Recording material treatment liquid, recording material treated with same, and methods for producing same

Abstract

[Problem] To obtain a recording material treatment liquid that can form a receiving layer that exhibits improvement in inkjet printing performances regarding ink smear, feathering, print density, and bleeding, and that can further form, when being applied to a base material such as a resin film or glass, an ink-receiving layer free from blocking in a coating film. [Solution] A recording material treatment liquid is characterized by containing at least components (i)-(iii). (i) A water-soluble anionic polymer (ii) A polyvalent metal cation (iii) A surfactant

Description

Processing liquid for recording material, recording material treated with the same, and manufacturing method thereof

[0001] The present invention relates to an inexpensive formulation for substrates that does not change the visual surface condition (e.g., transparency, opacity) of the substrate from before coating and does not cause texture (stickiness, tack, blocking), an inkjet coating method, and a treatment liquid for recording materials that is suitable for inkjet printing with various coating methods, recording materials treated with the same, and a method for manufacturing such recording materials.

[0002] Printer inks are generally divided into organic solvent-based inks and water-based inks. Organic solvent-based inks have excellent water resistance, but they have problems such as bleeding on plain paper, odor, and safety, so water-based inks have become the mainstream in recent years. In particular, inkjet recording methods allow for the simple and inexpensive production of a wide variety of images in small quantities, and have therefore been applied to a variety of printing fields on both liquid-absorbing and liquid-non-absorbing substrates, including printing of text, documents, photographs, labels, fabric printing, marking, color filters, and special printing such as circuit printing.

[0003] The colorants used in water-based inks are dyes or pigments that can be dispersed or dissolved in water. When these colorants are used in inkjet printing, nozzles with pore diameters of 20 μm or less are used, and therefore pigment inks such as anionic polymer-dispersed inks in which pigment is uniformly dispersed into water, inks in which pigment particles are encapsulated in anionic polymers, and inks in which pigment particles are self-dispersed, as well as water-soluble dye inks that are dissolved and used, particularly anionic direct dye inks and acid dye inks, are used. These coloring components are designed to allow printing without clogging the nozzles.

[0004] When the inkjet ink is used to record on a medium such as paper, film, or fabric, it is required to have the following performance characteristics: high density of images and characters, vivid color tones, the ink being quickly absorbed by the medium so that the ink does not flow even when ink dots overlap, and the ink dots not spreading laterally more than necessary, resulting in smooth, non-blurred peripheries.

[0005] The water-based inks used in inkjet printing contain a large amount of solvent to control printing speed and dot formation, which can cause issues with degradation of image quality, such as print density on the recording material, bleeding, feathering (a phenomenon in which ink droplets applied to the recording material penetrate through the mesh of the fibers that make up the recording material, such as cellulose, to the periphery of the printed image, causing the printed image to appear fluffy), and bleeding (a phenomenon in which ink from the printed image area bleeds into the unprinted area at the boundary between the printed image and unprinted area, like whiskers) due to insufficient solvent absorption. For this reason, various measures have been taken to develop recording materials.

[0006] A known method for preventing bleeding is to coat the surface of the recording material with a water-absorbent polymer and an inorganic porous pigment, thereby allowing the solvent in the ink to be quickly absorbed.

[0007] However, when a wet inorganic porous pigment or a swelling water-absorbing polymer is blended on the surface of a recording material, bleeding can be suppressed, but ink bleeding, feathering, and print density cannot be improved. Furthermore, the addition of particles with an average dispersed particle size of 0.1 to 5 μm results in a decrease in transparency, an increase in hiding power, and changes in texture such as matte finish, which can impart surface properties contrary to the intended purpose.

[0008] As a method for improving image quality by preventing ink bleeding, feathering, and increasing print density, a method in which a cationic substance is incorporated into the surface of a recording material is known.

[0009] However, when a cationic substance alone is applied to a liquid-non-absorbent substrate such as a film or a liquid-absorbent substrate such as paper or cloth, it is not possible to prevent stickiness or bleeding.

[0010] In particular, non-liquid-absorbent substrates such as films can suffer from the problem of blocking after coating and drying the recording material. Blocking, which is caused by the softness, glass transition point, softening point, and minimum film-forming temperature of each polymer, can cause problems such as show-through of the recording material when the film is wound up.

[0011] Methods that combine the features of each method are disclosed to solve each problem.

[0012] Patent Document 1 discloses a technology that improves the water resistance of recording materials by using a recording material treatment liquid containing water-insoluble organic composite particles that combine a cationic polymer and an anionic polymer without incorporating an inorganic porous pigment. However, this patent discloses that the recording material, which is compatible with ink bleeding, feathering, print density, and bleeding, is highly effective on liquid-absorbent substrates such as paper and canvas. However, when applied to non-liquid-absorbent substrates such as film, although the bleeding effect is exhibited, there is a problem of stickiness due to the blocking phenomenon exhibited by the characteristics of the cationic polymer, and its use on non-liquid-absorbent substrates such as film is limited. Furthermore, the addition of particles with an average dispersed particle diameter of 0.1 to 5 μm results in reduced transparency, increased hiding power, and changes in texture such as matte finish, resulting in surface properties that are contrary to the intended purpose.

[0013] Patent Document 2 discloses a technology for obtaining a recording material treatment liquid with high film strength and no stickiness by using a crosslinkable cationic polymer as part of the cationic polymer. While this patent solves the problem of stickiness caused by the blocking phenomenon inherent in cationic polymers through crosslinking, it also suffers from problems with application due to high viscosity and crosslinked properties, resulting in poor product storage stability. Furthermore, crosslinking reduces ink bleeding, feathering, and print density.

[0014] Patent Document 3 discloses a method in which a porous coating film is formed by curing a crosslinkable resin without using an inorganic pigment, and then the film is impregnated with a cationic composition or the like to impart functionality. However, this method requires that a porous film be formed first and then impregnated with a cationic composition, which makes the coating process complicated and unrealistic. Furthermore, the impregnated cationic composition can migrate due to ink liquid or moisture after printing, causing problems such as ring bleeding.

[0015] Patent Document 4 discloses a method of applying a pretreatment agent comprising insoluble resin particles made of polyolefin resin and polyurethane resin, a flocculant, and water by inkjet. However, this method requires the emulsion aggregates to be refined for inkjet application. While ink bleeding, feathering, and print density are improved, the improvement of bleeding, which is a problem of liquid absorption, is achieved by constructing a coating film using a coating method, and this performance cannot be achieved by a simple coating method. Furthermore, the addition of particles with an average dispersed particle diameter of 0.1 to 5 μm results in reduced transparency, increased hiding power, and changes in texture such as matte finish, resulting in surface properties that are contrary to the intended purpose.

[0016] Patent Document 6 uses the cationic polymer of Patent Document 1, performs a specific treatment, and applies a specific coating amount to specific paper. However, while it achieves effects such as ink bleeding, feathering, print density, and bleeding on paper, it has problems with films, particularly with regard to bleeding and blocking. Attempts to form a receiving layer without adding inorganic pigments are also disclosed in Patent Documents 5 to 7, and claim to increase the strength of the recording material, avoid coloring by inorganic pigments, and improve the color development of black ink.

[0017] Patent Document 8 discloses a method of using a mixture of an aqueous resin and a calcium ion salt as an anchor coating agent. However, to ensure the storage stability of the anchor coating agent, the acid value of the aqueous resin is specified to be low. As a result, there are limitations on the polymers that can be selected, making it difficult to apply the method to a variety of substrates, especially non-absorbent substrates.

[0018] Patent Document 9 discloses a pretreatment agent (ink flocculant) for textile printing that contains a cationic polymer, a polyvalent metal salt, and an organic acid. This is a technology that has the potential to contribute to shortening processes, etc., because it does not contain particles and can be sprayed. However, the polymer binders that can be added to the pretreatment agent are limited to nonionic polymers, taking into account their reactivity with the cationic polymer, polyvalent metal salt, and organic acid, narrowing the options. Furthermore, the use of cationic polymers and nonionic polymers causes stickiness in the coating film, which places limitations on the substrates that can be used.

[0019] Japanese Patent No. 3015739, Japanese Patent No. 6510862, Japanese Patent No. 5341514, Japanese Patent No. 6988915, Japanese Patent No. 6712669, Japanese Patent Application Laid-Open No. 2003-320745, Japanese Patent Application Laid-Open No. 2007-38625, Japanese Patent Application Laid-Open No. 2020-111708, Japanese Patent No. 7405854

[0020] For liquid-nonabsorbent substrates, higher solvent absorbency is required for the receiving layer compared to liquid-absorbent substrates. Furthermore, suppression of blocking due to stickiness on the receiving layer surface and higher transparency and strength of the coating film are also required. Furthermore, the coating liquid for forming the receiving layer formed by the above-mentioned method contains porous pigments or composite particles, so the coating liquid itself or the formed receiving layer may have a pale white tinge, which may prevent the substrate from exhibiting its original color. Therefore, a transparent treatment liquid that can make the most of the color of the coated substrate is also needed. In other words, there is a need for a treatment liquid for recording materials suitable for inkjet printing that does not change the visual surface condition (e.g., transparency, opacity) of the substrate from before coating, and that exhibits inkjet ink receptivity without causing texture (stickiness, tack, blocking), regardless of whether the substrate is liquid-absorbent or liquid-nonabsorbent.

[0021] In view of the above circumstances, an object of the present invention is to provide a means for improving ink bleeding, feathering, and print density, even when applied to a liquid-non-absorbent substrate such as a resin film or glass, and for obtaining a recorded image free of bleeding and blocking, while still allowing the original color of the substrate to be utilized in the non-printed areas.

[0022] The present inventors conducted extensive research to address the above-mentioned issues. They found that while the use of the water-insoluble organic particles described in Patent Document 1 improved ink bleeding, feathering, print density, and bleeding, blocking occurred, making the method unusable. They then discovered that blocking was caused by a specific cationic polymer. They then discovered that changing the water-soluble cationic polymer to a polyvalent metal cation could prevent the coating film from becoming sticky, and that the inclusion of a specific compound could achieve transparency in the coating solution and coating film. Furthermore, this method eliminates the need to include a crosslinkable polymer, as in Patent Document 2, and therefore eliminates concerns about the stability of the solution even during long-term storage. Furthermore, methods that precipitate particles with an average dispersed particle size of 0.1 to 5 μm result in reduced transparency, increased hiding power, and changes in visual texture, such as a matte finish. These problems of imparting surface properties that contradict these objectives can also be avoided. As a result, they discovered that the method can be used effectively in transparent applications and applications where the texture of the media needs not to be altered. The present invention is based on the inventors' idea and ingenuity of forming solubilized micelles from poorly water-soluble substances using a solubilizing agent. The size of the resulting solubilized micelles is 10 nm or less per single particle, which is sufficiently smaller than the wavelength of visible light, so the solution remains transparent even when micelles are formed. The inventors believe that this was the inspiration behind their success in forming solubilized micelles. Furthermore, they discovered that the particle size of the micelles formed as solubilized micelles can be adjusted from 1 nm to 99 nm, and that they are transparent, have no change in visual texture, and exhibit good ejection properties without causing nozzle clogging during inkjet ejection.

[0023] That is, the present invention provides: (1) a treatment liquid for recording materials, characterized by containing at least the following components (i) to (iii): (i) a water-soluble anionic polymer; (ii) a polyvalent metal cation; and (iii) a surfactant. (2) The treatment liquid for recording materials according to the above item 1, characterized in that (iii) the surfactant is a compound represented by the following chemical formula: (In chemical formula (1), R: a linear or branched alkyl group or aryl group having 10 to 50 carbon atoms, which may have a substituent. R 1: a linear or branched alkyl group having 1 to 3 carbon atoms, N: an integer from 1 to 50 (3) The recording material processing liquid according to (1) above, wherein (iii) the surfactant is a compound represented by the following chemical formula (2): In the formula, R １ is a linear or branched alkyl group having 1 to 3 carbon atoms, n is an integer of 1 to 50, R ２ is the following chemical formula, m is an integer of 1 to 3, and X is SO3M, -COOM, -PO ３ M ２ One or more of the above, M is NH4, Na, or K (4) The treatment liquid for recording materials according to (1) above, characterized in that the polymer having an anionic functional group is at least one of a styrene-acrylic acid copolymer, an α-methylstyrene-acrylic acid copolymer, and a styrene-α-methylstyrene-acrylic acid copolymer; (5) The treatment liquid for recording materials according to (1) above, characterized in that the polyvalent metal cation is at least one of a calcium cation, a magnesium cation, and an aluminum cation;

[0024] (6) A method for producing a treatment liquid for recording materials according to (1) above, characterized in that the mixing ratio of the water-soluble anionic polymer and the polyvalent metal cation is such that the amount of polyvalent metal cation added is 30 to 100 mol % relative to the acid value of the water-soluble anionic polymer; (7) A method for producing a recording material, characterized in that the treatment liquid for recording materials according to (1) above is applied to a substrate; (8) A method for producing a recording material, characterized in that the treatment liquid for recording materials according to (1) above is applied to a substrate, wherein the substrate is a liquid non-absorbing substrate;

[0025] (9) A method for recording on a recording material, characterized in that recording is performed with an ink containing a colorant on a recording material formed by coating a substrate with the treatment liquid for recording material described in (1) above; (10) An inkjet recording method, characterized in that inkjet printing is performed on a recording material formed by coating a substrate with the treatment liquid for recording material described in (1) above; and (11) A method for producing a recording material, characterized in that when inkjet printing is performed on a recording material formed by coating a substrate with the treatment liquid for recording material described in (1) above, coating is performed continuously by an inkjet system.

[0026] The present invention relates to the above-described recording material treatment liquid, regardless of the substrate, and to a recording material obtained by coating a substrate with this treatment liquid. The treatment liquid of the present invention can be used as a treatment liquid for impregnation or application (including coating and printing (including lettering and printing, regardless of inkjet printing or other printing methods), and the application method is not limited) to various substrates (substrates are not limited), i.e., as a recording material treatment liquid. In this way, a coating layer can be formed on the substrate. The treatment liquid of the present invention can also be called a coating liquid, since it is applied to a substrate to treat the substrate. It can also be called a pretreatment liquid, since it treats the substrate prior to printing. The layer formed by applying the treatment liquid of the present invention to a substrate functions as a so-called ink-receiving layer that receives ink when ink such as colored ink is printed (whether letters, figures, or solid colors). For example, an inkjet ink-receiving layer formed on the surface of printing paper for inkjet printing is a typical example, but is not limited thereto. Any layer formed on a substrate to be printed for purposes such as easy ink fixation and easy color development is also limited. The material on which such a receiving layer is formed is the recording material. The receiving layer formed by the present invention improves inkjet printing performance, such as ink bleeding, feathering, print density, and bleeding, and can also be an ink-receiving layer that does not cause coating film blocking even when applied to substrates such as resin films and glass. The present invention makes it possible to obtain a treatment liquid for recording materials that can form a recording material equipped with a receiving layer having such excellent performance. The treatment liquid itself also has excellent storage stability. Furthermore, since the treatment liquid is transparent and the coating layer formed by applying the treatment liquid is also transparent, the original color of the substrate can be utilized.

[0027] FIG. 1 shows the results of printing on a pongee cloth without pretreatment and the results of printing on a pongee cloth after pretreatment with the coating liquid of the present invention in the examples.

[0028] The recording material treatment liquid of the present invention may further contain a binder in addition to the components (i) to (iii) described below. Transparent particles are formed by mixing a water-soluble polymer, a polyvalent metal cation, and a surfactant, as described below. These particles are believed to be transparent due to the reaction of these components to form micelles and become solubilized. The coating liquid containing these particles is also transparent and maintains its transparency even after application to a substrate, without impairing the visual texture of the substrate. It is believed that the micelles break down upon contact with liquid components in the ink (especially solvent components other than water, such as alcohols, diols, and glycols), causing the particles to become insoluble in water and aggregate and precipitate, while absorbing and expanding the liquid components, thereby preventing bleeding. Furthermore, anionic functional groups, such as carboxyl groups, in the water-soluble polymer immobilize polyvalent metal cations, and the action of these polyvalent metals immobilizes anionic pigments and dyes to the water-soluble polymer via the polyvalent metal. This is believed to improve inkjet printing performance, such as ink bleeding, feathering, and print density. Furthermore, by fixing the polyvalent metal to the anionic polymer, it is presumed that migration of the polyvalent metal after application due to the ink liquid after printing or moisture after printing, as was the case with conventional technology, can be suppressed, thereby improving poor water resistance such as ring bleeding.

[0029] The treatment solution of the present invention contains (i) a water-soluble anionic polymer, (ii) a polyvalent metal cation, and (iii) a surfactant. These components may interact with each other in the treatment solution, chemically reacting or forming a complex. The water-soluble anionic polymer is a polymer having an anionic functional group, and is not particularly limited as long as it is what is commonly referred to as an anionic polymer. Here, the anionic functional group may be ionized or ionizable. For example, a carboxyl group ionizes upon addition of an alkali and exhibits anionic properties, so in the present invention, it is considered an anionic functional group regardless of whether it is ionized or not. Generally, an anionic polymer is solubilized by adding an alkaline substance to a polymer having an anionic functional group, thereby ionizing the anionic functional group, and is used as a so-called water-soluble anionic polymer. In the present invention, such a water-soluble anionic polymer is mixed in the presence of a polyvalent metal cation and a surfactant, as described below, to bring the anionic functional group of the polymer and the polyvalent metal cation into close proximity and solubilize the polymer, thereby producing transparent particles. In this way, transparent fine particles containing a polymer having an anionic functional group and a polyvalent metal can be obtained. When such transparent fine particles of the present invention are analyzed by infrared spectroscopy (IR), the type of functional group contained in the polymer can be confirmed, thereby confirming that they have anionic functional groups, and when analyzed by energy dispersive X-ray analysis (EDS), the presence of a polyvalent metal can be confirmed.

[0030] 1. Materials [Polyvalent Metal Cations] The polyvalent metal cations used in the present invention are not limited in valence or element, as long as they are divalent or higher. However, taking into consideration the coagulation properties of the water-soluble anionic polymer, the pH of the treatment liquid, and residues on the coating film, divalent or trivalent polyvalent metals such as calcium and magnesium are preferably used. Specifically, calcium (divalent), magnesium (divalent), and aluminum (trivalent) are preferred. The method of mixing with the polyvalent metal cations is not particularly limited as long as the material is capable of releasing these metals as cations. Typically, this can be easily achieved by mixing with salts of these metals, such as magnesium chloride, calcium chloride, or aluminum sulfate. Furthermore, the amount and type of polyvalent metal affect the color development of the ink when used as a recording material and the pH of the recording material treatment liquid itself. Therefore, the amount and type of polyvalent metal can be selected according to these systems, but essentially, any of the above metal cations can be used without any problems.

[0031] [Water-Soluble Anionic Polymer] The water-soluble anionic polymer is not particularly limited as long as it is an anionic water-soluble polymer. However, generally, anionic polymers, i.e., polymers having anionic functional groups such as carboxyl groups, sulfonic acid groups (SO3H), sulfate ester groups, or phosphate ester groups, can be used, which have been rendered water-soluble by anionizing them with an alkaline substance such as ammonia, organic amines, or alkali metals. Examples of polymers having anionic functional groups include one or more of styrene-acrylic acid copolymers, α-methylstyrene-acrylic acid copolymers, styrene-α-methylstyrene-acrylic acid copolymers, styrene-acrylic acid copolymers, polyacrylic acid, styrene-maleic anhydride copolymers, acrylic acid ester-acrylic acid copolymers, polyesters, and salts thereof. These anionic polymers can be used alone or in combination.

[0032] Examples of alkaline substances for imparting water solubility include those generally called neutralizing agents, and typical examples include organic amines such as trimethylamine, triethylamine, tri-n-propylamine, tributylamine, triethanolamine, aminomethylpropanol, aminomethylpropanediol, aminoethylpropanediol, trihydroxymethylaminomethane, monoethanolamine, and triisopropanolamine, as well as inorganic alkali salts such as aqueous ammonia, potassium hydroxide, and sodium hydroxide, which are preferred because they can provide stable water solubility. In particular, aqueous ammonia is preferred because it is easily volatilized and removed.

[0033] Selecting a polymer with an anionic functional group, particularly one with a high glass transition point, can further improve blocking of the coating when applied to non-absorbent substrates. Furthermore, selecting a polymer with a high softening point can further improve blocking. The glass transition point refers to the temperature at which a resin becomes prone to molecular motion and assumes a soft, rubbery state when heated above a certain temperature, and is the temperature at which the resin's properties change drastically. The glass transition point is 50°C or higher, preferably 70°C or higher, and more preferably 70°C to 140°C. The higher the proportion of styrene and α-methylstyrene in the monomer composition of styrene-acrylic acid copolymer, α-methylstyrene-acrylic acid copolymer, and styrene-α-methylstyrene-acrylic acid copolymer, the higher the glass transition point. The composition ratio of styrene and α-methylstyrene in the polymer is 20% to 80%, preferably 50% to 80%, more preferably 60% to 75%. Furthermore, the higher the proportion of α-methylstyrene in the composition ratio of styrene and α-methylstyrene, the higher the glass transition point. If the glass transition point is low, blocking problems may occur, and the particles produced may fuse together, increasing the particle size. If it is too high, the composition ratio with carboxylic acid group-containing acrylic acid, etc. may be disrupted, making it impossible to make the resin water-soluble. The higher the composition ratio of styrene and alpha-methylstyrene, the more hydrophobic the resin becomes, resulting in a rigid, less flexible polymer, which leads to improved blocking properties. Furthermore, the higher the composition ratio of alpha-methylstyrene, the more hydrophobic the resin becomes, resulting in a rigid, less flexible polymer, which leads to further improved blocking properties.

[0034] The softening point is the temperature at which a resin begins to soften and deform when heated. The softening point is 100°C or higher, preferably 140°C or higher, and more preferably 150°C or higher. Temperatures below 100°C can cause blocking problems. In applications where printed material is transferred using heat, a low softening point can lead to transfer to areas other than the printed surface. The weight-average molecular weight (Mw) of the polymer is preferably 5,000 to 20,000. More preferably, a molecular weight of 10,000 to 18,000 is preferred, with 10,000 to 17,000 being even more preferred. If the molecular weight is too low, the glass transition temperature will decrease, which will not improve blocking. If the molecular weight is too high, the composition ratio with carboxylic acid-containing acrylic acid or the like will be disrupted, making it impossible to make the polymer water-soluble. The amount of carboxylic acid functional groups is determined by the acid value.

[0035] Among the polymers having anionic functional groups, α-methylstyrene-acrylic acid copolymers and styrene-α-methylstyrene-acrylic acid copolymers are preferred in terms of the coatability of the treatment liquid to the recording material, the printing characteristics during recording, and the improvement of blocking. Specific examples include commercially available products such as JONCRYL 678, 67, 690, and JDX-C3080 (all manufactured by BASF Japan Ltd.). These can be solubilized with any alkaline agent, as described above, and used. Furthermore, solubilized products of these polymers having anionic functional groups, such as JONCRYL 60J, 63J, 70J, JDX-6180, JDX-6500, the ammonium neutralized salt of J819, and J52J (the ammonium neutralized salt of J682) (all manufactured by BASF Japan Ltd.), can also be used. Among these, JONCRYL 60J, 63J, 70J, and JDX-6180 are particularly excellent in terms of stability over time. The pH of the water-soluble anionic polymer is usually set to 8 or higher to obtain stable water solubility. The acid value of the water-soluble anionic polymer is 50 to 300 mgKOH / g, preferably 60 to 250 mgKOH / g, and more preferably 70 to 250 mgKOH / g, from the viewpoint of inkjet printing performance, such as ink bleeding, feathering, and print density. If the acid value is 50 mgKOH / g or less, stable water solubility cannot be obtained, and if the acid value is 300 mgKOH / g or more, ink bleeding, feathering, and a decrease in print density may occur.

[0036] [Surfactant] In the present invention, a surfactant is contained. There are no limitations on the type of surfactant, but particularly preferred are ionic surfactants, and even more preferred are anionic surfactants. In particular, it is a compound represented by the following chemical formula (1), and even more preferred are compounds represented by chemical formulas (2), (3), and (4). In chemical formula (1), R: a linear or branched alkyl or aryl group having 10 to 50 carbon atoms, which may have a substituent. R 1 : a straight-chain or branched alkyl group having 1 to 3 carbon atoms; N: an integer of 1 to 50;

[0037]

[0038]

[0039] In the formula, R １ is a linear or branched alkyl group having 1 to 3 carbon atoms, n is an integer of 1 to 50, R ２ is the following chemical formula, m is an integer of 1 to 3, and X is SO3M, -COOM, -PO ３ M ２ One or more of the above, M is NH4, Na, or K

[0040]

[0041] n is preferably 5 to 50, more preferably 7 to 25. X is preferably SO3M. M is preferably NH4 or Na. R １ is preferably a linear alkyl group having 1 to 3 carbon atoms, and more preferably an alkyl group having 2 carbon atoms. Preferred compounds include, for example, polyoxyethylene styrenated phenyl ether ammonium sulfate, polyoxyethylene lauryl ether ammonium sulfate, polyoxyethylene styrenated phenyl ether, polyoxyethylene styrenated phenyl ether ammonium sulfate, and polyoxyethylene polyoxypropylene polycyclic phenyl ether sulfate. Among these, polyoxyethylene styrenated phenyl ether ammonium sulfate is particularly preferred.

[0042]

[0043]

[0044] Particularly preferred compounds include those having the following structures:

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] Among the compounds corresponding to the above chemical formulas (3) to (9), those in which the number of ethylene oxide chains, i.e., n, is 5 to 50, and particularly 8 to 25, are preferred. Such compounds have an excellent balance of hydrophilicity due to the ethylene oxide chains and non-polarity of hydrocarbons, and the interaction with the water-soluble polymer results in excellent ink-receptivity, resulting in excellent color development and bleeding prevention. Furthermore, the high hydrophilicity due to the ethylene oxide chains also provides excellent stability during high-temperature storage.

[0051] Preferred commercially available products include, for example, "Hitenol NF-08," "Hitenol NF-17," "Noigen EA-207D," "Noigen EA-157," "Newcol 710-F," "Newcol 714-F," "Newcol 2600-FB," "Newcol 2616-F," "Newcol CMP-60-SF," and "Newcol 707-SF." Among these, "Hitenol NF-08," "Hitenol NF-17," and "Newcol 707-SF" are particularly preferred.

[0052] 2. Manufacturing Method [Preparation of Treatment Solution] The treatment solution of the present invention can be prepared by mixing the water-soluble anionic polymer, the polyvalent metal cation, and the surfactant. The order of mixing can be as follows: first, homogenize the water-soluble anionic polymer and the stabilizer in water, then add the polyvalent metal cation and precipitate it while stirring, and then add the surfactant. The stabilizer used in this case is not particularly limited, but a typical example is a polymer stabilizer, i.e., a polymer dispersant, such as a styrene-maleic anhydride ethylene oxide adduct. When the water-soluble anionic polymer and the polyvalent metal cation are mixed, particles are formed and precipitate. This can be easily detected by the cloudiness of the mixture. It is presumed that the anions of the water-soluble anionic polymer and the polyvalent metal cation are attracted to each other and approach each other, forming particles. Adding a surfactant to this mixture makes the solution transparent. As mentioned above, this is thought to be due to the formation of micelles by the surfactant, which solubilize the particles.

[0053] While this method may be used in the present invention, it is cumbersome and may cause problems because the particles must first be aggregated and then solubilized. Therefore, a method in which an anionic polymer and a surfactant are mixed together and then metal cations are added to the mixture can be considered. In this case, the liquid maintains its transparency consistently, and particles of approximately 30 nm or less can be produced, which are larger than a few nanometers and detectable by a particle size distribution analyzer, while maintaining transparency. This is thought to be because when metal cations are added to a system containing an anionic polymer and a surfactant, the anionic polymer and the metal cations interact to form particles, and the surfactant also contributes to the solubilization of these particles. In other words, the hydrophobic portions of the anionic polymer and the surfactant interact (π-π bonds) to stabilize and maintain stability. Therefore, this method exhibits particularly excellent effects when an anionic polymer containing an aromatic ring such as a benzene ring, such as a styrene-acrylic polymer, is used, and a surfactant containing an aromatic ring such as a benzene ring, such as a compound represented by the above-mentioned chemical formula, is used. Therefore, in the method of mixing the above three components, the particles may be precipitated in advance and then clarified, or the metal cation may be added to a mixture of the anionic polymer and surfactant, or all may be mixed at the same time. However, as explained above, the method of premixing the anionic polymer and surfactant and then adding the metal cation thereto is the most efficient and preferred.

[0054] The blending ratio (b) of the water-soluble anionic polymer to the polyvalent metal cation is calculated from the amount of the water-soluble anionic polymer used, its acid value, and the amount and valence of the polyvalent metal cation. The amount of polyvalent metal cation added is 30% or more equivalent by molar ratio to the acid value of the water-soluble anionic polymer (30% of the amount of polyvalent metal compound that theoretically generates an amount of cations that can react with 100% of the acid value of the water-soluble anionic polymer). As mentioned above, the addition may be in the form of a metal salt. However, excess residual polyvalent metal salt may cause deterioration in water resistance and contamination, and may also lead to a decrease in color density and deterioration in image quality. Therefore, the maximum amount is preferably 200% equivalent by molar ratio to the acid value of the water-soluble anionic polymer. On the other hand, if the amount is too small, particle formation may not occur. Therefore, the molar ratio relative to the acid value of the water-soluble anionic polymer is preferably 30 to 200% equivalent, more preferably 30 to 150% equivalent, most preferably 35 to 120% equivalent, and most preferably 35 to 100% equivalent.

[0055] The blending ratio b of the water-soluble anionic polymer to the polyvalent metal cation (the blending ratio (%) of the compound that generates the polyvalent metal cation) can be calculated by the following formula: b = (56.11 × 10 5 x Z x V) / (A x z x X) In the above formula, b: blending ratio (%) of compound that generates polyvalent metal cations, Z: mass (g) of compound that generates polyvalent metal cations, V: valence of polyvalent metal cations, A: acid value (mg KOH / g) of anionic polymer, z: molecular weight of compound that generates polyvalent metal cations, and X: mass (g) of anionic polymer.

[0056] The water-soluble anionic polymer and the polyvalent metal cation may be blended, mixed, and stirred as described above, but since the water-soluble anionic polymer is usually in the form of a 15 wt % to 60 wt % aqueous solution, it is often not necessary to newly add a dispersion medium such as water, and the polyvalent metal cation may also be in the form of an aqueous solution, and then these may be mixed. The concentrations of these components during the reaction are not limited, but since the amount of water contained in these aqueous solutions is sufficient to allow the reaction to proceed sufficiently uniformly, considering the effort required to adjust the concentration to an appropriate level when made into a coating solution, there is no need to make the concentration excessively low or high, and there is no need to newly add a dispersion medium.

[0057] The blending ratio of the surfactant and the water-soluble anionic polymer is 50 to 200 parts by weight, preferably 70 to 200 parts by weight, of the surfactant per 100 parts by weight of the polymer, as this range provides the best performance.

[0058] The presence of other components that may react with these components during the reaction may interfere with the formation of the composite particles of the present invention. For example, the presence of a water-soluble cationic polymer may result in the formation of a polymer complex with the water-soluble anionic polymer (Patent Documents 1 and 2), or the presence of an alkali metal may result in the formation of a metal salt (WO / 2011 / 115280). Furthermore, the presence of a water-soluble cationic polymer can cause stickiness, and if a crosslinkable water-soluble cationic polymer is used to reduce stickiness, the stability of the resulting particles is low. For this reason, the presence of a water-soluble cationic polymer should be avoided as much as possible, preferably at 80 parts by weight or less, even 50 parts by weight or less, particularly 10 parts by weight or less, and most preferably 5 parts by weight or less per 100 parts by weight of the water-soluble anionic polymer. Other than water-soluble cationic polymers, for example, resin emulsions not only do not contribute to the formation of composite particles between a water-soluble anionic polymer and a polyvalent metal cation, but the surfactants required for emulsification may also interfere with the stability of the composite particles. For this reason, the presence of a resin emulsion is preferably avoided as much as possible, and the amount is preferably 150 parts by weight or less, particularly 120 parts by weight or less, and even more preferably 100 parts by weight or less, per 100 parts by weight of the water-soluble anionic polymer. Furthermore, the presence of components that can react with polyvalent metal cations such as alkali metals is preferably avoided as much as possible, and the amount of the polyvalent metal cations remaining after subtracting the equivalent amount that can react with alkali metals is preferably not less than the preferred blend ratio with the water-soluble anionic polymer described above.

[0059] For the stirring method, various stirrers can be used, such as a dissolver mixer, a homogenizer, a shear mixer (a homomixer or an ultra mixer), or a disper mixer suitable for high viscosity materials.

[0060] The median particle size (D50) of the transparent particles in the treatment solution thus obtained is preferably 1 to 99 nm. It is more preferably 1 to 50 nm, and most preferably 1 to 30 nm. This range provides particularly excellent liquid stability and receptor layer performance. The particle size is the particle size detected in the solution and can be measured by a means for measuring so-called dispersed particle size. A typical example is the median particle size (D50) calculated in monodisperse mode using dynamic light scattering and frequency analysis with a Microtrac product (trade name: Nanotrac Wave II), ion-exchanged water as the solvent during measurement. Furthermore, the particle size measured in this manner serves as an indicator of transparency. The liquid maintains transparency within the above range.

[0061] [Treatment Liquid for Recording Materials] In the present invention, the transparent liquid obtained by reacting the components using the method described above can be used as is, or a binder such as PVP (polyvinylpyrrolidone) can be added. The addition of a binder allows for uniform application to the substrate and, as a film-forming component, forms a coating film, providing excellent retention of the polymer-metal composite particles of the present invention to the substrate. The binder is not particularly limited as long as it is film-forming and compatible with the other components in the treatment liquid. In addition to PVP, various anionic and nonionic binders can also be selected. The binder content is not particularly limited, but is 1 to 20 wt %, more preferably 1 to 10 wt %, and even more preferably 2 to 5 wt % of the total treatment liquid. The content in the treatment liquid is 10 to 300 wt %, more preferably 20 to 200 wt %, and even more preferably 30 to 100 wt %, per 100 wt % of the solids content of the treatment liquid.

[0062] In order to ensure that the coating film obtained by applying the treatment liquid is transparent, it is necessary to avoid the cloudiness caused by the addition of an excessive amount of cationic substances or a large amount of hydrophobic solvent. Therefore, when adding a cationic polymer, care should be taken not to add too much. As for the binder resin, as mentioned above, PVP, as well as various anionic and nonionic binders are preferred because they can prevent cloudiness. Furthermore, glycerin and propylene glycol are preferred as solvents, and the amount to be added is preferably 50 wt% or less of the total treatment liquid.

[0063] The treatment liquid of the present invention is also suitable for application to a substrate by inkjet printing. Viscosity and D50 particle size are important liquid properties that allow inkjet ejection. A viscosity of 5 mPa·s or less is usable even under strict standards, and in some cases, a viscosity of 10 mPa·s or less is usable. A D50 particle size of 200 nm or less is usable even under strict standards, and in some cases, a D50 particle size of 500 nm or less is usable. Furthermore, these physical property standards are necessary for inkjet ejection even over time. As will be apparent from the examples described below, the treatment liquid of the present invention can maintain liquid properties that allow inkjet ejection even over time.

[0064] [Coating liquid for non-absorbent or poorly absorbent substrates] If the substrate to be printed is a non-absorbent or poorly absorbent substrate such as PET film, the ink cannot be received without an ink-receiving layer. In this case, the ink droplets remain on the film and do not fixate, and they do not dry easily even after a long time, and the ink may stick to the surface when touched or come off when rubbed. Furthermore, if the receptive layer does not contain a binder component, it is difficult to fixate the coloring components in the ink, and it is also difficult to maintain the receptive layer itself on the substrate. For this reason, it is preferable to include a binder in the coating liquid. The type and amount of the binder component in this case are as described above.

[0065] [Coating Solution for Absorbent Substrates] When printing on absorbent substrates such as paper, the ink may penetrate too deeply. Without a receptive layer, the ink may bleed, resulting in a blurred image, or the ink may be absorbed, resulting in a low image density. Therefore, by forming a receptive layer using the coating solution of the present invention, the receptive layer can retain only the ink's coloring components on the surface of the paper, allowing the ink's solvent to penetrate into the paper, suppressing bleeding, improving the ink's color development, and resulting in a clearer image. Because absorbent substrates such as paper are inherently porous, the receptive layer can retain the coloring components even without a binder component. However, if additional properties such as water resistance are desired for the receptive layer, a binder component may be added. The type of binder, if added, can be selected depending on the desired properties; a wide range of nonionic or anionic polymers can be used. The amount added is preferably 20 to 90 wt% of the total solids content in the coating film. As shown in the examples below, the coating solution of the present invention achieves excellent results even without a binder component.

[0066] [Coating Liquid for Fibrous Substrates] In recent years, there has been an increasing need for inkjet printing on textile products such as clothing. In particular, there is a strong need to treat substrates using the inkjet method not only with inks for printing and charactering, but also with pretreatment agents. Because fibers are absorbent, the required properties are similar to those of paper, but there are also required properties specific to fibers, as well as required properties for inkjet printing. One required property specific to fibers is washability, as there is a need for washing. This need can be met by selecting the right binder. Furthermore, in order to treat substrates using the inkjet method, the treatment liquid must also have physical properties that allow it to be ejected using the inkjet method. The required properties for this are as described above. As shown in the examples described below, the present invention can also exhibit excellent effects on fibrous substrates such as polyester fabrics.

[0067] [Other Materials] If necessary, additives such as viscosity modifiers, e.g., polyvinylpyrrolidone and polyvinyl alcohol, and stabilizers, e.g., styrene-maleic anhydride ethylene oxide adducts, may be blended into the recording material treatment liquid of the present invention, for example, to improve fluidity, within the scope that does not impair the object of the present invention. In addition to these, additives such as surface sizing agents, gelatin, casein, starch, modified starch, starch derivatives, glue, cellulose derivatives such as carboxymethyl cellulose, surface sizing agents such as algin, synthetic rubber emulsions such as styrene butadiene rubber and acrylonitrile-butadiene rubber, styrene-maleic acid copolymer, polyvinyl acetate, ethylene vinyl acetate copolymer, ketene dimer, colloidal silicic acid unsaturated polyester resin, polyvinyl butyrate, alkyd resin, epoxy resin, pigment dispersant, thickener, flow modifier, antifoaming agent, foam suppressor, mold release agent, foaming agent, penetrating agent, water resistant agent, moisturizer, preservative, antioxidant, fluorescent whitening agent, ultraviolet absorber, coloring dye, titanium oxide, calcium carbonate, satin white, barium sulfate, talc, silica, clay, zinc oxide, coloring pigments such as white pigments such as aluminum hydroxide, etc. may also be blended. When film applications require high film toughness, it is advisable to add a crosslinking component, and when higher anti-blocking properties are required, it is advisable to add wax particles or silicone. These materials are preferred because they improve the quality of the treatment liquid and the receiving layer when added to the treatment liquid of the present invention, which is prepared by mixing the anionic polymer, metal cations, and surfactant described above to generate transparent particles.

[0068] The treatment liquid for recording materials obtained as described above can improve bleeding and feathering when printing by ink jet, increase print density, and improve water resistance.

[0069] [Preparation of Recording Material] The recording material of the present invention is obtained by treating a coating film (substrate) with the recording material treatment liquid. The coating film may be absorbent or non-absorbent. Examples include paper made primarily of plant fibers, such as non-wood fibers or wood fibers, paper made from kenaf, a non-wood pulp-making plant, and synthetic paper, woven fabrics made from materials such as cotton, hemp, and polyester fibers, thin wooden boards, and transparent or opaque resin sheets or films made from polyester, polystyrene, polyvinyl chloride, polyethylene, polycarbonate, polypropylene, polyolefin, polyethylene terephthalate, polycarbonate, polymethyl methacrylate, cellulose acetate, etc., but the present invention is not limited to these examples. In the present invention, among these various materials, whether absorbent or non-absorbent, there is an excellent effect of preventing blocking in particular with non-absorbent materials such as polyvinyl chloride film, polyvinylidene chloride film, polyester film, polycarbonate film, polystyrene film, polyacrylonitrile film, ethylene-vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, nylon film, and cellophane, and especially with polyethylene film and polypropylene film.

[0070] Examples of a method for treating an object to be coated (substrate) with the treatment liquid for recording materials include a coating method, an impregnation method, and a coating method such as inkjet printing, in which the treatment liquid for recording materials is applied to the object to be coated. The method can be selected depending on the type and material of the substrate to be used.

[0071] Examples of the coating method include size press methods represented by horizontal size press methods, roll bead coater methods, and calendar size press methods; knife coater methods represented by air knife coater methods; roll coater methods represented by transfer roll coater methods such as gate roll coater methods, direct roll coater methods, reverse roll coater methods, and squeeze roll coater methods; blade coater methods represented by bill blade coater methods, short duel coater methods, and two-stream coater methods; bar coater methods represented by rod bar coater methods; cast coater methods; gravure coater methods; curtain coater methods; die coater methods; spray coater methods; and brush coater methods.

[0072] Examples of the impregnation method include a pre-wet method, a float method, and a doctor bar method.

[0073] In the inkjet printing method, the recording material treatment liquid is used as ink and is applied to the required areas before printing color inks. Since the recording material treatment liquid does not contain inorganic pigment particles, it is less likely to cause nozzle clogging. Coating by this inkjet method can also be performed continuously.

[0074] The amount of the recording material treatment liquid to be applied varies depending on the type of substrate (substrate) and cannot be determined in general terms. However, in the case of a non-liquid-absorbing substrate, in order to obtain inkjet printing performance, such as ink bleeding, feathering, print density, and bleeding performance, the dry film thickness is 0.5 to 5 μm, preferably 0.7 to 5 μm. If the dry film thickness is too thin, the ink liquid retention is low, causing bleeding. If the dry film thickness is too thick, the uniformity and smoothness of the coating film tend to be impaired. After treating the substrate with the recording material treatment liquid, the substrate may be dried. There are no particular limitations on the drying method, but examples include hot air drying, infrared drying, and drum drying.

[0075] The recording material thus obtained has been treated with the recording material treatment liquid, and therefore has the excellent properties of improving the clarity and density of the recorded image. Furthermore, when the substrate is a transparent resin film, the recording material has an ink-receiving layer with excellent transparency, and is therefore suitable for use as packaging films, labels, stickers, and the like with high design appeal.

[0076] Furthermore, when used in a transfer film for the DTF (direct-to-film) method, the receiving layer does not contain inorganic pigments during thermal transfer, and the polymer with a glass transition point becomes thermoplastic during thermal transfer, allowing it to also function as a protective film for the image, making it ideal for use in improving the performance of transfer-printed materials.

[0077] The recording material having the treatment liquid and the receiving layer of the present invention exhibits excellent performance, particularly in inkjet printers using pigment inks, and is also suitable for use with laser printer inks and gravure inks. These printing methods can also be carried out continuously.

[0078] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. Note that parts and % represent parts by weight and % by weight, respectively. The surfactants and anionic water-soluble polymers used in the examples and comparative examples are shown in Tables 1 and 2. Note that the "coating liquid" in the following examples is a liquid that can be applied to a substrate that can be used for printing and recording after application, thereby improving the performance of the substrate, and corresponds to the "treatment liquid for recording material" in the present invention.

[0079]

[0080]

[0081] [Preparation of Coating Solutions 1 to 37] (1) Preparation of Coating Solution 1 Coating Solution 1 was prepared by the following method. 21.11 parts (5.70 parts as solids) of JONCRYL JDX-6180 (manufactured by BASF Japan Ltd., ammonium neutralized salt of styrene acrylic polymer, glass transition point 134°C, solid acid value 230, nonvolatile content 27%, MW 14000) were added to ion-exchanged water and stirred. 7.00 parts (6.65 parts as solids) of Hitenol NF-17 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., polyoxyethylene styrenated phenyl ether ammonium sulfate, concentration 95%) were added thereto and stirred thoroughly. Further, 0.15 parts of Surfynol 104PG-50 (manufactured by EVONIK) was added to suppress foaming, and then 4.54 parts (1.20 parts as solids, of which 0.91 parts as calcium chloride solids) of a 20% aqueous calcium chloride solution (prepared by adding and dissolving 26.44 g of granular calcium chloride (manufactured by Tokuyama Corporation, calcium chloride concentration 75.6%) in 73.56 g of ion-exchanged water to give a calcium chloride concentration of 20%) was added, thoroughly stirred, and 0.1 parts of Biohope (manufactured by K.I. Kasei Co., Ltd.) was added to finish the mixture.

[0082] (2) Preparation of Coating Solutions 2 to 16 Coating Solutions 2 to 16 were prepared in the same manner as Coating Solution 1, except that the Hitenol NF-17 in Coating Solution 1 was replaced with another compound. The blending ratios (by mass) of the materials for Coating Solutions 1 to 16 are shown in Tables 3 and 4. In Tables 3 to 7 below, the percentages to the right of each material name column indicate the solids concentration of each material, the numbers on the left of the blending ratio column for each material (under "Apparent") are the apparent amount added, and the numbers on the right (under "Solids") are the solids value, all shown in parts by mass.

[0083]

[0084] (3) Preparation of Coating Solutions 17 to 26 Coating Solutions 17 to 20 were prepared by changing the amount of calcium chloride and the amount of Hitenol NF-17 from Coating Solution 1. Coating Solution 21 was prepared by increasing the solids concentration of Coating Solution 1. Coating Solutions 22 to 26 were prepared by changing the type and amount of surfactant in Coating Solution 17. The compounding ratios of the materials for Coating Solutions 17 to 26 are shown in Table 5.

[0085]

[0086] (4) Preparation of Coating Solutions 27 to 31 Coating solutions 27 to 31 were prepared using a similar formulation to that of Coating Solution 1, but by changing the amount of calcium chloride relative to the acid value of the water-soluble anionic polymer. The compounding ratios of the materials in Coating Solutions 27 to 31 are shown in Table 6.

[0087]

[0088] (5) Preparation of Coating Solutions 32 to 37 Coating Solutions 32 to 37 were prepared by changing the styrene acrylic polymer of Coating Solution 1 to other water-soluble anionic polymers. The blending ratios of Coating Solutions 32 to 37 are shown in Table 7.

[0089]

[0090] [Measurement of initial physical properties of coating solutions 1 to 37] The initial physical properties were measured using the following measurement methods. The results are shown in Tables 8 to 12. <Method of measuring particle size> A product name: "Nanotrac Wave II" manufactured by Microtrac Co., Ltd. was used using dynamic light scattering and frequency analysis, ion-exchanged water was used as the solvent during measurement, and the median diameter: D50 calculated in mono-disperse mode was used as the measured value.

[0091] <Observation of Transparency> The coating liquid was visually observed to check for cloudiness or opacity. <Method of Measuring Viscosity> The viscosity of the obtained liquid mixture was measured using an E-type viscometer at a liquid temperature of 25°C and 50 rpm. The number of rotations was changed according to the viscosity of the object being measured. Only liquid mixture 26 had too high a viscosity to be measured using the E-type viscometer, so the viscosity was measured using a B-type viscometer at a liquid temperature of 25°C and 60 rpm.

[0092] <Initial overall evaluation> Evaluation was carried out according to the following criteria: ◎: Appearance is transparent (D50≦30nm) and viscosity is 5mPa・s or less; ○: Appearance is slightly cloudy (30nm<D50≦50nm), but it can be used on transparent substrates and viscosity is 5mPa・s or less; △: Appearance is slightly cloudy (30nm<D50≦50nm), but it can be used on transparent substrates, but the viscosity is 5mPa・s to 50mPa・s and it is not suitable for inkjet ejection; ×: The particle size is large (50nm<D50), and it changes the appearance when used on transparent substrates, so it is not suitable.

[0093]

[0094]

[0095]

[0096]

[0097] As shown in Tables 8 to 12, the results of particle size measurements and visual observation confirmed the following relationship between particle size and transparency: If D50 ≦ 30 nm, the particles were transparent when visually observed, if 30 nm < D50 ≦ 50 nm, slight turbidity was observed, and if 50 nm < D50, the particles were clearly cloudy.

[0098] As can be seen from Tables 8 to 12, coating solutions 1 to 15, 17 to 23, 27 to 31, 32 to 34, 36, and 37, which used compounds of chemical formulas (3) to (9) as surfactants, received an initial overall rating of ⊚. Coating solutions 16 and 26, which used a compound other than chemical formula (1) as a surfactant, received an initial overall rating of x. This demonstrates that the coating solutions of the present invention, which use a compound of chemical formula (1) as a surfactant, have excellent initial physical properties. Coating solution 25, which used a combination of compounds of chemical formulas (3) and (4) at 82 parts by weight per 100 parts by weight of polymer, and coating solution 35, which used an ammonium salt of an acrylic polymer (Joncryl JDX-6500) with a Tg of 65°C and an acid value of 85 mgKOH / 1 g, received an initial rating of ⊚, indicating that they could be used without any problems as receiving layer-forming coating solutions.

[0099] [Evaluation of Stability Over Time] The stability over time of Coating Solutions 1 to 4, 17, 18, 20, 24, 27, and 32 to 34 was evaluated. The coating solutions were stored at 25°C and 50°C immediately after preparation. One week, two weeks, and one month after preparation, each physical property was measured using the same method as for the initial physical property measurements, and the properties were evaluated according to the following criteria. The results are shown in Table 13. <Overall Evaluation Over Time> ◎: Maintains the original state (D50≦30 nm, viscosity maintained at 5 mPa s or less). ○: Transparency has deteriorated (30 nm < D50 ≦ 50 nm), so caution is required when using on transparent substrates. △: Does not maintain the original state, and is not suitable for use on transparent substrates. Suitability for inkjet applications has been lost. Particle size is larger than 50 nm, and viscosity has changed. ×: No fluidity, and a coating film cannot be formed.

[0100]

[0101] Table 13 shows that the condition of coating solutions 1 to 4, 17, 18, 20, 24, 27, and 32 to 34, which used as surfactants Hitenol NF-17, NF-13, Newcol 707-SF, and Noigen EA-207D, compounds of chemical formula (5) and chemical formula (6), remained good over time. In particular, coating solutions 1, 2, 4, 20, 27, and 32 to 34, which used compounds of chemical formula (5) and had a molar ratio of polyvalent metal cation to the acid value of the water-soluble anionic polymer of 70% equivalent or less, received an overall rating of ⊚ over time, indicating that the condition of the solution remained extremely good even after aging. Furthermore, coating solution 3, which uses Hitenol NF-08, a compound of chemical formula (5), as a surfactant, and coating solutions 17, 18, and 24, which similarly use compounds of chemical formula (5) or (6) and in which the blending ratio of polyvalent metal cations to the acid value of the water-soluble anionic polymer is 100% equivalent in molar ratio, were also evaluated as "Good," indicating that the liquid state after aging is satisfactory. As such, all of the coating solutions of the present invention have good liquid state after aging, and it can be seen that the coating solutions using the compounds of chemical formula (5) and (6) in particular have very good initial state and stability over time.

[0102] Furthermore, as shown in Tables 8 to 12, all of these coating solutions had a dispersed particle size D50 of 200 nm or less, which is a strict standard for inkjet ejection, and a viscosity of 10 mPa s or less. These physical property values ​​all satisfied the above even after aging, indicating that the inkjet ejection properties were also excellent.

[0103] [Preparation of Coating Solutions for PET Film] (Coating Solutions 38 to 52) (1) Preparation of Coating Solution 38 To 49.75 parts of Coating Solution 17 (7.00 parts as solid content), 20.25 parts of ion-exchanged water was added and stirred to thoroughly mix, and then 30.00 parts (3.00 parts as solid content) of 10% PVP-K30 (10 parts of PVP-K30 manufactured by Nippon Shokubai Co., Ltd. was added to 90 parts of ion-exchanged water with stirring and dissolved) was added, and further stirred to prepare a coating solution.

[0104] (2) Preparation of Coating Solutions 39-52: Coating Solutions 39-41 were prepared in the same manner as Coating Solution 38, except that Coating Solution 1 was used in place of Coating Solution 17 in the composition shown in Table 14. Coating Solutions 3, 10, 27, 28, and 29 were prepared in the same manner as Coating Solutions 42-46, except that Vinyl Blanc V700 was used as the binder component in the composition ratios shown in Table 15. Coating Solutions 47-52 were prepared in the same manner as Coating Solution 26, except that Coating Solution 26 and each binder component were used in the composition ratios shown in Table 16. The compositions are shown in Tables 12-14. The number on the left side of the composition ratio column in the tables (under "Apparent") is the apparent amount added, and the number on the right side (under "Solids") is the solids content, each in parts by mass. The 10% PVA 28-98 was prepared by adding 10.00 parts of Poval 28-98 manufactured by Kuraray Co., Ltd. to 90.00 parts of ion-exchanged water at room temperature while mixing, then heating the mixture to 80°C and stirring until it was completely dissolved.

[0105]

[0106]

[0107]

[0108] [PET film printing evaluation] Coating solutions 38 to 52 were applied to a PET film ("Lumirror T60" manufactured by Toray Industries, Inc.) using a bar coater and dried at 110°C for 3 minutes to obtain a coating film. The resulting coating film was evaluated for transparency and printing using the methods described below. The bar coater numbers used for coating and the evaluation results of the coating film are shown in Tables 15 to 17. Comparative Example 12 shows the results when printing was performed directly on a PET film without applying a coating solution.

[0109]

[0110]

[0111]

[0112] <Transparency> The transparency of the coating film made on the PET film was evaluated by measuring the haze with a haze meter NDH-5000 manufactured by Nippon Denshoku Industries Co., Ltd. ○: Less than 5 (transparent) △: 5 to 10 (slightly cloudy), usable for film ×: 10 or more (cloudy), film transparency is impaired when used for film

[0113] <Printing evaluation> A test pattern was printed on the coating film using a Seiko Epson Corporation pigment ink-equipped IJ printer PX-105 in super fine paper and clean mode. The print was dried at 80°C for 3 minutes and then left at room temperature overnight, after which the print quality was evaluated using the following method.

[0114] - Printing Evaluation A The color density (OD) of the solid printed areas (cyan, magenta, yellow, black, brown) was measured using an eXact ADVANCE manufactured by X-rite. All color densities were then totaled and a comprehensive evaluation was made. The total print density was evaluated based on the following criteria: 〇: Total is 8.0 or more 〇': Total is less than 8.0 to 7.6 or more △: Total is less than 7.6

[0115] - Printing evaluation B The print samples produced in printing evaluation A were visually evaluated and compared with ref. 〇: Print quality clearly better than ref 〇': Print quality better than ref, but not as good as 〇 △: Print quality better than ref ▲: Print quality inferior to ref ×: Print quality clearly inferior to ref, image not formed For ref, the same binder as used for coating was applied alone (in the case of Coating Liquid 38, Coating Liquid 48 was the ref), and comparison was made.

[0116] <Overall Evaluation of Printing> The lower of the two evaluations, printing evaluation A and printing evaluation B, was taken as the overall evaluation of printing.

[0117] The above evaluation of transparency and printing revealed the following: Coating Solutions 50 and 52 had a large particle diameter of Coating Solution 26 itself (D50 = 941 nm), which caused the coating film to become cloudy and impaired transparency. Coating Solution 51 had poor compatibility between Liquid Mixture 26 and PVA28-98, which caused large aggregates of foreign matter to form in the coating film, so evaluation was discontinued.

[0118] All PET films coated with Coating Liquids 38 to 43 received an overall rating of 'Good'. The ratings for Coating Liquid 44 (Coating Liquid 27, where the molar ratio of polyvalent metal cations to the acid value of the styrene acrylic polymer was 50% equivalent), 45 (Liquid Mixture 28, 40% equivalent), and 46 (Liquid Mixture 29, 35% equivalent) varied depending on the ratio of polyvalent metal cations used, but all were within a range suitable for use without any problems. Furthermore, no image formation was possible when the PET film was left uncoated (Comparative Example 12) or when it was coated with Coating Liquid 49 (Viniblan V700 diluted with ion-exchanged water to a solids content of 10%). These results demonstrate that non-absorbent substrates coated with the coating liquid of the present invention, particularly those coated with a coating liquid using chemical formula (5) as a surfactant, are capable of forming images with excellent print density and print quality.

[0119] [Preparation of Coating Solutions for Paper (Coating Solutions 53 to 60)] 25.60 g of ion-exchanged water was added to 74.40 g (10.00 g of solids) of Coating Solution 1 and mixed to prepare Coating Solution 53. Coating Solutions 54 to 57 were prepared in the same manner, except that the coating solutions shown in Table 20 were used in place of Coating Solution 1, with the compositions shown in Table 20.

[0120]

[0121] Cationic polymers Papiogen P-105 (manufactured by Senka Corporation, DMA / NH3 / ECH, solids content 60%) and Unisense FPA-1000L (manufactured by Senka Corporation, DADMAC, solids content 43%) were each diluted with ion-exchanged water to a solids content of 10.00 g to obtain coating solutions 58 and 59. JONCRYL JDX-6180 was diluted with ion-exchanged water to a solids content of 10.00 g to obtain coating solution 60. The compositions of coating solutions 21 to 23 are shown in Table 21.

[0122]

[0123] [Evaluation of printing on paper] The above coating solutions 53 to 60 were applied to Catherine paper (uncoated paper, manufactured by Tokushu Tokai Paper Co., Ltd.) using a bar coater to form a coating film, which was then dried at room temperature and evaluated using the following method. The bar coater numbers used and the evaluation results are shown in Tables 22 and 23.

[0124] A test pattern was printed on the coating film using a Seiko Epson PX-105 pigment ink-equipped IJ printer in the fine mode on super fine paper.

[0125] Printing Evaluation A The color density (OD) of the solid print area (cyan, magenta, yellow, black, brown) was measured using an eXact ADVANCE manufactured by X-rite. All color densities were then totaled and a comprehensive evaluation was made. The total print density was evaluated based on the following criteria: ◯: Total is 5 or more △: Total is less than 5

[0126] Printing evaluation B The print samples prepared in printing evaluation A were visually evaluated and compared with ref (uncoated comparative example 13). ◯: Print quality clearly better than ref ◯': Print quality better than ref, although not as good as ◯ △: Print quality better than ref ▲: Print quality worse than ref ×: Print quality clearly worse than ref, image formation not possible

[0127] <Overall Evaluation> The lower of Print Evaluation A and Print Evaluation B was taken as the overall evaluation. From the results in Table 22, it can be seen that Coating Solutions 53 to 57, which contain Coating Solutions 1, 28, 29, 30, and 31 using chemical formula (5), all received an overall evaluation of ◯ or ◯', indicating that they are excellent. Of these, Coating Solutions 53 and 54, in which the blending ratio of polyvalent metal cations to the acid value of the styrene acrylic polymer is 35% or more equivalent in molar ratio, received an overall evaluation of ◯, indicating that they are even more excellent.

[0128] [Evaluation of inkjet ejection properties and printing on synthetic fibers] Pongee cloth (polyester cloth) was pretreated using the following method. Coating Solution 1 was filled into the ink tank of a Seiko Epson Corporation inkjet printer PX-S160T, and a solid print was made on pongee cloth (polyester cloth) and dried overnight at room temperature. Images were printed on the pretreated pongee cloth and non-pretreated pongee cloth using a Seiko Epson Corporation PX-105 printer in "Super Fine Paper" and "Fine Mode." The image quality was compared between the pretreated and non-pretreated pongee cloths to confirm (i) the inkjet ejection properties of Coating Solution 1 and (ii) its effectiveness on synthetic fiber materials, which are prone to inkjet ink bleeding.

[0129] Inkjet ejection was possible without any problems. Treatment liquid 1 has a viscosity of 2.5 mPa s and a D50 particle size of 17 nm, which generally meets the strict standards for inkjet ejection. Furthermore, since the treatment liquids of the present invention other than treatment liquid 1 also have the same level of physical properties, it can be seen that there are no problems with inkjet ejection in any of them.

[0130] Furthermore, when comparing samples printed on pongee cloth, it was clear to the naked eye that the images printed on the pretreated pongee cloth were clearer and had significantly better color development than those printed on untreated pongee cloth. It was also clear that pre-treatment with the treatment solution of the present invention provided excellent printing properties even when solid printing was performed on pongee cloth. This demonstrates that the treatment solution of the present invention is also effective on synthetic fiber materials, such as polyester and nylon, which are prone to ink-jet ink bleeding. Images printed on the pretreated pongee cloth and those printed on untreated pongee cloth were scanned using a Fujifilm Apeos C3570 multifunction printer (color mode: automatic, document quality: photo, resolution: 600 dpi) and imported as JPG files. The difference in clarity between the two images was clearly visible when displayed on a PC screen and viewed with the naked eye. This JPG image was input / output at 600 pixels / inch in Adobe Photoshop Elements 2021(R), converted to two-tone monochrome using the error diffusion method (Tiser), and the image resolution was adjusted to a width of 2677 pixels and a height of 1893 pixels with a fixed aspect ratio, and saved in PNG format (Windows format, no compression or interlacing) using the bicubic method. This is shown in Figure 1 (left image: "without preprocessing" and right image: "with preprocessing"). The two-tone monochrome conversion and image resolution adjustment reduced the visibility of the difference in clarity between the two images, but a slight difference is still visible.

[0131] According to the present invention, it is possible to obtain a treatment liquid for a recording material that can form an ink-receiving layer that improves ink-jet printing performance such as ink bleeding, feathering, print density, and bleeding, and that does not cause coating film blocking even when applied to a substrate such as a resin film or glass.

Claims

1. A processing liquid for recording materials, characterized by containing at least the following components (i) to (iii): (i) a water-soluble anionic polymer, (ii) a polyvalent metal cation, and (iii) a surfactant.

2. The processing liquid for recording materials according to claim 1, wherein (iii) the surfactant is a compound represented by the following chemical formula (1): (wherein R is a linear or branched alkyl or aryl group having 10 to 50 carbon atoms, which may have a substituent) 1 : a linear or branched alkyl group having 1 to 3 carbon atoms, N: an integer from 1 to 50 3. The processing liquid for recording materials according to claim 1, wherein (iii) the surfactant is a compound represented by the following chemical formula (2): In the formula, R １ is a linear or branched alkyl group having 1 to 3 carbon atoms, n is an integer of 1 to 50, R ２ is the following chemical formula, m is an integer of 1 to 3, and X is SO3M, -COOM, -PO ３ M ２ One or more of the above, M is NH4, Na, or K 4. The treatment liquid for recording materials according to claim 1, wherein the polymer having an anionic functional group is one or more of a styrene-acrylic acid copolymer, an α-methylstyrene-acrylic acid copolymer, and a styrene-α-methylstyrene-acrylic acid copolymer.

5. The processing liquid for recording materials according to claim 1, wherein the polyvalent metal cation is at least one of calcium, magnesium and aluminum cations.

6. The method for producing a treatment liquid for recording materials according to claim 1, characterized in that the mixing ratio of the water-soluble anionic polymer and the polyvalent metal cation is such that the amount of polyvalent metal cation added is 35 to 100 mol % relative to the acid value of the water-soluble anionic polymer.

7. A method for producing a recording material, comprising coating the recording material treatment liquid according to claim 1 onto a substrate.

8. A method for producing a recording material, comprising applying the recording material treatment liquid according to claim 1 to a substrate, wherein the substrate is a liquid non-absorbent substrate.

9. A method for recording on a recording material, comprising coating a substrate with the recording material treatment liquid according to claim 1 and then recording on the recording material with an ink containing a colorant.

10. An ink-jet recording method comprising: applying the recording material treatment liquid according to claim 1 to a substrate to form a recording material; and then carrying out ink-jet printing on the recording material.

11. A method for producing a recording material, characterized in that when inkjet printing is performed on a recording material formed by coating a substrate with the recording material treatment liquid according to claim 1, coating is performed continuously by an inkjet method.

Images