFCF ₃ (manufactured by Chemours, Vertrel (registered trademark) XF) and the like.

Examples of the fluorinated aromatic compound include hexafluorobenzene, trifluoromethylbenzene, perfluorotoluene, and bis (trifluoromethyl) benzene.

The carbon number of the fluoroalkyl ether is preferably 4-12. The fluoroalkyl ether composition can be cited as commercially available _{3 CH 2 OCF 2 CF 2 H} ( manufactured by Asahi Glass Co., ASAHIKLIN (registered _{trademark) AE-3000) C 4 F} 9 OCH 3 (3M Corporation, (registered trademark CF, Novec ) 7100), C ₄ F ₉ OC ₂ H ₅ (3M company, Novec (registered trademark) 7200), C ₂ F ₅ CF (OCH ₃ ) C ₃ F ₇ (3M company, Novec (registered trademark) 7300) Wait.

Examples of the fluorinated alkylamine include perfluorotripropylamine and perfluorotributylamine.

Examples of the fluoroalcohol include 2,2,3,3-tetrafluoropropanol, 2,2,2-trifluoroethanol, and hexafluoroisopropanol.

Other examples of the fluorine-containing solvent include dichloropentafluoropropane (HCFC-225) and perfluoro (2-butyltetrahydrofuran). Commercially available products of dichloropentafluoropropane include AK-225cb (manufactured by Asahi Glass Co., Ltd.).

For example, the reaction is preferably carried out by dissolving the fluoropolymer containing the unit (1a) and the unit (2) in the above-mentioned fluorinated solvent and adding a hydrazine compound at 0 to 30 ° C. Further, it is heated to 30 to 100 ° C. and allowed to react for 1 minute to 10 hours to obtain a target fluoropolymer.

[Sclerosing composition, coating composition] The cured product of the fluorinated polymer according to this embodiment can be produced using only the above-mentioned fluorinated polymer. Moreover, it can also manufacture from the curable composition containing the said fluoropolymer (however, it does not contain a solvent) or the coating composition containing the said curable composition and a solvent.

Examples of the components other than the fluoropolymer in the curable composition include inorganic particles, silane coupling agents, and fluoropolyether compounds. These components can be added within a range that does not significantly affect the transparency of the cured product. Here, the silane coupling agent and the fluoropolyether compound may be as described in International Publication No. 2015/098773.

The inorganic particles are preferably metal oxides such as silicon dioxide, titanium oxide, zirconia, and aluminum oxide, or various phosphor particles. The diameter of the inorganic particles is preferably 1 nm to 10 μm, and from the viewpoint of suppressing light scattering to ensure the transparency of the composition, it is more preferably 1 nm to 1 μm. From the viewpoint of improving the refractive index of the cured product, the content of the inorganic particles is preferably 20 to 200 parts by mass, and more preferably 50 to 100 parts by mass, relative to 100 parts by mass of the fluoropolymer. If the content of the inorganic particles is above the lower limit of the aforementioned range, the refractive index of the cured product can be further increased; if it is below the upper limit of the aforementioned range, the moldability is good.

Examples of the solvent in the coating composition include the aforementioned fluorine-containing solvents. The coating composition may contain an alcohol within a range in which the fluoropolymer does not precipitate.

The solid content in the coating composition is preferably 1 to 99% by mass. The content of the fluoropolymer in the coating composition is preferably 1 to 99% by mass.

[Manufacturing method of hardened material made of fluoropolymer] The hardened material made of fluorinated polymer having a hydrazine group in this embodiment can be heated or irradiated to the fluorinated polymer. Active energy ray method. You can also use heating and active energy rays. It is particularly desirable to heat the fluoropolymer to harden it. When the fluoropolymer is heated to harden, the heating temperature is preferably 150 to 300 ° C, and more preferably 200 to 250 ° C. The heating time depends on the temperature, but it should be 1 minute to 10 hours, preferably 1 to 5 hours, and more preferably 2 to 4 hours.

[Manufacturing method of molded article] The molded article can be produced using a curable composition containing a fluoropolymer or a coating composition containing a curable composition and a solvent. Examples of the method for manufacturing the molded body include a method of heating the hardening composition to flow and pouring it into a mold into a predetermined shape, and casting the hardening composition on the surface of the mold to form a sheet-like or film-shaped molded body. Method, a method of forming a hardenable composition into a predetermined shape by extrusion molding or transfer injection molding, a method of cutting a formed sheet or film material into a predetermined shape or performing secondary processing such as bending, and the like. When manufacturing a film-shaped molded body or a film-shaped molded body integrated with a substrate, a coating composition is preferably used.

The coating method of the coating composition may be, for example, a spin coating method, a wipe coating method, a spray coating method, a knife coating method, a dip coating method, a die coating method, an inkjet method, a flow film application method, a roll coating method, a casting method, Langmu-Blodge method and gravure coating method.

[Hardened product of fluorinated polymer] The cured product of fluorinated polymer has no foaming, high visible light transmittance of 400 nm or more, and no light deterioration, so it can be effectively used as a sealing material or lens for high output LEDs. In addition, since the molecular structure is essentially non-absorptive at a wavelength of 300 to 400 nm, it can also be effectively used as a light-transmitting sealing material or lens for ultraviolet LEDs with a wavelength of 365, 380, and 405 nm. Examples

Examples and Comparative Examples are shown below to explain the present invention in detail. However, the present invention is not limited by the following description. Example 1 is an example, and Examples 2 and 3 are comparative examples. The evaluation of each case was performed according to the method described below.

[Evaluation method] <mass average molecular weight> The mass average molecular weight of the fluoropolymers P1, Q1, and R1 is based on CF ₂ ClCF ₂ CHClF (produced by Asahi Glass Co., Ltd., trade name: AK-225cb) as a solvent, and gel permeation chromatography (GPC) is calculated in terms of molecular weight in terms of PMMA (polymethyl methacrylate).

<Fluoropolymer content of the group -COOCH _3> of the fluoropolymer-based -COOCH ₃ group content determined by the ¹⁹ F-NMR.

<Elastic Modulus> The films produced in each example were used to measure the viscoelasticity analysis mode of TMA / EXSTAR SS7100 manufactured by Hitachi Advanced Technology Corporation. Measurement temperature range: -40 ℃ ~ 200 ℃, heating rate: 5 ℃ / minute, frequency: 0.05Hz.

<UV-LED lighting test> Using a constant-current power supply device (manufactured by Sunhayato) without a heat sink to energize 300 mA at room temperature, the LED was measured with a small integrating sphere-optical fiber multichannel beam splitter USB2000 (manufactured by Ocean Optics) Its output.

[Unit] The units mentioned in the following manufacturing examples are as follows.

[Chemical Formula 11]

[Manufacturing Example 1: Production of fluoropolymer P2 with (a2) unit and (b1) unit] After degassing a stainless steel autoclave with a stirrer with a volume of 1 L and a vacuum, it was fed into PERBUTYL PV as a polymerization initiator (50 mass% AK-225cb solution: manufactured by NOF _{Corporation) 11.2g, CF 2 = CFOCF 2} CF 2 CF 2 COOCH 3 18.7g, CF 2 = CFOCF 2 CF 2 CF 3 OCF = CF 2 4.2g, CF 2 = CFOCF ₂ CF ₂ CF ₃ (hereinafter also referred to as "PPVE") 412.7g and AC-2000 517.2g. After stirring, 48.7 g of TFE was pushed in, and then the internal temperature was raised to 60 ° C. to initiate polymerization. Polymerization was performed for 3 hours while maintaining the pressure in the autoclave at 0.47 MPa while adding TFE to the autoclave. The total feed of TFE is 104.9g.

After the inside of the autoclave was cooled, the contents were transferred to a 5 L glass beaker, and 2200 g of AE-3000 was added while stirring to thereby precipitate a fluoropolymer. After removing the supernatant, it was dried to obtain 125.0 g of a fluoropolymer P1. The fluoropolymer P1 is soluble in AK-225cb and AC-2000, and insoluble in methanol, acetone, and tetrahydrofuran (hereinafter also referred to as "THF"). The unit composition of the fluoropolymer P1 is unit (a1): unit (c1): unit (d1) = 1.3: 68.8: 29.9 (molar ratio), and the mass average molecular weight is 32,700. The ratio of the unit (b1) is estimated from the feed rate with the unit (a1), and is a mole ratio of 0.3.

After 4 g of the fluoropolymer P1 was dissolved in 22.8 g of AC-2000, 0.17 g of a solution in which hydrazine monohydrate (79% purity, manufactured by Tokyo Chemical Industry Co., Ltd.) was diluted 5 times with methanol was added, and quickly stirred. After stirring at 40 ° C for 2 hours, 0.2 g of methanol was added, and the mixture was further heated at 40 ° C for 5 hours. A part of the reaction solution was cast on a glass plate, and the solvent was evaporated by heating at 60 ° C. to produce a film having a thickness of 50 μm. As a result of measuring infrared absorption (IR), it was found that the absorption of 1,794 cm ^-1 derived from the C = O of the -COOCH ₃ group in the unit (a1) disappeared, and another C = O derived from the -CONHNH ₂ group was generated. The absorption of 1,718 cm ^-1 confirmed that the unit (a1) was converted into the unit (a2). Methanol was added to the reaction solution, and as a result, a precipitate was formed. The precipitate was vacuum-dried at 60 ° C to obtain 3.8 g of a fluoropolymer P2. The molecular weight of the -COOCH ₃ group is the same as that of the -CONHNH ₂ group, so the mass average molecular weight of the fluoropolymer P2 is the same as the fluoropolymer P1, and is the same as the fluoropolymer P1.

[Example 1: Hardened product of fluoropolymer P2] 0.7g of fluoropolymer P2 was placed on a 5 cm square glass plate, and heated and degassed in a vacuum oven at 150 ° C. After returning to normal pressure, a spacer frame having a thickness of 0.5 mm was set around P2, and then a fluororesin release film and a glass plate were sequentially placed thereon, and then a 150 g weight was placed thereon and left for 10 minutes. After taking it out of the oven and cooling it naturally, an oval film having a thickness of 0.5 mm was prepared. The release film was peeled from the oval film together with the glass plate placed thereon, and then heated to 200 ° C. in a N ₂ gas environment and held for 30 minutes. The temperature was further raised to 250 ° C and heated for 2 hours. After cooling, the oval film was peeled from the glass plate on which it was placed, and a colorless, transparent and oval-shaped hardened film was obtained. As a result of measuring the light transmittance, 90% was obtained at a wavelength of 400 nm, and 87% was obtained at a wavelength of 365 nm.

After measuring the viscoelasticity of the hardened film, a decrease in the elastic modulus equivalent to the glass transition temperature (Tg) was observed around 5 ° C, and at a temperature above Tg, at least 200 ° C showed a substantially constant rubber-like flat portion, It was confirmed that the crosslinking reaction was initiated by heating at 250 ° C.

A small piece of film of unhardened fluoropolymer P2 was placed on a cup-shaped aluminum package with 1W UV-LED (emission wavelength: 365 nm) manufactured by NITRIDE SEMICONDUCTORS. Co., Ltd., and was melted by heating in a vacuum oven After reaching 170 ° C, while degassing, the concave portion of the packet is molded by flowing by its own weight. After being taken out from the vacuum oven, it was heated at 200 ° C for 30 minutes in an N ₂ gas environment, and then heated and hardened at 250 ° C for 2 hours, thereby sealing the UV-LED. After the UV-LED package was soldered to an aluminum wiring substrate to continuously light at 300 mA, the output at the beginning of 365 nm UV was the same as the unsealed package, but the output increased by 15% in about 50 hours, and the output level was maintained at 1000 hour.

[Manufacturing Example 2: Production of fluoropolymer Q2] In a 200-ml inner volume stainless steel autoclave with a stirrer, 0.1 g of V601 (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator was fed, degassed under reduced pressure, Feed CF ₂ = CFOCF ₂ CF ₂ CF ₂ COOCH ₃ 20g, PPVE 40g, AC-2000 103g. While stirring the contents of the autoclave, 12 g of TFE was pushed in, and then the internal temperature was raised to 80 ° C. to initiate polymerization. Polymerization was performed for 6 hours while maintaining the pressure in the autoclave at 0.72 MPa while adding TFE. The total feed of TFE is 28.3g.

After the inside of the autoclave was cooled, the contents were transferred to a 500-mL glass beaker, and 200 g of methanol was added while stirring to thereby precipitate a fluoropolymer. The supernatant was removed and dried to obtain 20.6 g of a fluoropolymer Q1. Fluoropolymer Q1 is soluble in AK-225cb and AC-2000, but insoluble in methanol, acetone and THF. The composition of the fluoropolymer Q1 is unit (a1): unit (c1): unit (d1) = 8.0: 75.7: 16.3 (mole ratio), and the mass average molecular weight is 21,700. In the same manner as in Production Example 1, the fluoropolymer Q1 was reacted with hydrazine monohydrate for a total reaction time of 3 hours, and the unit (a2) was produced from 1/2 unit (a1) of the fluoropolymer Q1. Fluoropolymer Q2. The mass average molecular weight of the fluoropolymer Q2 is the same as that of the fluoropolymer Q1.

[Example 2: Hardened product of fluoropolymer Q2] 0.7 g of fluoropolymer Q2 was placed on a 5 cm square glass plate, and heated and degassed in a vacuum oven at 130 ° C. After returning to normal pressure, a spacer frame with a thickness of 0.5 mm was set around the fluoropolymer Q2, and then a fluororesin release film and a glass plate were sequentially placed thereon, and then a 150 g weight was placed thereon. Leave for 10 minutes. After taking it out of the oven and cooling it naturally, an oval film having a thickness of 0.5 mm was prepared. After the release film placed on the fluoropolymer was peeled together with the glass plate placed on it, it was heated to 200 ° C. in a N ₂ gas environment, and then foamed vigorously. After heating and degassing the fluoropolymer Q2 again at 130 ° C as described above, it was left to stand to make an uncured oval film. After heating the obtained uncured oval film at 150 ° C for 1 hour, The temperature was further raised to 250 ° C. and heated for 2 hours. After cooling, the oval film was peeled from the glass plate on which it was placed, and a transparent hardened film having wrinkles and haze on the surface was obtained.

In addition, although the fluoropolymer Q2 was used to try to seal with the same UV-LED as in Example 1, but when it was heated and melted at 150 ° C for molding, it could not be decompressed and degassed due to foaming, and it hardened under the condition of air bubbles. The output of 365nmUV becomes about half.

[Manufacturing Example 3: Production of fluoropolymer R2] After vacuum degassing in a stainless steel autoclave with a stirrer with an internal volume of 1 L, 4.5 g of PERBUTYL PV as a polymerization initiator, CF ₂ = CFOCF ₂ CF ₂ CF ₂ COOCH ₃ 25.0g, PPVE 407.9g and AC-2000 514.2g. After stirring, 48.4 g of TFE was pushed in, and then the internal temperature was raised to 60 ° C. to initiate polymerization. Polymerization was performed for 4 hours while maintaining the pressure in the autoclave at 0.49 MPa while adding TFE. The total feed of TFE is 97.2g.

After the autoclave was cooled, the contents were transferred to a 5 L glass beaker, and 2200 g of AE-3000 was added while stirring to precipitate a fluoropolymer. The supernatant was removed and dried to obtain 107.1 g of a fluoropolymer R1. Fluoropolymer R1 is soluble in AK-225cb and AC-2000, but insoluble in methanol, acetone and THF. The unit composition of the fluoropolymer R1 is unit (a1): unit (c1): unit (d1) = 1.7: 67.6: 30.7 (molar ratio), and the mass average molecular weight is 39,400.

After dissolving 4 g of the fluoropolymer R1 in 22.8 g of AC-2000, 0.27 g of a solution in which hydrazine monohydrate (purity 79%, manufactured by Tokyo Chemical Industry Co., Ltd.) was diluted 5-fold with methanol was added and stirred rapidly. After stirring at 40 ° C for 2 hours, 0.3 g of methanol was added, and the mixture was further heated at 40 ° C for 6 hours. A part of the reaction solution was cast on a glass plate, and the solvent was evaporated by heating at 60 ° C. to produce a film having a thickness of 50 μm, and the infrared absorption (IR) thereof was measured. As a result, the absorption of 1,794cm ^-1 of _3-yl derived unit (a1) in the disappearance -COOCH C = O, and generate an additional group of from -CONHNH ₂ C = 1,718cm ^-1 of the absorption of O, Thereby, it is confirmed that the unit (a1) is converted into a unit (a2). Methanol was added to the remaining reaction solution, and as a result, a polymer precipitated. The precipitated polymer was dried under vacuum at 60 ° C to obtain 3.8 g of a fluoropolymer R2.

[Example 3: Hardened product of fluoropolymer R2] 0.7g of fluoropolymer R2 was placed on a 5 cm square glass plate, and heated and degassed in a vacuum oven at 150 ° C. After the inside of the vacuum oven was returned to normal pressure, a spacer frame having a thickness of 0.5 mm was set around the fluoropolymer R2, and a fluororesin release film and a glass plate were sequentially placed thereon, and then 150 g of the Weight, let stand for 10 minutes. Then, the fluorine-containing polymer R2 was taken out from the oven and naturally cooled, and an oval film having a thickness of 0.5 mm was prepared as a hardened product of the fluorine-containing polymer R2. After the release film was peeled from the oval film together with the glass plate placed on the upper part, it was heated to 200 ° C. for 30 minutes in a N ₂ gas environment, and further heated to 250 ° C. for 3 hours. After cooling, the oval film was peeled from the glass plate on which it was placed, and a colorless, transparent and oval-shaped hardened film was obtained. As a result of measuring the light transmittance, 88% was obtained at a wavelength of 400 nm, and 80% was obtained at 365 nm. The UV transmittance was slightly lower than that of the cured product of Example 1.

In addition, after measuring the viscoelasticity of the obtained hardened film, a decrease in the elastic modulus equivalent to the glass transition temperature (Tg) was observed around 5 ° C, and a rubber-like flat portion appeared at a temperature higher than Tg, but the elastic modulus was lower. The hardened material of Example 1 was slightly lower, and it was found that the crosslinking density was slightly lower.

The UV-LED was sealed with a fluoropolymer R2 in the same manner as in Example 1 by heating at 200 ° C for 30 minutes in a N ₂ gas environment, and then heating and curing at 250 ° C for 2 hours. As a result of energizing at 300 mA, the output of 365 nm UV was 10% lower than that when it was not sealed. After continuous energization for 300 hours, foaming occurred and the output became half.

For the fluorinated polymers of Production Examples 1 to 3 and the hardened products of Examples 1 to 3, the content of the -CONHNH ₂ group, the light transmittance of the cured film, the curing temperature, the presence of foaming and UV during LED sealing are listed in Table 1. -Results of LED lighting test.

[Table 1]

From the results of Example 1, it can be seen that the fluoropolymer of this embodiment contains a unit (1) of a cross-linking group and a unit (2) as a branching structure formed by giving the cross-linking group, and therefore can be used without impairing melt flow The LED is sealed without foaming and has excellent melt moldability. In addition, the cured product made of the fluoropolymer according to this embodiment has excellent heat and light resistance from the results of a continuous lighting test for 1,000 hours. On the other hand, in Example 2 where the unit (1) has a high content ratio and does not contain the unit (2), although it can be cured at a lower temperature than the ratio 1, it occurs when the LED is molded by heating and flowing. It hardens and it is difficult to suppress foaming. In addition, although the content of the unit (1) is the same as that of Example 1 and the fluoropolymer of Example 3 not containing the unit (2) can be molded without foaming, foaming occurs during continuous lighting, so that It can be seen that the crosslinking is insufficient and the heat resistance is poor.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a fluoropolymer that is heat-curable and has both melt moldability and heat and UV resistance. The fluoropolymer of this embodiment is effective as an optical material, a sealing material for an element, an inorganic EL phosphor dispersion material, a material for an optical waveguide, a heat-resistant and resistant sealing material, an adhesive, and a coating material. The coating composition of this embodiment can be effectively used as a release agent, a material for antifouling coating, a material for chemical resistance protection coating, and the like. The fluoropolymer of the present invention can also be UV-cured, so it can also be applied to a substrate having low heat resistance such as a plastic material. The cured product of the fluoropolymer of this embodiment can be effectively used as a light-transmitting sealing material for UV-LED. It can also be used as an underfill material for flip chip components. A molded article composed of a cured product of the fluoropolymer of this embodiment can be effectively used as a core material or a covering material for an optical fiber, a core material or a covering material for an optical waveguide, and a lens material. The base material provided with the cured material of the fluoropolymer of this embodiment is effective as a light-emitting element, a semiconductor element, a solar cell element, a short-wavelength light-emitting element, etc., and is particularly effective as a hardened object having a light-emitting element and a fluoropolymer Light emitting device.

Claims (11)

A fluoropolymer containing a unit represented by the following formula (1) and a unit represented by the following formula (2); [Chemical Formula 1] (In formula (1), R ^f1 is a fluoroalkylene group or a fluoroalkylene group having 2 or more carbon atoms having an etheric oxygen atom between carbon and carbon atoms, and R ¹ and R ² are each independently a hydrogen atom or an alkyl group. ); [Chemical Formula 2] (In the formula (2), X ¹ , X ² , and X ³ are each independently a fluorine atom or a hydrogen atom, two Q ² are each independently a single bond or an etheric oxygen atom, and R ^f2 is a fluorine atom having 1 to 6 carbon atoms. An alkyl group or a fluoroalkylene group having 2 to 25 carbon atoms having an etheric oxygen atom between carbon and carbon atoms). The fluoropolymer according to claim 1, wherein at least a part of the unit represented by the aforementioned formula (1) is-[CF ₂ -CF (O (CF ₂ ) ₃ CONHNH ₂ )]-. The fluoropolymer of claim 1 or 2, further comprising a unit derived from fluoroethylene. The fluoropolymer according to any one of claims 1 to 3, further comprising a unit represented by the following formula (3) (except for units derived from vinyl fluoride);-[CX ⁴ X ⁵ -CY ¹ Y ² ] -... (3) (In the formula (3), X ⁴ and X ⁵ are each independently a hydrogen atom, a fluorine atom or a chlorine atom, Y ¹ is a hydrogen atom, a fluorine atom or a chlorine atom, and Y ² is a hydrogen atom, a fluorine atom Alkyl group, fluoroalkyl group having 2 or more carbon atoms having etheric oxygen atoms between carbon-carbon atoms, fluoroalkoxy group, or fluoroalkoxy group having 2 or more carbon atoms having etheric oxygen atoms between carbon-carbon atoms ). For example, the fluorine-containing polymer according to any one of claims 1 to 4, wherein the ratio of the units represented by the aforementioned formula (1) is 0.1 to 20 mol% relative to the total amount of the units contained in the fluorine-containing polymer, and the aforementioned formula ( 2) The ratio of the units shown is 0.05 to 3 mol%. The fluorinated polymer according to any one of claims 1 to 4, wherein the ratio of the unit represented by the aforementioned formula (1) is 0.1 to 5 mol% relative to the total amount of the units contained in the fluorinated polymer, and the aforementioned formula ( 2) The ratio of the units shown is 0.05 to 3 mol%. For example, the fluoropolymer of any one of claims 1 to 6, its mass average molecular weight is 3,000 to 100,000. For example, the fluoropolymer of any one of claims 1 to 6, its mass average molecular weight is 5,000 to 100,000. A method for manufacturing a cured product of a fluoropolymer, characterized in that the fluoropolymer according to any one of claims 1 to 8 is heated at 150 to 300 ° C. A light-emitting device comprising a light-emitting element and a cured product of a fluoropolymer according to any one of claims 1 to 8. The light-emitting device according to claim 10, wherein the light-emitting element is a white LED or an ultraviolet LED.