JPH0443941A - Method and device for evaluating phase inversion of emulsion - Google Patents

Abstract

PURPOSE:To evaluate the phase inverting process of the emulsion objectively by sliding two movable and fixed plates relatively across a body to be tested and evaluating the phase inversion of the emulsion from the ratio of the direction of the slide on the fixed plate and the speed of the movable plate. CONSTITUTION:The emulsion phase inversion evaluation device consists of the movable plate 1 which moves reciprocally at the constant speed, the fixed plate 2 which sandwiches the sample with the movable plate 1, a sensor 3 which measures a force applied to the fixed plate 2 from the sample, an air blowing fan 4 which sends air to the surface of the sample to accelerate the vaporization of a volatile component in the sample, a spring mechanism 5 which applies constant pressure to the fixed plate 2, and an elevation mechanism 6 for moving up and down the fixed plate 2. In this constitution, the sample is sandwiched between the fixed plate 2 and movable plate 1 and measured. The process of the phase inversion is found from the start time of a decrease in the force amplitude and the variation width.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method and apparatus for evaluating phase inversion processes of emulsions.

(Prior Art and Problems to be Solved by the Invention) Emulsions, which are coexisting bodies of immiscible liquids such as oil and water, range from familiar foods such as milk, mayonnaise, and cream, to paints, and cosmetic creams. It is used in a wide range of industrial products such as adhesives, pharmaceuticals, agricultural chemicals, and asphalt (civil engineering material).

Generally, if an emulsion is left undisturbed, the dispersed particles will separate from each other through unstable processes such as creaming, agglomeration, and coalescence, and will separate into two liquids.

When trying to use emulsions in industry, it is important not only to ensure that they are chemically stable, but also to evaluate them from the viewpoint of mechanical properties such as hardness, fluidity, and deformation.

Steady state viscosity can be measured by a viscometer,
In the case of emulsions whose viscosity changes during use, whether the emulsion is good or bad in use depends on sensory tests based on the senses of experienced panelists.

Although human sense organs are highly sensitive, they are greatly affected by health conditions, individual differences, the environment, etc., and have the drawback of large variations in data and lack of reliability.

Therefore, an object of the present invention is to provide a method and apparatus that can objectively evaluate the phase inversion process of an emulsion, which could not be quantitatively measured using a conventional viscometer.

(Means for solving the problem) The above problem consists of a movable plate that reciprocates in an in-plane direction,
A fixed plate spaced apart from the movable plate at a predetermined distance, a sensor means for detecting a force applied in the in-plane direction of the fixed plate, and an emulsion specimen supplied between the movable plate and the fixed plate. and fan means for continuously changing the component composition,
The two plates are slid relative to each other with the specimen in between, and the phase change of the emulsion is evaluated from the ratio of the sliding direction force applied to the fixed plate and the speed of the movable plate.
This problem is solved by a phase inversion evaluation device characterized by the following.

According to another aspect of the present invention, an emulsion specimen is supplied between two plates spaced apart from each other by a certain distance, and while the composition of the emulsion specimen is continuously changed by blowing air onto the emulsion specimen, A phase inversion evaluation characterized in that the two plates are slid relative to each other with a specimen in between, and the phase inversion of the emulsion is evaluated from the ratio of the sliding direction force applied to the plates and the sliding motion speed. provide a method.

(Example) In order to explain the method of the present invention in detail, an example performed using an apparatus for carrying out the method of the present invention will be described.

FIG. 1 shows an example of the configuration of the apparatus of the present invention.

The present invention consists of a movable plate 1 that reciprocates at a constant speed, a fixed plate 2 that sandwiches a sample with the movable plate 1, a sensor 3 that measures the force exerted by the sample on the fixed plate 2, and a sensor 3 that measures the force applied by the sample to the sample surface. It consists of a blower fan 4 for promoting the evaporation of volatile components within, a spring mechanism 5 for applying a constant pressure to the fixed plate 2, and a lifting mechanism 6 for raising and lowering the fixed plate 2.

FIG. 2 shows the movement of each part when a sample on the plate and block surface of one part of the sensor is sandwiched between the fixed plate 2 and the movable plate 1 and measured in the present invention. Figure 2 (A) shows the displacement of the movable plate 1, Figure 2 (B)
) shows the vertical movement of the fixed plate 2, and FIG. 2(C) shows the force generated on the fixed plate 2. FIG. 3 shows the result of plotting this force amplitude against the logarithm of time. The process of phase inversion can be understood from the start time and change width of this force amplitude.

The two plates that can be used in the present invention have chemical stability, impact resistance (thermal and mechanical), and abrasion resistance in terms of materials, and are also made of materials and surface morphology that are suitable for the specimen and evaluation purpose. It is desirable to have one.

Although metals, ceramics, and polymers can be used alone as materials, it is preferable to use them in combination.

Metals include aluminum, stainless steel, copper, etc. Ceramics include glass, quartz, etc. Polymers include polyethylene, polystyrene, polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polymethyl methacrylate, polyethyl methacrylate, and polyacetic acid. Vinyl compounds and addition polymers of vinyl compounds such as vinyl, polyacrylonitrile, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, vinylidene fluoride/trifluoroethylene copolymer, ethylene/tetrafluoroethylene copolymer, vinylidene fluoride Copolymers of vinyl compounds or fluorine compounds such as /tetrafluoroethylene copolymers, vinylidene cyanide/vinyl acetate copolymers, compounds containing fluorine such as polytrifluoroethylene, polytetrafluoroethylene, polyhexafluoropropylene, nylon 6. Polyamide such as nylon 66, polyimide, polyurethane, polyester such as polyethylene terephthalate, polyester,
Polyethers such as polycarbonate, polyoxymethylene, polyethylene oxide, polypropylene oxide,
Further, thermosetting resins such as unsaturated polyester, epoxy, Bakelite, etc. can be mentioned.

More specifically, the metal plate can be used as it is after being cut, but it can also be used after being subjected to treatments such as vapor deposition or plating with different metals. The cut resin can be used as is, but it can also be used after chemical etching, corona treatment, or plasma treatment to change the chemical properties of the surface. Films that can be formed into films by casting or extrusion can also be used as they are, but alkali metal solution treatment, alkali metal amalgam method, chemical etching such as electrolytic etching, silver/
It is possible to use materials that have been subjected to metal vapor deposition such as aluminum, vacuum discharge treatment, (reverse) sputter etching, corona treatment, graft treatment, plasma treatment, sandblasting treatment, or the like.

Among these, particularly suitable plate materials include fluorine-based films that have been chemically etched or (reversely) sputtered, taking into consideration chemical stability, impact resistance (thermal and mechanical), and abrasion resistance.

Example 1 An untreated tetrafluoroethylene film (hereinafter referred to as PTFE) having a thickness of 15 μm was reverse sputtered using a sputtering device to obtain a sputter etched film. As a result of SEM observation, the surface of the sputtered film was uniformly raised (0.5 to 1
．． 0μm). The membrane surface showed hydrophilicity.

This membrane was attached to the plate of the present apparatus, and the phase inversion process of a cosmetic cream (commercial product M), which undergoes a phase change from an oil-in-water type to a water-in-oil type, was measured at room temperature under ventilation conditions.

At the same time, during the measurement process, the emulsion extracted from the sample stage was observed using an optical microscope. The results are shown in Figure 4.

In Figure 4, the horizontal axis is the number of times the plate slides (logN
), and the vertical axis indicates shear force (logf). The sliding speed of the plate is 9 reciprocations per minute, and one measurement is 230 reciprocations.
Finishes in about 25 minutes. In the figure, a, b, c, d, and e indicate the emulsion collection points in the measurement process.

In FIG. 4, it is an oil-in-water emulsion at time a (at the start of measurement). At point b, it is an oil-in-water emulsion, which is a partially di-water-in-water-in-oil-in-complex emulsion.

At points c and d, there is a phase inversion process from an oil-in-water emulsion to a water-in-oil emulsion. At time e, the phase has completely changed to a water-in-oil emulsion. As is clear from the figure, the specimen is of a phase inversion type from an oil-in-water type to a water-in-oil type, and as the measurement begins (a), the oil particles become unstable as they aggregate and coalesce, gradually decreasing the viscosity. It increases (b). It can be seen that as the phase inversion progresses further and the phase changes from oil-in-water to water-in-oil, water particles become dispersed in the oil phase that develops like an oil film. At this stage, the viscosity increases rapidly (C).

It can be seen that as the phase inversion progresses further, the water particles become finer and finer. At this stage, the viscosity begins to decrease (d
). The final result is a water-in-oil emulsion with water particles dispersed in the oil phase. At this stage, no major viscosity change occurs (e).

Example 2 An untreated PTFE film with a thickness of 15 μm was treated with a complex compound solution made from a tetrahydrofuran solution of naphthalene and metallic sodium and washed with water to obtain a chemically etched film. As a result of SEM observation, no remarkable change was observed on the etched surface. The membrane surface changes color from white to brown. The treated surface showed hydrophilicity. This membrane was attached to the plate part, and using the same experimental method as in Example 1, this measuring device was used to measure different types of cosmetics, as well as creams with a feeling of use and creams with a bad feeling for which the sensory test results were known by five panelists. The measured data was compared with the feel data of Nokuneler. All creams are oil-in-water type.

Table 1 shows the sensory test results for two types of nutritional creams (commercial products A and B) and cleansing emulsion (commercial products C and D), and the results of measurement using the apparatus are shown in FIGS. 5 and 6. All specimens were oil-in-water emulsions.

As is clear from FIG. 5, FIG. 6, and Table 1, there is a clear difference in the measurement charts of the creams with good and poor feeling of use. In addition, good agreement was observed with the tactile sensation chart of the female panelist, indicating that changes in perceived firmness were well reproduced. As described above, this measuring device is capable of objectively evaluating the phase inversion process of an emulsion, which could not be quantitatively measured using a conventional viscometer.

Example 3 In the same manner as in Example 2, a PTFE film was treated with a liquid ammonium solution of metallic sodium to obtain a chemically etched film. Further, a porous film was obtained by hot stretching at a high temperature. Using a chemically etched film, a porous film, an untreated film, and a sputtered film obtained in Example 1, the phase inversion process of a nutritional cream (commercial product A) was measured under air blowing. The results are shown in FIG.

In FIG. 7, the untreated PTFE, sputtered PTFE and porous film surfaces are -F, and the chemically etched film surface is -C. Furthermore, while the surfaces of untreated PTFE and chemically etched films are substantially smooth, the sputtered film has raised naps of 1 to 1.5 μm, and the porous film has pores of 2 μm in diameter.

From FIG. 7, it can be seen that the phase inversion behavior of an emulsion is greatly influenced by the component composition and surface structure of the material surface. This means that the overall phase inversion greatly depends on the composition and morphology of the emulsion formed at the initial stage of phase inversion.

Example 4 In Example 3, the phase inversion process of a nutritional cream (commercial product B) was measured under air blowing. The results are shown in FIG.

Example 5 Using the chemically etched PTFE film obtained in Example 2, the phase inversion process of a cleansing cream (commercial product E) was measured under air blowing and no air conditions. The results are shown in Figure 9.

Example 6 Unsaturated polyester resin (oxidation 13, styrene content 4
100%) of an aqueous solution in which a certain amount of triethanolamine (hereinafter referred to as TEA) was dissolved while stirring.
An emulsion was prepared by adding a small amount of At this time, T
The amount of EA added is a) 0 for unsaturated polyester resin.
．． 10 mmol/gr) 0.20 mmol/gr
c) 0.30 mmol/gr d) 0.40 m
mol/gr was used.

In the method of Example 1, the chemically etched PTFE film obtained in Example 2 was attached to the plate part, and the phase inversion process of the emulsion was measured, and the change in the morphology of the emulsion was observed using an optical microscope. The measurement results are shown in Figures 10 to 1.
Shown in Figure 3.

a) When TEA is added at 0.10 mmol/gr,
The obtained emulsion had non-uniform polyester particles but was of water-in-oil type (hereinafter referred to as W10).

Immediately after starting the measurement, the emulsion cohesively failed (Figure 10).

b) When 0.20 mmof/gr of TEA is added, the resulting emulsion is oil-in-water type (hereinafter referred to as 0/W), and the polyester particles are uniform in size with a diameter of approximately 1 μm, but when starting the measurement After passing through the unstable W2O type, it rapidly aggregated and was destroyed (Fig. 11).

c) When 0.30 mmol/gr of TEA is added, the polyester salt dissolves in the aqueous phase to form micelles, resulting in a partially W10/W double emulsion.
/W type emulsion. When the measurement was started, the polyester particles became a uniform O/W type with a diameter of about 1 μm, and then rapidly agglomerated and broke through the O/W type where the polyester particles were uneven in size (Figure 12). .

d) When 0.40 mmol/gr of TEA was added, the resulting emulsion was of the W2O type and the water particles were emulsified to a size of 1 μm or less. When measurement begins, a W10/W type double emulsion is partially formed, and phase inversion from W2O type to O/W type occurs. After that, W again from 0/W type
Although the phase inverted to 2O type, this W10 type emulsion was non-uniform and rapidly aggregated and destroyed (Figure 13).

From the measurement results of this device and the optical microscope observation results, it can be seen that even if the same emulsifier is used, three types of emulsions can be formed depending on the concentration, which is clearly reflected in the change in the viscosity of the system. When water becomes the continuous phase 0/W type, the viscosity decreases rapidly,
It can be seen that the viscosity increases when the phase changes to W2O type.

Example 7 While stirring 100 parts of heavy oil A, 15 parts of cement supernatant liquid was shear-mixed to obtain an emulsion fuel.

Incidentally, the cement supernatant liquid was prepared by adding 5 parts of cement powder to 100 parts of water, mixing and stirring, and allowing the mixture to stand.Then, the supernatant liquid was used. In the method of Example 1, the temperature of the stage of the specimen was changed to 25° C. and 70° C., and the changes in the state of the emulsion were observed using an optical microscope.

The results are shown in FIG. The emulsion when formed is W2O
The water particle size was uniform in the mold, ranging from 5 to 8 μm. Even after 50 minutes of measurement, the emulsion remained stable with no change in form.

(Effects of the Invention) The method and device of the present invention enable continuous measurement of changes in the mechanical properties of a system whose composition ratio changes over time, making it possible to perform objective evaluation in place of conventional human sensory evaluation. .

[Brief explanation of the drawing]

Fig. 1 shows a configuration example of the device of the present invention, Fig. 2 is a principle diagram for evaluating the phase inversion process of the present invention, and Fig. 3 shows the relationship between force amplitude and time of the device of the present invention. FIG. 4 is a comparison diagram of the measurement results of cosmetic cream measured using the device of the present invention and the microscopic observation results, and the photograph shows the particle structure of the emulsion observed with an optical microscope. , FIG. 5 is a comparison diagram of the phase inversion process of a nutritious cream with a good feeling of use (commercial product A) and a nutritious cream with a poor feeling of use (commercial product B) measured using the device of the present invention, and FIG. FIG. 7 is a comparative diagram of the phase inversion process of a cleansing emulsion with a good feeling of use (commercial product C) and a cleansing emulsion with a poor feeling of use (commercial product D) measured using the apparatus of the present invention. Figure 8 shows the effect of plate material on the phase inversion behavior of nutritional cream (commercial product A) measured using the device of the present invention. FIG. 9 is a diagram showing the effect of plate material on behavior; FIG. 9 is a comparison diagram of blown air and no air flow on the phase inversion behavior of cleansing cream (commercial product E) measured using the device of the present invention; Figures 10 to 13 are diagrams showing the effect of TEA addition on the phase inversion behavior of an unsaturated polyester resin emulsion measured using the apparatus of the present invention, and Figure 14 is a diagram showing the effect of TEA addition on the phase inversion behavior of an unsaturated polyester resin emulsion measured using the apparatus of the present invention. FIG. 3 is a diagram showing the effect of plate temperature on the measured phase inversion behavior of emulsion fuel. Figure 2 Figure 1 Figure 3 og N Figure 1 1 ■ og N Figure 1 3 ■ og N Figure 1 2 ■ 1 og N Figure 14

Claims (4)

[Claims] (1) A movable plate that reciprocates in the in-plane direction, a fixed plate spaced apart from the movable plate at a certain distance, a sensor means for detecting a force applied in the in-plane direction of the fixed plate, and the movable plate. and a fan means for continuously changing the composition of the emulsion specimen by blowing air to the emulsion specimen supplied between the fixed plate, and the two plates are slid relative to each other with the specimen in between, A phase change evaluation device, characterized in that the phase change of the emulsion is evaluated from the ratio of the force in the sliding direction applied to the fixed plate and the speed of the movable plate. (2) Adjust the temperature of the movable plate from -20℃ to 100℃.
2. The apparatus according to claim 1, further comprising temperature control means for selectively setting or changing the temperature within a range of .degree. (3) A membrane member having a component composition and surface structure selected according to the component composition, form, and evaluation purpose of the specimen is attached to the opposing surfaces of the two plates.
The apparatus according to claim 1 or 2, characterized in that: (4) Supply the emulsion specimen between two plates separated by a certain distance, and while continuously changing the composition of the emulsion specimen by blowing air to the emulsion specimen, insert the two plates with the specimen in between. A method for evaluating phase inversion, characterized in that the phase inversion of an emulsion is evaluated from the ratio of the force in the sliding direction applied to the plate and the speed of sliding motion by relative sliding.