JP5510501B2 - Emulsion - Google Patents

Description

The present invention relates to an emulsion. More particularly, it relates to an emulsion of perfluoropolyether oil.

Polyfluoroalkylphosphonic acid esters are widely used as raw materials for synthesizing release agents. The mold release performance when used as a mold release agent is most easily manifested in compounds having 8 to 12 carbon atoms in the perfluoroalkyl group, and is particularly a C ₈ telomer compound.
CF ₃ (CF ₂ ) ₇ CH ₂ CH ₂ P (O) (OC ₂ H ₅ ) ₂
However, it is preferably used for this kind of application (see Patent Documents 1 to 4).

By the way, it has been reported that a telomer compound having a perfluoroalkyl group having 8 to 12 carbon atoms is biodegraded in the environment and converted into a compound having a relatively high bioaccumulation property and environmental concentration property. exposure and waste, the discharge, diffusion and the like are environmental concerns from the treated substrate or the like. In addition, compounds having a perfluoroalkyl group with 14 or more carbon atoms are very difficult to handle because of their physical and chemical properties, and are rarely used in practice.

  Furthermore, telomer compounds having a perfluoroalkyl group having 8 or more carbon atoms cannot avoid the generation or contamination of perfluorooctanoic acids having high bioaccumulation potential in the production process. For this reason, manufacturers of such telomer compounds are proceeding withdrawing from the production or replacing them with compounds having a perfluoroalkyl group having 6 or less carbon atoms.

On the other hand , in the compound having 6 or less carbon atoms in the perfluoroalkyl group, the orientation on the surface of the treated substrate is remarkably lowered, and the melting point, the glass transition point Tg, etc. are remarkably lower than the compound having 8 carbon atoms. It will be greatly affected by environmental conditions such as temperature, humidity, stress, and contact with organic solvents. Therefore, the required sufficient performance cannot be obtained, and the durability is also affected.

Aqueous mold release agent composition of the ammonium salt or amine salt and a polyether-modified organopolysiloxane is dissolved or dispersed in water perfluoroalkyl alkyl phosphonic acids have also been proposed (see Patent Document 5), also in this case Perfluorooctyl ethyl phosphonate is used, and it is said that a transparent release agent solution is obtained.

  Perfluoropolyether oils widely used as water and oil repellents and lubricants are excellent in water and oil repellency and lubricity, but lack compatibility with other compounds. Is limited.

  Perfluoropolyether oil is also used as a leather treatment agent by adding a greasing agent to the perfluoropolyether oil (see Patent Document 6). As the greasing agent, in a general description thereof, a phosphonic acid derivative having a fluoroalkyl group, a fluoroalkenyl group or a fluoroether group or an ammonium salt, an alkali metal salt or an alkaline earth metal salt thereof is used. However, the use ratio of the greasing agent is 10 to 0.5, preferably 5 to 1, with respect to the fluorinated oil.

Fluorine oil and greasing agent used in such a weight ratio are said to be tanned leather treated in the greasing process by a leather treating agent usually contained in the form of an emulsion. In the processing agent to be used, the average particle size of the emulsion is reduced in proportion to the amount of emulsifier used, and the stability over time is ensured. The product becomes hydrophilic and water repellency is lowered, and it is not possible to avoid a drop in mold release performance when this is used as a mold release agent (see Comparative Examples below).

  The present applicant has previously proposed a method for producing perfluoroalkylethylphosphonic acid by thermally decomposing or hydrolyzing perfluoroalkylethylphosphonic acid diester (see Patent Document 7). Since the perfluoroalkylethylphosphonic acid obtained here does not dissolve in an aqueous medium such as water, it cannot be used as an aqueous emulsifier solution.

On the other hand, perfluoropolyether oils, which enables use as a surface treatment agent by emulsifying, water- and oil-repellent, and can be applied to the release agent or the like. Moreover, by emulsifying, it can be applied to medical use and cosmetic use. For example, by blending into cosmetics, for example, by blending with lipstick, the effect of preventing the lipstick from being transferred to other places is exhibited.

However, in an emulsion as described in Patent Document 6, since a large excess of a greasing agent (ammonium salt or metal salt of perfluoroalkylalkylphosphonic acid) is used in combination with fluorine-based oil, leather is used. Even if it is suitable as a treatment method, when it is applied to an emulsion of perfluoropolyether oil , the properties of these compounds themselves are not sufficiently exhibited.

Japanese Examined Patent Publication No. 2-45572 Japanese Patent Publication No. 3-78244 Japanese Patent Publication No. 4-4923 Japanese Patent Publication No. 4-11366 Japanese Patent Publication No. 8-5063 Japanese Patent No. 3077231 JP 58-210096

An object of the present invention is to provide a perfluoropolyether oil emulsion using an emulsifier having a perfluoroalkyl group having a carbon number of 6 or less, which is said to have low bioaccumulation, and having excellent emulsification performance. It is in.

The object of the present invention is to provide a general formula
RfO [CF (CF ₃ ) CF ₂ O] _m Rf ′ (I)
(Wherein Rf and Rf ′ are perfluoro lower alkyl groups having 1 to 5 carbon atoms, and m is an integer of 2 to 200). formula
C _n F _{2n + 1} CH ₂ CH ₂ P (O) (OM ¹ ) (OM ² )
(Wherein, M ¹ is a hydrogen atom or a tri-ethylamino group, M ² is triethyl amino group, n represents an is an integer from 1 to 6) perfluoroalkylethyl phosphonic acid triethylamine salt 0.01 to 30 weight represented by Achieved by an emulsion formed with an aqueous solution containing parts.

Perfluoroalkylethyl phosphonic acid triethylamine salt emulsifier used in the present invention is a compound having a perfluoroalkyl group having 6 or less carbon atoms which bioaccumulation potential is said to lower, also because it has excellent emulsification performance , an emulsion consisting of a perfluoropolyether oil represented by the aqueous solution and the general formula of emulsifier [I] can form a stable emulsion.

Emulsions with perfluoropolyether oil are suitably used for applications such as surface treatment agents, mold release agents, and cosmetics due to their good emulsification stability .

Perfluoroalkylethylphosphonic acid triethylamine salt used as emulsifier
C _n F _{2n + 1} CH ₂ CH ₂ P (O) (OM ¹ ) (OM ² )
Perfluoroalkylethylphosphonic acid described in Patent Document 7
C _n F _{2n + 1} CH ₂ CH ₂ P (O) (OH) ₂
And triethylamine .

Triethylamine forms a mono-salt when used in equimolar amounts relative to perfluoroalkylethylphosphonic acid, and forms a di-salt when used in double molar amounts. Generally, it is used in the necessary theoretical number of moles or more, and when used in an equimolar amount or more and less than twice the molar amount, a mixture of a mono salt and a di salt is formed.

Perfluoroalkylethylphosphonic acid triethylamine salt is used as an aqueous solution dissolved in water.

The aqueous solution of the emulsifier is added to the perfluoropolyether oil in an amount of about 0.01 to 30 parts by weight, preferably about 0.1 to 15 parts by weight per 100 parts by weight of the perfluoropolyether oil, and emulsified. To form a perfluoropolyether oil emulsion. When the emulsifier is used in a proportion higher than this, the characteristics of the perfluoropolyether oil itself are not sufficiently exhibited. For the emulsification treatment, pre-emulsification is performed using a homogenizer or the like at a rotational speed of about 500 to 10,000 rpm, and further emulsified using a high-pressure homogenizer at a pressure of about 100 to 800 kgf / cm ² (about 9.8 to 78.4 MPa). Done.

The perfluoropolyether oil to be emulsified has a general formula
RfO [CF (CF ₃ ) CF ₂ O] _m Rf ′ (I)
The number average molecular weight Mn represented by is about 300 to 50000, preferably about 500 to 20000 . Here, Rf and Rf ′ are perfluoro lower alkyl groups having 1 to 5 carbon atoms such as a perfluoromethyl group and a perfluoroethyl group, and m is 2 to 200 . This by completely fluorinating the precursor produced by photooxidation polymerization of hexafluoropropene, or a hexafluoropropene oxide was subjected to anionic polymerization in the presence of cesium fluoride catalyst, resulting terminal -CF (CF ₃ ) It can be obtained by treating an acid fluoride compound having a COF group with a fluorine gas.

As this perfluoropolyether oil [I] , any value of kinematic viscosity can be used, but the lubricant is 5 to 2000 mm ² / sec (40 ° C), considering use under high temperature conditions. Those having a thickness of 100 to 1500 mm ² / sec (40 ° C.) are preferably used. In other words, those with about 5 mm ² / sec or less have a large evaporation amount and do not satisfy the condition of an evaporation amount of 1.5% or less stipulated in the JIS rolling bearing grease type 3 which is a standard for heat-resistant grease. Also, those with a kinematic viscosity of 2000 mm ² / sec or higher have a pour point (JIS K-2283) of 10 ° C or higher, and the bearing does not rotate at low temperature startup in the normal method. There is a need to.

Further, the perfluoropolyether oil emulsion is an aqueous solution diluted with water so that the solid content (perfluoropolyether oil) concentration is about 0.01 to 30% by weight, preferably about 0.05 to 10% by weight. When used as a surface treatment agent such as a water / oil repellent and a mold release agent, the emulsion exhibits good emulsification stability. When it is used as a mold release agent, it is applied to a molding die surface, and when it is applied to a substrate such as a molded product, it is used as an anti-sticking agent .

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

Example
(1) A 200 ml capacity equipped with a stirrer and a dripping device was charged into a reactor while keeping 50 g of water heated to 40 ° C. while keeping 2- (perfluorohexyl) ethylphosphonic acid (Unimatec CHEMINOX FHP). 2-OH) (5 g, 11.7 mmol) was added, then triethylamine ( 1.71 g, 16.9 mmol) was added, and the mixture was stirred for 1 hour to carry out a neutralization reaction. As a result, an aqueous solution (active ingredient concentration 8.9 % by weight) of 2- (perfluorohexyl) ethylphosphonic acid triethylamine salt at pH 8 was obtained [Emulsifier aqueous solution I].

This aqueous emulsifier solution I was added little by little in water, and the surface tension of the aqueous solution was measured. It had a critical micelle concentration [CMC] of 1.2 % by weight and a minimum surface tension of 27.7 mN / m. The surface tension was measured at 20 ° C. by the maximum bubble method using a SITA dynamic surface tension meter.

When stirring for 1 hour without adding triethylamine to 2- (perfluorohexyl) ethylphosphonic acid, the added 2- (perfluorohexyl) ethylphosphonic acid was separated without dissolving in water, Was not obtained.

(2) In a 1,000 ml reactor equipped with a stirrer and a dropping device, 231 g of water heated to 40 ° C. was charged while being kept there, and 169 g of the emulsifier aqueous solution I and the general formula
C ₃ F ₇ O [CF (CF ₃ ) CF ₂ O] _m C ₂ F ₅ (m: 2 to 100)
After adding 100 g (overall amount 500 g) of perfluoropolyether oil (NOK Kluber product BARRIERTA J 100 FLUID; kinematic viscosity (40 ° C.) 95 mm ² / sec) represented by the following, using a homogenizer at a rotational speed of 3000 rpm Preliminarily emulsify for 2 minutes, and further emulsify with a high pressure homogenizer (manufactured by Nippon Seiki Co., Ltd.) at a pressure of 600 kgf / cm ² (58.8 MPa) to obtain 100 parts by weight of perfluoropolyether oil emulsion A (perfluoropolyether oil). In contrast, 483 g (recovery rate 97%) of 15.0 parts by weight of triethylamine perfluoroalkylethylphosphonate was obtained.

The average particle diameter of the obtained perfluoropolyether oil emulsion A was 405 nm. The average particle size was measured by a dynamic light scattering method using a Nikkiso Microdrug Particle Size Distribution Analyzer UPA150.

Comparative example
In the examples, when the amount of water was changed to 385 g and 15 g of 2- (perfluorohexyl) ethylphosphonic acid was used in place of the emulsifier aqueous solution I, the liquid mixture immediately caused liquid-liquid separation, and an emulsion was formed. There wasn't.

Claims (4)

General formula
RfO [CF (CF ₃ ) CF ₂ O] _m Rf ′ (I)
(Wherein Rf and Rf ′ are perfluoro lower alkyl groups having 1 to 5 carbon atoms, and m is an integer of 2 to 200). formula
C _n F _{2n + 1} CH ₂ CH ₂ P (O) (OM ¹ ) (OM ² )
(Wherein, M ¹ is a hydrogen atom or a tri-ethylamino group, M ² is triethyl amino group, n represents an is an integer from 1 to 6) perfluoroalkylethyl phosphonic acid triethylamine salt 0.01 to 30 weight represented by An emulsion formed using an aqueous solution containing parts. The emulsion according to claim 1, wherein the emulsifier is used as an aqueous solution. A surface treatment agent comprising an aqueous solution obtained by further diluting the perfluoropolyether oil emulsion according to claim 1 with water. The surface treating agent according to claim 3, which is used as a water / oil repellent or a release agent.