JPS6027003B2 - Magnetic-responsive display article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to color displays and in particular to shutter elements of color displays that do not by themselves qualify as displays.
ents).

The color display of the present invention operates by variable information underlying the surface shutter layer of the display article in the form of an image or in a contrasting shade (h). The invention particularly relates to a magnetically operated substantially two-dimensional shutter to produce a reversible and variable degree of transparency or translucency.

The present invention particularly relates to an improved shutter display that increases visual differentiation by providing a contrasting coloration when comparing the shutter layer to the underlying substrate. The present invention relates to a shutter display having such a distinguishing tint color. U.S. Pat. No. 2,971,916, issued on February 14, 1961, discloses that magnetic particles are dispersed in a pongee-like liquid, encapsulated in microcapsules, and the capsules are coated on the magnetized portion of a magnetic sheet. However, it is disclosed that the capsule is finally destroyed by pressure, and as a result, the magnetic particles are transferred to the receiving sheet.

U.S. Patent No. 322131 issued on November 30, 1963
No. 5 uses iron flakes as a desirable magnetic material that has the shutter effect and is dispersed in the oil contained in the microcapsules used in the display.
) details a magnetically responsive display using

The patented display uses magnetic particles that are oriented in response to an effective magnetic force applied to the selected portion to create an appearance between the selected portion and the non-selected portion using a method that increases or decreases the transmission of light. represents the difference between However, the patent does not discuss the effects of color contrast or the use of colorants with respect to the various elements of the capsule, including the display base material and binder film. 1967
U.S. Pat. No. 3,320,523, issued May 16, 2006, discloses a magnetic field detector that includes dry emulsion coating of magnetic material in an aqueous medium.

the magnetic particles are arranged to varying degrees at varying magnetic field strengths;
The arrangement is revealed by changes in the reflection of the projected light.
However, it does not discuss the effect of contrast in hue or the suitability of coloring materials. U.S. Pat. However, this display used a coating of mobile magnetic particles in the substrate layer, and the coating was of such a thickness that all projected light on the coating was completely absorbed without being reflected from the magnetic particles. Therefore, light does not completely pass through the coating in any mode of particle arrangement. The shutter effect is then completely eliminated and therefore no mention can be made of the combined effect of the various shades provided in the substrate layer or the coating. U.S. Pat. No. 3,673,597, issued on June 27, 1972, discloses a magnetically responsive display that utilizes coatings of microcapsules containing light reflective pigments and magnetic flakes in a metastable dispersion medium. Contains.

Once melted, the metastable medium is the microphone. Permanently position the flakes and pigments in the capsule. Projected light on the display appears reflected from the flakes or from the pigment. The contents of the microcapsules do not transmit the projected light and either reflect or absorb it. A magnetically responsive display, which operates by reflecting projected light and uses a coating of mobile magnetic flake particles as a reflector, is a display in which the mobile magnetic flake particles are uniformly coated so as to significantly reflect the projected light. It becomes a “reflective type” when arranged in When the magnetic particles are arranged in such a way that the projected light is transmitted and not reflected, the particles are generally "absorbing," in which case the coating is thick enough to penetrate deep into the coating without coming out of the coating. It is absorbed and captured by internal reflection between particles. “
Transmissive type is indicated when the coating is not so thick that the non-reflective projected light is absorbed by particles below the surface. The magnetic particles are arranged so that the projected light is transmitted and the rays are The "transmission type" is exhibited when the concentration of particles below the surface is low enough to emerge from the coating.Prior art magneto-responsive displays have generally been unsatisfactory for at least two reasons.

First, displays using such high magnetic particle concentrations and thick coatings that all light that enters the coating and is not reflected from it is absorbed within the coating, producing a black display image. These thick "ray-trapping" coatings do not allow adequate light transmission to take advantage of the contrast provided by the substrate layer. Such coatings are generally expensive because they require multiple materials. Additionally, relatively strong signal-like magnetic fields are required to properly align large amounts of magnetic material and provide optimal imaging. Second, shutter-type displays, which do not use colorant components and the presence of a small amount of magnetic material, generally have weak visual contrast between reflective and absorptive or transmissive types, and there is no difference in hue shown between each type. Met. Additionally, to maximize the contrast of a display that does not have the advantage of different shades between types, the alignment of the magnetic material needed to be nearly perfect. The present invention significantly improves magnetically responsive displays by providing a shutter display with enhanced contrast between reflective and transmissive types through the use of colorants in the coating with magnetic particles.

Also, the improvement is that a coloring material is provided in the base material,
Colorants may also be used in the film-forming matrix binder present in the paint or overcoat. The colorant may be dispersed or dissolved; if dissolved, it is considered a molecular dispersion. One object of the present invention is to provide an improved magnetically responsive obscurant with increased visual contrast using a colorant as the element in contact with the magnetically responsive material.
bscmant) to provide a shutter display.

In addition, it is an object of the present invention to provide an improved shutter having microcapsules containing a colored village as a visual contrast enhancer and an oily dispersion of magnetic particles as a reflective element. Another object of the present invention is to provide an improved shutter having a number of microcapsules contained and arranged in a film, wherein the shutter has a visual appearance between transmissive and reflective types due to the arrangement of magnetic particles. This shows a remarkable contrast.

Another object of the invention is to provide a display having an improved shutter with high transmission properties in a film having microcapsules containing a colorant either in the wall of the microcapsules or in the microcapsules, wherein the microcapsules are The shutter is in contact (at least partially) with an underlying substrate having a hue that contrasts with the hue of the colorant in the microcapsules, which is present in the film in such a quantity that it virtually overlaps with neighboring microcapsules. In addition, it is a further object of the present invention to have a clear contrast in color in terms of the difference between reflective and transmissive types, and to make the capsules within a critical mass suitable for the amount of magnetic material and the size of the capsule. The purpose is to provide a shutter using capsule film.

The article of the invention is essentially a two-dimensional shutter capable of reversibility and a clear, variable display.

The article is magnetically operable and consists of a binder enriched with microcapsules containing a dispersion of color particles and magnetic material in a liquid medium. The magnetic material is generally in the form of flakes, mobile and free to move in the liquid medium in the microcapsules. A magnetic field near the capsule's film aligns the magnetic flakes. The plane on which particle alignment occurs reflects the projected light when parallel to the plane of the flake film, and transmits the projected light when the flake is perpendicular to the plane of the film. A key feature of the article of the invention is the use of color villages and different shades to improve the visual contrast between the transmissive and reflective versions of the shutter display element. In this application, the term "coloring material" means a colored substance, and the visual impression of the substance is defined as a "hue." The use of color villages and their different shades is achieved by providing a color village in a dispersion of encapsulated magnetic particles, and when the alignment of the magnetic particles is parallel to the substrate display surface, the shade of the encapsulated colorant is displayed. The present invention relates to providing a colorant on a display surface of a substrate such that when the magnetic particles are aligned perpendicularly to the surface of the substrate, the hue of the surface of the substrate is indicated. The proper concentration and density of magnetic particles is critical to the success of the article. The microcapsules are generally substantially spherical and range in size from about 5 to about 1000 microns (or slightly larger) in average diameter.

The shape of the spherical capsule is important to ensure that the magnetic particles move within the capsule. The size of the capsule is also related to the mobility of the magnetic particles. The longest part of the magnetic particle must not be so large relative to the size of the capsule that the mobility of the particle within the capsule is impaired. Too large magnetic particles restrict its mobility, while too small particles tend to lose its flaky properties. The capsule wall material is generally a film-forming polymeric material or combination of materials that does not affect or dissolve the materials within the capsule, and is substantially permeable to allow operation of the present invention.

Examples of suitable materials include those commonly used to form capsules for other purposes: natural materials such as gelatin and gum arabic; poly(acrylic acid), poly(methacrylic acid), poly(vinyl synthetic polymeric materials such as poly(methyl vinyl ether-co-monohydric maleic anhydride) and poly(styrene-co-mono-maleic anhydride) (hydrolysed and non-hydrolysed). Combined. The encapsulating liquid is generally an oily material that is substantially insoluble in water, since suitable capsule wall materials are usually water soluble. However, organic solvent soluble polymers can also be used in the capsules of the present invention, provided there are no adverse effects between the capsule wall and the capsule contents. The capsule-containing liquid is also preferably oily and water-resistant, as described above.

Exemplary materials include key oils and vegetable oils, including volatile liquids such as benzene, toluene and cyclohexane and non-volatile liquids such as chlorinated biphenyls and peanut oil. Depending on the choice of capsule wall material, hydrophobic or aqueous capsule contents may also be used. It should be understood that combinations of liquids may also be used. The collusive liquid acts as a dispersion medium for the colorant and mobile magnetic particles. The success of the present invention is dependent on the mobility of the magnetic particles in a magnetic field, and the containing dispersion medium is within the range of about 1 to about 1000 centipoise or perhaps slightly higher, preferably within the range of about 5 to 30 centipoise, compared to It was found that the viscosity should be unaffected by the target temperature. A dispersion medium that is too thick will respond slowly to the magnetic field, while a dispersion medium that is too low in viscosity will provide an unstable shutter. The magnetic particles should be flakes, discs, plates or leaves in nature.

The particles have an average longest length ranging from about 1 to about 40 microns and an average thickness of about 0.5 microns. The “flake degree” of the particles is referred to as the “aspect ratio”.
Stated in quantities known as. Aspect ratio is the ratio of the surface area of one average flake side to the cross-sectional area of the average flake, and the aspect ratio of suitable magnetic particles can be between about 5 and 100, preferably between about 5 and 40. be. It should be stated that effective shutter operation requires that the projected light be completely transmitted through the shutter element without being absorbed. It seems that as the aspect ratio of the magnetic particles increases, more of the projected light passes through the shutter film in the transmission type. The magnetic particles may be iron, especially carbonyl iron, nickel, stainless steel and other alloys and other paramagnetic materials. The magnetic particles may be non-magnetic flakes coated with or otherwise combined with a magnetic material to provide magnetic responsiveness. The colorant is molecularly dispersed (dissolved) in the dispersion medium.
Although preferred, insoluble colorants are also effective if finely dispersed.

The purpose of the colorant is to increase the visual contrast between the projected light reflected from the capsule coating colorant and the projected light reflected from a substrate of a different shade than the colorant. A finely dispersed colorant scatters projected light more than a molecularly dispersed colorant. The average particle size of the undissolved colorant should not exceed about 1 micron, and the final undissolved colorant particle size is preferably about 0.1 to 0.5 micron. An example of a suitable color village is the following product name: Hilton Depis Chemical Company/Guni, Cincinnati, Ohio (Hilbn).
Dasis Chemical Company, Cinc
Oil Red Hidaco 20-, a dye sold by Innatj, 0hio)
6051: Oil Yellow Hidako
Hidaco) 20-4434: Oil Orange Hidaco (OilOrangeHidaco) 20-5015:
Western Solvent and Chemical Company, Romulus, Michigan (Westem
Solvent and Chemicals Com
Oil Yellow 30, a dye sold by Pany, Rom Mountain US, Michigan). −
AR15138: Oil Yellow 151137: Oil Yellow 10SI5679: E, I, DuPont de Nemours & Coboration under the following product name
Wilmington, Delaware (E.1. duPontd)
e Nemou Dai & Co. , Wilmington
Oil Yellow NB (also known as Solvent Yellow 50 P-Diethylaminoazobenzene - Color Index 11021): Oil Blue A, sold by Hilton-Davis Chemical Company under the trade name The pigment, permanent red. 5-17-F-
102: Phthalocyanine green, blue shudder, 5
There are -65 and F-41. The capsules can be manufactured by any convenient method already disclosed in the prior art.

The capsule manufacturing method for the present invention is not part of the present invention. A preferred method of manufacturing the capsules is as follows: September 1, 1967
U.S. Patent No. 3 issued on April 1, 1969, respectively.
It is disclosed in I No. 1466 and No. 3436355. Depending on the particular concentration to be maintained of magnetic particles in the shutter film, the following concentrations and volumes are preferably used in combination with other conditions: the capsules contain a liquid capsule core material dispersion of about 50 to about 95 Preferably, the liquid capsule core material should contain from about 5 to about 60% by weight of magnetic particles, and in addition preferably from about 1 to about 20% by weight of magnetic particles. 〈is 2 to 1
% by weight of colorant. To create a cohesive and effective shutter, the core capsule is held in a film formed from a polymeric binder material.

the binder material does not interfere with the transmission of light between the capsules;
It also serves as an adhesive between the capsule and the base. The binder material can be dissolved in any solvent used to disperse the capsules. The only requirement for the solvent is that it not have an adverse effect on the capsule wall material and at the same time dissolve the binder material. Of course, the binder material must dry as a substantially transparent film.
When using an aqueous solvent to disperse the capsules,
Binder materials such as starch, guar gum, gum arabic, polyvinyl alcohol, gelatin, carboxymethyl cellulose, water-soluble acrylate polymers, etc. are suitable, and polymers such as acrylates, copolymers, etc. Latex paint systems are also suitable. When using an organic solvent, suitable binder materials include polystyrene and polystyrene copolymers, polyvinyl acetate and its copolymers, organic solvent soluble acrylate polymers and copolymers, nitrocellulose, ethylcellulose, polybutadiene, polyurethane, etc. There is. In short, any substantially transparent polymeric material that meets the above requirements can be used as a binder. The dry film from the binder material and capsule is the shutter of the present invention.

The film is constructed such that when the magnetic particles are aligned parallel to the film, they substantially block the transmission of the projected light, and when the magnetic particles are aligned perpendicular to the film, the projected light is substantially transmitted. It must be done. To produce a film in this manner, the capsules must be present in the film in such an amount that adjacent capsules are in virtual contact with each other, and the concentration of magnetic flake particles in the film must be The total side grain area should be about 1 to 10 times the shutter area covered by the film, preferably 1.5 to 4.73 parts. "Flat grain area" is the surface area of one side of each grain. I don't fully understand the reason, but
is the total flat side grain area relative to the shutter film area.
'Covera bag retjo' is characterized by irregularities in particle shape, imperfections in the film formation, imperfect alignment of the particles when reflective and flakes in some capsules. is clearly larger than 1 due to the possibility of incomplete dispersion of . The above idea is that when the shutter is a reflective type, the individual magnetic particles need to overlap to some extent, but when the shutter is a transmissive type, care must be taken not to make the concentration of magnetic particles so high that the projected light is absorbed. There must be. Measurement of the planar area of magnetic particles involves floating a known amount of the magnetic flake particles on a water surface under carefully controlled conditions and then measuring the covered surface to calculate the surface shielded per unit amount of particles. This can be done by measuring.

Detailed information on how to determine the area of particle planes can be found in “Aluminum Paints and Powders” by J. Naedward and R.I. Uley, Reinhold Publishing Company, New York (
1959 King) on pages 18-22. The film can be used with or without adhesion to a substrate display surface having a contrasting tint.

In any event, the shutter film is used in combination with an underlying surface of at least some degree of different tint. The shutter film can be formed by coating a substrate surface (regular or irregular) with a dispersion of the capsules in a liquid solution of a binder material.
The painted dispersion is then dried, creating a thin film of capsules encapsulated in a binder material, conforming and adhering to the substrate surface. An example of a regular substrate surface is a plastic film of polyethylene terephthalate. An example of an irregular substrate surface is paper or other fibrous material (bound or unbound). Gross irregularities exhibited by the surface of embossed, molded or otherwise made articles are also included within the meaning of regular or irregular surfaces. The shutter film can be used in combination with a different shade of underlying surface, with the shutter placed directly below the surface in contact but without bushing.

This method is not preferred as it requires substantial contact between the film and the underlying surface for satisfactory operation. As a method for coating the composition, the thickness of the coating can be sufficiently controlled;
Any coating method that allows adjustment of the concentration of magnetic particles in the shutter film is therefore suitable.

Bar-draw-down on small surfaces
For large surfaces, spray, air knife, revere rolls are commonly used.
), extrusion, curtain (cmbin), etc. can be used as coating methods. The visual response of the coating of the present invention as a function of the coating weight used to make the magnetically responsive display is described with reference to various figures. The coating weight is “active (
active)'' refers to the coating weight and does not contain binder substances. The "active" coating weight is a 25 x 50 inch (330 square foot) series of dry coated capsules and pounds of capsule contents. Schematics were made from the coatings and displays produced in Examples 1 and 2 of the invention, generally relating to the shutter and the colorant effects of the substrate of the invention. In these examples, the colored capsules are yellow in color and the underlying substrate is red in color. Figure 1 shows the active coating weight and the Hunter color light reflection value (Hunter color light reflection value) on the “a” chromaticity axis (red → green) for reflective and transmissive display coatings.
This shows the relationship between Meval and Meval.

[Hunter chromaticities scale developed by Richard S. Hunter]
Cales) is established by equally aligning human visual senses with the "L" axis which corresponds to luminous intensity, the "a" axis which shows the hue from red to green, and the "b" koji value which measures the hue from yellow to blue. represents what has been done. R. S. Hunter, "Photoelectric tristimulus value neck using three color filters. Color method" National Pierreau of Standard Circular Ichiro. 429 U.S. Government Printing Office 1942 King] FIG. 2 shows the difference in the "a" axis of Hunter color units between reflective and transmissive types for various active coating weights. Figure 3 shows the color purity of the projected light from the display (reflective and transmissive) for various active coating weights.
color.

FIG. 4 shows the dominant wavelength of the projected light from the display in reflection and transmission for various active coating weights.

To elaborate on the diagram, the vertical axis of FIG. 1 generally shows hue extending from red human vision at one end to green human vision at the other end.

The test shutter display considered in this invention has a red opaque substrate layer, and the effectiveness of the shutter is determined by how much of the red substrate is blocked by operation of the shutter for various paint weights. A decrease in the value on the vertical axis means a decrease in redness. First, the line labeled "reflective" represents the test shutter display in which the magnetic flakes are aligned parallel to the substrate surface, thus obscuring the red substrate as much as possible. It can be seen that at points where the active coating weight is very low, the red color is not well hidden because it is incompletely covered by the magnetic flakes. The reflective curve goes from a red scale to a green scale at about 15 pounds per series of active coating. The line labeled "transmission" then represents the test shutter display when the magnetic flakes are oriented perpendicular to the substrate surface, thus maximizing the visibility of the red substrate. At very low active paint weights, the magnetic particles hardly mask the red color, but as the paint weight increases, the magnetic flakes are in a backward direction that prevents the red substrate from appearing. The transmission curve goes from a red scale to a green scale at 35-40 pounds per series of active coats. As described above, the line in FIG. 2 represents the difference (Δ) in the "a" axis unit between the reflective and transmissive hunter colors described in FIG. The difference shows the difference in colorants between reflective and transmissive types at various paint weights. It can be seen that the curve peaks at about 15 pounds per series. On either side of the peak, the color difference is reduced. On the side where the coating weight is lighter, when using the reflective type, the color difference in the substrate is sufficiently covered and not hidden, reducing the difference in color, while on the side where the coating weight is heavier, when using the transmissive type, the arrangement of the magnetic particles is reduced. badness and edge effects (edg
eeffecG) hides some of the hue of the substrate, thus reducing color differences. If you read Figures 3 and 4 together,
The dominant wavelength of reflected light from the test shutter display in reflective and transmissive types and the percentage of reflected light (within 1 or 2 nanometers) of the dominant wavelength can be measured.

It should be understood that the shade of the uncoated substrate exhibits a dominant wavelength of 613 nanometers and a color purity of 71% at that wavelength. Reflective type: 45-50 for the entire paint weight range
percent color purity, and above about 15 pounds per series of active coating weight, the dominant reflection wavelength is about 574-577
/meter (yellow). The color purity of the transmission type decreases as the coating weight increases, and the color purity is 600.
It decreases almost linearly in the dominant wavelength from more than a nanometer (clear color) to less than 0 nanometers. The figures described above are useful for describing shutter displays generally.

It is contemplated that the diagram could be used to depict the paint weight very much through an effective shutter display. However, since shutter displays are made for human visual response, the effectiveness of the display is best judged by visual response. An effective shutter display requires a surprisingly narrow range of active coating weights, which in turn requires a narrow range of magnetic flake concentrations or, more specifically, a narrow range of satisfactory active coating weights. It becomes a power shielding ratio. Looking at FIG. 2, it can be seen that the difference between the coloring material of the capsule and the coloring of the substrate is about 60%.
At low percentages, shutter displays have been found to be visually effective. Figure (Examples 1 and 2)
The range of acceptable active coating weights for the component system is therefore:
From about 10 to about 30 pounds per series. The active coating weight range is about 1-1/20%, as further detailed in the Examples.
represents a range of magnetic flake shielding ratios of approximately 4-3/4.
Capsules for use in the present invention can be made by any of several known encapsulation methods.

The presently preferred method is similar to that disclosed in US Pat. No. 3,341,466, issued September 12, 1967. The method has a small amount of capsule core, 10
From less than a micron to more than 1000 microns and maybe 15
Capsules of relatively uniform size are produced, typically having average diameters ranging up to 1,000 microns in size. As mentioned above, preferred encapsulation methods are disclosed in the prior art, but for clarity, suitable encapsulation methods are repeated below.

The wall-forming polymeric materials are pork skin gelatin and gum arabic having an isotropic point of about PH 8-9.

2 Place the following items into the movie car.

800ml water pH 8-9
180 ml of an aqueous gelatin solution containing 11% by weight of pigskin gelatin having a uniform point of 180 ml of an aqueous solution of gum arabic containing 11% by weight of gum arabic Next, the system was stirred and the temperature was raised to about 40-5yo. and 2% by weight
Adjust the - of the system to about 9 using an aqueous sodium hydroxide solution.

Next, 160 g of a magnetic particle dispersion in oil is added to the system as a capsule inner layer. The system is stirred until the magnetic particle-containing oil is dispersed to the desired size, such as on the order of about 5-80 microns. Once this point is reached, the pH of the system is slowly lowered to 4.2-4.4, which takes only a few minutes, to allow coacervation to occur. While continuing to pray, the temperature of the system was lowered to room temperature (2
When the temperature is lowered to 5.+-.5.degree. C.), a composite polymer liquid material is precipitated around the oil droplets that form the internal phase containing the magnetic particle suspension. While continuing to cool the system, the system is cooled to about 1.0 psi, causing the liquid wall precipitate of the polymer composite to form a gel. These gelled capsules are complete apart from the next step of crosslinking and curing in the remaining aqueous vehicle. Curing is 2
10 parts of a 5% by weight aqueous glutaraldehyde solution is added and allowed to stand for 1 to 2 hours, during which time the temperature of the capsule slurry is adjusted to room temperature. The capsules are generally used, preferably in an aqueous medium, and are painted. When using capsules made in the manner described above,
It is convenient to paint the capsules directly from the aqueous capsule manufacturing vehicle. However, if otherwise desired or necessary, additional materials can be used with the production vehicle or the aqueous production vehicle can be replaced with other aqueous component systems and different or additional binders. It is also possible to use substances. Capsules with dry capsule walls can be formulated into coating compositions having aqueous or organic vehicle component systems.

It is, of course, required of any coating composition that the viscosity and solids content be appropriate for the desired application process. In the examples below, "percent" means percent by weight.

Example 1 In this example, a coating composition was prepared using the previously disclosed encapsulation method.

The capsule-containing oil can be, for example, dioctyl phthalate, chlorinated piphenyl or a high boiling petroleum solvent. Small amounts of surfactants can be used to facilitate dispersion of the nuclear magnetic particles. The high boiling point petroleum solvent is, for example, a solvent consisting of 486% paraffin and 51.4% naphthene and having a boiling point range of 390 to 49 F [Magnaflux
Corporation
[commercially available under the trade name Magna Flux Oil] available from Amazon.com). The surfactant may be solpitan triolate. Combinations of solvents can also be used. The magnetic particles are flakes of metallic nickel with an aspect ratio of about 16 and a longest dimension of about 40 microns. The magnetic flakes may be commercially available from AZcan Aluminum Corporation, Elizabase, New Jersey under the trade name MD-756. The flakes contain 56 g/g of flakes.
It has been measured by Alcan Aluminum Corporation using the method described above to have a specific shielded area of 0 square centimeters. The specific shielding area is approximately 1 per series.
．． 2 lbs. theoretically good D results in complete flake shielding.
The magnetic particles are about 19% of the capsule component system (about 33% for oil). The color range is 1-5% of the above-mentioned oil yellow medicinal capsule component system. The capsules are about 5 to 80 microns in flat diameter and contain about 80% particle oil dispersion. The vehicle for the coating composition is aqueous and includes binders such as acrylic or styrene-petagene latex, methyl- or carboxymethyl cellulose, starch or poly(vinyl alcohol).

Binder substances can be used alone or in combination.

When prepared, a typical coating composition is prepared by filtering water from the capsule component system to about 40% capsules and then adding about 10 parts by weight of the capsule slurry to 10% poly( (vinyl alcohol) solution in combination with 10 parts by weight. The dyes can be used alone or in combination to obtain the desired shade, and typical dyes that can be used as colorants in the production of capsules and displays for the coating compositions of this example are listed above.

If desired or necessary, different types of magnetic flakes can be used in combination.

Example 2 The composition of Example 1 is coated onto a transparent sheet of polymeric material such as polystyrene or polyethylene terephthalate, and when dry, the composition is covered with an opaque substrate layer of red enamel.

In the first exemplary shutter, the composition was applied to a thickness of approximately 43 microns when dry. The dry thickness corresponds to a total coating weight of about 25 pounds per series and an active coating weight of about 20 pounds per series. The dry film thickness of the composition of Example 1 represents a magnetic flake concentration of about 3.8 pounds per series. As specified in Example 1, the flakes used in this example have a theoretical shielding of about 1.2 pounds per block, and the coated flakes have a shielding of about 38 pounds per series. . The shielding ratio in this example is approximately 3.2. When viewed through the transparency sheet, this first exemplary shutter exhibited a bright red color when in transmissive mode and a deep yellow-gold color when in reflective mode. When the shutter of the display is partially reflective and partially transmissive,
There was a noticeable contrast between the yellow-gold and red colors. In a second exemplary shutter, the composition was applied to a dry thickness of approximately 36 microns (approximately 12 pounds active coating weight per series).
I painted it to look like this.

The corresponding occlusion ratio is approximately 1.9, and when viewed through the transparent sheet, this second exemplary shutter exhibits a bright red color when in transmissive mode, substantially the same shade as the first exemplary shutter when in transmissive mode. It was the same. However, when reflective, this second exemplary shutter exhibited a mixed red and yellow hue without the strong red-gold contrast of the first exemplary shutter when reflective. The flakes do not adequately shield the substrate. In the third exemplary application, the composition was applied to a dry thickness of approximately 70 microns (approximately 33 pounds active coating weight per series).

The corresponding shielding ratio is approximately 53. This third exemplary device exhibited a yellow-gold color when viewed through a reflective transparent sheet. When this third exemplary paint was placed in what was previously referred to as the transmission type, however, it showed a golden color (Ken'ichi Golden Color). The fact that the film was gold in color and the red color was virtually invisible indicates that the projected light did not pass through the film and was absorbed there. Therefore, if the coating is too thick, the projected light will be absorbed rather than transmitted, turning the transmission type into an absorption type, and the coating becoming a light trap rather than a shutter. Several additional exemplary shutters were made with various paint weights and the results of testing of the exemplary shutters resulted in the accompanying figures. Neither the thin coating (second example) nor the thick coating (third example) increased the contrast due to the difference in hue.

If the coating is too thin, the color of the base will be dominant, and if the coating is too thick, the color of the paint will be dominant. In particular, there is no correlation between different shades unless the colorant concentration and magnetic flake shielding comply with the critical conditions of the present invention. It should, of course, be understood that the narrow coating weight range is critical to the concentration or density of magnetic particles used therein. The fundamental determining parameter for making a shutter display effective is the planar area of the magnetic particles per unit area of the display surface, previously defined as the shielding ratio. Approximately 1-1
It has been observed that only occlusion ratios of /2 to about 4-3/4 result in visually pleasing shutter displays. Example 3 The coating of Example 1, except that the capsule-containing colorant was a phthalocyanine green microdispersed pigment, used at a concentration of about 2% based on oil, and had an average particle size of about 0.1 micron. The composition was manufactured again.

Displays made using this composition exhibited the same critical paint weight range for shutter effect as found in Example 2 above using dissolved dyes. Example 4 In this example, the coloring material was oil yellow NB (p-
Diethylaminoazobenzene, color index 11
021), 1.4% of the capsule component system is used, and the magnetic material is International Nickel (Inte
rMtio Tsukuda I NickelCO. ,lm. ,) Painted as in Example 1, except that metallic nickel flakes (aspect ratio of approximately 40 and longest length approximately 40 microns) were commercially available from Huntington, West Virginia under the trade name BM-155-Hiro. A composition was produced.

The magnetic flakes are about 20% of the encapsulated component. The oil to be encapsulated was selected from those mentioned in Example 1.
The composition was applied to a flexible transparent film, such as a 3 mil thick polyethylene terephthalate film, in an amount such that the flake shielding ratio in this application was about 3.2. Dry coatings on transparent films can be used with a variety of substrate elements to provide effective color shutter elements.
The shutter element is guided over a substrate printed with a different shade than the color villages in the shutter element to create a complete shutter display.

The shutter element was placed on a printed substrate sheet with green text. When using the reflective type, the printing on the substrate was not visible.
When in transmission mode, the printing on the substrate was clearly visible through the shutter element. The comparative shade difference between the colorants of the shutter element and the color gamut of the print provides a pronounced subjective visual contrast resulting in an improved display of the print.
The effectiveness of the display of this embodiment is enhanced if the substrate print is placed on a substrate substrate having a hue as close as possible to that of the colorant of the shutter element.

In fact, the unprinted substrate viewed through the transmissive shutter had the same appearance as the reflective shutter. The shutter effect and therefore the value of the display is compromised when the coating is not within a satisfactory range.

When the coating weight is very light, the substrate printing is always easy to see; when the coating weight is very heavy, the substrate printing is difficult to see, no matter what type of shutter the shutter is. Example 5 In this example, a coating composition is made using capsules made by the preferred method previously disclosed, separated from the making vehicle, and dried.

The capsules, with an average diameter of about 40 microns, contain about 10% oily internal phase dispersion consisting of about 2% color chloride, 19% magnetic flakes, and the remainder pot oil as an oily liquid. The coloring material is a green finely dispersed pigment such as phthalocyanine green, about 0.
It has an average particle size of 1 micron. The magnetic flakes are nickel with an aspect ratio of about 16 and a longest length of about 40 microns. To make the composition, capsules are dispersed in a solution of 5% ethylcellulose in toluene as a solvent, making the capsules 25% of the composition. The present compositions are used in the same manner as the compositions of the previous examples.

A coating of one shade provides a planar surface coverage within the defined range of 1.5 to 4.76 square meters per square meter for the color shutter display elements described herein, when used with a substrate having a different shade, the present invention This is a concrete example. Example 6 In this example, the coating composition of Example 5 was spray-coated onto a black-painted molded body.

The thickness of the coating is adjusted to 1-3 mils to provide coverage of a planar area within the specified range. The shutter effect of this example was the same as the previous example. Example 7 In this example, a transparent film with a substrate tint was used to make a shutter display.

A magnetic flake capsule coating composition such as the yellow composition of Example 1 was coated with a dry film magnetic flake shielding ratio of 1-1.
The coating weight is from /2 to 4-3'4 and coated on a transparent carrier sheet. The capsule coating is then sequentially coated with a colored lacquer, such as nitrocellulose, containing an oil blue dye dissolved in a suitable organic solvent. When projected onto the capsule side of the display and the white light is reflected from the display with reflected heat, the reflected light has a yellow tint. On the other hand, if the display is transmissive, the reflected white light will have a green tint. The brightness of the green tint is enhanced by placing a highly reflective surface on the lacquer side of the display.

[Brief explanation of the drawing]

FIG. 1 shows the relationship between active coating weight and Hunter value. FIG. 2 shows the relationship between the difference in Hunter value and the amount of active coating between the reflective type and the transmission type. FIG. 3 shows the relationship between the amount of active coating and the color purity of reflected light in the reflective type and the transmission type. FIG. 4 shows the relationship between the amount of active coating and the dominant wavelength of reflected light from the reflective type and the transmissive type. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

Claims: 1. (i) a substrate display surface of a selected color shade, and (ii) (a) a plurality of substantially spherical microcapsules containing a liquid and magnetic flakes;
A display comprising a magnetically responsive, reversible shutter film coated on a substrate display surface 1 consisting of a substantially transparent polymeric binder material surrounding colorants (c) (a) and (b). the article, wherein the colorant hue prevails when the flakes are parallel to the display surface, and the hue of the display surface prevails when the flakes are perpendicular to the display surface; A display article comprising: a magnetic field in the vicinity of causing an alignment of said magnetic flakes.