JP6091963B2 - Fluorine-containing phosphate ester compound and salt thereof, and surface treatment agent - Google Patents

Description

  The present invention relates to a novel fluorine-containing phosphate ester compound and a salt thereof, and a surface treatment agent.

  Fluorine-containing phosphates are widely used as mold release agents, water and oil repellent treatment agents, lubricating oil additives and the like. As a fluorine-containing phosphate ester, a compound having one phosphate group and 1 to 3 perfluoroalkyl groups or perfluoroalkenyl groups per molecule is known (for example, Patent Document 1). These conventional fluorine-containing phosphates exhibit good release properties and are said to have a longer release life than other release agents. However, with the recent complication of molded product shapes, further improvement in mold release properties is required as a mold release agent.

Japanese Patent Laid-Open No. 05-194560

  An object of the present invention is to provide a novel fluorine-containing phosphoric acid ester compound and a salt thereof, and a surface treatment agent that are sufficiently excellent in surface properties such as releasability, water and oil repellency, and low surface tension.

  As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have sufficiently good release properties, water / oil repellency, low surface tension, etc., with certain novel fluorine-containing phosphoric acid ester compounds and salts thereof. Was found to exhibit surface characteristics.

  The present invention relates to a fluorine-containing phosphate compound represented by the following general formula (1) or a salt thereof:

［Ｒｆはそれぞれ独立して炭素原子数が６以下のパーフルオロアルキル基である；ｎはそれぞれ独立して４〜１２の整数である］。

[Rf is each independently a perfluoroalkyl group having 6 or less carbon atoms; n is each independently an integer of 4 to 12].

  The present invention also relates to a surface treatment agent containing the above-mentioned fluorine-containing phosphate ester compound or a salt thereof.

  The present invention provides a novel fluorine-containing phosphate ester compound and a salt thereof. The novel compound of the present invention is sufficiently excellent in surface properties such as releasability, water / oil repellency, and low surface tension.

[Fluorine-containing phosphate ester compound]
The fluorine-containing phosphate compound according to the present invention is a bisperfluoroalkyl bisphosphate ester represented by the following general formula (1).

In the general formula (1), Rf is a perfluoroalkyl group having 6 or less carbon atoms, particularly 1 to 6, preferably 4 to 6. From the viewpoint of surface characteristics, a perfluoroalkyl group having 6 carbon atoms is particularly preferred. Specific examples of Rf include trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluorobutyl group, perfluoropentyl group, perfluorohexyl group and the like. Rf may be linear or branched, but is usually linear. The _{Rf, - (CF 2) 2} F, - (CF 2) 4 F, - (CF 2) 6 F, preferably _{- (CF 2) 4 F,} - (CF 2) 6 F, and most preferably - (CF ₂ ) ₆ F can be mentioned. In the general formula (1), the two Rf's may be independently within the above range, but are preferably the same perfluoroalkyl group.

  n is an integer of 4 to 12, and is preferably an integer of 4 to 10, more preferably an integer of 8 to 10, from the viewpoint of surface characteristics. In the general formula (1), two ns may be independently within the above range, but are preferably the same integer.

  Specific examples of the compound represented by the general formula (1) include the following compounds:

  The fluorine-containing phosphate ester of the present invention can form a metal salt, an amine salt, an ammonium salt or the like by reacting with a basic metal compound, an amine compound, ammonia or the like, and these salts are also represented by the above general formula ( It has the same utility as the fluorine-containing phosphate ester of 1). Examples of the metal salt include alkali metal salts, alkaline earth metal salts, and transition metal salts. Specific examples of the metal atom forming the metal salt include Li, Na, K, Ca, Mg, Cu, Co, Ni, Zn, Mn, Fe, Pb, Hg, and Zr. Examples of the amine compound or ammonia that forms an amine salt or an ammonium salt include ammonia, trimethylamine, triethylamine, benzylamine, methylbenzylamine, dimethylbenzylamine, monoethanolamine, diethanolamine, triethanolamine, morpholine, pyridine, and the like.

[Method for producing fluorine-containing phosphate compound]
The fluorine-containing phosphate ester according to the present invention can be obtained, for example, by a method including the following steps, but is not limited to the method:
(A) a step of producing a fluorine-containing diol;
(B) The process of obtaining a fluorine-containing phosphate ester compound by making a phosphorus compound react with fluorine-containing diol, and then hydrogenating.

(A) Production process of fluorine-containing diol:
The fluorine-containing diol is a compound having two fluoroalkyl groups and two hydroxyl groups in one molecule, and in the target fluorine-containing phosphate compound of the present invention, two phosphate groups are substituted with hydroxyl groups. It is a compound which has this.

  The fluorine-containing diol may be produced by any method and can be obtained, for example, according to the following reaction formula.

  In the above reaction formula, Rf and n are the same as Rf and n in the general formula (1), respectively.

  Specifically, as shown in the above synthesis route, a diol was obtained from an allyl group-containing aldehyde compound, which is a starting material, by McMurry coupling reaction (Scheme a1), then reacted with a fluoroalkyl halide and reduced. A fluorine-containing diol can be obtained through a step reaction (Scheme a2).

  In the McMurray coupling reaction, when low-valent titanium is reacted with a carbonyl compound, reductive coupling proceeds and a corresponding diol can be obtained (Scheme a1).

  It is preferable to prevent moisture during the McMurray coupling reaction, and it is particularly preferable to use a dehydration apparatus such as a Dean-Stark apparatus or to proceed the reaction while dehydrating using a molecular sieve or the like.

  In the McMurray coupling reaction, the solvent is a conventional solvent that does not adversely affect the reaction, for example, a highly coordinating ether solvent or a mixed solvent thereof, and specific examples include dioxane, tetrahydrofuran, dimethoxyethane and the like. it can. It is preferable to use a solvent that has been dehydrated and distilled before use.

  The reaction temperature of the McMurray coupling reaction is preferably about −20 ° C. to 30 ° C., more preferably about −10 ° C. to 25 ° C. The reaction time is usually 1 to 3 hours.

  In scheme a2, reaction (i) with a fluoroalkyl halide is an addition reaction of a fluoroalkyl halide to a double bond in an allyl group. The reaction is performed at 60 to 100 ° C. for 6 to 10 hours in the presence of a radical generator such as azobisisobutyronitrile.

  In scheme a2, the reduction reaction (ii) is a reaction in which the added halogen atom is replaced with a hydrogen atom. For example, acetic acid is added in the presence of zinc and heated to reflux for 3 to 7 hours.

  In addition to the above synthetic route, the fluorine-containing diol can also be obtained by performing McMurry coupling after reaction / reduction of a fluoroalkyl halide and an allyl group-containing aldehyde compound.

(B) Phosphate esterification-hydrocracking step:
In this step, the fluorine-containing diol is reacted with a phosphorus compound and then oxidized (scheme b1) according to the following reaction formula, followed by a hydrogenolysis reaction (scheme b2).

In the above reaction formula, Rf and n are the same as Rf and n in the general formula (1), respectively.
R and R ′ each independently represents an alkyl group, an aryl group or an arylalkyl group. The alkyl group is not particularly limited, but is usually an alkyl group having 1 to 10, preferably 1 to 6, and more preferably 1 to 3 carbon atoms. Preferable specific examples of the alkyl group include, for example, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group and the like. The aryl group is not particularly limited, but is usually an aryl group having 6 to 10 carbon atoms. Preferable specific examples of the aryl group include a phenyl group and a toluyl group. The arylalkyl group is a group obtained by substituting one hydrogen atom of the above alkyl group with the above aryl group. Specific examples of the arylalkyl group include a benzyl group and a 2-phenylethyl group. The alkyl group, aryl group and arylalkyl group as R and R ′ may have a substituent such as an alkoxy group or a halogen atom. R and R ′ are preferably the same group.

  In detail in scheme b1, first, the fluorine-containing diol is reacted with a phosphorus compound, for example, a chlorophosphite such as dibenzylchlorophosphite, and then oxidized with an oxidizing agent such as hydrogen peroxide to obtain a fluorine-containing diol. To obtain a phosphoric ester.

  Chlorophosphite is a compound represented by (R—O) (R′—O) P—Cl in the above reaction formula.

  Solvents used in the substitution reaction with chlorophosphite and the subsequent oxidation reaction are those which are inert to the above reaction and in which the reaction substrate is sufficiently dissolved, for example, halogen solvents such as dichloromethane and chloroform. Can do.

  The reaction between the fluorinated diol and the chlorophosphite is preferably carried out in the presence of a tertiary amine such as trimethylamine, triethylamine, pyridine, N, N-dimethylaniline and the like. The temperature at the time of mixing the fluorine-containing diol and the chlorophosphite is preferably about -20 ° C to 10 ° C, more preferably -15 ° C to -5 ° C. The reaction temperature after mixing is preferably about 5 ° C to 30 ° C, more preferably 10 ° C to 20 ° C. The reaction time is preferably 10 to 30 hours, more preferably 15 to 20 hours. During the reaction, it is preferable to prevent moisture, and it is particularly preferable to use a dehydration device such as a Dean-Stark device or to proceed the reaction while performing a dehydration treatment using a molecular sieve or the like.

  The oxidation reaction with the oxidizing agent is performed by stirring the reaction system for 0.5 to 3 hours, preferably 1 to 2 hours while maintaining the reaction temperature.

  After obtaining the phosphoric ester of the fluorine-containing diol, a hydrogenolysis reaction is performed (Scheme b2). Thereby, the fluorine-containing phosphoric acid ester compound of this invention can be obtained.

  The hydrogenolysis reaction is a reaction in which hydrogen is decomposed in the presence of hydrogen. For example, a known hydrogenation method such as a hydrogenation reduction reaction using palladium carbon can be used. Specifically, the mixture is stirred in the presence of hydrogen gas and palladium on carbon at room temperature, preferably 10 ° C. to 20 ° C., for 24 to 72 hours, preferably 36 to 60 hours.

  The solvent in the hydrogenolysis reaction is preferably an alcohol solvent, an ether solvent, or an ester solvent, and examples thereof include methanol, ethanol, dioxane, tetrahydrofuran, methyl acetate, and ethyl acetate.

[Usefulness of fluorinated phosphate ester compounds]
The fluorine-containing phosphate compound and the salt thereof of the present invention are useful as, for example, a surface treatment agent such as a mold release agent, a metal surface treatment agent or a water / oil repellent treatment agent; a lubricating oil additive; or a surfactant. .

The mold release agent is a treatment agent that is applied to the surface of a mold in the plastic molding field to prevent fusion between the plastic and the mold.
A metal surface treatment agent is a treatment agent applied to a metal surface in the metal field to modify surface properties.
The water / oil repellent treatment agent is a treatment agent for imparting water / oil repellency to the surface in the fields of fiber, paper, glass, plastic, metal and the like.
Lubricating oil additives are treatment agents that are added to lubricating oils used in fields such as metals and plastics to reduce friction.
The surfactant is a compound having both a hydrophilic part and a lipophilic part in the molecule, and is used as an emulsifier, a dispersant, a detergent, etc. by utilizing such a structure.

  The present invention also provides a surface treatment agent in the state of an organic solution, an organic dispersion or an aqueous dispersion.

The surface treating agent of the present invention in the state of an organic solution is obtained by dissolving the fluorine-containing phosphate compound in an organic solvent.
The surface treatment agent of the present invention in the state of an organic dispersion is obtained by dispersing the fluorine-containing phosphate compound in an organic solvent.
The surface treatment agent of the present invention in the form of an aqueous dispersion is obtained by dispersing the fluorinated phosphate ester compound in an aqueous medium.

  The organic solvent constituting the surface treatment agent in the state of an organic solution or an organic dispersion is not particularly limited as long as it is a solvent capable of dissolving or dispersing the fluorine-containing phosphate compound. Specific examples of such organic solvents include, for example, fluorinated solvents such as metaxylene hexafluoride, paraxylene hexafluorolide, hydrofluoroether, perfluorocarbon, perfluoropolyether, hydrofluoropolyether, methanol, ethanol, Monohydric alcohols such as propanol and isopropanol, polyhydric alcohols such as ethylene glycol and propylene glycol, ketones such as acetone and methyl ethyl ketone, ethers such as ethyl ether, isopropyl ether, dioxane and tetrahydrofuran, and mixtures thereof Can be mentioned.

  Examples of the aqueous medium constituting the surface treatment agent in the state of an aqueous dispersion include water and a mixed liquid of one or more organic solvents having compatibility with water among the above organic solvents and water. Examples of the organic solvent having compatibility with water include methanol, ethylene glycol, and acetone.

  In the surface treatment agent of the present invention, the blending amount of the fluorine-containing phosphate represented by the general formula (1) is usually 0.1 to 10.0% by weight, preferably based on the total weight of the surface treatment agent. Is 0.7 to 3.0% by weight.

  The surface treatment agent of the present invention may contain a fluorine-free polymer, a rust preventive agent, a catalyst, an antibacterial agent, a flame retardant, a surfactant, and the like, as long as the object of the present invention is not impaired.

  The surface treating agent of the present invention can be used by applying and drying the region to be treated with the surface treating agent. The coating method is not particularly limited, and examples thereof include a spray coating method, a brush coating method, a roll coater coating method, and a dipping coating method. Examples of the drying method include a method of forming a film by evaporating the solvent by air drying or heating. The dry thickness of the film containing the surface treating agent of the present invention is usually 0.1 to 15 μm, preferably 0.2 to 5.0 μm.

[Example 1]
(A) Production process of fluorine-containing diol:
(Scheme a1)
A three-necked flask (300 mL) was charged with 8.0 g (122 mmol) of zinc powder and 150 mL of 1,4-dioxane, cooled with ice / salt while stirring, and 10.6 g (55.9 mmol) of titanium tetrachloride with a syringe. ) Was slowly added dropwise. After the completion of dropping, 6.23 g (37.0 mmol) of 10-undecenal was added with a syringe, and the mixture was stirred for 2 hours while being irradiated with ultrasonic waves. Thereafter, 200 mL of 1N hydrochloric acid and 150 mL of diethyl ether were added and stirred, and then filtered through Celite to remove residual zinc powder. The organic layer of the filtrate was washed with an aqueous ammonium chloride solution and saturated brine, concentrated under reduced pressure, and recrystallized in hexane to obtain 8.4 g of Compound (I-1) (yield 77%).

(Scheme a2)
In a three-necked flask (200 mL) equipped with a condenser, 13.4 g (30.0 mmol) of perfluorohexyl iodide, 3.38 g (10.0 mmol) of compound (I-1), azobisisobutyronitrile 0.657 g (4.00 mmol) was added, and the inside of the container was replaced with argon, and then heated at 80 ° C. for 8 hours with stirring. The reaction mixture was dissolved in 100 ml of ethanol, 5.00 g (76.5 mmol) of zinc powder was added and stirred for 15 minutes, and then 3.00 g (50.0 mmol) of acetic acid was added and heated to reflux for 5 hours. After standing to cool to room temperature, the mixture was filtered through celite to remove residual zinc powder. The filtrate was concentrated under reduced pressure, diethyl ether was added, and the filtrate was washed with water to remove excess acetic acid. After concentration under reduced pressure, 6.35 g (yield 68%) of fluorine-containing diol (I-2) was obtained by column chromatography.

(B) Phosphate esterification-hydrocracking step:
(Scheme b1)
In a three-necked flask (300 mL) equipped with a dropping funnel, 2.85 g (2.91 mmol) of fluorinated diol (I-2), 30 mL of methylene chloride and 0.911 g (9.00 mmol) of triethylamine were added and stirred. Under ice / salt cooling, 2.53 g (9.00 mmol) of dibenzylchlorophosphite was added dropwise to the dropping funnel over 1 hour. Thereafter, the mixture was stirred at room temperature for 18 hours. After confirming disappearance of the fluorinated diol (I-2) by thin layer chromatography, 1.5 mL of 30% aqueous hydrogen peroxide was added and stirred for 1 hour.
A 1N aqueous sodium sulfite solution (60 mL) and diethyl ether (70 mL) were added, and the mixture was stirred and allowed to stand. Then, the organic layer was washed with water and then dried over anhydrous sodium sulfate. After sodium sulfate was filtered off and concentrated under reduced pressure, 2.09 g (yield 53%) of fluorine-containing phosphate ester precursor (I-3) was obtained by column chromatography.

(Scheme b2)
Using a pressure vessel (30 mL), under hydrogen pressure (10 atm), 5% palladium carbon 0.2 g in ethanol (5 mL) suspension, fluorine-containing phosphate ester derivative (I-3) 2.01 g (1.47 mmol) ) And stirred at room temperature for 2 days. After palladium carbon was filtered off, the filtrate was concentrated under reduced pressure to obtain 1.67 g (yield 97%, total yield 26.9%) of the desired fluorine-containing phosphate ester (I-4). Table 1 shows ¹ H-NMR data of the resulting fluorine-containing phosphate ester (I-4).

[Example 2]
Except for using 4-pentenal instead of 10-undecenal, 1.32 g (total yield: 23.2%) of fluorine-containing phosphate (II) was obtained in the same manner as in Example 1. Table 2 shows the ¹ H-NMR data of the obtained fluorine-containing phosphate (II).

[Comparative Example 1]
In a three-necked flask (200 mL) equipped with a condenser tube, 8.93 g (20.0 mmol) of perfluorohexyl iodide, 1.70 g (10.0 mmol) of 10-undecenol, 0.657 g of azobisisobutyronitrile. (4.00 mmol) was added, and the inside of the container was replaced with argon, followed by heating at 80 ° C. for 8 hours while stirring. The reaction mixture was dissolved in 100 ml of ethanol, 5.00 g (76.5 mmol) of zinc powder was added and stirred for 15 minutes, and then 3.00 g (50.0 mmol) of acetic acid was added and heated to reflux for 5 hours. After standing to cool to room temperature, the mixture was filtered through celite to remove residual zinc powder. The filtrate was concentrated under reduced pressure, diethyl ether was added, and the filtrate was washed with water to remove excess acetic acid. After concentration under reduced pressure, 4.04 g (yield 82%) of fluorinated alcohol (III-1) C ₆ F ₁₃ — (CH ₂ ) ₁₁ —OH was obtained by recrystallization in hexane.

In a three-necked flask (300 mL) equipped with a dropping funnel, 3.87 g (7.89 mmol) of fluorinated alcohol (III-1), 70 mL of methylene chloride, 2.42 g (24.0 mmol) of triethylamine were added and stirred. Under ice / salt cooling, 6.74 g (24.0 mmol) of dibenzylchlorophosphite was placed in the dropping funnel and added dropwise over 1 hour. Then, after stirring for 18 hours at room temperature and confirming disappearance of fluorinated alcohol (III-1) by thin layer chromatography, 3.0 mL of 30% aqueous hydrogen peroxide was added and stirred for 1 hour.
1N Aqueous sodium sulfite solution (120 mL) and diethyl ether (150 mL) were added, and the mixture was stirred and allowed to stand. Then, the organic layer was washed with water and then dried over anhydrous sodium sulfate. After sodium sulfate was filtered off and concentrated under reduced pressure, 3.67 g (yield 62%) of fluorine-containing phosphate ester precursor (III-2) was obtained by column chromatography.

2.25 g (3.00 mmol) of the fluorine-containing phosphate derivative (III-2) was added to a suspension of ethanol (10 mL) in a pressure vessel (30 mL) under hydrogen pressure (10 atm) and 5% palladium carbon 0.5 g. ) And stirred at room temperature for 2 days. After palladium carbon was filtered off, the filtrate was concentrated under reduced pressure to obtain 1.66 g (yield 97%, total yield 49.3%) of the desired fluorine-containing phosphate ester (III-3). Table 2 shows ¹ H-NMR data of the resulting fluorine-containing phosphate ester (III-3).

[Releasability test]
A release agent composition was prepared by dissolving 0.2 g of the fluorine-containing phosphate ester obtained in Examples / Comparative Examples in 9.8 g of metaxylene hexafluoride.
Using a spray gun (“Cup Gun W-101” manufactured by Iwata Co., Ltd .; caliber 1 mm), 10 g of the obtained release agent composition was used, and an iron mold (molded product shape: width 50 mm × 50 mm, height 40 mm, thickness 5 mm) Was applied to the inner wall of the box-like shape with the upper part of the open part and dried. The dry thickness of the film was 1.0 μm. 80 g of rubber raw material (EPDM rubber manufactured by Marubeni Techno Rubber Co., Ltd., EP 1) was placed in a mold and vulcanized at 170 ° C. for 5 minutes at 17 MPa. Then, the mold release performance was evaluated by measuring the load when the mold was opened. Thereafter, the same molding process was repeated without applying the release agent composition again, and the molding process was performed 25 times. The number of times when the load required for opening the mold was less than 30 N was determined as the number of times of release. The measurement results are shown in Table 4 below.

  From Table 4, the fluorine-containing phosphate ester of the present invention has a number of mold releasable times as compared with a phosphate ester having only one phosphate group and one perfluoroalkyl group in one molecule of Comparative Example 1. Many show that it has excellent continuous releasability.

  The fluorine-containing phosphate ester and salt thereof of the present invention are useful as a surface treatment agent such as a mold release agent, a metal surface treatment agent or a water / oil repellent treatment agent, a lubricant additive, or a surfactant.

Claims (4)

Fluorine-containing phosphate compound represented by the following general formula (1) or a salt thereof:

[Rf is each independently a perfluoroalkyl group having 6 or less carbon atoms; n is each independently an integer of 4 to 12].   A surface treatment agent comprising the fluorine-containing phosphate compound according to claim 1 or a salt thereof.   The surface treatment agent according to claim 2, wherein the fluorine-containing phosphate compound or a salt thereof is contained in an amount of 0.1 to 10.0% by weight based on the total weight of the surface treatment agent.   The surface treatment agent according to claim 2 or 3, wherein the surface treatment agent is a mold release agent, a metal surface treatment agent or a water / oil repellent treatment agent.