Fluorine-containing nitrile-oxide compound

Abstract

A stable and easily producible compound of the formula (I): ##STR00001##
wherein R.sup.1 represents a hydrocarbon group; and R.sup.2 and R.sup.3 represent each independently a hydrogen atom or a hydrocarbon group: provided that in at least one of R.sup.1, R.sup.2 and R.sup.3, at least one hydrogen atoms are substituted by a fluorine atom, and each of R.sup.1, R.sup.2 and R.sup.3 is attached via its carbon atom to a carbon atom to which a nitrileoxide group is attached.

Claims

1. A compound of the formula (I): ##STR00024## wherein R.sup.1 represents a fluoroalkyl group or a group substituted by one or more fluoroalkyl groups; R.sup.2 and R.sup.3 represent each independently a hydrogen atom or a hydrocarbon group; and a carbon atom of R.sup.1 is attached to a carbon atom to which a nitrile oxide is attached, and when one or both of R.sup.2 and R.sup.3 is represented by a hydrocarbon group, a carbon atom of the hydrocarbon group is attached to a carbon atom to which a nitrile oxide group is attached.

2. The compound according to claim 1 wherein at least one of R.sup.1, R.sup.2 and R.sup.3 are a perfluoroalkyl group or comprise one or more perfluoroalkyl groups.

3. The compound according to claim 1 wherein R.sup.1 represents a perfluoroalkyl group, or an alkyl group substituted by one or more perfluoroalkyl groups.

4. The compound according to claim 1 which meets one or more of the following items (b)-(c); (b) R.sup.2 is an aryl group, a tert-alkyl group or a sec-alkyl group which may be substituted by one or more substituents; and (c) R.sup.3 is an aryl group, a tert-alkyl group or a sec-alkyl group which may be substituted by one or more substituents.

5. The compound according to claim 1 wherein at least one of R.sup.2 and R.sup.3 are an aryl group, a tert-alkyl group or a sec-alkyl group which may be substituted by one or more substituents.

6. The compound according to claim 1 wherein R.sup.1 is a perfluoroalkyl group, or an alkyl group substituted by one or more perfluoroalkyl groups; and R.sup.2 and R.sup.3 are a phenyl group which may be substituted by one or more substituents.

7. The compound according to claim 1 wherein at least one of R.sup.2 and R.sup.3 are a perfluoroalkyl group or an alkyl group which is substituted by one or more perfluoroalkyl groups.

8. The compound according to claim 2 wherein the perfluoroalkyl group is C.sub.mF.sub.2m+1 wherein m represents an integer of 1-16.

9. A process for preparing the compound of the formula (I) described in claim 1 comprising the following steps: (i) reacting a compound of the formula (II): ##STR00025## wherein: R.sup.2 and R.sup.3 are as defined in claim 1 with a compound of the formula (III):
R.sup.1L(III) wherein: R.sup.1 is as defined in claim 1; L represents MX.sub.t; M represents Li, Zn, Na, K, Al, Cu, B, Si, Ti, Cr, Fe, Ni, Pd, Pt, Rh, Ru, Ir, Mg or Sm; X represents a halogen atom or an alkoxy group; and t represents an integer of 0-6; and then, (ii) dehydrating.

10. A composition applied to a material containing a group reactive with a nitrileoxide group which comprises one or more compounds according to claim 1.

11. The composition according to claim 10 which is a surface treatment agent.

12. The composition according to claim 10 which is a modifying agent.

13. An article comprising a base material and a layer which is formed from the surface treatment agent according to claim 11 on the surface of the base material.

14. A modified polymer material treated with the modifying agent according to claim 12.

Description

EXAMPLES

Example 1

(1) ##STR00021##

Step 1: Synthesis of fluorine-containing benzaldehyde 2

(2) 4-hydroxybenzaldehyde 1 (0.67 g, 5.5 mmol), 1-iodo-3-(perfluorooctyl)propane (2.9 g, 5.0 mmol), and cesium carbonate (5.3 g, 17 mmol) were added to anhydrous dimethylformamide (DMF) (20 mL), and reacted under an argon atmosphere at a room temperature for 20 hours. The solvent was distilled off under reduced pressure and dichloromethane was added. The mixture was extracted with water one time and with aqueous sodium hydrogen carbonate solution three times, and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure to obtain a white powder 2.8 g (4.8 mmol, 96%).

Step 2: Synthesis of fluorine-containing nitrostyrene 3

(3) Fluorine-containing benzaldehyde (22.4 g, 4.0 mmol), nitromethane (0.67 g, 11 mmol), and ammonium acetate (0.31 g, 0.48 mmol) are added to acetic acid (2 mL), and refluxed at 100 C. for 9 hours. Dichloromethane (100 mL) was added to the mixture, and the mixture was washed with water and aqueous sodium hydrogen carbonate solution, and then dried over magnesium sulfate. The mixture was filtered and the filtrate was distilled off under reduced pressure. The solid was dissolved in ethyl acetate, reprecipitated in hexane, and filtered, and then the filtrate was distilled off under reduced pressure to obtain a yellow powder (0.59 g, 0.93 mmol, 23%).

Step 3: Synthesis of fluorine-containing aliphatic nitrileoxide 4

(4) Fluorine-containing nitrostyrene 3 (0.51 g, 0.80 mmol) was added to tetrahydrofuran (THF) (8 mL), and cooled to 0 C. under an argon atmosphere. Tert-butylmagnesium chloride (0.8 mL, 1.6 mmol) was added, and the mixture was stirred at a room temperature for 1 hour. After the mixture was cooled to 10 C., concentrated sulfuric acid (>95%, 0.42 mL, 8.0 mmol) was added, and the mixture was stirred for 30 minutes. After the mixture was extracted with water 3 times, it was dried over magnesium sulfate.

(5) The solvent was distilled off under reduced pressure, and the mixture was purified by HPLC to obtain a white powder (0.23 g, 0.35 mmol, 43%).

Comparative Example 1

(6) ##STR00022##

Step 1: Synthesis of fluorine-containing dimethoxybenzaldehyde 2

(7) 4-hydroxy-2,6-dimethoxybenzaldehyde (10.68 g, 3.7 mmol), 1-iodo-3-(perfluorooctyl)propane (2.0 g, 3.4 mmol) and cesium carbonate (3.7 g, 18 mmol) were added to anhydrous DMF (15 mL), and reacted under an argon atmosphere at a room temperature for 22 hours. The solvent was distilled off under reduced pressure and dichloromethane was added. The mixture was extracted with water one time and with aqueous sodium hydrogen carbonate solution three times, and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure to obtain a white powder (2.0 g, 3.2 mmol, 93%).

Step 2: Synthesis of fluorine-containing dimethoxy benzaldoxime 3

(8) While fluorine-containing dimethoxybenzaldehyde (21.2 g, 1.9 mmol) was suspended in ethanol (5 mL), a solution that hydroxylamine hydrochloride (0.15 g, 2.1 mmol) and sodium hydroxide (0.17 g, 4.3 mmol) were dissolved in water (5 mL) was added at 0 C. and stirred at a room temperature for one day. The reaction solution was filtered, and the residue was washed with pure water and chloroform and dried no obtain a white powder (1.1 g, 1.6 mmol, 85%).

Step 3: Synthesis of fluorine-containing aromatic nitrileoxide 4

(9) While fluorine-containing dimethoxy benzaldoxime (30.14 g, 0.21 mmol) was stirred and suspended in chloroform (0.042 mL) at 0 C., triethylamine (0.040 g, 0.30 mmol), followed by N-chlorosuccinimide (NCS) (0.030 g, 0.30 mmol) were added to perform the reaction for 30 minutes. Dichloromethane was added, the mixture was extruded with water 2 times, and then dried over magnesium sulfate. The solvent was distilled off under reduced pressure to obtain a white powder (0.13 g, 0.2 mmol, 97%).

Text Example 1

Thermal Stability Test

(10) For each of compounds obtained in Example 1 and Comparative Example 1, thermal gravimetric analysis (TGA) was performed. As a result, a temperature at which 5% weight was lost of the compound of Example 1 was 211 C., while a temperature at which 5% weight was lost of the compound of Comparative Example 1 was 180 C. It was confirmed that the compound of the present invention has superior thermal stability.

Example 2

(11) ##STR00023##

Step 1: Synthesis of fluorine-containing Grignard reagent 6

(12) 2-(perfluorohexyl)ethyl iodide (4.74 g, 10 mmol) was slowly dropped in portion into diethyl ether (25 mL) containing metallic magnesium (0.26 g, 12 mmol). The reaction solution was stirred at a room temperature for 3 hours to obtain Grignard reagent as a nucleophilic reagent (0.263 M, determined by titration with salicylaldehyde phenylhydrazone as an indicator).

Step 2: Synthesis of fluorine-containing aliphatic nitrileoxide 7

(13) A solution of 1,1-diphenyl nitroethene (451 mg, 2.0 mmol) in dried THF (30 mL) was cooled to 0 C. under an argon atmosphere, and then the solution of Grignard reagent in diethyl ether obtained in Step 1 (8.37 mL, 2.2 mmol) was dropped in portion and stirred for 30 minutes. Then, the reaction solution was cooled to 10 C., and concentrated sulfuric acid (>95%, 1.96 g, 20 mmol) was added, and stirred at 0 C. for 30 minutes. After the reaction, the product was extracted by adding methylene chloride (50 mL) to the reaction solution, and washed with saturated sodium bicarbonate solution. The organic phase was dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain a crude product. Then, the crude product was purified by silica gel chromatography (hexane:diethyl ether=20:1) to obtain 1,1-diphenyl-3-(perfluorohexyl)propyl nitrileoxide of interest as a yellow liquid (yield 81%, 0.90 g, 1.61 mmol).

(14) .sup.1H-NMR (400 MHz, 298 K, CDCl.sub.3): 7.42-7.29 (br, aromatic), 2.74-2.69 (m, CF.sub.2CH.sub.2), 2.20-2.07 (m, CH.sub.2CH.sub.2) ppm

(15) IR (KBr): 2292 (CNO), 1636 (Ar, CC), 1240 (CF) cm.sup.1

Example 3

Solid-Phase Reaction of Natural Rubber (NR) with Fluorine-Containing Nitrileoxide 7

(16) NR (50 mg, 0.735 mmol of repeating units) and fluorine-containing nitrileoxide 7 (C.sub.6F.sub.13C.sub.2H.sub.4CPh.sub.2CNO, 40 mg, 0.074 mmol) (i.e., 10 mol % of nitrileoxide with respect to a CC bond of NR) were added to a mortar, and mixed under pressure at 160 C. for 2 hours. After cooling to a room temperature, the mixture was dissolved in chloroform, precipitated in methanol, and filtered to be recovered. The recovered product was dried under vacuum to obtain a modified NR. For the obtained modified NR, the reaction rate was measured by .sup.1H-NMR. In particular, depending on the progress of the reaction with nitrileoxide, proton peaks of the aromatic ring (10H, 7.3 ppm), methylene next to the perfluoro chain (2H, 2.2 ppm), and methylene further next to it (2H, 2.7 ppm) could be determined, and the reaction ratio (or conversion) was calculated based on integral value ratios between these peaks. As a result, the reaction rate was 94.7%, thus it is confirmed that the reaction was proceeded well.

Example 4

Solid-Phase Reaction of Ethylene-Propylene-Diene Rubber (EPDM) with Fluorine-Containing Nitrileoxide 7

(17) EPDM (50 mg, 0.118 mmol of repeating units) and fluorine-containing nitrileoxide 7 (C.sub.6F.sub.13C.sub.2H.sub.4CPh.sub.2CNO, 137.2 mg, 0.247 mmol) were added to a mortar, and mixed under a pressure at 160 C. for 2 hours. It is noted that since the contents of the diene component was 10% in EPDM, about twice nitrileoxide were used. Then, the mixture was cooled to a room temperature, and dissolved in chloroform. The product was recovered by precipitating the product in methanol. The product was dried under vacuum to obtain a modified EPDM. The reaction rate was measured by using .sup.1H-NMR, as a result, it was 84.4%.

Example 5

Solid-Phase Reaction of Polyacrylonitrile (PAN) with Fluorine-Containing Nitrileoxide 7

(18) PAN (100 mg, 1.89 mmol of repeating units) and fluorine-containing nitrileoxide 7 (523.7 mg, 0.94 mmol: corresponding to 50% of the nitrile group in PAN) were mixed under a pressure at 130 C. for 2 hours in a mortar.

(19) After the reaction, purification was performed by extracting the mixture with acetone. The reaction rate was calculated based on the decrease of a peak of a nitrile group at 2243 cm.sup.1 in the FTIR (a peak at 1455 cm.sup.1 which can be observed before and after the reaction was referenced to). The reaction rate is 42.2%.

Example 6

Solid-Phase Reaction of Nitrile-Butadiene Rubber (NBR) with Fluorine-Containing Nitrileoxide 7

(20) NBR (100 mg, 1.86 mmol of repeating units) and fluorine-containing nitrileoxide 7 (516.6 mg, 0.93 mmol) were mixed under a pressure at 130 C. for 2 hours in a mortar. After the reaction, purification was performed by extracting the mixture with acetone. Thought there is no referenceable peak after the reaction in NBR and it was difficult to determine an accurate reaction rate from the FTIR, the progress of the reaction was confirmed because a peak derived from CF.sub.3 (at around 1200 cm.sup.1) and a peak derived from CF.sub.2 at the low wave number side (at 702 cm.sup.1) were observed.

Example 7

Glass Surface Treatment

(21) A glass slide subjected to a piranha treatment (a blank sample) was dried, and immersed in chloroform. Then, a few drops of allyltrichlorosilane (about 15 L) were added, and the reaction was allowed at a room temperature for 12 hours. The glass slide to whose surface an allyl group was introduced was washed with chloroform several times and stored in methanol.

(22) The glass slide to whose surface an allyl group was introduced (an allyl treated glass) was dried, and nitrileoxide 7 containing a fluorine chain (C.sub.EF.sub.13C.sub.2H.sub.4CPh.sub.2CNO, 70 mg, 0.126 mmol) was applied thereon. The reaction was allowed on a hot plate at 70 C. for 6 hours to obtain a nitrileoxide treated glass. After the reaction, it was washed with acetone several times. The contact angle of the surface after the reaction was measured. The result is shown in the following table.

(23) TABLE-US-00001 TABLE 1 Contact Contact Critical angle angle Surface surface (water, (CH.sub.2I.sub.2, energy energy Glass sample degree) degree) (mJ/m.sup.2) (mJ/m.sup.2) blank 41.8 39.0 62.7 allyl 59.0 37.3 53.5 34.8 treated nitrileoxide 95.8 69.7 25.6 20.7 treated

(24) The water contact angle of the glass after the piranha treatment was 41.8, the water contact angle of the glass into which the allyl group was introduced was 59, and the contact angles of the samples A and B into which the fluoro chain was introduced were not less than 95. Additionally, in view of the contact angle for CH.sub.2I.sub.2, it was confirmed that the contact angle for an organic solvent was also improved in addition to water repellency. From these results, it was confirmed that the surface free energy was lowered and the reaction was proceeded.

Example 8

Rubber Surface Treatment

(25) Nitrileoxide 7 containing a fluoro chain (C.sub.6F.sub.13C.sub.2H.sub.4CPh.sub.2CNO, 30 mg) was applied to cross-linked NR film of about 15 mm15 mm, and heated on a hot plate at 70 C. for 12 hours. After reaction, it was washed several time to remove an unreacted nitrileoxide. After the washing, the cross-liked NR film was dried.

(26) A water contact angle of the surface of the obtained cross-linked NR film were measured. As the result, the contact angles was 86 for the unreacted NR film, and it is 92 for the NR film surface-treated with the nitrileoxide having a fluoro chain, thus it was confirmed that the reaction was proceeded.

INDUSTRIAL APPLICABILITY

(27) The compound of the present invention can be suitably used in various applications, for example, as a surface treatment agent, a modifying agent, a filler modifier, a fiber treatment agent, a compatibilizing agent and a modifier of a rubber having a low-temperature properties.