JP2023048074A - Pretreatment liquid, ink set, and printed material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a pretreatment liquid that can form a printed material, in particular on a non-permeable substrate, while inhibiting color-mixing bleeding and color unevenness, and realizing good solidness and good reproducibility of images and characters, and also excellent post-processing suitability such as blocking resistance and lamination suitability; an ink set that contains the pretreatment liquid and a water-based inkjet ink that can form a printed material having the properties described above; and a printed material produced using the ink set.

SOLUTION: The pretreatment liquid comprises resin particles (A), multiple calcium carboxylates (B) at least including a calcium hydroxycarboxylate (B-1), and water. If R (g) and C (mmol) refer to the amount of the resin particles (A) and the millimolar amount of calcium ions contained in 100 g of the pretreatment liquid, respectively, then the C is 10-60 mmol and the ratio (R/C) between the R value and the C value is from 0.11 to 0.50.

SELECTED DRAWING: None

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to a pretreatment liquid used with water-based inkjet ink, an ink set containing the pretreatment liquid, and a printed material produced using the pretreatment liquid.

Compared to analog printing, digital printing can reduce costs and handle a wide variety of products because it does not require a plate, and can improve the working environment by reducing odors and noise. Therefore, digital printing is not only used in offices and homes, but in recent years, it has also been adopted in industrial applications.

Inkjet printing, a type of digital printing method, uses fine droplets of ink to form images, so it can achieve high resolution. It is expected to be the most promising alternative to analog printing in industrial applications due to its low running cost and other advantages.

Solvent inkjet inks and UV inkjet inks have been the main inkjet printing inks that have been used in industrial applications. However, in recent years, from the viewpoint of safety, health, and environmental considerations, switching to water-based inkjet ink (hereinafter also simply referred to as "water-based ink" or "ink") is under consideration.

So far, image formation with a quality that can be practically used even in industrial applications has been achieved using water-based inkjet inks on permeable substrates such as woodfree paper and coated paper. On the other hand, for non-permeable substrates such as films, image formation with quality capable of substituting analog printing has not yet been realized. As a factor for this, liquid components such as water and organic solvents contained in water-based inkjet ink may not permeate into the non-permeable substrate and may remain on the substrate, resulting in the ink liquid Degradation of image quality occurs, such as droplets spreading more than expected, and droplets coming into contact with each other to cause color mixture bleeding or color unevenness (non-uniform state of the color in a portion of the same color).

As means for enabling image formation on an impermeable substrate, a method of applying a pretreatment liquid to the substrate before landing the water-based inkjet ink is well known. When the pretreatment liquid and the ink come into contact with each other, aggregation of pigments and resins (solid content) present in the ink and/or thickening of the ink occurs. As a result, unnecessary wetting and spreading of ink droplets can be suppressed, and bleeding of droplets and the like can be suppressed by aggregating pigments and the like before the droplets come into contact with each other. In order to develop such an effect, the pretreatment liquid is blended with a coagulant component such as a polyvalent metal salt or a cationic polymer.

In the present application, the term "applying the pretreatment liquid" is used as a generic term for non-contact printing of the pretreatment liquid and application of the pretreatment liquid while being brought into contact with the base material.

However, in order to obtain printed matter having an image quality that can be practically used even in industrial applications, it is necessary to cope with various printing conditions and usage conditions. For example, in the same printed matter, there are various portions such as portions where multiple colors of ink overlap, single-color solid portions (portions where the print rate is 100%), low print rate portions, characters, and the like. It is extremely difficult to prevent the image quality from deteriorating at all these locations simply by using the pretreatment liquid.

In addition, it is difficult to obtain sufficient adhesion with a printed material on a non-permeable base material that does not allow ink to permeate at all. If the adhesion is insufficient, the printed matter may come off due to rubbing, or when the printed matter is stored in a wound or stacked state, pressure is applied to the printed surface, causing blocking (substrate sticking to the printed surface). A phenomenon in which part of the ink is removed by the base material occurs when the ink is peeled off. Furthermore, when the film is laminated (laminated) with another film via an adhesive (laminate adhesive), there is a risk of delamination occurring between layers due to insufficient adhesion. In particular, printed matters on impermeable substrates are often post-processed for use as packaging materials, and improvement in blocking resistance and lamination suitability is an essential issue.

In order to address the above-described problems, for example, Patent Document 1 discloses a pretreatment liquid containing a flocculant component, a polyoxyalkylenealkylamine, and a resin. , there is a description that it is trying to achieve both storage stability. Further, Patent Document 2 discloses a pretreatment liquid containing a coagulant component, a hydrophobically modified water-soluble urethane resin (thickener), and resin particles. There is a description that it is possible to obtain a printed matter excellent in quality. However, in both patent documents, the pretreatment liquids specifically disclosed in the examples, for example, when producing a printed matter in which portions with extremely different printing ratios exist simultaneously in one image, color mixture blurring and While the color unevenness is good, it is not possible to completely achieve both the adhesion of the high print area and the character reproducibility of the low print area. On the other hand, Patent Document 3 discloses a primer composition (pretreatment liquid) containing a water-soluble polyvalent metal salt and a polyester-based polyurethane emulsion, and is described as having excellent image quality, adhesion and lamination suitability. However, the examples of Patent Document 3 only disclose examples in which only one type of flocculant component is used. When these pretreatment liquids are used, depending on the image to be printed and the conditions (for example, during overprinting), the ink aggregation effect may be insufficient. Further, Patent Document 4 discloses a receiving solution (pretreatment liquid) containing an organic acid salt having 3 or more carbon atoms, an organic acid salt or inorganic salt having 2 or less carbon atoms, and a water-soluble organic solvent having a boiling point of 180° C. or more. Calcium pantothenate, calcium propionate, calcium lactate, calcium acetate and the like are used in combination as flocculant components in the disclosed examples. However, no resin-containing system is disclosed, and it is easily expected that when used on a non-permeable substrate, printed matter will be inferior in adhesion, blocking properties, suitability for lamination, and the like.

As described above, especially for non-permeable substrates, mixed color bleeding and color unevenness are suppressed, solid filling (no white spots, solid parts are filled with ink), and image and character reproducibility are good. In addition, there has been no pretreatment liquid that gives printed matter excellent in post-processing aptitude such as anti-blocking property and aptitude for lamination.

JP 2021-91765 A JP 2020-75436 A JP 2020-75954 A JP 2014-76619 A

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. A further object of the present invention is to provide a pretreatment liquid that can provide a printed matter excellent in post-processing suitability such as blocking resistance and lamination suitability. Another object of the present invention is to provide an ink set containing a pretreatment liquid and a water-based inkjet ink, and a printed matter obtained using the ink set, from which printed matter having the above properties can be suitably obtained.

That is, the present invention provides a pretreatment liquid for use with a water-based inkjet ink containing a pigment, a water-soluble organic solvent, and water,
The pretreatment liquid contains resin particles (A), a plurality of calcium carboxylates (B), and water,
at least one of the plurality of carboxylic acid calcium salts (B) is a hydroxycarboxylic acid calcium salt (B-1),
When the amount of the resin particles (A) contained in 100 g of the pretreatment liquid is R (g), and the millimol amount of calcium ions contained in 100 g of the pretreatment liquid is C (mmol), the C is 10. 60 mmol, and the ratio of the value of R to the value of C (R/C) is 0.11 to 0.50.

Further, in the present invention, all of the calcium carboxylates constituting the plurality of calcium carboxylates have a solubility in water at 20° C. of 3 to 30 g/100 g H ₂ O. It relates to the above pretreatment liquid.

The present invention further includes a water-soluble organic solvent (C) having one hydroxy group in its molecular structure,
The ratio of the molar amount of hydroxycarboxylic acid ions contained in the pretreatment liquid to the molar amount of the water-soluble organic solvent (C) having one hydroxy group in the molecular structure is 0.08 to 0. .4 with respect to the pretreatment liquid.

The present invention also relates to an ink set comprising the above pretreatment liquid and a water-based inkjet ink containing a pigment, a water-soluble organic solvent, and water.

The present invention also relates to a printed material obtained by printing a water-based inkjet ink containing a pigment, a water-soluble organic solvent, and water on a base material to which the pretreatment liquid has been applied.

According to the present invention, especially for non-permeable substrates, mixed color bleeding and color unevenness are suppressed, solid filling, image and character reproducibility are good, and post-processing suitability such as blocking resistance and lamination suitability is achieved. Therefore, it is possible to provide a pretreatment liquid that can obtain printed matter excellent in both. In addition, it is possible to provide an ink set containing a pretreatment liquid and a water-based inkjet ink, and a printed matter obtained using the ink set, from which printed matter having the above properties can be suitably obtained.

A pretreatment liquid (hereinafter also simply referred to as "the pretreatment liquid of the present invention"), which is an example of a preferred embodiment of the present invention, will be described below. The present invention is not limited to the following embodiments, and includes various modifications implemented within the scope of the invention.

As explained in the Background Art section, when water-based inkjet ink is printed on a non-permeable substrate, mixed color bleeding and color unevenness are likely to occur. It is well known to apply a pretreatment liquid comprising a substrate to a substrate. When the water-based inkjet ink droplets land on the pretreatment liquid layer (pretreatment liquid layer), the coagulant component present in the pretreatment liquid is released and diffused into the ink droplets, and the ink cause agglomeration or thickening of the solid components (pigments and resins) in the As a result, the wetting and spreading of the ink is suppressed, and the color mixture bleeding and color unevenness are reduced, making it possible to form an image on a non-permeable substrate.

However, when multiple types of ink and/or a large amount of ink land on the same spot, as in overprinting, the amount of the coagulant component becomes insufficient and the distribution of the coagulant component in the ink becomes uneven. As a result, it becomes difficult to control the aggregation speed of the particles, resulting in deterioration of image quality.

As a countermeasure against the above problem, a method of adding an excessive amount of the coagulant component to the pretreatment liquid can be considered. However, as a matter of course, the aggregation or thickening progresses rapidly, so the ink droplets do not spread sufficiently, and there is a risk of adverse effects such as solid filling and deterioration of image and character reproducibility. be.

Furthermore, the type and amount of the flocculant component also affect post-processing suitability such as blocking resistance and lamination suitability of the printed matter. Specifically, it is believed that the degree of blocking resistance and lamination suitability is also affected by the amount of cross-linking of the solid components in the ink via the flocculant component. Therefore, for example, if the amount of the flocculant component is small, the cross-linking of the solid component is insufficient, and the anti-blocking property is degraded. Conversely, if the flocculant component is added in excess, the solid component in the ink will also be excessively crosslinked. will run out.

As described above, simply adjusting the amount of the flocculant component not only makes it difficult to achieve both color bleeding, color unevenness, solid filling, and image and character reproducibility, but also makes it difficult to achieve both blocking resistance and lamination suitability. becomes.

On the other hand, generally, a binder component is used to impart adhesion to the impermeable substrate to the pretreatment liquid layer. There are two types of resin used as a binder component, namely water-soluble resin and resin particles, which are appropriately used according to the properties required for the pretreatment liquid and the printed matter. Among them, it is preferable to use resin particles as the binder component from the viewpoint of improving adhesion. In addition, resin particles are a material that contributes to the improvement of post-processing suitability such as blocking resistance and lamination suitability. It is also a suitable material in that water resistance and the like can be enhanced. However, the resin particles in the pretreatment liquid may inhibit the release and diffusion of the flocculant component into the ink. It becomes more difficult to achieve both blocking resistance and lamination suitability.

Therefore, in order to solve the above problems, the inventors of the present invention conducted intensive research, and as a result, it was found that the ink Regardless of the amount of printing, the flocculant component is always uniformly released and diffused, and both of the above characteristics can be achieved. pinpointed.

As described above, the amount of the flocculant component in the pretreatment liquid affects the image quality, and the present inventors have found that the water solubility of the flocculant component also greatly affects the image quality. . For example, when the flocculant component is dissolved excessively in the ink, the flocculant component that did not participate in the aggregation and thickening of the ink becomes the interface between the ink droplet and the pretreatment liquid layer, that is, the dot. There is a risk that many will be oriented to the surroundings. In that case, the amount of the coagulant component in the central portion of the dot is relatively small, resulting in uneven distribution of the coagulant component on the printed matter layer after printing the ink. In this case, when another ink is landed later, the degree of aggregation and thickening will be uneven, and the image quality will be deteriorated.

Conversely, if the water solubility of the flocculant component is too low, it will not dissolve and diffuse into the ink droplets in the first place. Even if another ink droplet lands again, it cannot be instantly dissolved in the droplet, and the effect of aggregation and thickening is not manifested, resulting in character thickening in low-printing areas and color mixing in high-printing areas. This leads to deterioration of image quality such as occurrence of bleeding.

Therefore, in the present invention, the image quality is improved by using a certain amount of a coagulant component having moderately low water solubility. Specifically, a plurality of carboxylic acid calcium salts (B) including a hydroxycarboxylic acid calcium salt (B-1) are used as the flocculant component, and the millimole amount of calcium ions contained in 100 g of the pretreatment liquid is When C (mmol) is defined, the C is defined as 10 to 60 mmol.

As described above, in order to improve the image quality, it is effective to suppress excessive dissolution of the coagulant component in the ink, and it is considered preferable to use a coagulant component with low solubility in water. However, if the solubility in water is simply reduced, the image quality is still deteriorated. Therefore, the inventors of the present invention have made intensive studies, and as a result, have found calcium carboxylate (B), which has a high ionization tendency and easily generates cations, as a flocculant component. However, since carboxylic acid calcium salts generally have low solubility in water, the mere use of carboxylic acid calcium salts (B) cannot avoid deterioration of image quality. Therefore, in the present invention, in order to achieve the above-described amount of calcium ions, a plurality of types of carboxylic acid calcium salts (B) are used to improve solubility due to an effect similar to the effect of different ions, and to reduce the amount of calcium ions in the pretreatment liquid. made it possible to increase

Further, in the pretreatment liquid of the present invention, when the amount of the resin particles (A) contained in 100 g is R (g), the relationship between the above C and R/C = 0.11 to 0.50 holds. By doing so, it is possible to achieve both development of adhesiveness, anti-blocking property and lamination suitability by the resin particles (A) and high image quality by optimal release of the coagulant component. Furthermore, by setting the millimole amount (C) of calcium ions to 10 to 60 mmol, the distribution of the coagulant component released and diffused in the ink does not become non-uniform, and high image quality is maintained while anti-blocking. It is possible to improve the properties and lamination strength.

In addition, in order to improve the image quality regardless of the conditions of use, for example, in order to obtain prints with excellent image quality even during overprinting or after the pretreatment liquid has been completely dried, the above-mentioned reprocessing It is considered necessary to suppress crystallization. Therefore, the pretreatment liquid of the present invention essentially contains a hydroxycarboxylic acid calcium salt (B-1) as a flocculant component. Although the details are unknown, carboxylate ions having a hydroxy group tend to maintain solubility and are less likely to recrystallize even if the system changes, for example, changes in the composition of the liquid component due to drying. Prints with excellent image quality can be obtained regardless of the conditions of use of the treatment liquid.

Incidentally, the carboxylic acid calcium salt (B) including the hydroxycarboxylic acid calcium salt (B-1) is considered to form hydrogen bonds with carboxyl groups and hydroxy groups. This hydrogen bond forms cross-links with the solid components in the ink, optimizing the viscoelasticity of the entire printed matter, and further improving blocking resistance and lamination suitability.

As described above, it is possible to obtain a printed matter that suppresses color mixture bleeding and color unevenness on impermeable substrates, has good solid filling, good image and character reproducibility, and is also excellent in blocking resistance and lamination suitability. In order to obtain this, a pretreatment liquid having the above constitution is indispensable.

Subsequently, each component constituting the pretreatment liquid of the present invention will be described in detail below.

<Resin particles (A)>
The pretreatment liquid of the present invention contains resin particles (A). In addition, the "resin particles" in the present application are measured by a dynamic light scattering method using a particle size distribution analyzer (e.g. Nanotrac UPAEX-150 manufactured by Microtrac Bell Co.), based on a cumulative volume of 50% The diameter value (median diameter, D50) is 5 to 1,000 nm.

The resin particles (A) improve adhesion to non-permeable substrates, as well as blocking resistance, lamination suitability, abrasion resistance, etc. of printed matter, and by using the ratio with calcium ions, A printed matter with excellent image and character reproducibility can be obtained without color bleeding or color unevenness.

As described above, the content of the resin particles (A) is determined according to the millimole amount of calcium ions. On the other hand, from the point of maintaining and improving the adhesion to the substrate and the blocking resistance of the printed matter, and also from the point of improving the coating suitability and storage stability of the pretreatment liquid, the resin contained in the pretreatment liquid The amount of particles is preferably 3.5 to 15% by weight, particularly preferably 6 to 12% by weight.

In the present invention, any resin can be used as the resin particles (A). Specific examples of usable resins include urethane (urea) resin, urethane-(meth)acrylic resin, (meth)acrylic resin, styrene-(anhydride) maleic acid resin, olefin-(anhydride) maleic acid resin, rosin ester resin, Rosin phenol resins, terpene phenol resins, amine resins, amide resins, amine-amide resins, amine-epihalohydrin resins, amine-amide-epihalohydrin resins, polyolefin resins, polyester resins and the like can be used. As the resin particles (A), only one resin selected from the above group may be used, or two or more resins may be used in combination.
Moreover, in this specification, "(meth)acryl" means acryl or methacryl. Moreover, "urethane (urea)" means urethane or urethane urea. However, the (meth)acrylic resin may contain, as a structural unit, a structure derived from a styrene-based monomer such as styrene, methoxystyrene, vinyltoluene, and divinylbenzene.

Among these, from the viewpoint of obtaining a printed matter excellent in blocking resistance and lamination suitability, the resin particles (A) consist of (meth)acrylic resin particles, urethane (urea) resin particles, and urethane-(meth)acrylic resin particles. It is preferable to select at least one type selected from the group.

In addition, as the resin particles (A), emulsion-type resin particles containing a surfactant or a polymer dispersant as an emulsifier may be used, or an emulsifier may be used depending on functional groups such as acid groups present in the resin molecule. Dispersion-type resin particles that are dispersed in a liquid without dehydration may also be used. For example, when (meth)acrylic resin particles or styrene-(meth)acrylic resin particles are used as the resin particles (A), emulsion-type resin particles are preferably used from the viewpoint of storage stability of the pretreatment liquid. .

As the resin particles (A), those synthesized by a conventionally known synthesis method may be used, or commercially available products may be used. When selecting from commercially available products, for example, Parasol series (manufactured by Ohara Palladium Chemical Co., Ltd.); Ucoat series, Permaline series (manufactured by Sanyo Chemical Industries); Superflex series, Superflex E series (above, Daiichi Kogyo Seiyaku company); WEM series, WBR series (manufactured by Taisei Fine Chemical Co., Ltd.); Hydran series (manufactured by DIC); Hitech series (manufactured by Toho Chemical Industry Co., Ltd.); Nichigo polyester series (manufactured by Nippon Synthetic Chemical Co., Ltd.); AQUACER series, Hordamer series (manufactured by BYK Chemie); Takelac series (manufactured by Mitsui Chemicals); Pascal series (manufactured by Meisei Chemical Industry Co., Ltd.); (manufactured by Unitika), NeoCryl series, NeoRez series (manufactured by DSM Coating Resins); ADEKA BONDITATER HUX series (manufactured by ADEKA); Juliano series (manufactured by Arakawa Chemical Industries); ) etc. can be used.

<Carboxylic Acid Calcium Salt (B)>
The pretreatment liquid of the present invention contains a plurality of carboxylic acid calcium salts (B) as flocculant components. Compared to other polyvalent metal ions, calcium salts have a greater tendency to ionize and generate cations more easily, have a greater agglomeration effect, and have a smaller ionic radius, making it easier to diffuse into ink droplets, resulting in color bleeding. It is preferably used in that it is suppressed. Moreover, since the carboxylic acid metal salt has a low solubility in water and can suppress excessive dissolution in ink, it is possible to suppress color mixture bleeding and color unevenness during overprinting or printing at a high printing rate. In addition, due to an effect similar to the effect of different ions, a sufficient amount of the coagulant component can be added to the pretreatment liquid, so blocking resistance and laminate strength can be improved without deteriorating image quality.

Furthermore, by using a hydroxycarboxylic acid calcium salt (B-1) to suppress recrystallization after drying, aggregation can occur even during overprinting or after completely drying the pretreatment liquid. The agent components are easily dissolved instantaneously, making it possible to obtain printed matter excellent in image and character reproducibility, and further improving blocking resistance and lamination suitability.

By suppressing excessive dissolution of the coagulant component, the image quality of the printed part and the overprinted part at a high printing rate is improved, and in order to obtain a printed matter with excellent adhesion etc., 100 g of water at 20 ° C. The solubility of the carboxylic acid calcium salt (B) in is preferably 1 to 35 g/100 g H ₂ O, particularly preferably 3 to 30 g/100 g H ₂ O.

The calcium carboxylate (B) used in the pretreatment liquid of the present invention may be either an anhydride or a hydrate. However, the above solubility shall use the value in an anhydride.

In addition to sufficiently causing aggregation and thickening of the ink, a printed matter having excellent image quality can be obtained, and the effects of the resin particles (A), such as adhesion and post-processing suitability, are not hindered. When C (mmol) is the millimole amount of calcium ions contained in 100 g of the treatment liquid, the C is 10 to 60 mmol, more preferably 15 to 50 mmol, particularly preferably 20 to 40 mmol.

From the viewpoint of achieving both the development of adhesion and post-processing suitability by the resin particles (A) and the improvement of image quality by the coagulant component, and the elimination of the trade-off between adhesion, image quality, and post-processing suitability, When the amount of resin particles (A) contained in 100 g of the pretreatment liquid (in terms of solid content) is R (g), R/C is 0.11 to 0.50, and 0.20 to 0.40. is more preferable.

Examples of carboxylic acid calcium salts (B) that can be used in the pretreatment liquid of the present invention include calcium formate, calcium acetate, calcium propionate, calcium butyrate, calcium benzoate, calcium lactate, calcium gluconate, calcium pantothenate, and malic acid. Calcium etc. are mentioned. For the reasons described above, among these, it is selected from the group consisting of calcium formate, calcium acetate, calcium propionate, calcium lactate, and calcium gluconate, which have a solubility in 100 g of water at 20° C. of 3 to 30 g/100 g H ₂ O. can be preferably used. Furthermore, for the same reason, it is preferable that all of the plurality of carboxylic acid calcium salts (B) present in the pretreatment liquid are selected from the above-described preferably usable carboxylic acid calcium salts.

In addition, as described above, the hydrogen bond formed by the calcium carboxylate salt (B) optimizes the viscoelasticity of the entire printed matter and improves the blocking resistance and suitability for lamination. ) may also vary depending on the amount of hydroxy groups contained therein. From this point of view, in the pretreatment liquid of the present invention, when the molar amount of hydroxy groups derived from the hydroxycarboxylic acid calcium salt (B-1) contained in 100 g of the pretreatment liquid is HB1 (mmol), the HB1 is 5. It is preferably up to 48 (mmol), more preferably 7 to 38 (mmol), and particularly preferably 9 to 28 (mmol).

The method for calculating HB1 will be described using a pretreatment liquid containing 3% by mass of calcium lactate as an example. Since the molecular weight of calcium lactate is 218.2 and the number of hydroxyl groups present in one molecule of calcium lactate is two (because two lactate ions are present in one molecule of calcium lactate), HB1 is {(3÷ 218.2)×2}×1000≈27.5 (mmol).

<Water>
The content of water contained in the pretreatment liquid of the present invention is preferably 40 to 90% by mass, more preferably 60 to 80% by mass, based on the total amount of the pretreatment liquid. Water can increase the mutual solubility of the materials essential to the pretreatment liquid of the present invention, such as the resin particles (A) and the calcium carboxylate (B), thereby improving the storage stability of the pretreatment liquid. It is an essential material for

<Surfactant>
The pretreatment liquid of the present invention preferably contains a surfactant from the viewpoint of uniform coating on an impermeable substrate. As the surfactant, siloxane-based, acetylenediol-based, acryl-based, polyoxyalkyl ether-based surfactants, etc. can be suitably used. In particular, it is preferable to use an acetylene diol-based surfactant and/or a siloxane-based surfactant from the viewpoint of not inhibiting the expression of the effects of the resin particles (A) and the calcium carboxylate (B).

Examples of acetylene diol surfactants include 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 2,5,8,11-tetramethyl-6-dodecyne-5,8- diol, hexadec-8-yn-7,10-diol, 6,9-dimethyl-tetradeca-7-yn-6,9-diol, 7,10-dimethylhexadec-8-yn-7,10-diol, and its ethylene oxide and/or propylene oxide adducts.

Examples of commercially available acetylenediol-based surfactants include Surfynol 61, 104E, 104H, 104A, 104BC, 104DPM, 104PA, 104PG-50, 420, 440, 465, and 485 manufactured by Nissin Chemical Industry Co., Ltd. , SE, SE-F, Dynol 604, 607, Olphine E1004, E1010, E1020, PD-001, PD-002W, PD-004, PD-005, EXP. 4001, EXP. 4200, EXP. 4123, EXP. 4300 (manufactured by Nissin Chemical Industry Co., Ltd.) and the like.

Examples of commercially available siloxane-based surfactants include BY16-201, FZ-77, FZ-2104, FZ-2110, FZ-2162, F-2123, L-7001, L-7002, SF8427, SF8428, and SH3749. 、ＳＨ８４００、８０３２ＡＤＤＩＴＩＶＥ、ＳＨ３７７３Ｍ（東レ・ダウコーニング社製）、ＴＥＧＯＧｌｉｄｅ４１０、ＴＥＧＯＧｌｉｄｅ４３２、ＴＥＧＯＧｌｉｄｅ４３５、ＴＥＧＯＧｌｉｄｅ４４０、ＴＥＧＯＧｌｉｄｅ４５０、ＴＥＧＯＴｗｉｎ４０００、ＴＥＧＯＴｗｉｎ４１００、ＴＥＧＯＷｅｔ２５０、ＴＥＧＯＷｅｔ２６０、ＴＥＧＯＷｅｔ２７０、ＴＥＧＯＷｅｔ２８０（エボニックデグサ社製）、ＳＡＧ－００２、ＳＡＧ－５０３Ａ (manufactured by Nissin Chemical Industry Co., Ltd.), BYK-331, BYK-333, BYK-345, BYK-346, BYK-347, BYK-348, BYK-349, BYK-UV3500, BYK-UV3510 (manufactured by BYK-Chemie), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-6004, KF-6011, KF-6012, KF-6013, KF-6015, KF-6016, KF-6017, KF- 6043, KF-615A, KF-640, KF-642, KF-643 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

The surfactants listed above may be used alone, or two or more of them may be used in combination.

The content of the surfactant in the pretreatment liquid of the present invention is preferably 0.01 to 10% by mass, more preferably 0.1 to 8% by mass, based on the total amount of the pretreatment liquid. 0.5 to 6 mass % is more preferable.

<Organic solvent>
The pretreatment liquid of the present invention may further contain an organic solvent. By using an organic solvent in combination, the solubility of the coagulant component and the surfactant, and the drying property and wet-spreading property of the pretreatment liquid can be adjusted to be suitable. In addition, in the pretreatment liquid of the present embodiment, only one type of organic solvent may be used, or two or more types may be used in combination.

The organic solvent that can be used is not particularly limited, but it preferably contains a water-soluble organic solvent. In the present application, the term "water-soluble organic solvent" refers to a solvent that is liquid at 25°C and has a solubility in water at 25°C of 1% by mass or more.

When the pretreatment liquid of the present embodiment contains an organic solvent, it has a high affinity with the resin particles, the coagulant component, and the surfactant, and from the viewpoint of improving the storage stability of the pretreatment liquid, a hydroxy group is added to the molecular structure. It is preferable to use a water-soluble organic solvent containing one or more of Water-soluble organic solvents containing one or more hydroxy groups in the molecular structure include water-soluble organic solvents containing one hydroxy group, such as monohydric alcohol solvents and glycol monoalkyl ether solvents; alkanediol solvents, polyalkylene glycols. water-soluble organic solvents having two hydroxy groups, such as system solvents; and water-soluble organic solvents having three or more hydroxy groups, such as glycerin, trimethylolpropane, butanetriol, hexanetriol, and diglycerin. Among these, it is more preferable to use a water-soluble organic solvent having one or two hydroxy groups in its molecular structure. It is particularly preferred to include

In addition, from the viewpoint that it can be uniformly applied to an impermeable substrate and that a printed matter with excellent adhesion and image quality can be obtained, a water-soluble organic polymer containing one or more hydroxy groups in the molecular structure As the solvent, it is preferable to select one having a boiling point of 75 to 200°C under 1 atm, more preferably 75 to 180°C, and more preferably 80 to 160°C. More preferred. The above-mentioned "boiling point under 1 atm" is a value measured by a conventionally known method such as differential thermal analysis (DTA) method or differential scanning calorimetry (DSC) method.

Furthermore, for the same reason as in the selection of the boiling point of the water-soluble organic solvent described above, when the pretreatment liquid contains two or more organic solvents, the weighted average value of the boiling points of those organic solvents under 1 atmosphere is , preferably 75 to 200°C, more preferably 75 to 180°C, even more preferably 80 to 160°C. The above-mentioned "weighted average value of boiling points" is a value obtained by adding up the multiplication values of the boiling point under 1 atmosphere and the mass ratio with respect to the total amount of the organic solvent for each organic solvent.

On the other hand, the pretreatment liquid of the present invention contains a plurality of carboxylic acid calcium salts (B) including hydroxycarboxylic acid calcium salt (B-1). Also, as described above, these carboxylic acid calcium salts (B) form hydrogen bonds. This hydrogen bond is preferable from the viewpoint of improving post-processing suitability such as blocking resistance and lamination suitability. is likely to have an adverse effect on If the drying property of the pretreatment liquid deteriorates, problems such as deterioration of image quality such as color mixture bleeding and color unevenness, and deterioration of adhesion to impermeable substrates may occur.

As described above, the pretreatment liquid of the present invention functions to inhibit excessive hydrogen bonding until the pretreatment liquid layer is formed by drying, and the formation of hydrogen bonds in the pretreatment liquid layer after drying. from the viewpoint of achieving compatibility between post-processing suitability and image quality and adhesion by making Water-soluble organic solvents having one hydroxy group (monohydric alcohol solvents, glycol monoalkyl ether solvents, etc.) are particularly preferably selected. Further, as a result of studies by the present inventors, from the viewpoint of optimizing the amount of hydrogen bonding, the molar amount of hydroxycarboxylic acid ions contained and the molar amount of water-soluble organic solvents having one hydroxy group in the molecular structure The ratio is preferably (molar content of hydroxycarboxylic acid ion/molar content of water-soluble organic solvent having one hydroxy group in its molecular structure)=0.08 to 0.4. 1 to 0.35 is particularly preferred.

The total content of the organic solvent in the pretreatment liquid is preferably 1 to 50% by mass, more preferably 2 to 40% by mass, more preferably 3 to 30% by mass, relative to the total amount of the pretreatment liquid. is particularly preferred. By setting the content of the organic solvent within the above range, it is possible to improve the affinity of the hydroxycarboxylic acid calcium salt (B-1) having a hydroxy group, and as a result, the storage stability of the pretreatment liquid and the printed matter. Improves image quality. In addition, regardless of the application method of the pretreatment liquid, it is possible to apply the pretreatment liquid stably and uniformly over a long period of time without causing printing defects.

<Other materials>
In addition to the materials described above, the pretreatment liquid of the present invention may optionally contain materials such as a pH adjuster, a coloring agent, a viscosity adjuster, and an antiseptic.

(pH adjuster)
For example, the pretreatment liquid of the present invention reduces damage to members included in a device (pretreatment liquid application device) used for applying the pretreatment liquid, and pretreatment by suppressing pH fluctuation over time. From the viewpoint of improving the storage stability of the liquid, a pH adjuster may be included. There is no limitation on materials that can be used as the pH adjuster, and only one type may be used, or two or more types may be used in combination.

For example, when the pretreatment liquid is basified, alkanolamines such as dimethylethanolamine, diethanolamine, triethanolamine and N-methyldiethanolamine; ammonia water; alkalis such as lithium hydroxide, sodium hydroxide and potassium hydroxide. Metal hydroxides; alkali metal carbonates such as lithium carbonate, sodium carbonate, sodium hydrogencarbonate and potassium carbonate, and the like can be used. In the case of acidification, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid and boric acid; carboxylic acids such as formic acid, acetic acid, propionic acid, lactic acid and gluconic acid can be used.

From the viewpoint of effectively expressing the effects described above, the amount of the pH adjuster is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, relative to the total amount of the pretreatment liquid. more preferred.

<Colorant>
The pretreatment liquid of the present invention preferably does not substantially contain coloring agents such as pigments and dyes. By using a pretreatment liquid that does not contain a coloring agent and is substantially transparent, it is possible to obtain a printed matter that takes advantage of the color and transparency that are unique to the base material. In the present application, "substantially free" means that intentional addition of the material is not permitted to the extent that the effect of the present invention is hindered. It does not exclude unintended contamination as a product. Specifically, the material should not be contained in an amount of 2.0% by mass or more, preferably 1.0% by mass or more, more preferably 0.5% by mass or more, based on the total amount of the pretreatment liquid. It should not be contained, and particularly preferably should not be contained in an amount of 0.1% by mass or more.

On the other hand, in another preferred embodiment, the pretreatment liquid contains a white pigment as a coloring agent. By using a white pretreatment liquid on a colored and/or transparent base material, it is possible to obtain a printed matter with particularly excellent sharpness and visibility and good image quality. When the pretreatment liquid contains a white pigment, a conventionally known material such as titanium oxide can be used as the white pigment.

<Physical properties of pretreatment liquid>
The pretreatment liquid of the present invention preferably has a viscosity at 25° C. of 5 to 200 mPa·s, more preferably 5 to 180 mPa·s, even more preferably 8 to 160 mPa·s. 140 mPa·s is particularly preferred. Since the pretreatment liquid satisfying the above viscosity range can be evenly applied to the impermeable base material, the printed matter is excellent in image quality, adhesion, anti-blocking property, and suitability for lamination. The viscosity of the pretreatment liquid can be determined according to the viscosity of the treatment liquid using, for example, an E-type viscometer (TVE25L viscometer manufactured by Toki Sangyo Co., Ltd.) or a B-type viscometer (TVB10 viscometer manufactured by Toki Sangyo Co., Ltd.). can be measured

In addition, the static surface tension of the pretreatment liquid of the present invention imparts suitable wetting and spreading properties on non-permeable substrates and forms a uniform and even pretreatment liquid layer, thereby improving image quality and adhesion. From the viewpoint of obtaining a printed matter excellent in durability, blocking resistance, and lamination suitability, it is preferably 20 to 40 mN/m, more preferably 21 to 37 mN/m, and 22 to 35 mN/m. is particularly preferred. The static surface tension in this specification can be measured in the same manner as the surface tension of the water-soluble organic solvent described above.

<Method for producing pretreatment liquid>
The pretreatment liquid of the present invention comprising the components described above includes, for example, the resin particles (A), the calcium carboxylate (B), and, if necessary, an organic solvent, a surfactant, a pH adjuster, and the like. It is manufactured by adding the listed materials, stirring and mixing, and filtering if necessary. However, the method for producing the pretreatment liquid is not limited to the above method. For example, when a white pigment is used as the colorant, a white pigment dispersion containing the white pigment and water may be prepared in advance and then mixed with the resin particles (A) and the calcium carboxylate (B). .
When stirring and mixing, the mixture may be heated in the range of 40 to 100° C., if necessary. At that time, it is preferable to heat at a temperature equal to or lower than the minimum film-forming temperature (MFT) of the resin particles (A).

<Water-based inkjet ink>
The pretreatment liquid of the present invention can be used in the form of an ink set in combination with one or more water-based inkjet inks. Preferably, the water-based inkjet ink contains a pigment, a water-soluble organic solvent, and water. Furthermore, it may contain a binder resin, a surfactant, and the like.

Pigments contained in water-based inkjet inks are excellent in color development and lightfastness, and C.I. I. Blue pigments such as Pigment Blue 15:3, 15:4;
C. I. Pigment Red 122, 150, 166, 185, 202, 209, 266, 269, 282, C.I. I. Red pigments such as Pigment Violet 19;
C. I. Yellow pigments such as Pigment Yellow 12, 13, 14, 74, 120, 180, 185, and 213;
black pigments such as carbon black;
White pigments such as titanium oxide;
etc. can be preferably used.

Further, the water-soluble organic solvent contained in the water-based inkjet ink includes a glycol monoalkyl ether solvent, an alkanediol solvent and/or a polyalkylene glycol solvent, from the viewpoint of improving compatibility and affinity with the pretreatment liquid. and is preferably contained.

At that time, when used in combination with the pretreatment liquid of the present invention, printed matter with excellent image quality can be obtained even in high-speed printing and/or overprinting, and the ejection stability is also excellent. From this point of view, the weighted average boiling point of the water-soluble organic solvent contained in the water-based inkjet ink under 1 atmosphere is preferably 145 to 215°C, more preferably 150 to 200°C, more preferably 155 to 190° C. is particularly preferred. In addition, from the viewpoint of obtaining printed matter with good blocking resistance and free from defects in image quality such as color mixture bleeding when combined with the pretreatment liquid, a water-soluble organic solvent having a boiling point of 220° C. or higher under 1 atm is used. The amount is preferably 5% by mass or less (may be 0% by mass), particularly preferably 2% by mass or less (may be 0% by mass), and 1% by mass or less (0% by mass) relative to the total amount of water-based ink. %) is particularly preferred.

Further, when the water-based inkjet ink contains a surfactant, it is preferable to use an acetylenediol-based surfactant. At that time, the amount of the surfactant added is preferably 0.01 to 5.0% by mass, more preferably 0.05 to 3.0% by mass, relative to the total amount of the water-based inkjet ink. . Specific examples of commercially available products that can be used as the acetylene diol-based surfactant are the same as those listed above that can be used for the pretreatment liquid.

<Manufacturing method of printed matter>
As a method for producing a printed matter by combining the pretreatment liquid of the present invention and the water-based inkjet ink, the pretreatment liquid is applied to a non-permeable substrate, and then the water-based inkjet ink is applied onto the non-permeable substrate. There is a way to print
Preferably, the water-based inkjet ink is printed on the portion of the impermeable substrate to which the pretreatment liquid has been applied by a one-pass inkjet printing method. Also preferably, after printing with the water-based inkjet ink, the printed matter is produced through a step of drying the pretreatment liquid and the impermeable substrate on which the water-based inkjet ink has been printed.

In the present application, the "one-pass inkjet printing method" refers to a method in which an inkjet head is scanned only once against a stationary substrate, or a substrate is passed through the bottom of a fixed inkjet head only once for printing. There is no re-printing of ink on top of the printed ink. However, when the inkjet head is scanned, it is necessary to adjust the ejection timing in consideration of the movement of the inkjet head, which tends to cause deviation of the landing position. Therefore, in the present invention, the method of passing the base material under the fixed inkjet head is preferably used.

Details of each step of the above-described printed matter manufacturing method will be described below.

<Method of Applying Pretreatment Liquid>
As a method of applying the pretreatment liquid to the impermeable substrate, there is a method of printing without contacting the substrate like inkjet printing, and a method of applying the pretreatment liquid to the substrate by contacting it. can be adopted. In addition, as a method of applying the pretreatment liquid, when selecting a method of coating by contacting the pretreatment liquid, offset gravure coater, gravure coater, doctor coater, bar coater, blade coater, flexo coater, roll coater, etc. format can be preferably used.

<Drying method after application of pretreatment liquid>
After applying the pretreatment liquid to the impermeable substrate, the impermeable substrate is dried, and the pretreatment liquid on the substrate is dried, and then the water-based inkjet ink may be printed. Water-based inkjet ink may be printed before the upper pretreatment liquid is completely dried. In one embodiment, it is preferable to completely dry the pretreatment liquid before printing the water-based inkjet ink, ie, the liquid component of the pretreatment liquid is substantially removed. By printing with water-based inkjet ink after the pretreatment liquid has completely dried, printed matter with excellent image quality, lamination suitability, and abrasion resistance can be produced without causing poor drying of the water-based inkjet ink that lands later. Because it can be obtained.

The method for drying the pretreatment liquid is not particularly limited, and conventionally known methods such as heat drying, hot air drying, infrared drying, microwave drying, and drum drying can be used. Although the above drying methods may be used alone or in combination, it is preferable to use a hot air drying method in order to reduce damage to the impermeable substrate and to dry efficiently. In addition, from the viewpoint of preventing damage to the substrate and bumping of the liquid component in the pretreatment liquid, when using the heat drying method, the drying temperature should be 35 to 100 ° C., and the hot air drying method should be used. In this case, it is preferable to set the hot air temperature to 50 to 150°C.

<Method for printing water-based inkjet ink>
The water-based inkjet ink is preferably printed on the portion of the impermeable substrate to which the pretreatment liquid has been applied by 1-pass inkjet printing. The design resolution of the inkjet head used in 1-pass inkjet printing is preferably 600 dpi (Dots Per Inch) or more, more preferably 720 dpi or more, from the viewpoint of obtaining an image with excellent image quality.

<Drying method after water-based inkjet ink printing>
After printing the water-based inkjet ink, it is preferable to include a step of drying the impermeable substrate printed with the water-based inkjet ink in order to dry the water-based inkjet ink and the undried pretreatment liquid. The drying method preferably used is the same as in the case of the pretreatment liquid.

<Applied amount of pretreatment liquid and water-based inkjet ink>
The ratio of the printing amount of the water-based inkjet ink to the application amount of the pretreatment liquid is preferably 0.1 or more and 10 or less. The above ratio is more preferably 0.5 or more and 9 or less, and particularly preferably 1 or more and 8 or less. By keeping the ratio between the two within the above range, a printed matter with excellent image quality can be obtained without causing a change in texture of the base material.

<Impermeable substrate>
The pretreatment liquid of the present invention can be suitably used for impermeable substrates. As the impermeable substrate, conventionally known substrates can be arbitrarily used, for example, polyvinyl chloride sheet, polyethylene terephthalate (PET) film, polypropylene film, polyethylene film, nylon film, polystyrene film, polyvinyl alcohol film. and a metal substrate such as aluminum foil. The substrates listed above may have smooth or uneven surfaces, and may be transparent, translucent, or opaque. Moreover, what laminated two or more types of these base materials mutually may be used. Furthermore, a release adhesive layer or the like may be provided on the opposite side of the printed surface, or an adhesive layer or the like may be provided on the printed surface after printing. Further, the shape of the base material when producing a printed matter using the pretreatment liquid of the present invention may be roll-like or sheet-like.

Among them, in order to fully exhibit the functions of the pretreatment liquid of the present invention, the impermeable substrate is preferably a thermoplastic resin substrate, and is preferably a PET film, a polypropylene film, a polyethylene film, or a nylon film. Especially preferred.

In addition, from the viewpoint of uniformly applying the pretreatment liquid of the present invention without unevenness and particularly improving adhesion, surface modification methods such as corona treatment and plasma treatment are applied to the non-permeable substrates exemplified above. is also preferred.

<Coating treatment>
The printed matter produced using the pretreatment liquid of the present invention can be coated on the printed surface, if necessary. Specific examples of the coating treatment include coating or printing of a coating composition, dry lamination method, solventless lamination method, extrusion lamination method, and the like. You can combine them.

In the case of applying a coating treatment to the printed material by coating and printing the coating composition, the coating or printing method may be a method of printing without contact with the substrate such as inkjet printing, or Either of the methods in which the coating composition is brought into contact with the coating may be adopted.

Further, when laminating printed matter, the adhesive used for laminating the sealant substrate is preferably composed of a mixture of a polyol component and a polyisocyanate component.

The above-mentioned polyol component is a resin component having a hydroxyl group, and polyurethane resins and polyester resins are preferably used in view of coatability, wet-spreadability and permeation to the printed matter interface, and laminate strength that develops after aging. Among them, the interface of the printed matter obtained using the pretreatment liquid of the present invention, such as the printed layer (printed area) and the pretreatment liquid layer (non-printed area), has good wettability and spreadability. The polyol component preferably contains a polyester polyol from the viewpoint of excellent lamination strength of the laminate). The polyol component may be a single component, or may be a combination of multiple components.

The polyisocyanate component reacts with the polyol component to form urethane bonds, thereby increasing the molecular weight of the adhesive layer and improving the laminate strength. Among them, from the viewpoint of compatibility with the polyol component, wet spreadability on the interface of the printed matter obtained using the pretreatment liquid of the present invention, and lamination strength of the laminated printed matter (laminate), the polyisocyanate component is used. , an isocyanate group-terminated polyether-based urethane resin. From the same point of view as above, the blending amount of the polyisocyanate component is preferably 50 to 80% by mass based on the polyol component. The above polyisocyanate component may be a single component, or may be a combination of multiple components.

Examples of sealant base materials used for lamination include polypropylene films and polyethylene films such as unstretched polypropylene (CPP) films and linear short-chain branched polyethylene (LLDPE) films. Also, a film having a metal (oxide) deposited layer such as aluminum oxide may be used.

Examples and comparative examples are given below to more specifically describe the method for producing a printed matter using the pretreatment liquid of the present invention and an ink set containing the pretreatment liquid and a water-based inkjet ink. In the following description, "parts" and "%" represent "mass parts" and "mass%", respectively, unless otherwise specified.

<Production example of pretreatment liquid 1>
The following materials were put into a mixing vessel equipped with a stirrer, mixed at room temperature (25° C.) for 1 hour, heated to 50° C., and further mixed for 1 hour. After that, the mixture was cooled to room temperature and then filtered through a nylon mesh with a pore size of 100 μm to obtain a pretreatment liquid 1. Details of the following materials will be described later.
・NeoCryl XK-190 16.7 parts ・Hitec E-6400 3.3 parts ・Calcium formate 3.0 parts ・Calcium lactate 2.0 parts ・2-Propanol 5.0 parts ・Surfinol 440 1.0 parts ・Proxel GXL 0.05 parts Ion-exchanged water 68.95 parts

<Production Examples of Pretreatment Liquids 2 to 67>
Pretreatment liquids 2 to 67 were produced in the same manner as pretreatment liquid 1, except that the materials listed in Table 1 were used.

The details of the product names and abbreviations shown in Table 1 are as follows.
・NeoCryl A-1127: (meth)acrylic resin particles manufactured by DSM Coating Resins, solid content 44%
・NeoCryl XK-188: (meth)acrylic resin particles manufactured by DSM Coating Resins, solid content 44.5%
・NeoCryl XK-190: (meth)acrylic resin particles manufactured by DSM Coating Resins, solid content 45%
・NeoRez R-600: Urethane (urea) resin particles manufactured by DSM Coating Resins, solid content 33%
・NeoRez R-9621: Urethane (urea) resin particles manufactured by DSM Coating Resins, solid content 38%
・ Super Flex 300: Urethane (urea) resin particles manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 30%
・ Super Flex 460: Urethane (urea) resin particles manufactured by Daiichi Kogyo Seiyaku Co., Ltd., solid content 38%
・WEM-3000: Taisei Fine Chemical urethane-(meth)acrylic resin particles, solid content 32.5%
・ Plus Coat Z-880: manufactured by GOO Chemical Industry Co., Ltd. (water-soluble polyester resin, solid content 25%)
・ Plus Coat Z-3310: manufactured by GOO Chemical Industry Co., Ltd. (water-soluble polyester resin, solid content 25%)
・ Hitec E-6400: polyolefin resin particles manufactured by Toho Chemical Co., Ltd., solid content 35%
・Arrow Base SB-1230N: Unitika polyolefin resin particles, solid content 25%
・IPA: isopropyl alcohol (monohydric alcohol solvent, boiling point under 1 atm = 83°C)
EtOH: Ethyl alcohol (monohydric alcohol solvent, boiling point under 1 atmosphere = 78°C)
- PGM: propylene glycol monomethyl ether (glycol monoalkyl ether solvent, boiling point under 1 atm = 121°C)
・ MB: 3-methoxybutanol (monohydric alcohol solvent, boiling point under 1 atmosphere = 150 ° C.)
1,2PD: 1,2-propanediol (alkanediol-based solvent, boiling point under 1 atm = 188°C)
1,3BD: 1,3-butanediol (alkanediol solvent, boiling point under 1 atm = 208°C)
・ SF104: Surfynol 104 (Acetylene diol-based surfactant manufactured by Nissin Chemical Industry Co., Ltd.)
・ SF440: Surfynol 440 (Acetylene diol-based surfactant manufactured by Nissin Chemical Industry Co., Ltd.)
・ SF485: Surfynol 485 (Acetylene diol-based surfactant manufactured by Nissin Chemical Industry Co., Ltd.)
· BYK349: BYK-Chemie siloxane-based surfactant · Proxel GXL: 1,2-benzisothiazol-3-one dipropylene glycol solution (solid content 20%, arch chemical preservative)

<Production of water-based inkjet ink>
<Production Example of Pigment Dispersion Resin 1>
A reaction vessel equipped with a gas inlet tube, a thermometer, a condenser and a stirrer was charged with 95 parts of butanol and purged with nitrogen gas. After heating the inside of the reaction vessel to 110 ° C., 45 parts of styrene, 30 parts of acrylic acid, 25 parts of lauryl methacrylate as polymerizable monomers, and V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator 6 A mixture of parts was added dropwise over 2 hours. After the completion of dropping, the inside of the reaction vessel was maintained at 110°C and the polymerization reaction was continued for 3 hours, then 0.6 part of V-601 was added and the polymerization reaction was further continued at 110°C for 1 hour. Then, after cooling the inside of the reaction vessel to room temperature (25° C.), dimethylaminoethanol was added to completely neutralize the acid groups in the reaction product, and then 100 parts of water was added. After that, the mixture containing the reaction product is heated to 100° C. or higher, butanol is azeotroped with water to distill off the butanol, and water is added to adjust the solid content to 30%, thereby obtaining a pigment. An aqueous solution of dispersion resin 1 (a solution containing an aqueous solvent and components dispersed and/or dissolved in the aqueous solvent) was obtained.
The theoretical acid value of Pigment Dispersion Resin 1 calculated by the FOX formula was 233.6 mgKOH/g.

<Production Example of Black Pigment Dispersion>
15 parts of carbon black (“PrinteX85” manufactured by Orion Engineered Carbons Co., Ltd.), 10 parts of the aqueous solution (solid content 30%) of the above pigment dispersion resin 1, 75 parts of water, and a stirrer Dumped into the provided mixing vessel and premixed for 1 hour. Thereafter, circulating dispersion was carried out using a Dyno Mill (manufactured by Shinmaru Enterprises, volume 0.6 L) filled with 1800 g of zirconia beads having a diameter of 0.5 mm to produce a black pigment dispersion.

<Production Examples of Cyan Pigment Dispersion, Magenta Pigment Dispersion, and Yellow Pigment Dispersion>
A cyan pigment dispersion, a magenta pigment dispersion, and a yellow pigment dispersion were obtained in the same manner as for the black pigment dispersion, except that the following pigments were used.
・ Cyan: LIONOL BLUE 7358G (C.I. Pigment Blue 15:3) manufactured by Toyocolor Co., Ltd.
・Magenta: A mixture of equal amounts of FASTGEN SUPER MAGENTA RG (C.I. Pigment Red 122) manufactured by DIC and Toshiki Red 150TR (C.I. Pigment Red 150) manufactured by Tokyo Shikizai Co., Ltd. ・Yellow: BASF Paliotol Yellow D 1155 (C.I. Pigment Yellow 185) manufactured by

<Production example of white pigment dispersion>
50 parts of titanium oxide (“Tipake CR-60” manufactured by Ishihara Sangyo Co., Ltd.), 20 parts of an aqueous solution of pigment dispersion resin 1 (30% solid content), and 30 parts of water, equipped with a stirrer It was put into a mixing container and premixed for 1 hour. Thereafter, circulating dispersion was performed using a Dyno Mill (manufactured by Shinmaru Enterprises, volume 0.6 L) filled with 1800 g of zirconia beads having a diameter of 0.5 mm to produce a white pigment dispersion.

<Production Example of Black Ink 1 (K1)>
33.3 parts of a black pigment dispersion, 13.4 parts of an aqueous solution of a binder resin 28 (30% solid content) produced by the method described in the example of JP-A-2020-180178, 1, 20 parts of 2-propanediol, 4 parts of propylene glycol monomethyl ether, 1.5 parts of TEGO Wet 280 (polyether-modified siloxane surfactant manufactured by Evonik), and Surfynol 465 (manufactured by Nissin Chemical Industry Co., Ltd. 1 part of acetylenic diol-based surfactant) was successively added to a mixing vessel, water was added so that the total amount added was 100 parts, and the mixture was stirred with a stirrer until sufficiently uniform. After that, filtration was performed with a membrane filter having a pore size of 1 μm to remove coarse particles that cause head clogging, and black ink 1 (K1) was prepared.

<Production Example of Cyan Ink 1 (C1), Magenta Ink 1 (M1), Yellow Ink 1 (Y1), and White Ink 1 (W1)>
Cyan ink 1 (C1), Cyan ink 1 (C1), Magenta ink 1 (M1), yellow ink 1 (Y1), and white ink 1 (W1) were obtained. A set of K1, C1, M1, Y1, and W1 was used as inkjet ink set 1 for the following evaluations.

<Preparation example of film substrate to which pretreatment liquid is applied>
Using a non-wire bar coater 250-OSP-02 manufactured by OSG System Products Co., Ltd., the pretreatment liquid prepared above was applied to the following film substrate so that the wet film thickness was 2.0 ± 0.2 μm. The coated film substrate was placed in an air oven at 70° C. and dried for 2 minutes to prepare a film substrate to which the pretreatment liquid was applied.

(Film substrate used for evaluation)
・ OPP: Biaxially oriented polypropylene film “OPU-1” manufactured by Mitsui Chemicals Tohcello (thickness 20 μm)
・ PET: Futamura polyethylene terephthalate film “FE2001” (thickness 12 μm)

<Printed Matter Production Example 1>
Four inkjet heads "KJ4B-1200" (manufactured by Kyocera Corporation, design resolution 1,200 dpi) are installed on the upper part of the conveyor that can transport the substrate, and white ink 1 is excluded from the water-based inkjet ink set 1 manufactured above. Four colors were filled in the order of K1, C1, M1, and Y1 from the inkjet head installed on the upstream side with respect to the conveying direction of the base material. Next, after fixing the film substrate to which the pretreatment liquid was applied, which was produced above, on a conveyor, the conveyor was driven at a constant speed. After that, when the film substrate passed through the installation portion of the inkjet head, each ink was ejected with a drop volume of 2 pL to print an image. Then, immediately after printing, the printed material was placed on an experimental hot plate preheated to 70±1° C. and dried for 3 minutes to prepare a 4C printed material.

As an image of 4C printed matter, a 5 cm × 10 cm solid patch with a print rate of 100% is an image adjacent in the order of CMYK (hereinafter referred to as a "solid patch image"), and a total print rate (total print rate of each color ) is continuously changed from 40 to 320% (hereinafter referred to as a “gradation image”. Note that the printing rate of each color is the same for each total printing rate). We prepared and produced each print.

<Production example 2 of printed matter>
Four inkjet heads "KJ4B-1200" (manufactured by Kyocera Corporation, design resolution 1,200 dpi) are installed on the upper part of the conveyor that can transport the substrate, and white ink 1 is excluded from the water-based inkjet ink set 1 manufactured above. Four colors were filled in the order of K1, C1, M1, and Y1 from the inkjet head installed on the upstream side with respect to the conveying direction of the base material. Next, after fixing the film substrate to which the pretreatment liquid was applied, which was produced above, on a conveyor, the conveyor was driven at a constant speed. After that, when the film substrate passed through the installation portion of the inkjet head, each ink was ejected with a drop volume of 2 pL to print an image. Then, immediately after printing, the printed material was placed on an experimental hot plate preheated to 70±1° C. and dried for 3 minutes to prepare a printed material.
Next, the ink (K1) filled in the inkjet head located on the most upstream side with respect to the transport direction was replaced with white ink 1. After that, the dried printed material was again fixed on the conveyor, and the conveyor was driven at a constant speed. Then, when the printed material passed under the installation portion of the inkjet head, the white ink 1 was ejected with a drop volume of 2 pL only from the inkjet head on the most upstream side, and a solid image with a coverage of 100% was printed. At this time, a solid image was printed so as to completely overlap the printed material. Then, immediately after printing, the printed material was placed on an experimental hot plate preheated to 70±1° C. and dried for 3 minutes to prepare a 5C printed material.

In Printed Material Production Example 2, a solid patch image (hereinafter referred to as a 5C printed material made using the solid patch image) is used as an image of a printed material produced using four colors of ink, K1, C1, M1, and Y1. JIS X 9201 high-definition color digital standard image data (CMYK / SCID) natural image N1 (portrait) (Hereinafter, 5C printed matter created using the natural image N1 is referred to as "5C port and, for each color, an image printed with characters consisting of 4-point MS Mincho typeface, in which hiragana and kanji are mixed (hereinafter, 5C printed matter made using the character image is referred to as "5C (referred to as "character image"); were prepared, and printed matter was produced for each.

[Examples 1 to 51, Comparative Examples 1 to 16]
Each of the pretreatment liquids produced above was combined with inkjet ink set 1 to produce a printed matter. Using this printed matter, the following evaluations were carried out. The evaluation results were as shown in Table 2.

<Evaluation 1: Evaluation of mixed color bleeding>
Based on the above method, a gradation image was printed on the OPP film substrate under the conditions of conveyor drive speeds of 25 m/min, 50 m/min, and 75 m/min. Then, the dot shape of the gradation image printed matter was observed with an optical microscope at a magnification of 200 to evaluate color mixture bleeding. The evaluation criteria were as follows, and ⊚, ◯, and Δ were regarded as practically usable.
◎: Printed matter printed at 75 m / min, no coalescence of dots or uneven dot shape was observed ○: Coalescence of dots or uneven dot shape in printed matter printed at 75 m / min Δ: Coalescence between dots and non-uniformity in dot shape were observed in prints printed at 50 m/min, but not in prints printed at 50 m/min. Not seen in prints printed at 25 m/min. ×: Coalescence between dots and uneven dot shape were observed in prints printed at 25 m/min.

<Evaluation 2: Evaluation of solid filling>
Based on the method described above, solid patch images were printed on OPP film substrates at conveyor drive speed conditions of 25 m/min, 50 m/min, and 75 m/min. Then, after laminating a white backing paper to the non-printing surface of the solid patch printed matter, the solid filling was evaluated by visually observing the degree of white voids. The evaluation criteria were as follows, and ⊚, ◯, and Δ were regarded as practically usable.
◎: White spots were not seen in the printed matter printed at 75 m / min ○: White spots were seen in the printed matter printed at 75 m / min, but not seen in the printed matter printed at 50 m / min △: White spots were seen in the printed matter printed at 50 m/min, but were not seen in the printed matter printed at 25 m/min. ×: White spots were seen in the printed matter printed at 25 m/min.

<Evaluation 3: Evaluation of character reproducibility>
Based on the above method, a 5C character image was printed on the OPP film under the conveyor driving speed condition of 50 m/min. Character reproducibility was evaluated by visually observing the character shape of the 5C character image printed matter. The evaluation criteria are as follows, and ⊚, ◯, and Δ are considered practically usable.
◎: In addition to being able to recognize characters in all colors, character images were reproduced as expected without fading, thickening, or crushing of characters. ○: Recognizing characters in all colors, but some characters. Slightly faint characters, thick characters, crushed characters, etc. were observed in the image. △: Although all colors could be recognized as characters, part of the character image clearly showed faint characters, thick characters, and characters. Collapsed, etc. were observed ×: There were characters that were difficult to read

<Evaluation 4: Evaluation of superimposed image quality>
Based on the above method, 5C portrait images were printed on OPP film under the conditions of conveyor drive speeds of 25 m/min, 50 m/min, and 75 m/min. Then, from the non-printed side of the 5C portrait image print, observe at 200x using an optical microscope, and comprehensively judge the degree of white voids, the degree of dot shape, and the presence or absence of color mixture. Image quality was evaluated. The evaluation results are as follows, and ⊚, ◯, and Δ are considered practically usable.
⊚: Neither white spots nor irregular dot shapes were observed in the printed matter printed at 75 m/min, and no color mixture was observed.
○: One or more of white spots, irregular dot shape, and color mixture was observed in the printed matter printed at 75 m / min. No color mixing was observed.
Δ: At least one of white spots, irregular dot shape, and color mixture was observed in the printed matter printed at 50 m/min, but both white spots and irregular dot shape were observed in the printed matter printed at 25 m/min. No color mixing was observed.
x: At least one of white spots, irregular dot shape, and color mixture was observed in printed matter printed at 25 m/min.

<Evaluation 5: Evaluation of adhesion>
Based on the above method, a 5C solid patch image was printed on the OPP film under the conveyor driving speed condition of 50 m/min. Next, cellophane tape (18 mm wide) manufactured by Nichiban Co., Ltd. was firmly attached to four locations on the printed surface of the 5C solid patch image print so that solid patches of each color were included. Then, by holding the end of the cellophane tape and instantly peeling it off while maintaining an angle of 60 degrees, and visually checking the surface of the printed matter after peeling off the cellophane tape and the adhesive surface of the cellophane tape, Adhesion was evaluated. The evaluation criteria were as follows, and ⊚, ◯, and Δ were regarded as practically usable. The evaluation results shown in Table 2 are for the color with the worst evaluation among the four colors evaluated.
◎: The area of the peeled portion relative to the area of the portion to which the cellophane tape was pasted was less than 5% ○: The area of the peeled portion to the area of the portion to which the cellophane tape was pasted was 5% or more and less than 10% △: The area of the peeled portion relative to the area of the portion to which the cellophane tape was pasted was 10% or more and less than 20% ×: The area of the peeled portion to the area of the portion to which the cellophane tape was pasted was 20% or more. there were

<Evaluation 6: Evaluation of blocking resistance>
Based on the method described above, a solid patch image was printed on the OPP film under the condition of a conveyor drive speed of 50 m/min. A 4 cm×4 cm square was cut out from the solid patch image printed matter with 1 printed portion of black ink. After that, the printed surface of the cut out black ink 1 and the non-printed surface (film back surface) of the same film used for printing were superimposed as a test piece, and a constant load type permanent strain tester (Tester Sangyosha (manufactured) was used to conduct a blocking test. The environmental conditions for the blocking test were a load of 10 kg/cm2, a temperature of 40°C, a humidity of 80% RH, and a standing time of 24 hours. The blocking resistance was evaluated by visually checking the printed surface after peeling. The evaluation criteria are as follows, and evaluations of ⊚, ∘, and Δ are possible for practical use.
A: There was no peeling of the printed surface of the film laminated later, and there was no peeling resistance. ○: There was no peeling of the printed surface of the film laminated later, but there was a slight resistance when peeling. △: The print surface of the film superimposed later was less than 30% of the total area of the superimposition ×: The print surface of the film superimposed later was taken over the entire superimposed area was over 30%

<Evaluation 7: Evaluation of lamination strength (adhesive strength)>
Based on the method described above, a solid patch image was printed on the OPP film under the condition of a conveyor drive speed of 50 m/min. Next, using a solvent-free test coater, a solvent-free laminating adhesive ("EA-N373A/B" manufactured by Toyo-Morton Co., Ltd.) was applied to the printed surface of the obtained solid patch print at a temperature of 60°C and a coating speed of 50 m/min. (coating amount: 2 g/m2). After that, the corona-treated surface of CPP (unstretched polypropylene film "FHK2" (thickness 25 μm) manufactured by Futamura Chemical Co., Ltd.) was superimposed on the coated surface of the laminate adhesive, and then subjected to 1 hour at 40 ° C. and 80% RH. The solvent-free lamination adhesive was cured by aging for 2 days to produce a laminated product. Then, the black ink 1 printed part of the obtained laminated product was cut into a test piece having a length of 100 mm and a width of 15 mm. and measured the T-type peel strength (N). This test was performed 5 times, and the average value was calculated as the adhesive strength (laminate strength) to evaluate the laminate strength. The evaluation criteria are as follows, and ⊚, ◯, and Δ evaluations are considered practically usable.
◎: Lamination strength was 1.5 N or more ○: Lamination strength was 1.0 N or more and less than 1.5 N △: Lamination strength was 0.5 N or more and less than 1.0 N ×: Lamination strength was 0 was less than .5N

As a result of the evaluation, resin particles (A) and a plurality of carboxylic acid calcium salts (B) including hydroxycarboxylic acid calcium salts as flocculant components were included, and millimolar amounts of calcium ions (C), and the C and In Examples 1 to 51, in which the pretreatment liquid that satisfies the regulation regarding the ratio to the amount (R) of the resin particles (A) was used, all evaluated items had practically usable quality. I was able to confirm that there is.

On the other hand, in Comparative Example 1, since the amount of calcium ions was too small relative to the amount of resin particles (A), the cross-linking of the solid components in the ink was insufficient, resulting in poor blocking resistance. On the other hand, in Comparative Example 2, since the amount of calcium ions is excessive, the speed of aggregation and thickening of the ink to be printed later is too high, and the droplets of the ink do not wet and spread, causing the ink droplets to become solid. The result was poor character reproducibility. Moreover, it was confirmed that the effect of the resin particles (A) was inhibited by an excessive amount of calcium ions, resulting in deterioration of adhesion.
In Comparative Examples 3 and 4, since the calcium salt of hydroxycarboxylic acid (B-1) was not contained, recrystallization during drying could not be completely suppressed, resulting in deterioration of the overlapping image quality. In Comparative Examples 5 to 7, since a plurality of carboxylic acid calcium salts (B) were not included, a trade-off was observed between mixed color bleeding and solid filling, as well as blocking resistance and lamination suitability. Furthermore, Comparative Example 8 is an example in which magnesium salt was used instead of calcium salt, resulting in poor character reproducibility and superimposed image quality. This is probably because the diffusion of the magnesium salt into the landed ink was slow, and the aggregation speed of the ink droplets was slowed down.

Comparative Example 9 is a system in which the amount of the resin particles (A) is too small relative to the amount of calcium ions, and deterioration in adhesion to the substrate was confirmed. On the contrary, in Comparative Example 10, the amount of the resin particles (A) was excessive, and deterioration of color mixture bleeding occurred, which is considered to be caused by the delay in diffusion of the coagulant component into the ink. Moreover, as in Comparative Example 1, the solid content in the ink was insufficiently crosslinked, resulting in poor blocking resistance.
In Comparative Example 11, the content of calcium ions was excessive, and the aggregation speed of the ink was too high, so that the droplets of the ink did not spread sufficiently, resulting in poor filling property. On the contrary, in Comparative Example 12, the content of calcium ions was insufficient, and the aggregation speed of the ink was low, resulting in poor color bleeding, character reproducibility, and overlapping image quality.

Comparative Examples 13 to 16 reproduce the examples described in Patent Documents 1 to 4 mentioned above. Comparative Example 13 reproduces Example 72 of Patent Document 1, and Comparative Example 14 reproduces Example 75 of Patent Document 2, respectively. was insufficient. Both examples are considered to be due to the excessive content of calcium ions relative to the resin particles (A). On the other hand, Comparative Example 15 is a reproduction of Example 2 of Patent Document 3, but does not contain calcium hydroxycarboxylic acid salt (B-1) and contains only one type of calcium carboxylic acid salt, Character reproducibility and superimposed image quality deteriorated due to a lack of the coagulant component, and in addition, blocking resistance deteriorated due to insufficient cross-linking of the solid content in the ink, and adhesion also deteriorated. deterioration was also confirmed. In addition, Comparative Example 16 is a reproduction of Example 2 of Patent Document 4, and since it does not contain the resin particles (A), the pretreatment liquid layer does not adhere to the substrate, and furthermore, it has anti-blocking properties. Deterioration in the properties and lamination aptitude was also observed.

Claims (5)

A pretreatment liquid for use with a water-based inkjet ink containing a pigment, a water-soluble organic solvent, and water,
The pretreatment liquid contains resin particles (A), a plurality of calcium carboxylates (B), and water,
at least one of the plurality of carboxylic acid calcium salts (B) is a hydroxycarboxylic acid calcium salt (B-1),
When the amount of the resin particles (A) contained in 100 g of the pretreatment liquid is R (g), and the millimol amount of calcium ions contained in 100 g of the pretreatment liquid is C (mmol), the C is 10. 60 mmol, and the ratio of the value of R to the value of C (R/C) is 0.11 to 0.50. 2. The pretreatment liquid according to claim ₁ , wherein the solubility in water at 20.degree. Further containing a water-soluble organic solvent (C) having one hydroxy group in the molecular structure,
The ratio of the molar amount of hydroxycarboxylic acid ions contained in the pretreatment liquid to the molar amount of the water-soluble organic solvent (C) having one hydroxy group in the molecular structure is 0.08 to 0. 3. The pretreatment liquid according to claim 1 or 2, which is .4. An ink set comprising the pretreatment liquid according to any one of claims 1 to 3 and a water-based inkjet ink containing a pigment, a water-soluble organic solvent, and water. 4. A printed matter obtained by printing a water-based inkjet ink containing a pigment, a water-soluble organic solvent, and water on a substrate to which the pretreatment liquid according to any one of claims 1 to 3 is applied.