JP5757189B2 - Thermosetting fluorine-containing polyether compound and method for producing the same - Google Patents

Description

The present invention relates to a thermosetting fluorine-containing polyether compound and a method for producing the same. More specifically, the present invention relates to a thermosetting fluorine-containing polyether compound having a reactive site at both ends of a polymer main chain and a method for producing the same.

で表わされる化合物が知られている(特許文献１参照)。 As the fluorine-containing polyether compound having a functional group at the molecular end, for example, a general formula

Is known (see Patent Document 1).

で表わされる化合物が知られている(特許文献２参照)。 Further, as a more general compound obtained by oligomerizing the main chain structure of the above compound, a general formula

Is known (see Patent Document 2).

  The compounds represented by these general formulas are cured by a fluorine-containing organohydrogensiloxane compound having a plurality of Si-H groups in the molecule and a platinum compound catalyst, and have excellent properties (chemical resistance, heat resistance, low temperature It is said that an elastomeric molded product having characteristics) can be provided, and in particular, it can be used without loss of flexibility even under a low temperature condition of about -50 ° C. Moreover, the curable composition which has these as a main component has outstanding moldability, and also enables RIM molding. However, since this cured product has a siloxane bond in its intramolecular cross-linked structure, its mechanical strength decreases due to chemical degradation when used under conditions where acidic substances such as hydrogen fluoride are present. May give undesirable results.

Japanese Patent Laid-Open No. 11-343336 Japanese Patent No. 2,990,646 WO 2008/126436 A1 WO 90/15042 A2

Fluoropolymers l: Synthesis (edited by G. Hougham et. Al.), 25-50, Plenum Press, New York (1999) J. Am. Chem. Soc. 128, 7055 (2006) Tetrahedron Letters 36, 6373 (1995) Tetrahedron Letters 38, 5831 (1997)

(ここで、R^１は水素原子または炭素数1〜3のアルキル基であり、Xはヨウ素原子または臭素原子であり、Xのフェニル基上の置換位置はNR^１結合置換基に対してm-またはp-位であり、lおよびmはそれぞれ独立に10以上の整数であり、l+mは30〜130である)で表わされる含フッ素ポリエーテル化合物を提案している(特許文献３参照)。 The present inventor previously can cure without the need for a fluorine-containing organohydrogensiloxane compound having a Si—H bond, and is excellent in heat resistance, low temperature characteristics and moldability, and used under acidic conditions. As a fluorine-containing polyether compound that gives a cured product that can withstand

(Wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, X is an iodine atom or a bromine atom, and the substitution position on the phenyl group of X is m− with respect to the NR ¹ bond substituent. Or a p-position, l and m are each independently an integer of 10 or more, and l + m is 30 to 130) (see Patent Document 3). .

An object of the present invention is to provide a thermosetting fluorine-containing polyether compound having a trifluorovinyloxy group instead of an iodine atom or a bromine atom at both ends of a polymer main chain, and a method for producing the same.

(ここで、R¹は炭素数1〜3のアルキル基であり、lおよびmはそれぞれ独立に10以上の整数であり、l+mは30〜200である)で表わされる熱硬化性含フッ素ポリエーテル化合物が提供される。 According to the present invention, the general formula [I]

(Wherein, R ¹ is an alkyl group having 1 to 3 carbon atoms, l and m are each independently an integer of 10 or more, l + m is a is 30 to 200) thermosetting fluorine represented by A polyether compound is provided.

(ここで、lおよびmはそれぞれ独立に10以上の整数であり、l+mは30〜200である)で表わされる含フッ素ジカルボン酸フルオリド化合物を、一般式〔III〕

(ここで、R¹は炭素数1〜3のアルキル基であり、R²は水素原子またはトリメチルシリル基である)で表わされるビス(トリフルオロビニロキシ)アニリン化合物と、好ましくはピリジンまたはトリエチルアミン等の3級アミン化合物の存在下で、反応させることにより製造される。 Such a thermosetting fluorine-containing polyether compound has the general formula [II]

(Wherein l and m are each independently an integer of 10 or more, and l + m is 30 to 200), a fluorine-containing dicarboxylic acid fluoride compound represented by the general formula [III]

(Wherein R ¹ is an alkyl group having 1 to 3 carbon atoms, and R ² is a hydrogen atom or a trimethylsilyl group), and preferably a bis (trifluorovinyloxy) aniline compound, such as pyridine or triethylamine It is produced by reacting in the presence of a tertiary amine compound.

  The fluorine-containing polyether compound according to the present invention has four trifluorovinyloxy groups as reaction sites at both ends of the polymer main chain. Can be given. Molded products obtained by curing such compositions are excellent in low-temperature characteristics, chemical resistance, etc., so that they are excellent in automobile fuel supply system seal materials, oil seal materials, aircraft fuel systems and hydraulic system seal materials, and semiconductor manufacturing equipment seals. It is suitably used for various applications such as materials.

において、lおよびmはそれぞれ独立に10以上の整数であり、l+mは30〜200の整数である。特に、エラストマー性高分子材料の主原料として用いる場合には、硬化後十分な機械的強度を有する成形物を得るために、l+mは50〜150であることが好ましい。R¹は炭素数1〜3のアルキル基であって、分子間水素結合の形成が妨げられることにより、含フッ素ポリエーテル化合物の粘度を低下させることができる。 Thermosetting fluorine-containing polyether compound [I] of the present invention

In the formula, l and m are each independently an integer of 10 or more, and l + m is an integer of 30 to 200. In particular, when used as a main raw material for an elastomeric polymer material, l + m is preferably 50 to 150 in order to obtain a molded product having sufficient mechanical strength after curing. R ¹ is an alkyl group having 1 to 3 carbon atoms, which can lower the viscosity of the fluorinated polyether compound by preventing the formation of intermolecular hydrogen bonds.

注) HFPO：ヘキサフルオロプロペンオキシド
HFP：ヘキサフルオロプロペン The fluorine-containing polyether compound [I] of the present invention can be produced, for example, through the following series of steps.

Note) HFPO: Hexafluoropropene oxide
HFP: Hexafluoropropene

In the bis (trifluorovinyloxy) aniline compound [III] used in the second step, R ¹ is an alkyl group having 1 to 3 carbon atoms, and R ² is a hydrogen atom or a trimethylsilyl group. The substitution positions on the benzene ring of the trifluorovinyloxy group (CF ₂ ═CFO—) are the 3rd and 5th positions with respect to the amino group (—NR ¹ R ² ). Specific examples of the bis (trifluorovinyloxy) aniline compound [III] include 3,5-bis (trifluorovinyloxy) -N-methylaniline, 3,5-bis (trifluorovinyloxy) -N-ethyl. Examples thereof include aniline, 3,5-bis (trifluorovinyloxy) -Nn-propylaniline, and N-trimethylsilyl derivatives thereof.

The 3,5-bis (trifluorovinyloxy) aniline used as a starting material for the bis (trifluorovinyloxy) aniline compound [III] is produced using, for example, methyl 3,5-dihydroxybenzoate as a starting material. Can do. In methyl 3,5-dihydroxybenzoate, conversion of a hydroxyl group to a trifluorovinyloxy group can be performed with reference to Non-Patent Document 1. Specifically, after making the hydroxyl group a potassium salt, 1,2-dibromotetrafluoroethane is allowed to act to form a 2-bromotetrafluoroethoxy group (BrCF ₂ CF ₂ O-), followed by dehydrobromination reaction. Thus, it can be converted into a trifluorovinyloxy group (CF ₂ = CFO-).

Conversion of the carboxylic acid ester moiety (CH ₃ COO—) of methyl 3,5-dihydroxybenzoate to an amino group (NH ₂ —) can be performed with reference to Patent Document 4 and Non-Patent Document 2. Specifically, the carboxylic acid ester moiety is hydrolyzed to a free carboxylic acid, and a halogenating agent such as thionyl chloride is allowed to act on the carboxylic acid ester site to obtain a carboxylic acid chloride. Next, it is converted into a carboxylic acid azide (—CON ₃ ) by, for example, sodium azide, and this is converted into an isocyanate group (—N═C═O) by heating in an inert solvent (Crutius reaction). Finally, hydrolysis to this achieves conversion to the amino group.

An example of a method for producing 3,5-bis (trifluorovinyloxy) aniline includes the following route.
Methyl 3,5-dihydroxybenzoate → Methyl 3,5-dihydroxybenzoate dipotassium salt → Methyl 3,5-bis (2-bromotetrafluoroethoxy) benzoate → 3,5-bis (2-bromotetrafluoro) Ethoxy) benzoic acid → 3,5-bis (2-bromotetrafluoroethoxy) benzoic acid chloride → 3,5-bis (2-bromotetrafluoroethoxy) benzoic acid azide → 1-isocyanato-3,5-bis (2 -Bromotetrafluoroethoxy) benzene → 1-isocyanato-3,5-bis (2-bromotetrafluoroethoxy) aniline → 3,5-bis (trifluorovinyloxy) aniline

The bis (trifluorovinyloxy) aniline compound [III] in which R ¹ is an alkyl group having 1 to 3 carbon atoms is produced by N-monoalkylation of a primary amino group and conversion to a secondary amino group . A secondary amino group (—NHR ¹ ) may be converted to an amino group (—NR ¹ R ² ) in which R ² is a trimethylsilyl group by reacting with trimethylsilyl chloride or hexamethyldisilazane.

The conversion from the primary amino group (—NH ₂ ) to the secondary amino group (—NHR ¹ ) can be performed using an alkylating agent such as dialkyl sulfuric acid and alkyl iodide. In addition, in the direct alkylation reaction of primary amine with an alkylating agent, N, N-dialkylated product is also produced as a by-product in addition to N-monoalkylated product, so that N, N-dialkylated product from the reaction mixture. Need to be removed.

  In addition, as a conversion method from a primary amino group to a secondary amino group, a method via a sulfonamide described in Non-Patent Documents 3 to 4 is preferable. Specifically, a primary amine is reacted with 2-nitrobenzenesulfonyl chloride or 2,4-dinitrobenzenesulfonyl chloride, sulfonamidated, then N-alkylated with alkyl iodide, etc., and then thiophenol or mercaptoacetic acid The desired N-monoalkylated secondary amine can be selectively obtained by reacting with.

Further, as an example of a method for producing 3,5-bis (trifluorovinyloxy) -N-methylaniline, the following route can be exemplified.
3,5-bis (2-bromotetrafluoroethoxy) aniline → 3,5-bis (2-bromotetrafluoroethoxy) -N-methylaniline → 3,5-bis (trifluorovinyloxy) -N-methylaniline

  The reaction between the fluorine-containing dicarboxylic acid fluoride compound [II] and the bis (trifluorovinyloxy) aniline compound [III] is a basic nitrogen-containing heterocyclic compound having no active hydrogen such as pyridine or a tertiary amine such as triethylamine. -50 to 150 ° C, preferably in a fluorine-containing solvent such as hydrochlorofluorocarbon, hydrofluorocarbon, hydrofluoroether, or a mixed solvent of these fluorine-containing solvent and aprotic non-fluorinated solvent in the presence of the compound Is carried out at a reaction temperature of 0-100 ° C. Specific examples of fluorine-containing solvents include HCFC-225, HFE-449 (Sumitomo 3M product HFE-7100), HFE-569 (Sumitomo 3M product HFE-7200), 1,3-bis (trifluoromethyl) benzene, etc. Can be mentioned. Examples of the aprotic non-fluorinated solvent include diethyl ether, diisopropyl ether, cyclopentyl methyl ether, tetrahydrofuran, dioxane and the like. Considering the solubility of the bis (trifluorovinyloxy) aniline compound [III], it is more preferable to use a mixed solvent of a fluorinated solvent and an aprotic non-fluorinated solvent.

などが例示される。 As a specific example of the thermosetting fluorine-containing polyether compound of the present invention,

Etc. are exemplified.

  The fluorine-containing polyether compound of the present invention is cured by heating it alone. That is, since this fluorine-containing polyether compound has four trifluorovinyloxy groups per molecule as a reaction site, the dimerization reaction of the trifluorovinyloxy group proceeds by heating, and the chain extension It can be cured with reaction to give an elastomeric molding.

  Next, the present invention will be described with reference to examples.

攪拌装置、温度センサ、ガス導入口およびドライアイス／エタノール冷却凝縮器を備えた内容量1Lのガラス製反応容器を低温恒温槽に設置し、ジアルコキシド化合物 CsOCF_２CF(CF_３)OCF_２CF_２OCF(CF_３)CF_２OCs を23ミリモルを含むテトラグライム溶液60gを仕込んだ。内温を-33〜-30℃に調整した後、ガス導入口よりヘキサフルオロプロペンを40g仕込んだ。次に、ヘキサフルオロプロペンオキシドを10g/hr、ヘキサフルオロプロペンを4g/hrの供給速度で反応容器内に仕込んだ。42時間経過後、ガスの供給を停止し(ヘキサフルオロプロペンオキシド総仕込量428g)、さらに1時間-33〜-30℃に内温を保った。減圧下でヘキサフルオロプロペンを反応系内より除去した後、室温までゆっくり昇温した。さらに100℃まで昇温し、減圧下でヘキサフルオロプロペンオリゴマーを反応混合物より除去した。このようにして、フッ化セシウム、テトラグライムおよび含フッ素ジカルボン酸フルオリドからなる混合物を淡黄色粘稠な懸濁液として478g得た。これを精製せずに、次の工程に用いた。 Reference example 1
Preparation of fluorinated dicarboxylic acid fluoride compounds

A 1 L glass reaction vessel equipped with a stirrer, temperature sensor, gas inlet and dry ice / ethanol cooled condenser was placed in a low-temperature thermostatic chamber and dialkoxide compound CsOCF ₂ CF (CF ₃ ) OCF ₂ CF ₂ 60 g of a tetraglyme solution containing 23 mmol of OCF (CF ₃ ) CF ₂ OCs was charged. After adjusting the internal temperature to -33 to -30 ° C, 40 g of hexafluoropropene was charged from the gas inlet. Next, hexafluoropropene oxide was charged into the reaction vessel at a feed rate of 10 g / hr and hexafluoropropene at 4 g / hr. After 42 hours, the gas supply was stopped (total amount of hexafluoropropene oxide charged: 428 g), and the internal temperature was kept at -33 to -30 ° C for 1 hour. After removing hexafluoropropene from the reaction system under reduced pressure, the temperature was slowly raised to room temperature. The temperature was further raised to 100 ° C., and the hexafluoropropene oligomer was removed from the reaction mixture under reduced pressure. Thus, 478 g of a mixture composed of cesium fluoride, tetraglyme and fluorine-containing dicarboxylic acid fluoride was obtained as a pale yellow viscous suspension. This was used in the next step without purification.

s＝F^ａ(-131ppm)ピーク積分値
t＝F^ｂ(-133ppm)ピーク積分値
u＝F^ｃ(-146ppm)ピーク積分値
注) ケミカルシフトはCFCl_３基準
二官能性比＝(t／s-0.5)／(t／s+0.5)＝0.89
ヘキサフルオロプロペンオキシド数平均重合度＝4u／(2t+s)＝102 Further, after a part of the above mixture was converted into a diester form [A] with methanol, the number average polymerization degree of hexafluoropropene oxide and the bifunctional ratio (mole fraction with hexafluoropropene oxide oligomer [B] were determined by ¹⁹ F-NMR. Rate).

s = F ^a (-131ppm) peak integrated value
t = F ^b (-133ppm) peak integrated value
u = F ^c (-146ppm) peak integral value
Note) Chemical shift is based on CFCl ₃ Bifunctional ratio = (t / s-0.5) / (t / s + 0.5) = 0.89
Hexafluoropropene oxide number average degree of polymerization = 4u / (2t + s) = 102

を、僅かに黄色味を帯びた透明な液体として65g得た。E型粘度計(東機産業製TEV-22)により粘度を測定したところ、15Pa・s(25℃)であった。
¹⁹F-NMR(ケミカルシフトはCFCl₃基準)： -124ppm(F^b)
-147ppm(F^c)
-120ppm(F^d)
-124ppm(F^e)
-135ppm(F^f)
¹H-NMR(ケミカルシフトはTMS基準)： 7.2ppm(H^a)
6.8ppm(H^b)
3.1ppm(H^c)
IR(neat)： 1840cm ^-1 (C=C)
1710cm ^-1 (C=O)
1560cm ^-1 (Ar)
1590cm ^-1 (Ar)
Example 78 g (about 4.5 mmol) of a mixture comprising the fluorine-containing dicarboxylic acid fluoride, cesium fluoride and tetraglyme obtained in Reference Example 1 was dissolved in 90 ml of a fluorine-containing solvent (Sumitomo 3M product HFE-7100). To this was added 1.9 g (19 mmol) of triethylamine and 36 ml of diethyl ether. Thereto was added 3.6 g (12 mmol) of 3,5-bis (trifluorovinyloxy) -N-methylaniline, and the reaction was carried out at 30 ° C. for 2 hours. The obtained reaction mixture was added to saturated brine, and the separated organic layer was washed with 1.5 wt% aqueous potassium hydroxide solution, dried over anhydrous magnesium sulfate and filtered. After distilling off the fluorine-containing solvent and diethyl ether from the filtrate under reduced pressure, the resulting viscous liquid was washed several times with diethyl ether, and then diethyl ether was completely distilled off under reduced pressure. Thus, a fluorine-containing polyether compound

65 g were obtained as a slightly yellowish transparent liquid. When the viscosity was measured with an E-type viscometer (TEV-22 manufactured by Toki Sangyo), it was 15 Pa · s (25 ° C.).
¹⁹ F-NMR (chemical shift based on CFCl ₃ ): -124 ppm (F ^b )
-147ppm (F ^c )
-120ppm (F ^d )
-124ppm (F ^e )
-135ppm (F ^f )
¹ H-NMR (chemical shift is based on TMS): 7.2 ppm (H ^a )
6.8ppm (H ^b )
3.1ppm (H ^c)
IR (neat): 1840cm ^-1 (C = C)
1710cm ^-1 (C = O)
1560cm ^-1 (Ar)
1590cm ^-1 (Ar)

Reference example 2
100 parts by weight of the fluorine-containing polyether compound of Example 1 and 13 parts by weight of acetylene carbon black were mixed to prepare a curable composition.

This curable composition was measured for curing behavior at 150 ° C. for 30 minutes using a Monsanto disc rheometer, and the following results were obtained.
ML 0.7 dN ・ m
MH 8.5 dN ・ m
t ₁₀ 6.0 minutes
t ₅₀ 10 minutes
t ₉₀ 15 minutes

  Further, a P24 O-ring was formed by compression molding at 150 ° C. for 30 minutes, and then oven vulcanization (secondary vulcanization) at 80 ° C. for 5 hours and 230 ° C. for 15 hours was performed in a nitrogen atmosphere. The compression set (according to ASTM D395 Method B; 200 ° C., 70 hours) was measured and a value of 50% was obtained.

  Further, when the glass transition temperature Tg of the P24 O-ring was measured using a differential scanning calorimeter (DSC6220 manufactured by SII Nanotechnology), a value of −55 ° C. was obtained.

Claims (6)

General formula [I]

(Wherein, R ¹ is an alkyl group having 1 to 3 carbon atoms, l and m are each independently an integer of 10 or more, l + m is a is 30 to 200) thermosetting fluorine represented by Polyether compounds. The thermosetting fluorine-containing polyether compound according to claim ¹ , wherein R ¹ in the general formula [I] is a methyl group. The thermosetting fluorine-containing polyether compound according to claim 1, wherein l + m is 50 to 150 in the general formula [I]. General formula [II]

(Wherein l and m are each independently an integer of 10 or more, and l + m is 30 to 200), a fluorine-containing dicarboxylic acid fluoride compound represented by the general formula [III]

(Wherein R ¹ is an alkyl group having 1 to 3 carbon atoms and R ² is a hydrogen atom or a trimethylsilyl group), and is reacted with a bis (trifluorovinyloxy) aniline compound represented by Item 2. A process for producing a thermosetting fluorine-containing polyether compound according to Item 1. The method for producing a thermosetting fluorine-containing polyether compound according to claim 4, wherein the reaction is carried out in the presence of pyridine or a tertiary amine compound. General formula [III]

A bis (trifluorovinyloxy) aniline compound represented by (wherein R ¹ is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and R ² is a hydrogen atom or a trimethylsilyl group).