JP2006249354A - Water-based fluorescent printing ink and recording method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water-based fluorescent ink having color developability required for determination and measurement, high fluorescence intensity and high fastness properties, and to provide an inkjet recording method using the same. <P>SOLUTION: A water-based fluorescent printing ink comprises resin particles colored with at least two fluorescent colorants, wherein one colorant of the fluorescent colorants is a first fluorescent colorant which emits light having a reference fluorescence wavelength utilized for measurement or determination from fluorescence-emitting wavelengths when a reference excitation wavelength is applied; the other colorant of the fluorescent colorants is a second fluorescent colorant which emits fluorescent light by the reference excitation wavelength; and the light-emitting wavelength region of the second fluorescent colorant at least substantially includes a peak wavelength region corresponding to the peak region adjacent to the reference fluorescence wavelength in the excitation wavelength region for emitting light having the reference fluorescence wavelength of the first fluorescent colorant in the ink. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a printing ink containing resin particles colored with a plurality of fluorescent color materials, a printing ink capable of improving fluorescence and fastness in a printed image using the same, and ink jet recording using the ink Regarding the method. Furthermore, specifically, the second used for the printing ink containing the first fluorescent color material that emits light of the reference wavelength used for measurement or determination among the wavelengths of fluorescence emitted by providing the reference excitation wavelength. The present invention relates to a correlation technique based on a novel technical idea for improving fluorescence emission characteristics by using resin fine particles colored with a fluorescent color material.

  In recent years, there has been a demand for inks that can be used in various applications. Such applications are not limited to merely forming beautiful colored images. For example, by providing ink with fluorescence, letters, numbers, and symbols can be used. Development of technology to record information such as barcodes on a recording medium and to give fluorescent ink colored light by irradiating ultraviolet light of an appropriate wavelength to give information other than visible information (for example, security information) Proposed. In particular, in a method of reading authenticity determination (anti-counterfeiting) information and security information using a device that emits fluorescence and reads the emission intensity, excitation is performed at a reference wavelength (for example, 254 nm) used in the method (reference). Excitation wavelength), fluorescent color material is fluorescently colored and used for determination and measurement.

  For example, it is also used in a mailing system such as printing of digital watermarks and indicia of postage items paid separately. As this mailing system, it is common to perform fluorescent red printing in the United States. I. A dye such as Acid Red 52 (AR52) is used. AR52 is exemplified as a fluorescent dye, and an ink including a fluorescent dye, a pigment, and a polymer as a pigment dispersant is disclosed (for example, see Patent Document 1). In addition, as described in this specification, in order to adjust the color tone that is captured as a so-called human sense to change the formed “color tone” to a desired color tone, a dye that matches the color tone is used. Combining has been known as a design matter long before the present invention. It contains a pigment dispersed with a fluorescent dye and a polymer dispersant, and has improved fastness such as water resistance, but it is still not sufficient.

  On the other hand, an ink containing a pigment in which a fluorescent dye is immobilized on a latex basis has been proposed (see, for example, Patent Document 2). In addition, an ink containing a fluorescent toner encapsulated with a resin, a water-soluble solvent, and an auxiliary penetrant has been proposed (for example, see Patent Document 3). Although these inks have improved water resistance, when these inks are used in a mailing system or the like, more stable fluorescence intensity is obtained when the fluorescence intensity of printed matter using these inks is used as a threshold value. It is important to emit. However, in the prior art, more stable fluorescence intensity could not be obtained.

Furthermore, in ink jet recording (referred to as bubble jet (registered trademark)) in which ink is ejected by thermal energy for recording, various characteristics of color materials used for ink ejection are taken into account in order to perform stable ink ejection. You must choose what you did.
US Pat. No. 6,176,908 JP-A-8-53640 JP-A-9-291246

  A conventional ink combining a plurality of fluorescent dyes and pigments is merely a combination to improve the fluorescence intensity in a desired fluorescence wavelength (for example, 580 nm to 620 nm) region. Therefore, the relationship between a plurality of fluorescent dyes, the characteristics, composition as ink, or analysis of the formed image itself is the discovery of the technical problem of the present invention. It is the main object of the present invention to provide technical directionality using a plurality of fluorescent dyes for fluorescence intensity.

  Therefore, the present inventors have pursued basic technology by considering the phenomenon and mechanism of “fluorescence”, and in order to improve the fluorescence intensity, at least one of the following problems (preferably a plurality of the following problems) To the conclusion that it is important to resolve

  Originally, if sufficient fluorescence intensity can be obtained only with the first fluorescent color material exhibiting fluorescence in a desired fluorescent wavelength region (for example, 580 nm to 620 nm) with respect to the reference excitation wavelength, other fluorescent color materials (hereinafter, There is no need to add a second colorant). As described above, when AR52 is used as the first color material, sufficient fluorescence intensity is exhibited even at 0.01% by mass or less as a single characteristic. It is one of the matters to be considered to have an effective relationship between the color materials with the idea of reversing the fact.

  Further, as described above, when AR52 is used as the first color material, as a single characteristic, sufficient fluorescence intensity is exhibited even at 0.01% by mass or less. However, paper or a recording medium for forming an image can be used. Consideration is also given to problems such as concentration quenching in which the fluorescence intensity decreases conversely when the amount of the first and second color materials in the ink increases as the amount of the first and second colorants in the ink cannot be fixed to the envelope surface fibers and is wasted. This is one of the things that should be done. On the other hand, one of the considerations is that the energy applied is limited to the reference excitation wavelength.

  Accordingly, the first problem of the present invention is that it is suitable for ink jet printing by using resin fine particles colored with a fluorescent color material, and is more resistant to water than in the case of an ink using a conventional fluorescent dye. Another object of the present invention is to provide a printing ink capable of improving fastness such as weather resistance.

  The second problem of the present invention is to improve energy efficiency by paying attention to the correlation between the fluorescence emission emitted by the second color material generated by the provision of the resin fine particle reference excitation wavelength and the excitation characteristic of the first color material. And providing a printing ink capable of improving the fluorescence intensity at a desired wavelength.

  The third object of the present invention is to achieve high energy efficiency by focusing on the absorption spectrum exhibited by the first color material and the fluorescence emitted by the second color material generated by the provision of the reference excitation wavelength. An object of the present invention is to provide a printing ink capable of improving the fluorescence intensity of the wavelength.

  The fourth problem of the present invention is that the knowledge obtained by the structural analysis of the color materials, that is, the association of the color materials can be rationally solved and the amount of the color material added can be increased, so that the fluorescence intensity at the desired wavelength can be increased. It is to provide a printing ink that can be improved.

  A fifth problem of the present invention is that in addition to the fourth problem, an excitation wavelength for obtaining a fluorescence emission emitted from the second color material generated by providing a reference excitation wavelength and a desired fluorescence wavelength of the first color material. Focusing on the characteristic, it is to provide a printing ink capable of improving the fluorescence intensity at a desired wavelength.

  A sixth problem of the present invention is to provide a printing ink that can improve the fluorescence intensity of a desired wavelength more stably as a characteristic of the ink itself having a plurality of fluorescent color materials.

  The seventh problem of the present invention is that the fluorescence intensity at a desired wavelength can be improved without being greatly influenced by the knowledge obtained by analysis from the formed image, that is, the type and characteristics of the recording medium on which the image is formed. It is to provide a printing ink.

  The eighth object of the present invention is to improve energy efficiency by focusing on the correlation between the excitation characteristics of the first color material and the absorption spectrum of the second color material in addition to the first problem. An object of the present invention is to provide a printing ink capable of improving the fluorescence intensity of the wavelength.

  Further problems and objects of the present invention will become apparent from the following description. Therefore, an object of the present invention is to solve at least one of the above-mentioned problems (preferably, a plurality of the above-mentioned problems) and to provide a printing ink satisfying both excellent fluorescence intensity and fastness. To do. Another object of the present invention is to provide an ink jet recording method using this printing ink.

  As a means for solving the above problems, the present inventors have obtained a sufficient fluorescence intensity by giving an effective relationship between color materials in a plurality of fluorescences in order to obtain a fluorescence intensity that cannot be achieved by a single fluorescent color material. Further, by using resin fine particles colored with these fluorescent coloring materials, a new ink was obtained that has more stable characteristics and has fastness such as water resistance and weather resistance. That is, the present invention is achieved by the following means.

1) In a printing ink containing resin particles colored with at least two or more fluorescent coloring materials, one of the fluorescent coloring materials is measured or judged out of the wavelengths that emit fluorescent light by providing a reference excitation wavelength. Is a first fluorescent color material that emits light of a reference fluorescence wavelength used for
The other color material of the fluorescent color material is a second fluorescent color material that emits fluorescence by the reference excitation wavelength, and the emission wavelength range of the second fluorescent color material is at least in the ink. An aqueous fluorescent printing ink comprising substantially a peak wavelength region corresponding to a peak region adjacent to the reference fluorescence wavelength among excitation wavelength regions for obtaining light emission of the reference fluorescence wavelength of the material.

  2) The reference excitation wavelength is 254 nm, the peak wavelength region is 475 nm or more and 600 nm or less, and the emission wavelength region of the second fluorescent color material includes 600 nm as the reference wavelength, and the emission wavelength is 450 nm or more and 600 nm or less. 2. The aqueous fluorescent printing ink according to 1 above, which has a range.

  3) The first fluorescent color material has an absorption spectrum peak region in the visible light region, and the second fluorescent color material has a fluorescence emission wavelength region at a wavelength lower than the absorption spectrum peak region. 3. The aqueous fluorescent printing ink according to 1 or 2 above, wherein the region is included.

  4) A printing ink containing a first fluorescent color material that emits light having a reference wavelength used for measurement or determination, among the wavelengths that emit fluorescence by providing a reference excitation wavelength, and emits fluorescence by the reference excitation wavelength. A second fluorescent color material, and an emission wavelength range of the second fluorescent color material is at least an excitation wavelength range for obtaining emission of the reference wavelength of the first fluorescent color material in the ink, 2. The aqueous fluorescent printing ink according to 1, wherein the first fluorescent colorant has a wavelength range including a main absorption wavelength range in an absorption spectrum.

  5) The main absorption wavelength range of the first fluorescent color material is 500 nm or more and 580 nm or less, and the emission wavelength range of the second fluorescent color material has an emission wavelength range of 450 nm or more and 600 nm or less. Ink for printing.

  6) The aqueous fluorescent printing ink according to any one of 1 to 5, wherein the second fluorescent color material is a color material having a structure having a plurality of fluorescent luminophores.

  7) A printing ink containing a first fluorescent color material that emits light of a reference wavelength used for measurement or determination among wavelengths that emit fluorescence by providing a reference excitation wavelength, and emits fluorescence by the reference excitation wavelength. And the second fluorescent color material for enhancing the emission intensity of the reference wavelength, wherein the second fluorescent color material has a structure having a plurality of fluorescent luminophores. .

  8) The emission wavelength range of the second fluorescent color material is at least an excitation wavelength range for obtaining the reference wavelength of the first fluorescent color material in the ink. Aqueous fluorescent printing ink.

  9) A printing ink including a first fluorescent color material that emits light having a reference wavelength used for measurement or determination among wavelengths that emit fluorescence by providing a reference excitation wavelength, and emits fluorescence by the reference excitation wavelength. A first fluorescent color material having a structure in which the second fluorescent color material has a plurality of fluorescent luminophores, and an emission wavelength region of the second fluorescent color material is in the ink; 2. The ink for water-based fluorescent printing according to 1, wherein the color material has a wavelength region common to at least a part of an excitation wavelength region for obtaining light emission of the reference wavelength.

  10) The aqueous fluorescent printing ink according to any one of 1 to 9, wherein each of the plurality of fluorescent luminophores of the second fluorescent color material has a basic structure for fluorescent whitening.

  11) The ink for aqueous fluorescent printing according to any one of 1 to 10, which is colored by including a third color material in addition to the first fluorescent color material and the second fluorescent color material.

  12) The aqueous fluorescent printing ink as described in 1 above, wherein the resin constituting the resin fine particles is a copolymer comprising a monomer component containing at least one hydrophobic monomer and contains a hydrophilic group.

  13) The aqueous fluorescent printing ink as described in 12 above, wherein the resin constituting the resin fine particles is a copolymer comprising a monomer component containing at least one kind of hydrophobic monomer and at least one kind of hydrophilic monomer.

  14) In an inkjet recording method for recording by discharging from an ink discharge port and adhering to a recording medium, the ink is the water-based fluorescent printing ink described in any one of 1 to 13 above. Method.

  According to the present invention, it is possible to provide a water-based fluorescent ink and an ink jet recording method capable of achieving both high fluorescence intensity and high fastness that cannot be achieved by the prior art while having color developability necessary for determination and measurement. it can.

  Next, the present invention will be described in detail with reference to preferred embodiments of the invention.

(Resin fine particles)
The “resin fine particles” used in the present invention are fine particles formed essentially of a polymer, and have a hydrophilic group on the surface and can be dispersed for use in aqueous ink.

  As the resin constituting the resin fine particles in the present invention, any resin component such as any natural or synthetic polymer generally used or a polymer newly developed for the present invention can be used without limitation. Examples of resin components that can be used include acrylic resins, styrene / acrylic resins, polyester resins, polyurethane resins, polyurea resins, polysaccharides, and polypeptides. In particular, acrylic resins and styrene / acrylic resins are classified from the viewpoint that they can be generally used and the functional design of resin fine particles can be easily performed.

  The resin fine particle of the present invention is a copolymer resin composed of a monomer component containing at least one kind of hydrophobic monomer, and preferably contains a hydrophilic group.

  Examples of the hydrophobic monomer in the present invention include methyl acrylate, ethyl acrylate, isopropyl acrylate, acrylic acid-n-propyl, acrylic acid-n-butyl, acrylic acid-t-butyl, benzyl acrylate, methyl methacrylate. (Meth) acrylic acid esters such as ethyl methacrylate, isopropyl methacrylate, methacrylate-n-propyl, methacrylate-n-butyl, isobutyl methacrylate, tert-butyl methacrylate, tridecyl methacrylate, benzyl methacrylate, etc. Styrene monomer such as styrene, α-methyl styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-tert-butyl styrene, etc .; itaconate such as benzyl itaconate; dimethyl maleate, etc. Male like Phosphate esters; fumaric acid such as fumaric acid esters such as dimethyl acrylonitrile, methacrylonitrile, vinyl acetate, and the like.

  Among the hydrophobic monomers, it is also a preferred form to contain at least a monomer having a methyl group at the α-position and having a radical polymerizable unsaturated double bond. By forming resin fine particles using a radical polymerizable monomer having a methyl group at the α-position, particularly in a thermal ink jet method in which ink is ejected by thermal energy, the ejectability of an aqueous ink jet recording ink containing a water-insoluble colorant is improved. Become very good. The reason for this is not clear, but resins using a radically polymerizable monomer having a methyl group at the α-position cause depolymerization at high temperatures, and therefore have a methyl group at the α-position when thermal energy is applied to the ink. Since the resin composed of the monomer component undergoes depolymerization and sticking into the discharge port is less likely to occur, it is considered that the discharge property is improved.

  The hydrophilic group for allowing the resin fine particles in the present invention to be dispersed may be an anionic group such as a carboxylic acid group or a sulfonic acid group, or a cationic polar group such as an amide group, and an ethylene oxide group. It may be a nonionic group that can impart dispersibility in water.

  In another preferred embodiment of the present invention, the resin constituting the resin fine particle is a copolymer comprising a monomer component containing at least one hydrophobic monomer and at least one hydrophilic monomer. It is preferable. Examples of the hydrophobic monomer include those described above, and examples of the hydrophilic monomer include monomers having an anionic group such as acrylic acid, methacrylic acid, crotonic acid, ethacrylic acid, propylacrylic acid, and isopropylacrylic. Monomers having a carboxyl group such as acid, itaconic acid, fumaric acid and the like and salts thereof, styrenesulfonic acid, sulfonic acid-2-propylacrylamide, acrylic acid-2-ethyl sulfonate, methacrylic acid-2-ethyl sulfonate, Examples thereof include monomers having a sulfonic acid group such as butyl acrylamide sulfonic acid and the like, and salts thereof, monomers having a phosphonic acid group such as ethyl methacrylate-2-phosphonate and ethyl acrylate-2-phosphonate. Among these, it is particularly preferable to use acrylic acid and methacrylic acid. Monomers having a cationic group include monomers having a primary amino group such as aminoethyl acrylate, aminopropyl acrylate, methacrylamide, aminoethyl methacrylate, aminopropyl methacrylate, and the like, and methylaminoethyl acrylate. Secondary amino groups such as methylaminopropyl acrylate, ethylaminoethyl acrylate, ethylaminopropyl acrylate, methylaminoethyl methacrylate, methylaminopropyl methacrylate, ethylaminoethyl methacrylate, ethylaminopropyl methacrylate, etc. Monomers having dimethylaminoethyl acrylate, diethylaminoethyl acrylate, dimethylaminopropyl acrylate, diethylaminopropyl acrylate, dimethylaminoethyl methacrylate, Monomers having a tertiary amino group such as diethylaminoethyl silylate, dimethylaminopropyl methacrylate, diethylaminopropyl methacrylate, dimethylaminoethyl methyl chloride salt, dimethylaminoethyl methyl chloride salt, dimethylaminoethyl acrylate Examples thereof include monomers having a quaternary ammonium group such as benzyl chloride salt and dimethylaminoethyl benzyl chloride salt, and various vinylimidazoles. As the nonionic hydrophilic monomer, specifically, for example, monomers having a radical polymerizable unsaturated bond and a hydroxyl group exhibiting strong hydrophilicity in the structure are applicable. Hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxylpropyl (meth) acrylate and the like are classified into this. In addition, various known or novel oligomers and macromonomers can be used without limitation.

  When the dispersed particle diameter of the resin fine particles in water according to the present invention can be measured by, for example, a dynamic light scattering method, the average value of the dispersed particle diameter is preferably in the range of 10 nm to 500 nm. desirable. Furthermore, from the viewpoint of long-term storage stability of the dispersible colorant, it is more preferable that the polydispersity index of the dispersed particle diameter is suppressed to less than 0.2. When the average value of the dispersed particle diameter is larger than 500 nm, the original purpose of finely dispersing and stabilizing the coloring material may not be sufficiently achieved. Further, when the average value of the dispersed particle diameter is smaller than 10 nm, the form as the resin fine particles cannot be sufficiently maintained, and the resin is easily dissolved in water, so that the merit of the present invention may not be obtained. . On the other hand, when the particle diameter is smaller than the color material particles themselves in the range of 10 nm to 500 nm, the dispersion stabilization of the color material by the fixing of the resin fine particles of the present invention is effectively expressed.

(Fluorescent color material)
As the first and second fluorescent color materials used in the present invention, those satisfying the above-described configurations are used, and a dye is preferable in order to satisfy higher fluorescence intensity. As the dye, water-soluble or water-insoluble disperse dyes or oil-soluble dyes are appropriately selected and used as appropriate in the production process of the colored resin fine particles.

Examples of specific water-soluble dyes include the following.
C. I. Basic Red: 1, 2, 9, 12, 13, 14, 17,
C. I. Basic violet: 1, 3, 7, 10, 11: 1, 14,
C. I. Acid Yellow: 73, 184, 250,
C. I. Acid Red: 51, 52, 92, 94
C. I. Direct yellow: 11, 24, 26, 87, 100, 147,
C. I. Direct orange: 26, 29, 29: 1, 46,
C. I. Direct Red: 1, 13, 17, 239, 240, 242, 254,
C. I. Solvent Green: 7
The amount of the first and second fluorescent color materials used in the present invention is preferably 0.01% by mass or more and 15% by mass or less, based on the total amount of ink, as a total amount of the first and second fluorescent color materials. Is preferably 0.05% by mass or more and 10% by mass or less. If it is 0.01% by mass or less, the fluorescence intensity as a printed matter may not be obtained, and if it is 15% by mass or more, ejection characteristics may be affected. In particular, it is more preferable to select from the range of 0.01 to 1% by mass. Furthermore, it is preferable that the second fluorescent color material is contained in the ink more than the first fluorescent color material.

  In addition, the fluorescent dyes shown above include fluorescent dyes that are known to cause a phenomenon in which the fluorescence becomes weaker when the concentration exceeds a specified concentration. There is a concentration range where can be expressed. In that case, it is preferable to use it in a concentration range in which strong fluorescence intensity is expressed.

  As means for satisfying the fluorescence intensity, it is preferable that the first and second fluorescent color materials have the following modes (1) and (2), and the first and second fluorescences corresponding to this mode: A combination of color materials can be arbitrarily selected from the color materials shown above.

  As a preferred example of the combination of the corresponding fluorescent color materials, the first fluorescent color material is C.I. I. Acid red 52, and a combination in which the second fluorescent color material is a compound (A) having the following structure may be mentioned. The structure of compound (A) is shown below. Here, the reference emission wavelength used for measurement or determination is 600 nm in the following description, but this wavelength regulation may be in the range of 580 nm or more and 620 nm or less, or any wavelength within this range. Also good.

  First, AR52, which is the first fluorescent color material, will be described. As shown in FIG. 1, fluorescence emission with a reference excitation wavelength of 254 nm starts from 550 nm, has a peak at 600 nm, and a wide range of fluorescence emission region up to around 675 nm. have. In other words, it emits light of 600 nm, which is the reference emission wavelength defined here, but emits light in the entire range from 580 nm to 620 nm. Further, the visible light absorption spectrum of AR52, which is the first fluorescent color material, starts at 460 nm and has a peak of 565 nm up to 610 nm as shown in the lower graph of FIG.

  Hereinafter, each aspect of the printing ink according to the present invention will be described below by taking this combination as an example.

  (1) A second excitation wavelength region different from the first excitation wavelength for obtaining the main fluorescence of the first fluorescent color material obtained at the first excitation wavelength is obtained at the first excitation wavelength. 1st and 2nd fluorescent color material with which the fluorescence emission wavelength range of a fluorescent color material overlaps.

  A specific example of this relationship will be described using the above color material. As shown in FIG. 1, C.I. I. Acid Red 52 (AR52) emits fluorescence having a peak (600 nm) in a wavelength range of 550 nm to 650 nm when excitation is performed at 254 nm which is the first excitation wavelength. The excitation wavelength that can excite the fluorescence emission including the wavelength of 600 nm is expressed as the absorption spectrum as shown in FIG. That is, the AR 52 has a second excitation wavelength region that does not include the first excitation wavelength (254 nm) at 400 to 700 nm. This second excitation wavelength region is in the range of 450 nm to 620 nm and has a maximum absorption wavelength in the range of 500 to 600 nm. Here, the “peak wavelength region corresponding to the peak region adjacent to the reference wavelength” of the fluorescence emission of the first fluorescent color material in the present invention is AR52 as the first color material and the reference wavelength of the fluorescence emission is 600 nm. In this case (excitation reference wavelength: 254 nm), the wavelength region occupied by the peak region in the excitation spectrum from 475 nm to 600 nm shown in FIG. 2 is shown.

  On the other hand, as shown in FIG. 3, the compound (A) described later as the second fluorescent colorant has a peak (510 nm) in the wavelength region of 450 nm to 650 nm when excited at the first excitation wavelength of 254 nm. ).

  A comparison between the excitation wavelength spectrum of the first fluorescent color material and the fluorescence emission wavelength region of the second fluorescence color material is as shown in FIG. 4. In the fluorescence emission wavelength region of the compound (A), It can be understood that the second excitation wavelength region is included. Thus, the second excitation wavelength region adjacent to the wavelength (600 nm) indicating the maximum emission intensity of the first fluorescence emission is included in the emission wavelength region including the wavelength indicating the maximum emission intensity of the second fluorescent color material. By using a combination of the first and second fluorescent color materials, it is possible to improve the fluorescence intensity at the first excitation wavelength.

  FIG. 5 shows a comparison between the excitation spectrum of AR52 for obtaining fluorescence emission at 600 nm and the absorption spectrum of compound (A). Therefore, in the first fluorescent color material and the second fluorescent color material, the maximum absorption of the second fluorescent color material is within a range of 400 nm to 700 nm where the second excitation wavelength region of the first fluorescent color material is located. Preferably no wavelength is present. The reason for this is that, as described above, the energy received in order to improve the fluorescence intensity in the second excitation wavelength region of the first fluorescent color material is deprived by the absorption of the second fluorescent color material. This is because the strength cannot be improved.

  One of the reasons why the fluorescence intensity enhancement effect is obtained in the combination of these fluorescent colorants is that the wavelength range of the fluorescence emission of the compound (A) is in the second excitation wavelength range of AR52, and from the compound (A) It is conceivable that the emitted light is further used for excitation of AR52.

  That is, in the machine that detects fluorescence, the excitation wavelength is fixed. Therefore, even if the target fluorescence emission wavelength has another excitation wavelength, the fluorescence is not improved. If the fluorescence emission wavelength region generated when the color material is excited at the first excitation wavelength is the same wavelength region as the excitation wavelength region of the first color material, the fluorescence from the second fluorescence color material Light emission becomes a new excitation wavelength of the first color material, and fluorescence can be improved.

  Further, as is apparent from the comparison between FIGS. 1 and 3, the wavelength region of the fluorescence emission of AR52 and the wavelength region of the fluorescence emission of compound (A) partially overlap, which also causes the intensity of the fluorescence emission of AR52. Is thought to improve.

  In the combination of the two fluorescent color materials, the first fluorescent color material AR52 has a peak region of an absorption spectrum in the visible light region as shown in FIG. The wavelength region of the fluorescence emission of the compound (A) is a region on the wavelength side lower than the peak region of the absorption spectrum of AR52 (region indicated by α in FIG. 6). By using such two kinds of fluorescent color materials, the fluorescence intensity as a whole can be enhanced. The reason for this is that this α region overlaps the second excitation wavelength region of AR52, which is the first fluorescent color material, and thus contributes to improving the fluorescence intensity of AR52, which is the first fluorescent color material. Because you can.

  Next, for comparison, the first fluorescent color material is AR52, and the second fluorescent color material is C.I. I. The case of Acid Yellow 73 (AY73) will be described.

  As shown in FIG. 10, AY73 as the second fluorescent color material generates fluorescence having a peak (530 nm) in the wavelength range of 500 to 600 nm when excited at 254 nm, which is the first excitation wavelength. .

  When the excitation wavelength spectrum of the first fluorescent color material and the fluorescence emission wavelength region of the second fluorescence color material are compared, as shown in FIG. 11, the second excitation wavelength region of AR52 is included in the fluorescence emission wavelength region of AY73. Only a part is included, which is an insufficient region for improving the fluorescence intensity.

  Further, when comparing the excitation spectrum of AR52 and the absorption spectrum of AY73 for obtaining fluorescence emission at 600 nm, it becomes as shown in FIG. 12, and the range of 400 to 700 nm where the excitation wavelength region of the first fluorescent color material is located. Since the maximum absorption wavelength of the second fluorescent color material exists, the second excitation wavelength region of the first fluorescent color material, which is a means for improving the fluorescence intensity in the present invention, cannot be used effectively.

  Furthermore, as shown in FIG. 13, the first fluorescent color material AR52 has an absorption spectrum peak region in the visible light region, and the second fluorescent color material AY73 has a fluorescence emission wavelength region, It can be understood that there is no region on the lower wavelength side than the peak region of the absorption spectrum of AR52, and the fluorescence emission of the second fluorescent color material is absorbed by the absorption spectrum of the first fluorescent color material.

  On the other hand, the fluorescence spectrum at the reference excitation wavelength of 254 nm in the ink containing both the AR 52 and the compound (A) has two peaks as shown in FIG.

  Further, the fluorescence spectrum at the reference excitation wavelength of 254 nm in the image obtained with this ink also has two peaks as shown in FIG. That is, it is possible to provide a fluorescent ink in which concentration quenching hardly occurs even by a combination of fluorescent dyes having two peaks.

  The reference wavelength of fluorescence emission in the present invention can be selected depending on the use of the ink and the image formed thereby. For example, the excitation spectra when the fluorescence emission wavelength (reference wavelength) in AR52 is changed to 580, 600, and 620 are as shown in FIG. Therefore, according to the present invention, a peak wavelength region that is a peak region adjacent to each reference wavelength can be set.

  In addition to the compound (A), C.I. I. Solvent Green 7 (SG7) may be mentioned. C. is added to the first fluorescent color material. I. Acid Red 52 is used as the second fluorescent color material. I. When Solvent Green 7 is used, the relationship between fluorescence, excitation, and absorption by this combination is shown in FIGS.

  Furthermore, in the present invention, a colored resin fine particle may be prepared by further adding a third color material for the purpose of toning and replenishment of color development. At this time, it is preferable to use a color material that does not impair the fluorescence characteristics obtained by the first fluorescent color material and the second fluorescent color material as much as possible.

  (2) A combination of the first and second fluorescent color materials, wherein at least one of the first and second fluorescent color materials has the basic structure shown below and can enhance the intensity of the main fluorescence. .

  According to the study by the present inventors, at least one of the first and second fluorescent color materials, preferably the second fluorescent color material has the following atoms or atomic groups, and the basic fluorescent luminophore described below. By using a combination of the first and second fluorescent color materials including the structure, the intensity of fluorescence emission at the first excitation wavelength in the first fluorescent color material can be improved.

  In particular, it is preferable to have a plurality of the fluorescent luminophores in the color material structure. That is, a color material having a plurality of fluorescent luminophores in the same molecular structure is structurally larger and more steric than a conventional fluorescent color material, and therefore has a regularity like a conventional fluorescent color material. Since certain aggregation and association are less likely to occur, it is expected that the fluorescence intensity can be hardly lowered even if the content of the fluorescent color material in the ink is increased as compared with the conventional color material. In addition, a color material having a plurality of fluorescent luminophores in the same molecular structure increases the fluorescence emission intensity because the fluorescence emission per unit molecule is increased by having a plurality of fluorescent luminophores in one molecule of the color material. I expect to be able to. Further, at this time, it is considered that the directivity of the color material further improves the fluorescence emission.

  Due to the mechanism described above, the ink of the present invention is expected to improve the fluorescence intensity by coloring the resin fine particles using the first fluorescent color material and the second fluorescent color material. When the coloring material having a plurality of the same in the same molecular structure uses a sulfonic acid having a strong affinity for water as a hydrophilic group, the effect of the present invention is further improved when coloring in water.

  Moreover, as a preferable fluorescent luminophore, a derivative of aminostilbene disulfonic acid is suitable for those who satisfy the above requirements.

  Depending on the type of fluorescent color material, there is a case where the fluorescence intensity does not increase or the fluorescence intensity decreases even if the concentration in the ink is increased. When such a fluorescent color material is used, there is a limit to the narrowness of the concentration (content in the ink) that can be used or to increase the fluorescence intensity. On the other hand, in the combination of the first and second color materials according to the present invention, when the content of the fluorescent color material is increased, the fluorescence intensity can be further increased according to the increase rate. .

  Examples of the fluorescent luminophore having an atomic group and a group that can exhibit the fluorescent whitening function and that can be applied to the fluorescent color material of the present invention include the following. Here, in the fluorescent color material of the present invention, the light absorption wavelength region may be in the visible light region or other than the visible light region. It is important that the color material to be used.

（上記（１）〜（３）式中の各Ｚは夫々独立に、ＮＲ_１Ｒ_２、ＳＲ_３又はＯＲ_３を表し、（２）式中のＹは、Ｈ、Ｃｌ、上記Ｚ、ＳＲ_４又はＯＲ_４を表し、（３）式中のＥは、Ｃｌ又はＣＮを表す。Ｒ_１、Ｒ_２、Ｒ_３及びＲ_４は各々独立に、Ｈ、アルキル基、置換アルキル基、アリール基、置換アリール基、アラルキル基又は置換アラルキル基、水酸基を表し、Ｒ_１及びＲ_２は、窒素原子と共に５又は６員環を形成してもよい。

(In the formulas (1) to (3), each Z independently represents NR ₁ R ₂ , SR ₃ or OR _3, and Y in the formula (2) represents H, Cl, the above Z, SR _4. Or E ₄ in the formula (3) represents Cl or CN R ₁ , R ₂ , R ₃ and R ₄ are each independently H, alkyl group, substituted alkyl group, aryl group, substituted An aryl group, an aralkyl group or a substituted aralkyl group and a hydroxyl group are represented, and R ₁ and R ₂ may form a 5- or 6-membered ring together with the nitrogen atom.

（上記式（４）中、Ｒ^５は、独立に、水素原子、アルキル基、置換アルキル基、アルコキシ基、ハロゲン原子、ＣＮ、ウレイド基及びＮＨＣＯＲ^６から選択される。Ｒ^６は、水素原子、アルキル基、置換アルキル基、アリール基、置換アリール基、アラルキル基及び置換アラルキル基から選択される。式（５）中、Ｔは、アルキル基を示し、Ｗは、水素原子、ＣＮ、ＣＯＮＲ_７Ｒ_８、ピリジウム基及びカルボキシル基から選択される。Ｒ_７及びＲ_８は夫々独立に、水素原子、アルキル及び置換アルキル基から選択される。ｍは、炭素数２〜８のアルキレン鎖を示し、式（６）中、Ｂは、水素原子、アルキル基及びカルボキシル基から選択される。）
尚、上記式（１）〜（６）における各置換基における具体例は基準発光とする蛍光発光性に応じて選択することができる。

(In the above formula (4), R ⁵ is independently selected from a hydrogen atom, an alkyl group, a substituted alkyl group, an alkoxy group, a halogen atom, CN, a ureido group, and NHCOR ^6. R ⁶ is a hydrogen atom, Selected from an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an aralkyl group and a substituted aralkyl group, wherein T represents an alkyl group, W represents a hydrogen atom, CN, CONR ₇ R; ₈ , selected from a pyridium group and a carboxyl group, R ₇ and R ₈ are each independently selected from a hydrogen atom, an alkyl and a substituted alkyl group, m represents an alkylene chain having 2 to 8 carbon atoms, (In (6), B is selected from a hydrogen atom, an alkyl group, and a carboxyl group.)
In addition, the specific example in each substituent in the said Formula (1)-(6) can be selected according to the fluorescence light-emitting property used as standard light emission.

  The reason why the fluorescence intensity obtained by the excitation of the first fluorescent color material at the first excitation wavelength by including the fluorescent luminophore in this manner is increased in addition to the reason described above. This is because the fluorescence emission in the first excitation wavelength region of one fluorescent color material is improved. In particular, aminostilbene disulfonic acid derivatives are preferable because they have a wide fluorescent emission region.

  On the other hand, as shown in the above structural formula, the compound (A) has a structure as a dimer having a plurality of fluorophores and a plurality of sulfone groups.

  The second fluorescent color material used in the present invention preferably has a plurality of fluorescent luminophores, and more preferably has a basic structure for fluorescent whitening. Further, the plurality of fluorescent luminophores of the second fluorescent color material are preferably dimers.

  Examples of the cyclic skeleton of the second fluorescent dye can include a cyclic structure having a double bond or a conjugated double bond, an aromatic ring structure, a cyclocyclic structure, or a heterocyclic structure, Benzene, thiophene, pyridine, pyrrole, coumarin, indene, benzothiazole, benzoxazole, benzimidazole, benzoselenazole, naphthalene, thionaphthene, quinoline, indole, naphthene, fluorene, diphenylene sulfide, phenanthrene, anthracene, aphridine, fe And nanthridine, carbazole, fluorene, naphthacene, fluoranthrene, pyrene, xanthene, chrysene, triphenylene, perylene, pyrene, picene, quinacridone, phthalocyanine, and the like.

  More preferable specific examples are selected from pyrene, coumarin, oxazole, imidazole, thiazole, imidazolone, pyrazole, benzidine, benzidine sulfone, diaminocarbazole, naphthal ring, diaminostilbenzyl sulfonic acid and derivatives thereof as mentioned above. A coloring material having a plurality of at least one structure via the above-described linking groups can be exemplified.

(Colored resin fine particles)
The colored resin fine particles in the present invention can be used by coloring the above-mentioned resin fine particles with the above-described fluorescent dye.

  Several methods are conceivable as the method for coloring the resin fine particles in the present invention. First, as a simple method, after dispersing the resin fine particles as described above in water, a method of adding a first color material and a second color material and stirring and coloring can be mentioned. At this time, in order to sufficiently color the resin fine particles, the first and second coloring materials may be sufficiently dissolved in a solvent such as water. Moreover, it is good to adjust stirring conditions and heating conditions suitably.

  Another method is to swell the above-described resin fine particles in a dispersion to improve the colorability with a dye. Specifically, for example, when resin fine particles of a styrene-acrylic copolymer are used, a dye may be added and stirred in the presence of a good solvent such as diethylene glycol. At this time, the addition amount is preferably 10% to 200%. Moreover, when using the copolymer using acid monomers, such as acrylic acid, you may adjust pH value. At this time, although it depends on the amount of acid monomer in the copolymer, it is preferably adjusted to pH 9 to pH 11.

  Furthermore, a method of adding a dye during the synthesis of resin fine particles may be used. At this time, a water-soluble dye or a water-insoluble dye may be appropriately selected depending on the polymerization method.

  Further, if necessary, various additives, dispersion stabilizers, surfactants as dispersion stabilizers, polymer dispersion stabilizers, and the like may be added.

(Ink containing colored fine particles)
The water-based ink of the present invention is characterized by containing the colored resin fine particles described above. The content of the colored fine particles is determined by the more effective dye concentration as described above in the resin fine particles, and is preferably 0.1 to 20%, more preferably 0.3 to 15% in the ink. used.

(Aqueous liquid medium)
Next, components other than the aqueous dispersion constituting the ink in the present invention will be described. The aqueous liquid medium used in the present invention preferably contains water as a main component, and the water content in the ink is 10 to 95% by mass, preferably 25 to 93% by mass with respect to the total mass of the ink. %, More preferably 40 to 90% by mass. As the water used in the present invention, ion-exchanged water is preferably used.

  In the ink of the present invention, water may be used alone as an aqueous liquid medium, but the effect of the present invention can be made more remarkable by using a water-soluble organic solvent in combination with water.

  Specific examples of the water-soluble organic solvent that can be used in the present invention include methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, sec-butyl alcohol, tert-butyl alcohol, and isobutyl alcohol. Alkyl alcohols having 1 to 5 carbon atoms such as n-pentanol; amides such as dimethylformamide and dimethylacetamide; ketones or ketoalcohols such as acetone and diacetone alcohol; ethers such as tetrahydrofuran and dioxane; Oxyethylene or oxypropylene such as triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol Lene addition polymers; alkylene glycols containing 2 to 6 carbon atoms such as ethylene glycol, propylene glycol, trimethylene glycol, butylene glycol, pentanediol, hexylene glycol; glycerin, trimethylolethane, trimethylol Triols such as propane and 1,2,6-hexanetriol; thiodiglycol; bishydroxyethyl sulfone; ethylene glycol monomethyl (or ethyl, butyl) ether, diethylene glycol monomethyl (or ethyl, butyl) ether, triethylene glycol monomethyl ( Or lower alkyl glycol ethers such as ethyl, butyl) ether; triethylene glycol dimethyl (or ethyl) ether, tetraethylene glycol dimethyl ether Lower dialkyl glycol ethers such as ru (or ethyl) ether; alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; sulfolane, N-methyl-2-pyrrolidone, 2-pyrrolidone and 1,3-dimethyl-2 -Imidazolidinone and the like. The water-soluble organic solvents as described above can be used alone or as a mixture.

  The content of these water-soluble organic solvents in the ink is generally 50% by mass or less, preferably 5 to 40% by mass, more preferably 10 to 30% by mass with respect to the total mass of the ink. It is desirable to be in the range.

  Among these solvents, ethylene glycol, diethylene glycol, triethylene glycol, 2-pyrrolidone, glycerin, polyethylene glycol, 1,2,6-hexanetriol and the like are preferably used.

(Other ingredients)
In the ink of the present invention, in addition to the above components, if necessary, a surfactant, an antifoaming agent, a surface tension adjusting agent, a pH adjusting agent, a viscosity adjusting agent, and an antiseptic to give the ink desired performance. Additives such as antioxidants, evaporation accelerators, rust inhibitors, fungicides, and chelating agents may be blended.

  As the surfactant, a nonionic surfactant may be added in order to adjust the surface tension and improve the discharge property. As the nonionic surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, ethylene oxide adduct of acetylene glycol and the like are preferable. HLB is preferably 10 or more, particularly 12 or more, and more preferably 15 or more. These surfactants are used in an amount of 0.3% by mass or more, particularly 0.5% by mass or more, more preferably 0.8% by mass or more, based on the total mass of the ink in order to obtain a sufficient discharge sustaining effect. If the amount is too large, the viscosity of the ink becomes too high. Therefore, it is preferably 3% by mass or less, particularly 2.5% by mass or less, more preferably 2.0% by mass or less, based on the total mass of the ink. .

  The viscosity of the ink of the present invention is preferably in the range of 0.7 to 12 cP at 25 ° C. When the viscosity of the ink is within the above range, it is preferable that normal ejection can be performed in ink jet recording, and the penetration into the recording material is quick due to the viscosity resistance, and there is no problem in terms of fixing properties.

  The surface tension of the ink used in the present invention is preferably adjusted to a range of 20 to 60 mN / m at 25 ° C. When the surface tension is 20 mN / m or more, there is a strong force to pull back the meniscus after ejecting droplets in ink jet recording, or conversely, when the meniscus protrudes, the force to pull back is relatively strong. There is no problem of hugging or causing the orifice to get wet. By using the ink as described above, the ink proposed in the present invention is excellent in the water resistance of the obtained image, the ink storage stability, and the recording density, particularly as an ink used for plain paper compatible ink jet recording. In addition, it is possible to provide an ink excellent in performance of fixing property, printing quality, and fixing property.

  The water-based ink of the present invention configured as described above can be used as a stamp or pen ink, but is particularly effective when used in ink jet recording. Inkjet recording methods include a recording method in which mechanical energy is applied to ink to eject droplets, and an inkjet recording method in which thermal energy is applied to ink and droplets are ejected by foaming of the ink. The recording ink of the present invention is particularly suitable for the method.

(Recorded image)
The ink jet recording image of the present invention is formed on a recording medium using the water based ink of the present invention by an ink jet recording apparatus as will be described later. As the recording medium in the present invention, any medium capable of ink jet recording can be used without limitation.

(Image recording method and recording apparatus)
The dispersible color material and the water-based ink of the present invention are used in an ink jet discharge type head, and are effective as an ink tank in which the ink is stored or as a filling ink. In particular, the present invention provides an excellent effect in a bubble jet (registered trademark) type recording head and recording apparatus among ink jet recording methods.

  As its typical configuration and principle, for example, those performed using the basic principle disclosed in US Pat. Nos. 4,723,129 and 4,740,796 are preferable. This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, the electric circuit arranged corresponding to the sheet or liquid path holding the ink is used. By applying at least one drive signal corresponding to the recording information and giving a rapid temperature rise exceeding nucleate boiling to the heat conversion body, heat energy is generated in the electrothermal conversion body, and the heat acting surface of the recording head This is effective because the film can be boiled, and as a result, the drive signals can be made to correspond one-to-one and bubbles in the ink can be formed. By the growth and contraction of the bubbles, ink is ejected through the ejection openings to form at least one droplet. It is more preferable that the drive signal has a pulse shape, because the bubble growth and contraction is performed immediately and appropriately, and thus ink discharge with particularly excellent responsiveness can be achieved. As this pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. Further excellent recording can be performed by employing the conditions described in US Pat. No. 4,313,124 of the invention relating to the temperature rise rate of the heat acting surface.

  As the configuration of the recording head, in addition to the combination configuration (linear liquid channel or right-angle liquid channel) of the discharge port, the liquid channel, and the electrothermal transducer as disclosed in each of the above-mentioned specifications, the heat acting part The present invention is also effective for configurations using US Pat. No. 4,558,333 and US Pat. No. 4,459,600, which disclose a configuration in which is disposed in a bending region. In addition, the present invention is also effective for a configuration in which the discharge hole is a discharge portion of the electrothermal transducer when common to a plurality of electrothermal transducers (JP-A No. 123670/93). is there.

  Furthermore, as a full-line type recording head having a length corresponding to the width of the maximum recording medium that can be recorded by the recording apparatus, the length is set by combining a plurality of recording heads as disclosed in the above specification. Either a satisfying configuration or a single integrated recording head configuration may be used, but the present invention can exhibit the above-described effects more effectively.

  In addition, it is mounted on the main body of the device so that it can be electrically connected to the main body of the device and supplied with ink from the main body of the device. The present invention is also effective when a cartridge type recording head is used.

  In the present invention, it is preferable to add recovery means for the recording head, preliminary auxiliary means, etc. provided as the configuration of the recording apparatus to be applied, because the effects of the present invention can be further stabilized. . Specific examples thereof include a capping unit for the recording head, a cleaning unit, a pressure or suction unit, an electrothermal converter, a heating element different from this, or a preheating unit using a combination thereof, This is a preliminary ejection mode in which ejection different from recording is performed.

  Next, an Example and a comparative example are given and this invention is demonstrated concretely. The present invention is not limited by the following examples unless it exceeds the gist. In the text, “part” or “%” is based on mass unless otherwise specified.

  For the absorption wavelength region, the maximum absorption wavelength, and the fluorescence wavelength region, values measured with a pure water dilution of the color material were used. When the dilution wavelength is adjusted so that the absorbance is in the range of 0.5 to 0.7 using an absorptiometer, the absorption wavelength region of the coloring material is higher than the baseline and the peak value is obtained. Was the maximum absorption wavelength. Further, the fluorescence wavelength was measured by using the diluent used for the absorbance, setting the measurement conditions so that the fluorescence intensity did not exceed the measurement limit value, and fixing the excitation wavelengths of the first and second color materials. The fluorescence emission wavelength region was set higher than the baseline.

  Inks in the following examples satisfy both configurations of the aqueous fluorescent printing inks according to the first and second aspects described above.

First, the following components were added to a predetermined concentration, and these were sufficiently mixed and stirred to prepare colored fine particles.
・ C. I. Acid Red 52 (first fluorescent color material) 1 part by mass · Compound (A) (second fluorescent color material) 4 parts by mass · 20 parts by mass of styrene-acrylic copolymer emulsion · 75 parts by mass of ion-exchanged water The resulting colored fine particles and the following components were added to obtain a predetermined concentration, and these were mixed and stirred thoroughly, followed by pressure filtration with a microfilter (manufactured by Fuji Film) having a pore size of 0.2 μm to prepare an ink. did. Here, the amount of the colored resin fine particles is such that the amount of the dye in the resin fine particles is C.I. I. The acid red 52 was adjusted to 0.2 parts by mass and the compound (A) was adjusted to 2.0 parts by mass.
-Colored resin fine particles 5 parts by mass-Glycerin 7.5 parts by mass-Ethylene glycol 5 parts by mass-Urea 5 parts by mass-Acetylenol E100 1 part by mass (Acetylene glycol EO adduct made by Kawaken Fine Chemicals)
-Ion-exchanged water 76.5 parts by mass The fluorescence emission spectra and excitation spectra of the first and second fluorescent color materials were measured using a fluorescence measuring instrument FP-750 manufactured by JASCO Corporation. In order to eliminate the influence of water as a measurement sample, ink obtained by evaporating water was used.

  The absorption wavelength regions of the first and second color materials were measured by using an absorbance meter U-3200 manufactured by Hitachi, Ltd. and diluted with pure water so that the dye was diluted 100000 times. The absorption wavelength region of the first color material was 450 to 620 nm, and the maximum absorption wavelength was 565 nm. Further, the absorption wavelength region of the second color material was 300 to 450 nm, and the maximum absorption wavelength was 372 nm.

(Comparative Example 1)
The following components were added to a predetermined concentration, and these were sufficiently mixed and stirred, followed by pressure filtration with a microfilter (manufactured by Fuji Film) having a pore size of 0.2 μm to prepare an ink.
・ C. I. Acid Red 52 (first fluorescent colorant) 0.25 parts by mass, 7.5 parts by mass of glycerin, 5 parts by mass of ethylene glycol, 5 parts by mass of urea, 1 part by mass of acetylenol E100 (acetylene glycol EO adduct made by Kawaken Fine Chemicals) )
・ Ion exchange water 76.25 parts by mass

(Comparative Example 2)
In Example 1, C.I. I. Resin fine particles colored only with Acid Red 52 were prepared, and ink was prepared in the same manner as in Example 1. At this time, when preparing the colored fine particles, first, the following components were added to obtain a predetermined concentration, and after sufficiently mixing and stirring them, the colored fine particles were prepared.
・ C. I. Acid Red 52 (first fluorescent coloring material) 1 part by mass, styrene-acrylic copolymer emulsion 20 parts by mass, ion-exchanged water 79 parts by mass

The following components were added to a predetermined concentration, and these were sufficiently mixed and stirred, followed by pressure filtration with a microfilter (manufactured by Fuji Film) having a pore size of 0.2 μm to prepare an ink.
-Colored resin fine particles 5 parts by mass-Glycerin 7.5 parts by mass-Ethylene glycol 5 parts by mass-Urea 5 parts by mass-Acetylenol E100 1 part by mass (Acetylene glycol EO adduct made by Kawaken Fine Chemicals)
・ 76.5 parts by mass of ion exchange water

(Evaluation)
(1) Fluorescence intensity Canon inkjet paper SW using an inkjet recording apparatus BJS600 (manufactured by Canon) having an on-demand type multi-recording head that ejects ink by applying thermal energy corresponding to the recording signal to the ink. A solid pattern of 50% Duty was printed on -101, and the fluorescence intensity was measured under the following conditions using a spectrophotometer (FP-750) manufactured by JASCO Corporation. The results were evaluated according to the following criteria and are shown in Table 1. The measurement conditions were as follows. The excitation wavelength was 254 nm, the fluorescence intensity at the maximum fluorescence wavelength was measured, and the measured fluorescence intensity value was standardized with the fluorescence intensity value of the ink of Reference Example 1 being 100. Evaluated by criteria.

A: The measured fluorescence intensity value is 150 or more. O: The measured fluorescence intensity value is 110 or more and less than 150. Δ: The measured fluorescence intensity value is less than 110.

(2) Color development properties Canon ink jet plain paper SW using an ink jet recording apparatus BJS600 (manufactured by Canon) having an on-demand multi-recording head that ejects ink by applying thermal energy according to a recording signal to the ink. A solid pattern of 50% Duty was printed on -101, and measurement was performed using a Macbeth RD-918 as a density measuring device for printed recorded matter.

◎: It was 0.7 or more that can be easily read visually as printed matter ○: It was 0.5 or more and less than 0.7 that can be visually read as printed matter △: Not visually read as printed matter It was less than 0.3 and less than 0.5. ×: Less than 0.3 that was not visually readable as printed matter

(3) Robustness Canon inkjet inkjet plain paper SW using an inkjet recording apparatus BJS700 (manufactured by Canon) having an on-demand multi-recording head that ejects ink by applying thermal energy corresponding to a recording signal to the ink. A solid pattern of 50% Duty was printed on -101, allowed to stand for 24 hours, then immersed in tap water for 5 minutes, and the change in print density was evaluated using Macbeth RD918 according to the following criteria.

A: Density change that can be easily read visually as printed matter was less than 50% ○: It was 50% or more and less than 70% visually readable as printed matter △: Unreadable visually as printed matter It was over 70%

Colored fine particles were prepared in the following manner, and an ink was prepared in the same manner as in Example 1. In a reaction vessel equipped with a reflux tube, 55 parts by mass of ion-exchanged water, 2 parts by mass of sodium lauryl sulfate, 35 parts by mass of methyl methacrylate, 5 parts by mass of sodium methacrylate, 1 part by mass of acid red 52, and 4 parts by mass of compound (A) were charged. The mixture was heated to 70 ° C. under a nitrogen stream while mixing and stirring, and 0.1 part by mass of ammonium persulfate was added to 5 parts by mass of ion-exchanged water and stirred for 5 hours to complete the reaction, whereby colored fine particles were obtained. . Next, the following components were added to obtain a predetermined concentration, and these were sufficiently mixed and stirred, followed by pressure filtration with a microfilter (manufactured by Fuji Film) having a pore size of 0.2 μm to prepare an ink.
-Colored resin fine particles 5 parts by mass-Glycerin 7.5 parts by mass-Ethylene glycol 5 parts by mass-Urea 5 parts by mass-Acetylenol E100 1 part by mass (Acetylene glycol EO adduct made by Kawaken Fine Chemicals)
-Ion-exchanged water 76.5 parts by mass The obtained ink was evaluated in the same manner as in Example 1. As a result, all the items (1) to (3) were as good as in Example 1. The results are shown in Table 2.

In addition to the first fluorescent color material and the second fluorescent color material, colored fine particles and ink were prepared in the same manner as in Example 1 except that the third fluorescent color material shown below was added. First, the following components were added to obtain a predetermined concentration, and after sufficiently mixing and stirring these, colored fine particles were prepared.
・ C. I. Acid Red 52 (first fluorescent color material) 1 part by mass Compound (A) (second fluorescent color material) 4 parts by mass C.I. I. Acid Red 92 (third colorant) 2.5 parts by mass 20 parts by mass of styrene-acrylic copolymer emulsion 72.5 parts by mass of ion-exchanged water

Next, the obtained colored fine particles and the following components are added to obtain a predetermined concentration, and after sufficiently mixing and stirring these, the ink is filtered under pressure with a microfilter (manufactured by Fuji Film) having a pore size of 0.2 μm. Was prepared. Here, the amount of the colored resin fine particles is such that the amount of the dye in the resin fine particles is C.I. I. The acid red 52 was adjusted to 0.2 parts by mass and the compound (A) was adjusted to 2.0 parts by mass.
-Colored resin fine particles 5 parts by mass-Glycerin 7.5 parts by mass-Ethylene glycol 5 parts by mass-Urea 5 parts by mass-Acetylenol E100 1 part by mass (Acetylene glycol EO adduct made by Kawaken Fine Chemicals)
-Ion-exchanged water 76.5 parts by mass The obtained ink was evaluated in the same manner as in Example 1 and shown in Table 2.

(Comparative Example 3)
The second fluorescent color material is C.I. I. An ink was prepared in the same manner as in Example 1 except that Acid Red 73 was used. First, the following components were added to obtain a predetermined concentration, and after sufficiently mixing and stirring these, colored fine particles were prepared.
・ C. I. Acid Red 52 (first fluorescent color material) 1 part by mass · Compound (A) (second fluorescent color material) 4 parts by mass · Styrene-acrylic copolymer emulsion 20 parts by mass · Ion-exchanged water 75 parts by mass

Next, the obtained colored fine particles and the following components are added to obtain a predetermined concentration, and after sufficiently mixing and stirring these, the ink is filtered under pressure with a microfilter (manufactured by Fuji Film) having a pore size of 0.2 μm. Was prepared. Here, the amount of the colored resin fine particles was adjusted so that the amount of the dye in the resin fine particles was 0.2 parts by mass for Acid Red 52 and 2.0 parts by mass for Compound (A) with respect to the entire ink.
-Colored resin fine particles 5 parts by mass-Glycerin 7.5 parts by mass-Ethylene glycol 5 parts by mass-Urea 5 parts by mass-Acetylenol E100 1 part by mass (Acetylene glycol EO adduct made by Kawaken Fine Chemicals)
-Ion-exchanged water 76.5 parts by mass The obtained ink was evaluated in the same manner as in Example 1 and shown in Table 2.

C. I. It is a figure which shows the fluorescence emission spectrum in case the excitation wavelength of Acid Red 52 is 254 nm. C. I. It is a figure which shows the excitation spectrum whose fluorescence emission wavelength of Acid Red 52 is 600 nm. It is a figure which shows the fluorescence emission spectrum in the excitation wavelength of 254 nm of a compound (A). C. I. It is a figure which shows the contrast of the excitation spectrum whose fluorescence emission wavelength of Acid Red 52 is 600 nm, and the fluorescence emission spectrum when the excitation wavelength of compound (A) is 254 nm. C. I. It is a figure which shows the contrast of the excitation spectrum in 600 nm fluorescence emission of Acid Red 52, and the absorption spectrum of a compound (A). A fluorescence spectrum of compound (A) at 254 nm; I. It is a figure which shows the contrast of the absorption spectrum of Acid Red 52. C. I. It is a figure which shows the fluorescence spectrum in excitation wavelength 254nm in the mixed ink of acid red 52 and a compound (A). C. I. It is a figure which shows the fluorescence spectrum in the printed matter with the mixed ink of acid red 52 and a compound (A). C. I. It is a figure which shows the excitation spectrum in 580, 600, and 620 nm of Acid Red 52. C. I. It is a figure which shows the fluorescence emission spectrum in the excitation wavelength of 254 nm of Acid Yellow 73. C. I. Acid Red 52 has an excitation spectrum of 600 nm in fluorescence emission wavelength and C.I. I. It is a figure which shows the contrast of the fluorescence emission spectrum in case the excitation wavelength of Acid Yellow 73 is 254 nm. C. I. The excitation spectrum of Acid Red 52 at 600 nm fluorescence and C.I. I. It is a figure which shows the contrast of the absorption spectrum of Acid Yellow 73. C. I. Acid Yellow 73 fluorescence spectrum at 254 nm, C.I. I. It is a figure which shows the contrast of the absorption spectrum of Acid Red 52. C. I. It is a figure which shows the fluorescence emission spectrum in excitation wavelength 254nm of Solvent Green 7. C. I. Acid Red 52 has an excitation spectrum of 600 nm in fluorescence emission wavelength and C.I. I. It is a figure which shows the contrast of the fluorescence emission spectrum in case the excitation wavelength of Solvent Green 7 is 254 nm. C. I. The excitation spectrum of Acid Red 52 at 600 nm fluorescence and C.I. I. It is a figure which shows contrast of the absorption spectrum of Solvent Green 7. FIG. C. I. Fluorescence spectrum of Solvent Green 7 at 254 nm; I. It is a figure which shows the contrast of the absorption spectrum of Acid Red 52.

Claims (14)

  In an aqueous fluorescent printing ink containing resin particles colored with at least two fluorescent color materials, one of the fluorescent color materials is measured or determined from among the wavelengths that emit fluorescence when a reference excitation wavelength is applied. A first fluorescent color material that emits light of a reference fluorescence wavelength, and the other color material of the fluorescent color material is a second fluorescent color material that emits fluorescence by the reference excitation wavelength, and the second fluorescent color material The emission wavelength range of the material is at least the peak wavelength corresponding to the peak area adjacent to the reference fluorescence wavelength in the excitation wavelength range for obtaining the emission of the reference fluorescence wavelength of the first fluorescent color material in the ink An aqueous fluorescent printing ink characterized by substantially including a region.   The reference excitation wavelength is 254 nm, the peak wavelength region is 475 nm or more and 600 nm or less, the emission wavelength region of the second fluorescent color material includes 600 nm as the reference wavelength, and the emission wavelength range is 450 nm or more and 600 nm or less. The water-based fluorescent printing ink according to claim 1.   The first fluorescent color material has a peak region of an absorption spectrum in a visible light region, and a region on a lower wavelength side than the peak region of the absorption spectrum is present in a wavelength region of fluorescence emission of the second fluorescent color material. The aqueous fluorescent printing ink according to claim 1 or 2, which is contained.   A printing ink containing a first fluorescent color material that emits light of a reference wavelength used for measurement or determination, among the wavelengths that emit fluorescence when a reference excitation wavelength is applied, and that emits fluorescence at the reference excitation wavelength. A fluorescent color material, and an emission wavelength range of the second fluorescent color material is at least one of the excitation wavelength ranges for obtaining emission of the reference wavelength of the first fluorescent color material in the ink. The aqueous fluorescent printing ink according to claim 1, which is in a wavelength range including a main absorption wavelength range in an absorption spectrum of one fluorescent color material.   5. The aqueous fluorescence according to claim 4, wherein the first fluorescent color material has a main absorption wavelength range of 500 nm to 580 nm, and the second fluorescent color material has an emission wavelength range of 450 nm to 600 nm. Ink for printing.   The aqueous fluorescent printing ink according to any one of claims 1 to 5, wherein the second fluorescent color material is a color material having a structure having a plurality of fluorescent luminophores.   An aqueous fluorescent printing ink containing a first fluorescent color material that emits light having a reference wavelength used for measurement or determination among wavelengths that emit fluorescence when a reference excitation wavelength is applied, and emits fluorescence by the reference excitation wavelength. And a second fluorescent color material for enhancing the emission intensity of the reference wavelength, wherein the second fluorescent color material has a structure having a plurality of fluorescent luminophores. ink.   The ink for aqueous fluorescent printing according to claim 7, wherein the emission wavelength range of the second fluorescent color material is at least an excitation wavelength range for obtaining the reference wavelength of the first fluorescent color material in the ink.   An aqueous fluorescent printing ink containing a first fluorescent color material that emits light having a reference wavelength used for measurement or determination among wavelengths that emit fluorescence when a reference excitation wavelength is applied, and emits fluorescence by the reference excitation wavelength. The first fluorescent color material has a second fluorescent color material, the second fluorescent color material has a structure having a plurality of fluorescent luminophores, and an emission wavelength region of the second fluorescent color material is in the ink. The water-based fluorescent printing ink according to claim 1, wherein the color fluorescent material has a wavelength region common to at least a part of an excitation wavelength region for obtaining light emission of the reference wavelength of the color material.   The aqueous fluorescent printing ink according to any one of claims 1 to 9, wherein each of the plurality of fluorescent luminophores of the second fluorescent color material has a basic structure for fluorescent whitening.   The aqueous fluorescent printing ink according to any one of claims 1 to 10, further comprising a third color material in addition to the first fluorescent color material and the second fluorescent color material.   The aqueous fluorescent printing ink according to claim 1, wherein the resin constituting the resin fine particles is a copolymer composed of a monomer component containing at least one kind of hydrophobic monomer and contains a hydrophilic group.   13. The aqueous fluorescent printing ink according to claim 12, wherein the resin constituting the resin fine particles is a copolymer comprising a monomer component containing at least one kind of hydrophobic monomer and at least one kind of hydrophilic monomer.   An ink jet recording method for recording by discharging from an ink discharge port and adhering to a recording medium, wherein the ink is the aqueous fluorescent printing ink according to any one of claims 1 to 13. Inkjet recording method.

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