WO2016117632A1 - Film formation method, image formation method, film, and ink composition - Google Patents
Film formation method, image formation method, film, and ink composition Download PDFInfo
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- WO2016117632A1 WO2016117632A1 PCT/JP2016/051655 JP2016051655W WO2016117632A1 WO 2016117632 A1 WO2016117632 A1 WO 2016117632A1 JP 2016051655 W JP2016051655 W JP 2016051655W WO 2016117632 A1 WO2016117632 A1 WO 2016117632A1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05D7/00—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
- B05D7/24—Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
- B32B5/14—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by a layer differing constitutionally or physically in different parts, e.g. denser near its faces
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D11/00—Inks
- C09D11/30—Inkjet printing inks
- C09D11/32—Inkjet printing inks characterised by colouring agents
- C09D11/322—Pigment inks
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D201/00—Coating compositions based on unspecified macromolecular compounds
Definitions
- the present invention relates to a film forming method, an image forming method, a film, an ink composition, and the like.
- One method of forming a white image is to form a film on a substrate using white ink in which white pigment particles are dispersed.
- white ink in which white pigment particles are dispersed.
- metal pigment particles such as titanium oxide particles are often used as the white pigment particles. Since the specific gravity of the metal oxide particles is large, if the white ink in which the metal oxide particles are dispersed is allowed to stand in the ink tank, the particles will settle over time. When particles settle in the ink tank, not only unevenness occurs in the formed film but also nozzle clogging may occur. Therefore, it is necessary to circulate and stir the ink in the ink tank periodically.
- Patent Document 1 a white ink using titanium oxide particles having a small particle diameter and resin hollow particles having a small specific gravity has been proposed.
- titanium oxide particles having an average particle diameter of 10 nm or more and 200 nm or less are used in order to suppress sedimentation of the ink.
- the degree of whiteness of the film decreases. Therefore, the film formed on the base material using the white ink described in Patent Document 1 may not have a sufficiently high degree of whiteness.
- an object of the present invention is to form a film with a higher degree of whiteness than before while suppressing sedimentation of particles in the ink.
- the film formation method according to the present invention is a film formation method for forming a film on a substrate, and the film includes a plurality of first to fourth regions each defined by a refractive index and a region size.
- the refractive index of the first and second regions is 0.4 or more larger than the refractive index of the third and fourth regions, and the first region has an equivalent circle diameter.
- the second region is a region made of high refractive index particles having an average particle size of 10 nm or more and 100 nm or less
- the third region is a region having an equivalent circle diameter of more than 100 nm.
- the fourth region is a region having an equivalent circle diameter that is equal to or greater than an average particle diameter of the high refractive index particles and smaller than the equivalent circle diameter of the third region.
- FIG. 4 is an electron micrograph of a film formed on a substrate according to Example 2. It is an electron micrograph of the film
- the film forming method according to the present embodiment is a film forming method for forming the film 12 on the substrate 10.
- FIG. 1 is a cross-sectional view of a film 12 formed on a substrate 10 according to the first embodiment.
- the image forming method according to the present embodiment is an image forming method in which an image is formed by forming a film on a substrate by the above-described film forming method.
- a printed matter 102 obtained by the image forming method according to the present embodiment includes a base material 10 and a film 12 formed on the base material 10.
- the film 12 is preferably a white film. By forming the white film 12, a white image can be formed.
- the film 12 includes a first region (A), a second region (B), a third region (C), and a fourth region (D) defined by the refractive index and the region size.
- a plurality of the films are arranged so as to be mixed. Note that “mixed” here means that there are a plurality of regions in the film thickness direction and a plurality of regions in the direction perpendicular to the film thickness direction. That is, each region exists in a dispersed manner in the film.
- the first region (A) is a region that is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D).
- the first region (A) is a region having an equivalent circle diameter of 250 nm or more. Further, the equivalent circle diameter of the first region (A) is preferably 500 nm or less. By setting the equivalent circle diameter of the first region (A) to 250 nm or more, the degree of whiteness of the film 12 can be improved. Further, by setting the equivalent circle diameter of the first region (A) to 500 nm or less, the existence ratio of the interface between the first region (A) and the other regions in the film 12 can be increased. . As a result, the degree of whiteness of the film 12 can be improved.
- the equivalent circle diameter of the first region (A) can be measured from, for example, an electron micrograph of a cross section in the film thickness direction of the film 12. You may image-process an electron micrograph and measure an equivalent circle diameter. In addition, it can measure similarly about the equivalent circle diameter of the other area
- the refractive index of the first region (A) is not particularly limited as long as it is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D). It is preferable that they are 0.7 or more and 2.8 or less. Thus, the degree of whiteness of the film 12 can be improved by increasing the refractive index of the first region (A).
- the refractive index of the first region (A) can be calculated based on the refractive index of the material constituting the first region (A). For example, when the first region (A) is made of titanium oxide particles, the refractive index of the first region (A) can be regarded as the refractive index of titanium oxide.
- titanium oxide for example, titanium oxide, barium titanate, zirconium oxide, zinc oxide, niobium oxide or the like is preferably used.
- titanium oxide is preferable from the viewpoint of high whiteness and cost.
- the refractive index of titanium oxide is 2.52 to 2.71, although it varies depending on the crystal form.
- the second region (B) is a region that is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D).
- the second region (B) is a region composed of the high refractive index particles 3.
- the high refractive index particle 3 is a particle having a refractive index larger by 0.4 or more than both the refractive index of the third region (C) and the refractive index of the fourth region (D).
- the refractive index of the high refractive index particle 3 is not particularly limited as long as it is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D), but 1.7. It is preferable that it is 2.8 or less. Thus, by increasing the refractive index of the high refractive index particles 3, the degree of whiteness of the film 12 can be improved.
- the high refractive index particles 3 for example, titanium oxide particles, barium titanate particles, zirconium oxide particles, zinc oxide particles, niobium oxide particles and the like are preferably used. Among these, titanium oxide particles are preferable from the viewpoint of high whiteness and cost.
- the refractive index of the titanium oxide particles is 2.52 to 2.71, although it varies depending on the crystal form.
- the average particle diameter of the high refractive index particles 3 is 10 nm or more and 100 nm or less.
- the average particle size of the high refractive index particles 3 is preferably 10 nm or more and 50 nm or less.
- a high refractive index region (first region (A) or second region (B)) and a low refractive index region (third region (C) or fourth region (D)) are formed of a film.
- the film 12 is preferably formed so that at least one film exists in the film thickness direction. In other words, when light passes through the film 12, the first region (A), the second region (B), the third region (C), and the fourth region on a straight line through which the light travels straight. It is preferable to form the film 12 so that one (D) exists.
- the third region (C) or The area where only the fourth area (D) exists can be reduced.
- the degree of whiteness of the film 12 can be improved.
- the third region (C) is a region having a refractive index smaller by 0.4 or more than both the refractive index of the first region (A) and the refractive index of the second region (B).
- the refractive index of the third region (C) is not particularly limited as long as it is 0.4 or more smaller than both the refractive index of the first region (A) and the refractive index of the second region (B). .8 or more is preferable, and 1.0 or more is more preferable.
- the refractive index of the third region (C) is preferably 1.0 or more and less than 1.7. Thus, by reducing the refractive index of the third region (C), the difference in refractive index between the first region (A) and the second region (B) is increased. The degree of whiteness of the film 12 can be improved.
- the third region (C) can be constituted by solid particles or hollow particles made of a low refractive index material such as a polymer material, bubbles, voids, or the like.
- a low refractive index material such as a polymer material, bubbles, voids, or the like.
- acrylic resin, styrene resin, styrene-acrylic resin, fluororesin, silica, magnesium fluoride and the like can be used.
- the third region (C) is preferably composed of hollow particles.
- the refractive index difference between the first region (A) and the third region (C) and between the second region (B) and the third region (C) is hollow. It can be regarded as a difference in refractive index between the cavities in the particles. Since the refractive index of the air present in the cavities in the hollow particles is approximately 1.0, the above refractive index difference can be increased, and the degree of whiteness of the film 12 can be further improved.
- the hollow particles Light can also be diffusely reflected or diffused at the interface between the shell and the cavity. Therefore, the degree of whiteness of the film 12 can be increased.
- the hollow particles are not limited as long as they have cavities inside.
- examples include acrylic resin, styrene resin, styrene-acrylic resin, and hollow resin particles made of methyl methacrylate resin.
- acrylic resin styrene resin
- styrene-acrylic resin styrene-acrylic resin
- hollow resin particles made of methyl methacrylate resin As these commercially available products, for example, highly crosslinked hollow particles manufactured by JSR Corporation, high hollowness hollow particles, and the like can be used. Further, hollow inorganic particles such as hollow silica particles may be used.
- the third region (C) is a region having an equivalent circle diameter larger than 100 nm.
- the equivalent circle diameter is preferably 700 nm or less, and more preferably 500 nm or less.
- the average particle diameter (inner diameter) of the cavities in the hollow particles is preferably 100 nm or more and 400 nm or less, and is 100 nm or more and 350 nm or less. It is more preferable.
- the porosity of the hollow particles is preferably 20% by volume or more and 90% by volume or less.
- the first low refractive index region (B) having a circle-equivalent diameter larger than 100 nm in the film 12, the light irradiated on the film 12 can be effectively irregularly reflected or scattered.
- the degree of whiteness of the film 12 can be improved.
- the volume ratio of the third region (C) in the film 12 is preferably 30% or more and 60% or less. By setting the ratio to 30% or more, the degree of whiteness of the film 12 can be improved. Moreover, the mechanical strength of the film
- membrane 12 can be improved because the said ratio shall be 60% or less.
- the fourth region (D) is a region having a refractive index smaller by 0.4 or more than both the refractive index of the first region (A) and the refractive index of the second region (B). Thereby, the light at the interface between the fourth region (D) and the first region (A) and at the interface between the fourth region (D) and the second region (B). The reflectance can be increased. As a result, the light irradiated on the film 12 is irregularly reflected at the interface or the like, and the degree of whiteness of the film 12 can be improved.
- the refractive index of the fourth region (D) is not particularly limited as long as it is 0.4 or more smaller than both the refractive index of the first region (A) and the refractive index of the second region (B). .8 or more is preferable, and 1.0 or more is more preferable.
- the refractive index of the fourth region (D) is preferably 1.0 or more and less than 1.7. Thus, by reducing the refractive index of the fourth region (D), the difference in refractive index between the first region (A) and the second region (B) is increased. The degree of whiteness of the film 12 can be improved.
- region (D) can be comprised by a bubble, a space
- the fourth region (D) is a region whose equivalent circle diameter is not less than the average particle diameter of the high refractive index particles 3 and smaller than the equivalent circle diameter of the third region (C).
- the first region (A), the second region (B), the third region (C), and the fourth region (D) are respectively
- a film having a high degree of whiteness can be formed by forming a plurality of films arranged so as to be mixed.
- the film 12 can be formed by adhering an ink composition containing the particles constituting the first region (A) and the third region (B), the high refractive index particles 3 and the like onto the substrate 10.
- a method for attaching the ink composition onto the substrate 10 is not particularly limited.
- an ink jet method that is a method of causing droplets of the ink composition to fly and land on the substrate 10 can be suitably used.
- Examples of the ink jet system include thermal jet ink jet and piezo ink jet.
- the base material 10 examples include, but are not limited to, paper, films of polymer materials such as vinyl chloride and PET, plastic, metal, wood, cloth, glass, ceramics, and the like.
- the substrate 10 may be a recording medium, for example.
- the shape of the base material 10 is not specifically limited.
- the ink composition according to this embodiment is an ink composition containing the particles constituting the first region (A) and the third region (B) and the high refractive index particles 3.
- the total content of the particles constituting the first region (A) and the high refractive index particles 3 in the ink composition is 1% by mass or more and 20% by mass or less with respect to the total mass of the ink composition. Preferably, it is 5 mass% or more and 15 mass% or less.
- the content of the particles exceeds the above upper limit value, there is a possibility that the head is clogged when an image is formed by the ink jet method.
- the degree of whiteness of the formed film 12 tends to be insufficient.
- a commercially available dispersion in which white pigment particles are dispersed in advance may be used.
- neutral titania sol “TTO-W-5” manufactured by Ishihara Sangyo Co., Ltd. can be used.
- the ink composition according to this embodiment may have a dispersant for dispersing each particle in the ink composition.
- a dispersant for dispersing each particle in the ink composition.
- the dispersant those that can be used for ordinary pigment inks can be used without particular limitation.
- a cationic dispersant, an anionic dispersant, a nonionic dispersant, a surfactant, and the like can be used.
- anionic dispersant examples include polyacrylic acid and styrene-acrylic acid copolymer.
- nonionic dispersants include polyvinyl pyrrolidone and polypropylene glycol.
- surfactant examples include sodium dodecylbenzenesulfonate and sodium lactylate. Among these, it is preferable to use a styrene-acrylic acid copolymer in that the dispersion stability of each particle can be improved.
- these dispersants also serve to bind each particle in the film 12.
- the ratio of these dispersants to the total amount of the ink composition is preferably 1% by weight to 20% by weight, and more preferably 2% by weight to 10% by weight.
- the ink composition according to this embodiment may have a surfactant such as an acetylene glycol surfactant or a polysiloxane surfactant.
- a surfactant such as an acetylene glycol surfactant or a polysiloxane surfactant.
- acetylene glycol surfactant examples include POE (10) acetylene glycol.
- a commercial item can also be utilized for acetylene glycol surfactant, for example, acetylenol E100 (above, Kawaken Fine Chemical Co., Ltd. product) is mentioned.
- surfactants such as an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant may be added to the ink composition according to this embodiment.
- the content of the surfactant exemplified above is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 1% by mass or less, with respect to the total mass of the ink composition. is there.
- the ink composition according to this embodiment may further include a resin serving as a binder in order to improve the fixability of the film to the substrate.
- a resin serving as a binder in order to improve the fixability of the film to the substrate.
- the binder resin include urethane resin, acrylic resin, and methacrylic resin. These resins may be either an emulsion type dispersed in a solvent in a solvent form or a solution type dissolved in a solvent.
- the ratio of these resins to the total amount of the ink composition is preferably 0.1% by weight or more and 10% by weight, and more preferably 0.5% by weight or more and 5% by weight or less.
- the ink composition according to this embodiment may further include a polyhydric alcohol.
- a polyhydric alcohol By adding a polyhydric alcohol, the drying speed of the ink can be suppressed. As a result, for example, clogging of ink in the head can be prevented when the ink composition is ejected onto the substrate 10 by the inkjet method.
- polyhydric alcohol examples include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol.
- the content of the polyhydric alcohol is preferably 0.1% by mass or more and 20% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less with respect to the total mass of the ink composition.
- the ink composition according to this embodiment usually contains water as a solvent.
- water it is preferable to use ion exchange water, ultrafiltration water, reverse osmosis water, ultrapure water, or the like.
- an organic solvent may be used in combination. Examples of such an organic solvent include alcohols such as ethanol, methanol, butanol, and propanol.
- the film forming method according to the present embodiment is a film forming method for forming the film 13 on the substrate 10.
- FIG. 2 is a cross-sectional view of the film 13 formed on the substrate 10 according to the second embodiment.
- the image forming method according to the present embodiment is an image forming method in which an image is formed by forming a film on a substrate by the above-described film forming method.
- a printed material 103 obtained by the image forming method according to the present embodiment includes a base material 10 and a film 13 formed on the base material 10.
- the film 13 is preferably a white film. By forming the white film 13, a white image can be formed.
- the film 13 includes a first region (A), a second region (B), a third region (C), which are defined by the refractive index and the size of the region, and ,
- the fourth region (D) is a film that is arranged so as to be plural and mixed.
- the present embodiment is characterized in that the first region (A) is a region where the high refractive index particles 3 are aggregated. That is, the first region (A) is constituted by secondary particles produced by aggregation of the high refractive index particles 3.
- the high refractive index particles 3 in the ink composition are aggregated after the ink composition is discharged or applied to form the first region (A). More preferably, after the ink composition is deposited on the substrate 10, the high refractive index particles 3 aggregate to form the first region (A).
- the first region (A) is not composed of particles having a large particle diameter, but is composed of high refractive index particles 3 having a small particle diameter, thereby suppressing sedimentation of particles in the ink composition. be able to.
- the sedimentation rate of particles dispersed in a dispersion medium can be reduced by reducing the particle diameter.
- sedimentation of the particles dispersed in the dispersion medium can be suppressed by using particles having a particle size of 100 nm or less.
- the particles constituting the first region (A) and the high refractive index particles 3 have a large specific gravity and tend to settle when the particle size is large.
- all of the high refractive index particles contained in the ink composition according to the present embodiment have an average particle size of 100 nm or less, it is easy to keep the state dispersed in a solvent. Therefore, according to this embodiment, in addition to improving the whiteness of the formed film, it is possible to improve the storage stability in the state of the ink composition.
- a void as the fourth region (D) is formed.
- the degree of whiteness can be further improved.
- the portion of the high refractive index particles 3 that has not remarkably aggregated constitutes the second region (B).
- an inorganic metal salt containing a metal ion or an organic acid as an aggregating agent.
- an inorganic metal salt containing a metal ion an inorganic salt containing a divalent or higher polyvalent metal ion is preferable, and one soluble in water is preferable.
- polyvalent metal ions include divalent metal ions such as Ca 2+ , Mg 2+ , Ba 2+ and Zn 2+, and trivalent metal ions such as Al 3+ and Fe 3+ .
- the salt include nitrate, acetate, sulfate, chloride and the like. Among these, calcium nitrate is particularly preferable.
- the content of the inorganic metal salt as the flocculant is preferably 0.001% by mass or more and 0.01% by mass or less, more preferably 0.001% by mass or more, based on the total mass of the ink composition. It is 0.005 mass% or less.
- the content is less than 0.001% by mass, the high refractive index particles 3 are not sufficiently aggregated, and the degree of whiteness is not sufficiently improved.
- the content is more than 0.01% by mass, the aggregation of the high refractive index particles 3 proceeds in the state of the ink composition, and sedimentation of the particles in the ink composition occurs.
- the ink composition containing the flocculant is discharged or applied onto the substrate 10
- the ink composition on the substrate 10 is dried, and a solvent such as water in the ink composition is dried. Volatilize.
- flocculant in the ink composition in the middle of drying rises gradually, As a result, the high refractive index particle
- grains 3 can be aggregated.
- the aggregation of the high refractive index particles 3 is not limited to that which occurs on the substrate 10, and for example, aggregation may occur during the flight when the ink composition is ejected.
- the printed matter (film on the substrate) obtained in the example was observed using a scanning electron microscope (FESEM S-4800, manufactured by Hitachi, Ltd.) at an acceleration voltage of 5 kV.
- the resolution of the scanning electron microscope (FESEM S-4800, manufactured by Hitachi, Ltd.) was 1.0 nm (acceleration voltage 15 kV, working distance 4 mm) or 2.0 nm (acceleration voltage 1 kV, working distance 1.5 mm).
- a first solution was prepared by adding titanium n-butoxide (TBOT) to an ethanol (EtOH) solution. Thereafter, a mixed solution of ethanol and 1 wt% aqueous ammonia (NH 3 aq.) was added to the first solution, and the mixture was stirred for about 1 day. Thereby, a solution containing titanium oxide particles A was obtained.
- the average particle diameter of the obtained titanium oxide particles A was about 300 nm.
- titanium oxide particles A high refractive index particles having a large particle size
- titanium oxide particles B high refractive index particles having a small particle size
- TTO-W-5 is an aqueous sol of rutile ultrafine titanium oxide, a neutral sol (pH 6 to 8) having a solid concentration of about 30%, and an average particle size of several tens of nm.
- SX868 (B) As the hollow particles, commercially available “SX868 (B)” (manufactured by JSR Corporation) was used. SX868 (B) was obtained by dispersing polymer hollow particles having an outer diameter of 500 nm and an inner diameter of 370 nm in water, and the solid content concentration was about 20%.
- styrene acrylic resin mass average molecular weight of about 30,000
- resin A mass average molecular weight of about 30,000
- a solution type styrene-acrylic acid copolymer solution having a solid content of about 22% was used.
- Urethane resin (resin B) was used as a binder.
- the urethane resin used was an emulsion type in which a urethane resin was dispersed in an aqueous solution, and a solid content concentration of about 40% was used.
- Acetylenol E100 (manufactured by Kawaken Fine Chemicals) was used.
- Acetylenol E100 is an acetylene glycol surfactant.
- Example 2 calcium nitrate was used as the inorganic metal salt.
- Example 1 and Comparative Examples 1 to 3 were applied using a bar coater onto a PET film (manufactured by A-One Godo Co., Ltd.) on which an ink receiving layer was formed. Thereafter, the substrate was dried at room temperature for one day to form a white image on a PET film as a base material, thereby producing a printed matter.
- the film thicknesses of the white images obtained in the examples and comparative examples were both about 2.5 ⁇ m.
- Example 1 A cross-sectional SEM photograph of the printed matter obtained in Example 1 is shown in FIG.
- Example 1 As shown in FIG. 3, titanium oxide particles 42 (titanium oxide particles B) having an average particle diameter of several tens of nm, titanium oxide particles 41 (titanium oxide particles A) having an average particle diameter of about 300 nm, A membrane having hollow particles 43 was obtained.
- a large number of voids having a size larger than the average particle size of the titanium oxide particles B and smaller than the average particle size of the hollow particles 43 were formed between the particles. That is, in Example 1, the first region (A), the second region (B), the third region (C), and the fourth region (D) are arranged so as to be plural and mixed. A finished membrane was obtained.
- the brightness (L * value) was 52.
- Example 2 A cross-sectional SEM photograph of the printed matter obtained in Example 2 is shown in FIG.
- titanium oxide particles 42 titanium oxide particles B having an average particle diameter of several tens of nanometers and secondary particles 44 (average particle diameter) formed by aggregation of the titanium oxide particles 42. Is about 350 nm) and hollow particles 43 are obtained.
- a large number of voids having a size larger than the average particle size of the titanium oxide particles B and smaller than the average particle size of the hollow particles 43 were formed between the particles. That is, in Example 2, the first region (A), the second region (B), the third region (C), and the fourth region (D) are arranged so as to be plural and mixed. A finished membrane was obtained. Furthermore, the 1st area
- the brightness (L * value) was 61.
- Comparative Example 1 a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm and hollow particles was obtained. In addition, voids having a size larger than the average particle size of the titanium oxide particles B and smaller than the average particle size of the hollow particles 43 were not formed between the particles.
- Comparative Example 2 In Comparative Example 2, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm was obtained. In addition, voids having a size larger than the average particle diameter of the titanium oxide particles B were not formed between the particles.
- Comparative Example 3 In Comparative Example 3, a film having hollow particles was obtained.
- Comparative Example 4 image formation was performed in the same manner as in Example 2 except that calcium nitrate was not used. A cross-sectional SEM photograph of the printed matter obtained in Comparative Example 4 is shown in FIG. In Comparative Example 4, as shown in FIG. 5, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm and hollow particles 43 was obtained. In addition, voids having a size larger than the average particle diameter of the titanium oxide particles B were not formed between the particles.
- Comparative Example 5 a film having titanium oxide particles (titanium oxide particles A) having an average particle diameter of about 300 nm was obtained.
- the brightness (L * value) was 70.
- Example 1 contains high refractive index particles having a large particle size in the ink composition, and thus, although settling is suppressed as compared with the case where only the high refractive index particles having a large particle size are used, it is stored for a long period of time. It was found that a part of the high refractive index particles settled. On the other hand, in Example 2, since the high refractive index particles having a large particle diameter were not contained in the ink composition, it was found that the high refractive index particles did not easily settle even when stored for a long period of time. From this, it was found that Example 2 was able to improve the whiteness of the formed film, and in addition, the storage stability of the ink composition was higher.
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Abstract
A film formation method for forming a film 12 on a base material 10, wherein the film 12 is such that each of a plurality of first through fourth regions (A to D) defined by refractive index and region size is arranged in a mixed state. The refractive index of the first region (A) and the second region (B) is at least 0.4 higher than the refractive index of the third region (C) and the fourth region (D). The first region (A) has an equivalent circle diameter of 250 nm or greater. The second region (B) comprises high-refractive-index particles 3 having an average grain size of from 10 nm to 100 nm. The third region (C) has an equivalent circle diameter greater than 100 nm. The fourth region (D) has an equivalent circle diameter equal to or greater than the average grain size of the high-refractive-index particles 3 and less than the equivalent circle diameter of the third region (C).
Description
本発明は、膜形成方法、画像形成方法、膜、およびインク組成物等に関する。
The present invention relates to a film forming method, an image forming method, a film, an ink composition, and the like.
近年、商業印刷の市場では透明または半透明のフィルム、あるいは着色された紙など、白色以外の基材上に画像を形成する方法が強く求められている。これらの白色以外の基材上に画像を形成する際には、白色画像を形成する必要がある。
In recent years, there is a strong demand in the commercial printing market for a method for forming an image on a substrate other than white, such as a transparent or translucent film, or colored paper. When forming an image on a substrate other than white, it is necessary to form a white image.
白色画像を形成する方法の一つに、白色の顔料粒子を分散させた白色インクを用いて基材上に膜を形成する方法がある。白色の顔料粒子としては一般に、酸化チタン粒子などの金属酸化物粒子を用いることが多い。金属酸化物粒子は比重が大きいため、この金属酸化物粒子を分散させた白色インクをインクタンク内に静置しておくと、時間の経過とともに粒子が沈降してしまう。インクタンク内で粒子が沈降すると、形成される膜にムラが生じるだけでなく、ノズルの目詰まりが発生してしまう可能性がある。そのため、インクタンク内のインクを定期的に循環させたり撹拌したりする必要があった。
One method of forming a white image is to form a film on a substrate using white ink in which white pigment particles are dispersed. In general, metal pigment particles such as titanium oxide particles are often used as the white pigment particles. Since the specific gravity of the metal oxide particles is large, if the white ink in which the metal oxide particles are dispersed is allowed to stand in the ink tank, the particles will settle over time. When particles settle in the ink tank, not only unevenness occurs in the formed film but also nozzle clogging may occur. Therefore, it is necessary to circulate and stir the ink in the ink tank periodically.
そこでインクタンク内での粒子の沈降を抑制するために、粒径の小さな酸化チタン粒子と、比重の小さな樹脂製の中空粒子とを用いた白色インクが提案されている(特許文献1)。
Therefore, in order to suppress sedimentation of particles in the ink tank, a white ink using titanium oxide particles having a small particle diameter and resin hollow particles having a small specific gravity has been proposed (Patent Document 1).
特許文献1に記載の白色インクでは、インクの沈降を抑制するために、平均粒子径が10nm以上200nm以下の酸化チタン粒子を用いている。基材上に形成された膜中における白色顔料粒子の粒径が小さくなると、膜の白さの度合いは低くなる。そのため、特許文献1に記載の白色インクを用いて基材上に形成した膜は、白さの度合いが十分に高くない場合があった。
In the white ink described in Patent Document 1, titanium oxide particles having an average particle diameter of 10 nm or more and 200 nm or less are used in order to suppress sedimentation of the ink. As the particle size of the white pigment particles in the film formed on the substrate decreases, the degree of whiteness of the film decreases. Therefore, the film formed on the base material using the white ink described in Patent Document 1 may not have a sufficiently high degree of whiteness.
そこで本発明では、インク内での粒子の沈降を抑制しつつ、従来よりも白さの度合いの高い膜を形成することを目的とする。
Accordingly, an object of the present invention is to form a film with a higher degree of whiteness than before while suppressing sedimentation of particles in the ink.
本発明に係る膜形成方法は、基材上に膜を形成する膜形成方法であって、前記膜は、屈折率および領域の大きさで規定される第1から第4の領域がそれぞれ複数かつ混在するように配置されており、前記第1および第2の領域の屈折率が、前記第3および第4の領域の屈折率より0.4以上大きく、前記第1の領域は、円相当径が250nm以上の領域であり、前記第2の領域は、平均粒径10nm以上100nm以下の高屈折率粒子からなる領域であり、前記第3の領域は、円相当径が100nmより大きい領域であり、前記第4の領域は、円相当径が前記高屈折率粒子の平均粒径以上、前記第3の領域の円相当径より小さい領域であることを特徴とする。
The film formation method according to the present invention is a film formation method for forming a film on a substrate, and the film includes a plurality of first to fourth regions each defined by a refractive index and a region size. The refractive index of the first and second regions is 0.4 or more larger than the refractive index of the third and fourth regions, and the first region has an equivalent circle diameter. Is a region of 250 nm or more, the second region is a region made of high refractive index particles having an average particle size of 10 nm or more and 100 nm or less, and the third region is a region having an equivalent circle diameter of more than 100 nm. The fourth region is a region having an equivalent circle diameter that is equal to or greater than an average particle diameter of the high refractive index particles and smaller than the equivalent circle diameter of the third region.
本発明によれば、インク内での粒子の沈降を抑制しつつ、従来よりも白さの度合いの高い膜を形成することができる。
According to the present invention, it is possible to form a film with a higher degree of whiteness than before while suppressing sedimentation of particles in the ink.
以下、本発明を適用した各実施形態について、適宜図面を参照して詳細に説明する。
Hereinafter, each embodiment to which the present invention is applied will be described in detail with reference to the drawings as appropriate.
(第1の実施形態)
本実施形態に係る膜形成方法は、基材10上に膜12を形成する膜形成方法である。図1は、第1の実施形態に係る、基材10上に形成された膜12の断面図である。また、本実施形態に係る画像形成方法は、上述の膜形成方法によって基材上に膜を形成することによって、画像を形成する画像形成方法である。本実施形態に係る画像形成方法によって得られる印刷物102は、基材10と、基材10上に形成された膜12と、を有する。膜12は、白色膜であることが好ましい。白色の膜12を形成することによって、白色画像を形成することができる。 (First embodiment)
The film forming method according to the present embodiment is a film forming method for forming thefilm 12 on the substrate 10. FIG. 1 is a cross-sectional view of a film 12 formed on a substrate 10 according to the first embodiment. The image forming method according to the present embodiment is an image forming method in which an image is formed by forming a film on a substrate by the above-described film forming method. A printed matter 102 obtained by the image forming method according to the present embodiment includes a base material 10 and a film 12 formed on the base material 10. The film 12 is preferably a white film. By forming the white film 12, a white image can be formed.
本実施形態に係る膜形成方法は、基材10上に膜12を形成する膜形成方法である。図1は、第1の実施形態に係る、基材10上に形成された膜12の断面図である。また、本実施形態に係る画像形成方法は、上述の膜形成方法によって基材上に膜を形成することによって、画像を形成する画像形成方法である。本実施形態に係る画像形成方法によって得られる印刷物102は、基材10と、基材10上に形成された膜12と、を有する。膜12は、白色膜であることが好ましい。白色の膜12を形成することによって、白色画像を形成することができる。 (First embodiment)
The film forming method according to the present embodiment is a film forming method for forming the
膜12は、屈折率および領域の大きさで規定される第1の領域(A)、第2の領域(B)、第3の領域(C)、および、第4の領域(D)が、それぞれ複数かつ混在するように配置された膜である。なおここでいう「混在」とは、各領域が、膜厚方向にそれぞれ複数存在しており、かつ、膜厚方向に垂直な方向にもそれぞれ複数存在していることをいう。すなわち、各領域が、膜中で互いに分散し合って存在している。
The film 12 includes a first region (A), a second region (B), a third region (C), and a fourth region (D) defined by the refractive index and the region size. A plurality of the films are arranged so as to be mixed. Note that “mixed” here means that there are a plurality of regions in the film thickness direction and a plurality of regions in the direction perpendicular to the film thickness direction. That is, each region exists in a dispersed manner in the film.
[第1の領域(A)]
第1の領域(A)は、第3の領域(C)の屈折率および第4の領域(D)の屈折率のいずれよりも0.4以上大きい領域である。これにより、第1の領域(A)と第3の領域(C)との間の界面、および、第1の領域(A)と第4の領域(D)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記の界面等において乱反射または拡散され、膜12の白さの度合いを向上させることができる。 [First region (A)]
The first region (A) is a region that is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D). Thereby, the light at the interface between the first region (A) and the third region (C) and at the interface between the first region (A) and the fourth region (D) The reflectance can be increased. As a result, the light applied to thefilm 12 is diffusely reflected or diffused at the interface or the like, and the degree of whiteness of the film 12 can be improved.
第1の領域(A)は、第3の領域(C)の屈折率および第4の領域(D)の屈折率のいずれよりも0.4以上大きい領域である。これにより、第1の領域(A)と第3の領域(C)との間の界面、および、第1の領域(A)と第4の領域(D)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記の界面等において乱反射または拡散され、膜12の白さの度合いを向上させることができる。 [First region (A)]
The first region (A) is a region that is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D). Thereby, the light at the interface between the first region (A) and the third region (C) and at the interface between the first region (A) and the fourth region (D) The reflectance can be increased. As a result, the light applied to the
第1の領域(A)は、円相当径が250nm以上の領域である。また、第1の領域(A)の円相当径は500nm以下であることが好ましい。第1の領域(A)の円相当径を250nm以上とすることで、膜12の白さの度合いを向上させることができる。また、第1の領域(A)の円相当径を500nm以下とすることで、膜12中における第1の領域(A)とその他の領域との間の界面の存在割合を増加させることができる。その結果、膜12の白さの度合いを向上させることができる。
The first region (A) is a region having an equivalent circle diameter of 250 nm or more. Further, the equivalent circle diameter of the first region (A) is preferably 500 nm or less. By setting the equivalent circle diameter of the first region (A) to 250 nm or more, the degree of whiteness of the film 12 can be improved. Further, by setting the equivalent circle diameter of the first region (A) to 500 nm or less, the existence ratio of the interface between the first region (A) and the other regions in the film 12 can be increased. . As a result, the degree of whiteness of the film 12 can be improved.
第1の領域(A)の円相当径は、例えば、膜12の膜厚方向の断面の電子顕微鏡写真から計測することができる。電子顕微鏡写真を画像処理して、円相当径を計測してもよい。なお、後述する他の領域の円相当径ついても同様に計測することができる。
The equivalent circle diameter of the first region (A) can be measured from, for example, an electron micrograph of a cross section in the film thickness direction of the film 12. You may image-process an electron micrograph and measure an equivalent circle diameter. In addition, it can measure similarly about the equivalent circle diameter of the other area | region mentioned later.
第1の領域(A)の屈折率は、第3の領域(C)の屈折率および第4の領域(D)の屈折率のいずれよりも0.4以上大きければ特に限定はされないが、1.7以上2.8以下であることが好ましい。このように、第1の領域(A)の屈折率を大きくすることで、膜12の白さの度合いを向上させることができる。
The refractive index of the first region (A) is not particularly limited as long as it is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D). It is preferable that they are 0.7 or more and 2.8 or less. Thus, the degree of whiteness of the film 12 can be improved by increasing the refractive index of the first region (A).
第1の領域(A)の屈折率は、第1の領域(A)を構成する材料の屈折率に基づいて算出することができる。例えば、第1の領域(A)が酸化チタン粒子からなる場合には、第1の領域(A)の屈折率は酸化チタンの屈折率とみなすことができる。
The refractive index of the first region (A) can be calculated based on the refractive index of the material constituting the first region (A). For example, when the first region (A) is made of titanium oxide particles, the refractive index of the first region (A) can be regarded as the refractive index of titanium oxide.
第1の領域(A)を構成する材料としては、例えば、酸化チタン、チタン酸バリウム、酸化ジルコニウム、酸化亜鉛、酸化ニオブ等を用いることが好ましい。これらの中でも、白さの度合いの高さやコストの観点から、酸化チタンが好ましい。なお、酸化チタンの屈折率はその結晶形態によって異なるが、2.52~2.71である。
As the material constituting the first region (A), for example, titanium oxide, barium titanate, zirconium oxide, zinc oxide, niobium oxide or the like is preferably used. Among these, titanium oxide is preferable from the viewpoint of high whiteness and cost. The refractive index of titanium oxide is 2.52 to 2.71, although it varies depending on the crystal form.
[第2の領域(B)]
第2の領域(B)は、第3の領域(C)の屈折率および第4の領域(D)の屈折率のいずれよりも0.4以上大きい領域である。これにより、第2の領域(B)と第3の領域(C)との間の界面、および、第2の領域(B)と第4の領域(D)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記の界面等において乱反射または拡散され、膜12の白さの度合いを向上させることができる。 [Second area (B)]
The second region (B) is a region that is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D). Thereby, the light at the interface between the second region (B) and the third region (C) and at the interface between the second region (B) and the fourth region (D) The reflectance can be increased. As a result, the light applied to thefilm 12 is diffusely reflected or diffused at the interface or the like, and the degree of whiteness of the film 12 can be improved.
第2の領域(B)は、第3の領域(C)の屈折率および第4の領域(D)の屈折率のいずれよりも0.4以上大きい領域である。これにより、第2の領域(B)と第3の領域(C)との間の界面、および、第2の領域(B)と第4の領域(D)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記の界面等において乱反射または拡散され、膜12の白さの度合いを向上させることができる。 [Second area (B)]
The second region (B) is a region that is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D). Thereby, the light at the interface between the second region (B) and the third region (C) and at the interface between the second region (B) and the fourth region (D) The reflectance can be increased. As a result, the light applied to the
第2の領域(B)は、高屈折率粒子3からなる領域である。
The second region (B) is a region composed of the high refractive index particles 3.
高屈折率粒子3は、第3の領域(C)の屈折率および第4の領域(D)の屈折率のいずれよりも0.4以上大きな屈折率を有する粒子である。これにより、高屈折率粒子3と第3の領域(C)との間の界面、および、高屈折率粒子3と第4の領域(D)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記界面等において乱反射または拡散され、膜12の白さの度合いを向上させることができる。
The high refractive index particle 3 is a particle having a refractive index larger by 0.4 or more than both the refractive index of the third region (C) and the refractive index of the fourth region (D). Thereby, the reflectance of light at the interface between the high refractive index particle 3 and the third region (C) and the interface between the high refractive index particle 3 and the fourth region (D) is increased. can do. As a result, the light irradiated on the film 12 is irregularly reflected or diffused at the interface or the like, and the degree of whiteness of the film 12 can be improved.
高屈折率粒子3の屈折率は、第3の領域(C)の屈折率および第4の領域(D)の屈折率のいずれよりも0.4以上大きければ特に限定はされないが、1.7以上2.8以下であることが好ましい。このように、高屈折率粒子3の屈折率を大きくすることで、膜12の白さの度合いを向上させることができる。
The refractive index of the high refractive index particle 3 is not particularly limited as long as it is 0.4 or more larger than both the refractive index of the third region (C) and the refractive index of the fourth region (D), but 1.7. It is preferable that it is 2.8 or less. Thus, by increasing the refractive index of the high refractive index particles 3, the degree of whiteness of the film 12 can be improved.
高屈折率粒子3としては、例えば、酸化チタン粒子、チタン酸バリウム粒子、酸化ジルコニウム粒子、酸化亜鉛粒子、酸化ニオブ粒子等を用いることが好ましい。これらの中でも、白さの度合いの高さやコストの観点から、酸化チタン粒子が好ましい。なお、酸化チタン粒子の屈折率はその結晶形態によって異なるが、2.52~2.71である。
As the high refractive index particles 3, for example, titanium oxide particles, barium titanate particles, zirconium oxide particles, zinc oxide particles, niobium oxide particles and the like are preferably used. Among these, titanium oxide particles are preferable from the viewpoint of high whiteness and cost. The refractive index of the titanium oxide particles is 2.52 to 2.71, although it varies depending on the crystal form.
高屈折率粒子3の平均粒径は、10nm以上100nm以下である。また、高屈折率粒子3の平均粒径は、10nm以上50nm以下であることが好ましい。高屈折率粒子3の平均粒径を100nm以下とすることで、膜12の膜厚方向において第3の領域(C)および第4の領域(D)のみが存在する領域を減らすことができる。
The average particle diameter of the high refractive index particles 3 is 10 nm or more and 100 nm or less. The average particle size of the high refractive index particles 3 is preferably 10 nm or more and 50 nm or less. By setting the average particle size of the high refractive index particles 3 to 100 nm or less, the region where only the third region (C) and the fourth region (D) exist in the film thickness direction of the film 12 can be reduced.
膜12の膜厚方向において第3の領域(C)および第4の領域(D)のみが存在する領域は、基材10を遮蔽する能力である遮蔽性が低くなる傾向がある。そのため、高屈折率領域(第1の領域(A)または第2の領域(B))と、低屈折率領域(第3の領域(C)または第4の領域(D))とが、膜12の膜厚方向に少なくとも1つずつ存在するように膜12を形成することが好ましい。換言すると、膜12を光が透過する場合に、光が直進する直線上に、第1の領域(A)、第2の領域(B)、第3の領域(C)、および第4の領域(D)がそれぞれ1つずつ存在するように、膜12を形成することが好ましい。本実施形態では、第1の領域(A)の円相当径に比べて小さな平均粒径を有する高屈折率粒子3を用いることで、膜12の膜厚方向において第3の領域(C)または第4の領域(D)のみが存在する領域を減らすことができる。その結果、膜12の白さの度合いを向上させることができる。
In the region where only the third region (C) and the fourth region (D) exist in the film thickness direction of the film 12, the shielding property, which is the ability to shield the substrate 10, tends to be low. Therefore, a high refractive index region (first region (A) or second region (B)) and a low refractive index region (third region (C) or fourth region (D)) are formed of a film. The film 12 is preferably formed so that at least one film exists in the film thickness direction. In other words, when light passes through the film 12, the first region (A), the second region (B), the third region (C), and the fourth region on a straight line through which the light travels straight. It is preferable to form the film 12 so that one (D) exists. In the present embodiment, by using the high refractive index particles 3 having an average particle diameter smaller than the equivalent circle diameter of the first region (A), the third region (C) or The area where only the fourth area (D) exists can be reduced. As a result, the degree of whiteness of the film 12 can be improved.
[第3の領域(C)]
第3の領域(C)は、第1の領域(A)の屈折率および第2の領域(B)の屈折率のいずれよりも0.4以上小さい屈折率を有する領域である。これにより、第3の領域(C)と第1の領域(A)との間の界面、および、第3の領域(C)と第2の領域(B)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記界面等において乱反射され、膜12の白さの度合いを向上させることができる。 [Third region (C)]
The third region (C) is a region having a refractive index smaller by 0.4 or more than both the refractive index of the first region (A) and the refractive index of the second region (B). Thereby, the light at the interface between the third region (C) and the first region (A) and at the interface between the third region (C) and the second region (B). The reflectance can be increased. As a result, the light irradiated on thefilm 12 is irregularly reflected at the interface or the like, and the degree of whiteness of the film 12 can be improved.
第3の領域(C)は、第1の領域(A)の屈折率および第2の領域(B)の屈折率のいずれよりも0.4以上小さい屈折率を有する領域である。これにより、第3の領域(C)と第1の領域(A)との間の界面、および、第3の領域(C)と第2の領域(B)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記界面等において乱反射され、膜12の白さの度合いを向上させることができる。 [Third region (C)]
The third region (C) is a region having a refractive index smaller by 0.4 or more than both the refractive index of the first region (A) and the refractive index of the second region (B). Thereby, the light at the interface between the third region (C) and the first region (A) and at the interface between the third region (C) and the second region (B). The reflectance can be increased. As a result, the light irradiated on the
第3の領域(C)の屈折率は、第1の領域(A)の屈折率および第2の領域(B)の屈折率のいずれよりも0.4以上小さければ特に限定はされず、0.8以上小さいことが好ましく、1.0以上小さいことがより好ましい。第3の領域(C)の屈折率は、1.0以上1.7未満であることが好ましい。このように、第3の領域(C)の屈折率を小さくすることで、第1の領域(A)との間、および、第2の領域(B)との間の屈折率の差を大きくすることができ、膜12の白さの度合いを向上させることができる。
The refractive index of the third region (C) is not particularly limited as long as it is 0.4 or more smaller than both the refractive index of the first region (A) and the refractive index of the second region (B). .8 or more is preferable, and 1.0 or more is more preferable. The refractive index of the third region (C) is preferably 1.0 or more and less than 1.7. Thus, by reducing the refractive index of the third region (C), the difference in refractive index between the first region (A) and the second region (B) is increased. The degree of whiteness of the film 12 can be improved.
第3の領域(C)は、ポリマー材料などの低屈折率材料製の中実粒子や中空粒子、あるいは気泡、空隙(ボイド)などによって構成することができる。上記低屈折率材料としては、例えば、アクリル樹脂、スチレン樹脂、スチレン-アクリル樹脂、フッ素樹脂、シリカ、フッ化マグネシウムなどを用いることができる。
The third region (C) can be constituted by solid particles or hollow particles made of a low refractive index material such as a polymer material, bubbles, voids, or the like. As the low refractive index material, for example, acrylic resin, styrene resin, styrene-acrylic resin, fluororesin, silica, magnesium fluoride and the like can be used.
第3の領域(C)は、これらの中でも中空粒子で構成することが好ましい。中でも、可視光波長の1/4以下に相当する、100nm以下の厚みの殻を有する中空粒子を用いることが特に好ましい。この場合、第1の領域(A)と第3の領域(C)との間、および、第2の領域(B)と第3の領域(C)との間の屈折率差は、それぞれ中空粒子中の空洞との間の屈折率差とみなすことができる。中空粒子中の空洞内に存在する空気の屈折率はおよそ1.0であるため、上記の屈折率差を大きくすることができ、膜12の白さの度合いをより向上させることができる。なお、殻の厚みが大きな中空粒子を用いた場合においても、第1の領域(A)または第2の領域(B)と中空粒子の殻との間の界面における乱反射または拡散に加え、中空粒子の殻と空洞との間の界面でも光を乱反射または拡散させることができる。そのため、膜12の白さの度合いを高めることができる。
Among these, the third region (C) is preferably composed of hollow particles. Among these, it is particularly preferable to use hollow particles having a shell with a thickness of 100 nm or less corresponding to 1/4 or less of the visible light wavelength. In this case, the refractive index difference between the first region (A) and the third region (C) and between the second region (B) and the third region (C) is hollow. It can be regarded as a difference in refractive index between the cavities in the particles. Since the refractive index of the air present in the cavities in the hollow particles is approximately 1.0, the above refractive index difference can be increased, and the degree of whiteness of the film 12 can be further improved. Even when hollow particles having a large shell thickness are used, in addition to irregular reflection or diffusion at the interface between the first region (A) or the second region (B) and the shell of the hollow particles, the hollow particles Light can also be diffusely reflected or diffused at the interface between the shell and the cavity. Therefore, the degree of whiteness of the film 12 can be increased.
中空粒子としては、内部に空洞を有していれば限定されない。例えば、アクリル樹脂、スチレン樹脂、スチレン-アクリル樹脂、メタクリル酸メチル樹脂製の中空樹脂粒子等が挙げられる。これらの市販品としては、例えば、JSR株式会社製の高架橋中空粒子、高中空率中空粒子等を用いることができる。また、中空シリカ粒子などの中空無機粒子を用いてもよい。
The hollow particles are not limited as long as they have cavities inside. Examples include acrylic resin, styrene resin, styrene-acrylic resin, and hollow resin particles made of methyl methacrylate resin. As these commercially available products, for example, highly crosslinked hollow particles manufactured by JSR Corporation, high hollowness hollow particles, and the like can be used. Further, hollow inorganic particles such as hollow silica particles may be used.
第3の領域(C)は、円相当径が100nmより大きい領域である。また、円相当径が700nm以下であることが好ましく、500nm以下であることがより好ましい。
The third region (C) is a region having an equivalent circle diameter larger than 100 nm. The equivalent circle diameter is preferably 700 nm or less, and more preferably 500 nm or less.
また、第3の領域(C)が中空粒子で構成されている場合には、中空粒子中の空洞の平均粒径(内径)が100nm以上400nm以下であることが好ましく、100nm以上350nm以下であることがより好ましい。また、中空粒子の空孔率は20体積%以上90体積%以下であることが好ましい。
When the third region (C) is composed of hollow particles, the average particle diameter (inner diameter) of the cavities in the hollow particles is preferably 100 nm or more and 400 nm or less, and is 100 nm or more and 350 nm or less. It is more preferable. The porosity of the hollow particles is preferably 20% by volume or more and 90% by volume or less.
このように、100nmより大きな円相当径を有する第1の低屈折率領域(B)を膜12中に形成することで、膜12に照射された光を効果的に乱反射または散乱させることができ、膜12の白さの度合いを向上させることができる。
In this way, by forming the first low refractive index region (B) having a circle-equivalent diameter larger than 100 nm in the film 12, the light irradiated on the film 12 can be effectively irregularly reflected or scattered. The degree of whiteness of the film 12 can be improved.
第3の領域(C)が膜12において占める体積比率は30%以上60%以下であることが好ましい。上記比率を30%以上とすることで、膜12の白さの度合いを向上させることができる。また、上記比率を60%以下とすることで、膜12の機械的な強度を向上させることができる。
The volume ratio of the third region (C) in the film 12 is preferably 30% or more and 60% or less. By setting the ratio to 30% or more, the degree of whiteness of the film 12 can be improved. Moreover, the mechanical strength of the film | membrane 12 can be improved because the said ratio shall be 60% or less.
[第4の領域(D)]
第4の領域(D)は、第1の領域(A)の屈折率および第2の領域(B)の屈折率のいずれよりも0.4以上小さい屈折率を有する領域である。これにより、第4の領域(D)と第1の領域(A)との間の界面、および、第4の領域(D)と第2の領域(B)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記界面等において乱反射され、膜12の白さの度合いを向上させることができる。 [Fourth region (D)]
The fourth region (D) is a region having a refractive index smaller by 0.4 or more than both the refractive index of the first region (A) and the refractive index of the second region (B). Thereby, the light at the interface between the fourth region (D) and the first region (A) and at the interface between the fourth region (D) and the second region (B). The reflectance can be increased. As a result, the light irradiated on thefilm 12 is irregularly reflected at the interface or the like, and the degree of whiteness of the film 12 can be improved.
第4の領域(D)は、第1の領域(A)の屈折率および第2の領域(B)の屈折率のいずれよりも0.4以上小さい屈折率を有する領域である。これにより、第4の領域(D)と第1の領域(A)との間の界面、および、第4の領域(D)と第2の領域(B)との間の界面での光の反射率を高くすることができる。その結果、膜12に照射された光は上記界面等において乱反射され、膜12の白さの度合いを向上させることができる。 [Fourth region (D)]
The fourth region (D) is a region having a refractive index smaller by 0.4 or more than both the refractive index of the first region (A) and the refractive index of the second region (B). Thereby, the light at the interface between the fourth region (D) and the first region (A) and at the interface between the fourth region (D) and the second region (B). The reflectance can be increased. As a result, the light irradiated on the
第4の領域(D)の屈折率は、第1の領域(A)の屈折率および第2の領域(B)の屈折率のいずれよりも0.4以上小さければ特に限定はされず、0.8以上小さいことが好ましく、1.0以上小さいことがより好ましい。第4の領域(D)の屈折率は、1.0以上1.7未満であることが好ましい。このように、第4の領域(D)の屈折率を小さくすることで、第1の領域(A)との間、および、第2の領域(B)との間の屈折率の差を大きくすることができ、膜12の白さの度合いを向上させることができる。
The refractive index of the fourth region (D) is not particularly limited as long as it is 0.4 or more smaller than both the refractive index of the first region (A) and the refractive index of the second region (B). .8 or more is preferable, and 1.0 or more is more preferable. The refractive index of the fourth region (D) is preferably 1.0 or more and less than 1.7. Thus, by reducing the refractive index of the fourth region (D), the difference in refractive index between the first region (A) and the second region (B) is increased. The degree of whiteness of the film 12 can be improved.
第4の領域(D)は、気泡、空隙(ボイド)などによって構成することができる。
4th area | region (D) can be comprised by a bubble, a space | gap (void), etc.
第4の領域(D)は、円相当径が高屈折率粒子3の平均粒径以上、第3の領域(C)の円相当径より小さい領域である。
The fourth region (D) is a region whose equivalent circle diameter is not less than the average particle diameter of the high refractive index particles 3 and smaller than the equivalent circle diameter of the third region (C).
本実施形態に係る膜形成方法によれば、上記の第1の領域(A)、第2の領域(B)、第3の領域(C)、および、第4の領域(D)が、それぞれ複数かつ混在するように配置された膜を形成することで、白さの度合いの高い膜を形成することができる。
According to the film forming method according to the present embodiment, the first region (A), the second region (B), the third region (C), and the fourth region (D) are respectively A film having a high degree of whiteness can be formed by forming a plurality of films arranged so as to be mixed.
膜12は、第1の領域(A)や第3の領域(B)を構成する粒子、高屈折率粒子3などを含むインク組成物を基材10上に付着させて形成することができる。インク組成物を基材10上に付着させる方法は、特に限定はされない。例えば、インク組成物の液滴を飛翔させて基材10に着弾させる方式であるインクジェット方式を好適に用いることができる。インクジェット方式としては、例えば、サーマルジェット式インクジェット、ピエゾ式インクジェットなどが挙げられる。
The film 12 can be formed by adhering an ink composition containing the particles constituting the first region (A) and the third region (B), the high refractive index particles 3 and the like onto the substrate 10. A method for attaching the ink composition onto the substrate 10 is not particularly limited. For example, an ink jet method that is a method of causing droplets of the ink composition to fly and land on the substrate 10 can be suitably used. Examples of the ink jet system include thermal jet ink jet and piezo ink jet.
基材10としては、例えば紙、塩化ビニルやPETなどの高分子材料のフィルム、プラスチック、金属、木材、布、ガラス、セラミックスなどが挙げられるが、これらに限定はされない。基材10は、例えば、被記録媒体であってもよい。なお、基材10の形状は特に限定はされない。
Examples of the base material 10 include, but are not limited to, paper, films of polymer materials such as vinyl chloride and PET, plastic, metal, wood, cloth, glass, ceramics, and the like. The substrate 10 may be a recording medium, for example. In addition, the shape of the base material 10 is not specifically limited.
以下、本実施形態に係るインク組成物について説明する。
Hereinafter, the ink composition according to this embodiment will be described.
[インク組成物]
本実施形態に係るインク組成物は、第1の領域(A)や第3の領域(B)を構成する粒子、高屈折率粒子3を含有するインク組成物である。 [Ink composition]
The ink composition according to this embodiment is an ink composition containing the particles constituting the first region (A) and the third region (B) and the high refractive index particles 3.
本実施形態に係るインク組成物は、第1の領域(A)や第3の領域(B)を構成する粒子、高屈折率粒子3を含有するインク組成物である。 [Ink composition]
The ink composition according to this embodiment is an ink composition containing the particles constituting the first region (A) and the third region (B) and the high refractive index particles 3.
インク組成物中における第1の領域(A)を構成する粒子および高屈折率粒子3の合計含有量は、インク組成物の全質量に対して、1質量%以上20質量%以下であることが好ましく、5質量%以上15質量%以下であることがより好ましい。上記粒子の含有量が上記した上限値を超えると、インクジェット方式によって画像を形成する際にヘッドの目詰まり等を生じる可能性がある。一方、上記した下限値未満であると、形成される膜12の白さの度合いが不足する傾向がある。
The total content of the particles constituting the first region (A) and the high refractive index particles 3 in the ink composition is 1% by mass or more and 20% by mass or less with respect to the total mass of the ink composition. Preferably, it is 5 mass% or more and 15 mass% or less. When the content of the particles exceeds the above upper limit value, there is a possibility that the head is clogged when an image is formed by the ink jet method. On the other hand, when it is less than the above lower limit value, the degree of whiteness of the formed film 12 tends to be insufficient.
インク組成物を調製する際には、白色顔料粒子が予め分散された市販の分散液を使用してもよい。例えば、石原産業株式会社製の中性チタニアゾル「TTO-W-5」などを用いることができる。
When preparing the ink composition, a commercially available dispersion in which white pigment particles are dispersed in advance may be used. For example, neutral titania sol “TTO-W-5” manufactured by Ishihara Sangyo Co., Ltd. can be used.
本実施形態に係るインク組成物は、各粒子をインク組成物中で分散させるための分散剤を有していてもよい。分散剤を添加することで、インク組成物をインクジェット方式によって基材10上に吐出する際の吐出安定性を向上させることができる。分散剤としては、通常の顔料インクに使用可能であるものを、特に制限なく用いることができる。例えば、カチオン性分散剤、アニオン性分散剤、ノニオン性分散剤や界面活性剤等を用いることができる。
The ink composition according to this embodiment may have a dispersant for dispersing each particle in the ink composition. By adding the dispersant, it is possible to improve the ejection stability when the ink composition is ejected onto the substrate 10 by the inkjet method. As the dispersant, those that can be used for ordinary pigment inks can be used without particular limitation. For example, a cationic dispersant, an anionic dispersant, a nonionic dispersant, a surfactant, and the like can be used.
アニオン性分散剤の例としては、ポリアクリル酸、スチレン-アクリル酸共重合体などが挙げられる。ノニオン性分散剤としては、ポリビニルピロリドン、ポリプロピレングリコールなどが挙げられる。界面活性剤としては、ドデシルベンゼンスルホン酸ナトリウム、ラクリル酸ナトリウムなどが挙げられる。これらの中でも、各粒子の分散安定性を向上できる点で、スチレン-アクリル酸共重合体を用いることが好ましい。
Examples of the anionic dispersant include polyacrylic acid and styrene-acrylic acid copolymer. Examples of nonionic dispersants include polyvinyl pyrrolidone and polypropylene glycol. Examples of the surfactant include sodium dodecylbenzenesulfonate and sodium lactylate. Among these, it is preferable to use a styrene-acrylic acid copolymer in that the dispersion stability of each particle can be improved.
また、これらの分散剤は膜12中において各粒子間を結着させる役割も果たす。これらの分散剤のインク組成物の全量に対する割合は、1重量%以上20重量%であることが好ましく、2重量%以上10重量%以下であることがより好ましい。
Further, these dispersants also serve to bind each particle in the film 12. The ratio of these dispersants to the total amount of the ink composition is preferably 1% by weight to 20% by weight, and more preferably 2% by weight to 10% by weight.
本実施形態に係るインク組成物は、アセチレングリコール系界面活性剤またはポリシロキサン系界面活性剤などの界面活性剤を有していてもよい。界面活性剤を添加することで、基材10の記録面へのインク組成物の濡れ性や浸透性を高めることができる。
The ink composition according to this embodiment may have a surfactant such as an acetylene glycol surfactant or a polysiloxane surfactant. By adding the surfactant, the wettability and penetrability of the ink composition to the recording surface of the substrate 10 can be enhanced.
アセチレングリコール系界面活性剤としては、例えばPOE(10)アセチレングリコールなどが挙げられる。また、アセチレングリコール系界面活性剤は、市販品を利用することもでき、例えば、アセチレノールE100(以上、川研ファインケミカル株式会社製)が挙げられる。
Examples of the acetylene glycol surfactant include POE (10) acetylene glycol. Moreover, a commercial item can also be utilized for acetylene glycol surfactant, for example, acetylenol E100 (above, Kawaken Fine Chemical Co., Ltd. product) is mentioned.
さらに、本実施形態に係るインク組成物には、アニオン性界面活性剤、ノニオン性界面活性剤、両性界面活性剤等のその他の界面活性剤を添加してもよい。
Furthermore, other surfactants such as an anionic surfactant, a nonionic surfactant, and an amphoteric surfactant may be added to the ink composition according to this embodiment.
上記例示した界面活性剤の含有量は、インク組成物の全質量に対して、好ましくは0.01質量%以上5質量%以下であり、より好ましくは0.1質量%以上1質量%以下である。
The content of the surfactant exemplified above is preferably 0.01% by mass or more and 5% by mass or less, more preferably 0.1% by mass or more and 1% by mass or less, with respect to the total mass of the ink composition. is there.
本実施形態に係るインク組成物は、基材に対する膜の定着性を向上させるために、さらにバインダーとなる樹脂を有していてもよい。バインダー樹脂として、例えばウレタン系樹脂、アクリル系樹脂、メタクリル系樹脂などが挙げられる。これらの樹脂は、溶媒中に粒子状で分散させたエマルションタイプ、溶媒中に溶解させた溶液タイプのいずれのものを用いても良い。これらの樹脂のインク組成物の全量に対する割合は、0.1重量%以上10重量%であることが好ましく、0.5重量%以上5重量%以下であることがより好ましい。
The ink composition according to this embodiment may further include a resin serving as a binder in order to improve the fixability of the film to the substrate. Examples of the binder resin include urethane resin, acrylic resin, and methacrylic resin. These resins may be either an emulsion type dispersed in a solvent in a solvent form or a solution type dissolved in a solvent. The ratio of these resins to the total amount of the ink composition is preferably 0.1% by weight or more and 10% by weight, and more preferably 0.5% by weight or more and 5% by weight or less.
本実施形態に係るインク組成物はさらに、多価アルコールを有していてもよい。多価アルコールを添加することで、インクの乾燥速度を抑制することができる。その結果、例えばインク組成物をインクジェット方式によって基材10上に吐出する際の、ヘッドにおけるインクの目詰まりを防止することができる。
The ink composition according to this embodiment may further include a polyhydric alcohol. By adding a polyhydric alcohol, the drying speed of the ink can be suppressed. As a result, for example, clogging of ink in the head can be prevented when the ink composition is ejected onto the substrate 10 by the inkjet method.
多価アルコールとしては、例えばグリセリン、エチレングリコール、ジエチレングリコール、トリエチレングリコール、ポリエチレングリコール、ポリプロピレングリコールなどが挙げられる。
Examples of the polyhydric alcohol include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol.
多価アルコールの含有量は、インク組成物の全質量に対して、好ましくは0.1質量%以上20質量%以下であり、より好ましくは0.5質量%以上10質量%以下である。
The content of the polyhydric alcohol is preferably 0.1% by mass or more and 20% by mass or less, and more preferably 0.5% by mass or more and 10% by mass or less with respect to the total mass of the ink composition.
本実施形態に係るインク組成物は、通常、溶媒として水を含有する。水は、イオン交換水、限外ろ過水、逆浸透水、超純水などを用いることが好ましい。また、溶媒として水以外に、有機溶媒を併用してもよい。このような有機溶媒としては、例えばエタノール、メタノール、ブタノール、プロパノールなどのアルコール類などが挙げられる。
The ink composition according to this embodiment usually contains water as a solvent. As the water, it is preferable to use ion exchange water, ultrafiltration water, reverse osmosis water, ultrapure water, or the like. In addition to water, an organic solvent may be used in combination. Examples of such an organic solvent include alcohols such as ethanol, methanol, butanol, and propanol.
(第2の実施形態)
本実施形態に係る膜形成方法は、基材10上に膜13を形成する膜形成方法である。図2は、第2の実施形態に係る、基材10上に形成された膜13の断面図である。また、本実施形態に係る画像形成方法は、上述の膜形成方法によって基材上に膜を形成することによって、画像を形成する画像形成方法である。本実施形態に係る画像形成方法によって得られる印刷物103は、基材10と、基材10上に形成された膜13と、を有する。膜13は、白色膜であることが好ましい。白色の膜13を形成することによって、白色画像を形成することができる。 (Second Embodiment)
The film forming method according to the present embodiment is a film forming method for forming the film 13 on thesubstrate 10. FIG. 2 is a cross-sectional view of the film 13 formed on the substrate 10 according to the second embodiment. The image forming method according to the present embodiment is an image forming method in which an image is formed by forming a film on a substrate by the above-described film forming method. A printed material 103 obtained by the image forming method according to the present embodiment includes a base material 10 and a film 13 formed on the base material 10. The film 13 is preferably a white film. By forming the white film 13, a white image can be formed.
本実施形態に係る膜形成方法は、基材10上に膜13を形成する膜形成方法である。図2は、第2の実施形態に係る、基材10上に形成された膜13の断面図である。また、本実施形態に係る画像形成方法は、上述の膜形成方法によって基材上に膜を形成することによって、画像を形成する画像形成方法である。本実施形態に係る画像形成方法によって得られる印刷物103は、基材10と、基材10上に形成された膜13と、を有する。膜13は、白色膜であることが好ましい。白色の膜13を形成することによって、白色画像を形成することができる。 (Second Embodiment)
The film forming method according to the present embodiment is a film forming method for forming the film 13 on the
また、膜13は第1の実施形態と同様に、屈折率および領域の大きさで規定される第1の領域(A)、第2の領域(B)、第3の領域(C)、および、第4の領域(D)が、それぞれ複数かつ混在するように配置された膜である。以下、第1の実施形態と同様の構成についての説明は省略し、第2の実施形態に特有の構成についてのみ説明する。
Similarly to the first embodiment, the film 13 includes a first region (A), a second region (B), a third region (C), which are defined by the refractive index and the size of the region, and , The fourth region (D) is a film that is arranged so as to be plural and mixed. Hereinafter, the description of the same configuration as that of the first embodiment is omitted, and only the configuration unique to the second embodiment will be described.
[第1の領域(A)]
本実施形態は、第1の領域(A)が、高屈折率粒子3が凝集した領域であることを特徴とする。すなわち、第1の領域(A)は、高屈折率粒子3が凝集して生成した二次粒子によって構成されている。 [First region (A)]
The present embodiment is characterized in that the first region (A) is a region where the high refractive index particles 3 are aggregated. That is, the first region (A) is constituted by secondary particles produced by aggregation of the high refractive index particles 3.
本実施形態は、第1の領域(A)が、高屈折率粒子3が凝集した領域であることを特徴とする。すなわち、第1の領域(A)は、高屈折率粒子3が凝集して生成した二次粒子によって構成されている。 [First region (A)]
The present embodiment is characterized in that the first region (A) is a region where the high refractive index particles 3 are aggregated. That is, the first region (A) is constituted by secondary particles produced by aggregation of the high refractive index particles 3.
本実施形態に係る膜形成方法では、インク組成物を吐出または塗布した後にインク組成物中の高屈折率粒子3が凝集して、第1の領域(A)が形成されることが好ましい。より好ましくは、インク組成物を基材10上に付着させた後に高屈折率粒子3が凝集して、第1の領域(A)が生成する。
In the film forming method according to the present embodiment, it is preferable that the high refractive index particles 3 in the ink composition are aggregated after the ink composition is discharged or applied to form the first region (A). More preferably, after the ink composition is deposited on the substrate 10, the high refractive index particles 3 aggregate to form the first region (A).
このように、第1の領域(A)を大きな粒径の粒子によって構成するのではなく、小さな粒径の高屈折率粒子3によって構成することで、インク組成物中における粒子の沈降を抑制することができる。
As described above, the first region (A) is not composed of particles having a large particle diameter, but is composed of high refractive index particles 3 having a small particle diameter, thereby suppressing sedimentation of particles in the ink composition. be able to.
ストークスの式から、粒子径を小さくすることで、分散媒中に分散させた粒子の沈降速度を小さくすることができることが知られている。分散媒として水を用いた場合には、100nm以下の粒径の粒子を用いることで、分散媒に分散させた粒子の沈降を抑制することができる。
From the Stokes equation, it is known that the sedimentation rate of particles dispersed in a dispersion medium can be reduced by reducing the particle diameter. When water is used as the dispersion medium, sedimentation of the particles dispersed in the dispersion medium can be suppressed by using particles having a particle size of 100 nm or less.
高い屈折率を有する材料としては上述の金属酸化物のように、比重の大きな粒子が多い。そのため、第1の領域(A)を構成する粒子や高屈折率粒子3は比重が大きく、粒径が大きいと沈降しやすい傾向がある。しかし、本実施形態に係るインク組成物に含まれる高屈折率粒子はいずれも、平均粒径が100nm以下であるため、溶媒に分散させた状態を保つことが容易である。したがって、本実施形態によれば、形成される膜の白さを向上させることに加えて、インク組成物の状態における保存安定性を向上させることができる。
As a material having a high refractive index, there are many particles having a large specific gravity like the above-mentioned metal oxide. For this reason, the particles constituting the first region (A) and the high refractive index particles 3 have a large specific gravity and tend to settle when the particle size is large. However, since all of the high refractive index particles contained in the ink composition according to the present embodiment have an average particle size of 100 nm or less, it is easy to keep the state dispersed in a solvent. Therefore, according to this embodiment, in addition to improving the whiteness of the formed film, it is possible to improve the storage stability in the state of the ink composition.
また、高屈折率粒子3を凝集させることによって、第4の領域(D)としての空隙が形成される。これにより、さらに白さの度合いを向上させることができる。また、高屈折率粒子3のうち、顕著に凝集しなかった部分は、第2の領域(B)を構成する。
Further, by agglomerating the high refractive index particles 3, a void as the fourth region (D) is formed. Thereby, the degree of whiteness can be further improved. Further, the portion of the high refractive index particles 3 that has not remarkably aggregated constitutes the second region (B).
高屈折率粒子3を凝集させる方法としては、金属イオンを含む無機金属塩や有機酸を凝集剤として用いる方法がある。金属イオンを含む無機金属塩としては、2価以上の多価金属イオンを含む無機塩が好ましく、水に可溶なものが好ましい。
As a method of aggregating the high refractive index particles 3, there is a method of using an inorganic metal salt containing a metal ion or an organic acid as an aggregating agent. As the inorganic metal salt containing a metal ion, an inorganic salt containing a divalent or higher polyvalent metal ion is preferable, and one soluble in water is preferable.
多価金属イオンの具体例としては、例えば、Ca2+、Mg2+、Ba2+、Zn2+などの2価金属イオン、Al3+、Fe3+などの3価金属イオン等が挙げられる。また、塩の種類としては硝酸塩、酢酸塩、硫酸塩、塩化物などが挙げられる。これらの中でも、特に、硝酸カルシウムが好ましい。
Specific examples of the polyvalent metal ions include divalent metal ions such as Ca 2+ , Mg 2+ , Ba 2+ and Zn 2+, and trivalent metal ions such as Al 3+ and Fe 3+ . Examples of the salt include nitrate, acetate, sulfate, chloride and the like. Among these, calcium nitrate is particularly preferable.
これらの凝集剤としての無機金属塩の含有量は、インク組成物の全質量に対して、好ましくは0.001質量%以上0.01質量%以下であり、より好ましくは0.001質量%以上0.005質量%以下である。含有量が0.001質量%より少ないと、高屈折率粒子3の凝集が十分に起こらず、白さの度合いの向上が不十分である。また0.01質量%より多いと高屈折率粒子3の凝集がインク組成物の状態で進んでしまい、インク組成物中での粒子の沈降が起こってしまう。
The content of the inorganic metal salt as the flocculant is preferably 0.001% by mass or more and 0.01% by mass or less, more preferably 0.001% by mass or more, based on the total mass of the ink composition. It is 0.005 mass% or less. When the content is less than 0.001% by mass, the high refractive index particles 3 are not sufficiently aggregated, and the degree of whiteness is not sufficiently improved. On the other hand, when the content is more than 0.01% by mass, the aggregation of the high refractive index particles 3 proceeds in the state of the ink composition, and sedimentation of the particles in the ink composition occurs.
本実施形態に係る膜形成方法では、凝集剤を含むインク組成物を基材10上に吐出または塗布した後、基材10上のインク組成物を乾燥させ、インク組成物中の水等の溶媒を揮発させる。これにより、乾燥途中のインク組成物中における凝集剤の濃度が次第に上昇していき、その結果、高屈折率粒子3を凝集させることができる。なお、高屈折率粒子3の凝集は、基材10上において生じるものに限定はされず、例えば、インク組成物を吐出した際の飛翔中に凝集が生じていていもよい。
In the film forming method according to the present embodiment, after the ink composition containing the flocculant is discharged or applied onto the substrate 10, the ink composition on the substrate 10 is dried, and a solvent such as water in the ink composition is dried. Volatilize. Thereby, the density | concentration of the coagulant | flocculant in the ink composition in the middle of drying rises gradually, As a result, the high refractive index particle | grains 3 can be aggregated. The aggregation of the high refractive index particles 3 is not limited to that which occurs on the substrate 10, and for example, aggregation may occur during the flight when the ink composition is ejected.
以下、実施例および比較例を用いて、本発明をより具体的に説明する。ただし、本発明は以下の実施例に限定されるものではない。
Hereinafter, the present invention will be described in more detail using examples and comparative examples. However, the present invention is not limited to the following examples.
なお、実施例によって得られた印刷物(基材上の膜)の観察は、走査電子顕微鏡(FESEM S-4800、日立製作所製)を用い、加速電圧を5kVとして行った。走査電子顕微鏡(FESEM S-4800、日立製作所製)の分解能は1.0nm(加速電圧15kV、作動距離4mm)もしくは2.0nm(加速電圧1kV、作動距離1.5mm)であった。
Note that the printed matter (film on the substrate) obtained in the example was observed using a scanning electron microscope (FESEM S-4800, manufactured by Hitachi, Ltd.) at an acceleration voltage of 5 kV. The resolution of the scanning electron microscope (FESEM S-4800, manufactured by Hitachi, Ltd.) was 1.0 nm (acceleration voltage 15 kV, working distance 4 mm) or 2.0 nm (acceleration voltage 1 kV, working distance 1.5 mm).
(酸化チタン粒子Aの作製)
エタノール(EtOH)溶液にチタニウムn-ブトキシド(TBOT)を添加することで、第1の溶液を調製した。その後、第1の溶液に、エタノールと1wt%アンモニア水(NH3aq.)の混合液を添加し、約1昼夜撹拌した。これにより、酸化チタン粒子Aを含む溶液を得た。各原料のモル比は、TBOT:EtOH:NH3aq.=1:100:7.5とした。 (Preparation of titanium oxide particles A)
A first solution was prepared by adding titanium n-butoxide (TBOT) to an ethanol (EtOH) solution. Thereafter, a mixed solution of ethanol and 1 wt% aqueous ammonia (NH 3 aq.) Was added to the first solution, and the mixture was stirred for about 1 day. Thereby, a solution containing titanium oxide particles A was obtained. The molar ratio of each raw material was TBOT: EtOH: NH 3 aq. = 1: 100: 7.5.
エタノール(EtOH)溶液にチタニウムn-ブトキシド(TBOT)を添加することで、第1の溶液を調製した。その後、第1の溶液に、エタノールと1wt%アンモニア水(NH3aq.)の混合液を添加し、約1昼夜撹拌した。これにより、酸化チタン粒子Aを含む溶液を得た。各原料のモル比は、TBOT:EtOH:NH3aq.=1:100:7.5とした。 (Preparation of titanium oxide particles A)
A first solution was prepared by adding titanium n-butoxide (TBOT) to an ethanol (EtOH) solution. Thereafter, a mixed solution of ethanol and 1 wt% aqueous ammonia (NH 3 aq.) Was added to the first solution, and the mixture was stirred for about 1 day. Thereby, a solution containing titanium oxide particles A was obtained. The molar ratio of each raw material was TBOT: EtOH: NH 3 aq. = 1: 100: 7.5.
その後遠心分離機を用いて酸化チタン粒子Aを沈降させて分離し、エタノールにより洗浄して、酸化チタン粒子Aを得た。得られた酸化チタン粒子Aの平均粒径は約300nmであった。
Thereafter, the titanium oxide particles A were settled and separated using a centrifuge, and washed with ethanol to obtain titanium oxide particles A. The average particle diameter of the obtained titanium oxide particles A was about 300 nm.
(インク組成物の調製)
表1に示す配合量で、酸化チタン粒子A、酸化チタン粒子B、中空粒子、分散剤、多価アルコール、界面活性剤、無機金属塩、およびイオン交換水を混合撹拌し、実施例1~2および比較例1~4の各インク組成物を得た。なお、表1の実施例および比較例に記載されている数値の単位は質量%である。また、酸化チタン粒子B、中空粒子および分散剤については、いずれも固形分濃度で換算した質量%である。 (Preparation of ink composition)
In the amounts shown in Table 1, the titanium oxide particles A, the titanium oxide particles B, the hollow particles, the dispersant, the polyhydric alcohol, the surfactant, the inorganic metal salt, and the ion-exchanged water are mixed and stirred. In addition, ink compositions of Comparative Examples 1 to 4 were obtained. In addition, the unit of the numerical value described in the Example of Table 1 and a comparative example is the mass%. Moreover, about titanium oxide particle B, a hollow particle, and a dispersing agent, all are the mass% converted into solid content concentration.
表1に示す配合量で、酸化チタン粒子A、酸化チタン粒子B、中空粒子、分散剤、多価アルコール、界面活性剤、無機金属塩、およびイオン交換水を混合撹拌し、実施例1~2および比較例1~4の各インク組成物を得た。なお、表1の実施例および比較例に記載されている数値の単位は質量%である。また、酸化チタン粒子B、中空粒子および分散剤については、いずれも固形分濃度で換算した質量%である。 (Preparation of ink composition)
In the amounts shown in Table 1, the titanium oxide particles A, the titanium oxide particles B, the hollow particles, the dispersant, the polyhydric alcohol, the surfactant, the inorganic metal salt, and the ion-exchanged water are mixed and stirred. In addition, ink compositions of Comparative Examples 1 to 4 were obtained. In addition, the unit of the numerical value described in the Example of Table 1 and a comparative example is the mass%. Moreover, about titanium oxide particle B, a hollow particle, and a dispersing agent, all are the mass% converted into solid content concentration.
酸化チタン粒子A(大粒径の高屈折率粒子)としては、上述の方法で作製した酸化チタン粒子(平均粒径約300nm)を用いた。酸化チタン粒子B(小粒径の高屈折率粒子)としては、市販品の「TTO-W-5」(石原産業株式会社製)を用いた。TTO-W-5は、ルチル型超微粒子酸化チタンの水系ゾルであり、固形分濃度が約30%の中性ゾル(pH6~8)であり、平均粒径は数十nmであった。
As the titanium oxide particles A (high refractive index particles having a large particle size), titanium oxide particles (average particle size of about 300 nm) prepared by the above-described method were used. Commercially available “TTO-W-5” (manufactured by Ishihara Sangyo Co., Ltd.) was used as the titanium oxide particles B (high refractive index particles having a small particle size). TTO-W-5 is an aqueous sol of rutile ultrafine titanium oxide, a neutral sol (pH 6 to 8) having a solid concentration of about 30%, and an average particle size of several tens of nm.
中空粒子としては、市販品の「SX868(B)」(JSR株式会社製)を用いた。SX868(B)は、外径500nm、内径370nmのポリマー製中空粒子を水に分散させたものであり、固形分濃度が約20%であった。
As the hollow particles, commercially available “SX868 (B)” (manufactured by JSR Corporation) was used. SX868 (B) was obtained by dispersing polymer hollow particles having an outer diameter of 500 nm and an inner diameter of 370 nm in water, and the solid content concentration was about 20%.
分散剤として、スチレンアクリル樹脂(質量平均分子量約3万)(樹脂A)を用いた。スチレン-アクリル酸共重合体の溶液タイプのものを用い、固形分濃度が約22%のものを用いた。バインダーとして、ウレタン樹脂(樹脂B)を用いた。ウレタン樹脂はウレタン樹脂が水溶液中に分散したエマルションタイプのものを用い、固形分濃度が約40%のものを用いた。
As a dispersant, styrene acrylic resin (mass average molecular weight of about 30,000) (resin A) was used. A solution type styrene-acrylic acid copolymer solution having a solid content of about 22% was used. Urethane resin (resin B) was used as a binder. The urethane resin used was an emulsion type in which a urethane resin was dispersed in an aqueous solution, and a solid content concentration of about 40% was used.
界面活性剤としては「アセチレノールE100」(川研ファインケミカル製)を用いた。アセチレノールE100はアセチレングリコール系界面活性剤である。
As the surfactant, “acetylenol E100” (manufactured by Kawaken Fine Chemicals) was used. Acetylenol E100 is an acetylene glycol surfactant.
実施例2では、無機金属塩として、硝酸カルシウムを用いた。
In Example 2, calcium nitrate was used as the inorganic metal salt.
(画像形成)
実施例1および比較例1~3の各インク組成物を、インク受容層が形成されているPETフィルム(エーワン合同株式会社製、OHPフィルム)上にバーコーターを用いて塗工した。その後室温で1昼夜乾燥させることにより、基材であるPETフィルム上に白色画像を形成し、印刷物を作成した。実施例および比較例で得られた白色画像の膜の厚みは、いずれも約2.5μmであった。 (Image formation)
The ink compositions of Example 1 and Comparative Examples 1 to 3 were applied using a bar coater onto a PET film (manufactured by A-One Godo Co., Ltd.) on which an ink receiving layer was formed. Thereafter, the substrate was dried at room temperature for one day to form a white image on a PET film as a base material, thereby producing a printed matter. The film thicknesses of the white images obtained in the examples and comparative examples were both about 2.5 μm.
実施例1および比較例1~3の各インク組成物を、インク受容層が形成されているPETフィルム(エーワン合同株式会社製、OHPフィルム)上にバーコーターを用いて塗工した。その後室温で1昼夜乾燥させることにより、基材であるPETフィルム上に白色画像を形成し、印刷物を作成した。実施例および比較例で得られた白色画像の膜の厚みは、いずれも約2.5μmであった。 (Image formation)
The ink compositions of Example 1 and Comparative Examples 1 to 3 were applied using a bar coater onto a PET film (manufactured by A-One Godo Co., Ltd.) on which an ink receiving layer was formed. Thereafter, the substrate was dried at room temperature for one day to form a white image on a PET film as a base material, thereby producing a printed matter. The film thicknesses of the white images obtained in the examples and comparative examples were both about 2.5 μm.
(白さの度合いの評価)
実施例および比較例で得られた膜の白さの度合いの評価は、目視および明度(L*値)を測定することによって評価した。明度の測定は、分光測色計(コニカミノルタ株式会社製、CM-2600d)を用いて、正反射光を含むSCI方式で行った。 (Evaluation of degree of whiteness)
Evaluation of the degree of whiteness of the films obtained in Examples and Comparative Examples was evaluated by visual observation and measuring lightness (L * value). The brightness was measured using a spectrocolorimeter (Konica Minolta Co., Ltd., CM-2600d) by the SCI method including specularly reflected light.
実施例および比較例で得られた膜の白さの度合いの評価は、目視および明度(L*値)を測定することによって評価した。明度の測定は、分光測色計(コニカミノルタ株式会社製、CM-2600d)を用いて、正反射光を含むSCI方式で行った。 (Evaluation of degree of whiteness)
Evaluation of the degree of whiteness of the films obtained in Examples and Comparative Examples was evaluated by visual observation and measuring lightness (L * value). The brightness was measured using a spectrocolorimeter (Konica Minolta Co., Ltd., CM-2600d) by the SCI method including specularly reflected light.
(実施例1)
実施例1で得られた印刷物の断面SEM写真を図3に示す。実施例1では図3に示すように、平均粒径が数十nmの酸化チタン粒子42(酸化チタン粒子B)と、平均粒径が約300nmの酸化チタン粒子41(酸化チタン粒子A)と、中空粒子43と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上、中空粒子43の平均粒径より小さいサイズの空隙が多数形成されていた。すなわち、実施例1では、第1の領域(A)、第2の領域(B)、第3の領域(C)、および、第4の領域(D)が、それぞれ複数かつ混在するように配置された膜が得られた。 (Example 1)
A cross-sectional SEM photograph of the printed matter obtained in Example 1 is shown in FIG. In Example 1, as shown in FIG. 3, titanium oxide particles 42 (titanium oxide particles B) having an average particle diameter of several tens of nm, titanium oxide particles 41 (titanium oxide particles A) having an average particle diameter of about 300 nm, A membrane havinghollow particles 43 was obtained. In addition, a large number of voids having a size larger than the average particle size of the titanium oxide particles B and smaller than the average particle size of the hollow particles 43 were formed between the particles. That is, in Example 1, the first region (A), the second region (B), the third region (C), and the fourth region (D) are arranged so as to be plural and mixed. A finished membrane was obtained.
実施例1で得られた印刷物の断面SEM写真を図3に示す。実施例1では図3に示すように、平均粒径が数十nmの酸化チタン粒子42(酸化チタン粒子B)と、平均粒径が約300nmの酸化チタン粒子41(酸化チタン粒子A)と、中空粒子43と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上、中空粒子43の平均粒径より小さいサイズの空隙が多数形成されていた。すなわち、実施例1では、第1の領域(A)、第2の領域(B)、第3の領域(C)、および、第4の領域(D)が、それぞれ複数かつ混在するように配置された膜が得られた。 (Example 1)
A cross-sectional SEM photograph of the printed matter obtained in Example 1 is shown in FIG. In Example 1, as shown in FIG. 3, titanium oxide particles 42 (titanium oxide particles B) having an average particle diameter of several tens of nm, titanium oxide particles 41 (titanium oxide particles A) having an average particle diameter of about 300 nm, A membrane having
得られた膜の白さの度合いを目視で評価したところ、十分な白さを有していた。また、明度(L*値)は52であった。
When the degree of whiteness of the obtained film was visually evaluated, the film had sufficient whiteness. The brightness (L * value) was 52.
(実施例2)
実施例2で得られた印刷物の断面SEM写真を図4に示す。実施例2では図4に示すように、平均粒径が数十nmの酸化チタン粒子42(酸化チタン粒子B)と、酸化チタン粒子42が凝集して形成された2次粒子44(平均粒径が約350nm)と、中空粒子43と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上、中空粒子43の平均粒径より小さいサイズの空隙が多数形成されていた。すなわち、実施例2では、第1の領域(A)、第2の領域(B)、第3の領域(C)、および、第4の領域(D)が、それぞれ複数かつ混在するように配置された膜が得られた。さらに、第1の領域(A)は酸化チタン粒子Bが凝集した二次粒子で構成されていた。 (Example 2)
A cross-sectional SEM photograph of the printed matter obtained in Example 2 is shown in FIG. In Example 2, as shown in FIG. 4, titanium oxide particles 42 (titanium oxide particles B) having an average particle diameter of several tens of nanometers and secondary particles 44 (average particle diameter) formed by aggregation of thetitanium oxide particles 42. Is about 350 nm) and hollow particles 43 are obtained. In addition, a large number of voids having a size larger than the average particle size of the titanium oxide particles B and smaller than the average particle size of the hollow particles 43 were formed between the particles. That is, in Example 2, the first region (A), the second region (B), the third region (C), and the fourth region (D) are arranged so as to be plural and mixed. A finished membrane was obtained. Furthermore, the 1st area | region (A) was comprised with the secondary particle which the titanium oxide particle B aggregated.
実施例2で得られた印刷物の断面SEM写真を図4に示す。実施例2では図4に示すように、平均粒径が数十nmの酸化チタン粒子42(酸化チタン粒子B)と、酸化チタン粒子42が凝集して形成された2次粒子44(平均粒径が約350nm)と、中空粒子43と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上、中空粒子43の平均粒径より小さいサイズの空隙が多数形成されていた。すなわち、実施例2では、第1の領域(A)、第2の領域(B)、第3の領域(C)、および、第4の領域(D)が、それぞれ複数かつ混在するように配置された膜が得られた。さらに、第1の領域(A)は酸化チタン粒子Bが凝集した二次粒子で構成されていた。 (Example 2)
A cross-sectional SEM photograph of the printed matter obtained in Example 2 is shown in FIG. In Example 2, as shown in FIG. 4, titanium oxide particles 42 (titanium oxide particles B) having an average particle diameter of several tens of nanometers and secondary particles 44 (average particle diameter) formed by aggregation of the
得られた膜の白さの度合いを目視で評価したところ、十分な白さを有していた。また、明度(L*値)は61であった。
When the degree of whiteness of the obtained film was visually evaluated, the film had sufficient whiteness. The brightness (L * value) was 61.
(比較例1)
比較例1では、平均粒径が数十nmの酸化チタン粒子(酸化チタン粒子B)と、中空粒子と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上、中空粒子43の平均粒径より小さいサイズの空隙は形成されていなかった。 (Comparative Example 1)
In Comparative Example 1, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm and hollow particles was obtained. In addition, voids having a size larger than the average particle size of the titanium oxide particles B and smaller than the average particle size of thehollow particles 43 were not formed between the particles.
比較例1では、平均粒径が数十nmの酸化チタン粒子(酸化チタン粒子B)と、中空粒子と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上、中空粒子43の平均粒径より小さいサイズの空隙は形成されていなかった。 (Comparative Example 1)
In Comparative Example 1, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm and hollow particles was obtained. In addition, voids having a size larger than the average particle size of the titanium oxide particles B and smaller than the average particle size of the
得られた膜の白さの度合いを目視で評価したところ、実施例1で得られた膜に比べて、相対的に白さが十分ではなかった。また、明度(L*値)は45であった。
When the degree of whiteness of the obtained film was visually evaluated, the whiteness was relatively insufficient as compared with the film obtained in Example 1. The brightness (L * value) was 45.
(比較例2)
比較例2では、平均粒径が数十nmの酸化チタン粒子(酸化チタン粒子B)を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上のサイズの空隙は形成されていなかった。 (Comparative Example 2)
In Comparative Example 2, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm was obtained. In addition, voids having a size larger than the average particle diameter of the titanium oxide particles B were not formed between the particles.
比較例2では、平均粒径が数十nmの酸化チタン粒子(酸化チタン粒子B)を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上のサイズの空隙は形成されていなかった。 (Comparative Example 2)
In Comparative Example 2, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm was obtained. In addition, voids having a size larger than the average particle diameter of the titanium oxide particles B were not formed between the particles.
得られた膜の白さの度合いを目視で評価したところ、実施例1で得られた膜に比べて、相対的に白さが十分ではなかった。また、明度(L*値)は39であった。
When the degree of whiteness of the obtained film was visually evaluated, the whiteness was relatively insufficient as compared with the film obtained in Example 1. The brightness (L * value) was 39.
(比較例3)
比較例3では、中空粒子を有する膜が得られた。 (Comparative Example 3)
In Comparative Example 3, a film having hollow particles was obtained.
比較例3では、中空粒子を有する膜が得られた。 (Comparative Example 3)
In Comparative Example 3, a film having hollow particles was obtained.
得られた膜の白さの度合いを目視で評価したところ、実施例1で得られた膜に比べて、相対的に白さが十分ではなかった。また、明度(L*値)は45であった。
When the degree of whiteness of the obtained film was visually evaluated, the whiteness was relatively insufficient as compared with the film obtained in Example 1. The brightness (L * value) was 45.
(比較例4)
比較例4では、硝酸カルシウムを用いないこと以外は実施例2と同様に画像形成を行った。比較例4で得られた印刷物の断面SEM写真を図5に示す。比較例4では図5に示すように、平均粒径が数十nmの酸化チタン粒子(酸化チタン粒子B)と、中空粒子43と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上のサイズの空隙は形成されていなかった。 (Comparative Example 4)
In Comparative Example 4, image formation was performed in the same manner as in Example 2 except that calcium nitrate was not used. A cross-sectional SEM photograph of the printed matter obtained in Comparative Example 4 is shown in FIG. In Comparative Example 4, as shown in FIG. 5, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm andhollow particles 43 was obtained. In addition, voids having a size larger than the average particle diameter of the titanium oxide particles B were not formed between the particles.
比較例4では、硝酸カルシウムを用いないこと以外は実施例2と同様に画像形成を行った。比較例4で得られた印刷物の断面SEM写真を図5に示す。比較例4では図5に示すように、平均粒径が数十nmの酸化チタン粒子(酸化チタン粒子B)と、中空粒子43と、を有する膜が得られた。また、各粒子の間には、酸化チタン粒子Bの平均粒径以上のサイズの空隙は形成されていなかった。 (Comparative Example 4)
In Comparative Example 4, image formation was performed in the same manner as in Example 2 except that calcium nitrate was not used. A cross-sectional SEM photograph of the printed matter obtained in Comparative Example 4 is shown in FIG. In Comparative Example 4, as shown in FIG. 5, a film having titanium oxide particles (titanium oxide particles B) having an average particle diameter of several tens of nm and
得られた膜の白さの度合いを目視で評価したところ、実施例1で得られた膜に比べて、相対的に白さが十分ではなかった。また、明度(L*値)は47であった。
When the degree of whiteness of the obtained film was visually evaluated, the whiteness was relatively insufficient as compared with the film obtained in Example 1. The brightness (L * value) was 47.
(比較例5)
比較例5では、平均粒径が約300nmの酸化チタン粒子(酸化チタン粒子A)を有する膜が得られた。 (Comparative Example 5)
In Comparative Example 5, a film having titanium oxide particles (titanium oxide particles A) having an average particle diameter of about 300 nm was obtained.
比較例5では、平均粒径が約300nmの酸化チタン粒子(酸化チタン粒子A)を有する膜が得られた。 (Comparative Example 5)
In Comparative Example 5, a film having titanium oxide particles (titanium oxide particles A) having an average particle diameter of about 300 nm was obtained.
得られた膜の白さの度合いを目視で評価したところ、十分な白さを有していた。また、明度(L*値)は70であった。
When the degree of whiteness of the obtained film was visually evaluated, the film had sufficient whiteness. The brightness (L * value) was 70.
(インク組成物の沈降性の評価)
実施例および比較例の各インク組成物について、沈降性の評価を行った。各インク組成物を50mLのガラス製サンプル瓶に30mL入れて密栓し、室温で静置した。2週間(14日間)静置した後、各サンプル瓶をゆっくり傾けてサンプル瓶の底の沈殿物の有無を確認した。沈殿物が見られなかった場合をA、一部が沈殿していた場合をB、ほとんど全てが沈降していた場合をCとして、沈降性評価を行った。結果を表1に示す。 (Evaluation of sedimentation property of ink composition)
For each ink composition of Examples and Comparative Examples, the sedimentation property was evaluated. 30 mL of each ink composition was placed in a 50 mL glass sample bottle, sealed, and allowed to stand at room temperature. After allowing to stand for 2 weeks (14 days), each sample bottle was slowly tilted to confirm the presence or absence of sediment at the bottom of the sample bottle. Sedimentation evaluation was performed with A as the case where no precipitate was observed, B as the case where a part was precipitated, and C as the case where almost all was precipitated. The results are shown in Table 1.
実施例および比較例の各インク組成物について、沈降性の評価を行った。各インク組成物を50mLのガラス製サンプル瓶に30mL入れて密栓し、室温で静置した。2週間(14日間)静置した後、各サンプル瓶をゆっくり傾けてサンプル瓶の底の沈殿物の有無を確認した。沈殿物が見られなかった場合をA、一部が沈殿していた場合をB、ほとんど全てが沈降していた場合をCとして、沈降性評価を行った。結果を表1に示す。 (Evaluation of sedimentation property of ink composition)
For each ink composition of Examples and Comparative Examples, the sedimentation property was evaluated. 30 mL of each ink composition was placed in a 50 mL glass sample bottle, sealed, and allowed to stand at room temperature. After allowing to stand for 2 weeks (14 days), each sample bottle was slowly tilted to confirm the presence or absence of sediment at the bottom of the sample bottle. Sedimentation evaluation was performed with A as the case where no precipitate was observed, B as the case where a part was precipitated, and C as the case where almost all was precipitated. The results are shown in Table 1.
(結果)
各実施例で得られた膜は、十分な白さを有していた。一方、各比較例で得られた膜は、白さが十分ではなかった。このことから、実施例1および実施例2は、膜の白さを向上させることができることがわかった。 (result)
The film obtained in each example had sufficient whiteness. On the other hand, the film obtained in each comparative example was not white enough. From this, it was found that Example 1 and Example 2 can improve the whiteness of the film.
各実施例で得られた膜は、十分な白さを有していた。一方、各比較例で得られた膜は、白さが十分ではなかった。このことから、実施例1および実施例2は、膜の白さを向上させることができることがわかった。 (result)
The film obtained in each example had sufficient whiteness. On the other hand, the film obtained in each comparative example was not white enough. From this, it was found that Example 1 and Example 2 can improve the whiteness of the film.
また、実施例1はインク組成物中に大粒径の高屈折率粒子を含有するため、大粒径の高屈折率粒子のみを用いた場合に比べると沈降が抑制されるものの、長期間保存しておくと高屈折率粒子の一部が沈降してしまうことがわかった。一方で、実施例2はインク組成物中に大粒径の高屈折率粒子が含有していないため、長期間保存しても高屈折率粒子が沈降しにくいことがわかった。このことから、実施例2は形成される膜の白さを向上できることに加えて、インク組成物の保存安定性もより高いことがわかった。
Further, Example 1 contains high refractive index particles having a large particle size in the ink composition, and thus, although settling is suppressed as compared with the case where only the high refractive index particles having a large particle size are used, it is stored for a long period of time. It was found that a part of the high refractive index particles settled. On the other hand, in Example 2, since the high refractive index particles having a large particle diameter were not contained in the ink composition, it was found that the high refractive index particles did not easily settle even when stored for a long period of time. From this, it was found that Example 2 was able to improve the whiteness of the formed film, and in addition, the storage stability of the ink composition was higher.
本発明は上記実施の形態に制限されるものではなく、本発明の精神及び範囲から離脱することなく、様々な変更及び変形が可能である。従って、本発明の範囲を公にするために以下の請求項を添付する。
The present invention is not limited to the above embodiment, and various changes and modifications can be made without departing from the spirit and scope of the present invention. Therefore, in order to make the scope of the present invention public, the following claims are attached.
本願は、2015年1月23日提出の日本国特許出願特願2015‐011626および2016年1月15日提出の日本国特許出願特願2016‐006444を基礎として優先権を主張するものであり、その記載内容の全てをここに援用する。
This application claims priority based on Japanese Patent Application No. 2015-011626 filed on January 23, 2015 and Japanese Patent Application No. 2016-006444 filed on January 15, 2016, All the descriptions are incorporated herein.
A 第1の領域(高屈折率)
B 第2の領域(高屈折率)
C 第3の領域(低屈折率)
D 第4の領域(低屈折率)
3 高屈折率粒子
10 基材
12、13 膜 A First region (high refractive index)
B 2nd region (high refractive index)
C Third region (low refractive index)
D Fourth region (low refractive index)
3 HighRefractive Index Particles 10 Base Material 12, 13 Film
B 第2の領域(高屈折率)
C 第3の領域(低屈折率)
D 第4の領域(低屈折率)
3 高屈折率粒子
10 基材
12、13 膜 A First region (high refractive index)
B 2nd region (high refractive index)
C Third region (low refractive index)
D Fourth region (low refractive index)
3 High
Claims (18)
- 基材上に膜を形成する膜形成方法であって、
前記膜は、屈折率および領域の大きさで規定される第1から第4の領域がそれぞれ複数かつ混在するように配置されており、
前記第1および第2の領域の屈折率が、前記第3および第4の領域の屈折率より0.4以上大きく、
前記第1の領域は、円相当径が250nm以上の領域であり、
前記第2の領域は、平均粒径10nm以上100nm以下の高屈折率粒子からなる領域であり、
前記第3の領域は、円相当径が100nmより大きい領域であり、
前記第4の領域は、円相当径が前記高屈折率粒子の平均粒径以上、前記第3の領域の円相当径より小さい領域であることを特徴とする膜形成方法。 A film forming method for forming a film on a substrate,
The film is arranged such that a plurality of first to fourth regions defined by the refractive index and the size of the region are mixed and plural,
A refractive index of the first and second regions is 0.4 or more larger than a refractive index of the third and fourth regions;
The first region is a region having an equivalent circle diameter of 250 nm or more,
The second region is a region composed of high refractive index particles having an average particle size of 10 nm or more and 100 nm or less,
The third region is a region having an equivalent circle diameter larger than 100 nm,
The film formation method, wherein the fourth region is a region having an equivalent circle diameter that is equal to or greater than an average particle size of the high refractive index particles and smaller than the equivalent circle diameter of the third region. - 前記第1の領域が、前記高屈折率粒子が凝集した領域であることを特徴とする請求項1に記載の膜形成方法。 The film forming method according to claim 1, wherein the first region is a region where the high refractive index particles are aggregated.
- 前記膜が、前記膜を光が透過する場合に前記光が直進する直線上に、前記第1から第4の領域が少なくとも1つずつ存在する膜であることを特徴とする請求項1または請求項2に記載の膜形成方法。 2. The film according to claim 1, wherein the film is a film in which at least one of the first to fourth regions exists on a straight line through which the light travels straight when light passes through the film. Item 3. The film forming method according to Item 2.
- 前記第1の領域の屈折率が、1.7以上2.8以下であることを特徴とする請求項1乃至請求項3のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 3, wherein a refractive index of the first region is not less than 1.7 and not more than 2.8.
- 前記第3の領域の屈折率が、1.0以上1.7未満であることを特徴とする請求項1乃至請求項4のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 4, wherein a refractive index of the third region is 1.0 or more and less than 1.7.
- 前記第4の領域の屈折率が、1.0以上1.7未満であることを特徴とする請求項1乃至請求項5のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 5, wherein a refractive index of the fourth region is 1.0 or more and less than 1.7.
- 前記第3の領域が前記膜において占める体積比率が、30%以上60%以下であることを特徴とする請求項1乃至請求項6のいずれか一項に記載の膜形成方法。 The film formation method according to any one of claims 1 to 6, wherein a volume ratio of the third region in the film is 30% or more and 60% or less.
- 前記高屈折率粒子が、酸化チタン粒子であることを特徴とする請求項1乃至請求項7のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 7, wherein the high refractive index particles are titanium oxide particles.
- 前記第3の領域が、中空粒子からなる領域であることを特徴とする請求項1乃至請求項8のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 8, wherein the third region is a region made of hollow particles.
- 前記第3の領域が、空隙からなる領域であることを特徴とする請求項1乃至請求項9のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 9, wherein the third region is a region made of a void.
- 前記第4の領域が、空隙からなる領域であることを特徴とする請求項1乃至請求項10のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 10, wherein the fourth region is a region made of a void.
- 前記膜が、白色膜であることを特徴とする請求項1乃至請求項11のいずれか一項に記載の膜形成方法。 The film forming method according to any one of claims 1 to 11, wherein the film is a white film.
- 請求項1乃至請求項12のいずれか一項に記載の膜形成方法によって、前記基材上に前記膜を形成することで画像を形成する画像形成方法。 An image forming method for forming an image by forming the film on the substrate by the film forming method according to any one of claims 1 to 12.
- 屈折率および領域の大きさで規定される第1から第4の領域がそれぞれ複数かつ混在するように配置されており、
前記第1および第2の領域の屈折率が、前記第3および第4の領域の屈折率より0.4以上大きく、
前記第1の領域は、円相当径が250nm以上の領域であって、
前記第2の領域は、平均粒径10nm以上100nm以下の高屈折率粒子からなる領域であり、
前記第3の領域は、円相当径が100nmより大きい領域であり、
前記第4の領域は、円相当径が前記高屈折率粒子の平均粒径以上、前記第3の領域の円相当径よりも小さい領域であることを特徴とする膜。 The first to fourth regions defined by the refractive index and the size of the region are arranged so as to be plural and mixed, respectively.
A refractive index of the first and second regions is 0.4 or more larger than a refractive index of the third and fourth regions;
The first region is a region having an equivalent circle diameter of 250 nm or more,
The second region is a region composed of high refractive index particles having an average particle size of 10 nm or more and 100 nm or less,
The third region is a region having an equivalent circle diameter larger than 100 nm,
The fourth region is a film having an equivalent circle diameter that is equal to or greater than an average particle diameter of the high refractive index particles and smaller than the equivalent circle diameter of the third region. - 前記第1の領域が、前記高屈折率粒子が凝集した領域であることを特徴とする請求項14に記載の膜。 The film according to claim 14, wherein the first region is a region where the high refractive index particles are aggregated.
- 平均粒径が10nm以上100nm以下の高屈折率粒子と、
平均粒径が100nmより大きく700nm以下の中空粒子と、
前記高屈折率粒子を凝集させる凝集剤と、を含有するインク組成物。 High refractive index particles having an average particle diameter of 10 nm to 100 nm,
Hollow particles having an average particle size of more than 100 nm and 700 nm or less;
An ink composition comprising a flocculant for aggregating the high refractive index particles. - 前記高屈折率粒子が、酸化チタン粒子であることを特徴とする請求項16に記載のインク組成物。 The ink composition according to claim 16, wherein the high refractive index particles are titanium oxide particles.
- 水をさらに含有し、
前記凝集剤は、前記水が蒸発することによって前記高屈折率粒子を凝集させることを特徴とする請求項16または請求項17に記載のインク組成物。 Further containing water,
The ink composition according to claim 16 or 17, wherein the aggregating agent aggregates the high refractive index particles by evaporating the water.
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