JP2017110185A - Ink set and recording method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink set showing excellent abrasion resistance when an aggregating liquid and an ink composition are adhered to a recording medium.SOLUTION: The ink set includes an ink composition containing a resin and an ink composition containing wax, or an ink composition containing a resin and wax; and the ink set also includes an aggregating liquid containing an aggregating agent capable of aggregating a component of the above ink composition(s). The above resin and wax include such a resin and a wax that aggregability of the resin is greater than aggregability of the wax.SELECTED DRAWING: None

Description

  The present invention relates to an ink set and a recording method.

  The ink jet recording method is capable of recording high-definition images with a relatively simple device, and has been rapidly developed in various fields. Among them, various studies have been made on obtaining a more stable and high-quality recorded matter.

  For example, Patent Document 1 discloses a water-soluble ink for the purpose of providing an ink, an ink-jet recording method, and a recorded matter in which a coloring material is not scraped even when a recording portion is rubbed when an image is formed by a two-component system. Water-soluble ink used together with a reaction liquid containing a reactive component that causes the ink to aggregate or gel by reacting with water, and the water-soluble ink is at least hydrophilic, different from water, water-soluble organic solvents and pigments An ink comprising two or more water-soluble polymer compounds, wherein at least one of the polymer compounds has a coagulation value of twice or more as compared with other polymer compounds and further has a film-forming property. Inkjet recording methods and recorded matter are disclosed.

JP 2006-160850 A

  When the reaction liquid and the ink composition disclosed in Patent Document 1 are attached to a recording medium to form a recorded material, the abrasion resistance may not be sufficient. That is, the “coagulation value” described in Patent Document 1 is for determining the cohesiveness after mixing the reaction liquid and the polymer and leaving it for 60 minutes, and the reaction liquid and the ink composition are in contact with each other. Thus, it is different from the reactivity within the reaction time required for immobilization. Further, since the “aggregation value” is also affected by the structure, particle size, etc. of the particles after the reaction, the correlation between the “aggregation value” and the reactivity is low. Therefore, even if this “aggregation value” is set to be twice or more, it is difficult to ensure a higher level of abrasion resistance. Also, in the ejection head that ejects the inkjet composition, moisture in the ink composition volatilizes, and among the water-soluble polymer compounds contained in the ink composition, those having higher hydrophobicity are likely to be dissolved or formed into a film. Due to this, the discharge head may be clogged.

  Accordingly, the present invention has been made to solve at least a part of the above-described problems, and is excellent in abrasion resistance when an image is improved by attaching an aggregating liquid and an ink composition to a recording medium. An object is to provide an ink set.

  As a result of intensive studies to solve the above problems, the present inventors have one or two or more ink compositions containing a resin and a wax in the same or different ink composition, and an aggregate liquid, By using an ink set in which the cohesiveness of the resin is larger than the cohesiveness of the wax, the present invention has been found to have excellent abrasion resistance when the aggregated liquid and the ink composition are attached to a recording medium to improve the image quality. Completed the invention. Furthermore, the present invention was completed by finding out that it was excellent in abrasion resistance and glossiness.

  That is, the present invention relates to an aggregation liquid containing one or more ink compositions containing a resin and a wax in the same or different ink compositions, and an aggregating agent capable of aggregating the ink compositions. And the cohesiveness of the resin is larger than the cohesiveness of the wax. The reason why such an ink set can solve the problems of the present invention is considered as follows. However, the factor is not limited to this. That is, the resin has a larger cohesiveness than the wax, and after the aggregation liquid and the ink composition (hereinafter referred to as “ink composition etc.”) adhere to the recording medium, the resin in the adhering ink composition etc. The resin and the aggregating agent in the aggregating liquid aggregate and settle to the recording medium side. The sedimented agglomerated component improves the bonding strength between the coating film and the recording medium by the ink composition in the recorded material, so that the recorded material has excellent abrasion resistance. On the other hand, the wax is less cohesive than the resin, and after the ink composition or the like is attached to the recording medium, the wax is present on the surface side of the attached ink composition or the like (the side opposite to the recording medium side). . Due to the fact that the wax present on the surface side forms a uniform film on the surface side of the ink composition or the like, the recorded matter is excellent in abrasion resistance and glossiness. In addition, a relatively small amount of wax is also present on the recording medium side such as the adhered ink composition, and as a result, aggregation and sedimentation including the wax occurs, resulting in the coating of the ink composition and the recording medium. The binding force is improved as compared with the case of resin alone. On the other hand, due to the presence of a relatively small amount of resin on the surface side of the attached ink composition or the like, film forming properties of the ink composition or the like are further enhanced.

In addition, the ink set of the present invention includes one or more ink compositions selected from the group consisting of a colored ink composition further containing a color material and a clear ink composition substantially free of a color material. Preferably, the colored ink composition and the clear ink composition, the colored ink composition contains the resin, and the clear ink composition more preferably contains the wax. It is more preferable that at least the colored ink composition is included, and the colorant in the colored ink composition contains one or more pigments selected from the group consisting of self-dispersed pigments and resin-dispersed pigments. The resin is preferably two or more resins having different cohesiveness, and the resin and the wax are represented by the following relational expression (1):
0.1 mL ≦ (W−J) ≦ 3.0 mL (1)
(In the formula, J represents the required amount of resin aggregation (mL), and W represents the required amount of wax aggregation (mL).)
Preferably, the flocculant is one or more selected from the group consisting of organic acids, polyvalent metal salts, and cationic compounds, and the ink composition is used in an ink jet system. The ink composition preferably contains the resin and the wax independently in an amount of 0.5% by mass or more and 15% by mass or less in terms of solid content based on the total amount of the ink composition.

  In addition, the recording method of the present invention includes an ink composition adhesion step for adhering the ink composition contained in the ink set to a recording medium, and the aggregation liquid adhesion for adhering the aggregation liquid to the recording medium. The ink composition is preferably a colored ink composition and a clear ink composition, and the ink composition deposition step is preferably a step of depositing on a wet on wet basis. In the ink set of the present invention, it is preferable that the cohesiveness as a weighted average of the resin contained in the ink composition is larger than the cohesiveness as the weighted average of the wax contained in the ink composition.

1 is a side view showing an outline of an example of an inkjet recording apparatus that can be used in the present embodiment.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as “the present embodiment”) will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to this, and the gist thereof is described below. Various modifications are possible without departing from the scope. In the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, positional relationships such as up, down, left and right are based on the positional relationships shown in the drawings unless otherwise specified. Further, the dimensional ratios in the drawings are not limited to the illustrated ratios.

[Ink set]
The ink set of the present embodiment includes one or more ink compositions containing a resin and a wax in the same or different ink compositions, and a flocculant capable of aggregating the ink compositions. A coagulating liquid. Moreover, the cohesiveness of the resin is greater than the cohesiveness of the wax. The ink set of the present embodiment is excellent in glossiness and image quality (betamula) in addition to abrasion resistance when an aggregating liquid and an ink composition are adhered to a recording medium.

[Ink composition]
The ink set of the present embodiment has one or more ink compositions, and the same one ink composition may contain a resin and a wax. The ink composition may contain a resin, and another type of ink composition may contain a wax. The ink composition may contain a colorant, a surfactant, a solvent, water, and other components as necessary. The ink composition is preferably a water-based ink composition in which a resin is dispersed in water. By using such an ink composition, there is a tendency that the abrasion resistance of the obtained recorded matter is further improved.

  In the present embodiment, the ink set preferably has one or two or more ink compositions selected from the group consisting of a colored ink composition and a clear ink composition. Here, an ink composition further containing a color material is referred to as a “colored ink composition”, and an ink composition that substantially does not contain a color material is referred to as a “clear ink composition”. Here, “substantially does not contain” means that the content of the color material is 0.10% by mass or less with respect to the total amount (100% by mass) of the ink composition. Hereinafter, when the colored ink composition and the clear ink composition are not distinguished, they are simply referred to as “ink composition”. The clear ink of the present embodiment is not used for coloring the recording medium but is used for the quality of the recorded material such as abrasion resistance and glossiness, and may contain a coloring material. The content of the color material is preferably 0.1% by mass or less, and more preferably 0.05% by mass or less.

The ink set preferably includes a colored ink composition and a clear ink composition, the colored ink composition contains a resin, and the clear ink composition preferably contains a wax.
Accordingly, the resin to be agglomerated and settled tends to settle to the recording medium side by attaching the colored ink composition first and then the clear ink composition to the recording medium, and the ink composition The wax tends to exist more easily on the surface side.

<Resin, wax>
The ink composition of this embodiment contains a resin and a wax. Here, when the ink composition is heated on the recording medium, a film can be formed by containing the resin. In addition, when the ink composition is heated when the ink composition is heated on a recording medium, a film cannot be formed by the inclusion of the wax. Whether or not the film can be formed is not particularly limited, but its molecular weight, melting point or glass transition temperature can be used as an index. For example, the resin has a molecular weight of 10,000 or more, preferably 30,000 or more, and more preferably about tens of thousands of weight average molecular weight. The upper limit is preferably 100,000 or less. On the other hand, the wax has a molecular weight of less than 10,000, and preferably has a weight average molecular weight of about 8,000 or less, more preferably 6,000 or less, and even more preferably 4,000 or less. The lower limit is preferably 1,000 or more. As a method for distinguishing between the resin and the wax, the above molecular weight may be used.
Here, the “resin” is a substance made of a natural or synthesized polymer, preferably made of a synthesized polymer, and showing plasticity under a certain state. The “wax” refers to an ester wax, a paraffin wax, an olefin wax, or a mixture of a higher fatty acid and a higher monohydric alcohol or dihydric alcohol (preferably monohydric alcohol).

  In this embodiment, the cohesiveness of the resin is greater than the cohesiveness of the wax. Here, the “aggregability” is an index indicating the aggregability with the aggregating agent contained in the aggregating liquid, and the minimum resin or wax necessary for causing aggregation and precipitation with the aggregating agent in the solvent. Measured as added amount. The smaller the amount added (hereinafter also referred to as “aggregation requirement (mL)”), the greater the aggregation property.

  When the resin or wax is one type or two or more types, the weighted average may be calculated based on the content thereof, and the above-mentioned aggregation required amount (mL) of each resin or wax may be obtained. The agglomeration property as a weighted average of all the resins contained in the ink is shown. It is preferable that this is larger than the cohesiveness as a weighted average of all the waxes contained in the same or different inks from the viewpoint that the effect of this embodiment is particularly excellent. The weighted average is a required amount of aggregation obtained by weighting and averaging the mass of each resin with respect to the total mass of all resins contained in the same or different ink composition. The same applies to the wax.

  Specifically, the cohesiveness is measured by the method described in Examples described later. Specifically, an aqueous medium liquid (aqueous solution or aqueous dispersion) having a resin or wax content of 0.5 mass% is prepared. Alternatively, if the other components contained in the ink do not interfere with the confirmation of the cohesiveness of the resin or wax, the ink composition containing the resin or wax should be washed with water so that the resin or wax content becomes the above value. A sample liquid of a diluted ink composition may be prepared. 0.1 mL of 0.1M calcium acetate aqueous solution is dropped into 3.0 mL of these, and it is determined whether or not aggregation and sedimentation occur within 30 seconds. After that, until the aggregation sedimentation occurs within 30 seconds, repeat the determination of dropping in the same amount of 0.1 mL (increase in increments of 0.1 mL as the total amount dropped), and determine the minimum amount of droplets where aggregation sedimentation occurred. The required amount of aggregation (mL) was used as an index of aggregation. The greater the cohesiveness resin or wax, the smaller the required coagulation amount (mL), and the smaller the cohesiveness resin or wax, the greater the cohesive requirement (mL). Whether or not coagulation sedimentation has occurred is confirmed visually. Here, 0.1M calcium acetate aqueous solution is used for confirmation of the cohesiveness, and calcium acetate is known to have a function of well aggregating the components of the ink composition as an aggregating agent which is a polyvalent metal salt. It is also easy to obtain and is used as an indicator of the cohesiveness of the resin and wax. In this embodiment, the cohesiveness is an index indicating the magnitude relationship between the cohesiveness of the resin and the wax. On the other hand, the aggregating agent used as the aggregating liquid of the present embodiment is not limited to calcium acetate, and may be any one described later. If the aggregating agent to be used is described later and the aggregating liquid is an aggregating liquid described later, the cohesiveness relationship between the resin and the wax tends to be the same, and the effects of this embodiment can be achieved.

  In the ink composition, the cohesiveness of the resin is greater than the cohesiveness of the wax, so that when the aggregating liquid and the ink composition are adhered to the recording medium, the resin is excellent in abrasion resistance and glossiness, and the image quality. It is also excellent in (suppression of bethamra). This factor is guessed as follows. However, the factor is not limited to this. That is, the resin of the present embodiment has a larger cohesiveness than wax, and after the ink composition or the like adheres to the recording medium, the resin and the aggregating agent in the aggregating liquid in the attached ink composition or the like. Aggregate and settle to the recording medium side. Due to the fact that the precipitated agglomerated components are fused and united with each other, the strength of the coating film is improved, and the bonding force between the coating film and the recording medium by the ink composition in the recorded matter is improved. As a result, the recorded matter has excellent abrasion resistance. On the other hand, the wax of the present embodiment has less cohesiveness than the resin, and after the ink composition or the like has adhered to the recording medium, the surface side of the adhered ink composition or the like (the side opposite to the recording medium side) ) Is higher. Due to the fact that the wax present on the surface side is present at a relatively high concentration on the surface side of the ink composition or the like, the recorded matter is excellent in abrasion resistance and glossiness. In addition, a relatively small amount of wax is also present on the recording medium side such as the adhered ink composition, and as a result, coagulation and sedimentation including the wax occurs. As a result, phase separation in the coating film is suppressed, and coating is performed. The film strength is improved. Further, the bonding force between the coating film of the ink composition and the recording medium is improved as compared with the case of using only the resin. On the other hand, due to the presence of a relatively small amount of resin on the surface side of the attached ink composition or the like, film forming properties of the ink composition or the like are further enhanced. The amount of aggregation of the resin and wax is not limited independently, but is preferably 0.1 to 3.0 mL, more preferably 0.2 to 1.0 mL, and still more preferably 0.3-0.6 mL.

  The term “betamura” means that when the ink is applied so that the entire ground of the recording medium is covered with the ink in the area where the ink is attached, the density of the ink is uneven in the area.

  The resin and the wax may be contained in the same or different ink composition, but two or more kinds of resins and / or two or more kinds of waxes may be used. In the ink composition of the present embodiment, among resins and waxes contained in the same or different ink composition, any one of the resins and any one of the waxes has a relationship that the resin is more cohesive than the wax. Any relationship that can be satisfied is sufficient (Relationship 1). Two or more resins and / or waxes that satisfy the relationship 1 may be included.

  The resin and the wax may be included in the same or different ink composition, and one type of resin and wax satisfying the above relationship 1 may be included, but in addition, those that do not satisfy the relationship 1 are also included. You can leave. Preferably, in any one of a resin and a wax contained in the same or different ink composition, a resin capable of satisfying the relation 1 is 50% by mass or more of a total mass of all resins contained in the same or different ink composition The wax capable of satisfying the relation 1 is 50% by mass or more of the total mass of all the waxes included in the same or different ink composition.

The resin and wax preferably satisfy the following relational expression (1) from the viewpoint of further improving the abrasion resistance, glossiness and film-forming property.
0.1 mL ≦ (W−J) ≦ 3.0 mL (1)
In the formula, J represents the necessary amount of resin aggregation (mL), and W represents the required amount of wax aggregation (mL). That is, the formula (1) is a difference in the cohesiveness between the resin and the wax.

From the viewpoint of further improving the abrasion resistance, glossiness and film forming property, (WJ) in formula (1) is more preferably 0.1 mL or more and 1.0 mL or less, and further preferably 0.1 mL or more and 0. .5 mL or less.
It is also preferable that the difference in the amount of aggregation required as a weighted average of the above-mentioned resin or wax satisfies the above relationship.

  The resins are preferably two or more resins having different cohesive properties. As a result, the resin that tends to coagulate and settle tends to settle on the recording medium side, the resin that is relatively difficult to coagulate and settle thereafter, and then the recording medium side such as the adhered ink composition in the order of wax. A layer is formed from the surface to the surface side, and it is preferable because it has excellent abrasion resistance due to the high bonding force between the layers. More preferably, the difference between the aggregation requirement of one type of resin and the aggregation requirement of another type of resin is 0.1 mL or more. One type of ink composition may contain the two or more types of resins, and each of the two or more types of ink compositions may contain at least one of the two or more types of resins. Good. The above difference is not limited, but 0.5 mL or less is preferable. When two or more kinds of wax are included, it is also preferable that the difference between the required amount of aggregation of one type of wax and the required amount of aggregation of another type of wax is within the above range.

  The case where each of the two or more ink compositions contains at least one of the two or more kinds of resins is not particularly limited, but the cohesiveness of the resin contained in the colored ink composition is not limited to the clear ink composition. It is preferable that it is larger than the cohesiveness of the resin contained in the product. Thereby, the resin that tends to aggregate and settle in the colored ink composition is more likely to settle on the recording medium side by attaching the colored ink composition first and then the clear ink composition to the recording medium. Then, a layer can be formed from the recording medium side to the surface side of the adhered ink composition in the order of the resin, which is relatively hard to coagulate and settle in the clear ink composition, and then the wax, and is resistant to damage. It is preferable because it is more excellent in rubbing properties.

Although it does not specifically limit as resin, For example, (meth) acrylic-type resin, urethane type resin, polyether-type resin, and polyester-type resin are mentioned. Among these, the resin is preferably a (meth) acrylic resin.
On the other hand, the wax is preferably a polyolefin resin and a paraffin resin. The resin and wax are preferably in the form of fine particles. In particular, the resin and the wax are preferably included in the form of an emulsion. Examples of the resin fine particles include polyester resin fine particles (for example, product name “Vylonal MD-1500” manufactured by Toyobo Co., Ltd.), polyethylene resin fine particles (for example, product name “Zyxen A” manufactured by Sumitomo Seika Co., Ltd.), urethane. Resin fine particles (for example, product name “Rezamin D4200” manufactured by Dainichi Seika Kogyo Co., Ltd.). By including such resin fine particles, the amount of the aggregating liquid used can be reduced, and stickiness of the recording surface, stickiness and bleeding can be further suppressed. Resin and wax are used individually by 1 type or in combination of 2 or more types, respectively. Hereinafter, examples of each resin and wax will be described.

  Examples of the (meth) acrylic resin include an acrylic resin emulsion. Although it does not specifically limit as an acrylic resin emulsion, For example, what polymerized (meth) acrylic-type monomers, such as (meth) acrylic acid and (meth) acrylic acid ester, and (meth) acrylic-type monomer And other monomers are copolymerized. These commercially available products are not particularly limited. For example, mobile vinyl 966A, 972, 8055A (trade names manufactured by Nippon Synthetic Chemical Industry Co., Ltd.), Microgel E-1002, Microgel E -5002 (above trade name, manufactured by Nippon Paint Co., Ltd), Boncourt 4001, Boncourt 5454 (above trade name, manufactured by DIC), SAE1014 (trade name, manufactured by Zeon Corporation) Cybinol SK-200 (trade name, manufactured by SAIDEN CHEMICAL INDUSTRY CO., LTD.), Jongkrill 7100, Jongkrill 390, Jongkrill 711, Jongkrill 511, Jongkrill 7001, Jongkrill 632, John Krill 741, John Krill 450, John Krill 840, John Krill 62J, Jo Nkrill 74J, Johnkrill HRC-1645J, Johnkrill 734, Johnkrill 852, Johnkrill 7600, Johnkrill 775, Johnkrill 537J, Johnkrill 1535, Johnkrill PDX-7630A, Johnkrill 352J, Johnkrill 352D, Johnkrill PDX -7145, Jonkrill 538J, Jonkrill 7640, Jonkrill 7641, Jonkrill 631, Jonkrill 790, Jonkrill 780, Jonkrill 7610 (above trade name, manufactured by BASF), and NK binder R-5HN (Shin Nakamura Chemical) Company name, solid content 44%). In the present specification, “(meth) acryl” is a concept including both “methacryl” and “acryl”.

  Among these, the resin is preferably at least one selected from the group consisting of a (meth) acrylic resin and a styrene- (meth) acrylic acid copolymer resin, and an acrylic resin and a styrene-acrylic acid copolymer system. At least one selected from the group consisting of resins is more preferable, and styrene-acrylic acid copolymer resins are more preferable. In addition, said copolymer may be any form among a random copolymer, a block copolymer, an alternating copolymer, and a graft copolymer. As the wax, at least one selected from polyolefin resins and paraffin resins is more preferable, and polyolefin resins are more preferable.

  An example of the urethane resin is a urethane resin emulsion. The urethane resin emulsion is not particularly limited as long as it is a resin emulsion having a urethane bond in the molecule. For example, a polyether type urethane resin having an ether bond in the main chain, a polyester type urethane resin having an ester bond in the main chain, And a polycarbonate type urethane resin containing a carbonate bond in the main chain. Although it does not specifically limit as a commercial item of the said urethane resin emulsion, For example, Sancure 2710 (The brand name made from The Lubrizol Corporation), Permarin UA-150 (Sanyo Chemical Industries, Ltd.) .) Product name), Superflex 460, 470, 610, 700, 860 (the product name manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), NeoRez R-9660, R- 9637, R-940 (above, trade name made by Kusumoto Chemicals, Ltd.), Adeka Bon titer HUX-380, 290K (above, trade name made by Adeka), Takerak (registered trademark) W -605, W-635, WS-6021 (trade name of Mitsui Chemicals, Inc.) and polyether (Taisei Fine Chemicals Co., Ltd.) (TAISEI FINECHEMICAL CO, .LTD) trade name, Tg = 20 ° C.).

  The polyolefin wax is not particularly limited. For example, Chemipearl S120, S650, S75N (product names manufactured by Mitsui Chemicals), and AQUACER501, AQUACER506, AQUACER513, AQUACER515, AQUACER526, AQUACER593, and AQUACER582 (manufactured by AQUACER582) Can be mentioned.

  Although it does not specifically limit as a paraffin type wax, For example, AQUACER497, AQUACER539, (the product name by BYK) is mentioned.

The polyester resin is not particularly limited, and examples thereof include polybutylene terephthalate, polytrimethylene terephthalate, polyethylene terephthalate, polyethylene naphthalate, copolymers thereof, and fine particles thereof. A sulfopolyester resin (polysulfoester resin) substituted with a sulfo group (sulfonic acid group) can also be preferably used as the polyester resin.
The polyether resin may be any resin having a polyether skeleton.

  The resin or wax preferably has a functional group selected from the group consisting of a carboxyl group, a sulfonic acid group, an amino group, and salts thereof. Among these, it is preferable that resin and wax have a carboxyl group or its base. By using such a resin or wax, the dispersion stability of the resin or wax tends to be further improved. In particular, since the resin or wax has a carboxyl group or its base, the cohesiveness between the resin or wax and the flocculant can be ensured, and the resulting printed matter tends to be more restrained from the sticky lines and the ruled line balls. It is in. Furthermore, from the viewpoint of improving dispersion stability, resins having an anionic functional group are preferable as the resin and the wax.

The cohesiveness of resins and waxes, for example, tends to increase as the number of functional groups per unit mass of the resin or wax increases, and the cohesiveness can be increased by designing the resin or wax by controlling the number of functional groups. Can be adjusted. In this case, from the tendency that the acid value of the resin or wax increases as the number of the functional groups increases, the higher the acid value of the resin or wax, the higher the aggregation property.
In addition, when the resin or wax is in the form of fine particles such as an emulsion and an emulsifier used to disperse the resin or wax is used, the greater the content of the emulsifier relative to the unit mass of the resin or wax, the lower the cohesiveness. Therefore, the cohesiveness can be adjusted depending on the presence / absence and content of the emulsifier.

  Thus, the cohesiveness of the resin or wax may be designed, confirmed by the above-described coagulability confirmation method, fed back, redesigned, and adjusted to achieve the target cohesiveness.

  The glass transition point (Tg) of the resin is preferably −35 ° C. or higher, more preferably 0 ° C. or higher, still more preferably 20 ° C. or higher, still more preferably 35 ° C. or higher, and even more preferably. Is 40 ° C. or higher. The glass transition point of the resin is preferably 70 ° C or lower, more preferably 60 ° C or lower. Tg can be changed, for example, by changing at least one of the type and composition ratio of monomers used for polymerization of the resin and wax, polymerization conditions, and modification of the resin. For example, the glass transition point can be adjusted by reducing the number of polymerizable functional groups, reducing the crosslinking density of the resin, or using a monomer having a relatively large molecular weight (a monomer having a large number of carbon atoms). . Examples of the polymerization conditions include the temperature during polymerization, the type of medium containing the monomer, the monomer concentration in the medium, and the types and amounts of polymerization initiators and catalysts used during the polymerization. The glass transition point of the resin can be measured by a differential scanning calorimetry method (DSC method) based on JIS K7121.

  The melting point of the wax is preferably 50 ° C. or higher and 200 ° C. from the viewpoint of suppressing the performance of the wax from being excessively melted by heating in the ink composition adhering step of the recording method described later and drying after that step. It is 70 degreeC or less, More preferably, it is 70 degreeC or more and 180 degrees C or less, More preferably, it is 90 degreeC or more and 180 degrees C or less.

  The ink composition preferably contains the resin and the wax independently from 0.5% by mass to 15% by mass in terms of solid content with respect to the total amount (100% by mass) of the ink composition. When the resin content is within the above range, the abrasion resistance tends to be further improved, and when the wax content is within the above range, a film in the ink composition can be formed more uniformly, and The rub and gloss tend to be further improved.

The content of the resin and the wax is independently preferably from 0.7% by mass to 10% by mass, more preferably from 0.7% by mass to 10% by mass, in terms of solid content, with respect to the total amount (100% by mass) of the ink composition. It is 1.0 mass% or more and 5.0 mass% or less. Furthermore, the resin is particularly preferably 2.0% by mass or more, and the wax is particularly preferably 2.0% by mass or less.
Further, it is more preferable that the contents of the resin and the wax capable of satisfying the above relationship 1 are independently in the above range with respect to the total amount (100% by mass) of the ink composition.

<Color material>
A pigment can be used as the color material. Although it does not specifically limit as a pigment, For example, the following are mentioned.

  The carbon black used for the black ink is not particularly limited. 2300, no. 900, MCF88, No. 33, no. 40, no. 45, no. 52, MA7, MA8, MA100, no. 2200B, etc. (Mitsubishi Chemical Corporation), Raven 5750, Raven 5250, Raven 5000, Raven 3500, Raven 1255, Raven 700, etc. (above, Columbia Carbon, Carbon 1 Rubbi 400, Carbon Co. Rega1 330R, Rega1 660R, Mogul L, Monarch 700, Monarch 800, Monarch 880, Monarch 900, Monarch 1000, Monarch 1100, Monarch 1300, Monarch 1400, etc. (Cabot Corp. CA Kol. , Color B lack FW2, Color Black FW2V, Color Black FW18, Color Black FW200, Color B1ack S150, Color Black S160, Color Black S170, Printex 35, Printex U, Printex V, Printex 140U, Special Black 6, Special Black 5, Special Black 4A , Special Black 4 (manufactured by Degussa).

  Although it does not specifically limit as a pigment used for white ink, For example, C.I. I. Pigment white 6, 18, 21, titanium oxide, zinc oxide, zinc sulfide, antimony oxide, zirconium oxide, white hollow resin particles and polymer particles.

  Although it does not specifically limit as a pigment used for yellow ink, For example, C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 16, 17, 24, 34, 35, 37, 53, 55, 65, 73, 74, 75, 81, 83, 93, 94, 95, 97, 98, 99, 108, 109, 110, 113, 114, 117, 120, 124, 128, 129, 133, 138, 139, 147, 151, 153, 154, 167, 172, 180.

  Although it does not specifically limit as a pigment used for a magenta ink, For example, C.I. I. Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 40, 41, 42, 48: 2, 48: 5, 57: 1, 88, 112, 114, 122, 123, 144, 146, 149, 150, 166, 168, 170, 171, 175, 176, 177, 178, 179, 184, 185, 187, 202, 209, 219, 224, 245, or C.I. I. Pigment violet 19, 23, 32, 33, 36, 38, 43, 50.

  Although it does not specifically limit as a pigment used for cyan ink, For example, C.I. I. Pigment Blue 1, 2, 3, 15, 15: 1, 15: 2, 15: 3, 15:34, 15: 4, 16, 18, 22, 25, 60, 65, 66, C.I. I. Bat Blue 4, 60.

  The pigments other than those described above are not particularly limited. I. Pigment green 7,10, C.I. I. Pigment brown 3, 5, 25, 26, C.I. I. Pigment orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63.

  In an ink set having at least a colored ink composition, it is preferable that the coloring material in the colored ink composition contains one or more pigments selected from the group consisting of self-dispersed pigments and resin-dispersed pigments. As a result, the color material tends to be excellent in gloss due to being uniformly dispersed in the recorded matter.

  Further, the pigment of the present embodiment may be a self-dispersing pigment and / or a polymer dispersing pigment.

The self-dispersing pigment is a pigment having a hydrophilic group on its surface. As the hydrophilic group, -OM, -COOM, -CO -, - SO 3 M, -SO 2 M, -SO 2 NH 2, -RSO 2 M, -PO 3 HM, -PO 3 M 2, -SO 2 It is preferably at least one hydrophilic group selected from the group consisting of NHCOR, —NH ₃ , and —NR ₃ .

  In these chemical formulas, M represents a hydrogen atom, an alkali metal, ammonium, an optionally substituted phenyl group, or organic ammonium, and R represents an alkyl group having 1 to 12 carbon atoms or a substituted group. A naphthyl group which may have a group is represented. The above M and R are selected independently of each other.

  Specifically, the self-dispersing pigment is produced by subjecting the pigment to physical treatment and / or chemical treatment to bond (graft) the hydrophilic group to the surface of the pigment. Specific examples of the physical treatment include vacuum plasma treatment. Further, as the chemical treatment, specifically, a wet oxidation method in which oxidation is performed with an oxidizing agent in water, a method in which p-aminobenzoic acid is bonded to the pigment surface to bond a carboxyl group via a phenyl group, and the like can be mentioned. It is done.

  The polymer-dispersed pigment is a pigment that can be dispersed in a liquid by a polymer. The polymer content relative to the pigment can be expressed as the coverage of the polymer that coats the pigment. The polymer coverage is preferably 1.0% to 50%, more preferably 1.0% to 10%, and still more preferably 1.0% to 5.0%. When the coverage is 1.0% or more, the dispersibility tends to be good. Further, when the coverage is 50% or less, the color developability tends to be further improved, and when it is 5.0% or less, the color developability tends to be even better. is there.

70 mass% or more of the said polymer is preferable in it being a polymer by copolymerization of styrene, (meth) acrylate, and (meth) acrylic acid among the structural components. Thereby, it tends to be further excellent in the fixing property and glossiness of the ink. More preferably, at least one of the alkyl (meth) acrylate having 1 to 24 carbon atoms and the cyclic alkyl (meth) acrylate having 3 to 24 carbon atoms is polymerized from a monomer component of 50% by mass or more. Specifically, as the monomer component, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl ( (Meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, lauryl (meth) acrylate, isobornyl (meth) acrylate Cetyl (meth) acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, tetramethylpiperidyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dis Ropenteniru (meth) acrylate, dicyclopentenyloxy (meth) acrylate, and behenyl (meth) acrylate. In addition, as other monomer components for polymerization, hydroxy (meth) acrylate having a hydroxyl group such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, diethylene glycol (meth) acrylate, urethane (meth) acrylate, epoxy (meth) ) Acrylate and the like. In the present specification, “(meth) acrylate” is a concept including both “methacrylate” and “acrylate”.

  In the colored ink composition, the content of the coloring material is preferably 0.2% by mass or more and 10% by mass or less, more preferably 0.5% by mass or more, with respect to the total amount (100% by mass) of the ink composition. It is 7.5 mass% or less, More preferably, it is 1.0 mass% or more and 7.5 mass% or less. When the content of the color material is within the above range, the color developability tends to be further improved.

  The clear ink composition contains substantially no color material. In the clear ink composition, the content of the color material is 0.10% by mass or less and preferably 0.05% by mass or less from the viewpoint of glossiness. Moreover, the lower limit of content is not specifically limited, It may be less than a detection limit value.

<Surfactant>
The ink composition preferably contains a surfactant from the viewpoint of glossiness. The surfactant is not particularly limited, and examples thereof include acetylene glycol surfactants, fluorine surfactants, and silicone surfactants.

  The acetylene glycol surfactant is not particularly limited, but 2,4,7,9-tetramethyl-5-decyne-4,7-diol and 2,4,7,9-tetramethyl-5-decyne- One selected from alkylene oxide adducts of 4,7-diol and alkylene oxide adducts of 2,4-dimethyl-5-decyn-4-ol and 2,4-dimethyl-5-decyn-4-ol The above is preferable. Although it does not specifically limit as a commercial item of an acetylene glycol type surfactant, For example, E series (A product made by Air Products Japan (Inc)) (air products Japan, Inc. brand name), such as Olfine (registered trademark) 104 series and Olfine E1010, Surfynol (registered trademark) 104, 465, 61, DF110D (trade name manufactured by Nissin Chemical Industry CO., Ltd.). One acetylene glycol surfactant may be used alone, or two or more acetylene glycol surfactants may be used in combination.

  Although it does not specifically limit as a fluorine-type surfactant, For example, perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl phosphate ester, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl betaine, and A perfluoroalkylamine oxide compound is mentioned. Although it does not specifically limit as a commercial item of a fluorochemical surfactant, For example, S-144, S-145 (Asahi Glass Co., Ltd. product); FC-170C, FC-430, Fluorard-FC4430 (Sumitomo 3M Co., Ltd. product) FSO, FSO-100, FSN, FSN-100, FS-300 (manufactured by Dupont); FT-250, 251 (manufactured by Neos). A fluorine-type surfactant may be used individually by 1 type, and may use 2 or more types together.

  Although it does not specifically limit as a silicone type surfactant, For example, a polysiloxane type compound and a polyether modified organosiloxane are mentioned. Although it does not specifically limit as a commercial item of a silicone type surfactant, Specifically, BYK-306, BYK-307, BYK-333, BYK-341, BYK-345, BYK-346, BYK-347, BYK -348, BYK-349 (above trade name, manufactured by Big Chemie), KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF- 642, KF-643, KF-6020, X-22-4515, KF-6011, KF-6012, KF-6015, KF-6017 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. A silicone type surfactant may be used individually by 1 type and may use 2 or more types together.

  The surfactant content is preferably 0.05% by mass to 2.5% by mass and more preferably 0.1% by mass to 1.5% by mass with respect to the total amount (100% by mass) of the ink composition. It is below mass%. When the content of the surfactant is within the above range, the wettability of the ink composition attached to the recording medium tends to be further improved.

<Solvent>
The ink composition may contain a solvent. Although it does not specifically limit as a solvent, For example, an organic solvent or water can be used.

  The organic solvent is not particularly limited. For example, hydrocarbon solvents such as toluene, hexane, cyclohexane, benzene, octane and isooctane; ester solvents such as ethyl acetate, butyl acetate and γ-butyrolactone; acetone, methyl ethyl ketone and methyl Ketone solvents such as isobutyl ketone and cyclohexanone; alcohol solvents such as methanol, ethanol, propanol, isopropanol, butanol, propylene glycol and 1,3-butanediol; halogen solvents such as dichloroethane and chloroform, diethyl ether, tetrahydrofuran and the like Ether solvents: N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, 2-pyrrolidone, N-methyl ε- caprolactam, hexamethylphosphoramide and the like amide solvent, glycerin, triethylene glycol, triethylene glycol monobutyl ether, and a water-soluble organic solvent.

  The content of the organic solvent is preferably 0.1% by mass or more and 90% by mass or less, and more preferably 1.0% by mass or more and 50% by mass or less, with respect to the total amount (100% by mass) of the ink composition. . When the content of the organic solvent is within the above range, the wettability of the ink composition attached to the recording medium tends to be further improved.

  Examples of water include water from which ionic impurities have been removed as much as possible, such as pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, and distilled water, and ultrapure water. In addition, when water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is used, generation of mold and bacteria can be prevented when the aggregated liquid is stored for a long period of time. This tends to improve the storage stability.

  The ink composition and the aggregating liquid of the present embodiment are preferably an aqueous composition containing water as one of the main solvent components from the viewpoint of environmental friendliness and the effect of the present embodiment being particularly excellent. The content of water is preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 60% by mass or more with respect to the total mass of the composition (aggregated liquid). The upper limit of the water content is preferably 98% by mass or less.

  The ink composition includes, as other components, a dissolution aid, a viscosity modifier, a pH adjuster, an antioxidant, an antiseptic, an antifungal agent, a corrosion inhibitor, and a chelate for capturing metal ions that affect dispersion. Various additives such as an agent (for example, sodium ethylenediaminetetraacetate) can be appropriately contained.

  The ink composition is preferably used in an inkjet method described later from the viewpoint of more effectively and reliably achieving the effects of the present invention. For example, in the ink composition attaching step in the recording method described later, the ink composition can be used for attaching to a recording medium by an ink jet method.

[Aggregating liquid]
The aggregating liquid of this embodiment contains an aggregating agent capable of aggregating the ink composition described above. Specifically, it includes an aggregating agent capable of aggregating the ink composition by aggregating the components contained in the ink composition described above. The aggregating agent in the aggregating liquid interacts with the ink composition, thereby aggregating components contained in the ink composition and thickening or insolubilizing the ink composition. Thereby, landing interference and bleeding of the ink composition to be subsequently attached can be prevented, and lines, fine images, and the like can be drawn uniformly. The component aggregated by the coagulant contained in the ink composition is at least one or both of a resin and a wax, but may be a component that also aggregates other components. Examples of other components include coloring materials. Aggregating the components contained in the ink composition described above also means aggregating by reacting with the components contained in the ink composition, and the aggregate liquid is also referred to as a reaction liquid.

<Flocculant>
The flocculant is not particularly limited, but is preferably one or more selected from the group consisting of organic acids, polyvalent metal salts, and cationic compounds. Thereby, it is in the tendency for a bethamra and a bleed to be suppressed more. Among the components contained in the ink composition, examples of the component that aggregates with the flocculant include the above-described pigment, resin, and wax.

  The organic acid is not particularly limited, but is preferably a carboxylic acid, and examples thereof include maleic acid, acetic acid, phosphoric acid, oxalic acid, malonic acid, and citric acid. Of these, monovalent or divalent or higher carboxylic acids are preferred. By including such a carboxylic acid, the aggregation effect of the resin fine particles is further improved, and as a result, the color developability tends to be more excellent. In addition, an organic acid may be used individually by 1 type, and may use 2 or more types together.

  The polyvalent metal salt is not particularly limited, but a polyvalent metal salt of an inorganic acid or a polyvalent metal salt of an organic acid is preferable from the viewpoint of more effectively and reliably achieving the effects of the present invention. Such a polyvalent metal salt is not particularly limited, but examples thereof include alkaline earth metals belonging to Group 2 of the periodic table (eg, magnesium, calcium), and transition metals belonging to Group 3 of the periodic table (eg, lanthanum). And salts of earth metals from group 13 of the periodic table (eg, aluminum) and lanthanides (eg, neodymium). Moreover, as a salt of these polyvalent metals, carboxylate (for example, formic acid, acetic acid, benzoate), sulfate, nitrate, chloride, and thiocyanate are suitable. Among them, as polyvalent metal salts, calcium salts or magnesium salts of carboxylic acids (formic acid, acetic acid, benzoates, etc.), calcium salts or magnesium salts of sulfuric acid, calcium salts or magnesium salts of nitric acid, calcium chloride, magnesium chloride, And one or more selected from the group consisting of calcium salts or magnesium salts of thiocyanate are preferred. In addition, a polyvalent metal salt may be used individually by 1 type, and may use 2 or more types together.

Although it does not specifically limit as a cationic compound, For example, a cationic polymer, a cationic surfactant, and a water-soluble metal compound are mentioned. From the viewpoint of more effectively and reliably achieving the effects of the present invention, examples of the cationic polymer include polyethyleneimine, polydiallylamine, polyallylamine, alkylamine polymer, JP-A-59-20696, 59-33176, and 59. 33177, 59-155508, 60-11389, 60-49990, 60-83882, 60-109894, 62-198493, 63-49478, 63-115780 No. 63-280681, JP-A-1-40371, JP-A-6-234268, JP-A-7-125411, JP-A-10-19376, etc. The polymer having is preferably used. From the same viewpoint, the weight average molecular weight of these cationic polymers is preferably 5000 or more, more preferably about 5000 to 100,000. The weight average molecular weight of the cationic polymer is measured by gel permeation chromatography using polystyrene as a standard substance.
Examples of the cationic surfactant include salts of compounds having a cationic group, such as quaternary ammonium salts and sulfonates.

The content of the flocculant is preferably 1.0% by mass or more and 20% by mass or less, more preferably 2.0% by mass or more and 17.5% by mass or less, with respect to the total amount (100% by mass) of the aggregation liquid. 0.0 mass% or more and 15 mass% or less is more preferable, and 5.0 mass% or more and 10.0 mass% or less is especially preferable.
The content of the flocculant is preferably 0.1 to 1 mol / L, more preferably 0.2 to 0.9 mol / L with respect to the total amount (1 L (liter)) of the flocculant, and 0.3 to 0.8 mol / L is more preferable. Mol / L as a unit is also described as M.
When the content of the flocculant is within the above range, betalam and bleed tend to be further suppressed.

  The aggregation liquid used in the present embodiment may contain the same surfactant, organic solvent, and water as those used in the ink composition described above. In addition, the agglomerated liquid captures, as other components, dissolution aids, viscosity modifiers, pH adjusters, antioxidants, preservatives, antifungal agents, corrosion inhibitors, and metal ions that affect dispersion. Various additives such as chelating agents can be appropriately added.

〔Recording method〕
The recording method of the present embodiment includes an ink composition attaching step for attaching the ink composition of the ink set of the present embodiment to a recording medium. Further, the ink composition may further include an aggregation liquid adhesion step for adhering the aggregation liquid to the recording medium, and the ink composition may be a colored ink composition or a clear ink composition.

[Aggregating liquid adhesion process]
The aggregation liquid attaching step is a step of attaching the aggregation liquid to the recording medium. The means for attaching the aggregating liquid is not particularly limited, and for example, roller coating, spray coating, or an ink jet method can be used. Among these, it is preferable to make it adhere by an inkjet system. By adhering the aggregating liquid by an ink jet method, there is a tendency that the surface quality change of the media is suppressed and the wet friction resistance is further improved.

The adhesion amount of the flocculant to the recording medium is preferably 0.01 mg / inch ² or more and 1.0 mg / inch ² or less, more preferably 0.01 mg / inch ² or more and 0.50 mg / inch in terms of solid content. ² or less, more preferably 0.01 mg / inch ² or more and 0.2 mg / inch ² or less. When the amount of adhesion is within the above range, the resulting printed matter tends to be more suppressed from the sticky lines and the ruled line balls.

  The time interval from the end of the aggregation liquid adhesion process to the start of the ink composition adhesion process is preferably 60 seconds or less, more preferably 0.10 seconds or more and 60 seconds or less, and even more preferably 0.10 seconds or more. It is 30 seconds or less, and particularly preferably 0.10 seconds or more and 10 seconds or less. Since the time interval from the end of the aggregate liquid adhesion process to the start of the ink composition adhesion process is 60 seconds or less, the reaction efficiency between the aggregate liquid and the ink composition is further improved, and the image quality of the obtained recorded matter is further improved. It tends to improve. In particular, when the film thickness of the coating film of the ink composition is small, it is preferable that the time interval is short.

[Ink composition adhesion process]
The ink composition attaching step is a step of attaching the ink composition to the recording medium, and can be performed simultaneously with or before or after the above-described flocculant attaching step, but is preferably performed after the flocculant attaching step. . The means for attaching the ink composition is not particularly limited, and for example, roller coating, spray coating, and an ink jet method can be used. Among these, it is preferable to make it adhere by an inkjet system. By adhering the ink composition by an ink jet method, there is a tendency that the surface quality change of the media is suppressed and the wet friction resistance is further improved.

  The ink composition attaching step is preferably a step of attaching by wet on wet. Here, “attaching by wet-on-wet” is a step of attaching two or more ink compositions, and two or more ink compositions are simultaneously attached to a recording medium or the ink composition first attached. In the state where 60% by mass or more of the volatile component contained in the product remains on the recording medium, the next ink composition is further adhered, or within 30 seconds after the first ink composition is adhered. In the state where the surface temperature of the ink is 38 ° C. or lower, at least one of the following ink compositions starts to be adhered. By using wet-on-wet adhesion, when using an ink set in which the ink composition containing the resin and the ink composition containing the wax are different, the two or more kinds of adhered ink compositions are uniformly mixed. As a result, the abrasion resistance tends to be further improved.

  The film thickness of the dried film after drying the recording area to which the ink composition and the aggregating liquid are adhered is preferably 0.10 to 3.0 μm, more preferably 0.10 to 2.0 μm, More preferably, it is 0.10 to 1.0 μm. When the film thickness of the dry film is 0.10 μm or more, the resulting printed matter tends to be further suppressed from being sticky and ruled lines. Moreover, when the film thickness of the dry film is 3.0 μm or less, the change in glossiness of the obtained recorded product tends to be further suppressed. Here, the “recording area” refers to an area where an image on the surface of the recording medium is formed. Note that the ruled line ball has a shape in which the outline of the ruled line is connected to the ball when the ruled line is recorded.

The adhesion amounts of the resin and the wax to the recording medium are each preferably 0.01 mg / inch ² or more and 1.0 mg / inch ² or less, more preferably 0.01 mg, in terms of solid content. / inch ² or more 0.75 mg / inch ² or less, more preferably 0.02 mg / inch ² or more 0.6 mg / inch ² or less, still more preferably 0,05Mg / inch ² or more 0.5 mg / inch ² or less. When the adhesion amount is 0.01 mg / inch ² or more, the resulting printed matter tends to be more suppressed in the printed matter. Further, when the amount of the resin adhering to the recording area is 0.75 mg / inch ² or less, the gloss of the obtained recorded matter tends to be more excellent.

The coating weight of the total of the resin and the wax on the recording medium is a solid content basis, preferably, 0.02 mg / inch ² or more and 2.0 mg / inch ² or less, more preferably 0.02 mg / inch ² or more 1.5 mg / inch ² or less, more preferably 0.04 mg / inch ² or more 1.2 mg / inch ² or less, still more preferably 0,1mg / inch ² or more 1.0 mg / inch ² or less It is.

[Recording medium]
Examples of the recording medium include an absorptive, low-absorbing, and non-absorbing recording medium. Among these, the recording medium is preferably a low absorption recording medium or a non-absorbing recording medium. When a low-absorbing recording medium or a non-absorbing recording medium is used, since the ink composition is repelled on the surface and the aggregating agent is difficult to be applied uniformly, it is more likely to cause sticky or bleeding. However, the present embodiment is particularly useful because the ink composition can be prevented from being repelled by the aggregation liquid. In addition, when a low-absorbing recording medium or a non-absorbing recording medium is used, the flocculant does not penetrate into the recording medium and tends to remain on the surface of the recording medium. Tend to. However, in this embodiment, since the amount of the aggregate liquid used can be reduced by using the ink composition, the stickiness of the recording surface can be improved, which is particularly advantageous.

Here, the “low-absorbing recording medium” or “non-absorbing recording medium” refers to a recording medium having a water absorption of 10 mL / m ² or less from the start of contact to 30 msec in the Bristow method. . This Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Paper Pulp Technology Association (JAPAN TAPPI). For details of the test method, refer to Standard No. of “JAPAN TAPPI Paper Pulp Test Method 2000”. 51 "Paper and paperboard-Liquid absorbency test method-Bristow method".

  Further, the non-absorbent recording medium or the low-absorbing recording medium can be classified by the wettability of the recording surface with respect to water. Specifically, a 0.5 μL water droplet is dropped on the recording surface of the recording medium, and the contact angle reduction rate (comparison of the contact angle at 0.5 milliseconds after the landing and the contact angle at 5 seconds) is measured. Can be used to characterize the recording medium. More specifically, as a property of the recording medium, the non-absorbing property of the “non-absorbing recording medium” indicates that the above-described reduction rate is less than 1%, and the low absorption of the “low-absorbing recording medium”. The property indicates that the decrease rate is 1% or more and less than 5%. Moreover, absorptivity means that said reduction rate is 5% or more. In addition, a contact angle can be measured using portable contact angle meter PCA-1 (made by Kyowa Interface Science Co., Ltd.) etc.

  The absorbent recording medium is not particularly limited. For example, plain paper such as electrophotographic paper having high penetrability of the ink composition, inkjet paper (an ink absorbing layer composed of silica particles or alumina particles, or polyvinyl chloride). Art paper used for general offset printing in which the ink composition has a relatively low permeability from an alcohol (PVA) or polyvinyl pyrrolidone (PVP) or other hydrophilic polymer such as an ink-absorbing layer. , Coated paper and cast paper.

  Although it does not specifically limit as a low absorptive recording medium, For example, the coated paper by which the coating layer for accepting oil-based ink was provided in the surface is mentioned. The coated paper is not particularly limited, and examples thereof include printing paper such as art paper, coated paper, and matte paper.

  The non-absorbable recording medium is not particularly limited. For example, a plastic film that does not have an ink absorbing layer, a substrate such as paper coated with plastic, or a plastic film bonded thereto Etc. Examples of the plastic here include polyvinyl chloride, polyethylene terephthalate, polycarbonate, polystyrene, polyurethane, polyethylene, and polypropylene.

  In addition to the recording medium, a non-ink-absorbing or low-absorbing recording medium such as a plate of metal such as iron, silver, copper, or aluminum, or glass can be used.

  In particular, the recording medium is preferably in the form of a roll. When recording, the roll-shaped recording medium can be used in such a manner that the head is scanned once relative to the recording medium and wound by a winding roller. When such a recording medium is used, when all the colors cannot be recorded by one feeding due to a large number of types of colored ink to be used, and the recording medium is recorded many times, the recording medium is recorded multiple times. On the other hand, a recorded product can be obtained by repeating the operation of scanning the head relatively once and winding it with a winding roller. However, because of the roll shape, the resin layer tends to crack. When a crack occurs, the image quality of the obtained recorded matter tends to deteriorate due to the reason that the aggregate liquid penetrates into the crack. However, the coating film made of the ink composition obtained by the recording method of the present embodiment is less susceptible to cracking. Therefore, the present invention is particularly useful when a recording medium having such a shape is used.

[Recording device]
Next, a recording apparatus that can be used in the recording method of the present embodiment will be described. 1 is a side view showing an outline of an example of an inkjet recording apparatus 1 that can be used in the present embodiment. As shown in FIG. 1, the inkjet recording apparatus 1 includes a recording medium feeding unit 10, a transport unit 20, a recording unit 30, a drying device 90, and a discharge unit 70.

  Among these, the drying device 90 includes a first drying unit 40 that dries the aggregation liquid, and a second drying unit 50 that dries the recorded matter obtained by the recording method according to the present embodiment.

  Further, the feeding unit 10 is provided so that the roll-shaped recording medium F can be fed to the transport unit 20. Specifically, the feeding unit 10 includes a roll medium holder 11, and the roll medium holder 11 holds a roll-shaped recording medium F. Then, by rotating the roll-shaped recording medium F, the recording medium F can be fed to the conveyance unit 20 on the downstream side in the feeding direction Y.

  Further, the transport unit 20 is provided so that the recording medium F sent from the feeding unit 10 can be transported to the recording unit 30. Specifically, the transport unit 20 includes a first feed roller 21 and is configured to be able to transport the sent recording medium F further to the recording unit 30 on the downstream side in the feed direction Y.

  The recording unit 30 is provided so that the recording medium F sent from the transport unit 20 is coated with an aggregating liquid, and an ink composition can be discharged and recorded. Specifically, the recording unit 30 includes heads 31 and 32 that perform an aggregation liquid adhesion step, a recording head 33 that performs an ink composition adhesion step, and a platen 34 as a medium support unit. The recording may be performed by a multi-pass method in which recording is performed by alternately performing scanning performed by the head in a direction crossing the recording medium conveyance direction and conveyance of the recording medium in the conveyance direction. . Alternatively, the recording may be performed by a single pass method in which the position is fixed during recording by the head and recording is performed while the recording medium is continuously transported in the transport direction.

  Among these, the platen 34 is provided so that the recording medium F can be supported from the back surface. The platen 34 is provided with a first drying unit 40 that dries the agglomerated liquid adhering to the recording medium F and the ink composition adhering to the recording medium F. Further, a second feed roller 43 is provided downstream of the platen 34 in the feed direction Y. The second feed roller 43 is configured to send the recorded recording medium F to the second drying unit 50 on the downstream side in the feed direction Y.

  The second drying unit 50 is configured to further dry the aggregating liquid adhering to the recording medium F and the ink composition adhering to the recording medium F. Further, a third feed roller 65 is provided in the vicinity of the outlet 64 of the second drying unit 50. The third feed roller 65 is disposed so as to be in contact with the back surface of the recording medium F, and is configured to be able to feed the recording medium F to the discharge unit 70 on the downstream side in the feeding direction Y.

  Further, the discharge unit 70 is provided so that the recording medium F sent from the second drying unit 50 can be further sent downstream in the feed direction Y and discharged to the outside of the inkjet recording apparatus 1. Specifically, the discharge unit 70 includes a fourth feed roller 71, a fifth feed roller 72, a sixth feed roller 73, a seventh feed roller 74, and a take-up roller 75. Among these, the 4th feed roller 71 and the 5th feed roller 72 are arrange | positioned so that the surface of the recording medium F may be contacted. Moreover, the 6th feed roller 73 and the 7th feed roller 74 are arrange | positioned so that a roller pair may be comprised. The recording medium F discharged by the sixth feed roller 73 and the seventh feed roller 74 is provided so as to be taken up by the take-up roller 75.

  Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples. The present invention is not limited in any way by the following examples.

[Required amount of aggregation]
For the resin and wax used below, the required amount of aggregation (mL) was measured. Specifically, 0.1 M calcium acetate aqueous solution was added to 3.0 mL of a sample solution of a resin or wax aqueous dispersion prepared by diluting with water so that the resin or wax content was 0.5 mass%. .1 mL was dropped, and it was judged whether or not coagulation sedimentation occurred within 30 seconds. After that, repeat the determination of dripping in the same amount of 0.1 mL until agglomeration and sedimentation occur within 30 seconds (increase in increments of 0.1 mL as the total amount dripped). The required amount of aggregation (mL) was used as an index of aggregation. The greater the cohesiveness resin or wax, the smaller the required coagulation amount (mL), and the smaller the cohesiveness resin or wax, the greater the cohesive requirement (mL). Whether or not coagulation sedimentation occurred was visually confirmed. The obtained results are shown together with the following types of resin and wax.

[Material for first or second ink composition]
The main materials for the first or second ink composition used in the following Examples and Comparative Examples are as follows.
[Pigment]
Carbon black (resin)
Chemipearl S120 (trade name, Mitsui Chemicals Co., Ltd., required aggregation amount 0.1 mL, solid content 27% by mass)
Chemipearl S75N (trade name of Mitsui Chemicals, aggregation required amount 0.2 mL, solid content 25% by mass)
Movinyl 8055A (Nippon Synthetic Chemical Co., Ltd., trade name, required aggregation amount 0.3 mL, solid content 43 mass%)
Superflex 860 (trade name, manufactured by Taiichi Kogyo Seiyaku Co., Ltd., coagulation required amount 0.6 mL, solid content 40% by mass)
Mobile 972 (Nippon Gosei Kagaku Co., Ltd., trade name, required amount of aggregation 3.0 mL, solid content 50 mass%)
〔wax〕
AQUACER 526 (trade name, manufactured by Big Chemie Co., Ltd., required aggregation amount 0.1 mL, solid content 30% by mass)
AQUACER 593 (trade name, big chemi 0.2 ml, solid content 30% by mass, manufactured by Big Chemie)
AQUACER 582 (Brand name, manufactured by Big Chemie, coagulation required amount 0.6 mL, solid content 40% by mass)
AQUACER 539 (trade name, manufactured by Big Chemie, required amount of aggregation: 3.0 mL, solid content: 35% by mass)
[Surfactant]
BYK348 (trade name, silicone surfactant manufactured by Big Chemie)
Surfynol DF110D (trade name, manufactured by Nissin Chemical Industry Co., Ltd.)
〔solvent〕
1,3-butanediol propylene glycol 2-pyrrolidone water [additive]
Triethanolamine Sodium ethylenediaminetetraacetate

[Preparation of first and second ink compositions]
Each material was mixed with the composition shown in Table 1 below and stirred sufficiently to obtain first and second ink compositions. In addition, in the following Table 1, a numerical value shows solid content, the unit of this numerical value is mass%, and a sum total is 100.0 mass%.

[Material for flocculant]
The main materials for the aggregating liquid (reaction liquid) used in the following examples and comparative examples are as follows.
[Flocculant]
Magnesium sulfate (surfactant)
BYK348 (trade name, silicone surfactant manufactured by Big Chemie)
〔solvent〕
1,3-butanediol propylene glycol 2-pyrrolidone water

[Preparation of flocculant]
Each material was mixed with the composition shown in Table 2 below, and stirred sufficiently to obtain an aggregate liquid. In Table 2 below, the numerical value indicates the solid content, the unit of the numerical value is% by mass, and the total is 100.0% by mass. In reaction liquid 1 and reaction liquid 2, the flocculant has a concentration of about 0.5 M with respect to the flocculant liquid.

[Preparation of recorded material]
The recording medium is loaded into PX-G930 (trade name of Epson printer), and the aggregate liquid (reaction liquid) filled in the head is inkjet with a resolution of 720 × 720 dpi and an adhesion amount of 1.7 mg / inch ^2. Applied. Next, the first ink composition filled in the head is inkjet-applied to the aggregated liquid adhesion surface with a resolution of 720 × 720 dpi and an adhesion amount of 7 mg / inch ² , and an example using the second ink composition is The second ink composition filled in was applied to the ink composition adhesion surface by inkjet at a resolution of 720 × 720 dpi and an adhesion amount of ² mg / inch ² to obtain a recorded material on the recording medium. During the coating, the surface temperature of the recording medium was adjusted to 25 ° C. An example using the second ink composition was application by a wet-on-wet method. In addition, after coating and discharging the recording medium from the printer, the recording medium was left to stand in an environment of 60 ° C. for 10 minutes and dried. Coated paper (trade name “ELITEL CAST 73” manufactured by Daio Paper Co., Ltd.) was used as the recording medium. Table 4 summarizes the required amount of aggregation of resin and wax contained in the ink composition used in each example, and the required amount of weighted average aggregation.

[Image quality (Bethamra)]
Except for producing a 10 × 10 mm solid pattern, for the recorded matter obtained by the same method as in [Preparation of recorded matter], the solidity was confirmed visually, and the image quality ( (Bethamra) was evaluated. The results obtained are shown in Table 3.
(Evaluation criteria)
A: Unevenness inside the pattern (coloring by ink looks uneven) is not recognized.
○: Large non-uniformity is not recognized inside the pattern, but some unevenness (fine non-uniformity) is recognized.
(Triangle | delta): A considerable nonuniformity (large nonuniformity) is recognized inside a pattern.

[Abrasion resistance]
The obtained recorded matter is a friction material in which a white cotton cloth (JIS L 0803 compliant) is attached to a Gakushin type friction fastness tester AB-301 (trade name, manufactured by Tester Sangyo Co., Ltd.), and a load of 300 g is applied to the recorded matter. Rubbing was performed until the film was peeled off or 30 reciprocations. And the peeling of the recorded matter of the recording medium was observed visually, and the abrasion resistance was evaluated according to the following evaluation criteria. The results obtained are shown in Table 3.
(Evaluation criteria)
(Double-circle): Even if it rubs 30 times, peeling of a recorded matter is not recognized.
○: Peeling of the recorded material was observed at 20 to 29 reciprocations.
Δ: Peeling of recorded material was observed at 10 to 19 reciprocations.
X: Peeling of recorded material was observed within 9 round trips.

[Glossiness]
The recorded material was measured for 60 ° gloss using a gloss meter GM-268Plus (trade name, manufactured by Konica Minolta), and the gloss was evaluated according to the following evaluation criteria. The results obtained are shown in Table 3.
(Evaluation criteria)
◎: 84 or more ○: 60 or more and less than 84 △: 45 or more and less than 60 ×: Less than 45

  From the evaluation results, a resin containing a cohesive property greater than that of the wax and the wax is used, and the ink composition containing the resin and the ink composition containing the wax or the ink composition containing the resin and the wax are used. It was found that Examples 1-8 used were excellent in image quality and abrasion resistance.

  Among them, from Examples 1 and 7, when one ink composition is used, the same ink composition contains a resin and a wax having a resin cohesiveness larger than the wax cohesiveness, whereby the image quality and the abrasion resistance are increased. Was found to be excellent.

  Further, from Example 8, it was found that the image quality and the abrasion resistance were also excellent by containing a resin and a wax having a resin cohesion larger than that of the wax in another ink composition.

  Further, from Examples 2 and 3, even when two ink compositions are used, one ink composition contains a resin having a larger cohesiveness of the resin than the cohesiveness of the wax and the wax in the same ink composition. As a result, it was found that the image quality and abrasion resistance were excellent.

  In addition, when two ink compositions are used from Examples 4 and 5, each of the two ink compositions contains a resin and a wax having a larger resin cohesiveness than the wax cohesiveness in the same ink composition. As a result, it was found that image quality and abrasion resistance were particularly excellent and glossiness was also excellent.

  Further, from Example 6, when two ink compositions are used, at least one ink composition contains a resin having a resin cohesiveness greater than that of the wax and a wax in the same ink composition. It was found that the image quality and abrasion resistance were excellent. Further, from comparison between Example 1 and Example 6, it is excellent in glossiness that the cohesiveness of the resin is larger than the cohesiveness of the wax as a weighted average of the resin contained in the same or different ink composition. Was found to be particularly superior.

  On the other hand, Comparative Examples 1 to 1 which do not use an ink composition containing a resin and a wax having a larger cohesiveness of resin than the cohesiveness of wax in the same or different ink composition, or do not use an aggregation liquid No. 5 was inferior in image quality or abrasion resistance.

  DESCRIPTION OF SYMBOLS 1 ... Inkjet recording apparatus, 10 ... Feed part, 11 ... Roll medium holder, 20 ... Conveyance part, 21 ... 1st feed roller, 30 ... Recording part, 31 ... Head, 32 ... Head, 33 ... Recording head, 34 ... Platen 40 ... first drying section 43 ... second feeding roller 50 ... second drying section 64 ... exit 65 ... third feeding roller 70 ... discharge section 71 ... fourth feeding roller 72 ... fifth Feed roller 73 ... Sixth feed roller, 74 ... Seventh feed roller, 75 ... Winding roller, 90 ... Drying device, F ... Recording medium, Y ... Feed direction.

Claims (13)

An ink composition containing a resin and an ink composition containing a wax, or an ink composition containing a resin and a wax,
An aggregating liquid containing an aggregating agent capable of aggregating the components of the ink composition;
The ink set according to claim 1, wherein the resin and the wax include a resin and a wax in which the cohesiveness of the resin is larger than the cohesiveness of the wax.   The ink set according to claim 1, wherein each of the ink compositions is a colored ink composition or a clear ink composition further containing a coloring material.   An ink composition containing the resin and an ink composition containing the wax, the ink composition containing the resin being the colored ink composition, and the ink composition containing the wax being the clear ink The ink set according to claim 2, which is a composition. At least the colored ink composition,
The ink set according to claim 2 or 3, wherein the color material contained in the colored ink composition contains at least one of a self-dispersed pigment and a resin-dispersed pigment.   The ink set according to any one of claims 1 to 4, wherein the resin contains two or more resins having different cohesive properties. The ink set according to claim 1, wherein the resin and the wax satisfy the following relational expression (1).
0.1 mL ≦ (W−J) ≦ 3.0 mL (1)
(In the formula, J represents the required amount of resin aggregation (mL), and W represents the required amount of wax aggregation (mL).)   The ink set according to claim 1, wherein the flocculant is at least one of an organic acid, a polyvalent metal salt, and a cationic compound.   The ink set according to any one of claims 1 to 7, wherein the ink composition is used by adhering to a recording medium by an inkjet method.   The said resin and the said wax are 0.5 mass% or more and 15 mass% or less respectively in conversion of solid content with respect to the total amount of an ink composition in the said ink composition, respectively. Ink set.   The ink set according to any one of claims 1 to 9, wherein the cohesiveness as a weighted average of the resin contained in the ink composition is larger than the cohesiveness as the weighted average of the wax contained in the ink composition.   An ink composition attaching step for attaching the ink composition of the ink set according to any one of claims 1 to 10 to a recording medium, and an aggregating liquid for attaching the aggregating liquid of the ink set to the recording medium A recording method comprising: an attaching step.   The recording method according to claim 11, wherein the ink composition includes an ink composition containing a wax and an ink composition containing a resin having a higher cohesiveness than the wax.   The recording method according to claim 12, wherein the ink composition attaching step is a step of attaching by wet on wet.

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