JP2005521798A - Anti-tamper articles containing multiple response physical colorants - Google Patents

Abstract

An anti-fraud article comprising elements such as filaments, fibers (including hollow fibers) and twisted yarns, and their thin cross-sections and shreds, wherein such elements are dispersed within the article. Using particle scattering and luminescent techniques based on scattering, electronic, magnetic and / or optical properties, physical response in response to various parts of the electromagnetic spectrum including ultraviolet, ambient and infrared Provided is a chemically colored compound. The coloring effect can be highly stable or can depend on a specific switching effect associated with, for example, thermal or actinic radiation. This anti-fraud product is a high-level fraud to prevent counterfeiting of objects including banknotes and banknotes, stock certificates and corporate bonds, identification cards, credit cards, debit cards and ATM cards, driver's licenses and barcodes. Prevention is provided.

Description

  Various methods have been reported for imparting color, including luminescence, to polymer compositions and articles, such as fibers, filaments, films, molded articles, and the like. Dyes, pigments or luminescent agents, eg doped zinc sulfide, metal aluminate oxides, rare earth oxysulfides, eg Group 3 inorganic oxides containing lanthanide series dopants of the Periodic Table of Elements to obtain coloration Additives such as (Monday 21). As another approach, it can also be colored using particle scattering techniques, as described in US Pat. No. 5,932,309; US Pat. No. 6,074,742; US Pat. No. 6,150, No. 019; and US Pat. No. 6,153,299. Each of the above identified patents and patent applications is incorporated herein to the extent permitted. For the purposes of the present invention, luminescence includes both fluorescence and phosphorescence.

  Tamper-proof fiber refers to a fiber incorporated into a document or other article for identity verification, authentication, and prevention of counterfeiting, counterfeiting or tampering. The term “security tread” is used to describe strips of twisted or braided fiber or film for the same purpose.

  German patent 1802588 describes a cellulose fiber containing a luminescent additive for the purpose of preventing fraud.

  European Patent No. 066854B1 describes fraud-proof fibers of cellulose acetate and fraud-proof paper containing those fibers. This tamper-proof fiber is spun from an acetone solution containing a lanthanide chelate. This fiber is colorless under normal illumination, but exhibits narrow band emission in the visible or infrared (IR) region when excited with ultraviolet (UV) light. A tamper-proof twisted yarn combining fibers containing different light emitters is described, and information encoded on the tamper-proof twisted yarn is printed.

  U.S. Pat. Nos. 4,655,788 and 4,921,280 contain tamper-proof fibers that cannot be read by sunlight or artificial light but exhibit luminescence when excited by IR, UV or X-rays. Has been described. The tamper-proof fibers are prepared by a method of dyeing ordinary textile fibers such as polyester, polyamide and cellulosic fibers with rare earth chelates.

  German Patent No. A14 46 851 describes a tamper-proof twisted yarn having microprints using various colors.

  U.S. Pat. No. 4,897,300 describes a tamper-proof twisted yarn having a luminescent color that is provided in a continuous overlapping portion in the length direction of the tamper-proof twisted yarn that cannot be read by ordinary light. When the color is excited, it is long enough to be seen even with the naked eye, and a unique mixed luminescence appears in the superimposed region. This tamper-proof yarn is produced by printing a strip on a flat sheet and then cutting it.

  US Pat. No. 6,068,895 describes a detectable filament produced by adding about 20 weight percent of an inorganic phosphor to a polyester dope and spinning the filament from the dope. A tamper-proof label fabric incorporated.

  U.S. Pat. No. 4,183,989 describes a tamper-proof paper having at least two machine-identifiable anti-tampering properties, one of which is a magnetic substance. A luminescent material can be used as 2. The luminescent material is dispersed in the lacquer and is coated on the film. The film is divided into planchettes with a diameter of about 1 mm and incorporated into paper.

  Korean Patent No. 9611906 and International Publication No. 9945200 describe methods for preparing luminescent fibers by dyeing. Korean Patent No. 9611906 describes the incorporation of fibers into paper material.

  Chinese Patent No. 1092119 describes a 1 to 10 mm long polyvinyl alcohol fiber containing pigments, dyes and fluorescent materials.

  U.S. Pat. Nos. 5,876,068, 5,990,197 and 6,099,930 describe yet other means of providing an anti-fraud element including a luminescent material.

  In the related field, British Patent 1,569,283 describes an apparatus for verifying the authenticity of a material coded with a fluorescent material.

  Luminescent materials have also been incorporated into fibers for general purposes unrelated to fraud prevention applications, and without specifying purposes.

  U.S. Pat. It is then extruded and spun into fibers to make doll hair.

  U.S. Pat. No. 5,321,069 describes a process for producing a thermoplastic polymer phosphorous bulky continuous filament (BCF) yarn by melt spinning for use in textiles. The method includes mixing the polymer pellets with a wetting agent, preferably mineral oil, adding a phosphor powder such as zinc sulfide to coat the pellets substantially uniformly, and heating in an extruder. Extruding the melt and thereby uniformly dispersing the phosphorescent pigment throughout the filament is included. The individual filaments may be solid or hollow and may have any conventional shape.

  The method for preparing luminescent fibers described in US Pat. No. 5,674,437 includes combining a thermoplastic polymer and a luminescent metal aluminate pigment in an extruder, heat mixing the polymer. And a step of extruding the melt to form a fiber.

  U.S. Pat. No. 3,668,189 describes a fiber-forming fluorescent polycarbonamide prepared by copolymerizing a fused ring polynuclear aromatic hydrocarbon containing at least three fused rings.

  Japanese Patent No. 7300722A2 and Japanese Patent Application Laid-Open No. 2000-096349A2 describe a sheath-core fiber having a core containing a luminescent material.

  US Patent Application Serial No. 09/790041 (Filing Date February 21, 2001), assigned to the assignee of the present invention, contains a tamper-proof article comprising fibers, twisted yarns and fiber sections having specific multiple verification properties. Is disclosed. Specifically, fraud prevention objectives are achieved by fibers having complex cross sections, components and multiple luminescent responses. The disclosure of that application, to the extent permitted, is incorporated herein by reference.

  A major advance in generating color in articles including fibers, yarns and films is disclosed in US Pat. No. 5,932,309, assigned to the assignee of the present invention, which is acceptable. To the extent they are incorporated, they are incorporated herein by reference. The invention utilizes particle scattering effects and / or electron transition colorants to achieve the purpose of coloring, as defined in that invention. The coloring obtained thereby in the article is very stable or responds to the switching effects of exposure to, for example, temperature, heat exposure, hygroscopicity and actinic radiation. For purposes of the present invention and for convenience, this technique will generally be referred to as “particle scattering”.

  Each of these methods has the advantage of obtaining the desired coloring effect, but prevents counterfeiting, targeting the performance and characteristics of a single type of pigment or method used to obtain the color. There is still a need for additional coloring effects that are particularly useful in fraud prevention applications that can individually create properties that can be uniquely identifiable only to specific users.

Summary of the Invention Anti-fraud articles include a matrix component in which: (A) at least one particle scattering colorant is dispersed; and (B) at least one luminescent material is dispersed. Wherein: (1) the at least one particle scattering colorant includes particles selected from the group consisting of semiconductors, metal conductors, metal oxides, metal salts, or mixtures thereof; The average cross-sectional diameter of the at least one particle scattering colorant is less than about 0.2 microns at its smallest; (3) the polymer matrix component is substantially non-absorbing in the visible region of the spectrum; (4) the same particle scattering colorant having an average particle size of more than about 20 microns, with a minimum intensity ratio of transmitted light in the region of 380 to 750 nanometers; Compared to the case of a semiconductor, a metal conductor, a metal oxide, a metal salt or mixtures thereof of at least 10 nanometers; and (5) the luminescent material is at least one fluorescent material Selected from the group consisting of at least one phosphor, a mixture of at least one phosphor and at least one phosphor, wherein the luminescent material is an electromagnetic wave of about 200 to about 2,000 nanometers. It exhibits a luminescent spectral response peak when excited by at least one wavelength selected from the spectral region.

  In yet another embodiment, an anti-fraud article comprising at least one first composition and at least one second composition is provided: (A) the first composition comprises a first And a particle scattering colorant and at least one luminescent material dispersed therein; (B) the at least one second composition includes a polymer second matrix; A component and a colorant selected from the group consisting of electronic transition colorants, dyes and pigments dispersed therein; (C) the at least one first composition; (1) an article; On the second composition on at least one side of the substrate; substantially outside; or (2) the first and second compositions substantially penetrate each other. Where: (i) said first Having at least one incident visible light wavelength and one incident light angle such that the composition absorbs less than about 90% of the light incident on the article; (ii) the at least one first type The composition has an extinction coefficient that is less than about 50% of the extinction coefficient of the second composition at a wavelength in the visible region of the spectrum; (iii) the maximum extinction peak of the particle scattering colorant is visible in the spectrum (Iv) the luminescent material from the group consisting of at least one phosphor, at least one phosphor, and a mixture of at least one phosphor and at least one phosphor; Selected, wherein the luminescent material is excited by one or more wavelengths selected from the electromagnetic spectral region of about 200 to about 2,000 nanometers And (v) the following: (a) the particle scattering colorant has a refractive index that matches the refractive index of the first matrix component at a wavelength in visible light. The average particle size is less than about 2000 microns; or (b) the average refractive index of the particle scattering colorant in the visible wavelength region is at least about 5% that of the first matrix component The particle scattering colorant is either less than about 2 microns where the average particle shape of the particle scattering colorant is the smallest, and the particle scattering colorant is a colorless etc. having a substantially different refractive index When dispersed in an isotropic liquid, the wavelength of visible light has an effective maximum absorbance that is at least twice the effective minimum absorbance.

  Fraud prevention articles include filaments, fibers, filaments, sometimes referred to as dots, and thin cross sections of fibers, strands, chopped filaments and fibers or strands, also referred to as fibrils, films, slit films, and filaments, fibers, Various articles including twisted yarns, dots, fibrils, films and slit films. Included in such goods are banknotes, ID cards, credit and debit cards, ATM cash cards, and printed with materials required to prevent licenses, diplomas and other counterfeiting Paper, barcode, etc.

Detailed Disclosure The present invention includes fibers, twists, thin cross sections of fibers (also referred to as “dots”) and chopped fibers (referred to herein as “fibrils” for convenience), as well as films and slit films. Regarding fraud prevention articles, such fraud prevention articles have multiple verification characteristics. In addition, such articles are thicker than film, for example, a few tenths of an inch, or a few inches thick, such as cards or boards, such as sheets or planes. It is also possible to take the form of a shaped structure. These fibers have a combination of ingredients, compositions and multiple luminescent responses that are unique and difficult to duplicate. The verification properties of these anti-fraud fibers, twists, fibrils and dots make it highly possible to prevent unauthorized copying of articles incorporating them, and are specific to specific applications and multiple users It is possible to provide a new means for imparting the identity proof property.

  For the purposes of the present invention, the luminescent response includes phosphorescence response, fluorescence response and phosphorescence response and fluorescence to excitation light energy in the ultraviolet, visible (eg, white light) and infrared (IR) regions of the electromagnetic spectrum. A combination of responses is included. Such a response can be observable under a variety of conditions, for example, ambient light, sunlight, dimness or darkness, or illumination from ultraviolet or infrared regions of the electromagnetic spectrum. Furthermore, this luminescent effect may be a fluorescent effect that is observable only when the excitation source is present or for less than 1 second after the excitation source is turned off, For example, it may be a phosphorescent effect that can be observed only for a short period of time from about 1 to about 10 minutes after the completion, or a phosphorescent effect that can be observed for a long time after the activation energy ends ( Such an effect may be referred to as “afterglow” in this specification. Such periods of afterglow may be from about 10 minutes to about 200 minutes or more, such as from about 15 minutes to about 120 minutes, or from about 15 minutes to about 60 minutes. The unique anti-fraud article of the present invention can be a combination of permutations and combinations of various luminescent responses brought about by particle scattering effects, as well as phosphorescence and fluorescence. The ability to observe these effects while coexisting with each other is particularly valuable for developing anti-fraud articles that are resistant to counterfeiting.

  The tamper-proof article of the present invention includes tamper-proof fibers, which may be a single filament (monofilament) or a collection of monofilaments. In the following description of the cross section of the fiber, it should be understood that the cross section of the monofilament is described unless otherwise specified. The fibers, twists and dots of the present invention can provide a high level of fraud prevention effect by incorporating them into paper, materials and other articles using suitable methods known to those skilled in the art.

  The tamper-proof fiber of the present invention is preferably formed from a synthetic polymer by, for example, melt spinning, wet spinning, dry spinning, gel spinning, or other continuous methods. Synthetic fibers are typically spun using conventional methods into circular cross-sections, as well as various known shapes such as triangles, rectangles, trilobes, quadrilobes, and the like. The cross section of the fiber may include, for example, a circular or elliptical hole extending in the direction of the entire length of the fiber, and even if the cross-sectional size is constant in the length direction, It may have changed. The higher the degree of complexity of the cross section of the fiber, the more difficult it is to design a spinneret to produce the same, and it is more difficult for a fraudster to duplicate the design. Hollow fibers and sheath / core fibers are particularly useful in combination with particle scattering effect technology.

  The fibers of the present invention can be varied depending on the number, arrangement, composition and physical properties of the components. Multicomponent fibers, such as bicomponent fibers, as is well known, have two distinct cross-sectional areas from two polymer types (eg, polyester and nylon) that are distinctly different in composition from each other. Thus, it is possible to further change the composition and the visual response, eg color. Bicomponent fibers and methods for producing them are described in, for example, US Pat. Nos. 4,552,603, 4,601,949, and 6,158,204. The disclosures in these patents are incorporated herein by reference, to the extent permitted. These components may be in a side-by-side relationship or in a sheath-core relationship. In one embodiment, the number of components in the tamper proof fiber of the present invention is at least two. In a preferred arrangement, the components in the multicomponent fiber are in a side-by-side relationship with each other as described in US Pat. No. 6,158,204. The sections of the transverse section named A and B in FIGS. 2-6 of said patent represent another component.

  The components may be separate polymer compositions, including separate polymers or polymer mixtures, sometimes referred to herein as a matrix. For the purposes of the present invention, a matrix refers to a polymer or polymer composition in which a coloring effect agent (s) is dispersed. The components are composed of the same polymer, but with different pigments, luminescent agents and / or structures using, for example, particle scattering techniques, so that normal or peripheral It is preferable to allow different coloring responses under illumination conditions, or even different luminescent responses under UV or IR irradiation. Polymers useful in the present invention include those selected from the group consisting of polyamide, polyester, polyolefin, polyacrylic resin, polyalcohol, polyether, polyketone, polycarbonate, polysulfide, polyurethane, cellulosic and polyvinyl derivatives. Polyolefin, polyester and polyamide are preferred. The most preferred polymers are polypropylene, polyethylene terephthalate, polytrimethylene terephthalate, nylon 6 and nylon 66.

  Fibers useful in the present invention are those having an effective diameter of about 0.01 mm to about 3 mm. For the purposes of the present invention, the “effective diameter” is the diameter of the smallest circle surrounding the cross-fiber section. In one embodiment of the present invention, the fibers are traversed into cross-section flakes having a thickness of about 0.005 mm to about 0.5 mm. The resulting flakes are referred to herein as “dots”, which can be incorporated into paper or other articles and applied by the naked eye or by applying a certain amount of magnification or appropriate illumination to produce cross-sections, components. And the luminescent response can be easily identified.

  Another tamper-proof feature of the fibers of the present invention is the multiluminescent response of the pigments used. Specifically, the luminescent response resulting from the incorporation of these additives includes phosphorescence, fluorescence and afterglow. This luminescent response includes wavelengths in the infrared, visible and ultraviolet regions of the spectrum. For purposes of the present invention, the various regions of the electromagnetic spectrum are defined as follows: the infrared spectrum begins at wavelengths above about 700 nanometers (nm) and extends to about 2000 nm; the visible light spectrum ranges from about 380 to about The wavelength region up to 750 nm; and the ultraviolet spectrum is the region from about 200 to about 400 nm. Although the numbers listed above are overlapping, those skilled in the art will readily understand that each of these regions has well-understood characteristics. The luminescent material is included in one or more components of the tamper proof article of the present invention. Even a single luminescent material can have a multiluminescent response, as can be seen from the multiple intensity peaks in its luminescent spectrum. For the purposes of the present invention, spectral peaks having an intensity lower than about one fifth of the maximum peak intensity are ignored.

  In one embodiment, the tamper proof fiber includes one component that includes one or more luminescent materials that exhibit different luminescent responses to the same or different wavelengths of radiation. Is included. In yet another embodiment, the tamper proof fibers are multicomponent fibers, each containing a single luminescent material and exhibiting different luminescent responses for the same or different wavelengths. In yet another embodiment, the tamper proof fiber is a multicomponent fiber, at least one of which has multiple luminescent materials that exhibit different luminescent responses to the same or different wavelengths of irradiation. included.

  The luminescence of the anti-fraud article of the present invention can be achieved by incorporating a luminescent material comprising a copolymer, pigment or dye before or during spinning, or by dyeing the spun fiber with a luminescent dye, or even This is achieved by utilizing various physical and structural aspects of the particle scattering technique. When used, the luminescent copolymer, pigment or dye is incorporated into the polymer matrix prior to or during the fiber spinning or film preparation process, for example, in articles such as fibers or films. It is preferable to incorporate it as one piece. For example, it is most preferred to incorporate the luminescent material by mixing with the polymer using a twin screw extruder with a mixing element, followed by extrusion and spinning in the case of fibers. As is known to those skilled in the art, polymer films can be similarly produced using mixing and extrusion processes.

  The multiluminescent response obtained by using the photoresponsive additive is in one or more of the infrared, visible and ultraviolet regions of the spectrum. If the anti-fraud article includes multiple luminescent responses, the peak intensity of those responses are separated by at least about 20 nm, preferably at least about 50 nm, more preferably at least about 100 nm in wavelength. Most preferably, the multiluminescent response has peak wavelengths in at least two different regions of the spectrum. The multiluminescent response is preferably in the region of the spectrum selected from the infrared and visible regions and from the UV and visible regions. The multiluminescent response of the anti-fraud article of the present invention is excited by one or more illumination wavelengths selected from the infrared, visible and ultraviolet spectrum regions. The luminescent response is preferably excited by one or more wavelengths among infrared and ultraviolet; ultraviolet and visible light; and infrared and visible light.

  The luminescent pigment or dye may be an organic, inorganic or organometallic material. Examples of thermally stable organic materials useful in the present invention include 4,4′-bis (2-methoxystyryl) -1,1′-biphenyl, 4,4′-bis (benzoaxazol-2-yl) ) Stilbene, and 2,5-thiophenediylbis (5-tert-butyl-1,3-benzoxazole). Examples include Ciba Specialty Chemicals Inc. under the trade names Uvitex (registered trademark) FP, Ubitex (registered trademark) OB-ONE, and Ubitex (UVITEX). (Registered trademark) OB and a compound commercially available from Honeywell Specialty Chemicals under the trade name Lumilux (R) Effect Light Blue CO. These compounds emit fluorescence in the ultraviolet region and visible light region of the spectrum when excited by irradiation with ultraviolet rays.

Examples of inorganic substances useful in the present invention include La ₂ O ₂ S: Eu, ZnSiO ₄ : Mn, and YVO ₄ : Nd. These materials are available from Honeywell Specialty Chemicals, respectively, Lumilux® Red CD168, Lumilux® Green CD145 and Lumilux®. It is commercially available under the trade name IR-DC139. Both are excited by ultraviolet irradiation. Lumilux® Red CD168 and Lumilux® Green CD145 fluoresce in the visible region, and Lumilux® IR-DC139 in the infrared region. Fluoresce. Another useful material other than these is rare earth oxysulfide, which is commercially available from Honeywell Specialty Chemicals under the trade name Lumilux® Red UC6. This substance is excited by infrared rays and emits fluorescence in the visible light region. In addition, some zinc sulfide compounds doped with, for example, silver, copper, aluminum or manganese are also commercially available from Honeywell Specialty Chemicals. Some of these articles are characterized by being excited by UV and white light to give both fluorescence and phosphorescence response, and also have long afterglow properties (Lumilux ( Lumilux® Green N5, N-PM and N2); another is excited by UV irradiation and emits fluorescence in colors such as blue, green, red, yellow and yellow orange (Lumilux ( Lumilux® effects: Blue A, Green A, Red A, Blue CO, Green CO, Yellow CO and Yellow / Orange); and others are excited by UV and white light and exhibit fluorescence and phosphorescence ( Lumilux® effect: Blue SN and Blue SN-F; Al Luminous silicate; Luminlux® effects: Green N, Green NL, Green NE, Green NF, Green N-3F, Green N-FG and Green N-FF); and Lumilux® effect: a calcium sulfide compound doped with red N100, europium and thulium, which is excited by white light and has a red fluorescent and phosphorescent response. These materials can also be used as a mixture, and some mixtures are commercially available (Lumilux® Effect Shipi: Yellow and Red).

  Luminescent copolymers are also useful and are disclosed in U.S. Pat. Nos. 3,668,189, 5,292,855 and 5,461,136. They are described as thermally stable copolyamides, copolyesters and copolyester-amides containing a fluorophore compound copolymerized therein. The copolymer of US Pat. No. 5,292,855 is excited and emits fluorescence at wavelengths in the near infrared region of the spectrum. The disclosures in these patents are incorporated herein by reference, to the extent permitted.

Typically, in a fluorescent material, if there is an excitation stop, the generation of fluorescence stops substantially instantaneously, for example, about 1 / 1000th of a second. In contrast, phosphors continue to emit light for a few ten minutes or even a few hundred minutes even after excitation is stopped. U.S. Pat. Nos. 5,424,006 and 5,674,437 describe special types of phosphors and their preparation, which have long persistence and are The anti-fraud article can be used because its luminescence decay rate can be used as one of the distinguishable properties of such articles. These patents, to the extent permitted, are incorporated herein by reference. US Pat. No. 5,674,437 discloses the incorporation of such materials into fibers. The phosphor is generally described as a doped metal aluminate oxide pigment, where the metal can be, for example, calcium, strontium, barium or mixtures thereof, and the dopant is preferably europium and elemental A lanthanide series element of the periodic table, for example, an element selected from the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and tin and bismuth. In one example, SrAl ₂ O ₄ : EuDy, such as that described in US Pat. No. 5,424,006, such a pigment can be found in United Mineral Corporation, New Jersey. It is commercially available from Mineral Corporation (NJ) under the trade name Luminova.

  Such luminescent materials can be used at concentrations suitable to obtain the desired luminescent effect. In other words, depending on the particular end use or article for which anti-fraud properties are desired, it may be desirable to use a mixture of phosphor and phosphor, or just phosphor or just phosphor. It may be desirable to use Overall, the concentration of the luminescent material in the matrix is at least about 0.05 weight percent; more preferably at least about 0.10 weight percent; even more preferably about 0.50 weight percent; for example about 1.0 weight. Percent; typically about 2.5 weight percent. Conversely, the maximum concentration of one or more luminescent materials is determined by the application, the physical properties required for the article, such as fiber strength, ease of manufacture, cost considerations, and the like. Overall, the concentration of the luminescent material in the matrix is up to about 85 weight percent; more preferably up to about 50 weight percent; even more preferably about 25 weight percent; for example about 20 weight percent; typically About 15 weight percent; for example, up to about 10 weight percent. A useful range for the concentration of the luminescent material is obtained by a combination of the above minimum and maximum values. For example, useful concentrations of luminescent materials are from about 0.05 to about 85 weight percent; from about 0.05 to about 15 weight percent; from about 1.0 to about 20 weight percent; and permutations of the above numbers And further ranges based on combinations.

  The anti-fraud articles of the present invention incorporating physical coloring based on particle scattering effects can be prepared by methods known in the art and are published, for example, on August 3, 1999 Can be considered in US Pat. No. 5,932,309, commonly assigned under the title of “Colored Articles and Compositions and Methods for Ther Production”. . Compositions based on this technique can be prepared, for example, by dispersing non-absorbing particle scattering colorants in a polymer or polymer mixture matrix. Alternatively, absorptive particle scattering colorants, particularly absorptive particle scattering colorants produced in situ, can be used as disclosed in recognized patents. Among substances that develop physical coloration, light scattering is performed by particles dispersed within a matrix that is at least partially light transmissive. Colorants useful in the present invention are called particle scattering colorants. Such a colorant is called a colorant that develops coloration due to reflection between light reflected from the interface between the opposite parallel double-sided or plate-like particles called plate-like interference colorant, and an electron transition colorant. Therefore, it is distinguished from a colorant that develops coloration due to electronic transition. Particle scattering colorants can develop some degree of coloration due to electronic transitions, but the coloration depends on the size of the particles, and if there is no significant coloration due to interference of reflected light from two opposing surfaces or parallel plate interfaces For example, the colorant is a particle scattering colorant.

  The particle scattering colorant is either an absorbing particle scattering colorant or a non-absorbing particle scattering colorant, depending on whether the particle scattering colorant significantly absorbs light in the visible region of the spectrum. Absorption can be characterized as being so significant that when the particle size is sufficiently large, the particle scattering of the light is evidenced by less visual color recognition.

  For the first category, the particle colorant is used by dispersing the particle colorant in a solid matrix having a refractive index that differs significantly from the refractive index of the particle scattering colorant in the visible range. For this first category, particle scattering colorants are defined as materials having either A or B characteristics as defined below.

The A or B characteristics are determined by dispersing the employed particle scattering colorant in a colorless isotropic liquid having a refractive index different from the refractive index of the employed particle scattering colorant as is commonly available. It is done. The most reliable test comes from choosing to enlarge the refractive index difference between the liquid and the particle scattering colorant to be employed as much as possible. This liquid-solid mixture containing only the targeted particle scattering colorant and a colorless isotropic liquid is referred to as a particle test mixture. The inverse log ratio of transmitted light intensity to incident light intensity (−log (I / I ₀ )) is measured for the particle test mixture as a continuous function of the wavelength over the entire wavelength range, including the entire visible spectral range of 380-750 nm. The Such a measurement is conveniently performed using an ordinary UV-visible spectrometer. Since the resulting quantity (-log (I / I ₀ )) encompasses both scattering and absorption effects on the decrease in transmitted light intensity, this quantity is called effective absorbance.

  The A-characteristic is the only legitimate determinant of particle scattering colorants for materials that do not absorb much in the visible region of the spectrum, which is not so great that the absorption overwhelms the coloring effect due to particle scattering. Means. For the sole purpose of the A-characteristic test, the average particle size of the employed particle scattering colorant is increased to greater than about 20 microns without changing the weight concentration of the employed particle scattering colorant in the particle test mixture. Sometimes, in the spectral region of about 380 to about 750 nm, a material that does not absorb much in the visible region is defined as a material that has an effective maximum absorbance that reduces the particle test mixture by at least about 2 fold, and preferably at least about 3 fold.

It should be understood that the aforementioned ratio of absorbance generally depends only slightly on the concentration of particle scattering colorant employed in the particle test mixture. Such dependencies are usually so weak that they are not important in determining whether a material is a particle scattering colorant. However, if the material is marginally a particle scattering colorant (or is not a critical particle scattering colorant), the aforementioned ratio of absorbance is considered a possible particle scattering colorant to be considered for the application of the material. Should be evaluated at a concentration of Also, the concentration of the particle scattering colorant to be employed in the particle test mixture should be sufficiently large that I / I ₀ is significantly deviated from 1, but since I is very small, reliable measurement is not possible. It should be apparent to those skilled in the art that it should not be so high.

  The particle test mixture has an effective maximum absorbance that is at least about 2 times and preferably at least about 3 times the effective minimum absorbance in the same wavelength region in the spectral range of about 380 to about 750 nm, and the average particle size of the material Is less than about 20 microns, particle scattering colorant objects that do not significantly absorb in the visible range have A characteristics.

  If the target particle scattering colorant absorbs significantly in the visible range, another substance will have A characteristics, and the material will not absorb as much in the visible range and will have the same particle size distribution and shape as the target particle scattering colorant. Alternatively, it can be determined that the particle scattering colorant to be employed is a particle scattering colorant.

  For objects that adopt scattering colorants that absorb significantly in the visible range, the B characteristic is also suitable for determining whether the particulate matter is a particle scattering colorant. Determining whether the B-characteristic criteria are met requires the same measurement of the effective absorbance spectrum in the visible range used above. If the particle scattering colorant to be employed has a minimum that shifts by at least 10 nm compared to the transmitted light intensity obtained for the same composition having an average particle size greater than 20 microns in transmitted light intensity, then a criterion for the B characteristic Is satisfied.

In another embodiment, a colorant is formed when fine particles, called primary particles, are embedded inside large particles. In this case, it can be determined whether the substance to be employed is a particle scattering colorant by applying either the A characteristic criterion or the B characteristic criterion to either the primary particles or the embedded particles containing the primary particles.
In deciding what is a particle scattering colorant, such complexity is eliminated in the second category of embodiments, in which case the refractive index of the particle scattering colorant is at a certain wavelength in the visible range. This is consistent with the refractive index of the matrix material. In such cases, any material having a particle size of less than 2000 microns is a particle scattering colorant. Similarly, determining whether an adopted object is an adopted particle scattering colorant is readily apparent when the adopted object includes a two-dimensional or three-dimensional regular array of primary particles. Large particles of such particle scattering colorants have an opal iridescent color that is clearly visible to the eye.

  While it may seem cumbersome to determine whether a particulate is a particle scattering colorant as described above, it is quite simple and convenient to apply. The particulates are much easier to disperse in a liquid than in a solid matrix that provides the article used in the present invention. Also, the effective absorbance measurement required to apply either the A or B characteristic criteria can be performed by conventional procedures using a rapid and inexpensive spectrometer. . Therefore, applying such property criteria can save a lot of time in identifying materials (ie, particle scattering colorants) that are suitable for the practice of the present invention.

In some embodiments, electronic transition colorants are used in conjunction with particle scattering colorants. An electronic transition colorant is defined as a substance that has an absorption coefficient greater than 10 ⁻¹ cm ^{−1 at} wavelengths in the visible range and does not meet the criteria for particle scattering colorants. Dyes and pigments are also used with the particle scattering colorant in embodiments of the present invention. In this regard, a dye or pigment is defined as a substance that absorbs light in the visible range to a degree sufficient to develop a visually recognizable coloration. Depending on the particle size, the pigment can be a particle scattering colorant or an electronic transition colorant. Also, in general, electronic transition colorants, dyes, and pigments can be used interchangeably in embodiments of the present invention.

  In use, the particle scattering colorant used in the present invention is dispersed as particles in the surrounding matrix. These particle scattering colorant particles may be randomly arranged or arranged in a manner that is positionally interrelated within the host matrix. In either case, a strong coloring effect can be developed as a result of the scattering of these particles. An arrangement of particle scattering colorants that are interrelated in location is somewhat like between bundles, and in some cases is preferred for obtaining a coloring effect that develops a dramatically different color at different viewing angles. Such scattering particles in an array of particles with translational order are called Bragg scattering. In order to obtain a relatively sharp coloring effect that may be strong even in the case of a non-absorbing particle scattering colorant, an uncorrelated particle scattering colorant is preferred.

  Since the visual limit of light is approximately between 380 nm and 750 nm, such a limit is preferred for purposes of the present invention to define the optical properties of the particle scattering colorant. In some embodiments of the present invention, the preferred particle scattering colorant has a refractive index that differs from the refractive index of the host matrix over the entire visible spectral region of 380-750 nm, and the particle scattering effect is an electronic transition colorant, Preferably it is enhanced using dyes or pigments. This situation differs from the state of the prior art Christiansen filter, which provides a match between the refractive index of the host material and the refractive index of the matrix material at at least one wavelength in the visible range. The performance of colorants, dyes or pigments is usually reduced. Unless otherwise indicated, the stated refractive indices are those measured at room temperature. Also, the particle scattering colorant is said to have a different refractive index, lower refractive index, or higher refractive index than the matrix material when there is a polarization direction to which this applies.

  The particle scattering colorant, or its subcomponents, should be sufficiently low to scatter light effectively in a chromatic manner. If there is no visible wavelength where the refractive index of the scattering particle colorant and the refractive index of the matrix substantially match, this means that the average particle size of such colorant is less than about 2 microns in the smallest dimension. Means that is preferred. For the present inventor, (for example) a common arithmetic mean rather than a root mean square mean value is taken to mean mean grain size. In the case of embodiments of the invention in which chromatic coloring occurs as a result of the large difference between the refractive index of the matrix and the refractive index of the particle scattering colorant over the entire visible spectral range, the particle scattering colorant More preferably, the average particle size is from about 0.01 to about 0.4 microns. In this case, the smallest average particle size is most preferably less than about 0.2 microns. In particular, if the particle scattering colorant absorbs light significantly in the visible range, an average particle size of even less than 0.01 microns is within the preferred range. Also, if the particle scattering colorant particles are not preferentially oriented, the average of the ratio of the maximum size to the minimum size of the individual particles of the particle scattering colorant is preferably less than about 4, and the particle scattering colorant particles are It is preferable that there is almost no variation in particle size or shape. On the other hand, in embodiments of the present invention in which the refractive index of the particle scattering colorant and matrix is substantially extinguished at wavelengths in the visible range, the particle shape can be quite irregular and the preferred average particle size is rather large, preferably It can be smaller than about 2000 microns. If the particle scattering colorant contains a smaller particle scattering colorant therein, a much larger particle size can be present in the preferred range. Such complications of preferred particle size in the case of alternative embodiments of the present invention will be further elucidated in the discussion of these embodiments below.

  Rather than expressing the particle size as the average particle size or the average particle size at the smallest dimension, the particle size of a particular particle scattering colorant can be expressed as the percentage of particles having the smallest dimension below the display limit. Such an indication is extremely useful in embodiments of the invention where the refractive index of the particle scattering colorant is significantly different from the refractive index of the matrix at all wavelengths in the visible range. In such embodiments, it is preferred that at least about 50% of all particles have very small dimensions of less than about 0.2 microns.

The matrix in which the particle scattering colorant is dispersed may be absorptive or non-absorptive in the visible spectral region. Such absorption characteristics can be defined using either a path length dependent amount or a path length independent amount for characterization. For example, the initial light intensity I _0, when after the light passes through the thickness t of the matrix is reduced to I _t by absorption process, percent transmittance is 100 (I t / _{I 0).} The corresponding absorption coefficient is-(1 / t) ln (I _t / I ₀ ). Unless otherwise indicated, the described absorption characteristics are those for the polarization direction in which there is a minimum absorption of light. For some applications, it is preferred that the particle scattering colorant is substantially non-absorbing in the visible range. For other applications it is sufficient that the particle scattering colorant does not have a very high peak in the absorption peak in the visible range. For other applications, it is preferred that the particle scattering colorant has the highest absorption coefficient at wavelengths in the visible range. The latter provides an embodiment of the invention in which the particle scattering colorant contains an overcoat layer of an absorbing material that is sufficiently thin that it absorbs little light.

  Light scattering that is not strongly frequency dependent in the visible range often occurs as a result of defects in the matrix material. One example of such a defect is a crystallite-amorphous boundary in a semicrystalline polymer matrix material. Such non-chromatic scattering can prevent the achievement of coloration using particle scattering colorants. Thus, it is useful to define an “effective absorption coefficient” using the above expression without correcting for the matrix absorption coefficient that does not occur from the particle scattering colorant.

Matrixes useful in the compositions of the present invention because the above colorants are useful for the construction of various articles such as universal article codes, tamper-proof labels, and molded articles where new optical effects are desired. Materials include cellulosic compositions such as paper, and organic polymers. For the purposes of the present invention, the term polymer includes homopolymers, copolymers, and various mixtures thereof. Various inorganic matrix materials, and mixed organic and inorganic matrix materials are also suitable for use as the matrix material, particularly suitable for particle scattering techniques such as SiO ₂ glass and mixtures of inorganic and organic polymers. is there. The main limitation in selecting such a matrix material is that neither absorption nor wavelength insensitive light scattering is so dominant that wavelength selective scattering (ie, color scattering) by particle scattering colorants is negligible. It is. This constraint means that such a matrix material must have a certain degree of transparency. Using the effective absorption coefficient defined above, such a requirement for transparency is that the effective absorption coefficient of the host matrix in which the particle scattering colorant particles are dispersed is about 10 ⁻ for some wavelengths in the visible spectrum. It means that it is preferably less than ^{4 ４ -1} . More preferably, the effective absorption coefficient of the host matrix is less than about 10 ^{−5 −１ −1} at a wavelength in the visible range, and most preferably the effective absorption coefficient is about 10 at a wavelength in the visible range. Less than ^-6 Å- ¹ . A number of commercially available transparent organic polymers that have a relatively low effective absorption coefficient in the visible range are particularly suitable for use as the matrix material of the present invention. These include, for example, polyamides, polyurethanes, polyesters, polyacrylonitrile, and hydrocarbon polymers such as polyethylene and polypropylene. Particular preference is given to amorphous polymers which have little scattering due to defects, for example the optical properties polyvinyl, acrylic, polysulfone, polycarbonate, polyacrylate or polystyrene.

  Depending on the intensity of color desired, the concentration of the particle scattering colorant in the host matrix can vary over a wide range. As long as the particle scattering colorant does not agglomerate to the extent that large variations in refractive index are eliminated at the interface between the particles, the intensity of coloring generally increases with the concentration of the particle scattering colorant. However, very high particle scattering colorant loadings can degrade mechanical properties, dramatically reduce the refractive index change at the interface due to close particle aggregation, and reduce the effective size of the scattering particles. It can change dramatically. For this reason, the volume loading concentration of the particle scattering colorant in the host matrix is preferably less than about 70%, more preferably less than about 30%, and most preferably less than about 10%. However, to obtain a significant coloring effect, the particle scattering colorant preferably comprises at least about 0.01 weight percent of the matrix component; more preferably comprises at least about 0.1 weight percent of the matrix component; and most preferably Contains at least about 1.0 weight percent of the matrix component. Also, the required concentration of the particle scattering colorant can be lower for the absorbent particle scattering colorant than for the non-absorbing particle scattering colorant, and the refraction between the matrix and the particle scattering colorant. As the rate difference increases and as the thickness of the matrix containing the particle scattering colorant increases, in some embodiments of the invention, the formulation concentration can be reduced.

  Various methods of particle construction can be employed in the materials of the present invention to achieve the refractive index difference necessary to obtain strong particle scattering. Preferred methods include (1) a simple particle method, (2) a surface-enhanced particle method, and (3) an onion-skin particle method. . In the single particle method, the particles are substantially uniform in the composition and the refractive index of these particles is chosen to be different from the refractive index of the host matrix. Unless otherwise indicated, (1) the views presented herein regarding the difference between the refractive index of the particle and the refractive index of the host matrix are related to the particle refractive index of the single particle method, or more Either related to the outer particle layer in the case of complex particles. (2) In the surface-enhanced particle method, the particles comprise a protective coating of a drug having a refractive index different from that of the matrix. The refractive index of the surface-enhancing drug and the refractive index of the host matrix should preferably differ by at least about 5%. More preferably, this refractive index difference is greater than about 25%. (3) Finally, in the onion-skin particle method, since the scattering particles are a multi-layer type (onion-skin shape) of layers having different refractive indexes, scattering occurs from each interface between the layers. If there are multiple layers in the onion-skin structure, it is useful to be able to use a smaller index difference, but this index difference is preferably greater than about 5%.

  In certain embodiments of the single particle method, the refractive index of the scattering particles is higher than the refractive index of the matrix. In another embodiment, the refractive index of the matrix is higher than the refractive index of the scattering particles. In both of these embodiments, the difference between the refractive index of the scattering center and the refractive index of the matrix should be maximized to enhance coloration by particle scattering. Accordingly, these embodiments are referred to as large Δn embodiments, and more specifically, when the scattering center is an inorganic particle and the matrix is an organic polymer, The difference in refractive index should be maximized. This difference in refractive index is generally determined by the polarization direction.

  In another embodiment, the refractive index of the particle scattering colorant is exactly the same at at least one wavelength in the visible range. In these embodiments, (1) there is a large difference in the wavelength dependence of the refractive index of the particle scattering colorant and the matrix polymer in the visible spectral region, and (2) the matrix polymer and the particle scattering colorant are optically It is preferable to have an isotropic state and (3) the pure matrix polymer has a very high transparency in the visible range. In such an embodiment, called the vanishing Δn embodiment, coloring is obtained using the concept of a Christiansen filter. Except for wavelengths near the wavelength where the refractive index of the matrix and the refractive index of the particle scattering colorant match, the size of the particle scattering colorant is chosen so that all wavelengths in the visible range are scattered. This wavelength dependence of the scattering efficiency also colors the article and enhances it.

  Both high Δn and extinct Δn embodiments provide a means for obtaining both stable and color-switchable coloring. In high Δn embodiments, coloration that can be switched in a desired manner is achieved using the combined effect of particle scattering effects and wavelength dependent absorption effects associated with electronic transitions in the visible range. preferable. In an extinction Δn embodiment, coloring that can be switched in a desired manner can be achieved by the following effects (light or actinic radiation exposure, heat exposure, electric field, humidity, etc.), this effect being (1) The wavelength at which Δn disappears is shifted between two types of wavelengths inside the visible range, (2) the wavelength at which Δn disappears is shifted inside the visible region, or (3) the wavelength at which Δn disappears Shifting outside the visible range, or (4) colored by a combination of the effect of particle scattering and the effect of absorption chromism in the visible range associated with electronic transition colorants, dyes or pigments One of the causes of the shift. Ferroelectrics, color-switchable antiferroelectric compositions, and light-ferroelectric compositions provide preferred compositions for obtaining color-switchable coloration using particle scattering colorants.

Even when the electronic transition colorant, dye or pigment does not switch the color of the electronic absorption color, such a colorant is particularly preferred to obtain a color switchable color in the case of high Δn embodiments. . The reason for this can be understood by considering a material that is sufficiently thin (eg, a polymer film) that the particles do not necessarily scatter all of the incident visible light. For such high Δn embodiments, the difference between the refractive index of the particle scattering colorant and the refractive index of the matrix is large over the entire visible spectral region (compared to the wavelength dependence of Δn across this region). Thus, the change in refractive index difference between the particle scattering colorant and the matrix generally increases the total intensity of the scattered light approximately logarithmically proportional to (Δn) ² , but the wavelength distribution of such scattered light is Does not change substantially. On the other hand, the amount of incident light generated by an electronic transition colorant, dye or pigment can depend on the amount of light that is not scattered by the particle scattering colorant, so the color reflection and absorption of the electron absorbing colorant can cause the color characteristics of the scattered light. As an example, the scattering efficiency and thickness of the particle scattering colorant layer is so large that it is assumed that there is virtually no light transmitted through the layer containing the electronic transition colorant. May be. If the refractive index of the particle scattering colorant is then switched so that the refractive index of the particle scattering colorant is very close to the refractive index of the matrix, then the light is substantially transferred from the particle scattering colorant layer to the electron transition colorant. Can propagate to layers. Next, it is possible to switch colors in coloring an article by the color switching property of the refractive index of the particle scattering colorant. This situation is quite different from the case of the extinction Δn embodiment, in which the color of the scattered light by an article that is thin enough that it does not necessarily scatter light completely, even in the absence of electron absorption. Gender switching can be demonstrated. This can be true as long as Δn disappears and there is a color switchability at wavelengths in the visible range, where Δn is largely determined by the wavelength in the visible range. Wavelength dependency of the refractive index of the visible _region, n F -n _C or, alternatively Abbe (Abbe) number _{((n D -1 / (n} F -n C)) is helpful is defined by either Yes, where the subscripts F, D and C represent refractive index values at 486.1, 589.3 and 656.3 nm, respectively, in order to obtain enhanced coloration of an extinction Δn embodiment. Preferably, the absolute difference between n _F -n _C of the particle scattering colorant and n _F -n _C of the matrix in which the color is dispersed is greater than about 0.001.

The particle scattering colorant and the electronic transition colorant may be mixed together in the same matrix, or collected with or without substantially interpenetrating each other. It can also be mixed in separate matrices. The latter case where the particle scattering colorant and the electronic transition colorant are in separate matrices that do not substantially penetrate each other as it optimizes the total intensity of the light scattered by the particle scattering colorant Provides a more preferred embodiment. In this type of embodiment, the matrix containing the particle scattering colorant is preferably substantially separate from the matrix containing the electronic transition colorant on at least one side of the new article. The thickness of the matrix containing the particle scattering colorant passes through the matrix layer of the particle scattering colorant so that the effect of both the electronic transition colorant and the non-absorbing particle scattering colorant can be observed. There should be a wavelength of visible light at which about 10% to about 90% light transmission occurs to reach the electronic transition colorant matrix layer. The preferred thickness (t _e ) of the matrix layer containing the electron absorbing colorant underlying the particle scattering colorant containing layer is the absorption coefficient of the electronic transition colorant at the wavelength (λ _m ) at which maximum absorption occurs in the visible range ( α called _e), and the volume fraction of the matrix is an electronic transition colorant depends (V _e). Preferably, α _e t _e V _e is greater than 0.1, which corresponds to an absorption of 9.5% at λ _m . Similarly, for embodiments in which the particle scattering colorant and the electron absorbing colorant are mixed in the same phase, it is useful to define a similar amount for the particle scattering colorant (subscript) The slight difference that is α _s in the case of particle scattering colorants includes the effect of light absorption and light scattering on the reduction in the amount of light transmitted through the material, _s depends on the particle size. For these embodiments, α _e V _e and α _s V _s are preferably less than about 10 times, and more preferably less than about 3 times. Similarly, the preferred embodiment represents the case where the particle scattering colorant and the electronic transition colorant are arranged in separate phases that are substantially interpenetrating each (volumes are v _s and v _{e, respectively} ). be able to. In this case, α _e v _e V _e and α _s v _s V _s are preferably less than about 10 times, and more preferably less than about 3 times.

  The variation in refractive index due to the composition of the organic polymer is much less than the corresponding variation for inorganic particles. Typical average values at 589 nm for various non-oriented organic polymers are: polyolefin (1.47-1.52), polystyrene (1.59-1.61), polyfluoro-olefin (1.35-1.42), non-aromatic non-halogenated polyvinyl (1.45-1.52), polyacrylate (1.47-1.48), polymethacrylate (1.46-1.57) Polydienes (1.51-1.56), polyoxides (1.45-1.51), polyamides (1.47-1.58), and polycarbonates (1.57-1.65). Particularly preferred polymers for use as the polymer host matrix are polymers that have little light scattering in the visible due to defects, for example, amorphous or much smaller than the wavelength of visible light Either a polymer with a size. The latter polymer can be obtained, for example, by a rapid melting-quenching method.

In high Δn embodiments, preferred scattering particles for combination in composites with such low refractive index polymers are: 1) of titanium dioxide, zinc oxide, silica, zirconium oxide, antimony trioxide and alumina. 2) carbon phases such as diamond (n = about 2.42), ronsdaleate, and diamond-like carbon; 3) bismuth oxychloride (BiOCl), barium titanate (for wavelengths of 420-670 nm) N ₀ = 2.543 to 2.339, n _e = 2.64 to 2.392), lithium potassium niobate (for wavelengths of 532 to 1064 nm, n ₀ = 2.326 to 2.392). _208, n e = _{2.197~2.112),} with respect to the wavelength of lithium niobate _(420~2000nm, n 0 = 2.304 _2.124, n e = _{2.414~2.202),} with respect to the wavelength of lithium tantalate _{(450~1800nm, n 0 = 2.242~2.112,} n e = 2.247~2. 117), palerite (for wavelengths of 633 to 1709 nm, n ₀ = 2.739 to 2.542, n _e = 3.019 to 2.765), zinc oxide (for wavelengths of 450 to 1800 nm). N ₀ = 2.106 to 1.923, n _e = 2.123 to 1.937), alpha-zinc sulfide (for wavelengths from 360 to 1400 nm, n ₀ = 2.705 to 2.285). , N _e = 2.709-2.288), and other high refractive index inorganics such as beta-zinc sulfide (n ₀ = 2.471-2.265 for wavelengths of 450-2000 nm), High refractive index material such as The A high refractive index organic phase is also preferred as a particle scattering colorant when used in a low refractive index phase. Examples of high refractive index organic phases that can be used as particle scattering colorants with low refractive index organic matrix phases (eg, polyfluoroolefins) are polycarbonate or polystyrene. Conventionally, n ₀ and n _e in the list of index of refraction with respect to the optical crystal is anisotropic, respectively, represent the ordinary index and the extraordinary refractive index. The n ₀ refractive index is for light propagating along the principal axis, so there is no birefringence, while the _ne refractive index is for light with a bias along the principal axis.

Preferred particle scattering colorants where a high refractive index matrix is required along with low refractive index scattering particles are 1) such as fluorinated linear polymers, fluorinated carbon tubules, fluorinated graphite, and fluorinated fullerene phases. Low refractive index materials, 2) low refractive index particles such as pores filled with air or other gases, and 3) low refractive index inorganic materials such as MgF ₂ which may be crystalline or amorphous. Various inorganic glasses such as silicate glasses are preferably used as particle scattering colorants in a number of organic polymer matrices for the extinction Δn embodiment. The reason for this choice is that such glasses are inexpensive and can be formulated well at a certain wavelength in the visible range to be important and consistent with the refractive index of commercially available polymers. In addition, since the dispersion of the refractive index of such glass may be completely different from the dispersion of the polymer, a substantial coloring effect can be clarified upon particle scattering. The host matrix chosen for the high Δn embodiment for a particular glass particle is either much higher or much lower than the matrix chosen for the annihilation Δn embodiment for the same glass particle Although it is clear that it must have a rate, inorganic glass is also preferred for use in high Δn embodiments. For example, a glass with a refractive index of 1.592 would be a suitable particle scattering colorant for polystyrene in an extinction Δn embodiment because polystyrene has approximately this refractive index. On the other hand, poly (heptafluorobutyl acrylate) with a refractive index of 1.367 could be used with the same glass particles in high Δn embodiments. In connection with the construction of these colorant systems, it should be noted that the refractive index of conventional glasses used in optical instruments is in the range of about 1.46 to 1.96. For example, the refractive index of normal crown, borosilicate crown, barium flint, and light barium flint is in the range of 1.5171 to 1.5741, and the refractive index of heavy flint glass reaches about 1.9626. The value of _n F -n _e of these glasses having a refractive index of 1.5171 to 1.5741 is in the range of 0.0082 to 0.0101. The range corresponding to the Abbe number is 48.8-59.6. The refractive index at the lower end of the above range of widely used optical glass is obtained in the case of fused silica, which is also a preferred particle scattering colorant. The refractive index of fused silica ranges from 1.4619 at 509 nm to 1.4564 at 656 nm.

Ferroelectric ceramics (eg, solid solutions of the aforementioned barium titanate and BaTiO ₃ and any of SrTiO ₃ , PbTiO ₃ , BaSnO ₃ , CaTiO ₃ , or BaZrO ₃ ) are particles of the composition of the present invention. A preferred composition for the scattering colorant phase. The reason for such a choice consists of two elements. First, a very high refractive index can be obtained with such a large number of compositions. For high Δn embodiments, these high refractive indices can dramatically enhance coloration by increasing scattering due to the large difference in refractive index compared to the refractive index of the matrix phase. Second, if the matrix phase and the host phase match at the refractive index at a particular wavelength without the presence of an applied electric field (for the embodiment of annihilation Δn), the applied electric field will have Can be changed--which allows the color state to be switched. Alternatively, a ferroelectric phase that is an organic polymer can be selected as the host phase. If the particle phase is again chosen to match the refractive index of the unpolarized ferroelectric at a particular wavelength, this polarization process can introduce a colored electrical switching change. Such a match between the refractive index of the host phase and the refractive index of the particle scattering colorant can be a match that exists only in a specific direction of polarization. However, since it is highly preferred that the matrix material and the particle scattering colorant have little optical anisotropy, the match of the refractive indices has little to do with the polarization direction.

Ceramics that are relaxor ferroelectrics are preferred ferroelectrics for use as the particle scattering colorant phase. These relaxor ferroelectrics undergo a high degree of diffusion transition between the ferroelectric state and the paraelectric state. This transition is characterized by a temperature T _m, the the T _m is the temperature of the frequency-dependent peak in dielectric constant. As is conventional, even if such a ferroelectric does not have a single transition temperature from a pure ferroelectric state to a pure paraelectric state, we have herein described T _m Is called the Curie temperature (T _c ) of the relaxor ferroelectric. Such compositions can exhibit field induced changes with very high refractive index, so that relaxor ferroelectrics are preferred for use as particle scattering colorants when field induced color switching is desired during coloring. It is a ferroelectric material. Since these field induced refractive index changes generally decrease as the particle size decreases, the particle size should be chosen to be compatible with the desired color state to be obtained.

A preferred relaxor ferroelectric for use in the present invention has a lead titanate type structure (PbTiO ₃ ), and even a Pb type site (referred to as A site) or a Ti type site (referred to as B site). But it is chaotic. Examples of relaxor ferroelectrics having such B-site compositional disorder are Pb (Mg _1/3 Nb _2/3 ) O ₃ (called PMN), Pb (Zn _1/3 Nb _2/3 ) O. ₃ (referred to as PZN), Pb (Ni _1/3 Nb _2/3 ) O ₃ (referred to as PNN), Pb (Sc _1/2 Ta _1/2 ) O ₃ , Pb (Sc _1/2 Nb _1/2 ) O ₃ (referred to as PSN), Pb (Fe _1/2 Nb _1/2 ) O ₃ (referred to as PFN), and Pb (Fe _1/2 Ta _1/2 ) O ₃ . These have the form A (BF _1/3 BG _2/3 ) O ₃ and A (BF _1/2 BG _1/2 ) O ₃ , where BF and BG are the types of atoms on the B site. Represent. Further examples of relaxor ferroelectrics with disordered B sites are solid solutions of the above composition, for example (1-x) Pb (Mg _1/3 Nb _2/3 ) O ₃ -xPbTiO ₃ and (1-x) Pb (Zn _1/3 Nb _2/3 ) O ₃ —xPbTiO ₃ . Another preferred for use in the present invention, more complex relaxor ^{_{ferroelectric, Pb 1-x 2+ La x}} 3+ (Zr y Ti z) is _1-x / 4 _{O 3,} called PLZT. PZT (lead zirconate titanate, PbZr _1-x Ti _x O ₃ ) is a particularly preferred ferroelectric ceramic for use as a particle scattering colorant. PMN (magnesium lead niobate, Pb (Mg _1/3 Nb _2/3 ) O ₃ ) is another particularly preferred material, and becomes ferroelectric when it is below room temperature. Adding PT to the PMN provides a way to change the properties (eg, increasing the Curie transition temperature and changing the refractive index), and add (ie, alloyed) PT A ceramic composition obtained by adding up to 35 mole percent of PbTiO ₃ (PT) to the PMN can also be used as a particle scattering colorant, as relaxor ferroelectric states can be obtained using up to 35 mole percent. Particularly preferred.

A ceramic composition that undergoes an electric field induction type phase transition from an antiferroelectric state to a ferroelectric state is also preferable for obtaining a composite material that performs colored electric field induction type color switching. One preferred family is Brooks et al. (Journal of Applied Physics) for performing a ferroelectric transition to an antiferroelectric at an electric field as low as 0.027 MV / cm. ), 1994, vol. 75, pp. 1699-1704, Pb _0.97 La _0.02 (Zr, Ti, Sn) O ₃ family group. The lineage group includes “Piezoelectricity in the Field-Induced Ferroelectric Phase of Lead Zirconate-Based Antiferro-Piezoelectricity in the Field-Induced Ferroelectric Phase of Lead Zirconate-Based Antiferroelectrics”. s ", Journal of American Ceramics Society, 1992, Vol. 75, p. 795-799, and Furuta, etc." To Shape Memory Ceramics and Its Chain Locking Relays " Application of “Shape Memory Ceramics and Theirer Applications to Latching Relays”, Sensors and Materials, 1992, Vol. 3, No. 4, p. 205-215. examples of known compositions of this type is said to .PNZST family is lead-based antiferroelectric the general formula _{Pb 0.99 Nb 0.02 [(Zr 0.6} Sn 0.4) 1 _y is a Ti _{y] 0.98} O _3. composition encompassed by this system in the group indicates a field-induced ferroelectric behavior that is maintained even after the polarization field is removed. Such No behavior is observed for the type I material (y = 0.060), in which case the ferroelectric state reverts to the antiferroelectric state when the electric field is removed, however, the type II material (y = 0.63) maintains the ferroelectric state until a small reverse electric field is applied, and the type III material (y = 0.65) is antiferroelectric until thermally annealed above 50 ° C. Reflecting these property differences, Type I materials can be used in articles that change color when an electric field is applied and return to the original color state when the electric field is removed. . On the other hand, using Type II and Type III materials, an electric-field-switched color state until an electric field is applied in the opposite direction or until the material is thermally annealed. Can be obtained.

  Ferroelectric polymer compositions are suitable for providing both particle scattering colorants and matrix materials to composites that are electrically switchable from one color state to another. As used herein, the term ferroelectric polymer encompasses both homopolymers and all categories of copolymers, such as random copolymers and various types of block copolymers. The term also includes various physical and chemical mixtures of polymers. Poly (vinylidene fluoride) copolymers such as poly (vinylidene fluoride-trifluoroethylene), ie P (VDF-TrFE), are preferred ferroelectric polymer compositions. Additional copolymers of vinylidene fluoride useful in the compositions of the present invention are described in Macromolecular Symposium, 1994, 82, p. 99-109, described by Tournut. Other preferred ferroelectric polymer compositions include copolymers of vinylidene cyanide and vinyl acetate (especially an equimolar ratio copolymer), and odd value nylons such as nylon 11, nylon 9, nylon 7, nylon 5, nylon 3 And copolymers thereof.

  Other particle scattering colorants include colorants that are absorbent particle scattering colorants. One preferred family of such absorbent particle scattering colorants are metal colloidal particles (eg, gold, silver, platinum, palladium, lead, copper, tin, zinc, nickel, aluminum, iron, rhodium, Osmium, iridium, and alloys, metal oxides such as copper oxide, and metal salts). Preferably the particles are less than about 0.5 microns in average size. More preferably, the particles are less than about 0.1 microns in average size. Most preferred are particles smaller than about 0.02 microns in average size to obtain a special coloring effect. Whether or not a colloidal solution can be formed, particles having colloidal dimensions are referred to herein as colloidal particles. A particle size of less than about 0.02 microns exhibits a maximum of the refractive index and absorption coefficient of the particles determined by such a fine particle size, thus obtaining a wide range of coloring effects from certain compositions of absorbing particle scattering colorants. It is particularly useful for. Variations in wavelength-dependent refractive index and absorption coefficient due to such dimensions are greatly enhanced in particles sometimes called quantum dots. Such quantum dot particles preferably have a narrow particle size distribution and an average particle size of about 0.002 to about 0.010 microns.

  Convenient methods for forming colloidal particles include various methods well known in the art, such as reaction of metal salts in solution, or crystallization of a material such as a solid matrix or vesicle in an enclosed space. . Similarly, colloidal sized liquid or solid particles dispersed in a gas or vacuum are reacted or otherwise transformed into solid particles of the desired composition, for example by crystallization. Any known method for producing colloidal particles can be used. As an example of forming colloidal particles useful in the present invention by a solution reaction method, Q, Yitai et al. (Materials Research Bulletin, 1995, Vol. 30, p. Note in (601-605) that hydrothermal treatment of a mixed solution of sodium sulfide and zinc acetate produces 0.006 micron diameter zinc sulfide particles with a very narrow particle distribution. . Also, D. Daichuan et al. (In Materials Research Bulletin, 1995, Vol. 30, p. 537-541) used microwave heating in the presence of urea. Report the production of colloidal particles of uniform size of beta-FeO (OH) by hydrolyzing iron (III) salts. These particles were rod-shaped and had a narrow size distribution. Using a similar method (the method described in Materials Research Bulletin, 1995, Vol. 30, p. 531-535), these authors are close to square to spherical (about Colloidal particles of alpha-FeO were produced having a uniform shape (and dimensions) that can range (with an average particle size of 0.075 microns). T. Smith et al. Reported the production of colloidal particles in co-assigned US Pat. No. 5,932,309, in which gold chloride (such as III) was reported. Colloidal particles are prepared in situ by blending a metal salt with a polymer such as nylon 6 and then extruding the mixture.In addition, this patent uses a metal salt such as gold (III) chloride. Disclosed is the formation of colloids in solution in the solid state in the presence of a reducing agent, such as trisodium citrate, and fibrous particle scattering colorants having colloidal size in at least two dimensions are also particularly anisotropic. Some unique embodiments for forming very fine fibers that can be used as particle scattering colorants are preferred for some invention embodiments where a sexual coloring effect is desired. By depositing material inside the empty fiber containment space, the particle scattering colorant can then contain filled nanoscale diameter fibers, or remove the sheath generated by the initial hollow fibers. (Which can be either physical or chemical means) can also be included, and common methods for producing such fibers by filling with nano-sized hollow fibers are, for example, buoys, buoys, Superlatives and Microstructures, 1994, Vol. 16, No. 2, pp. 133-135, such as P. V. Poborchii. Are present in the chrysotile asbestos fibers It has been announced that nano-fibers with a diameter of about 6 nm can be obtained by injecting molten gallium arsenide inside a 2-10 nm channel and subsequent crystallization, whether fibrous or not, The advantage of such finely sized particles is that the quantum mechanical effect provides a refractive index and electronic transition energy that are strongly influenced by the particle size. Different coloring effects can be obtained, and colloidal fibers of metal and semiconductor can obtain a high degree of dichroism in the visible range, and such a high degree of dichroism can be used as a particle scattering colorant. New appearances can be obtained with articles incorporating fibers.

  Colloidal particle scattering colorants, as well as particle scattering colorants having relatively large dimensions, including an outer layer that absorbs in the visible range, are among the preferred particle scattering colorants for use in high Δn embodiments. . In such high Δn embodiments, there is a large difference in refractive index between the particle scattering colorant and the matrix in the visible wavelength region. The reason for this choice is that a very thin layer of visible light absorbing colorant outside the colorless particle scattering colorant can dramatically increase scattering at the particle-matrix interface, but substantially increase light absorption. It is impossible. In order to achieve the advantages of such a particle scattering colorant configuration, (1) the visible light absorbing colorant coating on the surface of the particle scattering colorant averages more than 50% of the total volume of particles. Contains less particle scattering colorant; (2) the average particle size of the particle scattering colorant is less than 2 microns; and (3) the refractive index of the coating of the particle scattering colorant is such that the particle scattering particles are dispersed. It is preferred that the refractive index of the matrix differ by at least 10% at visible wavelengths. More preferably, (1) the visible light absorbing colorant coating on the surface of the particle scattering colorant comprises, on average, less than 20% of the particle scattering colorant less than the total volume of particles, (2) particles The average particle size of the scattering colorant is less than 0.2 microns. Such surface-enhanced particle scattering colorants are preferably applied to coatings, polymer fibers, polymer films, and polymer moldings. A method for producing colloidal particles containing a visible light absorbing colorant on the surface of a colorless support particle is disclosed in Materials, Chemistry, and Physics (LM, Gan, etc.). Materials and Chemistry and Physics), 1995, 40, p. 94-98. These authors synthesized barium sulfate particles coated with conductive polyaniline using the inverse microemulsion method. This composite particle size (about 0.01 to about 0.02 microns) is convenient for practicing the high Δn embodiments of the present invention.

  The colloidal particles can be added to the matrix in colloidal form, or the colloidal particles can be formed after being added to the matrix. Similarly, these processes of colloid formation and dispersion can also be performed on a matrix precursor, which is then converted to a matrix composition by a chemical process such as polymerization. For example, if the matrix is an organic polymer such as nylon, the metal colloid is formed in a liquid, mixed with the ground polymer, and heated to a temperature above the melting point of the polymer to produce a nylon colored with a particle scattering colorant. Can be manufactured. On the other hand, whether it is colloidal metal particles or not, their precursors can also be added to the monomer of the polymer, in which the colloidal particles can be formed, which can then be polymerized. Precursors for metal colloids can also be added to the polymer matrix and then colloidal particles can be formed in subsequent steps. Such a process that incorporates the formation of colloidal particles is a process of melting, dissolving, gelling, or solvent-swelling the polymer (or its precursor) in the process of colloid incorporation, colloid formation, or colloid formation and incorporation. It can be promoted by using. Alternatively, high energy mechanical mixing involving the solid state of the polymer (or its precursor) can be used to incorporate colloids, colloid formation or colloid formation.

  Incorporation of colloidal sized particle scattering colorants in the gel state polymer into the polymer fibers prior to formation of the gel state provides an additional preferred embodiment. In this method, the particle scattering colorant should have a refractive index at visible wavelengths that is preferably at least 10% different from that of the solid polymer matrix of the fiber. The average particle size of the particle scattering colorant is preferably less than about 0.2 microns, more preferably less than about 0.08 microns, and most preferably less than about 0.02 microns. For particle sizes less than about 0.02 microns, the particle scattering colorant preferably absorbs very well in the visible. When the particle scattering colorant is substantially non-absorbing in the visible, the polymer fiber preferably includes an electronic transition colorant mixed with the particle-scattering colorant in the gel state. Preferably, the electronic transition colorant is substantially in the form of black carbon, such as carbon black, and the particle scattering colorant comprises an inorganic component. To avoid interfering with fiber strength, both the particle scattering colorant and the optical electronic transition colorant used in these fibers should be of very small dimensions, preferably less than about 0.02 microns. Such an embodiment solves the longstanding problem that arises in high strength fibers spun in the gel state, such as high molecular weight polyurethanes spun from mineral oil gels. The problem is that conventional organic dyes or pigments prevent the formation of high quality articles from the gel state. An important example of a high-strength fiber article spun from the gel state is Spectra® manufactured by Honeywell International (formerly AlliedSignal). It is a gel to be processed and is widely used for fishing lines, fishing nets, sails, ropes and harnesses.

Ultrafine metal particles suitable for use as particle scattering colorants can be located on the surface of much larger particles that are themselves particle scattering colorants. Combinations of this form of particle scattering colorant are also suitable for use in the present invention. Such particle scattering colorants have metal particles deposited on a much larger polymer and their preparation is described by H. Tamai et al., Journal of Applied Physics, 56, 441-449. Page (1995). As another alternative, colloidal particle scattering colorants can be placed in larger particles that can additionally provide particle scattering coloring depending on their size and refractive index in the visible (relative to the matrix). In any case, the larger particles are referred to as particle scattering colorants as long as the particles involved are particle scattering colorants. In a preferred case, the colloidal particles are metal or metal alloy particles in a glass matrix. A method for obtaining colloidal copper dispersed in a glass containing SiO ₂ is described in Journal of Non-crystalline Solids 120, 199-206 (1990). Methods for obtaining silicate glasses containing colloidal particles of various metals are described in U.S. Pat. Nos. 2,515,936, 2,515,943, and 2,651,145. Is incorporated herein by reference. Glass containing these colloidal particle scattering colorants can be converted into particles by grinding or melting treatment and used as a particle scattering colorant. In such embodiments, the particle scattering colorant is preferably dispersed in the polymer matrix, thereby providing particle scattering coloration to an article comprising the resulting polymer composite.

The advantage of this colloid-within-particle designed particle scattering colorant is that glass particles can stabilize colloidal particles with respect to degradation processes such as oxidation. The second advantage is that high temperature methods can be used for colloid formation in glass, which could not be used for direct colloidal particle dispersion in an organic polymer matrix. A third advantage of the colloid-within-particle method is that the colloid formation and dispersion process is separate from the dispersion process of the particle scattering colorant in the final polymer matrix. Economic efficiency can be improved. The fourth advantage is that the particle matrix is electrically / conductive, magnetic, so that when appropriate fields are applied, the color can be changed, substantially reduced, or both changed and substantially reduced. And / or can be adjusted in response to light properties. As an alternative to melt synthesis of colloid-within-particle particle scattering colorants, such colorants are described in Nanostructure Materials 5, pp. 155-169 (1995). K. J. et al. It can be synthesized by the method used by Burham et al. The authors incorporated colloidal particles into silica by doping metal salts with silanes used in the solid-gel synthesis of silicates. By such means, they obtained Ag, Cu, Pt, Os, Co ₃ C, Fe ₃ P, Ni ₂ P, or Ge dispersed in silica. For the purposes of the present invention, colloidal particles dispersed in silica can be ground to a particle size suitable for use as a particle scattering colorant.

  The particles containing colloidal particles can be polymers rather than inorganic glass. It is known in the art to make films of colloidal dispersions of various metals in the presence of vinyl polymers with polar groups such as poly (vinyl alcohol), polyvinyl pyrrolidone, and poly (methyl vinyl ether). Particle scattering colorants suitable for embodiments of the present invention can be obtained by cutting or grinding (preferably at low temperature) polymer films formed by solvent evaporation of colloidal dispersions. More preferably, such particle scattering colorants can be formed by removing the solvent from an aerosol comprising colloidal particles dispersed in a polymer-containing solvent. Particle scattering colorants, either semiconductors or metal conductors, are the preferred main components for use with polymer fibers. Such particle scattering colorants generally provide large absorption at visible wavelengths. In such cases, the average diameter of the particle scattering colorant in the smallest dimension is less than about 2 microns, the neat polymer matrix is substantially visible and non-absorbing, and the transmitted visible light intensity of the particle scattering colorant is It is preferred that the minimum move at least about 10 nm as a result of the finite particle size of the particle scattering colorant. More preferably, this migration is at least about 20 nm for the selected particle scattering colorant particle size and the selected matrix material. In order to evaluate the effect of particle size on the minimum transmitted light intensity, a particle size f greater than about 20 microns gives a good approximation of an infinite particle size limit.

  For particle scattering colorant compositions that give a single maximum absorption coefficient in the visible region when the particle size is large, the preferred transmitted light intensity ratio can be applied separately to allow identification of preferred particle scattering colorants. Become. This method identifies particle scattering colorants having a transmitted light intensity ratio occurring in the visible wavelength region having at least two minimum values. These two minimums are probably caused by the difference between the minimum value resulting from the absorption and scattering processes for the bimodal distribution of particle sizes, or for a unimodal distribution of particle sizes, in addition to other minimum values. sell. Where particle scattering colorants are required for applications where color state switchability is required, it is preferred that these two minimums occur in a unimodal distribution of particle sizes. The reason for this preference is that the switchability in the difference in refractive index between the matrix and the particle scattering colorant can provide a switchable color when the particle scattering effect is dominant. Thus, in another embodiment of this technique, switchable coloration due to refractive index change is combined with color change or loss due to particle aggregation. Unimodal or bimodal particle distribution (see above) represents the particle distribution of the weight fraction with one or two vertices, respectively.

For applications where reversible color changes corresponding to temperature changes are desired, certain ceramics that produce reversible electronic phase changes are preferred particle scattering colorants. Composition as experience reversible transition to simultaneously high conductivity state and temperature _{rise, VO 2, V 2, O} 3, NiS, NbO 2, FeSi 2, Fe 3 O 4, NbO 2, Ti 2 O ₃ , Ti ₄ O ₇ , Ti ₅ O ₉ , and V _1-X M _X O ₂ , where M is a dopant that lowers the transition temperature from that of VO 2 (such as W, Mo, Ta, or Nb) , X is much smaller than one. VO ₂ is a particularly preferred color-changing particle additive because it exhibits dramatic changes in both the actual and virtual components of the refractive index at a particularly convenient temperature (about 68 ° C.). The synthesis and electronic properties of these inorganic phases are described by Speck et al. In Thin Solid Films 165, 317-322 (1988) and by Jorgenson and Lee in Solar Energy Materials (Solar). Energy Material) 14, 205-214 (1986).

  Various forms of aromatic carbon are preferred electronic transition colorants for use in enhancing the coloring effect of particle scattering colorants because of their stability and light absorption capability in a broad band. Such preferred compositions include various carbon blacks such as channel black, furnace black, bone charcoal, and lamp black. Other inorganic and organic colorants conventionally used in the pigment and dye industry are also useful depending on the color effect desired from the effect of the combination of particle scattering colorants and electronic colorants. Examples of such inorganic pigments include iron oxide, chromium oxide, lead chromate, ammonium ferrocyanide, chromium green, ultramarine, and cadmium pigments. Examples of suitable organic pigments are azo pigments, phthalocyanine blue and green pigments, quinacridone pigments, dioxazine pigments, isoindolinone pigments, and vat pigments.

  The use of electronic transition colorants that are dichroic or dichroic matrix compositions can be used to provide a novel appearance. Such a new appearance arises, for example, because the scattering of the particle scattering colorant can indicate the degree of polarization. Preferred orientation of the dichroic axis is preferred, preferably horizontal or perpendicular to the fiber axis for the fiber, or in the film plane for the film, and conventional adoption such as mechanical drawings used to make polarizers It can be easily achieved by the method used. Dichroic behavior can be usefully developed in the same matrix component or in different matrix components in which the particle scattering colorant is dispersed. One preferred method of providing a dichroic polymer matrix for large Δn embodiments is to incorporate the dye molecules into the polymer and then uniaxially stretch the matrix containing the dye molecules. Such dye molecules function as dichroic electron absorbing colorants. The effect of the mechanical stretching step is to preferentially orient the optical fiber axis of the dye molecule with respect to the polymer stretching axis. Preparation of a polarizing film by mechanical stretching of a polymer host matrix is described in Direx et al., Macromolecule 28, 486-491 (1995). In the examples given by these authors, the dye was Sudan Red and the host matrix was polyethylene. However, combinations of various other dye molecules and polymer matrices are also suitable for achieving a polarizing effect that can be usefully employed in the particle scattering colorant compositions of embodiments of the present invention.

  Various chemical compositions that can provide switchability of refractive index or absorption coefficient are useful for host matrix, particle scattering colorants, or electronic transition colorants that enhance the scattering effect of particle colorants. In order to achieve an anisotropic new coloring effect, all of these switchable chemical compositions that are anisotropic can optionally be incorporated into the prefabricated article in a preferentially oriented form. . By providing refractive index and electronic transition changes that occur as a function of heat exposure, light exposure, or humidity changes, such materials (either with or without a preferential orientation) can be switchable colored. Provide state. Various discoloration chemicals suitable for use in the present invention, for example, the sentence entitled “Organic Photochromes” (AV El'ssov (Consultant Bureau, New York, 1990) ), Indigo, fulgide, spiropyran and other photochromic organics are known. Such discoloration chemicals are employed as electronic transition colorants that alter the visual effect of the particle scattering colorant in the polymer composite. Also, discoloration that responds to temperature, light exposure, or humidity can be generated using a material that, as an alternative, changes its refractive index in response to these effects and does not significantly change its absorption coefficient at visible wavelengths. Can do. Such materials can be used either as matrix materials or as particle scattering colorants in a color changing composite.

  Photopolymerizable monomers, photodoped polymers, photodegradable polymers, and photocrosslinkable polymers also have switchable refractive index and switchable electron absorption properties that allow the construction of articles with switchable particle scattering coloration. Available for provision. Suitable materials for this use are described, for example, in J. E. Lai, “Polymers for Electronic Applications”, Chapter 1, pages 1-32; E. Lai (CRC Press, Boca Raton, Florida, 1989). Improved materials are described in G.G. M.M. Described by Wallluff et al. In CHEMTECH, pages 22-30, April 1993, and a new type of composition is described in M.C. S. A. Abdou et al., In Chem. Mater. 3, 1003-1006 (1991). Examples of photopolymerizable monomers and oligomers include two or more conjugated diacetylene groups (polymerizable in the solid state), vinyl ether-terminated esters, vinyl ether-terminated urethanes, vinyl ether-terminated ethers, vinyl ether-terminated functional siloxanes, various It contains hybrid systems including diolefins, various epoxies, various acrylates, and mixtures thereof. Various photoinitiators, such as triarylphonium salts, are also useful in such systems.

  Polymer-colored articles include fillers, processing aids, antistatic agents, antioxidants, antiozonants, stabilizers, lubricants, mold release agents, antifogging agents, plasticizers, and other technical fields. Standard additives can also be included. Unless such additives additionally function as a particle scattering colorant or electronic transition colorant for the desired purpose, such additives are preferably uniformly dissolved in the polymer containing the particle scattering colorant or such additives. Should have some degree of transparency and a refractive index close to that of the matrix polymer. Dispersants such as surfactants are particularly useful for dispersing particle scattering colorant particles. A number of suitable dispersants and other polymer additives are well known in the art and are described in “Additives for Plastics”, 1st edition, J. MoI. Shuen and N.I. It is described in books such as the edition of Mehlberg (D.A.T.A., Inc., 1987). Coupling agents that bind the particle scattering particles to the host matrix are particularly important additives for Δn disappearance embodiments because they can eliminate crack formation or low wetting at the particle-matrix interface. When either glass or ceramic is a particle scattering colorant and the host matrix is an organic polymer, the preferred coupling agent improves bonding in commercially available composites involving both inorganic and organic phases There are various silanes designed to do. Examples of suitable coupling agents for this type of particle scattering colorant composite are 7169-45B and X1-6124 from Dow Corning Company.

  Various methods can be employed for blending and secondary processing of the composite. For example, particle scattering colorants can be (1) melt phase dispersed, (2) solution phase dispersed, (3) dispersed in a colloidal polymer suspension, or (4) dispersed in either a prepolymer or monomer of the polymer. Can be blended with the polymer matrix material. Composite films can be formed by solvent evaporation or by sample filtration, drying, and hot pressing after adding a non-solvent to a solution containing dispersed ceramic powder and dissolved polymer. In method (4), the ceramic particles can be dispersed in a monomer or prepolymer that is later thermally polymerized or polymerized using actinic radiation such as ultraviolet, electron or gamma radiation. . The particle scattering colorant can also be combined with the matrix by methods well known in the art such as xerography, powder coating, plasma deposition and the like. For example, particle scattering colorants may be added to “Textile Fabrics with Xerography” (WW Carr, FL Cook, WR Lanigan). ), M. S. Sikorski and W. C. Tinche, Textile Chemist and Colorist, Vol. 23, No. 5, 1991). Can be added to fabrics or carpets by using xerographic techniques. Coating fabrics, carpet fibers, and wallpaper articles with particle scattering colorants in a fusible polymer matrix to obtain coloration is a rapid response to frequent style and color changes and individual consumer preferences. This is a particularly important embodiment because the delivery of goods is commercially important. Such deposition can optionally be preceded by separately depositing an electronic transition colorant to enhance the effect of the particle scattering colorant.

  In order to uniformly mix the ceramic in the host polymer, an ultrasonic mixer can be used in the low viscosity composite precursor state, and a static mixer and a more general mixer can be used in the melt mixing process. Static mixers are particularly useful in the melt mixing process and are commercially available from Kenics Corporation, Denver, Mass., USA, and chemical engineering by Chen and MacDonald, March 19th issue, 1973, pages 105-110. Melt phase formulation and melt phase secondary processing are preferred for the compositions useful in the present invention. Examples of useful melt phase secondary processing methods are hot rolling, extrusion, flat pressing, and injection molding. For secondary processing of more complex shapes, injection molding and extrusion are particularly preferred.

  In some cases, it is desirable to obtain some controlled aggregation of the particle scattering colorant to obtain anisotropy in the coloring effect. Such agglomeration to create anisotropy in coloration is preferably either one-dimensional or two-dimensional, with the direction of such agglomeration correlating for different particle agglomerations. Such a correlation of aggregation is most conveniently achieved by plastic mechanical deformation of the matrix heavily loaded with particle scattering colorants. For example, such mechanical deformation can occur in one or both of two orthogonal directions of the fiber direction for fibers and the film surface for films. As an alternative to using particle aggregation to obtain anisotropy in coloration, similar effects can be obtained using particle shape anisotropy. For example, due to mechanical deformation of the film and fibers during processing, the plate-like particles are generally preferentially oriented on the plate surface perpendicular to the film surface, and the fiber-like particles are preferred over the particle fiber axis parallel to the fiber axis of the composite. Oriented.

A special type of particle scattering colorant orientation effect is particularly useful in embodiments where Δn disappears. In such embodiments, it is usually preferred that the particle scattering colorant and the matrix material be isotropic in optical properties. However, to obtain a new angle-dependent coloring effect, the plate-like particles of anisotropic particle scattering colorant in the polymer film are preferentially oriented so that the optical axis of the particles is perpendicular to the film surface. Can do. Such particles and polymer matrix, the ordinary ray refractive index of the particles (n _o) is selected to be equal to that of the matrix in the visible wavelength. Thus, the film article appears to appear highly colored when light perpendicular to the film surface is transmitted through the film. However, light of similar appearance that is tilted towards the film surface is scattered at all wavelengths, so the article appears either colorless or slightly weakly colored. In such an embodiment, the particle scattering colorant is selected to have an optical axis perpendicular to the particle plate surface, which applies to any number of materials that are either hexagonal, triangular, or square symmetric. Preferential orientation of the planes of plate-like particles parallel to the film plane can be obtained by various conventional processes such as film rolling, solution precipitation, and biaxial stretching. Note that such plate-like particle scattering colorants are quite different from prior art plate interference colorants. For these prior art colorants, matching of the refractive index of the matrix and the particles is not required, and in fact a large difference in the refractive index of the particles and the matrix in the entire visible can increase the coloring effect.

  Fibers useful in the present invention can be formed by conventional spinning techniques or by cutting the film into continuous fibers or staples following melt processing of the film. An electronic transition colorant can optionally be included in the composite film composition. Alternatively, the polymer film containing the particle scattering colorant can be adhesively bonded to one or both sides of the polymer film containing the electronic transition colorant. The adhesive bonding layer between these polymer film layers can be any of those generally used for film lamination. However, it is preferable to employ the same matrix polymer as the bonded film and to select a bonding layer having approximately the same refractive index as the matrix polymer. Alternatively, the central film layer containing the electronic transition colorant and the outer film layer containing the particle scattering colorant can be coextruded in one step using well-known polymer film coextrusion techniques. If the desired final article is a polymer fiber, these multilayer film assemblies can later be cut into fiber form. Micro slitters and winding devices are available from Ito Seisakusho Co., Ltd. (Japan) and are suitable for converting such film materials into continuous fibers. A particularly interesting visual effect is obtained when these fibers are cut from a bilayer film consisting of a polymer film layer containing a particle scattering colorant on one side and a polymer film layer containing an electronic transition colorant on the other side. Fibers that give different appearance at different viewing angles together produce a spatially colored material with the appearance at one viewing angle of alternating segments of different coloration in various applications such as carpets and fabrics. One coloring effect is obtained when the closest visible fiber side is the particle scattering colorant film layer, and another coloring effect is obtained when the closest visible side is the electron transition colored film layer. This special coloring effect of the cut film fibers is most visually noticeable when the width to thickness ratio of the cut film fiber bands is at least 5. Furthermore, the dimensional compatibility for blending such fibers with conventional polymer fibers in textile and carpet applications is increased when the cut film fiber has a denier of less than 200. As an alternative to the slit film method, either bilayer or multilayer fibers with these characteristics can be directly melt-spun using a spinneret designed using available spinneret technology.

  Suitable sheath core fibers for use in the present invention are fibers comprising a first composition sheath and a second composition core. Either the sheath or the core can be inorganic, organic, or a mixture of inorganic and organic, regardless of the composition of the other component. Preferably, both the sheath and the core of such fibers contain an organic polymer composition. Further, the particle scattering colorant is preferably disposed within the sheath and the electronic transition colorant is preferably disposed within the core. By selecting a cross-sectional shape of the sheath or core that is not cylindrically symmetric, it is possible to give different coloration when viewed in different lateral directions. For example, the outer sheath shape may be a cylinder and the core may be a high aspect ratio ellipse. When viewed at right angles to the fiber direction along the long axis direction of the ellipse, the effect of the electronic transition colorant becomes the dominant coloration. On the other hand, the corresponding view along the minor axis of the ellipse gives a visual effect that is less affected by the electronic transition colorant. More generally, to achieve such an angle-dependent visual effect, the maximum ratio of the orthogonal axis dimensions of the outer cross-section of the sheath is preferably less than one-half of the corresponding ratio of the core. Alternatively, both the sheath and core preferably have a maximum ratio of orthogonal axis dimensions in cross section of greater than 2 and the major axis dimensions of the sheath and core sections are preferably not aligned. Such fibers that give different visual appearances with different visions can be combined into spatially colored materials with different visual appearances of alternating segments of different colors in various applications such as carpets and textiles. Can be produced.

  The possibility of changing the color of the sheath-core fibers by changing the relative cross-sectional area of the sheath and core is useful for normal production of yarns that exhibit interesting visual effects based on changing the color of the various fibers in the yarn. Such a change can be achieved, for example, by changing the relative or absolute size of the sheath and core, the relative shape, and the relative configuration of the cross section of the sheath and core. For any of these cases, the above changes can be made along the length of each fiber or for the various fibers of the yarn. In these embodiments, it is preferred if the particle scattering colorant is in the fiber sheath and the electronic transition colorant is in the fiber core. That is, it is preferable to integrate yarns made of such fibers immediately after spinning from a porous spinneret. By changing the individual hole structure of the spinneret or by changing the feed pressure of the sheath and core for the various fiber spinning holes, the inter-fiber relationship can be changed as desired in the sheath cross section, the core cross section or both cross sections. Alternatively, the color of individual fibers along the length of the fibers can be changed by conventional means. Depending on the spinning time, the above means can either (1) change the sheath polymer feed pressure or the core polymer feed pressure, or (2) change the relative temperature of the sheath polymer and the core polymer in the spinneret. Of these methods, a color change along the length of the individual fibers is preferred, and such changes are preferably accomplished by changing the relative feed pressures of the sheath and core fiber components. Such pressure changes are preferably made simultaneously for the spinneret holes used in the production of various fibers, and such spinneret holes for the various fibers are preferably substantially the same. The yarn is preferably formed from fibers in the vicinity of the spinning point, and thus the relevance of the position of the same color tone for the various fibers does not disappear. As a result of such a preferred embodiment, the color changes of the individual fibers are spatially related between the fibers, and thus these color changes are very clear in the yarn.

  The fact that the fiber tone depends on the sheath / core ratio and the mechanical stretching process when the particle scattering colorant is in the sheath and the electronic transition colorant is in the core provides an important sensor application. For these sensor applications, color changes due to fiber wear and other fiber damage processes are utilized. Examples of the fiber damage process described above include fiber fragmentation that gives color tones due to deformation of the cross section of the sheath and core, wear or fiber dissolution that will change the cross section of the fiber sheath and (change the cross section of the sheath and core , Particle scattering colorant aggregation, polymer chain coordination and fiber crystallinity). In any case, the basis for these tone changes is generally a change in the relative contribution from the particle scattering colorant and the electronic transition colorant to the colored article. Such sensors are used for articles (eg, ropes, suspension cords and tire cords) where such defects and instabilities will induce frequent article changes if significant defects occur. Can provide effective indication of damage. These sheath / core fibers can be used as a few or many color indicator articles in such articles.

  Other methods can be used to obtain a particle-induced color tone for fibers spun into a hollow shape. Particles that impart a color tone through scattering can be dispersed in a suitable liquid so that the liquid fills the hollow fibers. In order to enhance the coloring effect, any electronic transition colorant can be introduced into the liquid. This approach involves the use of precursor fibers that are staples (ie, short cut lengths with open ends) or, if the hollow fiber core breaks to the surface, possibly hollow fibers containing micropores. Easy to use. The presence of these micropores allows for rapid filling of the fibers. A moderate pressure, preferably below 2000 psi, can be used to facilitate rapid filling of the fibers. The low viscosity carrier fluid is preferably selected as a fluid that can be photopolymerized or heat polymerized after the filling process. As an alternative to this approach, a particle scattering colorant can be introduced into the molten polymer for melt spinning hollow fibers. In this case, the polymerizable fluid drawn into the hollow fiber after spinning can contain an electronic transition colorant to enhance the coloring effect of the particle scattering colorant. Various variations of these methods can be used. For example, melt spun fibers can contain various combinations of particle scattering colorants and electronic transition colorants, as well as fluid drawn into the hollow fibers. As another variation of these methods, the inner wall of a hollow fiber spun from a melt containing a particle scattering colorant can be coated with a material that absorbs part of the light that is not scattered by the particle scattering colorant. For example, such a coating can be obtained by applying an oxidant-containing monomer solution for a conductive polymer, that is, a solution for polymerizing the conductive polymer to the inner wall of the hollow fiber, and then removing the solution used for the polymerization from the hollow fiber. Can be achieved. The inner wall of the hollow fiber is preferably coated with an electronic transition colorant using a solution colorant process that requires thermal curing. For example, by applying an appropriate pressure, the colorant solution can be sucked into the hollow fiber, some colorant solution on the outer surface of the fiber can be washed away, and the color of the colorant can be fixed by heat treatment, The included colorant solution can be removed (eg, by evaporation of the aqueous solution). Instead of thermal curing, colorant curing on the inner surface of the hollow fiber can be performed by photochemical or thermal effects of radiation (eg, electron beam, ultraviolet or infrared). Such thermal or light-related curing of the colorant can be performed in a patterned manner, thus providing fibers that exhibit the type of spatial tone effect required for carpet and textile applications.

  The same method described above for achieving the inner wall coloration of the hollow fiber can be used to achieve a new optical effect by depositing particle scattering colorant within the hollow fiber. These particle colorants are preferably deposited by drawing a colloidal solution containing the particle scattering colorant into the hollow fibers and then vaporizing the fluid that is the carrier of the colloidal particles. The liquid in which the colloidal particles are dispersed can optionally include a material that forms a solid matrix of colloidal particles after removal of the fluid component. Such a colloidal particle-dispersed colorant deposited as a normal layer on the inner wall or as a dispersion in a matrix is then optionally coated with a method as described above for coating the inner wall of a hollow fiber that is not coated with a particle scattering colorant. Can coat the electronic transition colorant. Note that the deposition of colloidal particles on the inner wall of the hollow fiber will result in agglomeration of the particles to the extent that the transition from the particle scattering colorant to the electronic transition colorant occurs. Depending on the desired coloring effect, agglomeration may or may not be desirable. Agglomeration can be enhanced by selecting particles that respond to electrical / conductive, magnetic and / or optical properties, thus changing color, substantially reducing, and applying the appropriate field Both changes and substantial reductions can be realized.

In the following embodiments, the particle scattering colorant is used in the hollow fiber for the formation of photochromism. Such photochromism can be achieved by the use of a particle scattering colorant that is a photoferroelectric. Preferred photoferroelectrics for this use are compositions that include, for example, BaTiO ₃ , SbNbO ₄ , KNbO ₃ , LiNbO ₃ and optional dopants (eg, iron). These and related compositions are described in “Photoferroelectrics” by Fridkin (Springer Publishing, Berlin, 1979), Chapter 6 (p85-114). For photoferroelectrics, a photovoltage on the order of 10 ³ -10 ⁵ volts can be generated. However, it must be recognized that the photovoltage decreases with decreasing particle size in the polarization direction. The corresponding electric field generated by light can be used to reversibly form agglomeration (ie, particle chain) of photoferroelectric particles dispersed within the hollow fiber cavity in a low conductivity liquid. If these photoferroelectric particles have suitably small dimensions, the agglomeration / decomposition process results in a light-induced change in the appearance and color of the fiber. The conductivity of the fluid can determine the return rate of the color tone to the initial state after the exposure is completed. This is because this conductivity can compensate for the photoinduced charge separation that creates the photoinduced field. The above method can be used to fill hollow fibers with a photoferroelectric-containing liquid, and such liquids within the fibers by a variety of processes (eg, by periodic closure of hollow pipes utilizing mechanical deformation). Can be enclosed. Articles made of these photochromic fibers can be used for various purposes (for example, as clothing in which the color tone automatically changes upon exposure).

  In other embodiments, the particle scattering colorant has the same refractive index as the photoferroelectric at certain visible wavelengths (if the photoferroelectric is not exposed) or after being exposed or both). A photo-ferroelectric material dispersed in a solid matrix having This aspect shifts the wavelength at which index matching occurs (or induces or eliminates such index matching) and thus occurs during exposure of a photoferroelectric that induces a color change in response to light. Use refractive index change.

  In the case of the previous embodiment studied (for sheath core fiber, 3 layer film, 2 layer film, derived cut film fiber and hollow polymer fiber), the layer outside the layer containing the electronic transition colorant The use of particle scattering colorants is described. One advantage of the description is the new coloring effect achieved. Other advantages of such a configuration are particularly noteworthy. That is, particularly particle scattering colorants that give a blue hue generally produce significant scattering that induces fading of many electronic transition colorants in the ultraviolet region of the spectrum. Accordingly, this ultraviolet scattering prevents fading due to ultraviolet light exposure of the lower electronic transition colorant.

The preferred embodiment results from the advantage of using a particle scattering colorant that serves for ultraviolet light protection of ultraviolet light sensitive textile and film articles. Articles in which a particle scattering colorant is dispersed in a first matrix material that is substantially outside of a second matrix component that substantially includes an electronic transition colorant (eg, hollow fibers, sheath core fibers, three-layer films and derivatized as described above) (1) the first matrix component and the material contained therein absorb less than about 90% of the total visible light incident from at least one possible viewing angle, and (2) the first matrix The absorption coefficient of the component and the material contained therein is less than about 50% of the absorption coefficient of the second matrix component and the material contained therein at visible wavelengths, (3) and the particle scattering colorant is It is preferably substantially non-absorbable in the visible range. Furthermore, if the first matrix component and the material contained therein absorb or scatter about 50% or more of the uniform radiation at the ultraviolet wavelength where the second matrix component including the electron dopant receives the maximum tone fading rate. preferable. The phrase “uniform radiation” means radiation having the same intensity for all spherical angles around the sample. Uniform radiation conditions exist when the same radiation intensity exists for all possible viewing angles of the article. The most effective average particle size to reduce the transmission of light through a matrix at a wavelength λ0 is typically greater than lambda _0/10, less than λ _0/2. Therefore, for the most rapid maximum protection of the fading to the electronic transition colorant at lambda _0, the average particle diameter of the particles scattering colorant is preferred if the range of about lambda _{0 /.} 2 to about λ _0/10. Furthermore, for this reason, the particle scattering colorant is preferably generally spherical (the average value of the ratio between the maximum dimension and the minimum dimension of each particle is smaller than 4), and in this case, the dispersion of the sizes of the various particles Must be small. Most preferably, the average particle size of the particle scattering colorant used for ultraviolet light protection of the electronic transition pigment is in the range of about 0.03 to about 0.1 microns. Particularly preferred particle scattering colorants for providing ultraviolet light protection of electronic transition colorants are titanium dioxide and zinc oxide.

  Suitable materials for the current technology include inorganic materials or organic materials having any combination of organic coatings, any combination of inorganic coatings, or organic coating-inorganic coating mixtures. The only fundamental limitation on such coating materials is that the coating material provides transparency in the visible spectral range when the entire surface of the article is coated with such coating material. Preferred coating materials for use on film, fiber or cast surface are well known materials called anti-reflective coating materials because they minimize external reflections. Such an anti-reflective coating can enhance the visual effect of the particle scattering colorant by reducing the amount of light reflected in multiple colors. The article so that the refractive index of the coating is in the vicinity of the square root of the refractive index of the article surface and the thickness of the coating is in the vicinity of λ / 4, where λ is the approximate wavelength of the light in question. By coating the surface, an antireflective coating can be obtained. For example, anti-reflective coatings can be obtained from solutions by means well known for polymers, such as by surface fluorination for polycarbonate, polystyrene and poly (methyl methacrylate), by plasma deposition of fluorocarbon polymers on the surface. Or by in situ polymerization of fluoromonomers impregnated on the surface. If the refractive index of the antireflective polymer layer does not approximate the square root of the refractive index of the article surface, the light is incident obliquely on the surface and the wavelength of the light is substantially different from λ and is appropriate for the current application. Anti-reflective properties are obtained through the use of such a single layer. Furthermore, in the case of known broadband technology, a multilayer antireflection coating can be used to obtain an antireflection coating with improved function. Thus, an antireflective coating that reduces multicolored surface reflections that can interfere with the visual effects of particle scattering colorants can be provided for essentially any substrate (eg, a polymer film).

  The ability to arrange the light scattering particles in a patterned manner is important in achieving the desired spatial coloration for many articles (eg, polymer fibers). A group of processes can be used to achieve such spatial coloring. In one method, the magnetic field effect is used to order the magnetic colloid fluid. Such fluids can be converted to solid materials by thermal or photochemical curing. Such thermal curing is preferably by a glass transition temperature or a temperature drop below the melting point or thermal polymerization. Such photochemical curing is preferably by photopolymerization to a glassy state. Another useful curing process is solvent evaporation from a colloidal suspension. Such curing is preferably carried out while the magnetic material is in a field-ordered state, thus providing the article with new optical properties due to the scattering and absorption effects of the ordered magnetic material. . Examples of magnetic colloidal suspensions that can be used to obtain a novel coloring effect are nanoscale magnetic oxide water-based or organic solvent-based suspensions. Such a suspension is called a ferrofluid and is manufactured by Ferrofluidics Co. (Nashua, N.H.), which is commercially available from Journal of Magnetics and Magnetic Materials, Vol. 85, p233-245 (1990), described by Raj and Moskowitz. One example of how magnetic particles can be deposited in spatially different paths is shown by returning to the hollow fiber example. Such hollow fibers can be filled with a dispersion of magnetic particles in a polymerizable fluid. The magnetic particles can be spatially distributed in a desired pattern along the length of the hollow fiber using a magnetic field. Furthermore, the fluid can be polymerized or crosslinked thermally or by actinic exposure for structural fixation. The thermal effect of polyurethane provides a type of thermally cured fluid that is preferred for this application.

  The spatially different coloration of the fibers and films can be achieved quite simply by a mechanical stretching process that varies along the length of the fibers or films. If the degree of stretching is changed, the refractive index of the polymer matrix and the degree of crystallinity induced by stretching can be changed. This change results in a spatially dependent change in color tone due to the particle scattering colorant. For such spatially dependent changes in visually perceived color tone, if the separation between ranges with different optical properties is not short enough to give a diffraction grating or holographic-like effect, Tonal changes must occur less frequently than 200 micron intervals.

  A particularly interesting and attractive visual effect can be achieved by depositing the particle scattering colorant as a spatially varying pattern of light wavelength scale. The result of such patterning is the creation of a holographic-like effect. Preferred particle scattering colorants useful in this embodiment have a refractive index that differs from the refractive index of the host matrix at the same wavelength that contrasts with the Christiansen filter case for all wavelengths in the visible range. Indeed, a particle scattering colorant patterned to provide a holographic effect is preferred if it differs from the effect of the matrix by at least about 10% over the visible range. Most preferably, this difference in the refractive index of the particle scattering colorant and the matrix is at least about 20% over the visible region of the spectrum.

  Useful embodiments of the particle scattering colorants of the present invention described above do not necessarily require an array of particles as an array with translational periodicity. Such an arrangement is desirable in some cases. This is because a new visual appearance, in particular an iridescence tone, is obtained. The problem is that it is crucial to achieve the desired two-dimensional or three-dimensional periodic arrangement on a time scale that is consistent with the economics driven polymer processing requirements. The particle scattering colorant of this embodiment consists of primary particles arranged in a translational periodic manner of m dimensions (where m is 2 or 3). It is preferred if the translational periodicity of the particle scattering colorant is similar to the wavelength of light in the visible spectrum. More particularly, this preferred translational periodicity is in the range of about 50 to about 2000 nm. More preferably, this translational periodicity is in the range of about 100 to about 1000 nm. In order to obtain such translational periodicity, it is desirable that the particle scattering colorant be composed of primary particles having a substantially uniform size in at least the m dimension. The particle scattering colorant can optionally include other primary particles. In this case, however, these other primary particles are smaller than the primary particles, or such other primary particles have a relatively uniform size at least in the m dimension. There is a restriction that it must be done. Preferably, the average size of the smallest primary particles is less than about 500 nm.

  The first step of the process is the preparation of a translationally ordered collection of primary particles. Since this first step is not necessarily performed in the production line of polymer articles (eg, fibers, films or other members), the productivity of such production line is particles composed of primary particles having translational periodicity. It is not reduced by the time required to form the scattering colorant. In the second step of the process, the particle scattering colorant is mixed with the polymer host matrix or precursor thereof. Then, as one or more third steps, any necessary polymerization or crosslinking reaction can be performed, and an article can be formed from a matrix polymer containing particles of particle scattering colorant. In order to optimize the desired visual effect, it is very important that such second and third steps do not completely disturb the translational periodic arrangement of the primary particles in the particle scattering colorant. This can be guaranteed in a group of ways. First, the average size of the smallest dimension particles of the particle scattering colorant should preferably be less than about one third of the smallest dimension of the polymer particles. Otherwise, mechanical stress during article manufacture will disturb the periodicity of the primary particles in the particle scattering colorant. The particle scattering colorant dimensions referred to herein are those of the particle scattering colorant in the shaped polymer matrix of the polymer article. In addition, however, the particle size of the particle scattering colorant in the polymer matrix formed of the polymer article is the particle size initially formed during the assembly of the primary particle array. The point is that if a mechanical process (e.g., mechanical grinding) potentially disturbs the translational periodicity in the particle scattering colorant, e.g., by the creation of cracks or grain boundaries in the particle scattering colorant, These steps are to be avoided as much as possible.

  A variety of methods can be used for the first step of forming particles of the particle scattering colorant comprising translationally periodic primary particles. One useful method is described by Philipse in Journal of Materials Science Letters 8, p1371-1373 (1989). This article describes the preparation of particles having an opal-like appearance (with strong red and green scattering tones) by a collection of silicon spheres having substantially uniform dimensions of about 135 nm. The article further states that the mechanical fastness of such particle scattering colorants having a three-dimensional periodic array of silica spheres can be increased by high temperature treatment (for several hours at 600 ° C.) of the silica sphere aggregate. Teach that. Such treatment reduces the optical effectiveness of the particle scattering colorant. This is because the particles become opaque. However, Philipse teaches that a particle aggregate can restore its original irradiant appearance if it is impregnated with silicone oil for several days. Further, such treatment (preferably using accelerated pressure, high temperature or low viscosity fluids) can be used to produce particle scattering colorants useful in the present invention. However, by forming a translational periodic aggregate of spherical primary particles from a fluid that can be polymerized after (1), (2) the fluid is sucked into the as-formed translational periodic particle aggregate or Evaporate and then polymerize the fluid, or (3) slowly cool the translational periodic particle assembly (as Philipse did), or suck or draw fluid into the interior of the particle assembly. More preferably, mechanical robustness is achieved by vaporizing and then polymerizing the fluid. Alternatively, the material can be dispersed within the periodic array of primary particles by gas phase physical or chemical deposition (eg, gas phase to polymerization). Such methods and related methods apparent to those skilled in the art can be used to form particle scattering colorants useful in this embodiment. For example, the primary particles may be organic, inorganic, or organic / inorganic hybrid. Similarly, any material dispersed within the primary particle array of the particle scattering colorant may be organic, inorganic, or organic / inorganic hybrid. If the hollow space between the primary particles is filled with gas only, and if the particle scattering colorant is too opaque to optimize the visual coloring effect, the liquid material or It is beneficial to use a solid material. Liquid or solid materials can minimize unwanted scattering due to cracks and grain boundaries that interrupt the periodic packing of primary particles. In such a case, it is preferable if such a liquid or solid has a visible range refractive index within 5% of the primary particles.

  Another method of providing useful particle scattering colorants uses polymer primary particles that form a regular array within a polymer host that serves as a binder. Films suitable for the preparation of such particle scattering colorants were produced by Kamenetzky et al. As part of the work described in Science 263, p207-210 (1994). These authors formed a regular three-dimensional array of colloidal polystyrene spheres by UV-induced curing of acrylamide methylenebisacrylamide gels containing such a regular array of spheres. The size of the polymer sphere is approximately 0.1 microns, and the closest separation line of the sphere is equivalent to the wavelength of visible light. A method for producing a film consisting of a three-dimensionally regular array of polymer primary particles without the use of a binder polymer is described by Macromolecules 25, 1870-1875 (1992) by Ma and Fukutomi. These films were mechanically stabilized by a crosslinking reaction using dihalobutane or p- (chloromethyl) styrene. A particle scattering colorant suitable for use in this embodiment can be made by cutting the film type to obtain particles of the desired size. One preferred cutting method is the process used at New York's Meadowbrook Inventions to make sparkling particles from metallized films. Various mechanical grinding processes can be used for the same purpose. In this case, however, it should be recognized that low temperatures can be used effectively to provide the brittleness that allows such a grinding process. For use as a particle scattering colorant, it is preferred that the cutting or milling process produce particles of a size suitable for introduction without substantial damage to the host matrix, which is preferably a polymer.

  The particle scattering colorant of this aspect is preferably formed to the required size during the assembly of primary particles. Any method used for particle size reduction after formation must be sufficiently gentle so as not to interfere with the desired periodicity of the primary particles. Similarly, the processing conditions during the mixing of the particle scattering colorant into the polymer matrix (or its precursor) and the processing conditions during the other steps leading to the formation of the final particles are dependent on the optical properties of the periodic aggregate of primary particles. The physical effect should not be substantially degraded. For particle scattering colorants that are not designed to be mechanically robust, the preferred process for mixing the particle scattering colorant and the matrix polymer (or precursor thereof) is in the solution of the polymer used in the monomer, prepolymer or matrix. Thus, it is in a state of a low viscosity fluid. For polymers that are not designed to be mechanically robust, film manufacturing and article coating using solution deposition methods are preferred to obtain a particle scattering colorant dispersed in a shaped matrix polymer. Similarly, for such non-fast particle scattering colorants, the polymer matrix can be formed in the mold by reaction of a particle scattering colorant-containing liquid, for example, thermal polymerization, photopolymerization or polymerization using other actinic radiation. Preferably formed. Reaction casting is particularly preferred for obtaining molded parts containing particle scattering colorants that are not mechanically robust.

  In other embodiments, the particle scattering colorant consists of primary particles that exhibit a translational periodicity in two dimensions rather than three dimensions. Fibrous primary particles having a substantially uniform cross section perpendicular to the fiber axial direction thus show a tendency to aggregate when dispersed in a suitable liquid. Similarly, spherical primary particles tend to aggregate as an array having a two-dimensional periodicity when deposited on a flat surface. For example, such particles can be formed on the surface of a liquid (or rotating drum) in a polymer binder that adhesively bonds spherical particles to a two-dimensional array. These array sheets can be cut or ground to the desired particle size for the particle scattering colorant.

  For each of the above embodiments of particle scattering colorants comprised of translationally periodic primary particles, it is preferred if the volume occupied by the particle scattering colorant is less than about 75% of the matrix polymer and particle scattering colorant or less than the total volume. The reason for this preference is that the use of a low charge level of particle scattering colorant improves the mechanical properties of the composite compared to composites obtained at high charge levels. As noted above for particle scattering colorants that are not aggregates of periodically arranged primary particles, the visual effect of particle scattering colorants consisting of a regular array of primary particles is enhanced by the use of electronic transition colorants. The Such enhancement means and methods of achieving a suitable color changing effect are similar to those described herein for other types of particle scattering colorants.

  From the standpoint of achieving a coloration effect on polymer particles that can be easily removed during polymer recycling, particle scattering colorants consisting of a translationally regular primary particle array, in particular, primary particles are substantially visible. There is a special advantage when there is no absorption in the region and the polymer particles do not contain an electronic transition colorant. The reason is that the process of separating such an array greatly reduces the coloring effect. From this point of view of polymer recycling, it is beneficial to use a particle scattering colorant that is suitably separated by thermal, mechanical or chemical processes.

  The tamper-proof article of the present invention can rely on films, slit films, sheets and fibers. The fibers can be formed into tamper-proof twisted yarns by conventional fiber processes such as twisting, cabling, braiding, texturing and thermosetting. The same or different anti-tamper fibers can be incorporated into the anti-tamper yarn. The tamper-proof article may be a film, a slit film, a fiber or a tamper-proof twisted yarn, and also an object or film in which at least one fiber or twisted is dispersed, a slit film, at least one fiber or twisted yarn, for example, , It may be an object to be incorporated by lamination. In the case of a structure incorporating a film, slit film, fiber, twisted yarn, etc. in or on the article, the length of the incorporated material is substantially equal to the length or width dimension of the object into which the material is incorporated. May be equal. For example, the average size may be approximately equal to the subject. Alternatively, the average size may be in the range of about 25 to about 100% or in the range of about 30 to about 90% of the subject size. Manufacturing and use concepts typically determine such characteristics. For articles containing fibrils and / or dots, the average dimension of the latter material is typically substantially less than the average dimension of the article, including the typical thickness of such articles. Useful anti-fraud goods and objects include passports, stacked identity cards, currency and banknotes, circulation securities, stock certificates and guarantees, licenses including driver's licenses, diplomas, credit and debit cards, anti-fraud certification cards, Includes certification records such as automated teller machines (ATM) or banking access cards and other important records dispersed or coated with anti-tamper yarns, dots, fibrils and / or slit plastic films that include the anti-tamper features of the present invention . In addition, plastic films containing tamper-proof features can be used directly to make the types described above and other types of tamper-proof articles. Furthermore, twisted yarns can be used to make luminescent logos that also incorporate anti-fraud features in textiles or clothing. The anti-fraud article of the present invention can further be used to make barcodes for use in various certification and anti-fraud applications. For example, each bar of the barcode can include fibers, twists or fibrils that include the same or different anti-fraud techniques described above. Cable twist tamper proof yarns can be tailored for specific end uses by a combination of color, luminescent response and particle scattering techniques.

  Further, provided that the anti-fraud article includes at least one luminescent material and at least one particle scattering colorant, there is one luminescent type material on one side and another luminescent material on the other side. An anti-fraud contribution component (eg, a chopped filament or fiber, which is present, or in which there is a combination of one particle scattering colored material and one luminescent material on one side and a luminescent material on the other side. It is within the scope of the present invention to incorporate a mixture of fibrils, dots, filaments and fibers). Thus, an anti-fraud effect that can significantly invalidate the forgery effect of the anti-fraud article can be achieved. For example, fibrils can be added to a plastic or cellulose matrix, in which case the fibrils exhibit a mixed coloring effect. For example, some of the fibrils exhibit particle scattering tones combined with fluorescence, and other portions exhibit only phosphorescence. Alternatively, the dots exhibit fluorescence in combination with a filament that exhibits particle scattering tones in combination with phosphorescence. Alternatively, the dots and fibrils exhibit particle scattering tone and fluorescence, respectively. Furthermore, other actions are also conceivable. The ability to keep the coloring effects in combination through the use of the specific techniques described herein provides a fraud prevention level for a variety of previously unusable articles and applications.

  Accordingly, the tamper-proof article of the present invention comprises a polymer matrix component, a cellulose matrix component or a glass matrix component, and in various combinations, a colorant that relies on the luminescent and particle scattering techniques described above. The polymer matrix component can further comprise a mixture of homopolymers or copolymers, and other additives typically present in the polymer composition simplify the processing of the composition, provide antioxidant, ozone stability. Can be used to improve color or tone stability, or to achieve one or more physical or functional characteristics in special applications. In particular, the anti-fraud article includes at least one particle scattering colorant and at least one luminescent material. A dispersion of dots and / or fibrils in a papermaking composition containing paper suitable for printing anti-fraud records (eg, diplomas, licenses and banknotes or currency) produces paper that contains anti-fraud features that prevent counterfeiting Can be used to Similarly, if the anti-fraud article of the present invention is incorporated into paper used for manufacturing credit cards, borrowing cards, automatic teller machine access cards, etc., the intended use of counterfeit cards or counterfeit cards can be prevented as well. . Such paper and cards can be used for printing including phrases and images.

  In the following examples, the formic acid concentration (FAV) of nylon 6 was measured using the method described in ASTM-D789-97. However, instead of the calibrated pipette type viscometer specified in the above standard, a Cannon-Feske viscometer (also called an improved Oswald viscometer) is used, and further, the specified amount is 11 per 100 mL of 90% formic acid. , 00 g instead of 5,50 g per 50 mL 90% formic acid.

  All reference signs herein relating to elements or metals belonging to some groups relate to the periodic table of elements as described in Hawley's Condensed Chemical dictionary, 13 size. That is, any reference signs relating to one or more families relate to one or more families shown in the periodic table of elements using a “new notation” system for family numbering.

  The following examples are given as specific illustrations of the invention. However, it should be understood that the invention is not limited to the specific details set forth in the examples. All parts and percentages in the examples and the rest of the detailed description relate to weight unless otherwise specified.

  Further, any numerical range cited in the detailed description or section set forth below or claiming various aspects of the invention, such as representing a particular set of properties, measurement unit, measurement unit, condition, physical state or percentage, Any numerical value falling within such a range or including any subset of a range, including any subset of such a range, is intended to be incorporated literally, as clearly indicated herein, such as by reference signs. To do. The phrase “about” used as a qualifier for or in combination with a variable is flexible in the numerical value and range disclosed herein and is either temperature, concentration, amount, content, carbon number, out of range or single In practicing the present invention by those skilled in the art using properties that are different from numerical values, the desired results are achieved, i.e., compositions, colored articles prepared from the above compositions and responsive to various ranges of the electromagnetic spectrum, and methods for their preparation. Is intended.

Examples Each of the compositions shown in the table below was prepared by Honeywell International Inc. Nylon 6 (grade: MBM, 55FAV) was used. Except for the control examples, each mixture was inverted mixed for about 2 hours in a two-shell dry mixer. The ingredients including the control sample and the mixture were dried separately in a vacuum oven at 120 ° C. overnight. LUMILUX® pigment, LUMILUX® Red CD 740 was manufactured by Honeywell Specialty Chemicals. The phosphorescent afterglow pigment (referred to as NYA) was a 30% by weight master-batch concentrate of green Luminova® pigment in nylon 6 (Nemoto Co., Ltd., Tokyo, Japan).

  The mixed mixture was fed to a Leistritz brand twin screw extruder with a diameter of 18 mm and an L / D ratio of 40: 1. The extruder screw has a mixing and kneading member and a conveyor member. The temperature of the extruder barrel zone was set at 250-255 ° C. The polymer melt was sent to a Zenith brand gear pump and then passed through a stepped screen pack consisting of 17 screens ranging from 20 mesh to 325 mesh (aperture 44 μm). After passing through the screen pack, the polymer melt was drawn from a 14-hole spinneret having a capillary diameter of 0.024 inches and a depth of 0.72 inches to form a circular filament cross section. The drawn molten filaments were solidified by a cocurrent quench air stream at about 19.5 ° C. The extrusion speed was 44.6 g / min, and the initial fiber take-out speed was 579 m / min. The fiber was drawn and spun inline at a ratio of 3.3: 1. The final fiber dimensional properties and tensile properties (measured by ASTM-D2256) are shown in the table below.

The filament of this example has a complex cross section (complexity factor 7) as shown in FIG. 1, and one component, when illuminated with a mercury UV lamp, is 622 nm (red) and 880 nm and 1060 nm (red Multiple fluorescent responses with peaks in the outer). Under normal lighting, AgNO ₃ -containing filaments were colored beige and AuCl ₃ -containing filaments were colored silver. For use as a dot, a thin cross section of the filament was cut and a filament section was prepared. Filaments, dots and filament sections were dispersed in cellulose matrices, films and plastic cards for the preparation of tamper-proof articles. The article exhibited color and luminescent properties under appropriate lighting.

  The principles, preferred embodiments and modes of operation of the present invention are described in the preceding detailed description. However, inventions intended to be protected here are not to be construed as limited to the particular forms disclosed. Because these should be considered as explanations rather than as constraints. Those skilled in the art can make changes and modifications without departing from the spirit of the invention.

Claims (65)

An anti-fraud article comprising a matrix component, wherein:
(A) at least one particle scattering colorant is dispersed; and
(B) at least one luminescent material is dispersed;
here:
(1) The at least one particle scattering colorant comprises particles selected from the group consisting of semiconductors, metal conductors, metal oxides, metal salts or mixtures thereof;
(2) the average cross-sectional size of the at least one particle scattering colorant is less than about 0.2 microns in the smallest dimension;
(3) the polymer matrix component is substantially non-absorbing in the visible light region of the spectrum;
(4) The particle scattering colorant has a minimum intensity ratio of transmitted light at 380-750 nanometers, which is the same semiconductor, metal conductor, metal oxide, having an average particle size greater than about 20 microns, A shift of at least 10 nanometers compared to that obtained for the metal salt or mixture thereof; and
(5) The luminescent material is selected from the group consisting of at least one phosphor, at least one phosphor, and a mixture of at least one phosphor and at least one phosphor, wherein The anti-fraud article, wherein the centric material exhibits a response peak in the luminescent spectrum when excited by at least one wavelength selected from the electromagnetic spectral region of about 200 to about 2,000 nanometers. An anti-fraud article comprising at least one first composition and at least one second composition comprising:
(A) the first composition comprises a solid first matrix component, a particle-dispersed colorant and at least one luminescent material dispersed therein;
(B) The at least one second composition comprises a polymer second matrix component and a colorant selected from the group consisting of an electronic transition colorant, a dye and a pigment dispersed therein. Including;
(C) the at least one first composition is;
(1) deposited on and substantially outside of the second composition on at least one side of the article; or
(2) the first composition and the second composition are either substantially penetrating each other;
here:
(I) there is at least one incident visible light wavelength and one incident light angle such that the first composition absorbs less than about 90% of the light incident on the article;
(Ii) the absorption coefficient of the at least one first composition is less than about 50% of the absorption coefficient of the second composition at a wavelength in the visible light region of the spectrum;
(Iii) The maximum absorption peak of the particle scattering colorant is not in the visible region of the spectrum;
(Iv) the luminescent material is selected from the group consisting of at least one phosphor, at least one phosphor, and a mixture of at least one phosphor and at least one phosphor, wherein The luminescent material exhibits a response peak in the emission spectrum when excited by one or more wavelengths selected from the electromagnetic spectral region of about 200 to about 2,000 nanometers; and
(V) (a) the particle scattering colorant has a refractive index comparable to that of the first matrix component at a wavelength in the visible light region and has an average particle size of less than about 2000 microns; or
(B) The average refractive index of the particle-dispersed colorant is at least about 5% different from that of the first matrix component in the visible wavelength range, and the average particle size of the smallest dimension of the particle scattering colorant is less than about 2 microns. And the particle scattering colorant has an effective maximum absorption that is at least about 2 times the effective minimum absorption at visible wavelengths when dispersed in a colorless isotropic liquid having substantially different refractive indices. Said article, characterized in that any of the above.   The particle scattering colorant particles are selected from the group consisting of gold, platinum, copper, aluminum, lead, palladium, silver, rhodium, osmium, iridium, and alloys thereof, wherein the particle scattering colorant particles are about 0.2. The article of claim 1 having an average diameter with a minimum dimension of less than a micron.   The article of claim 3, wherein the particle scattering colorant particles comprise one or more colloidal particles.   The article of claim 4, wherein the transmitted light intensity ratio has two minimum values in the wavelength region of the visible spectrum, and the particle distribution of the particle scattering colorant is approximately equal to the nodal distribution.   The at least one first composition absorbs or disperses more than about 50% of the uniform radiation at an ultraviolet wavelength at which the at least one second composition has a maximum fading rate. Goods.   The article of claim 2, wherein the particle scattering colorant is substantially non-absorbing in the visible light region.   The refractive index of the particle scattering colorant is substantially different from that of the first matrix component at all wavelengths in the visible region of the spectrum, and at least 50% of all particles of the particle scattering colorant are: The article of claim 2 having a minimum dimension of less than about 0.25 microns. For particle scattering colorants:
(A) the average particle size is from about 0.001 to about 0.4 microns;
(B) the average ratio of the largest dimension to the smallest dimension for the individual particles is less than about 4; and
The article of claim 2, wherein the refractive index is substantially different from that of the matrix at all wavelengths in the visible region of the spectrum. (A) the average particle size for the particle scattering colorant is less than about 1000 microns;
(B) both the first matrix component and the particle scattering colorant are substantially optically isotropic;
(C) there is a wavelength in the visible light region of the spectrum where the refractive index of the first matrix component is substantially equal to that of the particle scattering colorant;
(D) the refractive index difference between the first matrix component and the particle scattering colorant is substantially dependent on the wavelength in the visible range; and
3. The article of claim 2, wherein (e) the first matrix component is substantially non-absorbing at wavelengths in the visible region of the spectrum. The difference in n _F -n _C with respect to the particle scattering colorant and the first matrix component is greater than 0.001 in absolute amounts, where n _F and n _C are the particle scattering colorant and the first matrix component, respectively. The article of claim 10 having a refractive index of 486.1 nm and 656.3 nm.   The article of claim 1 or 2, wherein the matrix component is selected from the group consisting of a polymer, a cellulosic composition and glass, and the luminescent material comprises at least one fluorescent material and at least one phosphorescent material.   The article of claim 12, wherein the phosphor has afterglow characteristics.   At least one of the first and second matrix components includes at least one material selected from the group consisting of polyamide, polyester, polyolefin, polyvinyl, acrylic resin, polysulfone, polycarbonate, polyacrylate and polystyrene homopolymers and copolymers. The article according to claim 1 or 2. The first matrix component and the first matrix component is penetrated substantially mutually, the second component relates to alpha _e v _e V alpha regarding _e and the first component _s v _s V _s is the visible light range Where α _e is the absorption coefficient for the electronic transition colorant; α _s is the effective absorption coefficient for the particle scattering colorant; and v _s and v _e are each at least Volume of one first composition and second composition; and V _s and V _e are the volume fraction and electronic transition of said at least one first composition, respectively, which is a particle scattering colorant The article of claim 2, wherein the article is a volume fraction of the at least one second composition that is a colorant. At least one first composition is deposited on and substantially outside the second matrix composition on at least one side of the article; said at least one second composition is an electronic transition coloration There is a wavelength of visible light and a light incident angle at which light transmission of about 10% to about 90% occurs through the at least one first composition; and α _e t _e V _e Is greater than 0.1 for the at least one second composition; where α _e is the absorption coefficient at wavelengths in the visible region where maximum absorption occurs for the electronic transition colorant or the pigment T _e is the maximum thickness of the layer comprising the at least one second composition; and V _e is the volume of the at least one second composition comprising the electronic transition colorant or pigment. Claim 2 which is a fraction Article.   An article comprising a composition selected from the group consisting of filaments and fibers and selected from a plurality of compositions according to any of claims 1 and 2.   18. The article of claim 17, wherein the at least one first composition forms a sheath that substantially covers a filament or fiber core comprising the second matrix composition.   The article of claim 18, wherein the sheath and the core have different cross-sectional shapes.   20. The article of claim 19, wherein the maximum ratio of orthogonal axis dimensions of the cross-section of the outer surface of the sheath is less than about one-half of the corresponding ratio of the core.   The article of claim 18, wherein both the sheath and the core have a maximum ratio of orthogonal axis dimensions at a cross section greater than 2, and the long axis dimensions of the cross section of the sheath and the core are not aligned.   19. An element comprising a plurality of articles according to claim 18 having a spatially dependent color tone for individual articles, or a color tone for individual articles due to changes in sheath cross-section or core cross-section. element.   The article of claim 2, wherein the particle scattering colorant in the at least one first composition comprises an inorganic composition. Inorganic composition is bismuth oxychloride, titanium dioxide, antimony trioxide; BaTiO ₃ and solid solution of SrTiO ₃ , PbTiO ₃ , BaSnO ₃ , CaTiO ₃ , or BaZrO ₃ , lithium potassium niobate, aluminum hydroxide, zirconium oxide 24. The article of claim 23 comprising at least one material selected from the group consisting of: colloidal silica, lithium niobate, lithium tantalate, palerite; zinc oxide, alpha-zinc sulfide, and beta-zinc sulfide. .   The article of claim 1 or 2, wherein the particle scattering colorant comprises a ferroelectric material, an antiferroelectric material, or a photoferroelectric material.   26. The article of claim 25, wherein the ferroelectric material is a ceramic that is a relaxor ferroelectric.   27. The article of claim 26, wherein the relaxor ferroelectric ceramic has a Curie transition temperature of about 250 ° K to about 350 ° K. Ceramics that are relaxor ferroelectrics have the form of A (BF _1/2 BG _1/2 ) O ₃ (wherein BF and BG are the types of atoms on the B site in a lead titanate type structure). Or an alloy of one or more compositions of the above form with another ceramic composition, wherein A is Pb, BF _1/2 and BG _1/2 are independently 27. The article of claim 26, wherein the article is Sc1 _{/ 2} , Ta1 _{/ 2} , Fe1 _{/ 2} , or Nb1 _{/ 2} . Ceramics that are relaxor ferroelectrics have the form A (BF _1/3 BG _2/3 ) O ₃ , where BF and BG are the types of atoms on the B site in a lead titanate type structure. Or an alloy of one or more compositions of the above form with another ceramic composition, wherein A is Pb, BF _1/3 is Mg _1/3 , Ni _{1 /} 27. The article of claim 26, wherein the article is ₃ or Zn _1/3 and BG _2/3 is Nb _2/3 . 30. The article of claim 29, wherein the relaxor ceramic is Pb (Mg _1/3 Nb _2/3 ) O ₃ . Containing PbTiO ₃ alloyed up 35 mole percent The article of claim 30, wherein.   In the form of a film-like or planar structure, wherein at least one layer of the first composition is bonded to one side of the at least one second composition that is a film-like or planar structure 3. An article according to claim 1 or 2, wherein the article is or is joined to both back-to-back sides.   35. An article selected from the group consisting of a visual display including the article of claim 32 and a switchable image.   34. The article of claim 33, wherein the applied electric field changes a property selected from the group consisting of the refractive index and absorption coefficient of the colorant.   34. The article of claim 33, wherein the article comprises a ferroelectric material, an antiferroelectric material, or a photoferroelectric material.   The refractive index difference between the first polymer matrix component and either the particle scattering colorant or the electronic transition colorant is either temperature change, humidity change, heat exposure due to electric field integration, or light or actinic radiation. The article of claim 2, wherein the article undergoes a substantial change in wavelength in the visible spectrum as a result of one or more of the exposure to.   38. The article of claim 36, wherein the article undergoes a detectable color change in response to one or more of chemical, pressure, temperature, moisture uptake, temperature limitation, or time-temperature exposure.   38. The article of claim 36, wherein the electronic transition colorant comprises a photochromic anil, fulgide, or spiropyran.   3. An electronic transition colorant or a matrix polymer exhibiting an electronic transition colorant, wherein dichroism in the visible light region is due to a preferential orientation of either the electronic transition colorant or the matrix polymer. The article described. The fiber is a hollow fiber comprising a cavity in the center of the fiber and having an average dimension that is smaller than the overall average dimension of the fiber, wherein the hollow fiber comprises a particle scattering colorant, wherein:
(A) the particle scattering colorant is present inside the cavity; or (b) the particle scattering colorant is deposited in a polymer-containing matrix that forms a sheath surrounding the hollow fibers;
The article of claim 17, wherein (c) the inner surface of the hollow fiber proximate to the cavity is colored with a material that absorbs light significantly in the visible region of the spectrum.   Including a plurality of transverse holes extending from a fiber cavity to the outer surface of the fiber, wherein an average separation of adjacent holes along the length of the fiber is less than about 25.4 cm, and the average hole size is 13 41. The hollow fiber of claim 40, wherein the hollow fiber is capable of absorbing liquid into the fiber at a pressure of less than 8 MPa.   41. The hollow fiber of claim 40, comprising an electronic transition colorant.   When the average particle size of the particle scattering colorant is less than about 0.1 microns and the particle scattering colorant is dispersed in a colorless isotropic liquid having a substantially different refractive index, at visible wavelengths 41. The hollow fiber of claim 40, having an effective maximum absorption of at least about twice the effective minimum absorption.   The particle scattering colorant is selected from the group consisting of semiconductors and metal conductors; the polymer matrix component is substantially non-absorbing in the visible light region of the spectrum; and the particle scattering colorant is in the region of 380-750 nanometers 41. The transmitted light intensity ratio is minimized in at least 10 nanometers compared to that obtained for the same semiconductor or metal conductor having an average particle size greater than about 20 microns. Hollow fiber.   The article of claim 17 comprising at least one element selected from the group consisting of at least two fibers and at least two filaments.   The article of claim 17, wherein the effective dimension of the filament is about 0.01 to 3 mm.   48. The article of claim 46, comprising at least two fibers.   The article of claim 1 or 2, wherein the at least one luminescent response is generated by a wavelength in the infrared region of the electromagnetic spectrum.   The article of claim 1 or 2, wherein the at least one luminescent response is generated by a wavelength in the visible region of the electromagnetic spectrum.   The article of claim 1 or 2, wherein the at least one luminescent response is generated by a wavelength in the ultraviolet region of the electromagnetic spectrum.   The article of claim 1 or 2, wherein at least two excitation wavelengths selected from different members of the group consisting of infrared, visible and ultraviolet regions of the electromagnetic spectrum produce a luminescent response.   The article of claim 2, wherein the particle scattering colorant comprises a gas.   53. The article of claim 52, wherein the gas is air.   The article of claim 1 or 2, wherein the particle scattering colorant has an average particle size of less than 3 microns and comprises a plurality of layers, each of the layers having a different refractive index.   55. The article of claim 54, wherein the refractive index difference is greater than about 5%.   55. The article of claim 54, wherein the refractive index difference is greater than about 10%.   The article of claim 1 or 2, wherein the luminescent material comprises at least one phosphor and at least one phosphor having afterglow characteristics and is selected from the group consisting of filaments and fibers.   58. The article of claim 57, wherein the article is adapted for use on or in a subject and is selected from the group consisting of films, slit films, fibers, dots, and fibrils.   59. The article of claim 58, wherein the fiber, film, or slit film has an average length that is substantially equal to the length or width dimension of the object to be dispersed or incorporated.   59. The article of claim 58, wherein the fibrils or dots have an average maximum dimension that is substantially less than the length or width dimension of the object to be dispersed or incorporated.   61. The article of claim 60, wherein the fibrils or dots have a thickness that is substantially less than the thickness of the object to be dispersed or incorporated.   59. The article of claim 58, wherein the subject comprises at least one structural element selected from the group consisting of films and sheets.   64. The article of claim 62, wherein the at least one surface is suitable for incorporating information in a form selected from the group consisting of at least one image, a typeface, and a mixture of at least one image and typeface.   64. The article of claim 63, wherein the object is selected from the group consisting of banknotes, banknotes, circulation securities, passports, licenses, identification cards, credit cards, debit cards, and barcodes. Specific embodiments of the present application that can be described as follows:
1. An anti-fraud article comprising a matrix component, wherein:
(A) at least one particle scattering colorant is dispersed; and
(B) at least one luminescent material is dispersed;
here:
(1) The at least one particle scattering colorant comprises particles selected from the group consisting of semiconductors, metal conductors, metal oxides, metal salts or mixtures thereof;
(2) the average cross-sectional size of the at least one particle scattering colorant is less than about 0.2 microns in the smallest dimension;
(3) the polymer matrix component is substantially non-absorbing in the visible light region of the spectrum;
(4) The particle scattering colorant has a minimum intensity ratio of transmitted light at 380-750 nanometers, which is the same semiconductor, metal conductor, metal oxide, having an average particle size greater than about 20 microns, A shift of at least 10 nanometers compared to that obtained for the metal salt or mixture thereof; and
(5) The luminescent material is selected from the group consisting of at least one phosphor, at least one phosphor, and a mixture of at least one phosphor and at least one phosphor, wherein The cent material exhibits a response peak of the luminescent spectrum when excited by at least one wavelength selected from the electromagnetic spectral region of about 200 to about 2,000 nanometers; and
(6) the particle scattering colorant particles comprise a metal conductor selected from the group consisting of gold, platinum, copper, aluminum, lead, palladium, silver, rhodium, osmium, iridium, and alloys and mixtures thereof;
(7) the matrix component is selected from the group consisting of a polymer, a cellulosic composition, and glass;
here:
(A) the luminescent material includes at least one fluorescent material and at least one phosphor having afterglow characteristics;
(B) the at least one phosphor and at least one phosphor having afterglow characteristics are present in the matrix at a total concentration of about 0.5 to about 15 weight percent;
(C) the article is selected from the group consisting of filaments, fibers, films, slit films, dots, and fibrils, and the article is adapted for use with a subject;
(D) the object is adapted to receive on the at least one surface thereof information selected from the group consisting of at least one image, a typeface, and a mixture of at least one image and typeface; At least one structural element that has been made;
(E) The fraud prevention article, wherein the object is selected from the group consisting of banknotes, banknotes, circulation securities, passports, licenses, identification cards, credit cards, debit cards, and barcodes.